JPH05331215A - 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, further readily being granulated, by polymerizing the second monomer in the dispersed particles formed by dispersion polymerization of the first monomer to form particles having many small points. CONSTITUTION:In the polymer particles formed by dispersion polymerization of the first monomer, the second monomer is polymerized to form points on the particle surfaces whereby the objective resin particles having roughened surface. A dispersed polymer particles including pigments also may be employed. As the first monomer, is used styrene, acrylic acid, vinyl acetate and the polymer which is deposited on the surface is different from the first polymer, for example a combination of styrene and methacrylate is preferred. The dispersed polymer particles of 5 to 8mum volume-average particle size are preferred in order to obtain images of high quality.

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 the particles, and the first method by the dispersion polymerization method is used.
In the dispersion-polymerized particles obtained by polymerizing the above-mentioned monomer, a second monomer different from the above-mentioned monomer is polymerized to form protrusions on the surface of the dispersion-polymerized particles.

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, the dispersion-polymerized particles 1 obtained by dispersion-polymerizing the first monomer are dispersed in a solvent 2 that does not dissolve the dispersion-polymerized particles 1 ((1) in FIG. 1), and then the above-mentioned When the second monomer and the polymerization initiator different from the first monomer are added, the second monomer and the polymerization initiator penetrate into the dispersion-polymerized particle 1 to swell the dispersion-polymerized particle 1. When heated in this state, polymerization occurs inside the dispersion-polymerized particles 1 to form a different type of polymer 3 ((2) in FIG. 1). Then, as the heterogeneous polymer 3 grows, the polymer 3 becomes dispersed polymer particles 1
The surface of the resin is pushed up to form the protrusions 4, whereby resin particles 5 having irregularities on the surface are obtained ((3) in FIG. 1).

The projections 4 are formed because the different polymer 3 is not compatible with the dispersed polymer particle 1 when the different polymer 3 is formed inside the dispersed polymer particle 1. A heterogeneous polymer 3 domain (region or mass) inside the
Is formed. The electrophotographic toner of the present invention is formed by polymerizing a first monomer by a dispersion polymerization method, and in a colored particle main body containing a colorant dispersed therein,
It is a spherical monodisperse polymer having irregularities on the surface, characterized in that a protrusion is formed on the surface of the particle body by polymerizing a second monomer different from the first monomer. ..

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 first monomer used for preparing the dispersion-polymerized particles is a vinyl-based unsaturated monomer having a radical-polymerizable property, such as a monovinyl aromatic monomer and an acrylic-based monomer. Monomer, vinyl ester monomer, vinyl ether monomer, diolefin monomer,
Monoolefin-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 as the first monomer in the present invention include styrene, (meth) acrylic acid ester, a combination system of styrene and (meth) acrylic acid ester, and styrene. And a combination system of divinylbenzene and the like.

To prepare dispersion-polymerized particles using these monomers, a first monomer, a dispersion stabilizer and a dispersion stabilizer are added to a solvent which dissolves the first monomer but not the polymer. The first initiator is polymerized by dissolving the polymerizable initiator and heating with stirring. As the solvent, various solvents can be used depending on the kind of the first monomer, for example, water; lower alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; ethylene glycol, propylene glycol, butanediol. , Polyethylene alcohols such as 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 singly or in combination of two or more kinds, and are mixed with the first monomer so that the first monomer is dissolved but the polymer is not dissolved. It is appropriately selected according to the combination of. 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 40:60 to 5:95, and particularly 30:70 to 10: 9.
It is preferably in the range of 0. The amount of the solvent used is preferably in the range of 50 to 5000 parts by weight, particularly 500 to 2500 parts by weight, per 100 parts by weight of the first monomer.

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 the dispersion stabilizer used is 0.1 to 0.1 with respect to the first monomer.
It is in the range of 30% by weight, preferably 1 to 10% by weight.

As the polymerization initiator, those which are insoluble in water and compatible with the first monomer are preferable, for example, azo compounds such as azobisisobutyronitrile; cumene hydroperoxide, t-butylhydro. Peroxides, dicumyl peroxide, di-t-butyl peroxide, benzoyl peroxide, lauroyl peroxide, and other peroxides can be used, and in the case of performing polymerization by irradiation with ultraviolet rays or visible light, conventionally known photopolymerization initiation Agents can also be used.
The amount of the polymerization initiator used is 0.00 with respect to the first monomer.
It is in the range of 1 to 10% by weight, preferably 0.01 to 0.5% by weight. 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 first monomer is polymerized and deposited in the reaction solution as dispersed polymer particles. 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 diameter of 4 to 8 μm, especially 5 to obtain a high-resolution image.
It is preferably ˜8 μm.

On the other hand, the second monomer that is polymerized in the dispersion-polymerized particles to form protrusions is any of the above-mentioned monomers as long as it is different from the first monomer that forms the dispersion-polymerized particles. Momo can be used. The reason for excluding the same kind of monomer as the first monomer is that even if this monomer penetrates into the dispersion-polymerized particles and polymerizes, they do not form domains, and therefore no protrusions are formed. .. Preferable combinations of the first monomer and the second monomer include, for example, combinations of styrene and methacrylic acid ester, styrene and acrylonitrile, styrene and acrylic acid, methyl methacrylate and butyl methacrylate. .. At this time, it is possible to arbitrarily determine which of these combinations is used as the monomer for forming the dispersion-polymerized particles and the monomer for forming the protrusions.

Further, the polymerization of the second monomer for forming the protrusions may be carried out after the dispersion-polymerized particles are polymerized by using the same solvent or in a different solvent. .. The same solvent and polymerization initiator as those described above can be used. Depending on the polymerization conditions, in addition to the polymerization of the second monomer inside the dispersion-polymerized particles, the polymerization of the second monomer also occurs outside the dispersion-polymerized particles, and the generated fine polymer particles are dispersed. May adhere to the surface of polymer 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.

The colorant used in the former method includes
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, especially 10 ^-6 times the weight of the reaction solution 1. It is preferable. 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.

[0037]

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 In a 1-liter separable flask, 200 g of isopropyl alcohol, 40 g of water, 60 g of styrene, 0.5 g of divinylbenzene, and 0.5 g of sodium styrenesulfonate were added.
02 g, styrene-acrylic acid copolymer 2.5 g and azobisisobutyronitrile 2.5 g were charged, and the mixture was stirred at 70 ° C. for 8 hours at 70 ° C. under a nitrogen stream while stirring at a stirring speed of 40 rpm.
Polymerization was carried out for a time. As a result, about 6 μm with uniform particle size
Of monodisperse particles were obtained. A scanning electron micrograph of the particles is shown in FIG. (2) Concavo-convex surface of particles To the emulsion obtained in (1) above, 20 g of 2-ethylhexyl methacrylate and 2.5 g of azobisisobutyronitrile were added, and the mixture was stirred at a stirring speed of 40 rpm at 70 ° C. The reaction was carried out 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 surface of this particle had 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 the above (2) and 1 g of a black disperse dye (Black # 200 manufactured by Mitsui Toatsu Dyes Co., Ltd.) in 100 g of water using 0.2 g of sodium stearate. Was dispersed in the mixture, charged into an autoclave, and dyed at 120 ° C. for 2 hours. After dyeing, filtration and drying were performed to obtain a black toner. In addition,
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 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.

In general, according to this method, the image density is 0.10 to 0.14 when there is no toner on the drum, whereas when 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-mentioned evaluation method, the measured value was 0.13, which was almost the same as the value when no toner remained on the drum. By the way, this developer is
When the Munsell N2.0 original was mounted on the 1205 and copied, the density of the copied image was about 1.2. Comparative Example 1 After cleaning the spherical dispersion-polymerized particles synthesized in (1) of Example 1 without unevenness, the cleaning property was evaluated in the same manner as in Example 1. As a result, the measured value is 1.021,
The toner on the drum was barely cleaned. Comparative Example 2 In the emulsion of the dispersion-polymerized particles obtained in (1) of Example 1,
20 g of styrene and azobisisobutyronitrile 2.
5 g was added and reacted at 70 ° C. for 8 hours while stirring at 40 rpm, then filtered, washed and dried to obtain resin particles. Observation of the particles with a scanning electron microscope revealed that the particle diameter increased from 7 μm to 8 μm, but remained spherical. Example 2 (1) Synthesis of dispersion-polymerized particles Heptane 200 was added to a 1-liter separable flask.
g, methyl methacrylate 60 g, divinylbenzene 0.
5 g, sodium styrenesulfonate 0.02 g, polybutadiene 2.5 g and azobisisobutyronitrile 2.5 g were charged, and polymerization was performed at 70 ° C. for 8 hours while stirring at a stirring speed of 40 rpm under a nitrogen stream. As a result, monodisperse particles having a uniform particle size of about 7 μm were obtained.
A scanning electron micrograph of the particles is shown in FIG. (2) Roughening of particle surface The emulsion obtained in (1) above was further mixed with styrene 2
0 g and azobisisobutyronitrile 2.5 g were added, and the mixture was reacted at 70 ° C. for 8 hours while stirring at 40 rpm. The emulsion is filtered, washed and dried,
Resin particles were obtained. A scanning electron micrograph of the particles is shown in FIG. As shown in the figure, the surface of this particle had 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 The resin particles obtained in (2) above were dyed in the same manner as in Example 1 to obtain a black toner. (4) Evaluation of Cleaning Property The cleaning property of the toner obtained in (3) above was evaluated in the same manner as in Example 1. As a result, the measured value was 0.130, which was almost the same as the value when there was no toner on the drum. On the other hand, when this developer was mounted on the DC-1205 and a document of Munsell N2.0 was copied, the density of the copied image was about 1.2. Examples 3 to 4 As the first monomer and the second monomer,
Instead of the styrene used in (1) and the 2-ethylhexyl methacrylate used in (2) of Example 1, the results are shown in Table 1.
Polymerization was performed in the same manner as in Example 1 except that the first and second monomers shown in 1 were used. The resin particles obtained in each of the examples had unevenness. These 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. Examples 5 to 6 As the first monomer and the second monomer,
Methyl methacrylate used in (1) and (2) of Example 2
Example 2 except that the first and second monomers shown in Table 1 were used instead of the styrene used in
Polymerization was carried out in the same manner as in. The resin particles obtained in each of the examples had unevenness. Hereinafter, Examples 3 and 4
A black toner was obtained by treating in the same manner as above, and its cleaning property was evaluated. The results are also shown in Table 1.

[0040]

[Table 1] Example 7 In (1) of Example 1, isopropyl alcohol 20
0 g, water 40 g, styrene 60 g, divinylbenzene 0.5 g, sodium styrenesulfonate 0.02 g,
In addition to 2.5 g of styrene-acrylic acid copolymer and 2.5 g of azobisisobutyronitrile, an oil-soluble dye (Black FS-Special A, manufactured by Chuo Gosei Kagaku Co., Ltd.) 3
In the same manner as in Example 1 except that g 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 0.11, which was almost the same as the value when there was no toner on the drum. On the other hand, when this developer is loaded on the DC-1205, Munsell N2.0
When the above document was copied, the density of the copied image was about 1.1.

[0042]

INDUSTRIAL APPLICABILITY The resin particles of the present invention are the same as those of the above-mentioned
Since it has a structure in which a protrusion is formed on the surface of dispersion-polymerized particles by polymerizing a second monomer different from the above-mentioned monomer, there is an effect that it can be suitably used as a toner having irregularities 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 view showing a process of forming protrusions in the present invention.

FIG. 2 is a scanning electron micrograph showing the particle structure of dispersion-polymerized particles obtained in Example 1 of the present invention.

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

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 dispersion-polymerized particles obtained in Example 2 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 graph showing the particle size distribution of resin particles having irregularities on the surface obtained in Example 2 of the present invention.

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Claims (3)

[Claims] 1. A dispersion-polymerized particle obtained by polymerizing a first monomer by a dispersion polymerization method, wherein a second polymer different from the first monomer is used.
Resin particles having irregularities on the surface, characterized in that projections are formed on the surface of dispersion-polymerized particles by polymerizing the above monomer. 2. A colored dispersion-polymerized particle formed by polymerizing a first monomer by a dispersion polymerization method and containing a colorant dispersed therein, which is different from the first monomer. A toner for electrophotography, which is a spherical monodisperse polymer having irregularities on the surface, characterized in that projections are formed on the surface of dispersion-polymerized particles by polymerizing a second monomer. 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.