JP2002091236A - Image forming method and image forming toner - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] For an image forming apparatus using an ultrasonic motor capable of providing a good copy or print on any transfer material, a stable and good image for a long period of time. The present invention provides an image forming method and an image forming toner which are compatible with the two-component developer obtained in the above. A latent image forming step of forming an electrostatic latent image on the charged latent image carrier; a developing step of developing the electrostatic latent image with a two-component developer; And a transfer step of transferring the toner image 19a on the electrostatic latent image carrier onto the transfer material 25. In the image forming method, the latent image carrier, the conveyance belt, and / or the intermediate transfer body are driven. The two-component developer 19 has a toner and a magnetic material-dispersed resin carrier, and the toner has a shape factor SF-1 of 100 to 160.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a latent image carrier and / or a latent image carrier.
Alternatively, the present invention relates to an image forming method using an ultrasonic motor as a rotating body driving device for use in a transfer process and using a two-component developer composed of a magnetic material-dispersed resin carrier and a toner as a developer.

[0002]

2. Description of the Related Art As an electrophotographic method, US Pat.
Various methods are described in JP-B-97,691, JP-B-42-23910 and JP-B-43-24748. In these methods, an electrostatic image is formed by irradiating a photoconductive layer with a light image corresponding to an original, and then toner is adhered on the electrostatic image to develop the electrostatic image, and if necessary, After transferring the toner image onto a transfer material such as paper, the toner image is fixed by heat, pressure, heat and pressure or solvent vapor to obtain a copy or print.

In recent years, with the development of computers and multimedia, there is a demand for means for outputting higher definition images in a wide range of fields from offices to homes. Heavy users demand high durability without deterioration in image quality even when copying or printing a large number of sheets, and in small offices and homes, obtain high-quality images, reduce the size of the device from the viewpoint of space saving and energy saving, and reduce waste toner. There is a demand for recycling, waste toner-less (cleaner-less), and lowering the fixing temperature, and various studies have been made from each viewpoint to achieve these objects. The above requirements are particularly high in full-color images.

Further, in the case of a full-color copying machine or a color printer, since a given image is full color as compared with an ordinary black-and-white copying machine or a black-and-white printer, there is an increasing demand for forming images on various types of paper. Therefore, it is necessary to provide a good image for transparency (hereinafter, trapen) used for various types of paper, for example, thick paper and OHP. As a specific example from the viewpoint of fixing, the fixing speed of the fixing device in the apparatus is set to be slower than usual depending on the type of paper (especially, thick paper or trappen) so that an image can be fixed on various types of paper (normally 1/3 ~
(Approximately 1/4), the amount of heat supplied to the paper is increased, thereby coping with the image formation of thick paper and trappen.

In order to prevent the image quality from deteriorating due to inconsistency in the paper conveyance speed between the fixing device and the image forming unit (around the photosensitive drum), the image forming speed of the image forming unit (photosensitive drum surface speed) Should be adjusted according to the speed of the fixing device that has become low. However, as a characteristic of a DC motor generally used as a drum drive motor, when the rotation speed of the motor is reduced, the rotation accuracy (variation width with respect to a predetermined rotation speed) is much higher than that at the time of high-speed rotation. To decline. For example, a fluctuation of about 0.8% with respect to a desired rotation during normal rotation becomes about 2%.

When the rotation accuracy of the photosensitive drum is reduced, the charging, development and transfer phenomena on the photosensitive drum are performed non-uniformly in accordance with the speed fluctuation, and the density of the image may change depending on the location. is there. In particular, in a full-color image, the density unevenness appears as a change in color, so that it becomes very noticeable.

In order to solve this problem and form a high-precision image, it is required to use a motor having higher rotational accuracy as a motor for driving the photosensitive member or for driving the transfer member. To achieve this, ultrasonic motors have been used.

An ultrasonic motor is disclosed in, for example,
It is a motor using ultrasonic vibration proposed in Japanese Patent No. 14682, and its driving means is described in, for example, JP-A-63-1379, JP-A-60-176470, and JP-A-59-204477. As described in detail in the official gazette, a drive frequency, a drive voltage, or a drive voltage pulse, which is a control amount according to a difference between a speed signal from a speed detection unit such as an encoder signal and a preset target speed, Stable rotational performance at a constant speed is realized by so-called "speed feedback loop control" in which the width is constantly adjusted.

When accelerating or decelerating this type of ultrasonic motor in the above-described control system, a speed corresponding to a target constant speed is set as a target speed. The vehicle gradually accelerates or decelerates, finally reaches the set speed, and shifts to a constant speed rotation state.

However, in this case, the speed change of the ultrasonic motor at the time of acceleration / deceleration differs depending on the inherent characteristics of the motor. It is necessary to periodically update the intermediate target speed up to that point.

On the other hand, the speed adjustment during the constant speed rotation is always performed by adjusting the drive frequency, the drive voltage and the pulse width of the drive voltage which are control amounts in the feedback loop control system. Need not be performed on a regular basis.

However, the friction between the stator and the rollers of the ultrasonic motor generated when the ultrasonic motor and the motor driving member of the control device are operated and the friction between a plurality of motor driving members driven by the motor are generated. Abrasion of the motor and the motor drive member is, in principle, inevitable. If the level exceeds a certain level, the rotation speed cannot be controlled electrically, and there is a fear that the constant speed rotation performance may be reduced and the motor and the motor driving member may be damaged.

Therefore, when an ultrasonic motor is used as the rotating body driving means, in order to provide a stable and high-quality image for a long period of time, how to reduce the load on the motor and suppress the wear of the driving member of the motor. An important point is whether or not the system is unlikely to cause deterioration of image characteristics such as image density unevenness even if the constant speed rotation performance deteriorates.

To reduce the load on the ultrasonic motor,
It is necessary to reduce the torque with the member that contacts the rotating body rotated by the motor.

On the other hand, in the electrophotographic method, the step of developing an electrostatic image is to form an image of the charged toner particles on the electrostatic image by utilizing the electrostatic interaction of the electrostatic image. Of a developer for developing an electrostatic charge image using a toner, a magnetic one-component developer using a magnetic toner in which a magnetic material is dispersed in a resin, and charged by a charging member such as an elastic blade There is a non-magnetic one-component developer to be developed, and a two-component developer in which a non-magnetic toner is mixed with a magnetic carrier.In a full-color image forming apparatus such as a full-color copying machine or a full-color printer, which is particularly required to have high image quality, The latter is preferably used.

As a magnetic carrier used in a two-component developer, an iron powder carrier, a ferrite carrier, or a resin-coated carrier in which magnetic fine particles are dispersed in a binder resin are known. A developer using a resin-coated carrier in which the surface of the carrier core material is coated with a resin can optimize resistance, has excellent charge controllability, and is relatively easy to improve environmental dependence and stability over time. Therefore, it is preferably used.

Further, with the miniaturization of the electrostatic latent image, both toner particles and carrier particles have been reduced in diameter in order to faithfully develop the electrostatic latent image and obtain higher image quality output. In particular, the image quality is often improved by reducing the average particle diameter of the toner.

The two-component developer greatly contributes to the above-mentioned rotating body. That is, there is a load on the latent image carrier due to the contact of the two-component developer. In order to reduce this, it is necessary to reduce the magnetic properties and apparent density of the carrier and to weaken the compression of the latent image carrier at the developing nip. In addition, in the transfer step, in order to maintain and improve the transferability of the toner, to increase the pressure of the contact transfer portion against the latent image carrier, and to remove image defects due to fog toner and scattered toner, the transfer belt and Contacting the cleaning member with the intermediate transfer member increases the load on the motor. Therefore, in order to reduce these, it is necessary to use a toner having a good transfer property and little fogging and scattering, and a carrier having little adhesion to the latent image carrier.

Next, in order to prevent image characteristics such as image density unevenness from deteriorating even if the constant speed rotation performance of the motor slightly deteriorates due to durability, a two-component system having a stable and high developing / transferring property. Developer is required.

That is, a developer having excellent durability stability suitable for using an ultrasonic motor as a driving device for a latent image carrier and / or a rotating body used in a transfer process has not been provided yet. is there.

[0021]

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming method and an image forming toner which solve the above-mentioned problems.

That is, an object of the present invention is to use a supersonic motor as a driving device for a latent image carrier and / or a rotating body for use in a transfer process to obtain a good copy or print on any transfer material. It is an object of the present invention to provide an image forming method and an image forming toner adapted to a two-component developer capable of obtaining a good image stably over a long period of time for an image forming apparatus that can be provided.

[0023]

The above objects can be achieved by the following constitutions of the present invention.

According to the present invention, there is provided a charging step of charging a latent image carrier by bringing a contact charging means into contact with a latent image carrier for carrying an electrostatic latent image; A latent image forming step of forming a latent image; a developing step of developing the electrostatic latent image with a two-component developer toner to form a toner image on the electrostatic latent image carrier; and on the electrostatic latent image carrier Transferring the toner image to a transfer material with or without an intermediate transfer member, wherein the ultrasonic wave is used as a rotating member driving device for driving the latent image carrier. The present invention relates to an image forming method using a motor, wherein the two-component developer has a toner and a magnetic material-dispersed resin carrier, and the toner has a shape factor SF-1 of 100 to 160. .

The present invention provides a charging step of charging a latent image carrier for carrying an electrostatic latent image by charging means; a latent image forming step of forming an electrostatic latent image on the charged latent image carrier; Developing the electrostatic latent image with a two-component developer toner to form a toner image on the electrostatic latent image carrier; and developing the toner image on the electrostatic latent image carrier via an intermediate transfer member With or without
A transfer step of transferring onto the transfer material while pressing the transfer material conveyed by the conveyance belt by using the contact transfer means, wherein the ultrasonic wave is used as a rotating body driving device for driving the conveyance belt. Using a motor, the two-component developer has a toner and a magnetic material-dispersed resin carrier, and the toner has a shape factor SF
The present invention relates to an image forming method, wherein -1 is 100 to 160.

The present invention provides a charging step of charging a latent image carrier for carrying an electrostatic latent image by charging means; a latent image forming step of forming an electrostatic latent image on the charged latent image carrier; A developing step of developing the electrostatic latent image with a two-component developer toner to form a toner image on the electrostatic latent image carrier; and applying a bias to the toner image on the electrostatic latent image carrier. Transferring the toner image transferred onto the intermediate transfer member, and transferring the toner image transferred onto the intermediate transfer member onto a transfer material by a transfer unit. An ultrasonic motor is used as the rotating member driving device, and the intermediate transfer member is in contact with the latent image carrier, and / or the transfer means is in contact with the intermediate transfer member. The component developer has a toner and a magnetic material-dispersed resin carrier. Cage, the toner, the shape factor SF-
The present invention relates to an image forming method, wherein 1 is 100 to 160.

According to the present invention, there is provided a charging step of charging a latent image carrier by bringing a contact charging means into contact with a latent image carrier for carrying an electrostatic latent image; A latent image forming step of forming a latent image; a developing step of developing the electrostatic latent image with a two-component developer toner to form a toner image on the electrostatic latent image carrier; and on the electrostatic latent image carrier Transferring the toner image to a transfer material with or without an intermediate transfer member. The image forming method according to claim 1, wherein the rotating member driving device for driving the latent image carrier is super-conductive. An image forming toner using an ultrasonic motor and an image forming method using a two-component developer having a toner and a magnetic material-dispersed resin carrier as the two-component developer, wherein the toner has a shape factor SF- 1 is 100 to 160. The present invention relates to an image forming toner.

The present invention provides a charging step of charging a latent image carrier for carrying an electrostatic latent image by charging means; a latent image forming step of forming an electrostatic latent image on the charged latent image carrier; Developing the electrostatic latent image with a two-component developer toner to form a toner image on the electrostatic latent image carrier; and developing the toner image on the electrostatic latent image carrier via an intermediate transfer member With or without
A transfer step of transferring onto the transfer material while pressing the transfer material conveyed by the conveyance belt using the contact transfer means; and a super rotator driving device for driving the conveyance belt. An image forming toner using an ultrasonic motor and an image forming method using a two-component developer having a toner and a magnetic material-dispersed resin carrier as the two-component developer, wherein the toner has a shape factor SF- The present invention relates to an image forming toner, wherein 1 is 100 to 160.

The present invention provides a charging step of charging a latent image carrier for carrying an electrostatic latent image by charging means; a latent image forming step of forming an electrostatic latent image on the charged latent image carrier; A developing step of developing the electrostatic latent image with a two-component developer toner to form a toner image on the electrostatic latent image carrier; and applying a bias to the toner image on the electrostatic latent image carrier. A transfer step of transferring the toner image transferred onto the intermediate transfer member and transferring the toner image transferred onto the intermediate transfer member onto a transfer material by transfer means;
An image forming method including at least an ultrasonic motor as a rotating body driving device for driving the intermediate transfer body, wherein the intermediate transfer body is in contact with the latent image carrier, and / or An image forming toner in which the transfer unit is in contact with the intermediate transfer member and an image forming method using a two-component developer having a toner and a magnetic material-dispersed resin carrier as the two-component developer. The toner relates to an image forming toner, wherein the shape factor SF-1 is 100 to 160.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have conducted intensive studies and as a result,
As a carrier when an ultrasonic motor is used as a latent image carrier and / or a rotating body driving device used in a transfer process,
By applying a magnetic material-dispersed resin carrier and applying a toner having a shape factor SF-1 of 100 to 160 as the toner, the load on the motor is reduced due to the characteristics of the carrier and the toner, and the driving member is worn due to durability. It has been found that not only deterioration can be suppressed, but also good image quality can be provided even when the rotation accuracy is slightly reduced.

Particularly, when an ultrasonic motor is used in the transfer step of the transfer belt and / or the intermediate transfer member, and a cleaning member is brought into contact with the cleaning member, more specifically, in the case of blade cleaning in which the load increases, a magnetic material dispersed resin carrier Further, it has been found that the effect of the toner having a shape factor SF-1 of 100 to 160 is improved.

The magnetic material-dispersed resin carrier can easily be controlled to a desired magnetization amount and resistance by the magnetic characteristics and content of the magnetic material used, and the carrier particle size distribution is sharp and the sphericity is high. Are suitable for use in the present invention.

When we carried out various studies on the load on the rotating motor of the latent image carrier, it was found that the magnetic properties and apparent density of the carrier had a great influence. That is, if the apparent density and the saturation magnetization of the carrier are high, the spikes in the developing nip are coarse and rigid, and the load on the motor increases.

Further, the relationship between the amount of carrier adhered to the latent image carrier and the motor torque in the transfer step when an ultrasonic motor was used in the transfer step was examined. Torque increases due to the presence of the carrier. When the cleaning member is brought into contact with the transfer belt and / or the transfer step of the intermediate transfer member, the carrier adhered to the latent image carrier also contaminates the transfer member and accumulates on the cleaning portion, thereby increasing the torque of the motor. .

That is, as the carrier from the viewpoint of reducing the torque of the motor, a carrier having a low apparent density and a low saturation magnetization and little carrier adhesion to the latent image carrier is preferable. However, simply lowering the saturation magnetization of the carrier deteriorates the carrier adhesion to the latent image carrier.

On the other hand, when the constant speed rotation speed of the motor and the image quality (density unevenness, etc.) were examined, the carrier having low saturation magnetization was the ear at the development nip portion as a carrier for stably having high developability. It was clarified that the standing was low, the density was good and the standing was good.

Therefore, it has been found that a carrier having a low apparent density and a low saturation magnetization at a level at which the carrier does not adhere to the latent image carrier is preferred.

Next, when the toner was examined in the same manner as in the case of the carrier, from the viewpoint of reducing the torque of the motor, toner having less fogging and toner scattering and having better transferability was better for each rotating member. It has become clear that the increase in the load of the cleaning unit can be suppressed, and the pressing setting of the cleaning member can be reduced from the initial setting, so that the load on the motor can be greatly reduced, which is preferable. As a configuration of the toner, a toner having a shape factor SF-1 of 100 to 160 has been found. In other words, a toner having a shape closer to a sphere having a shape factor SF-1 of 160 or less tends to rotate on a carrier as a two-component developer, and thus is easily imparted with uniform high chargeability.
Therefore, fog and toner scattering are reduced. Also,
In the transfer step, the more spherical toner has fewer contact points with the latent image carrier or the intermediate transfer body,
Good transfer onto the transfer material is possible. Therefore, the transfer residual toner is reduced. As a result, the load on the motor can be reduced as described above.

On the other hand, when the constant speed rotation speed of the motor and the image quality (density unevenness, etc.) were examined, it was found that a toner having a moderately fine particle size is preferable as a toner for stably having a high developing property. Obtained.

Further, the spent property of the toner and the external additive to the carrier was examined from the viewpoint of the durability of the developer. As for the physical properties of the carrier, those having a high magnetization and a small particle diameter were better in toner and external additive. It has been found that the agent has a high spent property. The reason for this is that when the magnetization is high, the compression of the developer in the developing device becomes strong and the spent property increases, and when the particle size is small, the chance of contact with the toner in the developing device increases and the spent It is thought that the nature increases.

On the other hand, in order to faithfully reproduce the latent image,
Since the toner having a smaller particle size must be uniformly charged, a carrier having a small particle size is required to some extent.
That is, satisfying the contradictory characteristics of the carrier can provide developing characteristics with high image quality and excellent durability.

According to the results of the various studies described above, the following two-component developer has a structure capable of satisfactorily expressing the object of the present invention.

The magnetic material-dispersed resin carrier is 1000 /
The magnetization intensity at 4π (kA / m) is 30 to 60 Am
² / kg, preferably 35 to 50 Am ² / kg
Is more preferable.

When the magnetization intensity at 1000 / 4π (kA / m) is larger than 60, the carrier ears are long and coarse, and the torque of the ultrasonic motor for driving the latent image carrier increases to deteriorate the durability. In addition, it becomes difficult to provide high-definition images. Also, the compression of the developer in the developing device is increased,
The spent property of the carrier increases, and the external additive of the toner deteriorates remarkably, causing fog and toner scattering in the latter half of the durability.

When the magnetization strength at 1000 / 4π (kA / m) is smaller than 30, even if the particle size distribution is sharpened, carrier adhesion to the latent image bearing member cannot be satisfactorily suppressed.
The torque of the cleaning member of the rotating body rotated by the ultrasonic motor increases, and the durability of the motor is impaired.

The magnetic material-dispersed resin carrier preferably has an apparent density of 2.3 g / cm ³ or less.
g / cm ³ or less is more preferable. 2.3g apparent density
If it exceeds / cm ³ , the load on the ultrasonic motor for the latent image carrier increases, and the durability of the motor is impaired.

The magnetic material-dispersed resin carrier has a particle size of 25.
To 55 μm, more preferably 30 to 43 μm. If it is larger than 55 μm, it is insufficient to uniformly and favorably charge the toner, which makes it difficult to faithfully reproduce a latent image, and causes fog and toner scattering. On the other hand, if it is smaller than 25 μm, the carrier is strongly attached to the latent image bearing member, and the load on the ultrasonic motor for driving the rotator is increased, thereby impairing the durability of the motor.

In the present invention, the specific resistance of the carrier is 5
It is preferably from × 10 ^{10 to} 5 × 10 ¹⁴ Ω · cm,
More preferably, it is 1 × 10 ¹¹ to 1 × 10 ¹⁴ Ω · cm.

[0049] When the specific resistance of the carrier is less than 5 × ¹⁰ 10 Ω · cm, the developing bias is susceptible to carrier adhesion to the injected photosensitive member surface through the carrier. As a result, the load on the ultrasonic motor increases, and the durability of the motor is impaired. In addition, the photoreceptor is likely to be scratched or transferred directly to paper, thereby causing image defects. Further, the developing bias may leak through the carrier and disturb the electrostatic latent image drawn on the photosensitive drum.

If the specific resistance of the carrier exceeds 5 × 10 ¹⁴ Ω · cm, a sharp edge-enhanced image is easily formed, and the charge on the carrier surface is hardly leaked.
The image density may drop due to the charge-up phenomenon, and fogging and scattering may occur due to the inability to apply charge to newly replenished toner, increasing the load on the ultrasonic motor for driving the rotating body. , Impairs the durability of the motor.

The method for measuring the physical properties of the carrier is described below.

<Measurement Method of Carrier Particle Size> The carrier particle size is measured by a laser diffraction particle size distribution analyzer (Heros <H
The measurement was performed using ELOS>) under the conditions of a feed air pressure of 3 bar and a suction pressure of 0.1 bar. The average particle size of the carrier refers to a 50% particle size based on the volume of the carrier particles.

<Measurement Method of Carrier Magnetic Properties> The magnetic properties of the carrier were measured using an oscillating magnetic field type automatic magnetic property recording apparatus BHV-35 manufactured by Riken Denshi Co., Ltd. As the measurement conditions, the magnetic properties of the carrier powder were 1000 /
An external magnetic field of 4π (kA / m) was created, and the intensity of magnetization at that time was determined. The carrier is packed in a cylindrical plastic container so that the carrier particles are sufficiently dense so that the carrier particles do not move, the magnetization moment is measured in this state, and the actual weight when the sample is placed is measured. And the intensity of magnetization (Am ² / kg).

(Method of Measuring Apparent Density of Carrier) JIS
According to -Z2504 (test method for apparent density of metal powder).

(Measurement Method of Specific Resistance of Carrier) The specific resistance of the carrier was measured using a powder insulation resistance measuring instrument manufactured by Vacuum Riko Co., Ltd. Measurement conditions: 23 ° C, 60%
Carrier left for 24 hours or more under the conditions
(0.283 cm ² ) in a measuring cell, 11.7k
Pa (120 g / cm ² ) between the load electrodes, the thickness is 2
mm and the applied voltage was measured at 500V.

When the physical properties of the carrier are measured from the developer, the developer is washed with ion-exchanged water containing 1% of contaminone N (surfactant) to separate the toner and the carrier. After drying, the above measurement is performed.

The toner has a shape factor SF-1 of 100 to 16.
It is preferably 0, more preferably 100 to 130, and most preferably 100 to 120. In a toner having a shape factor SF-1 of more than 160, the initial transferability can be maintained to some extent by the external additive, but the transferability is significantly deteriorated in the latter half of the durability due to the deterioration of the external additive. For this reason, the torque of the cleaning member of the rotating body rotated by the ultrasonic motor is increased, and the durability of the motor is easily damaged. Further, it is difficult to roll on the carrier, and it is hard to receive uniform high charge. For this reason, it is difficult to suppress the occurrence of fogging and toner scattering for a long period of time, and the durability of the motor tends to be impaired.

The toner preferably has a weight average particle size of 5 to 9.5 μm, more preferably 6 to 9 μm. When the weight average particle diameter of the toner is less than 5 μm,
The charge amount distribution is broadened, and problems such as fogging and poor transferability due to charge-up and low image density due to charge-up in a low humidity environment are liable to occur.In high humidity, problems such as toner scattering, fog, and transferability deteriorate. Occurs. Thereby, the torque of the cleaning member of the rotating body rotated by the ultrasonic motor is increased, and the durability of the motor is easily damaged. Conversely, the weight average particle size of the toner is 9.5.
If it exceeds μm, problems such as scattering and fogging are likely to occur particularly under high temperature and high humidity, and the effect of using the carrier of the present invention cannot be sufficiently obtained. Further, toner particles 1
Since the size becomes large, it is difficult to obtain a high-resolution and dense image. Further, when electrostatic transfer is performed, toner scattering is likely to occur.

The method for measuring the physical properties of the toner will be described below.

(Method of Measuring Average Particle Size and Particle Size Distribution of Toner) 0.1 to 5 ml of a surfactant (alkylbenzene sulfonate) is added to 100 to 150 ml of the electrolyte solution.
To this, 2 to 20 mg of a measurement sample is added. The electrolytic solution in which the sample is suspended is subjected to dispersion treatment with an ultrasonic disperser for 1 to 3 minutes, and a Coulter Counter Multisizer (manufactured by Coulter)
Using an aperture appropriately adjusted to the toner size such as 17 μm or 100 μm, 0.3
A particle size distribution of ４０40 μm is measured. The number average particle diameter and the weight average particle diameter measured under these conditions are obtained by computer processing, and the cumulative ratio of 1/2 or less of the number average particle diameter to the cumulative distribution of the number average particle diameter is calculated from the number-based particle diameter distribution. The cumulative value equal to or smaller than the cumulative diameter distribution is obtained. Similarly, a cumulative ratio equal to or larger than the double diameter cumulative distribution of the weight average particle diameter is calculated from the volume-based particle size distribution, and a cumulative value equal to or larger than the double diameter cumulative distribution is obtained.

(Method of Measuring Shape Factor SF-1 of Toner) The shape factor SF-1 of the toner is determined by FE-SEM manufactured by Hitachi, Ltd.
Using (S-800), a toner image (magnification 300 times)
More than 00 samples are randomly sampled, and the image information is
Through the interface, an image analysis device made by Nireco (L
uzex3) and analyzed, and the value calculated from the following equation was defined as the toner shape factor SF-1.

[0062]

(Equation 1) (Where MXLNG indicates the maximum diameter of the toner, and AREA
Indicates the projected area of the toner. )

In the present invention, a preferred embodiment of the magnetic material-dispersed resin carrier core will be described. Examples of the metal compound particles to be used include magnetite or ferrite having magnetism represented by the following formula (1) or (2).

MO.Fe ₂ O ₃ ... (1) M.Fe ₂ O ₄ ... (2) (In the formula, M represents a trivalent, divalent or monovalent metal ion.)

As M, Mg, Al, Si, Ca, S
c, Ti, V, Cr, Mn, Fe, Co, Ni, Cu,
Zn, Sr, Y, Zr, Nb, Mo, Cd, Sn, B
a, Pb, and Li, which can be used alone or in combination.

Specific examples of the compound of the metal compound particles having magnetism include magnetite and Zn—Fe
Ferrite, Mn-Zn-Fe ferrite, Ni-
Zn-Fe ferrite, Mn-Mg-Fe ferrite, Ca-Mn-Fe ferrite, Ca-Mg-Fe
Ferrite, Li-Fe ferrite and Cu-Zn
And iron-based oxides such as Fe-based ferrite.

Further, in the present invention, as the metal compound particles used for the carrier core, a mixture of the above magnetic metal compound and the following nonmagnetic metal compound may be used.

As the non-magnetic metal compound, for example, A
l ₂ O ₃ , SiO ₂ , CaO, TiO ₂ , V ₂ O ₅ , CrO,
MnO ₂ , α-Fe ₂ O ₃ , CoO, NiO, CuO, Z
nO, SrO, include Y ₂ O ₃ and ZrO _2. In this case, one kind of metal compound can be used, but it is particularly preferable to use a mixture of at least two or more kinds of metal compounds. In that case, it is more preferable to use particles having similar specific gravities and shapes in order to increase the adhesion to the binder resin and the strength of the carrier core particles.

Specific examples of the combination include, for example, magnetite and hematite, and magnetite and γ-Fe
₂ O ₃ , magnetite and SiO ₂ , magnetite and Al ₂ O
_3, magnetite and TiO _2, magnetite and Ca-Mn
-Fe-based ferrite, magnetite and Ca-MgFe-based ferrite can be preferably used. Among them, a combination of magnetite and hematite can be particularly preferably used.

When the above-mentioned magnetic metal compound is used alone or in combination with a non-magnetic metal compound, the number average particle diameter of the magnetic metal compound is determined by the number average particle diameter of the carrier core. It is preferably 0.02 to 2 μm, and more preferably 0.05 to 1 μm.

When the number average particle diameter of the magnetic metal compound is less than 0.02 μm, it becomes difficult to obtain preferable magnetic properties. Number average particle size of magnetic metal compound is 2μ
When m exceeds m, it is difficult to obtain a carrier having a high strength and a preferable particle diameter due to uneven granulation.

When a mixture of a magnetic metal compound and a nonmagnetic compound is used, the number average particle diameter of the nonmagnetic metal compound is preferably 0.05 to 5 μm, more preferably 0.1 to 3 μm. Good to be. In this case, the number average particle diameter (average particle diameter ra) of the metal compound having magnetism,
The particle size ratio (rb / ra) to the number average particle size (average particle size rb) of the nonmagnetic metal compound is preferably 1.0 to 5.0.
0, more preferably 1.2 to 5.0.

The non-magnetic metal compound has a number average particle diameter of 0.1.
When the thickness is less than 05 μm, favorable resistance cannot be obtained, and the carrier tends to adhere. When the number average particle diameter of the nonmagnetic metal compound exceeds 5 μm, it is difficult to obtain a carrier having a preferable particle diameter having high strength due to non-uniform granulation.

Further, when rb / ra is less than 1.0, ferromagnetic metal compound particles having a low specific resistance tend to emerge on the surface, it is difficult to increase the specific resistance of the carrier core, and the effect of preventing carrier adhesion is obtained. It is difficult to obtain. When rb / ra exceeds 5, the strength of the carrier tends to decrease, and the carrier is likely to be destroyed.

The number average particle diameter of the metal oxide was measured by a transmission electron microscope H-800 manufactured by Hitachi, Ltd.
Using a photographic image magnified 00 to 20000 times, 300 or more particles having a particle size of 0.01 μm or more were randomly extracted, and an image processing analysis device Luzex3 manufactured by Nireco Co., Ltd. was used.
Was measured as the metal oxide particle size with the Feret diameter in the horizontal direction, and averaged to calculate the number average particle size.

The specific resistance of the metal compound dispersed in the binder resin is such that the specific resistance of magnetic metal compound particles is 1 × 1.
It is preferably in the range of 0 ³ Ω · cm or more. In particular, when a magnetic metal compound and a nonmagnetic compound are used in combination, the specific resistance of the magnetic metal compound particles is 1
× 10 ³ Ω · cm or more is preferable, and the other nonmagnetic metal compound particles preferably have higher specific resistance than the magnetic metal compound particles, and are preferably used.
The specific resistance of the nonmagnetic metal compound used in the present invention is 1 × 10
^It is preferably ⁸ Ω · cm or more, more preferably 1 × 10 ¹⁰ Ω · cm or more.

The specific resistance of the magnetic metal compound particles is 1
When the content is less than × 10 ³ Ω · cm, it is difficult to obtain a desired high specific resistance even if the content is reduced, which leads to charge injection, image quality deterioration and carrier adhesion. When a mixture of a magnetic metal compound and a nonmagnetic compound is used, the specific resistance of the nonmagnetic metal compound is 1 × 10 ⁸ Ω · cm.
If it is less than the specific resistance of the magnetic carrier core becomes low,
It becomes difficult to obtain the effects of the present invention.

In the present invention, the method of measuring the specific resistance of the magnetic metal compound and the non-magnetic metal compound is performed according to the method of measuring the specific resistance of the carrier particles.

In the carrier core of the present invention, the content of the metal compound is preferably 80
The content is preferably up to 99% by mass.

When the content of the metal compound is less than 80% by mass, the chargeability tends to be unstable, and the carrier is charged particularly in a low-temperature and low-humidity environment, and the residual charge tends to remain. And an external additive easily adhere to the surface of the carrier particles, and a proper specific gravity cannot be obtained. When the content of the metal compound exceeds 99% by mass, the strength of the carrier decreases, and problems such as cracking of the carrier due to durability tend to occur.

Further, in a preferred embodiment of the present invention, in the carrier core containing a mixture of a magnetic metal compound and a non-magnetic compound, the content of the magnetic metal compound in the whole metal compound is preferably The content is preferably 50 to 95% by mass, more preferably 55 to 95% by mass.

When the content of the metal compound having magnetism in the whole metal compound is less than 50% by mass, the resistance of the core is improved, but the magnetic force as a carrier is reduced, and the adhesion of the carrier is reduced. May be invited. If the content of the magnetic metal compound in the whole metal compound exceeds 95% by mass, depending on the specific resistance of the magnetic metal compound, it may not be possible to achieve a more desirable high core resistance.

The binder resin for the carrier core particles used in the present invention is preferably a thermosetting resin, and a part or all of the binder resin is 3%.
It is preferable that the resin is a cross-linked resin. Thereby, the dispersed metal compound particles can be firmly bound, so that the strength of the carrier core can be increased, and the detachment of the metal compound hardly occurs even in a large number of copies,
Further, the coating resin can be coated better.

The method for obtaining the magnetic material-dispersed carrier core is not particularly limited to the method described below, but in the present invention, a solution in which the monomer and the solvent are uniformly dispersed or dissolved is used. From the inside, the production method of the polymerization method of generating particles by polymerizing the monomer, particularly, by subjecting the metal oxide dispersed in the carrier core particles to lipophilic treatment, a sharp particle size distribution, fine powder A method of obtaining a small resin-coated carrier core is suitably used.

In the present invention, in the case of a carrier used in combination with a small particle size toner having a weight average particle size of 5 to 9.5 μm in order to achieve high image quality, the carrier particle size also depends on the toner particle size. In the above-mentioned production method, it is particularly preferable because even if the carrier particle diameter is reduced, a carrier having a small amount of fine powder can be produced regardless of the average particle diameter.

As the monomer used for the binder resin of the carrier core particles, a radical polymerizable monomer can be used. For example, styrene; o-methylstyrene,
Styrene derivatives such as m-methylstyrene, p-methoxystyrene, p-ethylstyrene, p-tert-butylstyrene; acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, n-propyl acrylate, acrylic Isobutyl acid, octyl acrylate,
Dodecyl acrylate, 2-ethylhexyl acrylate,
Stearyl acrylate, 2-chloroethyl acrylate,
Acrylic esters such as phenyl acrylate; methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-methacrylic acid Ethylhexyl, stearyl methacrylate, phenyl methacrylate,
Methacrylic esters such as dimethylaminomethyl methacrylate, diethylaminoethyl methacrylate, and benzyl methacrylate; 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate; acrylonitrile, methacrylonitrile, acrylamide; methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, vinyl ethers such as n-butyl ether, isobutyl ether, β-chloroethyl vinyl ether, phenyl vinyl ether, p-methylphenyl ether, p-chlorophenyl ether, p-bromophenyl ether, p-nitrophenyl vinyl ether and p-methoxyphenyl vinyl ether; butadiene And diene compounds such as

These monomers can be used alone or as a mixture, and a suitable polymer composition capable of obtaining preferable characteristics can be selected.

As described above, the binder resin of the carrier core particles is preferably three-dimensionally cross-linked. However, as a cross-linking agent for three-dimensionally cross-linking the binder resin,
It is preferable to use a crosslinking agent having two or more polymerizable double bonds per molecule. Examples of such a crosslinking agent include aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; ethylene glycol diacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, and 1,3-butylene glycol. Dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, 1,4-butanediol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, penta Erythritol dimethacrylate, pentaerythritol tetramethacrylate, glycerol Alkoxy dimethacrylate, N, N-divinyl aniline, divinyl ether, and a divinyl sulfide and divinyl sulfone. These may be used by mixing two or more kinds as appropriate. The cross-linking agent can be previously mixed with the polymerizable mixture, or can be added as needed during the polymerization.

Other monomers for the binder resin of the carrier core particles include bisphenols and epichlorohydrin as starting materials for the epoxy resin; phenols and aldehydes of the phenolic resin; ureas and aldehydes of the urea resin; melamine and aldehydes. No.

The most preferred binder resin is a phenolic resin. The starting materials are phenol, m
-Phenol compounds such as cresol, 3,5-xylenol, p-alkylphenol, resorcil, p-tert-butylphenol, and aldehyde compounds such as formalin, paraformaldehyde and furfural. Particularly, a combination of phenol and formalin is preferred.

When these phenol resins or melamine resins are used, a basic catalyst can be used as a curing catalyst. As the basic catalyst, various catalysts used in the production of ordinary resol resins can be used. Specific examples include amines such as aqueous ammonia, hexamethylenetetramine, diethyltriamine and polyethyleneimine.

In the present invention, the metal compound contained in the carrier core is subjected to lipophilic treatment to sharpen the particle size distribution of the magnetic carrier particles and prevent the metal compound particles from being detached from the carrier. Preferred above.
In the case of forming carrier core particles in which a lipophilic metal compound is dispersed, particles insoluble in a solution are generated at the same time as the polymerization reaction proceeds from a liquid in which a monomer and a solvent are uniformly dispersed or dissolved. At that time, it is considered that the metal oxide has an effect of uniformly and densely taking in the inside of the particles and an effect of preventing aggregation of the particles and sharpening the particle size distribution. Furthermore, when a metal compound subjected to lipophilic treatment is used, there is no need to use a suspension stabilizer such as calcium fluoride, and the suspension stabilizer remains on the carrier surface, thereby impairing the chargeability. It is possible to prevent the nonuniformity of the coating resin and the inhibition of the reaction when coating with a reactive resin such as a silicone resin.

In the lipophilic treatment, an organic compound having one or more functional groups selected from an epoxy group, an amino group and a mercapto group, or a lipophilic treatment agent which is a mixture thereof is used. Is preferred. In particular, an epoxy group is preferably used in order to easily achieve the range of the amount of adsorbed water of the present invention and to obtain a carrier having a stable charging ability.

The magnetic metal oxide particles are preferably treated with 0.1 to 10 parts by weight, more preferably 0.2 to 6 parts by weight, per 100 parts by weight of the magnetic metal oxide particles. Is preferred in order to increase the lipophilicity and hydrophobicity of the magnetic metal oxide particles.

Examples of the lipophilic treatment agent having an epoxy group include γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, β
-(3,4-epoxycyclohexyl) trimethoxysilane, epichlorohydrin, glycidol and styrene-glycidyl (meth) acrylate copolymer.

Examples of the lipophilic treatment agent having an amino group include γ-aminopropyltrimethoxysilane, γ-aminopropylmethoxydiethoxysilane, γ-aminopropyltriethoxysilane, and N-β (aminoethyl)-
γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, ethylenediamine, ethylenetriamine, styrene-dimethylamino (meth) acrylate Ethyl copolymer and isopropyl tri (N-aminoethyl) titanate are used.

As the lipophilic treatment agent having a mercapto group, for example, mercaptoethanol, mercaptopropionic acid and γ-mercaptopropyltrimethoxysilane are used.

The resin for coating the carrier core surface is not particularly limited. Specifically, for example, polystyrene, acrylic resin such as styrene-acrylic copolymer, vinyl chloride, vinyl acetate, polyvinylidene fluoride resin, fluorocarbon resin, perfluorocarbon resin, solvent-soluble perfluorocarbon resin, polyvinyl alcohol, polyvinyl acetal, Polyvinyl pyrrolidone, petroleum resin, cellulose, cellulose derivative, novolak resin, low molecular weight polyethylene, saturated alkyl polyester resin, aromatic polyester resin, polyamide resin, polyacetal resin, polycarbonate resin, polyether sulfone resin, polysulfone resin, polyphenylene sulfide resin, poly Ether ketone resin, phenol resin, modified phenol resin, maleic resin, alkyd resin, epoxy resin, acrylic resin, anhydrous male Unsaturated polyester obtained by polycondensation of emissions and terephthalic acid and polyhydric alcohol, urea resins, melamine resins,
Urea-melamine resin, xylene resin, toluene resin, guanamine resin, melamine-guanamine resin, acetoguanamine resin, gliptal resin, furan resin, silicone resin, polyimide resin, polyamideimide resin, polyetherimide resin and polyurethane resin. it can.

Among them, silicone resins are preferably used from the viewpoint of adhesion to the core and prevention of spent. The silicone resin can be used alone, but is preferably used in combination with a coupling agent in order to increase the strength of the coating layer and control the charging to a preferable level. Further, the above-mentioned coupling agent is preferably used as a so-called primer agent, a part of which is treated on the carrier core surface before coating the resin, and the subsequent coating layer has a covalent bond. , Can be formed with higher adhesion.

As the coupling agent, aminosilane is preferably used. As a result, a positively chargeable amino group can be introduced into the carrier surface, and the toner can be favorably imparted with negative charge characteristics. Furthermore, in the case of a magnetic material-dispersed resin carrier, the presence of the amino group activates both the lipophilic treatment agent preferably treated with the metal compound and the silicone resin, so that the silicone resin adheres to the carrier core. By further enhancing the properties and simultaneously promoting the curing of the resin, a stronger coating layer can be formed.

During the coating treatment of the coating layer, the coating is preferably performed under reduced pressure at a temperature of 30 ° C. to 80 ° C.
The reason is not clear, but is expected to be described below. (1) An appropriate reaction proceeds in the coating stage, and the coating material is uniformly and smoothly coated on the carrier core surface. (2) In the baking step, a low-temperature treatment at a temperature of at least 160 ° C. or less can be performed, and excessive crosslinking of the resin can be prevented, and the durability of the coating layer can be increased.

The toner used in combination with the carrier of the present invention is particularly effective when at least a polyester resin is contained as a binder resin of the toner.
That is, the polyester resin is excellent in fixing property and color mixing property, and is particularly preferably used as a binder resin for a color toner. However, on the other hand, the polyester resin has a strong negative charging ability, and has a problem that the charging tends to be excessive particularly in a low humidity environment. I was However, when used in combination with the carrier of the present invention, it is possible to suppress excessive charging of the toner and obtain excellent developability.

Other binder resins for the toner include polystyrene; polymer compounds obtained from styrene derivatives such as poly-p-chlorostyrene and polyvinyl toluene;
Styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylate copolymer, styrene-methacrylate copolymer, styrene-α-
Styrene copolymers such as methyl chloromethacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer Polymer; polyvinyl chloride, phenolic resin, modified phenolic resin, maleic resin, acrylic resin, methacrylic resin, polyvinyl acetate,
Silicone resin; Polyester resin having a monomer selected from aliphatic polyhydric alcohol, aliphatic dicarboxylic acid, aromatic dicarboxylic acid, aromatic dialcohols and diphenols as a structural unit; polyurethane resin, polyamide resin, polyvinyl Butyral, terpene resin, cumarone indene resin, petroleum resin.

A toner having a core / shell structure and a core formed of a low softening point substance is also preferably used. Although the above toner uses a low softening point substance, it is advantageous for low-temperature fixing.However, it tends to be disadvantageous to heat generation due to mechanical shear, and toner spent may occur in a developing device. The use of the carrier of the invention eliminates that concern.

As a method for encapsulating the low softening point substance in the toner particles, the polarity of the material in the aqueous medium is set to be smaller for the low softening point substance than for the main monomer, and a small amount of the larger polarity is used. By adding a resin or a monomer, toner particles having a so-called core / shell structure in which a low softening point substance is coated with an outer shell resin can be obtained.

The particle size distribution and the particle size of the toner can be controlled by changing the type and amount of the hardly water-soluble inorganic salt or the dispersing agent acting as a protective colloid, or by using mechanical device conditions such as a roller. A predetermined toner can be obtained by controlling the peripheral speed, the number of passes, stirring conditions such as the shape of the stirring blade, the shape of the container, or the solid concentration in the aqueous medium.

As the outer shell resin of the toner, styrene-
(Meth) acrylic copolymers, polyester resins, epoxy resins, styrene-butadiene copolymers may be mentioned.
In a method of directly obtaining toner particles by a polymerization method, those monomers are preferably used. Specifically, styrene; o (m-, p-)-methylstyrene, m (p-)
A styrene monomer such as ethylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, (meth) acrylic acid Dodecyl, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate,
(Meth) acrylate monomers such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate; ene monomers such as butadiene, isoprene, cyclohexene, (meth) acrylonitrile and acrylamide are preferred Used.

In these toners, it is preferable to use at least silica fine particles and / or titanium oxide fine particles as an external additive, since the fluidity can be favorably imparted to the developer and the life of the developer is improved. Further, by using these fine powders, a developer having less environmental fluctuation can be obtained.

Other external additives include metal oxide fine powder (aluminum oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, tin oxide, zinc oxide, etc.) and nitride fine powder (silicon nitride, etc.) , Carbide fine powder (silicon carbide, etc.), metal salt fine powder (calcium sulfate, barium sulfate, calcium carbonate, etc.), fatty acid metal salt fine powder (zinc stearate, calcium stearate, etc.), carbon black, resin fine powder (polytetra Fluoroethylene, polyvinylidene fluoride, polymethyl methacrylate, polystyrene, silicone resin, etc.) are preferred. Even if these external additives are used alone,
Also, a plurality of them may be used in combination. It is more preferable that the above-mentioned external additives including the silica fine powder have been subjected to a hydrophobic treatment.

The above-mentioned external additive has a number average particle size of 0.2.
It is preferably not more than μm. Number average particle size is 0.2
If it exceeds μm, the fluidity will decrease and the image quality will deteriorate during development and transfer.

The external additive is preferably used in an amount of preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, based on 100 parts by mass of the toner particles.

[0112] the external additive has a specific surface area by nitrogen adsorption according to the BET method is preferably 30 m ² / g or more, more preferably is suitable in the range of 50 to 400 m ² / g.

The mixing treatment of the toner particles and the external additive can be performed using a mixer such as a Henschel mixer.

In the present invention, examples of the colorant used in the toner include the following.

Examples of yellow colorants include condensed azo compounds, isoindolinone compounds, anthraquinone compounds,
Compounds represented by azo metal complexes, methine compounds and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 6
2, 74, 83, 93, 94, 95, 109, 110,
111, 128, 129, 147, 168 and 180 can be suitably used.

Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds and perylene compounds. Specifically, C.I.
I. Pigment Red 2, 3, 5, 6, 7, 23, 4
8: 2, 48: 3, 48: 4, 57: 1, 81: 1, 1
44, 146, 166, 169, 177, 184, 18
5, 202, 206, 220, 221, 254 can be suitably used.

Examples of the cyan coloring agent include copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, and basic dye lake compounds. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 1
5: 3, 15: 4, 60, 62, 66 can be suitably used.

These colorants can be used alone or as a mixture or in the form of a solid solution.

Examples of the black coloring agent include carbon black and the above-described yellow / magenta / cyan coloring agents which are toned to black.

In the case of a color toner, the hue angle,
The selection is made in consideration of saturation, lightness, weather resistance, OHP transparency, and dispersibility in toner. The content of the colorant is preferably 1 to 20 parts by mass based on 100 parts by mass of the binder resin for toner.

As the charge control agent used in the toner,
Known ones can be used. In the case of a color toner, a charge control agent which is colorless or light-colored and has a high toner charging speed and can stably maintain a constant charge amount is particularly preferable. Further, in the present invention, when a toner is produced by a polymerization method, a charge control agent having no polymerization inhibition and having no soluble matter in an aqueous medium is particularly preferable. Further, the toner used in the present developer may have at least one peak in the range of 280 to 350 nm when the absorbance of an extract obtained by extraction with 0.1 mol / L sodium hydroxide is measured. preferable. This peak is a peak derived from oxycarboxylic acid which is preferably used in the toner for the purpose of controlling charging, accelerating the curing of the binder resin and increasing the fluidity, and the like. Such an oxycarboxylic acid can impart high chargeability to the toner. However, depending on the binder resin and other materials, and the method of manufacturing the toner, an extremely low charge amount under high humidity or a charge-up of the toner under low humidity may be observed. there were.

However, by using the carrier of the present invention, it has become possible to effectively suppress the toner charge-up phenomenon particularly under low humidity.

The amount of sodium hydroxide extracted was 0.1 mol
1 g of the toner is weighed and added to 50 ml of an aqueous solution of 1 / liter sodium hydroxide, and then 50 rpm using a stirrer.
And uniformly disperse. After the dispersion treatment for 3 hours, the membrane filter (pore size: 0.45 μm)
m), and the absorbance of the obtained filtrate was measured.

Examples of negative charge control agents include metal compounds of salicylic acid, dialkylsalicylic acid, naphthoic acid, dicarboxylic acid and derivatives thereof; high molecular compounds having sulfonic acid or carboxylic acid in the side chain; boron compounds; A urea compound; a silicon compound; and carricks arene are preferably used. As positive charge control agents,
For example, a quaternary ammonium salt; a polymer compound having the quaternary ammonium salt in a side chain; a guanidine compound; and an imidazole compound are preferably used. The content of the charge control agent is 0.5 to 10 with respect to 100 parts by mass of the binder resin.
It is preferably in parts by mass. However, the addition of the charge control agent to the toner particles is not essential.

The toner particles can be produced by melt-kneading a binder resin, a colorant, and other internal additives, cooling the kneaded material, pulverizing and classifying, and directly using a suspension polymerization method. A method for producing particles, a method for dispersion polymerization in which toner particles are directly produced using an aqueous organic solvent in which the obtained polymer is insoluble in a monomer, or a method in which polymerization is carried out directly in the presence of a water-soluble polar polymerization initiator A method of producing toner particles using an emulsion polymerization method typified by a soap-free polymerization method for producing toner particles is exemplified.

In the present invention, the shape factor SF of the toner
-1 can be easily controlled to 100 to 160, and a method of producing toner particles by a suspension polymerization method that can relatively easily obtain a fine particle toner having a sharp particle size distribution and a weight average particle size of 5 to 9.5 μm is preferable.

When toner particles are produced by a polymerization method, 2,2′-azohis- (2,2) is used as a polymerization initiator.
4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile, 2,2'-azobis-4-methoxy-2,4-dimethylvalero Azo polymerization initiators such as nitrile and azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide;
A peroxide-based polymerization initiator such as lauroyl peroxide is used.

The amount of the polymerization initiator varies depending on the desired degree of polymerization.
0 mass% is added and used. The type of the polymerization initiator varies slightly depending on the polymerization method, but is used alone or in combination with reference to the 10-hour half-life temperature. Known crosslinking agents, chain transfer agents, polymerization inhibitors and the like for controlling the degree of polymerization can be further added and used.

In the case where suspension polymerization is used as a method for producing a toner, tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, carbonate Examples include magnesium, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, and alumina. Examples of the organic compound include polyvinyl alcohol, gelatin, methylcellulose, methylhydroxypropylcellulose, ethylcellulose, sodium salts of carboxymethylcellulose, starch and the like. These are used by being dispersed in an aqueous phase. These dispersants are used in an amount of 0.2 to 100 parts by mass of the polymerizable monomer.
It is preferred to use 10.0 parts by weight.

As these dispersants, commercially available ones may be used as they are, but in order to obtain finely dispersed particles having a uniform particle size, the inorganic compound may be formed under high-speed stirring in a dispersion medium. I can do it. For example, in the case of tricalcium phosphate, a dispersant suitable for a suspension polymerization method can be obtained by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring. Further, 0.001 to 0.1 parts by mass of a surfactant for miniaturization of these dispersants may be used in combination. Specifically, commercially available nonionic, anionic or cationic surfactants can be used, for example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate. Calcium oleate is preferably used.

In the case where the direct polymerization method is used for the production method of the toner, it is possible to specifically produce the toner by the following production method. A monomer composition obtained by adding a release agent, a colorant, a charge control agent, a polymerization initiator, and other additives made of a low-softening substance to a monomer and uniformly dissolving or dispersing the mixture using a homogenizer, an ultrasonic disperser, or the like. The product is dispersed in an aqueous phase containing a dispersion stabilizer using a conventional stirrer, homomixer, homogenizer, or the like. Preferably, the stirring speed and the time are adjusted so that the droplets composed of the monomer composition have a desired size of the toner particles, and the droplets are granulated. Thereafter, by the action of the dispersion stabilizer, the stirring may be performed to such an extent that the particle state is maintained and the sedimentation of the particles is prevented. The polymerization temperature is 40 ° C. or higher, generally 50 to 9
The polymerization is carried out at a temperature of 0 ° C. The temperature may be raised in the latter half of the polymerization reaction, and further, for the purpose of improving the durability properties, in order to remove unreacted polymerizable monomers and by-products, in the latter half of the reaction or after completion of the reaction, a part of the aqueous medium is distilled You may leave. After the reaction, the generated toner particles are collected by washing and filtration, and dried. In the suspension polymerization method, the monomer system 1 is usually used.
It is preferable to use 300 to 3000 parts by mass of water as a dispersion medium with respect to 00 parts by mass.

The toner may be classified to control the particle size distribution, and a multi-segment classifier utilizing inertial force is preferably used as the method. By using this apparatus, a toner having a preferable particle size distribution in the present invention can be efficiently produced.

Next, the image forming method of the present invention will be described.

In the image forming method of the present invention, an ultrasonic motor is used as a rotator driving device for driving a latent image carrier and / or a rotator driving device for driving a transport belt using contact transfer means. As a two-component developer, a toner having a shape factor SF-1 of 100 to 160 and a magnetic material-dispersed resin carrier are used, and a latent image carrier for carrying an electrostatic latent image is contact-charged. Means for charging the latent image carrier, forming an electrostatic latent image on the charged latent image carrier, and developing the electrostatic latent image with a two-component developer toner. Forming a toner image on a carrier, the toner image on the electrostatic latent image carrier, with or without an intermediate transfer member,
The toner image is transferred onto a transfer material, and the toner image on the transfer material is heated and pressed and fixed.

Hereinafter, an example of the image forming method of the present invention will be described with reference to the accompanying drawings.

First, an example around the electrostatic latent image carrier will be described.

In FIG. 1, a magnetic brush made of magnetic particles 23 is formed on the surface of the transfer sleeve 22 by the magnetic force of the magnet roller 21, and the electrostatic brush is rotated by an ultrasonic motor (not shown). The photosensitive drum 1 is charged by bringing it into contact with the surface of the carrier (photosensitive drum) 1. A charging bias is applied to the transport sleeve 22 by a bias applying unit (not shown). By irradiating the charged photosensitive drum 1 with laser light 24 by an exposure device (not shown), a digital electrostatic charge image is formed. The electrostatic charge image formed on the photosensitive drum 1 includes a magnet roller 12 and a two-component developer 19 carried on a developing sleeve 11 to which a developing bias is applied by a bias applying device (not shown). Is developed by the toner 19a.

The developing device 4 as a developing means includes a partition 17
, And is divided into a developer chamber R1 and a stirring chamber R2, and developer conveying screws 13 and 14 are provided respectively. Above the stirring chamber R2, a toner storage chamber R3 containing the toner 18 for replenishment is provided, and a replenishing port 20 is provided below the storage chamber R3.

The developer transport screw 13 rotates to transport the two-component developer 19 in the developer chamber R1 in one direction along the longitudinal direction of the developing sleeve 11 while stirring. The partition 17 is provided with openings (not shown) on the near side and the back side in the figure, and the two-component developer 19 conveyed to one side of the developer chamber R1 by the screw 13 passes through the opening of the partition 17 on one side. Is fed into the stirring chamber R2 through the developer transfer screw 14. The rotation direction of the screw 14 is opposite to that of the screw 13 and the stirring chamber R
The two-component developer 19 in 2, the two-component developer 19 transferred from the developer chamber R1, and the toner supplied from the toner storage chamber R3 are stirred and mixed in the opposite direction to the screw 13 while being mixed. The developer is conveyed in the chamber R2, and is sent into the developer chamber R1 through the other opening of the partition wall 17.

To develop the electrostatic charge image formed on the photosensitive drum 1, the developer 19 in the developer chamber R1 is pumped up by the magnetic force of the magnet roller 12, and the developing sleeve 1
1 is carried on the surface. The two-component developer 19 carried on the developing sleeve 11 is conveyed to the regulating blade 15 with the rotation of the developing sleeve 11, where it is regulated to a developer thin layer having an appropriate layer thickness. The photosensitive drum 1 reaches a development area facing the photosensitive drum 1. A magnetic pole (development pole) is provided at a portion of the magnet roller 12 corresponding to the development area.
N1 is located, and the developing pole N1 forms a developing magnetic field in the developing area, and the developer magnetically rises by the developing magnetic field,
A magnetic brush of the two-component developer 19 is generated in the development area. Then, the magnetic brush comes into contact with the photosensitive drum 1, and the toner 19a attached to the magnetic brush and the toner 19 attached to the surface of the developing sleeve 11 are formed by the reversal developing method.
a is transferred to and adheres to the region of the electrostatic charge image on the photosensitive drum 1, and the electrostatic charge image is developed to form a toner image.

The two-component developer 19 that has passed through the development area
Is returned into the developing device 4 with the rotation of the developing sleeve 11, is peeled off from the developing sleeve 11 by a repelling magnetic field between the magnetic poles S1 and S2, and the developer chamber R1 and the stirring chamber R2
Drops inside and is collected.

When the T / C ratio (mixing ratio of toner and carrier, that is, the toner concentration in the developer) of the two-component developer 19 in the developing device 4 is reduced by the above-described development, the toner 18 is transferred from the toner storage chamber R3 to the toner 18 Is supplied to the stirring chamber R2 in an amount corresponding to the amount consumed in the development, and the T /
C is kept at a predetermined amount. To detect the T / C ratio of the two-component developer 19 in the container 4, a toner concentration detection sensor that measures a change in the magnetic permeability of the two-component developer 19 using the inductance of the coil is used. The toner concentration detection sensor has a coil (not shown) therein.

The regulating blade 15 which is disposed below the developing sleeve 11 and regulates the layer thickness of the two-component developer 19 on the developing sleeve 11 is a non-magnetic blade 15 made of a non-magnetic material such as aluminum or SUS316. It is. The distance between the end and the surface of the developing sleeve 11 is 250 to
It is 1000 μm, preferably 300 to 900 μm.
If this distance is smaller than 250 μm, the magnetic carrier is clogged during this time, and the developer layer is likely to be uneven, and it is difficult to apply a two-component developer necessary for good development, and the density is low and there are many unevenness. An image is easily formed.
This distance is preferably 300 μm or more in order to prevent non-uniform application (so-called blade jam) due to unnecessary particles mixed in the developer. If this distance is larger than 1000 μm, the amount of the developer applied on the developing sleeve 11 increases, and it is difficult to regulate the predetermined thickness of the developer layer, and the adhesion of the magnetic carrier particles to the photosensitive drum 1 increases, and the developer The development regulation by the circulation and regulation blade 15 is weakened, so that the toner tribo is reduced and fogging is easily caused.

Even when the developing sleeve 11 is rotationally driven in the direction of the arrow, the magnetic carrier particle layer is separated from the surface of the sleeve by the balance between the restraining force based on magnetic force and gravity and the conveying force in the moving direction of the developing sleeve 11. Movement slows down. Some fall under the influence of gravity.

Accordingly, by appropriately selecting the arrangement positions of the magnetic poles N and S and the fluidity and magnetic properties of the magnetic carrier particles, the magnetic carrier particle layer becomes closer to the sleeve so that the magnetic pole N1 becomes closer to the sleeve.
To form a moving layer. Due to the movement of the magnetic carrier particles, the developer is conveyed to the developing area with the rotation of the developing sleeve 11 and is used for development.

The developed toner image is transferred onto a conveyed transfer material (recording material) 25 by a transfer blade 27 which is a transfer unit to which a transfer bias is applied by a bias applying unit 26, and is transferred onto the transfer material. The transferred toner image is fixed to a transfer material by a fixing device (not shown). In the transfer step, the transfer residual toner remaining on the photosensitive drum 1 without being transferred to the transfer material is adjusted in charge in the charging step, and is collected during development.

FIG. 3 is a schematic diagram in which the image forming method of the present invention is applied to a full-color image forming apparatus.

The main body of the full-color image forming apparatus includes a first image forming unit Pa, a second image forming unit Pb,
An image forming unit Pc and a fourth image forming unit Pd are provided side by side, and images of different colors are formed on a transfer material through a process of forming, developing, and transferring a latent image.

The configuration of each image forming unit provided in the image forming apparatus will be described by taking the first image forming unit Pa as an example.

The first image forming unit Pa includes an electrophotographic photosensitive drum 6 having a diameter of 30 mm as an electrostatic image carrier.
The photosensitive drum 61a is rotated by an ultrasonic motor (not shown) in the direction of arrow a. 6
2a is a primary charger as a charging means, and has a diameter of 16 m.
The magnetic brush formed on the surface of the m sleeve is arranged so as to contact the surface of the photosensitive drum 61a. 67
Reference symbol a denotes a laser beam for forming an electrostatic charge image on the photosensitive drum 61a whose surface is uniformly charged by the primary charger 62a, and is irradiated by an exposure device (not shown). Reference numeral 63a denotes a developing device as developing means for developing a static toner image carried on the photosensitive drum 61a to form a color toner image, and holds a two-component developer having a carrier and a color toner. ing. 64
The symbol “a” transfers the color toner image formed on the surface of the photosensitive drum 61 a to the surface of the transfer material (recording material) conveyed by rotating the belt-shaped transfer material carrier 68 by an ultrasonic motor (not shown). The transfer blade 64a is capable of applying a transfer bias by contacting the back surface of the transfer material carrier 68.

The first image forming unit Pa uniformly charges the photosensitive drum 61a with the primary charger 62a, forms an electrostatic image on the photosensitive member with the exposure device 67a, and transfers the formed electrostatic image to the photosensitive drum 61a. The developing device 63a develops the image with the two-component developer color toner, and the developed toner image is carried and transported by a first transfer section (a contact position between the photosensitive member and the transfer material). A transfer bias is applied from a transfer bias applying unit 60a to a transfer blade 64a that is in contact with the back surface side of the belt-shaped transfer material carrier 68, thereby transferring the image onto the surface of the transfer material.

When the toner is consumed by the development and the T / C ratio decreases, the decrease is detected by a toner concentration detection sensor 85 for measuring a change in the magnetic permeability of the developer using the inductance of the coil, and the toner is consumed. The supply toner 65 is supplied according to the toner amount. The toner density detection sensor 85 has a coil (not shown) therein.

The present image forming apparatus has the same configuration as the first image forming unit Pa, and has a second image forming unit Pb, a third image forming unit Pc, and a second image forming unit Pc having different colors of the color toner held in the developing device. Four image forming units of the fourth image forming unit Pd are provided side by side. For example, yellow toner is used for the first image forming unit Pa, magenta toner is used for the second image forming unit Pb, cyan toner is used for the third image forming unit Pc, and black toner is used for the fourth image forming unit Pd. The transfer of each color toner onto the transfer material is sequentially performed in the transfer section of each image forming unit. In this step, while the registration is being performed, each color toner is superimposed on the same transfer material by one transfer of the transfer material, and when the transfer is completed, the transfer material is separated from the transfer material carrier 68 by the separation charger 69. The sheet is sent to a fixing device 70, which is a heating / pressing fixing unit, by a conveying unit such as a conveying belt, and a final full-color image is obtained by a single fixing.

The fixing device 70 has a pair of a fixing roller 71 having a diameter of 40 mm and a pressure roller 72 having a diameter of 30 mm. The fixing roller 71 has heating means 75 and 76 therein.
have.

The unfixed color toner image transferred onto the transfer material passes through the pressure contact portion between the fixing roller 71 and the pressure roller 72 of the fixing device 70, and is applied to the transfer material by the action of heat and pressure. Is established.

In FIG. 3, the transfer material carrier 68 is an endless belt-like member, which is moved in the direction of arrow e by 80 drive rollers rotated by an ultrasonic motor. . 79 is a transfer belt cleaning device, 81 is a belt driven roller, and 82 is a belt static eliminator. 83 is a pair of registration rollers for conveying the transfer material in the transfer material holder to the transfer material carrier 68.

The transfer means is a contact transfer in which a transfer bias can be directly applied by contacting the back surface of a transfer material carrier such as a roller-shaped transfer roller instead of the transfer blade contacting the back surface of the transfer material carrier. Means can be used.

Next, an example of another image forming method of the present invention will be described with reference to FIG.

FIG. 4 is a schematic diagram showing an example of an image forming apparatus capable of performing the image forming method of the present invention.

This image forming apparatus is configured as a full-color copying machine. As shown in FIG. 4, the full-color copying machine has a digital color image reader unit 35 at the upper part and a digital color image printer unit 36 at the lower part.

In the image reader section, the original 30 is placed on an original platen glass 31 and is exposed and scanned by an exposure lamp 32, so that a reflected light image from the original 30 is condensed by a lens 33 to a full color sensor 34, and a color image is formed. Obtain a decomposed image signal. The color separation image signal is processed by a video processing unit (not shown) through an amplification circuit (not shown), and is sent to a digital image printer unit.

In the image printer section, the photosensitive drum 1, which is an electrostatic image carrier, is a photosensitive body such as an organic photoconductor, and is rotatably carried in an arrow direction by an ultrasonic motor (not shown). . Around the photosensitive drum 1, a pre-exposure lamp 41, a corona charger 2 as a primary charging member, a laser exposure optical system 3 as a latent image forming means,
Potential sensor 42, four developing units 4Y and 4 having different colors
C, 4M, 4K, on-drum light amount detecting means 43, transfer device 5A, and cleaning device 6 are arranged.

In the laser exposure optical system 3, an image signal from the reader unit is converted into an image scan exposure light signal by a laser output unit (not shown), and the converted laser light is reflected by the polygon mirror 3a. , Lens 3b
And is projected onto the surface of the photosensitive drum 1 via the mirror 3c.

[0164] When an image is formed, the photosensitive drum 1
Is rotated in the direction of the arrow, and after the charge is eliminated by the pre-exposure lamp 11, the photosensitive drum 1 is uniformly negatively charged by the charger 2 to irradiate a light image E for each separation color, and the latent image is formed on the photosensitive drum 1. To form

Next, the latent image on the photosensitive drum 1 is developed by operating a predetermined developing device, and a visible image, that is, a toner image is formed on the photosensitive drum 1 by a negatively chargeable toner having a resin as a base material. I do. The developing devices 4Y, 4C, 4M, and 4K alternately approach the photosensitive drum 1 in accordance with each separated color and perform development by the operation of the eccentric cams 24Y, 24C, 24M, and 24K.

The transfer device 5A includes a transfer drum 5, a transfer charger 5b, a suction charger 5c for electrostatically attracting a recording material and a suction roller 5g opposed thereto, an inner charger 5d, an outer charger 5e, It has a separation charger 5h. The transfer drum 5 is rotatably supported so as to be rotatable, and a transfer sheet 5f, which is a recording material carrier for supporting a recording material (transfer material) in an opening area around the transfer drum 5, is integrally adjusted in a cylindrical shape. A polycarbonate film is used for the transfer sheet 5f.

The recording material is conveyed from the recording material cassette 7a, 7b or 7c to the transfer drum 5 through the recording material conveyance system, and is carried on the transfer sheet 5f. Transfer drum 5
The recording material carried thereon is repeatedly conveyed to a transfer position facing the photosensitive drum 1 as the transfer drum 5 rotates, and is transferred onto the photosensitive material by the action of the transfer charger 5b while passing through the transfer position. 1 is transferred.

In the above image forming step, yellow (Y),
By repeating the process for cyan (C), magenta (M), and black (K), a color image in which four color toner images are superimposed and transferred on the recording material on the transfer drum 5 is obtained.

In the case of single-sided image formation, the recording material onto which the four color toner images have been transferred in this way is separated by the action of the separation claw 8a, the separation push-up roller 8b, and the separation charger 5h.
The sheet is separated from the transfer drum 5 and sent to the heat fixing device 9.
The heat fixing device 9 includes a heat fixing roller 9a having a heating unit therein and a pressure roller 9b. The full-color image carried on the recording material is fixed on the recording material by passing the recording material through the pressure contact portion between the heat fixing roller 9a and the pressure roller 9b as a heating member. That is, in this fixing step, toner color mixing, color development, and fixing to the recording material are performed to form a full-color permanent image, which is then discharged to the tray 10 to complete one full-color copy. On the other hand, the photosensitive drum 1 is subjected to the image forming process again after the residual toner on the surface is cleaned and removed by the cleaning device 6.

In the image forming method of the present invention, it is possible to transfer a toner image obtained by developing the electrostatic charge image formed on the latent image carrier to a recording material via an intermediate transfer member.

That is, in this image forming method, the toner image formed by developing the electrostatic image formed on the electrostatic image carrier is transferred to an intermediate transfer member, and the toner image transferred to the intermediate transfer member is developed. Is transferred to a recording material.

An example of an image forming method using an intermediate transfer member will be specifically described with reference to FIG.

In the apparatus system shown in FIG. 5, the cyan developing device 54-1, the magenta developing device 54-2, the yellow developing device 54-3, and the black developing device 54-4 are respectively provided with a cyan developer containing a cyan toner and a magenta developer. A magenta developer having a toner, a yellow developer having a yellow toner, and a black developer having a black toner have been introduced. An electrostatic latent image is formed on a photosensitive member 51 as a latent image holding member by a latent image forming means 53 such as a laser beam. By a developing method such as a magnetic brush developing method, a non-magnetic one-component developing method or a magnetic jumping developing method,
The electrostatic charge image formed on the photoconductor 51 is developed with these developers, and a toner image of each color is formed on the photoconductor 51.
The photosensitive member 51 is a photosensitive drum or a photosensitive belt having a conductive substrate 51b and a photoconductive insulating material layer 51a such as amorphous selenium, cadmium sulfide, zinc oxide, an organic photoconductor, and amorphous silicon formed on the conductive substrate 51b. is there. The photoconductor 51 is rotated in the direction of an arrow by a device driven by an ultrasonic motor (not shown). As the photoconductor 51, a photoconductor having an amorphous silicon photosensitive layer or an organic photosensitive layer is preferably used.

The organic photosensitive layer may be a single layer type in which the photosensitive layer contains a charge generating substance and a substance having a charge transporting property in the same layer, or a functional separation type in which the charge transporting layer contains the charge generating layer as a component. It may be a photosensitive layer. A laminated photosensitive layer having a structure in which a charge generation layer and then a charge transport layer are laminated on a conductive substrate in this order is one of preferred examples.

As the binder resin for the organic photosensitive layer, a polycarbonate resin, a polyester resin, or an acrylic resin has good cleaning properties, and poor cleaning, fusion of toner to a photoreceptor, and filming of an external additive hardly occur.

In the charging step, there are a non-contact type with the photosensitive member 51 using a corona charger and a contact type with a contact charging member such as a roller, and both types are used. For efficient uniform charging, simplification, and low ozone generation, a contact type as shown in FIG. 5 is preferably used.

The charging roller 52 as a primary charging member includes:
Conductive elastic layer 5 having central core 52b and outer periphery thereof
2a as a basic configuration. Charging roller 52
Is pressed against the surface of the photoconductor 51 with a pressing force, and the photoconductor 5
The rotation follows the rotation of 1.

As a preferable process condition when the charging roller is used, the contact pressure of the roller is 4.9 to 490 N.
/ M (5 to 500 g / cm), when an AC voltage is superimposed on a DC voltage, the AC voltage is 0.5 to 5
kVpp, AC frequency = 50 Hz to 5 kHz, DC voltage = ± 0.2 to ± 5 kV.

Other contact charging members include a method using a charging blade and a method using a conductive brush. These contact charging members are effective in that high voltage is not required and generation of ozone is reduced.

The material of the charging roller and the charging blade as the contact charging member is preferably conductive rubber, and a release coating may be provided on the surface thereof. As the release coating, a nylon resin, PVDF (polyvinylidene fluoride), PVDC (polyvinylidene chloride), or a fluorine acrylic resin can be used.

The toner image on the photosensitive member is applied with a voltage (for example, ±
(0.1 to ± 5 kV). The intermediate transfer member 55 includes a pipe-shaped conductive core 55b and a medium-resistance elastic layer 55 formed on the outer peripheral surface thereof.
a. The cored bar 55b may be provided with a conductive layer (for example, conductive plating) on the surface of plastic.

The medium-resistance elastic body layer 55a is made of silicone rubber, Teflon (registered trademark) rubber, chloroprene rubber, urethane rubber, EPDM (ethylene propylene diene).
An electrical resistance value (volume resistivity) of 10 ⁵ to 10 ¹¹ by blending and dispersing a conductivity-imparting material such as carbon black, zinc oxide, tin oxide, and silicon carbide in an elastic material such as
It is a solid or foamed layer adjusted to a medium resistance of Ω · cm.

The intermediate transfer member 55 is provided in parallel with the photoreceptor 51 so as to be in contact with the lower surface of the photoreceptor 51, and is arranged in the counterclockwise direction indicated by an arrow at the same peripheral speed as the photoreceptor 51. Rotate.

The first color toner image formed and carried on the surface of the photosensitive member 51 is transferred by the transfer bias applied to the intermediate transfer member 55 while passing through the transfer nip where the photosensitive member 51 and the intermediate transfer member 55 are in contact with each other. The intermediate transfer is sequentially performed on the outer surface of the intermediate transfer body 55 by the electric field formed in the nip area.

The untransferred toner on the photosensitive member 51 that has not been transferred to the intermediate transfer member 55 is removed by the photosensitive member cleaning member 5.
8 and is collected in the photoconductor cleaning container 59.

A transfer means is provided in parallel with the intermediate transfer body 55 and is brought into contact with the lower surface of the intermediate transfer body 55. The transfer means 57 is, for example, a transfer roller or a transfer belt. It rotates clockwise with the same peripheral speed as the arrow. The transfer means 57 may be provided so as to directly contact the intermediate transfer body 55, or a belt or the like may be provided so as to contact between the intermediate transfer body 55 and the transfer means 57.

In the case of the transfer roller, the transfer roller is basically composed of a central core bar 57b and a conductive elastic layer 57a forming the outer periphery thereof.

For the intermediate transfer member and the transfer roller, general materials can be used. By setting the volume resistivity of the elastic layer of the transfer roller smaller than the volume resistivity of the elastic layer of the intermediate transfer body, the voltage applied to the transfer roller can be reduced, and a good toner image can be formed on the transfer material. In addition, it is possible to prevent the transfer material from being wound around the intermediate transfer member. In particular, it is particularly preferable that the volume specific resistance of the elastic layer of the intermediate transfer member is at least 10 times the volume specific resistance of the elastic layer of the transfer roller.

The hardness of the intermediate transfer member and the transfer roller is J
It is measured in accordance with IS K-6301. The intermediate transfer member used in the present invention is preferably composed of an elastic layer belonging to the range of 10 to 40 degrees. On the other hand, the hardness of the elastic layer of the transfer roller is higher than the hardness of the elastic layer of the intermediate transfer member. Those having a value of from -80 degrees are preferred in order to prevent the transfer material from winding around the intermediate transfer member. When the hardness of the intermediate transfer body and that of the transfer roller are reversed, a concave portion is formed on the transfer roller side, and the winding of the transfer material around the intermediate transfer body is likely to occur.

The transfer means 57 rotates the intermediate transfer member 55 at a constant speed or a peripheral speed. The transfer material 56 is conveyed between the intermediate transfer body 55 and the transfer means 57,
The toner image on the intermediate transfer body 55 is transferred to the surface of the transfer material 56 by applying a bias having a polarity opposite to the frictional charge of the toner to the transfer unit 57 from the transfer bias unit.

The untransferred toner remaining on the intermediate transfer member that has not been transferred to the transfer material 56 is removed by the cleaning member 6 for the intermediate transfer member.
0 and is collected in the intermediate transfer body cleaning container 62. The toner image transferred to the transfer material 56 is fixed on the transfer material 56 by the heat fixing device 61.

As the material of the transfer roller, the same material as that of the charging roller can be used. The preferable transfer process condition is that the contact pressure of the roller is 2.94 to 490.
N / m (3 to 500 g / cm) (more preferably, 19.
6 to 294 N / m), DC voltage = ± 0.2 to ± 10 k
V.

When the linear pressure as the contact pressure is less than 2.94 N / m, it is not preferable because the transfer of the transfer material and the occurrence of transfer failure tend to occur.

For example, the conductive elastic layer 5 of the transfer roller 57
7a is an elastic material such as polyurethane rubber or EPDM (ethylene propylene diene terpolymer), and a conductive agent such as carbon black, zinc oxide, tin oxide or silicon carbide is mixed and dispersed in the material to obtain an electric resistance value (volume resistivity). ) From 10 ⁶
It is a solid or foamed layer adjusted to have a medium resistance of 10 ¹⁰ Ω · cm.

Although not shown, the image forming apparatus shown in FIGS. 3 to 5 is provided with an atmosphere heater for controlling the inside of the apparatus to a constant temperature. This is a preferred embodiment.

For example, by controlling the inside of the apparatus to a constant temperature, it is possible to suppress environmental fluctuations such as developability, transferability, and fixability in the present invention. In particular, in the image forming apparatus shown in FIG.
It is possible to efficiently collect toner during development.

As the heater, a heating element may be used. More specifically, an electric resistance heating element such as a wound heater of a sheath-shaped heater, a plate-shaped heater, and a ceramic heater, and a heat radiation element such as a halogen lamp and an infrared lamp. Examples of the heating element include a lamp heating element, a heating element using heat exchange means using a liquid, a gas, or the like as a heating medium. As the surface material of the heating element, metals such as stainless steel, nickel, aluminum, and copper, ceramics, heat-resistant polymer resin, and the like can be used. Regarding the temperature control of the heating element, any of the methods of installing a thermoswitch near the heating element and controlling the temperature by sensing the temperature in the vicinity may be used.

[0198]

The present invention will now be described in detail with reference to Examples, but it should not be construed that the present invention is limited thereto.

Carrier Production Example 1 • Phenol 7.0 parts by mass • Formalin solution 11.55 parts by mass (formaldehyde about 40%, methanol about 10%, remainder water) • γ-glycidoxypropyltrimethoxysilane 1.0 Magnetite fine particles 58.5 parts by mass (average particle size 0.21 μm, specific resistance 8 × 10 ⁵ Ω · cm, magnetization intensity at 1000 / 4π (kA / m) 49 Am ² / kg) 32.5 parts by mass of α-Fe ₂ O ₃ fine particles I lipophilized with 1.0% by mass of γ-glycidoxypropyltrimethoxysilane (average particle size: 0.62 μm, specific resistance: 3 × 10 ⁹ Ω)・ Cm,)

The magnetite and α-Fe ₂ used here
The lipophilic treatment of O ₃ is performed by using 99 parts by mass of magnetite and α-
To each of 99 parts by mass of Fe ₂ O ₃ , 1.0 part by mass of γ-glycidoxypropyltrimethoxysilane was added,
Premixing and stirring were performed at 100 ° C. for 40 minutes in a Henschel mixer.

While keeping the above materials and 11 parts by mass of water at 40 ° C., mixing was carried out for 1 hour. 2.0 parts by mass of 28% by mass ammonia water as a basic catalyst and 11 parts by mass of water were added to the slurry, and the mixture was heated and maintained at 85 ° C. for 40 minutes with stirring and mixing, and reacted for 3 hours.
A phenolic resin was formed and cured. Thereafter, the mixture was cooled to 30 ° C., 100 parts by mass of water was added, the supernatant was removed, and the precipitate was washed with water and air-dried. Next, this was dried at 180 ° C. under reduced pressure (5 mmHg or less) to obtain spherical magnetic carrier core particles containing magnetite fine particles using a phenol resin as a binder resin.

Coarse particles are removed from the particles by a sieve of 60 mesh and 100 mesh, and then a multi-divided air classifier utilizing the Coanda effect (Eppo Jet Lab EJ-L-3, manufactured by Nippon Mining Co., Ltd.) Fine particles and coarse particles are removed using a 50% volume average particle size of 35 μm.
Was obtained.

The obtained carrier core particles were charged into a coater, and humidified nitrogen was introduced to adjust the water content to 0.3% by mass. Thereafter, the core surface was treated with 3% by mass of γ-aminopropyltrimethoxysilane diluted with a toluene solvent while continuously applying a shearing stress. At that time,
This was carried out at 40 ° C. and 13300 Pa (100 Torr) under a dry nitrogen stream while evaporating the solvent. Subsequently, a mixture of 0.5% by mass of a straight silicone resin in which all the substituents are methyl groups and 0.015% by mass of γ-aminopropyltrimethoxysilane were coated with toluene as a solvent. At that time, 40 ° C, 66500Pa (500T
orr) under a dry nitrogen stream while evaporating the solvent.

Further, this magnetic coated carrier was
Baked at 100 ° C., cut the aggregated coarse particles with a 100-mesh sieve, and then removed the fine powder and coarse powder with a multi-split air classifier to adjust the particle size distribution.
o. 1 was obtained. The obtained magnetic coated carrier No. Table 1 shows the production method and physical properties of No. 1.

Carrier Production Example 2 In the same manner as in Carrier Production Example 1, except that the stirring speed before and after the addition of the basic catalyst was increased by 2.8 times, 2 was obtained. When the average particle size of the carrier was measured, it was 23 μm. The obtained magnetic coated carrier No. Table 1 shows the production methods and physical properties of No. 2.

Carrier Production Example 3 In the same manner as in Carrier Production Example 1, except that the stirring speed before and after the addition of the basic catalyst was increased to 0.48 times, the magnetic coated carrier No. 3 was prepared in the same manner. 2 was obtained. When the average particle size of the carrier was measured, it was 57 μm. The obtained magnetic coated carrier No. Table 1 shows the production methods and physical properties of No. 3.

Carrier Production Example 4 In Carrier Production Example 1, the average particle size was 0.22 μm as magnetite, the specific resistance was 5.2 × 10 ⁵ Ω · cm,
Magnetization intensity 73 Am ^{2 at} 00 / 4π (kA / m)
/ Kg of magnetite II, except that
Magnetic coated carrier N in the same manner as in Carrier Production Example 3
o. 4 was obtained. When the magnetization intensity at 1000 / 4π (kA / m) was measured, it was 63.0 Am ² / kg. The obtained magnetic coated carrier No. Table 1 shows the manufacturing methods and physical properties of No. 6.

Carrier Production Example 5 The same procedure as in Carrier Production Example 1 was carried out except that the ratio of magnetite to hematite was 53:47. 5 was obtained. When the magnetization intensity at 1000 / 4π (kA / m) was measured, it was 28 Am ² / kg. The obtained magnetic coated carrier No. Table 1 shows the manufacturing methods and physical properties of No. 5.

Carrier Production Example 6 The same procedure as in Carrier Production Example 1 was carried out except that the amount of the phenol resin and the amount of the formalin solution were reduced. 6 was obtained. When the apparent density was measured, it was 2.48 g / cm ³ . The obtained magnetic coated carrier No. Table 1 shows the manufacturing methods and physical properties of No. 6.

[0210]

[Table 1]

Toner Production Example 1 (Polymerized Toner 1) To 710 parts by mass of ion-exchanged water, 450 parts by mass of an aqueous 0.1 M Na ₃ PO ₄ solution were added, and after heating to 60 ° C., TK
1300 using a homo homomixer (manufactured by Tokushu Kika Kogyo)
The mixture was stirred at 0 rpm. To this, 68 parts by mass of a 1.0 M CaCl ₂ aqueous solution was gradually added to obtain an aqueous medium containing Ca ₃ (PO ₄ ) ₂ .

On the other hand, styrene 165 parts by mass n-butyl acrylate 35 parts by mass C.I. I. Pigment Blue 15: 3 (coloring agent) 15 parts by mass ・ Dialkylsalicylic acid metal compound (charge controlling agent) 5 parts by mass ・ Saturated polyester (polar resin) 10 parts by mass ・ Ester wax (melting point 70 ° C.) 50 parts by mass C., and uniformly dissolved and dispersed at 11,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). In this, 10 parts by mass of a polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) was dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition was charged into an aqueous medium, and the mixture was stirred at 60 ° C. under a N ₂ atmosphere at 11,000 rpm for 10 minutes using a TK homomixer to form a polymerizable monomer composition. Granulated. Thereafter, while stirring with a paddle stirring blade, the temperature was raised to 80 ° C., and the reaction was performed for 10 hours. After completion of the polymerization reaction, the remaining monomer was distilled off under reduced pressure, and after cooling, hydrochloric acid was added to dissolve calcium phosphate, followed by filtration, washing with water,
After drying, cyan toner particles were obtained. Hydrophobized silica fine powder (number average particle diameter of primary particles: 0.03 μm) 0.9 parts by weight with respect to 100 parts by weight of the obtained cyan toner particles.
Parts by mass and 0.9 parts by mass of hydrophobically treated titanium oxide fine powder (number average particle size of primary particles: 0.02 μm) were externally added using a Henschel mixer, and cyan toner No. 1 having a weight average particle size of 6.6 μm was added. 1 was obtained. The obtained toner No. Table 2 shows the composition and physical properties of No. 1.

Toner Production Example 2 (Polymerized Toner 2) Hydrophobizing titanium oxide fine powder and hydrophobizing treatment using an aqueous medium containing more Ca ₃ (PO ₄ ) ₂ compound than in toner producing example 1. The total added amount of the oxidized silica fine powder is 2.4.
4.8 μm cyan toner No. 2 was obtained. The obtained toner No. Table 2 shows the composition and physical properties of Sample No. 2.

Toner Production Example 3 (Polymerized Toner 3) A water-based medium having a smaller content of Ca ₃ (PO ₄ ) ₂ compound than that of Toner Production Example 1 was used, the rotational speed of the homomixer was set to 9000 rpm, and the toner was made hydrophobic. The total amount of the treated titanium oxide fine powder and the hydrophobized silica oxide fine powder is 1.2% by mass.
9.8 μm cyan toner No. 3 was obtained. The obtained toner No. Table 2 shows the composition and physical properties of Sample No. 3.

Toner Production Example 4 (Polymerized Toner 4) I. Pigment Blue 1
Except that 8 parts by mass of quinacridone was used instead of 5: 3, 6.4 μm magenta toner No. 1 was used in the same manner as in Production Example 1 of the toner. 4 was obtained. The obtained toner No. 4
Is shown in Table 2.

Toner Production Example 5 (Polymerized Toner 5) I. Pigment Blue 1
Magenta toner No. 4.7 m in the same manner as in Production Example 2 of toner except that 8 parts by mass of quinacridone was used instead of 5: 3. 5 was obtained. The obtained toner No. 5
Is shown in Table 2.

Toner Production Example 6 (Polymerized Toner 6) I. Pigment Blue 1
Except that 8 parts by mass of quinacridone was used in place of 5: 3, a 9.7 μm magenta toner No. was produced in the same manner as in Production Example 3 of the toner. 5 was obtained. The obtained toner No. 5
Is shown in Table 2.

Toner Production Example 7 (Polymerized Toner 7) I. Pigment Blue 1
Except that 6.5 parts by mass of Pigment Yellow 93 was used in place of 5: 3, the same procedure as in Toner Production Example 1 was repeated except that the yellow toner No. 6.5 having a particle size of 6.5 μm was used. 7 was obtained. The obtained toner No. Table 2 shows the composition and physical properties of No. 7.

Toner Production Example 8 (Polymerized Toner 8) The C.I. I. Pigment Blue 1
Pigment Yellow 93 was replaced with 6.5 parts by mass of Pigment Yellow 93 in the same manner as in Production Example 2 of the toner except that the yellow toner No. 4.6 of 4.6 μm was used. 8 was obtained. The obtained toner No. Table 2 shows the composition and physical properties of No. 8.

Toner Production Example 9 (Polymerized Toner 9) C.I. I. Pigment Blue 1
Pigment Yellow 93 was replaced with 6.5 parts by mass of Pigment Yellow 93 in the same manner as in Production Example 3 of the toner except that Yellow toner No. 9.9 μm was used. 9 was obtained. The obtained toner No. Table 2 shows the composition and physical properties of No. 9.

Toner Production Example 10 (Polymerized Toner 10) The C.I. I. Pigment Blue 1
Except that 10 parts by mass of carbon black was used instead of 5: 3, 6.4 μm was obtained in the same manner as in Production Example 1 of the toner.
m of black toner No. 10 was obtained. The obtained toner No. Table 2 shows the composition and physical properties of No. 10.

Toner Production Example 11 (Polymerized Toner 11) The C.I. I. Pigment Blue 1
4.6 μm in the same manner as in Production Example 2 of the toner except that 10 parts by mass of carbon black was used instead of 5: 3.
m of black toner No. 10 was obtained. The obtained toner No. Table 2 shows the composition and physical properties of No. 10.

Toner Production Example 12 (Polymerized Toner 12) The C.I. I. Pigment Blue 1
Except for using 10 parts by mass of carbon black instead of 5: 3, 9.6 μm was prepared in the same manner as in Production Example 3 of the toner.
m of black toner No. 12 was obtained. The obtained toner No. Table 2 shows the composition and physical properties of No. 12.

Production Example 13 of Toner (Pulverized Toner 1 ) 100 parts by mass of polyester resin (condensed polymer of propoxylated bisphenol A and fumaric acid, acid value 10.8 mg KOH / g) I. Pigment Blue 15:35 parts by mass ・ Aluminum compound of dialkyl salicylic acid 5 parts by mass ・ Low molecular weight polypropylene 5 parts by mass Melt kneading was performed. This melt-kneaded material was crushed by a hammer mill to obtain a crushed material having a mesh path of 1 mm. Further, after finely pulverizing with a jet mill, classification was performed with a multi-segment classifier (Elbow Jet) to obtain cyan toner particles.

With respect to 100 parts by mass of the cyan toner particles, 0.2 parts by mass of hydrophobic treated silica fine powder (number average particle diameter of primary particles: 0.03 μm) and hydrophobic treated titanium oxide fine powder (primary particles (Number average particle size: 0.02 μm)
1.5 parts by mass were mixed with a Henschel mixer, and cyan toner No. having a weight average particle size of 6.5 μm was used. 13 was obtained.
The obtained toner No. Table 2 shows the composition and physical properties of No. 13.

Toner Production Example 14 (Pulverized Toner 2) I. Pigment Blue 15: 3 and 6 parts by mass of quinacridone, except that magenta toner No. 14 was obtained. The obtained toner No. Table 2 shows the composition and physical properties of No. 14.

Toner Production Example 15 (Pulverized Toner 3) I. Pigment Blue 15: 3 and 4 parts by mass of Pigment Yellow 93, except that Yellow Toner No. 13 was manufactured in the same manner as in Production Example 13 of the toner. 15 was obtained. Obtained toner N
o. Table 2 shows the composition and physical properties of No. 15.

Toner Production Example 16 (Pulverized Toner 4) I. Pigment Blue 15: 3 and the same procedure as in Preparation Example 13 of the toner, except that 7 parts by mass of carbon black was used. 16 was obtained. The obtained toner No. 16
Is shown in Table 2.

Toner Production Examples 17 to 20 (crushed toners 5 to 5)
8) In the same manner as in Toner Production Examples 13 to 16, except that a jet mill was finely pulverized and then a thermal spheroidizing treatment was performed. 17-20 yellow, magenta, cyan and black toners were obtained.

[0231]

[Table 2] Toner composition and physical properties

Example 1 Toner No. 1, No. 4,
No. 7, no. Using No.10, four types of two-component developers were prepared.

The obtained two-component developer of four colors is applied to developing devices 63a, 63b and 63c of the full-color image forming apparatus shown in FIG. 3 having a configuration around the latent image carrier as shown in FIG.
And 63d, and a full-color image was formed under the following conditions. As a result, a good full-color image was obtained, and a full-color image having a stable image density was obtained even when copying a large number of sheets.

As the developing bias, one using the developing bias of FIG. 2 was used, and the fixing device was changed to a roller whose surface layer was covered with PFA by 1.2 μm for both the heating roller and the pressure roller, and the oil application mechanism was removed. And the image area is 10% and X-Rite 50
An original manuscript having five circles each having a diameter of 20 mm and having an image density of 1.5 as measured by a type 4 reflection densitometer was copied, and then 23 ° C./5% (N / L) and 32.5 ° C./90% (H
/ H) in each environment, a 50,000-sheet passing test was performed, and the evaluation was performed based on the following evaluation method. As shown in Table 3,
Good results were obtained in all image characteristics. Here, as the photoconductor, an organic photoconductor having a diameter of 30 mm provided with a surface layer having a volume resistance of 3 × 10 ¹² Ω · cm so as to be easily charged was used.

(1) Image Density In an endurance test in an H / H environment, the image density after 50,000 sheets of durability was measured. The image density was 50 by X-Rite.
The reflection density of an image formed on plain paper was measured using a type 4 reflection densitometer.

(2) Carrier Adhesion The initial carrier adhesion level on the photoreceptor under the N / L environment was determined. This evaluation method is described in Vback. Taping was performed on the solid white drum at 300 V, and a 25 × loupe was observed in a 5 × 5 cm field of view, and visually judged with a loupe. (Decision level) A: No carrier adhesion B: 5 or less carrier particles are observed C: 5 to 10 carrier particles are observed D: 10 to 20 carrier particles are observed E: Carrier 20 to 50 particles are observed. F: More than 50 carrier particles are observed.

(3) Fog In a durability test under N / L and H / H environments, fog after 50,000 sheets of durability was measured. As a method, the average reflectance Dr (%) of plain paper before image output is measured by a reflectometer equipped with a green filter (“REFLECOMETER ODEL TC-6D” manufactured by Tokyo Denshoku Co., Ltd.).
S "). On the other hand, a solid white image was formed on plain paper, and the reflectance Ds (%) of the solid white image was measured. Fog (%) is calculated from the following equation: Fog (%) = Dr (%)-Ds (%). (Evaluation criteria) A: less than 0.6% B: 0.6 to less than 1.1% C: 1.1 to less than 1.6% D: 1.6 to less than 2.1% E: 2.1 to less Less than 4.1% F: 4.1% or more

(4) Image Quality In a durability test under an H / H environment, gradation, highlight uniformity, fine line reproducibility, and
Was visually evaluated on a 6-point scale. A: Excellent B: Good C: Normal D: Bad E: Very bad F: Not usable

(5) Toner Scattering The amount of toner scattering in the machine when 50,000 sheets were printed in an H / H environment was visually evaluated on a six-point scale. A: There is no toner scattering B: There is almost no toner scattering C: There is some scattering but there is no problem in actual use D: There is scattering, and there is a case where the image is contaminated in the latter half of the endurance E: There is scattering, from the first half of the endurance The image may be contaminated. F: Scatters poorly and does not endure actual use.

(6) Measurement of Transfer Efficiency The transfer efficiency was measured at normal temperature and normal humidity (N / N) using the initial developer.
Performed in First, a solid black image is formed on a photosensitive drum, the solid black image is collected with a transparent adhesive tape, and the image density (D1) is measured using a color reflection densitometer (co).
lor reflection densitometry
er X-RITE 404A manufactur
ed by X-Rite Co. ). Next, a solid black image is formed again on the photosensitive drum, the solid black image is transferred to a recording material, the solid black image transferred on the recording material is collected with a transparent adhesive tape, and its image density (D2 ) Was measured. The transfer efficiency was calculated from the obtained image densities (D1) and (D2) based on the following equation.

Transfer efficiency (%) = (D2 / D1) × 100

(7) Ultrasonic Motor Life Test An image with an area ratio of 30% of total was continuously passed, and the number of sheets passed until the motor was stopped was counted.

(8) Back Smear The amount of back smear due to toner on the transfer paper when 50,000 sheets were printed in an H / H environment was visually evaluated comprehensively on a six-point scale. A: There is no back dirt. B: There is almost no back dirt. C: There is some back dirt, but there is no problem in actual use. D: Back dirt occurs in the second half of durability. E: Back dirt occurs in the first half of durability. Cannot withstand actual use

(9) Image quality at 25% speed After producing 50,000 images in an H / H environment, the image is subjected to normal 25% (30 mm / s) using CG3700 transparency.
The image quality when an image was formed at the speed of ec) was visually judged comprehensively in six stages. A: Excellent B: Good C: Normal D: Bad E: Very bad F: Not usable

[Examples 2 to 11 and Comparative Examples 1 to 3] Table 3
A two-component developer was produced in the same manner as in Example 1 except that the combination of the carrier and the toner as shown in
An image was formed and evaluated. Table 3 shows the evaluation results.

[0246]

[Table 3]

[0247]

According to the present invention, the use of an ultrasonic motor as a drive for a latent image carrier and / or a rotating body for use in a transfer process allows the image quality when the image forming speed is changed to correspond to the material. It is possible to maintain good image quality and further improve the life of the ultrasonic motor and maintain image quality by using a two-component developer consisting of a magnetic material-dispersed resin carrier and toner as a developer. Becomes

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a preferred example of a periphery of a latent image carrier in an image forming method of the present invention.

FIG. 2 is a diagram showing an alternating electric field used in Example 1.

FIG. 3 is a schematic diagram illustrating a preferred example of a copying machine that forms a full-color image according to the present invention.

FIG. 4 is a schematic explanatory view showing another example of the image forming apparatus for performing the image forming method of the present invention.

FIG. 5 is a schematic explanatory view showing another example of the image forming apparatus for performing the image forming method of the present invention.

[Explanation of symbols]

 Reference Signs List 1 electrostatic image carrier (photosensitive drum) 2 charger 3 laser exposure optical system 3a polygon mirror 3b lens 3c mirror 4 developing device 4Y developing device 4C developing device 4M developing device 4K developing device 5 transfer drum 5a transfer device 5b transfer charging device 5c Adsorption charger 5d Inner charger 5e Outer charger 5f Transfer sheet 5g Suction roller 5h Separation charger 6 Cleaning device 7a Recording agent cassette 7b Recording agent cassette 7c Recording agent cassette 8a Separating claw 8b Separation push-up roller 9 Heat fixing device 9a Heating Fixing roller 9b Pressure roller 10 Tray 11 Developer carrier (development sleeve) 12 Magnet roller 13, 14 Developer transport screw 15 Regulator blade 17 Partition wall 18 Replenishment toner 19 Developer 19a Toner 19b Carrier 20 Refill 21 Magnet roller L 22 Conveying sleeve 23 Magnetic particle 24 Laser beam 24Y Eccentric cam 24M Eccentric cam 24C Eccentric cam 24K Eccentric cam 25 Transfer material (recording material) 26 Bias applying means 27 Transfer blade 28 Toner density detection sensor 30 Document 31 Document platen glass 32 Exposure lamp 33 Lens 34 Full-color sensor 35 Image reader section 36 Digital image printer section 41 Pre-exposure lamp 42 Potential sensor 43 Drum light amount detecting means 53 Latent image forming means 54-1 Cyan developing unit 54-2 Magenta developing unit 54-3 Yellow developing unit 54-4 Black Developing Device 55 Intermediate Transfer Body 55a Elastic Layer 55b Core Metal 56 Transfer Material 57 Transfer Means (Transfer Roller) 57a Conductive Elastic Layer 57b Core Metal 58 Photoconductor Cleaning Member 59 Photoconductor Cleaning Container 60 Intermediate transfer member cleaning member 61 Heat fixing device 61a Photosensitive drum 62 Intermediate transfer member cleaning container 62a Primary charger 63a Developing device 64a Transfer blade 65a Replenishing toner 67a Laser beam 68 Transfer material carrier 69 Separation charger 70 Fixing device 71 Fixing roller 72 Pressure roller 73 Web 75, 76 Heating means 79 Transfer belt cleaning device 80 Drive roller 81 Belt driven roller 82 Belt neutralizer 83 Registration roller 85 Toner density detection sensor 90 Conveyor belt cleaning member 91 Conveyor belt cleaning box R1 Developer Room R2 Stirring room R3 Storage room Pa 1st image forming unit Pb 2nd image forming unit Pc 3rd image forming unit Pd 4th image forming unit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) G03G 15/16 G03G 9/10 331 (72) Inventor Kazumi Yoshizaki 3-30-2 Shimomaruko, Ota-ku, Tokyo No. Canon Inc. (72) Inventor Ryoichi Fujita 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masayoshi Kato 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Stocks Within the company (72) Inventor Naotaka Ikeda 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kenichi Nakayama 3-30-2, Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (Reference) 2H005 AA15 BA03 EA02 EA05 EA10 2H032 BA09 BA18 2H035 CA07 CB01 CG03 2H071 CA02 CA05 DA27

Claims (39)

[Claims] 1. A charging step of charging a latent image carrier by bringing a contact charging means into contact with a latent image carrier for carrying an electrostatic latent image; and an electrostatic latent image on the charged latent image carrier. Forming a latent image; developing the electrostatic latent image with a two-component developer to form a toner image on the electrostatic latent image carrier; and toner on the electrostatic latent image carrier. A transfer step of transferring an image onto a transfer material with or without an intermediate transfer member, wherein an ultrasonic motor is used as a rotating member driving device for driving the latent image carrier. Used, wherein the two-component developer has a toner and a magnetic material-dispersed resin carrier, and the toner has a shape factor SF-1 of 10
0 to 160. An image forming method. 2. The magnetic material-dispersed resin carrier comprises 100
The magnetization intensity at 0 / 4π (kA / m) is 30 to 6
The image forming method according to claim 1, characterized in that 0Am a ² / kg. 3. The image forming method according to claim 1, wherein the magnetic material-dispersed resin carrier has an apparent density of 2.3 g / cm ³ or less. 4. The image forming method according to claim 1, wherein the magnetic material dispersed resin carrier has an average particle size of 25 to 55 μm. 5. The toner has a weight average particle size of 5 to 9.5 μm.
The image forming method according to claim 1, wherein m is m. 6. The toner has a shape factor SF-1 of 100 to 100.
The image forming method according to claim 1, wherein the number is 130. 7. A charging step of charging a latent image carrier for carrying an electrostatic latent image by charging means; a latent image forming step of forming an electrostatic latent image on the charged latent image carrier; Developing the latent image with a two-component developer toner to form a toner image on the electrostatic latent image carrier; and applying the toner image on the electrostatic latent image carrier via an intermediate transfer member or A transfer step of transferring the transfer material onto the transfer material while pressing the transfer material conveyed by the transfer belt by using the contact transfer means without using the contact transfer means. An ultrasonic motor is used as the device, and the two-component developer has a toner and a magnetic material-dispersed resin carrier, and the toner has a shape factor SF-1 of 10
0 to 160. An image forming method. 8. The magnetic material-dispersed resin carrier according to claim 1, wherein
The magnetization intensity at 0 / 4π (kA / m) is 30 to 6
The image forming method according to claim 7, characterized in that 0Am a ² / kg. 9. The image forming method according to claim 7, wherein the magnetic material dispersed resin carrier has an apparent density of 2.3 g / cm ³ or less. 10. The magnetic material dispersed resin carrier has an average particle size of 25 to 55 μm.
10. The image forming method according to any one of claims 1 to 9. 11. The toner has a weight average particle size of 5 to 9.5.
The image forming method according to claim 7, wherein the thickness is μm. 12. The toner has a shape factor SF-1 of 100.
The image forming method according to any one of claims 7 to 11, wherein 13. The cleaning device according to claim 7, wherein the cleaning is performed by bringing a cleaning member into contact with the transport belt.
13. The image forming method according to any one of claims 1 to 12. 14. The image forming method according to claim 13, wherein the cleaning member is a blade. 15. A charging step of charging a latent image carrier for carrying an electrostatic latent image by charging means; a latent image forming step of forming an electrostatic latent image on the charged latent image carrier; Developing a latent image with a two-component developer to form a toner image on the electrostatic latent image carrier; and applying a bias to the toner image on the electrostatic latent image carrier. A transfer step of transferring the toner image transferred onto the body and transferring the toner image transferred onto the intermediate transfer body onto a transfer material by a transfer unit. An ultrasonic motor is used as a body driving device, and the intermediate transfer member is in contact with the latent image carrier, and / or the transfer means is in contact with the intermediate transfer member; The agent has a toner and a magnetic material-dispersed resin carrier. The toner shape factor SF-1 of 10
0 to 160. An image forming method. 16. The magnetic material-dispersed resin carrier comprises 10
The magnetization intensity at 00 / 4π (kA / m) is 30 to
The image forming method according to claim 15, characterized in that 60Am a ² / kg. 17. The image forming method according to claim 15, wherein the magnetic substance-dispersed resin carrier has an apparent density of 2.3 g / cm ³ or less. 18. The magnetic material-dispersed resin carrier according to claim 1, wherein the average particle size is 25 to 55 μm.
18. The image forming method according to any one of 5 to 17. 19. The toner has a weight average particle size of 5 to 9.5.
The image forming method according to claim 15, wherein the thickness is μm. 20. The toner has a shape factor SF-1 of 100.
20. The image forming method according to claim 15, wherein 21. The cleaning device according to claim 1, wherein a cleaning member is brought into contact with said intermediate transfer member to perform cleaning.
21. The image forming method according to any one of 5 to 20. 22. The image forming method according to claim 21, wherein the cleaning member is a blade. 23. A charging step of charging a latent image carrier by bringing a contact charging means into contact with a latent image carrier for carrying an electrostatic latent image; and an electrostatic latent image on the charged latent image carrier. A developing step of developing the electrostatic latent image with a two-component developer to form a toner image on the electrostatic latent image carrier;
And a transfer step of transferring the toner image on the electrostatic latent image carrier onto a transfer material with or without an intermediate transfer member. An image forming toner used in an image forming method using an ultrasonic motor as a rotator driving device and using a two-component developer having a toner and a magnetic material-dispersed resin carrier as the two-component developer. The image forming toner, wherein the toner has a shape factor SF-1 of 100 to 160. 24. The magnetic material-dispersed resin carrier comprises 10
The magnetization intensity at 00 / 4π (kA / m) is 30 to
The image forming toner according to claim 23, characterized in that used in the image forming method is 60 Am ² / kg. 25. The image forming toner according to claim 23, wherein the magnetic material dispersed resin carrier is used in an image forming method having an apparent density of 2.3 g / cm ³ or less. 26. The toner according to claim 23, wherein the magnetic material-dispersed resin carrier is used in an image forming method having an average particle size of 25 to 55 μm. 27. The toner has a weight average particle size of 5 to 9.5.
The image forming toner according to any one of claims 23 to 26, wherein the particle diameter is μm. 28. The toner having a shape factor SF-1 of 100.
The image forming toner according to any one of claims 23 to 26, wherein 29. A charging step of charging a latent image carrier for carrying an electrostatic latent image by charging means; a latent image forming step of forming an electrostatic latent image on the charged latent image carrier; Developing the latent image with a two-component developer toner to form a toner image on the electrostatic latent image carrier; and applying the toner image on the electrostatic latent image carrier via an intermediate transfer member or A transfer member for transferring the transfer material onto the transfer material while pressing the transfer material conveyed by the transfer belt using the contact transfer means without using the contact transfer means. An image forming toner used in an image forming method using an ultrasonic motor as a driving device and using a two-component developer having a toner and a magnetic material-dispersed resin carrier as the two-component developer, wherein the toner is Shape factor SF- Toner image forming, characterized in that but is 100 to 160. 30. The magnetic material-dispersed resin carrier comprises 10
The magnetization intensity at 00 / 4π (kA / m) is 30 to
The image forming toner according to claim 29, characterized in that used in the image forming method is 60 Am ² / kg. 31. The image forming toner according to claim 29, wherein the magnetic substance dispersed resin carrier is used in an image forming method having an apparent density of 2.3 g / cm ³ or less. 32. The image forming toner according to claim 29, wherein the magnetic material dispersed resin carrier is used in an image forming method having an average particle size of 25 to 55 μm. 33. The toner has a weight average particle size of 5 to 9.5.
The image forming toner according to any one of claims 29 to 32, wherein the particle diameter is μm. 34. The toner has a shape factor SF-1 of 100.
The image forming toner according to any one of claims 29 to 32, wherein 35. The cleaning device according to claim 2, wherein the cleaning is performed by bringing a cleaning member into contact with the transport belt.
35. The image forming toner according to any one of 9 to 34. 36. The image forming toner according to claim 35, wherein the cleaning member is a blade. 37. A charging step of charging a latent image carrier for carrying an electrostatic latent image by charging means; a latent image forming step of forming an electrostatic latent image on the charged latent image carrier; Developing a latent image with a two-component developer to form a toner image on the electrostatic latent image carrier; and applying a bias to the toner image on the electrostatic latent image carrier. Transferring the toner image transferred onto the body and transferring the toner image transferred onto the intermediate transfer body onto a transfer material by a transfer unit. Using an ultrasonic motor as a rotating body driving device, and the intermediate transfer body is in contact with the latent image carrier,
And / or image formation used in an image forming method in which the transfer unit is in contact with the intermediate transfer member and a two-component developer having a toner and a magnetic material-dispersed resin carrier is used as the two-component developer. The toner for forming an image, wherein the toner has a shape factor SF-1 of 100 to 160. 38. The magnetic material-dispersed resin carrier comprises 10
The magnetization intensity at 00 / 4π (kA / m) is 30 to
The image forming toner according to claim 37, characterized in that used in the image forming method is 60 Am ² / kg. 39. The image forming toner according to claim 37, wherein the magnetic substance dispersed resin carrier is used in an image forming method having an apparent density of 2.3 g / cm ³ or less.