JP3342272B2 - Color toner, two-component developer, image forming apparatus, and image forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color toner for developing an electrostatic image in electrophotography, electrostatic recording and electrostatic printing, and more particularly to a color image having a wide color reproducibility and excellent offset resistance. Color toner, developer for developing an electrostatic image using the color toner, image forming apparatus
And about the image forming how.

[0002]

2. Description of the Related Art In recent years, full-color copying machines have begun to attract attention. In particular, digitized full-color copiers are receiving attention and are being widely deployed in the market.

In general, color image formation by full-color electrophotography uses three color toners of three primary colors, yellow, magenta, and cyan, or reproduces colors using four colors including black.

In the general color image forming method, an electrostatic latent image is formed on a photoconductive layer by passing light from an original through a color separation light transmitting filter having a complementary color relationship with the color of the toner. Next, the toner is held on a support through development and transfer steps. The above-described steps are sequentially performed a plurality of times, and while the registration is being performed, the toner is superimposed on the same support,
A final full-color image can be obtained by fixing only once.

In such a color electrophotography method in which development is performed a plurality of times and several types of toner layers of different colors are superposed on the same support as a fixing step, the fixing characteristics that the color toner should have Is a very important factor.

That is, the fixed color toner is required to suppress irregular reflection by toner particles as much as possible and to have appropriate glossiness and gloss.

The color toner must be transparent and have a wide color reproducibility so as not to obstruct the toner layers of different colors below the toner layer.

As color toners that can satisfy these requirements,
The present applicants disclose Japanese Patent Application Laid-Open No. 50-62442,
JP-A-1-144625 and JP-A-59-57256 disclose a novel combination of a binder resin for a color toner and a colorant.

The color toners described above have a considerable sharp melt property, and when combined with a silicone rubber roller capable of applying silicone oil, the toner shape changes to a state close to complete melting at the time of fixing, which is preferable. Gloss and color reproducibility can be obtained.

These effects mean that the viscosity term is more important than the elastic term in the viscoelastic property of the binder resin as the fixing property of the toner.

That is, at the time of heating, the toner behaves more viscously so that the heat melting property is increased and the gloss is obtained.

However, such a binder resin design emphasizing the viscosity term inevitably reduces intermolecular cohesion at the time of heat melting, and also increases the adhesion of the toner to the heat roller when passing through the fixing device. become. These make it easy to cause a high-temperature offset phenomenon.

In particular, when a silicone rubber roller is used as a fixing roller, if the silicone rubber roller is repeatedly used irrespective of application of a releasing oil, a high-temperature offset is likely to occur due to a substantial decrease in the releasability of the surface of the silicone rubber roller. In the initial stage of use of the silicone rubber roller, a certain degree of mold releasability can be maintained because of the silicone oil impregnated inside the silicone rubber and the smoothness and cleanliness of the roller surface. However, the color copy has a large image area like a color image, and the toner holding amount on a support such as plain paper is much larger than a white / black copy image.
If copying continues, the oil in the silicone rubber will naturally be depleted, and the roller surface will be roughened, and the releasability of the roller will gradually decrease. The speed at which the releasability deteriorates reaches several times that of black and white copying.

Further, since the toner itself has almost no elasticity as described above, the anti-offset effect is low. As a result, after only several thousand to several tens of thousands of sheets, a toner film or a granular attachment is formed on the surface of the fixing roller, and the toner upper layer on the image surface is peeled off when passing through the heat roller. A so-called high-temperature offset occurs.

Various approaches have been tried with toner to solve or alleviate the above problems, but further improvements are desired. For example, JP-A-55-60960, JP-A-57-208559, and JP-A-58-1195.
No. 3, JP-A-58-14144 and JP-A-58-14144.
As described in JP-A No. 0-123852, a method of adding a low-molecular-weight polyethylene, polypropylene, wax, higher fatty acid, or the like, which is a releasing component, to a toner in order to increase releasability is also performed. Although these methods are effective in preventing offset, the content of a large amount that exhibits sufficient effect in offset resistance deteriorates the compatibility with the main binder resin. For example, the transparency of the OHP image of the color toner may be reduced. There are also adverse effects such as impairment; unstable charging characteristics; and reduced durability;

JP-A-47-12334, JP-A-5-12334
In JP-A-7-37353 and JP-A-57-208559, an etherified bisphenol monomer is used.
A non-linear copolymer obtained from a monomer component containing a dicarboxylic acid monomer, a trihydric or higher polyhydric alcohol monomer and / or a trivalent or higher polyhydric carboxylic acid monomer. A toner containing a polyester as a binder has been proposed. This technology is based on a method of converting a polyester comprising an etherified bisphenol monomer and a dicarboxylic acid monomer into a trihydric or higher polyhydric alcohol monomer and / or a trihydric alcohol monomer. The toner has an anti-offset property by containing, as a binder, a polyester obtained by crosslinking with a large amount of a monomer component containing a polyvalent carboxylic acid monomer. However, these toners have a slightly higher softening point, which makes it difficult to fix the toner at a good low temperature. Further, when used for full-color copying, the anti-high-temperature offset resistance is at a practically usable level. However, since the fixing property and the sharp melt property are difficult as described above, the color mixing property and the color reproducibility due to the superposition of the full-color toner using the polyester are not sufficient. JP-A-57-109825, JP-A-62-109825
JP-A-78568, JP-A-62-78569, and JP-A-59-7960 and JP-A-59-29256 by the present applicant disclose etherified bisphenol monomers and long-chain aliphatic monomers. A dicarboxylic acid monomer introduced with a hydrocarbon or another dicarboxylic acid monomer;
A non-linear copolymer obtained from a monomer component containing a polyhydric alcohol monomer having a valence of 3 or more and / or a polycarboxylic acid monomer having a valence of 3 or more, wherein the side chain has 3 carbon atoms. To 22 containing a polyester having a saturated or unsaturated aliphatic hydrocarbon group as a binder,
These polyester resins are mainly intended for toners for high-speed copying.The viscoelastic properties of the resin are, as opposed to the viscosity-oriented polyester described above, completely enhanced elasticity and markedly offset high-temperature offset to the rollers. It has been reduced. Then, at the time of fixing, the pressure and heating of the heat roller are increased as much as possible, and the toner is pressed between the fibers of the transfer paper in a semi-molten state to perform pressure and heat fixing to achieve the object. is there.

Therefore, it is almost impossible to obtain a smooth surface by fusing the toner layer necessary for color copying to form a continuous film, and the fixed toner exists in the form of particles on the transfer paper, and the obtained color The image is dull and has a poor saturation. In an OHP image, light is scattered and diffused on the surface of the toner particles, hardly transmits light, and becomes practically unusable.

The present applicants have proposed a new polyester resin having excellent high-temperature offset resistance and applicable to color copying in JP-A-2-73366 and JP-A-1-224776. Although the resin is better than the conventional color toner resin, the effect of preventing the offset to the fixing roller is exhibited at most about 20,000 to 50,000 repeated copies, and the effect of preventing the offset of the black and white toner is 100,000. Although more than one sheet is sufficient, it is preferable to further improve the performance in view of the fact that printing resistance and offset resistance of several hundred thousand sheets are currently required. The polyester has a large charge difference between a low-temperature and low-humidity environment and a high-temperature and high-humidity environment, and tends to have a slightly lower density on a low-humidity side in a color image after repeated copying. Scattering and fogging may occur.

Japanese Patent Application Laid-Open Nos. 62-195676, 62-195678 and 62-19568
No. 0 discloses polyester resins in which the ratio of hydroxyl value to acid value is specified, but these polyester resins are also intended for high-speed fixing, and according to the study of the present inventors. The color toner using the resin did not reach the point where sufficient color mixing was obtained.

In particular, at least three problems are specific to color copying.
The color balance of the color toners, preferably four, must be in harmony. It is meaningless to discuss the fixing characteristics and color reproducibility of only one color. It is necessary to design and select the resin in consideration of the above.

In principle, if there are three primary colors, yellow, magenta, and cyan, almost all colors can be reproduced by the subtractive color mixing method.
Therefore, currently available full-color copying machines have a configuration in which three primary color toners are superposed. This should ideally enable all colors to be achieved in all density ranges, but in reality, there are still points that need to be improved, such as the spectral reflection characteristics of the toner, the mixing properties when superimposing and fixing the toner, and the decrease in chroma. have.

In the case where black is obtained by superimposing three colors, three times more toner layers are formed on the transfer paper than in the case of a single color, and furthermore, it is difficult to achieve offset resistance.

On the other hand, the demand for the quality of a full-color copy image is increasing more and more. For general users who have considered printing, full-color copied images are not yet at a satisfactory level, and they want a level closer to printing and a level closer to photography. That is, a toner having an image density output covering a wide dynamic range from high density to low density, a solid image having a large image area in a large image area, a uniform image of a halftone image, an OHP image having print-level transparency, For example, the transparency of the toner used for this purpose.

The shortest and preferred method for meeting these requirements is to first improve the dispersibility of the colorant present in the toner.

JP-A-61-117565 and JP-A-61-156054 disclose a method in which a binder resin, a colorant and a charge control agent are dissolved in a solvent in advance, and the solvent is removed to obtain a toner. However, these have problems such as difficulty in controlling the dispersibility of the charge controlling agent; and the fact that the solvent remains in the final product toner and gives an unpleasant odor.

Japanese Patent Application Laid-Open No. 61-91666 discloses a toner production method using a halogen-based solvent.
Halogen solvents have a strong polarity, and thus have problems such as limitations on the colorant used.

JP-A-4-39671, JP-A-4-39671
JP-A-39672 and JP-A-4-242275 disclose a method of producing a toner while applying heat and pressure in a kneader. This method is more preferable for dispersing a colorant, but it is preferable to use a method for dispersing a toner. The molecular chains of the constituent binder resin are cut by a strong kneading load, and partial reduction of the molecular weight in the polymer is promoted. Therefore, a high-temperature offset easily occurs in the fixing process. Especially in color copying, since the three- or four-color toner is fixed in a layered state, the latitude of high-temperature offset resistance is much more severe than that of the black-and-white toner, and the number of molecules in the polymer is small. Cutting easily causes hot offset.

JP-A-5-34978 discloses that a resin and an aqueous press cake of a pigment are charged in a kneader and kneaded with heat to achieve dispersion of the pigment in the resin. Although it is preferable for dispersion, it does not mention the characteristics of the resin at all, and it is highly pigmented by using a resin designed to improve not only the fixing property and the offset resistance as in the present invention but also the dispersibility of the pigment during kneading. The toner of the present invention is to increase the dispersibility of the toner, to achieve the target pigment dispersion particle size, to achieve both offset resistance and fixability, which have been difficult so far, and to simultaneously improve color reproducibility. Are different.

[0029]

The object of the present invention is to solve the above, the color toner, a two-component developer having the color toner, the image forming apparatus and the color toner having the color toner having good fixability and color mixing image forming how using
It is to provide.

Furthermore, object of the present invention, a color toner having a sufficient triboelectric chargeability, two-component developer having the color toner, use an image forming apparatus and <br/> the color toners having the color toner it is to provide a gastric image forming how.

Still another object of the present invention is to provide a high gloss color toner capable of significantly improving image quality,
Two-component developer having the color toner is to provide an image forming how using the image forming apparatus and the color toner having the color toner.

[0032] Furthermore, an object of the present invention, high temperature offset is sufficiently prevented, fixable temperature range is wide color toner, a two-component developer having the color toner, the image forming apparatus and the having the color toner it is to provide an image forming how using a color toner.

Still another object of the present invention is to provide a color toner which maintains the anti-offset property even after repeated fixing paper passing and is hardly wrapped around a fixing roller, a two-component developer having the color toner, is to provide an image forming <br/> how using the image forming apparatus and the color toner having a color toner.

Still another object of the present invention is to provide an image forming apparatus comprising:
That is, the development sleeve, blade, toner fusion occurs hardly color toner to such parts of the application roller, a two-component developer having the color toner, an image forming apparatus and an image formation using the color toners having the color toner mETHODS
It is to provide.

[0035] Furthermore, an object of the present invention, filming hardly occurs a color toner to the photosensitive member surface, a two-component developer having the color toner using the image forming apparatus and the color toner having the color toner it is to <br/> provide an image forming how.

[0036] Furthermore, an object of the present invention, good color toner dispersibility of the colorant, a two-component developer having the color toner, the image forming apparatus 及 having the color toner
It is to provide an image forming how using finely the color toners.

[0037] Furthermore, an object of the present invention, the coloring power is high, the color toners high image density is obtained, a two-component developer having the color toner, an image forming apparatus and the color toner having the color toner it is to <br/> provide an image forming how using.

[0038] Furthermore, an object of the present invention, color toners saturation is excellent in high transparency, a two-component developer having the color toner using the image forming apparatus and the color toner having the color toner it is to provide an image forming how.

[0039]

The present invention provides at least a colorant and a compound represented by the following formula (1):

[0040]

Embedded image A color toner having color toner particles containing a non-linear polyester resin synthesized using the compound represented by the formula or an acid anhydride thereof, wherein the colorant is formed of pigment particles, The pigment particles in the particles have a number average particle size of 0.7 μm or less, and 0.1 to
Containing 60% by number or more of pigment particles having a particle size of 0.5 μm;
The color toner contains 10% by number or less of pigment particles having a particle diameter of 0.8 μm or more, and has a softening point Tm of 85 ° C. to 120 ° C. calculated from a flow tester curve. .

The present invention also relates to a two-component developer having the above color toner and carrier.

According to the present invention, there is provided an image forming apparatus having a latent image holding member for holding an electrostatic image and a developing device for developing the electrostatic image of the latent image holding member. (I) a developer container holding a non-magnetic one-component developer, (ii) a developer carrier for supporting the non-magnetic one-component developer held in the developer container, and (iii) A) a developer application member for applying the non-magnetic one-component developer in a thin layer on the developer carrier;
The non-magnetic one-component developer relates to an image forming apparatus comprising the above color toner.

Further, according to the present invention, at least one of a cyan toner, a magenta toner and a yellow toner is formed on a recording material.
A step of forming a color toner image using a color toner of a color, and a step of heating and fixing the formed color toner image to a recording material to obtain a color image, wherein the cyan toner, the magenta toner and Each of the yellow toners is a pigment particle whose colorant is cyan,
The present invention relates to a color image forming method, wherein the color toner is a magenta pigment particle and a yellow pigment particle.

[0044]

[0045]

BEST MODE FOR CARRYING OUT THE INVENTION The inventors of the present invention have proposed a toner fixing property,
After extensive studies on color reproducibility, highlight reproducibility, charging stability, cleaning properties, transfer properties, etc., the binder resin was found to have the following formula (1)

[0046]

Embedded image Has a non-linear polyester resin synthesized using the compound or an acid anhydride thereof, and the pigment particles forming the colorant have a specific excellent dispersion particle size as described below It has been found that a color toner having high color reproducibility without adversely affecting the offset resistance can be provided for the first time.

That is, the binder resin according to the present invention has a polyester resin having a weak cross-linking structure, and preferably has a regular structure in a linear polymer chain in which a diol component and a dicarboxylic acid component are repeated. Is a polyester having a weakly crosslinked structure in which a trivalent or higher polyvalent carboxylic acid component is introduced as a crosslinkable monomer component. However, despite its weak cross-linking structure, the whole polymer is constituted as one three-dimensional polymer, and it is more than a simple mixture of linear polymers.
The offset resistance is much improved. The level of cross-linking of the binder resin is within a range that does not impede the ease of movement of the binder resin due to heat, and by limiting the composition and amount of the monomer component, full color with good color mixing and color reproducibility can be obtained. Images can be obtained. Nevertheless, a slight difference in color reproducibility was inevitably produced when compared with a conventional linear polymer having sharp melt properties.

Therefore, in the present invention, a colorant is highly dispersed in order to enhance color reproducibility and color mixing, that is, the pigment particles in the color toner particles have a number average particle diameter of 0.7 μm.
pigment particles having a particle size of 0.1 to 0.5 μm and containing 60% by number or more, and pigment particles having a particle size of 0.8 μm or more and containing 10% or less by number. By controlling the dispersed particle size of the, it was possible to achieve both the improvement of the offset resistance, the color reproducibility, and the color mixing property.

The present inventors have found that when the pigment particles in the toner are uniformly dispersed and the dispersion particle diameter is controlled as described above, the toner composed of the binder resin may be used in a superposed state. Enables reproduction of any color tone,
It has been found that a color tone by an ideal subtractive color mixing method can be realized in various density regions.

That is, when the number average particle size of the pigment particles in the color toner particles is larger than 0.7 μm, it means that there are basically many pigment particles that are not sufficiently dispersed. If the color reproducibility and the transparency of the transparency film are not good and the pigment particles in the toner are present as agglomerates in a non-uniform state, the variation in charging between the toner particles becomes remarkable, so-called The tribo distribution becomes broad. In this case, a desired high-quality full-color image cannot be obtained.

Further, the present invention is characterized in that the pigment particles in the color toner contain 60% by number or more of pigment particles having a particle diameter of 0.1 to 0.5 μm.

That is, when the dispersed particle size of the colorant has been discussed so far, only the average particle size has been regarded as important. However, according to the study of the present inventors, the colorant is dispersed in the color toner particles. It has been found that the dispersed particle size distribution of pigment particles is extremely important for improving color reproducibility.

More specifically, when the dispersed particle size of the pigment particles is broad, a large difference occurs in the degree of dispersion of the colorant among the toner particles. Even if the size is small, irregular reflection of light due to relatively large colorant particles that are not sufficiently dispersed cannot be avoided, and the desired color reproduction cannot be achieved. In particular, in the subtractive color mixing method by superimposing three colors of magenta, cyan, and yellow, it is desirable to have a sharply dispersed particle size distribution as much as possible so as to maximize the spectral reflection characteristics of the colorant.

Basically, pigment particles having a fine particle diameter of less than 0.1 μm are considered to have no adverse effect on light reflection and absorption characteristics, and provide good color reproducibility and excellent transparency of a transparency film. I do. On the other hand, if there are many pigment particles having a particle size larger than 0.5 μm, the brightness and color of the projected image will necessarily decrease.

Therefore, in the present invention, 0.1 to 0.5
60% by number or more, preferably 6%
The content is preferably 5% by number or more, more preferably 70% by number or more.

Further, the present invention is characterized in that it contains 10% by number or less of pigment particles having a particle size of 0.8 μm or more, and it is basically preferable that the number of particles of 0.8 μm or more is small. In the case where pigment particles having a large particle size of 0.8 μm or more are contained in an amount of more than 10% by number, especially when there are many pigment particles having such a large particle size near the surface, the toner surface is inevitably removed. Unavoidable,
It causes various problems such as fog, drum contamination and poor cleaning. Further, when such a color toner is used as a two-component developer, problems such as carrier contamination are caused, and a stable image cannot be obtained in long-term durability. Naturally, good color reproducibility cannot be expected and uniform chargeability cannot be obtained.

Next, a method of dispersing pigment particles to achieve the object of the present invention will be described.

In the color toner of the present invention, the conventional method of kneading at a high temperature or under pressure as in the conventional method easily cuts the molecular chains, improves the offset resistance and improves the quality of a full-color image. The intended effect on the color toner design cannot be sufficiently exhibited.

In the present invention, in order to achieve a specific dispersion state of the pigment particles in the color toner particles as described above, the first binder resin, the dispersion medium and the pigment particles insoluble in the dispersion medium are used. A paste pigment containing 50% by mass is charged into a kneader or a mixer, and heated while mixing under non-pressure to melt the first binder resin, and the paste pigment, that is, the pigment in the liquid phase is heated. After distributing or transferring to the first binder resin, that is, the molten resin phase, the first binder resin and the pigment particles are melt-kneaded, a liquid component is removed and evaporated, and the first binder resin is dried. And first having pigment particles
The mixture obtained by adding the second binder resin and, if necessary, an additive such as a charge controlling agent to the first mixture is heated and melt-kneaded to obtain a second mixture. It is preferable that the obtained second kneaded material is cooled and then pulverized to form a toner.

In the present invention, the above-mentioned paste refers to a state in which the pigment particles exist in the pigment particle production step without undergoing a single drying step. In other words, when the pigment particles are almost primary particles, 5 to 5
0 mass% is present. The remaining 50-95% by weight of the paste is occupied by most volatile liquids with some dispersants, auxiliaries and the like. The volatile liquid is not particularly limited as long as it is a liquid that evaporates by general heating, but water, which is particularly preferably used in the present invention and is preferably used ecologically, is water.

In the present invention, the insoluble pigment particles are
Pigment particles insoluble in the dispersion medium, which is a volatile liquid in the paste, and can be dispersed in the paste. For example, when water is selected as the volatile liquid, all water-insoluble pigment particles are insoluble pigment particles.

The paste pigment used in the present invention contains 5 to 50% by mass, more preferably 5 to 50% by mass of water-insoluble pigment particles.
It is good to contain 45 mass%. When the content of the insoluble pigment exceeds 50% by mass, the dispersion efficiency in the resin is low, the kneading temperature must be high, or the kneading time has to be set long. Further, a strong screw or paddle structure is essential for the kneading device, and this easily causes polymer chain breakage.

Conversely, when the paste pigment contains less than 5% by mass of insoluble pigment in solid content, a large amount of the paste pigment must be introduced into the apparatus in order to obtain the desired pigment content. In addition, the size of the apparatus cannot be avoided. Further, when the amount is less than 5% by mass, the step of removing water in the step after the first kneading is strengthened, and water must be completely blown off, resulting in a large load on the resin. Become.

When kneading or mixing the paste pigment and the resin, the ratio of the pigment to the resin in terms of solid content is 10:
90-50: 50, preferably 15: 85-45: 55
Is good.

When the ratio of the pigment to the resin is less than 10% by mass, a large amount of the resin must be charged into the kneader with respect to the paste pigment, and the segregation of the pigment tends to occur in the kneaded material. In order to bring it, the kneading time must be set long. In this case, an extra load is applied to the resin, and desired resin characteristics cannot be obtained.

When the ratio of the pigment to the resin is more than 50% by mass, the pigment particles in the liquid phase are not smoothly transferred to the resin. The product does not show a uniform molten state, and as a result, high dispersibility cannot be obtained.

As a specific means for achieving the specific dispersion state of the pigment particles of the color toner particles as described above, a mixture containing at least the first kneaded material and the second binder resin is melted and kneaded to form the second kneaded resin. When obtaining the kneaded product, the specific non-linear polyester resin as the first binder resin is metal-crosslinked using an organometallic complex, and kneading is performed in a state where a sufficient shear is applied to the second kneaded product. Preferably, the kneading conditions of the kneading machine are not used without using the organometallic complex, for example, by setting the kneading machine, taking measures such as lowering the kneading temperature.
It is also possible to perform kneading in a state where a sufficient shear is applied to the second kneaded material. However, the former method is more preferable for reducing the diameter of the pigment particles, dispersing the pigment particles more uniformly, and bringing the dispersed particle diameter of the pigment sharply.

As a means for achieving a specific dispersion state of the pigment particles in the color toner particles as described above, the first method using dry powder pigment particles instead of the above-mentioned method using the paste pigment is used. In the step of melting the binder resin and the pigment particles to obtain the first kneaded product, in order to perform kneading more sufficiently than in the past, the number of kneading is increased a number of times, specifically, 5 or more, preferably Can be repeated eight or more times.

However, when the dispersibility of the pigment particles is improved by increasing the number of kneadings, a mechanical stress is applied to the first binder resin, so that the molecular chains in the first binder resin are cut. Is likely to occur, and the storage stability of the toner is deteriorated, and a part of the toner is easily taken to the fixing roller due to the durability of a large number of sheets. Therefore, the above-described method using the paste pigment is more preferable than the above-described method using the pigment particles in the form of dry powder, in view of the durability of the multi-sheet image formation.

In the present invention, since the first kneading step is performed under no pressure, the softening point temperature Tm calculated from the flow tester curve of the binder resin is preferably 85 ° C. to 115 ° C.

If the softening point temperature Tm of the binder resin is higher than 115 ° C., in the step of dispersing under no pressure as in the present invention, the melting of the resin becomes insufficient, and the water phase of the paste pigment changes from the aqueous resin phase to the molten resin phase. Distribution or migration does not occur smoothly, and does not reach the dispersed particle size as described above. Further, although a resin having a Tm higher than 115 ° C. has excellent offset resistance, the fixing set temperature must be increased,
Also, even if the degree of dispersion of the pigment can be controlled, the surface smoothness in the image area is significantly reduced,
High color reproducibility cannot be expected.

With a resin having a Tm lower than 85 ° C., the kneading process proceeds smoothly, but the obtained toner has low blocking resistance. Even if it is a polyester having a three-dimensional structure, a high offset resistance can be expected. Will be gone.

The reason for melt-kneading under non-pressurization in the present invention is that, under pressure, the liquid in the paste pigment, for example, water violently attacks the polyester resin, causing a partial hydrolysis reaction or altering the quality of the resin. In this case, the effect of using a binder resin having a weakly crosslinked structure may not be obtained. Therefore, in the present invention, it is preferable to perform the melt-kneading of the first binder resin and the paste pigment under no pressure.

Examples of the kneading apparatus used in the present invention include a heating kneader, a single-screw extruder, a twin-screw extruder, and a kneader, and particularly preferably a heating kneader.

As described above, the color toner of the present invention uses a binder resin that satisfies both the offset resistance and the full-color high image quality, and maintains the characteristics of the binder resin in the color toner production process while maintaining the characteristics of the binder resin. The object as described above has been achieved by efficiently and effectively dispersing the colorant in the binder resin.

The color toner of the present invention has a softening point temperature Tm calculated from the flow tester curve of 85 ° C. ≦ Tm.
It is also characteristic that ≦ 120 ° C.

When the softening point temperature Tm of the toner is higher than 120 ° C., although the offset resistance is excellent, the fixing temperature must be increased, and even if the degree of dispersion of the pigment can be controlled, The surface smoothness in the image area is greatly reduced, and high color reproducibility cannot be expected.

When the Tm of the toner is lower than 85 ° C., although the surface of the fixed image certainly has high smoothness, the offset tends to occur in durability. In addition, storage stability is poor, and there is a concern about a new problem such as fusion of toner in a developing device. Accordingly, the softening point temperature Tm of the color toner is preferably 85 ° C. ≦ Tm ≦ 120 ° C., and more preferably 90 ° C. ≦ Tm ≦ 115 ° C.

Therefore, in the color toner of the present invention, the softening point temperature Tm of the color toner is 85 ° C. to 120 ° C.
In addition to having a specific color, the above-mentioned specific non-linear polyester resin is used as a binder resin of the color toner, and a good specific dispersion state of the pigment particles in the color toner particles is obtained. Since the dispersibility of the pigment particles is superior to that of the toner, even if the color toner image is fixed at a fixing temperature lower than the conventional fixing temperature and the gloss value of the fixed color image is set to a low value, it is the same as or equal to the conventional value. It has good color reproducibility and transparency of the color image fixed on the transparency film as described above.

Pigment particles suitable for the purpose of the present invention include conventionally known chromatic and black to white pigments.
Among them, particularly preferred are organic pigments having high lipophilicity.

For example, naphthol yellow S, Hansa yellow G, permanent yellow NCG, permanent orange GTR, pyrazolone orange, benzidine orange G, permanent red 4R, watching red calcium salt, brilliant carmine 3B, fast violet B, methyl violet lake, Phthalocyanine blue, fast sky blue, and indanthrene blue BC are mentioned.

Preferred are highly light-resistant pigments such as polycondensed azo type, insoluble azo type, quinacridone type, isoindolinone type, perylene type, anthraquinone type and copper phthalocyanine type.

Particularly preferred magenta pigments include
C. I. Pigment Red 1, 2, 3, 4, 5, 6,
7, 8, 9, 10, 11, 12, 13, 14, 15, 1
6, 17, 18, 19, 21, 22, 23, 30, 3
1,32,37,38,39,40,41,48,4
9, 50, 51, 52, 53, 54, 55, 57, 5
8,60,63,64,68,81,83,87,8
8, 89, 90, 112, 114, 122, 123, 1
46,150,163,184,185,202,20
6,207,209,238; C.I. I. Pigment Violet 19; I. Butt Red 1,2,10,1
3, 15, 23, 29, and 35.

Particularly preferred cyan pigments include:
C. I. Pigment Blue 2, 3, 15, 16, 17;
C. I. Bat blue 6; I. Acid Blue 45
Alternatively, a copper phthalocyanine pigment in which 1 to 5 phthalimidomethyl groups are substituted on a phthalocyanine skeleton having a structure represented by the following formula (2) is given.

[0085]

Embedded image

Particularly preferred yellow pigments include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6,
7, 10, 11, 12, 13, 14, 15, 16, 1
7, 23, 65, 73, 74, 81, 83, 93, 9
5,97,98,109,117,120,137,1
38,139,147,151,154,167,17
3,180,181,183, C.I. I. Bat Yellow 1, 3, 20.

In the present invention, a paste-like pigment obtained through a single step of drying from a pigment slurry before the filtration step in the above-mentioned known process for producing a colorant is a powder of a once-dried powder. It is more preferable than a paste obtained by returning pigment particles to an aqueous system.

The content of the yellow pigment is OH
The amount of the yellow toner sensitive to the transmittance of the P film is 12 parts by mass or less, preferably 0.5 to 7 parts by mass, per 100 parts by mass of the binder resin.

When the amount is 12 parts by mass or more, the reproducibility of green, red, which is a mixed color of yellow, and an image of human skin color is inferior.

For the other magenta toner and cyan toner, the content of the magenta pigment or the cyan pigment is 15 parts by mass or less, more preferably 0.1 to 9 parts by mass, per 100 parts by mass of the binder resin. Parts by weight are preferred.

In the present invention, the divalent acid component constituting the polyester resin preferably used includes, for example, aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, and diphenyl-P.P'-dicarboxylic acid. , Naphthalene-2,7-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, diphenylmethane-P.
P'-dicarboxylic acid, benzophenone-4,4'-dicarboxylic acid, and 1,2-diphenoxyethane-PP'-dicarboxylic acid can be used, and as other acids, maleic acid, fumaric acid, and glutaric acid can be used. , Cyclohexanedicarboxylic acid, succinic acid, malonic acid, adipic acid, mesaconic acid,
Itaconic acid, citraconic acid, sebacic acid, anhydrides and lower alkyl esters of these acids can be used.

As the dihydric alcohol, the following formula (3)

[0093]

Embedded image

Wherein R ₁ is an alkylene group having 2 to 5 carbon atoms, X and Y are positive numbers, and a diol represented by 2 ≦ X + Y ≦ 6, for example, polyoxypropylene (2 , 2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis ( 4-hydroxyphenyl) propane, polyoxypropylene (13) -2,2
-Bis (4-hydroxyphenyl) propane.

Other dihydric alcohols include, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol,
Diols such as 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol, 1,4-bis (hydroxymethyl)
Cyclohexane, and bisphenol A, hydrogenated bisphenol A.

The non-linear polyester resin according to the present invention comprises:
As described above, the following equation (1)

[0097]

Embedded image It is also characterized in that the compound represented by the formula (1) or an acid anhydride thereof is used as an essential component.

Specific examples of the above compounds include those represented by the following formulas (4) to (8).

[0099]

Embedded image Examples of the compound include trimellitic acid, tri-n-ethyl 1,2,4-tricarboxylate, tri-n-butyl 1,2,4-tricarboxylate, tri-n-hexyl 1,2,4-tricarboxylate, Triisobutyl 2,4-benzenetricarboxylate, tri-n-octyl 1,2,4-benzenetricarboxylate and tri-2-ethylhexyl 1,2,4-benzenetricarboxylate can be used. However, it is not limited to this.

In the polyester resin of the present invention, for example, maleic acid, fumaric acid, glutaric acid, succinic acid, malonic acid having n-dodecenyl group, isododecenyl group, n-dodecyl group, isododecyl group, isooctyl group,
Acids having an alkyl or alkenyl substituent such as adipic acid and / or ethylene glycol, 1,3-propylene diol, tetramethylene glycol, 1,4
-Alcohols such as butylene diol and 1,5-pentyldiol may be contained.

The production method for obtaining the polyester resin used in the toner of the present invention is, for example, as follows.

First, a linear condensate is formed, and in the process, the molecular weight is adjusted so as to be 1.5 to 3 times the target acid value and hydroxyl value, and the molecular weight is made higher than before so that the molecular weight becomes uniform. In order for the condensation reaction to proceed slowly and slowly, for example, (i) reacting at a lower temperature and longer time than in the prior art;
The reaction is controlled by (i) reducing the amount of the esterifying agent, (iii) using a less reactive esterifying agent, or (iv) using a combination of these methods. Thereafter, under these conditions, a crosslinking acid component and, if necessary, an esterifying agent are further added, and the mixture is reacted to form a three-dimensional condensate. The temperature is further increased, the reaction is allowed to proceed slowly and for a long time so that the molecular weight distribution becomes uniform, the crosslinking reaction proceeds, and when the hydroxyl value or the acid value or the MI value decreases to the target value, the reaction is terminated to obtain a polyester resin.

The color toner of the present invention is not limited to negative chargeability or positive chargeability. When a negatively chargeable toner is used, it is preferable to add a charge control agent for the purpose of stabilizing the negative charge characteristics. Examples of the negative charge control agent include an organometallic complex such as a metal complex of an alkyl-substituted salicylic acid (for example, a chromium complex or a zinc complex of di-tert-butylsalicylic acid).

When a positively chargeable toner is used, nigrosine, a triphenylmethane compound, a rhodamine dye, or polyvinylpyridine can be used as a charge control agent having a positive charge. When a color toner is prepared, 0.1 to 40 mol%, preferably 1 to 30 mol% of a positively chargeable aminocarboxylic acid ester such as dimethylaminomethyl methacrylate is used as a monomer.
It is preferable to use a binder resin containing ol% or a colorless or light-colored positive charge control agent which does not affect the color tone of the toner.

The method of addition is not particularly limited.

The color toner of the present invention is preferably composed of a mixture of color toner particles and an external additive. Examples of the external additive include a fluidity improving agent for improving the fluidity of the toner. Agents. As the fluidity improver, by adding to the colorant-containing resin particles, if the fluidity can be increased compared to before the addition,
Anything can be used.

For example, fluororesin powders such as vinylidene fluoride fine powder and polytetrafluoroethylene fine powder;
Fatty acid metal salts such as zinc stearate, calcium stearate, lead stearate, etc .; metal oxides such as titanium oxide powder, aluminum oxide powder and zinc oxide powder, or powders obtained by hydrophobizing the above metal oxides; and wet-processed silica , Silica fine powder such as dry-process silica or
A surface-treated silica fine powder obtained by subjecting such silica to a surface treatment with a treating agent such as a silane coupling agent, a titanium coupling agent, or silicone oil may be used.

The color toner of the present invention can be used as a two-component developer or a one-component developer.

When the color toner of the present invention is used as a two-component developer, the carrier used may be, for example, a surface-oxidized or unoxidized iron, nickel, copper, zinc, cobalt, manganese, chromium, rare earth element or the like. Metals and their alloys or oxides and magnetic ferrites can be used. There is no particular restriction on the manufacturing method.

A system in which the surface of the carrier is coated with a resin is particularly preferable. Conventionally known methods include a method of dissolving or suspending a coating material such as a resin in a dissolving agent, coating and attaching the coating material to a carrier, and a method of simply mixing and coating a powder of the coating material with a carrier. Either method can be applied.

The substance (coating material) fixed to the carrier surface varies depending on the toner material. Examples thereof include polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, styrene resin, and acrylic resin. It is appropriate to use one or a plurality of resins, polyamides, polyvinyl butyral, nigrosine, amino acrylate resins, basic dyes and lakes thereof, silica fine powder, alumina fine powder, metal complexes or metal salts of dialkylsalicylic acid.

The treatment of the compound (fixing substance) may be appropriately determined so that the carrier satisfies the above conditions.
Generally, the total amount is 0.1 to 30% by mass based on the carrier.
(Preferably 0.5 to 20% by mass).

The average particle size of these carriers is 20 to 100.
μm, preferably 25-70 μm, more preferably 25
It is better to have a thickness of up to 65 μm.

In a particularly preferred embodiment, Cu—Zn—
Fe ternary ferrite whose surface is singly or in combination of resins such as fluorine resin and styrene resin, for example, polyvinylidene fluoride and styrene-methyl methacrylate resin, polytetrafluoroethylene and styrene-methyl methacrylate Resin; fluorinated copolymer; etc., alone or in the form of a mixture in a suitable ratio at an appropriate time, preferably coated with 0.01 to 5% by mass, preferably 0.1 to 1% by mass.

When a two-component developer is prepared by mixing with the toner of the present invention, the mixing ratio is from 1% by mass to 15% by mass, preferably from 2% by mass to 1% by mass, as the toner concentration in the developer.
Good results are usually obtained with 3% by weight. If the toner density is less than 1% by mass, the image density becomes low,
If it exceeds, fogging and scattering in the machine are increased, and the useful life of the developer tends to be shortened.

When the color toner of the present invention is used as a non-magnetic one-component developer, the above-mentioned magnetic carrier is not used, and the above-mentioned fluidity improver is appropriately added and used.

Next, an image forming apparatus using a non-magnetic one-component developer having a color toner according to the present invention will be described.

The image forming apparatus of the present invention has a latent image holding member for holding an electrostatic image and a developing device for developing the electrostatic image of the electrostatic holding member. ,
(I) a developer container holding a non-magnetic one-component developer having the color toner of the present invention; and (ii) a developer for supporting the non-magnetic one-component developer held in the developer container. A carrier and (iii) a developer applying member for applying the non-magnetic one-component developer in a thin layer on the developer carrier.

The image forming apparatus of the present invention will be described with reference to a schematic diagram of a specific example of a developing apparatus using a non-magnetic one-component developer as shown in FIG.

In the latent image carrier 1, the latent image is formed by an electrophotographic process means or an electrostatic recording means (not shown). The developer carrier 2 is formed of a non-magnetic sleeve made of a metal such as aluminum or stainless steel. The non-magnetic one-component developer is stored in a hopper 3 as a developer container.
Supplied up. The supply roller 4 also removes the developer on the developer carrier 2 after the development. The developer supplied onto the developer carrier 2 is uniformly and thinly applied by a developer application blade 5 serving as a developer application member elastically pressed against the developer carrier 2. The contact pressure between the developer applying blade 5 and the developer carrier 2 is 3 to 250 g / cm, preferably 10 to 250 g / cm, as a linear pressure in the sleeve generatrix direction.
120 g / cm is effective. When the contact pressure is less than 3 g / cm, it becomes difficult to apply the developer uniformly, the charge amount distribution of the developer becomes broad, and fog and scattering are likely to occur. If the contact pressure exceeds 250 g / cm, a large pressure is applied to the toner particles, so that the toner particles are not easily aggregated or pulverized. By adjusting the contact pressure to 3 to 250 g / cm, it becomes possible to satisfactorily loosen the aggregation of the small-sized toner particles, and it is possible to instantaneously raise the triboelectric charge of the developer. The developer coating blade 5 is preferably made of a material of a triboelectric series suitable for charging the developer to a desired polarity.

In the present invention, the developer coating blade comprises:
Elastic blades formed from rubbers such as silicone rubber, urethane rubber and styrene-butadiene rubber are preferred. It is preferable to use a conductive rubber because it is possible to prevent the toner from being excessively triboelectrically charged. Further, the surface of the blade 5 may be coated as necessary. In particular, when used as a negative toner, it is preferable to coat a positively chargeable resin such as a polyamide resin.

In a system in which the developer is thinly coated on the developer carrier 2 by the blade 5, the thickness of the developer layer on the developer carrier 2 is adjusted in order to obtain a sufficient image density. It is preferable that the length of the gap between the body 2 and the latent image holding member 1 is made thinner, and an alternating electric field is applied to this gap.
By applying a developing bias in which an alternating electric field or a DC electric field is superimposed on the alternating electric field between the developer carrier 2 and the latent image holder 1 by the bias power source 6 shown in FIG. Facilitates the movement of the developer on the holder 1,
Further, a high quality image can be obtained.

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

According to the color image forming method of the present invention, a color toner image is formed on a recording material using at least one color toner of cyan toner, magenta toner and yellow toner, and the formed color toner image is recorded on the recording material. To obtain a color image by heating and fixing the toner, the cyan toner, the magenta toner, and the yellow toner having the configuration of the color toner of the present invention.

FIG. 2 shows the color image forming method of the present invention.
A full-color image forming apparatus using the color image forming method of the present invention shown in FIG.

The color image forming apparatus shown in FIG. 2 includes a recording material transport system I provided from the right side (upper side in FIG. 2) of the apparatus main body 101 to a substantially central portion of the apparatus main body, and a general structure of the apparatus main body 101. At the center, a latent image forming section II provided close to the transfer drum 115 constituting the recording material transport system I, and a developing means provided close to the latent image forming section II That is, it is roughly classified into a rotary developing device III.

The recording material transport system I has the following configuration. Right wall of the apparatus main body 101 (right side in FIG. 2)
The recording material supply trays 102 and 103, which are detachable from the opening, are partially disposed outside the apparatus. Feed rollers 104 and 105 are disposed almost directly above the trays 102 and 103, and the feed rollers 104 and 105 are linked to a transfer drum 115 rotatable in the direction of the arrow disposed to the left. So that the paper feed roller 106 and the paper feed guides 107 and 10
8 are provided. In the vicinity of the outer peripheral surface of the transfer drum 115, the contact roller 109, the gripper 110, and the recording material separating charger 11 are arranged from the upstream side to the downstream side in the rotation direction.
1. Separating claws 112 are sequentially arranged.

On the inner peripheral side of the transfer drum 115, a transfer charger 113 and a recording material separating charger 114 are provided. A transfer sheet (not shown) made of a polymer such as polyvinylidene fluoride is attached to a portion of the transfer drum 115 around which the recording material is wound, and the recording material is electrostatically placed on the transfer sheet. It is stuck on. At the upper right side of the transfer drum 115, a conveying belt means 116 is disposed in close proximity to the separation claw 112. At the end (right end) of the conveying belt means 116 in the recording material conveying direction, a color toner image is heated on the recording material. Fixing device 118 for fixing
Are arranged. Further downstream of the fixing device 118 in the conveying direction, the fixing device 118 extends outside the apparatus main body 101 and
A discharge tray 117 that is detachable with respect to the tray 01 is provided.

Next, the configuration of the latent image forming section II will be described. A photosensitive drum (for example, an OPC photosensitive drum) 119, which is a latent image holding member rotatable in the direction of the arrow in FIG. 2, is provided with its outer peripheral surface in contact with the outer peripheral surface of the transfer drum 115. Above the photosensitive drum 119 and in the vicinity of the outer peripheral surface thereof, from the upstream side to the downstream side in the rotation direction of the photosensitive drum 119, the charge removing charger 120 and the cleaning unit 121 are arranged.
And a primary charger 123 are sequentially disposed. Further, an image exposure unit 124 such as a laser beam scanner for forming an electrostatic latent image on the outer peripheral surface of the photosensitive drum 119 and an image exposure reflection unit 125 such as a mirror are provided. It is arranged.

The construction of the rotary developing device III is as follows. A rotatable housing (hereinafter referred to as a “rotating body”) 1 is provided at a position facing the outer peripheral surface of the photosensitive drum 119.
26, and four types of developing devices are mounted in the rotating body 126 at four positions in the circumferential direction.
Is visualized (that is, developed) on the outer peripheral surface of the electrostatic latent image. The four types of developing devices include a yellow developing device 127Y, a magenta developing device 127M, a cyan developing device 127C, and a black developing device 127BK.

The sequence of the entire image forming apparatus having the above-described configuration will be described by taking a full color mode as an example. When the above-described photosensitive drum 119 rotates in the direction of the arrow in FIG. 2, the photosensitive member on the photosensitive drum 119 is charged by the primary charger 123. In the apparatus shown in FIG. 2, the operation speed of each unit (hereinafter referred to as process speed) is 100 mm / sec or more (for example, 130 to 250 mm).
/ Sec). When the photosensitive drum 119 is charged by the primary charger 123, image exposure is performed by the laser light E modulated by the yellow image signal of the document 128, and an electrostatic latent image is formed on the photosensitive drum 119, and the rotation is performed. By the rotation of the body 126, the electrostatic latent image is developed by the yellow developing device 127Y fixed at the developing position in advance, and a yellow toner image is formed.

A paper feed guide 107, a paper feed roller 106,
The recording material conveyed via the paper feed guide 108
It is held by the gripper 110 at a predetermined timing,
The transfer roller 115 is electrostatically wound around the contact roller 109 and the electrode facing the contact roller 109. The transfer drum 115 is a photosensitive drum 119
The image is rotated in the direction indicated by the arrow in FIG. 2 in synchronization with the yellow toner image formed by the yellow developing device 127Y.
The outer peripheral surface of the photosensitive drum 119 and the transfer drum 115
Is transferred onto a recording material by the transfer charger 113 at a portion where the outer peripheral surface of the transfer member contacts. The transfer drum 115 continues to rotate as it is, and the next color (magenta in FIG. 1)
Prepare for transcription.

The photosensitive drum 119 is connected to the charge removing charger 12.
After being eliminated by 0 and cleaned by a cleaning means 121 using a conventionally known blade method, the image is charged again by a primary charger 123, and image exposure is performed by the next magenta image signal to form an electrostatic latent image.
The rotary developing device rotates while an electrostatic latent image is formed on the photosensitive drum 119 by image exposure based on a magenta image signal, and places the magenta developing device 127M at the above-described predetermined developing position, thereby causing a predetermined magenta developing device. Develop with toner. Subsequently, the above-described process is also performed for the cyan and black colors, respectively, and when the transfer of the four color toner images is completed, the four-color visible image formed on the recording material is transferred to each of the chargers 122 and The charge is removed by 114, the gripping of the recording material by the gripper 110 is released, and the recording material is separated from the transfer drum 115 by the separation claw 112, sent to the fixing device 118 by the transport belt 116, and heated and pressured. A series of full-color print sequences are completed by heating and fixing, and a required full-color print image is formed on one surface of the recording material.

In the above description, a full-color image is formed using four color toners of black toner in addition to cyan toner, magenta toner and yellow toner. However, black image formation is performed without using black toner. It is also possible to form a full-color image by using three color toners of cyan toner, magenta toner and yellow toner, and using these three color toners.

Further, in the present invention, cyan toner,
During the formation of a single color image using one of the magenta toner and the yellow toner, a color image using two colors may be formed.
It is also possible to form a full-color image by combining at least one of the magenta toner and the yellow toner with a commercially available black toner.

The measuring method in the present invention will be described below.

(1) Measurement of glass transition temperature Tg In the present invention, measurement is made using a differential thermal analyzer (DSC measuring device), DSC-7 (manufactured by PerkinElmer).

The measurement sample is 5 to 20 mg, preferably 10
Weigh the mg precisely.

This was put in an aluminum pan, and an empty aluminum pan was used as a reference.
The measurement is performed at a temperature rising rate of 10 ° C./min under normal temperature and normal humidity between 00 ° C.

In this heating process, an endothermic peak of a main peak in a temperature range of 40 to 100 ° C. is obtained.

The intersection between the line of the midpoint of the baseline and the differential heat curve before and after the endothermic peak at this time is expressed by:
In the present invention, the glass transition temperature is defined as Tg.

(2) Gloss (Glossiness) Measuring Method Using a VG-10 gloss meter (manufactured by Nippon Denshoku Co., Ltd.), each solid image used for chromaticity measurement is measured as a sample.

As a measurement, first, a voltage of 6 V was applied by a constant voltage device.
Set to.

Next, the light projection angle and the light reception angle are each set to 60
Adjust to °.

Using the zero-point adjustment and the standard plate, after setting the standard, place the sample image on the sample table,
Perform overlay measurement on the sheet, and read the numerical value shown in the marked part in%.

(3) Measurement of softening point temperature of resin Flow tester CFT-500 type (manufactured by Shimadzu Corporation) is used. The sample weighs about 1.0 g of a 60 mesh pass product. This is pressurized with a load of 100 kg / cm ² for 1 minute using a molding machine.

The pressurized sample is subjected to a flow tester measurement under the following conditions under normal temperature and normal humidity (temperature: about 20 to 30 ° C., humidity: 30 to 70% RH) to obtain a temperature-apparent viscosity curve. From the obtained smooth curve, the temperature (= T _1/2 ) at the time when the sample flows out by 50% by volume is determined, and this is defined as the softening point temperature Tm of the resin.

RATE TEMP 6.0 (° C./min) SET TEMP 50.0 (° C.) MAX TEMP 180.0 (° C.) INTERVAL 3.0 (° C.) PREHEAT 300.0 (second) LOAD 20.0 (kg) DIE (Diameter) 1.0 (mm) DIE (Length) 1.0 (mm) PLUNGER 1.0 (cm ² )

(4) Measurement of Average Particle Size of Pigment Particles in Color Toner Particles Toner is added to a 2.3 M sucrose solution, stirred well, and a small amount is put on a sample holder pin, and then put into liquid N ₂ And set it on the sample arm head immediately.

A sample was prepared by cutting with an ultramicrotome FC4E equipped with a cryo-apparatus (manufactured by Nissan Sangyo) according to a conventional method.

A photograph was taken at an acceleration voltage of 100 kV using an electron microscope H-8000 (manufactured by Hitachi, Ltd.). The magnification is arbitrary according to the sample.

The image information is introduced into an image analyzer (Luzex3) manufactured by Nicole via an interface, and
Convert to value image data. Among them, only the pigment particles having a particle size of 0.1 μm or more shall be analyzed at random, and the measurement is repeated until the sampling number exceeds 300 times, the number average particle size of the pigment particles required in the present invention, In addition, the particle size distribution was determined.

That is, here, only particles larger than 0.1 μm were measured. The particle size referred to in the present invention, after each pigment particle image approximates a circle shape, and the value defined by the diameter obtained.

[0154]

The present invention will be described in detail with reference to the following examples.

(Production Example 1 of Polyester Resin) 2 mol of terephthalic acid, 1.09 mol of dodecenyl succinic anhydride
l, 3.4 mol of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and 0.01 g of dibutyltin oxide in 2 liters of glass
Put in a two-necked flask, thermometer, stirring rod, condenser,
And a nitrogen inlet tube was attached and placed in the heating mantle. Next, after the inside of the flask was replaced with nitrogen gas, the temperature was gradually increased with stirring, the reaction was performed at 170 ° C. for 5 hours, and then the temperature was increased to 190 ° C. and the reaction was performed for 4 hours. The hydroxyl value of the resin formed at this point was 59.8.

Thereafter, trimellitic anhydride 0.2 mol
l, and 0.08 g of dibutyltin oxide,
The mixture was further reacted at 3 ° C. for 3 hours, further heated to 200 ° C., and reacted for 5 hours to complete the reaction, thereby obtaining a polyester resin (1).

The polyester resin (1) has a softening point of 1
The temperature was 04 ° C, and the glass transition temperature was 64 ° C.

(Production Example 2 of Polyester Resin) 1.9 mol of isophthalic acid, 1.22 mol of octylsuccinic acid
1, polyoxyethylene (2.0) -2,2-bis (4
3.34 mol of (-hydroxyphenyl) propane was reacted in a nitrogen atmosphere in the same manner as in Production Example 1 of a polyester resin. Then, trimellitic anhydride 0.13
mol, 0.09 g of dibutyltin oxide, 180 ° C
For 5 hours to obtain a polyester resin (2).

The polyester resin (2) had a glass transition temperature of 62 ° C. and a softening point temperature of 106 ° C.

(Production Example 3 of Polyester Resin) 3.0 mol of terephthalic acid, polyoxypropylene (2.2)
1.6 mol of -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2
-Bis (4-hydroxyphenyl) propane 1.6mo
1, Dibutyltin oxide (0.01 g) was placed in a glass 2-liter four-necked flask and reacted in a nitrogen atmosphere in the same manner as in Production Example-1 of polyester resin. Next, 0.3 mol of tri-n-butyl 1,2,4-benzenetricarboxylate was added, the temperature was raised to 220 ° C., and the reaction was carried out for 5 hours, and the reaction was completed to obtain a polyester resin (3).

The polyester resin (3) has a softening point of 1
The glass transition temperature was 01 ° C and the glass transition temperature was 60 ° C.

(Production Example 4 of Polyester Resin) 2.0 mol of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2.0) -2,2- Bis (4-hydroxyphenyl) propane 2.1 mol, terephthalic acid 2 mol, dodecenylsuccinic acid 1.6 mol, trimellitic acid 0.4
6 mol was reacted at 250 ° C. for 8 hours using the same apparatus as in Production Example 1 of a polyester resin to obtain a polyester resin (4).

The polyester resin (4) had a softening point of 118 ° C. and a glass transition temperature of 61.5 ° C.

(Production Example 5 of Polyester Resin) 2.0 mol of isophthalic acid, 1.4 mol of fumaric acid, 1.5 mol of polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, Oxyethylene (2) -2,2-bis (4-hydroxyphenyl)
1.5 mol of propane, 0.02 g of dibutyltin oxide
Was placed in a glass two-liter four-necked flask, and a polyester resin (5) was obtained in substantially the same manner as in Production Example-1 of polyester resin.

The polyester resin (5) had a glass transition temperature of 51 ° C. and a softening point temperature of 82 ° C.

(Production Example of Polyester Resin-6) 1.4 mol of fumaric acid, polyoxypropylene (2.2)-
2,2-bis (4-hydroxyphenyl) propane
Using 4 mol and 0.02 g of dibutyltin oxide, a polyester resin (6) was obtained in substantially the same manner as in Production Example-1 of a polyester resin.

The polyester resin (6) had a glass transition temperature of 58 ° C. and a softening point of 92 ° C.

(Production Example 7 of Polyester Resin) Except that 0.3 mol of 1,2,5-hexanetricarboxylic acid was used instead of 0.2 mol of trimellitic anhydride in Production Example 1 of polyester resin. A polyester resin (7) was obtained in substantially the same manner as in Preparation example 1 of polyester resin.

The polyester resin (7) had a glass transition temperature of 58 ° C. and a softening point temperature of 102 ° C.

Obtained polyester resins (1) to (7)
Table 1 shows the glass transition temperature (Tg) and softening point temperature (Tm).

[0171]

[Table 1]

(Example 1) First kneading step 70 parts by mass of polyester resin (1) I. Pigment Blue 15: 3 manufactured by a known method by removing a certain amount of water from the pigment slurry before the filtration step, and obtaining a paste-like pigment having a solid content of 30% by mass without passing through a drying step (the remaining 70% by mass). % Is water) 100 parts by mass

The above-mentioned raw materials are charged into a kneader-type mixer according to the above-mentioned recipe, and the temperature is raised under non-pressure while mixing. When the highest temperature is reached (necessarily determined by the boiling point of the solvent in the paste; in this case, about 90 to 100 ° C.), the pigment in the aqueous phase is distributed or transferred to the molten resin phase, and this is confirmed. After that, the mixture is heated and kneaded for another 30 minutes to sufficiently transfer the pigment in the paste. Then, once the mixer was stopped and the hot water was discharged, one more
The temperature was raised to 30 ° C., and the mixture was heated and kneaded for about 30 minutes to disperse the pigment and distill off the water. After the completion of this step, the mixture was cooled and the kneaded product was taken out. The water content of the final kneaded product was about 0.5% by mass.

Second Kneading Step The above-mentioned kneaded product (pigment particle content: 30% by mass) 16.7 parts by mass Polyester resin (1) 88.3 parts by mass Chromium complex of di-tert-butylsalicylic acid (charge control agent) 4 parts by mass

Premixing was sufficiently performed with the above formulation using a Henschel mixer, and the temperature was adjusted to 120 ° C. with a twin-screw extruder.
, Melt kneading, cooling, and about 1 hour using a hammer mill.
The mixture was coarsely pulverized to about 2 mm, and then finely pulverized by an air jet pulverizer to a particle size of 40 μm or less. Further, the obtained finely pulverized product is classified and selected so that the volume average diameter in the particle size distribution becomes 8.2 μm to obtain cyan toner particles (classified product), for the purpose of improving fluidity and imparting charging characteristics. 1.0 part by mass of titanium oxide fine powder hydrophobically treated with a Si-based compound was added to 100 parts by mass of cyan toner particles to obtain a cyan toner (A).

To 5.0 parts by mass of the cyan toner (A), styrene-methyl methacrylate (copolymer weight ratio: 6
5:35) coated with about 0.35% by mass of Cu—
A two-component developer was prepared by mixing Zn-Fe-based ferrite carriers in a total amount of 100 parts by mass. The toner concentration in the two-component developer was 5.0% by mass.

A copy test was conducted using this two-component developer in a commercially available plain paper color copying machine (color laser copier 550) shown in FIG. At this time, the fixing roller has a thickness of 5
2 mm thick RTV (room temperature vulcanization type) silicone rubber layer on an aluminum core bar of 50 mm, a 50 μm thick fluorine rubber layer on the outside, and a 230 μm thick HTV (high temperature vulcanization type) silicone on the outside A rubber roller having a diameter of 60 mm was used. The pressure roller was a 2 mm thick RTV silicone rubber layer on a 5 mm thick aluminum core bar, and a 50 μm thick fluorine rubber layer on the outside. 200μ thick
One having an HTV silicone rubber layer of m m was used.

In this copying test, an initial image was obtained, but the color tone was excellent and vivid.

Further, even after the endurance of 60,000 sheets, a cyan image which faithfully reproduces the original without fog is obtained.
Excellent color reproducibility. The conveyance in the copying machine and the detection of the developer density were good, and a stable image density was obtained. Even when the fixing temperature was set to 160 ° C. and 60,000 sheets were repeatedly copied, no offset to the fixing roller occurred. In addition,
The occurrence of offset to the fixing roller was determined by visually observing the surface of the fixing roller after repeated copying.

For comparative study of the amount of high-temperature offset, a new fixing roller was provided and provided in the fixing device. The driving of the silicone oil impregnated web is stopped, and the area ratio is 2 in that state.
Using the 0% image as an original, 5,000 sheets were repeatedly copied. Thereafter, the toner attached to the web, so-called,
To quantify the high-temperature offset toner, the portion was measured with a Macbeth reflection densitometer, and the density was extremely low at 0.3.

In this method, if the high-temperature offset amount is large,
When the reflection density value of the toner-adhered web increases and decreases when the reflection density value decreases, the high-temperature offset is quantified.

The charge amount was measured in each environment of low temperature and low humidity (15 ° C./10% RH) and high temperature and high humidity (32.5 ° C./85% RH). Was 1.35.

As a method of evaluating a color copied image, there is a method of determining the quality of a color image by measuring the gloss (gloss) of the image surface. That is, as the gloss value is higher, the image surface is determined to have a smoother, more glossy color quality with high gloss, and when the gloss value is lower, it is determined that the image surface is less dull and less saturated. In Example 1, the image density at a contrast potential of 300 V was 1.68 (Macbeth reflection density), and the gloss at that time was 21%. The color image formed on the transparency film is transferred to an overhead projector (O
HP), the transparency of the OHP image projected was also good.

The offset to the fixing roller, the color reproducibility and the transparency of the OHP image in the above Examples were evaluated as follows.

The occurrence of the offset to the fixing roller was determined by visually observing the surface of the fixing roller after repeated copying.

The color reproducibility was quantitatively evaluated by the color difference (ΔE) between the original image and the copied image based on the definition of the color system standardized by the International Commission on Illumination (CIE) in 1976. Was evaluated based on the following evaluation criteria.

ΔE = ｛(L ₁ ^* −L ₂ ^* ) ² + (a ₁ ^* −a ₂ ^* ) ² + (b ₁ ^* −b ₂ ^* ) ² ｝ ^1/2 [L ₁ ^* : of the original image lightness a ₁ ^*, b ₁ ^*: chromaticity L ₂ showing the hue and saturation of the original image ^*: lightness a ₂ ^* of the copied image, b ₂ ^*: chromaticities showing the hue and saturation of the copy image]

(Evaluation Criteria) ：: Excellent color reproducibility and high chroma. ΔE ≦ 5 (good) Δ: Although lacking in vividness, there is no practical problem.
5 <ΔE ≦ 10 (possible) ×: lacks vividness and is inferior in color reproducibility of secondary colors. ΔE
> 10 (impossible)

The transparency of the OHP image was evaluated based on the following evaluation criteria by projecting a color image formed on a transparency film using a commercially available overhead projector.

(Evaluation Criteria) A: Excellent in transparency, no unevenness in brightness, and excellent in color reproducibility. (Good) Δ: There is slight unevenness in brightness, but there is no practical problem.
(Possible) ×: There is uneven brightness and poor color reproducibility. (Not possible)

Example 2 A magenta toner (B) was obtained in the same manner as in Example 1 except that the following formulation was changed.

First kneading step : 58.3 parts by mass of polyester resin (2) I. 100 mass parts of a water-paste pigment containing 25 mass% of Pigment Red 122 Second kneading step 16.7 parts by mass of the kneaded product (pigment particle content: 30% by mass) polyester resin (1) 88 0.3 parts by mass Chromium complex 4 parts by mass

Using the obtained magenta toner (B),
When a durability test was carried out by repeating copying in the same manner as in Example 1, up to 30,000 sheets were not offset to the fixing roller and the transparency of the OHP image was excellent.

At this time, the maximum image density (Dmax) is 1.
74.

Example 3 A yellow toner (C) was produced in the same manner as in Example 1 except that the following formulation was changed.

First kneading step : 80 parts by mass of polyester resin (3) C.I. I. Pigment Yellow 17 containing 20% by mass of water paste pigment 100 parts by mass Second kneading step Kneaded product (pigment particle content 20% by mass) from the first kneading step 17.5 parts by mass Polyester resin (3) 86 Parts by mass chromium complex 4 parts by mass

Using the obtained yellow toner (C),
A durability test by repeated copying was performed in the same manner as in Example 1. As a result, up to 30,000 sheets were not offset to the fixing roller, and the transparency of the OHP image was excellent.

(Embodiment 4) Three toners of the cyan toner (A) used in Embodiment 1, the magenta toner (B) used in Embodiment 2, and the yellow toner (C) used in Embodiment 3 are used. To obtain a full-color image.

As a result, a good image faithfully reproducing the original image was obtained. 1000 in endurance test
Up to the zero sheet, there was no offset to the fixing roller, high image quality was maintained, and a full-color image excellent in gradation was obtained over a long period of time. The light transmission of the OHP image was also very good.

The color reproducibility in the green, blue and red portions was also good.

Example 5 A black toner (X) was obtained in the same manner as in Example 1 except that the following formulation was changed.

First kneading step : 70 parts by weight of polyester resin (1) 100 parts by weight of water paste pigment containing 26% by weight of carbon black having a primary particle diameter of 60 nm Second kneading step Kneaded product from first kneading step 67 parts by mass (carbon black content 27% by mass) Polyester resin (1) 87.83 parts by mass

The obtained black toner (X), Example 1
A full-color image was obtained by using the four toners of the cyan toner (A) used in Example 1, the magenta toner (B) used in Example 2, and the yellow toner (C) used in Example 3.

As a result, a good image which faithfully reproduced the original image was obtained. 2000 in endurance test
Up to zero sheets, there was no offset to the fixing roller, high image quality was maintained, and a full-color image excellent in gradation was obtained over a long period of time. The light transmittance of the OHP image was also good.

Example 6 First kneading step 100 parts by mass of polyester resin (1) Copper phthalocyanine pigment / C.I. I. Pigment Blue 15: 3 (dry powder) 30 parts by mass

The above materials were sufficiently premixed with a Henschel mixer, melt-kneaded six times with a three-roll mill, cooled, and the kneaded material was taken out.

Second kneading step The above-mentioned kneaded material (pigment particle content: 30% by mass) 16.7 parts by mass Polyester resin (1) 88.3 parts by mass Chromium complex (charge control agent) 4 parts by mass

With the above formulation, a cyan toner (G) having a volume average diameter of 8.1 μm was obtained in the same manner as in Example 1.

Using the obtained cyan toner (G), an endurance test by repeated copying was conducted in the same manner as in Example 1. As a result, no offset was observed up to 10,000 sheets, but it was used in Example 3. When a green image was formed in two colors by using a combination of the yellow toner (C) and the cyan toner (G), the saturation of the green was determined in Example 4.
Although it was lower than the green saturation in the above, it was within a practical level for the time being.

(Example 7) In Example 1, except that the chromium complex was not used in the second kneading step, and the temperature of the twin-screw extruder was set to 100 ° C and the kneading was changed so as to be melt-kneaded. In the same manner as in Example 1, a cyan toner (Y) was obtained.

Using the obtained cyan toner (Y), a durability test by repeated copying was performed in the same manner as in Example 1, and no offset to the fixing roller was observed up to 10,000 sheets. However, the fog increased with the endurance, and only a sparse image was obtained as a whole. When green was imaged in two colors using a combination of the yellow toner (C) used in Example 3 and the cyan toner (Y), the saturation of green was the same as the saturation of green in Example 4. It was lower than that. However, everything was within a practical level.

Comparative Example 1 The procedure of Example 1 was repeated except that the polyester resin (4) was used instead of the polyester resin (1) used in the first kneading step and the second kneading step. In the same manner as in Example 1, a cyan toner (D) was obtained.

Using the obtained cyan toner (D), an endurance test by repeated copying was performed in the same manner as in Example 1. As a result, although no offset to the fixing roller was observed even on 10,000 sheets, the OHP image was not removed from the beginning. Light transmittance was unacceptable.

Comparative Example 2 The procedure of Example 1 was repeated except that the polyester resin (5) was used instead of the polyester resin (1) used in the first kneading step and the second kneading step. In the same manner as in Example 1, a cyan toner (E) was obtained.

A durability test by repeated copying was performed using the obtained cyan toner (E) in the same manner as in Example 1. As a result, an unacceptable level of offset to the fixing roller occurred from the initial stage of the durability.

Comparative Example 3 100 parts by mass of polyester resin (1) Copper phthalocyanine pigment / C.I. I. Pigment Blue 15: 3 (dry powder) 5 parts by mass Chromium complex (charge control agent) 4 parts by mass

The above formulation was sufficiently premixed with a Henschel mixer, the temperature was set to 120 ° C. with a twin screw extruder and melt kneaded, and the cyan toner having a volume average diameter of 8.0 μm was obtained in the same manner as in Example 1. (F) was obtained.

Using the obtained cyan toner (F), a durability test by repeated copying was performed in the same manner as in Example 1. As a result, an image with much fog was obtained from the beginning, and toner scattering was confirmed. With a durability of 10,000 sheets, a slight offset was seen on the roller surface.

When the yellow toner used in Example 3 and the cyan toner (F) were used in combination to produce a green image in two colors, the green saturation was as high as that in Example 4. It has dropped significantly compared to the degree. That is, good color reproduction was not possible with the cyan toner (F).

Comparative Example 4 The procedure of Example 1 was repeated, except that the polyester resin (6) was used instead of the polyester resin (1) used in the first kneading step and the second kneading step. A durability test by repeated copying was carried out in the same manner as in Example 1 by using the cyan toner (H) in the same manner as in Example 1. As a result, offset was observed on the roller surface after 10,000 sheets, and the durability was interrupted.

Comparative Example 5 The procedure of Example 1 was repeated except that the polyester resin (7) was used instead of the polyester resin (1) used in the first kneading step and the second kneading step. In the same manner as in Example 1, cyan toner (I) was obtained.

Using the obtained cyan toner (I), a durability test by repeated copying was performed in the same manner as in Example 1. As a result, although the offset resistance was good, the transparency of the OHP image was poor from the beginning, and the saturation was low. Was also lower.

Comparative Example 6 A cyan toner (J) was prepared in the same manner as in Example 6, except that the number of kneading in the first kneading step was changed from 6 to 2. Obtained.

Using the obtained cyan toner (J), a durability test by repeated copying was performed in the same manner as in Example 1. As a result, the transparency of the OHP image was poor from the beginning, and the yellow toner (C) and this cyan toner (J) were used. J) was used to produce a green image in two colors. As a result, the saturation of the green was lower than that of Example 6 and was at an unpracticable level.

(Comparative Example 7) In Example 6, the polyester resin (6) was used in place of the polyester resin (1) used in the first kneading step and the second kneading step. A cyan toner (K) was obtained in the same manner as in Example 6, except that the number of kneading was changed from 6 times to 2 times.

Using the obtained cyan toner (K), an endurance test by repeated copying was performed in the same manner as in Example 1. As a result, offset was observed on the roller surface after 5,000 sheets, and the endurance was interrupted.

Comparative Example 8 The same procedure as in Example 1 was carried out except that the polyester resin in the first kneading step was mixed with the paste pigment by heating at 120 ° C. under pressure. Thus, a cyan toner (L) was obtained.

Using the obtained cyan toner (L), a durability test by repeated copying was performed in the same manner as in Example 1. As a result, a slight offset was observed on the fixing roller surface on 10,000 sheets. The softening point of the toner (L) has dropped to 101 ° C., and it is considered that the molecular chain was broken by heating and mixing under pressure.

(Comparative Example 9) In Example 1, a polyester resin (6) was used in place of the polyester resin (1) used in the first kneading step and the second kneading step. A cyan toner (M) was obtained in the same manner as in Example 1, except that the polyester resin and the paste pigment were heated and mixed at 120 ° C. under pressure.

A durability test by repeated copying was performed in the same manner as in Example 1 using the obtained cyan toner (M). As a result, an image with much fog was obtained from the beginning, and toner scattering was confirmed. A slight offset was seen on the roller surface after 5,000 sheets of durability.

Comparative Example 10 A cyan toner (N) was prepared in the same manner as in Example 1 except that the chromium di-tert-butylsalicylate used in the second kneading step was not used. I got

Using the obtained cyan toner (N), a durability test by repeated copying was carried out in the same manner as in Example 1. As a result, an image having much fog was obtained from the beginning, and toner scattering was confirmed. Further, the transparency of the OHP image was lower than that of Example 1.

Table 2 shows the physical properties of the toners A to N, X and Y used in the above Examples and Comparative Examples, and Table 3 shows the evaluation results of Examples 1 to 7 and Comparative Examples 1 to 10.

[0234]

[Table 2]

[0235]

[Table 3]

Example 8 A cyan toner (A) similar to that of Example 1 was used, except that the developing device in the color electrophotographic apparatus was replaced with a developing device using a non-magnetic one-component developer as shown in FIG. ) Was repeated repeatedly at a high temperature and high humidity for 5.0000 sheets, but there was no fusion to the developing sleeve 2, blade 5 and supply roller 4, and the image density was 1.70 at a potential contrast of 300 V, which was as high as 1.70. Dmax was obtained.

No scattering or fogging in the machine due to a decrease in the charge amount of the toner occurred. Also, no offset to the fixing roller occurred during that time.

The evaluation results are shown in Table 4.

Example 9 Example 8 was repeated, except that the magenta toner (B) used in Example 2 was used instead of the cyan toner (A). A durability test was performed by copying.

The evaluation results are shown in Table 4.

Example 10 The same procedure as in Example 8 was repeated, except that the yellow toner (C) used in Example 3 was used instead of the cyan toner (A). A durability test was performed by copying.

Table 4 shows the evaluation results.

(Embodiment 11) The procedure of Example 8 was repeated, except that the cyan toner (G) used in Example 6 was used instead of the cyan toner (A). A durability test was performed by copying.

The evaluation results are shown in Table 4.

Example 12 Example 8 was repeated in the same manner as Example 8, except that the cyan toner (Y) used in Example 7 was used instead of the cyan toner (A). A durability test was performed by copying.

The evaluation results are shown in Table 4.

(Comparative Example 11) The same procedure as in Example 8 was repeated except that the cyan toner (D) used in Comparative Example 1 was used instead of the cyan toner (A). A durability test was performed by copying.

The evaluation results are shown in Table 4.

(Comparative Example 12) The same procedure as in Example 8 was repeated, except that the cyan toner (E) used in Comparative Example 2 was used instead of the cyan toner (A). A durability test was performed by copying.

The evaluation results are shown in Table 4.

(Comparative Example 13) The same procedure as in Example 8 was repeated, except that the cyan toner (F) used in Comparative Example 3 was used instead of the cyan toner (A). A durability test was performed by copying.

The evaluation results are shown in Table 4.

(Comparative Example 14) The same procedure as in Example 8 was repeated, except that the cyan toner (H) used in Comparative Example 4 was used instead of the cyan toner (A). A durability test was performed by copying.

Table 4 shows the evaluation results.

(Comparative Example 15) The same procedure as in Example 8 was repeated, except that the cyan toner (A) used in Comparative Example 5 was used instead of the cyan toner (A). A durability test was performed by copying.

The evaluation results are shown in Table 4.

(Comparative Example 16) The same procedure as in Example 8 was repeated, except that the cyan toner (J) used in Comparative Example 6 was used instead of the cyan toner (A). A durability test was performed by copying.

The evaluation results are shown in Table 4.

(Comparative Example 17) The same procedure as in Example 8 was repeated, except that the cyan toner (K) used in Comparative Example 7 was used instead of the cyan toner (A). A durability test was performed by copying.

The evaluation results are shown in Table 4.

(Comparative Example 18) The same procedure as in Example 8 was repeated, except that the cyan toner (A) was replaced with the cyan toner (L) used in Comparative Example 8, except that the cyan toner (L) used in Comparative Example 8 was used. A durability test was performed by copying.

Table 4 shows the results of the evaluation.

(Comparative Example 19) The same procedure as in Example 8 was repeated, except that the cyan toner (M) used in Comparative Example 9 was used instead of the cyan toner (A). A durability test was performed by copying.

Table 4 shows the results of the evaluation.

(Comparative Example 20) The same procedure as in Example 8 was repeated, except that the cyan toner (N) used in Comparative Example 10 was used instead of the cyan toner (A). A durability test was performed by copying.

The evaluation results are shown in Table 4.

[0267]

[Table 4]

[0268]

According to the present invention, a colorant having color toner particles using the above-mentioned non-linear polyester resin as a binder resin and having a specific particle size distribution can be incorporated into the binder resin. Due to the dispersion, it is possible to form a color image which is excellent in fixing property, color mixing property, triboelectric charging property and glossiness, and has high image density, high chroma and excellent transparency.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing a specific example of a developing device using a non-magnetic one-component toner to which the color toner of the present invention can be applied.

FIG. 2 is a schematic explanatory view of a full-color image forming apparatus using the color image forming method of the present invention.

[Explanation of symbols]

 Reference Signs List 1 latent image holder (photosensitive drum) 2 developer carrier (developing sleeve) 3 hopper 4 supply roller 5 developer application blade 6 power supply

Continuation of the front page (51) Int.Cl. ⁷ identification symbol FI G03G 9/097 G03G 9/08 346 9/10 361 (56) References JP-A-5-158282 (JP, A) JP-A-4-317070 JP-A-6-266156 (JP, A) JP-A-6-95429 (JP, A) JP-A-2-282758 (JP, A) JP-A-5-34978 (JP, A) Kaihei 6-161154 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 9/08

Claims (20)

(57) [Claims] At least a coloring agent and the following formula (1): A color toner having color toner particles containing a non-linear polyester resin synthesized using a compound represented by the formula (I) or an acid anhydride thereof, wherein the colorant is formed of pigment particles, The pigment particles in the particles have a number average particle size of 0.7 μm or less, contain 60% by number or more of pigment particles having a particle size of 0.1 to 0.5 μm, and a pigment having a particle size of 0.8 μm or more. A color toner containing 10% by number or less of particles, wherein the color toner has a softening point Tm of 85 ° C to 120 ° C calculated from a flow tester curve. 2. The non-linear polyester resin according to claim 1, wherein the linear polymer chain has a cross-linked structure cross-linked by the compound represented by the formula (1) or an acid anhydride thereof. The color toner described in the above. 3. The non-linear polyester resin according to claim 1, wherein the non-linear polyester resin is synthesized by reacting the linear polyester with the compound represented by the formula (1) or an acid anhydride thereof. 2. The color toner according to 1. 4. The color toner according to claim 1, wherein the color toner particles contain an organometallic compound. 5. The color toner according to claim 4, wherein the organometallic compound is an organometallic complex. 6. The color toner according to claim 1, wherein the color toner contains a mixture of the color toner particles and an external additive. 7. The color toner according to claim 6, wherein the external additive contains a fluidity improver. 8. The fluidity improver comprises a fluororesin powder,
The color toner according to claim 7, comprising one or more members selected from the group consisting of fatty acid metal salts, metal oxides, and silica fine powder. 9. In a two-component developer having a color toner having color toner particles and a carrier, the color toner particles have at least a coloring agent and the following formula (1). And a non-linear polyester resin synthesized using an acid anhydride thereof, wherein the colorant is formed of pigment particles, and the pigment particles in the color toner particles are The number average particle size is 0.7 μm or less, contains 60% by number or more of pigment particles having a particle size of 0.1 to 0.5 μm, and contains 10% or less of pigment particles having a particle size of 0.8 μm or more. The two-component developer, wherein the color toner has a softening point Tm of 85 ° C. to 120 ° C. calculated from a flow tester curve. 10. The two-component developer according to claim 9, wherein the color toner is the color toner according to any one of claims 2 to 8. 11. An image forming apparatus having a latent image holding member for holding an electrostatic image and a developing device for developing the electrostatic image of the latent image holding member, wherein the developing device comprises: (i) A developer container holding a non-magnetic one-component developer, (ii) a developer carrier for supporting the non-magnetic one-component developer held in the developer container,
And (iii) a developer applying member for applying the non-magnetic one-component developer in a thin layer on the developer carrier, wherein the non-magnetic one-component developer comprises a colorant and a compound represented by the following formula: (1) A color toner having color toner particles containing a non-linear polyester resin synthesized using a compound represented by the formula or an acid anhydride thereof, wherein the colorant is formed of pigment particles, The pigment particles in the color toner particles have a number average particle size of 0.7 μm or less, contain 60% by number or more of pigment particles having a particle size of 0.1 to 0.5 μm, and a particle size of 0.8 μm or more. An image forming apparatus comprising 10% by number or less of the pigment particles described above, wherein the color toner has a softening point temperature Tm of 85 ° C. to 120 ° C. calculated from a flow tester curve. 12. The image forming apparatus according to claim 11, wherein said latent image holding member is an electrophotographic photosensitive member. 13. The developer applying member according to claim 11, wherein the developer applying member is elastically pressed against the developer carrying member.
3. The image forming apparatus according to 2. 14. The developer application member according to claim 11, wherein the developer application member is a rubber blade formed of at least one material selected from the group consisting of silicone rubber, urethane rubber and styrene-butadiene rubber.
14. The image forming apparatus according to any one of claims 13 to 13. 15. The apparatus according to claim 11, wherein a thickness of the developer layer applied on the developer carrier is smaller than a gap length between the latent image carrier and the developer carrier. 15. The image forming apparatus according to any one of 14. 16. The image forming apparatus according to claim 11, wherein the color toner is the color toner according to any one of claims 2 to 8. 17. A step of forming a color toner image on a recording material using at least one color toner of a cyan toner, a magenta toner and a yellow toner, and heating and fixing the formed color toner image to the recording material. In a color image forming method having a step of obtaining a color image, a) the cyan toner comprises at least a colorant and the following formula (1): Having cyan toner particles containing a non-linear polyester resin synthesized using the compound represented by the formula (1) or an acid anhydride thereof, wherein the colorant is formed of cyan pigment particles; The cyan pigment particles in the toner particles have a number average particle size of 0.7 μm or less, and 0.1 to 0.5 μm.
Containing at least 60% by number of the cyan pigment particles having a particle size of 0.8 μm or more and 1% of the cyan pigment particles having a particle size of 0.8 μm or more.
The cyan toner has a softening point Tm of 85 ° C. to 120 ° C. calculated from a flow tester curve. B) The magenta toner has at least a colorant and the following formula (1) ) And magenta toner particles containing a non-linear polyester resin synthesized using the compound represented by the formula (1) or an acid anhydride thereof, wherein the colorant is formed of magenta pigment particles, The magenta pigment particles in the toner particles,
The number average particle size is 0.7 μm or less, and 0.1 to 0.5
The magenta pigment particles having a particle size of 0.8 μm or more are contained in an amount of 60% by number or more, and the magenta pigment particles having a particle size of 0.8 μm or more are included in an amount of 10% or less. Having a softening point temperature Tm of 85 ° C. to 120 ° C. calculated from the curve; c) the yellow toner contains at least a colorant and the following formula (1): Having yellow toner particles containing a non-linear polyester resin synthesized using a compound represented by the formula (1) or an acid anhydride thereof, wherein the colorant is formed of yellow pigment particles; The yellow pigment particles in the toner particles,
The number average particle size is 0.7 μm or less, and 0.1 to 0.5
The yellow toner contains 60% by number or more of the yellow pigment particles having a particle diameter of μm and 10% by number or less of the yellow pigment particles having a particle diameter of 0.8 μm or more. A color image forming method having a softening point temperature Tm of 85 ° C. to 120 ° C. calculated from a curve. 18. The color image according to claim 17, wherein said color image is a full color image formed by combining said cyan toner, said magenta toner and said yellow toner.
2. The image forming method according to 1., 19. The image forming method according to claim 17, wherein the color image is a full-color image formed by combining a black toner in addition to the cyan toner, the magenta toner, and the yellow toner. . 20. The color toner according to claim 2, wherein the cyan toner, the magenta toner, and the yellow toner are all color toners according to claim 2.
20. The image forming method according to any one of claims 1 to 19.