JPH04265980A - Capsule toner - Google Patents

Abstract

PURPOSE:To improve mechanical strength and electrostatic chargeability by forming an outer shell with a material which is able to form radical and by sticking a polymer containing a vinyl monomer containing specific quaternary ammonium salt as a monomer component. CONSTITUTION:A capsule is constituted of a core material and the outer shell covering the core material and the outer shell is formed with the material which is able to form radical. And moreover, the polymer containing the quaternary ammonium salt as the monomer component is stuck on the surface of the outer shell. In the formula, each of R1-R3 is hydrogen atom, 1-8C alkyl group or benzyl group, X<-> is anion group having-COO<-> group, SL3- group.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capsule toner for electrophotography.

0002

[Prior Art] Conventionally, as one type of electrophotographic toner for developing an electrostatic charge image formed on the surface of an electrophotographic photoreceptor, an electrostatic recording medium, etc., toner is formed from a core material and an outer shell. Microcapsule toners are known, and various proposals have been made. For example, JP-A-58-120263, JP-A-54-124731, and JP-A-59-187351 disclose capsule toners in which a specific quaternary ammonium salt polymer is present in the capsule shell.

0003

[Problems to be Solved by the Invention] However, since the polymer described in the above publication uses a halogen atom as an anion in the quaternary ammonium salt structure, the environmental stability of charging, especially the humidity stability, is poor. It had the disadvantage of being bad. In addition, since this polymer is contained as one of the constituent components of the capsule outer shell, it is difficult to achieve both the mechanical strength of the toner and the chargeability of the toner with a single outer shell constituent, and material selection is difficult. It had the disadvantage of having a narrow degree of freedom.

The present invention has been made in view of the above-mentioned problems in the prior art. That is, an object of the present invention is to provide a capsule toner having high mechanical strength and excellent charging characteristics.

[0005]

[Means for Solving the Problems] The present invention provides a capsule toner comprising a core material and an outer shell covering the core material.
The outer shell is made of a substance capable of generating radicals, and on the surface of the outer shell is a quaternary ammonium salt-containing vinyl monomer represented by the following general formula (I): (wherein R1 to R3 are each a hydrogen atom, represents an alkyl group or benzyl group having 1 to 8 carbon atoms,
X- represents an anion having a -COO- or -SO3- group. ) is attached as a monomer component.

Next, the present invention will be explained in detail. The capsule toner of the present invention has a so-called capsule structure consisting of a core material and an outer shell covering the core material, and the outer shell is formed of a substance capable of generating radicals.

[0007] In the present invention, the term "substance capable of generating radicals" refers to a substance that undergoes an abstraction reaction or an addition reaction of hydrogen atoms with monomer radicals or cerium (IV) ions to generate radicals, in particular,
Examples include polymers such as 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 present invention, the outer shell resin includes polyurea resin, polyurethane resin, polyamide resin, polyester resin, epoxy resin, epoxyurea resin,
Epoxyurethane resins are preferred, and among these, polyurea resins or polyurethane resins alone, or mixtures of both, or epoxyurea resins or epoxyurethane resins alone, or mixtures of both are more preferred.

In the present invention, a polymer containing the vinyl monomer represented by the above general formula (I) as a monomer component is attached to the surface of the outer shell. This attachment may be physical or chemical bonding. Specific examples of the vinyl monomer represented by the above general formula (I) include those represented by the following structural formula as a cation moiety.

0010

[0011] Further, examples of the anion moiety X- include those shown by the following structural formula. CH3 CO2 −, CH3 CH2 CO2 −, C
H3 CH2 CH2 CO2 −, CH3 (CH2
)6 CO2 −, CH3 (CH2 )10CO2
- aliphatic carboxylic acid groups such as

0012 aromatic carboxylic acid groups such as

[0013] Examples include aromatic sulfonic acid groups such as, and sulfate ions such as lauryl sulfate anion and dodecyl sulfate anion. Furthermore, the anion X- may be an anion residue of an acid dye such as acid red, acid orange, acid violet, acid blue, or the like.

In the present invention, the polymer containing the monomer represented by the above general formula (I) as a monomer component may be a copolymer containing the monomer as one monomer component. . When included as one component of the copolymer, the content of the above monomer is 1% to the total polymer.
It ranges from mol% to 80 mol%, preferably from 5 mol% to 60 mol%.

Examples of monomers that can be copolymerized with the monomer represented by the above general formula (1) include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, Butyl (meth)acrylate, Pentyl (meth)acrylate, Hexyl (meth)acrylate, Lauryl (meth)acrylate, Cyclohexyl (meth)acrylate, (meth)acrylic acid 2
-Ethylhexyl, benzyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, glycidyl (meth)acrylate, phenyl (meth)acrylate, etc. fatty acid vinyl esters such as (meth)acrylic acid esters, vinyl formate, vinyl acetate, 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,
Examples include vinyl ethers such as 2-ethylhexyl vinyl ether and phenyl vinyl ether, vinyl ketones such as methyl vinyl ketone and phenyl vinyl ketone, and vinyl aromatic compounds such as styrene, chlorostyrene, hydroxystyrene, and α-methylstyrene. . One or more of these can be mixed and copolymerized with the monomer represented by the above general formula (I). Among these, (meth)acrylic acid esters are particularly preferred.

In the present invention, in order to attach the polymer containing the monomer represented by the general formula (I) as a monomer component to the surface of the outer shell, direct polymerization is performed from the monomer already having the anion moiety X-. However, according to the studies of the present inventors, first, a corresponding halogenated ammonium salt monomer is used to introduce a halogen ion-containing heavy compound onto the surface of the outer shell. A preferred method is to convert the halogen ion into the above-mentioned anion by ion exchange after the coalescence is deposited. This method is excellent in that it has a wide degree of freedom in selecting anion species and can save time and effort in monomer synthesis.

Next, the core material in the present invention will be explained. As the core material, when the purpose is pressure fixing, a core material mainly containing a component having pressure fixing properties is used. Particularly when the purpose is pressure fixing, it is preferable that the core material mainly consists of a binder resin, a high boiling point solvent for dissolving it, and a coloring material, or one that mainly consists of a soft solid material 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 a high boiling point solvent 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 binder resin, known fixing resins can be used. Specifically, acrylic ester polymers such as polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, poly2-ethylhexyl acrylate, and polylauryl acrylate, polymethyl methacrylate, polybutyl methacrylate, and polymethacrylate. methacrylic acid ester polymers such as hexyl acid, poly2-ethylhexyl methacrylate, and polylauryl methacrylate;
Copolymers of styrene monomers and acrylic esters or methacrylic esters, polyvinyl acetate, polyvinyl propionate, polyvinyl butyrate, ethylene polymers and their copolymers such as polyethylene and polypropylene, styrene-butadiene copolymers styrene 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. They can be used alone or in combination. Alternatively, it can be prepared as a monomer and polymerized after encapsulation to form a binder resin.

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, Moder
n Plastics Encyclopedia (1
975-1976) can be selected from among those described in Plasticizers.

It has also been disclosed as a core material for pressure fixing capsule toner (for example, Japanese Patent Laid-Open No. 58-145964).
(No. 63-163373) may be selected from high boiling point solvents. Specifically, phthalate esters (e.g., diethyl phthalate, dibutyl phthalate); aliphatic dicarboxylic acid esters (e.g., diethyl malonate, dimethyl oxalate); phosphoric acid esters (e.g., tricresyl phosphate); , tricylyl phosphate); citric acid esters (e.g., o-acetyltriethyl citrate)
Benzoic acid esters (e.g., butyl benzoate, hexyl benzoate); Fatty acid esters (e.g., hexadecyl myristate, dioctyl adipate); Alkylnaphthalenes (e.g., methylnaphthalene, dimethylnaphthalene, monoisopropylnaphthalene, diisopropylnaphthalene); Alkyl diphenyl ethers (e.g. o-
, m-, p-methyl diphenyl 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 dimethylphenyl phenylmethane, 1-
diarylethanes such as phenyl-1-methylphenylethane, 1-dimethylphenyl-1-phenylethane, and 1-ethylphenyl-1-phenylethane; and chlorinated paraffins. In addition, when a polymer having a long chain alkyl group such as a lauryl methacrylate homopolymer or copolymer is used as the binder polymer, an aliphatic saturated hydrocarbon or an organic solvent mainly composed of an aliphatic saturated hydrocarbon (for example, Exxon Chemical Company-made I
sopar-G Isopar-H, Isopar-
L etc.) can also be used.

Colorants include inorganic pigments such as carbon black, red iron, navy blue, and titanium oxide, azo pigments such as Fast Yellow, Disazo Yellow, Pyrazolone Red, Chelate Red, Brilliant Carmine, and Para Brown, copper phthalocyanine, and metal-free phthalocyanine. Examples include condensed polycyclic pigments such as phthalocyanine, flaavanthrone yellow, dibromoanthrone orange, perylene red, quinacridone red, and dioxazine violet. Further, disperse dyes, oil-soluble dyes, etc. can also be used.

Furthermore, in 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. In addition, magnetic powder may be surface-treated with a coupling agent such as a silane coupling agent or titanate coupling agent or an oil-soluble surfactant, or the surface may be coated with an acrylic resin, styrene resin, or epoxy resin. good. Furthermore, a coloring agent or magnetic powder charged as a component of the core material may be present at the interface between the core and the outer shell or in the outer shell after the capsule is formed.

[0023] The soft solid material may be of any kind as long as it is flexible at room temperature and has fixing properties, but polymers with a Tg in the range of -60°C to 5°C or polymers thereof may be used. Mixtures of polymers with other polymers are preferred.

[0024] In producing the capsule toner of the present invention,
Although there are no particular restrictions on the encapsulation method, an encapsulation method using interfacial polymerization is superior in terms of the holes in the coating and the mechanical strength of the outer shell. Capsules can be produced by interfacial polymerization using known methods (for example, Japanese Patent Application Laid-Open No.
No. 7-179860, No. 58-66948, No. 59-
(Refer to No. 148066 and Publication No. 59-162562)

[
The thickness of the outer shell is desirably different depending on whether the purpose is pressure fixing or heat fixing, and the types or composition ratios of the constituent components may also be changed. A method for incorporating a polymer into a capsule as one of the core material components is to prepare the polymer in advance together with other core material components, a low boiling point solvent, and an outer shell forming component, and then form the outer shell through interfacial polymerization. It is possible to use a method in which the low boiling point solvent is expelled from the system to form the core material at the same time or after the formation of the outer shell is completed. Alternatively, a method may be used in which the core material component is introduced in the form of a monomer, an outer shell is formed by interfacial polymerization, and then the monomer is polymerized to form the core material.

Further, external additives such as silicon oxide, aluminum oxide, titanium oxide, and carbon black may be added to the capsule toner in order to impart fluidity or chargeability. External additives can be added to the toner surface by drying after drying the capsule toner using a mixer such as a V blender or Henschel mixer, or by adding external additives to the toner surface using water or water/alcohol. After being dispersed in an aqueous liquid such as an aqueous liquid, it may be added to a capsule toner in a slurry state and dried to adhere an external additive to the surface of the toner.

[0027]

[Example] Example 1 (Preparation of capsule particles) 30 g of polyisobutyl methacrylate (MW = 16 x 104) and styrene-n-
Butyl methacrylate copolymer (MW = 6 × 104
) was added and dissolved. Add magnetic powder (EPT) to this.
-1000: manufactured by Toda Kogyo Co., Ltd.) and dispersed in a ball mill for 16 hours. Next, 200 g of this dispersion
30 g of isocyanate (Sumidur L, manufactured by Sumitomo Bayer Urethane) and 24 g of ethyl acetate were added thereto and thoroughly mixed (this liquid is referred to as liquid A). On the other hand, 10 g of hydroxypropyl methylcellulose (Metrose 65H50: manufactured by Shin-Etsu Chemical Co., Ltd.) was added to 200 g of ion-exchanged water.
g 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 for emulsification. In this way, an O/W emulsion in which the average particle diameter of oil droplets in the emulsion was about 12 μm was obtained. Next, instead of the emulsifier, a stirrer equipped with propeller-type stirring blades (three-one motor: manufactured by Shinto Kagakusha) was used, and 40
Stirred at 0 revolutions/min. After 10 minutes, 100 g of a 5% aqueous diethylenetriamine solution was added dropwise. After the dropwise addition was completed, the mixture was heated to 60°C and an encapsulation reaction was carried out 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 settle,
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. Ion-exchanged water was added to the capsule particles to prepare a suspension with a solid content concentration of 40%.

(Formation of toner) To 125 g of the suspension of capsule particles prepared as described above (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 ( The mixture was stirred at 200 rpm using a three-one motor (manufactured by Shinto Kagaku Co., Ltd.). 1N for this
After adding 5 g of nitric acid and 4 g of 10% cerium sulfate aqueous solution, 0.5 g of ethylene glycol dimethacrylate was added.
g was added thereto, and the reaction was carried out at 15°C for 3 hours. After the reaction was completed, it was poured into 1 liter 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 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.

The capsule particles were resuspended in ion-exchanged water and stirred at 200 revolutions/minute using a stirrer equipped with propeller-type stirring blades (Three-One Motor; manufactured by Shinto Kagakusha Co., Ltd.). Next, add 0.4 g of potassium persulfate to this,
0.2 g of the chloride of the exemplary compound (1) and 2.
0 g of methyl methacrylate and 0.16 g of sodium bisulfite were sequentially added, 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.

Next, 2 g of a 5% aqueous solution of sodium 1-naphthalenesulfonate was added to this capsule particle suspension.
The ion exchange reaction was performed by stirring at room temperature for 30 minutes. After the reaction is complete, dissolve the capsule particles in 1 liter of ion-exchanged water.
The capsule toner of the present invention was obtained by washing twice. The obtained capsule suspension was poured into a stainless steel vat and dried in a dryer at 60° C. for 10 hours.

3 g of the obtained capsule toner was mixed with 100 g of iron powder carrier whose surface was coated with phenolic resin in an environment of a temperature of 20° C. and a humidity of 50%, and the amount of charge of the capsule toner was measured by a blow-off method. By the way, +21
It was μC/g. Similarly, the temperature is 28℃ and the humidity is 80%.
The charge amount of the capsule toner was measured by blow-off method and found to be +18 μC/g. Next, hydrophobic silica (RA-2
After adding 1 part of 00H (manufactured by Nippon Aerosil Co., Ltd.) and thoroughly mixing, the image quality was evaluated in a high temperature and high humidity environment of 35° C. and 85% humidity. A copy sample was obtained using a copying machine manufactured by Fuji Xerox Co., Ltd. 2700 modified for use with capsule toner. As a result, stable copies without fog were obtained up to the 20,000th copy.

Comparative Example 1 The same treatment as in Example 1 was carried out except that the aqueous solution of sodium 1-naphthalenesulfonate was not added to obtain a capsule toner in which the anion was still a chlorine ion. 3 g of the obtained capsule toner was mixed with 100 g of iron powder carrier whose surface was coated with phenolic resin in an environment of 20°C and 50% humidity, and the amount of charge was measured using the blow-off method; it was +20 μC/g. there were. Similarly, when the mixture was mixed in an environment with a temperature of 28° C. and a humidity of 80%, and the amount of charge was measured by the blow-off method, it was found to be +4 μC/g. Next, hydrophobic silica (RA200
After adding 1 part of H: manufactured by Nippon Aerosil Co., Ltd. and mixing thoroughly, image quality was evaluated in the same manner as in Example 1 under a high temperature and high humidity environment of 35°C and 85% humidity. Fog occurred, and on the 100th sheet, the image density decreased and the image quality became significantly inferior in clarity.

Example 2 125 g of the suspension of capsule particles prepared in Example 1 (
(equivalent to 50g of capsule particles), 125g of ion-exchanged water
g was added thereto, and the mixture was stirred at 200 rpm using a stirrer equipped with a propeller-type stirring blade (Three-One Motor: manufactured by Shinto Kagakusha Co., Ltd.). After adding 5 g of 1N nitric acid and 4 g of 10% ammonium cerium (IV) sulfate aqueous solution, 0.5 g of ethylene glycol dimethacrylate was added, and 1
The reaction was carried out at 5°C for 3 hours. After the reaction was completed, it was poured into 1 liter 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 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.

The capsule particles were resuspended in ion-exchanged water and stirred at 200 revolutions/minute using a stirrer equipped with propeller-type stirring blades (Three-One Motor, manufactured by Shinto Kagakusha Co., Ltd.). Next, in this, 0.4 g of potassium persulfate,
0.2 g of the chloride of the exemplary compound (2) and 2.
0 g of methyl methacrylate and 0.16 g of sodium bisulfite were sequentially added, 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 settle,
The supernatant was removed. This operation was repeated four more times to wash the capsule particles. Next, 2 g of a 5% aqueous solution of sodium acetate was added to this capsule particle suspension, and 30 g of a 5% aqueous solution of sodium acetate was added.
The ion exchange reaction was performed by stirring at room temperature for a minute. After the reaction is complete, dissolve the capsule particles in 1 liter of ion-exchanged water.
The capsule toner of the present invention was obtained by washing twice. Pour the obtained capsule suspension into a stainless steel vat,
It was dried at 60° C. for 10 hours in a dryer (manufactured by Yamato Scientific Co., Ltd.).

3 g of the obtained capsule toner was mixed with 100 g of iron powder carrier whose surface was coated with phenolic resin in an environment of a temperature of 20° C. and a humidity of 50%, and the amount of charge of the capsule toner was measured by a blow-off method. However, +20μ
C/g. Similarly, 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 the blow-off method, and it was found to be +18 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 thoroughly mixing, image quality was evaluated in a high temperature and high humidity environment of 35°C and 85% humidity. . Copy samples were obtained using a copying machine manufactured by Fuji Xerox Co., Ltd. 2700 modified for use with capsule toner. As a result, stable copies without fog were obtained up to the 20,000th copy.

Comparative Example 2 The same treatment as in Example 2 was carried out except that the aqueous sodium acetate solution was not added, to obtain a capsule toner in which the anion was still a chlorine ion. When 3 g of the obtained capsule toner was mixed with 100 g of iron powder carrier whose surface was coated with phenolic resin in an environment of a temperature of 20°C and a humidity of 50%, and the amount of charge was measured using the blow-off method, it was found to be +14 μC/g. Ta. Similarly, 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 the blow-off method, and it was found to be +4 μC/g. Next, this toner 10
Add 1 part of hydrophobic silica (R972: manufactured by Nippon Aerosil Co., Ltd.) to 0 parts, mix well, and heat to 35°C.
When image quality was evaluated in the same manner as in Example 1 under a high temperature and high humidity environment of 85% humidity, fogging occurred from the first sheet.
On the 50th sheet, the image density decreased and the image quality became significantly inferior in clarity.

Example 3 (Preparation of capsule particles) Saturated hydrocarbon solvent (Isop
ar-H: Exxon Chemical Co., Ltd.) 40g, ethyl acetate 6
0g of polylauryl methacrylate (MW = 5 × 1
04) and 20 g of petroleum resin (FTR-6125: manufactured by Mitsui Petrochemicals) were added and dissolved. Magnetic powder 120 treated with a titanium coupling agent to make it hydrophobic
g and dispersed in a ball mill for 24 hours. next,
To 200 g of this dispersion, 10 g of isocyanate (Sumidur L, manufactured by Sumitomo Bayer Urethane Co., Ltd.) and 5 g of toluylene diisocyanate (Coronate T, manufactured by Nippon Polyurethane Co., Ltd.) were added and mixed (this liquid was mixed with liquid A). do.). On the other hand, add hydroxypropyl methylcellulose (Metrose 65SH50) to 250 g of ion-exchanged water.
(manufactured by Shin-Etsu Chemical Co., Ltd.) 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 for emulsification. In this way, O/W with an average particle size of oil droplets in the emulsion of about 12 μm
I got an emulsion. Next, in place of the emulsifier, a stirrer equipped with propeller-type stirring blades (Three-One Motor, manufactured by Shinto Kagakusha Co., Ltd.) was used to stir at 400 revolutions/minute. 10
After a few minutes, 100 g of a 2.5% diethylenetriamine aqueous solution was added dropwise thereto. After the dropwise addition was completed, the encapsulation reaction was carried out at 65°C for 3 hours. Thereafter, a reaction was carried out at 65° C. for 14 hours to polymerize the core material. After the reaction was completed, it was poured into about 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 five more times to obtain capsule particles. Ion-exchanged water was added to the capsule particles to prepare a suspension with a solid content concentration of 40%.

(Formation of toner) To 125 g of the suspension of capsule particles prepared as described above (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 ( The mixture was stirred at 200 rpm using a three-one motor (manufactured by Shinto Kagakusha). 1N for this
After adding 5 g of nitric acid and 4 g of 10% cerium sulfate aqueous solution, 0.5 g of ethylene glycol dimethacrylate was added.
g was added thereto, and the reaction was carried out at 15°C for 3 hours. After the reaction was completed, the mixture was poured into 1 liter 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 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.

The obtained capsule particles were resuspended in ion-exchanged water and stirred at 200 revolutions/minute using a stirrer equipped with propeller-type stirring blades (Three-One Motor, manufactured by Shinto Kagakusha Co., Ltd.). Next, 0.4 g of potassium persulfate, 0.2 g of the chloride of the above-mentioned exemplary compound (3), 2.0 g of methyl methacrylate, and 0.16 g of sodium bisulfite were sequentially added to the solution. 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.

Next, an acid dye (
Fast Red A: 5% aqueous solution 2 of Wako Pure Chemical Industries, Ltd.
g was added thereto, and the mixture was stirred at room temperature for 30 minutes to perform an ion exchange reaction. After the reaction was completed, the capsule particles were washed five times with 1 liter of ion-exchanged water to obtain the capsule toner of the present invention. The obtained capsule suspension was poured into a stainless steel vat and dried in a dryer at 60°C for 10 hours.

3 g of the obtained capsule toner was mixed with 100 g of iron powder carrier whose surface was coated with phenolic resin in an environment of a temperature of 20° C. and a humidity of 50%, and the amount of charge of the capsule toner was measured by a blow-off method. However, +20μ
C/g. 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 +16 μC/g. next,
To 100 parts of this toner, 1 part of alumina treated with a titanium coupling agent was added and mixed thoroughly, and image quality was evaluated in a high temperature and high humidity environment of 35° C. and 85% humidity. Copy samples were obtained using a copying machine manufactured by Fuji Xerox Co., Ltd. 2700 modified for use with capsule toner. As a result, stable copies without fogging were obtained up to the 20,000th copy.

Comparative Example 3 The same treatment as in Example 3 was carried out except that an aqueous solution of acid dye (Fast Red A, manufactured by Wako Pure Chemical Industries, Ltd.) was not added.
A capsule toner in which the anion remains a chlorine ion was obtained. 3 g of the obtained capsule toner was mixed with 100 g of iron powder carrier whose surface was coated with phenolic resin in an environment of 20°C and 50% humidity, and the charge amount of the capsule toner was measured using the blow-off method, and it was found to be +20 μC. /g. 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 found to be +4 μC/g. Next, this toner 1
After adding 1 part of the same alumina as in Example 3 to 0.00 parts and thoroughly mixing, the image quality was evaluated in the same manner as in Example 1 under a high temperature and high humidity environment of 35° C. and 85% humidity.
Fog occurred from the first sheet, and by the 50th sheet, the image density decreased and the image quality became significantly inferior in clarity.

Example 4 (Preparation of capsule particles) 30 g of styrene-n-butyl methacrylate copolymer (Mw=20,000) was added to 160 g of lauryl methacrylate monomer and 30 g of ethyl acetate.
was added and dissolved. 20 g of a red pigment (Hostapalm Scarlet GO: manufactured by Bayer AG) was added to this, and the mixture was dispersed in a ball mill for 16 hours. Next, to 200 g of this dispersion, 10 g of isocyanate (Sumidur L: manufactured by Sumitomo Bayer Urethane Co., Ltd.), 4 g of toluylene diisocyanate (Coronate L: manufactured by Nippon Polyurethane Co., Ltd.), and an epoxy resin (Epicote 812: Yuka Shell) were added. (manufactured by Epoxy Corporation) and 3 g of azobisisobutyronitrile were added and mixed (
This liquid is called liquid A. ). On the other hand, ion exchange water 250
Dissolve 10 g of hydroxypropyl methyl cellulose (Metrose 65H50: manufactured by Shin-Etsu Chemical Co., Ltd.) in
It was cooled to ℃ (this liquid is referred to as liquid B). Emulsifying machine (
Solution B was stirred using an autohomogen mixer (manufactured by Shukikako Co., Ltd.), and Solution A was slowly added thereto to effect emulsification. In this way, the average particle size of the oil droplets in the emulsion is approximately 12
A μm O/W emulsion was obtained. Next, in place of the emulsifier, a stirrer equipped with propeller-type stirring blades (Three-One Motor, manufactured by Shinto Kagakusha Co., Ltd.) was used to stir at 400 revolutions/minute. After 10 minutes, 100 g of a 2.5% diethylenetriamine aqueous solution was added dropwise thereto, and the encapsulation reaction was carried out for 2 hours while reducing the pressure in the reaction vessel and removing ethyl acetate. Thereafter, a reaction was carried out at 65° C. for 18 hours to polymerize the core material. After the reaction was completed, the mixture was poured into about 1 liter of ion-exchanged water, thoroughly stirred, and centrifuged. After the capsule particles were separated, the supernatant was removed. After repeating this operation five more times, the sample was further washed with methanol. In this way, red capsule particles were obtained. Ion-exchanged water was added to the capsule particles to prepare a suspension with a solid content concentration of 40%.

(Formation of toner) To 125 g of the suspension of capsule particles prepared as described above (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 ( The mixture was stirred at 200 rpm using a three-one motor (manufactured by Shinto Kagakusha). 1N for this
After adding 5 g of nitric acid and 4 g of 10% cerium sulfate aqueous solution, 0.5 g of ethylene glycol dimethacrylate was added.
g was added thereto, and the reaction was carried out at 15°C for 3 hours. After the reaction was completed, the mixture was poured into 1 liter of ion-exchanged water, thoroughly stirred, and 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. The obtained capsule particles were resuspended in ion-exchanged water, and a stirrer equipped with a propeller-type stirring blade (
Three-one motor: 200 rotations/manufactured by Shinto Kagakusha
Stir for 1 minute. Next, 0.4 g of potassium persulfate, 0.3 g of the chloride of the above-mentioned exemplary compound (1), 3.0 g of methyl methacrylate, and 0.16 g of sodium bisulfite were sequentially added to the solution. 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 centrifuged. After the capsule particles were separated, the supernatant was removed. Repeat this operation 4 more times
The capsule particles were washed repeatedly.

Next, to this capsule particle suspension, a 5% aqueous solution of an acid dye (Fast Red A: manufactured by Wako Pure Chemical Industries, Ltd.) was added.
g was added thereto and stirred at room temperature for 30 minutes to perform an ion exchange reaction. After the reaction was completed, the capsule particles were washed five times with 1 liter of ion-exchanged water to obtain the capsule toner of the present invention. The obtained capsule suspension was poured into a stainless steel vat and dried in a dryer at 60°C for 10 hours.

3 g of the obtained capsule toner was mixed with 100 g of iron powder carrier whose surface was coated with phenolic resin in an environment of a temperature of 20° C. and a humidity of 50%, and the amount of charge of the capsule toner was measured by a blow-off method. However, +18μ
C/g. 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 found to be +16 μC/g. Next, hydrophobic silica (RA200H) was added to 100 parts of this toner.
After adding 1 part of Nippon Aerosil Co., Ltd.) and thoroughly mixing, image quality was evaluated in a high temperature and high humidity environment of 35° C. and 85% humidity. Fuji Xerox 27 as a copying machine
A copy sample was obtained using a modified version of 00 for use with capsule toner. As a result, stable copies without fogging were obtained up to the 20,000th copy.

Comparative Example 4 The same treatment as in Example 4 was carried out except that an aqueous solution of acid dye (Fast Red A: manufactured by Wako Pure Chemical Industries, Ltd.) was not added.
A capsule toner in which the anion remains a chlorine ion was obtained. 3 g of the obtained capsule toner was mixed with 100 g of iron powder carrier whose surface was coated with phenolic resin in an environment of 20°C and 50% humidity, and the charge amount of the capsule toner was measured using the blow-off method, and it was found to be +20 μC. /g. 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 found to be +4 μC/g. Next, this toner 10
After adding 1 part of hydrophobic silica (RA-200H: manufactured by Nippon Aerosil Co., Ltd.) to 0 parts and mixing thoroughly, the mixture was heated to a temperature of 3.
When image quality was evaluated in the same manner as in Example 1 under a high temperature and high humidity environment of 5°C and 85% humidity, fogging occurred from the first sheet, and image density decreased and sharpness was significantly inferior at the 50th sheet. The result was a high-quality image.

[0048]

Effects of the Invention As described above, the capsule toner of the present invention has an outer shell made of a substance capable of generating radicals, and a quaternary ammonium salt represented by the above general formula (I) contained on the surface of the outer shell. Since a polymer containing a vinyl monomer as a monomer component is attached, it is possible to achieve both the mechanical strength of the toner and the chargeability of the toner with one outer shell component. Therefore, the capsule toner of the present invention has high mechanical strength and excellent charging properties, and can form copy images of good quality over a long period of time.

Claims (1)

[Claims] 1. A capsule toner consisting of a core material and an outer shell covering the core material, wherein the outer shell is made of a radical-generating substance, and the surface of the outer shell has the following general formula (
Quaternary ammonium salt-containing vinyl monomer represented by I): (wherein R1 to R3 each represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a benzyl group,
X- represents an anion having a -COO- or -SO3- group. ) as a monomer component is attached thereto.