JP3224510B2 - Method for producing colored fine particles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to colored fine particles, an electrophotographic toner using the same, and a method for producing the same. In particular, the present invention relates to a colored fine particle having excellent dispersibility and charge stability. The present invention relates to an electrophotographic toner and a method for producing the same.

[0002]

2. Description of the Related Art Colored fine particles obtained by dispersing and blending various pigments represented by carbon black into various resin materials are widely used, for example, as raw materials for electrophotographic toners.

[0003] As a method for producing such colored fine particles, a pigment component is mixed with a resin material, melt-kneaded and then pulverized to obtain colored fine particles, or a pigment component is dispersed and compounded in a polymerizable monomer. A suspension polymerization method for producing colored fine particles by performing suspension polymerization in an aqueous medium is known.

[0004] Among them, the suspension polymerization method has been widely used in recent years because fine particles having a relatively uniform particle size distribution and a spherical shape can be obtained. However, many colorants such as carbon black have a weaker affinity for other substances, for example, water, an organic solvent, or an organic polymer, than the cohesive force between particles, and tend to cause secondary agglomeration. Therefore, when performing the above-mentioned suspension polymerization, a problem is how to uniformly disperse the colorant.

JP-A-60-254050 discloses that a phenol-terpene copolymer is added for the purpose of improving the stability of suspension polymerization when additives such as carbon black and a charge control agent are added. A method is disclosed.

Japanese Patent Application Laid-Open No. 7-199536 discloses that
A monomer or polymer having a polar functional group in the oil phase,
In particular, a method is disclosed in which the dispersibility of a colorant is improved by adding a monomer and a polymer of sodium styrene sulfonate and p-carboxystyrene.

[0007] The addition of these substances improves the stability of the suspension polymerization or the dispersion of the colorant in the polymerizable monomer as compared with the case of adding any of them. No, start flocculation immediately. For this reason, the dispersion stability in the polymerizable monomer is insufficient, the dispersion stability during suspension and during the polymerization is inferior, and the colorant is dispersed in the colored fine particles after polymerization due to localization or aggregation. Not only is it non-uniform, but it also causes a reduction in the uniformity of the amount of colorant present between the individual particles. In addition, since the colorant is transferred to the aqueous phase during suspension and polymerization, the residual ratio of the colorant in the colored fine particles is reduced, the coloring power is reduced, the raw materials are lost, and the coloring is caused by the free colorant transferred to the aqueous phase. It causes problems such as contamination of fine particles and pollution of wastewater. In particular, it was remarkable in the case of a coloring agent having a hydrophilic group such as carbon black.

[0008]

Accordingly, an object of the present invention is to provide colored fine particles having improved properties, an electrophotographic toner using the same, and a method for producing the same. The present invention provides colored fine particles having particularly excellent dispersibility and charge stability, an electrophotographic toner using the same, and a method for producing the same.

[0009]

SUMMARY OF THE INVENTION The objects of the present invention are as follows: (1) A vinyl-based monomer composition obtained by dispersing a colorant in at least a vinyl-based monomer is prepared by using a rosin having an acid value of 5 to 100 KOH mg / g. From the group consisting of derivatives, aromatic petroleum resins having a weight average molecular weight of 1000 or less and a softening temperature of 70 ° C to 170 ° C, α-pinene resins, epoxy resins having a softening point temperature of 60 ° C to 150 ° C, and cumarone resins. in the presence of at least one resin selected comprising, in an aqueous dispersion medium using a device other than the dispersing apparatus having a high pressure type emulsifier and pore
This is achieved by a method for producing colored fine particles, characterized in that colored particles having a residual ratio of colorant in the colored fine particles of 70% or more are obtained by suspension polymerization .

The present invention also provides (2) a polymerizable monomer composition comprising at least a polymerizable monomer and a colorant dispersed therein, wherein the colorant is dispersed in the polymerizable monomer. The method for producing colored fine particles according to (1) above is 1 to 50 parts by weight with respect to parts by weight.

The present invention further provides (3) a dispersant for dispersing the colorant in the polymerizable monomer, wherein the dispersant has an acid value of 5 to 100 KOH.
mg / g rosin derivative, weight average molecular weight 10,000
Aromatic petroleum resin having a softening temperature of 70 ° C to 170 ° C below, α-pinene-based resin, softening point temperature of 60 ° C to 150 ° C
Wherein at least one resin selected from the group consisting of an epoxy resin, a cumarone resin and a styrene-acrylic resin is added as a dispersing agent. It shows a manufacturing method.

The above objects are also achieved by (4) the above (1) to (4).
It is also achieved by colored fine particles obtained by the production method according to any one of (3).

The present invention also provides (5) colored fine particles obtained by suspending and polymerizing a polymerizable monomer composition obtained by dispersing a colorant in at least a polymerizable monomer in an aqueous dispersion medium,
The dispersion of the colorant in the polymerizable monomer is at least one selected from the group consisting of a rosin derivative, an aromatic petroleum resin, a pinene resin, an epoxy resin, and a cumarone resin.
This is achieved by colored fine particles, which contain a resin of any kind and have a colorant content of 5% by weight or more in the colored fine particles.

[0014] The above objects are also achieved by an electrophotographic toner characterized by containing the colored fine particles according to the above (4) or (5).

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail based on embodiments. In the present invention, a polymerizable monomer composition obtained by dispersing a colorant in a vinyl monomer that forms a binder resin by polymerization (hereinafter, referred to as “ polymerizable monomer ” ) is dispersed in an aqueous dispersion. When producing colored fine particles by suspending and polymerizing in a medium, the dispersion of the colorant in the polymerizable monomer is performed by using a rosin derivative, an aromatic petroleum resin, a pinene resin,
Performed in the presence of at least one resin selected from the group consisting of an epoxy resin, a coumarone resin, and a styrene-acrylic resin to improve the dispersion stability of the colorant in the polymerizable monomer. Things. When the colorant is dispersed in the polymerizable monomer in the presence of the specific resin as described above, the dispersion stability of the colorant in the polymerizable monomer becomes good, and the coloring in the obtained colored fine particles is improved. The dispersion of the agent is uniform, and the uniformity of the content of the coloring agent among the coloring fine particles is also increased. In addition, the polymerizable monomer composition obtained by subjecting the colorant to the polymerizable monomer in the presence of the specific resin as described above is dispersed into the aqueous phase during suspension in an aqueous medium and during the polymerization process. , The residual ratio of the coloring agent in the obtained colored fine particles is increased, and the problem of contamination by the free coloring agent transferred to the aqueous phase is eliminated.

In the present invention, at least one resin selected from the group consisting of the rosin derivative, aromatic petroleum resin, pinene resin, epoxy resin and cumarone resin as a colorant dispersant is used. It is important to disperse the colorant by the method described above, and adding the dispersant after the colorant dispersion treatment has no effect.

The polymerizable monomer used in the method for producing colored fine particles of the present invention is not particularly limited as long as it is capable of suspension polymerization, and is generally used in the field of toner. Various vinyl monomers, for example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-
Styrene monomers such as methoxystyrene, p-tert-butylstyrene, p-phenylstyrene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrenestyrene, α-methylstyrene; methyl acrylate, ethyl acrylate N-butyl acrylate, isobutyl acrylate, dodecyl acrylate, stearyl acrylate, 2-ethylhexyl acrylate, tetrahydrofurfuryl acrylate, methyl methacrylate, ethyl methacrylate,
Propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate,
(Meth) acrylic ester monomers such as stearyl methacrylate; olefin resins such as ethylene, propylene and butylene, and others, acrylic acid, methacrylic acid,
Vinyl chloride, vinyl acetate, acrylonitrile, acrylamide, methacrylamide, N-vinylpyrrolidone and the like can be used alone or in combination of two or more. Among these, those containing a styrene monomer and / or a (meth) acrylate monomer as a main component are preferable. Further, the formation of a styrene- (meth) acrylate-based copolymer using a styrene-based monomer and a (meth) acrylate-based monomer is advantageous in terms of low-temperature fixability and storage stability. Desirably, styrene is used in an amount of 5 from the viewpoint of thermal characteristics of a toner using the obtained binder resin.
A styrene- (meth) acrylate mixture containing 0% by weight or more is preferred.

When the polymerizable monomer component is subjected to suspension polymerization to obtain colored fine particles in this manner, another polymer such as polyester may be present in the monomer component. Known additives such as a chain transfer agent for adjusting the degree may be appropriately blended. At the time of suspension polymerization, a crosslinking agent may be used.

Examples of the crosslinking agent include aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene and derivatives thereof, ethylene glycol dimethacrylate,
Diethylenically unsaturated carboxylic acid esters such as diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, trimethylolpropane triacrylate, allyl methacrylate, t-butylaminoethyl methacrylate, tetraethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, etc. , N, N-divinylaniline, divinyl ether,
Examples include all divinyl compounds of divinyl sulfide and divinyl sulfonic acid, and compounds having three or more vinyl groups. Further, polybutadiene, polyisoprene, unsaturated polyester, chlorosulfonated polyolefin and the like are also effective.

On the other hand, the colorant dispersed in such a polymerizable monomer is a pigment or the like well known to those skilled in the art, and may be an organic pigment, an inorganic pigment, or a mixture thereof.

Examples of inorganic pigments include carbon black, alumina, titanium dioxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, and diatomaceous earth. , Various inorganic oxide pigments, chromium oxide,
Powders or particles of cerium oxide, red iron oxide, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silica fine powder, silicon carbide, silicon nitride, boron carbide, tungsten carbide, titanium carbide, cerium oxide, etc. Is mentioned.
Further, such an inorganic pigment is a titanium coupling agent,
It may have been treated with a known hydrophobizing agent such as a silane coupling agent or a higher fatty acid metal salt.

Examples of the organic pigment include Navels Yellow, Naphthol Yellow S, Hanser Yellow G, Hanser Yellow 10G, Benzidine Yellow G,
Yellow pigments such as Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake, etc., Kilybdenum Orange, Permanent Orange R
Orange pigments such as K, benzidine orange G, indanthrene brilliant orange GK, permanent red 4
Red pigments such as R, Risor Red, Pyrazolone Red 4R, Watching Red Calcium Salt, Lake Red D, Brilliant Carmine 6B, Eomine Lake, Rhodamine Lake B, Buzarin Lake, Brilliant Carmine B, etc .; Blue pigments such as alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partial chloride, fast sky blue, and indanthrene blue BC; green pigments such as pyrakite green lake and final yellow green G; Is mentioned.

When a magnetic toner is to be obtained, for example, a magnetic powder such as a powder of a ferromagnetic metal such as iron, cobalt and nickel and a powder of a metal compound such as magnetite, hematite and ferrite are added. It is also possible. Since these magnetic powders also act as colorants,
When a magnetic toner is to be obtained, these magnetic powders can be used alone or in combination with the pigment as a colorant.

In the present invention, the amount of the colorant in the polymerizable monomer composition is not particularly limited and depends on the type of the colorant used. Colorant 1 to 100 parts by weight of monomer
20 parts by weight, preferably about 3 to 15 parts by weight. That is, if the colorant is less than 1 part by weight, the coloring degree of the obtained colored fine particles will not be sufficient, while if it exceeds 20 parts by weight, the effect of increasing the addition amount will not be seen much, Further, there is a possibility that the polymerization of the polymerizable monomer does not sufficiently proceed.

As a coloring agent, for example, a dye such as a nigrosine dye can be used together with the above-mentioned pigment.

Thus, in the present invention, such a colorant is dispersed in the polymerizable monomer by a rosin derivative,
It is carried out in the presence of at least one resin selected from the group consisting of aromatic petroleum resins, pinene resins, epoxy resins and cumarone resins (hereinafter, also referred to as "colorant dispersant"). .

Specific examples of the rosin derivative include rosin ester, hydrogenated rosin, hydrogenated rosin ester, dibasic acid-modified rosin, and polymerized rosin. Examples of the aromatic petroleum resin include neopolymer. 8, L-9
0, 100, 120, 130, 140, 150, 16
0, 170S (manufactured by Nippon Synthetic Resins Co., Ltd.) and the like, as pinene-based resins, for example, α-pinene resin and β-pinene resin, and as the epoxy resin, for example, room temperature (2
Bisphenol A solid or liquid at 5 ° C ± 2 ° C)
Types, halogenated bisphenol type, resorcinol type, bisphenol F type, novolak type, polyalcohol type, polyglycol type, polyolefin type, alicyclic type and the like. Further, as the coumarone resin, for example, Escron G-90 and N-100, V-120 (manufactured by Nippon steel Chemical Co.) indene copolymers such as the Oh
You .

As these colorant dispersants, rosin derivatives having an acid value of 5 to 100 KOH mg / g, a weight average molecular weight of 10,000 or less and a softening temperature of 70 ° C. to 170
At least one resin selected from the group consisting of an aromatic petroleum resin having a softening point of 60 ° C to 150 ° C, an epoxy resin having a softening point of 60 ° C to 150 ° C, a coumarone resin, and a styrene-acrylic resin. Desirably.

In the present invention, after dissolving or dispersing the colorant dispersant as described above in the polymerizable monomer in advance, the colorant is added to the polymerizable monomer, or the colorant dispersant is colored. The coloring agent is added at the same time, and then the colorant is dispersed using a suitable stirring device or the like. If the colorant dispersant has poor solubility in the polymerizable monomer and is solid at room temperature, the dispersant is melted in order to uniformly disperse the polymerizable monomer. It is necessary to raise the temperature to a temperature at which the polymerizable monomer can be dissolved, and even if the polymerizable monomer has solubility, it can be heated to promote the dissolution.

The amount of such a colorant dispersant to be added cannot be specified unconditionally because it depends on the type and amount of the colorant used and the type of the dispersant used. 1 to 50 parts by weight, more preferably 2 to 3 parts by weight, based on 100 parts by weight of the reactive monomer composition
About 0 parts by weight is appropriate. That is, the colorant dispersant 1
If the amount is less than 10 parts by weight, the dispersion stability of the colorant due to its addition and the effect of preventing the transfer of the colorant to the aqueous phase at the time of suspension and during the polymerization process cannot be sufficiently expected, and more than 50 parts by weight. Therefore, even if the addition amount is increased, the effect is not so much improved, and since the colorant dispersant is a relatively low molecular weight, there is a high possibility that the printing durability after printing is reduced. It is because it becomes.

The apparatus for dispersing the colorant in the polymerizable monomer in the presence of such a dispersant is not particularly limited, but examples thereof include a ball mill, an attritor, and a sand mill. Preferred examples thereof include a shear type dispersion device such as a media type dispersion device, a homomixer, a homogenizer, and a biomixer, and an ultrasonic dispersion device.

Further, an anti-offset agent, a charge control agent and the like can be added to the polymerizable monomer composition, if necessary. The offset inhibitor added to the polymerizable monomer composition as necessary is not particularly limited, but a polymer having a cyclic method softening point of 80 to 180 ° C,
For example, a polyolefin having a weight average molecular weight of 1,000 to 45,000, more preferably about 2,000 to 6,000, that is, a so-called polyolefin wax can be used. For example, as polyolefin wax, polyethylene,
Homopolymers such as polypropylene and polybutylene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-pentene copolymer, ethylene-3-methyl-1-butene copolymer, ethylene-propylene-butene copolymer Olefin copolymers such as coalescence, or olefins and other monomers, for example, vinyl methyl ether, vinyl-n-butyl ether, vinyl ethers such as vinyl phenyl ether, vinyl acetate, vinyl esters such as vinyl butyrate, Haloolefins such as vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, vinyl chloride, vinylidene chloride, tetrachloroethylene, methyl acrylate, ethyl acrylate, n-butyl acrylate, methyl methacrylate, ethyl methacrylate, n (Meth) acrylates such as butyl methacrylate, stearyl methacrylate, N, N-dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate, acrylic acid derivatives such as acrylonitrile, N, N-dimethylacrylamide, and acrylic Acid, methacrylic acid, maleic acid,
Examples thereof include organic acids such as fumaric acid and itaconic acid, and copolymers with diethyl fumarate, β-pinene, and the like.

Examples of the anti-offset agent include, in addition to the above-mentioned polyolefins, natural or synthetic paraffin waxes, particularly high-melting paraffin wax having a melting point of 60 to 70 ° C., zinc salt of stearic acid, barium salt, lead. Salts, cobalt salts, calcium salts and magnesium salts and magnesium salts. Fatty acid metal salts such as zinc, manganese, iron and lead salts of olefinic acids and zinc, cobalt and magnesium salts of palmitic acid,
Particularly, higher fatty acid salts having 17 or more carbon atoms, similarly higher alcohols such as myricyl alcohol, polyhydric alcohol esters such as glyceride stearate and glyceryl palmitate, fatty acid esters such as myristyl stearate and myristyl palmitate And partially saponified fatty acids such as partially saponified montanic acid esters, higher fatty acids such as stearic acid, palmitic acid and montanic acid, fatty acid amides such as ethylenebisstearoylamide, and mixtures thereof.

Examples of charge control agents include, for example, nigrosine, monoazo dyes, zinc, hexadecyl succinate, alkyl esters or alkylamides of naphthoic acid, nitrohumic acid, N, N-tetramethyldiaminebenzophenone, N, N-tetra Examples include methylbenzidine, triazine, and a metal salicylate complex. Incidentally, such a charge control agent, rather than added during suspension polymerization,
It is preferable that the resin be externally added to the resin particles obtained after the suspension polymerization.

In the suspension polymerization, a dispersion stabilizer may be added to stabilize the suspended particles. As dispersion stabilizers, polyvinyl alcohol, gelatin,
Water soluble polymers such as tragacanth, starch, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, sodium polyacrylate, sodium polymethacrylate, sodium dodecylbenzenesulfonate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, allyl-alkyl- Sodium polyethersulfonate, sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, calcium oleate, 3,3 '
Sodium disulfonediphenylurea-4,4'-diazo-bis-amino-8-naphthol-6-sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2 ', 5,5'-tetramethyl-tri Phenylmethane-1,1'-diazo-bis-β-naphthol-
Sodium disulfonate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate,
Sodium alkyldiphenyl ether disulfonate,
Sodium polyoxyethylene alkyl sulfate, triethanolamine polyoxyethylene alkyl ether sulfate, ammonium polyoxyethylene alkyl phenyl ether sulfate, sodium alkali sulfonate, sodium salt of β-naphthalenesulfonic acid formalin condensate, special aromatic sulfonic acid formalin condensate The sodium salt of
Special carboxylic acid type polymer surfactant, polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene sorbitan alkylate, lauryl Surfactants such as trimethylammonium chloride, stearyltrimethylammonium chloride, cetyltrimethylammonium chloride, distearyldimethylammonium chloride, alkylbenzyldimethylammonium chloride, and other alginates, zein, casein, barium sulfate, calcium sulfate, barium carbonate, and magnesium carbonate , Calcium phosphate, talc, clay, diatomaceous earth, bentonite, hydroxylated Tan, thorium hydroxide, metal oxide powder or the like is used.

These dispersion stabilizers should be used by appropriately adjusting the composition and amount thereof so that the particle diameter of the obtained colored fine particles is a predetermined size, for example, 1 to 100 μm, preferably 3 to 20 μm. For example, when a water-soluble polymer is used, the amount is 0.1 to 0.1 with respect to the polymerizable monomer component.
It is suitably from 1 to 10% by weight, preferably from 0.5 to 5% by weight. In the case of a surfactant, the amount is preferably 0.01 to 5% by weight, preferably 0.05 to 3% by weight, based on the polymerizable monomer.

As the polymerization initiator used for the polymerization, oil-soluble peroxide-based or azo-based initiators usually used for suspension polymerization can be used. By way of example, for example, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, orthochlorobenzoyl peroxide, orthomethoxybenzoyl peroxide, methyl ethyl ketone peroxide,
Peroxide initiators such as diisopropylperoxydicarbonate, cumene hydroperoxide, cyclohexanone peroxide, t-butyl hydroperoxide, diisopropylbenzene hydroperoxide, 2,2′-azobisisobutyronitrile, 2 '
Azobis (2,4-dimethylvaleronitrile), 2,
2'-azobis (2,3-dimethylbutyronitrile),
2,2′-azobis (2-methylbutyronitrile),
2,2′-azobis (2,3,3-toazobis (2-methylbutyronitrile), 2,2′-azobis (2,3
3-trimethylbutyronitrile), 2,2'-azobis (2-isopropylbutyronitrile), 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2
'-Azobis (4-methoxy-2,4-dimethylvaleronitrile), 2- (carbamoylazo) isobutyronitrile, 4,4'-azobis (4-cyanovaleric acid),
Dimethyl-2,2'-azobisisobutyrate and the like. The polymerization initiator is, with respect to the polymerizable monomer, 0.1 to
It is preferably used in an amount of 20% by weight, especially 1 to 10% by weight.

In the suspension polymerization, a polymerizable monomer composition prepared by dispersing a colorant in a polymerizable monomer in the presence of a colorant dispersant as described above is suspended in an aqueous medium. For example, at a temperature of 50 to 90 ° C, preferably 60 to 80 ° C. After the suspension polymerization is completed, the obtained colored fine particles are separated from the aqueous medium and dried, and then, if necessary, through a classification step, to obtain a desired particle diameter, for example, an average particle diameter of 1 to 10
Colored fine particles of 0 μm, more preferably about 3 to 20 μm can be obtained. The amount of the colorant in the thus obtained colored fine particles according to the present invention is such that the residual ratio is 70% with respect to the blending amount (the charged amount) of the colorant in the polymerizable monomer composition in the suspension polymerization. % Or more, more preferably 90% or more,
The content of the coloring agent in the coloring fine particles is at least 5% by weight, more preferably at least 6% by weight. Further, the dispersion of the coloring agent in the obtained colored fine particles is extremely good, and the uniformity among the fine particles is also high.

In the electrophotographic toner according to the present invention, the colored fine particles obtained as described above can be used as they are, or as required, with a usual charge controlling agent for adjusting the charge, a fluidizing agent and the like. It can be obtained by performing a process such as appropriately externally adding an additive commonly used in an electrostatic charge developing toner.

As the fluidizing agent, for example, inorganic fine particles such as colloidal silica, hydrophobic silica, hydrophobic titania, hydrophobic zirconia, and talc, and organic fine particles such as polystyrene beads and (meth) acrylic resin beads are used. Can be

The electrophotographic toner thus obtained has an average particle size of, for example, about 2 to 20 μm, preferably about 3.5 to 15 μm, and each toner particle contains a sufficient amount of a colorant. When the toner is used to form an image, the resulting image has a sufficient degree of coloration because the toner is uniformly dispersed with a high content and the colorant content among the toner particles is uniform. In addition, the toner has a blackening degree and a uniform charge amount between toner particles, so that a stable image without fogging or the like can be obtained.

[0042]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. In the following, "part" means "part by weight" and "%" means "% by weight" unless otherwise specified.

Example 1 85 parts of styrene, 15 parts of n-butyl acrylate, 0.3 part of divinylbenzene, 8 parts of carbon black (MA-100 manufactured by Mitsubishi Chemical Corporation), maleic acid-modified rosin (Luisol) as a dispersant Polymerization unit using 8 parts of 28-JA (acid value 37, manufactured by Rika Hercules Co., Ltd.), 1 part of ABNR (manufactured by Nippon Hydrazine Industry Co., Ltd.), and 2 parts of ABNV (manufactured by Nippon Hydrazine Industry Co., Ltd.) A monomer composition was prepared.

The dispersant (maleic acid-modified rosin) of the polymerizable monomer composition is dissolved in styrene in advance,
The mixture was placed in a 450 ml mayonnaise bottle together with 130 g of 2.5 mm glass beads, and dispersed and mixed on a paint shaker for 30 minutes. As a result of observing this polymerizable monomer composition dispersion mixture with an optical microscope, it was confirmed that carbon black was finely dispersed uniformly and that there were no coarse particles of 1 μm or more.
The dispersion stability was also good.

From the polymerizable monomer composition dispersion mixture,
The entire amount of 2.5 mm glass beads was removed, and 1% polyvinyl alcohol prepared in advance (PVA205 Co., Ltd.)
The solution was added to 480 g of an aqueous solution (manufactured by Kuraray Co., Ltd.), and stirred at 8000 rpm for 5 minutes using a homomixer (manufactured by Tokushu Kika Co., Ltd.) to obtain a suspension. As a result of observing this suspension with an optical microscope, individual particles were uniformly colored black, and no uncolored transparent particles were found.

The suspension was heated under a nitrogen atmosphere while uniformly stirring the whole to such an extent that the polymer particles did not settle.
Polymerization was performed at 8 ° C. for 8 hours. As a result of measuring the particle size of this polymerization solution using Coulter Multisider II (manufactured by Coulter Inc.), the volume average particle size was 6.4 μm.

Next, the mixture was cooled to room temperature, and solid-liquid separation and washing were repeatedly performed, followed by drying with a hot air drier at 60 ° C. for 24 hours to obtain colored fine particles (1) of the present invention.

The amount of carbon black in the colored fine particles (1) was measured by a thermal analyzer (high sensitivity Tg, TGA-50S, manufactured by Shimadzu Corporation). The measuring method is as follows: after heating at a temperature rising rate of 10 ° C./min from room temperature to 600 ° C. in a nitrogen atmosphere to completely decompose the polymer component, heating to 1000 ° C. in an air atmosphere at the same temperature rising rate; % Was defined as the amount of carbon black. As a result, the amount of carbon black in the colored fine particles was 6.8%. The residual ratio of carbon black in the colored particles is 99%. The colored fine particles (1) were used as an electrophotographic toner (1), and 0.3% of hydrophobic silica (Aerosil R-972 manufactured by Nippon Aerosil Co., Ltd.) was added thereto, mixed well, and then coated with a styrene acrylic resin. Using a ferrite carrier, the toner concentration was adjusted to 4% and mixed to form a two-component developer. This developer is used as Rheodry 7610 (Toshiba Corporation)
And a copying test was carried out. As a result, a good image having a sufficient degree of blackening and having no fog was obtained.

As a result of observing the dispersion state of the carbon black in the colored fine particles (1) with a TEM photograph, it was confirmed that the carbon black was uniformly finely dispersed in the particles.

Example 2 850 parts of styrene, 150 parts of n-butyl acrylate,
3 parts of divinylbenzene, 80 parts of carbon black (# 44 manufactured by Mitsubishi Chemical Corporation), and an aromatic petroleum resin (Neopolymer 100, manufactured by Nippon Synthetic Resins Co., Ltd.) 4 as a dispersant
0 parts, ABNR (manufactured by Nippon Hydrazine Industry Co., Ltd.) 20
Section and ABNV (manufactured by Nippon Hydrazine Industry Co., Ltd.) 4
A polymerizable monomer composition was prepared using 0 parts.

The dispersant (aromatic petroleum resin) of the polymerizable monomer composition is dissolved in styrene in advance and then DYN
O-MILLKDL (Willy A. Bachof
(enAG Maschinenfabrik). Observation of this polymerizable monomer composition dispersion mixture with an optical microscope confirmed that carbon black was uniformly and finely dispersed, and that there were no coarse particles, and that the dispersion stability was also good.

This polymerized monomer composition dispersion was washed with a previously prepared water 480 containing 0.04% sodium dodecylbenzenesulfonate and 4% calcium phosphate.
It was charged into Og and circulated at 1500 rpm for 10 minutes at Ebara Milder (manufactured by Ebara Corporation) to obtain a suspension.
As a result of observing this suspension with an optical microscope, individual particles were uniformly colored black, and no uncolored transparent particles were found.

The suspension was heated under a nitrogen atmosphere while uniformly stirring the whole to such an extent that the polymer particles did not settle out.
Polymerization was carried out at 6 ° C. for 6 hours. As a result of measuring the particle size of this polymerization solution using Coulter Multisider II (manufactured by Coulter Inc.), the weight average particle size was 7.2 μm.

Then, the mixture is cooled to room temperature, calcium phosphate is dissolved with hydrochloric acid, solid-liquid separation and washing are repeated. After sufficient washing, the colored fine particles (2) of the present invention are obtained by drying with a hot air drier at 60 ° C. for 24 hours. Was.

The colored fine particles (2) were measured for carbon black in the colored fine particles in the same manner as in Example 1. As a result, the amount of carbon black in the colored fine particles was 7.1%. The residual ratio of carbon black in the colored fine particles is 1
00%.

The colored fine particles (2) were used as an electrophotographic toner (2), and were added with hydrophobic silica (Aerosil®).
After adding 0.3% of -972 Nippon Aerosil Co., Ltd.) and mixing well, the toner concentration was adjusted to 4% using a styrene acrylic resin-coated ferrite carrier, and mixed to prepare a two-component developer. . The developer was set on a Rheodry 7610 (manufactured by Toshiba Corporation) and a copying test was carried out. As a result, a satisfactory image having a sufficient degree of blackening and having no fog was obtained. As a result of observing the dispersion state of the carbon black in the colored fine particles (2) with a TEM photograph, it was confirmed that the particles were uniformly finely dispersed in the particles.

Example 3 The same operation as in Example 2 except that the dispersant in the polymerizable monomer composition of Example 2 was 120 g of α-pinene resin (YS Resin A # 800, manufactured by Yashara Chemical Co., Ltd.) Thus, colored fine particles (3) were obtained. The polymerizable monomer composition after the dispersion treatment was evaluated in the same manner as in Example 1. As a result, it was confirmed that carbon black was finely dispersed uniformly and that there were no coarse particles, and the dispersion stability was also good. there were. The weight average particle diameter of the colored fine particles (3) was 4.5 μm.

The colored fine particles (3) were measured for carbon black in the colored fine particles in the same manner as in Example 1. As a result, the amount of the carpump rack in the colored fine particles was 6.5%. The residual ratio of carbon black in the colored fine particles is 9
8%.

The dispersion state of carbon black in the colored fine particles (3) was evaluated in the same manner as in Example 1 in the same manner. As a result, it was confirmed that the particles were uniformly dispersed in the particles.

The colored fine particles (3) were used as an electrophotographic toner (3), and were added with hydrophobic silica (Aerosil®).
After adding 0.3% of -972 Nippon Aerosil Co., Ltd.) and mixing well, the toner concentration was adjusted to 4% using a styrene acrylic resin-coated ferrite carrier, and mixed to prepare a two-component developer. . As a result of performing a copying test using this developer in the same manner as in Example 1, a good image having a sufficient degree of blackening and having no fog was obtained.

Example 4 The dispersant in the polymerizable monomer composition of Example 1 was changed to a cumarone resin (Escron N-100S, Nippon Steel Chemical Co., Ltd.).
Colored fine particles (4) were obtained in exactly the same manner as in Example 1, except that the amount was 20 g. The polymerizable monomer composition after the dispersion treatment was evaluated in the same manner as in Example 1. As a result, it was confirmed that carbon black was finely dispersed uniformly and that there were no coarse particles, and the dispersion stability was also good. there were. Colored fine particles (4)
Had a weight average particle size of 5.9 μm.

The colored fine particles (4) were measured for carbon black in the colored fine particles in the same manner as in Example 1. As a result, the amount of carbon black in the colored fine particles was 6.7%. The residual ratio of carbon black in the colored fine particles is 9
7%.

The dispersion state of carbon black in the particles of the colored fine particles (4) was evaluated in the same manner as in Example 1, and as a result, it was confirmed that the particles were uniformly dispersed in the particles.

The colored fine particles (4) were used as an electrophotographic toner (4), and were added with hydrophobic silica (Aerosil®).
After adding 0.8% of -972 Nippon Aerosil Co., Ltd.) and mixing well, a styrene acrylic resin-coated ferrite carrier was used to adjust the toner concentration to 4% and mixed to prepare a two-component developer. . The developer was set on a Rheodry 7610 (manufactured by Toshiba Corporation) and a copying test was carried out. As a result, a satisfactory image having a sufficient degree of blackening and having no fog was obtained.

Example 5 Except that the dispersant in the polymerizable monomer composition of Example 1 was 16 g of maleic acid-modified rosin (DP-180 (oxidized 9) manufactured by Rika Hercules Co., Ltd.), the same as in Example 1 was used. By the same operation, colored fine particles (5) were obtained.

The polymerizable monomer composition after the dispersion treatment was evaluated in the same manner as in Example 1. As a result, it was confirmed that carbon black was uniformly finely dispersed and no coarse particles were present. The dispersion stability was also good. The weight average particle diameter of the colored fine particles (5) was 5.9 μm.

The colored fine particles (5) were measured for carbon black in the colored fine particles in the same manner as in Example 1. As a result, the amount of carbon black in the colored fine particles was 6.8%. The residual ratio of carbon black in the colored fine particles is 9
9%.

The dispersion state of carbon black in the colored fine particles (5) was evaluated in the same manner as in Example 1 by the same method. As a result, it was confirmed that the particles were uniformly dispersed in the particles.

The colored microparticles (5) were used as an electrophotographic toner (5), and added to hydrophobic silica (Aerosil®).
After adding 0.3% of -972 Nippon Aerosil Co., Ltd.) and mixing well, the toner concentration was adjusted to 4% using a styrene acrylic resin-coated ferrite carrier, and mixed to prepare a two-component developer. . The developer was set on a Rheodry 7610 (manufactured by Toshiba Corporation) and a copying test was carried out. As a result, a satisfactory image having a sufficient degree of blackening and having no fog was obtained.

Example 6 An epoxy resin (Epicoat 1002 Yuka Shell Epoxy Co., Ltd.) was used as a dispersant in the polymerizable monomer composition of Example 1.
Colored fine particles (6) were obtained in the same manner as in Example 1, except that the softening temperature (ring and ball method: 78 ° C.) was 6 g and the amount of carbon black was 12 g.

The polymerizable monomer composition after the dispersion treatment was evaluated in the same manner as in Example 1. As a result, it was confirmed that the carbon black was finely and uniformly dispersed without any coarse particles. Was also good. The weight average particle diameter of the colored fine particles (6) was 5.3 μm.

The colored fine particles (6) were measured for carbon black in the colored fine particles in the same manner as in Example 1. As a result, the amount of carbon black in the colored fine particles was 10.1%. The residual ratio of carbon black in the colored fine particles is 99.6%.

The state of dispersion of carbon black in the particles of the colored fine particles (6) was evaluated in the same manner as in Example 1, and as a result, it was confirmed that the particles were uniformly dispersed in the particles.

The colored fine particles (6) were used as an electrophotographic toner (6), and were added with hydrophobic silica (Aerosil®).
After adding 0.3% of 972 (manufactured by Nippon Aerosil Co., Ltd.) and mixing well, the toner was adjusted to 4% using a styrene acrylic resin-coated ferrite carrier and mixed to prepare a two-component developer. Apply this developer to Rheodry 7
610 (manufactured by Toshiba Corporation) and a copying test was carried out. As a result, a good image having a sufficient degree of blackening and no fog was obtained.

Example 7 Maleic acid-modified rosin (pentalin 830 (acid value 79), manufactured by Rika Hercules Co., Ltd.) was used as a dispersant in the polymerizable monomer composition of Example 2, and 0.04% dodecylbenzene sulfone was used. Instead of 4800 g of water containing sodium phosphate and 4% calcium phosphate, a 0.2% aqueous solution 480 of Hytenol N08 (polyoxyethylene alkylphenyl ether sulfate ammonium, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)
Except that the amount was 0 g, the same procedure as in Example 2 was carried out to obtain colored fine particles (7).

The polymerizable monomer composition after the dispersion treatment was evaluated in the same manner as in Example 1. As a result, it was confirmed that carbon black was finely dispersed uniformly and that there were no coarse particles. Was also good. The weight average particle diameter of the colored fine particles (7) was 5.7 μm.

The colored fine particles (7) were measured for carbon black in the colored fine particles in the same manner as in Example 1. As a result, the amount of carbon black in the colored fine particles was 6.9%. The residual ratio of carbon black in the colored fine particles is 9
7%. The dispersion of carbon black in the colored fine particles (7) was evaluated in the same manner as in Example 1 by the same method. As a result, it was confirmed that the particles were uniformly dispersed in the particles.

The colored fine particles (7) were used as an electrophotographic toner (7), and were added with hydrophobic silica (Aerosil®).
After adding 0.3% of -972 Nippon Aerosil Co., Ltd.) and mixing well, the mixture was adjusted to a toner concentration of 4% using a styrene acrylic resin-coated ferrite carrier, and mixed to prepare a two-component developer. Apply this developer to Rheodry 7
610 (manufactured by Toshiba Corporation) and a copying test was carried out. As a result, a good image having a sufficient degree of blackening and no fog was obtained.

Comparative Example 1 Comparative fine particles (1) were obtained by the same composition and operation as in Example 1 except that the dispersant for the polymerizable monomer composition of Example 1 was not added. Each step was evaluated in the same manner as in Example 1. As a result, the dispersion state of carbon black in the dispersion mixture of the polymerizable monomer composition was observed by an optical microscope. As a result, carbon black was poorly dispersed, contained coarse particles of 1 μm or more, and exhibited dispersion stability. No secondary aggregation occurred immediately due to lack of.

As a result of observing the suspension with an optical microscope, the degree of blackness of the individual particles was not uniform, and the presence of transparent particles was confirmed.

Comparative colored fine particles obtained by polymerization (1)
Had a weight average particle size of 5.8 μm. The dispersion of carbon black in the comparative colored fine particles (1) was determined by T
As a result of observation with an EM photograph, carbon black was gathered in the vicinity of the particle surface and was hardly present at the center of the particle.

For the comparative colored fine particles (1), the carbon black in the colored fine particles was measured in the same manner as in Example 1. As a result, the amount of carpump rack in the colored fine particles was 2.
8%. The residual ratio of carbon black in the colored fine particles is 40%. Using the comparative colored fine particles (1) as a comparative toner (1), a developer was prepared in the same manner as in Example 1, and a copy test was performed. As a result, toner scattering was observed, and fogging was observed on the image. Only an image having a low degree of blackening was obtained.

Comparative Example 2 Dispersant (Luisol 28-JA (oxidized 37) Rika Hercules Co., Ltd.) in the polymerizable monomer composition of Example 1
Comparative Example 2) was obtained in the same composition and operation as in Example 2, except that 8 parts of the polymerizable monomer composition after the dispersion treatment of the colorant was added and dissolved. . Each step was evaluated in the same manner as in Example 1. As a result, as a result of observing the dispersion state of the carbon black in the dispersion mixture of the polymerizable monomer composition with an optical microscope, the dispersion of the carbon black was poor and contained coarse particles of 1 μm or more, and there was no dispersion stability. As a result, secondary aggregation immediately occurred.

As a result of observing the suspension with an optical microscope, the degree of blackness of each particle was not uniform, and the presence of transparent particles was confirmed.

Comparative colored fine particles obtained by polymerization (2)
Was 8.1 μm, and the dispersion of carbon black in the particles of this comparative color fine particle (2) was T
As a result of observation with an EM photograph, carbon black was gathered in the vicinity of the particle surface and was hardly present at the center of the particle.

For the comparative colored fine particles (2), carbon black in the colored fine particles was measured in the same manner as in Example 1. As a result, the amount of carbon black in the fine particles was 3.3%.
Met. The residual ratio of carbon black in the colored fine particles is 46%. Using this comparative colored fine particle (2) as a comparative toner (2), a developer was prepared in the same manner as in Example 1, and as a result of a copy test, toner scattering was observed.
Fogging was observed on the image, and only an image having low blackening property was obtained.

Comparative Example 3 The same composition and the same composition as in Example 1 except that the dispersant in the polymerizable monomer composition of Example 1 was a phenol / terpene copolymer (YS Polystar S145, manufactured by Yashara Chemical Co., Ltd.) By operation, comparative colored fine particles (3) were obtained. In each step, the basis value was the same as in Example 1. as a result,
As a result of observing the dispersion state of the carpump rack in the dispersion mixture of the polymerizable monomer composition with an optical microscope, the carbon black is finely dispersed and does not contain coarse particles but has low dispersion stability and secondary aggregation. Was easily dispersed.

As a result of observing the suspension under an optical microscope, the blackness of individual particles was not uniform, but the presence of transparent particles was not recognized.

Comparative colored fine particles obtained by polymerization (3)
Had a weight average particle size of 7.8 μm. The dispersion of carbon black in the comparative colored fine particles (3) was determined by T
As a result of observation with an EM photograph, the dispersion state was such that the particles were unevenly dispersed and aggregated in the particles.

For the comparative colored fine particles (3), carbon black in the colored fine particles was measured in the same manner as in Example 1. As a result, the amount of carbon black in the colored fine particles was 3.
8%. The residual ratio of carbon black in the colored fine particles is 53%. Using the comparative colored fine particles (3) as a comparative toner (3), a developer was prepared in the same manner as in Example 1, and a copy test was performed. As a result, toner scattering was observed, and fogging was observed on the image. Only an image having a low degree of blackening was obtained.

Comparative Example 4 Comparative fine particles (4) were obtained by the same composition and operation as in Example 1 except that the dispersant of the polymerizable monomer composition of Example 1 was changed to 3 parts of p-carboxystyrene. Was. Each step was evaluated in the same manner as in Example 1. As a result, as a result of observing the dispersion state of carbon black in the dispersion mixture of the polymerizable monomer composition with an optical microscope, carbon black was finely dispersed and did not contain coarse particles but had low dispersion stability.
The dispersion was likely to cause secondary aggregation.

As a result of observing the suspension with an optical microscope, the degree of blackness of individual particles was not uniform, but the presence of transparent particles was not recognized.

Comparative colored fine particles obtained by polymerization (4)
Had a weight average particle size of 6.1 μm. The dispersion of carbon black in the comparative colored fine particles (4) was determined by T
As a result of observation with an EM photograph, it was in a dispersed state in which carbon black was gathered near the particle surface.

For the comparative colored fine particles (4), carbon black in the colored fine particles was measured in the same manner as in Example 1. As a result, the amount of carbon black in the colored fine particles was 4.
2%. The residual ratio of carbon black in the colored fine particles is 58%. Using the comparative colored fine particles (4) as a comparative toner (4), a developer was prepared in the same manner as in Example 1, and a copy test was performed. As a result, an image having a degree of blackening was obtained. And fogging were observed.

[0095]

According to the present invention as described according to the present invention above, at least a high pressure emulsion vinyl vinyl <br/> monomer composition obtained by dispersing a colorant monomer to the aqueous dispersion medium Machine or pore
Using a device other than a dispersion device that uses porous glass having
When the suspension is polymerized to obtain colored fine particles, the colorant is dispersed in the polymerizable monomer by an acid value of 5 to 100 KOHm.
g / g rosin derivative, weight average molecular weight of 1000 or less
An aromatic petroleum resin having a softening point temperature of 70C to 170C ,
α- pinene-based resins, because the softening temperature is characterized in that is carried out in the presence of at least one resin selected comprised from the group consisting of 60 ° C. to 150 DEG ° C. for epoxy resins Contact and coumarone resin In addition, the dispersion of the coloring agent in the obtained coloring fine particles is uniform, and the uniformity of the coloring agent content among the coloring fine particles is also increased. For this reason, when such colored fine particles are used as an electrophotographic toner, the degree of coloring or blackening of the obtained image is sufficient, and there is no possibility that a problem such as image fogging will occur. It is. In addition, the polymerizable monomer composition obtained by performing the dispersion treatment of the colorant in the polymerizable monomer in the presence of the specific resin as described above becomes an aqueous phase during suspension in an aqueous medium and during the polymerization process. The transfer of the colorant to the aqueous microparticles is small, so that the residual ratio of the colorant in the obtained colored fine particles is high, and there is also an advantage in production that there is no problem of contamination by the free colorant transferred to the aqueous phase. Becomes

──────────────────────────────────────────────────続 き Continuing on the front page (72) Kazuhiro Anan 5-8 Nishiburi-cho, Suita-shi, Osaka Nippon Shokubai Co., Ltd. (72) Tatsuhito Matsuda 5-8 Nishi-Maburi-cho, Suita-shi, Osaka JP Nippon Shokubai Co., Ltd. (56) References JP-A-8-54755 (JP, A) JP-A-6-337541 (JP, A) JP-A 8-272137 (JP, A) JP-A 8-333478 (JP, A) JP-A-9-274338 (JP, A) JP-A-10-133415 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 9/087

Claims (2)

(57) [Claims] 1. A vinyl monomer composition obtained by dispersing a colorant in at least a vinyl monomer, and having an acid value of 5 to 100.
Rosin derivative of KOHmg / g, weight average molecular weight is 10
000 following softening temperature 70 ° C. to 170 ° C. of aromatic petroleum resins, alpha-pinene resin having a softening point temperature of 60 ° C. to 15
In the presence of at least one resin selected from the group consisting of an epoxy resin and a cumarone resin at 0 ° C., in an aqueous dispersion medium using a device other than a high-pressure emulsifier and a dispersion device having pores. A method for producing colored fine particles, comprising obtaining colored fine particles having a colorant residual ratio of 70% or more in the colored fine particles by suspension polymerization. 2. A dispersant for dispersing a colorant in a vinyl monomer, wherein at least 100 parts by weight of a vinyl monomer composition obtained by dispersing the colorant in the vinyl monomer, 1
The method for producing colored fine particles according to claim 1, wherein the amount is from 50 to 50 parts by weight.