JPH03243628A - Production of colored fine particle and toner for electrophotography using the same particle - Google Patents

Abstract

PURPOSE:To obtain colored fine particles useful for toner giving a clear picture, etc., having uniform size of particle and improved surface of particle by subjecting a polymerizing monomer to suspension polymerization in a suspension medium in the presence of a coloring matter, etc., making the obtained polymer granules blocky with heat treatment and crushing said blocky granules. CONSTITUTION:A polymerizing monomer such as styrene is subjected to suspension polymerization to attain >=90% polymerization yield in a suspension medium containing a stabilizer and a polymerization initiator, etc., in the presence of a coloring matter such as carbon black or magnetic powder such as cobalt (1-200 pts.wt. to 100 pts.wt. said monomer) with controlling a granular diameter to obtain a suspension having 3-50mum average granular diameter and a distribution of granular diameter of 0-80% coefficient of variation in the granular diameter. Next, the resultant suspension is heat-treated at 50-98 deg.C and aged with polymerization, then an organic solvent such as hexane is added to the suspension to make said granules blocky by fusing, thus crushed to fineparticles having the average particle diameter before the crushing to afford the aimed colored fine particles. Besides, said fine particles having 4-15mum average particles diameter is preferably used as toner for electrophotography.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Separation] The present invention relates to a method for producing colored fine particles and an electrophotographic toner using the same. More specifically, the present invention provides a method for producing colored fine particles in which the coloring agent is uniformly dispersed within the particles and the surface of the particles is modified, and which can therefore be used as a coloring agent for toner paints, inks, resin molded products, etc. The present invention relates to an electrophotographic toner that is made of the colored fine particles and that can form a clear image when used in a toner for a printer such as a laser printer or a product printer.

[Prior Art] In electrophotography, an electrical latent image is formed on a photoreceptor made of a photoconductor material such as selenium, zinc oxide, or cadmium sulfide, and this is developed with a powder developer and printed on paper. It is then transferred and fixed onto a paper.

Conventionally, toner used for electrophotographic development is generally made into a solidified product after coloring agents and other additives (charge control agents, anti-offset agents, lubricants, etc.) are melt-mixed and dispersed in a thermoplastic resin. has been finely pulverized and classified to produce colored fine particles with a particle size of 9.

However, the method of manufacturing toner by pulverization described above has some drawbacks. The first step is to manufacture the resin, knead the resin with colorants and other additives, pulverize the solid material, and classify the pulverized material to obtain colored fine particles with a desired particle size. This method requires many steps and various g settings, and the toner produced by this method is inevitably expensive. In particular, the step of classifying to obtain a toner having an optimum particle size range for forming a clear image with less fog is either an essential requirement or poses a problem in terms of productivity and yield. Second, it is extremely difficult to uniformly disperse colorants and other additives in the resin during the kneading process, and therefore, toners produced by this method have poor dispersion of colorants, charge control agents, etc. Because of this, the triboelectric properties of each particle are different, which leads to a decrease in resolution.

Such problems will become more prominent in the future as toner particles become smaller in diameter, which is an essential condition for achieving high quality images. In other words, there is a limit to the ability to obtain toner with small particle size using the current crusher, and even if toner with small particle size can be obtained, due to poor dispersion of the colorant and charge control agent,
Larger variations in the amount of charge may occur.

In order to improve the various defects found in toners due to their pulverizability, various methods for manufacturing toners using emulsion polymerization or suspension polymerization have been proposed (Special Publications Sho: 36).
-10,231, Special Publication No. 4B-10,799, Special Publication No. 47-518, 305r71 Special Publication No. 14, 89, 1977
No. 5, etc.). In these methods, a coloring agent such as carbon black and other additives are added to a polymerizable monomer, and the mixture is emulsified or suspended to polymerize, thereby synthesizing a toner containing the coloring agent all at once. With this method it is possible to considerably improve the drawbacks of conventional grinding methods. That is, since it does not involve any pulverization process, there is no need to improve brittleness, and since the shape is spherical and has excellent wide mobility, the triboelectrification property is uniform. However, there are also problems with toner manufacturing methods using polymerization methods. Firstly, the dispersant used during polymerization,
Since hydrophilic substances such as surfactants cannot be completely removed even in a cleaning process and remain on the surface of the toner, charging properties are easily influenced by the environment. Secondly, the toner obtained by the polymerization method has a spherical shape and a very smooth surface, making it difficult to remove the toner adhering to the photoreceptor, resulting in poor cleaning.

To solve these problems, various methods have been proposed in JP-A-61
-255,354, JP-A-53-17゜736, JP-A-63-17,460, JP-A-61-167.95
No. 6, etc., the effect is incomplete, or it leads to an increase in cost, so it is not practical.

In order to solve these problems, for example, the main resin components are manufactured by emulsifying and dispersing polymerizable monomers, colorants and/or magnetic powders, and tension initiators in the presence of an emulsifier and polymerizing them. Then, by coagulating the resulting coagulant at a temperature below the glass transition point of the main resin component, and heating the particles obtained after coagulation to a temperature above the glass transition point of the il resin component, it is completely converted to /8P+. [! l! A method for manufacturing an electrophotographic toner having a desired particle size by classifying the obtained particles is disclosed (Japanese Patent Laid-Open No. 167-955-1982, Japanese Patent Laid-open No. 167-198-956).
No., JP-A-61-167.957 and JP-A-61-
No. 72.258).

However, in this method, polymerization is mainly carried out by emulsion polymerization, so the particle size of the obtained polymer particles is on the order of submicrons, and colorants such as carbon black are not contained in the polymer particles and are not contained outside the particles. Therefore, it is impossible to uniformly disperse the particles even if they are included in larger particles in the next solidification step or heat-melting step. This causes non-uniformity of the colorant, which causes non-uniform charging or toner scattering when used as a toner for electrophotography, causing fogging and drum contamination. Also,
In the above method, since the particle system of the polymer obtained by polymerization is small, it is necessary to increase the particle size and control the particle size by coagulating at a temperature below the glass transition point in the coagulation step, but in this case, Is it necessary to use an inorganic acid, an organic acid, etc. as a coagulant? This coagulant cannot be completely removed no matter how much the resulting toner is washed, and the remaining 77: The coagulant is environmentally resistant. There were problems such as dependence and insufficient electrical characteristics.

[Issues to be criticized or solved] As a result of intensive research in view of the above-mentioned current situation, the Honko critics have found that
Colored fine particles obtained by processing colored spherical fine particles obtained by suspension polymerization in a specific order have all of the above-mentioned problems improved, and can be used in electrophotographic toners, paints,
It is suitably used as a coloring agent for ink, resin moldings, etc., and an electrophotographic toner using the colored fine particles is
We have discovered that when used in printer devices such as laser printers and finished product printers, it is possible to form extremely clear images without any of the problems of the prior art,
The present invention has now been completed.

[Means for Solving the Problems] The present invention involves suspending a polymerizable monomer in a suspension medium in the presence of a colorant and/or magnetic powder, and carrying out suspension polymerization while controlling particles. , the suspension EJ liquid of colored spherical fine particles having an average particle diameter of 3 to 50 μm was suspended at 50 to 98 μm.
Polymerization and ripening are carried out by heat treatment at a temperature of °C, and the particles are fused together to form a block, and then the block-shaped particles are pulverized to substantially the average particle size of the colored spherical fine particles before fusion. This is a method for producing colored fine particles.

The present invention also provides an electrophotographic toner containing the colored fine particles described above.

[Function] The colored spherical fine particles of the present invention are obtained by suspending a polymerizable monomer in a suspension medium in the presence of a colorant and/or magnetic powder, and performing suspension polymerization while controlling the particle size. It is obtained by The colored fine spherical particles obtained by this suspension polymerization have a particle size of 3 to 50 μm, preferably 3.5 to 20 μm, or the size of this particle size can be determined by heating and crushing the colored fine particles of the present invention. It has extremely important significance in terms of obtaining The average particle diameter of spherical polymers produced by polymerization methods other than suspension polymerization, such as emulsion polymerization, is usually 0.
The particle size is around 1 μm, and the fine particles obtained by heat treatment and crushing are significantly different in particle shape and particle size distribution compared to the colored fine particles obtained by Honhatsumon's old production process. Even if it is used as a toner, it is not possible to obtain an image of sufficient quality.

Examples of polymerizable monomers used as the polymerizable monomer component in suspension polymerization include the following, and these can be used alone or in combination of two or more.

Styrene, 0-methylstyrene, m-methylstyrene,
Styrenic monomers such as p-methylstyrene, α-methylstyrene, p-methkinstyrene, p-tert-butylstyrene, p-phenylstyrene, 0-chlorostyrene, m-chlorostyrene, p-chlorostyrene; acrylic acid Methyl, ethyl acrylate, n-phthyl acrylate, isobutyl acnolate, dodenyl acrylate, stearyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, methacrylic acid Acrylic acid or methacrylic acid monomers such as isobutyl, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate; ethylene, propylene, butylene, vinyl chloride,
Vinyl acetate, acrylonitrile.

Workability during crushing can be improved by subjecting the above-mentioned polymerizable monomers to suspension polymerization and heat-treating the resulting colored spherical fine particles under the conditions described below. If the fusion of particles during heat treatment progresses too much, the efficiency of the crushing process will decrease, and if the fusion is insufficient, a sufficient processing effect will not be obtained. To avoid excessive fusion, a crosslinking agent may be used during suspension polymerization.

Examples of the crosslinking agent include aromatic divinyl compounds such as divinylhensen, divinylnaphthalene, and derivatives thereof, ethylene glycol dimethacrylate, diethyllene glycol dimethacrylate, triethylene glycol methacrylate, trimethylolpropane triacrylate, and allyl. Diethylenically unsaturated carbonic acid esters such as methacrylate, t-butylaminoethyl methacrylate, tetraethylene glycol cymethacrylate, 1,3-butanediolne methacrylate, N
, N-divinylaniline, divinyl ether, divinyl sulfide, vinyl sulfonic acid, and compounds in which three or more vinyl groups are -6. Furthermore, bobutadiene, polyisoprene, unsaturated polyester, chlorosulfonated polyolefin, etc. are also effective.

The colorant used to obtain the colored spherical fine particles is a dye, a pigment, etc. well known to those skilled in the art, and may be organic or inorganic. Specific examples include carbon black, nicrosine dye, aniline blue, calco oil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, and oil black. , azo oil black, roast bengal, etc., and two or more of these may be used in combination if it is safe.

Moreover, a substance having magnetism, that is, a magnetic substance can also be used as a coloring agent. Examples of magnetic materials include iron, cobalt,
Examples include powders of ferromagnetic metals such as nickel, powders of metal compounds such as magnetite, hematite, and ferrite. These magnetic substances may be used alone or together with the dyes, pigments, etc.
- It can be used as a adhesive.

These colorants may be used as they are, but if a colorant whose surface has been treated with an appropriate method is used, colored fine particles in which the colorant is uniformly dispersed can be obtained, and when used in toner, for example, high quality images can be obtained. It is preferable because it is formed. For example, when carbon black is used as a coloring agent,
-270,767 and JP-A-63-265,913
The carbon black graft polymers described in the above publication are suitable. Furthermore, when using a colorant other than carbon black, a surface-treated colorant obtained by the method described in JP-A-1-118,573 is suitable.

The amount of the coloring agent added can vary widely depending on the type of coloring agent used and the purpose of use of the obtained shield-colored microstripes, but preferably 100 parts of the polymerizable monomer. 1 to
200 parts by weight, more preferably 1 to 100 parts by weight.

In order to obtain colored spherical fine particles using a coloring agent, a simple method is to prepare a polymerizable monomer in which the coloring agent is dissolved or dispersed, but in some cases, polymerizable monomers are added. A method may also be used in which the subsequent spherical polymer t+' is made to absorb the child coloring agent using a suitable solvent.

Stabilizers used in suspension polymerization include polyvinyl alcohol, starch, methyl cellulose, carboxyl methyl cellulose, hydroxyethyl cellulose, sodium polyacrylate, sodium polyacrylate, etc.
n-polymer: There are surfactants such as anionic surfactants, cationic surfactants, zwitterionic surfactants, nonionic surfactants, and other surfactants such as barium sulfate, barium sulfate, barium carbonate, and magnesium carbonate. , calcium phosphate, talc, clay, diatomaceous earth, metal oxide powder, etc. are used.

Examples of anionic surfactants include fatty acid salts such as sodium oleate and castor potash, alkyl sulfate ester salts such as sodium lauryl sulfate and ammonium lauryl sulfate, alkylbenzenesulfonates such as sodium dodecylbenzenesulfonate, and alkylnaphthalenesulfonic acids. salts, alkanesulfonates, dialkyl sulfosuccinates, alkyl phosphate ester salts, naphthalene sulfonic acid formalin condensates, polyoxyethylene alkylphenyl ether sulfate salts, polyoxyethylene alkyl sulfate ester salts, and the like.

Examples of nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxin sorbitan fatty acid ester, polyoxyethylene alkylamine/chrycerin fatty acid ester, and oxine ethylene. -Oxypropylene block polymer, etc.

Examples of the cationic surfactant include alkylamine salts such as laurylamine acetate and stearylamine acetate, and quaternary ammonium salts such as lauryltrimethylammonium chloride F.

Examples of the zwitterionic surfactant include lauryl dimethylamine oxide.

These stabilizers are used to adjust the particle size of the colored spherical fine particles obtained by
The composition and amount used should be adjusted as appropriate so that the thickness is 50 μm, preferably 3.5 to 20 μm. For example, when a water-soluble polymer is used as a stabilizer, it is suitably used in an amount of 0.01 to 20% by weight, preferably 0.1 to 10% by weight, based on the polymerizable monomer component. In the case of surfactant, 0.01 to the polymerizable monomer component
~10% by weight, preferably 0. The content is preferably 1 to 5% by weight.

As the polymerization initiator used in the polymerization, oil-soluble peroxide-based or azo-based initiators commonly used in suspension polymerization can be used. - For example, benzoyl peroxide,
lauroyl peroxide, octanoyl peroxide, orthochlorobenzoyl peroxide, orthomethoxybenzoyl peroxide,
Peroxide initiators such as methyl ethyl ketone peroxide, diisopropyl peroxydicarbonate, cumene hydroperoxide, cyclohexanone peroxide, t-butyl hydroperoxide, diisopropylbenzene hydroperoxide, 2,2'-azobisisobutyro Nitrile, 2゜2-azobis-(2
, 4-dimethylvaleronitrile), 2.2-azobis-2,3-dimethylbutyronitrile, 2.2-azobis-(2-dimethylbutyronitrile), 2.2=-azobis-2,3 , 3-trimethylbutyronitrile, 2.2
-azobis-2-isopropylbutyronitrile, 1.1
'-azobis-(cyclohexane-1-carbonitrile), 2.2''-azobis-(4-methin-2,4-onemethylhaleronitrile), 2(carbamoylazo)isobutyronitrile, 4゜4゛Examples include -azobis-4-cyanovaleric acid and trimethyl-2,2'-azobisophthalate.

The polymerization initiator has an amount of 0.01 to 2 with respect to the polymerizable monomer.
It is preferable to use 0% by weight, especially 0.1 to 10% by weight.

In this way, when obtaining colored spherical fine particles by suspension polymerizing the polymerizable monomer component, other polymers,
For example, polyester or the like may be present, and known additives such as a continuous lees transfer agent for adjusting the degree of polymerization may be added as appropriate. In addition, when the colored fine particles of the present invention are used in an electrophotographic toner, a magnetic substance or a charge control agent is blended with the polymerizable monomer, and the colored fine particles internally added with the magnetic substance or charge control agent are mixed with the polymerizable monomer. You can also get it. The colored spherical fine particles obtained in this way have an average particle size of 3 to 50 μm, preferably 3.5 to 20 μm, and a particle size distribution or coefficient of variation of particle size of 0.
-80%, preferably 1-50% controlled sphericity.

The colored fine particles of the present invention are produced by heat-treating the colored spherical fine particles obtained by the above procedure in a polymerization solution at a temperature of 50 to 98°C to perform polymerization ripening to further polymerize unreacted monomers. Afterwards, the colored spherical fine particles are fused together to obtain a block-shaped radish-r.

It is obtained by crushing colored spherical fine particles before substantial fusion to a uniform particle diameter.

As is clear from the scanning electron micrograph (magnification: 60x) shown in FIG. $1 as long as the interface between colored spherical fine particles does not completely disappear.
'The individual particles of the floc-like particles formed by fusing together the L particles are crushed to the unit of colored spherical fine particles before fusing, and F+i
! ! Before crushing, the fine particles are brought into a deformed state. However, it is actually difficult to uniformly control the fusion state at the fusion interface, and as is clear from the scanning electron micrograph shown in Figure 2 (1500x magnification), the normally obtained colored fine particles are fused. A mixture of colored spherical fine particles that have been deformed and partially missing before being set and crushed, and the missing parts adhere to each other, is obtained as a mixture of fine particles. Even with such a d compound, if the average particle size of the colored spherical fine particles obtained is substantially the same as the average particle size of the colored spherical fine particles before melting and crushing, the properties of the colored fine particles will be in the most ideal form. There is almost no difference compared to the case. At this time, if the average particle diameter of the colored fine particles changes within 20%, preferably within 10%, and more preferably within 5% of the average particle diameter of the colored spherical fine particles, the coloring The average particle diameters of the fine particles and the colored spherical fine particles can be considered to be substantially the same.

The above heat treatment is an extremely important and essential step for modifying the surface of the colored spherical fine particles. The temperature at that time is 5
If the temperature is less than 0°C, the colored spherical fine particles will not fuse together at all, or even if they do fuse, it will be insufficient, and no significant surface modification effect will be exhibited. On the other hand, if the temperature exceeds 98°C, an excessively fused state will occur, which will not only make the subsequent crushing process difficult, but also result in the resulting colored fine particles having a very large particle size distribution. Furthermore, if the temperature exceeds 100°C, it may be necessary to carry out the process under pressure. Preferably 60
~95°C. The colored spherical fine particles may be fused to each other by such heat treatment, or the fused state may be arbitrarily controlled depending on the desired processing effect. However, in order to obtain colored fine particles with a uniform particle size distribution and excellent physical properties as an electrophotographic toner in the subsequent crushing process, it is necessary to It is preferable to create a fused state with a field remaining.

Therefore, when the colored spherical fine particles are thermally fused together, the polymerization rate of the suspended polymer and the colored spherical fine particles during the night is preferably 90% or more.

Although the method of the present invention can be applied even if the polymerization rate is 100%, the higher the polymerization rate, the longer it takes to produce the above-mentioned suspended EJ polymer liquid, and the higher the heating temperature is. Since heating cannot be performed under normal pressure and requires heating under pressure using an autoclave or the like, a method in which some unreacted monomer remains is desirable. Therefore, industrially, the polymerization rate is preferably in the range of 90 to 99%, particularly preferably in the range of 93 to 99%. On the other hand, if the polymerization rate is less than 90%, the colored spherical fine particles will be plasticized by unreacted monomers, and the interface between the n particles will disappear and fuse together due to heating, so that they will be fused when crushed later. This is because it is a national problem to obtain the average particle diameter of colored spherical fine particles before coloring.

Furthermore, the bulk density of the floc-like particles obtained by tdE is 0.1 to 0.9 g/cm", particularly 0.2 to 0.7 g/cm".
g/cm", it is more luminous because of the forged condition.

The shape and size of floc-like particles may be limited, so the next step is f! Considering the filtration, drying, crushing, etc. of the particles, it is better to form ladles with a diameter of 20 to 10.000 μm, more preferably 30 to 1.000 μm. If the size is less than 20 μm, a very large amount of labor or special equipment is required to extract the particles, and if the size exceeds 10,00 μm, more energy is required for crushing. In order to produce the block-like particles of the above-mentioned size, flocculation or precipitation is necessary. For flocculation, known flocculants such as inorganic acids such as hydrochloric acid, organic acids such as oxalic acid, and water-active metal salts made of these acids and alkaline earth metals, aluminum, etc. may be used. However, these known aggregating agents may affect performance when the resulting colored fine particles are used as an electrophotographic toner, so care must be taken when using them.

The present inventors have discovered that a non-solvent for the colored spherical fine particles can be used as a precipitant during the isolation and purification or separation of high modulus substances, and that the colored fine particles obtained can be used as a precipitant when a flocculant is used. It was found that it does not have the drawbacks seen in Examples of such nonsolvents include hydrocarbons such as hexane, heptane, octane, and cardiopulmonary ether, and lower alcohols such as methanol and ethanol. The term "non-solvent for colored spherical fine particles" as used herein refers to a solvent that does not dissolve or disperse the resin of the colored spherical fine particles. It goes without saying that when such a non-solvent or precipitant is used, a known flocculant may be used in combination without any problem. Further, this heat treatment can be carried out under normal pressure, reduced pressure or increased pressure. Furthermore, it is a good idea to use an appropriate -U solvent for the purpose of further promoting fusion during heat treatment. The obtained block-like material was suspended.
Remove from l and dry. Next, dry the dried block-like material. i- Crush to the average particle size of the colored spherical fine particles before dyeing. Crushing has traditionally been carried out in the T industry using powder, tI
The mills used to produce r-J' etc. can be used without restriction.

The colored fine particles obtained in this way can be controlled arbitrarily in terms of particle diameter and particle size distribution.
The particle size should be 3 to 50 μm, preferably 3.5 to 20 μm, and the particle size distribution should be such that the coefficient of variation of particle size is 0 to 8.
It is suitable to set it to 0%, preferably 0 to 50%. However, the coefficient of variation of particle diameter referred to here is the percentage of the standard deviation divided by the average particle diameter. The shape of the colored fine particles is not particularly limited, but examples thereof include particles that are macroscopically spherical but have minute irregularities on the surface, non-spherical particles, and the like.

The toner for electrophotography according to the present invention uses the colored fine particles described above, and in order to make the toner chargeable in an appropriate state, the average particle diameter should be adjusted to 3.5 to 20 μm1.
Preferably, the thickness is 4 to 15 μm. The colored fine particles can also be used directly as an electrophotographic toner.

Further, additives commonly used in ordinary toners, such as a charge control agent and a fluidizing agent for charge adjustment, may be appropriately blended.

The method of incorporating the charge control agent is not particularly limited, and any conventionally known method can be employed. For example, when polymerizing a polymerizable monomer in which a colorant is dispersed, a charge control agent is included in the monomer in advance, or the colored fine particles of the present invention are colored by post-treatment with a charge control agent. A method of attaching a charge control agent to the surface of the fine particles can be appropriately employed.

[Examples] Hereinafter, the present invention will be explained in detail based on Examples, but the present invention is not limited to the following Examples. In addition,
All "parts" in Examples and Comparative Examples below are by weight unless otherwise specified.

Example 1 2,000 parts of deionized water in which 1 part of polyvinyl alcohol was dissolved was charged into a reaction vessel equipped with a stirrer, an inert gas introduction tube, a reflux condenser, and a thermometer. There, 585 parts of styrene and 39 parts of butyl methacrylate were prepared in advance.
A mixture of 80 parts of benzoyl peroxide dissolved in a polymerizable monomer consisting of 0 parts of glycyflumethacrylate and 125 parts of glycyfluormethacrylate was charged, and a homogeneous suspension was prepared by stirring at high speed.

Next, heat to 80°C while blowing nitrogen gas,
Stirring was continued at this temperature for 5 hours, and the water used for the polymerization reaction was removed to obtain a polymer having an Epoquine group as a reactive group.

400 parts of a polymer having an Epoquine group as a reactive group, 150 parts of carbon blank MA-100R (manufactured by Mitsubishi Chemical Corporation), and a charge control agent (AizcnSpilon).
Black TRH Hodogaya Chemical Industry Co., Ltd.) 5
0 part and 160°CC11OQr using a pressure kneader.
After kneading and reacting under the conditions of p, the mixture was cooled and pulverized to obtain Carhombra Knockruff 1 to Polymer as a coloring agent.

A reaction vessel similar to the above was charged with 8,970 parts of deionized water in which 5 parts of sodium dodecylhenzenesulfonate as an anionic surfactant was dissolved.

There, 800 parts of styrene, 200 parts of n-butyl acrylate and 0.03 parts of divinylhensen, which had been prepared in advance, were added.
500 parts of the carbon black graft polymer as the adhesive, 30 parts of azobisisobutyronitrile and 2,2-azobis(2
, 4-dimethylvaleronitrile) was added and stirred for 5 minutes at 8,000 rpm using a T, K, Homo mixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to form a uniform suspension.

Next, without blowing in nitrogen gas, the temperature was heated to 65°C.
After stirring at this temperature for 5 hours to carry out a turbid polymerization reaction, the polymerization rate was 9.
A suspension of colored spherical fine particles having an average particle size of 5.82 μm and a particle size variation coefficient of 20.5% was obtained. 75
Add 2 methanol to a suspension of colored spherical particles kept at °C.
,095 parts were added and heated for an additional hour to form a block-like material in which the particles were fused to each other. This was filtered and dried at 50°C for 10 hours using a hot air dryer, and the bulk density was 0.20 g: 70 in a fused state with grain boundaries remaining.
1,500 block-like objects in the shape of a millet millet measuring m3
I got the department. This block-like material is crushed by supersonic jet crusher I.
D52 model (manufactured by Nippon Pneumatic Industries Co., Ltd.) was used to disintegrate colored fine particles (
1) was obtained.

As a result of measuring the obtained colored fine particles (1) with a Coulter counter (aperture 100 μm), the average particle diameter was 5.
．． The particle diameter was 67 μm, and the coefficient of variation in particle size was 18.7%. These colored fine particles (1) are used as they are as an electrophotographic toner (
1) was used to produce an image using an electrostatic copying machine (type 4060 manufactured by Ricoh Co., Ltd.), and the results were as shown in Table 1.

Example 2 A reaction vessel similar to that used in Example 1 was charged with 8,970 parts of deionized water in which 30 parts of polyvinyl alcohol (PVA205, manufactured by Kuraray Co., Ltd.) was dissolved. 800 parts of styrene prepared in advance and acrylic acid n
- Polymerizable monomer component consisting of 200 parts of butyl, 50 parts of brilliant carmine 6B (manufactured by Kenma Kagaku Co., Ltd.) as a Ha agent, 30 parts of azobisisobutyronitrile and 2
．． 2'Azobis(2,4-dimethylvaleronitrile)3
A mixture containing 0 parts was prepared and heated at 6°000 rp using a T, K, homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.).
The mixture was stirred at m for 5 minutes to form a homogeneous suspension.

Next, the mixture was heated to 65° C. while blowing nitrogen gas, and stirring was continued at this temperature for 5 hours. After carrying out the suspension polymerization reaction, the polymerization rate was 98.
0%, average particle size is 6.42μm, particle size variation coefficient is 2
A suspension of 1.3% colored spherical particles was obtained. After adding 13 parts of an aqueous paste charge control agent (Bontron 5-34 manufactured by Orient Chemical Industry Co., Ltd.) containing 35% of the active ingredient to a suspension of colored spherical fine particles kept at 75°C, heat treatment was performed at 95°C for 1 hour. As a result, particles were fused together to form a floc-like substance. This was filtered and dried at 50'C for 8 hours using a vacuum dryer to obtain 1110 parts of a chestnut-shaped block with a bulk density of 0.28 g/cm3 in a fused state with grain boundaries remaining. Obtained.

This block-like material is processed using a supersonic jet pulverizer model ID52 (
12kg/
The powder was crushed at a feed rate of hr to obtain colored fine particles (2).

As a result of measuring the obtained colored fine particles (2) with a Coulter counter (aperture 100 μm), the average particle diameter was 6.
．． At 15 μm, the coefficient of variation in particle size was 23.0%.

The colored fine particles (2) are directly used as an electrophotographic toner (2).
) and an electrostatic copying machine (type 4060 manufactured by Ricoh Co., Ltd.) to produce images, and the results are shown in Table 1.

Example 3 200 parts of a polymer containing 100 Epoquin groups as reactive groups obtained in the same manner as in Example 1 and 40 parts of Mapico BL-200 (manufactured by Titan Kogyo Co., Ltd.), which is a powdered magnetic material.
0 parts and 100 at 160°C using a pressurized kneader.
After kneading for 7 hours under the conditions of rp[o, the mixture was cooled and pulverized to obtain a polymer-treated magnetic material.

A reaction vessel similar to that used in Example 1 was charged with 8,970 parts of deionized water in which 5 parts of sodium dodecylbenzenesulfonate was dissolved as an anionic surfactant. There, 800 parts of styrene prepared in advance and acrylic acid n-
The above polymer-treated magnetic material 700 was added to the polymerizable monomer component consisting of 200 parts of butyl and 0.1 part of divinylbenzene.
A mixture of 30 parts of azobisisobutyronitrile and 30 parts of 22' azobis(2,4-dimethylvaleronitrile) was charged and heated to 8° using a T, K, homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.). The mixture was stirred at 000 rpm for 5 minutes to obtain a uniform consistency.

Then, without blowing in nitrogen gas, it was heated to 65°C.
After continuing to stir at this temperature for 5 hours to perform a suspended polymerization reaction, the polymerization was further heated at 75°C for 1 hour, resulting in a polymerization rate of 98.
A suspension lr:J solution of colored spherical fine particles having an average particle size of 5.43 μm and a particle size variation coefficient of 22.5% was obtained. 7
An aqueous paste charge control agent (Bontron 5
-34. After adding 41 parts (manufactured by Orient Kagaku Kogyo Co., Ltd.) and 5 parts of aluminum chloride, heat treatment was performed at 95° C. for 30 minutes to form a floc-like material in which the particles were fused together. Filter this and use a vacuum dryer to
It was dried at 0° C. for 8 hours to obtain 1.700 parts of a block-like product in the shape of a millet roe and having a bulk density of 0.22 g/cm 3 in a fused state with grain boundaries remaining. This block-like material was crushed using a supersonic jet crusher ID52 model (manufactured by Nippon Pneumatic Industries Co., Ltd.) at a feed rate of 18 kg/hr to obtain colored fine particles (3).

As a result of measuring the obtained colored fine particles (3) with a Coulter counter (aperture 100 μm), the average particle diameter was 5.
．． At 24 μm, the coefficient of variation in particle size was 19.8%. These colored fine particles (3) are used as they are as an electrophotographic toner (
3) was used to produce an image using an electrostatic copying machine (NP-5000, manufactured by Canon Co., Ltd.), and the results were as shown in Table 1.

Example 4 A carphone fluff craft polymer was obtained in the same manner as in Example 1, and 10 parts of an anionic surfactant Hytenol N-08 (manufactured by Dai-Kogyo Seiyaku Co., Ltd.) was dissolved in the same flask as above. 8970 parts of ionized water was charged. 800 parts of styrene, 150 parts of n-butyl acrylate and polybutadiene Nl5S prepared in advance therein.
O-PB-B-3000 (manufactured by Nippon Soda Co., Ltd.) 50
A component consisting of 5 parts carbon black grafted polymer
00 parts, 20 parts of azobisisobutyronitrile and 2.
2'-azobis(2,4-dimethylvaleronitrile) 1
As a result, the polymerization rate was 92% and the average particle diameter was 6.3.
A suspension (4) of colored spherical fine particles having a diameter of 0 μm and a particle diameter variation coefficient of 19.5% was obtained.

When the resulting suspension of colored spherical fine particles was further heat-treated at 90°C for 2 hours, a floc-like substance was formed in which the particles were axially attached to each other. This was filtered and dried using a hot air dryer at 50°C for 10 hours, and 1.500 parts of a floc-like product with a bulk density of 0.31 g 7 cm3 in the shape of millet was dried in a fused state with grain boundaries remaining. I got it. This floc-like material was cleaved using a supersonic wet powder machine ID52 (manufactured by Nippon Pneumatisoku Kogyo Co., Ltd.) at a feed rate of 17 kg/hr to obtain colored fine particles (4).

The obtained colored fine particles (4) were calibrated using a Coulter counter (aperture 100 μm), and the average particle diameter was 6.14 μm, and the coefficient of variation of the particle diameter was 20.8%. These colored fine particles (4) are used as they are as an electrophotographic toner (
4) was used to produce an image using an electrostatic copying machine (type 4060 manufactured by Ricoh Co., Ltd.), and the results were as shown in Table 1.

Example 5 In a flask similar to that used in Example 1, sodium dodenrubensene sulfonate 5 was added as an anionic surfactant.
8,970 parts of deionized water was charged. To the polymerizable monomer component consisting of 800 parts of styrene and 200 parts of n-phthyl acrylate prepared in advance, 500 parts of carbon black graft polymer as a coloring agent,
30 parts of azobisisobutyronitrile and 2,2'-
A mixture containing 30 parts of azobis(2,4-dimethylvaleronitrile) was added, and a uniform suspension was obtained by pressing with a T, K, Homo mixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) at 8,000 rpm for 5 minutes. did.

Then, without blowing in nitrogen gas, it was heated to 65°C.
After continuing to stir at this temperature for 5 hours to perform a suspension tension reaction, the polymerization rate was 95.
0%, an average diameter of 5.92 μm, and an lt7 diameter radial dynamic coefficient of 23.0% were obtained. After adding 200 parts of IN hydrochloric acid in the cloudy night, heat treatment was performed at 85°C for 3 hours to form a block-like substance consisting of particles fused together.This was filtered and dried in a vacuum dryer. Use 50
The mixture was dried at °C for 8 hours to obtain 1.500 parts of a chestnut-shaped block with a bulk density of 0.35 g/cm 3 in a fused state with grain boundaries remaining. This floc-like material was crushed using a supersonic dient crusher ID52 model (manufactured by Nippon Pneumatic T-To Co., Ltd.) at a feed rate of 13 kg/hr to obtain colored fine particles (5).

The obtained colored fine particles (5) were measured using a Coulter counter (aperture 100 μm), and the average particle diameter was 5.
．． At 65 μm, the coefficient of variation in particle size was 21.2%.

The colored fine particles (5) are used as they are in the electrophotographic toner (5).
) and an electrostatic copying machine (type 4060 manufactured by Ricoh Co., Ltd.) to produce images, and the results are shown in Table 1.

Example 6 In place of 50 parts of polybutadiene in Example 4, H
YPALON20 (E, 1. duPont d
50 parts of chlorosulfonated polyethylene (manufactured by aNea+ors & Co.) were mixed with 20 parts of azobisisobutyronitrile.
The same procedure as in Example 4 was carried out except that 30 parts of hensyl peroxide was used instead of 10 parts of 2,2'-azobis(2,4-dimethylvaleronitrile), and as a result, the polymerization rate was 92% and the average particle size was 92%. A suspension of colored spherical fine particles with a diameter of 6.02 μm and a particle size variation coefficient of 21.2% was obtained. Suspension fX of colored spherical fine particles kept at 75°C: J7
In the evening, 3 parts of calcium chloride was added and heat treated at 95°C for 1 hour, resulting in the formation of a block-like material in which the particles were fused together.

This was filtered and dried at 50°C for 8 hours using a vacuum dryer, resulting in a fused state with grain boundaries remaining and a bulk density of 0.21 g/cm.
1,500 parts of a block-like product having the shape of millet roe as described in No. 3 was obtained. This block-like material is processed using a supersonic jet pulverizer ID.
1 using type 52 (manufactured by Nippon Pneumatic Industries Co., Ltd.)
Crushed with a feed rate of 8 kg/hr to produce colored fine particles (6)
I got it.

As a result of measuring the obtained colored fine particles (6) with a Coulter counter (aperture 100 μm), the average particle size was 6.
．． The coefficient of variation in particle size was 22.0% at 10 μm.

The colored fine particles (6) are used as they are in the Shigeko photographic toner (6).
) and an electrostatic copying machine (type 4060 manufactured by Ricoh Co., Ltd.) to produce images, and the results are shown in Table 1.

Example 7 Instead of 5 parts of dodenrubensene sulfonic acid as the anionic surfactant used in Example 1, Nonipol 200 (di-l'I-) was used as the nonionic surfactant.
The same procedure as in Example 1 was carried out except that 10 parts (manufactured by Kasei Co., Ltd.) were used.
γT-diameter 5.75 μm, coefficient of variation of particle size 19.5%
, we obtained a close relative of colored spherical microparticles. Thereafter, the mixture was maintained at 60° C., 750 parts of heptane was added, and heat treatment was performed for 1 hour, thereby forming a block-like material in which the particles were fused together. This was filtered and dried using a hot air dryer at 50°C for 10 hours, resulting in a fused state with grain boundaries remaining and a bulk density of 0.
1,500 parts of a block-like product having the shape of millet roe and weighing 22 g/cm3 were obtained. This professional material was crushed using a supersonic jet crusher ID52 type (manufactured by Japan Pneumatics Industry Co., Ltd.) at a feed rate of 15 kg/hr.
Colored fine particles (7) were obtained.

The resulting colored fine particles (7) were measured using a Coulter counter (aperture 100 μm), and the average particle size was 5.65 μm, with a coefficient of variation of particle size of 20.7%. The colored fine particles (7) were used as they were as an electrophotographic toner (7) to produce an image using an electrostatic copying machine (type 4060 manufactured by Ricoh Co., Ltd.), and the results were as shown in Table 1.

Comparative Example 1 Suspension of colored spherical fine particles obtained in Example 4 1+1(4)10
After adding 5 parts of aluminum chloride to 480 parts while maintaining the temperature at 75°C, heat treatment was performed at 150°C for 30 minutes under pressure to form a block-like product in which the particles were fused together. This was filtered, dried at 50°C for 8 hours using a vacuum dryer, and then coarsely ground.
Colored fine particles for comparison (a) were crushed at a feed rate of /hr.
Obtained 1,500 copies.

Particle properties of the comparative colored fine particles (a) and images produced by an electrostatic copying machine (type 4060 manufactured by Ricoh Co., Ltd.) using the comparative colored fine particles (a) as it is as a comparative electrophotographic toner (a). The results were as shown in Table 1.

Comparative Example 2 A suspension of colored spherical fine particles was obtained in the same manner as in Example 4. However, since the suspension polymerization reaction was carried out at 65°C for 4 hours, the polymerization rate was 86%.

When the obtained colored spherical fine particles were further heat-treated at 90° C. for 2 hours, the colored spherical fine particles became aggregates, making post-treatment difficult.

Comparative Example 3 Styrene-acrylic resin (TB-1000F manufactured by Sanyo Chemical Co., Ltd.) 2,228 parts, Carbon Fluff MA-10
187 parts of OR (manufactured by Mitsubishi Kasei Corporation) and a charge control agent (Aizen 5pilon Black TI?II)
) were preliminarily mixed in a Henschel mixer, melted and kneaded in a pressure kneader at 150°C for 30 minutes, and then cooled to obtain a toner mass. Example 1
The pulverized material was pulverized using the same scale at a feed rate of 5 kg/hr, and the pulverized material was classified using an air classifier (DS-2 model manufactured by Nippon Pneumatics Industry Co., Ltd.) to obtain 1,500 colored fine particles (b) for comparison. I got it.

Particle properties of the comparative colored fine particles (b) and image production using an electrostatic copying machine (type 4060 manufactured by Ricoh Co., Ltd.) using the comparative colored fine particles (b) as it is as a comparative electrophotographic toner (b) The results were shown in Table 1.

(/jE1) Crushing (pulverization) throughput The amount of crushing (pulverization) in feet when using a supersonic jet crusher ID52 model (manufactured by Japan Pneumatic T-Gyo Co., Ltd.)
(pulverization) processing amount.

(Note 2) Particle size: Measured using a Coulter counter (Model TA-II, manufactured by Coulter Electronics Inc.).

Coefficient of variation: Measured using a Coulter counter (Model TA-II, manufactured by Coulter Electronics Inc.).

Frictional charge amount diiron carrier (DSP'- manufactured by Dowa Iron Powder Co., Ltd.)
128) (toner concentration: 5% by weight) using a blow-off powder charge amount m11 constant device (manufactured by Toshiba Chemical Corporation: model TB-200).

Fluidity: The fluidity of the toner was evaluated visually.

◎Toner particles exist independently and exhibit smooth flow.

○The toner particles are slightly agglomerated, but exhibit normal flow.

△ Considerable aggregation of toner particles is observed, and fluidity is decreased.

× A significant agglomeration of toner particles was observed, resulting in a significant decrease in fluidity.

(Vt3) Evaluation of image output Images obtained by copying facsimile test chart No. 1 using an electrostatic copying machine Image Output Type 4060 manufactured by Ricoh Co., Ltd. or NP-5000 manufactured by Canon Inc.) were evaluated.

Fog: The phenomenon of spotty staining caused by ground or toner was investigated.

Fine line reproducibility: Evaluation was made based on the readability of an image obtained by copying facsimile test chart No. 1.

Cleanability: Facsimile test chart No.l
Evaluation was made from images obtained by copying.

[Effects of the Invention] As described above, the present invention comprises suspending a polymerizable monomer in a suspension medium in the presence of a colorant and/or magnetic powder,
Suspension polymerization is carried out while controlling the particle size, and the resulting suspension of colored spherical fine particles having an average particle size of 3 to 50 μm is subjected to polymerization ripening by heat treatment at a temperature of 50 to 98°C. Stone grain fine particles characterized in that the particles are then fused together to form a block shape, and then the block-shaped particles are substantially crushed into 10 uniform particles of colored spherical fine particles before fusion. Since it is an electrophotographic toner containing N-containing colored fine particles, the particle size is uniform, and the surface of the particles is uneven. The amount of chemical agents has been significantly reduced, and the fluctuations in physical properties that accompany changes in humidity have been almost completely eliminated. Therefore, the colored fine particles of the present invention can be suitably used as an electrophotographic toner that can form a clear image and has excellent fluidity and cleaning properties, and can also be used as a coloring agent for other paints, inks, and resin compositions. Alternatively, it can also be used as a modifier.

The electrophotographic toner of the present invention uses the colored fine particles described above, and can always form high-quality, fog-free images in any environment without being affected by humidity, so it can be used in a wide range of electrophotographic developing devices. .

[Brief explanation of drawings]

FIG. 1 is an electron micrograph of block-shaped particles obtained by the heat treatment step of the method of the present invention, and FIG. 2 is an electron micrograph of colored fine particles obtained by the method of the present invention.

Claims (14)

[Claims] (1) A polymerizable monomer is suspended in a suspension medium in the presence of a colorant and/or magnetic powder, and suspension polymerization is performed while controlling the particle size, resulting in average particles of 3 to 50 μm. A suspension of colored spherical fine particles having a diameter is heat-treated at a temperature of 50 to 98°C to perform polymerization ripening and fuse the particles together to form a block, and then substantially melt the block-shaped particles. A method for producing colored fine particles, which comprises crushing colored spherical fine particles to an average particle size before coloring. (2) The method for producing colored fine particles according to claim 1, wherein the polymerization rate of the colored spherical fine particles in the suspended polymer liquid is 90% or more when the particles are fused together. (3) The method for producing colored fine particles according to claim 1 or 2, which comprises adding an organic solvent as a non-solvent to the resin of the colored spherical fine particles when fusing the particles together. (4) The method for producing colored fine particles according to any one of claims 1 to 3, wherein the colored spherical fine particles are obtained by suspension polymerization using a carbon black graft polymer as a colorant. (5) High density of block particles is 0.1 to 0.9 g/c
The method for producing colored fine particles according to any one of claims 1 to 4, wherein the particle size is in the range of m^3. (6) The method for producing colored fine particles according to any one of claims 1 to 5, wherein the average particle diameter is 3 to 50 μm. (7) The method for producing colored fine particles according to claim 6, wherein the coefficient of variation of particle diameter is 0 to 80%. (8) An electrophotographic toner containing the colored fine particles according to claim 1. (9) The electrophotographic toner according to claim 8, wherein the polymerization rate of the colored spherical fine particles in the suspended polymer liquid is 90% or more when the particles are fused together. (10) The electrophotographic toner according to claim 8 or 9, wherein an organic solvent as a non-solvent is added to the resin of the colored spherical fine particles when the particles are fused together. (11) The electrophotographic toner according to any one of claims 8 to 10, wherein the colored spherical fine particles are obtained by suspension polymerization using a carbon black graft polymer as a colorant. (12) The bulk density of the block particles is 0.1 to 0. The electrophotographic toner according to any one of claims 8 to 11, which has a toner of 9 g/cm^3. (13) The electrophotographic toner according to any one of claims 8 to 12, which has an average particle diameter of 3 to 50 μm. (14) Claim 1, wherein the coefficient of variation of particle diameter is 0 to 80%.
3. The electrophotographic toner according to 3.