JPS6199164A - Electrophotographic developing method - Google Patents

Abstract

PURPOSE:To eliminate filming, etc. on the surface of a photosensitive body by developing the electrical latent image on the photosensitive body by a microcapsule toner in which a polishing material having the grain size of 0.1-5 times the thickness of a shell material is made to exist at the boundary between the core material and shell material. CONSTITUTION:The core material particles are preliminarily formed by a spray drying method, etc. and are dried; thereafter, the particles are mixed with the polishing material in a mixer to disperse these materials into good solvents consisting of >=1 kinds, then a bad solvent is gradually added into the dispersion thereof to set and fix the shell material on the surface of the core material particles. The microcapsule toner in which the polishing material having the grain size of 0.1-5 times the thickness of the shell material is made to exist is thus obtd. The electrical latent image on the photosensitive body consisting of an org. photosensitive body is developed by using such microcapsule toner. The generation of welding and filming etc. of the toner material is suppressed by the above-mentioned method.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for developing an electrical latent image on a photosensitive drum made of an organic photoconductor with a capsule toner suitable for pressure fixing.

11-3 Conventionally, as electrophotography methods, US Pat.
A number of methods are known, as described in Japanese Patent No. 24748, etc., but generally one uses a photoconductive substance.
forming an electrical latent image on a photoreceptor containing a photoconductive material by various means and then developing the latent image with a toner;
After transferring the toner image to a transfer material such as paper as necessary,
The toner is fixed on a transfer material by heat, pressure, solvent vapor, etc. to obtain a copy.

Methods for fixing toner on recording materials such as paper by applying pressure are disclosed in U.S. Pat. It has many advantages, such as copying without waiting time when the power is turned on, no risk of burning the copy paper, high-speed fixing, and simple fixing device.

However, in the conventional pressure fixing method, satisfactory fixing performance cannot be obtained unless the recording material is specially treated, and the fixing pressure is as high as 20 to 40 kg/cm linear pressure. It had certain drawbacks. Furthermore, soft materials are often used as toner materials for pressure fixing, and as a result, the pot life is poor, toner particles aggregate or coalesce during storage, and even blocking occurs. Undesirable phenomena such as filming on body surfaces, carrier contamination, and offset due to adhesion to the fusing roller occur.

Therefore, in recent years, in order to overcome these drawbacks, various microcapsule toners in which a soft material is covered with a hard shell material have been proposed, and these have contributed to improving the above drawbacks. In each process such as cleaning the photoreceptor, a part of the photoreceptor is destroyed, causing problems such as filming, fusion, and carrier contamination on the photoreceptor.

On the other hand, photoreceptors using organic photoconductors are superior to photoreceptors using inorganic photoconductive materials such as selenium, cadmium sulfide, zinc oxide, or amorphous silicon in terms of film formability and light weight. Sensitivity was a problem in the past, but by adopting an electrophotographic photoreceptor with a laminated photosensitive layer that has the functions of a charge generation layer and a charge transport layer, sensitivity to visible light has been improved. Improvements have been made in terms of charge retention, surface strength, etc.

Electronic photo 1Lli like this! The light body is e.g.
It is disclosed in t53837851, t3871882, etc.

However, since the charge transport layer that forms the surface of a photoreceptor using an organic photoconductor contains a charge transport substance and a polymeric binder for film formation, it is not compatible with toners using an organic resin binder. There is a problem in that the toner is more likely to adhere to the surface of the photoreceptor than inorganic photoreceptors such as selenium or amorphous silicon. Particularly when a pressure-fixable toner is used, since a soft material is inevitably used, the toner tends to adhere to the surface of the photoreceptor.

The purpose of the present invention is to provide an electrophotographic developing method that solves the above-mentioned drawbacks.

In other words, it is caused by the destruction of the capsule toner.

The present invention provides an electrophotographic development method in which filming and fusion on the surface of a photoreceptor are removed using an abrasive.

More particularly, the object of the present invention is to use organic photoconductors and microcapsule toners for pressure fixing.

In addition, it prevents the toner material from fusing and filming on the surface of the photoreceptor caused by the destruction of the capsule toner,
Another object of the present invention is to provide an electrophotographic method that prevents negative effects such as white spots and stains on images based on the method.

Another object of the present invention is to provide an electrophotographic developing method that makes it easier to store and use microcapsule toner by reducing the effects of microcapsule toner destruction.

&JJL11 The electrophotographic developing method of the present invention was developed to achieve the above-mentioned object. More specifically, the electrophotographic developing method of the present invention was developed to achieve the above object. It is characterized by developing with a microcapsule toner in which abrasive particles having a particle size of 0.1 to 5 times the thickness of the shell material are present at the interface with the shell material.

That is, to achieve the above-mentioned purpose, toner has conventionally contained abrasive particles.

Alternatively, it has been proposed to prevent IF of the toner material on the photoconductor from fusing, filming, or its adverse effects by using a toner with abrasive particles attached to the surface by externally adding and mixing toner and abrasive particles. However, in pressure fixing toners that use soft materials as a whole, even if abrasive particles are attached to the surface, the abrasive particles will be buried inside the toner and will not be used effectively, making it impossible to achieve the intended purpose. was not achieved. On the other hand, in the case of the present invention, the abrasive particles are present along the regular interface between the core material and the shell material, and particularly preferably, the core material with the abrasive particles attached to the surface is attached to the shell material. By using the microcapsule toner obtained in the form of coating with abrasive particles, the abrasive particles are firmly held and used effectively, and conversely, the microcapsule toner is reinforced by the abrasive particles. .For this reason,
In particular, phenomena such as fusion of toner materials and filming due to destruction of the capsule toner on the photoconductor, which were problems in the combination of a photoconductor using an organic photoconductor and a pressure-fixable toner, are less likely to occur. In addition, even if this occurs, by effectively utilizing the abrasive particles, it becomes possible to effectively remove the adverse effect on the development characteristics.

The present invention will be explained in more detail below. In the following description, "1%" and "part" expressing a quantitative ratio are based on weight unless otherwise specified.

1.1 As the binder for the core material used in the present invention, basically any soft resinous material is used, but among them, Kaheshinahachi wax, polyethylene wax, polyethylene oxide, paraffin, fatty acid ester, fatty acid Amide,
Fatty acid metal salts, waxes such as higher alcohols, ethylene-vinyl acetate resin, cyclized rubber, etc. can be suitably used.

Moreover, although the granulation method is arbitrary, a suspension method is particularly preferred.

Further, a coloring agent and a magnetic substance can be added to the core material as necessary.

As the coloring agent contained in the core material of the capsule toner of the present invention, known dyes and pigments can be used.

For example, various carbon blacks, nigrosine dyes, lamp black, Sudan Black SM, First Yellow G1
Benzidine Yellow, Pi) fLant Yellow, India First Orange, Irgazine Red, Varanitroaniline Red, Toluidine Red, Carmine FB, Perpennent Bordeaux FRR, Pigmento Orange R, Lysol Red 2G, Rake Fist Sid C,
Rhodamine FB, Rhodamine B Lake, Methyl A Hiolet) B Lake, Phthalocyanine Blue, Pigme
[1st blue, brilliant green B
, Phthalocyanine Green, Oil Yellow GG, Zapon First Niro 10 GG, Kayaset Y983, Kayaset YG, Sumiplast Jiro G, Zapon First Orange RR, Oil Scarlet, Sumiplast Orange G, Orazole Brown B, Pomelo Applicable to First Scarlet CG, Eizen Spiron Shi, Do BEH, Oil Pink OP, etc. These colorants.

It is preferably contained in the core material in a proportion of 1 to 15%, particularly 3 to 10%.

As the magnetic substance contained in the core material of the capsule toner of the present invention, ferromagnetic elements such as iron, cobalt, nickel, or manganese, and alloys and compounds containing these such as magnetite and ferrite are used. This magnetic substance may also be used as a coloring agent.Furthermore, particles of this magnetic substance are contained in the core material after being treated with various hydrophobizing agents such as silane coupling agents, titanium coupling agents, surfactants, etc. The content of this magnetic substance is preferably 15 to 100 parts by weight per 100 parts by weight of all the resin in the core material.

According to the present invention, the abrasive particles are preferably present at the interface between the core material and the shell material, which is obtained by covering the surface of the core material with abrasive particles attached to the shell material. Use capsule toner.

Metal saponides, nitrides, and carbides are preferably used as abrasives, and specific examples of metal oxides include:
For example, tin oxide, cerium oxide, zirconium oxide,
Examples of nitrides include titanium dibenride, zinc oxide, aluminum oxide, iron sesquioxide, calcium titanate, strontium titanate, and barium titanate.
Examples of carbides include boron carbide, silicon carbide, tungsten carbide, and titanium carbide.
The abrasive material used in the present invention not only has the function of strengthening the capsule toner, but also has the main effect of partially destroying the capsule toner during processes such as before image fixation, development transfer, and cleaning on the photoreceptor. If filming or fusion occurs, it is removed by the action of an abrasive, and the particle size is 0°1 to 5 times, especially 0.5 to 2 times, the thickness of the shell material. things are suitable.

Abrasive particles with a particle size less than 0.1 times the shell material thickness will not be separated from the shell material when the toner is destroyed, and the abrasive force will be small, and abrasive particles with a particle size greater than 5 times the shell material thickness will not be separated from the shell material when the toner is destroyed. It cannot be retained in the shell material and separates from the microcapsule toner, causing destruction of the toner and damage to the photoreceptor. The above particle size range may be satisfied as an average particle size, but more preferably, 95% or more of the abrasive particles are within the above particle size range.

In addition, in order to adhere the abrasive material to the surface of the core material, it is desirable to mix the core material and the abrasive material in a mixer.
It is preferably used in the range of 0.1 parts by weight to 5 parts by weight. If the amount added is less than 0.01 parts by weight, it is insufficient in quantity to remove filming or fused materials of toner material formed on the photoreceptor, and if it exceeds 10 parts by weight, it may cause damage to the core material. Not retained*
This is not preferable since it has the disadvantage of producing an abrasive material.

As the constituent material of the shell material, known resins can be used, such as resins made of homopolymers or copolymers of the following monomers. Styrene and its substituted products such as styrene, P-chlorostyrene, and P-dimethylamino-styrene; methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, N, N methacrylate - Acrylic acid or methacrylic acid esters such as dimethylaminoethyl ester; maleic anhydride or maleic anhydride halfesters, half amides or diesterimides; nitrogen-containing vinyls such as vinylpyridine and N-vinylimidazole; vinyl formal, vinyl butyral, etc. vinyl acetals; vinyl nitrates such as vinyl chloride, trigonitrile, alcoholic acid, and vinyl nitrile; vinylidene monomers such as vinylidene fluoride and vinylidene fluoride; and olefin monomers such as ethylene and fluoropylene. Also, polyester, polycarbonate, polysulfonate, polyamide, polyurethane, polyurea, epoxy resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin.

Melamine resins, polyether resins such as polyphenylene oxide, or thioether resins are also preferably used. Moreover, these resins can of course also be used as a mixture.

Various known encapsulation techniques can be used to produce capsule toners, such as spray drying, interfacial polymerization, coacervage, phase separation, 1n-situ polymerization, and U.S. Pat. 3,338,99
Specification No. 1, Specification No. 3,328,848, Specification No. 3
, 502.582 can be used.

In the present invention, a particularly preferred method is to generate core particles in advance by spray-trying or by applying a strong shearing force in an aqueous medium in the presence of an emulsifier or/and suspending agent. After drying, the shell material is mixed with the abrasive material in a mixer, then dispersed in a good solvent containing at least one kind of material, and by gradually adding a poor solubilizer to the already dispersion medium solution, the shell material material is made into a core. A method of encapsulating the material by fixing it on the surface of the material particles can be advantageously used. At this time, it is also possible to use the product after removing the emulsifier and/or suspending agent as a pretreatment for the encapsulation step, if necessary.

In this way, the abrasive particles are present at the interface between the core material and the shell material, and the a# thickness is 0.01 to 2 m, preferably 0.1 to 0.3 m, and the average particle size is However, a capsule toner having a size of 3 to 20 square meters, preferably 5 to 17 square meters can be obtained. The thickness of the shell material in the above is based on the value obtained by preparing a cross-sectional thin film of the toner using a microtome, taking a photograph of the cross-section using a transmission electron microscope, and averaging the film thickness per 100 toner pieces. ing.

Carbon black, various dyes and pigments, hydrophobic colloidal silica, etc. can be further added or mixed with the capsule toner for the purpose of charge control, imparting fluidity, R color, etc.

Photoconductive organic pigments for the photoreceptor used in the present invention include azo pigments and phthalocyanine pigments.

Quinacridone pigments, cyanine pigments, pyrylium pigments, thiopyrylium pigments, indigo pigments, scaric acid pigments, polycyclic quinone pigments, and the like can be used as charge-generating materials for electrophotographic photoreceptors.

As pigment dispersants, alcohol solvents such as methanol, ethanol, and isopropylfluorol, acetone,
Ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, aromatic solvents such as benzene, toluene, xylene, and chlorobenzene, DMF, D
Dispersion means that can use various solvents such as MAC include:
Methods such as a sand mill, colloid mill, attritor, and ball mill can be used.

Binder resins include polyvinyl butyral, formal resin, polyamide resin, polyurethane resin, cellulose resin, polyester resin, polysulfone resin,
Polycarbonate resin.

Acrylic resin, styrene resin, etc. are used.

The charge generation layer can be formed by coating a dispersion of the above pigment and resin onto a conductive support directly or via an adhesive layer. It may also be coated on the charge transport layer. The thickness of the charge generation layer is preferably a thin M layer with a thickness of 5K or less, preferably 0.01 to IIL, so that most of the incident light is absorbed by the charge generation layer and a large amount of charge is generated. The above film thickness is preferable because it is necessary to generate charge carriers and to inject the generated charge carriers into the charge transport layer without being deactivated by recombination or trapping.

For coating, dip coating method, spray coating method,
spinner coating method, beat coating method, Meyer bar coating method, blade coating method,
This can be carried out using a coating method such as a roller coating method or a curtain coating method. Drying is preferably carried out by drying to the touch at room temperature and then heating. Drying by heating can be carried out at a temperature of 30° C. to 200° C. for a period of 5 minutes to 2 hours, either stationary or under ventilation.

The charge transport layer is electrically connected to the charge generation layer described above, and has the function of receiving and taking charge carriers injected from the charge generation layer in the presence of an electric field, and transporting these charge carriers to the surface. have. In this case, the charge transport layer may be laminated on top of the charge generation layer or under it; however, the charge transport layer may be laminated on the charge generation layer. This is desirable.

Charge-transporting substances include electron-transporting substances and hole-transporting substances, and electron-transporting substances include chloranil, bromoanil, and tetracyanoethylene.

Tetrasia/quinodimethane, 2,4,7-)linitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4,7-dolinito-a-9-dicyanomethylenefluorenone, 2,4 .5.7-Titranitroxanthone.

2.4.8-) There are electron-withdrawing substances such as linito-a-thioxant 7 and polymerized versions of these electron-withdrawing substances.

Examples of hole transporting substances include pyrene, N-ethylcarbazole, N-isopropylcarbazole, N-methyl-N
-Phenylhydrazino-3-methylidene-9-ethylcarbazole, N,N-diphenylhydrazino-3-methylidene-9-ethylcarbazole, N,N-diphenylhydrazino-3-methylidene-10-ethylphenothiazine.

N,N-diphenylhydrazino-3-methylidene-10
-Dithylphenoxazine, P-diethylaminobenzaldehyde-N,N-diphenylhydrazone, P-diethylaminobenzaldehyde-N-α-naphthyl-N-phenylhydrazono, P-pyrrolidinobenzaldehyde-
N,N-diphenylhydrazone, 1,3.3-)sltylindolenine-ω-aldehyde-N,N-diphenylhydran, P-diethylbenzaldehyde-3-methylbenzthiazolinone-2-hydrazone, etc. Hydrazones, 2,5-bis(P-diethylaminophenyl)-1
,3,4-oxadiazole.

1-phenyl-3-(P-diethylaminostyryl)-
5-(P-diethylaminophenyl)hilazoline, l-
[quinolyl(2))-3-CP-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline, l-[pyridyl(2))-3-(P-diethylaminostyryl)-5-(P-diethylaminophenyl ) Pyrazoline, l-[6-medoxypyridyl (2))-3-
(p-diethylaminostyryl)-5-(,P-diethylaminophenyl)pyrazoline, l-[pyridyl (3)
)-3-(P-diethylaminostyryl)-5~(p-
diethylaminophenyl)pyrazoline, 1-[lepidyl (2))-3-(P-diethylaminostyryl)-5-
(P-diethylaminophenyl)pyrazoline, l-[pyridyl(2))-3-(P-diethylaminostyryl)
-4-Methyl-5-(P-diethylaminophenyl) hilazoline, l-(pyridyl(2))-3-(α-methyl-P-diethylaminostyryl)-5-(P-diethylaminophenyl)pyrazoline, l-phenyl -3-(P
-diethylaminostyryl)-4-methyl-5-(P-
diethylaminophenyl) hyazoline, l-phenyl-
3-(α-benzyl-P-diethylaminostyryl)-
Pyrazolines such as 5-(P-diethylaminophenyl)pyrazoline and spiropyrazoline, 2-(p-diethylaminostyryl)-6-dinithylaminobenzoxazole, 2-(P-diethylaminophenyl)-4-
Oxazole compounds such as (P-diethylaminophenyl)-5-(2-chlorophenyl)oxazole, 2-
Thiazole compounds such as (P-diethylaminostyryl)-6-dinithylaminobenzothiazole, bis(4-
Triarylmethane compounds such as diethylamino-2-methylphenyl)-phenylmethane, 1. l-bis (4
-N,N-diethylamino-2-methylphenyl)hebutane, 1,1,2゜2-tetrakis(4-N,N-
Polyarylalkanes such as dimethylamino-2-methylphenyl)ethane, triphenylamine, poly-N-
Examples include vinylcarbasol, polyvinylpyrene, polyvinylanthracene, polyvinylacridine, poly-9-vinylphenylanthracene, pyrene-formaldehyde resin, and ethyl cartazoole formaldehyde resin.

Further, these charge transport substances can be used alone or in combination of two or more.

When the charge transport material does not have film-forming properties, a film can be formed by selecting an appropriate binder and mixing it with the binder. Resins that can be used as binders include, for example, acrylic resins, polyarylates, polyesters, polycarbonates, polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-butadiene copolymer, polyvinyl butyral, polyvinyl formal, polysulfone polyacrylamide, polyamide, insulating rubber such as II rubber. or organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthra7ane, and polyvinylpyrene.

The charge transport layer cannot be made thicker than necessary because there is a limit to its ability to transport charge carriers. Generally, the thickness is 5 to 30 microns, but the preferred range is 8 to 20 microns. be. When forming the charge transport layer by coating, any suitable coating method as described above for the charge generation layer can be used.

A photosensitive layer having such a laminated structure of a charge generation layer and a charge transport layer is provided on a substrate having a conductive layer. Examples of substrates having a conductive layer include those in which the substrate itself is conductive;
For example, aluminum, aluminum alloy, copper, zinc, stainless steel, vanadium, molybdenum, chromium chloride, titanium, nickel, indium, gold, platinum, etc. can be used, and in addition, aluminum, aluminum alloy, indium oxide, tin oxide, tin oxide, etc. can be used. Plastics (e.g., polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, polyethylene fluoride, etc.), conductive particles (e.g., carbon black , silver particles, etc.) together with a suitable binder, a substrate in which plastic or paper is impregnated with conductive particles, a plastic having a conductive polymer, etc. can be used.

A subbing layer having barrier and adhesive functions can also be provided between the conductive layer and the photosensitive layer. The subbing layer is casein,
Polyvinyl alcohol, nitrocellulose, ethylene-
(acrylic acid copolymer, polyamide nylon 6, nylon 66, nylon 610, copolymerized nylon, alkoxymethylated nylon, etc.), polyurethane/, gelatin,
It can be formed from aluminum oxide, etc.

The thickness of the undercoat layer is suitably 0.1 to 5 microns, preferably 0.3 to 3 microns.

When using a photoreceptor in which a conductive layer, a charge generation layer, and a charge transport layer are laminated in this order, and the charge transport material is an electron transport material, the surface of the charge transport layer must be positively charged, and exposure after charging is required. Then, in the exposed area, electrons generated in the charge generation layer are injected into the charge transport layer, and then reach the surface and neutralize the positive charge, causing a decrease in surface potential and creating an electrostatic contrast with the unexposed area. . A visible image can be obtained by developing the electrostatic latent image thus formed with a negatively charged toner. This can be directly fixed, or the toner image can be transferred to paper, plastic film, etc. and then developed and fixed.

Alternatively, a method may be used in which the electrostatic latent image on the photoreceptor is transferred onto an insulating layer of transfer paper, and then visually imaged and fixed. The type of developer, the developing method, and the fixing method may be any known ones or known methods, and are not limited to specific ones.

On the other hand, if the charge transport material is a hole transport material, the surface of the charge transport layer must be negatively charged.

After charging, when exposed to light, holes generated in the charge generation layer in the exposed area are injected into the charge transport layer, and then reach the surface and neutralize the negative charge, resulting in attenuation of one surface type and the gap between the exposed area and the unexposed area. Electrostatic contrast occurs. During development, it is necessary to use a positively charged toner, contrary to the case where an electron transport material is used.

The electrophotographic developing method of the present invention using the photoreceptor as described above can be used not only in electrophotographic copying machines but also in a wide range of electrophotographic applications such as laser printers and CRT printers.

As described above, according to the present invention, when developing an electrical latent image on a photoreceptor made of an organic photoconductor, a thickness of the shell material is formed at the interface between the core material and the shell material. By using a microcapsule toner in which abrasive particles having a particle size of 0.1 to 5 times as large are present, it is possible to solve the problem of the combination of a photoreceptor using an organic photoconductor and a pressure-fixable capsule toner. A developing method is provided which effectively eliminates phenomena such as fusing of toner materials, filming, etc. due to destruction of the capsule toner on the body, or its negative effects on development properties.

Below, the present invention will be further described with reference to Examples and Comparative Examples.
0 parts (manufactured by Nippon Seirosha) Styrene-dimethylaminoethyl methacrylate magnetic material 30 parts (EFT-100
(manufactured by Toda Kogyo) Each of the above ingredients was heated to 20 Or
The mixture was kneaded for 3 hours at pm.

On the other hand, in a 20J1 Ajihomo mixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), add 20 grams of water and wood-loving silica (Aerosil #200) in advance.
(manufactured by Nippon Aerosil Co., Ltd.) was added thereto and heated to 90°C.

I kg of the cross-wire melt was put into this dispersion medium, and granulation was carried out for 1 hour using a homomixer at a peripheral speed of 20 m/sec and a number of passes of 6.9 times/min. After completion of granulation, cooling was performed using a heat exchanger.

50 g of sodium hydroxide was added to this dispersion, and stirring was continued at room temperature for 5 hours. As a result of analyzing the obtained spherical core material particles by optical emission spectrometry, no residual silica was observed.

Furthermore, using a centrifugal filtration machine, filtration and water washing are performed to obtain a wick with a number average particle size of 12.2 lm, a volume average particle size of 14.3 pm, and a coefficient of variation of the volume average particle size of 20.0%. Material particles are 95
% yield.

After drying the obtained core material, place the core material 8 in a Henschel mixer.
00g was taken, 8g of titanium dioxide (abrasive) with a particle size of 0.20ILm was added, and the mixture was abrasive at 2,000 rpm for 30 seconds to adhere titanium dioxide to the surface of the core material.

This core material was thoroughly dispersed again using a 20-liter Ajihomo mixer to form a mixture having the composition shown below.

Core material particles 800gS L -
DM copolymer 64g dimethylformamide (DMF) 49.

After dispersion, ethanol is gradually added dropwise to the surface of the core material particles.
L-DM copolymer was precipitated. After adding one drop of ethanol, the mouth was rinsed using a centrifugal filtration machine and dried.
This microcapsule toner had no coalescence of particles, and when observed under a scanning electron microscope, it had a smooth surface with the core material completely covered with the wall material.

The thickness of the wall material is determined by preparing a thin film of microcapsule toner using a microtome, taking a photograph of the cross section using a transmission electron microscope, and averaging the wall material thickness per 100 toner particles, and the value is 0. It was 25 lm.

・Positive silica is externally added to this toner, and the image is transferred onto plain paper using a PC-12 improved machine using a PC-12 (manufactured by Canon) developer kit that uses an organic photoconductor. Then, this image was transferred to a metal roller (linear pressure 10 kg
/cm).

A continuous copying test of 3,000 sheets was conducted using the above method.
The average image density during the continuous copying test was 1.3, with almost no change.

Since a photoreceptor using an organic photoconductor was used, 1,50
There is a white spot where part of the image disappears on the 0th photo.

800th photo. On the 1,900th sheet, stains (black dots) appeared on the image due to the transfer of the fused toner on the photoreceptor, but after printing 20 more images, both the white spots and black dots disappeared, indicating that the addition of the abrasive was effective. It was shown to be effective.

A microcapsule toner was prepared using the same recipe and method as in Example 1, except that titanium dioxide with a particle size of 0.015 μm was used as the abrasive material attached to the core material.

The thickness of the wall material was 0.24 pm. The particle size of titanium dioxide with respect to the thickness of the wall material was 0.0625 times.

3 in combination with a photoreceptor using the organic photoconductor of the PC-12 developer as in Example 1.

A continuous copying test of 000 sheets was conducted.

1. White spots and black spots appear on the 500th sheet, and as the number of continuous copies increases, both the area of white spots and the number of black spots increase.
There was no effect because the particle size of the abrasive was less than 0.147: of the thickness of the wall material.

The abrasive material to be attached to the core material has a particle size of 2. A microcapsule toner was prepared using the same recipe and method as in Example 1, except that Ogm titanium dioxide was used.

The thickness of the wall material was 0.251 Lm. The particle size of titanium dioxide was 8 times larger than the thickness of the wall material.

Because the particle size of titanium dioxide is so large, during encapsulation, titanium dioxide detaches from the core material and separates from the toner. When positive silica is externally added to the toner, it causes destruction of the toner and causes continuous A copy test was not possible.

"L1 Negative" A micro-capsule toner was prepared using the same recipe and method as in Example 1, except that no abrasive material was used.

As in Example 1, a continuous copying test of 3.000 sheets was conducted using a developing device for PC-12 in combination with a photoreceptor using an organic photoconductor.

L: A white spot appeared on the 300th sheet and a spot appeared on the 1,50000th sheet, and both the area of the white spot and the number of black dots increased with the number of consecutive copies.

On Ll Carnauba wax 10 parts Polypropylene 10 parts 5P-0145 (manufactured by Hiki Seiro Co., Ltd.) 20 parts S t -DM copolymer
10 part magnetic material 50 parts (EF
T-1000 (manufactured by Toda Kogyo)) The above mixture was mixed and granulated in the same manner as in the method of Example 1 to obtain number average particle diameters to, s, c=
Core particles having a volume average particle size of 14.8 gm and a coefficient of variation of the volume average particle size of 25.0% were obtained in a yield of 95%.

After drying the obtained core material, place the core material 8 in a Henschel mixer.
Take 00g, particle size 0.50gm17) 8g silicon carbide
was added and audible for 30 seconds at 2.00 rpm to adhere silicon carbide to the surface of the core material.

This core material was again sufficiently dispersed using a 201 Ajihomo mixer to form a mixture with the following composition.

Core material particles: 800 g 5 T-DM copolymer: 80 g DMF 51 When dispersed water was gradually dropped, there was no coalescence of the particles, and when observed with a scanning electron microscope, silicon carbide was completely retained in the wall material. .

The thickness of the wall material was 0.39 part m, and the particle size of silicon carbide was 1.28 times the thickness of the wall material.

This microcapsule toner contains 0” and 5% positive silica.
was added externally, and according to the method of Example 1, it was combined with a photoreceptor using an organic photoconductor of a developing device for PC-12 to obtain a 3.0
A continuous copying test of 00 sheets was conducted.

White spots occurred on the 1,900th image and black spots occurred on the 2,000th image, but they disappeared after 30 images were produced.

°Polyethylene 20 parts Paraffin wax (PF-40 parts 155 days Kiseirosha*) St-DM copolymer 30 parts Phthalocyanine blue 10 parts Mix the above composition,
Use attritor.

The mixture was kneaded at 120° C. and 200 rpm for 2 hours.

On the other hand, water 201 and 2 g of anionic surfactant Newlex NR (NOF It) were collected in advance into a 2017 dihomo mixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) and heated to 90°C.The above kneaded mixture was added to this dispersion medium. Insert Ikg of material and increase peripheral speed to 1
Granulation was carried out for 30 minutes under the conditions of 8 m7 sec and 5 passes.

After completion of granulation, it was cooled using a heat exchanger. Furthermore, the surfactant was removed by passing this dispersion through a column containing a mixture of 7 anion exchange resin and a cation exchange resin. Furthermore, a centrifugal filter was used to rinse the mouth with water, and the a-average particle size was 9.
．． Core particles having a volume average particle size of 5 gm and a volume average particle size of 13.8 pm and a coefficient of variation of the volume average particle size of 28°2% were obtained in a yield of 90%.

After drying the obtained core material particles, 800 g of the core material was placed in a Henschel mixer, and 12 g of 0.30 μm silicon nitride was added.
was added and heated at 2000 rpm for 30 seconds to adhere silicon nitride to the surface of the core material.

Core material particles 800gSL-DM copolymer 120gDMF
10 Sentences After the mixture with the above composition was sufficiently dispersed, it was discharged and atomized using a spray nozzle device (manufactured by Mitsubishi Kakoki Co., Ltd.) equipped with a 7-task tomizer. As a result, there was no coalescence of particles and the silicon nitride was completely removed. A microcapsule toner incorporated into the wall material was obtained. The thickness of the wall material is 0
, 311Lrn, and the grain size of silicon nitride was 0.97 times the thickness of the wall material.

0.5% positive silica was externally added to this toner, ) +
-12g Ni* +! J ya (E F V 250
/ 400 (manufactured by Nippon Tetsuko Co., Ltd.) at a ratio of 88 g and combined with a photoreceptor using an organic photoconductor of a PC-12 developer according to the method of Example 1, and a continuous copying test of 3,000 sheets was conducted. Ta.

White spots occurred on the 1,000th sheet, and on the 2,400th sheet [1], a white spot appeared, but these disappeared by continuously printing 30 images.

Claims (1)

[Scope of Claims] 1. An electrical latent image on a photoreceptor made of an organic photoconductor is polished by polishing the interface between the core material and the shell material to have a grain size of 0.1 to 5 times the thickness of the shell material. An electrophotographic developing method characterized by developing with a microcapsule toner in which material particles are present. 2. The electrophotographic developing method according to claim 1, wherein the microcapsule toner is obtained by covering a core material with abrasive particles attached to the surface with a shell material.