JPH06130713A - Thermocompression fixing capsule toner and production thereof - Google Patents

Abstract

PURPOSE:To stably form an bright image excellent in offset resistance, capable of fixing at a low temp., excellent in blocking resistance and free from fogging over many times in a thermocompression fixing system such as a heat roller. CONSTITUTION:In a thermocompression fixing capsule toner composed of a hot melt core material containing at least a thermoplastic resin and a coloring agent and an outer shell provided so as to cover the surface of the core material, the main component of the outer shell is made of an amorphous polyester and the content of the polyester is 3-50 pts.wt. based on 100 pts.wt. core material and the capsule toner is produced by forming the outer shell by applying the amorphous polyester on the surface of the core by in-situ polymerization method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat and pressure fixing capsule toner used for developing an electrostatic latent image formed in an electrophotographic method, an electrostatic printing method, an electrostatic recording method and the like, and a method for producing the same.

[0002]

2. Description of the Related Art Conventional electrophotographic methods include US Pat. Nos. 2,297,691 and 235780.
As described in, for example, No. 9, the photoconductive insulating layer is uniformly charged, and then the layer is exposed to light to dissipate the charge on the exposed portion to form an electrical latent image. After being formed, and further visualized by adhering a fine powder having a colored charge called a toner to the latent image (developing step), after transferring the obtained visible image to a transfer material such as transfer paper (Transfer step), permanent fixing by heating, pressure or other suitable fixing method (fixing step). As described above, the toner must have the functions required not only in the developing step but also in the transfer step and the fixing step.

Generally, toner is subjected to a mechanical frictional force due to a shearing force and an impact force received during mechanical operation in a developing device,
It deteriorates during the copying of thousands to tens of thousands of sheets. To prevent such toner deterioration, a tough resin having a large molecular weight that can withstand mechanical friction may be used, but these resins generally have a high softening point and are a non-contact fixing method such as oven fixing and infrared fixing. In the radiant fixing method, the heat efficiency is poor and therefore the fixing is not sufficiently performed.Also, in the heat pressure fixing method which is widely used because the heat efficiency is good in the contact fixing method, it is necessary to fix the heat roller It is necessary to raise the temperature, which not only causes deterioration of the fixing device, curling of the paper, increase of energy consumption, etc., but also when such a resin is used, the pulverizability is poor,
When manufacturing a toner, the manufacturing efficiency is significantly reduced. Therefore, a binder resin having a too high degree of polymerization and a softening point cannot be used.

On the other hand, the heat pressure fixing method using a heat roller or the like has remarkably good thermal efficiency because the surface of the heat roller and the toner image surface of the sheet to be fixed are in pressure contact, and is widely used from low speed to high speed. When the surface and the toner image surface come into contact with each other, the toner tends to adhere to the surface of the heating roller and transferred to the subsequent transfer paper or the like, so-called offset phenomenon occurs. In order to prevent this phenomenon, the surface of the heating roller is processed with a material having an excellent releasing property such as a fluororesin, and a releasing agent such as silicone oil is applied to the surface of the heating roller to deal with the problem. However, the method of applying silicone oil or the like is not preferable because it easily causes a trouble because the fixing device becomes large and the cost becomes high, and it becomes complicated. Further, as described in JP-B-57-493, JP-A-50-44836, and JP-A-57-37353, there is a method of improving the offset phenomenon by asymmetrically or cross-linking the resin, but there is a fixing point. Has not been improved.

Generally, since the minimum fixing temperature is between the low temperature offset and the high temperature offset, the usable temperature range is between the minimum fixing temperature and the high temperature offset, and the minimum fixing temperature should be lowered as much as possible and the high temperature offset generation temperature should be as high as possible. By raising the temperature, the fixing temperature can be lowered and the usable temperature range can be widened, energy saving, high speed fixing and paper curl can be prevented. Therefore, there is always a demand for a toner having good fixability and offset resistance.

Conventionally, there has been proposed a technique for attaining low-temperature fixability by using a capsule toner composed of a core material and an outer shell provided so as to cover the surface of the core material as the toner. . Among them, when a low melting point wax that is easily plastically deformed is used as the core material (US Pat. No. 3,
269,626, Japanese Patent Publication No. 46-15876, Japanese Patent Publication No. 44-9880,
JP-A-48-75032 and JP-A-48-75033), fixing is possible only by pressure, but the fixing strength is poor and it can be used only in limited applications. Also, when a liquid core material is used, if the strength of the shell material is low, fixing can be done only by pressure, but it may crack inside the developing device and stain the inside of the machine. It takes a lot of pressure to break, resulting in images that are too glossy,
It was difficult to adjust the strength of the shell material.

Therefore, when used alone as a core material for heat and pressure fixing, blocking occurs at high temperatures, but a resin having a low glass transition point which improves the fixing strength is used, and blocking resistance and the like are provided as an outer shell. For this purpose, a heat roller fixing capsule toner in which a resin wall having a high melting point is formed by interfacial polymerization has been devised. However, in JP-A-61-56352, the wall material has a high melting point,
Furthermore, since it is tough and hard to crack, the performance of the core material has not been fully achieved. Further, a heat roller fixing capsule toner having an improved fixing strength of a core material has been proposed in the same way (Japanese Patent Laid-Open Nos. 58-205162 and 58-2051).
63 publication, 63-128357 publication, 63-128358 publication,
63-128359, 63-128360, and 63-1283.
No. 61, 63-128362), the manufacturing method is a spray-drying method, which imposes a burden on the manufacturing equipment, and the shell material has not been devised so that the performance of the core material has not been fully drawn out. . Further, in the capsule toner proposed in JP-A-63-281168, it is described that the shell material is thermotropic liquid crystal polyester, and in the capsule toner proposed in JP-A-4-184358, the crystalline property is Although polyester is used, the polyester melts sharply because the polyester is not amorphous, but the amount of energy required for melting is large, and the Tg of the core material is high, so the fixability is poor. Further, in the encapsulation method proposed in Japanese Patent Laid-Open No. 63-128357, there is a description about a dipping method using a solvent, a spray drying method, and a fluidized bed method, but it is said that the operation is complicated. There was a problem.

On the other hand, there is an attempt to control the chargeability of the capsule toner by allowing a charge control agent to exist in the outer shell of the capsule toner or on the surface of the capsule toner. For example, the toner is charged by friction with the carrier during the developing process. The control agent is detached and adheres to the carrier, the charge amount of the toner is reduced, and as a result, scumming and toner contamination in the machine occur.
There was a problem. Further, when the charge control agent is not present on the surface of the toner, the charging speed may be slow depending on the type of carrier, and when high speed printing is performed, scumming may occur.
Toner scattering and the like sometimes occurred.

The present invention has been made under the circumstances described above, and its object is to provide excellent offset resistance in a thermal pressure fixing system such as a heat roller, which can be fixed at a low temperature, and blocking resistance. To provide an excellent capsule toner for heat and pressure fixing and a method for producing the same.

[0010]

As a result of intensive studies to solve the above problems, the present inventors have found that the presence of an amorphous polyester resin having a negative charging property on the surface of a capsule toner causes a background stain. The present invention has been completed by finding that it is possible to provide a capsule toner for heat and pressure fixing capable of stably forming a clear image without any defects many times.

That is, the gist of the present invention is: (1) a heat-melting core material containing at least a thermoplastic resin and a colorant, and a heat shell formed so as to cover the surface of the core material. In the pressure-fixing capsule toner, the main component of the outer shell is made of amorphous polyester, and the content of the polyester is 3 to 50 parts by weight with respect to 100 parts by weight of the core material. 2. The capsule toner for heat and pressure fixing according to claim 1, wherein the capsule toner comprises (2) at least an amorphous polyester as a component of the outer shell and a copolymer having one or more acid anhydride groups. And (3) a method for producing a capsule toner for heat and pressure fixing, comprising a heat-meltable core material containing at least a thermoplastic resin and a colorant, and an outer shell provided so as to cover the surface of the core material. There are, a method of manufacturing a heat-and-pressure fixing capsule toner and forming an outer shell covering the amorphous polyester on the surface of the core material by in situ polymerization method.

The heat and pressure fixing capsule toner of the present invention comprises
Amorphous polyester is used as a main component of the outer shell. The main component of the outer shell here means that the amorphous polyester constitutes the main component of the outer shell constituent, and includes the case where the outer shell constituent is composed of only the amorphous polyester. . The amorphous polyester in the present invention is usually obtained by polycondensation of one or more alcohol monomers (divalent or more) and one or more carboxylic acid monomers (divalent or more). Above all,
Those obtained by polycondensation using a monomer containing at least a trivalent or higher polyvalent alcohol monomer and / or a trivalent or higher polyvalent carboxylic acid monomer are preferably used.

Examples of the dihydric alcohol component include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (3.3) -2,
2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene (2.0) -2,2-bis (4-Hydroxyphenyl) propane, polyoxypropylene (6) -2,2-
Alkylene oxide adducts of bisphenol A such as bis (4-hydroxyphenyl) propane, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl Glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A, bisphenol A
Propylene adduct, bisphenol A ethylene adduct, hydrogenated bisphenol A and the like.

Examples of trihydric or higher alcohol components include sorbitol, 1,2,3,6-hexanetetrol, and 1,4.
-Sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,
4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene and the like can be mentioned. Trivalent alcohol is preferably used. A single monomer or a plurality of monomers can be used from these dihydric alcohol monomers and trihydric or higher polyhydric alcohol monomers.

The acid component is a carboxylic acid component and a divalent monomer such as maleic acid, fumaric acid,
Citraconic acid, itaconic acid, glutaconic acid, phthalic acid,
Isophthalic acid, terephthalic acid, succinic acid, adipic acid,
Sebacic acid, azelaic acid, malonic acid, n-dodecenylsuccinic acid, n-dodecylsuccinic acid, n-octylsuccinic acid, isooctenylsuccinic acid, isooctylsuccinic acid,
And anhydrides of these acids, or lower alkyl esters.

Examples of the trivalent or higher carboxylic acid component include 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid and 1,2,4- Butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-
2-methylenecarboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl)
Methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empol trimer acid and their acid anhydrides,
Lower alkyl ester and the like can be mentioned. Preferably 3
A valent carboxylic acid or its derivative is used. A single monomer or a plurality of monomers can be used from these divalent carboxylic acid monomers and trivalent or higher carboxylic acid monomers.

The method for producing the amorphous polyester in the present invention is not particularly limited and can be produced by esterification or transesterification reaction using the above-mentioned monomer. Here, amorphous is one which does not have a definite melting point, and when crystalline polyester is used in the present invention, the amount of energy required for melting is large and the toner fixability cannot be improved, which is not preferable.

The amorphous polyester thus obtained preferably has a glass transition point of 50 to 80 ° C. If it is less than 50 ° C, the storage stability of the toner will be poor, and if it exceeds 80 ° C, the fixing property of the toner will be poor.
In the present invention, the glass transition point is a differential scanning calorimeter (manufactured by Seiko Denshi Kogyo Co., Ltd.) and the temperature rising rate is 10 ° C./min.
The temperature at the intersection of the extension line of the base line below the glass transition point and the tangent line showing the maximum slope from the rising portion of the peak to the apex of the peak, when measured by.

The acid value of the amorphous polyester is 3
It is preferably -50 (KOHmg / g), more preferably 10-30 (KOHmg / g). Three
If it is less than (KOHmg / g), it becomes difficult for amorphous polyester, which is a component of the shell material, to come out to the interface during the in-situ polymerization, and the storage stability of the toner is deteriorated to 50 (KOHm
If it exceeds g / g), the polyester tends to migrate to the aqueous phase, resulting in poor production stability. Here, the method for measuring the acid value is JI
This is due to S K0070.

In the encapsulated toner of the present invention, the above-mentioned amorphous polyester and a copolymer having one or more acid anhydride groups can be used as an outer shell component. Examples of such a copolymer having one or more acid anhydride groups include, for example, an α, β-ethylenic copolymerizable monomer (A) containing an acid anhydride group and another α, β-ethylenic group. Copolymerizable monomer
Examples thereof include the copolymer (B). Here, as the α, β-ethylenic copolymerizable monomer (A) containing an acid anhydride group, itaconic anhydride, crotonic anhydride, etc., a compound represented by the following general formula,

[0021]

[Chemical 1]

(In the formula, Q ₁ and Q ₂ independently represent H, an alkyl group having 1 to 3 carbon atoms, or a halogen atom.)
For example, maleic anhydride, citraconic anhydride, a few anhydrous
-Dimethylmaleic acid, chloromaleic anhydride, dichloromaleic anhydride, bromomaleic anhydride, dibromomaleic anhydride and the like can be mentioned, and maleic anhydride and citraconic anhydride are preferable.

Examples of other α, β-ethylenic copolymerizable monomer (B) include, for example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethyl. Styrene or styrene derivatives such as styrene, 2,4-dimethylstyrene, p-chlorostyrene, vinylnaphthalene, etc., ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, isobutylene, etc., such as vinyl chloride, vinyl bromide, Vinyl esters such as vinyl fluoride, vinyl acetate, vinyl propionate, vinyl formate, vinyl caproate, etc., such as acrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-acrylate. Butyl, isobutyl acrylate,
T-Butyl acrylate, amyl acrylate, cyclohexyl acrylate, n-octyl acrylate, isooctyl acrylate, decyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, methoxyethyl acrylate, acrylate 2 -Hydroxyethyl, glycidyl acrylate, 2-acrylic acid
Chlorethyl, phenyl acrylate, α-methyl chloroacrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, Ethylenic monocarboxylic acids such as amyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, methoxyethyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, phenyl methacrylate and the like; Esters thereof, for example, ethylenic monocarboxylic acid substitution products such as acrylonitrile, methacrylonitrile, acrylamide, etc., ethylenic dicarboxylic acids such as dimethyl maleate, etc. Bon acids and derivatives thereof, for example, such as vinyl ketones such as vinyl methyl ketone, for example such as ether and vinyl methyl ether, for example such as vinylidene halides such as vinylidene chloride. Of these, styrene and (meth) acrylic acid ester are preferred because of their high reactivity.

The copolymer used in the present invention comprises 5 to 95 parts by weight of an α, β-ethylenic copolymerizable monomer (A) containing an acid anhydride group as described above and other α, β It can be obtained by polymerizing 95 to 5 parts by weight of the β-ethylenic copolymerizable monomer (B). At this time, the polymerization reaction can be carried out by ordinary addition polymerization or the like, but is not limited to these methods. Further, the copolymer may be a copolymer using two or more kinds of each of the above-mentioned monomers (A) and (B).

The glass transition point of this copolymer is 60.
The temperature is preferably ℃ or higher, more preferably 80 ℃ or higher.
This is because if the temperature is lower than 60 ° C., the blocking resistance of the capsule toner decreases. The above copolymers may be used alone or in combination of two or more.

In the present invention, the above-mentioned copolymer having one or more acid anhydride groups is used together with the above-mentioned amorphous polyester. At this time, the content of the copolymer is based on that of the amorphous polyester. 2 to 10% by weight is desirable. As described above, in addition to the amorphous polyester, by further using a copolymer having one or more acid anhydride groups as a component of the outer shell, the charge amount of the toner can be freely changed, and the charge amount can be changed. Has the advantage that it has a sharp distribution.

In the present invention, the amorphous polyester as described above can be the main component of the outer shell, but the content is usually 50 to 100% by weight in the total weight of the outer shell. Here, as the other component contained in the outer shell, polyamide, polyesteramide, polyurea, or the like can be used in an amount of 0 to 50% by weight. When the encapsulated toner of the present invention is manufactured by the in situ polymerization method, each component such as the amorphous polyester used as the outer shell is dissolved in the monomer of the resin constituting the core material, and therefore a single amount is used. Solubility in the body is required.

As described above, by using a copolymer having an amorphous polyester as a main component of the outer shell and further having one or more acid anhydride groups, it is possible to control the charge from the toner by friction with the carrier. It is possible to stably form a clear image without background stains without releasing the agent. In addition, blocking resistance can be improved while maintaining low-temperature fixability.

On the other hand, examples of the resin used as the main component of the thermofusible core material (thermoplastic core material) of the capsule toner of the present invention include thermoplastic resins such as polyester / polyamide resin, polyamide resin and vinyl resin. Of these, vinyl resins are preferable. The glass transition point derived from the thermoplastic resin which is the main component of such a heat-meltable core material is preferably 10 to 50 ° C, more preferably 20 ° C to 40 ° C. When the glass transition point is lower than 10 ° C, the storage stability of the capsule toner deteriorates, and when it exceeds 50 ° C, the fixing strength of the capsule toner deteriorates, which is not preferable.

Among the above-mentioned thermoplastic resins, examples of the monomer constituting the vinyl resin include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene and p-ethylstyrene. , 2,4-
Styrene or styrene derivatives such as dimethylstyrene, p-chlorostyrene, vinylnaphthalene, etc., ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, isobutylene, etc., such as vinyl chloride,
Vinyl esters such as vinyl bromide, vinyl fluoride, vinyl acetate, vinyl propionate, vinyl formate, vinyl caproate, etc., such as acrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, N-Butyl acrylate, isobutyl acrylate, t-butyl acrylate, amyl acrylate, cyclohexyl acrylate, n-octyl acrylate, isooctyl acrylate, decyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, acrylic acid Stearyl, methoxyethyl acrylate, acrylic acid 2-
Hydroxyethyl, glycidyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α-chloromethyl acrylate, methacrylic acid, methyl methacrylate,
Ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, methacrylic acid. Decyl, lauryl methacrylate, methacrylic acid 2
-Ethylhexyl, stearyl methacrylate, methoxyethyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, phenyl methacrylate,
Ethylenic monocarboxylic acids such as dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate and the like, and esters thereof such as ethylenic monocarboxylic acid substitution products such as acrylonitrile, methacrylonitrile, acrylamide, etc., such as ethylenic acid such as dimethyl maleate. Dicarboxylic acids and their substitution products, vinyl ketones such as vinyl methyl ketone, vinyl ethers such as vinyl methyl ether, vinylidene halides such as vinylidene chloride, eg N-
Examples thereof include N-vinyl compounds such as vinylpyrrole and N-vinylpyrrolidone.

Of the components constituting the resin for the core material according to the present invention, 50 to 90% by weight of styrene or a styrene derivative is used to form the main skeleton of the resin, and ethylenic is used to adjust the thermal characteristics such as the softening temperature of the resin. It is preferable to use 10 to 50% by weight of monocarboxylic acid or its ester because the glass transition point of the resin for core material can be easily controlled.

When a crosslinking agent is added to the monomer composition which constitutes the resin for the core material according to the present invention, for example, divinylbenzene, divinylnaphthalene, polyethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diethylene. Acrylate, 1,3-
Butylene glycol dimethacrylate, 1,6-hexylene glycol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2'-bis (4-methacryloxydiethoxyphenyl) propane, 2 General crosslinking such as 2,2'-bis (4-acryloxydiethoxyphenyl) propane, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, dibromoneopentyl glycol dimethacrylate, diallyl phthalate Appropriate agent (2 if necessary
A combination of two or more species can be used.

The amount of these crosslinking agents used is 0.001 to 15% by weight, preferably 0.1 to 10% by weight, based on the polymerizable monomer. The amount of these crosslinkers used is 15
If it is more than 5% by weight, the toner is less likely to be melted by heat, resulting in poor heat fixing property or heat pressure fixing property. Also the amount used
If the amount is less than 0.001% by weight, it is difficult to prevent the offset phenomenon in which a part of the toner adheres to the roller surface without being completely fixed to the paper and is transferred to the next paper in the heat and pressure fixing. Further, the above monomer may be polymerized in the presence of unsaturated polyester to give a graft or crosslinked polymer, which may be used as a resin for the core material.

Further, as the polymerization initiator used in producing the thermoplastic resin for the core material, 2,2'-azobis (2,4 '
-Dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4
-Dimethylvaleronitrile, other azo or diazo polymerization initiators: benzoyl peroxide, methyl ethyl ketone peroxide, isopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, dicumyl peroxide Examples thereof include peroxide-based polymerization initiators such as oxides.

Two or more kinds of polymerization initiators may be mixed and used for the purpose of controlling the molecular weight and the molecular weight distribution of the polymer, the reaction time or the like. The amount of the polymerization initiator used is 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the polymerized monomer.

In the present invention, a charge control agent may be further added to the core material, and the negatively chargeable charge control agent to be added is not particularly limited and may be, for example, a metal-containing azo dye "Vari. First Black 3804 "," Bontron S-31 "," Bontron S-32 "," Bontron S-34 "(above, manufactured by Orient Chemical Co., Ltd.)," Eisenspiron Black TVH "(manufactured by Hodogaya Chemical Co., Ltd.)
Etc., copper phthalocyanine dyes, metal complexes of alkyl derivatives of salicylic acid, such as “Bontron E-81”, “Bontron E-82”, “Bontron E-85” (above, manufactured by Orient Chemical Co.), quaternary ammonium salt, for example. "CO
PY CHARGE NX VP434 ”(manufactured by Hoechst), nitroimidazole derivatives and the like can be mentioned.

The positively chargeable charge control agent is not particularly limited, and examples thereof include nigrosine dyes such as "Nigrosine Base EX", "Oil Black BS", "Oil Black SO", "Bontron N-01", and "Bontron". N-07 "," Bontron N-11 "(above, manufactured by Orient Chemical Co., Ltd.), triphenylmethane dye containing a tertiary amine as a side chain, quaternary ammonium salt compound, for example," Bontron P-51 "( Orient Chemical Co., Ltd.),
Cetyl trimethyl ammonium bromide, "COPY CHARG
Examples thereof include EPX VP435 "(manufactured by Hoechst) and the like, and polyamine resins such as" AFP-B "(manufactured by Orient Chemical Co.) and imidazole derivatives. The above charge control agent is contained in the core material in an amount of 0.1 to 8.0% by weight, preferably 0.2 to 5.0% by weight. In the core material, if necessary, for the purpose of improving offset resistance in heat and pressure fixing, for example, polyolefin, fatty acid metal salt, fatty acid ester, partially saponified fatty acid ester, higher fatty acid, higher alcohol, paraffin wax, amide series Any one or more kinds of offset preventing agents such as wax, polyhydric alcohol ester, silicon varnish, aliphatic fluorocarbon, and silicone oil may be contained.

The polyolefin is, for example, a resin such as polypropylene, polyethylene or polybutene and has a softening point of 80 to 160 ° C. Examples of the fatty acid metal salt include maleic acid and zinc, magnesium,
Metal salts with calcium, etc .; Metal salts with stearic acid and zinc, cadmium, barium, lead, iron, nickel, cobalt, copper, aluminum, magnesium, etc .; Dibasic lead stearate; Oleic acid and zinc, magnesium, iron , Metal salts with cobalt, copper, lead, calcium, etc .; metal salts with palmitic acid, aluminum, calcium, etc .; caprylate; lead caproate; metal salts with linoleic acid, zinc, cobalt, etc .; calcium ricinoleate; Examples thereof include metal salts of ricinoleic acid and zinc, cadmium, and the like, and mixtures thereof. Examples of the fatty acid ester include maleic acid ethyl ester, maleic acid butyl ester, stearic acid methyl ester, stearic acid butyl ester, palmitic acid cetyl ester, montanic acid ethylene glycol ester and the like. Examples of the partially saponified fatty acid ester include partially saponified calcium of montanic acid ester. Examples of the higher fatty acid include dodecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, ricinoleic acid, arachidic acid, behenic acid, lignoceric acid, ceracoleic acid, and mixtures thereof. You can Examples of the higher alcohols include dodecyl alcohol, lauryl alcohol, myristyl alcohol, palmityl alcohol, stearyl alcohol, aralkyl alcohol, and behenyl alcohol. Examples of the paraffin wax include natural paraffin, microwax, synthetic paraffin, and chlorinated hydrocarbon. Examples of the amide wax include stearic acid amide, oleic acid amide, palmitic acid amide, lauric acid amide, behenic acid amide, methylenebisstearamide, ethylenebisstearamide, N, N'-m-xylylenebis. Examples thereof include stearic acid amide, N, N'-m-xylylenebis-12-hydroxystearic acid amide, N, N'-isophthalic acid bisstearylamide, and N, N'-isophthalic acid bis-12-hydroxystearylamide. Examples of the polyhydric alcohol ester include glycerin stearate,
Glycerin ricinoleate, glycerin monobehenate,
Examples thereof include sorbitan monostearate, propylene glycol monostearate and sorbitan trioleate. Examples of the silicon varnish include methyl silicon varnish and phenyl silicon varnish. Examples of the aliphatic fluorocarbon include low-polymerization compounds of tetrafluoroethylene and propylene hexafluoride, and fluorine-containing surfactants described in JP-A-53-124428. The ratio of these offset preventing agents to the resin in the core material is preferably 1 to 20% by weight.

In the present invention, a colorant is contained in the core material of the encapsulated toner, but all the dyes, pigments and the like used in conventional colorants for toner can be used. The colorant used in the present invention, various carbon black produced by thermal black method, acetylene black method, channel black method, lamp black method and the like,
Grafted carbon black coated with resin on the surface of carbon black, Nigrosine dye, Phthalocyanine blue, Permanent brown FG, Brilliant fast scarlet, Pigment green B, Rhodamine-B base, Solvent red 49, Solvent red 14
6, Solvent Blue 35, etc., and mixtures thereof, etc., usually 1 per 100 parts by weight of resin in the core material.
About 15 parts by weight is used.

In order to produce the magnetic capsule toner, magnetic particles may be added to the core material. As magnetic particles,
For example, ferrous metals such as ferrite and magnetite, cobalt, nickel, or other metals or alloys exhibiting ferromagnetism, compounds containing these elements, or ferromagnetism by being subjected to an appropriate heat treatment without containing ferromagnetic elements. An alloy such as manganese-copper-aluminum, a type of alloy called Heusler alloy containing manganese and copper such as manganese-copper-tin, or chromium dioxide.
Others can be mentioned. These magnetic materials are uniformly dispersed in the core material in the form of fine powder having an average particle size of 0.1 to 1 μm. The content is 20 to 70 parts by weight, preferably 30 to 70 parts by weight, per 100 parts by weight of the encapsulated toner. When magnetic fine powder is added to form a magnetic toner, the same treatment as in the case of the colorant may be performed.
Since the core material has a low affinity for organic substances such as monomers as it is, the magnetic fine powder is treated with a so-called coupling agent such as a titanium coupling agent, a silane coupling agent, and lecithin, or with a coupling agent. When used above, the magnetic fine powder can be uniformly dispersed.

The method of manufacturing the heat and pressure fixing capsule toner according to the present invention simplifies the manufacturing equipment and the manufacturing process.
Although the n situ polymerization method is preferable, for example, mother particles as a core material and child particles of an outer shell forming material having a number average particle diameter of 1/8 or less of the number average particle diameter of the mother particles are stirred at high speed in an air stream. May be performed by a dry method such as forming an outer shell.

The production method of the present invention by the in situ polymerization method will be described below. In this manufacturing method, the outer shell is formed by dispersing a mixed liquid of a core constituent material and an outer shell constituent material such as amorphous polyester in a dispersion medium so that the outer shell constituent material is unevenly distributed on the surface of the droplet. Can be done using. That is, the core material-constituting material and the outer shell-constituting material are separated from each other in the droplets of the mixed solution due to the difference in solubility index, and in this state, the polymerization proceeds to form a capsule structure. According to this method, since the outer shell is formed as a layer made of an outer shell constituent material such as amorphous polyester having a substantially uniform thickness, the charging characteristics of the toner are uniform.

In the case of this method, it is necessary to contain a dispersion stabilizer in the dispersion medium in order to prevent aggregation and coalescence of dispersoids. Examples of the dispersion stabilizer include gelatin, gelatin derivatives, polyvinyl alcohol, polystyrene sulfonic acid, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, sodium carboxymethyl cellulose, sodium polyacrylate, sodium dodecylbenzene sulfonate, sodium tetradecyl sulfate, and pentadecyl sulfate. Sodium, sodium octyl sulfate, sodium allyl-alkyl-polyethersulfonate, sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, calcium oleate, 3,3-disulfonediphenyl Urea-4,4-diazo-bis-amino-β-
Naphthol-6-sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-
Tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol-sodium disulfonate, colloidal silica, alumina, tricalcium phosphate, ferric hydroxide, titanium hydroxide, aluminum hydroxide and others are used. can do. Two or more kinds of these dispersion stabilizers may be used in combination.

Examples of the dispersion medium of the dispersion stabilizer include water, methanol, ethanol, propanol, butanol, ethylene glycol, glycerin, acetonitrile, acetone, isopropyl ether, tetrahydrofuran and dioxane. It is also possible to use these individually or in mixture.

In the production method of the present invention, the addition amount of the outer shell constituent material containing the amorphous polyester as a main component is
It is usually 3 to 50 parts by weight, preferably 5 to 40 parts by weight, based on 100 parts by weight of the core material. If the amount is less than 3 parts by weight, the outer shell film becomes too thin and the storage stability of the toner is deteriorated. If the amount is more than 50 parts by weight, the dispersed droplets have a high viscosity and it is difficult to atomize, and the manufacturing stability becomes poor. become worse.

Further, for the purpose of charge control, an appropriate amount of the charge control agent as exemplified above may be added to the outer shell material of the capsule toner of the present invention, or this charge control agent may be mixed with the toner. However, even if they are added, the addition amount can be small because the chargeability is controlled by the outer shell itself.

The particle size of the encapsulated toner of the present invention is not particularly limited, but the average particle size is usually 3 to 30.
It is assumed to be μm. The thickness of the outer shell of the capsule toner is 0.01-1
If it is less than 0.01 μm, the blocking resistance is deteriorated, and if it exceeds 1 μm, the heat melting property is deteriorated, which is not preferable.

The capsule toner of the present invention may contain a fluidity improver, a cleaning improver, etc., if necessary. As the fluidity improver, for example, silica,
Alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, red iron oxide, antimony trioxide, Magnesium oxide, zirconium oxide,
Examples thereof include barium sulfate, barium carbonate, calcium carbonate, silicon carbide and silicon nitride. Fine silica powder is particularly preferable. The fine silica powder is Si
It is a fine powder having a —O—Si bond and may be produced by a dry method or a wet method. In addition to anhydrous silicon dioxide, it may be any of aluminum silicate, sodium silicate, potassium silicate, magnesium silicate, zinc silicate, etc., but 85% by weight of SiO ₂
Those including the above are preferable. Further, a fine powder of silica surface-treated with a silane coupling agent, a titanium coupling agent, a silicone oil, a silicone oil having an amine in a side chain, or the like can be used.

Examples of the cleaning property improver include metal salts of higher fatty acids typified by zinc stearate, fine particles of fluorine-based high molecular weight particles, and the like. Further additives for adjusting the developability, for example, methacrylic acid methyl ester,
Fine particles of a polymer such as methacrylic acid butyl ester may be used. Further, a small amount of carbon black may be used for toning and resistance adjustment. As the carbon black, conventionally known ones, for example, various ones such as furnace black, channel black and acetylene black can be used.

The capsule toner of the present invention is used alone as a developer when it contains magnetic fine powder, and is a non-magnetic one-component developer when it contains no magnetic fine powder. Alternatively, a two-component developer can be prepared and used by mixing with a carrier. The carrier is not particularly limited, but iron powder, ferrite, glass beads and the like, or those coated with a resin thereof,
Further, a resin carrier obtained by kneading magnetite fine powder or ferrite fine powder into resin is used, and the mixing ratio of the toner to the carrier is 0.5 to 20% by weight. The carrier has a particle size of 15 to 500 μm.

The capsule toner of the present invention gives good fixing strength by fixing to a recording material such as paper by using heat and pressure together. As a heat and pressure fixing method, if heat and pressure are used together. , A known heat roller fixing method, or, for example, as described in JP-A-2-190870, an unfixed toner image on a recording material is passed through the heat-resistant sheet by a heating means composed of a heating section and a heat-resistant sheet. To heat and melt,
A fixing method of fixing, or a heating body fixedly supported as described in, for example, Japanese Patent Laid-Open No. 162356/1990, and a pressurizing member that is in pressure contact with the heating body and is in close contact with the heating body through a film. A method such as a method of heating and fixing the visible image of the toner on the recording material depending on the member is suitable for fixing the capsule toner of the present invention.

[0052]

EXAMPLES The present invention will be described in more detail with reference to Examples, Comparative Examples and Test Examples, but the present invention is not limited to these Examples.

Resin Production Example Propylene oxide adduct of bisphenol A 36
7.5 g (hereinafter abbreviated as BPA / PO), 146.4 g of ethylene oxide adduct of bisphenol A (hereinafter BP
A. EO), 126.0 g of terephthalic acid (hereinafter T
PA), 40.2 g of dodecenyl succinic anhydride (abbreviated as DSA below) and 77.7 g of trimellitic anhydride (abbreviated as TMA hereinafter) were placed in a glass 2-liter four-necked flask, a thermometer, and a stainless steel stirring rod. , A down-flow type condenser, and a nitrogen introduction tube were attached, and the reaction was carried out at 220 ° C. under a nitrogen stream in a mantle heater. The degree of polymerization was traced from the softening point according to ASTM E28-67, and the reaction was terminated when the softening point reached 110 ° C. This resin is called resin A. A resin was manufactured in the same manner as described below. The composition is shown in Table 1. The glass transition point of the obtained resin was measured by a differential scanning calorimeter (manufactured by Seiko Denshi Kogyo Co., Ltd.), and the value, softening point and acid value are also shown in Table 2.
Shown in. The acid value was measured by a method according to JIS K0070.

[0054]

[Table 1]

[0055]

[Table 2]

Example 1 69.0 parts by weight of styrene, 2-ethylhexyl acrylate
31.0 parts by weight, 0.9 parts by weight of divinylbenzene, 7.0 parts by weight of carbon black "# 44" (manufactured by Mitsubishi Kasei) and resin A
20 parts by weight of 2,2'-azobisisobutyronitrile 3.5
Add at least 1 part by weight, Attritor (Mitsui Miike Kakoki Co., Ltd.)
And was dispersed at 10 ° C. for 5 hours to obtain a polymerizable composition. Then, 240 g of the polymerizable composition was added to 560 g of an aqueous colloidal solution of 4% by weight of tricalcium phosphate prepared in a 2 liter glass separable flask, and TK homomixer (made by Tokushu Kika Kogyo Co., Ltd.) was used. Then, the mixture was emulsified and dispersed at 15 ° C. at a rotation speed of 12000 rpm for 5 minutes. Then, a 4-port glass lid was attached, a reflux cooling tube, a thermometer, a nitrogen introduction tube, and a stainless steel stirring rod were attached, and the glass was placed in an electric heating mantle heater. 85 ° C with continuous stirring under nitrogen
The temperature was raised to, and the reaction was allowed to proceed for 10 hours. After cooling, dissolve the dispersion medium with 10% aqueous hydrochloric acid, filter, wash with water, and then at 45 ° C.
Dry for 12 hours under reduced pressure at 20 mmHg and classify with a wind classifier.
An encapsulated toner having an outer shell of amorphous polyester having an average particle diameter of 8 μm was obtained. To 100 parts by weight of this capsule toner,
0.4 parts by weight of hydrophobic silica fine powder "Aerosil R-972" (manufactured by Nippon Aerosil Co., Ltd.) was added and mixed to obtain a capsule toner of the present invention. This is designated as Toner 1. The glass transition point derived from the resin in the core material was 30.6 ° C, and the softening point of Toner 1 was 125.5 ° C.

Example 2 Copolymer comprising 75 parts by weight of styrene and 25 parts by weight of n-butyl acrylate and having a softening point of 75.3 ° C. and a glass transition point of 40.5 ° C.
100 parts by weight of copper phthalocyanine "Sumikaprint Cyanine B
lue GN-0 ”(Sumitomo Chemical Co., Ltd.) 6 parts by weight, resin B 15 parts by weight, polypropylene wax“ Biscol 550P ”(manufactured by Sanyo Kasei Co., Ltd.) 5 parts by weight and premixed with a twin-screw extruder. The mixture was melt-kneaded, cooled, and then pulverized. 40 parts by weight of this kneaded material, 50 parts by weight of styrene, 15 parts by weight of n-butyl acrylate, 2.5 parts of 2,2'-azobisisobutyl nitrile.
Part by weight was mixed to obtain a polymerizable composition. Then, in a 2 liter glass separable flask, 560 g of an aqueous colloidal solution containing 4% by weight of tricalcium phosphate prepared in advance.
240 g of the above-mentioned polymerizable composition was added thereto, and the mixture was emulsified and dispersed at 15 ° C. at a rotation speed of 12000 rpm for 2 minutes using a TK homomixer. Then, a 4-port glass lid was attached, a reflux cooling tube, a thermometer, a nitrogen introduction tube, and a stainless steel stirring rod were attached, and the glass was placed in an electric heating mantle heater. While continuing stirring under nitrogen, the temperature was raised to 85 ° C. and the reaction was performed for 10 hours. After cooling, dissolve the dispersion medium with 10% aqueous hydrochloric acid, filter, wash with water, dry under reduced pressure at 20 mmHg for 12 hours at 45 ° C, classify with a wind classifier, and remove the outer shell with an average particle size of 8 μm. A capsule toner which is a crystalline polyester was obtained. To 100 parts by weight of this capsule toner, 0.4 parts by weight of hydrophobic silica fine powder "Aerosil R-972" (manufactured by Nippon Aerosil Co., Ltd.) was added and mixed to obtain a capsule toner of the present invention. This is designated as toner 2. The glass transition point derived from the resin in the core material is
The toner had a softening point of 122.8 ° C and a softening point of 33.2 ° C.

Example 3 50 parts by weight of styrene, 35.0 parts by weight of 2-ethylhexyl acrylate, 1.0 part by weight of divinylbenzene, 1.0 part by weight of dimethylaminoethyl methacrylate, carbon black "GP-" grafted with styrene E-
3 "(manufactured by Ryoyu Kogyo Co., Ltd.) and 20 parts of Resin C in 40.0 parts by weight.
Parts by weight and 5.0 parts by weight of lauroyl peroxide were added to obtain a polymerizable composition. Then, 240 g of the polymerizable composition was added to 560 g of an aqueous colloidal solution of 4% by weight of tricalcium phosphate prepared in a 2 liter glass separable flask, and a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) was used. Rotation speed 12000 at 15 ℃
Emulsified and dispersed at rpm for 5 minutes. Next, a 4-port glass lid was attached, a reflux cooling tube, a thermometer, a nitrogen introduction tube, and a stainless steel stirring rod were attached, and the lid was placed in an electric heating mantle heater. While continuing stirring under nitrogen, the temperature was raised to 85 ° C. and the reaction was performed for 10 hours. After cooling, dissolve the dispersion medium with 10% aqueous hydrochloric acid, filter, wash with water, and then at 45 ° C.
At 12 mmHg for 12 hours under reduced pressure and classified by an air classifier to obtain a capsule toner having an average particle diameter of 8 μm and an outer shell of amorphous polyester. To 100 parts by weight of this capsule toner, hydrophobic silica fine powder "Aerosil R-
972 "(manufactured by Nippon Aerosil Co., Ltd.) was added and mixed to obtain a capsule toner of the present invention. This is designated as toner 3. The glass transition point derived from the resin in the core material is 3
The toner 3 had a softening point of 3.5 ° C. and a softening point of 124.3 ° C.

Example 4 65.0 parts by weight of styrene, 35.0 parts by weight of 2-ethylhexyl acrylate, 0.9 parts by weight of divinylbenzene, and carbon black "# 44" (manufactured by Mitsubishi Kasei) 7.
To 0 parts by weight, 18 parts by weight of Resin A, a copolymer of maleic anhydride and styrene (maleic anhydride: styrene = 1: 3)
Molar ratio, molecular weight = 1900, glass transition point 124.7
C.) 2.0 parts by weight and 2,2'-azobisisobutyronitrile 3.5 parts by weight are added to an attritor (manufactured by Mitsui Miike Kakoki Co., Ltd.) and dispersed at 10 ° C. for 5 hours. A polymerizable composition was obtained. Then, the polymerizable composition 24 was added to 560 g of an aqueous colloidal solution containing 4% by weight of tricalcium phosphate in a glass separable flask having a volume of 2 liters.
0g was added and TK homomixer (made by Tokushu Kika Kogyo Co., Ltd.)
Was emulsified and dispersed at 15 ° C for 5 minutes at a rotation speed of 12000 rpm. Next, a 4-port glass lid was attached, a reflux cooling tube, a thermometer, a nitrogen introduction tube, and a stainless steel stirring rod were attached, and the vessel was placed in an electric heating mantle. While continuing to stir this under a nitrogen stream, raise the temperature to 85 ° C,
The reaction was carried out for 10 hours. After cooling, dissolve the dispersion medium with a 10% aqueous hydrochloric acid solution, filter, wash with water, and then at 45 ° C for 12 hours, 20 mm.
Dry under reduced pressure with Hg, classify with an air classifier, average particle size 8μ
A capsule toner was obtained in which the main component of the outer shell of m 2 was an amorphous polyester and a copolymer having at least one acid anhydride group. To 100 parts by weight of this capsule toner, 0.4 parts of hydrophobic silica fine powder "Aerosil R-972" (manufactured by Nippon Aerosil Co., Ltd.)
Parts by weight were added and mixed to obtain a capsule toner of the present invention. This is designated as toner 4. The glass transition point derived from the resin in the core material is 30.2 ° C, and the softening point of Toner 4 is 122.8.
It was ℃.

Comparative Example 1 70.0 parts by weight of styrene, 30.0 parts by weight of 2-ethylhexyl acrylate, 1.0 part by weight of divinylbenzene,
Carbon black "# 44" (manufactured by Mitsubishi Kasei) 10.0
2,2'-azobisisobutyronitrile 3.
5 parts by weight, 9.5 parts by weight of 4,4′-diphenylmethane diisocyanate “Millionate MT” (manufactured by Nippon Polyurethane Industry Co., Ltd.) were added, and the mixture was put into an attritor (manufactured by Mitsui Miike Kakoki Co., Ltd.) and heated at 10 ° C. for 5 minutes. Time dispersed,
A polymerizable composition was obtained. Then, 240 g of the polymerizable composition was added to 560 g of an aqueous colloidal solution of 4% by weight of tricalcium phosphate prepared in a 2 liter glass separable flask, and a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) was used. Rotation speed 12,000 rp at 15 ℃
emulsified and dispersed for 2 minutes. Next, a 4-port glass lid was attached, a reflux cooling tube, a thermometer, a nitrogen introduction tube, and a stainless steel stirring rod were attached, and the glass was placed in an electric heating mantle heater. A mixed solution of 7.5 parts by weight of ethylenediamine, 0.5 parts by weight of dibutyltin dilaurate, and 40 g of ion-exchanged water was prepared and added dropwise over 30 minutes while stirring with a dropping funnel. Then, while continuing to stir under nitrogen,
The temperature was raised to 80 ° C. and the reaction was carried out for 10 hours. After cooling, 1
The dispersion medium was dissolved in a 0% aqueous hydrochloric acid solution, filtered, washed with water, and dried under reduced pressure at 20 mmHg at 45 ° C. for 12 hours.
The particles were classified by an air classifier to obtain a capsule toner having an average particle size of 8 μm and an outer shell made of polyurea resin. To 100 parts by weight of this capsule toner, 0.4 parts by weight of hydrophobic silica fine powder "Aerosil R-972" (manufactured by Nippon Aerosil Co., Ltd.) was added and mixed to obtain a capsule toner. This is designated as comparative toner 1. The glass transition point derived from the resin in the core material is 33.5 ° C, and the softening point of comparative toner 1 is 137.0 ° C.
Met.

Comparative Example 2 The procedure of Example 1 was repeated, except that the resin A was omitted, and the procedure was the same as in Example 1 except that washing with water was carried out via the polymerization reaction. 20
The mixture was dried at 10 ° C. for 12 hours under reduced pressure at 10 mmHg and classified by an air classifier to obtain a non-capsule type toner having an average particle size of 8 μm. To 100 parts by weight of this non-capsule type toner, 0.4 parts by weight of hydrophobic silica fine powder "Aerosil R-972" (manufactured by Nippon Aerosil Co., Ltd.) was added and mixed to obtain a surface-treated toner. This is designated as comparative toner 2. Comparative toner 2
Had a glass transition point of 30.5 ° C and a softening point of 115.5 ° C.

Test Example 6 parts by weight of each of the toners obtained in the above Examples and Comparative Examples and 94 parts by weight of spherical ferrite powder coated with a styrene / methyl methacrylate resin having a particle size of 250 mesh to 400 mesh were placed in a poly container. Put in, the rotation speed is 150r
The developer was prepared by tumbling the entire container on a roller for 20 minutes at pm. The obtained developer was evaluated for charge amount, fixing property and blocking resistance.

(1) The charge amount was measured by the blow-off type charge amount measuring device described below. That is,
Using a specific charge measuring device equipped with a Faraday gauge, condenser, and electrometer, first, 500 mesh
W (g) (0.15 to 0.20 g) of the prepared developer was put in a brass measuring cell equipped with a stainless mesh (which can be appropriately changed to a size in which carrier particles do not pass). Next, after suctioning for 5 seconds from the suction port, the air pressure regulator is 0.6 kgf.
Blow was performed for 5 seconds at a pressure indicating / cm ² to remove only the toner from the cell. At this time, the voltage of the electrometer 2 seconds after the start of blowing was defined as V (volt). If the electric capacity of the condenser is C (μF), the specific charge of this toner is Q / m.
Is calculated by the following formula. Q / m (μC / g) = C × V / m Here, m is the weight of the toner contained in the developer in W (g), and the weight in the developer is T (g), When the weight of the agent is D (g), the toner concentration of the sample is T / D
It is expressed as × 100 (%), and m is calculated by the following formula. m (g) = W × (T / D) Table 3 shows the result of the charge amount measurement of the developer prepared under the normal environment. In addition, a commercially available electrophotographic copying machine (toner 1,
In the case of Nos. 2 and 4 and comparative toner 2, the photoconductor is selenium-arsenic, and in the case of toner 3 and comparative toner 1, the photoconductor is an organic photoconductor, and the rotation speed of the fixing roller is 255 mm / sec.
, Toner concentration is 6%), the charge amount after copying 50,000 sheets is also measured, and the image quality during continuous printing durability test (generation of scumming)
Also, the airborne scattering was evaluated, and these are also shown in Table 3.

[0064]

[Table 3]

(2) The fixability was evaluated by the method described below. That is, the prepared developer described above is used as a commercially available electrophotographic copying machine (for toners 1, 2 and 4 and comparative toner 2, the photoconductor is selenium-arsenic, toner 3 and comparative toner 1).
In the case of (1), an image was formed by using an organic photoconductor as the photoconductor, a rotation speed of the fixing roller of 255 mm / sec, a variable heat pressure temperature in the fixing device, and an oil coating device removed. Control the fixing temperature from 70 to 220 ℃,
The fixability and offset property of the image were evaluated. The results are shown in Table 4. The minimum fixing temperature here is 15 mm x 7 on the bottom.
A load of 500 g was put on a 5 mm sand eraser, and the image fixed through the fixing device was rubbed 5 times back and forth, and before rubbing, the optical reflection density was measured with a reflection densitometer of Macbeth Co., and the fixing rate was defined as follows. Is the temperature of the fixing roller when exceeds 70%. Fixing rate = (image density after rubbing / image density before rubbing)

(3) With respect to blocking resistance, the degree of aggregation was evaluated when each toner was left for 24 hours under the conditions of 50 ° C. and 40% relative humidity, and the results are also shown in Table 4.

[0067]

[Table 4]

As is clear from Table 3, the toners 1 to 4 of the present invention and the comparative toner 1 have proper charge amount values, and the change in charge amount after copying 50,000 sheets is small, so that a good image is obtained. Although the toner was maintained, the toner of the comparative toner 2 was spent on the carrier, so that the polarity was reversed and the toner was scattered inside the machine, resulting in many background stains on the image. Also, Table 4
As is clear from Toners 1 to 4, the minimum fixing temperature was low and the non-offset region was wide. However, Comparative Toner 1 has a high melting point of polyurea and thus has a high minimum fixing temperature. Because it consists only of the core material,
Blocking resistance was poor.

[0069]

EFFECT OF THE INVENTION According to the encapsulated toner for heat and pressure fixing of the present invention, it has excellent offset resistance in a heat and pressure fixing method such as a heat roller, can be fixed at a low temperature, has excellent blocking resistance, and is free from fog. A clear image can be stably formed many times.

Claims (9)

[Claims] 1. A capsule toner for heat and pressure fixing comprising a heat-fusible core material containing at least a thermoplastic resin and a colorant, and an outer shell provided so as to cover the surface of the core material. A capsule toner for heat and pressure fixing, wherein the main component of the shell is amorphous polyester, and the content of the polyester is 3 to 50 parts by weight with respect to 100 parts by weight of the core material. 2. The heat and pressure fixing capsule toner according to claim 1, wherein the outer shell component is composed of only amorphous polyester. 3. The capsule toner for heat and pressure fixing according to claim 1, which contains at least an amorphous polyester and a copolymer having one or more acid anhydride groups as a component of the outer shell. 4. The amorphous polyester is obtained by polycondensation of at least one divalent or higher valent alcohol monomer and at least one divalent or higher carboxylic acid monomer. 3. The capsule toner for heat and pressure fixing according to any one of 3 above. 5. The glass transition point of the amorphous polyester is
It is 50-80 degreeC, The capsule toner for heat-pressure fixing in any one of Claims 1-4 characterized by the above-mentioned. 6. The acid value of the amorphous polyester is 3 to 50.
(KOHmg / g).
5. The heat and pressure fixing capsule toner according to any one of 5 above. 7. The glass transition point derived from the thermoplastic resin as the main component of the heat-fusible core material in the encapsulated toner is 10 to 10.
The heat and pressure fixing capsule toner according to any one of claims 1 to 6, which has a temperature of 50 ° C. 8. A method for producing a capsule toner for heat and pressure fixing, comprising a heat-meltable core material containing at least a thermoplastic resin and a colorant, and an outer shell provided so as to cover the surface of the core material. A method for producing a capsular toner for heat and pressure fixing, characterized in that an outer shell is formed by coating the surface of a core material with an amorphous polyester by an in situ polymerization method. 9. The method according to claim 8, wherein the addition amount of the amorphous polyester used in the in situ polymerization method is 3 to 50 parts by weight with respect to 100 parts by weight of the core material.