JPH0424651A - Production of start developer - Google Patents

Abstract

PURPOSE:To produce the start developer which can form always stable images by continuing agitating and mixing further after an electrostatic charge quantity attains saturation by the agitating and mixing, thereby adjusting the electrostatic charge quantity of the start developer to 65 to 90% of the satd. electrostatic charge quantity. CONSTITUTION:The agitating and mixing are further continued after the electrostatic charge quantity is satd. by the agitating and mixing, by which the electrostatic charge quantity of the start developer is adjusted to 65 to 90% of the satd. electrostatic charge quantity at the time of producing the start developer of a two-component system by compounding toners and carriers at prescribed ratios and agitating and mixing the mixture. Namely, the sensor output value with respect to a toner concn. remains nearly constant from the initial period of image formation to the stable period of the image formation when the electrostatic charge quantity after the saturation of the start developer is adjusted to 65 to 90% of the satd. electrostatic charge quantity. The sensor is eventually able to recognize always the exact toner concn. The toner replenishment from the initial period of image formation to the stable period of the image formation is, therefore, exactly executed and the generation of various kinds of image defects is prevented.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a method for preparing toner and carrier in a predetermined manner, which is used in image forming apparatuses applying the so-called Carlson process, such as electrostatic copying machines and racer beam printers. The present invention relates to a method for producing a two-component starter developer mixed in proportions.

<Prior Art> The above-mentioned Carlson process uses a developing device to bring a developer containing toner into contact with an electrostatic latent image formed by exposure to light on the surface of a photoreceptor, and visualizes the electrostatic latent image as a toner image. After being imaged, this toner image is transferred from the surface of the photoreceptor onto paper and fixed.

A two-component developer containing a toner and a carrier that holds the toner and circulates within the developing device is generally used as the developer. The developer initially used in the developing device is a mixture of the above toner and carrier in a predetermined ratio and is called a start developer.

The performance of the start developer is determined by the amount of charge, and the amount of charge changes depending on the stirring and mixing conditions (especially the stirring and mixing time) when stirring and mixing the toner and carrier, so do not measure the amount of charge before stirring and mixing. , the amount of charge is adjusted to a predetermined amount. The change in charge amount due to stirring and mixing is as follows:
As shown in FIG. 1, the temperature rises rapidly after the start of stirring, reaches the saturation point, and then gradually falls.

<Invention or problem to be solved> Conventionally, the preferred range for the amount of charge is at the beginning of image formation.

It is set based on the image density at the initial stage and the presence or absence of toner scattering, and the preferred range is immediately after the charge amount is saturated.

However, with a developer having a charge amount immediately after saturation, the image density of the formed image is insufficient at the initial stage of image formation, and
When the image characteristics become stable after repeating 0 image formation approximately 00 times (hereinafter referred to as the "image formation stable period"), fogging, toner scattering, etc. may occur in the formed image, and the resolution may decrease. was there.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method for producing a starter developer that can always form a stable image from the initial stage of image formation to the stable period of image formation.

Means and Effects for Solving the Problems In order to solve the above problems, the present inventors investigated the causes of various image defects from various viewpoints, from the initial stage of image formation to the stable period of image formation. went.

As a result, the following became clear.

The toner concentration in the developer has a relationship with the output value of the sensor when the magnetic permeability of the developer is measured using a magnetic sensor, as shown by the solid line a in FIG. Toner concentration is estimated by measuring magnetic permeability with a sensor, and when the output value of the sensor exceeds a predetermined value, toner is automatically replenished.

However, as shown in Figure 2, the output value of the sensor corresponding to a predetermined toner concentration tends to gradually increase as the toner and carrier are stirred and mixed during the production of the start developer, and reaches the saturation point. Starting developer with a charge amount close to ,
Alternatively, if the starting developer is not sufficiently stirred and mixed before reaching the saturation point, the sensor output value corresponding to the toner concentration may not stabilize the image formation as shown by the two points gb in Fig. 3 in the early stage of image formation. There is a tendency for it to appear lower than the period (solid line a). Therefore, since the toner concentration is judged to be higher than the actual one, at the initial stage of image formation, the amount of toner corresponding to the consumed amount is not replenished, and as shown in FIG. The density decreases more than the level (indicated by the two-dot chain line in the figure), and the image density at the initial stage of image formation is insufficient.

This lack of image density at the initial stage of image formation is particularly noticeable in the starting developer, which has a high charge and is difficult to release carrier or toner, and whose charge is close to the saturation point.

In addition, the sensor output curve for the starting developer shown by the two-dot chain line in Figure 3 gradually increases as the developer is circulated and stirred within the developing device and as toner is replenished during image formation. and approaches solid line a. Therefore, during the rising phase of this sensor output curve, when the toner concentration decreases from Dl to D2, for example as shown by the white arrow in the figure, the sensor output value will not be shown by the two-dot chain line, but by the black arrow. It rises along the broken line C as shown in . Therefore, the difference between the sensor output values at both toner concentrations and D2 is detected as Δ■3, which is larger by Δ■2 than the actual value ΔV, so the lack of toner in the developer is greater than the actual value. The image is highlighted and a large amount of toner is replenished accordingly. Furthermore, due to the above stirring, the amount of charge on the developer tends to decrease along the curve shown in Figure 1, and as the amount of charge decreases, the carrier releases more toner, resulting in , a large amount of toner is ejected into the developing device, causing fog and toner scattering, resulting in a decrease in resolution.

Therefore, the present inventors further studied the relationship between the charge amount of the starting developer and stirring and mixing conditions and image defects, and as a result, completed the present invention.

Therefore, the method for producing the start developer of the present invention involves blending toner and carrier in a predetermined ratio, stirring and mixing the two.
When producing the starting developer of the component system, after the charge amount is saturated by stirring and mixing, stirring and mixing is continued to adjust the charge amount of the start developer to 65 to 90% of the saturated charge amount. There is.

In the production method of the present invention, after the charge amount is saturated by stirring and mixing, stirring is continued until the charge amount reaches 65 to 90% of the saturated charge amount for the following reason.

That is, the charge amount of the start developer is 90% of the saturation charge amount.
If the agitation and mixing is stopped before the toner and carrier drop to 0%, the agitation and mixing of the toner and carrier will be insufficient, resulting in insufficient image density at the initial stage of image formation for the reasons mentioned above, and the image formation will be delayed. During the stable period, fogging, toner scattering, etc. occur, resulting in a decrease in resolution.

On the other hand, the charge amount of the start developer is 65% of the saturation charge amount.
If the toner and carrier are stirred and mixed until the concentration decreases to less than
As shown by the two-dot chain line d in FIG.
It tends to appear higher than the solid line a). For this reason, the toner concentration is judged to be lower than it actually is, and more toner than is needed is supplied at the initial stage of image formation.Furthermore, as mentioned above, when the starting developer has a low charge amount, the carrier releases toner. As a result, fogging, toner scattering, etc. occur, and the resolution deteriorates.

Furthermore, the sensor output curve of the start developer shown by the two-dot chain line d is reversed from the previous case due to the developer being circulated and stirred in the developing device and the toner being replenished during image formation. gradually descends to approach solid line a. Therefore, in the descending period of this sensor output curve, when the toner concentration decreases from D3 to D4, for example, as shown by the white arrow in the figure, the sensor output value is not the two-dot chain line d, but the black line. It rises along the broken line e as shown by the arrow. Therefore, both toner concentrations D3. The difference between the sensor output values at D4 is ΔV less than the actual value Δv4.

Since Δv6 is detected to be as small as Δv6, it is determined that the amount of toner is insufficient or less than the actual amount, and an amount of toner corresponding to the consumed amount is not replenished, resulting in insufficient image density during the stable image formation period.

On the other hand, when the charge amount after saturation of the start developer is adjusted to 65 to 90% of the saturation charge amount, the sensor output value for toner density is almost constant from the initial stage of image formation to the stable stage of image formation. Therefore, the sensor can always accurately determine the toner concentration. Therefore, toner replenishment is performed accurately from the initial stage of image formation to the stable period of image formation, and the occurrence of the various image defects described above is prevented.

The method for producing a start developer of the present invention can be applied to start developers of various conventionally known combinations of toner and carrier.

Examples of the toner include colored particles having a particle size of about 10 M, which are prepared by blending additives such as a coloring agent, a charge control agent, and a mold release agent (offset prevention agent) in a binder resin.

As the binder resin, polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene- Vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer (
Styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-phenyl acrylate copolymer, etc.), styrene-methacrylate Acid ester copolymers (styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-phenyl methacrylate copolymer, etc.) Styrene-α-
Styrenic resins (homopolymers or copolymers containing styrene or styrene substitutes) such as methyl chloroacrylate copolymer, styrene-acrylonitrile-acrylic acid ester copolymer, polyvinyl chloride, low molecular weight polyethylene, low molecular weight Polypropylene, ethylene-ethyl acrylate copolymer, polyvinyl butyral, ethylene-vinyl acetate copolymer, rosin-modified maleic acid resin, phenol resin, epoxy resin, polyester resin, ionomer resin, polyurethane resin, silicone resin, ketone resin, xylene Examples include resins, polyamide resins, etc., and these may be used alone or in combination of two or more. Among these, styrene resins, particularly styrene-(meth)acrylate copolymers, are preferred.

Examples of the coloring agent include various colored pigments, extender pigments, conductive pigments, magnetic pigments, photoconductive pigments, and the like. These may be used singly or in combination of two or more depending on the purpose.

As the coloring pigment, the following are preferably used.

Furnace black, channel black, thermal,
Gas black, oil black, carbon black such as acetylene black, lamp black, aniline black.

White Zinc white, titanium oxide, antimony white, zinc sulfide.

Red Red Red Garla, Cadmium Red, Red Lead, Mercury Sulfide, Permanent Red 4R, Resolelet, Pyrazolone Red, Watching Red Calcium Salt, Lake Red D1
Brilliant Carmine 6B, Eosin Lake, Rhodamine Lake B1 Alizarin Lake, Brilliant Carmino 3B0 Orange Red Yellow Lead, Molybdenum Orange, Permanent Orange GTR, Pyrazolo Orange, Palkan Orange, Indanthrene Brilliant Orange RK1 Benzidine Orange G1 Indanthrene Brilliant Orange GK0 Yellow yellow lead, zinc white, cadmium yellow, yellow iron oxide, mineral fast yellow, Nirakera titanium yellow, navels yellow, naphthol yellow S1 Hansa Yellow G, Hansa Yellow 10G1 Benzidine Yellow G1 Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake.

Green chrome green, chromium oxide, pigment green B1
Malachite Green Lake, Final Yellow Green G0 Blue Navy Blue, Cobalt Blue Alkaline Blue Lake, Victoria Blue Lake, Phthalocyanine Blue Partial Chloride, First Sky Blue Indan Stremburu-BC
o Purple Manganese Purple, First Violet B, Methyl Violet Lake.

Examples of extender pigments include palite powder, barium carbonate, crane lica, white carbon, talc, and alumina white.

Examples of the conductive pigment include conductive carbon black and aluminum powder.

Magnetic pigments include various ferrites, such as triiron tetroxide (Feig4), iron sesquioxide (γ-Fe2O3), zinc iron oxide (ZTIFe204), iron yttrium oxide (Y3Fe15012), iron cadmium oxide (CdFe204) oxide, etc. Iron gadolinium (Gdi Fe504), iron oxide (CuFe20)
4), Iron oxide complex (PbFe 12019), Neodymium iron oxide (NdFeO3), Barium iron oxide (BaFe 12019), Magnesium iron oxide (1'bFe 204), Manganese iron oxide (11
nFe 20 < ) lanthanum iron oxide (LIFe O3
) Examples include iron powder, cobalt powder, nickel powder, etc.

Examples of photoconductive pigments include zinc oxide, selenium, cadmium sulfide, and cadmium selenide.

The colorant is used in an amount of 1 to 20 parts by weight, preferably 3 to 10 parts by weight, based on 100 parts by weight of the binder resin.

As the charge control agent, two types of charge control agents are used, one for positive charge control and one for negative charge control, depending on the polarity of the toner.

As a charge control agent for positive charge control, an organic compound having a basic nitrogen atom, such as a basic dye, aminopyrine,
Examples include pyrimidine compounds, polynuclear polyamino compounds, aminosilanes, and fillers surface-treated with the above compounds.

Examples of the charge control agent for negative charge control include compounds containing a carboxy group (for example, alkyl salicylic acid metal chelates, etc.), metal complex dyes, fatty acid soaps, naphthenic acid metal salts, and the like.

The charge control agent is used in an amount of 0.1 to 100 parts by weight of the binder resin.
It is used in a proportion of 10 parts by weight, preferably 0.5 to 8 parts by weight.

Examples of mold release agents (offset inhibitors) include aliphatic hydrocarbons, aliphatic metal salts, higher fatty acids, fatty acid esters or partially saponified products thereof, silicone oil, various waxes, and the like. Among them, those with a weight average molecular weight of 10
Aliphatic hydrocarbons having a molecular weight of about 00 to 10,000 are preferred.

Specifically, low molecular weight polypropylene, low molecular weight polyethylene, paraffin wax, low molecular weight olefin polymers consisting of olefin units having 4 or more carbon atoms, etc.
A species or a combination of two or more species are suitable.

The mold release agent is used in an amount of 0.1 to 10 parts by weight per 100 parts by weight of the binder resin.
It is used in proportions of 0.5 to 8 parts by weight, preferably 0.5 to 8 parts by weight.

The toner is prepared by pre-kneading the above components homogeneously using a dry blender, a Henschel mixer, a ball mill, etc.
It is produced by uniformly melting and kneading using a kneading device such as a axial or twin-screw extrusion kneader, and then cooling and pulverizing the obtained mixed material, and classifying as necessary.

The particle size of the toner is 5 to 35 μm, preferably 7 to 25 μm.
It is m.

Examples of carriers include particles of iron, oxidized iron, reduced iron, magnetite, copper, silicon steel, ferrite, nickel, cobalt, etc., particles of alloys of these materials with manganese, zinc, aluminum, etc., iron-nickel alloys, Particles such as iron-cobalt alloy, particles in which the above various particles are dispersed in a binder resin, titanium oxide, aluminum oxide, copper oxide, magnesium oxide, lead oxide, zirconium oxide, silicon carbide,
Ceramic particles such as magnesium titanate, barium titanate, lithium titanate, lead titanate, lead zirconate, lithium niobate, ammonium dihydrogen phosphate (
NH4H2PQ, ), potassium dihydrogen phosphate (KH2
Examples include particles of high dielectric constant substances such as PO4) and Rochelle salt. Among these, iron powder such as iron oxide and reduced iron, and ferrite are preferable because they have excellent image characteristics and are inexpensive.

In addition, the above-mentioned carrier can control the amount of charge and polarity of the toner,
A resin coating layer can also be formed on the surface for the purpose of improving humidity dependence, preventing filming, etc.

Examples of polymeric materials used for the resin coating layer include (meth)acrylic polymers, styrene polymers, and styrene-(
meth)acrylic copolymers, olefin polymers (polyethylene, chlorinated polyethylene, polypropylene, etc.),
Polyvinyl chloride, polycarbonate, polyester resin, unsaturated polyester resin, polyamide resin, polyurethane resin, epoxy resin, silicone resin, fluororesin (polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, etc.), phenolic resin, xylene resin, diallyl phthalate resin, etc. Among these, it is preferable to use a (meth)acrylic polymer, a styrene polymer, a styrene-(meth)acrylic copolymer, a silicone resin, or a fluororesin in terms of triboelectric charging properties with the toner and mechanical strength. . The above polymer materials may be used alone or in combination of two or more.

As a coating method for forming the resin coating layer made of the above-mentioned polymeric material on the surface of the carrier, any known method such as a fluidized bed method or a transfer calendar method can be employed.

The particle size of the carrier is 30 to 200 μm, preferably 50 to 200 μm.
About 130 yen is good.

The blending ratio of toner and carrier may be the same as before.

Further, in order to improve the fluidity of the start developer, a fluidizing agent such as colloidal silica may be further added to the toner and carrier.

Examples of mixing devices for carrying out the present invention include a Nauta mixer, a ball mill, and a type mixer.

The method for producing the start developer of the present invention is carried out by stirring and mixing the toner carrier and, if necessary, the fluidizing agent and the like using the above-mentioned mixing device while measuring the amount of charge. To measure the amount of charge, blow-off, etc.
A conventionally known charge amount measuring device can be used.

The amount of charge mainly depends on the stirring and mixing time as described above, but it also depends on other conditions such as the torque of the mixing device and the ambient temperature during stirring and mixing. For example, if the ambient temperature is high,
The amount of charge decreases. Therefore, in the present invention, by adjusting the conditions such as the torque and ambient temperature,
The stirring and mixing time can be shortened or conversely extended.

<Examples> The present invention will be described below based on Examples and Comparative Examples.

Examples 1 and 2, Comparative Example 3 Toner and carrier having the following composition were mixed at a weight ratio of 3.5:9.
6.5 and put into a Nauta mixer (trade name: NX-5, manufactured by Hosokawa Micron).

*Toner (center particle size: 10 kon) Styrene-acrylic copolymer: 100 parts by weight Carbon black 28.5 parts by weight Monoazo dye
2 parts by weight low molecular weight polypropylene
3 parts by weight *Carrier (center particle size 100 cape) Iron powder: 99.7 parts by weight Styrene
0.3 parts by weight of acrylic copolymer 2 Next, stirring and mixing was performed at an ambient temperature of 20° C. while measuring the amount of charge by blow-off, and after once the amount of charge was saturated, stirring and mixing was continued. A starting developer having the charge amount shown in Table 1 was manufactured. Note that the saturated charge amount during stirring and mixing was 28.0.

Comparative Example 1 A starter developer was produced in the same manner as in Examples 1 and 2 and Comparative Example 3, except that the stirring and mixing was completed before the charge amount was saturated.

Comparative Example 2 A starter developer was produced in the same manner as in Examples 1 and 2 and Comparative Example 3, except that the stirring and mixing was terminated immediately after the charge amount was saturated.

Examples 3 and 4, Comparative Example 6 Toner and carrier having the following composition were mixed at a weight ratio of 3.5:9.
6.5 and put into a Nauta mixer (trade name: NX-5, manufactured by Hosoka Micron Co., Ltd.).

*Toner (center particle size 1oμm) Styrene-acrylic copolymer; 9o parts by weight Permanent red = 5 parts by weight monoazo dye
: 5 parts by weight low molecular weight polypropylene :
2 parts by weight * Iron powder with a carrier center particle size of 100 μm Next, stirring and mixing was performed at an ambient temperature of 20°C while measuring the amount of charge by blow-off, and once the amount of charge was saturated, stirring and mixing was continued. A starting developer having the charge amount shown in Table 2 was produced. Note that the saturated charge amount during stirring and mixing was 31.0.

Comparative Example 4 A starter developer was produced in the same manner as in Examples 3 and 4 and Comparative Example 6, except that the stirring and mixing was completed before the charge amount was saturated.

Comparative Example 5 A starter developer was produced in the same manner as in Examples 3 and 4 and Comparative Example 6, except that the stirring and mixing was terminated immediately after the charge amount was saturated.

The following tests were conducted on the start developers obtained in each of the above Examples and Comparative Examples.

Sensor output measurement The above starting developer was used in an electrophotographic copying machine (model number DC-5585, manufactured by Sanda Kogyo Co., Ltd.), and the toner used in each example and comparative example was used as a replenishment toner. Continuous copying was performed. Then, at the initial stage of copying (when copying about 1 to 10 sheets), after 100,000 copies for Examples 1 and 2 and Comparative Examples 1 to 3, and after 5000 copies for Examples 3 and 4 and Comparative Examples 4 to 6. During the subsequent stable image formation period, an input voltage of 24 V was applied to the sensor attached to the developing device of the electrophotographic copying machine, and the output voltage (V) of the sensor was measured for a developer with a toner concentration of 3%.

Image Density Measurement Using the above-described starting developer in the same electrophotographic copying machine as described above, and using the toner used in each Example and Comparative Example as a replenishment toner, a black solid original was continuously copied. Then, a reflection densitometer (product name TC-6 manufactured by Tokyo Denshoku Co., Ltd.)
D) for the initial stage of copying (1st to 10th sheets), 100th sheet, and Examples 1 and 2 and Comparative Examples 1 to 3.
500 for the 10,000th sheet, Examples 3 and 4, and Comparative Examples 4 to 6
The density of the 0000th image was measured.

Fog Density Measurement Using the above starting developer in the same electrophotographic copying machine as above, and using the toner used in each Example and Comparative Example as a replenishment toner, black and white originals were continuously copied. Then, a reflection densitometer (product name TC-6D manufactured by Tokyo Denshoku Co., Ltd.)
) for the initial stage of copying (1st to 10th sheets), the 100,000th sheet for Examples 1 and 2 and Comparative Examples 1 to 3, and the 5,000,000th sheet for Examples 3 and 4 and Comparative Examples 4 to 6. The density of the margin part of the eye image was measured and used as the fog density.

Resolution measurement The above starting developer was used in the same electrophotographic copying machine as above, and the toner used in each example and comparative example was used as a replenishment toner to measure resolution in accordance with the provisions of JIS B7174-1962. Continuous copying of charts was carried out. The 100,000th sheet for Examples 1 and 2 and Comparative Examples 1 to 3, and the 50,000th sheet for Example 3°4 and Comparative Examples 4 to 6.
The resolution (book/screen) of the 00th image was determined.

Toner scattering test The margins of each copy image used for the resolution measurement above, 100,000 sheets for Examples 1.2 and Comparative Examples 1 to 3, and 100,000 sheets for Example 3.
, 4, and Comparative Examples 4 to 6, the inside of the copying machine was observed after 5000 copies were made. Cases in which toner scattering was hardly observed anywhere in the margins of the copied image or inside the copying machine were evaluated as O1; cases in which toner scattering was observed in at least one of the margins of the copied image and the interior of the copying machine were evaluated as ×. .

The above results are combined with data on the charge amount of each starting developer, as well as the ratio of the above charge amount to the saturated charge amount [charging ratio (
%)] are shown in Tables 1 and 2 together with the data.

As shown in the results of Comparative Example 1.4 in Tables 1 and 2 above, when stirring and mixing are completed before the charge amount is saturated, the charge amount is within the range of 65 to 90% of the saturated charge amount. However, due to insufficient stirring and mixing and low sensor output at the beginning of image formation, there is a large drop in image density after about 100 sheets from the start of image formation, and this is thought to be due to insufficient stirring and mixing. Fog occurs. In addition, since the sensor output increases significantly from the initial stage of image formation to the stable stage, fogging and toner scattering occur during the stable stage of image formation.
The resolution of the image during the stable period is poor.

As shown in the results of Comparative Example 2.5 in Tables 1 and 2 above, even when the stirring and mixing was terminated immediately after the charge amount was saturated, the stirring and mixing was still insufficient, and the image formation Because the initial sensor output is low, it takes 100 seconds from the start of image formation.
There is a significant drop in image density for approximately one sheet. Also,
Since the amount of charge is high, the image density at the initial stage of image formation is extremely low. Furthermore, since the sensor output increases significantly from the initial stage of image formation to the stable stage, fogging and toner scattering occur during the stable stage of image formation, and the resolution of the image during the stable stage is poor.

On the other hand, as shown in the results of Comparative Examples 3 and 6, if the stirring after the charge amount is saturated is not continued for a long time, the sensor output will decrease significantly from the initial stage of image formation to the stable stage. This results in a lack of concentration. Furthermore, since the amount of charge is low, fogging is observed at the initial stage of image formation.

On the other hand, in all of the start developers obtained in Examples 1 to 4, the sensor output was almost constant from the initial stage of image formation to the stable period, and stable image density was always obtained. High resolution without fogging or toner scattering. Therefore, according to the manufacturing method of the present invention, in which the charge amount is adjusted within the range of 65 to 90% of the saturated charge amount by stirring and mixing after the charge amount is saturated, the image is always stable from the initial stage of image formation to the stable period. It has been found that it is possible to obtain a stat developer capable of forming images.

<Effects of the Invention> Since the method for producing a start developer of the present invention is configured as described above, it is possible to produce a start developer that can always form a stable image from the initial stage of image formation to the stable period of image formation. becomes possible.

[Brief explanation of the drawing]

Figure 1 is a graph showing changes in the amount of charge due to stirring and mixing, Figure 2 is a graph showing changes in sensor output due to stirring and mixing,
3 and 4 are graphs showing the relationship between the toner concentration of the developer and the sensor output, and FIG. 5 is a graph showing the transition of the toner concentration accompanying continuous image formation.

Claims (1)

[Claims] 1. In the method of manufacturing a two-component start developer by blending toner and carrier in a predetermined ratio and stirring and mixing, after the amount of charge is saturated by stirring and mixing, stirring and mixing is continued to create a starting developer. The amount of charge is 65 to the saturation charge amount.
A method for producing a start developer, which comprises adjusting the starting developer to 90%.