JPH0749582A - Capsule toner for heat and pressure fixing and method for producing the same - Google Patents

Abstract

(57) [Summary] [Structure] A polymerizable composition is polymerized in a state of being suspended in a dispersion medium, and is composed of a heat-fusible core material and an outer shell provided so as to cover the surface of the core material. In the heat and pressure fixing capsule toner, the solvent is removed from the polymerizable composition containing the solvent in parallel with the polymerization, or the solvent is absorbed by the encapsulated particles obtained by the polymerization, and then the solvent is removed. A capsule toner for heat and pressure fixing, characterized in that the surface of the toner is irregularly shaped by removal, and a method for producing the capsule toner. [Effect] Since the toner surface of the encapsulated toner of the present invention is irregularly shaped, the untransferred toner on the photoconductor can be easily cleaned by blade cleaning. Further, in a heat pressure fixing system such as a heat roller, it is excellent in offset resistance, can be fixed at a low temperature, is excellent in blocking resistance, and can form a clear image without fog a number of times stably.

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 the specification of No. 9, etc., an electric latent image is formed by uniformly charging a photoconductive insulator layer, then exposing the layer, and dissipating the charge on the exposed portion. Was formed, and further, a fine powder having a colored charge called toner was attached to the latent image to make it visible (developing step), and the obtained visible image was transferred to a transfer material such as transfer paper. The subsequent (transfer step) comprises a step of permanently fixing (fixing step) by heating, pressure, or any other suitable fixing method. 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 by, the fixing is not sufficiently performed due to poor thermal efficiency. Further, even in a heat pressure fixing method using a heat roller or the like, which is a contact fixing method which is widely used because of its high thermal efficiency, it is necessary to raise the temperature of the heat roller in order to perform sufficient fixing, resulting in deterioration of the fixing device, This causes harmful effects such as curling of paper and increase of energy consumption. Further, when such a resin is used, the pulverizability is poor, so that the production efficiency is significantly reduced when the toner is produced. 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-57-37357, there is a method of improving the offset phenomenon by asymmetrically or cross-linking the resin, but the fixability is fixed. 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. 3,26,26).
9,626, Japanese Patent Publication No. 46-15876, Japanese Patent Publication No. 44-9880, Japanese Unexamined Patent Publication No. 48-75032, Japanese Unexamined Patent Publication No. 48-75033), but fixing is possible only by pressure, but fixing strength is poor and limited. It can be used only for the intended purpose. In addition, when a liquid core material is used, if the strength of the shell material is low, fixing is performed only by pressure, but it may crack inside the developing device and stain the inside of the device, and on the contrary, the strength of the shell material is high. Therefore, a large amount of pressure was required to break the capsule, which resulted in an image with too strong gloss, and 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. .

Therefore, a capsule toner using a compound having a heat dissociation property as a shell material (JP-A-4-212169)
Alternatively, a capsule toner (Japanese Patent Application No. 4-259088) using amorphous polyester as a shell material has been proposed. When these capsule toners are manufactured, a polymerizable monomer is suspended in a dispersion medium and its outer shell is formed by interfacial polymerization or in situ method in consideration of shortening the process, simplifying equipment, and the like. Is advantageous, and the capsule toner is usually manufactured by these methods. However, the capsule toner obtained by such a method is
If the shape is close to a sphere and the copying speed and printing speed are high,
Even if the untransferred toner remaining on the photoconductor is cleaned using a blade, the adhesion between the photoconductor and the toner is strong and the untransferred toner is not completely removed, leaving a black line in the final image. was there.

In order to solve such a problem of cleaning failure, a method of forming unevenness on the toner surface is disclosed in JP-A-63-898.
No. 67 and Japanese Patent Application Laid-Open No. 2-187768. However, in the method disclosed in JP-A-63-89867, since a high boiling point solvent is used inside the capsule toner, the shell material for achieving both the fixability and impact resistance as the toner as described above is used. The problem that strength adjustment is difficult has not been solved. Further, Japanese Patent Laid-Open No. 2-187768 describes a method of fixing solid fine particles to the toner surface, but if the processing amount is small, the toner may remain on the photosensitive member due to poor cleaning, and However, there are still some problems such as the increase of manufacturing cost.

Further, a method of forming a convex portion on the surface of the toner by incorporating inorganic fine particles in the core material is
Japanese Patent Application No. 4-27258, Japanese Patent Application No. 4-27259, Japanese Patent Application No. 4-27260
And Japanese Patent Application No. 4-27261. However, when the addition amount of the inorganic fine particles is large, the specific gravity of the toner is increased, and the toner consumption amount is increased.

Further, a polymerizable monomer in which a colorant and a charge control agent are dispersed is polymerized by a suspension polymerization method to produce a toner, and a solvent inert to polymerization is absorbed, and then the solvent is removed. Japanese Patent Laid-Open No. 1-100562 discloses a method of making toner particles irregularly shaped (irregularly shaped). But,
In this case, the toner is not encapsulated and the resin itself used as the binder resin of the toner has not been improved, and thus the fixing property remains a problem. Also, as a similar method,
The vinyl-based polymerizable monomer, the binder resin, and the organic solvent are mixed in advance, suspended in a dispersion medium, and then the organic solvent is evaporated in parallel with the polymerization of the vinyl-based monomer to obtain the toner. A method for deforming the above is described in JP-A-4-78862. However, when a toner is produced using such a method, the organic solvent used is subject to restrictions such as not inhibiting the polymerization of the monomer, and the polymerization temperature of the monomer is the boiling point of the organic solvent used. It is difficult to control the molecular weight and molecular weight distribution of the binder resin to be obtained, and it is difficult to obtain sufficient fixing strength as a toner.

The present invention has been made under the circumstances described above, and its object is to make the surface of the capsule toner irregularly shaped, and particularly, blade cleaning is good, and a clear image without fog is formed. An object of the present invention is to provide a capsule toner for heat and pressure fixing which can be stably formed many times and a method for producing the same.

[0013]

As a result of intensive research to solve the above-mentioned problems, the present inventors have found that by absorbing and removing a specific solvent from an encapsulated toner having a specific outer shell, The inventors have found that the above problems can be solved and completed the present invention.

That is, the gist of the present invention is to (1) polymerize a polymerizable composition containing at least a polymerizable monomer, a colorant, and an outer shell material in a state of being suspended in a dispersion medium, and heat the composition. In a method for producing a thermal pressure fixing capsule toner composed of a meltable core material and an outer shell provided so as to cover the surface of the core material, a polymerizable inert solvent is contained in advance in the polymerizable composition. Then, the solvent is removed in parallel with the polymerization of the polymerizable monomer, or the solvent is absorbed by the encapsulated particles obtained by the polymerization, and then the solvent is removed to remove the surface of the toner. A method for producing a capsule toner for heat and pressure fixing, which comprises deforming irregularly, and (2) a polymerizable composition containing at least a polymerizable monomer, a colorant, and an outer shell material in a dispersion medium. Polymerizes in a suspended state, heat melting In a heat and pressure fixing capsule toner composed of a material and an outer shell provided so as to cover the surface of the core material, the polymerizable composition containing the solvent is removed in parallel with the polymerization, or The present invention relates to a capsulated toner for heat and pressure fixing, characterized in that the surface of the toner is irregularly shaped by removing the solvent after absorbing the solvent in the encapsulated particles obtained by the polymerization.

In the production method of the present invention, a polymerizable composition containing an organic solvent is polymerized in situ in a dispersion medium to produce a capsule toner, which is carried out in parallel with the polymerization of the polymerizable monomer. By removing the solvent to form irregularities on the surface of the toner (first embodiment), or the encapsulated particles produced by in situ polymerization in a dispersion medium absorb the organic solvent, After that, the solvent is removed to make the surface of the toner irregularly shaped (second aspect). here,
Encapsulated particles are capsule toners obtained by polymerization, and refer to particles before the modification treatment in the second aspect of the present invention. The surface shape of the obtained toner becomes different as shown in FIG. 1 due to the irregular shape.
While the capsule toner obtained by tu polymerization is almost spherical, the shape of the toner is clearly changed.

The solvent used in the present invention has a solubility parameter of 12.0 (cal / cm ³ ) ^1/2 or less, preferably 6.5 to 10.0, and a boiling point of 1 at atmospheric pressure.
It is preferably in the range of 0 ° C to 150 ° C. When the solubility parameter is more than 12.0, the affinity between the dispersion medium such as water and the solvent becomes too good. Therefore, in the production method in which the solvent is added in advance to the polymerizable composition, the polymerizable composition is dispersed in the dispersion medium. It becomes difficult to obtain particles with a uniform distribution when suspended in, and in the manufacturing method in which the solvent is added after synthesizing the encapsulated particles, the solvent is easily dissolved in the dispersion medium and absorbed by the encapsulated particles. Therefore, it is difficult to obtain sufficient deformation (see FIG. 2). If the boiling point is lower than 10 ° C, the volatility is high and it becomes difficult to handle the solvent.
A solvent having a boiling point of more than 50 ° C requires heating at a high temperature for removal, which facilitates coalescence of the encapsulated particles, resulting in lower production efficiency and easy loss of water as a dispersion medium. Therefore, the efficiency of solvent removal is reduced.

Specific examples of the solvent used in the present invention include isopropyl ether, amyl ether, pentane, hexane, heptane, octane, cyclohexane,
Methyl ethyl ketone, diethyl ketone, diisopropyl ketone, isobutyl alcohol, isoamyl alcohol, lauryl alcohol, anisole, ethyl acetate, butyl acetate, dimethyl carbonate, benzene, toluene, xylene, chlorobenzene, dichloromethane, chloroform,
Carbon tetrachloride, 1,2-dichloroethane, 1,4-dioxane and the like can be mentioned, and these can be used alone or in combination of two or more kinds. Among these, alcohols and ethers are particularly preferable, and isobutyl alcohol and isopropyl ether are particularly preferable.

The method of absorbing and removing these solvents will be described in detail below. The method of adding the solvent to the polymerizable composition is not particularly limited, but can be mixed by ordinary stirring as long as it is soluble in the polymerizable monomer. Further, if necessary, a dispersion aid such as a surfactant may be used. On the other hand, the method of absorbing the solvent in the encapsulated particles produced by polymerization is not particularly limited, for example, the above solvent is emulsified in a dispersion medium such as water together with a dispersion stabilizer, and this is encapsulated. A method of adding it to a suspension in which particles are present and allowing it to stand for a certain period of time is mentioned as a preferable method because the operation is easy. Alternatively, the above solvent may be diluted with water or a lower alcohol, added to the suspension containing the encapsulated particles, and left standing for a certain period of time. The absorption of the solvent can be confirmed by microscopic observation, for example, when the encapsulated particles are enlarged. On the other hand, the method for removing the solvent is not particularly limited, and the following methods can be given as examples.
When adding a solvent in advance in the polymerizable composition,
A method of heating while stirring under reduced pressure is preferable because it is easy to adjust the polymerization rate and the removal rate of the solvent, but if the temperature required for the polymerization is sufficiently higher than the boiling point of the solvent, the solvent can be removed only by heating. Is possible. On the other hand, when removing the solvent from the encapsulated particles that have absorbed the solvent, the method of removing the solvent by heating the suspension containing the encapsulated particles as it is to the boiling point of the solvent, depressurizing while stirring, It can be mentioned as a preferable method because it is easy to operate. When the solvent is removed after the polymerization, the dispersion medium and the solvent may be simultaneously removed by spray drying. The removal of the solvent can be confirmed by gas chromatography or the like.

The amount of the solvent to be absorbed in the above solvent absorption operation is based on 100 parts by weight of the polymerizable monomer.
The amount is preferably 5 to 300 parts by weight, more preferably 50 to 200 parts by weight. If the addition amount is less than 5 parts by weight,
The change in shape of the toner is not sufficient. On the other hand, when the amount exceeds 300 parts by weight, the dispersion stability during production is adversely affected, and the toner is apt to aggregate during production.

In the present invention, the shape of the toner is evaluated by using the image analysis device Luzex (manufactured by Nireco Co., Ltd.) to determine the area (S) and the perimeter (L) of the toner from a photomicrograph of the toner, and evaluate from the following shape factor. it can. Shape factor = (L ² / S) / 4π In the modification in the present invention, the shape factor is preferably 1.1 or more, and more preferably 1.3 or more.
The above-mentioned method is simple and suitable for toner shape evaluation, but it is not limited to this method. In the present invention, by making the surface shape of the obtained toner different, the blade cleaning property of the toner becomes particularly good, and a clear image free from fog can be stably formed many times.

In the production method of the present invention, the capsule toner is deformed by the above method. As the capsule toner which can be deformed, the outer grain material has hydrophilicity,
There is no particular limitation as long as it can be produced by the in situ polymerization method. However, in the present invention, from the viewpoint that the performance of the core material is particularly drawn out and the toner has good fixing performance, the outer shell is mainly composed of an amorphous polyester having a glass transition point of 50 to 80 ° C. A capsule toner is preferably used in which the main component of the shell is a copolymer having at least one acid anhydride group having a glass transition point of 60 ° C. or higher. That is, these capsule toners show stable charging characteristics for a long period of time, and in the heat and pressure fixing method,
This is because the anti-offset property and the anti-blocking property are excellent, low-temperature fixing is possible, and a clear image free from fog can be stably formed many times.

The constituent materials, the manufacturing method and the like will be described below by taking these as examples. Both capsule toners are different only in the constituent material of the outer shell, and the constituent material of the core material, the manufacturing method and the like are all the same. Therefore, the constituent materials of the outer shell will be described first, and the constituent materials of the core material will be described as common contents.

The amorphous polyester of the capsule toner whose main component of the outer shell is amorphous polyester is usually one or more of divalent and / or trivalent or more alcohol monomers and 2 or more.
Those obtained by polycondensation of one or more carboxylic acid monomers having a valence of 3 and / or 3 or more are used. In the present invention, it is particularly preferable to use at least a trivalent or higher valent alcohol monomer and / or a trivalent or higher carboxylic acid monomer as constituent monomers.

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. 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 is 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. 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 it 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 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 it exceeds g), the polyester tends to move into the aqueous phase, resulting in poor production stability. Here, the acid value is measured according to JIS
This is due to K0070.

On the other hand, examples of the copolymer used in the capsule toner, which is composed of a copolymer whose main shell has at least one acid anhydride group, include α and β containing an acid anhydride group.
Examples thereof include copolymers of the ethylenic copolymerizable monomer (A) and other α, β-ethylenic copolymerizable monomer (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,

[0032]

[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, Amyl methacrylate, cyclohexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, decyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, methoxyethyl methacrylate, 2-hydroxyethyl methacrylate,
Ethylenic monocarboxylic acids such as glycidyl methacrylate and phenyl methacrylate and esters thereof, ethylenic monocarboxylic acid substitution products such as acrylonitrile, methacrylonitrile, acrylamide and the like, ethylenic dicarboxylic acids such as dimethyl maleate and the like. Examples thereof include vinyl ketones such as vinyl methyl ketone and the like, vinyl ethers such as vinyl methyl ether and the like, vinylidene halides such as vinylidene chloride and the like. 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 preferably 60 ° C or higher, more preferably 80 ° C 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.

As described above, by using the copolymer using the acid anhydride group-containing monomer as the main component of the outer shell, the charge control agent is not desorbed from the toner due to friction with the carrier. It is possible to stably form a clear image without background stains many times. In addition, blocking resistance can be improved while maintaining low-temperature fixability.

Examples of the resin used as the main component of the heat fusible core material of the capsule toner having the above outer shell include thermoplastic resins such as polyester resin, polyester / polyamide resin, polyamide resin and vinyl resin. Of these, vinyl resin is preferable. The glass transition point derived from the thermoplastic resin which is the main component of the heat-fusible core material is preferably 10 to 50 ° C., but when the glass transition point is less than 10 ° C., the storage stability of the capsule toner is low. If the temperature 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 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, 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 or the reaction time. 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 dye "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.

As a method for producing the encapsulated toner and the encapsulated particles of the present invention, an in situ polymerization method is used from the viewpoint of simplifying production equipment and production process. In this manufacturing method, the outer shell is formed by dispersing the mixed liquid of the core constituent material and the outer shell constituent in the dispersion medium, and utilizing the property that the outer shell constituent material is unevenly distributed on the surface of the droplet. You can 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 having a substantially uniform thickness, the charging property of the toner becomes uniform.

In this method, a dispersion stabilizer is contained in the dispersion medium in order to prevent aggregation and coalescence of dispersoids. Examples of the dispersion medium include water, methanol, ethanol, propanol, butanol, ethylene glycol, glycerin, acetonitrile, acetone, isopropyl ether, tetrahydrofuran, dioxane and the like. It is also possible to use these individually or in mixture.

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. , Sodium pentadecyl sulfate, sodium octyl sulfate, sodium allyl-alkyl-polyether sulfonate, sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, calcium oleate, 3,3 -Diphenylurea diphenylurea-4,4-diazo-bis-amino-β
-Sodium naphthol-6-sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5
-Tetramethyl-triphenylmethane-4,4-diazo-
It is possible to use sodium bis-β-naphthol-disulfonate, colloidal silica, alumina, tricalcium phosphate, ferric hydroxide, titanium hydroxide, aluminum hydroxide and the like. Two or more kinds of these dispersion stabilizers may be used in combination.

In the production method of the present invention, the addition amount of the above-mentioned amorphous polyester or the copolymer having one or more acid anhydride groups is usually 3 to 50 with respect to 100 parts by weight of the core material.
Parts by weight, preferably 5 to 40 parts by weight. If it is less than 3 parts by weight, the film thickness of the outer shell becomes too thin and the storage stability deteriorates. If it exceeds 50 parts by weight, the viscosity becomes high and atomization becomes difficult and the production stability deteriorates.

The particle size of the capsule 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.

If necessary, a fluidity improver, a cleaning property improver and the like can be used in the capsule toner of the present invention. 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 and fine particles of fluorine-based high molecular weight particles. 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 it is a non-magnetic one-component developer when it does not contain 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 prepared by kneading magnetite fine powder and ferrite fine powder into a 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 as described in, for example, JP-A-2-190870, the heat-resistant sheet is formed by heating the unfixed toner image on the recording material by a heating unit and a heat-resistant sheet. A fixing method in which the material is heated and melted through the fixing to fix it, or, for example, JP-A-2-1623
As described in Japanese Patent Publication No. 56, a visible image of the toner is recorded by a fixedly supported heating member and a pressing member that is brought into pressure contact with the heating member and presses a recording material to the heating member through a film. A method such as a method of heating, pressurizing and fixing the material is suitable for fixing the capsule toner of the present invention.

[0058]

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 is AST
Following the softening point according to ME28-67, the reaction was terminated when the softening point reached 110 ° C. This resin is called resin A. The glass transition point of the resin A measured with a differential scanning calorimeter (manufactured by Seiko Denshi Kogyo Co., Ltd.) is 65 ° C.
Met. The acid value measured by the method according to JIS K0070 was 18 (KOHmg / g).

Synthesis Example 1 of Encapsulated Particles 69.0 parts by weight of styrene, 31.0 parts by weight of 2-ethylhexyl acrylate, 1.1 parts by weight of divinylbenzene,
Carbon black GPT-505P (manufactured by Ryoyu Kogyo Co., Ltd.) 2
0 parts by weight, 15 parts by weight of resin A, and 4.5 parts by weight of 2,2′-azobisisobutyronitrile were added, and the mixture was dispersed for 1 hour using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), A polymerizable composition was obtained. Next, 120 g of the above polymerizable composition was added to 280 g of an aqueous colloidal solution containing 4% by weight of tricalcium phosphate prepared in a glass separable flask having a capacity of 1 liter, and the rotation speed was 10,000 rpm using a TK homomixer. And dispersed for 3 minutes. This is covered with a 4-necked glass lid, and is equipped with a reflux condenser, a thermometer, a nitrogen inlet tube,
A stainless steel stir bar was attached and placed in the electric heating mantle. Stir this under nitrogen stream at 80 ℃
The temperature was raised to and reacted for 8 hours. This is designated as Encapsulated Particle Suspension 1.

Synthesis Example 2 of Encapsulated Particles 70.0 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, a copolymer of maleic anhydride and styrene (maleic anhydride: styrene = 1: 3 molar ratio, molecular weight = 1900)
10.0 parts by weight and 4.0 parts by weight of 2,2′-azobisisobutyronitrile were added, and the mixture was put into an attritor (manufactured by Mitsui Miike Kakoki) and dispersed at 10 ° C. for 5 hours to give a polymerizable composition. I got a thing. Next, 120 g of the above-mentioned polymerizable composition was added to 280 g of an aqueous colloidal solution containing 4% by weight of tricalcium phosphate, which had been prepared in advance in a glass separable flask having a capacity of 1 liter, and a TK homomixer (made by Tokushu Kika Kogyo Co., Ltd. 2) at a rotation speed of 1000 rpm at 5 ° C.
It was emulsified and dispersed for a minute. A four-necked glass lid was attached, a reflux condenser, a thermometer, a nitrogen inlet tube, and a stainless steel stirring rod were attached, and the vessel was placed in an electric heating mantle. While continuing stirring under nitrogen, the temperature was raised to 85 ° C. and the reaction was performed for 10 hours. This is referred to as an encapsulated particle suspension 2.

Example 1 Isopropyl ether (Solubility parameter = 6.7)
60 g of (cal / cm ³ ) ^1/2 ) was added to 120 g of ion-exchanged water containing 0.06 g of sodium dodecylsulfonate, and ultrasonic waves were applied while stirring to emulsify. This was added dropwise to the encapsulated particle suspension 1 and left at room temperature for 30 minutes while continuing stirring under nitrogen. When observed under a microscope, it was confirmed that the encapsulated particles were enlarged by about 2 times, and it was confirmed that isopropyl ether was absorbed in the encapsulated particles. Then, after raising the temperature to 60 ° C, 400 mm
The pressure was reduced to Hg, and stirring was continued for 1 hour to remove isopropyl alcohol. After cooling, dissolve the dispersant with dilute hydrochloric acid,
After filtration and washing with water, it was dried at 45 ° C. and 20 mmHg for 12 hours and classified by an air classifier to obtain a capsule toner having an average particle size of 8 μm and an outer shell having irregularities on the outer surface 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 according to the present invention. This is designated as Toner 1. The glass transition point derived from the resin in the core material is 34.5.
C., and the softening point of Toner 1 was 126.2.degree.
When the obtained toner was observed with an electron microscope, irregularities were found on the toner surface. This is shown in FIG. When 50 toners were selected from the micrograph of this toner and the shape factor was calculated, the average was 1.50.

Example 2 In Example 1, isopropyl ether was mixed with isobutyl alcohol (solubility parameter = 10.5 (cal / cal
cm ³ ) ^1/2 ), except that the temperature at the time of removing the solvent was changed to 80 ° C., the same procedure as in Example 1 was performed until surface treatment to obtain a capsule toner. This is designated as toner 2. The glass transition point derived from the resin in the core material is 35.2.
C., and the softening point of Toner 2 was 128.1.degree.
When the obtained toner was observed with an electron microscope, irregularities were found on the toner surface. When 50 toners were selected from the micrograph of this toner and the shape factor was calculated, the average was 1.45.

Example 3 In the same manner as in Example 1, except that the encapsulated particle suspension 1 was replaced with the encapsulated particle suspension 2, surface treatment was performed in the same manner as in Example 1 to obtain a capsule toner. .
This is designated as toner 3. The glass transition point derived from the resin in the core material is 34.9 ° C., and the softening point of Toner 3 is 12
It was 9.0 ° C. When the obtained toner was observed with an electron microscope, unevenness was observed on the toner surface as in Example 1. When 50 toners were selected from the micrograph of this toner and the shape factor was calculated, the average was 1.48.

Example 4 68.0 parts by weight of styrene, 32.0 parts by weight of butyl acrylate, 1.1 parts by weight of divinylbenzene, 20 parts by weight of carbon black "GPT-505P" (manufactured by Ryoyu Kogyo Co., Ltd.), resin 15 parts by weight of A, 4.0 parts by weight of 2,2′-azobisisobutyronitrile and 5 parts of isopropyl ether.
0.0 parts by weight was added and dispersed for 1 hour using a TK homomixer (made by Tokushu Kika Kogyo Co., Ltd.) to obtain a polymerizable composition.
This was added to 400 g of an aqueous colloidal solution containing 4% by weight of tricalcium phosphate prepared in advance in a glass separable flask having a volume of 1 liter so that the polymerizable composition would be 30% by weight, and a TK homomixer was used. It was dispersed for 3 minutes at a rotation speed of 10,000 rpm. This was covered with a 4-necked glass lid, equipped with a flow-down condenser, a thermometer, a nitrogen introduction tube, and a stainless steel stirring rod, and placed in an electric heating mantle. This was heated to 85 ° C. while continuing stirring under a nitrogen stream and reacted for 8 hours while removing isopropyl ether. After cooling, the dispersant is dissolved with dilute hydrochloric acid, filtered, washed with water, dried at 45 ° C. and 20 mmHg for 12 hours, and classified by an air classifier. The outer shell having an average particle size of 8 μm and having irregularities on the surface is amorphous. A high quality polyester capsule toner was obtained. This capsule toner 1
Hydrophobic silica fine powder "Aerosil R-9"
72 "(manufactured by Nippon Aerosil Co., Ltd.) was added and mixed to obtain a capsule toner according to the present invention. This is designated as toner 4. The glass transition point derived from the resin in the core material was 30.2 ° C, and the softening point of Toner 4 was 131.4 ° C. When the obtained toner was observed with an electron microscope, irregularities were found on the toner surface. When 50 toners were selected from the micrograph of this toner and the shape factor was calculated, the average was 1.31.

Comparative Example 1 Capsule toner was obtained by carrying out the surface treatment in the same manner as in Example 1 except that the solvent addition and removal steps were not carried out. This is designated as comparative toner 1. The glass transition point derived from the resin in the core material is 34.5.
C., and the softening point of Comparative Toner 1 was 130.1.degree. When the obtained toner was observed with an electron microscope, the toner surface was almost spherical. When 50 toners were selected from the micrograph of this toner and the shape factor was calculated,
The average was 1.00.

Comparative Example 2 In Example 1, isopropyl ether was mixed with methanol (solubility parameter = 14.5 (cal / cm ³ ).
Instead ^1/2), except that the addition thereto of the encapsulated particle suspension 1 was mixed with ion-exchanged water 100 g, Example 1
By the same operation as above, the surface treatment was performed to obtain a capsule toner. This is designated as comparative toner 2. The glass transition point derived from the resin in the core material was 36.0 ° C., and the softening point of comparative toner 2 was 129.2 ° C. When the obtained toner was observed with an electron microscope, the toner surface was almost spherical. This is shown in FIG. When 50 toners were selected from the micrograph of this toner and the shape factor was calculated,
The average was 1.00.

Test Example 6 parts by weight of each of the toners obtained in the above Examples and Comparative Examples and styrene / particles having a particle size of 250 to 400 mesh were used.
94 parts by weight of spherical ferrite powder coated with methylmethacrylate resin was put in a plastic container, and the rotation speed was 150 rpm.
The mixture was tumbled on a roller together with the container for 20 minutes to prepare a developer. The obtained developer was evaluated for charge amount, fixing property, blocking resistance and cleaning property.

(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 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 atmospheric pressure regulator
Blow was performed for 5 seconds at a pressure of kgf / cm ² to remove only the toner from the cell. 2 from the start of blow at this time
The voltage of the electrometer after the second was set to V (volt). Here, if the electric capacity of the condenser is C (μF), the specific charge Q / m of this toner is obtained by the following equation. 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 of the toner in the developer is T (g). When the weight of the developer is D (g), the toner concentration of the sample is expressed as T / D × 100 (%), and m is calculated by the following formula. m (g) = W × (T / D) Table 1 shows the result of the charge amount measurement of the developer prepared under the normal environment.

[0070]

[Table 1]

(2) The fixability was evaluated by the method described below. That is, the prepared developer described above was used as a commercially available electrophotographic copying machine (selenium-arsenic as a photoreceptor, the rotation speed of the fixing roller was 450 mm / sec, the thermal pressure temperature in the fixing device was variable, and the oil coating device was removed. Image). The fixing temperature was controlled at 100 ° C to 220 ° C, and the fixing property and offset property of the image were evaluated. The results are also shown in Table 1. The minimum fixing temperature here is 5 for a sand eraser with a bottom surface of 15 mm x 7.5 mm.
A load of 00 g is placed, and the image fixed by the fixing device is rubbed 5 times back and forth, and the optical reflection density is measured with a reflection densitometer of Macbeth Co. before and after rubbing, and the fixing ratio defined below exceeds 70%. The temperature of the fixing roller at that time. Fixing rate = (image density after rubbing / image density before rubbing) ×
100

(3) Regarding 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. The results are also shown in Table 1.

(4) Further, continuous copying of 10,000 sheets was performed using the electrophotographic copying machine (the cleaning of the photoconductor was a blade cleaning method), and black streaks appeared on the paper as the transfer material due to poor cleaning. I checked the number to do. The results are also shown in Table 1.

As is clear from Table 1, the toners 1 to 4 of the present invention and the comparative toners 1 and 2 had proper charge amount values and good fixing properties and blocking resistance. However, the comparative toners 1 and 2 suffered from black streaks due to poor cleaning and the image quality was deteriorated, whereas the toners 1 to 4 of the present invention had no problem in cleaning property and were good even after 10,000 continuous copying. The image quality was maintained.

[0075]

EFFECTS OF THE INVENTION The capsule toner for heat and pressure fixing obtained by the present invention has a toner surface irregularly shaped, so that the untransferred toner on the photoconductor is bladed even when the copying speed and the printing speed are high. When cleaning, it can be easily cleaned. Further, in a heat pressure fixing method such as a heat roller, the offset resistance is excellent, fixing can be performed at a low fixing temperature, the blocking resistance is excellent, and a clear image without fog can be stably formed many times. .

[Brief description of drawings]

FIG. 1 is a photograph showing a particle structure of Toner 1 obtained in Example 1 as observed with an electron microscope.

FIG. 2 is a photograph showing a particle structure when Comparative Toner 2 obtained in Comparative Example 2 is observed with an electron microscope.

Claims (10)

[Claims] 1. A heat-meltable core material and a core material thereof are polymerized by suspending a polymerizable composition containing at least a polymerizable monomer, a colorant and an outer shell material in a suspension medium. In a method for producing a heat and pressure fixing capsule toner composed of an outer shell provided so as to cover the surface, a polymerizable inert solvent is contained in advance in the polymerizable composition. A feature that the surface of the toner is irregularly shaped by removing the solvent in parallel with the polymerization or by absorbing the solvent in the encapsulated particles obtained by the polymerization and then removing the solvent. And a method for producing a capsule toner for heat and pressure fixing. 2. The solvent has a solubility parameter of 12.0.
2. The method according to claim 1, wherein (cal / cm ³ ) ^1/2 or less, and the boiling point of the solvent at normal pressure is 10 ° C. to 150 ° C. 3. 3. The manufacturing method according to claim 1, wherein the main component of the outer shell material is amorphous polyester. 4. The method according to claim 3, wherein the amorphous polyester contains at least a trivalent or higher valent alcohol monomer and / or a trivalent or higher carboxylic acid monomer as constituent monomers. . 5. The acid value of the amorphous polyester is 3 to 50.
(KOHmg / g), The manufacturing method of Claim 3 or 4. 6. The production method according to claim 1, wherein the main component of the outer shell material is a copolymer having one or more acid anhydride groups. 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.
It is 50 degreeC, The manufacturing method in any one of Claims 1-6 characterized by the above-mentioned. 8. A heat-meltable core material and a core material thereof are polymerized by suspending a polymerizable composition containing at least a polymerizable monomer, a colorant and an outer shell material in a suspension medium. In a heat and pressure fixing capsule toner composed of an outer shell provided so as to cover the surface, the polymerizable composition containing a solvent is removed by removing the solvent in parallel with the polymerization, or a capsule obtained by the polymerization. A capsulated toner for heat and pressure fixing, characterized in that the surface of the toner is deformed into an irregular shape by absorbing the solvent into the emulsified particles and then removing the solvent. 9. The glass transition point of the main component of the outer shell is 50 to 8
The heat and pressure fixing capsule toner according to claim 8, which is an amorphous polyester at 0 ° C. 10. The main component of the outer shell has a glass transition point of 60.
The capsule toner for heat and pressure fixing according to claim 8, which is a copolymer having one or more acid anhydride groups having a temperature of not less than ° C.