JP2003316071A - Method for manufacturing electrostatic charge image developing toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an electrostatic charge image developing toner which has excellent low-temperature fixability, blocking property, electrostatic charge characteristic and cleanability and can form images of high image quality. <P>SOLUTION: The electrostatic charge image developing toner is manufactured by adding inorganic particles to capsulated toner particles consisting of inner layers which are composed of the matured particles obtained by maturating the flocculated particles containing the polymer primary particles obtained by at least a polymerization process and coloring agents and outer layers are essentially composed of a polymer. At this time, the addition of the inorganic particles is performed while the capsulated toner particles are heated. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a toner for developing an electrostatic charge image. More specifically, the present invention relates to a method of manufacturing an electrostatic charge image developing toner used in electrophotographic copying machines and printers. More specifically, the present invention relates to a method for producing a toner for developing an electrostatic charge image, which is excellent in low-temperature fixing property, blocking property, charging property and cleaning property and can obtain a high quality image.

[0002]

2. Description of the Related Art When a visible image is formed by an electrophotographic method, first an electrostatic latent image is formed on a photosensitive drum, then this is developed with toner, and then transferred to a transfer paper, etc. To form a visible image. Conventionally, generally used toners include resins and colorants produced by various methods, a charge control agent if necessary,
It has been produced by a so-called melt-kneading pulverization method, which is a method of dry-blending a magnetic material and the like, melt-kneading the mixture with an extruder, and then pulverizing and classifying it to obtain a toner.

On the other hand, in recent years, high image quality and high speed have been demanded as performances that printers and copying machines should have.
To achieve high image quality, the average particle size of the toner should be 3
It is necessary to have a small particle size distribution of about 8 μm and a narrow particle size distribution. In addition, low-temperature fixability is required to achieve high speed. However, in the conventional toner obtained by the melt-kneading and pulverization method, it is difficult to control the particle size of the toner at the time of production, and if a toner having a small particle size with an average particle size in the range of 3 to 8 μm is produced, it is inevitable. A large amount of fine powder having a desired particle size or less was by-produced, and it was difficult to remove this by-classification step. Further, in order to produce a low temperature fixing toner, it is necessary to mix a resin having a low softening point, but since there is a pulverization step in the production process of the melt kneading pulverization toner,
It was not possible to use low softening point resins that hinder brittleness.

As a method for improving the drawbacks of the melt-kneading and pulverization method, Japanese Patent Publication No. Sho 51-14895 discloses a method in which a liquid mixture of a polymerizable monomer, a colorant, a polymerization initiator and the like is suspended and dispersed in an aqueous medium. A suspension polymerization method in which the toner particles are subsequently polymerized to obtain a toner particle is disclosed in Japanese Patent Laid-Open No. 63-186253. Toner particles are obtained by associating a polymer emulsion with particles to which a colorant and optionally a charge control agent are added. An emulsion polymerization association method for forming is disclosed. When a toner is obtained by a production method called a polymerization method, it is easy to control the particle size, so that a toner having a small particle size and a narrow particle size distribution can be obtained, and since a pulverizing step is unnecessary, a low softening point is obtained. It is possible to manufacture a toner using a resin, and it is possible to obtain a toner having high resolution and low temperature fixability.

Although the toner manufactured by the polymerization method as described above can be fixed at a low temperature, problems such as blocking occur during storage of the toner. In order to solve this problem, JP-A-63-93346 discloses that fine particles having a low softening point are produced by a suspension polymerization method, and a resin having a high softening point is attached to the surface of the fine particles in an aqueous medium. A manufactured encapsulated toner is disclosed. The encapsulated toner has a problem of poor cleaning property when used in a model having a cleaning mechanism for removing the residual toner on the photoconductor. In order to solve this problem, JP-A-10-123748 discloses an encapsulated toner in which an outer layer of a polymer is formed on the surface of associated particles produced by an emulsion polymerization method, which is generally excellent. It has been shown to have performance.

[0006]

However, according to the studies made by the present inventors, the encapsulated toner produced by the polymerization method such as the suspension polymerization method and the emulsion polymerization method described above has a fluidizing agent and the like. It has been found that there is a problem that the external additive is easily desorbed upon addition (external addition), which causes deterioration of image quality.

[0007]

The inventors of the present invention have conducted extensive studies to find a method for solving the above problems, and as a result,
The inventors have found that this can be solved by devising the conditions for adding the external additive, and have reached the present invention based on this finding. That is, the gist of the present invention is at least a capsule consisting of an inner layer consisting of aged particles obtained by aging agglomerated particles containing a polymer primary particles obtained by a polymerization method and a colorant, and an outer layer containing a polymer as a main component. In the production of a toner for developing an electrostatic charge image by adding inorganic fine particles to the encapsulated toner particles, the production of the toner for developing an electrostatic charge image, wherein the inorganic fine particles are added while heating the encapsulated toner particles. Method.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. The present invention is to produce an electrostatic charge image developing toner by adding inorganic fine particles to encapsulated toner particles composed of a specific inner layer and a specific outer layer under specific conditions. First, the inner layer constituting the encapsulated toner particles will be described. The inner layer is composed of aged particles obtained by aging at least polymer primary particles obtained by a polymerization method and agglomerated particles containing a colorant. is there.

The above-mentioned polymer primary particles are produced by a polymerization method such as a method of obtaining primary particles by a suspension polymerization method or a method of obtaining primary particles by an emulsion polymerization method. Among these polymerization methods, a method of obtaining primary particles by an emulsion polymerization method is preferable because particles having a small particle diameter and relatively uniform particles can be obtained. The resin that constitutes the polymer primary particles may be any resin that is generally used as a binder resin when producing a toner,
Examples thereof include thermoplastic resins such as polystyrene-based resins, poly (meth) acrylic-based resins, polyolefin-based resins, and mixtures of these resins, with polystyrene-based copolymer resins and poly (meth) acrylic acid-based resins being preferred. It is a resin, more preferably a polystyrene-based copolymer resin.

The above polystyrene-based copolymer resin is a copolymer containing a styrene-based monomer as a main component, and examples of the styrene-based monomer include styrene, o-methylstyrene and p-methylstyrene. And the like, and styrene is particularly preferable. The poly (meth) acrylic acid-based resin is a (co) polymer containing one or more (meth) acrylic acid-based monomers as a main component, and examples of the monomer forming the resin include , Methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, i-butyl acrylate, n-octyl acrylate, methyl methacrylate, ethyl methacrylate, n-methacrylate
-Butyl, n-octyl methacrylate can be raised. It preferably has 1 to 12 carbon atoms, and more preferably 3 carbon atoms.
.About.8 (meth) acrylic acid ester of aliphatic alcohol are used alone or in combination of two or more.

The resin preferably has a polar group. Examples of the polar group include an acidic polar group such as a carboxyl group, a sulfone group, a phosphoric acid group and a formyl group, a basic polar group such as an amino group, a neutral polar group such as an amide group, a hydroxyl group and a cyano group. The polar group can be introduced into the resin by copolymerization, condensation polymerization, addition polymerization or the like of a monomer having a polar group. The polar group-containing monomer is used in the resin preferably in the range of 10 to 40%. If the amount of the polar group-containing monomer is too large, the chargeability under high humidity conditions tends to decrease.

Among the monomers having a polar group, examples of the monomer having an acidic polar group include, for example, an α, β-ethylenically unsaturated compound having a carboxyl group and an α, β-ethylenic group having a sulfone group. An unsaturated compound etc. can be mentioned. Examples of the α, β-ethylenically unsaturated compound having a carboxyl group include acrylic acid, methacrylic acid, fumaric acid, maleic acid, and cinnamic acid.

Examples of the α, β-ethylenically unsaturated compound having a sulfone group include sulfonated ethylene,
Mention may be made of its sodium salt, allyl sulfosuccinic acid. Among the polar group-containing monomers, examples of the basic polar group-containing monomer include amino groups, salts of amino groups, or (meth) acrylic acid esters of aliphatic alcohols having a quaternary ammonium group, and nitrogen. Mention may be made of vinyl compounds substituted with a containing heterocyclic group and N, N-diallylalkylamines or quaternary ammonium salts thereof. Preferably, an amino group, a salt of an amino group, or a (meth) acrylic acid ester of an aliphatic alcohol having a quaternary ammonium group is used.

Examples of the above-mentioned (meth) acrylic acid ester of an aliphatic alcohol having an amino group, a salt of an amino group or a quaternary ammonium group include, for example, dimethylaminoethyl acrylate and dimethylaminoethyl methacrylate. ,
Examples thereof include diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and quaternary salts thereof.

Examples of the vinyl compound substituted with the nitrogen-containing heterocyclic group include vinyl pyridine, vinyl pyrrolidone, vinyl N-methylpyridinium chloride, vinyl N-ethylpyridinium chloride and the like. Examples of the quaternary ammonium salt of N, N-diallylalkylamine include N, N-diallylmethylammonium chloride and N, N-diallylethylammonium chloride.

Among the above polar group-containing monomers, examples of the neutral polar group-containing monomer include (meth) acrylic acid amide, (meth) acrylic acid amide substituted on the nitrogen atom, and hydroxyl group. Examples thereof include (meth) acrylic acid esters and (meth) acrylonitrile having a cyano group. As the (meth) acrylic acid amide or the (meth) acrylic acid amide substituted on the nitrogen atom,
For example, acrylamide, N-butyl acrylamide,
N, N-dibutyl acrylamide etc. can be mentioned.

Examples of the (meth) acrylic acid ester having a hydroxyl group include 2-hydroxyethyl (meth) acrylate. Examples of the monomer having a carboxyl group as a polar group used in the condensation polymerization or addition polymerization include aromatic dicarboxylic acids such as phthalic anhydride and benzene-1,2,4-tricarboxylic acid; oxalic acid and malon. And aliphatic carboxylic acids such as acids, succinic acid, adipic acid and maleic anhydride; alicyclic carboxylic acids such as tetrahydrophthalic acid and hexahydrophthalic acid, and anhydrides thereof.

Examples of the monomer having an amino group as a polar group used in the condensation polymerization or addition polymerization include chain aliphatic amines such as ethylenediamine and diethylenetriamine; aromatic amines such as metaphenylenediamine and diaminodiphenylmethane. Etc. Examples of the monomer having a hydroxyl group as a polar group used in the condensation polymerization or addition polymerization include water, ethylene glycol, propylene glycol, and aliphatic diols such as triethanolamine.

The polymer primary particles in the present invention are produced by a polymerization method such as a suspension polymerization method or an emulsion polymerization method. Of these methods, the emulsion polymerization method is preferable. In the suspension polymerization method, the polymerizable monomer is subjected to a dispersion treatment using a disperser such as a disperser, and the monomer composition after the dispersion treatment is subjected to an appropriate agitator in a water-miscible medium. The particle size is adjusted to an appropriate value, and then the polymerizable monomer is polymerized.

When a suspension stabilizer is used, it is preferable to select one which is neutral or alkaline in water and which can be easily removed by acid washing after polymerization. further,
It is preferable to select a toner that can obtain a toner having a narrow particle size distribution. As suspension stabilizers satisfying these, calcium phosphate, tricalcium phosphate, magnesium phosphate,
Examples thereof include calcium hydroxide and magnesium hydroxide. These may be used alone or in combination of two or more. These suspension stabilizers are usually used in an amount of 1 per 100 parts by weight of the radical-polymerizable monomer.
-10 parts by weight are used.

As the polymerization initiator to be used, known polymerization initiators can be used alone or in combination of two or more kinds. For example, potassium persulfate, 2,2-azobisisobutyronitrile, 2,2-azobis (2,4-dimethylvaleronitrile), benzoyl peroxide, lauroyl peroxide, or a redox initiator can be used. . Among these, azo initiators are preferable.

In the emulsion polymerization method, the polymerizable monomer is dispersed in an aqueous medium containing a polymerization initiator and an emulsifier, and the polymerizable monomer is polymerized with stirring. The surfactant used as an emulsifier in emulsion polymerization may be any of a nonionic surfactant, anionic surfactant, cationic surfactant and amphoteric surfactant, but a nonionic surfactant and anionic surfactant are preferred. .

Examples of the nonionic surfactants include polyoxyalkylene alkyl ethers such as polyoxyethylene lauryl ether; polyoxyalkylene alkylphenol ethers such as polyoxyethylene octylphenol ether; sorbitan such as sorbitan monolaurate. Examples thereof include fatty acid esters.

Examples of the anionic surfactant include fatty acid salts such as sodium stearate and sodium oleate; alkyl aryl sulfonates such as sodium dodecylbenzene sulfonate; alkyl sulfate ester salts such as sodium lauryl sulfate. You can Examples of the cationic surfactant include alkylamine salts such as laurylamine acetate; quaternary ammonium salts such as lauryltrimethylammonium chloride. Examples of amphoteric surfactants include alkyl betaines such as lauryl betaine.

These surfactants may be used alone or in appropriate combination. Further, these surfactants are preferably used in the range of about 1 to 10% by weight based on the total weight of all the monomers. Examples of protective colloids that can be used during emulsion polymerization of the polymer used in the present invention include polyvinyl alcohols such as partially saponified polyvinyl alcohol and fully saponified polyvinyl alcohol;
Examples thereof include cellulose derivatives such as hydroxyethyl cellulose. These can be used alone or in combination of two or more kinds.

Further, examples of the polymerization initiator that can be used in emulsion polymerization of the polymer used in the present invention include persulfates such as sodium persulfate and ammonium persulfate; for example, t-butyl hydroperoxide, cumene hydroperoxide, Examples thereof include organic peroxides such as p-menthane hydroperoxide; hydrogen peroxide and the like.
These can also be used in any one kind or a combination of plural kinds. The amount used can be appropriately selected, but it is used, for example, in the range of about 0.05 to 2% by weight based on the total weight of the monomers used.

Further, a reducing agent may be optionally used in the emulsion polymerization of the polymer. Examples thereof include reducing organic compounds such as ascorbic acid, tartaric acid, and citric acid; sodium thiosulfate, sodium bisulfite,
Reducing inorganic compounds such as sodium metabisulfite may be mentioned. In carrying out the emulsion polymerization reaction, the total amount of the predetermined surfactant can be added to the reaction system in advance, but a part of the surfactant is added to the reaction system in advance to start the reaction, and the rest is continuously added during the reaction. Addition or divided addition at intervals may be possible, and it is preferable. In addition, the monomer, and optionally other comonomers for modification can be added all at once as a batch, divided addition, or continuous addition, but they should be added continuously from the viewpoint of reaction control. Is preferred. In addition to the above-mentioned surfactant and polymerization initiator, p during emulsion polymerization
An H regulator, a polymerization degree regulator, an antifoaming agent and the like can be added as appropriate.

The agglomerated particles are used in a dispersion of the polymer primary particles obtained by a polymerization method, for example, a polymer emulsion and a colorant, preferably an aqueous dispersion of a charge control agent, a magnetic material, a release agent and the like. Heating, pH adjustment, addition of salt, addition of curing agent, etc. to reduce the stability of the dispersion stabilizing solution of the polymer primary particles, and forcibly binding particles to each other. It is obtained by agglomerating the polymer primary particles.

Examples of the colorant include inorganic pigments,
An organic pigment and a synthetic dye can be mentioned, and an inorganic pigment or an organic pigment is preferably used. One or more pigments and / or one or more dyes may be used in combination. Examples of the inorganic pigments include metal powder pigments, metal oxide pigments, and carbon pigments.

Examples of metal powder pigments include iron powder and copper powder. Examples of the metal oxide pigments include magnetite, ferrite, red iron oxide and the like. Examples of the carbon-based pigment include carbon black and furnace black. Examples of the organic pigments include azo pigments, acidic dye pigments and basic dye pigments, mordant dye pigments, phthalocyanine pigments, quinacdrine pigments and dioxane pigments.

Examples of the azo pigments include benzidine yellow and benzidine orange. Examples of the acidic dye-based pigment and the basic dye-based pigment include quinoline yellow, acid green, and
Examples thereof include those obtained by precipitating a dye such as alkali blue with a precipitating agent, and those obtained by precipitating a dye such as rhodamine, magenta and macalite green with tannic acid, phosphomolybdic acid and the like. Examples of the mordant dye-based pigment include metal salts of hydroxyanthraquinones. Examples of the phthalocyanine-based pigment include phthalocyanine blue and sulfonated copper phthalocyanine. Examples of the quinacridone pigment and dioxane pigment include quinacridone red and quinacridone violet.

Examples of the above synthetic dyes include aniline black, azo dyes, naphthoquinone dyes, indigo dyes, nigrosine dyes, phthalocyanine dyes, polymethine dyes, tri- and diallylmethane dyes.
Preferably, aniline black, nigrosine dye, and azo dye are used, and more preferably, azo dye has salicylic acid, naphthoic acid or 8-oxyquinoline residue in the molecule, and chromium, copper, cobalt, A material that forms a complex salt with a metal such as iron or aluminum is used.

Examples of the charge control agent include nigrosine-based electron-donating dyes, quaternary ammonium salts of metal salts of naphthenic acid or higher fatty acids, chelate pigments, electron-accepting organic complexes, chlorinated polyesters, and the like. Examples include polyesters having an excess of acid groups. As the magnetic fine particles, various materials such as ferromagnetic metals and metal oxides are used.
It is not limited as long as it does not substantially inhibit the present invention. Preferably, magnetite, ferrite, etc. are used.

Examples of the releasing agent include higher fatty acid metal salts such as stearates, oleates, and palmitates, and natural and synthetic paraffins and fatty acid esters or partial saponification products thereof. One or a combination of two or more of these compounds is used appropriately. The aging treatment for obtaining aged particles from the agglomerated particles, the same method as the method for obtaining agglomerated particles from the polymer primary particles is applied to the agglomerated particles, strengthening the treatment conditions at that time, adjusting the treatment time The aggregated particles are aggregated by, for example,

In the aged particles, it is preferable that at least a part of the contact portion between the polymer primary particles and / or the agglomerated particles constituting the aged particles is film-fused, and more preferably the polymer primary particles and the agglomerated particles. It is preferable that most of the contact portions between the layers are fused and substantially integrated. The aged particles obtained by aging the primary particles of the polymer directly or by aggregating the agglomerated particles in an aqueous medium are generally in the form of irregular irregularities with severe irregularities. When stirring is continued at a temperature, preferably a glass transition temperature of the polymer to (glass transition temperature + 80 ° C.), contact portions between the polymer primary particles and / or agglomerated particles are melted to form a film. While the fusion and integration of the particles of (1) progresses, the surface gradually becomes smooth from an irregular irregular shape, and gradually approaches a spherical shape. This film fusion treatment is 1
It can be carried out for about 6 hours, preferably for about 2 to 4 hours. The aged particles subjected to the film-forming fusion treatment in this manner have a smooth surface and are particularly suitable for stable formation of the outer layer.

The aged particles obtained by such a method preferably have a particle size in the range of 3 to 15 μm. Then, an outer layer containing a polymer as a main component is formed on the surface of the inner layer composed of the aged particles to produce encapsulated toner particles. At this time, the outer layer preferably has a thickness of 0.01 to 0.5 μm.

The method of forming the outer layer on the surface of the inner layer is not particularly limited, but for example, a spray dry method, i
Examples thereof include n-situ polymerization method and submerged particle coating method.
As a method of forming the outer layer on the surface of the inner layer by the spray drying method, for example, a dispersion liquid is prepared by dispersing aged particles forming the inner layer and polymer particles forming the outer layer in an aqueous medium to prepare a dispersion liquid. The polymer particles forming the outer layer can be coated on the aged particles forming the inner layer by spraying and drying.

As a method for forming the outer layer on the surface of the inner layer by the in-situ polymerization method, for example, aged particles are dispersed in water, a monomer and a polymerization initiator are added, and adsorbed on the surface of the aged particles. Then, the monomer is polymerized by heating to form the outer layer on the surface of the aged particle which is the inner layer. As a method of forming the outer layer on the surface of the inner layer by the submerged particle coating method, the aged particles forming the inner layer and the polymer particles forming the outer layer are reacted or combined in an aqueous medium to form the inner layer. An outer layer can be formed on the surface of the particles.

The polymer particles used for forming the outer layer are not particularly limited as long as they are particles composed of a polymer, but from the viewpoint that the thickness of the outer layer can be controlled, they are aggregated particles or aggregates of the polymer primary particles. Aged particles are preferred. Polymer primary particles constituting the outer layer, agglomerated particles and aged particles, using the same polymer as the polymer primary particles, agglomerated particles and aged particles in the aged particles used for the inner layer, manufactured by a similar manufacturing method. be able to.

In the method of the present invention, the glass transition point (Tg) of the resin used in the outer layer is usually 60 ° C. or higher,
It is preferably 70 to 110 ° C. If Tg is too low,
Storage in a general environment is difficult, and if it is too high, sufficient meltability cannot be obtained, which is not preferable. Further, it is preferable that the glass transition temperature of the polymer in the outer layer is higher than the glass transition temperature of the polymer constituting the polymer primary particles in the inner layer.
Therefore, for example, if the resin of the inner layer and the resin of the outer layer have the same composition, the degree of polymerization is preferably increased in the outer layer.

When the encapsulated toner particles of the present invention are produced by forming the outer layer on the surface of the inner layer in an aqueous medium, the aqueous dispersion of the encapsulated toner particles is dehydrated, dried and powdered. It is possible to obtain encapsulated toner particles of The electrostatic charge image developing toner of the present invention is manufactured by adding and adhering inorganic fine particles to the obtained encapsulated toner particles.

As the inorganic fine particles, a charge control agent generally used as an additive (external additive) to toner particles,
A fluidizing agent or the like can be used. For example, the fluidizing agent is not particularly limited, and examples thereof include silica, titanium oxide,
A fine powder such as aluminum oxide can be used. Such a fluidizing agent is used in an amount of 0.
It is preferable to add 01 to 5 parts by weight, and more preferably 0.1 to 4 parts by weight.

The method of adding and adhering the inorganic fine particles to the encapsulated toner particles is not particularly limited, and for example, a method of mixing the toner particles and an external additive with a high speed mixer such as a super mixer or a Henschel mixer, a hybridizer or a mechanograph. A method of mechanochemically fixing the external additive to the surface of the toner particles by using fusion or the like can be adopted.

In the method of the present invention, when the inorganic fine particles are added to the encapsulated toner particles to produce a toner for developing an electrostatic image, the inorganic fine particles are added while heating the encapsulated toner particles. Is characterized by. Generally, it is preferable to add the inorganic fine particles while heating the encapsulated toner particles to a temperature higher than the glass transition temperature of the polymer of the outer layer. Therefore, suitable temperature conditions depend on the type of outer layer polymer used, but
Satisfactory results can be obtained by adding the inorganic fine particles while heating the encapsulated toner particles to a temperature range of usually 35 ° C. or higher, preferably 40 to 70 ° C.

[0045]

EXAMPLES Specific embodiments of the present invention will now be described in more detail with reference to Examples, but the present invention is not limited to the following Examples unless it exceeds the gist. In the following, "parts" means "parts by weight". Examples 1 to 4 and Comparative Examples 1 to 3 <Production of Polymer Primary Particles> In a glass reactor equipped with a stirrer, a heating / cooling device, a concentrating device, and a raw material / auxiliary charging device, the wax emulsions shown in the following table and Demineralized water was charged and the temperature was raised to 90 ° C. under a nitrogen stream.

[0046]

[Table 1] Behenyl behenate emulsion (average particle size 0.4 μm) (as solid content) 21.3 parts Deionized water (including water in wax emulsion) 404.9 parts Then, the monomers and emulsifiers in the following table And an initiator were added and emulsion polymerization was carried out for 5 hours.

[0047]

[Table 2] (Monomers) Styrene 64 parts Butyl acrylate 36 parts Acrylic acid 3 parts Hexane dimethyldiacrylate 1.0 part Trichlorobromomethane 1.3 parts (Emulsifier) Aqueous emulsifier solution 12 parts (Initiator) 2% Peroxide Aqueous hydrogen solution 43.0 parts 2% aqueous ascorbic acid solution 43.0 parts After completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer primary particle emulsion. (Hereinafter, referred to as resin emulsion A.) The average particle size of the obtained emulsion is 257n.
m, the weight average molecular weight of the polymer is 150,000, and the Tg is 6
It was 5 ° C.

<Formation of Association Particles (Encapsulated Toner Base Particle A)>

[0049]

[Table 3] Resin emulsion A (as solid content) 120 parts Charge control agent Bontron S-34 (10% dispersion) (as solid content) 0.65 parts Aqueous dispersion of phthalocyanine blue (as solid content) 6.7 While adding and dispersing the mixture shown in the table above with a disperser, an aqueous sodium chloride solution (9 parts as solid content) was added,
Hold for 1.5 hours. Then, with further stirring, 60
It was confirmed that the average particle diameter of the aggregated particles became 7 μm by raising the temperature to 0 ° C.

Thereafter, 5 parts of styrene / butyl acrylate polymer fine particles (Tg 80 ° C., average particle diameter 0.1 μm) were added as an encapsulating agent. After adding 1 part of sodium chloride and holding for 30 minutes, the pH was adjusted to 7 and the temperature was 95 ° C.
The temperature was raised to and held for 3 hours. After cooling, it was filtered with a Kiriyama funnel, washed with water, and dried to obtain encapsulated toner mother particles A.

<External Addition Treatment> The above encapsulated toner mother particles A were subjected to an external addition treatment using a Henschel mixer, using hydrophobized silica and titania as external additives. Table 1 shows the types and amounts of external additives and the conditions for external additive treatment.
Shown in. At that time, hot water of which temperature was adjusted was flowed through the jacket of the Henschel mixer to adjust the jacket temperature to a target temperature. The temperature of the toner in the mixer was measured using a thermocouple at the tip of the deflector. The toner and the external additive were mixed for 10 minutes at a blade rotation speed of 3000 rpm. After the mixing, the mixture was passed through a sieve having an opening of 75 μm to obtain a toner.

<Evaluation of Toner> Each of the obtained toners was evaluated. The evaluation results are shown in Table-1. The live-action evaluation is
It was carried out using a printer using a non-magnetic one-component developing system. The printing rate is 5% after confirming the initial image
It was carried out by repeating continuous printing on A4 paper.

In the storage stability test, 100 g of the toner was put in a polypropylene bottle and the lid was removed at a temperature of 50 ° C.
After leaving it for 24 hours under the condition of humidity of 90%, it was cooled to room temperature, and the degree of toner aggregation when the toner was taken out from the bottle was evaluated.

[0054]

[Table 4] Evaluation criteria: ◯: The toner taken out was completely powder and was good. Can be used without problems. Δ: It is possible to use, although there is a small lump that slightly collapses when touched. X: There is a hard mass that does not easily collapse and it cannot be used.

[0055]

[Table 5]

[0056]

According to the method of the present invention, the toner for developing an electrostatic charge image produced by externally adding the inorganic fine particles under specific conditions can be applied to the encapsulated toner while maintaining the excellent properties of the encapsulated toner. The problem that the external additive, which is a problem during addition, is easily removed and the image quality is deteriorated due to the problem is solved. Therefore, the method of the present invention provides a toner for developing an electrostatic charge image, which is excellent in low-temperature fixing property, blocking property, charging property and cleaning property and can obtain a high quality image.

Claims (8)

[Claims] 1. An encapsulated toner comprising an inner layer composed of aged particles obtained by aging agglomerated particles containing at least a polymer primary particle obtained by a polymerization method and a colorant, and an outer layer containing a polymer as a main component. A method for producing an electrostatic charge image developing toner, characterized in that, when inorganic fine particles are added to the particles to produce an electrostatic image developing toner, the inorganic fine particles are added while heating the encapsulated toner particles. 2. The glass transition temperature of the polymer of the outer layer is 60 ° C.
The method for producing a toner for developing an electrostatic charge image according to claim 1, which is the above. 3. The production of a toner for developing an electrostatic charge image according to claim 1, wherein the glass transition temperature of the polymer of the outer layer is higher than the glass transition temperature of the polymer constituting the polymer primary particles of the inner layer. Method. 4. The electrostatic charge image developing according to claim 1, wherein the inorganic fine particles are added while heating the encapsulated toner particles to a temperature higher than the glass transition temperature of the polymer of the outer layer. Toner manufacturing method. 5. The method for producing an electrostatic charge image developing toner according to claim 1, wherein the inorganic fine particles are added while heating the encapsulated toner particles in a temperature range of 35 ° C. or higher. 6. The method according to claim 1, wherein the inorganic fine particles are silica.
6. The method for producing a toner for developing an electrostatic charge image according to any one of 5 above. 7. The toner for developing an electrostatic charge image according to claim 1, wherein the aged particles have a particle size of 3 to 15 μm and the outer layer has a thickness of 0.01 to 0.5 μm. Production method. 8. The method for producing a toner for developing an electrostatic charge image according to claim 1, wherein the polymer primary particles are obtained by an emulsion polymerization method.