JPH03220561A - Toner for electrophotography and production thereof - Google Patents

Abstract

PURPOSE:To improve the environmental stability of electrification of a toner, to form a sharp electrostatic charge distribution and to prevent the deterioration of the electrostatic chargeability of the toner due to mechanical force by sticking a polymer contg. a specified F-contg. vinyl monomer as a monomeric component to the surfaces of the toner particles having a substance capable of forming a radical on the surfaces. CONSTITUTION:A polymer contg. an F-contg. vinyl monomer represented by formula I as a monomeric component is stuck to the surfaces of toner particles having a substance capable of forming a radical on the surfaces. In the formula I, X is H or F, Y is a group represented by formula II, R1 is H or 1-3C alkyl and (n) is 0 or an integer of 1-7. The environmental stability of electrification of the toner is improved, a sharp electrostatic charge distribution is formed and the deterioration of the electrostatic chargeability of the toner due to mechanical force is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a toner for developing an electrostatic latent image in electrophotography and electrostatic printing, and a method for producing the same.

(Prior Art) Various toners have been known in which a fluorine-containing compound is present on the surface of toner particles in order to improve development characteristics.

For example, JP-A-58-66950 discloses a capsule toner in which an organic fluorine compound is present on the capsule surface, and JP-A-59-181358 discloses a capsule toner in which a fluororesin is present on the capsule surface. A toner is disclosed, and JP-A-126657 discloses a capsule toner prepared using a fluorine atom-containing compound as one of the interfacially polymerizable monomers forming the outer shell material,
JP-A-61-120160 discloses an invention in which an alcohol having a fluorine atom is reacted with a carboxyl group or an isocyanate group present in the outer shell to impart chargeability. No. 177145, 13
No. 3-177147 and No. 63-177148 use those having a fluorine atom as a charge control group,
A capsule toner in which polymer chains are formed on the surface of the outer shell through graft polymerization is disclosed.

(Problems to be Solved by the Invention) However, none of the above-mentioned toners that have been proposed in the past has been fully satisfactory. That is,
The organic fluorine compound disclosed in Japanese Patent Application Laid-Open No. 58-66950 has a hydrophilic group in addition to a hydrophobic group containing a fluorine atom in one molecule. In particular, it has the disadvantage of poor humidity dependence, and the fluororesin disclosed in JP-A-59-181358 is a polymer in which the hydrogen atoms of hydrocarbons are replaced with fluorine atoms. Since it is a copolymer, it has poor adhesion to the outer shell of the capsule and is easily peeled off.The capsule toner disclosed in JP-A-60-126657 has the disadvantage that it has poor adhesion to the outer shell of the capsule and is easily peeled off. It is difficult to achieve both good physical properties and toner chargeability using the same outer shell material, and the disadvantage is that the degree of freedom in material selection is narrow.

Furthermore, in the case of forming the outer shell by interfacial polymerization, the outer shell disclosed in JP-A No. 61-120111tO is because carboxyl groups and isocyanate groups are both functional groups involved in interfacial polymerization. It is difficult to make these functional groups exist on the surface, and the reaction between these functional groups and alcohol does not proceed sufficiently in an aqueous solution, making it necessary to use an organic solvent. Therefore, it has the drawback of requiring high costs, such as installing a solvent recovery device and making the devices explosion-proof. Furthermore, JP-A-63-177145, JP-A No. 63-177145
What is disclosed in No. 3-177147 and No. 83-177148 only specifically exemplifies vinyl fluoride as a monomer as a monomer containing a fluorine atom. , vinyl fluoride has the disadvantage that it is a gas at room temperature and requires special reaction equipment in order to be grafted onto the capsule surface.

Furthermore, attempts have been made to maintain the charging stability of toner using metal complex salts, etc., but it is difficult to control the dispersion of metal complex salts in toner, and metal complex salts are generally colored, so color It had many drawbacks, such as not being able to be used for toner.

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner that overcomes the drawbacks of the conventional techniques as described above.

That is, the objects of the present invention are to have good environmental stability for charging, to have a sharp charge distribution so that the charging property is not impaired by mechanical force, to have a wide degree of freedom in material selection, and to be suitable for special reactions. An object of the present invention is to provide a toner that can be produced without requiring any equipment.

(Means for Solving the Problems) The electrophotographic toner of the present invention has a fluorine-containing vinyl monomer represented by the following general formula (1) on the surface of toner particles having at least a radical-generating substance on the surface. (wherein, X represents a hydrogen atom or a fluorine atom, and represents 0 0; 3, and n represents an integer of 0 or 1 to 7.) Next, the present invention will be described in detail.

In the present invention, a "substance capable of generating radicals" refers to a substance that generates radicals by an abstraction reaction or an addition reaction of hydrogen atoms with monomer radicals or cerium (IV) ions. , polyamide, polyurea, polyurethane, polyester, polyvinyl acetate, polyvinyl alcohol, cellulose, synthetic rubber, styrene/(meth)acrylic copolymer, epoxy resin, phenoxy resin, acrylic resin, and mixtures thereof. .

In the electrophotographic toner of the present invention, the toner particles having at least the surface of a substance capable of generating radicals may be particles formed of the above-mentioned substance alone, or particles formed by the above-mentioned substance coating a core substance. The toner particles may have a so-called capsule structure in which an outer shell is formed.

When toner particles are composed of the above substances alone,
A coloring agent can be contained in the particles. Colorants include inorganic pigments such as carbon black, red iron, navy blue, titanium oxide, fast yellow, disazo yellow,
Azo dyes such as pyrazolone red, chelate red, brilliant carmine, rose brown, copper phthalocyanine,
Examples include phthalocyanine pigments such as metal-free phthalocyanine, and condensed polycyclic pigments such as flavanthrone yellow, dibromoanthrone orange, perylene red, quinacridone red, and dioxazine violet. Further, disperse dyes, oil-soluble dyes, etc. can also be used. Furthermore, as a magnetic one-component toner, all or part of the black colorant can be replaced with magnetic powder. As the magnetic powder, magnetite, ferrite, or a single metal such as cobalt, iron, or nickel, or an alloy thereof can be used.

When the toner particles have a capsule structure, the resin constituting the outer shell may include polyurea resin, polyurethane resin,
Polyamide resins, polyester resins, epoxy resins, epoxyurea resins, or epoxyurethane resins are preferred, and among these, polyurea resins or polyurethane resins alone or in combination, or epoxyurea resins or epoxyurethane resins alone or in combination. A combination of both is more preferable.

It is preferable to change the thickness of the outer shell between a capsule toner intended for pressure fixing and a capsule toner intended for heat fixing. i. The type or composition ratio of bokubun may be changed.

As the core material of capsule toner particles, if the purpose is pressure fixing, a core material mainly consisting of a component having pressure fixing properties is used, and if the purpose is heat fixing, a core material containing a component having heat fixing properties is used. A main core material is used. Especially when the purpose is pressure fixing, the core substance mainly consists of a binder resin, a high boiling point solvent that dissolves it, and a coloring material,
Alternatively, it is preferable to use a material mainly consisting of a soft solid substance and a coloring material. If necessary, magnetic powder may be added in place of the colorant, or additives such as silicone oil may be added for the purpose of improving fixing properties. Further, a high boiling point solvent that does not dissolve the binder resin can be added to the high boiling point resin that dissolves the binder resin. It is desirable to change the types or composition ratios of the constituent components depending on whether the purpose is pressure fixing or heat fixing.

As the coloring agent, those mentioned above can be used.

As the binder resin, a known fixing resin can be used. Specifically, polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, polyacrylic acid 2-
Acrylic ester polymers such as ethylhexyl and polylauryl acrylate; methacrylic ester polymers such as polymethyl methacrylate, polybutyl methacrylate, polyhexyl methacrylate, poly 2-ethylhexyl methacrylate, and polylauryl methacrylate; styrene-based Copolymers of monomers and acrylic esters or methacrylic esters, polyvinyl acetate, polyvinyl propionate, polyvinyl acetate, ethylene polymers such as polyethylene and polypropylene, and their copolymers, styrene,
Butadiene copolymer, styrene/isoprene copolymer,
Styrenic copolymers such as styrene-maleic acid copolymers, polyvinyl ethers, polyvinyl ketones, polyesters, polyamides, polyurethanes, rubbers, epoxy resins, polyvinyl butyral, rosins, modified rosins, terpene resins, phenolic resins, etc., alone or They can be used in combination. Alternatively, the binder resin can be prepared by charging it in the form of a monomer and polymerizing it after encapsulation.

A high boiling point solvent that dissolves the binder resin has a boiling point of 14σ.
An oily solvent having a temperature of 160° C. or higher, preferably 160° C. or higher, can be used. For example, Modern Plastics
It can be selected and used from those described in the Plastlcizers column of Encyelopedla (1975-197B). In addition, high boiling point solvents disclosed as core materials of capsule toners for pressure fixing (for example, JP-A-58-1459134, JP-A No. 63-1988)
163373) may be selected and used.

Specifically, phthalate esters (e.g., diethyl phthalate, dibutyl phthalate); aliphatic dicarboxylic acid esters (e.g., diethyl malonate, dimethyl oxalate)
; Phosphate esters (e.g., tricresyl phosphate,
Trixyl phosphate); Citric acid esters (e.g., 0-acetyltriethyl citrate); Benzoic acid esters (e.g., butyl benzoate, hexyl benzoate); Fatty acid esters (e.g., hexadecyl myristate, dioctyl adipate); Alkyl Naphthalenes (
(e.g., methylnaphthalene, dimethylnaphthalene, monoisopropylnaphthalene, diisopropylnaphthalene); Alkyldiphenyl ethers (e.g., 0-1m-2p-methyldiphenyl ether); Amide compounds of higher fatty acids or aromatic sulfonic acids (e.g., N, N- dimethyllauramide, N-butylbenzenesulfonamide); trimellitic acid esters (e.g., trioctyl trimellitate); diarylalkanes (e.g., diarylmethane such as dimethylphenylphenylmethane, 1-phenyl-1-
diarylethanes such as methylphenylethane, 1-dimethylphenyl-t-phenylethane, 1-ethylphenyl-1-phenylethane); chlorinated paraffins, and the like.

The soft solid material is not particularly limited as long as it is flexible at room temperature and has fixing properties, but polymers with a Tg in the range of 160°C to 5°C or polymers thereof may be used. Mixtures of polymers with other polymers are preferred.

When producing something with a capsule structure, the encapsulation method is not particularly limited, but the completeness of the coating,
Considering the mechanical strength of the outer shell, the encapsulation method using interfacial polymerization is superior.

As the encapsulation method by interfacial polymerization, a known method can be used. For example, as a method of incorporating the core material into the capsule as one component, other core material components are preliminarily added in the state of a polymer to a material with a low boiling point. Two methods are used: one method is to charge the material with a solvent and shell-forming components and form the outer shell through interfacial polymerization, and the other is to charge it as a monomer, form the outer shell through interfacial polymerization, and then polymerize the monomer to form the core material. can. (For example, JP-A-57-179860, JP-A No. 5g-6694
No. 8, No. 59-148068 and No. 59-16256
Publication No. 2).

Next, a description will be given of a polymer that is attached to the surface of toner particles having at least the surface thereof the above-described substance capable of generating radicals.

Specific examples of the fluorine-containing vinyl monomer represented by the above general formula (1), which is a monomer component constituting the polymer, include:
Trifluoroethyl acrylate, trifluorovinyl acetate, trifluoromethyl vinyl ether, trifluoroethyl vinyl ether, pentafluoropropyl acrylate, pentafluoropropyl methacrylate, trifluoropropyl acrylate, trifluoropropyl methacrylate, trifluorobutyl acrylate,
Examples include trifluorobutyl methacrylate, trifluoropentyl acrylate, trifluoropentyl methacrylate, trifluorohexyl acrylate, trifluorohexyl methacrylate, and pentafluorooctyl methacrylate. Among these, trifluoroethyl acrylate, trifluorovinyl acetate, and trifluoroethyl vinyl ether are particularly preferred.

In the present invention, the polymer may be formed from the above-mentioned fluorine-containing vinyl monomer alone, or may further be formed using another vinyl monomer copolymerizable with it. Such vinyl monomers include methyl (meth)acrylate, ethyl (meth)acrylate, (
Propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, lauryl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, Benzyl (meth)acrylate, Hydroxyethyl (meth)acrylate, Hydroxypropyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, (
(Meth)acrylic esters such as glycidyl meth)acrylate, phenyl (meth)acrylate, and phenyl (meth)acrylate; vinyl group-containing cyano compounds such as acrylonitrile, methacrylaterile, and cyanostyrene; vinyl formate, vinyl acetate, Fatty acid vinyl esters such as vinyl propionate, vinyl butyrate, vinyl trimethyl acetate, vinyl caproate, vinyl caprylate, vinyl stearate; ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, hexyl vinyl ether,
Vinyl ethers such as 2-ethylhexyl vinyl ether and phenyl vinyl ether; vinyl ketones such as methyl vinyl ketone and phenyl vinyl ketone; vinyl aromatic compounds such as styrene, chlorostyrene, hydroxystyrene, and α-methylstyrene.

In the present invention, the fluorine-containing vinyl monomer represented by the above general formula (1) is present in an amount of 5 mol% or more, preferably 10 mol% or more, based on the total polymer. If the content of the fluorine-containing vinyl monomer is less than 5 mol %, a sufficient effect on the environmental dependence of charging cannot be expected.

In the present invention, the degree of polymerization of the polymer attached to the surface of the toner particles is preferably in the range of 20 to 2,000, particularly preferably in the range of 100 to 500. Also,
A preferable range of the amount of adhesion is 0.1 to 20 parts by weight based on 100 parts by weight of toner particles.

In the present invention, various methods can be used to attach the polymer to the surface of the toner particles, but a preferred method is a method in which a monomer is graft-polymerized to the toner surface.

As a method for graft polymerization, ■Ce(IV) is used as a catalyst on the surface of the toner particles, and the above general formula (
1) A method of redox polymerizing the fluorine-containing vinyl monomer 1 or the fluorine-containing vinyl monomer and another monomer copolymerizable therewith, and ■Ce(IV)
After graft polymerization of a monomer having two or more radical chain transfer groups using as a catalyst, redox polymerization is initiated using a radical polymerization initiator such as a peroxide or an azo compound, or a combination of a peroxide and a reducing agent. Preferably used is a method in which the fluorine-containing vinyl monomer represented by the above general formula (1), or the fluorine-containing vinyl monomer and another vinyl monomer copolymerizable therewith are subjected to radical polymerization using an agent.

The method of graft polymerization using Ce(IV) is described in detail in ``Graft Polymerization and Its Applications'' by Fumio Ide (published by Kobunshi Kankakai).

The radical polymerization initiator used in the method (■) above is as follows:
Examples include hydrogen peroxide, potassium persulfate, ammonium peroxonisulfate, alkyl hydroperoxide, dialkyl peroxide, diacyl peroxide, peroxide ester, azo compound, etc. Redox polymerization initiators include persulfate, hydrogen peroxide, Combinations of peroxides such as hydroperoxides and various reducing agents include, for example, hydrogen peroxide and ferrous salts, benzoyl peroxide and dimethylaniline, potassium persulfate and Na HSO*, and the like.

Examples of monomers having two or more radical chain transfer groups include polyacrylates and methacrylates of polyhydric alcohols, such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, trimethylolpropane triacrylate, and pentaerythritol dimethacrylate. Methacrylates, etc.; reaction products of acrylic acid and amines having two or more acrylic groups; polyvinyl ethers of polyhydric alcohols, such as ethylene glycol divinyl ether; polyvinyl esters of polyhydric carboxylic acids, such as divinyl Examples include succinate, divinyl phthalate, etc.; aromatic compounds having two or more vinyl groups, such as divinylbenzene and p-allylstyrene. The amount of the polymer chain obtained from the hexamer having two or more radical chain transfer groups is preferably 0.05 to 10% by weight based on the toner body.

Another method for attaching the polymer to the surface of the toner particles is to disperse the toner particles in a solution or dispersion of the polymer and dry the resulting dispersion by spray drying. .

(Example) Example 1 1) (Preparation of capsule particles) Polyisobutyl methacrylate (My-18xl
O') 30g, styrene/n-butyl methacrylate copolymer (My-8xlO') 4Or were added,
Dissolved. Add 120 g of magnetic powder (E P T-1000: manufactured by Toda Kogyo Co., Ltd.) to this, and mill it in a ball mill for 16 minutes.
Spread out time. Next, 30 g of isocyanate (Sumidur L, manufactured by Sumitomo Bayer Urethane) and 24 g of ethyl acetate were added to 200 g of this dispersion and thoroughly mixed. (This solution will be referred to as Solution A.) On the other hand, add 200 g of ion-exchanged water to 200 g of ion-exchanged water with a
was dissolved and cooled to 5°C (this liquid is called liquid B).
. Liquid B was stirred in an emulsifier (auto homo mixer, manufactured by Shukki Kako Co., Ltd.), and liquid A was slowly added into the emulsifier to perform emulsification.In this way, the average particle size of the oil droplets in the emulsified liquid was determined. A 0/W emulsion of about 12 m+ was obtained.Next, the emulsifier was replaced with a stirrer equipped with propeller-type stirring blades (Three-One Motor: manufactured by Shinraikagakusha), and the mixture was stirred at 400 rpm.10 After a few minutes, 100 g of a 5% diethylenetriamine aqueous solution was added dropwise to the solution.
The encapsulation reaction was carried out for 3 hours. After the reaction was completed, the mixture was poured into 2 liters of ion exchange solution, thoroughly stirred, and allowed to stand still. After the capsule particles had settled, the supernatant was removed. This operation was repeated seven more times to wash the capsule particles. In this way, capsule particles containing an oily binder were obtained. An ion exchange solution was added to the capsule particles to prepare a suspension with a solid content concentration of 40%.

2) (Preparation of toner) To 125 g of the suspension of capsule particles prepared in 1) (equivalent to 50 g of capsule particles), 125 g of ion-exchanged water was added, and a stirrer equipped with a propeller-type stirring blade (Three-One Motor: New) was added. The mixture was stirred at 200 revolutions/minute using a 200 revolutions/minute (manufactured by Raikagakusha). After adding 5 g of 1N nitric acid and 4 g of an 10% aqueous cerium sulfate solution, 0.5 g of ethylene glycol dimethacrylate was added thereto, and the mixture was reacted at 15° C. for 3 hours. After the reaction was completed, the mixture was poured into 1 g of ion-exchanged water, thoroughly stirred, and allowed to stand still. After the capsule particles had settled, the supernatant was removed. This operation was repeated two more times to clean the capsule particles.

In this way, capsule particles in which ethylene glycol dimethacrylate was graft-polymerized on the surface of the capsule shell were obtained. This was resuspended in ion-exchanged water and stirred at 200 rpm using a stirrer equipped with a propeller-type stirring blade (Three-One Motor, manufactured by Shinra Kagaku Co., Ltd.). Next, 0.4 g of potassium persulfate, 1 g of trifluoroethyl methacrylate, and 0.1 Bg of sodium bisulfite were sequentially added to the mixture, and the reaction was carried out at 25° C. for 3 hours. After the reaction was completed, the mixture was poured into 2 liters of ion-exchanged water, thoroughly stirred, and allowed to stand still.

After the capsule particles had settled, the supernatant was removed. This operation was repeated four more times to wash the capsule particles.

In this way, a capsule toner in which trifluoroethyl methacrylate was graft-polymerized on the surface of the capsule shell was obtained. The obtained capsule suspension was poured into a stainless steel vat and dried in a dryer (manufactured by Yamato Kagaku Co., Ltd.) at 60° C. for 10 hours.

3) (Evaluation test) 3 g of the obtained capsule toner and 100 g of iron powder carrier whose surface was coated with phenol resin were heated at a temperature of 20°C and a humidity of 5.
The capsule toner was mixed in an environment of 0° C., and the charge amount of the capsule toner was measured by a blow-off method and found to be -18 μC/g.

Similarly, the charge amount of the capsule toner was measured using the blow-off method in an environment with a temperature of 28°C and a humidity of 80% = 16
It was μC/g. Next, 1 part of hydrophobic silica (R972: manufactured by Nippon Aerosil Co., Ltd.) was added to 100 parts of this toner, and after thorough mixing, image quality was evaluated under a high temperature and high humidity environment of 35° C. and 85% humidity. . The copying machine used was a Fuji Xerox 2700 model modified to use capsule toner, and copy samples were obtained using a reversal phenomenon. the result,
Stable copies without fogging were obtained up to the 20,000th copy.

Immediately after collecting the 20,000th copy sample, we measured the charge distribution of the toner in the sleeve of the developing machine, and found that the distribution was sharp, and the amount of toner with opposite polarity was
It was less than 5% of the total toner.

Comparative Example 1 The same process as in Example 2 was carried out except that trifluoroethyl methacrylate tg was replaced with acrylonitrile tg to obtain a capsule toner in which acrylonitrile was graft-polymerized on the surface of the capsule shell. 8 g of the obtained capsule toner and iron powder carrier 1 whose surface was coated with phenol resin
00g in an environment with a temperature of 20°C and a humidity of 50%,
When the amount of charge was measured using the blow-off method, it was -14μC/
Met.

Similarly, when the capsule toner was mixed in an environment with a temperature of 28° C. and a humidity of 80% and the charge amount of the capsule toner was measured by a blow-off method, it was -6 μC/g. Next, 1 part of hydrophobic silica (R972: manufactured by Nippon Aerosil Co., Ltd.) was added to 100 parts of this toner and mixed thoroughly. When image quality was evaluated, shell fogging occurred on the 1000th sheet.
The image density of each sheet decreased and the image quality became significantly inferior in sharpness.

Immediately after collecting the 100th copy sample, we measured the charge distribution of the toner in the sleeve of the developing machine and found that the distribution was broad, and the amount of toner with opposite polarity was more than 50% of the total toner. Met.

Example 2 1) (Preparation of capsule particles) Polyisobutyl methacrylate (My -18xlo') 30 g was added to 150 g of lauryl methacrylate monomer.
g was added and dissolved. 20 g of a red pigment (Hostapalm Scarlet GO: manufactured by Bayer AG) was added to this and dispersed in a ball mill for 16 hours. Next, 200g of this dispersion
10 g of isocyanate (Sumidur L: manufactured by Sumitomo Bayer Urethane Co., Ltd.), 5 g of toluylene diisocyanate (Coronate T: manufactured by Nippon Polyurethane Co., Ltd.) and 3 g of azobisvaleronitrile were added and mixed. (This solution will be referred to as Solution A.) On the other hand, 10 g of hydroxypropyl methylcellulose (Metrose 65SH50, manufactured by Shin-Etsu Chemical Co., Ltd.) was dissolved in 250 g of ion-exchanged water and cooled to 5° C. (This solution will be referred to as Solution B). Solution B was stirred using an emulsifier (auto homomixer, manufactured by Shukki Kako Co., Ltd.), and solution A was slowly added thereto to perform emulsification. In this way, an O/W emulsion in which the average particle size of oil droplets in the emulsion was about 12 m was obtained. Next, instead of the emulsifier, we replaced it with a stirrer equipped with propeller-type stirring blades (Three-One Motor: manufactured by Shinraikagakusha).
Stirring was carried out at 400 rpm. After 10 minutes, there will be 2.5
% diethylenetriamine aqueous solution (10t1g) was added dropwise. After the dropwise addition was completed, stirring was continued at room temperature, and the capsule reaction was carried out for 2 hours. Thereafter, a reaction was carried out at 65° C. for 14 hours to polymerize the core material. After the reaction was completed, the mixture was poured into 2I ion-exchanged water, thoroughly stirred, and then centrifuged. After the capsule particles were separated, the supernatant was removed. Do this operation 5 more times
After repeating this process several times, the mixture was further washed with methanol. In this way, red capsule particles containing a soft solid substance were obtained. An ion exchange solution was added to the capsule particles to prepare a suspension with a solid content concentration of 40%.

2) Preparation of toner To 125 g of the suspension of capsule particles prepared in 1) (equivalent to 50 g of capsule particles), 125 g of ion-exchanged water was added, and a stirrer equipped with a propeller-type stirring blade (Three-One Motor: Shinra) was added. The mixture was stirred at a rate of 200 times/min (manufactured by Kagakusha Co., Ltd.). Add 5g of IN nitric acid to this.

After adding 4 g of 10% cerium sulfate aqueous solution, 0.5 g of ethylene glycol dimethacrylate was added, and the mixture was heated at 15°C.
The reaction was carried out for 3 hours. After the reaction was completed, the mixture was poured into IP ion-exchanged water, thoroughly stirred, and then centrifuged. After the capsule particles were separated, the supernatant was removed. This operation was repeated two more times to wash the capsule particles. In this way, capsule particles in which ethylene glycol dimethacrylate was graft-polymerized on the surface of the capsule shell were obtained. This was resuspended again in ion-exchanged water and stirred at 200 times/min using a stirrer equipped with propeller-type stirring blades (Three-One Motor, manufactured by Shinraikagakusha). Next, in this, 0.4 g of potassium persulfate, ) vinyl acetate t
g, 0.16 g of sodium bisulfite were sequentially added,
The reaction was carried out at 25°C for 3 hours. After the reaction was completed, the mixture was poured into 2p ion-exchanged water, thoroughly stirred, and centrifuged. After the capsule particles were separated, the supernatant was removed. This operation was repeated four more times to wash the capsule particles. In this way, a capsule toner in which trifluorovinyl acetate was graft-polymerized on the surface of the capsule shell was obtained. The obtained capsule suspension was placed in a stainless steel vat and dried in a dryer (manufactured by Yamato Kagaku Co., Ltd.) at 60° C. for 10 hours.

3) (Evaluation test) 3 g of the obtained capsule toner and 100 g of iron powder carrier whose surface was coated with phenol resin were mixed in an environment with a temperature of 20°C and a humidity of 50%, and the charge amount of the capsule toner was determined by the blow-off method. When measured, it was -16 μC/g. Similarly, mix in an environment with a temperature of 28 ° C and humidity of 80%,
When the charge amount of the capsule toner was measured by the pull-off method, it was -14 μC/g. Next, this toner 10
To 0 parts, 1 part of hydrophobic silica (R972: manufactured by Nippon Aerosil Co., Ltd.) was added, mixed thoroughly, and heated at a temperature of 35°C.
Image quality was evaluated under a high temperature and high humidity environment of 85% humidity. The copying machine used was a 2700 manufactured by Fuji Xerox Co., Ltd. modified to use capsule toner, and copy samples were obtained by reverse development. As a result, stable copies without fog were obtained up to the 20,000th copy.

Immediately after collecting the 20,000th copy sample, we measured the charge distribution of the toner in the sleeve of the developing machine, and found that the distribution was sharp, and the amount of toner with opposite polarity was
It was less than 5% of the total toner.

Comparative Example 2 A capsule toner in which methacrylic acid was graft-polymerized on the surface of the capsule shell was obtained by carrying out the same process as in Example 4, except that 1 g of methacrylic acid was used instead of vinyl trifluoroacetate (tg). 3 g of the obtained capsule toner and 100 g of iron powder carrier whose surface was coated with phenol resin were heated at a temperature of 2.
The mixture was mixed in an environment of 0° C. and 50% humidity, and the amount of charge was measured by the blow-off method, and it was found to be 10 μC/. Similarly, when the capsule toner was mixed in an environment with a temperature of 28°C and a humidity of 80%, and the charge amount of the capsule toner was measured using the blow-off method, the result was 4.
It was μC/g. Next, 1 part of hydrophobic silica (R972: manufactured by Nippon Aerosil Co., Ltd.) was added to 100 parts of this toner and mixed thoroughly. When evaluating the image quality,
Fog occurred from the 10th sheet, and image density decreased from the 100th sheet, resulting in image quality with significantly poor clarity.

Immediately after collecting the 100th copy sample, we measured the charge distribution of the toner in the sleeve of the developing machine and found that the distribution was broad, and the amount of toner with opposite polarity was more than 50% of the total toner. Met.

Example 3 1) (Preparation of capsule particles) Styrene/n-butyl methacrylate copolymer (My = 20000) Bog was added to a mixed solution of 40 g of styrene monomer, 20 g of n-butyl methacrylate monomer, and 20 g of 2-hydroxyethyl methacrylate. and dissolved. Carbon black (MA-600
: manufactured by Mitsubishi Chemical Industries, Ltd.) and milled in a ball mill for 24 hours.
Spread out time. Next, for 100 g of this dispersion,
3 g of azobisisobutyronitrile was added and mixed (this liquid is referred to as liquid A).

On the other hand, 5 g of hydroxypropyl methylcellulose (Metrose 651150: manufactured by Shin-Etsu Chemical Co., Ltd.) and polyvinyl alcohol (PV^110) were added to 250 g of ion-exchanged water.
: manufactured by Kuraray Co., Ltd.) Ig was dissolved and cooled to 5° C. (this liquid is referred to as liquid B). Solution B was stirred using an emulsifier (auto homomixer, manufactured by Shukki Kako Co., Ltd.), and solution A was slowly added thereto to perform emulsification.

In this way, the average particle size of the oil droplets in the emulsion is approximately 12
A 0/W emulsion of m was obtained. Next, a stirrer equipped with propeller-type stirring blades (Three-One Motor: Shinraikagaku Co., Ltd.) was used in place of the emulsifier, and the reaction was carried out at 65°C for 16 hours while stirring at 400 revolutions/min. did. After the reaction was completed, the mixture was poured into 2I ion-exchanged water, thoroughly stirred, and then the capsule particles were separated using a centrifuge, and the supernatant was removed. After repeating this operation 5 more times, it was further washed with methanol. In this way, black capsule particles were obtained. Ion-exchanged water was added to the capsule particles to obtain a suspension with a solid content concentration of 40%.

2) (Preparation of toner) 125 g of ion-exchanged water was added to 125 g of the suspension of capsule particles prepared in 1) (equivalent to 50 g of capsule particles), and a stirrer equipped with a propeller-type stirring blade (three-one motor: The mixture was stirred at 200 times/min using a Shinraikagakusha (manufactured by Shinraikagakusha). Add 5g of IN nitric acid to this.

After adding 4 g of 10% cerium sulfate aqueous solution, 0.5 g of ethylene glycol dimethacrylate was added, and reaction was carried out at 15° C. for 3 hours. After the reaction was completed, the mixture was poured into ion-exchanged water (11), thoroughly stirred, and centrifuged. After the capsule particles were separated, the supernatant was removed. 2 more steps
The capsule particles were washed repeatedly. In this way, toner particles in which ethylene glycol dimethacrylate was graft-polymerized on the surface of the capsule shell were obtained. This was resuspended again in ion-exchanged water, and then mixed with a stirrer equipped with propeller-type stirring blades (three-one motor: manufactured by Shinraikagakusha).
The mixture was stirred at 00 times/min. Next, in this, 0.4 g of potassium persulfate, 1) fluoroethyl methacrylate
．． 5g x sodium bisulfite 0.1B.

were added sequentially, and the reaction was carried out at 25°C for 3 hours. After the reaction was completed, the mixture was poured into 2 g of ion-exchanged water, thoroughly stirred, and centrifuged. After the capsule particles were separated, the supernatant was removed. This operation was repeated four more times to wash the capsule particles. In this way, a black capsule toner in which trifluoroethyl methacrylate was graft-polymerized on the surface of the capsule shell was obtained. The obtained toner suspension was poured into a stainless steel vat and dried in a dryer (manufactured by Yamato Kagaku Co., Ltd.) for 4 hours.
It was dried at 0°C for 20 hours.

3) (Evaluation test) 3 g of the obtained surface-treated capsule toner and an iron powder carrier whose surface was coated with phenol resin were heated at a temperature of 20 g.
When the capsule toner was mixed in an environment of 50% humidity and 50% humidity, and the charge amount of the capsule toner was measured using the blow-off method, -tSμC/
It was g. Similarly, the capsule toner was mixed in an environment with a temperature of 28 DEG C. and a humidity of 80%, and the charge amount of the capsule toner was measured by the blow-off method, and it was found to be -11 .mu.C/g. Next, hydrophobic silica (R972
After adding 1 part of Nippon Aerosil Co., Ltd.) and thoroughly mixing the mixture, image quality was evaluated under a high temperature and high humidity environment of 35° C. and 85% humidity.

The copying machine used was a 2700 manufactured by Fuji Xerox Co., Ltd. modified to use capsule toner, and copy samples were obtained by reverse development. As a result, stable copies without capri were obtained up to the 20,000th copy.

Immediately after collecting the 20,000th copy sample, we measured the charge distribution of the toner in the sleeve of the developing machine, and found that the distribution was sharp, and the amount of toner with opposite polarity was
It was less than 5% of the total toner.

Comparative Example 3 To 125 g of the suspension of capsule particles prepared in Example 3 (equivalent to 50 g of capsule particles), 3 g of particulate fluororesin (average particle size 0.2 to 0.4 a) was added and mixed by stirring. . This was poured into a stainless steel vat and dried in a dryer (manufactured by Yamato Kagaku Co., Ltd.) at 40° C. for 20 hours. In this way, a black toner having fine particulate fluororesin attached to the toner surface was obtained. 3 g of the obtained toner and an iron powder carrier whose surface was coated with phenol resin were heated at a temperature of 20 g.
When the capsule toner was mixed in an environment of ℃ and 50% humidity and the charge amount of the capsule toner was measured using the blow-off method, it was -12μC/
It was g. Similarly, the capsule toner was mixed in an environment with a temperature of 28 DEG C. and a humidity of 80%, and the charge amount of the capsule toner was measured by the blow-off method, and it was found to be -8 .mu.C/g. Next, 1 part of hydrophobic silica (R972: manufactured by Nippon Aerosil Co., Ltd.) was added to 100 parts of this toner, and after thorough mixing, the temperature was 35°C.
When image quality was evaluated in the same manner as in Example 2 under a high temperature and high humidity environment of The image quality was significantly inferior.

Immediately after collecting the 100th copy sample, we measured the charge distribution of the toner in the sleeve of the developing machine and found that the distribution was broad, and the amount of toner with opposite polarity was more than 50% of the total toner. Met.

(Effects of the Invention) Since the electrophotographic toner of the present invention has the above-mentioned polymer attached to the surface of the toner particles, it has good environmental charging stability and is negatively chargeable with a sharp charge distribution. It is something. Furthermore, since the charging property is not impaired by mechanical force, copy images of excellent image quality can be produced stably for a long period of time. Furthermore, the electrophotographic toner of the present invention has a wide degree of freedom in material selection and can be produced without the need for a special reaction device.

Claims (5)

[Claims] (1) It is confirmed that a polymer containing a fluorine-containing vinyl monomer represented by the following general formula (I) as a monomer component is attached to the surface of toner particles having at least a radical-generating substance on the surface. Characteristic toner for electrophotography. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, X represents a hydrogen atom or a fluorine atom, and Y represents a
▲There are mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
There are tables, etc.▼, -O- or ▲There are mathematical formulas, chemical formulas, tables, etc.▼, R_1 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and n is 0 or an integer from 1 to 7 shows. ) (2) The electrophotographic toner according to claim 1, wherein the polymer is chemically bonded to the surface of the toner particles. (3) The electrophotographic toner according to claim 1, wherein the toner particles have a capsule structure. (4) The electrophotographic toner according to claim 1, wherein the capsule shell is made of polyurea resin and/or polyurethane resin, or epoxyurea resin and/or epoxyurethane resin. (5) A monomer having two or more radical chain transfer groups is graft-polymerized on the surface of toner particles having at least a radical-generating substance on the surface, and then a fluorine-containing vinyl monomer represented by the above general formula (I) is graft-polymerized. Alternatively, the method for producing an electrophotographic toner according to claim 1, characterized in that the fluorine-containing vinyl monomer and a vinyl monomer copolymerizable with the fluorine-containing vinyl monomer are graft-polymerized.