JPH0915900A - Thermocompression fixing capsule toner and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide thermocompression fixing capsule toner excellent particularly in offset resistance and separating performance in a thermocompression fixing system using a heat roller or the like, fixable at the low temperature and also excellent in blocking resistance so as to be able to form clear images without fog stably many times. SOLUTION: In thermocompression fixing capsule toner composed of heat fused core material containing at least thermoplastic resin and a colorant, and an outer shell formed of hydrophilic resin provided in such a way as to cover the surface of the core material, the core material contains silicone oil with kinematic viscosity of 10-500cs (25 deg.C), and the capsule toner is formed by an 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 hot and pressure fixing capsule toner used for developing an electrostatic latent image formed in electrophotography, electrostatic printing, electrostatic recording, and the like, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, electrophotography has been disclosed in US Pat.
No. 97691, No. 2357809, etc., the photoconductive insulating layer is uniformly charged (charging step), then the layer is exposed (exposure step), and the exposed portion is exposed. To form an electrical latent image by dissipating the electric charge of the toner, and then to make the latent image visible by adhering a fine powder having a colored charge called a toner to the latent image (developing step). After the image is transferred onto a transfer material such as transfer paper (transfer step), it is permanently fixed by heating, pressure or other suitable fixing method (fixing step).
As described above, the toner must have functions required not only in the developing step but also in each of the transferring step and the fixing step.

In the above fixing step, the thermal pressure fixing method using a heat roller or the like is widely used from a low speed to a high speed because the heat roller surface and the toner image surface of the sheet to be fixed come into pressure contact with each other, so that the heat efficiency is extremely good. It is used.
However, in this method, when the surface of the heating roller contacts the surface of the toner image, the so-called offset phenomenon that the toner adheres to the surface of the heating roller and is transferred to the subsequent transfer paper or the like is likely to occur.

In order to prevent this phenomenon, the surface of the heating roller is processed with a material having excellent releasability, such as a fluororesin,
A coating agent such as silicone oil is applied to the surface of the heating roller to cope with the problem. However, the method of applying silicon oil or the like is not preferable because it not only increases the size of the fixing device and increases the cost but also complicates the trouble and easily causes trouble.

On the other hand, 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. By raising the temperature as much as possible, the usable fixing temperature can be lowered, and the usable temperature range can be widened. As a result, energy saving and high-speed fixing can be achieved, and furthermore, curling of the paper can be prevented. Therefore, as a toner for heat and pressure fixing, a toner having both good low-temperature fixability and high-temperature offset resistance is desired.

Conventionally, there has been proposed a technique for achieving low-temperature fixability and offset resistance 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. Have been.

As a technique for attaining low-temperature fixing property, a low melting point wax or the like which is easily plastically deformed is used as a core material (US Pat. No. 3,269,626, JP-B-46-15876, JP-B-44-9880, JP-A-48-75032, JP-A-48-7503
No. 3), using a liquid core material, or using a core material alone causes blocking at high temperatures, but uses a resin with a low glass transition point that improves fixing strength and uses it as an outer shell. Capsule toners for heat roller fixing in which a resin wall having a high melting point is formed by interfacial polymerization for the purpose of imparting blocking resistance and the like have been devised (JP-A-61-56352, JP-A-58-205162). Gazette).

Further, as the one using polyester as the shell material, a capsule toner in which the shell material is thermotropic liquid crystal polyester (Japanese Patent Laid-Open No. 63-281168) and a capsule toner using crystalline polyester (Japanese Patent Laid-Open No. -1843
No. 58), and further, a capsule toner (Japanese Patent Laid-Open No. 6130713) in which the shell material is amorphous polyester has been devised.

On the other hand, as a technique for improving the offset resistance of the capsule toner, a capsule toner containing silicone oil, a capsule toner using a resin in which an appropriate amount of a crosslinking agent is used as a core resin, and a releasable substance are used. There are capsule toners used as core materials, capsule toners containing silicone oil in core materials containing an oily solvent and a polymer, and the like.

Among these, the following are mentioned as the ones containing silicone oil. (A) Japanese Patent Publication No. 58-57102 discloses a heat-fixing microcapsule toner having a core substance mainly composed of a releasable substance such as silicone oil and a wall substance mainly composed of a thermoplastic resin. . (B) JP-A-60-184259 discloses a pressure-fixing microcapsule toner containing a specific silicone compound. (C) Japanese Patent Application Laid-Open No. 62-150260 discloses a capsule toner in which silicone is contained in a core substance without being substantially dissolved in a binder and metal oxide particles are contained in an outer shell. (D) Japanese Patent Application Laid-Open No. 62-150261 discloses a capsule toner in which a core material contains silicone oil having a kinematic viscosity of 500 to 9500 cs (25 ° C.).

In the prior art reference (a), it is described that a release agent substance such as silicone oil is mainly used as a core material, but a thermoplastic resin is not mainly used as the core material. Therefore, there is a problem that the fixability is poor.

All of the prior art references (b), (c) and (d) disclose pressure fixing capsule toners,
There is a problem that the fixing property is remarkably poor in the pressure fixing and that the image is easily peeled off especially when the fixed image is bent.
Further, in the pressure fixing capsule toner, since it is fixed at an extremely high linear pressure (10 kg / cm or more), a strong shell material can be used, and a liquid substance or silicone oil is enclosed in the core material. It was easy.

However, in the heat pressure fixing capsule toner, since the fixing is carried out at a relatively low linear pressure (3 kg / cm or less), a strong shell material cannot be used, and the toner melts at room temperature as in the present invention. It has been conventionally considered very difficult to incorporate the silicone oil in a state into the core material because the silicone oil easily bleeds out.

In addition, polyester resin is used in
When the outer shell is formed by the in situ polymerization method to produce the capsule toner for heat and pressure fixing, if silicone oil having a kinematic viscosity of 500 cs or more is used based on the disclosures of (a) to (d), in situ In the polymerization, since the silicone oil is not unevenly distributed near the surface of the toner, it is difficult to obtain sufficient offset resistance. Furthermore,
In particular, when a solid black image is printed, there is also a problem in that the release marks from the fixing roller are poor, and thus scratches are generated by the peeling nails.

Based on the above circumstances, the present inventors used a silicone oil having a specific kinematic viscosity and a specific polymerization method to contain the silicone oil in a core toner of a capsule toner for heat and pressure fixing. Find out what you can do,
It has been found that a toner having high fixability can be provided without bleeding out.

[0016]

That is, the object of the present invention is industrially advantageous in terms of manufacturing equipment and manufacturing process.
A capsule toner produced by the in situ polymerization method, comprising:
An object of the present invention is to provide a capsule toner for heat and pressure fixing which has excellent offset resistance and releasability at the time of fixing with a heat roller, can be fixed at a low temperature, and has excellent blocking resistance, and a method for producing the same.

[0017]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have designed a core material in consideration of fixing property and paper transfer resistance (Tg, composition, amount of crosslinking agent). age,
Furthermore, in order to improve the offset resistance and the prevention of scratches, by adding a low-viscosity silicone oil and using a hydrophilic resin such as amorphous polyester as the outer shell material of the capsule toner, it is possible to obtain a clear image without scumming. It was found that the image can be stably formed many times.

That is, the distribution of the low-molecular weight component and the high-molecular weight component in the toner is controlled, and the addition of a low-viscosity silicone oil improves the releasability at the time of fixing, thereby improving the offset resistance and the prevention of nail scratches. By using a shell material composition with good blocking resistance, in a heat pressure fixing method such as a heat roll, the capsule for heat pressure fixing has excellent offset resistance, can be fixed at low temperature, and has good storage stability. They have found that a toner can be provided, and have completed the present invention.

That is, the gist of the present invention is: (1) A heat-meltable core material containing at least a thermoplastic resin and a colorant, and an outer shell made of a hydrophilic resin provided so as to cover the surface of the core material. In the heat and pressure fixing capsule toner, the core material has a kinematic viscosity of 10 to 500 c.
Capsule toner for heat and pressure fixing, which contains s (25 ° C.) of silicone oil, and the capsule toner is formed by an in situ polymerization method, (2) 20 amount in silicone oil (1) The heat-and-pressure fixing capsule toner according to (1), in which the concentration of oligomers below the body is 1000 ppm or less; (3) The heat-and-pressure fixing capsule according to (1), wherein the outer shell is mainly composed of amorphous polyester. Toner, (4) Glass transition point of amorphous polyester is 50 to 8
(3) The capsule toner for heat and pressure fixing according to (3), which has a temperature of 0 ° C., and (5) the acid value of the amorphous polyester is 3 to 50 (KO
Hmg / g), the heat and pressure fixing capsule toner according to the above (3) or (4), (6) the glass transition point derived from the thermoplastic resin as the main component of the core material is 10 to 50 ° C. (1) to (5) the heat and pressure fixing capsule toner according to any one of (1) to (5), (7) in si having the following steps (a) to (c)
A method for producing a capsule toner for heat and pressure fixing for producing a capsule toner by a tu polymerization method, (a) an amorphous material in a mixture containing a monomer constituting a core resin, a polymerization initiator, a silicone oil and a colorant. The polymerizable composition in which the amorphous polyester is unevenly distributed on the surface of the droplets of the core material-constituting material is obtained by dispersing the mixture obtained in the step of dissolving the polyester and the step (b) of the step (a) in an aqueous dispersion medium. The step of obtaining
(C) polymerizing the polymerizable composition obtained in step (b),
The step of forming an outer shell made of an amorphous polyester and a core material coated therewith, (8) Further, the seed polymerization of the following step (d) is carried out to produce a capsule toner. Manufacturing method, (d) Capsule toner obtained by the in situ polymerization method is used as a precursor particle, and at least a vinyl polymerizable monomer and a vinyl polymerization initiator are added to an aqueous suspension of the precursor particle to form a precursor. A step of polymerizing the monomer component in the precursor particles after absorbing into particles, (9) the kinematic viscosity of the silicone oil is 10 to 500 cs
(25) The production method according to (7) or (8) above, (10) The production according to (7) or (8) above, wherein the concentration of the oligomer of 20-mer or less in the silicone oil is 1000 ppm or less. Method, (11) The amount of silicone oil used is the core resin 10
The manufacturing method according to any one of claims 7 to 10, which is 0.1 to 10.0 parts by weight with respect to 0 parts by weight.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The capsule toner for heat and pressure fixing of the present invention comprises a heat-fusible core material containing at least a thermoplastic resin and a colorant, and a hydrophilic resin provided so as to cover the surface of the core material. In a heat and pressure fixing capsule toner composed of an outer shell, the core material has a kinematic viscosity of 10 to 500 c.
It is characterized in that it contains s (25 ° C.) of silicone oil, and that the capsule toner is formed by an in situ polymerization method.

Here, the "in situ polymerization method" means
This is a polymerization method in which the monomer of the core material resin, the initiator and the like are polymerized inside the outer shell resin to form the core material resin, and the monomer and the like are supplied only from the inner phase of the dispersed phase.
It is included in the n situ polymerization method. The encapsulated toner of the present invention includes those obtained by such an in situ polymerization method alone, as well as in situ polymerization and s
It also includes those obtained by combining eed polymerization.

The silicone oil used is not particularly limited as long as it has a kinematic viscosity of 10 to 500 cs (25 ° C.), and various silicone oils can be used.

Specifically, a silicone oil having a dimethylsiloxane structure, a methyl-phenylsiloxane structure (a copolymer structure of dimethylsiloxane and biphenylsiloxane), a monomethylsiloxane structure, a methyl-carboxylsiloxane structure, or a modified silicone oil is used. Examples of commercially available products that are highly effective include "KF96-50" and "KF96-10" manufactured by Shin-Etsu Chemical Co., Ltd.
0 "," KF96SS-100 "," KF96-30 "
0 "," KF96SS-300 "," KF96-50 "
0 "," KF-54 "," KF-99 "," TSF451-50,100,300,35 "manufactured by Toshiba Silicone Co., Ltd.
0,500 "," TSF4300 "," L45-50,100,350,50 "manufactured by Nippon Unicar Co., Ltd.
0 "and the like. These silicone oils may be used as a mixture of two or more.

The kinematic viscosity of silicone oil is 10-50.
0 cs (25 ° C.), more preferably 50 to 50
0 cs (25 ° C.), particularly preferably 100 to 40
0 cs (25 ° C.). If the kinematic viscosity is higher than this range, the silicone oil is less likely to be unevenly distributed in the vicinity of the toner surface during the production of the toner by the in situ polymerization method. Therefore, the silicone oil is less likely to appear on the toner surface when the toner is fixed, so that the effect can be exhibited. However, the offset resistance tends to be insufficient, and when the kinematic viscosity is smaller than this range, the toner surface is likely to bleed during storage and the storage stability tends to be impaired.

That is, in the capsule toner of the present invention,
Silicone oil is also contained in the core material and partially in the shell material, but when it is produced by the in situ polymerization method,
Silicone oil does not exist on the outermost surface of the toner because the shell material is more hydrophilic. That is, the silicone oil does not exist on the toner surface during toner production, but is unevenly distributed in the vicinity of the surface of the core made of the core material, and appears on the toner surface for the first time at the time of fixing, which results in good offset resistance, releasability, and storage stability. Brings stability.

The concentration of the oligomer component of 20-mer or less in the silicone oil is preferably 1000 ppm or less, more preferably 800 ppm or less from the viewpoint of long-term storage stability. That is, by reducing the low molecular weight components in the silicone oil, when left at high temperature for a long period of time, the silicone oil does not easily bleed out, and the long-term storage stability is significantly improved.

To prepare such a silicone oil, heat treatment is carried out at a high temperature of 100 ° C. or higher for several hours,
By volatilizing low molecular weight components, the concentration of oligomer components of less than 20 mer in silicone oil can be reduced to 1000 p.
pm or less. Quantification of the concentration of such an oligomer component can be confirmed by gas chromatography or the like.

The content of silicone oil is 1
It is usually 0.1 to 10.0 parts by weight, preferably 0.5 to 5.0 parts by weight, based on 00.0 parts by weight. When the content is within this range, offset resistance and storage stability tend to be good.

The heat and pressure fixing capsule toner of the present invention comprises:
Although the surface of the core material is coated with a hydrophilic resin,
Examples of the hydrophilic resin include amorphous polyesters, polyamides, polyesteramides, and polyureas, and those containing amorphous polyester as a main component, that is, those containing 50 to 100% by weight in the total weight of the outer shell, are preferable. In particular, it is preferable that the outer shell is made of only amorphous polyester.
Amorphous polyesters are usually obtained by polycondensation of one or more alcohol monomers (divalent, trivalent or higher) and one or more carboxylic acid monomers (divalent, trivalent or higher). Therefore, it is 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.

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. Preferably, a trihydric alcohol is used. In the present invention, these dihydric alcohol monomers and polyhydric alcohol monomers having a valence of 3 or more may be used alone or in combination.

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 or lower alkyl esters of these acids.

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. In the present invention, these divalent carboxylic acid monomers and 3
A single or a plurality of monomers may be used from the carboxylic acid monomers having a valency or higher.

The method for producing the amorphous polyester in the present invention is not particularly limited, and the amorphous polyester can be produced using the above-mentioned monomers by a generally known esterification or transesterification reaction. Here, amorphous refers to a state having no distinct melting point, and in the present invention, when a crystalline polyester is used, the amount of energy required for melting is large,
It is not preferable because the toner fixing property cannot be improved.

The amorphous polyester used in the present invention preferably has a glass transition point of 50 to 80 ° C, more preferably 55 to 75 ° C. 50
If the temperature is less than ℃, the storage stability of the toner will be deteriorated,
If it exceeds, the fixability of the toner deteriorates. In the present invention, the glass transition point means a differential scanning calorimeter (“DSC 22
Type 0 ", manufactured by Seiko Denshi Kogyo Co., Ltd., and the heating rate is 10 ° C.
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 at / min.

The acid value of the amorphous polyester is 3
It is preferably -50 (KOHmg / g), more preferably 10-30 (KOHmg / g). 3
If it is less than (KOHmg / g), it becomes difficult for the amorphous polyester as the shell material to come out to the interface during the in-situ polymerization, so that the storage stability of the toner becomes poor, and 50 (KOHmg / g)
If the amount exceeds g), the polyester easily migrates to the aqueous phase, and the production stability deteriorates. Here, the method for measuring the acid value is based on JIS
It is based on K0070.

The capsule toner having an outer shell made of amorphous polyester, which is preferably used in the present invention, is in situ.
It is manufactured by forming an outer shell and a core material by a polymerization method. This encapsulated toner is composed of a heat-fusible core material containing at least a thermoplastic resin and a colorant, and an outer shell provided to cover the surface of the core material.

The resin used as the main component of the heat-fusible core material of the capsule toner in the present invention includes thermoplastic resins such as polyester polyamide resin, polyamide resin and vinyl resin, preferably vinyl resin. To be The glass transition point derived from the thermoplastic resin as the main component of such a heat-meltable core material is preferably 10 to 50 ° C, more preferably 20 to 45 ° 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, and vinylnaphthalene, for example, ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, and isobutylene; for example, vinyl chloride;
Vinyl esters such as vinyl bromide, vinyl fluoride, vinyl acetate, vinyl propionate, vinyl formate, vinyl caproate, etc., for example, 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, 2-acrylate
Hydroxyethyl, glycidyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α-methyl 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, for example, ethylenic monocarboxylic acid substitution products such as acrylonitrile, methacrylonitrile, and acrylamide; and ethylenic acid such as dimethyl maleate Dicarboxylic acids and substituted products thereof, for example, vinyl ketones such as vinyl methyl ketone; vinyl ethers such as vinyl methyl ether; vinylidene halides such as vinylidene chloride;
N-vinyl compounds such as vinylpyrrole, N-vinylpyrrolidone and the like can be mentioned.

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 constituting 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, tetramethylolmethanetetraacrylate, dibromoneopentylglycol dimethacrylate, diallyl phthalate Add the agent appropriately (2 if necessary
A combination of two or more species can be used. Preferably, divinylbenzene and diethylene glycol diacrylate are 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 crosslinking agents used is 15
If the amount is more than about 10% by weight, the toner is less likely to be melted by heat, resulting in poor heat fixing property or heat pressure fixing property. In addition,
If the content is less than 0.001% by weight, it is difficult to prevent the offset phenomenon in which a part of the toner does not completely adhere to the paper but adheres to the roller surface and is transferred to the next paper in the thermal pressure fixing.

Further, the above-mentioned monomer may be polymerized in the presence of unsaturated polyester to give a graft or cross-linked polymer, which may be used as a resin for the core material.

Further, as the polymerization initiator used when 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, dicumylper A peroxide-based polymerization initiator such as an oxide may be used.

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 or the reaction time. The amount of the polymerization initiator to be used is 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the polymerization monomer.

In the present invention, the colorant is contained in the core material of the capsule toner, but all of the dyes and pigments used in the conventional colorant for toner can be used.

As the colorant used in the present invention, various carbon blacks produced by the thermal black method, acetylene black method, channel black method, lamp black method and the like, and the graft of the carbon black surface coated with a resin Carbon Black, Nigrosine Dye, Phthalocyanine Blue, Permanent Brown FG,
Brilliant First Scarlet, Pigment Green B, Rhodamine-B Base, Solvent Red 49,
Solvent Red 146, Solvent Blue 35, etc. and mixtures thereof can be mentioned. Usually, the resin in the core material 1
About 1 to 15 parts by weight is used with respect to 00 parts by weight.

In the present invention, a charge control agent can be further added to the core material. The negative charge control agent to be added is not particularly limited. Black 3804 "," Bontron S-31 "," Bontron S-32 "," Bontron S-34 "(all manufactured by Orient Chemical Co., Ltd.)," T-
77 ”,“ Eizen Spiron Black TRH ”
Metal complexes of copper phthalocyanine dyes and alkyl derivatives of salicylic acid, such as "Bontron E-81", "Bontron E-82", "Bontron E"
-85 "(manufactured by Orient Chemical Co., Ltd.), and quaternary ammonium salts such as" COPY CHARGE NX VP434 "(manufactured by Hoechst), nitroimidazole derivatives and the like. Preferably, T-77 and Eisenspiron Black TRH can be used.

The positively chargeable charge control agent is not particularly limited. For example, nigrosine dyes such as "Nigrosine Base EX", "Oil Black BS", "Oil Black SO", "Bontron N-01", and "Bontron" N-07 "," Bontron N-11 "(all manufactured by Orient Chemical Co., Ltd.), etc., a triphenylmethane dye containing a tertiary amine as a side chain, a quaternary ammonium salt compound, for example," Bontron P-51 "( Orient Chemical Co.),
Cetyltrimethylammonium bromide, "COPY CHARG
Examples thereof include polyamine resins such as "E PX VP435" (manufactured by Hoechst), "AFP-B" (manufactured by Orient Chemical), and imidazole derivatives. Preferably, Bontron N-07 and AFP-B can be used. 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.

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 may be contained in the core material. Any one or more offset preventing agents such as amide 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, polybutene and the like, and has a softening point of 80 to 160 ° C. As the fatty acid metal salt, for example, 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 with zinc, magnesium, iron Metal salts of, cobalt, copper, lead, calcium, etc .; metal salts of palmitic acid with aluminum, calcium, etc .; caprylate; lead caproate; metal salts of linoleic acid with zinc, cobalt, etc .; calcium ricinoleate; Metal salts of ricinoleic acid with zinc, cadmium and the like, and mixtures thereof, and the like. Examples of the fatty acid ester include ethyl maleate, butyl maleate, methyl stearate, butyl stearate, cetyl palmitate, ethylene glycol montanate, and the like. Examples of the partially saponified fatty acid esters include calcium partially saponified montanic acid esters. Examples of the higher fatty acids include, for example, dodecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, ricinoleic acid, arachinic acid, behenic acid, lignoceric acid, seracoleic acid, and the like, and mixtures thereof. Can be. Examples of the higher alcohol include dodecyl alcohol, lauryl alcohol, myristyl alcohol, palmityl alcohol, stearyl alcohol, aralkyl alcohol, and behenyl alcohol. Examples of the paraffin wax include natural paraffin, micro wax, synthetic paraffin, Fischer-Tropsch wax, 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. Stearamide, N,
N'-m-xylylenebis-12-hydroxystearic acid amide, N, N'-isophthalic acid bisstearylamide, N,
N'-isophthalic acid bis-12-hydroxy stearyl amide etc. are mentioned. Examples of the polyhydric alcohol ester include glycerin stearate, glycerin ricinoleate, glycerin monobehenate, sorbitan monostearate, propylene glycol monostearate,
Examples thereof include sorbitan trioleate. Examples of the silicon varnish include methyl silicon varnish and phenyl silicon varnish. Examples of the aliphatic fluorocarbon include low-polymerized compounds of ethylene tetrafluoride and propylene hexafluoride, and fluorine-containing surfactants described in JP-A-53-124428. Among the above-mentioned offset preventing agents, polyolefin and Fischer-Tropsch wax are preferably used, and polypropylene is particularly preferably used. The ratio of these offset preventing agents to the resin in the core material is preferably 1 to 20% by weight.

The method for producing the capsule toner in the present invention will be described below. The encapsulated toner of the present invention is manufactured by the in situ polymerization method from the viewpoint of simplifying manufacturing equipment and manufacturing process.

The method of manufacturing the capsule toner for heat and pressure fixing of the present invention has the following steps (a) to (c). (A) Amorphous polyester is a constituent monomer of the core resin,
A step of dissolving in a mixture containing a polymerization initiator, a silicone oil and a colorant, and (b) dispersing the mixture obtained in step (a) in an aqueous dispersion medium, the amorphous polyester being a core material. The step of obtaining a polymerizable composition unevenly distributed on the surface of the droplets of the constituent material, and (c) the polymerizable composition obtained in the step (b) is polymerized by an in situ polymerization method, and the surface is covered with an outer shell. Of forming the formed core material.

For the above reason, the kinematic viscosity of the silicone oil is preferably 10 to 500 cs (25 ° C.), more preferably 50 to 500 cs (25 ° C.).
C), and particularly preferably 100 to 400 cs (25
° C). The silicone oil may be added by mixing it with the constituent monomer of the core resin, the polymerization initiator, and the colorant, and dissolving it by stirring or the like.

In this manufacturing method, the outer shell is formed by dispersing a mixed liquid of the core constituent material and the outer constituent material of amorphous polyester in a dispersion medium, and the outer shell constituent material is unevenly distributed on the surface of the droplet. This can be done by utilizing the property of doing.
That is, the core constituent material and the outer shell constituent material are separated from each other in the liquid mixture by the difference in the solubility index, and the polymerization proceeds in this state to form a capsule structure. According to this method, since the outer shell is formed as a layer made of amorphous polyester having a substantially uniform thickness, the toner has a characteristic that the charging characteristics are uniform.

By the way, in general encapsulation by in-situ polymerization, a monomer of a resin as an outer shell, an initiator and the like are supplied from either inside or outside the dispersed phase to form an outer shell by polymerization. This is performed by obtaining an encapsulated product (“Microcapsule” Sankyo Publishing Co., Ltd. 1987).
Year, Tamotsu Kondo, Naozumi Koishi). On the other hand, in the present invention,
Situ polymerization is different from encapsulation by general in situ polymerization, since the monomer of the core resin, the initiator, etc. are polymerized to form the core resin inside the outer shell resin. Since both are common in that monomers and the like are supplied only from the internal phase of the dispersed phase, the method of the present invention is also included in the in-situ polymerization in a broad sense.

In 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 dodecylbenzenesulfonate, 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 Sodium 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-
Sodium naphthol-disulfonate, colloidal silica, alumina, tricalcium phosphate, ferric hydroxide, titanium hydroxide, aluminum hydroxide, and others can be used. Two or more 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, of which water is an essential component. Those used as are preferable. It is also possible to use these individually or in mixture.

In the production method of the present invention, the amount of the amorphous polyester added 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.
It is more preferably 6 to 30 parts by weight. If it is less than 3 parts by weight, the thickness of the outer shell becomes too thin and storage stability deteriorates. If it exceeds 50 parts by weight, the viscosity becomes high and atomization becomes difficult, resulting in poor production stability.

In the present invention, the encapsulated toner obtained as described above may be used as a precursor particle, and a heat-pressure fixing encapsulated toner further subjected to seed polymerization may be used. Therefore, in the present invention, the encapsulated toner includes not only those obtained by the in situ polymerization method alone as described above but also those obtained by combining the in situ polymerization and the seed polymerization.

That is, seed polymerization is carried out by adding at least a vinyl polymerizable monomer and a vinyl polymerization initiator to an aqueous suspension of the capsule toner (hereinafter sometimes referred to as precursor particles) obtained as described above. After being absorbed in the precursor particles, the monomer components in the precursor particles are polymerized. For example, immediately after the production of the precursor particles by the in situ polymerization method, at least a vinyl polymerizable monomer and a vinyl polymerization initiator are added in a suspended state to be absorbed in the precursor particles, Seee monomer component in particles
d may be polymerized. By doing so, the manufacturing process can be further simplified. The vinyl polymerizable monomer or the like to be absorbed in the precursor particles may be added in advance as a water emulsion.

The water emulsion to be added is obtained by emulsifying and dispersing a vinyl polymerizable monomer and a vinyl polymerization initiator in water together with a dispersion stabilizer. In addition, a crosslinking agent, an offset preventing agent, a charge control agent, etc. Can also be included.

The vinyl polymerizable monomer used in the seed polymerization may be the same as that used in the production of the above-mentioned precursor particles. Further, the same vinyl polymerization initiator, crosslinking agent and dispersion stabilizer as those used in the production of the above-mentioned precursor particles can be used. seed
The amount of the crosslinking agent used in the polymerization is 0.001 to 15% by weight, preferably 0.1 to 15% by weight, based on the vinyl polymerizable monomer.
Good to use at 10% by weight. When the use amount of these crosslinking agents is more than 15% by weight, the obtained toner is less likely to be melted by heat, and the heat fixing property or the heat pressure fixing property is deteriorated.
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 does not completely adhere to the paper but adheres to the roller surface and is transferred to the next paper in the heat and pressure fixing.

In order to further improve the storage stability of the toner, the above amorphous polyester may be added to the water emulsion. The amount added at that time is usually 1 to 20 parts by weight, preferably 3 to 15 parts by weight, based on 100 parts by weight of the core material. Such an aqueous emulsion can be prepared by uniformly dispersing it using an ultrasonic oscillator or the like.

The acid value of the amorphous polyester used in the seed polymerization is 3 to 50 as in the case of the first stage reaction.
It is preferably (KOHmg / g), and more preferably 10 to 30 (KOHmg / g). 3 (KOH
If it is less than 100 mg / g), the amorphous polyester as the shell material is less likely to come out at the interface during seed polymerization, and the storage stability of the obtained toner is poor. Phase transition easily occurs and manufacturing stability deteriorates. Here, the acid value is measured according to JIS K007.
It is due to 0.

The water emulsion is added in such an amount that the vinyl polymerizable monomer is used in an amount of 10 to 20 with respect to 100 parts by weight of the precursor particles.
Adjust to be 0 parts by weight. If the amount is less than 10 parts by weight, there is no effect in improving the fixing property, and if it exceeds 200 parts by weight, it becomes difficult to uniformly absorb the monomer into the precursor particles.

By the addition of the water emulsion, the vinyl polymerizable monomer is absorbed in the precursor particles and the precursor particles swell. Then, in this state, the monomer component in the precursor particles is polymerized. That is, seed polymerization using precursor particles as seed particles.

When the seed polymerization is further carried out in this way, the following points are further improved as compared with the capsule toner produced by the in situ polymerization method alone. That is, the encapsulated toner produced by the in situ polymerization method is superior to the conventional one in terms of low-temperature fixability and storage stability, but by further performing the seed polymerization method, a more uniform outer shell is formed from an interface science perspective. , And further excellent storage stability. Further, since the polymerizable monomer of the core material can be polymerized in two stages (in situ polymerization reaction and seed polymerization reaction), the thermoplasticity in the core material can be further improved by appropriately using a crosslinking agent. The control of the molecular weight of the resin is facilitated, and the low-temperature fixability and the offset resistance can be further improved. In particular, it is possible to provide a toner suitable not only for high-speed fixing but also for low-speed fixing.

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 capsule toner in the present invention is not particularly limited, but the average particle size is usually 3 to 30 μm. The outer shell of the capsule toner has a thickness of 0.
It is preferably from 01 to 1 μm, and if it is less than 0.01 μm, the blocking resistance deteriorates, and if it exceeds 1 μm, the heat melting property deteriorates, which is not preferable.

If desired, the capsule toner of the present invention may contain a fluidity improver, a cleaning improver and the like. Examples of the fluidity improver include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, and chromium oxide. , Cerium oxide, red iron oxide, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride and the like. Fine silica powder is particularly preferable.

The fine silica powder is Si--O--Si.
It is a fine powder having a bond, and may be any of those manufactured by a dry method and a wet method. In addition to anhydrous silicon dioxide, aluminum silicate, sodium silicate,
Any of potassium silicate, magnesium silicate, zinc silicate and the like may be used, but those containing 85% by weight or more of SiO ₂ are preferable. Further, fine powder of silica surface-treated with a silane coupling agent, a titanium coupling agent, silicon oil, silicon 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 and fine particles of fluorine-based high molecular weight particles. Further additives for adjusting the developability, for example, methyl methacrylate,
Fine particle powder of a polymer such as butyl methacrylate may be used. Further, a small amount of carbon black may be used for toning and resistance adjustment. Conventionally known carbon blacks such as furnace black, channel black, and acetylene black can be used.

The heat and pressure fixing capsule toner of the present invention comprises
When it contains a magnetic fine powder, it is used alone as a developer. When it does not contain a magnetic fine powder, it is mixed with a non-magnetic one-component developer or a carrier to form a two-component developer. Can be prepared and used. The carrier is not particularly limited, but includes iron powder,
Ferrite, glass beads or the like, or a resin-coated material thereof, a magnetite fine powder, a resin carrier in which ferrite fine powder is kneaded in a resin, or the like is used. 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 heat and pressure fixing 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.
If heat and pressure are used in combination, a known heat roller fixing method, or a method in which an unfixed toner image on a recording material is heated by a heating unit and a heat-resistant sheet as described in, for example, JP-A-2-190870. Means, by heating and melting through the heat-resistant sheet, and fixing, or, for example, as described in JP-A-2-162356, a fixedly supported heating element, and pressure-contacted to the heating element, and a film A method such as a method in which a visible image of the toner is heated and pressed and fixed on the recording material by a pressure member for bringing the recording material into close contact with the heating element via the fixing member is suitable for fixing the capsule toner of the present invention.

[0076]

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, bisphenol A ethylene oxide adduct 146.4 g, terephthalic acid 126.0 g, dodecenyl succinic anhydride 40.2 g, trimellitic anhydride 77.
7 g was placed in a glass 2-liter four-necked flask, equipped with a thermometer, a stainless stirrer, a downflow condenser, and a nitrogen introduction tube, and allowed to react at 220 ° C. in a mantle heater under a nitrogen stream. .

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. The resin thus obtained is referred to as Resin A.
Further, the glass transition point of the obtained resin was measured by a differential scanning calorimeter (“DSC220 type”, manufactured by Seiko Instruments Inc.), and it was 65 ° C. In addition, the softening point and the acid value were measured to be 110 ° C and 18 KOHmg / g, respectively.
Met. The acid value was measured by a method according to JIS K0070.

In the present invention, the softening point is a Koka type flow tester (manufactured by Shimadzu Corporation), and a sample of 1 cm ³ is heated at a temperature rising rate of 6 ° C./min while a load of 20 kg / cm ² is applied by a plunger. Given, diameter 1mm, length 1
A nozzle of mm is pushed out, whereby a plunger drop amount (flow value) -temperature curve of the flow tester is drawn, and when the height of the S-shaped curve is h, the temperature corresponds to h / 2.

Example 1 69.0 parts by weight of styrene, 31.0 parts by weight of 2-ethylhexyl acrylate, 0.9 parts by weight of divinylbenzene,
Carbon black "# 44" (manufactured by Mitsubishi Kasei) 7.0 parts by weight, silicone oil "KF96-50" (manufactured by Shin-Etsu Chemical Co., Ltd., dimethylsiloxane structure, kinematic viscosity 50 cs)
2.0 parts by weight of Resin A, 20.0 parts by weight of 2,2'-
3.5 parts by weight of azobisisobutyronitrile was added and charged into an attritor (“MA-01SC type”, manufactured by Mitsui Miike Kakoki Co., Ltd.) and dispersed at 10 ° C. for 5 hours to give a polymerizable composition. Obtained. Then, 240 g of the polymerizable composition was added to 560 g of an aqueous colloidal solution containing 4% by weight of tricalcium phosphate prepared in a 2 liter glass separable flask, and TK homomixer (M type, manufactured by Tokushu Kika Kogyo Co., Ltd.) was added. ) Was used and the mixture was emulsified and dispersed for 5 minutes at a rotation speed of 12000 rpm at 15 ° C. Next, a four-necked glass lid was put on, a reflux condenser tube, a thermometer, a nitrogen introduction tube, and a stainless steel stirring rod were attached, and it was installed in an electric heating mantle heater.
While continuing to stir under nitrogen, raise the temperature to 85 ° C and
Let react for hours. After cooling, the dispersion medium is dissolved with a 10% aqueous hydrochloric acid solution, filtered, washed with water, and then at 45 ° C. for 12 hours.
After drying under reduced pressure at 20 mmHg, the powder was classified with an air classifier to obtain a capsule toner having an average particle size of 8 μm and an outer shell made of amorphous polyester. 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 72.0 parts by weight of styrene, 28.0 parts by weight of 2-ethylhexyl acrylate, 6.0 parts by weight of 2,2'-azobisisobutyronitrile, silicone oil "KF96-1"
00 "(manufactured by Shin-Etsu Chemical Co., Ltd., dimethylsiloxane structure, kinematic viscosity 100 cs) 3.0 parts by weight, Sazole wax" S "
15.0 parts by weight of Resin A is added to 3.5 parts by weight of PLAY105 "(manufactured by Sazol Co.) to dissolve Resin A. After the resin A is dissolved, the grafted carbon black “505
20.0 parts by weight of "-P" (manufactured by Ryoyu Kogyo Co., Ltd.) was added and dispersed by a magnetic stirrer for 1 hour to obtain a polymerizable composition. Then, 240 g of the above polymerizable composition was added to 560 g of an aqueous colloidal solution containing 4% by weight of tricalcium phosphate, which had been adjusted in advance in a 2 liter glass separable flask.
Was added and the mixture was emulsified and dispersed at 15 ° C. for 5 minutes at a rotation speed of 12000 rpm using a TK homomixer (M type, manufactured by Tokushu Kika Kogyo Co., Ltd.). Next, cover the four-necked glass lid,
A reflux condenser, a thermometer, a nitrogen introduction tube, and a stainless steel stirring rod were attached, and the apparatus was installed in an electric heating mantle heater. As the first-stage polymerization, the temperature was raised to 85 ° C. while stirring under nitrogen, and a polymerization reaction was carried out for 10 hours to form seed particles, which were cooled to room temperature to obtain toner precursor particles. Then
In the aqueous suspension of the precursor particles, an ultrasonic oscillator (US-
150, manufactured by Nippon Seiki Co., Ltd., 28.8 parts by weight of styrene, 2-ethylhexyl acrylate 1
Emulsion solution consisting of 1.2 parts by weight, 2,2′-azobisisobutyronitrile 2.4 parts by weight, divinylbenzene 0.4 parts by weight, sodium lauryl sulfate 0.2 parts by weight, and water 80.0 parts by weight. 123.0 parts by weight was added dropwise, and while stirring was continued under nitrogen, the temperature was raised to 85 ° C. and reacted for 10 hours as the second stage polymerization. After cooling, dissolve the dispersion medium with a 10% aqueous hydrochloric acid solution, filter, wash with water, and air-dry.
C. for 12 hours under reduced pressure at 20 mmHg, and classified by an air classifier to obtain a capsule toner having an average particle diameter of 8 .mu.m and an outer shell of amorphous polyester. 100 parts by weight of the encapsulated toner is added to hydrophobic silica fine powder “Aerosil R-9”.
72 "0.4 parts by weight was added and mixed to obtain the encapsulated toner of the present invention. This is referred to as toner 2. The glass transition point derived from the resin in the core material was 39.5 ° C, and the softening point of Toner 2 was 112.1 ° C.

Example 3 72.0 parts by weight of styrene, 28.0 parts by weight of 2-ethylhexyl acrylate, 6.0 parts by weight of 2,2'-azobisisobutyronitrile, silicone oil "KF96-5"
00 "(manufactured by Shin-Etsu Chemical Co., Ltd., dimethylsiloxane structure, kinematic viscosity 500 cs) 3.0 parts by weight, Sazole wax" S "
15.0 parts by weight of Resin A is added to 3.5 parts by weight of PLAY105 "(manufactured by Sazol Co.) to dissolve Resin A. After the resin A is dissolved, the grafted carbon black “505
20 parts by weight of "-P" was added and dispersed by a magnetic stirrer for 1 hour to obtain a polymerizable composition. Then, 240 g of the above polymerizable composition was added to 560 g of an aqueous colloidal solution containing 4% by weight of tricalcium phosphate, which had been adjusted in advance in a 2 liter glass separable flask, and a TK homomixer (M type, special machine) (Manufactured by Kogyo Co., Ltd.) at 15 ° C. and a rotation speed of 12000 rpm for 5 minutes for emulsion dispersion. Next, cover with a four-necked glass lid, reflux condenser, thermometer,
Attach a nitrogen introduction tube and a stainless steel stirring rod,
It was installed in an electric heating mantle heater. As the first-stage polymerization, the temperature was raised to 85 ° C while continuing stirring under nitrogen, and 1
Polymerization reaction was performed for 0 hours to obtain seed particles, which were cooled to room temperature to obtain toner precursor particles. Then, 28.8 parts by weight of styrene prepared by an ultrasonic oscillator (US-150, manufactured by Nippon Seiki Co., Ltd.) in an aqueous suspension of the precursor particles, 2
-Ethylhexyl acrylate 11.2 parts by weight, 2,
123.0 parts by weight of an emulsion solution consisting of 2.4 parts by weight of 2'-azobisisobutyronitrile, 0.4 parts by weight of divinylbenzene, 0.2 parts by weight of sodium lauryl sulfate and 80.0 parts by weight of water was added dropwise. While continuing stirring under nitrogen, the temperature was raised to 85 ° C. and reacted for 10 hours as the second-stage polymerization. After cooling, dissolve the dispersion medium with 10% aqueous hydrochloric acid, filter, wash with water, air-dry, and then at 45 ° C. for 12 hours.
After drying under reduced pressure at 20 mmHg, the powder was classified with an air classifier to obtain a capsule toner having an average particle size of 8 μm and an outer shell made of amorphous polyester. To 100 parts by weight of this capsule toner, 0.4 parts by weight of hydrophobic silica fine powder "Aerosil R-972" was added and mixed to obtain an encapsulated toner of the present invention. This is referred to as toner 3. The glass transition point derived from the resin in the core material is 41.2 ° C., and the softening point of Toner 3 is 114.4.
° C.

Example 4 In Example 3, the silicone oil "KF96-50" was used.
In the same manner as in Example 3, except that silicone oil "KF-54" (manufactured by Shin-Etsu Chemical Co., Ltd., methyl phenylsiloxane structure, kinematic viscosity 400 cs) was used instead of "0", a capsule toner was obtained. Obtained. This is referred to as toner 4. The glass transition point derived from the resin in the core material is 40.5 ° C, and the softening point of Toner 4 is 113.0 ° C.
Met.

Example 5 In Example 2, the silicone oil “KF96-10” was used.
Silicone oil "KF96SS-10" instead of "0"
0 "(manufactured by Shin-Etsu Chemical Co., Ltd., methyl phenyl siloxane structure, kinematic viscosity 100 cs) was used, and the surface treatment was performed in the same manner as in Example 2 to obtain a capsule toner. This is referred to as toner 5. The glass transition point derived from the resin in the core material is 39.8 ° C., and the toner 5 has a softening point of 1
It was 12.8 ° C.

Example 6 In Example 2, the silicone oil “KF96-10” was used.
Silicone oil "KF96-300" instead of "0"
(Shin-Etsu Chemical Co., Ltd., methyl phenyl siloxane structure,
By the same operation as in Example 2 except that a kinematic viscosity of 300 cs) was used, surface treatment was performed to obtain a capsule toner. This is referred to as toner 6. The glass transition point derived from the resin in the core material is 40.5 ° C., and the softening point of Toner 6 is 11
It was 3.0 ° C.

Example 7 In Example 2, the silicone oil "KF96-10" was used.
Silicone oil "KF96SS-30" instead of "0"
0 "(manufactured by Shin-Etsu Chemical Co., Ltd., methyl phenyl siloxane structure, kinematic viscosity 300 cs) was used, and the surface treatment was performed in the same manner as in Example 2 to obtain a capsule toner. This is designated as toner 7. The glass transition point derived from the resin in the core material is 40.7 ° C., and the softening point of Toner 7 is 1
It was 13.3 ° C.

Comparative Example 1 In Example 1, the silicone oil "KF96-5" was used.
By the same operation as in Example 1 except that "0" was not used, surface treatment was performed 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 31.0 ° C, and the softening point of comparative toner 1 is 127.3 ° C.
Met.

Comparative Example 2 When the precursor particles of the seed particles in Example 2 were produced, the surface treatment was carried out by the same operation as in Example 2 except that the silicone oil "KF96-100" therein was not used. Capsule toner was obtained. This is designated as comparative toner 2. The glass transition point derived from the resin in the core material is 41.8.
C., and the softening point of Comparative Toner 2 was 116.6.degree.

Comparative Example 3 In Example 2, the silicone oil "KF96-10" was used.
Silicone oil "KF96-100" instead of "0"
0 "(manufactured by Shin-Etsu Chemical Co., Ltd., dimethylsiloxane structure, kinematic viscosity 1000 cs) was used, and the surface treatment was performed in the same manner as in Example 2 to obtain a capsule toner.
This is designated as comparative toner 3. The glass transition point derived from the resin in the core material was 41.5 ° C, and the softening point of Comparative Toner 3 was 115.5 ° C.

Comparative Example 4 In Example 2, the silicone oil "KF96-10" was used.
Silicone oil "KF96-1000" instead of "0"
0 "(manufactured by Shin-Etsu Chemical Co., Ltd., dimethylsiloxane structure, kinematic viscosity 10,000 cs) was used, and the surface treatment was performed in the same manner as in Example 2 to obtain a capsule toner. This is designated as comparative toner 4. The glass transition point derived from the resin in the core material is 41.0 ° C., and the softening point of comparative toner 4 is 11
It was 4.7 ° C.

Comparative Example 5 Except that in Example 4, silicone oil "KF50-3000" (manufactured by Shin-Etsu Chemical Co., Ltd., methyl phenylsiloxane structure, kinematic viscosity 3000 cs) was used in place of silicone oil "KF-54". By the same operation as in Example 4, surface treatment was performed to obtain a capsule toner.
This is designated as comparative toner 5. The glass transition point derived from the resin in the core material was 40.8 ° C, and the softening point of comparative toner 5 was 115.1 ° 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 / methylmethacrylate 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 by the method described below.

(1) The charge amount was measured by a blow-off type charge amount measuring device described below. That is,
Using a specific charge measuring device equipped with a Faraday cage, a condenser, and an 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 1 shows the result of measurement of the charge amount of the developer prepared under the normal environment.

(2) Regarding the storage stability, toner 1
4 and comparative toners 1 to 5 were left to stand at 50 ° C. and RH of 40% for 24 hours, and the degree of aggregation was examined visually and with a finger.

(3) The fixability was evaluated by the method described below. That is, the prepared developer described above was used to form an image using a commercially available electrophotographic copying machine (a selenium-arsenic as a photoreceptor and a rotation speed of a fixing roller was 255 mm / sec). The fixing temperature was controlled to 70 to 240 ° C., and the fixing property and offset property of the image were evaluated. Table 1 shows the results.
Shown in

The minimum fixing temperature here means that the bottom surface is 15 mm ×
Apply a load of 500 g on a 7.5 mm sand eraser, rub the image fixed through the fixing device 5 times back and forth, measure the optical reflection density with a reflection densitometer of Macbeth before rubbing, and fix according to the definition below. The temperature of the fixing roller when the rate exceeds 70%. Fixing rate = (image density after rubbing / image density before rubbing)

The offset resistance was evaluated by measuring the low temperature offset disappearance temperature and the high temperature offset generation temperature. That is, the temperature of the heat roller surface is 70 to 240
A copy test was conducted by raising the temperature by 5 ° C. in the range of 0 ° C., and the adhesion of the toner on the surface of the heat roller was visually evaluated at each temperature.

(4) Further, the black solid part nail marks reflecting the releasability are commercially available electrophotographic copying machines (the photosensitive member is selenium-arsenic,
The fixing roller was rotated at a rotation speed of 255 mm / sec, and a fixing test was performed to evaluate the black solid portion of the chart after fixing. Here, ◯ means no claw mark in all temperature regions, Δ means claw mark generation in some temperature regions, and x means claw mark generation in all temperature regions. The results are shown in Table 1.

(5) With respect to long-term storage stability, the degree of agglomeration after the toners 2, 5, 6, and 7 were left at 50 ° C. and RH 40% for 1 month was examined visually and by touch. The results are shown in Table 2 together with the storage stability after standing for 24 hours.
Shown in The concentration of the oligomer component of 20-mer or less in each silicone oil was quantified by gas chromatography. Table 2 shows the results.

[0100]

[Table 1]

[0101]

[Table 2]

As is clear from the results shown in Table 1, the comparative toners 1 and 2 containing no silicone oil, and the comparative toners 3 to 5 whose kinematic viscosity is too high even if they are contained in the comparative toners 3 to 5 are
There were no problems with storage stability and minimum fixing temperature,
The high-temperature offset generation temperature was low, and nail marks on the black solid part were observed. On the other hand, in the toner of the present invention, the high temperature offset generation temperature was high, and no nail marks on the solid black portion were observed.

As is clear from the results in Table 2, toners 5 and 7 in which the concentration of the oligomer component of 20-mer or less in the silicone oil was 1000 ppm or less, the long-term storage stability was excellent. However, the concentration of the oligomer component of 20-mer or less in the silicone oil is 100
In toners 2 and 6 that exceeded 0 ppm, the toner was lightly aggregated. From this, it was found that superior results in long-term storage stability were obtained when the concentration of the oligomer component of the 20-mer or less in the silicone oil was 1000 ppm or less.

[0104]

INDUSTRIAL APPLICABILITY According to the heat-pressure fixing capsule toner of the present invention, particularly in the heat-pressure fixing method of a heat roller or the like, the offset resistance and the releasability are excellent, and the fixing can be performed at a low temperature, and the blocking resistance is high. It is possible to stably form an excellent clear image without fog a number of times.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Koji Akiyama, 1334 Minato Minato, Wakayama City, Kao Co., Ltd. (72) Inventor, Kuniyasu Kawabe, 1334 Minato, Wakayama City, Kao Co., Ltd.

Claims (11)

[Claims] 1. A capsule toner for heat and pressure fixing comprising a heat-melting core material containing at least a thermoplastic resin and a colorant, and an outer shell made of a hydrophilic resin provided so as to cover the surface of the core material. In, the core material has a kinematic viscosity of 10 to 5
A capsule toner for heat and pressure fixing, which contains 00 cs (25 ° C.) of silicone oil and is formed by an in situ polymerization method. 2. The encapsulated toner for heat and pressure fixing according to claim 1, wherein the concentration of the oligomer of 20-mer or less in the silicone oil is 1000 ppm or less. 3. The heat and pressure fixing capsule toner according to claim 1, wherein the main component of the outer shell is amorphous polyester. 4. The glass transition point of amorphous polyester is 5.
The heat and pressure fixing capsule toner according to claim 3, which has a temperature of 0 to 80 ° C. 5. The acid value of the amorphous polyester is 3 to 50.
(KOHmg / g), The heat and pressure fixing capsule toner according to claim 3 or 4. 6. The heat and pressure fixing capsule toner according to claim 1, wherein a glass transition point derived from a thermoplastic resin as a main component of the core material is 10 to 50 ° C. 7. An in having the following steps (a) to (c):
A method for producing a capsule toner for heat and pressure fixing, comprising producing a capsule toner by an in situ polymerization method. (A) a step of dissolving the amorphous polyester in a mixture containing a constituent monomer of the core resin, a polymerization initiator, a silicone oil and a colorant, and (b) the mixture obtained in the step (a) In an aqueous dispersion medium to obtain a polymerizable composition in which amorphous polyester is unevenly distributed on the surface of droplets of the core material constituting material, and (c) the polymerizable composition obtained in step (b). Polymerize
A step of forming an outer shell made of amorphous polyester and a core material coated therewith, 8. A seed comprising the following step (d):
The manufacturing method according to claim 7, wherein the capsule toner is manufactured by performing d polymerization. (D) Capsule toner obtained by the in situ polymerization method is used as a precursor particle, and at least a vinyl polymerizable monomer and a vinyl polymerization initiator are added to an aqueous suspension of the precursor particle to form a precursor particle in the precursor particle. A step of polymerizing a monomer component in the precursor particles after absorption, 9. The kinematic viscosity of the silicone oil is 10 to 50.
The production method according to claim 7 or 8, which is 0 cs (25 ° C). 10. The concentration of the oligomer of 20-mer or less in the silicone oil is 1000 ppm or less.
Or the manufacturing method of 8. 11. The method according to claim 7, wherein the amount of the silicone oil used is 0.1 to 10.0 parts by weight based on 100 parts by weight of the core resin.