JPS59177569A - Pressure fixable toner and its manufacture - Google Patents

Abstract

PURPOSE:To obtain an encapsulated toner having stable particle diameter distribution by forming a hardened epoxy resin shell on the outside of each particle of a core substance contg. a pressure fixable binder resin, an epoxy resin, and a colorant and/or a magnetic powder. CONSTITUTION:A mixture of a core substrate contg. a pressure fixalbe binder, an epoxy resin, and colorant, and/or a magnetic powder is dispersed or dissolved into an org. solvent. The obtained liquid dispersion or soln. is dispersed into an aq. soln. contg. an epoxy resin hardening agent, and heated to form an outer shell on each particle of the core substance. Then, the org. solvent in the capsules is extracted with a lower alcohol to form an encapsulated toner. As said pressure fixable substance, higher fatty acids, their metal salts, higher fatty acid derivs., etc. are used, alone or in combination of >=2 of them. As said epoxy resin, bisphenol A type epoxy resins are used, and a compds. used for their hardening agent is a compd. for opening the ring of the epoxy group and linking thereto, such as amines, acid anhydride, or org. acid.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a toner used to visualize an electrical latent image or a magnetic latent image in electrophotography, magnetic recording, etc. The present invention relates to an encapsulated toner having pressure fixing properties.

Technical background of the invention and its problems Electrophotography is an image forming method that uses physical processes or electronic phenomena by utilizing photoconductive phenomena in solids, and includes xerography, electrofax, persistent internal It is classified into polarization method, etc.

Among these, one type of xerography involves applying a charge to a photoreceptor using corona discharge, etc., and then exposing it to light to form an electrostatic latent image.This latent image is developed with fine particles, and the developed image is It consists of transferring the image to paper or other material and then scanning the transferred image. The principle of the electrofax method is the same as that of the xerography method, but the feature is that photoconductive paper is used. An electrostatic latent image is formed, the latent image is developed with fine particles, and then this is fixed to form an image.

In both the Kameko photography method and the magnetic recording method in which a latent image is formed magnetically, toner is used to visualize the latent image.

In order to visualize a latent image using toner, two-component development methods using a mixture of toner and carrier particles and one-component development methods using no carrier particles are known.

The image developed with toner in this manner is transferred onto a recording support such as paper, if necessary, and then subjected to a toner fixing step in order to make the image storable. The fixing process is broadly classified into a heat fixing method, a solvent fixing method, and a pressure fixing method.

The heat fixing method is a method in which a toner image is melted and fixed onto a recording support using a heat roller or a heat chamber. Therefore, it is necessary to provide a heating source, and furthermore, a separate device may be required to eliminate the excess heat accumulated inside the image forming apparatus, resulting in an increase in the size of the image forming apparatus or an increase in power consumption. There were problems such as: In addition, the heat fixing method requires a certain amount of time to melt the toner components, so it has the disadvantage that high-speed fixing is slow.

The solvent fixing method is a method in which a toner image is fixed on a recording support using a solvent.

This bath agent fixing method requires that the used solvent be completely removed from the fixing section or support, and requires a great deal of effort to control the toxicity, flammability, odor, etc. of the bath agent. It had the disadvantage of being.

In order to solve the technical drawbacks associated with these heat fixing methods or bath agent fixing methods, a pressure fixing method has been proposed in which a toner image formed on a recording support is fixed by pressure, and is attracting attention. According to this pressure fixing method, the image is fixed the moment the recording support on which the toner image is formed is passed between a pair of rollers, making it possible to fix the image at high speed. This has the advantage of eliminating the need for a heat source and electric power.However, according to the conventional pressure fixing method, it is generally necessary to
A linear pressure of up to 40 kg/an is required, which limits the ability to make the image forming apparatus smaller and lighter, and also causes the recording support to wrinkle or curl, and to reduce paper strength. Something happened. Furthermore, since the image is formed by pressurizing granular toner, there is a drawback that the surface of the resulting image may become smooth and glossy.

In order to solve the problems associated with such a pressure fixing method, it has been proposed to use a substance with a low softening point or a low melting point and low pressure fixability as a toner. Toner made of substances with a low softening point or low melting point may aggregate or form blocks during storage, or toner particles may adhere to the inside of the image forming device, polluting the inside of the device, or even recording problems. There is a problem in that when the toner fixed on a support is stored under a certain degree of pressure, it adheres to the back side of another support, causing damage to the image and the support. For this reason, we have created an encapsulated product that uses a low-pressure fixing substance as a core material and surrounds this material with a resin that has the characteristics required for toner powder to form an outer wall on the outside of the core material. Various toners have been proposed.

As these encapsulated toners, the following have been proposed.

1) A first wall made of a monohydrophilic film-forming polymer substance is provided on the outside of the core V/J material having pressure mud layer properties by a coacervation method to form primary capsule particles, and the primary capsule particles are A two-walled capsule is provided with a second wall made of the resin on the surface of the primary capsule particle by dispersing the particles in each simulated resin emulsion liquid and then spray-drying the particles. What is contained in the outer wall (for example, JP-A-51-104)
829, JP 51-122449, JP 4-124934, JP 5:U-1028, JP 53-36243, l JP 51-
124435, JP 51-132838, JP 52-113740).

2) A core material having pressure fixability and a certain particle size (3 to 2!5μ) is dispersed in a solution or emulsion of various resins and then spray-dried to coat the surface of the core material. Those with an outer wall (for example, Japanese Patent Application Laid-Open No. 55
-18655 publication, JP-A-55-89854 publication,
JP-A-55-1.66653, JP-A-55-89
(See Japanese Patent Application Laid-open No. 855 and Japanese Patent Application Laid-Open No. 56-64349).

However, the 2N wall capsule mentioned in 1) requires two steps during production because the first wall and second wall are provided on the core material, which has the disadvantage that the production process is complicated. . Furthermore, the encapsulated toner described in 2) has the disadvantage that it requires pulverization and classification steps in order to adjust the core material to a constant particle size (3 to 25 μm).

Furthermore, since the toners mentioned in 1) and 2) above are both dried by the spray drying method, although there is an advantage that most of the dispersion medium can be removed in a short time, the toners are dried during the spray drying process. Particle aggregation due to particle collisions is unavoidable, making it difficult to obtain toner with a particle size of 5 to 30 μm in high yield, and furthermore, the outer wall becomes porous due to the rapid removal of the dispersion medium from the outer wall. The disadvantage was that it was unavoidable. If the outer wall of the toner becomes porous, the core substance of the toner will seep out through the pores present in the outer wall, which is undesirable because the toner particles may aggregate or form blocks, impairing fluidity.

Furthermore, if an organic solvent is used as a dispersion medium, the organic solvent evaporates during the spray drying process, which is unfavorable from a safety standpoint such as static sulfur explosion and toxicity, and may cause the solvent to be removed from the toner. It must be completely removed (
・There were some problems.

OBJECTS OF THE INVENTION The present invention has been made in view of the above points, and it is an object of the present invention to provide an encapsulated toner having the following advantages and a method for manufacturing the same.

a) The manufacturing process is simple.

b) Have a stable particle size distribution.

C) No mutual aggregation or blocking of particles occurs during storage.

d) The particle shape is close to spherical, the surface is smooth and fluidity is high.

e) The capsule wall is not destroyed during the classification process, the mixing process with the carrier, the transport process inside the image forming apparatus, etc., and the capsule wall is destroyed and crushed only in the pressure fixing process.

f) There is no offset to the pressure roller.

g) Capri phenomenon is not observed, and the scale provides high-quality images with excellent resolution.

Summary of the Invention The pressure-fixable toner according to the present invention comprises: a) a pressure-fixable binder; b) an epoxy resin; and b) a core material containing either a colorant or magnetic particles, or both; It is characterized by consisting of a hardened resin wall formed on the outside of a core material. In addition, the method for producing the pressure fixable toner according to the present invention includes: a) a pressure fixable binding substance, a) an epoxy resin, and...) a core material mixture containing a colorant or magnetic particles, or both, in an organic solvent. The obtained dispersion or solution is dispersed in an aqueous solution containing an epoxy resin curing agent, and then heated to form a hardened epoxy resin wall on the outside of the core material to form an encapsulated toner. It is characterized by removing the organic solvent present in the encapsulated toner with a lower alcohol and then drying it.

The core substance in the pressure fixable toner according to the present invention is a)
It contains a pressure-fixable binder, (1) an epoxy resin, and (3) one or both of a coloring agent and magnetic particles.

A pressure-fixable binding substance is a natural substance that is easily deformed by pressure and is fixed on the surface of the recording support, and that forms a dense layer on the support after fixation (* indicates a synthetic substance). and generally has a low softening point or low melting point.Such pressure fixing materials include, but are not limited to, the following:

a) Higher fatty acids stearic acid, nomilmitic acid, myristic acid, lauric acid, capric acid, etc.

b) Metal salts of higher fatty acids such as stearic acid, ξlumitic acid, myristic acid, lauric acid, capric acid, etc. aluminum salts, lead salts, barium salts, zinc salts, etc.

C) Higher fatty acid derivatives such as hydrogen-cooled castor oil, hydrogenated coconut oil, methyl hydroxystearate, chrycerol, and monohydroxystearate.

d) Higher fatty acid amides such as octadecaneamide, hexadecaneamide, dodecanamide, octaneamide, hexaneamide P, etc.

e) Natural waxes paraffin wax, microcrystalline wax,
Montan wax, beeswax, wood wax, etc.

f) Synthetic waxes such as polyethylene wax and oxidized polyethylene wax.

g) Rosin derivatives Rosin, hydrogenated rosin, rosin ester, etc.

h) Polyolefins such as low molecular weight polyethylene, low molecular weight propylene, polyethylene oxide, polyisobutylene, polytetrafluoroethylene, etc.

1) Olefin copolymers: ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alkyl ether lj polymer, ethylene-methacrylic acid ester copolymer, etc.

j) Resins Silicone resins, alkyd resins, natural resin-modified phenolic resins, maleic acid-modified phenolic resins, etc.

k) Rubbers Isobutylene rubber, nitrile rubber, chlorinated rubber, etc.

l) Styrenic resin Low molecular weight polystyrene, styrene-butadiene copolymer, styrene-acrylic compound copolymer, etc.

These pressure-fixing binding substances may be used alone or in combination.
More than one species can be used in combination.

Epoxy resin means a polymer compound having at least two or more epoxy groups in its molecule and a synthetic compound produced by a ring-opening reaction of the epoxy groups. means a polymer compound having at least two or more epoxy groups in the molecule, and this epoxy resin is cured by ring-opening and addition reactions of the epoxy groups with an amine curing agent, etc., and is further cured by polymer decoupling. A cured epoxy resin wall is formed on the outside of the core material.

Such epoxy resins (bisphenol A type epoxy resin, resorcinol type epoxy resin, bisphenol F type epoxy resin, Nozerak type epoxy resin, etc.) are used as epoxy resins, and these epoxy resins can be used alone or Two or more types are used in combination.

As an epoxy resin curing agent, a compound that can cause crosslinking through ring opening and addition reactions to the epoxy groups contained in the epoxy resin is used, and amines, acid anhydrides, or organic acids are generally used, but amines are particularly used. is preferred.

Specific examples of the amine curing agent include the following compounds.

a) Chain aliphatic polyamines b) Cycloaliphatic polyamines C) Aliphatic polyamine adducts d) Ketominos e) Modified aliphatic polyamines f) Modified polyamines g) Polyamide/amines h) Aromatic amines Class l) Aromatic modified amines j) Aromatic modified polyamines These amine curing agents can be used alone or in combination of two or more.

For the purpose of accelerating the curing reaction of the epoxy resin, compounds such as tertiary amines, phenols, boron trifluoride amine complexes, and imidazoles can be used together with the above-mentioned epoxy resin curing agent.

As the coloring agent, a wide variety of conventionally known pigments and dyes can be used, and specific examples include the following compounds.

a) Carbon black b) Iron black C) Nigrosine dye d) Alinin blue e) Calco oil blue f) Chrome yellow g) Chrome green h) Ultramarine blue i) Cobalt sol J) DuPont oil red k) Benzyl yellow l) Quinoline yellow m) Methylene blue chloride n) Phthalocyanine blue or phthalocyanine green 0) Malachite green p) Oxalate q) Lamp black r) Rose pengan These colorants can be used alone or in combination of two or more. can.

The magnetic particles are particles of a substance that exhibits magnetism or can be magnetized, and are powders of ferromagnetic elements or compounds or alloys containing these elements, and specifically include the following.

a) Magnetite.

b) Ferrite.

c') Metal powders such as iron, manganese, nickel, and cobalt.

d) Powders of compounds containing iron, manganese, nickel, cobalt, etc.

e) Powders of alloys containing iron, manganese, nickel and cobalt.

These magnetic particles can be used alone or in combination of two or more.

When the pressure-fixable toner according to the present invention is used together with gearia particles, the core substance is composed of a) a pressure-fixable binding substance, a) an epoxy resin, and a) a colorant. . In addition, when the toner is used alone without being used in combination with carrier particles, the core material includes a) a pressure-fixing binding material, a) a finger of epoxy resin, and b) magnetic particles and a necessary material. It is composed of a coloring agent depending on the quality.

The amount of binding material in the core material is 40 to 95% by weight relative to the total amount of binding material and epoxy resin, preferably (
A) It is desirable that the amount of OM is as low as 1. The binding substance is 9
If it is more than 5 layers, the outer wall of the capsule will be too weak and will be easily destroyed, and if it is less than 10 layers, the pressure fixing properties of the obtained capsule will deteriorate, which is not preferable.

Note that the content of the colorant and magnetic particles in the core material can be varied over a wide range depending on the purpose.

Further, a nigrosine metal complex, colloidal silica, fluororesin, etc. may be added to the core material for the purpose of charge control, prevention of aggregation, prevention of offset, etc.

The core material having such a composition is cured after being dispersed in a water bath liquid containing an epoxy resin curing agent, or the amount of curing agent contained in the water bath liquid is Δ) with respect to 100 parts of the epoxy resin. ~200 parts by weight 1 desirably 50 to 170 parts by weight, and if the amount of curing agent is less than 2 parts by weight, the curing reaction is incomplete and cannot be separated as granules; Moreover, if the weight is 11 parts or more (200 weight), the advantages of the above will not be obtained and it will be undesirable.

The particle size of the pressure fixable toner according to the present invention is preferably controlled within the range of 5 to 10 μm. To this end, a core material containing a) a pressure-fixable binding material, a) an epoxy resin, and a) a coloring agent and/or magnetic particles is dispersed or dissolved in an organic solvent. That is essential. As such organic solvents, toluene, xylene, methyl ethyl ketone, ethyl acetate, etc. may be used alone or in combination.

When these organic solvents are used, these organic solvents can be easily extracted and removed from the obtained encapsulated toner with a lower alcohol such as methanol, ethanol, and isopropyl alcohol.

Hereinafter, a method for producing a pressure fixable toner according to the present invention will be explained.

When using a pressure-fixable toner together with carrier particles, a) a pressure-fixable binder, an epoxy resin, and a colorant are kneaded together by a conventionally well-known method. Coarsely ground according to the requirements. In addition, when the toner is used alone without being used together with carrier particles, a) a pressure-fixable binding substance, an epoxy resin, a) a magnetic particle, and, if necessary, a colorant, are the same. It is processed as follows.

The obtained toner core material is dispersed or dissolved in a solvent such as toluene, xylene, methyl ethyl ketone, acetic acid, and chill to prepare an organic phase. This organic phase is poured into an aqueous solution in which an epoxy resin curing agent is dissolved or dispersed.
The particles are dispersed under stirring at 800 to 800 i, o, ooo rotations per minute, and the particle size of the dispersed droplets is adjusted to about 5 to 30 μm.

The dispersion thus obtained is then gradually reduced to 60 to
The epoxy resin present on the outside of the core material is heated to a temperature of 90° C., and a hardened epoxy resin wall is formed on the outside of the core material, resulting in an encapsulated toner containing the core material. reactor. At this time, the organic solvent is also included within the cured epoxy resin wall. When dispersing the core substance in the aqueous solution, the organic phase containing the core substance is easily dispersed into the water bath liquid containing the double xyl resin curing agent, and the particle size of the resulting toner particles is controlled within an appropriate range. Therefore, compounds such as gelatin, gum arabic, and polyethylene oxide are preferably present in the aqueous solution.

The encapsulated toner thus obtained is sent door to door, washed with water, and then mixed with methanol, ethanol,
The organic solvent contained in the toner is extracted and removed by introducing it into a lower alcohol such as isopronomisole.

The encapsulated toner is then washed with water and then dried.

Effects of the Invention The pressure fixing toner and the manufacturing method thereof according to the present invention are as follows:
It has the following effects.

a) The manufacturing process is simple compared to double wall encapsulated toner.

b) The particle size of the obtained toner is within the range of 5 to 30 μm and has a stable particle size distribution.

C) The cured epoxy resin wall has appropriate strength, and since the toner is not spray-dried, the cured wall is not porous, so particles do not aggregate or block each other during storage.

d) The particle shape of the obtained toner is close to spherical, and has a smooth surface and high fluidity.

8) Since the cured epoxy resin wall has appropriate strength, the capsule wall will not be destroyed during the classification process, mixing process with carrier, transporting process inside the image forming apparatus, etc.
The capsule wall is destroyed for the first time in the pressure fixing process, resulting in vague pressure fixing properties and a filming phenomenon in which the photoreceptor surface, developing sleeve, carrier, etc. are contaminated.

f) Offset to the pressure roller is not recognized.

g)) Since the shape and particle size of Kerr particles are stable, no fogging phenomenon is observed, and high-quality images with good resolution can be obtained.

h) Since the capsule wall is made of cured epoxy resin, the image surface obtained after pressure fixing does not have gloss.

Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited to these Examples.

Flood Microcrystalline Wax (manufactured by PEROLITE, product name ULTRAFLEX, melting point h2°'C)
3 (l g and Carpon rack (manufactured by Tamako Kasei Co., Ltd., trade name Yobishi Kazen MA-1,00') i, 5 g,
After thoroughly melting and kneading with hot rolls, the mixture was dissolved and dispersed in 100 g of toluene. Next, 1.0 g of Ebicor 828 (trade name, manufactured by Shell Petrochemicals), which is an epoxy resin, was added and mixed to this, and the mixture was placed in a dropping funnel. Then, 400 g of water, 6 g of gum arabic, and 5 g of triethylenetetramine were placed in a 1e-type flask equipped with a stirring device, a condenser, and the above-mentioned dropping funnel.
While stirring this aqueous solution at a speed of 5000 revolutions per minute,
A core material consisting of microcrystalline wax, carbon black, and epoxy resin dissolved or dispersed in toluene was dropped from the dropping funnel over a period of 15 minutes. Next, the core material was dispersed in the water bath liquid while stirring for about a minute at room temperature, and then the temperature was gradually raised to bring the internal temperature of the flask to δO'C, and the temperature was increased to 80± for 6 hours after the temperature was raised.
The temperature was maintained at 1° C. to allow the epoxy resin to undergo a curing reaction.

After that, 1Vki2 (toner particles are separated in a furnace with a door paper,
After washing three times with warm water at 0''C, it was dispersed in 100m6 of methanol, and the toluene contained in the capsule was extracted into methanol.Then, the l·car particles were separated in a furnace and dried under reduced pressure. It was dried in a container at l;O''G overnight.

The average particle size of the encapsulated toner thus obtained was 16.7 μm, and the standard deviation was 1.72.

30g of the obtained encapsulated toner and carrier 2 coated with 250 to 400 meshes of iron powder.
70g, then use an electronic copying machine (Canon,
When the unfixed image was reshaped using the product name NP-500) and fixed under pressure with a linear pressure of 15'q/W,
No offset to the roll was observed, and a clear (1) image was obtained. When mixed with encapsulated toker carrier particles, no destruction of the capsule wall was observed, and when this toner was stored at a temperature of 50''C for 7 days, no aggregation of toner particles occurred.

40 g of flooded polyethylene wax (manufactured by PEROLITE, trade name POLYWAX500, melting point d6℃) and magnetic powder (7-E, manufactured by IJ Kogyo, magnetite, particle size 0.4μ)
After thoroughly melting and kneading the epoxy resin Epicor) 152 (trade name, manufactured by Shell Petrochemical Co., Ltd.) with toluene 1 in which 15 g is dissolved,
It was dissolved or dispersed in 50 g. Then, the obtained solution or dispersion was added dropwise to a 50''C aqueous solution in which 8 g of gum arabic was dissolved in 500 g of water under stirring conditions of 4000 revolutions per minute and maintained for 30 minutes.

Next, 9 g of Ebicure Z (trade name, manufactured by Shell Petrochemical Co., Ltd., S5 resin curing agent) was added to the obtained aqueous solution, and after holding for 30 minutes, the temperature was steadily raised to bring the internal temperature of the flask to li ( +''C, and after raising the temperature, it was maintained at 80±1°C for 5 hours to carry out a curing reaction of the epoxy resin.

The rear side was treated in the same manner as 1 to obtain an encapsulated toner.

The average particle size of the encapsulated toner thus obtained was 14.3μ, with a standard deviation of 1.・] It was 6.

60 g of the obtained encapsulated toner was supplied to the tonerx of a 3M Magne Dry Copy Machine (electronic copying machine manufactured by Sumitomo 3M Co., Ltd.) and a continuous copying test was conducted.

No difference was observed between the rescue image and the fixed image. Furthermore, no filming, offset, or fogging phenomena on the rollers were observed, and clear images were obtained. In addition, when we measured the minimum fixing pressure required to fix this encapsulated toner using a variable pressure roller, it was found to be 10.3 kg.
/ cm.

Comparative Example 1 After completing the curing reaction of the epoxy resin in the same manner as in Example 2, the toner was spray-dried to produce an encapsulated toner.

An image was formed using this encapsulated toner, but a toluene odor was observed in the resulting fixed image.

Furthermore, when this toner was stored at a temperature of 50° C. for 7 days, a toluene odor was still observed, and aggregation of toner particles was also observed.

Further, after melting and kneading the polyethylene wax and magnetic powder used in Example 2, the resulting mixture was pulverized in a jet mill, and then classified into 5-25μ particles to produce a toner. When trying to fix the toner using this toner, it was not possible to fix the toner because of severe offset and because the recording support was caught in the fixing roller.

Example 3 The same procedure as in Example 2 was carried out, except that instead of polyethylene wax, a copolymer (weight average molecular weight: 1d7500) consisting of 40 parts of methylene and 1 part of n-butyl methacrylate was used. An encapsulated toner was produced.

The average particle size of the obtained encapsulated toner was 14.7μ,
The standard deviation was 1.51. Also, the minimum fixing pressure is】2.
It was 7 Yu/-.

When a fixing test was conducted in the same manner as in Example 2, no filming on the roller was observed and a clear image was obtained.

Comparative Example 2 30 g of microcrystalline wax (manufactured by PEROLITE, trade name: ULTRAFLEX) and Carzen Black (manufactured by Mitsubishi Kasei, trade name: Mitsubishi Carbon MA-1)
00) 1.5 g of a molten mixture and 1.0 g of Epicoat 1001' (epoxy resin, part name, manufactured by Shell Petrochemicals) were dissolved and dispersed in a mixed solvent consisting of 250 g of toluene and 250 g of methyl ethyl ketone. After that, spray dryer (inlet temperature) 70℃, outlet (outlet temperature 140℃)
An encapsulated toner was produced by spray-drying the toner by spray-drying it using "C, air flow rate 9 m/rr++n, manufactured by Mitsubishi Kakoki."

The obtained encapsulated toner had a sugar-like appearance, did not have a film-like outer wall, had poor fluidity, and could not provide a good fixed image. Further, the average particle size was 32.4μ and the standard deviation was 2.94.

Comparative Example 3 After melt-kneading 40 g of polyethylene wax (manufactured by pERoffrTg, trade name POLYWAX500) and 20 g of magnetic powder (manufactured by Toda Kogyo, Magnetai), this was mixed with Ebiko 1009C (trade name, Shell Petrochemical Company). methyl ethyl ketone]-
It was dissolved or dispersed in 50 g. The obtained solution or dispersion was added dropwise to a 50'C water bath solution in which 8 g of gum arabic was dissolved in 500 g of water under stirring conditions of 1500 revolutions per minute for dispersion.

Next, without adding an epoxy resin curing agent to the water bath liquid, the dispersed particles were directly distributed from house to house to produce toner.

When an image was formed using the toner thus obtained, the image could not be fixed due to offset to the fixing roller. Furthermore, when this toner was stored at a temperature of 50 DEG C. for 7 days, aggregation of toner particles was observed.

Applicant's agent Kiyoshi Inomata

Claims (1)

[Claims] 1. A core material containing a) a pressure-fixable binding material, a) an epoxy resin, and c) a coloring agent and/or magnetic particles, and a A pressure fixable toner consisting of a hardened epoxy resin wall. 2. A core material mixture containing a) a pressure-fixable binding substance, an epoxy resin, and c) a coloring agent and/or magnetic particles is dispersed or dissolved in an organic solvent. The dispersion or bath liquid is dispersed in an aqueous solution containing an epoxy resin curing agent and then heated to form a hardened epoxy resin wall on the outside of the core material to form an encapsulated toner, which is then contained in the encapsulated toner. A method for producing a pressure fixable toner, which comprises removing the organic solvent with a lower alcohol and then drying the toner.