JPH05331216A - Resin particle having roughened surface and electrophotographic toner - Google Patents

Abstract

PURPOSE:To produce resin particles for electrophotographic toner which has narrow particle size distribution and excellent electric charge properties by polymerizing the second monomer in the presence of dispersed particles formed by dispersion polymerization of the first monomer to form particles having many fine particles adhering to their surfaces. CONSTITUTION:In the presence of dispersed polymer particles formed by dispersion polymerization of the first monomer, the second monomer is polymerized to form fine particles on the dispersed particle surfaces whereby the objective resin particles having roughened surface are obtained. A dispersed polymer particles including pigments also may be employed. As a monomer of the dispersed polymer particles, is used styrene, acrylic acid, or vinyl acetate and the polymer which is deposited on the surface is preferably the same as that of the dispersed particles, for example, a combination of styrene and styrene. In order to obtain images of high quality, the dispersed polymer particles are recommended to have 5 to 8mum volume-average particle size.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to resin particles having surface irregularities and a toner for electrophotography.

[0002]

2. Description of the Related Art Conventional electrophotographic toners are generally manufactured by melt-kneading a thermoplastic resin, a colorant and other additives, and then pulverizing and classifying. Since such a pulverized toner has a wide particle size distribution, it is difficult to make the charging uniform, and it is difficult to obtain an image with high resolution because the particle size is large.

Therefore, the inventors of the present invention have previously proposed various methods for producing a toner using a dispersion polymerization method (Japanese Patent Laid-Open No. HEI 3).
-16863 gazette, the same 3-140968 gazette etc.).
In this method, the monomer is polymerized in a water-miscible solvent in which the monomer dissolves but the polymer does not dissolve, in the presence of a dispersion stabilizer and optionally a colorant (oil-soluble dye etc.). Is.

The electrophotographic toner obtained by such a dispersion polymerization method has the characteristics that the particle size distribution is narrow and the particle size can be reduced, and therefore, it is excellent in charging characteristics and can obtain a high quality image. There is.

[0005]

However, since the toner particles for electrophotography obtained by the dispersion polymerization method are almost spherical in shape, they have poor cleaning properties when the residual toner on the photoconductor is cleaned with a blade. There was a problem. Therefore, a main object of the present invention is to provide a resin particle which has improved cleaning property and has a small particle size and a narrow particle size distribution, which can be suitably used for an electrophotographic toner.

Another object of the present invention is to provide an electrophotographic toner using the above resin particles.

[0007]

Means and Actions for Solving the Problems The resin particles of the present invention used for solving the above problems are those in which irregularities are formed on the surface of particles, and dispersion-polymerized particles obtained by a dispersion polymerization method. It is characterized in that the fine polymer particles are adhered to the surface of the dispersion-polymerized particles by polymerizing the monomer in the presence of.

As described above, since the projections are formed on the surface of the dispersed polymer particles and the surface of the particles is made uneven, when the resin particles are used for the toner, compared with the conventional substantially spherical dispersed polymer particles. Cleanability is greatly improved. The process of forming the resin particles of the present invention will be described with reference to FIG. First, dispersion-polymerized particles 1 obtained by dispersion-polymerizing a predetermined monomer are dispersed in a solvent 2 that does not dissolve the dispersion-polymerized particles 1 ((1) in FIG. 1), and then a micropolymer is added thereto. A monomer for forming particles and a polymerization initiator are added, and dispersion polymerization is carried out while stirring with a stirrer 3 ((2) in FIG. 1). As a result, the fine polymer particles 4 started to precipitate in the solvent (see FIG.
(3)), the fine polymer particles 4 adhere to the surface of the dispersion polymer particles 1 with stirring, and resin particles 5 having irregularities on the surface are obtained ((4) in FIG. 1).

In adhering the fine polymer particles to the dispersed polymer particles, it is desirable to stir the reaction solution, and the degree of adhesion of the fine polymer particles can be adjusted by the stirring speed. The electrophotographic toner of the present invention is formed by a dispersion polymerization method, and a monomer is polymerized in the presence of colored dispersion-polymerized particles containing a colorant dispersed therein. It is a spherical monodisperse polymer having irregularities on the surface, characterized in that fine polymer particles are adhered to.

Another electrophotographic toner of the present invention is a spherical monodisperse polymer having irregularities on the surface, characterized in that the resin particles are colored. As described above, the electrophotographic toner of the present invention is a monodisperse type that has excellent cleaning properties and has a small particle size and a narrow particle size distribution, because the particle surface has irregularities formed thereon. Therefore, it is possible to obtain an image with high fluidity, excellent charge stability, and high resolution.

In the present invention, the monomer used for preparing the dispersion-polymerized particles is a vinyl-based unsaturated monomer having a radical-polymerizable property, such as monovinyl aromatic monomer and acrylic monomer. , Vinyl ester-based monomers, vinyl ether-based monomers, diolefin-based monomers, mono-olefin-based monomers, halogenated olefin-based monomers, and polyvinyl-based monomers.

The monovinyl aromatic monomer has the following general formula (1):

[0013]

[Chemical 1] (In the formula, R ¹ is a hydrogen atom, a lower alkyl group or a halogen atom, R ² is a hydrogen atom, a lower alkyl group, a halogen atom, an alkoxy group, an amino group, a nitro group, a vinyl group, a sulfo group, a sodium sulfonate group, A monovinyl aromatic hydrocarbon represented by potassium sulfonate or a carboxyl group, for example, styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene, o, m, p
-Chlorostyrene, p-ethylstyrene, sodium styrenesulfonate, divinylbenzene and the like can be mentioned.

The acrylic monomer has the following general formula
(2):

[0015]

[Chemical 2] (In the formula, R ³ represents a hydrogen atom or a lower alkyl group, R ⁴ represents a hydrogen atom, a hydrocarbon group having up to 12 carbon atoms, a hydroxyalkyl group, a vinyl ester group or an aminoalkyl group.) Monomers such as acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate,
Methyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, β-hydroxy acrylate, γ-hydroxy acrylate, δ-hydroxy acrylate, β-hydroxy methacrylate, γ-amino acrylate, Examples include γ-N, N-diethylamino propyl acrylate, ethylene glycol dimethacrylic acid ester, tetraethylene glycol dimethacrylic acid ester and the like.

The vinyl ester-based monomer is represented by the following general formula (3):

[0017]

[Chemical 3] (In the formula, R ⁵ represents a hydrogen atom or a lower alkyl group.)
Examples thereof include vinyl formate, vinyl acetate, vinyl propionate and the like. The vinyl ether-based monomer has the following general formula (4):

[0018]

[Chemical 4] (In the formula, R ⁶ represents a monovalent hydrocarbon group having up to 12 carbon atoms).
For example, vinyl methyl ether, vinyl ethyl ether,
Examples thereof include vinyl-n-butyl ether, vinyl phenyl ether and vinyl cyclohexyl ether.

The diolefin-based monomer is represented by the following general formula (5):

[0020]

[Chemical 5] (In the formula, R ⁷ , R ⁸ and R ⁹ are the same or different,
It represents a hydrogen atom, a lower alkyl group or a halogen atom. The diolefin-based monomer represented by) is exemplified, and examples thereof include butadiene, isoprene, and chloroprene.

As the mono-olefin type monomer, the following general formula (6):

[0022]

[Chemical 6] (In the formula, R ¹⁰ and R ¹¹ are the same or different and each represents a hydrogen atom or a lower alkyl group.) A monoolefin monomer represented by, for example, ethylene, propylene,
Butene-1, pentene-1, 4-methylpentene-1 and the like can be mentioned.

As the halogenated olefin-based monomer,
Examples thereof include vinyl chloride and vinylidene chloride, and examples of polyvinyl monomers include divinylbenzene and
Examples include diallyl phthalate and tricyanurate. Each of the above monomers can be used alone or in combination of two or more. Among the above-mentioned monomers, the monomers preferably used in the present invention include styrene, (meth) acrylic acid ester, styrene and (meth)
Examples include a combination system with an acrylic ester and a combination system with styrene and divinylbenzene.

To prepare dispersion-polymerized particles using these monomers, the monomer, dispersion stabilizer and polymerizable initiator are dissolved in a solvent in which the monomer dissolves but the polymer does not dissolve. Then, the monomer is polymerized by heating under stirring.
As the solvent, various solvents can be used depending on the kind of the monomer used, for example, water; methyl alcohol,
Lower alcohols such as ethyl alcohol and isopropyl alcohol; polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, diethylene glycol and triethylene glycol; cellosolves such as methyl cellosolve and ethyl cellosolve; ketones such as acetone and methyl ethyl ketone; Ethers such as tetrahydrofuran; esters such as ethyl acetate.

These solvents may be used alone or in combination of two or more, and are appropriately selected depending on the combination with the monomer so that the monomer dissolves but the polymer does not dissolve. To be selected. Solvents preferably used in the present invention include lower alcohols such as ethanol, water or a mixed solvent of water and lower alcohol. In the above mixed solvent, the weight ratio of water to lower alcohol is 40: 6.
It is preferably in the range of 0 to 5:95, particularly 30:70 to 10:90. The amount of the above solvent used is 10
50-5000 parts by weight per 0 parts by weight, especially 500-2
It is preferably in the range of 500 parts by weight.

Examples of the dispersion stabilizer for stabilizing the dispersibility of the polymer in the solvent include polyacrylic acid, polyacrylic acid salt, polymethacrylic acid, polymethacrylic acid salt, (meth) acrylic acid- (meth) acrylic. Acid ester copolymer, acrylic acid-vinyl ether copolymer, methacrylic acid-styrene copolymer, carboxymethyl cellulose,
Examples thereof include poly (hydroxystearic acid-g-methyl methacrylate-co-methacrylic acid) copolymer, poly (ethylene oxide), polyacrylamide, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol and the like. Further, nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants and the like can also be used. The amount of such dispersion stabilizer used is in the range of 0.1 to 30% by weight, preferably 1 to 10% by weight, based on the monomers.

As the polymerization initiator, those which are insoluble in water and compatible with the monomer are preferable. For example, azo compounds such as azobisisobutyronitrile; cumene hydroperoxide, t-butyl hydroperoxide, dioctane, etc. In addition to peroxides such as mill peroxide, di-t-butyl peroxide, benzoyl peroxide, lauroyl peroxide, etc.,
When the polymerization is carried out by irradiation with ultraviolet rays or visible rays, conventionally known photopolymerization initiators can be used. The amount of the polymerization initiator used is in the range of 0.001 to 10% by weight, preferably 0.01 to 0.5% by weight, based on the monomers.
It is also possible to initiate the polymerization using γ-rays, accelerated electron beams, etc. In this case, it is not necessary to use a polymerization initiator. Further, the polymerization may be initiated by combining ultraviolet rays and various photosensitizers.

If necessary, in addition to the above components, a charge control agent, an offset preventive agent (release agent), etc. may be added. The charge control agent is compounded when the toner is used in a two-component developer, and is an oil-soluble dye such as nigrosine base (CI5045), oil black (CI26150) and spirone black; metal salt of naphthenic acid, fat Metal soap, resin acid soap, etc. are illustrated.

Examples of the anti-offset agent include low molecular weight polyethylene, low molecular weight polypropylene, various waxes, and silicone oil. When the reaction liquid containing each of the above components is polymerized at a temperature of -30 to 90 ° C, particularly 30 to 80 ° C with stirring for 0.1 to 50 hours,
The monomer polymerizes and precipitates as dispersed polymer particles in the reaction solution. At this time, it is preferable to replace the inside of the reaction system with an inert gas in order to suppress the termination reaction of the polymerization due to oxygen.
The dispersion-polymerized particles thus obtained have a volume average particle size of 4 to 8 μm, particularly 5 to 8 μm in order to obtain a high-resolution image.
It is preferably m.

On the other hand, as the monomer forming the fine polymer particles adhered to the surface of the dispersion-polymerized particles, the same or different monomer as the monomer forming the dispersion-polymerized particles can be used. In selecting the monomer forming the dispersion-polymerized particles and the monomer forming the fine polymer particles, it is preferable to combine particles of the same kind, such as styrene and styrene, to combine both particles in the same medium. It is preferable in that it can be generated and firmly adheres to the surface of the dispersed polymer particles of the fine polymer particles, but a combination of different kinds,
For example, even with a combination of styrene and methacrylic acid ester, acrylonitrile and acrylic acid ester, diallyl phthalate and vinyl acetate, methacrylic acid and vinyl chloride, the fine polymer particles can be firmly adhered to the dispersion-polymerized particles. In the case of a combination of different types, it can be arbitrarily determined which is used as the monomer for forming the dispersion-polymerized particles and which is the monomer for the fine polymer particles.

The amount of the fine polymer particles attached can be adjusted by the charged amount of the monomer and the stirring speed during the polymerization. In particular, if the stirring speed is increased, the amount of adhesion tends to increase. The polymerization of the monomer forming the fine polymer particles is preferably carried out by dispersion polymerization in order to obtain small particle size particles having a uniform particle size. In such dispersion polymerization, after the polymerization of the dispersion-polymerized particles, the dispersion polymerization may be continuously carried out using the same solvent, or may be carried out in another solvent. The same solvent and polymerization initiator as those described above can be used. The particle size of the fine polymer particles may be about 1: 3 to 1: 500, preferably about 1:10 to 1: 100 with respect to the particle size (average particle size) of the dispersed polymer particles. Specifically, the volume average particle diameter may be 0.02 to 3 μm, preferably 0.1 to 1 μm.

Further, in order to obtain the fine polymer particles, it is preferable to use the dispersion polymerization method from the viewpoint of productivity and adhesion strength of the fine polymerization particles, but instead of the dispersion polymerization method, the suspension polymerization method, It is also possible to adopt an emulsion polymerization method or the like. In addition,
When the fine polymer particles are formed by using different kinds of monomers for the dispersed polymer particles, the fine polymer particles are attached to the surface of the dispersed polymer particles, and the monomer is present inside the dispersed polymer particles. Polymerization may occur inside the dispersion-polymerized particles to form domains (regions or lumps) to form protrusions on the surface of the dispersion-polymerized particles. Even in this case, the functions of the resin particles and the toner of the present invention are not hindered at all, and conversely, since more unevenness is formed on the surface, more preferable results can be obtained by improving the cleaning property of the toner. it can.

The resin particles having irregularities on the surface of the present invention are
It can be used as it is as a filler for paints, cosmetics, etc., a spacer for liquid crystals, etc., and can also be suitably used as an electrophotographic toner by coloring itself. To color the resin particles, a colorant such as a dye is dissolved or dispersed in the reaction liquid for producing the dispersion-polymerized particles, and the dye is incorporated into the resin particles along with the polymerization of the monomer. There are a method of coloring and a method of coloring the resin particles after polymerization.

As the colorant used in the former method,
Dyes that dissolve better in the monomer than in the solvent, especially oil-soluble dyes, are preferably used. The oil-soluble dye mainly transfers to the polymer rather than to the solvent when the amount of the monomer decreases due to the progress of polymerization, so that efficient dyeing can be performed.
Specific examples of oil-soluble dyes are shown below. Black dye Black FS-Special A, Black S, Black #
103, black # 107, black # 215, black # 141 (all are trade names of Chuo Gosei Kagaku KK), OPLAS black HZ, oplas black # 83
6, Oplas Black # 838 (all are trade names manufactured by Orient Chemical Industry Co., Ltd.). Red dye Macrolex (MACROLEX) Red 5B, Macrolex Red Violet R (all are trade names manufactured by Bayer), Sumiplast (AS), Sumiplast Red B-2, Samiplast Red HLG-Z
(All are trade names manufactured by Sumitomo Chemical Co., Ltd.), Oprah Red RR, Oprah Red # 330 (all are trade names manufactured by Orient Chemical Co., Ltd.), Red 6B, Red TR-71
(All are trade names of Chuo Gosei Kagaku). Orange dye Macrolex Orange 3G, Macrolex Orange R (all are trade names manufactured by Bayer), Orange S, orange R, orange # 826N (all are trade names manufactured by Chuo Gosei Kagaku), Oplus Orange PS, Oh Plus Orange RR (both are trade names manufactured by Orient Chemical Industry Co., Ltd.) and Samiplast Orange HRP (trade name manufactured by Sumitomo Chemical Co., Ltd.). Yellow dye Macrolex Yellow 6G, Macrolex Yellow R (all are trade names manufactured by Bayer), Yellow D, Yellow GE, Yellow # 189 (all are trade names manufactured by Chuo Synthetic Chemicals), Samiplast Yellow GC, Sami Plast Yellow R (all are trade names manufactured by Sumitomo Chemical Co., Ltd.), Oplus Yellow 3G, Oplus Yellow # 130 (all are trade names manufactured by Orient Chemical Industry Co., Ltd.). Purple dye Macrolex Violet 3R, Macrolex Violet B (both are trade names manufactured by Bayer), Violet MVB (trade name manufactured by Chuo Gosei Kagaku), Samiplast Violet RR, Samiplast Violet B (all Sumitomo Chemical Co., Ltd. Trade names manufactured by the company), Oplas Violet # 370, and Oplas Violet # 732 (all are trade names manufactured by Orient Chemical Industry Co., Ltd.). Blue dye Macrolex Blue RR (Bayer brand name),
Blue BO, Blue # 8B (all are trade names manufactured by Chuo Gosei Kagaku), Samiplast Blue OR, Samiplast Blue GP, Samiplast Blue S (all are trade names manufactured by Sumitomo Chemical Co., Ltd.), Oplus Blue IIN , Oplas Blue # 630 (all are trade names manufactured by Orient Chemical Industry Co., Ltd.). Green dye Macrolex Green 5B, Macrolex Green G (all are trade names manufactured by Bayer), Green # 55
0, Green # 201 (all are trade names of Chuo Gosei Kagaku), Samiplast Green G (trade name of Sumitomo Chemical Co., Ltd.), Oplus Green # 502, Oplus Green # 503 (all are Orient Chemical Co., Ltd. Company product name). Brown Dyes Brown PB, Brown SG (all are trade names manufactured by Chuo Gosei Kagaku KK), Oplus Brown # 430, Oplus Brown # 431 (all trade names manufactured by Orient Chemical Industry).

The amount of the oil-soluble dye used varies depending on the desired degree of color density, but is usually 1 to 10 ^-9 times, particularly 10 ^-6 times the weight of the reaction solution 1. Preferably. On the other hand, the latter method of coloring the resin particles with a dye is carried out, for example, by dispersing the resin particles together with a dye such as a dispersible dye in an aqueous medium and stirring at a predetermined temperature for a predetermined time.

The temperature at the time of dyeing is not particularly limited, but it is preferably within the range of the glass transition temperature of the polymer constituting the resin particles or the glass transition temperature + 40 ° C. If the temperature is lower than the glass transition temperature of the polymer constituting the resin particles, it may not be dyeable to a desired coloring density, or it may take a long time to dye the glass transition temperature +4.
If the temperature is higher than 0 ° C, the resin particles may be fused to form a lump.

Examples of dispersible dyes used for dyeing include azo dyes, anthraquinone dyes, indigoid dyes, sulfur dyes and phthalocyanine dyes. The dispersible dye preferably has a high affinity for the polymer forming the resin particles and can dye the resin particles firmly. The amount of the dispersible dye used varies depending on the degree of the desired coloring density, but usually, for resin particles,
It is preferably at least 2% by weight, particularly preferably at least 4% by weight. Water is usually used as the aqueous medium, but when the dispersibility of the resin particles and the dye is poor, a small amount of a suitable organic solvent may be added. The amount of the aqueous medium used is preferably 500 parts by weight or more based on 100 parts by weight of the resin particles.

[0038]

EXAMPLES Next, the resin particles and the electrophotographic toner of the present invention will be described in more detail with reference to examples. Example 1 (1) Synthesis of dispersion-polymerized particles Ethanol 140 in a 1-liter separable flask.
g, methyl cellosolve 172 g, styrene 44 g, butyl methacrylate 20 g, polyvinylpyrrolidone 5 g, divinylbenzene 0.5 g, sodium styrenesulfonate 0.02 g and benzoyl peroxide 3 g were charged, and the mixture was stirred under a nitrogen stream at a stirring speed of 60 rpm. The polymerization was started at 65 ° C, and after 2 hours, the temperature was raised to 75 ° C to complete the polymerization, followed by filtration, washing and drying. as a result,
As a result, monodisperse particles having a uniform particle size of about 8.9 μm were obtained. (2) Roughening of the surface of dispersion-polymerized particles 10 g of the particles obtained in the above (1), 187 g of ethanol, 192 g of methyl cellosolve, 5 g of styrene, 5 g of polyvinylpyrrolidone and 3 g of benzoyl peroxide were charged in a separable flask of 1 liter, and a nitrogen stream was introduced. The mixture was reacted at 70 ° C. for 8 hours while stirring at a stirring speed of 250 rpm. The obtained emulsion was filtered, washed and dried to obtain resin particles. Scanning electron micrographs of the particles are shown in FIG. 2 (magnification: 2000 times) and FIG. 3 (magnification: 2 times).
50 times). As shown in these figures, the fine polymer particles adhered to the surface of the particles to form irregularities. The particle size distribution of the resin particles was measured with a Coulter counter. The measurement result is shown in FIG. (3) Coloring of resin particles 10 g of the resin particles obtained in (2) above and a black disperse dye (Disper
1 g of se Diazo Black B) was dispersed in 100 g of water using 0.2 g of sodium stearate, charged in an autoclave, and dyed at 120 ° C. for 2 hours. After dyeing, filtration and drying were performed to obtain a black toner. No change was observed in the unevenness of the particle surface after dyeing. (4) Evaluation of Cleaning Property The cleaning property of the black toner obtained in (3) above was evaluated by the following method.

(Evaluation method) Electrophotographic copying machine DC-120
5 (manufactured by Mita Industry Co., Ltd.) was used as an evaluation machine. A4
When a 30 mm strip of Munsell N2.0 is attached to a blank sheet of a plate as shown in FIG. 5 to make an original, and copying is performed without paper, the toner is developed in a strip shape in the center of the photosensitive drum in the longitudinal direction. When the power switch of DC-1205 is turned off before the cleaning process is completed and the photoconductor drum is taken out, when the cleaning is completed, there is no toner in the part where the cleaning process is completed. If the toner is not completely cleaned, the toner remains on the developed portion. Cellophane adhesive tape was sufficiently attached to the remaining portion, peeled off, the tape was attached to the paper as it was, and the image density (ID) was measured using an image densitometer.

Generally, according to this method, the image density is 0.10 to 0.14 when there is no toner on the drum, whereas when the toner remains, it depends on the toner amount. It is 0.2 to 1.4. (Evaluation Results) The black toner obtained in (3) above was mixed with a ferrite carrier so that the toner concentration was 3% by weight to prepare a developer. When the cleaning property of this developer was evaluated according to the above-described evaluation method, the measured value was 0.124, which was almost the same as the value when no toner remained on the drum. By the way, this developer was added to the DC
When the Munsell N2.0 original was mounted on a -1205 and copied, the density of the copied image was about 1.3. Comparative Example 1 After the dispersion-polymerized particles synthesized in (1) of Example 1 were dyed without unevenness, the cleaning property was evaluated in the same manner as in Example 1. As a result, the measured value was 1.01, and the developed toner was hardly cleaned. Also,
A scanning electron micrograph of the particles is shown in FIG. As shown in the figure, it is considered that high cleaning properties could not be obtained because the particles remained spherical and were not roughened. Comparative Example 2 5 g of the same dispersed polymer particles as obtained in (1) of Example 1, 200 g of isopropyl alcohol, 2.5 g of methacrylic acid (a monomer whose polymer is not soluble in isopropyl alcohol),
2.5 g of styrene-acrylic acid copolymer and 2.5 g of benzoyl peroxide were charged into a 1-liter separable flask and reacted at 70 ° C. for 8 hours while stirring at a stirring speed of 250 rpm under a nitrogen stream. When the obtained particles were observed with a scanning electron microscope, they remained spherical. Example 2 (1) Synthesis of dispersion-polymerized particles In a 1-liter separable flask, 240 g of isopropyl alcohol, 60 g of styrene, 2.5 g of styrene-acrylic acid copolymer, 0.02 g of sodium styrenesulfonate and 2,2'- 3 g of azobisisobutyronitrile was charged, and the mixture was reacted at 70 ° C. for 8 hours while stirring at a stirring rate of 40 rpm under a nitrogen stream, filtered, washed, and dried. As a result, about 10.6 μm monodisperse particles having a uniform particle size were obtained. (2) Uneven surface of dispersion-polymerized particles 5 g of the particles obtained in the above (1), isopropyl alcohol 20
0 g, 2.5 g of 2-ethylhexyl methacrylate, 2.5 g of styrene-acrylic acid copolymer and 2.5 g of benzoyl peroxide were charged in a 1 liter separable flask and stirred under a nitrogen stream at a stirring speed of 250 rpm, The reaction was carried out at 70 ° C for 8 hours. The emulsion was filtered, washed and dried to obtain resin particles. A scanning electron micrograph of the particles is shown in FIG. As shown in the figure, the fine polymer particles adhered to the surface of the particles to form irregularities. (3) Coloring of resin particles Dyeing was carried out in the same manner as in (3) of Example 1 to obtain a black toner. (4) Evaluation of Cleaning Property The cleaning property was evaluated in the same manner as in Example 1. As a result, the measured value was 0.135, and the cleaning property was good. As shown in FIG. 7, it can be seen that the toner obtained in Example 2 has sufficient cleaning property even though the amount of the fine polymer particles attached is smaller than that in Example 1. Example 3 (1) Synthesis of dispersion-polymerized particles Dispersion-polymerized particles were obtained in the same manner as in Example 1. (2) Concavo-convex surface of dispersion-polymerized particles The concavo-convex surface was formed in the same manner as in Example 1 except that the stirring speed was 100 rpm. The scanning electron micrograph is shown in FIG. (3) Coloring of resin particles Dyeing was carried out in the same manner as in (3) of Example 1 to obtain a black toner. (4) Evaluation of Cleaning Property The cleaning property was evaluated in the same manner as in Example 1. As a result, the measured value was 0.130, and the cleaning property was good. As shown in FIG. 8, it can be seen that the toner obtained in Example 3 had sufficient cleaning property even though the amount of the fine polymer particles attached was smaller than that in Example 1. Examples 4 to 5 As a monomer for dispersed polymer particles and a monomer for fine polymer particles, used in styrene and butyl methacrylate used in (1) of Example 1 and (2) of Example 1. Polymerization was carried out in the same manner as in Example 1 except that the monomers shown in Table 1 were used instead of the styrene. The resin particles obtained in each of the examples had unevenness. The resin particles were dyed in the same manner as in Example 1 to obtain a black toner. Then, the cleaning property of each black toner was evaluated in the same manner as in Example 1. The results are also shown in Table 1. Example 6 (1) Synthesis of dispersion-polymerized particles Octane (200 g) in a 1-liter separable flask,
Methyl methacrylate 60g, divinylbenzene 0.5
g, sodium styrenesulfonate 0.02 g, polybutadiene 2.5 g and benzoyl peroxide 3.0 g were charged and polymerized at a stirring speed of 40 rpm and 70 ° C. for 8 hours to produce particles having a uniform particle diameter of about 8 μm. Was there. (2) Concavo-convex surface of dispersed polymer particles To the emulsion obtained in (1) above, 20 g of methyl methacrylate was added, and the stirring speed was 250 rpm at 10 ° C.
And reacted for 8 hours. When the particles were observed with a scanning electron microscope, irregularities were found on the surface of the particles. (3) Coloring of resin particles Dyeing was carried out in the same manner as in (3) of Example 1 to obtain a black toner. (4) Evaluation of Cleaning Property Evaluation was carried out in the same manner as in Example 1. The results are shown in Table 1. Examples 7 to 8 Black toners were obtained in the same manner as in Example 6 except that the monomers shown in Table 1 were used as the monomers for the dispersed polymerized particles and the monomers for the fine polymerized particles. . Table 1 also shows the cleaning properties of each black toner and the density of the copied image.

[0041]

[Table 1] Example 9 In (1) of Example 1, 172 g of methyl cellosolve,
In addition to 44 g of styrene, 20 g of butyl methacrylate, 5 g of polyvinylpyrrolidone, 0.5 g of divinylbenzene, 0.02 g of sodium styrenesulfonate and 3 g of benzoyl peroxide, an oil-soluble dye (Black FS-Special manufactured by Chuo Gosei Kagaku Co., Ltd.) In the same manner as in Example 1 except that 5 g of A) was added, dispersion-polymerized particles dyed in black (particle size 7 μm) were obtained.

Then, in the same manner as in Example 1, the particles were roughened to obtain a black toner. With respect to this black toner, the cleaning property was evaluated in the same manner as in Example 1.
As a result, the measured value was 0.120, which was almost the same as the value when there was no toner on the drum. On the other hand, this developer is mounted on the DC-1205 and Munsell N2.
When the 0 original was copied, the density of the copied image was about 1.1.

[0043]

INDUSTRIAL APPLICABILITY The resin particles of the present invention are obtained by polymerizing a monomer in the presence of dispersion-polymerized particles obtained by a dispersion polymerization method to attach fine polymer particles to the surface of the dispersion-polymerized particles. Therefore, there is an effect that it can be suitably used as a toner having unevenness on the surface. The resin particles of the present invention can also be used as a filler for paints, cosmetics and the like.

Since the electrophotographic toner of the present invention obtained by coloring the above resin particles has irregularities on the surface,
As compared with the conventional dispersion-polymerized toner having a substantially spherical shape, the cleaning property by the blade is improved.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a concavo-convex forming process in the present invention.

FIG. 2 is a scanning electron micrograph (magnification: showing the particle structure of resin particles having irregularities on the surface obtained in Example 1 of the present invention.
2000 times).

FIG. 3 is a scanning electron micrograph (magnification: showing the particle structure of resin particles having irregularities on the surface obtained in Example 1 of the present invention.
250 times).

FIG. 4 is a graph showing the particle size distribution of resin particles having irregularities on the surface obtained in Example 1 of the present invention.

FIG. 5 is a diagram for evaluating cleaning properties in Examples.
It is a top view which shows the original which stuck the strip of 30 mm Munsell N2.0 on the white paper of A4 size.

FIG. 6 is a scanning electron micrograph showing the particle structure of resin particles obtained in Comparative Example 1 of the present invention.

FIG. 7 is a scanning electron micrograph showing the particle structure of resin particles having irregularities on the surface obtained in Example 2 of the present invention.

FIG. 8 is a scanning electron micrograph showing the particle structure of resin particles having irregularities on the surface obtained in Example 3 of the present invention.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical display location G03G 9/09 9/087 (72) Inventor Masami Tsujihiro 1-2 chome, Chuo-ku, Osaka-shi, Osaka No. 28 Mita Industry Co., Ltd.

Claims (3)

[Claims] 1. A method of polymerizing a monomer in the presence of dispersion-polymerized particles obtained by a dispersion polymerization method, whereby fine polymer particles are attached to the surface of the dispersion-polymerized particles.
Resin particles having irregularities on the surface. 2. A fine polymer formed on the surface of the colored dispersed polymer particles by polymerizing a monomer in the presence of the colored dispersed polymer particles formed by a dispersion polymerization method and containing a colorant dispersed therein. Characterized in that particles are attached,
An electrophotographic toner which is a spherical monodisperse polymer having irregularities on the surface. 3. A toner for electrophotography, which is obtained by coloring the resin particles according to claim 1 and is a spherical monodisperse polymer having irregularities on the surface.