JPH04306664A - Manufacture of toner for elecrostatic charge development - Google Patents

Abstract

PURPOSE:To obtain a latent image having high quality by reducing the particle diameter of a toner for electrostatic charge development and narrowing the particle diameter distribution through the easy manufacturing method by adding cross link transfer agents and crosslinking agents at least one time in the process for forming polymerized particles. CONSTITUTION:As for a process in which a high polymeric dispersants are dissolved into a hydrophilic organic liquid, and polymerizable monomers which are dissolved into the hydrophilic organic liquid and whose generated polymer is swollen and hardly dissolved in the hydrophilic organic liquid are added and polymerized particles are formed. Crosslink transfer agents and crosslinking agents are added at least one time. Accordingly, in the formation process of the toner for electrostatic charge development, high polymer dispersants are dissolved into the hydrophilic organic liquid, and polymerizable monomers, crosslinking transfer agent, and the cross-linking agents are added into the product, and polymerized particles are obtained, and coloring agents are added and dispersed. As the cross linking transfer agent, is used mercaptane, etc., and as the cross linking agent, are used divinyl benzene, divinyl benzene naphthalene, and the aromatic divinyl compounds thereof.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing toner for developing electrostatic images used in electrophotography, electrostatic printing, etc.

0002

[Prior Art] Conventionally, toners for electrophotographic dry developers have been prepared by dispersing a colorant such as carbon black in a binder resin made of natural or synthetic resin. A common method is to melt-knead a toner characteristic imparting agent such as a charge control agent, cool the mixed composition, crush it, and classify the crushed product to produce a toner having a target particle size range.

[0003] The toner obtained by the above method is widely used because the toner characteristic imparting agent has excellent dispersibility, but the process is complicated because it is created through kneading, cooling, crushing, and classifying operations. It is. Furthermore, in recent years, toner with small particle size has been required to improve the image quality of electrophotography.
In order to obtain such a toner, classification must be repeated many times, which has the drawback of poor yield and increased toner manufacturing cost.

[0004] Therefore, as a method for efficiently producing toner with a small particle size that does not require a classification step, for example, Japanese Patent Publications No. 36-10231, Japanese Patent Publications No. 51830-1983, Japanese Patent Publication No. 14895-1980, Japanese Patent Publication No. 53-17
Suspension polymerization methods have been proposed as described in JP-A No. 735, JP-A-53-17736, and JP-A-53-17737. In this method, a composition prepared by adding a water-insoluble monomer, additives such as a coloring agent, and a polymerization initiator in an aqueous solution is suspended and polymerized by high-speed uniform stirring using a homomixer or the like.

[0005] With this method, it is possible to produce toner with a small particle size relatively easily, and there is no need to consider pulverizability, so the toner does not become pulverized even when used for a long time, resulting in a longer life of the developer. It has the characteristics that it is possible to achieve high image quality and to achieve high image quality.

[0006] Furthermore, as a method for obtaining toner with a small particle size, Japanese Patent Publication No. 57-494 and Japanese Patent Publication No. 16-1394
As described in Japanese Patent No. 5, there is a method in which core particles containing a pigment and a charge control agent are formed by a spray granulation method.

[0007] Furthermore, as a method for obtaining a toner with a small particle size and a narrow particle size distribution, Japanese Patent Laid-Open Nos. 58-106554 and 61-18 disclose
As disclosed in Japanese Patent No. 965 and No. 61-275766, there is a method of producing a toner having a so-called core-shell structure by attaching or coating a coloring agent or a substance imparting toner characteristics onto particles having a narrow particle size distribution.

[0008] As a method of obtaining a small particle size toner with a narrow particle size distribution, an attempt is made to color resin particles obtained by dispersion polymerization by adding a dye to them, as described in JP-A-61-228458.

[0009]

[Problems to be Solved by the Invention] However, the suspension polymerization method has disadvantages such as poor dispersion of toner characteristic imparting substances such as carbon black, and a broad particle size distribution although the particle size is small. .

[0010] Furthermore, the spray granulation method has disadvantages in that particle size control is extremely difficult and classification treatment is required after granulation.

[0011] Furthermore, toner produced by the method of obtaining toner having a core-shell structure has problems in terms of electrical properties because the coloring agent and the like are concentrated on the surface.

Furthermore, the toner obtained by the dispersion polymerization method has a very sharp particle size distribution and it is possible to obtain high resolution images, but in order to obtain resin particles for low energy fixing, the molecular weight distribution must be broadened. If this is done, the particle size distribution will also become broader. In addition, sublimation of the dye and fusing of the toner to the PVC mat occur.

The present invention aims to solve the above-mentioned problems, and its purpose is to produce a static image that can be easily manufactured, has a small particle size, a narrow particle size distribution, and can provide high-quality images. An object of the present invention is to provide a method for producing a toner for developing a charge image.

[0014]

[Means for Solving the Problems] A method for producing a toner for developing an electrostatic image of the present invention includes adding a polymer dispersant that is soluble in a hydrophilic organic liquid to the hydrophilic organic liquid. In the step of forming polymerized particles by adding a polymerizable monomer that is soluble in the hydrophilic organic liquid, but the resulting polymer is swollen in the hydrophilic organic liquid but hardly soluble, a chain transfer agent and a crosslinking agent are added during the above step. It is characterized by adding the agent at least once or more.

Next, the present invention will be explained in detail. The toner for developing electrostatic images of the present invention is produced by dissolving a polymer dispersant in a hydrophilic organic liquid, adding a polymerizable monomer, a chain transfer agent, and a crosslinking agent thereto to obtain polymerized particles, and then coloring the resulting toner. It is obtained by adding an agent and dispersing it.

Examples of the hydrophilic organic liquid used in the present invention include methyl alcohol, ethyl alcohol, denatured ethyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, sec-butyl alcohol, and tert-amyl alcohol. Alcohol, 3-pentanol, octyl alcohol, benzyl alcohol, cyclohexanol, furfuryl alcohol, tetrahydrofurfuryl alcohol,
Alcohols such as ethylene glycol, glycerin, diethylene glycol, methyl cellosolve, cellosolve,
Examples include ether alcohols such as isopropyl cellosolve, butyl cellosolve, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, and diethylene glycol monoethyl ether.

[0017] These organic liquids can be used alone or in a mixture of two or more. In addition, alcohol,
By using it in combination with ether alcohols and ether alcohols, various SP values can be changed under conditions that do not give solubility to the polymer particles produced in the organic liquid, and by changing the polymerization conditions, coalescence of seed particles and new particles can be achieved. It is possible to suppress the occurrence of Organic liquids used in combination with these include hydrocarbons such as hexane, octane, petroleum ether, cyclohexane, benzene, toluene, and xylene, halogenated hydrocarbons such as carbon tetrachloride, trichlorethylene, and tetrabromoethane, ethyl ether, Ethers such as dimethyl glycol, trioxane, and tetrahydrofuran, acetals such as methylal and diethylacetal, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexane, and esters such as butyl formate, butyl acetate, ethyl propionate, and cellosolve acetate. , acids such as formic acid, acetic acid, propionic acid, nitropropene, nitrobenzene, dimethylamine, monoethanolamine,
It also includes sulfur- and nitrogen-containing organic compounds such as pyridine, dimethyl sulfoxide, and dimethylformamide, as well as water.

[0018] S is added to the solvent mainly composed of the hydrophilic organic liquid.
O42-, NO2-, PO43-, Cl-, Na
Polymerization may be carried out in the presence of +, K+, Mg2+, Ca2+, and other inorganic ions.

Furthermore, it is possible to adjust the average particle size, particle size distribution, drying conditions, etc. of the polymer particles produced by changing the type and composition of the mixed solvent at the start of the polymerization, during the middle of the polymerization, and at the end of the polymerization.

Examples of the dispersion stabilizer used in the present invention include acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid, or maleic anhydride. acids, or acrylic monomers containing hydroxyl groups, such as β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxypropyl methacrylate, 3-chloro-2-hydroxypropyl acrylate, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerin monoacrylate, glycerin monoacrylate Vinyl alcohol or ethers with vinyl alcohol such as methacrylic acid ester, N-methylolacrylamide, N-methylolmethacrylamide, etc., such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, etc., or compounds containing vinyl alcohol and a carboxyl group esters such as vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride and methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl Homopolymers or copolymers containing a nitrogen atom such as imidazole, ethyleneimine, or a heterocycle thereof, polyoxyethylene, polyoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkyl Polyoxyethylene type amides, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxyethylene nonylphenyl ester, cellulose such as methyl cellulose, hydroxypropyl cellulose, etc. or copolymers of the above hydrophilic monomers with those having a benzene nucleus such as styrene, α-methylstyrene, vinyltoluene or derivatives thereof, or acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, acrylamide, Further examples include copolymers with crosslinkable monomers such as ethylene glycol dimethacrylate, diethylene glycol methacrylate, allyl methacrylate, and divinylbenzene.

[0021] These polymer compound dispersants may be appropriately selected depending on the hydrophilic organic liquid used and the intended polymer particles. A material that has high affinity and adsorption to hydrophilic organic liquids and high solubility to hydrophilic organic liquids is selected. In addition, in order to enhance the repulsion between particles sterically, those with molecular chains of a certain length, preferably those with a molecular weight of 10,000 or more, are selected. However, if the molecular weight is too high, the viscosity of the liquid will increase significantly, the operability and stirring properties will deteriorate, and the probability of precipitation of the produced polymer on the particle surface will vary, so care must be taken.

[0022] Furthermore, it is also effective for particle stabilization to allow some of the monomers of the above-mentioned polymer compound dispersant to coexist with the monomers constituting the desired polymer particles.

In addition, in combination with these polymer compound dispersants, metals such as cobalt, iron, nickel, aluminum, copper, tin, lead, magnesium, etc. or their alloys (especially preferably 1μ or less), iron oxide, Fine powder of inorganic compounds of oxides such as copper oxide, nickel oxide, zinc oxide, titanium oxide, and silicon oxide, pigments and dyes such as carbon black, nigrosine dye, aniline blue, chrome yellow, phthalocyanine blue, and rose bengal, and higher alcohols. Sulfate ester salt, alkylbenzene sulfonate, α-
Anionic surfactants such as olefin sulfonates and phosphate esters, alkyl amine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazolines, alkyl trimethyl ammonium salts, dialkyl dimethyl ammonium salts, and alkyl dimethyl benzyl. Ammonium salts, pyridium salts, alkylisoquinolinium salts, quaternary ammonium salt type cations such as benzethonium chloride, surfactants, fatty acid amide derivatives,
Even if a nonionic surfactant such as a polyhydric alcohol derivative is used in combination with an amino acid type or betaine type amphoteric surfactant such as an alanine type [e.g. dodecyl di(aminoethyl)glycine, di(octylaminoethyl)glycine], The stabilization of the produced polymer particles and the improvement of the particle size distribution can be further enhanced.

Generally, the amount of the polymeric dispersant used varies depending on the type of polymerizable monomer for forming the desired polymer particles, but it is preferably 0.1% to 10% by weight based on the hydrophilic organic liquid. More preferably, the amount is from % by weight to 5% by weight. When the concentration of the polymer dispersion stabilizer is low, relatively large diameter polymer particles are obtained, and when the concentration is high, small particles are obtained, but even if the concentration exceeds 10% by weight, It has little effect on reducing the diameter.

The polymerizable monomers used in the present invention include:
Vinyl monomers are preferred because they are soluble in hydrophilic organic liquids, but the resulting polymers are swollen in hydrophilic organic liquids but hardly soluble.

The vinyl monomer is one that can be dissolved in a hydrophilic organic liquid, such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, etc.
Methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-
Butylstyrene, pn-hexylstyrene, pn-
Octylstyrene, pn-nonylstyrene, pn-
Styrenes such as decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, methyl acrylate, ethyl acrylate, n-butyl acrylate , isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, Methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate,
α-methyl fatty acid monocarboxylic acid esters such as n-octyl methacrylate, dodecyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, acrylonitrile, methacrylonitrile,
Acrylic acid or methacrylic acid derivatives such as acrylamide, vinyl chloride, vinylidene chloride, vinyl bromide,
Examples include vinyl halides such as vinyl fluoride, which may be used alone or in combination.

In the present invention, it is more preferable to contain at least styrene and methyl acrylate, and the ratio is 0.4 styrene to 1 methyl acrylate.
It is preferable that it is 4. This can prevent sublimation of the dye, fusion of the toner to the vinyl chloride mat, and the like.

In the present invention, the amount of polymerizable monomer used is
It is preferably 50 times or less that of the polymer dispersant. If it exceeds 50 times, the particle distribution cannot be narrowed. Also,
Although it varies somewhat depending on the type of hydrophilic organic liquid, it is preferably 50% by weight or less, more preferably 30% by weight or less, based on the hydrophilic organic liquid. If the amount of vinyl monomer is extremely large relative to the hydrophilic organic liquid, the resulting polymer will be completely dissolved and will not precipitate until the polymerization has progressed to a certain extent. As a result, polymer particles having a small particle size and a narrow particle size distribution can be obtained.

The chain transfer agent used in the present invention includes those conventionally used, such as mercaptans.

[0030] Examples of the crosslinking agent used in the present invention include those commonly used, such as divinylbenzene,
Divinylnaphthalene and aromatic divinyl compounds that are derivatives thereof, other ethylene glycol dimethacrylate, diethylene glycol methacrylate, triethylene glycol methacrylate, tritylpropane triacrylate, allyl methacrylate, tert-
diethylene carboxylic acid esters such as butylaminoethyl methacrylate, tetraethylene glycol dimethacrylate, 1,3-butadiol dimethacrylate,
All divinyl compounds such as N,N-divinylaniline, divinyl ether, divinyl sulfide, and divinyl sulfone, and compounds having three or more vinyl groups are preferred, and these may be used alone or in mixtures.

Further, in the present invention, a polymerization initiator may be added, for example, an azo initiator such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), etc. system polymerization initiator, lauryl peroxide,
A peroxide polymerization initiator such as benzoyl peroxide or tert-butyl peroctoate, a persulfide initiator such as potassium persulfate, or a combination thereof with sodium thiosulfate, an amine, etc. are used.

The concentration of the polymerization initiator is preferably 0.1 to 10 parts by weight per 100 parts by weight of the polymerizable monomer.

The polymerizable particles obtained in the present invention must have a small particle size and a narrow particle size distribution, with a ratio of volume average particle size to number average particle size of 1.15 or less, and a volume average particle size of 1.15 or less. It is preferable that the diameter is 2 to 12 μm.

[0034] The polymerization conditions are the target of the polymer particles, the average particle diameter,
The concentration and blending ratio of the polymer dispersant and polymerizable monomer in the hydrophilic organic liquid are determined according to the target particle size distribution.

Generally, if the average particle diameter of the polymer particles is to be made small, the concentration of the polymeric dispersant is set high, and if the average particle diameter is to be made large, the concentration of the polymeric dispersant is set to be low. .

On the other hand, if the particle size distribution is to be made very sharp, the concentration of the polymerizable monomer is set low, and if a relatively wide distribution is desired, the concentration of the polymerizable monomer is set high; In general, if the amount used is more than 50 times the amount of polymer dispersion stabilizer used, particles with a particle diameter within ±25% of the average particle diameter will have a distribution of 90% or more by weight. It's difficult.

Polymerization is carried out by completely dissolving the polymer dispersion stabilizer in a hydrophilic organic liquid, and then adding the polymerizable monomer, polymerization initiator,
If necessary, add inorganic fine powders, surfactants, dyes, pigments, etc., and stir in a tank using normal stirring at 30 to 300 rpm, preferably at a slow speed, and using turbine-type stirring blades rather than paddle-type stirring blades. Polymerization is carried out by heating at a temperature corresponding to the decomposition rate of the initiator used while stirring at a speed that makes the flow uniform. In addition, since the temperature at the initial stage of polymerization has a large effect on the diameter of the seed particles produced, it is better to dissolve the initiator in a small amount of solvent and add it after the temperature has been raised to the polymerization temperature after adding the polymerizable monomer. desirable.

During polymerization, it is necessary to sufficiently expel oxygen in the air in the reaction vessel using an inert gas such as nitrogen gas or argon gas. If the oxygen purge is insufficient, fine particles are likely to be generated.

[0039] Polymerization time of 5 to 40 hours is required to carry out polymerization at a high polymerization rate, but it is possible to stop the polymerization when the desired particle size and particle size distribution is achieved, or to add a polymerization initiator sequentially. and can speed up the polymerization rate.

A toner for developing electrostatic images can be obtained by adding a colorant to the polymer particles thus obtained and dispersing them.

[0041]

EXAMPLES The present invention will be explained in more detail below with reference to Examples and Comparative Examples. Preparation of Dispersion Stabilizer Solution The following items were placed in a sealable reaction vessel rotating in a constant temperature water bath. methanol
2000 parts by weight polyvinylpyrrolidone
The 100 parts by weight container was gently stirred at room temperature, and the polyvinylpyrrolidone was completely dissolved in about 1 hour.

Example 1 250 parts of a methanol solution in which a dispersion stabilizer was dissolved was transferred into a sealable reaction vessel rotating in a constant temperature water bath, and the following composition was added thereto. styrene
53.08 parts by weight Methyl acrylate
43.42 parts by weight 1,
3-Butanediol dimethacrylate 0.
75 parts by weight Dodecyl mercaptan
0.125 parts by weight

While mixing by rotating the container, the air was completely expelled by blowing N2 gas into the container, and the container was sealed. Thereafter, the water tank was kept at 60 degrees and polymerization was carried out while stirring at 100 revolutions per minute. At this time, 2,2'-azobisisobutyronitrile was used as an initiator, and the reaction was completed in 24 hours.

100μ by Coulter Multisizer
In particle size distribution measurement using an m-aperture tube, the volume average diameter was 3.12 μm and the number average diameter was 2.98 μm at a particle count of 50,000, and the ratio was 1.046.

A portion of the particles was sampled and purified by centrifugal sedimentation, and the softening point and outflow starting point of the dried particles were measured. The softening point and runoff point of the particles were 62°C and 89°C, respectively.

[0046] The softening point referred to here means that the particles were measured using a flow tester (manufactured by Shimadzu Corporation) under a load of 10 kg/cm2 with a plunger and at a heating rate of 3.
When 1 cm3 of the sample in the cylinder was extruded through a nozzle with a diameter of 0.5 mm and a length of 1 mm while heating at °C/min,
The temperature is such that the plunger gradually descends, compressing the particles so that the voids within the cylinder disappear and they appear to be one homogeneous transparent body or phase. Further, the outflow starting point is the temperature at which the plunger starts to descend again after the particles become a transparent body or phase under these conditions and there is no clear fluctuation in the position of the plunger.

Example 2 250 parts of a methanol solution in which a dispersion stabilizer was dissolved was transferred into a sealable reaction vessel rotating in a constant temperature water bath, the following composition was added, and polymerization was carried out in the same manner as in Example 1. . styrene
53.08 parts by weight Methyl acrylate
43.42 parts by weight 1,
3-Butanediol dimethacrylate 1.
5 parts by weight Dodecyl mercaptan
0.25
Weight part

Example 3 250 parts of a methanol solution in which a dispersion stabilizer was dissolved was transferred into a sealable reaction vessel rotating in a constant temperature water bath, the following composition was added, and polymerization was carried out in the same manner as in Example 1. . styrene
53.08 parts by weight Methyl acrylate
43.42 parts by weight 1,
3-Butanediol dimethacrylate 3.
0 parts by weight Dodecyl mercaptan
0.5
Weight part

The volume average diameter of the particles obtained with the above composition was 7.64 μm, the number average diameter was 7.32 μm, and the ratio thereof was 1.044.

[0049] The softening point and outflow starting point of these particles were 77.5°C and 131°C, respectively.

Example 4 250 parts of a methanol solution in which a dispersion stabilizer was dissolved was transferred into a sealable reaction vessel rotating in a constant temperature water bath, the following composition was added, and polymerization was carried out in the same manner as in Example 1. . styrene
53.08 parts by weight Methyl acrylate
43.42 parts by weight 1,
3-Butanediol dimethacrylate 4.
5 parts by weight Dodecyl mercaptan
0.9
Weight part

The volume average diameter of the particles obtained with the above composition was 11.52 μm, the number average diameter was 11.09 μm, and the ratio thereof was 1.039.

[0052] The softening point and outflow starting point of these particles were 98.1°C and 151°C, respectively.

Example 5 Polymerization was carried out in the same manner as in Example 1, and the water bath temperature was 60°C.
6 hours after reaching this point, the following composition was added to continue polymerization. methanol
8
Part by weight 1,3-butanediol dimethacrylate
2.25 parts by weight Dodecyl mercaptan
0.375 parts by weight

The volume average diameter of the particles thus obtained was 3.19 μm, and the number average diameter was 2.89.
The μm ratio was 1.104.

[0055] The softening point and outflow starting point of these particles were 77.6°C and 135°C, respectively.

[0056] As described above, by simultaneously adding a crosslinking agent and a chain transfer agent, the particle size of the particles produced hardly changes and the thermal properties can be improved.

Example 6 Polymerization was carried out in the same manner as in Example 2, and the water bath temperature was 60°C.
6 hours after reaching this point, the following composition was added to continue polymerization. methanol
8
Part by weight 1,3-butanediol dimethacrylate
1.5 parts by weight Dodecyl mercaptan
0.25 parts by weight

The volume average diameter of the particles thus obtained was 5.11 μm, and the number average diameter was 5.11 μm.
The ratio was 1.017.

[0059] The softening point and outflow starting point of these particles were 76.6°C and 135°C, respectively.

[0060] As described above, by simultaneously adding a crosslinking agent and a chain transfer agent, the particle size of the particles produced hardly changes and the thermal properties can be improved.

Example 7 Polymerization was carried out in the same manner as in Example 3, and the water bath temperature was 60°C.
6 hours after reaching this point, the following composition was added to continue polymerization. methanol
8
Part by weight 1,3-butanediol dimethacrylate
1.5 parts by weight Dodecyl mercaptan
0.25 parts by weight

The volume average diameter of the particles thus obtained was 7.50 μm, and the number average diameter was 7.50 μm.
The ratio was 1.015.

[0063] The softening point and outflow starting point of these particles were 99.6°C and 149°C, respectively.

[0064] As described above, by simultaneously adding a crosslinking agent and a chain transfer agent, the particle diameter of the particles produced hardly changes and the thermal properties can be improved.

Add 30.0 parts by weight of Oil Black 860 and 20 parts by weight of methanol, heat and dissolve, then cool to 1 μm.
10 parts by weight of the filtrate was prepared by filtration through a microfilter.

Polymer dispersion 1 obtained in Examples 1 to 7 was added to 135 parts by weight of each filtrate thus prepared.
Part by weight was added, stirred at 50°C for 1 hour, and then the dispersion was cooled to room temperature, centrifuged, and the supernatant was removed and redispersed in a mixed solvent of 50 parts by weight of methanol and 50 parts by weight of water. This operation was performed three times. Ta. After filtering, the mixture was air-dried and dried under reduced pressure at 40° C. for 6 hours to obtain resin particles colored with Oil Black 860.

After stirring 100 parts by weight of the colored resin particles and 0.5 parts by weight of Spiron Black THR (manufactured by Hodogaya Chemical Co., Ltd.) in an Ooster blender for 5 minutes, the rotation speed was adjusted using a hybridization NHS-1 (Nara Kikai Seisakusho). 70
A toner was obtained by processing at 00 rpm for 5 minutes.

Next, image evaluation of these toners was performed using a Ricoh copier FT-5510, and the image resolution was 7.1 lines/mm, and the image did not deteriorate even after running 30,000 copies. A clear black image was maintained as it was initially.

Comparative Example 1 250 parts of a methanol solution in which a dispersion stabilizer was dissolved was transferred into a sealable reaction vessel rotating in a constant temperature water bath, and the following composition was charged, and polymerized particles were prepared in the same manner as in Example 1. Obtained. styrene
53.08 parts by weight Methyl acrylate 43.
42 parts by weight

The volume average diameter of the particles obtained with the above composition was 7.84 μm, the number average diameter was 4.96 μm, and the ratio thereof was 1.580, and the particle size distribution was broad, and the generation of fine particles was particularly remarkable.

Comparative Example 2 250 parts of a methanol solution in which a dispersion stabilizer was dissolved was transferred into a sealable reaction vessel rotating in a constant temperature water bath, and the following composition was charged, and polymerized particles were obtained in the same manner as in Example 1. Ta. styrene
53.08 parts by weight Methyl acrylate 43.
42 parts by weight 1,3-butanediol methacrylate 1.5 parts by weight

When polymerization was carried out with the above composition, particles began to aggregate about 3 hours after the temperature of the water bath reached 60° C., and became complete aggregates after 24 hours.

Comparative Example 3 250 parts of a methanol solution in which a dispersion stabilizer was dissolved was transferred into a sealable reaction vessel rotating in a constant temperature water bath, and the following composition was charged, and polymerized particles were prepared in the same manner as in Example 1. Obtained. styrene
53.08 parts by weight Methyl acrylate 43.
42 parts by weight Dodecyl mercaptan
0.25 parts by weight

The volume average diameter of the particles obtained with the above composition was 3.81 μm, the number average diameter was 1.96 μm, and the ratio thereof was 1.944, and the particle size distribution was broad, and the generation of fine particles was particularly remarkable.

Comparative Example 4 Polymerization was carried out using the same preparation as in Example 2, and the water bath temperature was 60°C.
6 hours after reaching this point, the following composition was added to continue polymerization. methanol
8 parts by weight 1,3-butanediol dimethacrylate
1.5 parts by weight

[0076] Then, some aggregation was observed about 10 hours after polymerization, and after 24 hours, the particles were quite agglomerated, and some particles did not pass through a 100 μm aperture tube.

Comparative Example 5 Polymerization was carried out using the same preparation as in Example 2, and the water bath temperature was 60°C.
6 hours after reaching this point, the following composition was added to continue polymerization. methanol
8 parts by weight Dodecyl mercaptan
0.25 parts by weight

[0078]
The volume average diameter of the particles thus obtained was 4.39μ
m, number average diameter 3.19 μm, the ratio was 1.376, and the generation of fine particles was significant.

Toners were obtained using the particles obtained in Comparative Examples 1, 3, 4, and 5 in the same manner as in Example 1, and image evaluation was performed on these toners using a Ricoh copier FT-5510. etc., and a clear image could not be obtained.

Example 8 250 parts of a methanol solution in which a dispersion stabilizer was dissolved was transferred into a sealable reaction vessel rotating in a constant temperature water bath, and the following composition was added thereto, followed by polymerization in the same manner as in Example 1. styrene
80
Part by weight Methyl acrylate
20 parts by weight 1,3-butanediol dimethacrylate
1 part by weight dodecyl mercaptan
0.9 parts by weight

The volume average diameter of the particles obtained with the above composition was 5.21 μm, and the number average diameter was 4.21 μm.
99 μm, the ratio was 1.044.

[0082] The softening point and outflow starting point of these particles were 78.5°C and 120°C, respectively.

Example 9 250 parts of a methanol solution in which a dispersion stabilizer was dissolved was transferred into a sealable reaction vessel rotating in a constant temperature water bath, and the following composition was added thereto, followed by polymerization in the same manner as in Example 1. styrene
60
Part by weight Methyl acrylate
40 parts by weight 1,3-butanediol dimethacrylate
2.5 parts by weight dodecyl mercaptan
0.5 parts by weight

[0084] The volume average diameter of the particles obtained with the above composition was 4.02 μm, and the number average diameter was 3.78.
The μm ratio was 1.063.

[0085] The softening point and outflow starting point of these particles were 77.5°C and 121°C, respectively.

Example 10 250 parts of a methanol solution in which a dispersion stabilizer was dissolved was transferred into a sealable reaction vessel rotating in a constant temperature water bath, and the following composition was added thereto, followed by polymerization in the same manner as in Example 1. styrene
50
Part by weight Methyl acrylate
50 parts by weight 1,3-butanediol dimethacrylate
2.5 parts by weight dodecyl mercaptan
0.5 parts by weight

The volume average diameter of the particles obtained with the above composition was 5.05 μm, and the number average diameter was 4.98.
The μm ratio was 1.014.

[0088] The softening point and outflow starting point of these particles were 75.1°C and 122°C, respectively.

Example 11 250 parts of a methanol solution in which a dispersion stabilizer was dissolved was transferred into a sealable reaction vessel rotating in a constant temperature water bath, and the following composition was added thereto, followed by polymerization in the same manner as in Example 1. styrene
40
Part by weight Methyl acrylate
60 parts by weight 1,3-butanediol dimethacrylate
2.5 parts by weight dodecyl mercaptan
0.9 parts by weight

[0090] The volume average diameter of the particles obtained with the above composition was 6.1 μm, and the number average diameter was 5.91 μm.
The m ratio was 1.032.

[0091] The softening point and outflow starting point of these particles were 77.6°C and 121°C, respectively.

Example 12 250 parts of a methanol solution in which a dispersion stabilizer was dissolved was transferred into a sealable reaction vessel rotating in a constant temperature water bath, and the following composition was added thereto, followed by polymerization in the same manner as in Example 1. styrene
30
Part by weight Methyl acrylate
70 parts by weight 1,3-butanediol dimethacrylate
2.5 parts by weight dodecyl mercaptan
0.9 parts by weight

[0093] The volume average diameter of the particles obtained with the above composition was 7.21 μm, and the number average diameter was 7.09.
The μm ratio was 1.017.

[0094] The softening point and outflow starting point of these particles were 78.5°C and 121°C, respectively.

Toners were obtained from the polymer dispersions obtained in Examples 8 to 12 in the same manner as in Example 1, and image evaluation was performed on these toners using a Ricoh copier FT-5510. Regarding No. 12, the resolution of the image was 7.1 lines/mm, and the image did not deteriorate even after running 30,000 sheets, and the clear black image was maintained as it was at the beginning.

Furthermore, when these image samples were sandwiched between PVC mats and left in an environment of 50° C. for one week to conduct a PVC mat fusion test, the toner did not fuse to the PVC mat.

[0097]

Effects of the Invention As is clear from the above explanation, according to the method for producing toner for developing electrostatic images of the present invention, it is possible to easily obtain a toner having a small particle size and a narrow particle size distribution, and a high You can get quality images. Furthermore, sublimation of the dye and fusion of the toner to the PVC mat can be prevented.

Claims (6)

[Claims] Claim 1: A polymer dispersant that is soluble in the hydrophilic organic liquid is added to the hydrophilic organic liquid, and the resulting polymer is dissolved in the hydrophilic organic liquid. For electrostatic image development, characterized in that a chain transfer agent and a crosslinking agent are added at least once during the step of adding a swollen but hardly soluble polymerizable monomer to form polymer particles. Toner manufacturing method. 2. The method for producing a toner for developing an electrostatic image according to claim 1, wherein the polymerized monomer is one or more vinyl monomers. 3. The method for producing a toner for developing an electrostatic image according to claim 2, wherein at least styrene and methyl acrylate are used as the vinyl monomer. 4. The method for producing a toner for developing an electrostatic image according to claim 3, wherein the weight ratio of the styrene and methyl acrylate is 0.4/1 to 4/1. 5. The method for producing a toner for developing an electrostatic image according to claim 1, wherein the chain transfer agent and the crosslinking agent are added to the hydrophilic organic liquid at the same time. 6. The chain transfer agent and the crosslinking agent are added to the hydrophilic organic liquid at a monomer weight ratio of 1/1000 to 10/1000 and 1/100 to 10/100, respectively. The method for producing a toner for developing an electrostatic image according to claim 1.