JP2017181688A - Toner for electrostatic charge image development and method for producing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner excellent in fixability while keeping high image quality.SOLUTION: There are provided a toner for electrostatic charge image development containing at least a polymerization toner and a pulverization toner, where the polymerization toner contains a styrene-acryl copolymer as a binder resin, and the pulverization toner contains a polyester resin as a binder resin; and a method for producing a toner for electrostatic charge image development which includes a step of mixing base particles of a polymerization toner containing a styrene-acryl copolymer as a binder resin and base particles of a pulverization toner containing a polyester resin as a binder resin to obtain mixed base particles, and a step of surface-treating the mixed base particles with inorganic fine particles.SELECTED DRAWING: None

Description

  The present invention relates to an electrostatic charge image developing toner used in electrophotography, electrostatic photography and the like.

  The toner for developing an electrostatic image is used for image formation for visualizing an electrostatic image in a printer, a copying machine, a facsimile machine, a printing machine, or the like. For example, when an image is formed by electrophotography, an electrostatic latent image is first formed on a photosensitive drum, then developed with toner, transferred to transfer paper, and fixed by heat or the like. Image formation is performed. As a toner for developing an electrostatic image, usually, a binder resin and a colorant are mixed with a charge control agent, a release agent, a magnetic material, etc., if necessary, and then melt-kneaded with an extruder or the like. For the purpose of imparting various properties such as fluidity to the toner particles obtained by the so-called melt-kneading pulverization method for pulverization and classification, for example, solid fine particles such as silica are attached to the surface as external additives. Things are used.

  Furthermore, according to the recent demand for higher definition, wet methods such as suspension polymerization method, emulsion aggregation method, dissolution suspension method and the like which can easily control the particle size and particle size distribution of the toner have been proposed. Toners made by these methods are called polymerized toners. Since the particle size, shape, and toner structure of the toner particles can be precisely controlled, the polymerized toner is said to be superior in performance, particularly in image quality, compared to the pulverized toner produced by the melt-kneading pulverization method. However, there are problems with many production processes and poor productivity.

  The binder resin used for the toner is mainly styrene-acrylic or polyester. Styrene-acrylic toners are not as good as polyester toners in terms of performance such as fixability and durability, but are easily charged and images are easily formed. In addition, compared with polyester-based toner, it is characterized in that it is easily formed into particles and easy to produce. In contrast, polyester-based toners exhibit better fixability and durability than styrene-acrylic toners, but are less likely to become particles. In particular, the wet method uses an organic solvent, consumes more energy, and has poor productivity.

  In order to improve toner performance and particle productivity, a technique of mixing a polyester resin and a styrene-acrylic resin is known. For example, in the case of the melt-kneading pulverization method, a toner can be produced by kneading a polyester resin and a styrene-acrylic resin and then performing pulverization classification (see Patent Documents 1 and 2). Also in the wet method, an example in which a polyester resin and a styrene-acrylic resin are mixed at a stage before toner particles are disclosed (see Patent Documents 3 to 6).

  On the other hand, in order to improve toner performance, a technique of directly mixing pulverized toner and polymerized toner is also disclosed. For example, by mixing non-spherical polyester pulverized toner with a nearly spherical polyester resin polymerized toner, the image quality is improved by improving toner cleaning properties (see Patent Document 7).

JP-A-6-242630 JP 2002-229263 A Japanese Patent Laid-Open No. 9-50150 JP 2012-68341 A Japanese Patent Laying-Open No. 2015-138265 JP-A-2006-9060 JP 2007-079223 A

  However, when the polyester resin and the styrene-acrylic resin are mixed and granulated at the same time, it is difficult to uniformly mix and granulate due to the difference in performance between the polyester resin and the styrene-acrylic resin. There was a problem that the expected performance could not be achieved and the productivity was poor. An object of the present invention is to provide a toner excellent in fixability while maintaining high image quality.

As a result of intensive studies to solve the above-mentioned problems, the present inventors mixed a styrene-acrylic polymer toner obtained by a wet method with a polyester-based pulverized toner obtained by a melt-kneading pulverization method. Thus, it has been found that the above problems can be solved. That is, the gist of the present invention is as follows.
[1]
An electrostatic charge image developing toner containing at least a polymerized toner and a pulverized toner, wherein the polymerized toner contains a styrene-acrylic copolymer resin as a binder resin, and the pulverized toner contains a polyester resin as a binder resin. A toner for developing an electrostatic charge image.
[2]
The polymerized toner contains 50 parts by mass or more of styrene-acrylic copolymer resin with respect to 100 parts by mass of the total binder resin in the polymerized toner, and the pulverized toner is added to 100 parts by mass of the total binder resin in the pulverized toner. On the other hand, the electrostatic image developing toner according to [1], wherein the toner contains 50 parts by mass or more of a polyester resin.
[3]
The electrostatic image developing toner according to [1] or [2], wherein the content of the pulverized toner in the electrostatic image developing toner is 1 to 50% by mass.
[4]
When the volume median diameter of the polymerized toner is Dva (50) and the volume median diameter of the pulverized toner is Dvb (50), the particle size ratio Dvb (50) / Dva (50) is 0.9 to 1. 4. The toner for developing an electrostatic charge image according to any one of [1] to [3], wherein the toner is 4.
[5]
A method for producing a toner for developing an electrostatic charge image containing at least a polymerized toner and a pulverized toner, wherein the mother particles of a polymerized toner containing a styrene-acrylic copolymer resin as a binder resin and a pulverized toner containing a polyester resin as a binder resin A method for producing a toner for developing an electrostatic charge image, comprising: a step of mixing the mother particles to obtain mixed mother particles; and a step of surface-treating the mixed mother particles with inorganic fine particles.
[6]
The method for producing a toner for developing an electrostatic charge image according to [5], wherein the polymerized toner is obtained by an emulsion aggregation method.

  According to the present invention, by mixing the styrene-acrylic polymer toner obtained by the wet method and the polyester-based pulverized toner obtained by the melt-kneading pulverization method, the toner can be fixed while maintaining high image quality. An excellent toner can be provided.

Hereinafter, the present invention will be described in detail, but the present invention is not limited to the following embodiments, and can be arbitrarily modified without departing from the gist of the present invention. Hereinafter, “electrostatic image developing toner” may be abbreviated as “toner”.

<Toner for electrostatic image development>
The electrostatic charge image developing toner of the present invention contains at least a polymerized toner and a pulverized toner. The polymerized toner contains a styrene-acrylic copolymer resin as a binder resin, and the pulverized toner contains a polyester resin as a binder resin. The toner base particle manufacturing method is difficult to control the particle size and particle size distribution of the toner, but the melt kneading and pulverization method with low production cost and the toner particle size and particle size distribution are easy to control, but there are many production processes and the production cost is high. These can be roughly classified into wet polymerization methods such as suspension polymerization method, emulsion aggregation method and dissolution suspension method. The pulverized toner is a toner manufactured by a melt kneading pulverization method, and the polymerized toner is a toner manufactured by a wet polymerization method such as a suspension polymerization method, an emulsion aggregation method, or a dissolution suspension method.

  As binder resin for toner base particles, styrene-acrylic resin and polyester resin are mainly used. In contrast to styrene-acrylic resin-containing toners with good chargeability, high image quality, and relatively high productivity, polyester-based resin-containing toners are difficult to produce but have good durability and fixability. The fixing performance is also characteristic depending on the recording medium. For example, for a fibrous recording medium such as paper, the difference between a styrene-acrylic resin and a polyester resin is small, but a recording medium having a non-fibrous surface with little unevenness such as resin or resin-coated paper. On the other hand, the polyester-based resin has a strong adhesive strength with the non-fibrous surface and exhibits higher fixability than the styrene-acrylic resin. From the viewpoint of productivity and chargeability, the polymerized toner preferably contains 50 parts by mass or more of styrene-acrylic copolymer resin with respect to 100 parts by mass of the total binder resin in the polymerized toner, and 80 parts by mass or more. More preferred is 100 parts by mass. From the viewpoint of fixability to a recording medium having a non-fibrous surface, the pulverized toner preferably contains 50 parts by mass or more of a polyester resin with respect to 100 parts by mass of the total binder resin in the pulverized toner, and 80 parts by mass. The above is more preferable, and 100 parts by mass is particularly preferable.

The content of the pulverized toner in the toner is preferably 1% by mass or more, and more preferably 5% by mass or more from the viewpoint of fixability. From the viewpoint of obtaining a fine high-quality image, 50% by mass or less is preferable, and 30% by mass or less is more preferable.
The volume median diameter (Dva (50)) of the polymerized toner and the volume median diameter (Dvb (50)) ratio (Dvb (50) / Dva (50)) of the pulverized toner are usually 0.8-2. From the viewpoint of fixability to a recording medium and uniform dispersion, 0.9 to 1.4 is preferable.

  The toner to be mixed may be non-externally added toner mother particles or externally added toner particles. It is preferable that after the toner base particles are mixed, an external addition treatment is further performed using an external additive. By externally adding after mixing different kinds of particles, the surface of the different kinds of toner is likely to be uniform, and more uniform development can be realized. After mixing two or more types of toner base particles having different production methods and resin components, toner particles having a balance between performance and productivity can be obtained by externally adding them. Can be expanded. In order to further enhance the mixing effect, styrene-acrylic polymer toner base particles that are easy to charge, form images and control particles and have high productivity, and polyester systems that have high fixability and durability and are relatively easy to produce. It is preferable to externally add after mixing with pulverized toner base particles. As a result, a toner capable of realizing high fixing strength, high image quality, and high durability can be obtained. Hereinafter, the toner will be described in detail.

<Configuration of toner for developing electrostatic image>
In addition to the binder resin and the colorant (pigment), components constituting the toner used in the present invention include an internal additive such as a charge control agent and wax, an external additive, and the like as necessary.
As binder resin, polystyrene resin, epoxy resin, polyester resin, polyamide resin, styrene-acrylic resin, styrene methacrylate resin, polyurethane resin, vinyl resin, polyolefin resin, styrene butadiene resin, phenol resin, polyethylene resin, silicone resin, butyral There are resin, terpene resin, polyol resin and the like. In the present invention, the toner is a mixed toner of a polymerized toner and a pulverized toner, and the pulverized toner contains a polyester resin having excellent toner fixability and durability as a main component of the binder resin contained in the toner. On the other hand, the polymerized toner contains a styrene-acrylic copolymer resin having excellent chargeability and easy toner particle control.

  A known colorant can be arbitrarily used as the colorant. Specific examples of the colorant include carbon black, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa yellow, rhodamine dyes, chrome yellow, quinacridone, benzidine yellow, rose bengal, triallylmethane dye, monoazo, Any known dyes and pigments such as disazo dyes and condensed azo dyes can be used alone or in combination. Regarding the color toner, it is preferable to use benzidine yellow, monoazo-type, condensed azo-type dye / pigment for yellow, quinacridone, monoazo-type dye / pigment for magenta, and phthalocyanine blue for cyan. The colorant is preferably used in an amount of 3 to 20 parts by mass with respect to 100 parts by mass of the binder resin of the toner. When two or more types of toner particles are mixed as in the present application, the content of the pigment in each type of toner is not particularly limited, but from the viewpoint of uniform color development, the content of each type of toner with respect to the binder resin is the same. The closer one is preferable.

  A charge control agent may be used for the toner. When the charge control agent is used, any known one can be used alone or in combination. For example, a quaternary ammonium salt as a positively chargeable charge control agent, Examples include basic and electron-donating metal substances, and as negatively chargeable charge control agents, metal chelates, metal salts of organic acids, metal-containing dyes, nigrosine dyes, amide group-containing compounds, phenol compounds, naphthol compounds, and their Examples thereof include metal salts, urethane bond-containing compounds, and acidic or electron-withdrawing organic substances.

  In addition, when used as a toner other than a black toner in a color toner or a full color toner, it is preferable to use a charge control agent that is colorless or light in color and does not disturb the color tone of the toner. For example, as a positively chargeable charge control agent, A quaternary ammonium salt compound is a negatively chargeable charge control agent such as a metal salt or metal complex of salicylic acid or alkylsalicylic acid with chromium, zinc or aluminum, a metal salt of benzylic acid, a metal complex, an amide compound, a phenol compound, Hydroxylnaphthalene compounds such as naphthol compounds, phenolamide compounds, and 4,4′-methylenebis [2- [N- (4-chlorophenyl) amide] -3-hydroxynaphthalene] are preferred. In the toner of the present invention, it is preferable to adjust the chargeability of each toner by using a charge control agent. From the viewpoint of image quality and uniformity, it is preferable that the chargeability of the polymerized toner and the pulverized toner are close.

  The toner base particles preferably contain a wax. Specifically, olefinic waxes such as low molecular weight polyethylene, low molecular weight polypropylene, and copolymerized polyethylene; paraffin wax; Fischer-Tropsch wax; microcrystalline wax; silicone wax having an alkyl group; higher fatty acids such as stearic acid; eicosanol, etc. Long chain aliphatic alcohols; ester waxes having a long chain aliphatic group such as behenyl behenate, montanate ester, stearyl stearate; ketones having a long chain alkyl group such as distearyl ketone; hydrogenated castor oil, carnauba wax Plant waxes such as: esters or partial esters obtained from polyhydric alcohols such as glycerin and pentaerythritol and long chain fatty acids; higher fatty acid amides such as oleic acid amide and stearic acid amide; Polyester, and the like are preferable.

Among these waxes, in order to improve fixability, the wax has a melting point of 30 ° C.
The above are preferable, those having 40 ° C. or higher are more preferable, and those having 50 ° C. or higher are particularly preferable. Moreover, the thing of 100 degrees C or less is preferable, the thing of 95 degrees C or less is more preferable, and 90 degrees C or less is especially preferable. A wax having a melting point within the above range exhibits excellent fixability at low temperatures without causing stickiness or the like.

  The waxes may be used alone or in combination. The amount of the wax is preferably 1 part by mass or more per 100 parts by mass of the toner, more preferably 2 parts by mass or more, and further preferably 5 parts by mass or more. Moreover, it is preferable that it is 40 mass parts or less, More preferably, it is 35 mass parts or less, More preferably, it is 30 mass parts or less. If the wax content in the toner is too low, performance such as high-temperature offset may not be sufficient. If it is too high, the anti-blocking property may be insufficient or the wax may leak from the toner and contaminate the device. The amount of dust generated may increase.

  Examples of the external additive include inorganic particles such as silica, aluminum oxide (alumina), zinc oxide, tin oxide, barium titanate, and strontium titanate; organic acid salt particles such as zinc stearate and calcium stearate; methacrylate ester Examples thereof include organic resin particles such as polymer particles, acrylic acid ester polymer particles, styrene-methacrylic acid ester copolymer particles, and styrene-acrylic acid ester copolymer particles.

<Method for producing toner for developing electrostatic image>
Next, a method for producing an electrostatic charge image developing toner according to the present invention will be described.
[Manufacturing process of toner base particles]
<Crushing method>
A method for producing toner mother particles by a pulverization method will be described. In the case of the pulverization method, a predetermined amount of a binder resin, a colorant, and other components as required are mixed and mixed. Examples of the mixing apparatus include a double-con mixer, a V-type mixer, a drum-type mixer, a super mixer, a Henschel mixer, and a Nauter mixer.

  Next, each component is blended, and the mixed toner raw material is melt-kneaded to melt the resins and disperse the colorant and the like therein. In the melt-kneading step, for example, a batch kneader such as a pressure kneader or a Banbury mixer, or a continuous kneader can be used. For the kneading machine, a single-screw or twin-screw extruder is used. For example, KTK type twin screw extruder manufactured by Kobe Steel, TEM type twin screw extruder manufactured by Toshiba Machine Co., Ltd., twin screw extruder manufactured by K.C.K. , Bus Co., Ltd. co-kneader. Furthermore, the colored resin composition obtained by melt-kneading the toner raw material is rolled by a two-roll roll after melt-kneading, and then cooled through a cooling step of cooling by water cooling or the like.

  The cooled product of the colored resin composition obtained above is then pulverized to a desired particle size in a pulverization step. In the pulverization step, first, coarse pulverization is performed with a crusher, a hammer mill, a feather mill or the like, and further, pulverization is performed with a kryptron system manufactured by Kawasaki Heavy Industries, Ltd., a super rotor manufactured by Nisshin Engineering Co., Ltd. or the like. After that, if necessary, the particles are classified using a classifier such as an inertia classification type elbow jet (manufactured by Nippon Steel Mining Co., Ltd.) or a centrifugal classification type turboplex (manufactured by Hosokawa Micron Co., Ltd.). obtain. Further, the toner may be spheroidized using a conventionally used method. It is preferable to increase the degree of circularity close to the circularity of the polymerized toner to be mixed by the spheronization step.

<Wet polymerization method>
The method for producing the polymerized toner of the present invention is not limited, and examples thereof include wet methods such as a suspension polymerization method, an emulsion polymerization aggregation method, a dissolution suspension method, and an ester extension method. From the viewpoint of controlling the shape of the toner without using an organic solvent, the toner is preferably produced by an emulsion polymerization aggregation method.

(Suspension polymerization method)
In the suspension polymerization method, a colorant, a polymerization initiator, and, if necessary, additives such as wax, polar resin, charge control agent and cross-linking agent are added to the binder resin monomer and dissolved or dispersed uniformly. A monomer composition is prepared. This monomer composition is dispersed in an aqueous medium containing a dispersion stabilizer and the like. Preferably, granulation is performed by adjusting the stirring speed and time so that the droplets of the monomer composition have a desired toner particle size. Thereafter, polymerization is performed by stirring to such an extent that the particle state is maintained and the sedimentation of the particles is prevented by the action of the dispersion stabilizer. By collecting these by washing and filtration, toner mother particles can be obtained.

(Dissolution suspension method)
In the dissolution suspension method, a solution phase obtained by dissolving a binder resin in an organic solvent and adding a colorant or the like is dispersed by a mechanical shear force in an aqueous phase containing a dispersant and the like to form droplets. The toner base particles can be obtained by forming and removing the organic solvent from the droplets.

(Emulsion polymerization aggregation method)
In the emulsion polymerization aggregation method, polymer primary particles of a binder resin monomer obtained by an emulsion polymerization step, a colorant dispersion, a wax dispersion, etc. are prepared, and these are dispersed in an aqueous medium and heated. By performing the agglomeration step and further the aging step. These can be collected by washing and filtration to obtain toner base particles. Next, the toner base particles go through a drying process. Further, if necessary, an external additive or the like can be added to the toner base particles to obtain a toner.

  The emulsion polymerization aggregation method will be described in more detail. In the emulsion polymerization step, a polymerizable monomer that becomes a binder resin is usually polymerized in an aqueous medium in the presence of an emulsifier. At this time, each monomer is used to supply the polymerizable monomer to the reaction system. The body may be added separately, or a plurality of types of monomers may be mixed in advance and added simultaneously. The monomer may be added as it is, or may be added as an emulsion mixed and adjusted in advance with water or an emulsifier.

  As the acidic monomer, a polymerizable monomer having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, cinnamic acid, a polymerizable monomer having a sulfonic acid group such as sulfonated styrene, Examples thereof include polymerizable monomers having a sulfonamide group such as vinylbenzenesulfonamide. Examples of the basic monomer include aromatic vinyl compounds having an amino group such as aminostyrene, nitrogen-containing heterocyclic-containing polymerizable monomers such as vinylpyridine and vinylpyrrolidone, dimethylaminoethyl acrylate, diethylaminoethyl methacrylate, etc. And (meth) acrylic acid ester having an amino group. These acidic monomers and basic monomers may be used singly or as a mixture of a plurality of types, and may exist as a salt with a counter ion. Among these, it is preferable to use an acidic monomer, more preferably acrylic acid and / or methacrylic acid.

The total amount of the acidic monomer and the basic monomer in 100 parts by mass of the total polymerizable monomers constituting the binder resin is preferably 0.05 parts by mass or more, more preferably 0.5 parts by mass. More preferably, it is 1.0 part by mass or more, preferably 10 parts by mass or less, more preferably 5 parts by mass or less.
Examples of other polymerizable monomers include styrenes such as styrene, methylstyrene, chlorostyrene, dichlorostyrene, p-tert-butylstyrene, pn-butylstyrene, and pn-nonylstyrene, methyl acrylate, Acrylic esters such as ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, hydroxyethyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n methacrylate -Methacrylates such as butyl, isobutyl methacrylate, hydroxyethyl methacrylate, 2-ethylhexyl methacrylate, acrylamide, N-propylacrylamide, N, N-dimethylacrylamide,
N, N-dipropylacrylamide, N, N-dibutylacrylamide and the like can be mentioned, and the polymerizable monomers may be used alone or in combination. The electrostatic charge developing toner of the present invention contains, as a binder resin, a polymer of a styrene monomer alone, or a styrene-acrylic copolymer resin that is a polymer of a styrene monomer and an acrylic monomer. It is a waste.

  Furthermore, when the binder resin is a cross-linked resin, a polyfunctional monomer having radical polymerizability is used together with the above polymerizable monomer, for example, divinylbenzene, hexanediol diacrylate, ethylene glycol dimethacrylate, Examples include diethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, neopentyl glycol dimethacrylate, neopentyl glycol diacrylate, and diallyl phthalate. It is also possible to use a polymerizable monomer having a reactive group in a pendant group, such as glycidyl methacrylate, methylol acrylamide, acrolein and the like. Among these, radically polymerizable bifunctional polymerizable monomers are preferable, and divinylbenzene and hexanediol diacrylate are particularly preferable. These polyfunctional polymerizable monomers may be used alone or as a mixture of plural kinds.

When the binder resin is polymerized by emulsion polymerization, a known surfactant can be used as an emulsifier. As the surfactant, one or more surfactants selected from cationic surfactants, anionic surfactants, and nonionic surfactants can be used in combination.
Examples of the cationic surfactant include dodecyl ammonium chloride, dodecyl ammonium bromide, dodecyl trimethyl ammonium bromide, dodecyl pyridinium chloride, dodecyl pyridinium bromide, hexadecyl trimethyl ammonium bromide, and examples of the anionic surfactant include And fatty acid soap such as sodium stearate and sodium dodecanoate, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, sodium lauryl sulfate and the like. Nonionic surfactants include, for example, polyoxyethylene dodecyl ether, polyoxyethylene monohexadecyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene lauryl ether, polyoxyethylene sorbitan monooleate ether, monodecanoyl sucrose Etc.

The amount of the emulsifier used is preferably 0.1 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. In addition, these emulsifiers can be used as protective colloids, for example, one or more of partially or completely saponified polyvinyl alcohols such as polyvinyl alcohol and cellulose derivatives such as hydroxyethyl cellulose.
The volume average particle diameter of the polymer primary particles obtained by emulsion polymerization is preferably 0.02 μm or more, more preferably 0.05 μm or more, still more preferably 0.1 μm or more, preferably 3 μm or less, more preferably 2 μm. Hereinafter, it is more preferably 1 μm or less. If the particle size is too small, it may be difficult to control the aggregation rate in the aggregation process. If it is too large, the particle size of the toner particles obtained by aggregation tends to be large, and a toner having the target particle size is obtained. May be difficult.

In the emulsion polymerization aggregation method, a known polymerization initiator can be used as necessary, and the polymerization initiators can be used alone or in combination of two or more. For example, persulfates such as potassium persulfate, sodium persulfate, ammonium persulfate, and the like, and redox initiators combining these persulfates as a component with a reducing agent such as acidic sodium sulfite, hydrogen peroxide, 4,4 '-Azobiscyanovaleric acid, t-butyl hydroperoxide, cumene hydroperoxide, and other water-soluble polymerization initiators, and these water-soluble polymerization initiators as a component combined with a reducing agent such as ferrous salt Redox initiator systems, benzoyl peroxide, 2,2′-azobis-isobutyronitrile, and the like are used. These polymerization initiators may be added to the polymerization system before, simultaneously with the addition of the monomer, or after the addition, and these addition methods may be combined as necessary.

  A known chain transfer agent can be used as necessary, and specific examples include t-dodecyl mercaptan, 2-mercaptoethanol, diisopropylxanthogen, carbon tetrachloride, trichlorobromomethane and the like. The chain transfer agent may be used alone or in combination of two or more, and is used in an amount of 0 to 5% by mass based on the polymerizable monomer. Moreover, a well-known suspension stabilizer can be used as needed. Specific examples of the suspension stabilizer include calcium phosphate, magnesium phosphate calcium hydroxide, magnesium hydroxide and the like. These may be used alone or in combination of two or more, and may be used in an amount of 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the polymerizable monomer. The polymerization initiator and the suspension stabilizer may be added to the polymerization system at any time before, simultaneously with, or after the addition of the polymerizable monomer, and these addition methods are combined as necessary. May be. In addition, a pH adjuster, a polymerization degree adjuster, an antifoaming agent, and the like can be appropriately added to the reaction system.

  The blending of the colorant in the emulsion polymerization aggregation method is usually performed in an aggregation step. A dispersion of polymer primary particles and a dispersion of colorant particles are mixed to form a mixed dispersion, which is then aggregated to form a particle aggregate. The colorant is preferably used in the state of being dispersed in water in the presence of an emulsifier, and the volume average particle diameter of the colorant particles is preferably 0.01 μm or more, more preferably 0.05 μm or more, preferably 3 μm or less. More preferably, it is 1 μm or less.

  When a charge control agent is contained in the toner using the emulsion polymerization aggregation method, the charge control agent is added together with the polymerizable monomer during emulsion polymerization, or added in the aggregation step together with the polymer primary particles and the colorant. Or it can mix | blend by methods, such as adding after polymer primary particle, a colorant, etc. are aggregated and it becomes the target particle diameter substantially. Among these, it is preferable to disperse the charge control agent in water using a surfactant and add it to the aggregation step as a dispersion having a volume average particle size of 0.01 μm or more and 3 μm or less.

  The aggregation step in the emulsion polymerization aggregation method is performed in a tank equipped with a stirrer, and there are a method of heating, a method of adding an electrolyte, and a method of combining these. When polymer primary particles are aggregated with stirring to obtain particle aggregates of the desired size, the particle size of the particle aggregate is controlled from the balance between the cohesive force between the particles and the shearing force by stirring. However, the cohesive force can be increased by heating or adding an electrolyte.

When aggregation is performed by adding an electrolyte, both an organic salt and an inorganic salt can be used as the electrolyte. Specific examples of the electrolyte include NaCl, KCl, LiCl, Na ₂ SO ₄ , K ₂ SO ₄ , Li ₂ SO ₄ , MgCl ₂ , CaCl ₂ , MgSO ₄ , CaSO ₄ , ZnSO ₄ , and Al ₂ (SO ₄ ). ₃ , Fe ₂ (SO ₄ ) ₃ , CH ₃ COONa, C ₆ H ₅ SO ₃ Na, and the like. Of these, inorganic salts having a divalent or higher polyvalent metal cation are preferred.

  The amount of electrolyte added varies depending on the type of electrolyte, target particle size, etc., but is preferably 0.05 parts by mass or more, and more preferably 0.1 parts by mass or more with respect to 100 parts by mass of the solid component of the mixed dispersion. preferable. Further, it is preferably 25 parts by mass or less, more preferably 15 parts by mass or less, and particularly preferably 10 parts by mass or less. When the addition amount is in the above range, the agglomeration reaction can be rapidly advanced, and the particle size can be controlled relatively easily without causing fine powder or an irregular shape after the agglomeration reaction. Particle aggregates having an average particle size can be obtained. The aggregation temperature in the case of performing aggregation by adding an electrolyte is preferably 20 ° C. or higher, more preferably 30 ° C. or higher, preferably 70 ° C. or lower, more preferably 60 ° C. or lower.

  The aggregation temperature in the case of performing aggregation only by heating without using an electrolyte is preferably (Tg-20) ° C. or higher, and more preferably (Tg-10) ° C. or higher, where Tg is the glass transition temperature of the polymer primary particles. . Moreover, Tg or less is preferable and (Tg-5) degrees C or less is still more preferable. The time required for agglomeration is optimized depending on the shape of the apparatus and the processing scale, but in order for the toner particle size to reach the target particle size, it is usually held at the predetermined temperature for at least 30 minutes. preferable. The temperature rise until reaching the predetermined temperature may be raised at a constant rate, or may be raised stepwise.

  If necessary, particles having adhered or fixed resin particles may be formed on the surface of the particle aggregate after the aggregation treatment. In some cases, the chargeability and heat resistance of the obtained toner can be improved by attaching or fixing the resin particles whose properties are controlled to the surface of the particle aggregate, and further, the effects of the present invention can be made more remarkable. . When resin particles having a glass transition temperature higher than that of the polymer primary particles are used as the resin particles, it is preferable because blocking resistance can be further improved without impairing fixing properties. The volume average particle size of the resin particles is preferably 0.02 μm or more, and more preferably 0.05 μm or more. Moreover, 3 micrometers or less, Furthermore, 1.5 micrometers or less are preferable. As the resin particles, those obtained by emulsion polymerization of monomers similar to the polymerizable monomers used for the above-mentioned polymer primary particles can be used.

  Resin particles are usually used as a dispersion dispersed in water or a liquid mainly composed of water using a surfactant. However, when a charge control agent is added after the aggregation treatment, charge control is performed on the dispersion containing particle aggregates. It is preferable to add the resin particles after adding the agent. In order to increase the stability of the particle aggregate obtained in the aggregation step, it is preferable to perform fusion in the aggregated particles in the aging step after the aggregation step.

  In the emulsion polymerization aggregation method, the temperature of the aging step after the aggregation step is preferably at least Tg of the polymer primary particles, more preferably at least 5 ° C higher than Tg, and preferably Tg. The temperature is 80 ° C. or higher, more preferably 50 ° C. or lower than Tg. The time required for the aging step varies depending on the shape of the target toner, but is preferably 0.1 to 10 hours, more preferably 1 to 6 hours after reaching the glass transition temperature of the polymer primary particles. To do.

  In addition, it is preferable to add a surfactant or raise the pH value after the aggregation process, preferably before the aging process or during the aging process. As the surfactant used here, one or more emulsifiers can be selected from the emulsifiers that can be used when producing the polymer primary particles. In particular, the emulsifiers used when producing the polymer primary particles. It is preferable to use the same. Although the addition amount in the case of adding surfactant is not limited, Preferably it is 0.1 mass part or more with respect to 100 mass parts of solid components of a mixed dispersion liquid, More preferably, it is 1 mass part or more, More preferably, it is 3 masses. It is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and still more preferably 10 parts by mass or less. After the aggregation process, before the completion of the ripening process, by adding a surfactant or raising the pH value, it is possible to suppress aggregation of the particle aggregates aggregated in the aggregation process, In some cases, the generation of coarse particles can be suppressed.

  By heat treatment in the aging step, the polymer primary particles in the aggregate are fused and integrated, and the toner particle shape as the aggregate becomes close to a spherical shape. The particle aggregate before the aging step is considered to be an aggregate due to electrostatic or physical aggregation of the polymer primary particles, but after the aging step, the polymer primary particles constituting the particle aggregate are fused to each other. In addition, the toner base particles can have a nearly spherical shape. According to such a ripening step, by controlling the temperature and time of the ripening step, toner mothers having various shapes such as a shape in which the polymer primary particles are aggregated, a spherical shape in which the fusion has progressed, and the like have been performed. Particles can be obtained.

[Toner mother particle cleaning process]
The toner base particles obtained by a wet method such as a suspension polymerization method, an emulsion polymerization aggregation method, or a dissolution suspension method are obtained by solid-liquid separation of the toner base particles obtained from the wet medium, and the toner base particles are aggregated into particle aggregates. It is preferable to carry out washing as necessary after the recovery. As the liquid used for cleaning, water having a higher purity than the wet medium in which the toner is immersed in the final step of the wet method may be used, or an aqueous solution of acid or alkali may be used. As the acid, inorganic acids such as nitric acid, hydrochloric acid and sulfuric acid, and organic acids such as citric acid can be used. As the alkali, soda salts (sodium hydroxide, sodium carbonate, etc.), silicates (sodium metasilicate, etc.), phosphates, etc. can be used. Cleaning can also be performed by heating to room temperature or about 30 to 70 ° C.
From the toner mother particles, the suspension stabilizer, the emulsifier, the wet medium, the unreacted residual monomer, the toner having a small particle diameter, and the like are removed by the washing step. After the washing step, the toner base particles are preferably obtained in a wet cake state by filtration or decantation. This is because the handling becomes easy in the subsequent process. The washing process may be repeated a plurality of times.

[Moisture removal process of toner base particles]
The method for producing an electrostatic charge developing toner according to the present invention preferably includes a step of removing the water content of the toner base particles to 0.4% by mass or less before the drying step described later. Since the wet cake-like toner base particles after the washing step are in a wet state, the water content in the toner base particles is 50% by weight or less, more preferably 40% by weight or less, with respect to 100% by weight of the toner base particles. More preferably, it is 30 mass% or less. The wet mother toner particles are evaporated in advance until the water content becomes 0.4% by mass or less, whereby a volatile organic compound contained in the toner mother particles in the subsequent drying step. Can be efficiently diffused. As the dryer used in the moisture removal step, a fluid dryer, a jet dryer, a vacuum dryer, or the like can be used. The latent heat of moisture evaporation is directly applied to the toner base particles to increase the moisture removal rate. For this reason, it is preferable to use a fluidized drier in which gas is introduced and dried. For example, a fluidized dryer with a vibration device described later can be used, and a fluidized dryer without a vibration device can also be used. It is more preferable to use a fluidized dryer without a vibration device. The gas applied to the fluidized dryer used in the moisture removal process, the temperature of the gas, the temperature of the dryer, etc. are the gas applied to the fluidized dryer with vibrator used in the drying process described later, the temperature of the gas, the temperature of the dryer Etc., and similar gases and conditions can be applied.

[Drying process of toner base particles]
In the step of drying the toner base particles, a dryer such as a fluid dryer, a jet dryer, or a vacuum dryer can be used. Of these, drying with a fluidized dryer equipped with a vibration device is preferred. The fluidized dryer with a vibration device can quickly dry the toner base particles by using the latent heat of vaporization of the water contained in the toner base particles by flowing a gas into the main body of the dryer. In addition, by applying vibration to the toner base particles with a vibration device, the toner base particles can be fluidized even if the gas flow rate is reduced, and the aggregates gathered in the lower part are crushed and quickly and efficiently. Thus, the toner base particles can be dried. Drying is preferably performed under normal pressure or reduced pressure. Under reduced pressure, the amount of heat that can be given to the toner base particles by the gas becomes small. Therefore, drying at normal pressure is more preferable.

[Toner forming process]
Next, an external additive is added to the toner base particles, and the external additive is adhered or fixed to the surface of the toner base particles to form a toner. By adding an external additive, photoconductor filming and transfer efficiency can be improved. It is preferable that the polymerized toner base particles and pulverized toner base particles are mixed first and then externally added. This is because the toner surface external additives are close to each other and externally added at the same time, and a uniform image is easily obtained.

As a method for adding the external additive to the toner base particles, a method in which the external additive is added to the system charged with the toner base particles and mixed by stirring is used. For the stirring and mixing of the toner base particles and the external additive, it is preferable to use a mechanical rotary processing device, and specifically, a rotary mixer such as a Henschel mixer is preferably used. The speed (peripheral speed) of the tip of the stirring blade in the addition treatment by such an apparatus is a stirring speed of 21.2 to 95.5 m / sec, preferably 38.2 to 76.4 m / sec. Preferably, it is done. By adjusting the rotation speed, it is possible to adjust the embedding of the external additive in the colored particles by this stirring and mixing treatment, and as a result, the fluidity of the obtained toner can be controlled.

  In the toner of the present invention, it is preferable that the external additive is uniformly attached to the surface of the toner particles, but a plurality of particles having different particle diameters (hereinafter also referred to as “multiple diameter particles”). ) As an external additive, the external additives can be uniformly adhered to the surface of the toner particles by mixing each external additive by mixing two or more stages. It is preferable to use a multistage mixing method in which a small particle size external additive is added and mixed, and then a large particle size external additive is added and mixed. The stirring time for the stirring and mixing process can be determined according to the stirring speed and the like. As temperature which adds an external additive, 25 to 55 degreeC is preferable and 30 to 50 degreeC is more preferable.

[Physical properties of toner]
The average circularity of the toner is usually 0.94 or more in the case of a polymerized toner, and preferably 0.95 or more from the viewpoint of improving fluidity. Further, it is usually 0.99 or less, and preferably 0.98 or less from the viewpoint of improving the cleaning property. In the case of pulverized toner, it is usually 0.85 or more, and preferably 0.90 or more from the viewpoint of improving fluidity. Further, it is usually 0.99 or less, and preferably 0.98 or less from the viewpoint of cleaning properties. In the case of a mixed toner, it is preferably 0.93 or more, more preferably 0.94 or more. Further, from the viewpoint of improving cleaning properties, it is preferably 0.98 or less, and more preferably 0.97 or less.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist. In the following examples, “part” means “part by mass”. Each particle diameter, circularity, electrical conductivity and the like were measured as follows.
<Volume average diameter measurement (Mv)>
The volume average diameter (Mv) of the particles having a volume average diameter (Mv) of less than 1 micron is determined by Nikkiso Co., Ltd. model Microtrac Nanotrac150 (hereinafter abbreviated as “Nanotrack”) and the company's analysis software Microtrac Particle Analyzer Ver10.1.2-019EE. The method described in the instruction manual using the ion-exchanged water having an electric conductivity of 0.5 μS / cm as the solvent, the solvent refractive index: 1.333, the measuring time: 600 seconds, and the number of times of measurement: once. Measured with Other setting conditions were particle refractive index: 1.59, transparency: transmission, shape: true sphere, density: 1.04.

<Volume median diameter of wax dispersion and colored dispersion>
In order to determine the end point at the time of wax emulsification, Partica LA-950V2 (hereinafter abbreviated as LA950) manufactured by HORIBA, Ltd., which is a laser diffraction scattering type particle size distribution measuring apparatus capable of high-speed measurement, was used. The end point particle size at that time was set as the median diameter. The solvent used was ion exchange water having an electric conductivity of 0.5 μS / cm, and the measurement was performed by adjusting the sample amount in a concentration range of solvent refractive index: 1.333 and visible light transmittance of 70% to 90%.

<Measurement method and definition of median diameter (volume: Dv50 and number: Dn50)>
The pre-measurement pretreatment of the developed toner finally obtained through the external addition process was as follows. In a cylindrical polyethylene (PE) beaker having an inner diameter of 47 mm and a height of 51 mm, 0.100 g of toner using a spatula, 20% by weight DBS aqueous solution using a dropper (Daiichi Kogyo Seiyaku Co., Ltd., Neogen S-20A) 0.15 g was added. At this time, toner and a 20% DBS aqueous solution were added only to the bottom of the beaker so that the toner would not scatter on the edge of the beaker. Next, the mixture was stirred for 3 minutes using a spatula until the toner and 20% DBS aqueous solution became a paste. At this time, the toner was prevented from being scattered on the edge of the beaker. Subsequently, 30 g of dispersion medium Isoton II was added, and the mixture was stirred for 2 minutes using a spatula to make a uniform solution visually. Next, a fluororesin-coated rotor having a length of 31 mm and a diameter of 6 mm was placed in a beaker and dispersed using a stirrer at 400 rpm for 20 minutes. At this time, using a spatula at a rate of once every 3 minutes, macroscopic particles visually observed at the gas-liquid interface and the edge of the beaker were dropped into the beaker so as to form a uniform dispersion. Subsequently, this was filtered through a mesh having an opening of 63 μm, and the obtained filtrate was designated as “toner dispersion”. Regarding the measurement of the particle diameter during the production process of the toner base particles, the filtrate obtained by filtering the agglomerated slurry with a 63 μm mesh was used as the “slurry liquid”.

The median diameter (Dv50 and Dn50) of the particles is Multisizer III manufactured by Beckman Coulter.
(Aperture diameter 100 μm) (hereinafter abbreviated as “Multisizer”), Isoton II made by the same company is used as a dispersion medium, and the above-mentioned “toner dispersion liquid” or “slurry liquid” is used with a dispersoid concentration of 0.03. It diluted to the mass%, and measured with Multisizer III analysis software as KD value 118.5. The measurement particle diameter range is from 2.00 to 64.00 μm, and this range is discretized into 256 divisions so as to be equidistant on a logarithmic scale, and the volume calculated based on the statistical values on the basis of the volume is the volume. The median diameter (Dv50) and the value calculated based on the statistical value on the basis of the number were defined as the number median diameter (Dn50).

<Measuring method and definition of average circularity>
The “average circularity” in the present invention is measured as follows and is defined as follows. That is, the toner base particles are dispersed in a dispersion medium (Isoton II, manufactured by Beckman Coulter, Inc.) so as to be in the range of 5720-7140 particles / μL, and a flow type particle image analyzer (manufactured by Sysmex Corporation, FPIA 3000) is used. Measured under the following apparatus conditions, the value is defined as “average circularity”. In the present invention, the same measurement is performed three times, and an arithmetic average value of three “average circularity” is adopted as the “average circularity”.
・ Mode: HPF
-HPF analysis amount: 0.35 μL
-Number of HPF detected: 8,000-10,000 The following are measured by the above device and automatically calculated and displayed in the above device, but "roundness" is defined by the following formula The
[Circularity] = [Perimeter of a circle having the same area as the projected particle area] / [Perimeter of projected particle image]
Then, the number of HPF detected is 8,000 to 10,000, and the arithmetic average (arithmetic mean) of the circularity of each particle is displayed on the apparatus as “average circularity”.

<Electrical conductivity measurement>
The electrical conductivity was measured using a conductivity meter (a personal SC meter model SC72 and a detector SC72SN-11 manufactured by Yokogawa Electric Corporation).

<Method for measuring weight average molecular weight and molecular weight peak>
Measured by gel permeation chromatography (GPC) (apparatus: GPC apparatus HLC-8020 manufactured by Tosoh Corporation, column: PL-gel Mixed-B 10μ manufactured by Polymer Laboratory, solvent: tetrahydrofuran, sample concentration: 0.1 wt% Calibration curve: standard polystyrene).

<Preparation of black colorant dispersion>
The container stirrer with a propeller blade, manufactured by Mitsubishi Chemical Corporation Carbon black # 44 (catalog properties: particle size 24 nm, a nitrogen adsorption specific surface area 110m ² / g, coloring power 129%, DBP absorption, particulate 77cm ^3/100 g, Volatile matter 0.8%, pH value 8, PVC blackness 10) 20 parts, anionic surfactant (Daiichi Kogyo Seiyaku, Neogen S-20D) 1 part, nonionic surfactant (manufactured by Kao Corporation) Emulgen 120) 4 parts and 75 parts of ion-exchanged water having an electrical conductivity of 1 μS / cm were added and predispersed until the volume median diameter (Dv ₅₀ ) was about 90 μm to obtain a pigment premix solution. The pigment premix solution was supplied as a raw material slurry to a wet bead mill and subjected to one-pass dispersion. Note that zirconia beads (true density 6.0 g / cm ³ ) having a stator inner diameter of 120 mmφ, a separator diameter of 60 mmφ, and a dispersion medium of 50 μm in diameter were used. Since the effective internal volume of the stator was about 2 L and the filling volume of the media was 1.4 L, the media filling rate was 70%. The pigment premix slurry is supplied from the supply port at a supply speed of about 40 L / hr by a non-pulsating metering pump with a constant rotation speed of the rotor (the peripheral speed of the rotor tip is about 11 m / sec), and reaches a predetermined particle size. At that time, a black colorant dispersion was obtained from the outlet. During operation, cooling water of about 10 ° C. was circulated from the jacket. In this way, a black colorant dispersion having a volume median diameter of 157 nm, a number median diameter of 106 nm, and a solid content concentration of 24.6% as measured with LA950 was obtained.

<Preparation of wax dispersion A1>
Wax 1 (HiMic-1090 (manufactured by Nippon Seiwa Co., Ltd.), melting point 87 ° C.) 29.7 parts, decaglycerin decabehenate (acid value 3.2, hydroxyl value 27) 0.3 part, 20% dodecylbenzenesulfonic acid A sodium aqueous solution (Daiichi Kogyo Seiyaku Co., Ltd., Neogen S20D, hereinafter abbreviated as 20% DBS aqueous solution) 2.8 parts of aqueous solution and 67.3 parts of demineralized water were added and heated to 100 ° C., and a homogenizer with a pressure circulation line ( The primary circulation emulsification was performed under a pressure of 10 MPa using a LAB 60-10TBS type manufactured by Gorin. The particle diameter is measured every few minutes with LA950, and when the median diameter is reduced to around 500 nm, the pressure condition is further increased to 25 MPa, followed by secondary circulation emulsification. A wax dispersion A1 was produced by dispersing until the median diameter was 230 nm or less. The volume median diameter of the wax dispersion was 215 nm.

<Preparation of wax dispersion A2>
20.0 parts of wax 2 (HNP9 (manufactured by Nippon Seiwa Co., Ltd.), melting point 77 ° C.) was added to a 20% aqueous solution of sodium dodecylbenzenesulfonate (Daiichi Kogyo Seiyaku Co., Ltd., Neogen S20D, hereinafter abbreviated as 20% DBS aqueous solution). 1.44 parts and 50.0 parts of demineralized water are added and heated to 90 ° C., and circulation emulsification is carried out under a pressure condition of 25 MPa using a homogenizer with a pressure circulation line (manufactured by Gorin, LAB 60-10TBS type). Then, the particle diameter was measured with a nanotrack, and dispersed until the volume median diameter became 250 nm to prepare a wax dispersion A2.

<Preparation of wax dispersion A3>
Wax 3 (WEP-3 (manufactured by NOF Corporation), melting point 71 ° C.) 30.0 parts decaglycerin decabehenate (B100D (manufactured by Mitsubishi Chemical Foods), melting point 70 ° C.) 0.24 parts, 20% Sodium dodecylbenzenesulfonate aqueous solution (Daiichi Kogyo Seiyaku Co., Ltd., Neogen S20D, hereinafter abbreviated as 20% DBS aqueous solution) 1.93 parts of aqueous solution and 67.8 parts of demineralized water were added and heated to 90 ° C., pressurized circulation line Using a homogenizer with an attached (Gorin, LAB60-10TBS type), circulating emulsification under a pressure of 25 MPa, measuring the particle diameter with Nanotrac, dispersed until the volume median diameter is 245 nm, A wax dispersion A3 was prepared.

<Preparation of polymer primary particle dispersion B1>
A reactor equipped with a stirrer (three blades), a heating / cooling device, a concentrating device, and each raw material / auxiliary charging device was charged with 36.3 parts of the wax dispersion A1 and 231 parts of demineralized water and stirred. The temperature was raised to 90 ° C. under a nitrogen stream.
Then, the mixture of the following "polymerizable monomers etc.-1" and "emulsifier aqueous solution-1" was added over 5 hours, continuing stirring of the said liquid. The time at which this mixture was started to be dropped was designated as “polymerization start”, and the following “initiator aqueous solution-1” was added over 4.5 hours from 30 minutes after the start of polymerization. Further, after 5 hours from the start of polymerization, the following “ Additional initiator aqueous solution-1 ”was added over 2 hours, and the internal temperature was maintained at 90 ° C. for 1 hour while continuing stirring.

[Polymerizable monomers, etc.-1]
Styrene 75.9 parts Butyl acrylate 24.1 parts Acrylic acid 1.2 parts Hexanediol diacrylate 0.6 parts Trichlorobromomethane 1.0 part [Emulsifier aqueous solution-1]
20% DBS aqueous solution 1.0 part Demineralized water 66.9 parts [Initiator aqueous solution-1]
8% by mass aqueous hydrogen peroxide solution 15.5 parts 8% by mass L (+)-ascorbic acid aqueous solution 15.5 parts [additional aqueous initiator solution-1]
8 mass% L (+)-ascorbic acid aqueous solution 14.2 parts

  After completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer primary particle dispersion B1. The volume average diameter (Mv) measured using Microtrac UPA was 239 nm, and the solid content concentration was 22.3 mass%. The weight average molecular weight (Mw) was 78000.

<Preparation of polymer primary particle dispersion B2>
A reactor equipped with a stirrer (three blades), a heating / cooling device, and a raw material / auxiliary charging device was charged with 36.1 parts of the wax emulsion A2 and 259 parts of ion-exchanged water, and stirred under a nitrogen stream. The temperature was raised to 90 ° C.
Then, the mixture of the following "polymerizable monomers etc.-2" and "emulsifier aqueous solution-2" was added there over 5 hours, continuing stirring of the said liquid. The time at which the mixture was started to drop was defined as “polymerization start”, and 30 minutes after “polymerization start”, [Initiator aqueous solution-2] was added over 4.5 hours in parallel with the above operation. After the addition of the mixture and [Initiator aqueous solution-2] was completed, [Additional initiator aqueous solution-2] was added over 2 hours. Stirring was further continued after the addition of [Initiator aqueous solution-2], and the internal temperature was maintained at 90 ° C. for 1 hour.

[Polymerizable monomers, etc.-2]
Styrene 76.75 parts Butyl acrylate 23.25 parts Acrylic acid 1.5 parts Hexanediol diacrylate 0.7 parts Trichlorobromomethane 1.0 part
[Emulsifier aqueous solution-2]
20% DBS aqueous solution 1.0 part Ion-exchanged water 67.1 parts
[Initiator aqueous solution-2]
8% by mass aqueous hydrogen peroxide solution 15.52 parts 8% by mass L (+)-ascorbic acid aqueous solution 15.52 parts
[Additional initiator aqueous solution-2]
8 mass% L (+)-ascorbic acid aqueous solution 14.21 parts

  After completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer primary particle emulsion B2. The volume average diameter (Mv) measured using Microtrac UPA was 258 nm, and the solid content concentration was 20.4% by mass. The weight average molecular weight (Mw) was 77000.

<Preparation of polymer primary particle dispersion B3>
In a reactor equipped with a stirrer (three blades), a heating / cooling device, and each raw material / auxiliary charging device, 34.7 parts of the wax emulsion A3, 252 parts of ion-exchanged water, 0.5% iron sulfate (II) ) 0.02 part of an aqueous solution of heptahydrate was charged, and the temperature was raised to 90 ° C. under a nitrogen stream while stirring.
Then, the mixture of the following "polymerizable monomers etc.-3" and "emulsifier aqueous solution-3" was added over 4 hours, continuing stirring of the said liquid. The time when the mixture was started to be dropped was defined as “polymerization start”, and from the “polymerization start”, [Initiator aqueous solution-3] was added over 6 hours in parallel with the above operation. The following iron sulfate aqueous solution was added 240 minutes after the start of polymerization. The temperature was raised to 95 ° C. 300 minutes after the start of polymerization. Heating and stirring were continued until 540 minutes from the start of polymerization.

[Polymerizable monomers, etc.-3]
Styrene 70.9 parts Butyl acrylate 29.1 parts Acrylic acid 0.85 parts Hexanediol diacrylate 0.95 parts Trichlorobromomethane 1.0 part
[Emulsifier aqueous solution-3]
20% DBS aqueous solution 1.0 part Ion-exchanged water 66.9 parts
[Initiator aqueous solution-3]
8% by mass aqueous hydrogen peroxide solution 28.0 parts 8% by mass L (+)-ascorbic acid aqueous solution 28.0 parts [iron sulfate aqueous solution]
0.5% iron (II) sulfate heptahydrate aqueous solution 0.08 parts

  After completion of the polymerization reaction, the mixture was cooled to obtain a milky white polymer primary particle emulsion B3. The volume average diameter (Mv) measured using Microtrac UPA was 239 nm, and the solid content concentration was 24.1% by mass. The weight average molecular weight (Mw) was 88,000.

<Production of Toner Base Particle Ma1>
Polymer primary particle dispersion B1 (for core) 80 parts as solid content Polymer primary particle dispersion B2 (for shell) 20 parts as solid content Magenta pigment dispersion (EP1210 manufactured by Dainichi Seika Co., Ltd.) 9 as colorant solid content Parts 20% DBS aqueous solution 0.1 parts as solid content

Using the above components, toner base particles Ma1 were produced by the following procedure. Polymer primary particle dispersion B1 (core) in a mixer (volume 12 liters, inner diameter 208 mm, height 355 mm) equipped with a stirrer (double helical blade), heating / cooling device, concentrator, and raw material / auxiliary charging device And 20% DBS aqueous solution, and uniformly mixed for 5 minutes at an internal temperature of 12 ° C. Subsequently, while stirring at an internal temperature of 12 ° C., 0.52 part of FeSO4 · 7H2O was added as a 5% aqueous solution of ferrous sulfate over 5 minutes, and then the magenta colorant dispersion was added over 5 minutes. The mixture was uniformly mixed at an internal temperature of 12 ° C., and a 0.5% aluminum sulfate aqueous solution was added dropwise under the same conditions (the solid content relative to the resin solid content was 0.10 parts). Thereafter, the temperature was raised to 53 ° C. over 75 minutes, and further raised to 56 ° C. over 170 minutes. Here, when the volume median diameter (Dv50) was measured using a multisizer, it was 6.7 μm. Thereafter, polymer primary particle dispersion B2 (for shell) is added over 3 minutes and held for 60 minutes, followed by addition of 20% DBS aqueous solution (6 parts as solids) over 10 minutes, followed by 30 The temperature was raised to 95 ° C over a period of time, and stirring was continued over 120 minutes until the average circularity reached 0.970. Then, it cooled to 30 degreeC over 30 minutes, and obtained the slurry. At this time, the volume median diameter (Dva50) of the particles was 7.0 μm, and the average circularity was 0.97.

  This slurry was subjected to suction filtration with an aspirator using filter paper of type 5 C (No. 5C manufactured by Toyo Roshi Kaisha, Ltd.). The cake remaining on the filter paper is transferred to a stainless steel container having an internal volume of 10 L equipped with a stirrer (propeller blade), added with 8 kg of ion-exchanged water having an electric conductivity of 1 μS / cm, and uniformly dispersed by stirring at 50 rpm. Stirred for 30 minutes. Then, suction filtration is performed with an aspirator again using filter paper of 5 types C (Toyo Filter Paper Co., Ltd. No5C), and the solid matter remaining on the filter paper is again equipped with a stirrer (propeller blade) and has an electric conductivity of 1 μS / cm. It was transferred to a 10 L container with 8 kg of ion-exchanged water, and evenly dispersed by stirring at 50 rpm and kept stirring for 30 minutes. When this process was repeated 5 times, the electrical conductivity of the filtrate was 2 μS / cm. The obtained cake was spread on a stainless pad so as to have a height of 20 mm, and dried in an air dryer set at 40 ° C. for 48 hours to obtain toner mother particles Ma1.

<Production of Toner Base Particle Ma2>
Polymer primary particle dispersion B1 (for core) 70 parts as solid content Polymer primary particle dispersion B3 (for core) 10 parts as solid content
Polymer primary particle dispersion B2 (for shell) 20 parts as solid content
20% DBS aqueous solution 0.1 part as solid content Using each of the above components, instead of the polymer primary particle dispersion B1, a mixed solution of the polymer primary particle dispersion B1 and the polymer primary particle dispersion B3 is used. Otherwise, toner mother particles Ma2 were obtained in the same manner as toner mother particles Ma1. The volume median diameter (Dva50) of the mother particle slurry was 7.1 μm, and the average circularity was 0.97.

<Manufacture of toner base particles Bk1>
Polymer primary particle dispersion B1 (for core) 90 parts as solid content Polymer primary particle dispersion B2 (for shell) 10 parts as solid content Black colorant dispersion 6 parts as colorant solid content 20% DBS aqueous solution Solid content As 0.1 parts of toner The toner base particles Bk1 were obtained in the same manner as the toner base particles Ma1 except that the above components were used. The volume median diameter (Dva50) of the mother particle slurry was 7.0 μm, and the average circularity was 0.97.

<Manufacture of toner mother particles Bk2>
Toner base particles Bk2 were prepared according to the following blending ratio.
Resin A (polyester, softening point 135 ° C, glass transition point 66 ° C, acid value 7 mgKOH / g) 20.0 parts Resin B (polyester, softening point 110 ° C, glass transition point 57 ° C, acid value 12 mgKOH / g) 80.0 parts carbon black (product) Name Mitsubishi Chemical Co., Ltd. MA77) 4.5 parts Wax (Ester wax Product name NOF Corporation WEP-10) 6 parts Charge control agent (trade name Hodogaya Chemical Co., Ltd. T77) 0.5 part After mixing with a Henschel mixer, melt kneading with a twin screw extruder, coarsely pulverizing, finely pulverizing with a jet mill pulverizer, and classifying to obtain toner base particles Bk2 having a volume median diameter (Dvb50) of 7.2 μm. It was. The average circularity was 0.93.

<Production of Toner Base Particle Ma3>
A negatively chargeable nonmagnetic toner A was prepared according to the following blending ratio.
Resin C (polyester softening point 138 ° C. glass transition point 62 ° C. acid value 7 mg KOH / g) 89.5 parts PP wax (melting point 136 ° C., acid value 3.5 mg KOH / g, density 0.89 g / cm ³ )
1.5 parts PE wax (melting point 87 ° C., acid value 0 mg KOH / g, density 0.98 g / cm ³ )
1.5 parts Charge control agent (trade name: LR-147 manufactured by Nippon Carlit Co., Ltd.) 1.0 part Master batch (polyester resin D (Tg 65 ° C., Sp 111 ° C., acid value 6.5 mg)
KOH / g): Pigment Red 122 = 60 parts: 40 parts) 17.5 parts
The above raw materials are mixed with a Henschel mixer, melt-kneaded with a twin-screw extruder, coarsely pulverized, finely pulverized with a jet mill pulverizer, classified, and a toner base having a volume median diameter (Dvb50) of 9.5 μm. Particles Ma3 were obtained. The average circularity was 0.92.

<Create developer toner>
[Example 1]
In a sample mill (manufactured by Kyoritsu Riko Co., Ltd.), 99 parts of polymerized toner Ma1 and 1 part of pulverized toner Ma3 were introduced so that the total amount of toner base particles was 100 parts (200 g), followed by hexamethyldisilazane. And 2.0 parts of silica fine particles having a volume average primary particle diameter of 0.10 μm hydrophobized with 1.0 part and 1.0 part of silica fine particles having a volume average primary particle diameter of 0.01 μm hydrophobized with silicone oil. Toner for development 1 was obtained by mixing for 8 minutes at 4500 rpm and sieving with 200 mesh.

[Examples 2 to 10] and [Comparative Examples 1 to 4]
In the same operation as in Example 1, each toner base particle was charged in the amount of distribution shown in Table 1 so that the total amount of toner base particle was 100 parts (200 g) in a sample mill (manufactured by Kyoritsu Riko Co., Ltd.). Subsequently, 2.0 parts of silica fine particles having a volume average primary particle size of 0.10 μm hydrophobized with the same hexamethyldisilazane as in Example 1, and a volume average primary particle size of 0.1 μm hydrophobized with silicone oil. Toners 2 to 15 for development were obtained by adding 1.0 part of 01 μm silica fine particles, mixing at 4500 rpm for 8 minutes, and sieving with 200 mesh.

The obtained developing toner was evaluated as follows, and the evaluation results are shown in Table 2.
[Drawing out]
Two toner cartridges using a commercially available printer with a printing speed of 16 ppm, a non-magnetic single component developing rubber roller, a metal blade, and an organic photoreceptor charged with a charging roller (PCR), and a fixing unit removed. Was printed under the following conditions.

<Drawing condition 1>
On the recording paper (OKI Excellent White), an unfixed toner image having an adhesion amount of about 0.5 mg / cm 2 was printed with two toner layers.
<Drawing condition 2>
An unfixed toner image having an adhesion amount of about 0.8 mg / cm 2 was printed on glossy recording paper (waterproof paper cardet manufactured by Mitsubishi Chemical Media) with two layers of toner.

[Fixation evaluation 1]
The following fixing test 1 was performed using recording paper (OKI Excellent White) on which an unfixed toner image of two layers of toner obtained under Picture Condition 1 was printed.
<Fixing test 1>
The hot roll fixing machine has a roller diameter of 27 mm, a nip width of 9 mm, a fixing speed of 229 mm / sec, a heater on the upper roller, and the roller surface made of PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer). Silicone oil is not applied. The roller surface temperature was decreased from 170 ° C. in increments of 5 ° C., and a recording paper carrying an unfixed toner image having an adhesion amount of about 0.5 mg / cm 2 was conveyed to the fixing nip portion to obtain a fixed image.

<Low temperature fixability test by tape peeling>
A mending tape was affixed to the obtained fixed image, and a 2 kg weight was passed thereon to bring the tape and the fixed image into close contact. The mending tape was peeled off, and the degree to which the fixed image transferred to the tape was visually determined. Compared with the fixed image of the development toner externally added with 100 parts of the polymerized toner, the lowest temperature achieved by the fixing strength standard is judged according to the following standard.
Compared to the lowest fixing temperature of the development toner externally added with 100 parts of polymerized toner,
◎: Fix at a temperature lower by 10 ° C. ○: Fix at a temperature lower by 5 ° C. △: Fix at the same temperature ×: Fix at a temperature higher by 5 ° C. XX: Fix at a temperature higher than 10 ° C.

<Hot offset resistance test>
The surface temperature of the roller was increased from 175 ° C. in increments of 5 ° C., the recording paper carrying the unfixed toner image was conveyed to the fixing nip portion, and the state when discharged was observed. Compared with the fixed image of the development toner externally added with 100 parts of the polymerized toner, the highest temperature at which no hot offset occurs is determined according to the following criteria.
Compared to the highest fixing temperature of the development toner with 100 parts of polymerized toner added externally,
◎: Fix at a temperature 10 ° C or higher ○: Fix at a temperature 5 ° C higher △: Fix at the same temperature ×: Fix at a temperature lower by 5 ° C XX: Fix at a temperature lower than 10 ° C

[Fixation evaluation 2]
The following fixing test 2 was performed using a recording paper (waterproof paper carder manufactured by Mitsubishi Chemical Media Co., Ltd.) on which an unfixed toner image of two layers of toner obtained under Picture Condition 2 was printed.

<Fixing test 2>
The same heat roll fixing machine as in fixing test 1 was used, and the fixing speed was set to 95 mm / sec. The roller surface temperature was decreased from 175 ° C. in increments of 5 ° C., and a recording paper carrying an unfixed toner image having an adhesion amount of about 0.8 mg / cm ² was conveyed to the fixing nip portion to obtain a fixed image.

<Low temperature fixability test using a flathead screwdriver>
The obtained fixed image was subjected to a shaving test with a flat-blade screwdriver. The tip width of the flathead screwdriver was 1 mm, and the load on the tip was 100 g. The moving speed at the time of cutting was about 1 cm / s, and the angle between the moving method and the tip surface of the minus driver was 90 °. The degree of shaving was judged visually. Compared with the fixed image of the development toner externally added with 100 parts of the polymerized toner, the lowest temperature achieved by the fixing strength standard is judged according to the following standard.
Compared with the lowest fixing temperature of the developing toner with 100 parts of polymerized toner added externally,
◎: Fix at a temperature lower by 10 ° C. ○: Fix at a temperature lower by 5 ° C. ×: Fix at the same temperature XX: Fix at a temperature higher by 5 ° C. XX: Fix at a temperature higher than 10 ° C.

[Image quality evaluation]
The resulting toner is continuously printed at a printing rate of 5% using a commercial printer equipped with an organic photoreceptor charged with a printing speed of 16 ppm, a non-magnetic single component developing rubber roller, a metal blade, and a charging roller (PCR). Went.

<Measurement method of fog>
Using an image forming apparatus, the color difference of the white background of each standard paper (OKI Excellent White) after continuous printing, before printing and after printing is measured with X-Rite 938 (manufactured by X-Rite). , ΔE was determined according to the following criteria.
◎ (good): △ E ≦ 0.2
○ (possible): 0.2 <△ E <0.3
X (Generation): 0.3 ≦ ΔE

[Blocking resistance]
10 g of developing toner is put into a cylindrical container having an inner diameter of 3 cm and a height of 6 cm, a load of 20 g is put on it, and left in an environment of a temperature of 50 ° C. and a humidity of 55% for 48 hours. The degree of aggregation was confirmed by applying a load.
◯: collapses with a load of less than 100 g ×: collapses with a load of 100 g or more The toner evaluation results obtained in Examples 1 to 10 and Comparative Examples 1 to 5 are shown in Table 2 below.

  From the evaluation results, by mixing a polyester pulverized toner with a styrene-acrylic polymerized toner, the fixing property to a fibrous recording medium such as paper is maintained as compared with the case of a styrene-acrylic polymerized toner alone. It has been found that the fixing strength can be greatly improved even with a glossy recording medium having a non-fibrous surface, such as Kaleka paper, on which a styrene-acrylic toner is difficult to be fixed. Furthermore, by mixing pulverized toner, which is easier to produce, it is possible to produce at a lower cost while maintaining the high image quality of the polymerized toner.

Claims (6)

  An electrostatic charge image developing toner containing at least a polymerized toner and a pulverized toner, wherein the polymerized toner contains a styrene-acrylic copolymer resin as a binder resin, and the pulverized toner contains a polyester resin as a binder resin. A toner for developing an electrostatic charge image.   The polymerized toner contains 50 parts by mass or more of styrene-acrylic copolymer resin with respect to 100 parts by mass of the total binder resin in the polymerized toner, and the pulverized toner is added to 100 parts by mass of the total binder resin in the pulverized toner. 2. The electrostatic charge image developing toner according to claim 1, wherein the toner contains 50 parts by mass or more of a polyester resin.   3. The electrostatic image developing toner according to claim 1, wherein the content of the pulverized toner in the electrostatic image developing toner is 1 to 50% by mass. 4.   When the volume median diameter of the polymerized toner is Dva (50) and the volume median diameter of the pulverized toner is Dvb (50), the particle size ratio Dvb (50) / Dva (50) is 0.9 to 1. The electrostatic image developing toner according to claim 1, wherein the toner is 4.   A method for producing a toner for developing an electrostatic charge image containing at least a polymerized toner and a pulverized toner, wherein the mother particles of a polymerized toner containing a styrene-acrylic copolymer resin as a binder resin and a pulverized toner containing a polyester resin as a binder resin A method for producing a toner for developing an electrostatic charge image, comprising: a step of mixing the mother particles to obtain mixed mother particles; and a step of surface-treating the mixed mother particles with inorganic fine particles.   6. The method for producing a toner for developing an electrostatic charge image according to claim 5, wherein the polymerized toner is obtained by an emulsion aggregation method.