JPH0990671A - Electrostatic image developing toner and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner having an average particle diameter suitable for obtaining high resolution and a narrow particle diameter distribution and inner additive agents uniformly dispersed by using a jet homogenizer for a suspension device. SOLUTION: Oil droplets having an optional particle diameter of 4-8μm and a narrow particle diameter distribution can be formed by introducing a mixture of polymerizable monomers mixed into an aqueous medium in a ratio of 3/5-3/15 or separately each in a specified rate into the jet homogenizer and treated under a pressure of 0.5-5kgf/cm<2> . The suspension liquid comprises 2.5-6 pts.wt. of water per 1 pts.wt. of the polymerizable monomer, when a surfactant is added, 0.4-2 times the concentration of c.m.c., and 1.5-6 pts.wt. of a dispersion stabilizer per 1 pts.wt. of the water, and this suspension liquid does not change the particle diameters and their distribution and a dispersion state of the inner additive agents in the course of polymerization reaction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner having excellent fluidity, chargeability and resolution for developing an electrostatic image and a method for producing the toner.

[0002]

2. Description of the Related Art Conventionally, a toner for developing an electrostatic image is generally prepared by melt-kneading a magnetic material or a coloring agent such as a dye or pigment in a thermoplastic resin, uniformly dispersing it, and then pulverizing and classifying the toner. It has been manufactured as a pulverized toner having a controlled particle size distribution.

In the case of producing a pulverized toner, there is a limitation that it is easily pulverized, that is, a resin having high brittleness must be used. When toner is actually developed with a highly brittle resin, the toner is further pulverized due to development stress, and selective development and deterioration of toner spent are likely to occur. Further, in this method, it is difficult to disperse fine particles such as a colorant in the resin completely and uniformly, and depending on the degree of dispersion, the composition is distributed among the toners, and the image and printability due to the non-uniform charge is not obtained. In some cases, variations in toner development characteristics such as unevenness may be caused. Various attempts have been made to improve these drawbacks of the grinding method. As the most typical method, a method for producing a toner for electrostatic charge development by a polymerization method has been proposed.

As a method for producing a dry toner by a polymerization method, an emulsion polymerization method in an organic solvent, for example, JP-A-61-2 is used.
73552 and JP-A-61-273553 can be mentioned. Both methods have drawbacks such as using an organic solvent for the reaction and requiring a long time for particle formation.

On the other hand, examples of the aqueous suspension polymerization method include JP-A-61-22354 and JP-A-61-67039. These use a stirring homogenizer as a suspension device. When these devices are used in an open system at a high rotation speed, it is difficult to make energy uniformly act on the dispersion liquid due to entrainment of bubbles or air generated by cavitation, and it is not possible to control the particle size and particle size distribution. It is enough.

[0006] Japanese Patent Laid-Open No. 63-113561 and Japanese Patent Laid-Open No. 5-156555
In the publication, there is proposed a method of treating a dispersion liquid by a high-pressure homogenizer and a polymerizable monomer in the dispersion liquid for the purpose of reducing the particle size and narrowing the distribution of produced particles. In this method, several pass operations must be performed to obtain the target particle size and particle size distribution, and as a result, an emulsion is generated and the product particle size is 90% or more within the range of 5 μm to 16 μm. A suspension containing the compound was not obtained, and the average particle size was 4 μm
It is difficult to prepare a narrow distribution product on the order of 8 μm. Therefore, a classification process is required to obtain a small particle size narrow distribution product, and when a pass operation and a classification process are required, the cost is increased.

[0007]

The object of the present invention is to have an average particle size of 4 μm to 8 μm, which is suitable for high resolution in the production of toner for electrostatic charge development by the suspension polymerization method,
Another object of the present invention is to provide a toner in which the particle size distribution is extremely narrow and the additive to be internally added is uniformly dispersed, and a method for producing the toner.

[0008]

That is, the present invention relates to a polymerization toner in which a polymerizable monomer containing at least a colorant and a release agent is suspension-polymerized in an aqueous medium system, and jetted to a suspension device. The present invention relates to a method for producing a toner for developing an electrostatic charge image, which comprises using a formula homogenizer. Similarly, according to the present invention, during suspension, the inside of the suspension system is 0.5 to 5 kgf / c.
The present invention relates to a method for producing the toner for developing an electrostatic charge image, which comprises pressurizing to m ² . Furthermore, the present invention relates to a toner for developing an electrostatic charge image produced by any of the above production methods.

As a result of intensive studies on the suspension method relating to the toner production method by the above-mentioned suspension polymerization method, the inventors of the present invention have found that the suspension system is under pressure and the mixed solution is rotated from the rotor having the slit through a screen having slits. By using a jet homogenizer which ejects at a higher pressure, the toner has an arbitrary average particle size of 4 μm to 8 μm more efficiently than the conventional method, and is required as a toner for dry electrophotographic development.
Particles having a diameter of μm to 12 μm are 13 to 35 as compared with the conventional method.
It has been found that 0% more can be generated, the particle size distribution becomes extremely narrow, and at the same time, it is possible to prepare particles of uniform composition in which various additives are uniformly dispersed in the generated particles. Further, they have found a method capable of stably producing a high-performance toner having high resolution and fogging for electrostatic charge development by polymerization, with high productivity and at low cost.

That is, according to the present invention, at least a polymerizable monomer, a colorant, a releasing agent, a charge control agent, and a small amount of other internal additives are previously dispersed by stirring with a dispersing machine such as a ball mill. The system is 3/5 to 3 in water, dispersion stabilizer, and an aqueous medium liquid system to which a surfactant is added if necessary.
/ 15 (more preferably 3/7 to 3/12) mixed with a propeller mixer or the like, or each of the polymerizable monomer system and the aqueous medium system at a predetermined ratio in a jet homogenizer, for example, Claremix 0.8S
(M Technique Co., Ltd.)
^{5kgf / cm 2 ~5kgf / cm 2} ( more preferably 1
kgf / cm ² ~2kgf / cm have any particle size 4μm~8μm by pressurized process ^2), and found that it is possible to produce oil droplets in a very narrow range of particle size distribution. Further, they have found that it is possible to produce particles having a uniform composition in which a colorant, a release agent, a charge control agent, and other internal additives are uniformly dispersed in the oil droplets.

The composition of the suspension according to the present invention is such that water is 2.5 times to 6 times the weight of the polymerizable monomer, and c. m. c. 0.4 times concentration ~ 2
Double concentration, dispersion stabilizer 1.5% to 6% by weight of water
It is good to do in the range of. Next, the suspension liquid of the present invention is subjected to a heat polymerization reaction by a conventional method, but it does not change the particles and distribution of particles produced during suspension in the polymerization reaction process, and the dispersed state of the internal additive. . After the completion of the polymerization reaction, the surfactant and the dispersion stabilizer are removed by washing with water or the like and dried to obtain a toner powder.

Examples of the radical-polymerizable monomer that can be used in the present invention include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4.
-Dimethyl styrene, p-butyl styrene, pt-butyl styrene, p-hexyl styrene, p-octyl styrene, p-nonyl styrene, p-decyl styrene, p
Styrene monomers such as -dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene and 3,4-dichlorostyrene can be mentioned as preferable ones. In addition, ethylene unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride; vinyl acetate, vinyl propionate and vinyl benzoate. , Vinyl esters such as vinyl butyrate; acrylic acid, methacrylic acid and methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate Carboxylic acid esters of acrylic acid or methacrylic acid such as; α-methylene aliphatic monocarboxylic acid esters such as diethylaminoethyl methacrylate; acrylic acid such as acrylonitrile, methacrylonitrile, acrylamide, etc. Or methacrylic acid derivatives; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl carbazole, N-vinyl compounds such as N-vinylindole and N-vinylpyrrolidone;
Vinyl naphthalene, etc. can be mentioned. These monomers may be used alone or in combination of two or more, or may be used in combination to give a copolymer by polymerization. Among them, styrene or a styrene derivative is preferably used alone or in combination with another monomer as a polymerizable monomer from the viewpoint of developing characteristics and durability.

In order to improve fixability and anti-offset property in hot-press roller fixing, the monomer composition may have a releasing agent such as waxes such as paraffin wax, low molecular weight polyethylene and low molecular weight polyolefin such as low molecular weight polypropylene. It is preferable to add a low softening point compound (release agent) having properties. In that case, the addition amount is 1 to 30 parts by weight with respect to 100 parts by weight of the polymerizable monomer.

As the low softening point compound as a release agent,
Paraffin, wax, low molecular weight polyolefin, modified wax having aromatic group, hydrocarbon compound having alicyclic group, natural wax, long-chain aliphatic carboxylic acid having long-chain hydrocarbon chain having 12 or more carbon atoms, ester thereof, etc. Can be illustrated. Different low softening point compounds may be mixed and used. Specifically, Viscor 550P (Sanyo Kasei Co., Ltd.)
), Viscor 660P (manufactured by Sanyo Kasei), Viscor TS-200 (manufactured by Sanyo Kasei), Saniwax 151P (manufactured by Sanyo Kasei), beeswax, carnauba wax, montan wax, candelilla. Wax etc. can be given.

The polymer according to the present invention may be a crosslinked polymer obtained by polymerizing a polymer in the presence of a crosslinking agent. When the polymer, copolymer or cyclized rubber is not added to the monomer composition, it is particularly preferable to add it. The cross-linking agent preferably used is a compound mainly having two or more polymerizable double bonds, for example, an aromatic divinyl compound such as divinylbenzene, divinylnaphthalene and derivatives thereof, for example ethylene glycol dimethacrylate, diethylene glycol. Methacrylate,
Triethylene glycol methacrylate, trimethylolpropane triacrylate, allyl methacrylate, tetraethylene glycol dimethacrylate,
Diethylenic carboxylic acid esters such as 1,3-butanediol dimethacrylate, all divinyl compounds such as N, N-diviraniline, divinyl ether, divinyl sulfide, divinyl sulfone and compounds having three or more vinyl groups, etc., alone or Selected as a mixture.

The amount of such a crosslinking agent added to the monomer is 0.0
05% to 20% by weight, preferably 0.1% to 1
A range of 0% by weight is chosen. If this addition amount is too large, the softening point becomes high, and the heat fixing property or the heat pressure fixing property of the toner becomes poor. Further, if the addition amount is too small, it becomes difficult to impart properties such as durability, blocking resistance, and abrasion resistance, which are characteristics of the toner, and in particular, in a heat roll fixing type copying machine or the like, cross-linking expands the molecular weight distribution of the polymer. Also, due to the properties of the crosslinked polymerized toner itself, the action of preventing the offset phenomenon at the time of fixing is lowered.

The polymerizable monomer composition contains a colorant, and dyes and pigments or magnetic particles are preferably used as the colorant. Dyes that have been known as dyes and pigments,
Known pigments such as carbon black and grafted carbon black obtained by coating the surface of carbon black with a resin can be used. The dye / pigment is contained in an amount of 0.1% by weight to 20% by weight based on the polymerizable monomer.

On the other hand, as the magnetic particles that can be used when manufacturing the magnetic toner, substances that are magnetized by being placed in a magnetic field are used. For example, powders of ferromagnetic metals such as iron, cobalt and nickel, or magnetite. , Powders of alloys and compounds such as hematite and ferrite. Magnetic particles having a primary particle diameter of 0.05 μm to 5 μm (more preferably 0.1 μm to 1 μm) are preferably used. The content of the magnetic particles is preferably 10% by weight to 60% by weight (more preferably 25% by weight to 50% by weight) based on the weight of the toner. Further, these magnetic fine particles may be treated with a known surface modifier or a suitable reactive resin.

If necessary, a charge control agent and a fluidity modifier may be added (internally added) to the toner. The charge control agent and the fluidity modifier may be mixed (externally added) with the toner particles. Examples of the charge control agent include metal complexes of organic compounds having a carboxyl group or a nitrogen-containing group, metal-containing dyes, nigrosine, alkylonium salts and the like. Colloidal silica, aliphatic metal salts and the like are used as a flow modifier or a cleaning aid for the surface of the latent image bearing member (photoreceptor). Also,
For the purpose of increasing the amount, a filler such as calcium carbonate or fine powder silica may be blended in the toner in the range of 0.5% by weight to 20% by weight.

For the monomer polymerization, a radical polymerization initiator is usually used in the range of 0.1 to 10% by weight based on the weight of the radically polymerizable monomer. The appropriate amount is determined by the final degree of polymerization.

Specific examples of typical polymerization initiators include, for example, 2,4-dichlorobenzoyl peroxide, benzoyl peroxide, t-butylperoxyisobutyrate, di-t-butylperoxide and cumene hydroper. Peroxide type initiators such as oxides, 2,
2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2 ′
-Azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2-cyclopropylpropionitrile), 2, Examples thereof include azo initiators such as 2'-azobis (2-methylbutyronitrile) and dimethyl-2,2'-azobis (2-methylpropionate).

Further, a polar polymer or a polymer elastic material may be added during the polymerization to improve the physical properties of the polymerized toner.

Next, it is necessary to stably suspend the oil phase portion containing the above-mentioned polymerizable monomer as a main component in water to a desired particle size and particle size distribution. As this dispersion stabilizer,
For example, polyvinyl alcohol, gelatin, methyl cellulose, methyl hydropropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, polyacrylic acid and salts thereof, starch, gum alginsan salt, zein, casein, tricalcium phosphate, talc, barium sulfate, Examples thereof include bentonite, aluminum hydroxide, ferric hydroxide, hydrophilic silica and amino-treated products thereof. These dispersion stabilizers are related to the amount of water of the polymerizable monomer that is the oil phase part and the suspension medium, and are preferably 1.5% by weight to 6% by weight with respect to water.

The surfactants used when used in combination with the dispersion stabilizer are sodium dodecylbenzene sulfonate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium allyl-alkyl-polyether sulfonate. , Sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, sodium stearate, sodium oleate,
3,3-disulfonediphenylurea-4,4-diazo-
Sodium bis-amino-8-naphthol-6-sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol -Sodium disulfonate, etc. may be mentioned. The optimum amount of these surfactants used is:
Unique to each activator c. m. c. The concentration is 0.4 to 2 times the (critical micelle concentration).

Next, the amount of water used during suspension is preferably 2.5 times to 6 times the amount of the polymerizable monomer as the main component, and the water is ion-exchanged with little salt contamination. Water is suitable.

In the present invention, after forming oil droplets by suspension, the polymerization reaction is started at about 60 ° C. by a conventional method, and finally the reaction is completed at 90 ° C. to 100 ° C. After cooling, remove the dispersion stabilizer and surfactant, wash with water, and
After drying and crushing at 50 ° C., and optionally treating with a surface treating agent, a toner can be obtained in high yield.

When the present toner is used as a two-component developer, the carrier generally used as a toner carrier can be used. Specifically, iron powder carrier,
Ferrite-based carriers can be used, and polyester-based resin, fluorine-based resin,
It is also possible to use a resin-coated carrier whose surface is coated with a silicone-based resin or the like, or a so-called resin carrier obtained by kneading iron powder or ferrite with a binder resin and granulating.

The polymerized toner obtained by the production method of the present invention can be applied to a known dry electrostatic charge development method. In particular, it can be suitably used for high resolution toners that require a sharp particle size distribution and a small particle size toner having an average particle size of 4 μm to 8 μm.

[0029]

The present invention will be described in more detail with reference to the following examples, in which parts represent parts by weight.

Example 1 240 parts of styrene monomer and carbon black MA-1
00 (manufactured by Mitsubishi Kasei Co., Ltd.) 27 parts, charge control agent Aizen spirone black TRH (Hodogaya Chemical Co., Ltd.)
5 parts, acrylic-styrene resin (MW = 1455)
(00, Tg = 61.6 ° C.) 66 parts, glass beads were further added, and the mixture was dispersed for 45 minutes using a paint shaker to obtain a mixture A. Next, styrene monomer 1
A mixture of 00 parts and 25 parts of 2-ethylhexyl acrylate, 1 part of divinylbenzene, 15 parts of 2,2-azobis (2,4-dimethyl) valeronitrile, 3 parts of azobisisobutyronitrile, and the above-mentioned preparation. Mixture A
190 parts was added and the mixture was stirred and mixed for 30 minutes to obtain an oil phase containing a polymerizable monomer as a main component. Next, ion-exchanged water 82
A dispersion medium containing 254 parts of a 10% tricalcium phosphate solution (manufactured by Taihei Chemical Industry Co., Ltd.) in 0 part was added, and 315 parts of the oil phase part prepared above was added to Haydon Three-One Motor BL600 (Shinto Scientific ( Co., Ltd.) with stirring and mixing,
CLEARMIX CL under pressure of 1.0 kgf / cm ^2.
Dispersion processing was performed at 20000 rpm for 120 seconds with M-0.8S. The obtained main suspension was transferred to an autoclave equipped with a stirrer, and a polymerization reaction was carried out at 60 ° C. for 6 hours and at 90 ° C. for 1 hour, followed by cooling to dissolve tricalcium phosphate with hydrochloric acid. After filtration, the filtrate was washed with water until the pH became neutral and then dried to obtain a toner. The particle size of the toner was measured by Coulter Multisizer II. As a result, the average particle size was 7.34 μm, the generation rate of fine particles of 3 μm or less was 2.4% in number distribution, and the production rate of coarse particles of 12 μm or more was volume distribution. A toner having a narrow particle diameter of 3.1% and a pigment uniformly dispersed in the toner particles was obtained. This toner was almost spherical and had no color unevenness. Also, iron powder carrier D
Triboelectric charge distribution with SP-128 (manufactured by Dowa Iron Powder Co., Ltd.) was measured with an Espert Analyzer EST-1 type (manufactured by Hosokawa Micron Co., Ltd.), and a very sharp charge distribution of negative charge with no reverse polarity. showed that. Toner 1
1 part of colloidal silica was mixed with 00 parts to prepare a developer. When printing was evaluated with a commercially available one-component printer, a high-resolution printed matter with high density and sharpness and no fog or unevenness was obtained for the initial image. Further, when running was carried out, it was possible to maintain a good image without decreasing the density up to 2000 sheets.

Example 2 Styrene monomer-2-ethylhexyl acrylate-divinylbenzene (monomer ratio = 270: 30: 1.5)
15 parts of carbon black MA-100 (manufactured by Mitsubishi Kasei Co., Ltd.), 6 parts of Viscole 660P (manufactured by Sanyo Kasei Co., Ltd.), and 9 parts of 2,2-azobis (2,4-dimethyl) valeronitrile. , Azobisisobutyronitrile 3 parts, and charge control agent Aizen spirone black TRH (manufactured by Hodogaya Chemical Co., Ltd.) 3 parts were added, and T. K. Auto homomixer (made by Tokushu Kika Kogyo Co., Ltd.)
Was rapidly dispersed at 10,000 rpm for 20 minutes to prepare an oil phase part containing a polymerizable monomer as a main component. Next, a dispersion medium containing 456 parts of 10% tricalcium phosphate solution (manufactured by Taihei Chemical Industry Co., Ltd.) and 118 parts of 0.178% sodium dodecylbenzenesulfonate aqueous solution in 524 parts of ion-exchanged water was prepared. After adding 300 parts of the oil phase portion and stirring and mixing with Haydon Three-One Motor BL600 (Shinto Kagaku Co., Ltd.), it was applied with CLEARMIX CLM-0.8S under a pressure of 1.0 kgf / cm ^2. 2000
A dispersion process was performed at 0 rpm for 120 seconds. The obtained main suspension was transferred to an autoclave equipped with a stirrer, and a polymerization reaction was carried out at 60 ° C. for 6 hours and at 90 ° C. for 1 hour, followed by cooling to dissolve tricalcium phosphate with hydrochloric acid. Filtration / washing / drying, measured by Coulter Multisizer II (Nikkaki Co., Ltd.), average particle size 6.74 μm, fine particle generation rate of 3 μm or less 2.7% in number distribution, coarse particles of 12 μm or more A toner having a narrow particle diameter with a volume distribution of 0.9% and a pigment uniformly dispersed in the toner particles was obtained. This toner was almost spherical and had no color unevenness. In addition, when the triboelectric charge distribution with the iron powder carrier DSP-128 (manufactured by Dowa Iron Powder Co., Ltd.) was measured by an Espert Analyzer EST-1 type (manufactured by Hosokawa Micron Co., Ltd.), it was found that there was no negative polarity and no negative charge. Shows a sharp charge distribution. A developer was prepared by mixing 1 part of colloidal silica with 100 parts of the toner and further mixing it with a ferrite carrier to a toner concentration of 4%. When printing was evaluated with a commercially available copying machine, the sharpness was high and the fog
A high-resolution printed matter without unevenness was obtained.

Example 3 In Example 1, BL-220 was used instead of 27 parts of carbon black MA-100 (manufactured by Mitsubishi Kasei Co., Ltd.).
Example 2 except that 60 parts (manufactured by Titanium Industry Co., Ltd.) were used.
A toner was manufactured in the same manner as in. The toner particle size was measured with a Coulter Multisizer II, and the average particle size was 7.3.
Fine particle generation rate of 5 μm or 3 μm or less is 2.6%, 12
A toner was obtained in which the generation rate of coarse particles of μm or more was 2.6%, and the pigment was uniformly dispersed in the toner particles. This toner was almost spherical and had no color unevenness. Further, the triboelectric charge distribution with the iron powder carrier DSP-128 (manufactured by Dowa Iron Powder Co., Ltd.) was measured by an Espert Analyzer EST-1 type (manufactured by Hosokawa Micron Co., Ltd.), and it was found that there was no negative polarity, Shows a sharp charge distribution. When 1 part of colloidal silica was mixed with 100 parts of the toner and printing evaluation was carried out with a commercially available one-component printer, a high-resolution printed matter with high density, sharpness, fog and unevenness was obtained for the initial image. Obtained. Further, when running was carried out, it was possible to maintain a good image without decreasing the density up to 2000 sheets.

Comparative Example 1 The composition of Example 1 was used, except that the present suspension device was replaced with a jet homogenizer, a stirring homogenizer T. K. The treatment was carried out in the same manner as in Example 2 using an auto homomixer (made by Tokushu Kika Kogyo Co., Ltd.). The average particle size is as large as 8.20 μm,
Regarding the particle size distribution, the fine particle generation rate of 3 μm or less is 68.0% in the number distribution, and the production rate of coarse particles of 12 μm or more is 22.6% in the volume distribution, and the particle size distribution is very wide. It was a thing. A developer was prepared using the toner obtained in the same manner as in Example 1, and the printing evaluation was carried out with a commercially available copying machine.
The printed matter showed unevenness.

Comparative Example 2 With the composition of Example 1, the present suspension conditions were changed to normal pressure conditions instead of pressurized conditions, and the same treatment as in Example 1 was carried out. As a result, entrainment of air in the suspension was extremely severe, the average particle size was large at 8.75 μm, and the particle size distribution reached a fine particle generation rate of 3 μm or less in a number distribution of 29.0.
%, The production rate of coarse particles of 12 μm or more is 6.
9% was produced and it was a wide product. A developer was prepared using the toner obtained in the same manner as in Example 1, and a printing evaluation was carried out with a commercially available copying machine. As a result, the printed matter was lacking in sharpness and fine line reproducibility and had fog and unevenness.

[0035]

[Table 1]

[0036]

As described above, according to the method of the present invention, suspended oil droplets can be made to have a small particle diameter, a high particle generation rate of required 3 to 12 μm diameter, and an extremely narrow particle diameter distribution. It is possible to provide a toner for electrostatic charge development with high resolution and no fog or unevenness by polymerizing the above.

Front Page Continuation (72) Inventor Hiroshi Hamada 66-2 Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Hodogaya Chemical Co., Ltd. Head Office

Claims (4)

[Claims] 1. A polymerization toner produced by suspension polymerization of a polymerizable monomer system containing at least a colorant and a release agent in an aqueous medium system, wherein a jet homogenizer is used as a suspension device. A method for producing a toner for developing an electrostatic image, which is characterized. 2. When suspended, 0.5 kgf / cm in the suspension system.
^The method for producing an electrostatic charge image developing toner according to claim 1, wherein the pressure is applied to ² to ⁵ kgf / cm ² . 3. A polymerization method toner produced by suspension polymerization of a polymerizable monomer system containing at least a colorant and a release agent in an aqueous medium system, wherein a jet homogenizer is used as a suspension device. A toner for developing an electrostatic charge image produced by the method for producing a toner for developing an electrostatic charge image. 4. When suspended, 0.5 kgf / cm in the suspension system.
^A toner for developing an electrostatic charge image produced by the method for producing a toner for developing an electrostatic charge image, which comprises pressurizing to ² to ⁵ kgf / cm ² .