JPH0812477B2 - Colored fine particles and electrostatic charge image developing toner using the same - Google Patents

Description

The present invention relates to colored fine particles and a toner for developing an electrostatic charge image using the same. More specifically, the colorant is uniformly dispersed in the particle and the surface of the particle is modified, so that the colored fine particles that can be used as a colorant for toners, paints, inks, resin moldings, etc. The present invention relates to an electrostatic charge image developing toner that uses fine particles and can form a clear image when used as a toner in a printer device such as a laser printer or a liquid crystal printer.

[Conventional technology]

In electrophotography, an electrical latent image is formed on a photoconductor composed of a photoconductive material such as selenium, zinc oxide, cadmium sulfide, etc., developed with a powder developer, transferred to paper, and fixed. To do.

Conventionally, a toner used for developing an electrostatic image is generally prepared by melting and dispersing a colorant and other additives (charge control agent, offset preventive agent, lubricant, etc.) in a thermoplastic resin and then solidifying the solidified material. It has been finely pulverized and classified to produce colored fine particles having a desired particle size.

However, there are various drawbacks in the above-mentioned method of producing a toner by pulverization. First, a step of producing a resin, a step of kneading a resin with a colorant and other additives, a step of crushing a solid matter, a step of classifying the crushed matter to obtain colored fine particles having a desired particle size, etc. However, a large number of processes and various kinds of devices associated therewith are required, and the toner manufactured by this method is necessarily expensive. In particular, a classifying step is an essential requirement for obtaining a toner having an optimum particle size range for forming a clear image with less fog, but there is a problem in productivity and yield. Second, in the kneading step, it is extremely difficult for the colorant and other additives to be uniformly dispersed in the resin, and therefore, in the toner manufactured by this method, the colorant, the charge control agent, and the like have poor dispersion. Therefore, the frictional charging characteristics of each particle are different, which leads to a reduction in resolution. Such a problem will become more prominent in the future as the toner particle size becomes smaller, which is an essential condition for improving the image quality. That is, there is a limit in obtaining a small particle size toner with the current pulverizer, and even if a small particle size toner is obtained, the dispersion of the charge amount occurs due to the poor dispersion of the colorant and the charge control agent. .

In order to improve various drawbacks of the toner obtained by the pulverization method, various methods for producing the toner by the emulsion polymerization method or the suspension polymerization method have been proposed. (Japanese Patent Publication Sho 36-10
231, Japanese Patent Publication No. 43-10799, Japanese Patent Publication No. 47-518305, Japanese Patent Publication No. 51-14895, etc.).
Is a method in which a toner containing a colorant substance is synthesized all at once by emulsification or suspension polymerization of the colorant substance such as the above and other additives. By this method, the drawbacks of conventional grinding methods can be considerably improved. That is, since it does not include a crushing step at all, it is not necessary to improve brittleness, and since the shape is spherical and the fluidity is excellent, the triboelectric charging property is uniform.

However, there is a problem in the toner manufacturing method by the polymerization method. First, since the hydrophilic substances such as the dispersant and the surfactant used during the polymerization cannot be completely removed even by the washing process and remain on the toner surface, the chargeability is easily affected by the environment. Secondly, since the toner obtained by the polymerization method has a spherical shape and its surface is very smooth, it becomes difficult to remove the toner adhering to the photoconductor, resulting in poor cleaning.

Various methods have been proposed to solve these problems.
-255354, JP-A-53-17736, JP-A-63-17460,
Although it is proposed by JP-A-61-167956, its effect is incomplete, or the cost is increased, which is not practical.

[Problems to be solved by the invention]

As a result of intensive studies conducted by the present inventors in view of the above-mentioned current situation,
The colored fine particles obtained by treating the colored spherical fine particles obtained by the suspension polymerization by a specific procedure are those in which the above-mentioned problems are alleviated and improved, including toners for electrostatic image development, paints, inks, resin moldings. The above-mentioned problems of the prior art when the toner for electrostatic charge image development using the colored fine particles is suitably used as a colorant for an object or the like and is used in a printer device such as a laser printer, a liquid crystal printer, or the like. However, it was found that an extremely clear image could be formed, and the present invention was completed.

[Means for solving problems]

The present invention has an average particle size of 1 to 10 obtained by suspension polymerization.
The colored spherical fine particles of 0 μm were heat-treated under the condition of 30 to 200 ° C. to fuse the particles to each other to form a block-like substance, which was then crushed to the average particle diameter of the colored spherical fine particles before substantially being fused. The present invention relates to colored fine particles obtained and a toner for developing an electrostatic charge image using the same.

The colored spherical fine particles in the present invention are obtained by suspension polymerization of a polymerizable monomer containing a colorant by a well-known procedure. The colored spherical fine particles obtained by suspension polymerization are 1 to 100 μm, preferably 3 to 50 μm, and more preferably
The particle size is 3.5 to 20 μm, and the size of this particle size is extremely important for obtaining the colored fine particles of the present invention through the steps of heat treatment and crushing. The average particle diameter of the spherical polymer by a polymerization method other than suspension polymerization, for example, an emulsion polymerization method is usually around 0.1 μm, and the fine particles obtained by subjecting this to heat treatment and crushing are obtained by the production method of the present invention. The shape and particle size distribution of the particles are significantly different from those of the colored fine particles, and even if the particles are used as a toner, an image having a sufficiently satisfactory image quality cannot be obtained.

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

Styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, p-tert-butylstyrene, p-phenylstyrene, o-chlorostyrene, m-chlorostyrene, p -Styrene monomers such as chlorostyrene; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, dodecyl acrylate, stearyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, methacryl Acrylic acid or methacrylic acid type monomers such as propyl acrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate; ethylene, propylene Emissions, butylene, vinyl chloride,
Vinyl acetate, acrylonitrile.

During suspension polymerization of the polymerizable monomer, an appropriate cross-linking agent may be blended, and the obtained colored spherical fine particles may be provided with an appropriate cross-linking structure. It is preferable because workability is improved. That is, if fusion between particles during heat treatment progresses too much, efficiency at the time of subsequent crushing decreases, and if fusion is insufficient, sufficient treatment effect on the surface of particles cannot be obtained. Therefore, in order to bring the fusion of particles to an appropriate state, the crosslinking agent is 0.005 to 3 with respect to the polymerizable monomer.
It is preferably used in the range of 0% by weight, more preferably in the range of 0.05 to 5% by weight.

Examples of such a cross-linking agent include the following.

(A) a compound having at least two polymerizable unsaturated groups in the molecule, (B) selected from the group consisting of at least one polymerizable unsaturated group in the molecule, a carboxyl group, a sulfonyl group, and a phenol group. A compound having at least one functional group of at least one selected from the group (C) a compound having at least two functional groups capable of being crosslinked by addition or condensation reaction by heating, active energy rays or other appropriate means, ) In the process of polymerizing an ionically crosslinkable compound such as a polyvalent metal compound, and (E) a polymerizable monomer component, heat,
A compound capable of generating at least two radicals in the molecule by an active energy ray, a polymerization initiator or other suitable means.

Examples of the compound (A) include aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, and derivatives thereof, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, trimethylolpropane triacrylate, allyl methacrylate, t-. Diethylenically unsaturated carboxylic acid esters such as butylaminoethyl methacrylate, tetraethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate, N, N-
Some have all divinyl compounds of divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfonic acid and those having 3 or more vinyl groups.

Further, polybutadiene, polyisoprene, unsaturated polyester and Japanese Patent Publication No. 57-56507, Japanese Patent Publication No. 59-221304,
JP-A-59-221305, JP-A-59-221306, JP-A-59-2213
It is the reactive polymer described in 07 and the like.

As the compound (B), in the process of polymerizing the monomer component, it reacts with a reactive group remaining in the polymer portion of the carbon black graft polymer, that is, an aziridine group, an oxazoline group, an epoxy group or the like to form colored spherical fine particles. It provides a crosslinked structure. However, in this case, a monomer having a functional group such as an aziridine group, an oxazoline group, an epoxy group, an N-hydroxyalkylamide group or a thioepoxy group (B
-I) may be contained in the polymerizable monomer component.
Examples of the monomer (B-i) include the following.

The compound (C) is, for example, a low molecular weight compound or polymer compound having at least two epoxy groups, oxazoline groups and the like in the molecule, and examples thereof include polyepoxy (Denacol EX-211, Denacol EX-313, Denacol).
EX-314 and Denacol EX-321 manufactured by Nagase Kasei Kogyo Co., Ltd., 2-p-phenylene-bis- (2-oxazoline), 2-2 '-(1,3-phenylene) bis (2-
Oxazoline), 2- (1-aziridinyl) -2-oxazoline, RPS (Reactive polystyrene manufactured by Dowchemical)
Etc. The RPS is represented by the following general formula.

(However, x is 99 and n is an integer of 4 to 5) However, in order to crosslink using these compounds (C), a monomer having a group capable of reacting with a functional group contained in the compound (C) (C-i)
Must be contained in the polymerizable monomer component. Examples of the monomer (C-i) include the compound (B).

Examples of the compound (D) include ZnO, Zn (OH) ₂ , Al ₂ O ₃ , and Al.
(OH) ₃ , MgO, Mg (OH) ₂ , sodium methoxide, sodium ethoxide and the like can be mentioned. However, when crosslinking is performed using the compound (D), the polymerizable monomer component must include the compound (B).

As the compound (E), for example, the following formula (In the formula, R is H or CH ₃ , x is an integer of ₃ to 400, and n is an integer of 2 or more.) There is a chlorosulfonated polyolefin.

Colorants used for obtaining colored spherical fine particles are dyes and pigments well known to those skilled in the art, and may be organic or inorganic. Specific examples thereof include, for example, carbon black, nigrosine dye, aniline blue, chalco oil blue, chrome yellow, ultramarine blue, duPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachide green oxalate, lamp black, Oil black, azo oil black, rose bengal and the like can be mentioned, and if necessary, two or more kinds of them may be used in combination.

Further, a substance having magnetism, or a magnetic substance thereof can also be used as a coloring agent. Examples of the magnetic material include powders of ferromagnetic metals such as iron, cobalt and nickel, powders of metal compounds such as magnetite, hematite and ferrite.
These magnetic materials can be used alone or in combination with the dyes and pigments as colorants.

These colorants may be used as they are, but when a colorant whose surface is treated by an appropriate method is used, colored fine particles in which the colorant is uniformly dispersed can be obtained. For example, when used as a toner, a high quality image is obtained. It is preferable because it is formed. For example, when carbon black is used as a colorant, it is disclosed in
The carbon black graft polymers described in JP-A-270767 and JP-A-63-265913 are suitable. Also, when a colorant other than carbon black is used, the method disclosed in JP-A-1-118573 is used.
Surface-treated colorants obtainable by the method described in US Pat.

The amount of the colorant added may be in a wide range depending on the kind of the colorant used and the intended use of the colored fine particles to be obtained, but is preferably 1 per 100 parts by weight of the polymerizable monomer.
To 200 parts by weight, more preferably 1 to 100 parts by weight.

In order to obtain colored spherical fine particles using a colorant, it is usually convenient to carry out suspension polymerization of a polymerizable monomer in which the colorant is dissolved or dispersed, but in some cases, spherical particles after polymerization are used. Alternatively, a method may be used in which the colorant is absorbed in the polymer particles by using a suitable solvent.

Examples of stabilizers used in suspension polymerization include water-soluble polymers such as polyvinyl alcohol, starch, methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, sodium polyacrylate and sodium polymethacrylate; anionic surfactants and cationic surfactants. There are surfactants such as zwitterionic surfactants and nonionic surfactants. Others include barium sulfate, calcium sulfate, barium carbonate, magnesium carbonate, calcium phosphate, talc, clay, diatomaceous earth and metal oxide powders. To be

Examples of the anionic surfactant include fatty acid salts such as sodium oleate and potassium castor oil, alkyl sulfate salts such as sodium lauryl sulfate and ammonium lauryl sulfate, alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate, and alkylnaphthalenesulfonates. , Dialkyl sulfosuccinate, alkyl phosphate ester salt, naphthalene sulfonic acid formalin condensate,
There are polyoxyethylene alkyl sulfate ester salts and the like.

As the nonionic surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkylphenol ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxysorbitan fatty acid ester, polyoxyethylene alkylamine; glycerin fatty acid ester, oxyethylene-oxy There are propylene block polymers and the like.

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

Examples of the zwitterionic surfactant include lauryl dimethylamine oxide.

These stabilizers have a particle diameter of the obtained colored spherical fine particles of 1 to 100 μm, preferably 3 to 50 μm, and most preferably
The composition and the amount used should be appropriately adjusted so that the thickness becomes 3.5 to 20 μm. For example, when using a water-soluble polymer as a stabilizer, 0.01
It is suitable to be 20 to 20% by weight, more preferably 0.1 to 10% by weight. In the case of a surfactant, the amount is preferably 0.01 to 10% by weight, more preferably 0.1 to 5% by weight, based on the polymerizable monomer component.

As the polymerization initiator used for the polymerization, an oil-soluble peroxide type or azo type initiator which is usually used for suspension polymerization can be used. For example, benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, benzoyl orthochloroperoxide, benzoyl orthomethoxyperoxide, methyl ethyl ketone peroxide, diisopropyl peroxydicarbonate, cumene hydroperoxide, cyclohexanone peroxide, t -Butyl hydroperoxide, peroxide initiators such as diisopropylbenzene hydroperoxide, 2,2'-
Azobisisobutyronitrile, 2,2'-azobis- (2,4
-Dimethylvaleronitrile), 2,2'-azobis-2,3-
Dimethylbutyronitrile, 2,2'-azobis- (2-methylbutyronitrile), 2,2'-azobis-2,3,3-trimethylbutyronitrile, 2,2'-azobis-2-isopropylbutyro Ronitrile, 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'-
Examples include azobisisobutyrate. The polymerization initiator is 0.01 to 20% by weight, particularly 0.1 to 10% by weight with respect to the polymerizable monomer.
It is preferably used in weight percent.

In this way, when the polymerizable monomer component is suspension polymerized to obtain colored spherical fine particles, another polymer such as polyester may be present in the monomer component, and the degree of polymerization is further adjusted. Known additives such as chain transfer agents may be appropriately added. When the colored fine particles of the present invention are used in an electrostatic charge image developing toner, a magnetic substance or a charge control agent is blended with a polymerizable monomer, and the magnetic substance or the charge control agent is internally added to the colored particles. Fine particles can also be obtained. The colored spherical fine particles thus obtained have an average particle size of 1 to 100 μm, preferably 3 to 50 μm, most preferably 3.5 to 20 μm, and the particle size distribution is 0 to 80%, preferably 1 to 50% as a coefficient of variation of particle size. It has a spherical shape that can be controlled.

The colored fine particles of the present invention are obtained by heating the colored spherical fine particles obtained by the above-mentioned procedure under the condition of 30 to 200 ° C. to bring the colored spherical fine particles into a fused state, and then the substantially colored spherical fine particles before being fused. It is obtained by crushing to an average particle diameter of.

The most ideal form of the crushing of the colored spherical fine particles to the average particle diameter before the substantial fusion is performed by fusing the colored spherical fine particles to each other within a range that does not completely eliminate the interface between the colored spherical fine particles. That is, the block-like material is fused and the individual particles are crushed to the unit of the colored spherical fine particles before fusion, and the colored spherical fine particles before fusion crushing are simply returned to a deformed state. However, it is actually difficult to uniformly control the fusion state at the fusion interface, and the colored fine particles that are usually obtained are those in which the colored spherical fine particles before fusion crushing are deformed and partially lost Obtained as a mixture of fine particles with attached parts. Even if such a mixture, if the average particle size of the obtained colored spherical fine particles is substantially the same as the average particle size of the colored spherical fine particles before fusion crushing, the properties of the colored fine particles are in the most ideal form. Almost as good as it is. At this time, if the average particle diameter of the colored fine particles is within a range of usually 20%, preferably 10%, and more preferably 5% with respect to the average particle diameter of the colored spherical fine particles, the colored fine particles and the colored spherical particles are The average particle size of the fine particles can be considered to be substantially the same.

The 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 30
If the temperature is lower than 0 ° C., the fusion of the colored spherical fine particles does not occur at all, or even if the fusion occurs, the fusion is not sufficient, and the remarkable surface modifying effect is not exhibited. On the other hand, when the temperature exceeds 200 ° C., an excessive fusion state occurs, and the subsequent crushing process is not only difficult, but also the obtained colored fine particles have a very large particle size distribution. It is preferably in the range of 50 to 150 ° C. The colored spherical fine particles are fused with each other by such heat treatment, and the fused state may be arbitrarily controlled according to the desired treatment effect. However, in the subsequent crushing step, a uniform particle size distribution is obtained, and therefore, in order to obtain colored fine particles having excellent physical properties as a toner for developing an electrostatic image, a range in which the interface between particles does not completely disappear, that is, a grain boundary is proposed. It is preferable that the melted state remains. The fused state in which the grain boundaries are left can be easily confirmed by crushing the block-shaped material obtained by fusing the colored spherical fine particles and by an electron micrograph of the crushed cross section (see FIG. 1). Furthermore, the bulk density of the block-shaped product obtained by fusing is 0.1 to 0.9 g / cm ³ , particularly 0.2.
It is more preferable that the fused state is in the range of 0.7 g / cm ³ .
Such heat treatment may be performed on the colored spherical fine particles after drying, or in some cases, may be performed simultaneously with the drying step. Further, this heat treatment can be performed under normal pressure, reduced pressure or increased pressure. Furthermore, it is free to use an appropriate organic solvent for the purpose of further promoting fusion during heat treatment.

For crushing, a crusher conventionally used for industrially producing powder, particles and the like can be used without limitation.

The colored fine particles thus obtained have a particle size and a particle size distribution which can be arbitrarily controlled, but the particle size is 1 to 100 μm, more preferably 3 to 50 μm, and most preferably 3.5 to 20 μm. The particle size distribution preferably has a coefficient of variation of particle size of 0 to 80%, more preferably 1 to 50%. However, the coefficient of variation of the particle size mentioned here is the percentage of the value obtained by dividing the standard deviation by the average particle size.
The shape of the colored fine particles is not particularly limited,
For example, particles that are macroscopically spherical but have fine irregularities on the surface, non-spherical particles, and the like are included.

The toner for developing an electrostatic image according to the present invention comprises the above-mentioned colored fine particles, and in order to bring the chargeability of the toner into an appropriate state, the average particle diameter thereof is 3 to 50 μm, more preferably It is preferably 3.5 to 20 μm. The colored fine particles can be used as they are as a toner for developing an electrostatic image. Further, additives commonly used in ordinary toners such as a charge control agent for adjusting the charge and a fluidizing agent may be appropriately blended.

The method of blending the charge control agent is not particularly limited, and any conventionally known method can be adopted. For example, a method of preliminarily including a charge control agent in the monomer when polymerizing a polymerizable monomer in which a colorant is dispersed, or coloring by post-treating the colored fine particles of the present invention with the charge control agent. A method of attaching a charge control agent to the surface of the fine particles can be appropriately adopted.

〔The invention's effect〕

Since the colored fine particles of the present invention are obtained by subjecting the colored spherical fine particles obtained by suspension polymerization to heat treatment under specific conditions and then crushed, the particle surface is uneven. In addition, the dispersant used for suspension polymerization such as Poval is remarkably reduced, and the fluctuation of physical properties due to the change of humidity is almost eliminated. Therefore, the colored fine particles of the present invention can be suitably used as a toner for developing an electrostatic image, and can also be used as a colorant or a modifier for other paints, inks and resin compositions.

Since the toner for developing an electrostatic image of the present invention comprises the above-mentioned colored fine particles, the cleaning property is improved as compared with the colored spherical fine particles, and the image is always fogged with high image quality under any environment without being affected by humidity. Images can be formed. Therefore, the electrostatic image developing toner of the present invention can be used in a wide variety of electrophotographic developing devices.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following Examples. still,
All parts in the examples are by weight.

Synthesis Example 1 200 parts of deionized water in which 0.1 part of polyvinyl alcohol was dissolved was charged into a flask equipped with a stirrer, an inert gas introduction tube, a reflux condenser tube and a thermometer. 97.5 parts of styrene and glycidyl methacrylate that had been adjusted in advance 2.
A mixture in which 8 parts of benzoyl peroxide was dissolved in 5 parts of a polymerizable monomer was charged and stirred at high speed to form a uniform suspension. Then, the mixture was heated to 80 ° C. while blowing nitrogen gas, and the mixture was continuously stirred at this temperature for 5 hours to carry out a polymerization reaction and then water was removed to obtain a polymer having an epoxy group as a reactive group.

40 parts of a polymer having an epoxy group as a reactive group, 15 parts of carbon black MA-100R (manufactured by Mitsubishi Kasei Co., Ltd.), and 2 parts of a charge control agent (manufactured by Aizen Spilon Black TRH Hodogaya Chemical Co., Ltd.) 160 ° C using Labo Plastomill, 1
After kneading and reacting under the condition of 00 rpm, the mixture was cooled and pulverized to obtain a carbon black graft polymer as a colorant.

Add polyvinyl alcohol (PVA2
05 897 parts of deionized water prepared by dissolving 3 parts of Kuraray Co., Ltd. was charged. A polymerizable monomer component consisting of 80 parts of styrene, 20 parts of n-butyl acrylate and 0.3 part of divinylbenzene, which had been adjusted in advance, was added to 50 parts of the carbon black graft polymer as the colorant, and azobisisobutyrate. A mixture containing 3 parts of ronitrile and 3 parts of 2,2-azobis (2,4-dimethylvaleronitrile) was charged, and the mixture was mixed with TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) at 8000 rpm at 5 rpm.
Stir for a minute to make a uniform suspension. Then, the mixture was heated to 60 ° C. while blowing nitrogen gas, stirred at this temperature for 5 hours to carry out a suspension polymerization reaction, and then cooled to obtain a suspension (1) of colored spherical fine particles. The Coulter Counter (aperture 100 μm) was applied to the obtained suspension (1) of colored spherical fine particles.
As a result, the average particle diameter was 7.01 μm and the coefficient of variation of particle diameter was 18.5%.

Synthesis Example 2 The same flask as used in Synthesis Example 1 was charged with 897 parts of deionized water in which 3 parts of polyvinyl alcohol (PVA205 Kuraray Co., Ltd.) was dissolved. Brilliant carmine 6B (manufactured by Noma Kagaku Co., Ltd.) as a colorant was added to a polymerizable monomer component composed of 80 parts of styrene, 20 parts of n-butyl acrylate and 0.3 part of divinylbenzene, which had been adjusted in advance.
, 3 parts of azobisisobutyronitrile and 3 parts of 2,2'-azobis (2,4-dimethylvaleronitrile) were charged, and the mixture was mixed with TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) at 8000 rpm. And stirred for 5 minutes to form a uniform suspension. Then, the mixture was heated to 60 ° C. while blowing nitrogen gas, and the suspension polymerization reaction was continued by stirring at this temperature for 5 hours and then cooled to room temperature to obtain a suspension (2) of colored spherical fine particles. The obtained colored spherical fine particle suspension (2) was measured with a Coulter counter (aperture 100 μm) to find that the average particle size was 5.55 μm and the coefficient of variation of particle size was 19.8%.
Met.

Synthetic Example 3 Instead of 50 parts of the carbon black graft polymer used in Synthetic Example 1, a powdery magnetic material, Mapico BL-, was used.
A suspension (3) of colored spherical fine particles was obtained in the same manner as in Synthesis Example 1 except that 45 parts of 200 (manufactured by Titanium Industry Co., Ltd.) were used.
The obtained suspension (3) of colored spherical fine particles had an average particle diameter of 9.05 μm on average and a coefficient of variation of particle diameter of 19.1%.

Synthesis Example 4 In Synthesis Example 1, 1 part of the nonionic surfactant Nonipol 200 (manufactured by Sanyo Kasei Co., Ltd.) was used instead of 3 parts of polyvinyl alcohol, and the rotation speed of the TK homomixer was 6000 rp.
The same operation as in Synthesis Example 1 was carried out except that m was changed to obtain a suspension (4) of colored spherical fine particles. The obtained colored spherical fine particle suspension (4) was measured with a Coulter counter (aperture 100 μm), and as a result, the average particle size was 5.82.
μm, the coefficient of variation of particle diameter was 21.5%.

Synthetic Example 5 A carbon black graft polymer was obtained in the same manner as in Synthetic Example 1, and 1 part of an anionic surfactant Hitenol N-08 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was dissolved in the same flask as above to deionize. Prepared 897 parts of water. 50 parts of carbon black graft polymer and azobis were added to a component composed of 80 parts of styrene, 15 parts of n-butyl acrylate, and 5 parts of polybutadiene NISSO-PB-B-3000 (manufactured by Nippon Soda Co., Ltd.) which had been preliminarily adjusted. Isobutyronitrile 2
Part and 2,2'-azobis (2,4-dimethylvaleronitrile) (1 part) were charged, and the same procedure as in Synthesis Example 1 was performed to obtain a suspension (5) of colored spherical fine particles.
As a result of measuring the obtained colored spherical fine particle suspension (5) with a Coulter counter (aperture 100 μm), the average particle diameter was 6.30 μm on average, and the coefficient of variation of particle diameter was 19.3%.

Synthesis Example 6 Instead of 5 parts of polybutadiene in Synthesis Example 5, HY
5 parts of PALON20 (manufactured by EI.duont de Nomors & Co.), 2 parts of azobisisobutyronitrile and 2,2'azobis (2,4-
A suspension (6) of colored spherical fine particles was obtained by performing the same operation as in Synthesis Example 5 except that 3 parts of benzoyl peroxide was used instead of 1 part of (dimethylvaleronitrile). As a result of measuring the obtained suspension (6) of colored spherical fine particles with a Coulter counter (aperture 100 μm), the average particle diameter was 5.91 μm on average, and the coefficient of variation of particle diameter was 21.5%.

Example 1 1050 parts of the suspension (1) of colored spherical fine particles obtained in Synthesis Example 1 was filtered and washed, and then dried at 90 ° C. for 5 hours using a hot air dryer, and heat-treated to leave grain boundaries. Block-shaped material 150 with a bulk density of 0.30 g / cm ^{3 in} the fused state
Got a part. An electron micrograph of a fractured surface obtained by roughly crushing this block-like material is shown in FIG. This block-like material was roughly crushed and then crushed using a supersonic jet crusher Lapojet (manufactured by Nippon Pneumatic Mfg. Co., Ltd.) to obtain colored fine particles (1).

The obtained colored fine particles (1) were measured with a Coulter counter (aperture 100 μm), and the average particle diameter was
At 6.98 μm, the variation coefficient of the particle size was 18.1%. The colored fine particles (1) are used as they are for the electrostatic image developing toner (1).
Used as an electrostatic copier (type 4060 manufactured by Ricoh Co., Ltd.)
The results of image formation by the above are as shown in Table 1.

Example 2 1005 parts of the suspension (2) of the colored spherical fine particles obtained in Synthesis Example 2 was filtered and washed to obtain a colored spherical fine particle paste.
A colorless charge control agent (Bont
1.3 parts of ron E-84 manufactured by Orient Chemical Industry Co., Ltd. were uniformly mixed. The obtained mixture was dried at 120 ° C for 2 hours using a hot air dryer and heat-treated, and in a fused state with grain boundaries left, a block shape having a millet-like shape with a bulk density of 0.35 g / cm ³ I got 106 parts. This block-like material was crushed in the same manner as in Example 1 to obtain red colored fine particles (2). The characteristics of the particles of the colored fine particles (2) and the colored fine particles (2) were used as they were as the toner (2) for developing an electrostatic image, and an image was produced by an electrostatic copying machine (type 4060 manufactured by Ricoh Co., Ltd.). The results are as shown in Table 1.

Example 3 1048 parts of the suspension (1) of colored spherical fine particles obtained in Synthesis Example 4 was filtered and washed, and then dried under reduced pressure at 50 ° C. for 5 hours to obtain 150 parts of colored spherical fine particles. The colored spherical fine particles are heated to 110 ° C.
A heat treatment was carried out for 1 hour to obtain a block-shaped product having a millet-like shape with a bulk density of 0.28 g / cm ^{3 in} a fused state with grain boundaries left. This block-like material was crushed in the same manner as in Example 1 to obtain colored fine particles (3).

The properties of the colored fine particles (3) and the colored fine particles (3) were used as they were as the toner (3) for developing an electrostatic image, and an image was printed by an electrostatic copying machine (type 4060 manufactured by Ricoh Co., Ltd.). The results are as shown in Table 1.

Example 4 1045 parts of the suspension (3) of the magnetic substance-containing colored spherical fine particles obtained in Synthesis Example 3 was filtered and washed to obtain a magnetic substance-containing colored spherical fine particle paste. Water-based charge control agent (Bont
ron S-34 (manufactured by Orient Chemical Industry Co., Ltd.) (4.1 parts) was uniformly mixed, dried under reduced pressure at 40 mmHg at 80 ° C. for 5 hours, and heat-treated to give a bulk density of 0.52 in a fused state with grain boundaries left.
As a result, 146 parts of a block-like material having a shape of millet millet of g / cm ³ was obtained. This block-like material was crushed in the same manner as in Example 1 to obtain colored fine particles (4).

The properties of the colored fine particles (4) and the colored fine particles (4) are used as they are as the toner (4) for developing an electrostatic image, and an image is produced by an electrostatic copying machine (NP-5000 Canon KK). The results are shown in Table 1.

Example 5 1048 parts of the suspension (5) of colored spherical fine particles obtained in Synthesis Example 5 was filtered and washed, and then dried under reduced pressure at 50 ° C. for 5 hours to obtain 150 parts of colored spherical fine particles. The colored spherical fine particles at 90 ° C
A heat treatment was carried out for 1 hour to obtain a block-shaped product having a millet-like shape with a bulk density of 0.20 g / cm ^{3 in} a fused state with grain boundaries left. This block-like material was crushed in the same manner as in Example 1 to obtain colored fine particles (5).

The properties of the colored fine particles (5) and the colored fine particles (5) were used as they were as the toner (5) for developing an electrostatic image, and an image was produced by an electrostatic copying machine (type 4060 manufactured by Ricoh Co., Ltd.). The results are as shown in Table 1.

Example 6 1048 parts of the suspension (6) of colored spherical fine particles obtained in Synthesis Example 6 was filtered and washed, and then dried under reduced pressure at 50 ° C. for 5 hours to obtain 150 parts of colored spherical fine particles. The colored spherical fine particles are heated to 80 ° C.
A heat treatment was carried out for 1 hour to obtain a block-like substance having a millet-like shape with a bulk density of 0.35 g / cm ^{3 in} a fused state with grain boundaries left. This block-like material was crushed in the same manner as in Example 1 to obtain colored fine particles (6).

The properties of the colored fine particles (6) and the colored fine particles (6) were used as they were as the toner (6) for developing an electrostatic image, and an image was produced by an electrostatic copying machine (type 4060 manufactured by Ricoh Co., Ltd.). The results are as shown in Table 1.

Comparative Example 1 1050 parts of the suspension of colored spherical fine particles (1) obtained in Synthesis Example 1 was filtered and washed, and then dried under reduced pressure at 40 mmHg for 24 hours at 50 ° C. to obtain 150 parts of the colored fine particles for comparison (1). Obtained.

The particle properties of the comparative colored fine particles (1) and the comparative colored fine particles (1) were directly used as the comparative electrostatic image developing toner (1) to produce an electrostatic copying machine (type 4060).
The first result of image output by Ricoh Co., Ltd.
It was as shown in the table.

Comparative Example 2 Styrene-acrylic resin (TB-1000F Sanyo Kasei Co., Ltd.)
222.8 parts, carbon black (MA-100R manufactured by Mitsubishi Kasei Co., Ltd.) 18.7 parts and charge control agent (Aizen Spilon Black)
TRH) 2.5 parts by pre-mixing with a Henschel mixer, melt kneading this at 150 ° C. for 30 minutes with a pressure kneader,
Cooled to obtain a toner mass. 0.1m of this toner lump with a crusher
Coarsely pulverized to m ~ 2 mm, and this coarse toner was finely pulverized using a supersonic jet pulverizer (Labo Jet Nippon Pneumatic Mfg. Co., Ltd.), and the pulverized material was classified by a wind force classifier (MDS Nippon Pneumatic Mfg. Co., Ltd.). )) To obtain 150 parts of comparative colored fine particles (2).

The particle properties of the comparative colored fine particles (2) and the comparative colored fine particles (2) are used as they are as the comparative electrostatic image developing toner (2) to produce an electrostatic copying machine (type 4060).
The first result of image output by Ricoh Co., Ltd.
It was as shown in the table.

(Note 1) Properties of particles Particle size: Measured with a Coulter counter (TA-II type manufactured by Coulter Electronics INC).

Coefficient of variation: Measured with a Coulter counter (TA-II type manufactured by Coulter Electronics INC).

Triboelectric charge: Iron carrier (Dowa Iron Powder Co., Ltd .: DSP-12)
Blow-off powder charge amount measuring device (manufactured by Toshiba Chemical Co .: Model TB-) using a mixture with 8) (toner concentration 5% by weight)
200).

(Note 2) Evaluation of image output An image obtained by copying the facsimile test chart No. 1 by an electrostatic copying machine image output (type 4060 manufactured by Ricoh Co., Ltd. or NP-5000 Canon Co., Ltd.) was evaluated.

Fog: The presence or absence of a phenomenon in which the ground is contaminated with toner in spots was examined.

Fine line reproducibility: Evaluated by reading the image obtained by copying the facsimile test chart No.1.

Cleanability: The image obtained by copying the facsimile test chart No. 1 was evaluated.

[Brief description of drawings]

FIG. 1 is an electron micrograph showing the particle structure of colored fine particles obtained by crushing the block-shaped material in Example 1.

Front page continuation (72) Inventor Nobuaki Urashima 5-8 Nishimitabicho, Suita City, Osaka Prefecture Central Research Laboratory of Nippon Shokubai Chemical Co., Ltd. (72) Keiichi Uehara 5-8 Nishiomitabicho, Suita City, Osaka Japan (72) Inventor Masuji Izumibayashi, No. 5 Nishimitabicho, Suita City, Osaka Prefecture (72) Inside Central Research Institute, Catalytic Chemical Co., Ltd. (72) Inori Sano, Nishimitabi Suita City, Osaka Prefecture No. 5-8, Central Research Laboratory, Nippon Shokubai Kagaku Kogyo Co., Ltd. (56) Reference JP-A 56-43645 (JP, A) JP-A 64-40951 (JP, A) JP-A 56-110951 (JP, A) Actual development Sho 61-22041 (JP, U)

Claims (12)

[Claims] 1. The average particle size obtained by suspension polymerization is from 1 to 1.
After heat treating 100 μm colored spherical fine particles under the condition of 30 to 200 ° C. to fuse the particles to each other to form a block-like material,
Colored fine particles obtained by crushing to an average particle size of the colored spherical fine particles before being substantially fused. 2. The colored fine particles according to claim 1, wherein the colored spherical fine particles are obtained by suspension polymerization of a polymerizable monomer component containing a crosslinking agent in the range of 0.005 to 30% by weight. 3. The colored fine particles according to claim 1, wherein the fusion is performed within a range in which the interface between the particles is not completely lost. 4. The colored fine particles according to claim 1, wherein the block-shaped material has a bulk density of 0.1 to 0.9 g / cm ^{3 in} a fused state. 5. The colored fine particles according to claim 1, wherein the average particle diameter is in the range of 1 to 100 μm. 6. The colored fine particles according to claim 1, wherein the coefficient of variation of particle diameter is 0 to 80%. 7. The average particle size obtained by suspension polymerization is from 1 to
After heat treating 100 μm colored spherical fine particles under the condition of 30 to 200 ° C. to fuse the particles to each other to form a block-like material,
A toner for developing an electrostatic charge image, which comprises colored fine particles obtained by crushing to an average particle size of colored spherical fine particles before being substantially fused. 8. The toner for developing an electrostatic charge image according to claim 7, wherein the colored spherical fine particles are obtained by suspension polymerization of a polymerizable monomer component containing a crosslinking agent in a range of 0.005 to 30% by weight. . 9. The toner for developing an electrostatic charge image according to claim 7, wherein the fusion is performed within a range in which the interface between the particles is not completely lost. 10. A block-shaped material having a bulk density of 0.1 to 0.9 g / cm ^3.
8. The toner for developing an electrostatic charge image according to claim 7, which is in a fused state. 11. The colored fine particles have an average particle diameter of 3.5 to 20 μm.
The toner for developing an electrostatic charge image according to claim 7, which is in the range of. 12. The variation coefficient of the particle size of the colored fine particles is 0 to 80.
% Of the toner for developing an electrostatic charge image according to claim 7.