JPS6273277A - Toner for electrophotography and its production - Google Patents

Abstract

PURPOSE:To efficiently provide electrostatic chargeability to a titled toner by dispersing and dissolving coloring resin particles and radical polymerizable monomer having a charge controllable functional group or a combination of such monomer and other monomers into a reaction medium which dissolves the monomer but does not dissolve the formed polymer thereof, thereby subjecting the same to a radical polymn. CONSTITUTION:This toner for electrophotography is provided with a layer consisting of the polymer of the monomer (A) having the charge controllable functional group or the layer consisting of the copolymer of the monomer (A) and the resin constituting monomer for fixing or the monomer (B) having swellability with the resin for fixing in a chemically or physically bound state on the surface of the core consisting of the compsn. composed of the resin for fixing and the coloring agent dispersed into the resin. The monomer (A) for charge controlling is selectively incorporated only into the surface of the toner particles and therefore, the charge controlling effect and electrostatic chargeability lending effect are effectively obtd. with such toner with the amt. considerably less than the conventional toner. In actuality, the satisfactory chargeability is obtd. simply by using the monomer (A) at 0.1-5wt% per coloring resin.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electrophotographic toner and a method for producing the same. The present invention relates to an electrophotographic toner and a method for manufacturing the same. The present invention also relates to a method for economically producing the electrophotographic toner described above.

(Prior Art and Technical Problems of the Invention) In electrophotography, toner is used for the purpose of visualizing an electrostatic image. This toner must have chargeability such that it has a certain polarity of charge. For this purpose, when manufacturing toner, an organic dye as a charge control agent is kneaded with a coloring agent into a fixing resin, and the mixture is pulverized to manufacture toner particles. It is also known to incorporate a monomer having a polar group having a charge control effect into a fixing resin by copolymerization.

However, in these known means, the charge control agent (charge imparting agent) is uniformly dispersed or distributed in the toner particles, and therefore the majority of the amount exists inside the particles, which does not contribute to charging properties, resulting in poor efficiency. There is a problem.

It is already known that a charge control agent is present on the surface of toner particles, and Japanese Patent Publication No. 36-10231 discloses that a surfactant is adsorbed on the surface of toner particles obtained by suspension polymerization, and imparts charging properties to the However, the electrophotographic properties of this toner tend to deteriorate under high humidity conditions because the humidity dependence of the surfactant directly affects the charging properties of the toner.

(Gist and Object of the Invention) The present inventors have developed a radically polymerizable monomer having colored resin particles and a charge-controlling functional group, or a combination of this monomer and another monomer. Disperse and dissolve in a reaction medium that dissolves the polymer but does not dissolve the resulting polymer.
By performing radical polymerization, it is possible to form a layer of a polymer having a charge control effect on the core surface of the colored resin particles, and this toner has an excellent charge control effect with the use of a significantly smaller amount of charge control monomer. It was also found that it exhibits electrostatic properties.

That is, an object of the present invention is to provide an electrophotographic toner that overcomes the above-mentioned drawbacks of the conventional electrophotographic toner and can be efficiently imparted with chargeability using a small amount of charge control agent, and a method for producing the same. be.

Another object of the present invention is to provide a method capable of selectively forming a layer of a charge-controlling polymer on the surface of toner particles without any particular restriction on the charge-controlling monomer used.

Still another object of the present invention is to provide a method for easily imparting chargeability to any polarity to a colored resin.

(Structure of the Invention) According to the present invention, a polymer of a monomer (A) having a charge control functional group is formed on the surface of a core made of a composition of a fixing resin and a colorant dispersed in the resin. or a layer consisting of a copolymer of the monomer (A) and a monomer constituting the fixing resin, or a monomer (B) having swelling properties with respect to the fixing resin. An electrophotographic toner characterized in that the toner is provided in a physically bonded state is provided.

According to the present invention, particles comprising a fixing resin and a colorant dispersed in the resin, and a radically polymerizable monomer (A) having a charge controllable functional group, or the monomer (A) and The constituent monomers of the fixing resin or the combination with the monomer (B) that has swelling properties for the fixing resin are dispersed in a reaction medium that dissolves the monomers but does not dissolve the produced polymer. , and this polymerization system is polymerized in the presence of a radical initiator to form a layer of a polymer or copolymer of a monomer containing a charge control functional group on the surface of the colored resin particles. A method for producing an electrophotographic toner is provided.

(Characteristics and Effects of the Invention) The present invention provides particles comprising a fixing resin and a colorant dispersed in the resin (hereinafter also referred to as colored resin particles) and a monomer having a charge control functional group. (A) or the monomer (
Dispersing and dissolving a combination of A) and a monomer constituting the fixing resin or a monomer (B) having swelling properties for the fixing resin in a reaction medium to perform radical polymerization; and In this case, an important feature is to use a reaction medium that dissolves the above monomers but does not dissolve the produced polymer.

Generally, polymerization that proceeds in a solution is called solution polymerization, but in this solution polymerization, the produced polymer is dissolved in the solvent, whereas in the method of the present invention, the produced polymer is dissolved in the solvent, that is, the reaction They are distinguished by the fact that they do not dissolve in the medium.

In the above polymerization method, polymerization of monomers is initiated in the solution phase or in the surface layer of the dispersed colored resin particles, and the produced polymer or growing polymer chains are deposited on the surface of the dispersed colored resin particles. In particular, when monomer (A) and monomer (B) coexist, monomer (B) is easily absorbed by the dispersed colored resin particles, so polymerization occurs more smoothly and efficiently on the surface layer of the colored resin particles. will proceed. At this time, the monomer (
A) or chain growth of monomers (A) and (B) may occur. Thus, according to the present invention, the charge control layer made of monomer (A) or a polymer of monomers (A) and (B) is effectively and firmly bonded to the surface of the colored resin core. can be formed. In fact, in the process according to the invention, more than 50%, in particular more than 80%, of the monomers used can be converted into a coating layer bonded to the core surface, with very little formation of polymers free from the core particles. .

As described above, the electrophotographic toner of the present invention has monomer (A) or monomer (
A distinctive feature is that a thin layer of a charge control polymer consisting of a combination of A) and monomer (B) is chemically or physically bonded.

In the toner according to the present invention, since the charge control monomer (A) is selectively incorporated only into the toner particle surface,
Compared to conventional toners, the charge control effect and chargeability imparting effect can be effectively obtained with a significantly smaller amount. In fact, according to the invention, monomer (A) is added to 0.0% per colored resin. Ol
Satisfactory charging properties can be obtained by using only 10 to 10% by weight, particularly 0.1 to 5% by weight, and this fact will become clear with reference to the examples described below.

Moreover, unlike low-molecular compounds such as surfactants and dyes, the layer of charge-controlling polymer has a high molecular weight, so it is firmly bonded to the surface of the colored resin core, which allows it to withstand long-term use. Also, there is no tendency for charging properties to deteriorate at all, and it is not sensitive to humidity, so stable electrophotographic properties can always be obtained.

In addition, in order to incorporate a charge control monomer into a toner using the suspension polymerization method, it is necessary to coexist the charge control monomer in the monomer oil droplets. However, according to the present invention, any charge control monomer can be selectively incorporated into the surface of colored resin particles without being subject to such limitations. In particular, by preparing a certain type of colored resin particles and changing only the type of monomer (A) to be polymerized and deposited on the surface thereof, a toner having charging characteristics of either positive or negative polarity can be obtained. This is also one of the advantages of the present invention.

Further, according to the present invention, the manufacturing cost of the toner can be significantly reduced by unevenly distributing an expensive monomer for charge control only on the surface of the toner particles and incorporating it into the polymer layer.

The charge control monomer (A) can be used alone in the polymerization, or can be used in combination with other monomers. If the charge control monomer (A) has good compatibility (affinity) with the colored resin particles, this monomer (A) can be used alone; If the material is not compatible with the core, a combination of monomers constituting the fixing resin or monomers that have swelling properties with respect to the fixing resin may be used in combination to firmly bond to the surface of the core. A layer of charge control copolymer can be formed.

(Description of preferred embodiments of the invention) Sample The colored resin particles used in the present invention may be produced by any granulation method such as a kneading pulverization granulation method, a spray drying granulation method, or a suspension polymerization method. It's fine.

Suitable examples of the fixing resin include thermoplastic resins having fixing properties and electrodetection properties, including but not limited to resin, vinyl aromatic monomers, acrylic monomers, and vinyl esters. They are homopolymers and copolymers of vinyl ether monomers, diolefin monomers, monoolefin monomers, etc.

As a vinyl aromatic monomer, in the formula, R3 is a hydrogen atom, a lower alkyl group, or a halogen atom, and R2 is a hydrogen atom, a lower alkyl group, a halogen atom, an alkoxy group, a nitro group, or a vinyl group. vinyl aromatic hydrocarbons such as styrene, α-methylstyrene, vinyltoluene, α-chlorostyrene, 0-
Examples of monomers include 1m-1p-chlorostyrene, p-ethylstyrene, and divinylbenzene alone or in combination of two or more, and examples of the other monomers mentioned above include the following.

Formula, R3 CHz = CCo ORa −−−−−−−−−−
(2) In the formula, R3 is a hydrogen atom or a lower alkyl group, R4
is a hydrogen atom, a hydrocarbon group having up to 12 carbon atoms, a hydroxyalkyl group, or a vinyl ester group; acrylic monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate , cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, methyl methacrylate, 2-ethylhexyl methacrylate, ethyl β-hydroxyacrylate, propyl γ-hydroxyacrylate, δ
-Butyl hydroxyacrylate, β-hydroxyethyl methacrylate, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, etc.

Formula, CHI = CH o −c −R5−−−−−−−−−−−−−
--(3) where R2 is a hydrogen atom or a lower alkyl group, vinyl esters such as vinyl formate, vinyl acetate, vinyl propionate, etc.

Formula, CH2=CHO-R6-------1--. −・−1−(4
), where R6 is a monovalent hydrocarbon group having up to 12 carbon atoms, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl-n-7'thyl ether,
Vinyl phenyl ether, vinyl cyclohexyl ether, etc.

Diolefins of the formula, in which each of R'r, Re, and Rq is a hydrogen atom, a lower alkyl group, or a halogen atom, particularly butadiene, isoprene, chlorobrene, and the like.

Formula, IG CH,=C-R,,-------------・--
----(6) In formula (6), each of R1° and R11 is a hydrogen atom or a lower alkyl group, monoolefins, especially ethylene, propylene, isobutylene, butene-1, pentene-1,4-methyl Penten-1 etc.

Suitable resins include styrene resins, acrylic resins, styrene-acrylic copolymer resins, and the like.

As the colorant, various pigments and dyes (hereinafter simply referred to as coloring pigments) for coloring the toner are used.

Suitable examples of colored pigments are:

Black pigment carbon blank, acetylene blank, lamp black, aniline black.

Yellow pigment yellow lead, zinc yellow, cadmium yellow, yellow iron oxide, mineral fast yellow, nickel titanium yellow, navel yellow, naphthol yellow S1 Hansa Yellow G1
Hansa Yellow 10G1 Benzidine Yellow 61 Henjidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake.

Orange pigment red yellow lead, molybdenum orange, permanent orange GTR, pyrazolo orange, palkan orange, indanthrene brilliant orange RK, benzidine orange G1 indanthrene brilliant orange GK.

Red pigments red pigment Red Garla, Cadmium Red, Red Lead, Mercury Cadmium Sulfide, Permanent Red 4R, Lysol Resod, Pyrazolone Red, Watching Red Calcium Salt, Lake Red D1 Brilliant Carmine 6B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B.

Purple pigment Manganese Purple, Fast Violet B, Methyl Violet Lake.

Blue pigments navy blue, cobalt blue, alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partially chlorinated product, first sky blue, indanthremble-BC
.

Green pigment chrome green, chromium oxide, pigment green B1
Malachite Green Lake, Final Yellow Green G0 White pigment zinc white, titanium oxide, antimony white, zinc sulfide.

Extender pigments Palite powder, barium carbonate, clay, silica, white carbon, talc, alumina white.

As a magnetic material pigment, conventionally, for example, triiron tetroxide (Fe+
O*), iron sesquioxide (r7FezOs), zinc iron oxide (ZnFez04), yttrium iron oxide (YJesO
1□), cadmium oxide (CdFezOt), iron gadolinium oxide (GdzFesO+ 2), iron copper oxide (Cu
FezO4), iron oxide complex (PbPe + zo 19)
, neodymium iron oxide (NdFe03), barium iron oxide (BaFe + zo 19), magnesium iron oxide (
MgFezOt), iron manganese oxide (MnFe204)
, lanthanum iron oxide (Lace's), iron powder (Fe), cobalt powder (Co), nickel powder (Nt), etc., but in the present invention, any fine powder of these known magnetic materials can be used. You can use things.

The ratio of colorant to fixing resin can vary quite widely, but generally speaking, the ratio of colorant to fixing resin is 1:1.
A weight ratio of 100 to 20:100, especially 3:100 to 10:100 can be used.

The particle size of the colored resin particles is generally 3 to 30 μm, particularly 5 μm.
The particle size is preferably in the range of 20 μm to 20 μm, and the particle shape may be any shape such as spherical or irregular.

On the other hand, the charge control functional group-containing monomer (A) may be a sulfonic acid, phosphoric acid, or carboxylic acid type anionic group, or a primary, twelfth, or tertiary amino group, or a quaternary ammonium group. Examples include radically polymerizable monomers having an electrolytic group such as a cationic group, and suitable examples thereof are as follows.

Styrene sulfonic acid, sodium styrene sulfonate,
2-acrylamido 2-methylpropanesulfonic acid, 2
-Acid phosphooxypropyl methacrylate, 2-
Acid phosphooxyethyl methacrylate, 3-lysolo 2-acid phosphooxypropyl methacrylate,
Acrylic acid, methacrylic acid, fumaric acid, crotonic acid, tetrahydroterephthalic acid, itaconic acid, aminostyrene, aminoethyl methacrylate, aminopropyl acrylate, diethylaminopropyl acrylate, γ-N
-(N',N''-diethylaminoethyl)aminopropyl methacrylate, trimethylammonium propyl methacrylate.

As the other monomer (B) used in combination with the charge control monomer (A), the monomers constituting the fixing resin, that is, those exemplified above, are used, and the monomers of the same type are used. Even if the fixing resin is not used, one that exhibits swelling properties with respect to the fixing resin is used.

For example, styrenic monomers can also be used for polystyrene.
Alternatively, it is a copolymer that also exhibits swelling properties with respect to acrylic resins, and is therefore particularly suitable for the purpose of the present invention.

In the present invention, additive components that are desirable to be included in the toner can be blended into the polymerization system prior to polymerization. For example, in order to add an anti-offset effect to the toner, a release agent such as low molecular weight polyethylene, low molecular weight polypropylene, various waxes, silicone oil, etc. can be included.

According to the present invention, an organic solvent is used as the reaction medium which dissolves the monomers but does not dissolve the resulting polymer. Furthermore, it is desirable that the organic solvent be easily volatile in order to prevent the adverse effects of residual solvent in the toner.

Although the specific solvent name should be determined depending on the type of monomer and its polymer, generally speaking, suitable organic solvents include alcohols, cellosolves, ketones, or hydrocarbons. Furthermore, these compounds can be used as a mixed solvent with other organic solvents that are compatible with each other, water, etc., but of course the solvent is not limited thereto. As alcohols, lower alcohols such as methanol, ethanol, and propatool are used; as cellosolves, methyl cellosolve and ethyl cellosolve are used; as ketones, acetone, methyl ethyl ketone, and methyl butyl ketone are used; as hydrocarbons, n -hexane, n-hebutane, cyclohexane and the like.

As the polymerization initiator, ab compounds such as azobisisobutyronitrile, cumene hydroperoxide, t-butyl hydroperoxide, dicumyl peroxide, di-t-
Peroxides such as butyl peroxide, benzoyl peroxide, and lauroyl peroxide, which are soluble in the mixture of monomer and medium, are used. In addition, combinations of ionizing radiation such as gamma rays, accelerated electron beams, ultraviolet rays, and various photosensitizers are also used.

According to the present invention, colored resin particles are dispersed in a reaction medium,
The charge control monomer (A) or the combination of monomer (A> and comonomer (B)) is dissolved in a reaction medium to initiate polymerization.

The charged amount of colored resin particles is such that the core particles are 0.1% in the reaction medium.
The monomer (A) may contain from 0.01 to 100% by weight, especially from 1 to 50% by weight.
0% by weight, especially 0.1 to 5% by weight, when monomer (A) and comonomer (B) are combined, (B) is 100% of (A)
It is preferable to have it present in an amount less than twice as much.

The amount of the polymerization initiator such as an azo compound or peroxide may be a so-called appropriate amount of catalyst, and is generally 0.1 to 1 per monomer charged.
Preferably, it is used in an amount of 0% by weight.

The polymerization temperature and time may be those known in the art, and generally polymerization at a temperature of 40 to 100°C for 1 to 50 hours is sufficient. In addition, the reaction system may be stirred at a gentle level so that a homogeneous reaction occurs as a whole.Also, in order to prevent the polymerization from being inhibited by oxygen, the reaction system may be replaced with an inert gas such as nitrogen to carry out the polymerization. It's okay.

The monomer and polymerization initiator may be charged in their entirety, or a portion may be charged and the remaining portion may be supplied later in stages or continuously.

Since the polymerized product after the reaction is obtained in the form of granules having the particle size range described above, the resulting particles are filtered, washed with the above solvent if necessary, and dried to obtain colored particles for toner.

The colored particles for toner are sprinkled with carbon blank hydrophobic silica, etc., if necessary, to form a final toner.

Further, in the production of the toner according to the present invention, a dispersion stabilizer can be used as necessary.

Such dispersion stabilizers include polymers soluble in the medium, such as polyvinyl alcohol, methyl cellulose, ethyl cellulose, polyacrylic acid, polyacrylamide, polyethylene oxide, poly(hydroxystearate-g-methyl methacrylate) 〇-methacrylic acid) copolymer, nonionic or ionic surfactant, etc. are used as appropriate.

The invention is illustrated by the following example.

Example 1 Styrene-n-butyl methacrylate copolymer resin 10
0 parts by weight of carbon black, 7 parts by weight of carbon black, and 1.5 parts by weight of Boliolefinwanx were melt-kneaded, pulverized, and classified to obtain colored resin particles (A) having an average particle diameter of IO μm. next,
3 according to the recipe shown in Table 1 using colored resin particles (A).
(Experiment example No. 1. No. 2. No. 3)
7! into a separable flask and heated under a nitrogen stream for 15 minutes.
While stirring at 0r, p, n+, the reaction was carried out at 65°C for 5 hours to complete the polymerization. When the polymer was observed under an optical microscope, black particles with a uniform particle size of approximately 10 μm were observed, and almost no uncolored fine particles were present. The polymer was separated by filtration and dried under reduced pressure to obtain a toner. As shown in Table 5, the polarity of this toner was negative as shown in the results of measuring the amount of charge by the plow-off method. When this toner was put into a m1taDc 211 copying machine and copied, clear images without capri were obtained.

(The following is a blank space) Example 2 Using the colored resin particles (A>) of Example 1, three were prepared according to the recipe shown in Table 2 (Experimental Example No., 4. No., 5° No.
6) 17! Separable flask and stirred at 65℃ under nitrogen stream at 150r, p, m for 55 minutes.
The reaction was allowed to proceed for a period of time to complete the polymerization. When the polymer was observed under an optical microscope, only black particles with a uniform particle size of about IO μm were observed, and almost no uncolored fine particles were present. The polymer was separated by filtration and dried under reduced pressure to obtain a toner. The polarity of this toner was positive as shown in Table 5, which was the result of measuring the amount of charge by the plow-off method. When this toner was placed in a m1taDc-15 copying machine and copied, clear images without fogging were obtained.

Example 3 96 parts by weight of styrene, 4 parts by weight of divinylbenzene, 5 parts by weight of carbon blank, 1 part by weight of azobisisobutyronitrile
Mix the weight parts well and add partially saponified poval (saponification degree 8).
8%) and 500 parts by volume of distilled water in which 1 part by weight of sodium dodecyl sulfate was dissolved, and 10 parts by volume at 3000 r, p, m using a homomixer (manufactured by Tokushu Kika Kogyo).
After stirring for 1 minute, the mixture was charged into a separable flask No. 11 and stirred at 150 r, p, m under a nitrogen stream for 70 min.
The reaction was carried out at ℃ for 8 hours to complete the polymerization. After the polymer was separated by sedimentation and thoroughly washed, it was dried under reduced pressure and classified to obtain colored resin particles (B) having an average particle diameter of 10 μm. Next, 105 g of colored resin particles (B), 450 m of methanol I
l, distilled water 50ml 11 sodium styrene sulfonate 1
g, styrene 10g, azobisisobutyronitrile 0.
1 g was placed in a 1β separable flask and heated at 150 rpm under nitrogen flow.

The reaction mixture was stirred at 65° C. for 5 hours to complete the polymerization. When the polymerized product was observed under an optical microscope, only black particles with a uniform particle size of about 10 μm were observed, and almost no uncolored fine particles were present. The polymer was separated by filtration and dried under reduced pressure to obtain a toner. The polarity of this toner was negative as shown in Table 5 as a result of determining the amount of charge by the blow-off method. m this toner
When the image was copied using an ita DC-211 copying machine, a clear image without fogging was obtained.

Example 4 105 g of the colored resin particles (B) of Example 3, 450 mff of methanol, and 50 mj of turnip water! , 2 g of quaternized diethylaminoethyl methacrylate, 1 methyl methacrylate, and 0.1 g of azobisisobutyronitrile were placed in a separable flask (No. 11), and heated to 65° C. with stirring at 150 r, p, m under nitrogen flow. The reaction was carried out for 5 hours to complete the polymerization. When the polymer was observed with an optical microscope, it was found that approximately 1
Only black particles with a uniform particle size of 0 μm were observed, and almost no uncolored fine particles were present. The polymer was separated by filtration and dried under reduced pressure to obtain a toner. The polarity of this toner was positive as shown in Table 5 as a result of measuring the amount of charge by the blow-off method. This toner is m1taDC-1
5 When I put it in a copying machine and copied it, I got a clear image with no fog.

R Comparative Example 1 Melt-kneading, pulverizing, and classifying were performed according to the recipe shown in Table 3, and three types (Experimental Example No., 7.
No, 8. Toner No. 9) was obtained. As shown in Table 5, the result of measuring the amount of charge by the blow-off method shows that the polarity of the negative electrode was negative in all cases. m1 of this toner
When the image was copied using taDC-211, a clear image without fogging was obtained with the toner of prescription 3, but there was some fogging with the toner of prescription 1 and 2.

Table 3 Comparative Example 2 Melt-kneading, pulverization, and classification were performed according to the recipe shown in Table 4, and three types (experimental example No., 10.N.
o, 11. Toner No. 12> was obtained. The polarity of this toner was positive as shown in Table 5 as a result of measuring the amount of charge by the blow-off method. m this toner
When the image was copied using a 1taDc-15 copying machine, a clear image without fogging was obtained with the toner of formulation 3, but there was some fogging with the toners of formulation 1 and 2.

Table 4 Comparative Example 3 Methyleneno 96 parts by weight, divinylbenzene 4 parts by weight, 2-
1 part by weight of acid phosphooxyethyl methacrylate,
5 parts by weight of carbon blank and 1 part by weight of azobisisobutyronitrile were mixed well, and mixed with 500 parts by volume of distilled water in which 20 parts by weight of partially saponified POVAL (saponification degree 88%) and 1 part by weight of sodium dodecyl sulfate were dissolved. In addition, using a homo mixer (Tokushu Kika Kogyo Tank), 3000r, p, +n,
After stirring for 10 minutes at
The reaction was carried out at 0"C for 8 hours to complete the polymerization.

The polymer was separated by filtration and thoroughly washed, then dried under reduced pressure and classified to obtain a toner having an average particle size of 10 μm. The polarity of this toner was negative as shown in Table 5, as shown in the results of measuring the amount of charge by the blow-off method, but the amount of charge was smaller than that of the toner of Example 3. Mita this toner
When I put it in a DC-211 copier and copied it, the image had a slight capri.

Comparative Example 4 96 parts by weight of styrene, 4 parts by weight of divinylbenzene, 2 parts by weight of quaternized diethylaminoethyl methacrylate, 5 parts by weight of carbon blank, and 1 part by weight of azobisisobutyronitrile were thoroughly mixed, and partially saponified poval In addition to 500 parts by volume of distilled water in which 20 parts by weight of sodium dodecyl sulfate and 1 part by weight of sodium dodecyl sulfate were dissolved, a homomixer (
1 at 3000 r, p, m using a special mechanical industrial tank)
After stirring for 0 minutes, the mixture was charged into a separable flask and reacted at 70° C. for 8 hours while stirring at 15 Qr, p, m under a nitrogen stream to complete polymerization.

The polymer was separated by filtration and thoroughly washed, then dried under reduced pressure and classified to obtain a toner having an average particle size of 10 μm. The polarity of this toner was positive as shown in Table 5, as shown in the charge amount measurement results by the blow-off method, but the charge amount was smaller than that of the toner of Example 3. Add this toner to m1taDC-15
When I put it in a copy machine and made a copy, the image was slightly foggy.

Table 5

Claims (3)

[Claims] (1) A layer made of a polymer of monomer (A) having a charge control functional group, or a layer made of a polymer of monomer (A) having a charge control functional group, on the surface of a core made of a composition of a fixing resin and a colorant dispersed in the resin. Body (A)
and a fixing resin constituent monomer, or a monomer (B) having swelling properties with respect to the fixing resin, and a layer made of a copolymer thereof is provided in a chemically or physically bonded state. Toner for electrophotography. (2) The monomer (A) is 0.01 to 10 per core.
A toner according to claim 1, wherein the toner is incorporated into the surface layer in an amount of % by weight. (3) Particles consisting of a fixing resin and a colorant dispersed in the resin, and a radically polymerizable monomer (A) having a charge controllable functional group, or the composition of the monomer (A) and the fixing resin monomer, or a monomer that has swelling properties for the fixing resin (
The combination with B) is dispersed and dissolved in a reaction medium that dissolves the monomer but not the resulting polymer, and this polymerization system is polymerized in the presence of a radical polymerization initiator to obtain the coloring. A method for producing an electrophotographic toner, which comprises forming a layer of a polymer or copolymer of a monomer containing a charge-controlling functional group on the surface of resin particles.