JP2001134017A - Electrostatic charge image developing toner and method of producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner having excellent offset resistance during thermal fixing with which a visible image of high picture quality can be stably formed for a long time, and to provide a method of producing that toner. SOLUTION: The electrostatic charge image developing toner is prepared by salting-out/fusing at least resin particles, coloring agent particles and release agent particles. In the molecular weight distribution of the resin measured by GPC, the resin consists of a low mol.wt. component having a peak or shoulder in the range from 1,500 to 20,000 and a high mol.wt. component having a peak or shoulder in the range from 50,000 to 500,000. The release agent shows a peak in the region from 70 to 100 deg.C by DSC.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic image for visualizing an electrostatic latent image in an image forming method such as an electrophotographic method, an electrostatic printing method, and an electrostatic recording method, and its production. It is about the method.

[0002]

2. Description of the Related Art In a heat-pressure fixing method in which fixing is performed without using a silicone oil supply device, a releasing agent such as a low-molecular-weight polyolefin is contained in toner particles in order to prevent offset or winding of an image support around a fixing roller. And various waxes are added.

As a method of adding such a release agent to a toner, in a conventional pulverization method, when a release agent that is incompatible with a binder resin is melted and kneaded, the release agent is contained in the resin. However, the size of the island domains is hard to be uniform, and the size distribution is wide.
In a toner obtained by pulverizing such a kneaded material, a release agent released by the pulverization is generated and mixed with and present in the toner powder. Also, it is difficult to selectively remove the free release agent.

As described above, when the free release agent is present in the toner powder, the free release agent adheres to the surface of the developing sleeve, causing a draw-out and conveyance failure of the developer. There is a problem that the concentration decreases. Further, the free release agent adheres to the surface of the photoreceptor, and is not cleaned because the attached free release agent is considerably smaller than the toner particles. Toner filming occurs, grows, and the image becomes dirty.

In recent years, toners based on a polymerization method have been proposed. According to the polymerization method, generation of a free mold release agent can be prevented because there are no steps such as melt-kneading and pulverization.However, for example, in the case of a suspension-polymerized toner, since the toner shape is a true spherical shape, the adhesion to the photoconductor is poor. Strong and difficult to clean.

In order to solve the above-mentioned problem, it has been proposed to change the shape of the toner to a shape having irregularities on the toner surface rather than a true spherical shape. JP-A-7-36
No. 207 proposes an image forming method in which the level of toner deformation is defined by a shape factor. The toner deformation method disclosed therein is a method of forming resin particles on a conventional suspension polymerization toner surface. There is disclosed a method of deforming by attaching, or a method of immersing a suspension-polymerized toner in a solvent to swell, and then reducing the pressure and drying to deform.

[0007] However, in the deforming of the surface of the suspension polymerization toner due to the adhesion of resin particles, the resin particles adhered to the surface are dispersed from the toner surface due to frictional stress inside the developing device, or the charged charges are concentrated on the resin particles on the surface. In addition, the charge amount distribution tends to be broad, and the resolution of a character image or the like is deteriorated. Further, the toner whose surface is deformed by swelling the suspension polymerization toner by immersing it in a solvent has problems such as various toner characteristics being easily varied and an image being unstable depending on the production lot.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a toner for developing an electrostatic image, which is excellent in offset resistance of fixing and can stably form a high-quality visible image for a long period of time, and a method for producing the same. It is to provide.

[0009]

The object of the present invention is attained by adopting the following constitution.

(1) In a toner for developing an electrostatic charge image obtained by salting out / fusing at least resin particles, colorant particles and release agent particles, the resin has a molecular weight distribution of at least 1, as measured by GPC. A low molecular weight component having a peak or shoulder in the range of 500 to 20,000 and 50,000
Of a high molecular weight component having a peak or shoulder in the range of ~ 500,000, and
A toner for developing an electrostatic image, having a peak in a range of from 100 ° C. to 100 ° C.

(2) In a method for producing a toner for developing an electrostatic image, wherein at least resin particles, colorant particles, and release agent particles are salted out / fused, the resin particles are at least GP
The molecular weight distribution measured at C
Resin particles composed of low molecular weight components having peaks or shoulders in the range of 0 and resin particles composed of high molecular weight components having peaks or shoulders in the range of 50,000 to 500,000. ° C
Wherein the release agent particles having a peak in the region are salted out / fused.

The toner for developing an electrostatic image of the present invention (hereinafter, also simply referred to as a toner) comprises salting out at least resin particles, colorant particles and release agent particles prepared by emulsion polymerization.
It is made by fusion. This salting-out, fusion and, salting out is added by adding a salting-out agent to water in which resin particles and colorant particles are dispersed, adding an infinitely soluble organic solvent if necessary, and then heating. At the same time, the fusion proceeds
This is for preparing toner particles. In this method, unlike the method of fusing after forming the aggregated primary particles of the resin particles and the colorant particles, the method is capable of fusing without passing through an intermediate stage to prepare toner particles. The uniformity of toner particles formed by salting out and fusing is not impaired, and a toner having uniform chargeability can be stably obtained.

The fusion is performed at a temperature equal to or higher than the glass transition point of the resin particles.
It has a melting peak on the low temperature side of １００100 ° C., and since the release agent particles are melted during fusion, the release agent particles are surely included in the toner particles, and the generation of the released release agent is prevented. Was found to be nothing. Here, the peak means a peak on the left and right sides of the spectrum of the measurement chart that is clearly lower than the median and clearly has a pointed shape.

The release agent particles of the present invention are characterized by having a peak in the range of 70 to 100 ° C. by DSC (differential scanning calorimeter). If this peak is lower than 70 ° C., the storage stability of the toner is reduced, and the toner particles are aggregated, so that a stable image cannot be provided. On the other hand, this peak is 1
If the temperature is higher than 00 ° C., in the step of fusing with the resin particles, the release agent particles are not completely contained in the toner particles, and a released release agent is generated, and the released release agent adheres to the surface of the developing sleeve. As a result, a draw-out and conveyance failure of the developer occurs, and the image density decreases when image formation is repeated. Further, when the released release agent adheres to the surface of the photoreceptor, it is not cleaned, and during long-term use, toner filming with the release release agent as a nucleus occurs, grows, and the image becomes dirty.

[0015] As such a release agent, 70-
Although there is no particular limitation as long as there is a melting peak in the region of 100 ° C., specific examples (commercially available products) include carnauba wax N
o. 1 (manufactured by Noda Wax Co., melting peak = 83 ° C.), Hoechst Wax E (manufactured by Hoechst Japan Co., melting peak = 80 ° C.), Kao Wax 85P (manufactured by Kao Corporation, melting peak = 85 ° C.), FT-100 (Japan) Seiko Co., Ltd., melting peak = 89 ° C.), Paracor 5070 (Nippon Seiro Co., Ltd., melting peak = 86 ° C.), C80 (Schumann Sazol Co., melting peak = 82 ° C.), and the like.

The melting peak by DSC was measured by DSC-7 (manufactured by PerkinElmer). Specifically, 5
Weigh out mg sample and seal in aluminum sample pan. The temperature of the sample pan was raised from 0 ° C to 120 ° C at a rate of 1
The temperature is raised at 0 ° C./min, left at that temperature for 3 minutes, and then cooled to 0 ° C. at a decreasing temperature of 10 ° C./min. Next, this sample was again heated at a rate of 10 ° C./min for 12 hours.
Heat to 0 ° C. The endothermic peak of the change in calorific value at the time of the second temperature rise was taken as the melting peak.

The release agent particles of the present invention are used as an aqueous dispersion. Release agent particle aqueous dispersion, the release agent is added to the aqueous surfactant solution, at least the solid-liquid transition temperature of the release agent, or heated to the melting point or more, emulsification and stirring, further for stabilization It can be obtained by adding at least an alkali corresponding to the acid value of the release agent.

It is also possible to add at least an alkali equivalent to the acid value of the release agent from the beginning. In order to prevent the release agent from being oxidized during the emulsification, it is preferable to carry out the emulsification using degassed water under a nitrogen stream or a nitrogen atmosphere. Further, the use of a dedicated emulsifying and dispersing machine makes it possible to produce a stable emulsified and dispersed liquid.

As the surfactant, a nonionic surfactant is generally used. The addition amount is usually 1 to 20% by mass, preferably 3 to 18% by mass based on the mass of the release agent.
Is used. Further, in order to stabilize the emulsified dispersion, the pH of the emulsified dispersion is usually 8.5 to 13, preferably 9.0 to 1
Adjusted between 2.5. The concentration of the release agent particles in the aqueous dispersion can be selected according to the purpose, but is generally 10%.
-30% by mass, preferably 15-28% by mass.

The average particle size of the release agent particles in the aqueous dispersion is as follows:
Although it depends on emulsification conditions, a range of 20 nm to 300 nm, preferably 50 to 200 nm is used.

The resin component of the present invention has a molecular weight distribution measured by GPC (gel permeation chromatography) of at least 1,500 to 20,000 and 50,000 to 50,000.
It has a peak or a shoulder at 000. In order to achieve such a resin component,
The most preferable method is to mix a plurality of resin particles having different molecular weight distributions with the resin particles, disperse the mixture in a solvent, and prepare a toner by the above-mentioned salting-out and fusion method. That is, by using two or more kinds of resin particles having a uniform molecular weight distribution, the toner for developing an electrostatic charge image having a molecular weight distribution of the present invention can be achieved after the colorant particles in the toner are uniformly dispersed.

Here, the peak refers to a peak similar to that of the DSC, and the shoulder refers to a peak which does not have a sharp tip as clearly as the peak but has an inflection point.

By uniformly dispersing the pigment in the toner, the charge amount distribution of the toner becomes sharp, and the toner is less likely to be crushed even when shearing stress is applied to the toner. In addition, the toner has a stable chargeability, and has an effect of improving characteristics such that poor cleaning hardly occurs.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Each technical item will be described below in detail.

The resin particles used in the production of the toner in the present invention preferably have a mass average particle size of 50 to 2,000 nm, and the most preferable production method of these resin particles is an emulsion polymerization method. Hereinafter, examples of the material of the resin particles and the production method by the emulsion polymerization method will be described.

<< Materials >> [Monomer] As the polymerizable monomer, a radical polymerizable monomer is an essential component, and a crosslinking agent can be used as necessary. Further, it is preferable that at least one of the following radical polymerizable monomers having an acidic group or a radical polymerizable monomer having a basic group is contained.

(1) Radical polymerizable monomer The radical polymerizable monomer component is not particularly limited, and a conventionally known radical polymerizable monomer can be used. In addition, one kind or a combination of two or more kinds can be used so as to satisfy required characteristics.

Specifically, aromatic vinyl monomers, (meth) acrylate monomers, vinyl ester monomers, vinyl ether monomers, monoolefin monomers, diolefin monomers Monomers, halogenated olefin monomers and the like can be used.

As the aromatic vinyl monomer, for example,
Styrene, o-methylstyrene, m-methylstyrene,
p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, p-ethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n- Styrene-based monomers such as octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, 2,4-dimethylstyrene, and 3,4-dichlorostyrene, and derivatives thereof. .

The (meth) acrylate monomers include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, cyclohexyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, Butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate,
Ethyl β-hydroxyacrylate, γ-aminopropyl acrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate and the like.

Examples of the vinyl ester monomer include vinyl acetate, vinyl propionate, vinyl benzoate and the like.

Examples of the vinyl ether monomer include vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl phenyl ether and the like.

Examples of the monoolefin monomer include ethylene, propylene, isobutylene, 1-butene, 1-pentene and 4-methyl-1-pentene.

Examples of the diolefin-based monomer include butadiene, isoprene, chloroprene and the like.

The halogenated olefin monomers include:
Vinyl chloride, vinylidene chloride, vinyl bromide and the like.

(2) Crosslinking Agent As the crosslinking agent, a radical polymerizable crosslinking agent may be added in order to improve the properties of the toner. Examples of the radical polymerizable crosslinking agent include divinylbenzene, divinylnaphthalene,
Examples thereof include those having two or more unsaturated bonds such as divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, and diallyl phthalate.

(3) Radical polymerizable monomer having an acidic group or radical polymerizable monomer having a basic group Radical polymerizable monomer having an acidic group or radical polymerizable monomer having a basic group For example, an amine compound such as a carboxyl group-containing monomer, a sulfonic acid group-containing monomer, a primary amine, a secondary amine, a tertiary amine, and a quaternary ammonium salt may be used. it can.

Examples of the radical polymerizable monomer having an acidic group include carboxylic acid group-containing monomers such as acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, monobutyl maleate, And monooctyl maleate.

Examples of the sulfonic acid group-containing monomer include styrene sulfonic acid, allyl sulfosuccinic acid, octyl allyl sulfosuccinate and the like.

These may have a structure of an alkali metal salt such as sodium or potassium or an alkaline earth metal salt such as calcium.

Examples of the radical polymerizable monomer having a basic group include amine compounds, such as dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and the above four compounds. Quaternary ammonium salt, 3-dimethylaminophenyl acrylate, 2-hydroxy-3-methacryloxypropyltrimethylammonium salt, acrylamide, N-
Butylacrylamide, N, N-dibutylacrylamide, piperidylacrylamide, methacrylamide, N
-Butylmethacrylamide, N-octadecylacrylamide, vinylpyridine, vinylpyrrolidone, vinyl N
-Methylpyridinium chloride, vinyl N-ethylpyridinium chloride, N, N-diallylmethylammonium chloride, N, N-diallylethylammonium chloride and the like.

As the radical polymerizable monomer used in the present invention, a radical polymerizable monomer having an acidic group or a radical polymerizable monomer having a basic group is contained in an amount of 0.1 to 15% of the whole monomer. The radical polymerizable crosslinking agent is preferably used in an amount of 0.1% by mass to 0.1% by mass with respect to the total radical polymerizable monomer, although it depends on its properties.

[Chain transfer agent] For the purpose of adjusting the molecular weight, a commonly used chain transfer agent can be used.

The chain transfer agent is not particularly restricted but includes, for example, mercaptans such as octyl mercaptan, dodecyl mercaptan and tert-dodecyl mercaptan, and styrene dimers.

[Polymerization Initiator] The radical polymerization initiator used in the present invention can be appropriately used as long as it is water-soluble.
For example, persulfates (potassium persulfate, ammonium persulfate, etc.), azo compounds (4,4'-azobis-4-cyanovaleric acid and its salts, 2,2'-azobis (2-amidinopropane) salts, etc.), peroxides And the like.

Further, the above radical polymerization initiator can be combined with a reducing agent, if necessary, to form a redox initiator. By using a redox initiator,
The polymerization activity is increased, the polymerization temperature can be reduced, and further reduction in polymerization time can be expected.

As the polymerization temperature, any temperature may be selected as long as it is equal to or higher than the lowest radical generation temperature of the polymerization initiator, but for example, a range of 50 ° C. to 90 ° C. is used. However, it is also possible to polymerize at room temperature or higher by using a combination of a polymerization initiator started at room temperature, for example, a hydrogen peroxide-reducing agent (such as ascorbic acid).

[Surfactant] In order to carry out emulsion polymerization using the above-mentioned radically polymerizable monomer, it is necessary to carry out emulsion polymerization using a surfactant. The surfactant that can be used at this time is not particularly limited, but the following ionic surfactants can be mentioned as preferred examples.

Examples of the ionic surfactant include sulfonates (sodium dodecylbenzenesulfonate, sodium arylalkylpolyethersulfonate, 3,3-
Sodium disulfonediphenylurea-4,4-diazo-bis-amino-8-naphthol-6-sulfonate, ortho-carboxybenzene-azo-dimethylaniline,
2,2,5,5-tetramethyl-triphenylmethane-
Sodium 4,4-diazo-bis-β-naphthol-6-sulfonate), sulfate (sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, etc.), fatty acid salt (sodium oleate, laurin) Sodium acid,
Sodium caprate, sodium caprylate, sodium caproate, potassium stearate, calcium oleate, etc.).

[0050] Nonionic surfactants can also be used. Specifically, polyethylene oxide, polypropylene oxide, a combination of polypropylene oxide and polyethylene oxide, an ester of polyethylene glycol and higher fatty acid, an alkylphenol polyethylene oxide, an ester of higher fatty acid and polyethylene glycol, an ester of higher fatty acid and polypropylene oxide, a sorbitan ester Etc. can be given.

In the present invention, these are mainly used as emulsifiers at the time of emulsion polymerization, but they may be used for other steps or purpose.

[Colorant] Examples of the colorant include inorganic pigments and organic pigments.

Conventionally known inorganic pigments can be used. Although any pigment can be used, specific inorganic pigments are exemplified below.

Examples of black pigments include furnace black, channel black, acetylene black,
Carbon black such as thermal black and lamp black, and magnetic powder such as magnetite and ferrite are also used.

These inorganic pigments can be used alone or in combination of two or more as desired. The amount of the pigment added is 2 to 20 parts by mass, preferably 3 to 15 parts by mass, per 100 parts by mass of the polymer.

When used as a magnetic toner, the above-described magnetite can be added. In this case, from the viewpoint of imparting predetermined magnetic characteristics, 20 to 60
It is preferable to add by mass%.

As the organic pigment, conventionally known organic pigments can be used. Although any pigment can be used, specific organic pigments are exemplified below.

The pigments for magenta or red include:
C. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 5, C.I. I. Pigment Red 6, C.I. I. Pigment Red 7, C.I. I. Pigment Red 15, C.I. I. Pigment Red 16,
C. I. Pigment Red 48: 1, C.I. I. Pigment Red 53: 1, C.I. I. Pigment Red 57:
1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 123, C.I. I. Pigment Red 139,
C. I. Pigment red 144, C.I. I. Pigment Red 149, C.I. I. Pigment Red 166, C.I.
I. Pigment Red 177, C.I. I. Pigment Red 178, C.I. I. Pigment Red 222 and the like.

Examples of orange or yellow pigments include C.I. I. Pigment Orange 31, C.I. I. Pigment Orange 43, C.I. I. Pigment Yellow 12,
C. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 15, C.I.
I. Pigment Yellow 17, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 94, C.I. I.
Pigment Yellow 138 and the like.

The pigments for green or cyan include:
C. I. Pigment Blue 15, C.I. I. Pigment Blue 15: 2, C.I. I. Pigment Blue 15: 3,
C. I. Pigment Blue 16, C.I. I. Pigment Blue 60, C.I. I. Pigment Green 7 and the like.

These organic pigments can be used alone or in combination of two or more as desired. The amount of the pigment added is 2 to 20 parts by mass, preferably 3 to 15 parts by mass, per 100 parts by mass of the polymer.

The colorant can be used after surface modification. As the surface modifier, a conventionally known one can be used, and specifically, a silane coupling agent, a titanium coupling agent, an aluminum coupling agent and the like can be preferably used.

A so-called external additive is usually added to the toner obtained in the present invention for the purpose of imparting suitability as a recycled toner or for the purpose of improving fluidity and cleaning properties. These external additives are not particularly limited, and various inorganic fine particles, organic fine particles, and lubricants can be used.

As the inorganic fine particles used in the present invention, those having a particle diameter of 5 to 500 nm can be preferably used. This particle diameter is observed by a transmission electron microscope, and indicates a number average primary particle diameter measured by image analysis. As a material constituting the inorganic fine particles, various inorganic oxides, nitrides, borides and the like are suitably used. For example, silica,
Alumina, titania, zirconia, barium titanate,
Aluminum titanate, strontium titanate, magnesium titanate, zinc oxide, chromium oxide, cerium oxide, antimony oxide, tungsten oxide, tin oxide, tellurium oxide, manganese oxide, boron oxide, silicon carbide, boron carbide, titanium carbide, silicon nitride , Titanium nitride, boron nitride and the like. Further, the inorganic fine particles may be subjected to a hydrophobic treatment. When performing the hydrophobizing treatment, it is preferable to perform hydrophobizing treatment with a so-called coupling agent such as various titanium coupling agents and silane coupling agents, and silicone oil, and further, aluminum stearate, zinc stearate, and calcium stearate. It is also preferable to perform a hydrophobic treatment with a higher fatty acid metal salt such as

Hereinafter, the hydrophobizing agent for performing the hydrophobizing treatment and the treatment method will be described below. That is, examples of the titanium coupling agent include tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzenesulfonyl titanate, and bis (dioctyl pyrophosphate) oxyacetate titanate. Further, as the silane coupling agent, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β- (N
-Vinylbenzylaminoethyl) γ-aminopropyltrimethoxysilane hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane,
Isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane, p-methylphenyltrimethoxysilane, and the like.

Examples of fatty acids and metal salts thereof include undecylic acid, lauric acid, tridecylic acid, dodecylic acid, myristic acid, palmitic acid, pentadecylic acid, stearic acid, heptadecylic acid, arachiic acid, montanic acid, oleic acid, linoleic acid, Long-chain fatty acids such as arachidonic acid are mentioned, and as metal salts thereof, zinc, iron, magnesium,
Salts with metals such as aluminum, calcium, sodium, lithium and the like can be mentioned.

Examples of the silicone oil include dimethyl silicone oil, methylphenyl silicone oil, amino-modified silicone oil and the like.

These compounds are preferably added to the inorganic fine particles by 1 to 10% by mass and coated, and preferably 3 to 7% by mass. Further, these materials can be used in combination.

The surface may be treated with a polysiloxane having an ammonium salt as a functional group.

Further, as the inorganic fine particles, 5 to 50
Those having different particle diameters within the range of the number average primary particle diameter of 0 nm may be used in combination. Specifically, it is preferable to use a combination of a small particle size and a large particle size. A particle having a small particle diameter is about 5 to 50 nm, and a particle having a large particle diameter is one having a diameter exceeding 50 nm to 500 nm.

Further, in addition to the inorganic fine particles, organic fine particles may be added. Examples of the organic fine particles include styrene resin fine particles, styrene acrylic resin fine particles, polyester resin fine particles, and urethane resin fine particles.

The composition of the resin fine particles is not particularly limited. Generally, vinyl-based organic fine particles are preferable. The reason for this is that it can be easily produced by a production method such as an emulsion polymerization method or a suspension polymerization method. Specifically, styrene, α-methylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-phenylstyrene, p-ethylstyrene, 2,
Styrene or a styrene derivative such as 4-dimethylstyrene or pt-butylstyrene, a methacrylate derivative such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, or 2-ethylhexyl methacrylate; Methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-acrylate
Acrylic ester derivatives such as ethylhexyl, ethylene, propylene, olefins such as isobutylene, vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride,
Halogenated vinyls such as vinylidene fluoride, vinyl esters such as vinyl propionate and vinyl acetate, vinyl ethers such as vinyl methyl ether and vinyl ethyl ether, vinyl ketones such as vinyl methyl ketone, vinyl ethyl ketone and vinyl hexyl ketone; N-vinyl compounds such as N-vinylcarbazole, N-vinylindole and N-vinylpyrrolidone; vinyl compounds such as vinylnaphthalene and vinylpyridine; acrylonitrile, methacrylonitrile, acrylamide, N-butylacrylamide, N, N-dibutyl There are acrylic acid or methacrylic acid derivatives such as acrylamide, methacrylamide, N-butylmethacrylamide, and N-octadecylacrylamide. These vinyl monomers can be used alone or in combination.

The resin fine particles can be produced by an emulsion polymerization method or a suspension polymerization method. The emulsion polymerization method is a method in which the above-mentioned monomer is added to water containing a surfactant and emulsified, followed by polymerization. As the surfactant, sodium dodecylbenzenesulfonate, polyvinyl alcohol, an ethylene oxide adduct, As long as it is used as a surfactant such as sodium alcohol sulfate, it can be used without any particular limitation. Further, the use of a reactive emulsifier, a hydrophilic monomer, for example, polymerization with a persulfate initiator such as vinyl acetate or methyl acrylate, a method of copolymerizing a water-soluble monomer, a water-soluble resin, So-called non-emulsion polymerization methods such as a method using an oligomer, a method using a decomposable emulsifier, and a method using a cross-linkable emulsifier are also suitable. Examples of the reactive emulsifier include sulfonic acid salts of acrylic acid amide and salts of maleic acid derivatives. The non-emulsion polymerization method is not affected by the residual emulsifier, and is suitable when organic fine particles are used alone.

Polymerization initiators required for synthesizing resin fine particles include peroxides such as benzoyl peroxide and lauryl peroxide, and azo-based polymerization initiators such as azobisisobutyronitrile and azobisisovaleronitrile. Agents. The addition amount of these is preferably 0.1 to 2% by mass based on the monomer. If the amount is less than this, the polymerization reaction becomes insufficient, and the problem of residual monomer itself occurs. Further, when the amount is too large, a decomposition product of the polymerization initiator remains and affects the chargeability, and furthermore, the polymerization reaction is too early to cause a problem that the molecular weight becomes small. Further, in an emulsion polymerization method or the like, potassium persulfate, sodium thiosulfate, or the like can be used as a polymerization initiator.

The addition amount of these external additives is preferably about 0.1 to 5% by mass based on the toner. << Production Step >> The production step of the toner of the present invention is a polymerization step of preparing resin particles by performing polymerization, and using an aqueous medium by using the resin particle dispersion, the colorant particle dispersion, and the release agent particle dispersion. A step of salting out the particles, the colorant particles and the release agent particles and fusing them, a washing step of filtering the obtained particles from an aqueous medium to remove a surfactant and the like, a step of drying the obtained particles, It comprises an external additive adding step of adding an external additive and the like to the particles obtained by drying.

Here, the aqueous medium is a medium whose main component is water and whose water content is 50% by mass or more. Examples of the solvent other than water include an organic solvent soluble in water, such as methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran. Preferred are alcoholic organic solvents such as methanol, ethanol, isopropanol and butanol.

The colorant itself may be used after surface modification. The colorant surface modification method is to disperse the colorant in a solvent,
After the addition of the surface modifier, the temperature is raised and the reaction is carried out. After completion of the reaction, the mixture is filtered, washed and filtered repeatedly with the same solvent, and dried to obtain a pigment treated with a surface modifier.

The colorant particles may be prepared by dispersing the colorant in an aqueous medium. This dispersion is performed in a state where the surfactant concentration in water is equal to or higher than the critical micelle concentration (CMC).

The disperser for dispersing the pigment is not particularly limited, but is preferably an ultrasonic disperser, a mechanical homogenizer, a pressure disperser such as Manton-Gaulin or a pressure type homogenizer, a sand grinder, a Getzman mill, a diamond fine mill, or the like. A medium type dispersing machine may be used.

As the surfactant used here, the above-mentioned surfactants can be used. In the salting-out / fusion step, a salting-out agent composed of an alkali metal salt or an alkaline earth metal salt is added as a coagulant having a critical coagulation concentration or more in water in which resin particles and colorant particles are present. Then, the step of heating the resin particles to a temperature equal to or higher than the glass transition point to promote salting out and simultaneously perform fusion. In this step, a method may be used in which an organic solvent that is infinitely soluble in water is added, and the glass transition temperature of the resin particles is substantially lowered to effectively perform fusion.

Here, the alkali metal salt and alkaline earth metal salt as salting-out agents include lithium, potassium, sodium and the like as alkali metals, and magnesium, calcium, strontium, barium and the like as alkaline earth metals. And preferably potassium, sodium, magnesium, calcium and barium. Examples of the salt include chloride, bromide, iodine, carbonate, sulfate and the like.

Further, the organic solvent infinitely soluble in water includes methanol, ethanol, 1-propanol,
2-propanol, ethylene glycol, glycerin,
Acetone and the like can be mentioned, and alcohols of methanol, ethanol, 1-propanol and 2-propanol having 3 or less carbon atoms are preferable, and 2-propanol is particularly preferable.

When the fusion in the present invention is carried out by salting out / fusion,
It is preferable to minimize the time of standing after adding the salting-out agent. Although the reason for this is not clear, there is a problem that the aggregation state of the particles fluctuates due to the standing time after salting out, the particle size distribution becomes unstable, and the surface properties of the fused toner fluctuate. appear. Further, the temperature at which the salting-out agent is added must be at least equal to or lower than the glass transition temperature of the resin particles. This is because
If the temperature at which the salting-out agent is added is equal to or higher than the glass transition temperature of the resin particles, the salting-out / fusion of the resin particles proceeds rapidly, but the particle size cannot be controlled, and the particles having a large particle size cannot be controlled. Problems that occur. The range of the addition temperature may be lower than the glass transition temperature of the resin, but is generally 5 ° C to 55 ° C, preferably 10 ° C to 45 ° C.

In the present invention, it is preferable to use a method in which the salting-out agent is added at a temperature lower than the glass transition temperature of the resin particles, and thereafter, the temperature is raised as quickly as possible, and the temperature is raised to the glass transition temperature of the resin particles. The time until the temperature rise is preferably less than 1 hour. Further, it is necessary to raise the temperature promptly, but the rate of temperature increase is preferably 0.25 ° C./min or more. The upper limit is not particularly clear, but when the temperature is raised instantaneously, salting out proceeds rapidly, and there is a problem that the particle size cannot be controlled. Thus, the upper limit is preferably 5 ° C./min or less.

Here, the particle diameter of the toner obtained by fusing the resin particles in the present invention is preferably 3 to 9 μm in terms of volume average particle diameter. The volume average particle size of the toner is determined by using Coulter Counter TA-II, Coulter Multisizer, SALD
1100 (Shimadzu laser diffraction particle size analyzer)
And the like. In the Coulter Counter TA-II and the Coulter Multisizer, an aperture having an aperture diameter of 100 μm is used, and 2.0 to 4 is used.
It shows what was measured using the particle size distribution in the range of 0 μm.

The shape of the toner obtained by fusing has a shape factor represented by the following equation in a range of 1.3 to 2.2 and a shape factor in a range of 1.5 to 2.0. Is preferably 80% by number or more. Shape factor = ((maximum diameter / 2) ² × π) / projected area This shape factor is obtained by taking a photograph in which the toner particles are magnified 500 times with a scanning electron microscope, and then, based on the photograph, “SCANNING IMAGE ANALYZ”.
Analyze the photographic image using "ER" (manufactured by JEOL Ltd.). At this time, the shape factor is measured by using the above formula using 500 toner particles.

When the arithmetic average value of the shape coefficient is less than 1.3, the shape becomes spherical, so that the external additive is easily buried in the toner surface during toner recycling, and the developing property and the transfer rate of the recycled toner are improved. Is deteriorated, the adhesion to the photoreceptor is increased, and cleaning failure is likely to occur.

On the other hand, when the shape factor exceeds 2.1, the irregular shape becomes high, and when mechanical stress is applied during recycling, the toner is crushed and fine powder is easily generated. Also in this case, the developability and the transfer rate are deteriorated, the adhesion to the photoreceptor is increased, and cleaning failure is apt to occur.

Further, when the number of toner particles having a shape factor in the range of 1.5 to 2.0 is 80% by number or more, the distribution of the shape can be made uniform. Since the amount of the irregular toner can be reduced, the above-described problem can be suppressed for a long time.

[Tonerization Step] In the tonerization step, the toner particles obtained above may be used as they are, but for the purpose of, for example, improving the fluidity, chargeability, and cleaning properties, the above-described external additive is used. An agent may be added. As a method of adding the external additive, various known mixing devices such as a Turbula mixer, a Henschel mixer, a Nauter mixer, and a V-type mixer can be used.

The toner of the present invention may be used alone as a magnetic or non-magnetic one-component toner, or may be mixed with magnetic particles such as a carrier and used as a two-component developer. .

Incidentally, the toner may be added with a material capable of imparting various functions. Specific examples include a charge control agent and a lubricant. A method in which a charge control agent is added to a dispersion liquid at the stage of emulsion polymerization of resin particles, a method in which the charge control agent is added simultaneously with the resin particles and the colorant particles in the above-mentioned salting-out / fusion step, and which is included in the toner; It can be added by various methods such as a method of adding it to an aqueous solution. As a preferable method, a method in which the charge control agent particles are added in the form of a dispersion at the stage of emulsion polymerization of the resin particles, and a method in which the charge control agent particles are simultaneously added with the resin particles and the colorant particles in the salting-out / fusion step described above. Is added in the form of a dispersion, and salted out / fused.

As the charge control agent, a known charge control agent which can be dispersed in water can be used. Specific examples include a nigrosine dye, a metal salt of naphthenic acid or a higher fatty acid, an alkoxylated amine, a quaternary ammonium salt compound, an azo metal complex, a metal salt of salicylic acid, and a metal complex thereof.

The lubricant includes, for example, salts of zinc, aluminum, copper, magnesium, calcium and the like of stearic acid, salts of zinc, manganese, iron, copper, magnesium and the like of oleic acid, zinc and copper of palmitic acid, and the like. magnesium,
Metal salts of higher fatty acids such as salts of calcium and the like, salts of zinc and linoleic acid such as calcium, salts of ricinoleic acid such as zinc and calcium and the like.

<< Developer >> When the toner of the present invention is used as a one-component developer, the toner may be used as it is as a non-magnetic one-component developer, but usually about 0.1 to 5 μm is contained in the toner particles. And used as a magnetic one-component developer. As a method of containing the same, it is common to make the non-spherical particles contain the same as the coloring agent.

Further, it can be used as a two-component developer by mixing with a carrier. In this case, as the magnetic particles, conventionally known materials such as metals such as iron, ferrite and magnetite, and alloys of these metals with metals such as aluminum and lead can be used. Particularly, ferrite particles are preferable. The magnetic particles preferably have a volume average particle size of 15 to 100 μm, more preferably 25 to 60 μm. The volume average particle size of the carrier is typically measured by a laser diffraction type particle size distribution analyzer “HELOS” equipped with a wet disperser (SYMPATIC (SYMPIC)
(ATEC)).

The carrier is preferably a carrier further coated with a resin or a so-called resin-dispersed carrier in which magnetic particles are dispersed in a resin. Although there is no particular limitation on the resin composition for coating, for example, an olefin resin, a styrene resin, a styrene / acrylic resin, a silicone resin, an ester resin, a fluorine-containing polymer resin, or the like is used. The resin for forming the resin dispersion type carrier is not particularly limited, and a known resin can be used.For example, a styrene acrylic resin, a polyester resin, a fluorine-based resin, a phenol resin, or the like can be used. it can.

[0098]

EXAMPLES Examples of the present invention will be described below, but the embodiments of the present invention are not limited to these examples.

<Preparation of Colorant Particle Dispersion> Inner Volume 20 L
Adeka Hope LS-90 (made by Asahi Denka Co., Ltd.)
0.90 kg of sodium dodecyl sulfate) and pure water 1
Add 0.0 L and stir to dissolve. To this solution, with stirring, Regal 330R (carbon black manufactured by Cabot Corporation)
1.20 kg is gradually added, and after the addition, the mixture is stirred well for 1 hour. Next, continuous dispersion is performed for 18 hours using a sand grinder (medium type dispersion machine).

After the dispersion, the particle diameter of the dispersion was measured using an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd., and as a result, the mass average diameter was 118 nm. In addition, the solid content concentration of the dispersion was 16.5% by mass as measured by a static drying method. This dispersion was referred to as “colorant particle dispersion 1”.

<Preparation of release agent particle dispersion> Carnauba wax (manufactured by Noda Wax Co., melting peak = 80 ° C.)
05 kg is added to 2.45 kg of an aqueous solution of a surfactant (nonylphenoxyethanol), and the pH is adjusted to 9 with potassium hydroxide.

The temperature of the system is raised to a temperature equal to or higher than the softening point of the release agent under pressure, and the emulsification and dispersion treatment of the release agent is carried out. Make a dispersion. This dispersion is referred to as “release agent particle dispersion 1”
And

The average particle size of the release agent particles in the obtained “release agent particle dispersion liquid 1” was measured using an electrophoretic light scattering photometer ELS-800 manufactured by Otsuka Electronics Co., Ltd. The primary particle size was 120 nm.

An emulsification and dispersion treatment was carried out in the same manner as described above except that Kao wax 85P (manufactured by Kao Corporation, melting peak = 85 ° C.) was used as a release agent to prepare a “release agent particle dispersion liquid 2”. The number average primary particle size of the release agent particles in the obtained “release agent particle dispersion liquid 2” was 118 nm.

Further, emulsification and dispersion treatment was carried out in the same manner except that FT-100 (manufactured by Nippon Seiro Co., Ltd., melting peak = 89 ° C.) was used as a release agent to prepare “release agent particle dispersion liquid 3”. did. The number average primary particle size of the release agent particles in the obtained “release agent particle dispersion 3” was 121 nm.

Further, emulsification and dispersion treatment was carried out in the same manner except that C80 (manufactured by Schumann-Sazol Co., melting peak = 82 ° C.) was used as a release agent to prepare “release agent particle dispersion liquid 4”. The number average primary particle size of the release agent particles in the obtained “release agent particle dispersion 4” was 120 nm.

As a release agent, C105 (Schumann.
The emulsification and dispersion treatment was performed in the same manner except that the melting peak was 104 ° C. manufactured by Sasol Co., Ltd.
Was prepared. The number average primary particle size of the release agent particles in the obtained “release agent particle dispersion liquid 5” was 123 nm.

Further, Candelia wax N is used as a release agent.
o. Emulsion dispersion treatment was performed in the same manner except that No. 1 (manufactured by Noda Wax Co., melting peak = 63 ° C.) was used to prepare “release agent particle dispersion 6”. The number average primary particle size of the release agent particles in the obtained “release agent particle dispersion 6” is 119.
nm.

<Preparation of Low Molecular Weight Resin Particle Dispersion> 10 L
56 g of sodium dodecylbenzenesulfonate (manufactured by Kanto Chemical Co., Ltd.) is placed in a stainless steel pot, 4.0 L of ion-exchanged water is added, and the mixture is stirred and dissolved at room temperature. This was designated as “anionic surfactant solution A”.

15 g of Newcol 565C (manufactured by Nippon Emulsifier) is placed in a 10 L stainless steel pot, 4.0 L of ion-exchanged water is added, and the mixture is stirred and dissolved at room temperature. This was designated as “nonionic surfactant solution B”.

226.5 g of potassium persulfate (manufactured by Kanto Chemical Co., Ltd.) was placed in a 20 L enamel pot, and ion-exchanged water 1 was added.
Add 2.0 L and stir and dissolve at room temperature. This was designated as “initiator solution C”.

The “anionic surfactant solution A” and the “nonionic surfactant solution B” are placed in a 100 L glass-lined reaction vessel equipped with a temperature sensor, a cooling pipe, and a nitrogen introducing device, and stirring is started. Next, ion-exchanged water 44.
Add 0 L.

Next, heating is started, and when the liquid temperature reaches 74 ° C., “initiator solution C” is added. Then, while controlling the liquid temperature to 74 ° C. ± 1 ° C., the styrene 1
5.10 kg, 0.80 kg of n-butyl acrylate, 96 g of methacrylic acid and 554 t-dodecylmercaptan.
1 g.

Further, the liquid temperature was raised to 78 ° C. ± 1 ° C.
Heat and stir for 7 hours. Thereafter, the liquid temperature is cooled to 40 ° C. or less, and the stirring is stopped. This liquid was filtered with a pole filter to prepare “Low-molecular-weight resin particle dispersion liquid 1”. This dispersion was designated as “latex 1”.

A portion of “latex 1” was taken, and the peak of the molecular weight distribution and the average particle size of the resin particles in the dispersion were measured by GPC. The GPC peak position = 10,50
0, mass average particle size = 121 nm.

A "low molecular weight resin particle dispersion 3" was prepared in the same manner as in the preparation of the low molecular weight resin particle dispersion except that the amount of t-dodecyl mercaptan was changed to 100.0 g. This dispersion was designated as “latex 3”.

<Preparation of High Molecular Weight Resin Particle Dispersion> In a new 10 L stainless steel pot, 56 g of sodium dodecylbenzenesulfonate (manufactured by Kanto Chemical Co., Ltd.) is added, 4.0 L of ion-exchanged pure water is added, and the mixture is stirred and dissolved at room temperature. . this,
"Anionic surfactant solution D" was used.

15 g of Newcol 565C (manufactured by Nippon Emulsifier) is placed in a 10 L stainless steel pot, 4.0 L of ion-exchanged pure water is added, and the mixture is stirred and dissolved at room temperature. this,
"Nonionic surfactant solution E" was used.

207.0 g of potassium persulfate (manufactured by Kanto Chemical Co., Ltd.) was placed in a 20 L enamel pot, and ion-exchanged water 1 was added.
Add 2.0 L and stir and dissolve at room temperature. This was designated as “initiator solution F”.

In a 100 L glass-lined reaction vessel (a stirring blade is a Faudler blade) equipped with a temperature sensor, a cooling pipe, a nitrogen introduction device, and a comb baffle, “anionic surfactant solution D” and “nonionic surfactant solution E” were added. And start stirring the solution. Next, 44.0 L of ion-exchanged water
Input.

Next, the heating of the solution was started, and the temperature of the solution was reduced to 7
When the temperature reaches 0 ° C., “Initiator solution F” is added.
Thereafter, a solution in which 15.10 kg of styrene, 0.80 kg of n-butyl acrylate, 96 g of methacrylic acid and 9.26 g of t-dodecylmercaptan are mixed in advance is charged.

Thereafter, the liquid temperature was controlled at 76 ° C. ± 2 ° C., and the mixture was heated and stirred for 6 hours. Further, the liquid temperature is set at 76 ° C.
The temperature was raised to ± 2 ° C., and the mixture was heated and stirred for 13 hours.

Thereafter, the liquid temperature is cooled to 40 ° C. or less, and the stirring is stopped. This solution was filtered through a pole filter,
"High molecular weight resin particle dispersion liquid 2" was prepared. This dispersion was designated as “latex 2”.

A portion of “Latex 2” was sampled, and the molecular weight distribution peak and average particle size of the resin particles in the dispersion were measured by GPC. GPC peak position = 252, 60
0, mass average particle size = 119 nm.

"High molecular weight resin particle dispersion 4" was prepared in the same manner as in the preparation of the high molecular weight resin particle dispersion except that the amount of t-dodecyl mercaptan was changed to 58.5 g. This dispersion is referred to as “latex 4”.

<Preparation of Salting-out Agent Solution> Sodium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) was used as a salting-out agent in a 35 L stainless steel pot.
5.36 kg and 20.0 L of ion-exchanged water are added and dissolved by stirring. This was designated as “sodium chloride solution G”.

<Salt precipitation / fusion of resin particles, colorant particles and release agent particles> A temperature sensor, a cooling pipe, a nitrogen introducing device,
In a 100-L stainless steel reaction vessel equipped with a comb-shaped baffle (the stirring blade is an anchor blade), 20.0 kg of the “latex 1” and 5.0 kg of the “latex 2” prepared above were placed.
0.4 kg of “colorant particle dispersion 1”, 6.50 kg of “release agent particle dispersion 1”, and 20.0 L of ion-exchanged water are stirred. Then, the mixture is heated to 40 ° C., and 25 kg of “sodium chloride solution G” and 6.00 kg of isopropanol (manufactured by Kanto Chemical Co., Ltd.) are added in this order. afterwards,
After standing for 10 minutes, the temperature is raised and the temperature is raised to 95 ° C. over 60 minutes. The liquid temperature was controlled at 95 ° C. ± 2 ° C., and the mixture was heated and stirred for 5 hours to carry out salting out / fusion.

Thereafter, the liquid temperature is cooled to 40 ° C. or less, and the stirring is stopped. Next, the mixture was filtered through a sieve having an opening of 45 μm,
"Association liquid" was obtained.

<Washing and Drying of Associated Particles> Next, "wet cake-like non-spherical particles" were filtered from the "association liquid" using a Nutsche. Thereafter, the substrate was washed with ion-exchanged water.

The “wet cake-like non-spherical particles” which have been washed as described above are taken out from the nutsche and spread into five paper bats while finely crushing them. After covering with kraft paper, it was dried with a blow dryer at 40 ° C. for 100 hours.

The dried "block-shaped non-spherical particles" were crushed by a Henschel pulverizer to obtain "non-spherical particles".

<Preparation of Toner> Hydrophobic silica (primary average particle diameter = 12 nm) was added to the above “non-spherical particles” at 0.8.
By mass%, “Toner 1” was obtained.

In the above-mentioned “salting out / fusion step of resin particles, colorant particles and release agent particles”, the same procedure was carried out except that release agent particle dispersion liquid 2 was used instead of release agent particle separation liquid 1. Thus, “Toner 2” was produced.

In the above-mentioned “salting out / fusing step of resin particles, colorant particles and release agent particles”, except that release agent particle dispersion 3 was used instead of release agent particle separation liquid 1. Prepared "Toner 3" in the same manner.

In the above-mentioned “salting / fusing step of resin particles, colorant particles and release agent particles”, a release agent particle dispersion liquid 4 was used instead of the release agent particle separation liquid 1. Prepared "Toner 4" in the same manner.

In the above-mentioned “salting out / fusing step of resin particles, colorant particles and release agent particles”, except that release agent particle dispersion liquid 5 was used instead of release agent particle separation liquid 1. Produced "Comparative Toner 1" in the same manner.

In the above-mentioned “salting / fusing step of resin particles, colorant particles and release agent particles”, a release agent particle dispersion 6 was used in place of the release agent particle separation liquid 1. Produced "Comparative Toner 2" in the same manner.

In the above-mentioned “salting out / fusing step of resin particles, colorant particles and release agent particles”, the latex 1
Was used in the same manner except that latex 3 was used instead of latex 4 and latex 4 was used instead of latex 2 to prepare "Comparative Toner 3".

<Preparation of Developer> A mixture of “Toner 1 to 4 and Comparative Toner 1 to 3” and a ferrite carrier coated with a styrene acrylic resin and having a volume average particle diameter of 44 μm was prepared. "Developers 1-4" and "Comparative developers 1-3" were prepared and used for print evaluation.

<Evaluation>"Developers 1 to 1"
"4" and "Comparative developers 1 to 3" were mounted on a Konica 7060 digital copier modified by Konica Corporation and evaluated.
The evaluation conditions are the following conditions. (Developing conditions) Photoconductor: Laminated organic photoconductor DC bias: -520 V Dsd (distance between photoconductor and developing sleeve): 600 μm Developer layer regulation: Magnetic H-Cut method Developer layer thickness: 700 μm・ Developing sleeve diameter: 40 mm (Cleaning conditions) Rubber hardness J for cleaning
ISA 70 °, rebound resilience 25, thickness 2mm, free length 9m
A polyurethane elastic rubber blade having a contact angle of 20 ° was contacted in a counter direction with respect to the rotation of the photoreceptor at a contact pressure of 200 mN / cm by a weight load method. (Fixing Conditions) As the fixing device, a pressure fixing type heat fixing device was employed. The configuration of the fixing device and the fixing conditions are as follows.

The upper roller is made of a cylindrical aluminum alloy with a thickness of 30 mm and a total width of 310 mm, the surface of which is coated with a tetrafluoroethylene-perfluoroalkylvinyl ether copolymer (PFA) and having a total width of 310 mm and having a heater built in the center and having a thickness of 2 mm. And a sponge-like silicon rubber whose surface is coated with a tetrafluoroethylene-perfluoroalkyl ether copolymer (PFA) (Asker C hardness = 48:
It has a lower roller having a diameter of 40 mm and a thickness of 8 mm). The nip pressure was 100 kPa / cm ² (total load = 194 N) and the nip width was 5.8 mm.

As a cleaning mechanism of the fixing device, polydiphenyl silicone (viscosity at 20 ° C. is 10 Pa · s
) Was used. The fixing temperature is controlled by the surface temperature of the upper roll,
The temperature was set to ° C. The amount of silicone oil applied was 0.8 μg / cm ² .

Under the above conditions, temperature = 30 ° C., relative humidity =
In an environment of 75%, a character image with a pixel rate of 1% (original image in which a character image with a pixel rate of 7%, a portrait of a person, a solid white image, and a solid black image are each １ ／ equally divided) is A4 To form an image on 50,000 sheets in the single-sheet intermittent mode.
The image density of the image formed on the sheet was measured, and the image density reduction due to the free release agent and the image defect due to toner aggregation were visually evaluated.

The fixing offset was evaluated in an environment where the temperature was 24 ° C. and the relative humidity was 60%.

The evaluation method is shown below, and the evaluation results are shown in Table 1. <Evaluation method> (1) Image density: For a 10% solid black image portion of 20 mm × 20 mm, the relative image density to a white background portion was measured using a Macbeth reflection densitometer “RD-918”.

If the change in density is within 0.10, the change in image quality is small and the charge amount can be said to be stable. (2) Fixing rate: using the first image of the image formation,
For the patch part of the fixed image, Macbeth reflection densitometer "RD
-918 "to measure the image density. The image density is a relative density with respect to white, and a patch portion having a density of 1.00 ± 0.05 is selected as a measurement unit. The selected portion is rubbed 14 times with a weight of 22 g / cm ² using bleached cotton of plain weave. After rubbing, measure the image density of the measuring section,
The density ratio before and after rubbing was defined as the fixing rate.

If the fixing rate is 80% or more, it can be said that there is no practical problem. (3) Presence or absence of fixing offset: After transporting and fixing 10,000 A4 images having a 5 mm wide solid band image in the vertical direction with respect to the transport direction by longitudinal feeding, and then halftone having a width of 20 mm perpendicular to the transport direction. An A4 image having an image is transported continuously in a transverse direction for 10,000 sheets and temporarily stopped. After stopping the machine overnight, start the machine again,
The presence or absence of dirt on the image due to the fixing offset phenomenon occurring on the first sheet and the state of dirt on the pad were visually evaluated. The evaluation criteria are as follows. Evaluation rank Rank A: There is no dirt on the image, and the pad has almost no dirt. Rank B: There is no dirt on the image, but dirt is accumulated on the pad. Rank C: Extreme on the image Minor stains occur (no problem in practical use). Rank D: Minor stains occur in the image (there is a problem in practical use). Rank E: Stain on the image, which is not suitable for practical use.

[0148]

[Table 1]

It can be seen that Examples 1 to 4 in the present invention have good characteristics, whereas Comparative Examples 1 to 3 other than the present invention have problems in fixing offset and characteristics after long-term use.

[0150]

According to the present invention, it is possible to provide a toner for developing an electrostatic charge image, which is excellent in offset resistance at the time of heat fixing and can stably form a high-quality visible image for a long period of time, and a method for producing the same. I can do it.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Makoto Kono 2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Co., Ltd. F-term (reference) 2H005 AA01 AA06 AB03 CA13 CA14 DA06 EA03 EA06

Claims (2)

[Claims] 1. A toner for developing an electrostatic charge image obtained by salting out / fusing at least resin particles, colorant particles and release agent particles, wherein the resin has a molecular weight distribution of at least 1,500 measured by GPC. Low molecular weight component having a peak or shoulder in the range of 50,000 to 50,000
It consists of a high molecular weight component having a peak or shoulder in the range of 000, and the release agent is 70 to 10 by DSC.
A toner for developing an electrostatic image, having a peak in a region at 0 ° C. 2. A method for producing a toner for developing an electrostatic image by salting out / fusing at least resin particles, colorant particles and release agent particles, wherein the resin particles have at least a molecular weight distribution measured by GPC. A resin particle composed of a low molecular weight component having a peak or shoulder in the range of 1,500 to 20,000 and a resin particle composed of a high molecular weight component having a peak or shoulder in the range of 50,000 to 500,000, A method for producing a toner for developing an electrostatic charge image, which comprises salting out / fusing release agent particles having a peak in the range of 70 to 100 ° C. by DSC.