JPH01234859A - Image forming method - Google Patents

Abstract

PURPOSE:To stably form excellent images many times whose image density is appropriate without accompanying image staining by using toner having coloring particles and organic fine particles whose diameter is smaller than that of the coloring particles in an image forming method for recycling the toner. CONSTITUTION:The toner to be used possesses the coloring particles containing the toner component of colorant, etc., in binding resin and the organic fine particles whose diameter is smaller than that of the coloring particles. It is desirable that the mean diameter of primary particles of the organic fine particles constituting the toner is 0.01-5mum and it is especially desirable that it is 0.1-2.0mum. When the mean diameter of the organic fine particles is too large, the fluidity of the toner tends to be lowered. When the mean diameter of the organic fine particles is too small, cleaning defect easily occurs. Thus, excellent images can be stably formed many times without accompanying image staining caused by fogging, black dots and the cleaning defect.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an image forming method applied to, for example, electrophotography, electrostatic recording, electrostatic printing, etc. This relates to a forming method.

[Technology background]

At present, as a method for forming a visible image from certain image information, methods using electrostatic latent images, such as electrophotography, electrostatic recording, and electrostatic printing, are widely used.

For example, in electrophotography, a latent image carrier having a photosensitive layer made of a photoconductive material is given an electrostatic charge, and then image exposure causes the surface of the latent image carrier to correspond to the original. An electrostatic latent image is formed, and this electrostatic latent image is developed with a developer to form a toner image. This toner image is transferred to a recording material such as paper by electrostatic force or the like, and then fixed by heating or pressure to form a copy image. On the other hand, after the transfer process, the latent image carrier is neutralized, toner remaining on the latent image carrier without being transferred is cleaned, and then the toner is used for forming the next copy image.

However, recently, from the perspective of using toner economically,
An image forming method employing a so-called toner recycling system in which toner collected through cleaning is returned to a developing device and reused is attracting attention.

On the other hand, in order to form an image of good quality, the toner needs to have high fluidity. Conventionally, as a technique for improving the fluidity of toner, it has been known to add and mix a fluidizing agent such as silica fine particles to powder of colored particles in which toner components such as a colorant are contained in a binder resin. ing.

However, when a toner recycling system is used to form an image using a toner containing a fluidizing agent such as silica fine particles, the toner is frequently subjected to mechanical stress due to recycling. Fine particles are embedded in the colored particles and the fluidity of the toner gradually decreases, resulting in a slow build-up of the toner's frictional electrification, resulting in fogging on the image and smudging of the image due to poor cleaning. There is a problem.

As a technology to solve these problems, in an image forming method that employs a toner recycling system, a latent image carrier having a photosensitive layer with a Vickers hardness of 160 or more and a primary particle size of 2 buttons or more are used. A technique using toner with a fluidizing agent was proposed (Japanese Patent Laid-Open No. 62-180).
(See Publication No. 376).

[Problem to be solved by the invention]

However, even with this technology, it is still difficult to sufficiently prevent the embedding of the fluidizing agent into the colored particles.
Therefore, the toner is recycled and used for printing multiple times (
When an image is formed, fogging gradually occurs, and there are also problems in that the image becomes smudged due to poor cleaning.

Although the surface of the latent image carrier is hard, the particle size of the fluidizing agent is large, so when images are formed many times, scratches occur on the surface of the latent image carrier, and the fluidizing agent is applied to the scratches. There is a problem in that the colored particles are deposited and attached thereto, and the colored particles cause dot-like stains (hereinafter also referred to as "black spots") on the image.

Furthermore, a latent image carrier having a photosensitive layer having a Vickers hardness of 160 or more is expensive, resulting in increased manufacturing costs.
Furthermore, there is a problem that images with sufficient density cannot be obtained due to low charge retention.

The present invention has been made based on the above-mentioned circumstances, and an object of the present invention is to provide an image forming method that uses a toner recycling system to produce images without fogging, black spots, or image stains caused by poor cleaning. An object of the present invention is to provide an image forming method capable of stably forming a good image with sufficient density over many times.

[Means to solve the problem]

To achieve the above object, the present invention provides an image forming method employing a toner recycling system, in which an image is formed using a toner comprising colored particles and organic fine particles smaller in diameter than the colored particles. It is characterized by

The average diameter of the primary particles of the organic fine particles is preferably 0.01 to 5 am.

The organic fine particles are preferably made of a vinyl polymer, more preferably an acrylic polymer, and particularly preferably made of polymethyl methacrylate.

Preferably, the toner further includes a fluidizing agent made of inorganic fine particles whose primary particles have an average diameter of 20 sμ or less.

The present invention will be explained in detail below.

In the present invention, a toner paste cycle stem is employed, and an image is formed using a specific toner.

The toner used in the present invention includes colored particles in which a toner component such as a colorant is contained in a binder resin, and poly&tib particles having a smaller diameter than the colored particles.

The organic fine particles constituting the toner have an average diameter of primary particles (particles separated into individual unit particles) of 0.01 to 5 nm.
It is preferable that it is, and especially 0.1-2.0.71 is preferable. When the average diameter of the organic fine particles is too large, the fluidity of the toner tends to decrease. On the other hand, when the average diameter of the organic fine particles is too small, cleaning failures tend to occur.

The proportion of organic fine particles is 0.0% of the total toner. O is preferably 1 to 3.0% by weight, particularly preferably 0.1 to 2.0% by weight. When the proportion of organic fine particles is too small, the fluidity of the toner tends to decrease and cleaning defects tend to occur. On the other hand, when the proportion of organic fine particles is excessive, triboelectric charging of the toner is likely to be inhibited.

The organic substance for forming the organic fine particles is not particularly limited, but vinyl polymers are preferred because they are relatively hard and can sufficiently improve fluidity and cleaning properties. Such vinyl polymers can be produced by various polymerization methods such as emulsion polymerization and suspension polymerization, but the emulsion polymerization method is preferred because small-diameter, spherical organic fine particles can be efficiently obtained. In particular, it is preferable to obtain a vinyl polymer by emulsion polymerization without using an emulsifier in a system in which the monomer itself has an emulsifying effect.

Examples of vinyl polymers include acrylic polymers, styrene polymers, vinyl group-containing fluororesins, and the like. Among these, acrylic polymers are particularly preferred.

That is, the organic fine particles made of an acrylic polymer exhibit an excellent cleaning performance improvement effect.

Such acrylic polymers are homopolymers or copolymers obtained by polymerizing monomers selected from acrylic acid, acrylic esters, methacrylic acid, and methacrylic esters. .

Acrylic monomers used to obtain such acrylic polymers include acrylic acid, methyl acrylate,
Ethinoacrylate n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octinopea acrylate dodecyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, acrylic acid phenyl, α-
Methyl chloroacrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate,
n-butyl methacrylate, isobutinope methacrylate, n-octinope methacrylate, dodecyl methacrylate, lauryl methacrylate, 2-ethylhexynope methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, methacryl Diethylaminoethyl acid and the like can be mentioned.

Among the acrylic polymers, polymethyl methacrylate is particularly preferred. With polymethyl methacrylate, uniform and small-diameter organic fine particles can be easily obtained,
In addition, since it is appropriately hard, the effect of improving fluidity and cleaning properties is significantly improved, and since there is no fear of inhibiting the triboelectric charging properties of the toner, stable developing performance can be obtained.

The acrylic polymer may be copolymerized with other monomers, if necessary.

In this case, it is preferable to use the acrylic monomer in a proportion of 50% by weight or more in the monomer composition. Such other monomers include styrene, 0-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene. , p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, pT! - Styrenic monomers such as nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene,
Acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide; vinyl esters such as vinyl acetate and pininope 8M vinyl butyrate; vinyl ethers such as vinyl methyl ether and vinyl ethyl ether; vinyl ketones such as vinyl methyl ketone; Diene necks such as phtadiene and isoprene; unsaturated carboxylic acids such as maleic acid and fumaric acid; and others.

In the present invention, the toner further comprises a fluidizing agent made of inorganic fine particles whose primary particles (particles separated into individual unit particles) have an average diameter of 20 μm or less, preferably 5 to 18 μm. It is preferable.

By using such a fluidizing agent together with organic fine particles, images with excellent image quality can be stably formed many times in a toner recycling system. When the average diameter of the fluidizing agent is too large, damage is likely to occur on the surface of the latent image carrier, resulting in black spots on the image.

The proportion of such fluidizing agent is 0.05 to 2.0% of the total toner.
0% by weight is preferred, particularly 0.1-1.0% by weight. When the proportion of the fluidizing agent is too small, the effect of improving fluidity is low, and when the proportion is too large, black spots are likely to occur.

Examples of constituent materials of the inorganic fine particles constituting the fluidizing agent include oxides such as silica, titanium oxide, aluminum oxide, zirconium oxide, barium titanate, lead titanate, and barium carbonate; nitrides such as silicon nitride and boron nitride. ;Carbides such as silicon carbide, aluminum carbide, titanium carbide:
Others can be mentioned. These inorganic fine particles may be surface-treated. Particularly preferred are silica fine particles or surface-treated silica fine particles. As the surface treatment agent, for example, a silane coupling agent, a titanium coupling agent, etc. can be used. The surface-treated silica fine particles are highly stable against environmental changes such as temperature and humidity, so that the environmental dependence of the triboelectric charging property of the toner can be suppressed to a small level.

It is preferable that organic fine particles, which are essential components of the toner, and a fluidizing agent, which is used as necessary, be added to and mixed with the colored particle powder from the outside. Specifically, the organic fine particles and the fluidizing agent are made to exist on the surface of the colored particles by mixing the powder of the colored particles, the powder of the organic fine particles, and the fluidizing agent using a mixing device such as a V-type blender. It is preferable.

The colored particles are particles in which toner components such as a colorant, an anti-offset agent, a charge control agent, and a magnetic material are contained in a binder resin.

The binder resin constituting the colored particles is not particularly limited, and various resins can be used. Specifically, styrene resins, acrylic resins, styrene-acrylic copolymer resins, epoxy resins, polyester resins, etc. can be mentioned. These resins may be used in combination.

The styrene/acrylic copolymer resin used as the binder resin is a resin made of a copolymer of a styrene monomer and an acrylic monomer. Examples of styrenic monomers include styrene, 0-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, and p-methylstyrene. -tert-butylstyrene, p-n
-hexylstyrene, p-n-octylstyrene, p-
n-nonylstyrene, p-n-decylstyrene, p-n
-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, and the like.

Acrylic monomers include acrylic acid, methyl acrylate, ethyl acrylate, in-butyl acrylate, isobutynopear acrylate, propyl acrylate, and n-acrylate.
- octyl, dodecyl acrylate, urinoacrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, pheninope acrylate α-chloroacrylate metinope acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, Propyl methacrylate, n-butinope methacrylate, isobutinope methacrylate, n-octinope methacrylate, dodecyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearinope methacrylate, pheninope methacrylate, methacrylate Mention may be made of dimethylaminoethyl, diethylaminoethyl mecrylate, acrylonitrile, acrylamide, and others.

Examples of colorants include carbon black, nigrosine dye, aniline blue, calco oil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green offsalate,
Mention may be made of lamp black, rose bengal, mixtures thereof, and others.

Examples of the charge control agent include metal complex dyes, nigrosine dyes, ammonium salt compounds, and the like.

Examples of anti-offset agents include low softening point polyolefins, high melting point paraffin waxes, silicone resins, fatty acid esters or partially saponified products thereof, fatty acid amide compounds, higher alcohols, and the like.

Magnetic substances include substances that are strongly magnetized in the direction of a magnetic field, such as metals or alloys that exhibit ferromagnetism such as iron, ferrite, and magnetite, such as iron, nickel, and cobalt, compounds containing these elements, and ferromagnetic elements. Alloys that do not contain manganese and copper but become ferromagnetic through appropriate heat treatment, such as manganese-copper-aluminum, manganese-copper-tin, etc. Alloys called Heusler alloys that contain manganese and copper, dioxide Chromium, and others can be mentioned. The average particle size of the magnetic material is 0.1
It is preferable that it is uniformly dispersed and contained in the form of a finely divided powder of ~lIm. When obtaining a magnetic toner, the content of the magnetic material is preferably 20 to 80% by weight, particularly preferably 30 to 70% by weight, based on the total toner.

When forming a two-component developer, a carrier is mixed with the above toner. Such a carrier is not particularly limited, and conventionally known carriers can be used.

Specifically, there are uncoated carriers composed only of magnetic particles, coated carriers in which the surfaces of magnetic particles are coated with resin, and magnetic substance-dispersed carriers in which magnetic particles are dispersed in resin particles. Any of the above can be used.

The magnetic particles constituting the carrier include materials that are strongly magnetized in the direction of a magnetic field, such as iron, ferrite,
Metals or alloys that exhibit ferromagnetism, such as magnetite, iron, nickel, and cobalt, or compounds that contain these elements; alloys that do not contain ferromagnetic elements but become ferromagnetic through appropriate heat treatment, e.g. An alloy called Heusler alloy such as manganese-copper-aluminum or manganese-copper-tin, or particles made of chromium dioxide or the like can be used.

The average particle size of the carrier is preferably 30 to 200 tnR, particularly preferably 40 to 150 nR. When the average particle size of the carrier is too small, a so-called carrier adhesion phenomenon occurs in which the carrier adheres to and is fixed on the electrostatic latent image, resulting in an unclear image; on the other hand, when the average particle size of the carrier is too large In this case, image distortion may occur.

Here, the average particle diameter (weight) of the carrier is a value measured using "Microtrack" (manufactured by Nikkiso Co., Ltd.).

Next, each step of the image forming method of the present invention will be specifically explained.

(Developing process) Using a one-component developer or a two-component developer composed of a toner containing organic fine particles as an essential component, this is transported to a developing area by a developer transporting carrier, and this developer is used to The electrostatic latent image on the latent image carrier is developed to form an unfixed toner image.

The developing method is not particularly limited, and conventionally known methods can be applied. Specifically, the following methods can be mentioned.

■ A magnetic brush of the developer is formed on the developer transport carrier, and the thickness is larger than the gap in the development area. A contact magnetic brush development method that develops by attaching toner in a magnetic brush to an electrostatic latent image while rubbing.

■A magnetic brush of developer with a thickness smaller than the gap in the developing area is formed on the developer transporting carrier, and this magnetic brush is conveyed to the developing area, and a magnetic plan is created by applying an electric field of tJl to the developing area. A jumping magnetic brush development method that develops by causing the toner inside to fly and adhere to an electrostatic latent image.

■Cascade development method.

(Transfer step) The unfixed toner image on the latent image carrier obtained by development is transferred to a recording material. In this transfer step, either an electrostatic transfer method or a bias transfer method can be applied, and the electrostatic transfer method is particularly preferably used. Specifically, for example, a transfer device that generates a DC corona discharge is placed so as to face the latent image carrier through the recording material, and the latent image is carried by applying the DC corona discharge to the recording material from the back side. The unfixed toner image carried on the surface of the body is transferred to the surface of the recording material.

(Cleaning step) Toner remaining on the latent image carrier after the transfer step is cleaned. The cleaning means is not particularly limited, but a cleaning device having a cleaning blade disposed in contact with the surface of the latent image carrier can be preferably used. According to this cleaning device, residual toner is scraped off by rubbing the surface of the latent image carrier with the cleaning blade.

In order to facilitate cleaning, it is preferable to add a static elimination process to neutralize the surface of the latent image carrier before the cleaning process.

This static elimination step can be performed, for example, using a static eliminator that generates AC corona discharge.

(Recycling Step) The toner collected by cleaning is returned to the developing device through an appropriate recycling system and reused.

FIG. 1 is an explanatory diagram showing an example of a recycling system. 20 is a collection drum, and this collection drum 20 is supported coaxially with the drum-shaped latent image carrier (not shown) through a barrier (not shown) at the negative end side of the latent image carrier (not shown). A plurality of magnets 21 are fixedly provided inside the collection drum 2o along its outer periphery.
A conveyor belt 22 is suspended around the outer periphery of the conveyor belt 22 .

23 is a cleaning mechanism, and this cleaning mechanism 23 extends so as to face the cleaning area of the latent image carrier and also to face the collection drum 20.

In this cleaning mechanism 23, the toner remaining on the latent image carrier is scraped off and collected by, for example, a blade, and the collected toner is supplied to the exit 25 side by a screw conveyor 24 provided inside. be done.

26 is a developing mechanism, and this developing mechanism 26 includes a rotating drum-shaped magnetic brush mechanism 27 arranged to face the developing area of the latent image carrier and also face the collection drum 20;
It has a developer stirring mechanism 28 and a toner receiving and distributing mechanism 29 that receives the collected toner and distributes it into the developing mechanism 26. After passing through the gap with 27,
The toner receiving and distributing machine 82 of the developing mechanism 26 passes through the gap between the collection drum 20 and the outlet 25 of the cleaning mechanism 23.
The collecting drum 20 and the rollers 30 and 31 are mounted on a rack so as to reach the height of 9. 27a is a rotating sleeve, and 27b is a magnet.

In this example, when the conveyor belt 22 is moved, the conveyor belt 22 moves between the collecting drum 20 and the magnetic brush mechanism 2.
7, the magnetic plan mechanism 27 forms a magnetic blanket of the developer on the conveyor belt 22, and as the conveyor belt 22 moves, this magnetic plan is transferred to the IJ-ning mechanism 23. When transferred, the toner collected from the latent image carrier by the cleaning mechanism 23 and supplied to the exit 25 side by the screw conveyor 24 is picked up by the magnetic plan on the conveyor belt 22, and as the conveyor belt 22 moves, the toner is The toner picked up by the magnetic brush is conveyed to the toner receiving and distributing mechanism 29, where the toner is stored in the developing mechanism 26, and the collected toner is again used to develop the latent image on the latent image carrier. .

FIG. 2 is an explanatory diagram showing another example of the recycling system. 41 is a developing mechanism, 42 is a cleaning mechanism, 43 is a toner receiving and distributing mechanism, 44 is a magnetic brush mechanism, 45 is a latent image carrier, 46 is a screw conveyor, 47 is a first screw, and 48 is a second screw. In the example device, toner from the screw conveyor 46 is supplied to the toner receiving and distributing mechanism 43 by a first screen 5-47 and a second screen 5-48. That is, the first screw IJ, -47 and the second screw 'J 5-48 each have an internal rotating shaft and a blade spirally provided along the rotating shaft, and in the first screw 47, The toner sent by the screw conveyor 46 is sequentially pushed up by the blades as the rotary shaft rotates and is sent to the second screw L-48.
8, the toner is sequentially fed in the horizontal direction using the same principle as the first screw 47, and the toner receiving and distributing mechanism 43
The collected toner is used again to develop the latent image on the latent image carrier 45.

(Fixing Step) The recording material onto which the unfixed toner image has been transferred in the transfer step is subjected to a fixing process using a heat fixing device, a pressure fixing device, or the like, thereby forming a fixed toner image on the recording material.

〔Example〕

Examples of the present invention will be specifically described below, but the present invention is not limited to these Examples.

Example 1 (Production of binder resin) 299 g of terephthalic acid and polyoxypropylene <2.
2) 211 g of -2,2-bis(4-hydroxyphenyl)propane and 82 g of pentaerythritol were placed in a round-bottomed flask equipped with a thermometer, a stainless steel stirrer, a glass nitrogen gas inlet tube, and a down-flow condenser. and set this flask on the mantle heater,
Nitrogen gas was introduced through the nitrogen gas inlet tube to raise the temperature of the flask while maintaining an inert open atmosphere inside the flask. Next, 0.05 g of dibutyltin oxide was added and reacted at a temperature of 200°C while monitoring the reaction at the softening point.
01. : A polyester having a ring and ball softening point of 131°C was obtained. This is referred to as "binder resin 1."

(Manufacture of toner) 1100 parts by weight of the above-mentioned binder resin, carbon black "Mogul LJ" (manufactured by Cabot Corporation), 10 parts by weight of low molecular weight polypropylene "Viscol 660P" (manufactured by Sanyo Chemical Industries, Ltd.), and 3 parts by weight or more of the substance are melt-kneaded, After cooling, it is crushed, classified, and the average particle size is lb.
Colored particle powder 1 of zm was obtained.

Next, organic fine particles (polymethyl methacrylate) IJ particles, average diameter of primary particles = 500, were added to the colored particle powder 1.
xμ) powder at 1.0% by weight, the fluidizing agent “R-972J (
Hydrophobic silica fine particles, average diameter of primary particles = 16u,
(manufactured by Nippon Aerosil Co., Ltd.) was mixed and stirred at a ratio of 0.8% by weight to produce Toner 1.

(Preparation of developer) Ferrite particles whose surfaces are coated with methyl methacrylate-styrene copolymer resin have an average particle diameter of 100
A two-component developer 1 having a toner concentration of 4% by weight was produced by mixing the μ-dust coated carrier and the above-mentioned toner 1.

(Actual photocopying test) Using the above two-component developer 1, an electrophotographic copying machine rU-8ix 5000J (Konica
A photocopying test was carried out using a modified machine (manufactured by Kawasaki Co., Ltd.), in which a copy image was repeatedly formed 100,000 times.

(Evaluation) Up to the final round of the actual photocopying test, no fog, black spots, or image stains due to poor cleaning were observed, and copies of high image density and clear image quality were stably obtained.

Comparative Example 1 For comparison, a comparative toner was produced in the same manner as in Example 1 except that organic fine particles were not used.
A comparative two-component developer was prepared in the same manner using this comparative toner.

When a live copying test was conducted using this comparative two-component developer in the same manner as in Example 1, it was observed that fogging occurred due to a decrease in fluidity after the number of copies exceeded 50,000 times. Furthermore, after the number of copies exceeded 10,000, black spots due to scratches on the surface of the latent image carrier were observed, and
After the number of copies exceeded 350,000 times, I was forced to complain that some of the images were due to poor cleaning.

Example 2 In the production of the toner of Example 1, PL-containing fine particles were used, and the average diameter of the primary particles was 600! Toner 2 was obtained in the same manner except that the amount of polymethyl methacrylate fine particles (JJJ) was changed to 1.2% by weight.

A two-component developer was prepared in the same manner using this Toner 2.

When a live-action test was conducted using this two-component developer in the same manner as in Example 1, up to the final round of the live-action test,
No fogging, black spots, or image stains due to poor cleaning were observed, and furthermore, a copy image with high image density and clear image quality was stably obtained.

Example 3 Toner 3 was obtained in the same manner as in Example 1 except that the organic fine particles were changed to 0.7% by weight of polymethyl methacrylate fine particles having an average primary particle diameter of 300 μm.

A two-component developer was prepared in the same manner using this Toner 3.

When a live-action test was conducted using this two-component developer in the same manner as in Example 1, up to the final round of the live-action test,
No fogging, black spots, or image stains due to poor cleaning were observed, and furthermore, a copy image with high image density and clear image quality was stably obtained.

〔Effect of the invention〕

According to the present invention, since the toner contains organic fine particles, the fluidity and cleaning properties of the toner are improved due to the so-called spacer effect of the organic fine particles.Therefore, while the toner can be used economically due to the recycle stem, fogging can be prevented. Good images can be stably formed many times without black spots or image stains caused by poor cleaning.

Along with the organic fine particles, the average diameter of the primary particles is 20
When using a toner that contains a fluidizing agent made of inorganic fine particles with a shoulder μ or less, the organic fine particles present on the surface of the colored particles sufficiently prevent the fluidizing agent from embedding into the colored particles, making it easy to recycle. Therefore, even when the toner is subjected to considerable mechanical stress, the fluidity improving effect of the fluidizer is stably exhibited. Therefore, in order to prevent the fluidizer from being embedded, the average diameter of the fluidizer is increased. As a result, the effect of improving fluidity can be stably obtained without causing damage to the latent image carrier. Moreover, since the average diameter of the primary particles of the fluidizing agent is 20 μm or less, it is possible to effectively prevent the generation of scratches on the latent image carrier, and there is no need to use a particularly hard latent image carrier. Therefore, the selection range of latent image carriers is greatly expanded, and it becomes possible to use latent image carriers that are inexpensive and have excellent charge retention properties.As a result, it is possible to obtain sufficient image density without increasing costs. It is possible to stably form images over and over again.

Furthermore, organic fine particles whose primary particles have an average diameter of 0.01 to 5 μm can reliably exhibit a good spacer effect without impairing the toner properties.

Further, organic fine particles made of vinyl polymer are relatively hard and exhibit a good effect of improving cleaning properties.

Furthermore, organic fine particles made of an acrylic polymer exhibit an excellent effect of improving cleaning properties.

In particular, organic fine particles made of polymethyl methacrylate can be easily obtained as uniform and small-diameter organic fine particles, and because they are moderately hard, they exhibit a remarkable effect of improving fluidity and cleanability. Furthermore, since there is no risk of inhibiting the triboelectric charging properties of the toner, stable developing performance can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of a toner paste recycling system, and FIG. 2 is an explanatory diagram showing another example of a toner recycling system. 20... Collection drum 21... Magnet 22...
・Transport belt 23...Cleaning 14 stations 2
4...Screw conveyor 25...Outlet 26...Developing mechanism 27
...Magnetic brush mechanism 2B...Developer stirring mechanism 2
9... Toner receiving and distributing mechanism 30. 31... Roller 27a... Rotating sleeve 27t)... Magnet 41... Developing mechanism 42... Cleaning mechanism 43... Toner receiving and distributing mechanism 44...・Magnetic brush mechanism 45...Latent image carrier 4
6... Screw conveyor 47... 1st screen: L-48... 2nd screen + 1 figure 2 figure

Claims (6)

[Claims] (1) An image forming method employing a toner recycling system, characterized in that an image is formed using a toner comprising colored particles and organic fine particles smaller in diameter than the colored particles. . (2) The average diameter of the primary particles of organic fine particles is 0.01 to 5μ
The image forming method according to claim 1, wherein the image forming method is m. (3) The image forming method according to claim 1 or 2, wherein the organic fine particles are made of a vinyl polymer. (4) The image forming method according to claim 3, wherein the vinyl polymer is an acrylic polymer. (5) The image forming method according to claim 4, wherein the acrylic polymer is polymethyl methacrylate. (6) The image forming method according to any one of claims 1 to 5, wherein the toner further comprises a fluidizing agent made of inorganic fine particles whose primary particles have an average diameter of 20 mμ or less.