JPH11295931A - Full color toner and method for forming full color image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide full color toner capable of preventing the void of a toner image or toner scattering at the time of primary and secondary transferring, and the image fog in a full color copy image from occurring, being excellent in transfer property, and reproducing the monochrome image being excellent in line reproducibility (ruggedness), half tone dot reproducing property (dot reproducing property) and the follow-up ability, even when loading on a copying machine served for full color also for monochrome, and copying by a monochrome version. SOLUTION: This full color toner is consisting of yellow toner, magneta toner, cyan toner and black toner, while respective average circularity of the yellow toner, the magneta toner and the cyan toner is smaller than that of the black toner, and the average circularity of every toner is respectively >=0.95, and a standard deviation of the circularity of the every toner is respectively <=0.040.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a full-color image forming apparatus such as a full-color copying machine and a full-color printer,
In particular, a full-color printing method in which a toner image formed on an image carrier is pressure-transferred onto an intermediate transfer body for each color, and then the toner image transferred on the intermediate transfer body is pressure-transferred onto a recording member The present invention relates to a full-color toner used in an image forming apparatus. The present invention also relates to a full-color image forming method using the full-color toner.

[0002]

2. Description of the Related Art Conventionally, an electrophotographic method in which an electrostatic latent image formed on a photoreceptor is developed using toner, and the obtained toner image is transferred onto a recording member such as recording paper to form an image. An image forming apparatus using a method, for example, a copying machine, a printer, a facsimile, etc., is widely used. Forming devices have become popular.

A full-color image forming method in these apparatuses will be outlined with reference to a full-color image forming apparatus shown in FIG. When forming a full-color image,
First, when the printing operation is started, the photosensitive drum 10
The intermediate transfer belt 40 is driven to rotate at the same peripheral speed, and the photosensitive drum 10 is charged to a predetermined potential by the charging brush 11.

Subsequently, exposure of the yellow image is performed by the laser scanning optical system 20, and an electrostatic latent image of the yellow image is formed on the photosensitive drum 10. This electrostatic latent image is immediately developed by the developing device 31Y, and the toner image is pressed and transferred onto the intermediate transfer belt 40 in the primary transfer section. Immediately after the completion of the primary transfer, the developing device 31M is switched to the developing unit D, and subsequently, exposure, development, and primary transfer of the magenta image are performed. Further, switching to the developing device 31C, exposure, development, and primary transfer of the cyan image are performed. Further, switching to the developing device 31Bk, exposure of the black image, development, and primary transfer are performed, and the toner image is superimposed on the intermediate transfer belt 40 for each primary transfer.

When the final primary transfer is completed, the recording sheet S is sent to the secondary transfer section, and the full-color toner image formed on the intermediate transfer belt 40 is pressed and transferred onto the recording sheet S. When the secondary transfer is completed, the recording sheet S is conveyed to the belt-type contact heating and fixing device 70, and the full-color toner image is fixed on the recording sheet S and discharged to the upper surface of the printer main body 1.

As a full-color toner, a toner composed of a yellow toner, a magenta toner, a cyan toner, and a black toner is used by being loaded into each developing device for each color. All toners have the same shape.

However, using the above-described full-color toner and full-color image forming apparatus, primary and secondary
At the time of the next transfer, the transferability deteriorates due to the temperature / humidity environment or the fluctuation of the transfer condition. There is a problem that image noise occurs. Further, in recent years, as the demand for full-color and monochrome dual-purpose copying machines has increased, high image quality has been demanded for monochrome images. In such a monochrome image, there is a problem that sufficient required performance cannot be satisfied particularly in image quality such as line reproducibility (radiosity) and halftone dot reproducibility (dot reproducibility).

In order to solve the above-mentioned problems, attempts have been made to define the conditions for setting the transfer process. However, all of the above-mentioned problems cannot be solved at the same time. Is a new problem.

[0009]

DISCLOSURE OF THE INVENTION The present invention relates to a toner image having a defect in a primary image and a secondary image during image transfer and toner scattering.
No image fogging in full-color copied images, excellent transferability, and mounted on full-color and monochrome dual-purpose copiers / printers. It is an object of the present invention to provide a full-color toner capable of reproducing a monochrome image excellent in dot performance (dot reproducibility) and followability.

The present invention is also excellent in transferability without causing voids or toner scattering in a toner image at the time of primary and secondary transfer, and image fogging in a full-color copy image, and is compatible with full-color and monochrome. To provide a full-color image forming method capable of reproducing a monochrome image with excellent line reproducibility (radiosity), halftone dot reproducibility (dot reproducibility), and followability even when copied in a monochrome version by adopting a copier. Aim.

[0011]

According to the present invention, there is provided a full-color toner comprising a yellow toner, a magenta toner, a cyan toner and a black toner, wherein the yellow toner, the magenta toner and the cyan toner each have an average circularity of the black toner. The present invention relates to a full-color toner, which is smaller than that, has an average circularity of all toners of 0.95 or more, and a standard deviation of circularity of 0.040 or less.

According to the present invention, the toner image formed on the image carrier is pressed and transferred onto the intermediate transfer member for each color, and then the toner image transferred on the intermediate transfer member is transferred to the intermediate transfer member. The present invention relates to a full-color image forming method including press-transfer onto a recording member, wherein the above-described full-color toner is used.

The inventors of the present invention pay attention to the average circularity of the toner constituting the full-color toner, and set the average circularity of each of the yellow toner, magenta toner, cyan toner (hereinafter referred to as color toner) and black toner to 0. .95 or more, and the average circularity of the black toner is larger than the average circularity of the color toner. It has been found that it is possible to provide a full-color toner and a full-color image forming method which are excellent in transferability and do not cause image fogging or the like. Further, it has been found that, by defining the standard deviation of the circularity and suppressing the variation in the shape of each toner particle, excellent durability can be obtained without adversely affecting the copied image even by repeated copying. Further, the full-color toner of the present invention is mounted on a full-color and monochrome dual-purpose copying machine / printer (hereinafter, simply referred to as a dual-purpose copying machine). It was also found that a monochrome image with excellent characteristics (dot reproducibility) and excellent tracking ability can be reproduced.

As used herein, "full color toner" refers to a plurality of combined toners selected to be loaded into each developing device when forming a full color image. The “average circularity of the toner” means the average circularity of the toner particles contained in the toner.

In the present specification, the average circularity is represented by the following formula:

(Equation 1) The “perimeter of a circle equal to the projected area of a particle” and the “perimeter of a projected particle image” are flow particle image analyzers (FPIA-1000 or FIA).
PIA-2000; manufactured by Toa Medical Electronics Co., Ltd.) in an aqueous dispersion system. As described above, in the present invention, the average circularity is obtained from the “perimeter of a circle equal to the projected area of the particle” and the “perimeter of the projected image of the particle”. It is an indicator that accurately reflects the state. Further, since the value obtained by the above-mentioned analyzer is a value obtained as an average value of several thousand pieces, the reliability of the average circularity in the present invention is extremely high. In the present specification, the average circularity does not necessarily have to be measured by the above-described device, but may be measured by any device that can be determined in principle based on the above equation. The standard deviation of the circularity refers to the standard deviation in the circularity distribution, and the value is obtained simultaneously with the average circularity by the flow type particle image analyzer. The smaller the value is, the more uniform the toner particle shape is.

The full-color toner of the present invention comprises a yellow toner, a magenta toner, a cyan toner, and a black toner. The average circularity of the yellow toner, the magenta toner, and the cyan toner is smaller than that of the black toner. That is, the toner particles of the yellow toner, the magenta toner, and the cyan toner have lower sphericity than the toner particles of the black toner. In the present invention, if the average circularity of the black toner is smaller than the average circularity of the color toner, image fogging occurs during printing, causing a problem in transferability, or when copying in a monochrome version using a dual-purpose copying machine. The image quality of line reproducibility (radiosity) and halftone reproducibility (dot reproducibility) becomes insufficient. In addition, there is a problem in followability during durability.

In the present invention, the average circularity of the yellow toner, magenta toner and cyan toner is 0.95 to 0.95.
0.99, preferably 0.96 to 0.98. If it is less than 0.95, hollowing and scattering easily occur as described above, and image noise may be generated. When the value exceeds 0.99, the organic pigment generally used for color toners has relatively high electric resistance. If the average circularity of the color toner is too high, sufficient charging will not be performed, and the charging property, particularly the charging rise property, will decrease. However, problems such as fogging may occur. On the other hand, the average circularity of the black toner is 0.96 to 1.00, preferably 0.1 to 1.00.
It is desirable to be 97-1.00. If it is less than 0.96, the image quality such as fine line reproducibility deteriorates.
A monochrome image having excellent line reproducibility (radiusness) and halftone dot reproducibility (dot reproducibility) cannot be reproduced.

In the full-color toner of the present invention, the standard deviation of the circularity of all the toners is 0.040 or less, preferably 0.35 or less. In a full-color toner composed of a combination of a color toner and a black toner, if the standard deviation of the circularity exceeds 0.040, the durability is reduced and the effect of the present invention cannot be obtained.

As described above, in the present invention, since the average circularity of several thousand or more arbitrary toner particles, which is obtained by the equation accurately reflecting the toner particle shape, is defined together with the standard deviation of the circularity. The full-color toner of the present invention is
Each color has a desired shape without variation. Such a variation (non-uniformity) in the shape of the toner particles results in various characteristics of the toner, for example, non-uniform charging, selective development / consumption from a toner of a certain shape, and the like, resulting in poor durability. It is thought to have a significant effect.

In the full-color toner of the present invention, the volume average particle diameter of each toner is 2 to 10 μm, preferably 5 to 9 μm. More preferably, the volume average particle diameter of the black toner is smaller than the volume average particle diameter of the color toner. When all toner particle sizes are reduced,
Although it is relatively difficult to control the reliability and stability during durability, making the particle size of the black toner smaller than that of the color toner not only improves the balance of the overall full-color image quality, but also copies in a monochrome version. In this case, the image quality of the monochrome image is significantly improved. In the present invention, the volume average particle diameter of the color toner is 6 to 9 μm, preferably 6.5 to 8.5 μm, and the volume average particle diameter of the black toner is 5 to 8 μm, preferably 5.5 to 7.5 μm. Are suitable.

Further, the toner preferably used in the present invention has a content of not less than 1% by weight, preferably not more than 0.5% by weight, at least twice (2D) the volume average particle diameter (D),
In addition, the content ratio of 1/3 (D / 3) or less of the volume average particle diameter (D) is 5% by number or less, preferably 3% by number or less.
If the content of 2D or more exceeds 1% by weight or the content of D / 3 or less exceeds 5% by number, the effect of the present invention is hardly obtained. In the present specification, the measurement of the toner particle diameter is a value measured using a Coulter Multisizer (manufactured by Coulter Counter Co., Ltd.) with an aperture diameter of 50 μm.

The above-described full-color toner (including black toner) of the present invention containing at least a binder resin and a colorant can be produced by a conventionally known dry method or wet method. As a dry method,
After kneading, a kneading and pulverizing method of pulverizing to obtain toner particles is mentioned. As a wet method, toner particles are obtained by granulating in water or a mixed medium of water and a water-soluble organic solvent, followed by drying. Known methods include, for example, an emulsion dispersion granulation method, a suspension polymerization method, an emulsion polymerization method, and an encapsulation method. Among these production methods, it is preferable to produce by a kneading / pulverization method from the viewpoint of production cost and production stability, and from a viewpoint of controllability of the average circularity, a kneading / pulverization method, an emulsion dispersion granulation method, It is preferable to control the shape of the toner obtained by these methods, such as suspension polymerization and emulsion polymerization, by mechanical impact force, heat energy, and the like.

The kneading and pulverizing method includes a step of mixing a binder resin, a colorant and other desired additives with a mixer such as a Henschel mixer, a step of melting and kneading the mixture, and a step of cooling and kneading the kneaded material. The toner particles are manufactured by the following steps: a step of pulverizing the coarsely pulverized particles; and a step of classifying the obtained finely pulverized particles.

After the toner particles are manufactured by the above-described kneading and pulverizing method, any means can be used to control the average circularity of the toner particles within the above range, as long as the average circularity is controlled within the above range. After the coarse pulverization step, the fine pulverization step, or the fine particle classification step, a surface reforming apparatus, for example, a hybridization system (manufactured by Nara Machinery Co., Ltd.) using a high-speed airflow impact method, a cosmos system (Kawasaki Heavy Industries, Ltd.) ), An innomizer system (manufactured by Hosokawa Micron) and a turbo mill (manufactured by Turbo Kogyo), a mechanofusion system (manufactured by Hosokawa Micron) using a dry mechanochemical method, and a mechanomill (manufactured by Okada Seiko), a hot air stream reforming method System (made by Nippon Pneumatic Industries, Ltd.) and heat treatment equipment (Manufactured by Hosokawa Micron Corporation), and Disperbyk-coated (Nisshin Engineering Co., Ltd.) was applied wet coating method and coating miser (manufactured by Freund Corporation) is preferably subjected to surface modification treatment by like.

Among the above-mentioned surface reforming apparatuses, a surf fusing system (manufactured by Nippon Pneumatic Co., Ltd.) is most preferable in that the degree of circularity can be largely controlled for this purpose. Hereinafter, description will be made with reference to FIG. As shown in FIG. 1, high-temperature and high-pressure air generated by a hot-air generator 101 is injected from a hot-air injection nozzle 106 through an introduction pipe 102. On the other hand, the toner particles (sample) 105 to be subjected to the surface modification treatment are conveyed by a predetermined amount of pressurized air from the quantitative supply device 104 through the introduction pipe 102 ′, and the sample injection nozzle provided around the hot air injection nozzle 106. It is injected into the hot air flow from 107. In this case, the sample injection nozzle 107
It is preferable that the sample injection nozzle 107 be provided with a predetermined inclination with respect to the hot air injection nozzle 106 so that the jet flow of the hot air does not cross the hot air flow. Also, the sample injection nozzle 1
07 may be one or more, but it is desirable to equip three or more, preferably four or more from the viewpoints of productivity and uniform surface treatment of the shape. From the viewpoint, a ring-shaped nozzle provided with a slit portion may be provided, and the sample may be jetted from the entire peripheral region.

When the sample is jetted, the sample is supplied uniformly and at a low concentration in order to avoid the occurrence of agglomerated particles by locally increasing the dispersion concentration of the toner particles and causing the toner particles to collide with each other. Although it depends on the ejection speed of the sample from the viewpoint of the ejection angle,
It is preferable to set the angle to 5 ° or less, preferably 25 to 35 °. If it exceeds 45 °, the toner jet flow will be jetted across the hot air flow, and will collide with the toner particles jetted from other nozzles, causing aggregation of the toner particles, making uniform processing difficult, As a result, the toner particle shape tends to vary. When a plurality of sample ejection nozzles are used, toner is ejected from each of the sample ejection nozzles at the above-mentioned predetermined inclination toward the center of the hot air flow, and the toner particles collide with each other at an appropriate force at the center of the hot air flow. It is preferable that the toner particles are sufficiently dispersed in a hot air flow, and the heat treatment is performed uniformly for each toner particle. The toner particles thus ejected are instantaneously brought into contact with high-temperature hot air, and are uniformly subjected to a surface modification treatment.

Next, the toner particles subjected to the surface modification treatment are as follows:
Immediately, it is rapidly cooled by cold air introduced from the cooling air introduction unit 108. By such rapid cooling, adhesion to the device wall and aggregation of toner particles are eliminated, and the yield is improved. Next, the toner particles are collected by the cyclone 109 through the introduction pipe 102 "and accumulated in the product tank 111. The carrier air after the collection of the toner particles is further supplied to the bag filter 112.
After the fine powder is removed by passing through, the air is discharged to the atmosphere via a blower 113. The cyclone 109 is provided with a cooling jacket 110 that circulates cooling water (110a and 110b), and cools the toner particles in the cyclone with the cooling water to prevent aggregation.

As described above, it is preferable to add a fluidizing agent before controlling the shape for the purpose of controlling the shape of the toner particles without variation. As a result, the dispersibility of the toner particles during processing is improved, and it is possible to suppress the variation in the shape, and to improve the charging stability and environmental stability of the toner, and further, to improve the transferability and development characteristics of the toner (fog resistance). ) Can be improved. The addition amount is suitably from 0.1 to 6 parts by weight, preferably from 0.3 to 3 parts by weight, based on 100 parts by weight of the toner particles. The fluidizer described below can be used as the fluidizer.

For example, the average circularity obtained by a known kneading and pulverizing method is 0.92 to 0.95, and the particle size is 2 to 10 μm.
The fine particles of a degree are treated by the above surfing system at a processing temperature of 100 to 500 ° C., a residence time of 0.1 to 3 seconds, a powder dispersion concentration of 10 to 200 g / m ³ , and a cooling air temperature of 0 to 50.
℃, cooling water temperature -10 ~ 25 ℃ When surface modification treatment, average circularity 0.93 ~ 1.00, volume average particle size 2 ~ 10μ
m of toner particles are obtained.

After the toner fine particles are obtained by the above-mentioned kneading and pulverizing method, the above-mentioned particle size is obtained irrespective of whether the surface modification treatment is performed by the above-mentioned surface modification device or the like. In order to achieve the distribution, if necessary, a rotor classifier (Tiplex classifier type: 100 ATP;
It is desirable to classify using a classifier such as Hosokawa Micron Corporation, a DS classifier (Nippon Pneumatic), an elbow jet classifier (Nippon Steel Mining), or the like.

In the present invention, the toner particles can be produced by an emulsion dispersion granulation method. First, a coloring resin solution is prepared by dissolving or dispersing a toner component (for example, a binder resin, a colorant, and other desired additives) in a water-insoluble organic solvent. The solid content concentration in the colored resin solution is determined by heating an O / W emulsion obtained by emulsifying and dispersing the colored resin solution in water or a mixed medium of water and a water-soluble organic solvent (hereinafter, simply referred to as an aqueous medium). When removing the water-insoluble organic solvent from the droplets, the amount is preferably 5 to 50% by weight, and more preferably 10 to 40% by weight so that the droplets can be easily solidified into fine particles.

Next, the colored resin solution is emulsified and dispersed in an aqueous medium to form an O / W emulsion. O / W
In order to form a type emulsion, the above-mentioned colored resin solution is added to an aqueous medium, and droplets of the colored resin solution are dispersed in the aqueous medium, or a phase inversion is performed by adding the aqueous medium to the colored resin solution. And a method of dispersing droplets of the colored resin solution in an aqueous medium can be employed. In addition to this method, a microporous material is used, and a colored resin solution (dispersed phase) is dispersed in an aqueous medium (continuous phase) from the pores of the microporous material to form an O / W emulsion. Is also good.

In order to form a stable O / W emulsion, the ratio (Vp / Vw) of the volume (Vp) of the colored resin solution to the volume (Vw) of the aqueous medium in the O / W emulsion is Vp / Vw ≦ 1, preferably 0.3
It is desirable that ≦ Vp / Vw ≦ 0.7.

Examples of the aqueous medium used to form the O / W emulsion include water and those containing water and a water-soluble organic solvent that does not destroy the emulsion.
Water / methanol mixture (weight ratio 50 / 50-100 /
0), water / ethanol mixture (weight ratio 50 / 50-100
/ 0), water / acetone mixture (50 / 50-100 /
0), water / methyl ethyl ketone mixed solution (weight ratio 70/30)
１００100/0) can be used.

It is preferable to add an appropriate dispersion stabilizer to such an aqueous medium. For example, polyvinyl alcohol, gelatin, gum arabic, methylcellulose, ethylcellulose, methylhydroxypropylcellulose, sodium salt of carboxymethylcellulose, sodium dodecylbenzenesulfonate, sodium dodecylbenzenesulfonate, sodium octylsulfate, sodium laurate, calcium phosphate, magnesium phosphate, Aluminum phosphate, calcium carbonate, magnesium carbonate,
Barium sulfate, bentonite and the like can be mentioned, and these dispersion stabilizers can be used in an amount of 0.05 to 3% by weight.

In order to improve the dispersion stability of the droplets, a dispersion stabilizer may be used together with the dispersion stabilizer. Examples of the dispersion stabilizing aid include natural surfactants such as saponin, nonionic surfactants such as alkylene oxide, glycerin, and glycidol, carboxylic acid, sulfonic acid, phosphoric acid, sulfate group, and phosphate group. And an anionic surfactant containing an acidic group. In particular, anionic surfactants such as sodium dodecylbenzenesulfonate and sodium lauryl sulfate are preferred.

In the emulsification dispersion granulation method, the O / W emulsion is heated with stirring to remove the water-insoluble organic solvent, whereby the colored resin particles having a predetermined particle size are dispersed in the aqueous medium. Obtain a suspension. Thereafter, the aqueous medium is removed by filtration or the like to isolate the colored resin particles, washed and dried, and if necessary, classified to obtain toner particles. In addition, a method of spraying an O / W emulsion in a dry atmosphere, completely removing the water-insoluble organic solvent in the droplets, forming colored resin fine particles, and evaporating and removing the aqueous medium is used. You may. In addition, when a thing insoluble in water, such as calcium phosphate, is used as the dispersion stabilizer, it may be removed by dissolving it with an acid such as hydrochloric acid. The toner particles produced by the emulsification-dispersion granulation method as described above usually have a spherical shape as compared with the toner particles produced by the conventional kneading and pulverizing method, but further have a desired average circularity and circularity. May be subjected to a surface modification treatment to achieve a standard deviation.

The binder resin in the toner particles produced by the above method is not particularly limited, and may be, for example, a styrene resin, an acrylic resin,
Styrene-acrylic resin, polyamide-based resin, polyester-based resin, polyurethane-based resin, epoxy-based resin and other known resins can be used alone or in combination, and a suitable one is appropriately selected according to the application. And use it. For example, when preparing a color toner, it is preferable to use a polyester resin, and when preparing a black toner, it is preferable to use a polyester resin, a styrene-acrylic resin, or a combination thereof. The polyester resin useful for both the color toner and the black toner in the present invention includes the above-mentioned image characteristics such as hollow, scatter and fog, toner transferability, fixing properties including OHP translucency, cleaning properties and cleaning properties. It is most preferable from the viewpoint of durability.

The kneading and pulverizing method and the emulsification dispersion granulation method as described above are characterized in that there are many types of resins that can be used as compared with the suspension polymerization method and the like. That is, in the suspension polymerization method, since the polymerizable monomer is limited to a vinyl-based monomer, the obtained resin is also limited to a vinyl-based resin. In the emulsification dispersion granulation method, any resin can be used as long as it can be dissolved in a water-insoluble organic solvent to some extent. Not only vinyl resins but also polyesters and epoxy resins which cannot be produced by the suspension polymerization method, for example. Can also be used.

In the present invention, a preferred polyester resin comprises a bisphenol A alkylene oxide adduct as an alcohol component as a main component, and a phthalic dicarboxylic acid or a phthalic dicarboxylic acid and an aliphatic dicarboxylic acid as an acid component. It is synthesized by a polycondensation reaction.

As the bisphenol A alkylene oxide adduct, bisphenol A propylene oxide adduct and bisphenol A ethylene oxide adduct are suitable, and it is preferable to use a mixture of these.

As the alcohol component, the following diols or polyhydric alcohols may be used together with the bisphenol A alkylene oxide adduct. Such alcohol components include, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2
Diols such as propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, didiol Pentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, Trimethylolpropane, 1,3,
5-trihydroxymethylbenzene and the like.

Examples of the phthalic dicarboxylic acids include phthalic dicarboxylic acids such as terephthalic acid and isophthalic acid;
The acid anhydride or the lower alkyl ester thereof can be used.

The aliphatic dicarboxylic acids usable together with the phthalic dicarboxylic acids include aliphatic dicarboxylic acids such as fumaric acid, maleic acid, succinic acid, alkyl or alkenyl succinic acids having 4 to 18 carbon atoms, and acids thereof. Examples thereof include anhydrides and lower alkyl esters thereof.

In order to improve the dispersibility of the colorant in the binder resin, the binder resin should be 1.0 to 3
0.0 KOHmg / g, preferably 1.0 to 25.0 KO
Hmg / g, more preferably 2.0 to 20.0 KOHmg / g
It is desirable to have an acid value of This has an acid value of 1.0K
This is because if it is less than OH mg / g, the effect of improving the dispersibility is small, and if it is more than 30.0 KOH mg / g, the change in the charge amount due to environmental fluctuations is large.

In order to adjust the acid value of the binder resin,
A small amount of a polycarboxylic acid such as trimellitic acid may be used as long as the transparency of the toner is not impaired. Examples of such a polyvalent carboxylic acid component include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 2,4-naphthalenetricarboxylic acid, 1,2,
4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-
Methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, anhydrides thereof, lower alkyl esters and the like. Can be.

The binder resin used for the color toner particles in the present invention has a glass transition point of 50 to 75 ° C.
Preferably 55-70 ° C, softening point 80-120 ° C, preferably 90-118 ° C, number average molecular weight 2000-1.
2000, preferably 2500 to 5500, and a weight average molecular weight / number average molecular weight of 2 to 8, preferably 3 to 7. When the glass transition point is lowered, the heat resistance storage stability of the toner is lowered, and when the glass transition point is raised, the light transmittance and the color mixing property are lowered.
When the number average molecular weight is small, the toner is easily peeled off when the image is bent, and when the number average molecular weight is large, the fixing strength is reduced. When the weight average molecular weight / number average molecular weight is small, the glossiness is too high, and when the weight average molecular weight / number average molecular weight is large, the light transmittance is reduced.

When an oilless fixing toner is intended, the glass transition point is 50 to 75 ° C. and the softening point is 80 to 1
It is preferable to use a resin having a number average molecular weight of 1,000 to 10,000 and a weight average molecular weight / number average molecular weight of 30 to 100 at 60 ° C.

In the present invention, the toner particles can be produced by a suspension polymerization method. A polymerization composition containing a polymerizable monomer capable of forming a binder resin, a polymerization initiator, a colorant and other desired additives is suspended in water or a mixed medium of water and a water-soluble organic solvent (aqueous medium). The toner particles are produced by turbidity, polymerization, and granulation, followed by removal of the medium and drying. As the aqueous medium, those similar to the aqueous medium used in the above emulsification-dispersion granulation method can be used. In the present invention, the black toner is preferably produced by the suspension polymerization method. This is because it is advantageous to use a suspension polymerization method as a method for producing a spherical toner having a small particle diameter.

The following are examples of the polymerizable monomer used in the suspension polymerization method, and these can be used alone or in combination of two or more. Styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, p-tert-butylstyrene, p-phenylstyrene, o-chlorostyrene, m-chlorostyrene, p Styrene monomers such as chlorostyrene; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, stearyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, methacryl Propyl acid,
Acrylic or methacrylic monomers such as n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate; ethylene, propylene, butylene, vinyl chloride, vinyl acetate , Acrylonitrile.

The polymerizable monomer is subjected to suspension polymerization, and the resulting colored spherical fine particles are treated with warm water to remove contaminants such as a dispersant and a surfactant. Here, the warm water treatment means washing with warm water of 30 ° C to 70 ° C.

In the black toner, a gelling component may be contained by using a crosslinking agent. As the crosslinking agent, for example, aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, derivatives thereof, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, trimethylolpropane triacrylate, allyl methacrylate, t All of diethylenically unsaturated carboxylic acid esters such as butylaminoethyl methacrylate, tetraethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, N, N-divinylaniline, divinyl ether, divinyl sulfide and divinyl sulfonic acid; Examples include divinyl compounds and compounds having three or more vinyl groups. Further, polybutadiene, polyisoprene, unsaturated polyester, chlorosulfonated polyolefin and the like are also effective.

The toner particles produced by the suspension polymerization method generally have a spherical shape as compared with the toner particles produced by the kneading / pulverizing method. It may be subjected to a surface modification treatment to achieve circularity and circularity standard deviation.

As the colorant used in the full-color toner of the present invention produced by the above-described various known methods, various known colorants such as magenta, cyan, yellow, and black can be used. Can be used.
Examples of the magenta colorant include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1
1, 12, 13, 14, 15, 16, 17, 18, 1
9, 21, 22, 23, 30, 31, 32, 37, 3
8, 39, 40, 41, 48, 49, 50, 51, 5
2, 53, 54, 55, 57, 58, 60, 63, 6
4, 68, 81, 83, 87, 88, 89, 90, 11
2, 114, 122, 123, 163, 184, 20
Magenta pigments such as 2,206,207,209 and C.I.
I. Solvent Red 1, 3, 8, 23, 24, 25,
27, 30, 49, 81, 82, 83, 84, 100,
109, 121, C.I. I. Disperse Red 9, C.I.
I. Basic Red 1, 2, 9, 12, 13, 14,
15, 17, 18, 22, 23, 24, 27, 29, 3,
Magenta dyes such as 2, 34, 35, 36, 37, 38, 39, 40, etc. can be used.

Further, as the cyan coloring agent, for example,
C. I. For example, cyan pigments such as CI Pigment Blue 2, 3, 15, 16, 17 and the like can be used. Examples of the yellow colorant include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 1
3, 14, 15, 16, 17, 23, 65, 73, 8
3, 180, 185, C.I. I. Bat Yellow 1, 3,
Yellow pigments such as C.20 and the like; I. Yellow dyes such as Solvent Yellow 79 and 162 can be used.

As the black colorant, for example, magnetic particles of magnetite, iron and ferrite can be used alone or in combination in addition to carbon black, titanium black, activated carbon and the like. When it is intended to reproduce a line diagram image of a character or the like, an image having no gloss (glossiness) is often preferred, and when the purpose is to reproduce an image having various shades of each color such as a photographic image, Those having gloss (glossiness) are often preferred.

When a pigment is used as a colorant, the colorant is melted and kneaded with a small amount of a binder resin and pulverized to improve the dispersibility in the toner particles. It is preferably used in the form of a masterbatch dispersed in a resin. The weight ratio of the resin and the coloring agent during the production of the master batch is 80:20.
~ 50: 50 is appropriate.

The amount of the colorant used may be the same as that used in the prior art, and is usually 2 to 8 parts by weight, preferably 2 to 5 parts by weight for a color toner with respect to 100 parts by weight of a binder resin. Parts, 4 to 15 for black toner
Parts by weight, preferably 5 to 12 parts by weight. In addition,
When the colorant is used in the form of a masterbatch, the colorant may be used such that the content of the colorant with respect to 100 parts by weight of the binder resin to which the resin component in the masterbatch is added is within the above range.

When carbon black is used as the coloring agent, for example, carbon black obtained by graft polymerization of carbon black and a resin (polymer) is used for the purpose of improving the dispersibility of carbon black in the toner particles. A method using a graft polymer, a method using carbon black in which dispersed particles are reduced by wet pulverization in the presence of a resin component, A method using a master batch-treated carbon black having a small dispersed particle size can be adopted. Among these methods, it is most preferable to use a carbon black graft polymer from the viewpoint of carbon black dispersion uniformity.

In order to obtain a carbon black graft polymer, a functional group (for example, -O
H, -COOH,> C = O, etc.). As the polymer that can react with carbon black, any polymer can be used without particular limitation as long as it has a reactive group that can easily react with a functional group present on the surface of carbon black. Examples of the reactive group that can easily react with a functional group present on the surface of carbon black include an aziridine group, an oxazoline group, an N-hydroxyalkylamide group, an epoxy group, a thioepoxy group, an isocyanate group,
Examples thereof include a vinyl group, a silicon-based hydrolyzable group, and an amino group.

Examples of the polymer having reactivity with carbon black as described above include vinyl polymers, polyesters and polyethers having at least one reactive group in the molecule. Although the molecular weight of the polymer having reactivity is not particularly limited, the number average molecular weight is 500 to 1,000, in terms of a remarkable treatment effect on carbon black and workability at the time of reaction with carbon black.
000, more preferably 1,
000-500,000, most preferably 2,000-1
It is in the range of 00,000. The reactive group has an average of 1
It must have at least one in the molecule, but the greater the amount of the reactive group, the worse the dispersibility of the carbon black graft polymer in other substances becomes,
The average is preferably 1 to 5, more preferably 1 to 2, and most preferably 1 in one molecule.

In order to obtain such a polymer having reactivity with carbon black, for example, the above-mentioned polymerizable monomer having a reactive group in the molecule is optionally polymerized with other polymerizable monomers according to a known procedure. Or a method of reacting a compound having a reactive group in a molecule with a polymer having a group capable of reacting with the compound can be appropriately adopted. In the present invention, in terms of reactivity with functional groups present on the surface of carbon black, aziridine group,
It is preferable to use a polymer having one or more selected from oxazoline group, N-hydroxyalkylamide group, epoxy group, thioepoxy group and isocyanate group as a reactive group, more preferably an aziridine group, an oxazoline group and an epoxy group. It is a polymer having one or more selected from groups as a reactive group, and most preferably a polymer having at least one reactive group selected from the group consisting of an aziridine group and an oxazoline group. Further, when the toner particles are produced by the above suspension polymerization method, a vinyl polymer having these reactive groups is used in consideration of the affinity when the carbon black graft polymer is dispersed in the polymerizable monomer. Is particularly preferred.

When graft polymerizing a polymer having reactivity with carbon black and carbon black, 5-500 parts by weight of carbon black is added to 100 parts by weight of the above polymer in a prepared solvent, and 80 to 200 parts by weight is added.
It can be easily obtained by holding at 0 ° C. with stirring.

The carbon black graft polymer thus obtained can be used in various methods for producing toner particles, such as the above-mentioned kneading / pulverizing method, emulsion dispersion granulation method, suspension polymerization method and the like. This is particularly effective when toner particles are produced by a suspension polymerization method. The amount of the carbon black graft polymer used is not particularly limited as long as the content of the carbon black contained in the carbon black graft polymer is used so as to fall within the range of the use amount of the coloring agent. 4 to 15 parts by weight per 100 parts by weight of the resin is suitable. When the amount is less than 4 parts by weight, sufficient coloring power cannot be obtained, and when the amount is more than 15 parts by weight, carbon black cannot be stably taken into the toner, and the chargeability of the toner becomes unstable. Absent. When the carbon black graft polymer is used, the dispersibility of the carbon black in the toner is improved, so that the carbon black graft polymer can be used even when 10 to 20 parts by weight of carbon black is added at a high concentration. The coloring power of the particles can be improved, and the amount of toner required for obtaining a predetermined image density can be reduced.

The toner particles of the present invention may contain, in addition to the above-mentioned colorants, desired additives such as a charge control agent and an anti-offset agent.

As the charge control agent, a zinc salicylate complex or the like and other known charge control agents can be used.
The type may be selected according to the purpose of use. For color image copying, it is preferable to use a colorless, white or pale yellow charge control agent. There is no particular limitation for black copy. The amount of the charge control agent may be appropriately set according to the purpose of use, but is usually 0.1 to 10 parts by weight, preferably 0.5 to 5.0 parts by weight based on 100 parts by weight of the binder resin. Used in the range.

The anti-offset agent is not particularly limited. For example, polyethylene wax, oxidized polyethylene wax, polypropylene wax,
Oxidized polypropylene wax, carnauba wax, sasol wax, rice wax, candelilla wax, jojoba oil wax, beeswax, and the like can be used. This is a developing device (at the time of primary transfer) for developing an electrostatic latent image as well as improving the offset resistance.
In this case, the problem of toner sticking to the toner regulating blade and the developing sleeve can be reduced. Especially,
It is preferable to use a wax having an acid value of 0.5 to 30 KOH mg / g from the viewpoint of dispersibility in a binder resin having the above acid value. The amount of the wax added is 0.5 to 5 parts by weight based on 100 parts by weight of the binder resin.
Preferably 1 to 3 parts by weight is preferred.

In the full-color toner of the present invention, toner particles containing the above-mentioned binder resin, colorant, and desired additives such as a charge control agent and an anti-offset agent are respectively added to improve the fluidity. It is preferable to externally add a fluidizing agent. As a fluidizing agent, silicon carbide, boron carbide, titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, tantalum carbide, niobium carbide, tungsten carbide, chromium carbide, molybdenum carbide,
Various carbides such as calcium carbide and diamond carbon lactam, various nitrides such as boron nitride, titanium nitride and zirconium nitride, borides such as zirconium boride, iron oxide, chromium oxide, titanium oxide, calcium oxide, magnesium oxide and zinc oxide , Copper oxide, aluminum oxide,
Silica, colloidal silica, strontium titanate,
Various oxides such as magnesium titanate, sulfides such as molybdenum disulfide, fluorides such as magnesium fluoride and carbon fluoride, various metal soaps such as aluminum stearate, calcium stearate, zinc stearate and magnesium stearate, and talc And various non-magnetic inorganic fine particles such as bentonite can be used alone or in combination.

Further, these fine particles may be used in combination with a conventionally used hydrophobizing agent such as a silane coupling agent, a titanate coupling agent, a silicone oil, a silicone varnish, or a fluorine silane coupling agent or a fluorine silane coupling agent. The surface treatment is preferably performed by a known method using a treating agent such as a silicone oil, a coupling agent containing an amino group / quaternary ammonium salt, or a modified silicone oil.

It is preferable to use two or more fluidizing agents having different particle diameters from the viewpoint of stabilization of toner durability charging. Further, it is more preferable to use a fluidizing agent having a distribution in a necessary particle size region. That is, by adding particles having a relatively small particle diameter (for example, hydrophobic silica having a BET specific surface area of 130 m ² / g or more), the fluidity of the toner is improved (control of physical properties such as loose apparent specific gravity) and comparison. Large particles (for example,
Hydrophobic silica having a BET specific surface area of less than 130 m ² / g,
By adding titanium oxide, zinc oxide, strontium titanate) or the like, it is possible to control the cohesiveness of toner particles (the physical property control such as apparent specific gravity). Particularly, in order to improve the durability, it is preferable to add large-diameter particles. By using such a fluidizer,
The fluidity of the toner can be stably maintained from the beginning to the end of the life.

An appropriate amount of the fluidizing agent is 0.6 to 5 parts by weight, preferably 0.8 to 4 parts by weight, based on 100 parts by weight of the toner particles. If the amount is less than 0.6 parts by weight, desired transfer performance and durability cannot be secured. It causes side effects such as poor charging. When two or more fluidizing agents are used, they may be added so that the total amount thereof is within the above range. Further, when the fluidizing agent is added before the shape control for the purpose of controlling the toner particle shape without variation as described above, the total amount of the fluidizing agent may be added within the above range.

The above-mentioned fluidizing agents such as strontium titanate, magnesium titanate, aluminum stearate, calcium stearate, zinc stearate, magnesium stearate and the like, and / or the following cleaning aids for improving the cleaning property. It is preferred to use

As cleaning aids, an emulsion polymerization method,
Various organic materials such as styrene, (meth) acrylic, benzoguanamine, melamine, Teflon, silicon, polyethylene and polypropylene granulated by wet polymerization such as soap-free emulsion polymerization and non-aqueous dispersion polymerization, and gas phase method. Fine particles can be used.

The full-color toner of the present invention obtained as described above is obtained by pressing and transferring the toner image formed on the image carrier onto the intermediate transfer member for each color, and then transferring the toner image onto the intermediate transfer member. The method is effectively used in a full-color image forming method including press-transfer of a toner image transferred to a recording member. That is, in the full-color image forming method using the toner according to the present invention, no dropout of the toner image and no scattering of the toner occur at the time of the primary and secondary transfer.
It can be said that no image fogging occurs in the full-color copy image, and the transferability is excellent. Further, the black toner used in the present invention is excellent in shape, particle size and chargeability including variation, and can reproduce an image faithfully to a latent image. It is possible to provide a high-quality monochrome image even when used in a computer.

A method for forming a full-color image using the above-described full-color toner will be described using a known full-color image forming apparatus shown in FIG. In the following full-color image forming apparatus, a photoconductor is used as an image carrier,
An endless intermediate transfer belt is used as an intermediate transfer member, and a sheet-like recording paper is used as a recording member.

Referring to FIG. 2, a full-color image forming apparatus generally includes a photosensitive drum 1 which is rotationally driven in the direction of arrow a.
0, the laser scanning optical system 20, and the full-color developing device 3
0, an endless intermediate transfer belt 40 that is driven to rotate in the direction of arrow b, and a paper feed unit 60. Around the photoconductor drum 10, a charging brush 11 for charging the surface of the photoconductor drum 10 to a predetermined potential and a cleaner 12 having a cleaner blade 12a for removing toner remaining on the photoconductor drum 10 are further provided. is set up.

The laser scanning optical system 20 is a well-known type having a built-in laser diode, polygon mirror, and fθ optical element.
(Yellow) and Bk (black) print data are transferred from the host computer. The laser scanning optical system 20 sequentially outputs print data for each color as a laser beam, and scans and exposes the photosensitive drum 10. This allows
An electrostatic latent image for each color is sequentially formed on the photosensitive drum 10.

The full-color developing device 30 includes Y, M, C, and B
4 containing a one-component toner composed of k non-magnetic toners
The three color developing devices 31Y, 31M, 31C, and 31Bk are integrated, and can be rotated clockwise about the support shaft 81 as a fulcrum. Each developing device includes a developing sleeve 32 and a toner regulating blade 34. Developing sleeve 32
The toner conveyed by the rotation of the roller is charged by passing through a pressure contact portion (gap) between the blade 34 and the developing sleeve 32.

The positions of the developing devices for accommodating the yellow toner, the magenta toner, the cyan toner and the black toner can be determined by whether the full-color image forming apparatus is for the purpose of copying a line diagram image such as a character, or a photograph. It depends on whether the purpose is to copy an image with each color shade, such as an image, etc. For example, when the purpose is to copy a line diagram image such as a character, gloss (gloss) is used as a black toner. When using something that does not have
When the black toner layer is formed on the top of the full-color copy image, a sense of incongruity occurs. Therefore, it is preferable to load the black toner into the developing device so that the black toner layer is not formed on the top of the full-color copy image. In this case, it is most preferable that the black toner layer is formed on the intermediate transfer body at the time of primary transfer so that the black toner layer is formed on the lowermost position on the copy image. Will be loaded. At this time, the yellow toner, the magenta toner, and the cyan toner (color toner) may be arbitrarily loaded into the developing device so that the formation order of each layer in the primary transfer is any one of the first to third layers.

On the other hand, when the full-color image forming apparatus is intended to copy an image having various shades of each color such as a photographic image, a black toner having glossiness is used. Even if the black toner layer is formed on the top of the copied image, it does not cause a sense of incompatibility with other color toner layers.

The intermediate transfer belt 40 includes support rollers 41, 4
2 and endlessly stretched over the tension rollers 43 and 44, and are driven to rotate in the direction of arrow b in synchronization with the photosensitive drum 10. A projection (not shown) is provided on a side portion of the intermediate transfer belt 40. By detecting the projection by the microswitch 45, image forming processes such as exposure, development, and transfer are controlled. The intermediate transfer belt 40 is pressed by a rotatable primary transfer roller 46 and is in contact with the photosensitive drum 10. The contact portion is a primary transfer portion T _1. The intermediate transfer belt 40 is in contact with a rotatable secondary transfer roller 47 at a portion supported by the support roller 42. The contact portion is a secondary transfer portion T _2.

Further, a cleaner 50 is provided in a space between the developing device 30 and the intermediate transfer belt 40. The cleaner 50 has a blade 51 for removing residual toner on the intermediate transfer belt 40. The blade 51 and the secondary transfer roller 47 can contact and separate from the intermediate transfer belt 40.

The paper supply unit 60 includes a paper supply tray 61 that can be opened to the front side of the image forming apparatus main body 1, a paper supply roller 62,
And a timing roller 63. The recording sheets S are stacked on a sheet feed tray 61, fed one by one to the right in the drawing by the rotation of a sheet feed roller 62, and synchronized with an image formed on the intermediate transfer belt 40 by a timing roller 63. To the secondary transfer section. The horizontal conveyance path 65 of the recording sheet is constituted by an air suction belt 66 and the like including the above-mentioned paper feeding section. The recording sheet S is discharged from the vertical conveyance path 71 to the upper surface of the image forming apparatus main body 1.

Here, the printing operation of the full-color image forming apparatus will be described. When the printing operation is started, the photosensitive drum 10 and the intermediate transfer belt 40 are driven to rotate at the same peripheral speed, and the photosensitive drum 10 is charged to a predetermined potential by the charging brush 11.

Subsequently, exposure of the yellow image is performed by the laser scanning optical system 20, and an electrostatic latent image of the yellow image is formed on the photosensitive drum 10. This electrostatic latent image is immediately developed by the developing device 31Y, and the toner image is transferred onto the intermediate transfer belt 40 in the primary transfer section. Immediately after the end of the primary transfer, the developing device 31M is switched to the developing unit D,
Subsequently, exposure, development, and primary transfer of the magenta image are performed. Further, switching to the developing device 31C, exposure, development, and primary transfer of the cyan image are performed. Further, the developing device 3
Switching to 1Bk, exposure and development of the black image, and primary transfer are performed, and the toner image is superimposed on the intermediate transfer belt 40 for each primary transfer.

When the final primary transfer is completed, the recording sheet S is sent to the secondary transfer section, and the full-color toner image formed on the intermediate transfer belt 40 is transferred onto the recording sheet S. When the secondary transfer is completed, the recording sheet S is conveyed to the belt-type contact heat fixing device 70, where the full-color toner image is fixed on the recording sheet S, and
Is discharged to the upper surface of the

In the full-color toner of the present invention, the toner is charged by passing the developing device through the pressure contact portion between the toner regulating blade and the developing sleeve as described above.
Even if a two-component developing system is adopted, or a two-component developing system in which toner is charged by friction with a carrier is used, it can be effectively used. Generally, the stress applied to the toner particles is greater in the one-component development system than in the two-component development system, so that the toner used in the one-component development system has more excellent stress resistance than the toner used in the two-component development system. Characteristics are required. As described above, since the toner of the present invention can be effectively used in any of the developing systems, the toner of the present invention is particularly effective when used in the one-component developing system.

The full-color toner of the present invention is particularly preferably used in a full-color image forming apparatus having a brush cleaning device for removing residual toner on the surface of an image carrier. Hereinafter, description will be made with reference to FIG. 3 showing an example of a brush cleaning device. The brush member 2 that rubs the surface of the image carrier (photosensitive drum) 201
As 11, a brush provided with a conductive brush 211 a is used, and the brush member 211 is rotated in the opposite direction to the image carrier 201, and the brush 211 a provided on the brush member 211 is used to rotate the image carrier 201. Along with rubbing the surface, a bias voltage for toner recovery having a polarity opposite to the charging polarity of the toner 202 is applied from a power source 212 to the brush member 211 to remove the toner 202 remaining on the surface of the image carrier 201. The brush 211 is collected by the brush 211a.

Therefore, even if the toner 202 remaining on the surface of the image carrier 201 has a small particle size, the brush member 211 ensures that the toner 202 is removed from the surface of the image carrier 201 without fail. Has become. After the toner 202 is collected by the brush member 211, the brush 211a of the rotating brush member 211 is applied to the hitting rod 213 as described above, and the toner 202 collected by the brush 211a is brushed by the brush 211a. Strike out from inside.

Further, the toner 20 thus collected
After the toner 2 is beaten from the brush 211a, the toner 202 attached to the brush 211a is further collected by the collection roller 214. Here, the toner 202 adhering to the brush 211a is collected by the collection roller 2
14, the brush 211 a of the rotating brush member 211 is brought into contact with the peripheral surface of the rotating collection roller 214 and the power
Then, a bias voltage for toner collection higher than the bias voltage applied to the brush member 211 is applied to the collection roller 214, and the remaining toner 202 that is not beaten out from the brush 211a is applied to the peripheral surface of the collection roller 214. Let them be collected.

Next, the scraping member 216 is pressed against the peripheral surface of the collection roller 214 from which the toner 202 has been collected in this manner by a biasing means 217 such as a spring, and the collected toner 202 is conveyed to the peripheral surface of the collection roller 214. Then, the scraping member 216 scrapes the toner 202 from the peripheral surface of the collection roller 214, and the toner 202 thus scraped is transported by the toner transport coil 218. In the cleaning device, when the toner 202 attached to the brush 211a is collected by the collection roller 214 as described above, the cleaning agent 221 is supplied to the peripheral surface of the collection roller 214 by the cleaning agent supply unit. To do.

Here, when supplying the cleaning agent 221 to the peripheral surface of the collection roller 214, the cleaning agent 221 is applied on the scraping member 216 on the opposite side of the brush member 211 of the collection roller 214. The cleaning agent 221 is accommodated in such a manner as to be in contact with the peripheral surface of
The amount of the cleaning agent 221 supplied to the peripheral surface of the collection roller 214 is adjusted by the regulating blade 222, and the cleaning agent 221 is supplied thinly and uniformly to the peripheral surface of the collection roller 214. By supplying the cleaning agent 221 to the peripheral surface of the collection roller 214 in this manner, the toner 202 collected by the collection roller 214 can be easily scraped off from the peripheral surface of the collection roller 214 by the scraping member 216. Thus, the accumulation of the toner 202 on the peripheral surface of the collection roller 214 can be prevented.

As a result, the toner 202 adhered to the brush 211a as described above is stably collected by the collection roller 214 for a long time, and the toner 202 adhered to the brush 211a is gradually removed from the brush 211a.
1a, the toner 2 accumulated by the brush member 211
02 and the image carrier 2
Also, the removal of the toner 202 remaining on the surface of No. 01 is stably performed over a long period of time.

In this apparatus, when the cleaning agent 221 is supplied to the peripheral surface of the collection roller 214, a rubber regulating blade 222 is pressed against the peripheral surface of the collection roller 214, and the peripheral surface of the collection roller 214 is pressed. The amount of the cleaning agent 221 supplied is adjusted. However, instead of the rubber regulating blade 222 described above, a metal regulating blade may be used, or a regulating member formed of a sponge or the like may be used. It is also possible to adjust the amount of the cleaning agent 221 supplied to the peripheral surface of the collecting roller 214 by pressing the peripheral surface of the collecting roller 214 against the peripheral surface of the collecting roller 214.

In the following embodiment, an apparatus having the configuration of the above-described full-color image forming apparatus is replaced with a photosensitive member surface potential of -55.
0 V, a developing bias voltage of -200 V, a primary transfer bias voltage of 900 V, and a secondary transfer bias voltage of 500 V, the toner adhesion amount of the solid image portion on the recording sheet is 0.1 V.
7 mg / cm ² and a fixing temperature of 160
It was used under the condition of ° C. The present invention is described in more detail by the following examples. In the examples, unless otherwise specified, “parts”
Means “parts by weight”.

[0096]

EXAMPLES (Production of polyester resin A) 4.0 mol of polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as "PO"),
Polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as "EO")
6.0 moles of terephthalic acid (hereinafter referred to as "TPA")
9.0 mol and dibutyltin oxide as a catalyst were placed in a glass four-necked flask, fitted with a thermometer, a stainless steel stirring rod, a falling condenser, and a nitrogen inlet tube, and stirred in a mantle heater under a nitrogen stream. The reaction was performed while heating. The progress of the reaction was followed by measuring the acid value. When the acid value reached a predetermined value, the reaction was terminated and cooled to room temperature to obtain a polyester resin A. The physical properties of the polyester resin A are shown below. Number average molecular weight (Mn): 3,30
0, weight average molecular weight (Mw) / number average molecular weight (Mn):
4.2, glass transition point (Tg): 68.5 ° C, softening point (Tm): 110.3 ° C, acid value: 3.3 mgKOH /
g, OH number: 28.1 mg KOH / g.

The softening point was measured using a flow tester (CFT-500; manufactured by Shimadzu Corporation).
1.0 to 1.5 g of the resin was weighed, and a
Pressurize with a load of 0 kg / cm ² for 1 minute. This pressurized sample was subjected to a flow tester measurement under the following conditions, and the temperature at which half of the sample flowed out was taken as the softening point temperature. R
ATE TEM (heating rate); 3.0 ° C./min, SET
TEMP; 50.0 ° C., MAX TEMP; 120.0
° C, INTERVAL; 2.0 ° C, PREHEAT;
2.0 ° C., LOAD; 30.0 kgf, DIE (DI
A): 1.0 mm, DIE (LENG); 1.0 mm,
PLUNGER; 1.0 cm ² .

The temperature at which the sample began to flow was the temperature at which the sample began to flow. The glass transition point was measured using a differential scanning calorimeter (DSC-200; manufactured by Seiko Instruments Inc.). About 10 mg of the resin was precisely weighed and placed in an aluminum pan. As a reference, alumina was placed in the aluminum pan.
/ Min. The temperature was raised from room temperature to 200 ° C. to melt quench, then cooled, and the temperature was raised to 10 ° C./min. 2
The measurement is performed between 0 and 150 ° C. During this heating process, 30
The shoulder value of the endothermic peak of the main peak in the temperature range of ８０80 ° C. was defined as the glass transition point.

The acid value was represented by the number of mg of potassium hydroxide necessary to dissolve the weighed sample in an appropriate solvent and neutralize the acidic group using an indicator such as phenolphthalein. The hydroxyl value was represented by the number of mg of potassium hydroxide required to treat a weighed sample with acetic anhydride, hydrolyze the resulting acetylated product, and neutralize liberated acetic acid.

The molecular weight was determined by gel permeation chromatography (807-IT; manufactured by JASCO Corporation) using tetrahydrofuran as a carrier solvent in terms of polystyrene.

(Production of Pigment Master Batches a to c) The pigments used in the production of the following toners include polyester resin used in the production of each toner and C.I. I. P
igment Yellow 180, C.I. I. PigmentRed 184 or C.I. I. Pigment Blue 15-3 in a weight ratio of 7:
The mixture was charged into a pressure kneader at a ratio of 3 and kneaded at 120 ° C. for 1 hour. After cooling, a hammer mill roughly pulverized to obtain a pigment master batch having a pigment content of 30 wt%. In addition, the pigment master batch obtained according to any one of the pigments used will be referred to as master batches a to c in order.

(Production of Toner 1 (Y-1, M-1, C-1)) 100 parts of polyester resin A, 15 parts of pigment master batch a, zinc complex of salicylic acid as charge control agent (E-84; Orient Chemical Industries, Ltd.) 2.0 parts) and 2 parts of oxidized low molecular weight polypropylene (100TS; manufactured by Sanyo Chemical Industries, Ltd .: softening point 140 ° C., acid value 3.5) were sufficiently mixed with a Henschel mixer, and then twin-screw extruder (PCM). −
30; manufactured by Ikegai Iron Works Co., Ltd.), the kneaded material obtained by melt-kneading was rolled to a thickness of 2 mm with a cooling press roller, cooled with a cooling belt, and then coarsely milled with a feather mill. Crushed. After that, the Inomaizer (INM
-30 type; manufactured by Hosokawa Micron Corporation) with an average particle size of 7.5μ
m, the fine powder was classified using a rotor type classifier (Tiplex: type 100 ATP; manufactured by Hosokawa Micron Corporation) to obtain a toner Y-1. A toner M-1 was obtained in the same manner as in the method for producing the toner Y-1 except that the pigment master batch b was used.
A toner C-1 was obtained in the same manner as in the method for producing the toner Y-1, except that the pigment master batch c was used.

(Production of Toner 2 (Y-2, M-2, C-2)) Toner Y-1, M-1, or C-1 was 10
For 0 part, 0.5 part of hydrophobic silica A (TS-500; manufactured by Cabot Corporation) and 0.5 part of hydrophobic silica B (AEROS
IL90G (manufactured by Nippon Aerosil Co., Ltd.) treated with hexamethylene disilazane (HMDS) (BET specific surface area 65 m ^{2 /} g, pH 6.0, hydrophobicity 95%)
0 parts, and a peripheral speed of 30 m /
The mixing process was performed for 60 seconds. The obtained toner particles were subjected to a surface modification device (Surfusing System; manufactured by Nippon Pneumatic Industries, Ltd.) at a maximum temperature of 250 ° C., a residence time of 0.5 seconds, a powder dispersion concentration of 100 g / m ³ , and a cooling air temperature of 1
By processing at 8 ° C and cooling water temperature of 20 ° C,
Toners Y-2, M-2 and C-2 were obtained.

(Production of Toner 3 (Y-3, M-3, C-3)) 100 parts of a polyester resin A, 15 parts of a pigment master batch a, 1 part of a boron compound represented by the following formula (A),
Oxidized low molecular weight polypropylene wax (100TS: Sanyo Kasei Kogyo Co., Ltd., softening point 140 ° C, acid value 3.5KOHmg
/ G) 1 part and 400 parts of toluene were mixed and dissolved / dispersed for 30 minutes using an ultrasonic homogenizer (output: 400 μA) to prepare a colored resin solution.

[0105]

Embedded image

On the other hand, an aqueous dispersion was prepared by dissolving 0.1 part of sodium lauryl sulfate (manufactured by Wako Pure Chemical Industries, Ltd.) in 1000 parts of an aqueous solution containing 4% by weight of calcium phosphate as a dispersion stabilizer. While stirring 100 parts of the above aqueous dispersion with a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) at 4000 rpm, 50 parts of the above colored resin solution is dropped, and the droplets of the colored resin solution are dispersed in an aqueous solution. It was suspended in the solution. The suspension was allowed to stand at 60 ° C. and 100 mmHg for 5 hours to remove toluene from the droplets, thereby precipitating colored resin fine particles. Then, calcium hydroxide phosphate was dissolved with concentrated hydrochloric acid, and then filtration and washing with water were repeated. Thereafter, the colored resin particles were dried at 80 ° C. using a slurry drying device (Dispercoat: manufactured by Nisshin Engineering Co., Ltd.) to obtain a toner Y-3. Except that Pigment Masterbatch b was used, the above toner Y-3 was used.
In the same manner as in the production method described above, Toner M-3 was obtained. Except that Pigment Masterbatch c was used, the toner Y-
In the same manner as in the production method of No. 3, Toner C-3 was obtained.

(Production of Toner 4 (Y-4, M-4, C-4))
Except that after pulverizing to a mean particle size of 8 μm with a jet mill pulverizer (IDS; manufactured by Nippon Pneumatic Industries Co., Ltd.), the fine powder was classified using a DS classifier (manufactured by Nippon Pneumatics Co., Ltd.). In the same manner as in Production Method 1, toners Y-4, M-4, and C-4 were obtained.

(Production of Toner 5 (Y-5, M-5, C-5)) No wax was used, and polyester A
66.7 parts, 10 parts of a pigment master batch, 2/3 of the toner solid content (resin, pigment master batch, boron compound) with respect to toluene at the time of granulation, and the number of revolutions of the TK homomixer. Except that the rotation speed was set to 3,700 revolutions per minute,
Toners Y-5, M-5, and C-5 were obtained.

(Production of Toner Bk-1) 100 parts by weight of resin and 6 parts of carbon black (Mogal L; manufactured by Cabot Corporation) were used without using a pigment masterbatch. Toner particles were obtained in the same manner as in the method for producing toner 1, except that the classification conditions were adjusted by a machine. Then, hydrophobic silica A (TS-5) was added to 100 parts of the obtained toner particles.
00; Cabot Corporation) 0.5 part and hydrophobic silica B
(# 90 silica (manufactured by Nippon Aerosil Co., Ltd.) treated with hexamethylene disilazane (HMDS)) 1.0
And a peripheral speed of 30 m / s using a Henschel mixer
ec for 60 seconds. The obtained toner particles were subjected to a surface modification apparatus (Surfusing System; manufactured by Nippon Pneumatic Industries, Ltd.) at a maximum temperature of 270 ° C., a residence time of 0.5 seconds, a powder dispersion concentration of 100 g / m ³ , and a cooling air temperature of 1
By processing at 8 ° C and cooling water temperature of 20 ° C,
Thus, a toner Bk-1 was obtained.

(Production of Toner Bk-2) 217 parts of toluene was charged into a flask equipped with a dropping funnel, a stirrer, an inert gas inlet tube, a reflux condenser, and a thermometer, and heated to 90 ° C. while blowing nitrogen gas. . 480 parts of styrene and n-butyl acrylate 20 previously prepared there
Mercaptoethanol to the polymerizable monomer comprising
A mixture obtained by dissolving 61 parts and 1.32 parts of azobisisobutyronitrile was dropped from a dropping funnel over 2 hours.
Further, stirring was continued for 5 hours to carry out a polymerization reaction. Then
185.1 g of this reaction product (including a prepolymer having a hydroxyl group at a terminal) was added to 0.1 g of dibutyltin dilaurate and 2,4-toluylene diisocyanate.
After adding 38 g, the mixture was reacted at 80 ° C. for 30 minutes to obtain a solution of a polymer having an isocyanate group as a reactive group at a terminal. Using a lab blast mill, 57.1 parts of a solution of a polymer having an isocyanate group as a reactive group at a terminal and 20 parts of carbon black “MA-100S” preliminarily dried at 200 ° C. for 2 hours were used at 160 ° C. and 100 rpm. After kneading under the conditions and removing the solvent together with the reaction, the mixture was cooled and pulverized to obtain a carbon black graft polymer.

A preliminarily prepared reaction vessel equipped with an inert gas introduction pipe, a reflux condenser and a thermometer, containing deionized water containing 0.5% by weight of sodium dodecylbenzenesulfonate as an anionic surfactant. Put styrene 80
A mixture obtained by mixing 50 parts of a carbon black graft polymer, 3 parts of azobisisobutyronitrile and 3 parts of 2,2′-azobisisobutyronitrile with a polymerizable monomer component composed of 20 parts of n-butyl acrylate and 20 parts of n-butyl acrylate. Preparation,
T. K. After mixing and stirring using an auto homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to form a uniform suspension, the mixture was heated to 65 ° C. while blowing nitrogen gas, and stirring was continued for 5 hours at this temperature. After performing the turbid polymerization reaction, the mixture was further heated to 75 ° C. to terminate the polymerization reaction. Separately, a dispersion prepared by dispersing 2 parts of hydrophobic silica “H-2000” (manufactured by Wacker Inc.) and 2 parts of a silane coupling agent “TSL8311” (manufactured by Toshiba Silicone Co., Ltd.) in methyl alcohol was added to the above suspension. The mixture was added to the suspension and mixed, and filtration and washing with water were repeated three times. After this,
The suspension obtained here was dried by a slurry drying apparatus “Dispercoat” (manufactured by Nisshin Engineering Co., Ltd.) and subjected to air classification to obtain a toner Bk-2 having an average particle diameter of 6.2 μm.

(Production of Toners Bk-3 and 4) A twin-screw kneading extruder (PCM-30;
The kneaded product obtained by melt-kneading using Ikegai Iron Works Co., Ltd. was rolled to a thickness of 2 mm with a cooling press roller, cooled with a cooling belt, and coarsely ground with a feather mill. Then, after finely pulverizing with a jet pulverizer (IDS; manufactured by Nippon Pneumatic Industries, Ltd.), fine powder was classified using an air classifier (DS; manufactured by Nippon Pneumatics) to prepare toners Bk-3 and Bk-3. The toner Bk-3 and the toner Bk-4
Was prepared by adjusting the conditions of fine pulverization and classification.

The volume average particle diameter (D) of the obtained toner, the content ratio of twice (2D) or more of the volume average particle diameter (D), and 1/3 (D / 3) of the volume average particle diameter (D) The following content ratio was measured using a Coulter Multisizer (manufactured by Coulter Counter Co.) with an aperture diameter of 50 μm. Also,
The average circularity and the standard deviation (SD) of the circularity of the obtained toner were measured using a flow type particle image analyzer (FPIA-100).
0; Toa Medical Electronics Co., Ltd.). The results are summarized in Table 1 below.

[0114]

[Table 1]

The toners other than the toners Y-2, M-2, C-2 and Bk-1 were prepared by adding 0.5 parts of silica (R972; manufactured by Nippon Aerosil Co., Ltd.) and titanic acid to 100 parts of the toner. Strontium (particle diameter 350 nm, BE
0.5 parts of T specific surface area (9 m ^{2 /} g) was added and mixed for 3 minutes at a peripheral speed of 40 m / sec using a Henschel mixer, and used in the following Examples and Comparative Examples. Toners Y-2, M-2, C-2 and Bk-1 are toner 1
For 00 parts, 0.3 part of silica (R972; manufactured by Nippon Aerosil Co., Ltd.) and strontium titanate (particle size: 35
0 nm, BET specific surface area 9 m ^{2 /} g) 0.5 part was added, and 3 parts were added at a peripheral speed of 40 m / sec using a Henschel mixer.
The mixture processed for minutes was used in the following Examples and Comparative Examples.

(1 Component Development Method) Example 1 As full-color toners, toners Y-1, M-1, C-
The combination consisting of 1 and Bk-1 was selected.

Example 2 As full-color toners, toners Y-2, M-2 and C-
2 and Bk-2 were selected.

Example 3 As full-color toners, toners Y-3, M-3 and C-
3 and Bk-2 were selected.

Comparative Example 1 As full-color toners, toners Y-4, M-4 and C-
4 and Bk-3 were selected.

Comparative Example 2 As full-color toners, toners Y-1, M-1, C-
The combination consisting of 1 and Bk-3 was selected.

Comparative Example 3 As full-color toners, toners Y-1, M-1, C-
The combination consisting of 1 and Bk-4 was selected.

Comparative Example 4 As full-color toners, toners Y-5, M-5 and C-
The combination consisting of 5 and Bk-2 was selected.

(Evaluation) The full-color toners selected in the above Examples and Comparative Examples were evaluated for the following items. The initial evaluation was performed in an H / H environment (30 ° C./85%
RH) and L / L environment (10 ° C./15% RH) using a predetermined print pattern. After the initial evaluation, the sample was further subjected to an N / N environment (25 ° C./50% R
In H), using a print pattern with a B / W ratio of 6% for each color, 3
Evaluation was performed after continuous copying of 000 sheets. The evaluation method after 3000 continuous copies was that the evaluation was performed in an N / N environment.
The evaluation method was the same as that described below, except that evaluation was performed after copying 300 sheets, and a print putter of 6% for each color was used. The copying machine used was a modified type in which a full-color image forming apparatus (manufactured by Minolta) having a configuration shown in FIG. 2 was provided with a brush cleaning device shown in FIG.

[0124] The fog color toner, was loaded into the modified full-color image forming apparatus (manufactured by Minolta Co.), 4 color superimposition it printed by B / W
Copy images obtained by copying 10 character pattern images at a ratio of 30% were visually observed and evaluated according to the following ranking. The four types of toner are supplied to four developing devices.
The order of layer formation on the intermediate transfer belt is Y, M, C, B from the bottom.
k. ：: Fog was hardly recognized; Δ: Slight fog was recognized, but there was no problem in practical use; ×: Fog was present over the entire surface, and there was a problem in practical use.

[0125] The hollowing color toner, was loaded into the modified full-color image forming apparatus (manufactured by Minolta Co.), copies the full-color image (General pattern) by 4 color superimposition ne printing, color copying at 10 sheets and 3,000 sheets after copying the image,
Evaluation was made according to the following ranking. The four types of toners are loaded in the four developing devices such that the order of layer formation on the intermediate transfer belt is Y, M, C, and Bk from the bottom. ：: no hollowing occurred on the copied image; Δ: slight hollowing occurred on the copied image, but no practical problem; ×: many hollowing occurred on the copied image. There was a practical problem.

The scattered full-color toner is loaded into the above-mentioned modified full-color image forming apparatus (manufactured by Minolta), and a full-color line image (general pattern) is copied by four-color overprinting.
The full-color copied images after copying 0 and 3000 copies were visually observed and evaluated according to the following ranking. The four types of toner are applied to the four developing devices in order of layer formation on the intermediate transfer belt from the bottom in the order of Y, M, C, and Bk.
It is loaded to be. ：: no toner scattering was observed around the line copied image; Δ: toner scattering was found around the line copied image, but there was no practical problem; ×: toner was splashed around the line copied image. Were often recognized and recognized as bleeding, and had a practical problem.

The transferable full-color toner is loaded into the above-mentioned modified full-color image forming apparatus (manufactured by Minolta), and yellow, magenta, cyan, red, green, and blue (hereinafter, Y, M, C,
R, G, and B) and six types (six colors) of solid patterns are copied and evaluated according to the following ranking based on the ratio of the amount of toner adhered on the photosensitive drum to the amount of toner adhered on the photosensitive drum in the tenth copy process. did. ：: All of the above ratios for the six types of patterns are 80%
Δ: The minimum value among the above ratios for the six types of patterns was 70% or more and less than 80%; ×: The minimum value among the above ratios for the six types of patterns was less than 70%. there were.

[0128] 10 sheets of conformability B / W ratio of 30%, after the sheet passing, and print out the images of B / W100% to evaluate its density unevenness. ：: No density unevenness, Δ: Slight density unevenness occurred, but no practical problem occurred. X: Density unevenness occurred, practically problematic.

Half-dot reproducibility A 2-dot half-tone dot image is formed at 600 dpi, dots are observed with a loupe (50 times), dots are reproduced one by one, and variation in dot size is small. ○ indicates that the dots are separated and there is no defect, but the dots that vary greatly in size are △.
Ones that were missing or stuck together and were not sufficiently reproduced in dots were evaluated as x.

The results of the above evaluation are shown in Tables 2 and 3 below, separately for the initial stage and after the end of 3,000 prints.

[0131]

[Table 2]

[0132]

[Table 3]

In Comparative Example 1, the toner was stuck on the regulating blade at the time of the endurance of 1,000 sheets, a number of streak-like noises occurred on the image sample, and the durability test could not be continued. . Since the dot reproducibility of Comparative Example 2 was inferior, a printing durability test was not performed. With respect to Comparative Example 3, the test was stopped because poor followability occurred at the time of 1000 sheets of durability. Comparative Example 4
As for the test, the test was stopped because the fog increased at the time of 1000 sheets of durability.

(Two-Component Development Method) Example 4 As full-color toners, toners Y-3, M-3 and C-
3 and Bk-2 were selected, and a carrier described below was mixed with each toner so that the toner mixing ratio was 5% by weight.

Comparative Example 5 As full-color toners, toners Y-5, M-5 and C-
5 and Bk-3 were selected, and a carrier described later was mixed with each toner so that the toner mixing ratio was 5% by weight.

(Evaluation) Using the digital full-color copying machine CF900 (manufactured by Minolta), the toners of Example 4 and Comparative Example 5 were evaluated for 5 in an N / N environment (25 ° C., 50%).
The following evaluation was performed after 5,000 sheets were printed and at the beginning and after 5,000 sheets. The copying machine used was a modified type equipped with a brush cleaning device shown in FIG.

For each full-color toner having cohesiveness (white spots) , 5,000 sheets of B / W 15% images were printed under N / N environment using the above-mentioned modified copying machine. Solid image (ID = 1.2) on A3 paper after printing
Were imaged and evaluated according to the following criteria, and the average value of the three images was used as the evaluation result. The first three sheets before printing were evaluated in the same manner. The evaluation criteria are as follows. ×: ID of solid image with a size of 2 mm ² or more in solid image
Image unevenness (white spots) having an ID equal to or less than 1/2 of Δ was observed; Δ: the white spots were not generated, but 0.3 μm was found in the image.
Nuclei of aggregates of about m were observed, and three or more portions where the image density was slightly reduced around the core were observed in the image; 〇: One or two portions where the image density was reduced as described above. : ◎: Above-mentioned image density reduction portion did not occur at all.

[0138] developing the improved copying machine (manufactured by Minolta Co., Ltd.) on the photosensitive member using for transferability transferability, Y, M, C, R , G, B, a solid pattern of six (6 colors) Immediately after this was transferred to the transfer paper, the transfer paper was extracted and evaluated according to the following ranking from the ratio of the amount of toner adhered on the transfer paper to the amount of toner adhered on the photoreceptor. This evaluation was 1
This was performed in the 0th and 5000th copying steps. 〇; All of the above ratios for the six patterns are 90%
Δ: The minimum value among the above ratios for the six types of patterns was 85% or more and less than 90%; ×; The minimum value among the above ratios for the six types of patterns was less than 85%. Was.

Gradation ( Texture of Halftone Image) A gradation pattern of 0 to 256 gradations is created,
Continuous copying was performed, and the copied images at the initial stage (after 10 copies) and after 5000 copies were evaluated according to the following ranking. 〇: A uniform image without roughness was obtained from the highlight portion to the solid portion; Δ: There was a roughness in the highlight portion but no problem in practical use; ×: From the intermediate density range to the highlight portion Roughness and unevenness occurred.

[0140] The fog color toner, was loaded into the modified copiers, visually observed copy image after copying 10 sheets and 5000 sheets of B / W ratio of 30% of the character pattern image in continuous by 4 color superimposition ne printing And evaluated according to the following ranking.
The four types of toners are loaded into the four developing devices so that the order of layer formation on paper is C, M, Y, and Bk from the bottom. ：: Fog was hardly recognized; Δ: Slight fog was recognized, but there was no problem in practical use; ×: Fog was present over the entire surface, and there was a problem in practical use.

Halftone dot reproducibility A 2-dot halftone image is formed at 600 dpi, dots are observed with a loupe (50 times), dots are reproduced one by one, and variations in dot size are small. ○ indicates that the dots are separated and there is no defect, but the dots that vary greatly in size are △.
Ones that were missing or stuck together and were not sufficiently reproduced in dots were evaluated as x.

Table 4 below shows the evaluation results of Example 4 and Comparative Example 5. In Comparative Example 5, the endurance test was not performed because the mixing property was poor at the time when the toner was replenished to the starter, and the fogging that occurred when charging started deteriorated occurred when 100 sheets were printed.

[Table 4]

(Manufacture of carrier) Stirrer, condenser,
500ml capacity equipped with thermometer, nitrogen inlet tube and dropping device
Was charged with 100 parts of methyl ethyl ketone.
Separately, add methyl methacrylate at 80 ° C under nitrogen atmosphere.
6.7 parts of 2-hydroxyethyl methacrylate.
A solution obtained by dissolving 1 part, 58.2 parts of 3-methacryloxypropyltris (trimethylsiloxy) silane and 1 part of 1,1′-azobis (cyclohexane-1-carbonitrile) in 100 parts of methyl ethyl ketone was used. The mixture was dropped into the reaction vessel over 2 hours and aged for 5 hours.
Isophorone diisocyanate / trimethylolpropane adduct (NCO
% = 6.1%) was adjusted so that the OH / NCO molar ratio became 1/1, and then diluted with methyl ethyl ketone to prepare a coat resin solution having a solid ratio of 3% by weight. Fired ferrite powder F-300 as core material (volume average particle size: 50μ)
m, manufactured by Powdertech Co., Ltd.) and applied and dried with a spira coater (manufactured by Okada Seiko Co., Ltd.) so that the amount of coating resin with respect to the core material was 1.5% by weight. The obtained carrier is placed in a hot air circulating oven for 16 hours.
It was baked by leaving it at 0 ° C. for 1 hour. After cooling, the ferrite powder bulk was crushed using a sieve shaker equipped with a 106 μm and 75 μm screen mesh to obtain a resin-coated carrier.

[0144]

As described above, the full-color toner of the present invention does not cause dropout of toner images or toner scattering at the time of primary and secondary transfer, does not cause image fog on full-color copied images, and is excellent in transferability. Further, when the full-color toner of the present invention is mounted on a full-color and monochrome dual-purpose copying machine, and copied in a monochrome version, a monochrome image having excellent line reproducibility (raditness), halftone reproducibility (dot reproducibility), and followability is obtained. Can be reproduced.
Furthermore, the full-color toner of the present invention can maintain the above characteristics for a long period of time, that is, is excellent in durability. Further, the toner of the present invention can be effectively used in both the one-component developing system and the two-component developing system. According to the full-color image forming method of the present invention, no dropout of toner image or toner scattering occurs at the time of primary and secondary transfer, no image fogging occurs in the full-color copy image, and the transferability is excellent. . In addition, the method of the present invention is applied to a full-color and monochrome dual-purpose copying machine, and even when a monochrome version is copied, a monochrome image excellent in line reproducibility (raditness), halftone reproducibility (dot reproducibility) and tracking ability is obtained. Can be reproduced.

[Brief description of the drawings]

FIG. 1 shows a schematic flow sheet of a surface modifying device used for modifying the surface of a toner.

FIG. 2 shows a schematic configuration diagram of a full-color image forming apparatus.

FIG. 3 is a schematic configuration diagram illustrating an example of a brush cleaning device.

[Explanation of symbols]

10: photosensitive drum, 11: charging brush, 12: cleaner, 20: laser scanning optical system, 30: full color developing device, 31C, 31M, 31Y, 31Bk: developing device
32: developing sleeve (sleeve), 34: toner regulating blade (blade), 40: intermediate transfer belt, 41: support roller, 42: support roller, 43: tension roller, 44: tension roller, 46: primary transfer roller
47: secondary transfer roller, 60: paper feed unit, 61: paper feed tray, 62: paper feed roller, 63: timing roller, 6
6: air suction belt, 70: fixing device, 71: vertical conveyance path, 81: support shaft, 101: hot air generator, 10
2, 102 ′, 102 ″: introduction tube, 104: fixed-quantity supply device, 105: sample, 106: hot air injection nozzle, 107:
Powder injection nozzle, 108: cooling air introduction pipe, 109: cyclone, 110a: cooling water (in), 110b: cooling water (out), 111: product tank, 112: bag filter, 113: blower, 201: image bearing Body, 202: toner, 211: brush member, 211a: brush, 21
2: power supply, 213: tapping rod, 214: collection roller,
215: power supply, 216, 217: scraping member, 21
8: toner transport coil, 220: cleaning agent supply means, 221: cleaning agent, 222: regulating blade.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tsutsui Main Tax 2-3-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka Inside Osaka International Building Minolta Co., Ltd. (72) Inventor Minoru Nakamura Azuchi-cho, Chuo-ku, Osaka-shi, Osaka Osaka International Building Minolta Co., Ltd. (72) Inventor Hiroyuki Fukuda 2-3-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka

Claims (9)

[Claims] 1. A full-color toner comprising a yellow toner, a magenta toner, a cyan toner and a black toner, wherein each of the yellow toner, the magenta toner and the cyan toner has an average circularity smaller than that of the black toner. A full-color toner having an average circularity of the toner of 0.95 or more and a standard deviation of the circularity of 0.040 or less. 2. The full-color toner according to claim 1, wherein the volume average particle diameters of the yellow toner, the magenta toner and the cyan toner are larger than the volume average particle diameter of the black toner. 3. The glass transition temperature of at least a yellow toner, a magenta toner and a cyan toner is 50 to 75.
° C, softening point 80 ~ 120 ° C, number average molecular weight 2500 ~ 1
3. The full-color toner according to claim 1, comprising a binder resin having a weight average molecular weight of 2,000 and a weight average molecular weight / number average molecular weight of 2 to 8, and a colorant. 4. The method according to claim 1, wherein at least the black toner contains a binder resin and a colorant, and is granulated in water or a mixed medium of water and a water-soluble organic solvent, and then dried. The full-color toner according to any one of the above. 5. The method according to claim 1, wherein at least the black toner is granulated by a suspension polymerization method in water or a mixed medium of water and a water-soluble organic solvent, and then dried.
4. The full-color toner according to any one of 4. 6. A toner characterized in that at least a yellow toner, a magenta toner and a cyan toner contain a binder resin and a colorant, are granulated in water or a mixed medium of water and a water-soluble organic solvent, and then dried. Claim 1 to
5. The full-color toner according to any one of 5. 7. The full-color toner according to claim 1, wherein the binder resin of at least the yellow toner, the magenta toner, and the cyan toner is a polyester resin. 8. The toner according to claim 1, wherein the fluidizing agent is
8. The full-color toner according to claim 1, wherein 0.6 to 5 parts by weight are mixed with respect to 100 parts by weight of the toner. 9. After the toner image formed on the image carrier is pressed and transferred onto the intermediate transfer body for each color, the toner image transferred on the intermediate transfer body is transferred onto the recording member. In a full-color image forming method including pressure transfer,
A full-color image forming method using the full-color toner according to claim 1.