JPH06230598A - Electrophotographic capsule toner - Google Patents

Abstract

PURPOSE:To provide a capsule toner having high mechanical strength, excellent negative electrification property, and sharp electrification distribution with which copy images of excellent picdture quality can be produced and cleaing can be preferably performed at a low temp. and a low humidity. CONSTITUTION:This electrophotographic capsule toner consists of toner particles and a polymer containing sulfonic acid group-contg. vinyl monomers expressed by the formula as the monomer component deposited on the toner particles. The toner particle has a material which can produce radical at least on its surface. A conductive fine powder is externally added to the toner. In the formula, R1 is hydrogen atom or an alkyl group of 1-3 carbon number, X is -(CH2)n-, -CONHC(R2)(R3)R4-, -COO(CH2)m-, or -CONH-, (n) is an integer 0 to 20, R2 and R3 are hydrogen atoms or alkyl groups of 1-20 carbon number, R4 is an alkylene group of 1-20 carbon number, (m) is an integer 1 to 20, M<q+> is a cation and (q) is an integer 1 to 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner, especially a microcapsule toner, for developing an electrostatic latent image in electrophotography and electrostatic printing.

[0002]

2. Description of the Related Art Conventionally, a toner containing a sulfonic acid compound in order to improve developing characteristics has been known. A known toner charge control method is disclosed in JP-A-52-45931.
JP-A-59-124343, JP-A-59-124343
In JP-A-124344 and JP-A-63-88564, a method of internally adding a charge control agent having a sulfonic acid group to toner particles by a melt-kneading method or the like is proposed.

[0003]

However, the above-mentioned conventionally proposed method cannot satisfy the negative chargeability of the capsule toner. That is, in the method of dispersing the charge control agent inside the toner, it is difficult to effectively exist on the outer surface of the capsule toner shell, and it is necessary to use a large amount of the charge control agent. In addition, JP-A-52-4593
There is an attempt to maintain the charge stability of the toner by using a metal complex salt or the like in JP-A No. 1, but it is difficult to control the dispersion of the metal complex salt in the toner, and the metal complex salt is generally colored. Cannot be used for toner. In addition, there are many drawbacks such as the metal complex salt falling off during running, which lowers the charging property. Further, in JP-A-63-88564, it has been proposed to use a polymer having a sulfonate group bonded to an aromatic ring, but the present inventor made a study by adhering it to the outer surface of the capsule toner shell. As a result, the amount of negative charge was low, and satisfactory chargeability could not be obtained. Further, JP-A-59-126545 discloses a method for producing a toner in which a vinyl monomer is radically polymerized in a polymerization system in which magnetic powder is dispersed in the presence of a vinyl monomer having a sulfonic acid group. . However, in this method, the monomer having a sulfonic acid group is used as a dispersibility improving agent in the organic polymer of the magnetic powder, does not effectively exist on the toner surface, and the charge control function is insufficient. Further, in the case of the above-mentioned encapsulated toner, the polymer on the capsule wall and the surface is insulative, so that charge exchange between toner particles may be hindered when the toner is charged. As a result, the toner charge is not averaged and the charge distribution is widened, and the image quality of the copy deteriorates under a specific environment. Further, under low temperature and low humidity, the electrostatic adhesion to the photoconductor becomes high, and the toner remaining on the photoconductor is insufficiently cleaned, which is a drawback.

An object of the present invention is to provide a toner which solves the above-mentioned drawbacks of the prior art. That is, an object of the present invention is to provide a toner having a good negative chargeability. Another object of the present invention is to provide a toner capable of obtaining a stable negative charging property for a long time and producing a copy image with excellent image quality. Another object of the present invention is to provide a capsule toner having a good negative chargeability and a sharp charge distribution. Further, an object of the present invention is to provide a capsule toner which does not cause cleaning failure even at low temperature and low humidity.

[0005]

The present invention provides a sulfonic acid group-containing vinyl monomer represented by the following general formula (1) on the surface of capsule particles having a substance capable of generating a radical on at least the surface thereof;

(In the formula, R1 is a hydrogen atom or a carbon atom number 1 to
Indicates 3 alkyl group, X _{is, - (CH 2) n -} , - CO
_{NHC (R 2) (R 3} ) R 4 -, - CONH -, - COO
(CH ₂ ) _m −, n is an integer of 0 to 20, R ₂ and R ₃ are hydrogen atoms or an alkyl group having 1 to 20 carbon atoms, R ₄ is an alkylene group having 1 to 20 carbon atoms, and m is 1 to 20 represents an integer, and M ^{q +} represents a cation in which q is an integer of 1 to 3. )
Is attached to the polymer containing as a monomer component. Further, conductive fine particles are externally added to the toner.

The present invention will be described in detail below.
The encapsulated toner of the present invention has a so-called capsule structure composed of a core substance and an outer wall covering the core substance, and the outer wall has a substance capable of generating radicals on at least the surface thereof.

In the present invention, the term "substance capable of generating radicals" means a substance capable of generating radicals by a hydrogen atom abstraction reaction or an addition reaction with a monomer radical or cerium (IV) ion. is doing. Specifically, polymers such as polyamide, polyurea, polyurethane, polyester, polyvinyl acetate, polyvinyl alcohol, cellulose, synthetic rubber, polystyrene, styrene- (meth) acrylic copolymer, epoxy resin, phenoxy resin, acrylic resin and the like, and The mixture is given. The term "capsule particles on the surface" refers to a substance in which radical-generating substances are uniformly present or evenly scattered on the surface.

Next, there will be described a polymer in which a substance capable of generating a radical is attached to at least the surface of capsule particles having the surface. This attachment may be a physical attachment or an attachment by a chemical bond.

Specific examples of the sulfonic acid group-containing monomer represented by the general formula (1), which is a monomer component constituting the polymer, include methallyl sulfonic acid, metal salts of methallyl sulfonic acid, and methallyl sulfone. Ammonium acid, stearyl trimethyl ammonium methallyl sulfonate, perfluoroalkyl ammonium methallyl sulfonate, allyl sulfonic acid, metal salts of allyl sulfonic acid, ammonium allyl sulfonate, stearyl trimethyl ammonium allyl sulfonate, perfluoroalkyl ammonium allyl sulfonate , 2-sulfoethyl (meth) acrylate, ammonium 2-sulfoethyl (meth) acrylate, stearyltrimethylammonium 2-sulfoethyl (meth) acrylate, perfluoroalkylammonium 2- Ruhoechiru (meth) acrylate, a metal salt of 2-sulfoethyl (meth) acrylate,
1,1-dimethyl-2-sulfoethylacrylamide,
Ammonium 1,1-dimethyl-2-sulfoethyl acrylamide, stearyl trimethyl ammonium
1,1-dimethyl-2-sulfoethylacrylamide,
Perfluoroalkylammonium 1,1-dimethyl-2-sulfoethylacrylamide, metal salt of 1,1-dimethyl-2-sulfoethylacrylamide, 3-sulfopropyl (meth) acrylate, ammonium 3-
Examples thereof include sulfopropyl (meth) acrylate, stearyltrimethylammonium 3-sulfopropyl (meth) acrylate, perfluoroalkylammonium 3-sulfopropyl (meth) acrylate, and metal salts of 3-sulfopropyl (meth) acrylate. As the metal salt, sodium salt, potassium salt, lithium salt,
Calcium salt, magnesium salt, barium salt, zinc salt,
Examples include tin salts, titanium salts, and tungsten salts. Among these, a metal salt or ammonium salt of methallyl sulfonic acid and a metal salt or ammonium salt of allyl sulfonic acid are particularly preferable.

In the present invention, the polymer may be formed of the above-mentioned vinyl monomer containing a sulfonic acid group alone, or may be formed using another vinyl monomer copolymerizable therewith. Examples of such vinyl monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth)
Butyl acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, benzyl (meth) acrylate, (meth ) Hydroxyethyl acrylate, hydroxypropyl (meth) acrylate, (meth) acrylic acid 2-
(Meth) acrylic acid esters such as ethoxyethyl, glycidyl (meth) acrylate, phenyl (meth) acrylate, or vinyl group-containing cyano compounds such as acrylonitrile, methacrylonitrile, cyanostyrene, vinyl formate, vinyl acetate, propion Vinyl acid, vinyl butyrate, trimethyl vinyl acetate, vinyl caproate, vinyl caprylate, vinyl stearate and other fatty acid vinyl esters, or ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, 2-ethylhexyl vinyl ether, phenyl vinyl ether, etc. Vinyl ethers or vinyl ketones such as methyl vinyl ketone and phenyl vinyl ketone, styrene, chlorostyrene, hydroxystyrene,
Vinyl aromatic compounds such as α-methylstyrene, (meth)
Examples thereof include fluorine-containing vinyl monomers such as trifluoroethyl acrylate and hexafluoroisopropyl (meth) acrylate.

In the case of a copolymer, the sulfonic acid group-containing vinyl monomer represented by the general formula (1) is preferably present in an amount of 5 mol% or more based on the total amount of the copolymer. Particularly preferably, it is 10 mol% or more. If the content of the sulfonic acid group-containing vinyl monomer is less than 5 mol%, a sufficient effect cannot be expected in negative charging property. In the present invention, the degree of polymerization of the above-mentioned polymer attached to the surface of the toner particles is preferably in the range of 20 to 2000, particularly preferably 100 to 500. Further, the preferable range of the adhesion amount is 0.1 to 20 parts by weight with respect to 100 parts by weight of the toner particles. The cation of the sulfonate monomer component forming the polymer attached to the toner surface may be directly graft-polymerized with the sulfonate monomer to form the polymer component on the toner surface, but the graft polymerization was performed. After that, it may be formed by performing ion exchange to an appropriate cation.

As the core substance of the capsule toner particles, a core substance mainly composed of a component having a pressure fixing property is used for the purpose of pressure fixing, and a component having a heat fixing property for the purpose of heat fixing. A core material mainly composed of is used. Particularly for the purpose of pressure fixing, it is preferable that the core substance is mainly composed of a binder resin and a high-boiling-point solvent that dissolves the binder resin and a coloring material, or that is mainly composed of a soft solid substance and a coloring material. If necessary, a magnetic powder may be added in place of the coloring material, or an additive such as silicone oil may be added for the purpose of improving fixability. Further, a high boiling point solvent which does not dissolve the binder resin can be added to the high boiling point solvent which dissolves the binder resin. It is desirable to change the kinds or composition ratios of the constituents depending on whether the purpose is pressure fixing or heat fixing.

Examples of the colorant include inorganic pigments such as carbon black, red iron oxide, dark blue, titanium oxide, fast yellow, disazo yellow, pyrazolone red, chelate red, azo pigments such as brilliant carmine and para brown, copper phthalocyanine, metal-free phthalocyanine. And condensed polycyclic pigments such as flavantron yellow, dibromoanthrone orange, perylene red, quinacridone red, and dioxazine violet. Further, disperse dyes, oil-soluble dyes and the like can also be used. Furthermore, as the magnetic one-component toner, all or part of the black coloring material can be replaced with magnetic powder. As the magnetic powder, magnetite, ferrite, a simple metal such as cobalt, iron, nickel, or an alloy thereof can be used. In addition, a magnetic powder whose surface is coated with a coupling agent such as a silane coupling agent or a titanate coupling agent or an oil-soluble surfactant, or whose surface is coated with an acrylic resin, a styrene resin or an epoxy resin may be used. Good. Furthermore, the coloring material or magnetic powder charged as one component of the core substance may be present at the interface between the core and the outer shell or in the outer shell after capsule formation.

As the binder resin that can be used for the core substance, a known fixing resin can be used. Specifically, polymethyl acrylate, polyethyl acrylate,
Acrylic ester polymers such as polybutyl acrylate, 2-ethylhexyl polyacrylate and polylauryl acrylate, polymethyl methacrylate, polybutyl methacrylate, hexyl polymethacrylate, polymethacrylic acid 2
-Ethylhexyl, methacrylic acid ester polymers such as polylauryl methacrylate, copolymers of acrylic acid esters and methacrylic acid esters, copolymers of styrene-based monomers and acrylic acid esters or methacrylic acid esters, polyvinyl acetate, poly Ethylene polymers such as vinyl propionate, polyvinyl butyrate, polyethylene and polypropylene and their copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-copolymers such as styrene-maleic acid copolymers Coalescing,
Polyvinyl ether, polyvinyl ketone, polyester, polyamide, polyurethane, rubbers, epoxy resin, polyvinyl butyral, rosin, modified rosin, terpene resin, phenol resin and the like can be used alone or in combination. It is also possible to prepare a binder resin by polymerizing after charging and encapsulation in a monomer state.

The soft solid substance that can be used as the core substance of the pressure fixing capsule toner is not particularly limited as long as it has flexibility and fixing property at room temperature, but Tg is -60. A polymer in the range of 5 ° C to 5 ° C or a mixture of the polymer and another polymer is preferable.

As the high boiling point solvent for dissolving the binder resin, an oily solvent having a boiling point of 140 ° C. or higher, preferably 160 ° C. or higher can be used. For example, Modern Pla
stics Encyclopedia (1975-1
You may choose from what is described in Plasticizers of 976). Further, it is disclosed as a core substance of a pressure fixing capsule toner (for example, JP-A-58).
No. 145964, JP-A No. 63-163373, etc.). In particular,
Phthalic acid esters (eg, diethyl phthalate, dibutyl phthalate), aliphatic dicarboxylic acid esters (eg,
Diethyl malonate, dimethyl oxalate), phosphoric acid esters (eg, tricresyl phosphate, trixylyl phosphate), citric acid esters (eg, o-acetyl triethyl citrate), benzoic acid esters (eg, butyl benzoate) , Hexyl benzoate), fatty acid esters (eg, hexadecyl myristate, dioctyl adipate, linseed oil, castor oil, green oil), alkylnaphthalenes (eg, methylnaphthalene, dimethylnaphthalene, monoisopropylnaphthalene, diisopropylnaphthalene), Alkyl diphenyl ethers (eg, o
-, M-, p-methyldiphenyl ether), amide compounds of higher fatty acid or aromatic sulfonic acid (eg, N, N)
-Dimethyllauroamide, N-butylbenzenesulfonamide), trimellitic acid esters (eg, trioctyl trimellitate), diarylalkanes (eg, diarylmethane such as dimethyldiphenylmethane, 1-phenyl-1-methylphenylethane) , 1-dimethylphenyl-1-phenylethane, 1-ethylphenyl-1-phenylethane and other diarylethanes), saturated aliphatic hydrocarbons, unsaturated aliphatic hydrocarbons, chlorinated paraffins and the like.

In the case of producing one having a capsule structure, the encapsulation method is not particularly limited.
In particular, the encapsulation method by interfacial polymerization is preferable because it enables sufficient coating and the outer shell has good mechanical strength. A known method can be used for producing capsules by interfacial polymerization. For example, as a method of containing one component in the core substance in the capsule, a method of preliminarily charging another core substance component together with a low boiling point solvent and an outer shell forming component in a polymer state, and forming an outer shell by interfacial polymerization, A method may be used in which the outer shell is formed by charging interfacial polymerization in the state of a monomer, and then the monomer is polymerized to form a core substance (for example, JP-A-57-179860 and JP-A-58-66948).
JP-A-59-148066, 59-16
2562). The resin of the outer shell is polyurea resin, melamine resin, polyurethane resin, polyamide resin, polyester resin, epoxy resin or epoxy urea resin, epoxy urethane resin, polystyrene, styrene-acrylic resin, styrene-butadiene resin, polyamino acid, polypropylene, Polycarbonate is preferable, and among them, polyurea resin or polyurethane resin is preferably used alone or in combination thereof, or epoxyurea resin or epoxyurethane resin is used alone or in combination thereof. Further, in the case of the capsule toner for the purpose of pressure fixing and the case of the capsule toner for the purpose of heat fixing,
It is desirable to change the thickness of the outer shell, and the kind or composition ratio of the constituents may be changed.

In the present invention, various methods can be adopted as a method for attaching the above-mentioned polymer to the surface of the capsule toner particles, but a preferable method is a method of graft-polymerizing a monomer on the surface of the capsule toner. To be As the method of graft polymerization, Ce is used.
Using (IV) as a catalyst on the surface of the toner particles,
Using the sulfonic acid group-containing vinyl monomer represented by the general formula (1), or a method of redox polymerizing the sulfonic acid group-containing vinyl monomer and another monomer copolymerizable therewith, and using Ce (IV) as a catalyst. After graft-polymerizing a monomer having two or more radical chain transfer groups, a radical polymerization initiator such as a peroxide or an azo compound, and a redox polymerization initiator obtained by combining a peroxide and a reducing agent are used. Then, a method of radically polymerizing the sulfonic acid group-containing vinyl monomer represented by the general formula (1) or the sulfonic acid group-containing vinyl monomer and another vinyl monomer copolymerizable therewith can be preferably used.

The method of graft polymerization using Ce (IV) is described in detail in "Graft Polymerization and Its Application" by Fumio Ide (published by Kobunshi Kogakukai). As the radical polymerization initiator used in the above method, hydrogen peroxide,
Examples include potassium persulfate, ammonium peroxodisulfate, alkyl hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxide esters, azo compounds, and the like.
As the redox polymerization initiator, a combination of peroxides such as persulfate, hydrogen peroxide, hydroperoxide and various reducing agents, for example, hydrogen peroxide and ferrous salt, benzoyl peroxide and dimethylaniline, and peroxide. Examples include potassium sulfate and sodium hydrogen sulfite.

As the monomer having two or more radical chain transfer groups, polyacrylates and methacrylates of polyhydric alcohols such as ethylene glycol diacrylate, ethylene glycol dimethacrylate,
Diethylene glycol dimethacrylate, trimethylolpropane triacrylate, pentaerythritol dimethacrylate, 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; Examples thereof include polyvinyl esters of polycarboxylic acids such as divinyl succinate and divinyl phthalate; aromatic compounds having two or more vinyl groups such as divinylbenzene and p-allylstyrene. The amount of the polymer chain obtained from the monomer having two or more radical chain transfer groups is preferably 0.05 to 10% by weight based on the toner body.

The conductive fine particles added to the surface of the capsule particles may have an electrical resistivity of about 10 ⁸ Ωcm or less, preferably 10 ⁵ Ωcm or less. Among them, conductive fine particles whose conductivity is less dependent on humidity, for example, carbon fine powder such as carbon black and graphite;
Fine metal powders of copper, gold, silver, aluminum, nickel, etc .; metal sulfides of molybdenum sulfide, cadmium sulfide, etc .; zinc oxide, titanium oxide, tin oxide, aluminum oxide, indium oxide, silicon oxide, magnesium oxide, barium oxide, A metal oxide such as molybdenum oxide, iron oxide, or tungsten oxide, a metal oxide doped with a metal such as antimony, or a composite oxide thereof is preferable. Among these, carbon black, tin oxide, and titanium oxide are particularly preferable. The average particle size of these conductive fine particles is preferably 2 μm or less, and particularly preferably 0.5 μm or less. In the present invention, as the conductive fine particles, the fine particles may be used alone, or two or more kinds of the fine particles may be mixed and used. A known external additive may be added in order to impart fluidity or chargeability to the capsule toner. Specifically, fine powder of silicon oxide, titanium oxide, calcium titanate, strontium titanate, barium titanate, cerium oxide, etc., silicon carbide, silicon nitride, and polymer fine powder of polymethylmethacrylate, polyvinylidene fluoride, etc. , Metal salts of higher fatty acids such as sodium stearate. As a method for adding the conductive fine particles to the capsule particles, the capsule toner may be dried and then adhered to the toner surface in a dry manner by using a mixer such as a V blender or a Henschel mixer. After dispersing in an aqueous liquid such as / alcohol, it may be added to the capsule toner in a slurry state and dried to attach the external additive to the toner surface.

[0022]

【Example】

Example 1 1) Preparation of capsule particles Polyisobutyl methacrylate (Mw = 16 × 1) was added to a mixed solution of 60 g of dibutylnaphthalene and 60 g of ethyl acetate.
0 ⁴ ) 30 g and styrene-n-butyl methacrylate copolymer (Mw = 6 × 10 ⁴ ) 40 g were added and dissolved.
Magnetic powder (EPT-1000: manufactured by Toda Kogyo Co., Ltd.) 12
0 g was put and dispersed by a ball mill for 16 hours. Next, to 200 g of this dispersion, 30 g of isocyanate (Sumijour L: manufactured by Sumitomo Bayer Urethane Co., Ltd.) and 24 g of ethyl acetate were added and mixed well. (This liquid is referred to as liquid A.) On the other hand, 10 g of hydroxypropylmethyl cellulose (Metroses 65SH50: manufactured by Shin-Etsu Chemical Co., Ltd.) was dissolved in 200 g of ion-exchanged water and cooled to 5 ° C. (This solution is referred to as solution B.) Solution B was stirred with an emulsifying machine (auto homomixer: manufactured by Koki Kako Co., Ltd.), and solution A was slowly added to the mixture for emulsification. Thus, an O / W emulsion in which the average particle size of the oil droplet particles in the emulsion was about 12 μm was obtained. Then, instead of the emulsifier, the stirring machine was replaced with a propeller-type stirring blade (Three-one motor: manufactured by Shinto Kagaku Co., Ltd.), and stirring was performed at 400 rpm. After 10 minutes, 100% of a 5% diethylenetriamine aqueous solution was added to this.
g was added dropwise. After completion of dropping, the mixture was heated to 60 ° C. and the encapsulation reaction was performed for 3 hours. After completion of the reaction, the mixture was poured into 2 liters of ion-exchanged water, sufficiently stirred, and allowed to stand. After the capsule particles settled, the supernatant was removed. This operation was repeated 7 more times to wash the capsule particles. In this way, capsule particles containing the oily binder were obtained. Ion-exchanged water was added to the capsule particles to prepare a suspension having a solid content concentration of 40%.

2) Preparation of toner To 125 g of the suspension of capsule particles prepared in 1) (corresponding 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: Stirring was performed at 200 revolutions / minute by Shinto Kagaku Co., Ltd.). After adding 5 g of 1N nitric acid and 4 g of a 10% aqueous cerium sulfate solution, 0.5 g of ethylene glycol dimethacrylate was added and the reaction was carried out at 15 ° C. for 3 hours. After completion of the reaction, the mixture was poured into 1 liter of ion-exchanged water, sufficiently stirred and allowed to stand. After the capsule particles settled, the supernatant was removed. This operation was repeated twice more 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 rpm with a stirrer equipped with a propeller-type stirring blade (Three One Motor: manufactured by Shinto Scientific Co., Ltd.). Next, in this, 0.4 g of potassium persulfate, 2 g of sodium methallylsulfonate, 0.16 g
Of sodium bisulfite were sequentially added and reacted at 25 ° C. for 3 hours. After completion of the reaction, the mixture was poured into 2 liters of ion-exchanged water, sufficiently stirred, and then left standing. After the capsule particles settled, the supernatant was removed. This operation was repeated four more times to wash the capsule particles. Thus, a capsule toner in which sodium methallylsulfonate was graft-polymerized on the surface of the capsule shell was obtained. 0.4 g of tin oxide in the obtained capsule suspension (trade name S1: manufactured by Mitsubishi Metals)
After adding and mixing, the mixture was opened in a stainless steel vat and dried at 60 ° C. for 10 hours with a dryer (manufactured by Yamato Scientific Co., Ltd.).

3) Evaluation test 3 g of the obtained capsule toner and 100 g of an iron powder carrier whose surface was coated with a phenol resin were used at a temperature of 20 ° C. and a humidity of 4
When mixed in an environment of 0% and the charge amount of the capsule toner was measured by the blow-off method, it was -15 μC / g, and the charge distribution was sharp. Similarly, when the charge amount of the capsule toner was measured by the blow-off method after mixing in an environment of a temperature of 28 ° C. and a humidity of 80%, it was −14 μC / g,
The charge distribution was sharp. Next, the image quality of this toner was evaluated in an environment of a temperature of 20 ° C. and a humidity of 40%.
The copying machine used was a Fuji Xerox 2700 modified for capsule toner, and a copy sample was obtained by reversal development. As a result, a stable copy free of fog was obtained up to the 20,000th sheet. Under low temperature and low humidity (10 ° C, 15
%), The image quality was evaluated, and a stable and good copy was obtained even after 30,000 sheets.

Example 2 Capsule toner was obtained by performing the same procedure as in Example 1 except that 0.4 g of tin oxide in Example 1 was not added. 3 g of the obtained capsule toner and 100 g of an iron powder carrier having a surface coated with a phenol resin were mixed at a temperature of 20 ° C. and a humidity of 50.
%, And the charge amount of the capsule toner was measured by the blow-off method to find that it was −12 μC / g, and the charge distribution was three times wider than that in Example 1. Similarly, when mixed in an environment of a temperature of 28 ° C. and a humidity of 80% and measuring the charge amount of the capsule toner by the blow-off method, it is −10 μC.
The charge distribution was 3 times wider than that in Example 1. Next, for 100 parts of this toner, hydrophobic silica (R9
72: manufactured by Nippon Aerosil Co., Ltd.) and sufficiently mixed, and then image quality was evaluated in an environment of a temperature of 20 ° C. and a humidity of 50%. The copying machine used was a Fuji Xerox 2700 modified for capsule toner, and a copy sample was obtained by reversal development. As a result, a stable copy free from fog was obtained up to the 10000th sheet.

Comparative Example 1 The same treatment as in Example 2 was carried out except that 2 g of sodium methallylsulfonate in Example 2 was replaced with 2 g of sodium parastyrenesulfonate, and sodium parastyrenesulfonate was applied to the surface of the capsule shell. Graft-polymerized capsule toner was obtained. 3 g of the obtained capsule toner and 100 g of an iron powder carrier whose surface was coated with a phenol resin were mixed in an environment of a temperature of 20 ° C. and a humidity of 50%, and the charge amount was measured by a blow-off method to find −6 μC / g. It was Similarly, when mixed in an environment of a temperature of 28 ° C. and a humidity of 80% and the charge amount of the capsule toner was measured by the blow-off method, it was −4 μC / g. Next, to 100 parts of this toner, 1 part of hydrophobic silica (R972: manufactured by Nippon Aerosil Co., Ltd.) was added and thoroughly mixed, and then the image quality was evaluated in the same manner as in Example 1 in an environment of a temperature of 20 ° C. and a humidity of 50%. Where is 100
Fogging occurred on the 0th sheet, and on the 2000th sheet, the image density decreased and the sharpness was remarkably inferior.

Example 3 1) Preparation of Capsule Particles To 150 g of lauryl methacrylate monomer, 30 g of polyisobutyl methacrylate (Mw = 16 × 10 ⁴ ) was added and dissolved. 20 g of a red pigment (Hosta Palm Scarlet GO: manufactured by Bayer Co., Ltd.) was put into this and dispersed by a ball mill for 16 hours. Next, to 200 g of this dispersion, 10 g of isocyanate (Sumijour L: Sumitomo Bayer Urethane Co., Ltd.), 5 g of toluidine diisocyanate (Coronate T: Nippon Polyurethane Co., Ltd.) and 3 g of azobisvaleronitrile were added and mixed well. (This liquid is A
Use as liquid. ) On the other hand, 10 g of hydroxypropylmethyl cellulose (Metroses 65SH50: manufactured by Shin-Etsu Chemical Co., Ltd.) was dissolved in 250 g of ion-exchanged water and cooled to 5 ° C.
(This solution is referred to as solution B.) Solution B is stirred with an emulsifying machine (auto homomixer: manufactured by Tokushu Kiki Co., Ltd.), and solution A is added to the solution.
The liquid was added slowly to emulsify. Thus, an O / W emulsion in which the average particle size of the oil droplet particles in the emulsion was about 12 μm was obtained. Next, instead of an emulsifier, a stirrer equipped with propeller-type stirring blades (three-one motor:
It was changed to Shinto Kagaku Co., Ltd.) and stirred at 400 rpm. After 10 minutes, 100 g of a 2.5% aqueous solution of diethylenetriamine was added dropwise thereto. After completion of dropping, stirring was continued at room temperature to carry out a capsule reaction for 2 hours. Then 65
The reaction was performed at 14 ° C for 14 hours to polymerize the core substance. After completion of the reaction, the mixture was poured into 2 liters of ion-exchanged water, sufficiently stirred, and then centrifuged. After the capsule particles were separated, the supernatant was removed. After repeating this operation 5 more times,
Further, it was washed with methanol. Thus, red capsule particles containing a soft solid substance were obtained. Ion-exchanged water was added to the capsule particles to prepare a suspension having a solid content concentration of 40%.

2) Preparation of Toner 125 g of ion-exchanged water was added to 125 g of the capsule particle suspension prepared in 1) (corresponding to 50 g of capsule particles), and a stirring machine equipped with a propeller-type stirring blade (three-one motor: Stirring was performed at 200 revolutions / minute by Shinto Kagaku Co., Ltd.). After adding 5 g of 1N nitric acid and 4 g of a 10% aqueous cerium sulfate solution, 0.5 g of ethylene glycol dimethacrylate was added and the reaction was carried out at 15 ° C. for 3 hours. After completion of the reaction, the mixture was poured into 1 liter of ion-exchanged water, thoroughly stirred, and then centrifuged. After the capsule particles were separated, the supernatant was removed. This operation was repeated twice more 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 is resuspended in ion-exchanged water again, and it is 2 with a stirring machine equipped with a propeller-type stirring blade (Three-one motor: manufactured by Shinto Kagaku Co., Ltd.).
It was stirred at 00 rpm. Next, in this, 0.4 g of potassium persulfate, 2 g of sodium allylsulfonate,
Add 0.16 g of sodium bisulfite sequentially and add 25
The reaction was carried out at ℃ for 3 hours. After completion of the reaction, the mixture was poured into 2 liters of ion-exchanged water, sufficiently 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. Thus, a capsule toner in which sodium allylsulfonate was graft-copolymerized on the surface of the capsule shell was obtained. 0.15 g of carbon black (R
(egal 330R: manufactured by Cabot Co., Ltd.) An aqueous dispersion was added and mixed, and the mixture was poured into a stainless steel vat and dried at 60 ° C. for 10 hours by a dryer (manufactured by Yamato Scientific Co., Ltd.).

3) Evaluation test 3 g of the obtained capsule toner and 100 g of iron powder carrier whose surface was coated with a phenol resin were used at a temperature of 20 ° C. and a humidity of 4
When mixed in an environment of 0% and the charge amount of the capsule toner was measured by the blow-off method, it was −14 μC / g, and the charge distribution was sharp. Similarly, temperature 28 ℃, humidity 8
When mixed in an environment of 0% and the charge amount of the capsule toner was measured by the blow-off method, it was −13 μC / g, and the charge distribution was sharp. Next, the image quality of this toner was evaluated in an environment of a temperature of 20 ° C. and a humidity of 40%. The copying machine used was a Fuji Xerox 2700 modified for capsule toner, and a copy sample was obtained by reversal development. As a result, a stable copy free of fog was obtained up to the 20,000th sheet. Also, under low temperature and low humidity (10 ° C, 15
%), The image quality was evaluated, and a stable and good copy was obtained even after 30,000 sheets.

Example 4 The same treatment as in Example 3 was carried out except that 0.15 g of carbon black of Example 3 was not added. 3 g of the obtained capsule toner and 100 g of an iron powder carrier whose surface was coated with a phenol resin were mixed in an environment of a temperature of 20 ° C. and a humidity of 50%, and the charge amount of the capsule toner was measured by a blow-off method to find −15 μC / The charge distribution was 3 times wider than that in Example 3. Similarly, when the charge amount of the capsule toner was measured by the blow-off method after mixing in an environment of a temperature of 28 ° C. and a humidity of 80%, it was −11 μC / g, and the charge distribution was three times wider than that of Example 3. . Next, to 100 parts of this toner, 1 part of hydrophobic silica (R972: manufactured by Nippon Aerosil Co., Ltd.) was added and thoroughly mixed, and then the temperature was adjusted to 2
Image quality was evaluated under the environment of 0 ° C. and 50% humidity. The copying machine used was a Fuji Xerox 2700 modified for capsule toner, and a copy sample was obtained by reversal development. As a result, a stable copy free from fog was obtained up to the 10000th sheet.

Comparative Example 2 Without using 2 g of sodium allylsulfonate of Example 4,
Except for this, the same treatment as in Example 4 was performed. 3 g of the obtained capsule toner and 100 g of an iron powder carrier having a surface coated with a phenol resin were mixed in an environment of a temperature of 20 ° C. and a humidity of 50%, and the charge amount was measured by a blow-off method to find −3 μC / g. It was Similarly, temperature 28 ℃, humidity 8
When mixed in an environment of 0% and the charge amount of the capsule toner was measured by the blow-off method, it was −2 μC / g. Next, for 100 parts of this toner, hydrophobic silica (R972:
After adding 1 part (manufactured by Nippon Aerosil Co., Ltd.) and thoroughly mixing them, the image quality was evaluated in the same manner as in Example 2 in an environment of a temperature of 20 ° C. and a humidity of 50%.
On the 0th sheet, the image density was lowered and the image quality was remarkably inferior in sharpness.

Example 5 1) Preparation of capsule particles Polyisobutyl methacrylate (Mw = 16 × 1) was added to a mixed solution of 60 g of dibutylnaphthalene and 60 g of ethyl acetate.
0 ⁴ ) 30 g and styrene-n-butyl methacrylate copolymer (Mw = 6 × 10 ⁴ ) 40 g were added and dissolved.
Magnetic powder (EPT-1000: manufactured by Toda Kogyo Co., Ltd.) 12
0 g was put and dispersed by a ball mill for 16 hours. Next, to 200 g of this dispersion, 20 g of isocyanate (Sumijour L: Sumitomo Bayer Urethane Co., Ltd.), 5 g of toluidine diisocyanate (Coronate T: Nippon Polyurethane Co.) and an epoxy resin (Epicoat 801:
Oily Shell Epoxy) and 24 g of ethyl acetate were added and mixed thoroughly. (This liquid is referred to as liquid A.) On the other hand, 10 g of hydroxypropylmethyl cellulose (Metroses 65SH50: manufactured by Shin-Etsu Chemical Co., Ltd.) was dissolved in 200 g of ion-exchanged water and cooled to 5 ° C. (This solution is referred to as solution B.)
The liquid B was stirred by an emulsifying machine (auto homomixer: manufactured by Tokushu Kiki Co., Ltd.), and the liquid A was slowly added to the liquid for emulsification. Thus, an O / W emulsion in which the average particle size of the oil droplet particles in the emulsion was about 12 μm was obtained. Next, replace the emulsifying machine with a stirring machine equipped with propeller type stirring blades (three-one motor: manufactured by Shinto Kagaku Co., Ltd.)
Stirred at 0 rpm. After 10 minutes, 100 g of a 5% aqueous solution of diethylenetriamine was added dropwise thereto. After completion of dropping, the mixture was heated to 60 ° C. and the encapsulation reaction was performed for 3 hours. After completion of the reaction, the mixture was poured into 2 liters of ion-exchanged water, sufficiently stirred, and allowed to stand. After the capsule particles settled, the supernatant was removed. This operation was repeated 7 more times to wash the capsule particles. In this way, capsule particles containing the oily binder were obtained. Ion-exchanged water was added to the capsule particles to prepare a suspension having a solid content concentration of 40%.

2) Preparation of Toner 125 g of ion-exchanged water was added to 125 g of the capsule particle suspension prepared in 1) (corresponding to 50 g of capsule particles), and a stirring machine equipped with a propeller-type stirring blade (three-one motor: Stirring was performed at 200 revolutions / minute by Shinto Kagaku. After adding 5 g of 1N nitric acid and 4 g of a 10% aqueous cerium sulfate solution, 0.5 g of ethylene glycol dimethacrylate was added and the reaction was carried out at 15 ° C. for 3 hours. After completion of the reaction, the mixture was poured into 1 liter of ion-exchanged water, sufficiently stirred and allowed to stand. After the capsule particles settled, the supernatant was removed. This operation was repeated twice more 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 rpm with a stirrer equipped with a propeller-type stirring blade (Three One Motor: manufactured by Shinto Scientific Co., Ltd.). Next, 0.4 g of potassium persulfate, 1 g of sodium methallylsulfonate, 0.5 g of methyl methacrylate, and 0.16 g of sodium hydrogen sulfite were sequentially added to this, and the reaction was carried out at 25 ° C. for 3 hours. . After completion of the reaction, the mixture was poured into 2 liters of ion-exchanged water, sufficiently stirred, and then left standing. After the capsule particles 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 sodium methallylsulfonate and methyl methacrylate were graft-copolymerized on the surface of the capsule shell was obtained. The obtained capsule suspension was dried by spray drying, and further tin oxide was added.
4g (S1: manufactured by Mitsubishi Metals) and 0.3g of hydrophobic silica
(R972: manufactured by Nippon Aerosil Co., Ltd.) is added,
The mixture was mixed for 12 hours with a V blender (transparent mixer: manufactured by Tsutsui Rikagaku Kikai).

3) Evaluation test 3 g of the obtained capsule toner and 100 g of an iron powder carrier whose surface was coated with a phenol resin were used at a temperature of 20 ° C. and a humidity of 4
When the charge amount of the capsule toner was measured by the blow-off method after mixing in an environment of 0%, it was -15 μC / g and the charge distribution was sharp. Similarly, temperature 28 ℃, humidity 8
When mixed in an environment of 0% and the charge amount of the capsule toner was measured by the blow-off method, it was -11 μC / g, and the charge distribution was sharp. Next, the image quality of this toner was evaluated in an environment of a temperature of 20 ° C. and a humidity of 40%. The copying machine used was a Fuji Xerox 2700 modified for capsule toner, and a copy sample was obtained by reversal development. As a result, a stable copy free of fog was obtained up to the 20,000th sheet. Also, under low temperature and low humidity (10 ° C, 15
%), The image quality was evaluated, and a stable and good copy was obtained even after 30,000 sheets.

Example 6 The capsule suspension obtained in Example 5 was placed in a stainless steel vat and dried at 60 ° C. for 10 hours with a dryer (manufactured by Yamato Scientific Co., Ltd.).
It was dried for an hour to obtain a capsule toner. 3 g of the obtained capsule toner and 100 g of an iron powder carrier whose surface was coated with a phenol resin were mixed in an environment of a temperature of 20 ° C. and a humidity of 50%, and the charge amount of the capsule toner was measured by a blow-off method to find −15 μC / The charge distribution was 3 times wider than that in Example 5. Similarly, temperature 28 ℃, humidity 8
When mixed in an environment of 0% and the charge amount of the capsule toner was measured by the blow-off method, it was −10 μC / g, and the charge distribution was three times wider than that in Example 5. Next, to 100 parts of this toner, 1 part of hydrophobic silica (R972: manufactured by Nippon Aerosil Co., Ltd.) was added and thoroughly mixed, and then the temperature was adjusted to 20.
Image quality was evaluated in an environment of ° C and humidity of 50%. The copying machine used was a Fuji Xerox 2700 modified for capsule toner, and a copy sample was obtained by reversal development.
As a result, a stable copy free from fog was obtained up to the 10000th sheet.

Comparative Example 3 The same treatment as in Example 6 was performed except that 1 g of sodium methallylsulfonate and 0.5 g of methyl methacrylate in Example 6 were replaced with 0.5 g of methyl methacrylate. 3 g of the obtained capsule toner and 100 g of an iron powder carrier having a surface coated with a phenol resin were heated at a temperature of 20.
The mixture was mixed in an environment of ° C and humidity of 50%, and the charge amount was measured by the blow-off method, and it was -1 µC / g. Similarly,
When mixed in an environment of a temperature of 28 ° C. and a humidity of 80% and the charge amount of the capsule toner was measured by the blow-off method, it was 0 μC.
/ G. Next, to 100 parts of this toner, 1 part of hydrophobic silica (R972: manufactured by Nippon Aerosil Co., Ltd.) was added and thoroughly mixed, and then the image quality was evaluated in the same manner as in Example 2 in an environment of a temperature of 20 ° C. and a humidity of 50%. As a result, fog was generated on the 10th sheet, and the image density was lowered on the 100th sheet, resulting in a sharply deteriorated image quality.

Example 7 1) Preparation of toner After preparing capsule particles with the exact same formulation as in Example 1,
125 g of ion-exchanged water was added to 125 g of a suspension of capsule particles (corresponding to 50 g of capsule particles), and a stirring machine equipped with a propeller-type stirring blade (three-one motor:
Stirring was performed at 200 revolutions / minute by Shinto Kagaku Co., Ltd.). 1N nitric acid 5g, 10% cerium sulfate aqueous solution 4g
After the addition of ethylene glycol dimethacrylate.
5 g was added and the reaction was carried out at 15 ° C. for 3 hours. After completion of the reaction, the mixture was poured into 1 liter of ion-exchanged water, sufficiently stirred and allowed to stand. After the capsule particles settled, the supernatant was removed.
This operation was repeated twice more 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 in ion-exchanged water again, and a stirring machine equipped with a propeller-type stirring blade (three-one motor:
Stirring was performed at 200 revolutions / minute by Shinto Kagaku Co., Ltd.). Next, 0.4 g of potassium persulfate, 2 g of ammonium methallylsulfonate, and 0.16 g of sodium hydrogen sulfite were sequentially added to this, and the reaction was carried out at 25 ° C. for 3 hours. After completion of the reaction, the mixture was poured into 2 liters of ion-exchanged water, sufficiently stirred, and then left standing. After the capsule particles settled, the supernatant was removed. This operation was repeated four more times to wash the capsule particles. 125 g suspension of prepared capsule particles
(Equivalent to 50 g of capsule particles), ion-exchanged water 125
g, 0.1 g of a perfluoroalkyl quaternary ammonium salt (Unidyne DS-202: manufactured by Daikin Industries, Ltd.), and a stirring machine equipped with a propeller-type stirring blade (three-one motor: manufactured by Shinto Kagaku Co., Ltd.) was used. Stirred for 1 hour at revolutions / minute. After stirring, the mixture was poured into 2 liters of ion-exchanged water, thoroughly stirred, and then allowed to stand. After the capsule particles settled, the supernatant was removed. This operation was repeated four more times to wash the capsule particles. In this way, a capsulated toner in which a perfluoroalkyl quaternary ammonium methallylsulfonate was graft-polymerized on the surface of the capsule shell was obtained. To the obtained capsule suspension, 0.2 g of titanium black (13R: manufactured by Mitsubishi Metals Co., Ltd.) aqueous dispersion was added and mixed, and the mixture was opened in a stainless steel vat and dried at 60 ° C. for 10 hours with a dryer (manufactured by Yamato Scientific Co., Ltd.). Dried.

3) Evaluation test 3 g of the obtained capsule toner and 100 g of an iron powder carrier whose surface was coated with a phenol resin were used at a temperature of 20 ° C. and a humidity of 5
When the charge amount of the capsule toner was measured by the blow-off method after mixing in an environment of 0%, it was -15 μC / g and the charge distribution was sharp. Similarly, temperature 28 ℃, humidity 8
When mixed in an environment of 0% and the charge amount of the capsule toner was measured by the blow-off method, it was −10 μC / g, and the charge distribution was sharp. Next, the image quality of this toner was evaluated in an environment of a temperature of 20 ° C. and a humidity of 50%. The copying machine used was a Fuji Xerox 2700 modified for capsule toner, and a copy sample was obtained by reversal development. As a result, a stable copy free of fog was obtained up to the 20,000th sheet. In addition, at low temperature and low humidity (10 ° C, 1
When the image quality was evaluated at 5%), a stable and good copy was obtained even after 30,000 sheets.

Example 8 1) Preparation of Toner A capsule toner was obtained by the same process as in Example 7 except that 0.2 g of titanium black of Example 7 was not added. 3 g of the obtained capsule toner and 100 g of an iron powder carrier having a surface coated with a phenol resin were mixed in an environment of a temperature of 20 ° C. and a humidity of 50%, and the charge amount of the capsule toner was measured by a blow-off method to find −14 μC / The charge distribution was 3 times wider than that in Example 7. Similarly, when mixed in an environment of a temperature of 28 ° C. and a humidity of 80% and measuring the charge amount of the capsule toner by the blow-off method, −
10 μC / g, and the charge distribution is 3 as compared with that in Example 7.
It was twice as wide. Next, to 100 parts of this toner, 1 part of hydrophobic silica (R972: manufactured by Nippon Aerosil Co., Ltd.) was added and thoroughly mixed, and then image quality was evaluated in an environment of a temperature of 20 ° C. and a humidity of 50%. The copying machine used is Fuji Xerox 270.
A copy sample was obtained by reversal development with 0 being modified for capsule toner. As a result, a stable copy free from fog was obtained up to the 10000th sheet.

[0040]

As described above, the electrophotographic toner of the present invention comprises the sulfonic acid group-containing vinyl compound represented by the above general formula (1) on the surface of the capsule particles having at least the substance capable of generating a radical on the surface. Since the polymer containing the monomer as the monomer component is attached, the mechanical strength and negative chargeability of the toner are good. Therefore, the chargeability is not impaired by the mechanical force, so that it is possible to stably form a copy image with excellent image quality even after storage for a long time or when copying a large number of sheets. Furthermore, since the conductive fine particles are externally added to the electrophotographic toner, the charge distribution becomes sharp. Therefore, a copy image with excellent image quality can be produced, and cleaning under low temperature and low humidity becomes good.

Claims (2)

[Claims] 1. The following general formula (1) is provided on the surface of capsule particles having a substance capable of generating radicals on at least the surface thereof.
Sulfonic acid group-containing vinyl monomer represented by: (Wherein, R1 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, X is _{- (CH 2) n -,} - CONHC (R
_{2) (R 3) R 4} -, - COO (CH 2) m -, - CONH
-, N is an integer of 0 to 20, R ₂ and R ₃ are hydrogen atoms or alkyl groups having 1 to 20 carbon atoms, and R ₄ is 1 to 20 carbon atoms.
Alkylene group, m is an integer of 1 to 20, M ^{q +} is q
Represents a cation in which is an integer of 1 to 3. And a polymer containing) as a monomer component is attached to the capsule toner for electrophotography. 2. The surface of the capsule particles having a substance capable of generating radicals on at least the surface of the following general formula (1)
A sulfonic acid group-containing vinyl monomer represented by the formula:
Shows three alkyl groups, X is _{- (CH 2) n -,} - CON
_{HC (R 2) (R 3} ) R 4 -, - COO (CH 2) m -, -
CONH-, n is an integer of 0 to 20, R ₂ and R ₃ are hydrogen atoms or alkyl groups having 1 to 20 carbon atoms, R ₄ is an alkylene group having 1 to 20 carbon atoms, and m is an integer of 1 to 20. Shows,
M ^{q +} represents a cation in which q is an integer of 1 to 3. (3) as a monomer component is attached, and conductive fine particles are externally added to the capsule toner for electrophotography.