JP2001142252A - Electrostatic charge image developing toner and its producing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an electrostatic charge image developing toner excellent in anti-offsetting property in heat fixation and capable of stably forming a visible image having high image quality over a long period of time. SOLUTION: At least resin particles, colorant particles and releasing agent particles are subjected to salting-out/fusion to obtain the objective electrostatic charge image developing toner. The resin consists essentially of a low molecular weight component having a peak or a shoulder in the range of 1,500-20,000 in its molecular weight distribution measured by GPC and a high molecular weight component having a peak or a shoulder in the range of 50,000-500,000. The releasing agent is a low molecular weight polyolefinic polymer and the molecular weight distribution (Mw/Mn) of the releasing agent is 1.1-2.5.

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 the field of electrophotography, conventionally,
The heat roller fixing method is widely used because of the simplicity of the apparatus. This is a method in which a toner image is passed between a heating roller having a heat source and a roller made of an elastic material to be pressed against the heating roller, and the toner is melted and fixed on a recording material made of paper or the like. That is, the toner contacts the heating roller and is fixed on paper or the like by the pressure applied after melting. In this case, the toner melted by the heating roller adheres not only to the paper but also to the heating roller, and there is a problem that a so-called offset phenomenon occurs.

[0003] In order to solve this problem, it has been proposed to incorporate a low molecular weight polyolefin into a toner. Thereby, it is said that the adhesiveness to the heating roller can be reduced and the offset can be prevented.

On the other hand, as a method for producing a toner, a production method using a polymerization method such as an emulsion polymerization association method or a suspension polymerization method has been proposed in place of the conventional kneading and pulverizing method (for example, Japanese Patent Application Laid-Open No. 63-186253). No., JP-A-63-232749
JP, JP-A-4-51251, JP-A-6-32
9947, JP-A-9-50149 and JP-A-9-146295). Among them, the toner obtained by the emulsion polymerization association method has an irregular shape, so that it is excellent in blade cleaning property, and an excellent image can be obtained because of uniform charging property.

However, in the emulsion polymerization associating method, it is difficult to surely contain low molecular weight polyolefin in toner particles, and there is a problem that free low molecular weight polyolefin particles are generated and mixed into toner powder. is there. Also, it is difficult to selectively remove the free particles.

As described above, when free low molecular weight polyolefin particles are present in the toner powder, the free particles adhere to the surface of the developing sleeve, causing draw-out and conveyance failure of the developer. There is a problem that the image density is reduced. Also, these free particles adhere to the photoreceptor surface,
The adhered free particles are considerably smaller than the toner particles and thus are not cleaned. At the time of durability, filming of the toner with the free particles as a nucleus occurs, grows, and the image becomes dirty.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention 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 its production. Is to provide a way.

[0008]

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

(1) In a toner for developing an electrostatic image formed by salting out / fusing at least resin particles, colorant particles and release agent particles, at least the resin constituting the resin particles was measured by GPC. 1,500 to 20,000 in molecular weight distribution
A low molecular weight component having a peak or shoulder in the range of 00 and a high molecular weight component having a peak or shoulder in the range of 50,000 to 500,000, and the release agent is a low molecular weight polyolefin-based polymer; A toner for developing an electrostatic image, wherein the molecular weight distribution (Mw / Mn) of the agent is from 1.1 to 2.5.

(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
1,500 to 20,000 in the molecular weight distribution measured in C
And a resin consisting of a high molecular weight component having a peak or shoulder in the range of 50,000 to 500,000, and having a molecular weight distribution (Mw / Mn) of 1 .1 to
A method for producing a toner for developing an electrostatic image, wherein the toner is subjected to salting out / fusion with release agent particles which are a low molecular weight polyolefin polymer of 2.5.

The present inventors have studied the incorporation of release agent particles when salting out / fusing resin particles, colorant particles and release agent particles.

The toner of the present invention is characterized in that at least resin particles, colorant particles and release agent particles prepared by emulsion polymerization are salted out.
It is made by fusion. The salting-out and fusion are performed by adding a salting-out agent to water in which resin particles and colorant particles produced by emulsion polymerization or the like are dispersed, adding an organic solvent that can be dissolved infinitely as necessary, and then heating. By doing so, the salting-out is performed and the fusion is advanced at the same time to prepare the 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.

This fusion is carried out at a temperature not lower than the glass transition point of the resin particles. However, the conventional low molecular weight polyolefin-based polymer has a wide molecular weight distribution (Mw / Mn) of 4 or more, and thus has poor melting characteristics. It was found that particles that could not be fused were generated in the particles.

That is, by setting the molecular weight distribution (Mw / Mn) of the low-molecular-weight polyolefin-based polymer to 1.1 to 2.5, the melting characteristics become sharp, and the incorporation into the toner particles is stabilized and ensured. It has been found that there is no generation of low molecular weight polyolefin polymers that are included and free.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below.

The low molecular weight polyolefin in the present invention includes polyethylene, polypropylene, polybutene,
Examples include polymers (homopolymers) such as polypentene, polyhexene, and polyoctene, and copolymers (copolymers) using two or more monomers such as ethylene-propylene copolymers and ethylene-butene copolymers. Incidentally, polypropylene, polyethylene, ethylene-propylene copolymer and ethylene-butene copolymer are particularly preferable.

The molecular weight distribution (Mw / Mn) is 1.1 to 2.
As a method for obtaining a low-molecular-weight polyolefin of 5,
A method of synthesizing with a metallocene catalyst is preferred. Other methods, such as press sweating method, solvent method, recrystallization method, vacuum distillation method, supercritical gas extraction method or a method performed by fractionating low molecular weight polyolefins by molecular weight using a melt liquid crystal deposition method, There is a problem that the process becomes complicated and the stability of the synthesis is lacking.

The metallocene catalyst uses a main catalyst in which a cyclopentadiene ring and a transition metal compound are bonded, and methylalumoxane or an anionic species as cocatalysts. As the main catalyst in which the cyclopentadiene ring and the transition metal compound are bonded, the following compounds are used.

[0019]

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[0020]

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The following compounds are used as methylalumoxane or anionic species of the cocatalyst.

[0022]

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As the polymerization method, any of high pressure polymerization, gas polymerization and solution polymerization can be used.

The low molecular weight polyolefin of the present invention has a molecular weight distribution (Mw / Mn) of 1.1 to 2.5. here,
Mw is the weight average molecular weight in terms of polypropylene;
000-20,000 is preferred. Mn is the number average molecular weight in terms of polypropylene, and is 2,000 to 10,000.
00 is preferred. Mw / Mn is the ratio between the polypropylene-converted weight average molecular weight (Mw) and the polypropylene-converted number average molecular weight (Mn).

When Mw / Mn is smaller than 1.1, a special molecular weight fractionation step is required to produce such a low molecular weight polyolefin having a sharp molecular weight distribution, and the stability of the synthesis is lacking. is there. Also Mw /
When Mn is greater than 2.5, the amount of low molecular weight polyolefin particles released without being included in the toner particles increases, and the free particles adhere to the surface of the developing sleeve or the free particles adhere to the surface of the photoreceptor. No image failure occurs.

When the low-molecular-weight polyolefin has a weight-average molecular weight (Mw) of less than 4,000 or a number-average molecular weight (Mn) of less than 2,000, the low-molecular-weight component increases and the melting point decreases. The blocking resistance may decrease. Further, the surface of the toner is easily softened, and a problem of embedding an external additive added for imparting fluidity to the surface of the toner or fusing to the surface of the carrier or the developing sleeve occurs, and the durability may be reduced. is there. The weight average molecular weight (Mw) of the low molecular weight polyolefin is 4,
Number average molecular weight (M
n) is in the range of 2,000 to 10,000,
The low-temperature fixing property and the winding resistance become better.

The molecular weight of the low-molecular-weight polyolefin in the present invention is measured by using high-temperature GPC. In particular,
GPC-150C (manufactured by WATERS), SHOdex HT-806 as a column, and o-dichlorobenzene to which 0.1% ionol was added as a solvent,
The molecular weight is a molecular weight determined by flowing out at a temperature of 135 ° C. and a flow rate of 1 ml / min, detecting with a differential refractive index detector, and calculating the molecular weight in terms of polypropylene absolute molecular weight by a universal calibration method.

In the present invention, the amount of the low-molecular-weight polyolefin-based polymer added to the toner in the toner is from 0.5 to 0.5%.
It is preferable to add 5.0% by mass. A particularly preferred range is 1.0 to 4.0% by mass. That is, if the addition amount is too large, the amount of the release agent present on the toner surface increases, causing a decrease in the fluidity of the toner. Conversely, if the addition amount is too small, the effect in fixing is not exhibited. There is.

The release agent (low molecular weight polyolefin) 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 is obtained by adding an alkali.

In order to prevent the release agent from being oxidized during the emulsification, the emulsification is preferably carried out 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 1 to 20% by mass, and preferably 3 to 18% by mass, based on the mass of the usual release agent.
Used. In order to stabilize the emulsified dispersion, the pH of the emulsified dispersion is adjusted to 8.5 to 13, preferably 9.0 to 12.5. The concentration of the release agent in the aqueous release agent particle dispersion can be selected according to the purpose, but is generally from 10 to 10.
It is 30% by mass, preferably 15 to 28% by mass.

The average particle size of the release agent particles in the aqueous dispersion of the release agent particles varies depending on the emulsification conditions.
A range of nm, preferably 50-200 nm, is used.

The resin of the present invention comprises at least a low molecular weight component having a peak or a shoulder in the range of 1,500 to 20,000 in a molecular weight distribution measured by GPC (gel permeation chromatography), and 50 in a molecular weight distribution. It comprises a high molecular weight component having a peak or shoulder in the range of 2,000 to 500,000. By having a peak or a shoulder in the range of 1,500 to 20,000 in molecular weight distribution, fixing performance and mechanical strength against brittle fracture are improved. In addition, the molecular weight distribution is 50,000.
By having a peak or shoulder in the range of ~ 500,000, hot offset resistance is improved. Here, the peak refers to a portion where the spectrum of the measurement chart clearly has a peak shape, and the shoulder refers to a portion which does not reach that point but clearly forms an inflection point.

For measuring the molecular weight of the resin by GPC of the present invention, tetrahydrofuran is used as a solvent. Specifically, 1 mL of a tetrahydrofuran solvent is added to 1 mg of the resin for measurement, and the mixture is stirred at room temperature using a magnetic stirrer or the like to sufficiently dissolve the resin. Then, the mixture is filtered through a membrane filter having a pore size of 0.45 to 0.50 μm to prepare a sample for GPC measurement. Next, after the GPC measurement column was stabilized at 40 ° C., tetrahydrofuran was flowed at a rate of 1 mL per minute, and 1 mg / mg
The measurement is performed by injecting 100 μL of a measurement sample having a concentration of mL. The measurement column is preferably used in combination with a commercially available polystyrene gel column. For example, Showa Denko Sho
dex GPC KF-801, 802, 803, 80
4, 806, 807, and TSK manufactured by Tosoh Corporation
gelG1000H, G2000H, G3000H, G
4000H, G5000H, G6000H, G7000
H, a combination of TSK guard column and the like. As the detector, a refractive index detector (IR detector) or a UV detector may be used.
The molecular weight of the resin of the present invention is represented by a styrene resin equivalent molecular weight. The molecular weight in terms of styrene resin is determined from a styrene calibration curve. Styrene calibration curve is 1 for monodisperse polystyrene standard resin.
It is good to measure and create about 0 points.

In order to achieve such a resin component constitution, a plurality of resin particles having different molecular weight distributions are mixed as the resin particles, dispersed in a solvent, and salted out and fused as described above. The method of producing the toner by the method is most preferable. That is, resin particles having a uniform molecular weight distribution
By using more than one kind, the toner for developing an electrostatic image having the molecular weight distribution of the present invention can be achieved after the colorant particles in the toner are uniformly dispersed.

By making the dispersion of the pigment particles in the toner uniform, 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. Even if it is performed, the toner has a stable chargeability, and an effect of improving characteristics such that a cleaning failure hardly occurs can be obtained.

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. Less than,
An example of a material and a production method of resin particles by an 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 monomer include butadiene, isoprene, chloroprene and the like.

As the halogenated olefin-based monomer,
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 acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, cinnamic acid, monobutyl maleate, and carboxylic acid group-containing monomers. 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 arylalkyl polyethersulfonate, 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.).

[0062] 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 in other steps or for other purposes.

[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 to be added is generally 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-mentioned 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 green or cyan pigments 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.

The toner obtained in the present invention is usually used by adding a so-called external additive 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 and coated in an amount of 1 to 10% by mass with respect to the inorganic fine particles, preferably 3 to 7% by mass. Further, these materials can be used in combination.

The surface can 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.

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 necessary 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 a Menton-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.

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 a salting-out agent is added at a temperature equal to or lower than the glass transition temperature of the resin particles, and thereafter, the temperature is raised as quickly as possible and heated to a temperature equal to or higher than 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 volume average particle diameter. The volume average particle size of the toner is determined by using Coulter Counter TAII, Coulter Multisizer, SALD
1100 (Shimadzu laser diffraction particle size analyzer)
And the like. In the Coulter Counter TAII and the Coulter Multisizer, an aperture having an aperture diameter of 100 μm is used and 2.0 to 40 μm is used.
It shows what was measured using the particle size distribution in the range of μm.

The shape of the toner obtained by fusing has a shape factor represented by the following formula in the range of 1.3 to 2.2 and a shape factor in the 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 mean 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 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, by making the toner particles having a shape factor in the range of 1.5 to 2.0 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 improving the fluidity, the charging property and the cleaning property, for example, 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, and may be used 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, any known charge control agents 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.

Examples of the lubricant include salts of stearic acid such as zinc, aluminum, copper, magnesium and calcium, salts of oleic acid such as zinc, manganese, iron, copper and magnesium, and zinc and copper of palmitic acid. 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, there is a method in which the toner is 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 mixed with a carrier and used as a two-component developer. 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.

[0110]

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

[Release Agents 1-4 of the Present Invention]
Purified as a reaction medium in a stainless steel autoclave
Add 500 ml of toluene and purge the system with nitrogen gas.
I do. As a polymerization catalyst [Me _TwoSi (η_Five-3-Me_TwoC_Five
H_Two)_Two] ZrCl_TwoIs 2 × 10^-6~ 3 × 10^-6mo
1, the methylaluminoxane of Exemplified Compound-18 is Al /
Put under nitrogen gas so that the ratio of Zr becomes 10,000.
You. Gaseous monomers shown in Table 1 below at a polymerization temperature of 30 ° C
Is 3.2 × 10^FiveBlow to Pa to initiate polymerization.
After polymerization for 2 hours, unreacted monomers are removed
The polymer is separated from the slurry by filtration, washed, dried, and
Light release agents 1 to 4 "were obtained. The molecular properties of these release agents
The quantity distribution was determined.

1.05 kg of the obtained "release agent of the present invention 1"
Was added to 2.45 kg of an aqueous solution of a surfactant (nonylphenoxyethanol), and the pH was adjusted using potassium hydroxide.
Is adjusted to 9.

The temperature of the system is increased 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 performed, whereby the release agent particles having a solid content of 30% by mass are obtained. A dispersion was prepared. This dispersion was referred to as “release agent particle dispersion 1 of the present invention”.

Emulsifying and dispersing treatments were similarly performed on the "release agents 2 to 4 of the present invention", and
4 "was obtained.

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

[Comparative Release Agents 1 to 4] "Comparative release agents 1 to 4" shown in Table 1 below were obtained by a usual synthesis method using a Ziegler-Natta catalyst.

Further, emulsification and dispersion treatment was carried out for “Comparative release agents 1 to 4” in the same manner as for “Invention release agents 1 to 4”, and “Comparative release agent particle dispersions 1 to 4” were obtained. I got

[0118]

[Table 1]

[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 dispersion 1”.

[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 75 ° 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 76 ° 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 = 11,000.
0, mass average particle size = 120 nm.

"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 110.2 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 Kagaku 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 Co.) is placed in a 10 L stainless steel pot, 4.0 L of ion-exchange 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-liter glass-lined reaction vessel (a stirring blade is a Faudler blade) equipped with a temperature sensor, a cooling pipe, a nitrogen introducing 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
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 75 ° C. ± 2 ° C., and the mixture was heated and stirred for 6 hours. Further, the liquid temperature is set to 75 ° C.
The temperature was raised to ± 2 ° C., and the mixture was heated and stirred for 12 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 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. GPC peak position = 245,00
0, mass average particle size = 121 nm.

A "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 55.3 g. This dispersion is referred to as “latex 4”.

[Preparation of Salting-out Agent Solution] Sodium chloride (manufactured by Wako Pure Chemical Industries) 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,
20.0 kg of “latex 1” containing “low-molecular-weight resin particles 1” prepared above was placed in a 100-liter stainless steel reaction vessel equipped with a comb-shaped baffle (the stirring blade was an anchor blade).
5.0 kg of "latex 2" containing "high molecular weight resin particles 2", 0.4 kg of "colorant dispersion 1", and 6.50 kg of "release agent particle dispersion 1 of the present invention" Add 20.0 L of exchanged water and stir. 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. Then, after leaving it to stand for 10 minutes, the temperature rise is started and the temperature is raised to 95 ° C. over 60 minutes. Liquid temperature 9
The mixture was heated and stirred for 5.5 hours while controlling at 0 ° C. ± 2 ° C.
Fused.

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, the “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” that have been washed as described above are taken out of 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” in an amount of 0.8.
By mass%, “Invention Toner 1” was obtained. The volume average particle diameter and shape factor of this toner were measured.

The “toner 2 of the present invention” was prepared in the same manner as in the above “step of salting out / fusing resin particles, colorant particles and release agent particles” except that the dispersion 2 of the release agent particles of the present invention was used.
Was prepared.

In the above [Step of salting out / fusing resin particles, colorant particles and release agent particles], the same procedure as described in "Toner toner of the invention" was used except that the dispersion liquid 3 of the release agent particles of the present invention was used. 3 "was produced.

In the above-mentioned “salting out / fusing step of resin particles, colorant particles and release agent particles”, the procedure of “toner of the invention” was repeated except that the dispersion liquid 4 of the release agent particles of the present invention was used. 4 "was produced.

In the above-mentioned “salting out / fusing step of resin particles, colorant particles and release agent particles”, the same procedure was repeated except that comparative release agent particle dispersion 1 was used. 1 "was produced.

In the above-mentioned "salting out / fusing step of resin particles, colorant particles and release agent particles", the same procedure was repeated except that the comparative release agent particle dispersion 2 was used. 2 "was produced.

In the above-mentioned "salting out / fusing step of resin particles, colorant particles and release agent particles", the same procedure was repeated except that comparative release agent particle dispersion 3 was used. 3 "was produced.

In the above [Step of salting out / fusing resin particles, colorant particles and release agent particles], the same procedure was repeated except that the comparative release agent particle dispersion 4 was used. 4 "was produced.

In the above [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.

[Preparation of Developer] A mixture of “Toner toners 1 to 4 of the present invention and Comparative toners 1 to 5” and a ferrite carrier coated with a styrene acrylic resin and having a volume average particle diameter of 44 μm was mixed. % Of “Developers 1-4” and “Comparative developers 1-5” were prepared and used for print evaluation.

[Evaluation] "Developers 1 to 5"
"4" and "Comparative developers 1 to 5" were mounted on a Konica 7060 modified digital copying machine manufactured by Konica Corporation and evaluated. The evaluation conditions are the following conditions.

(Development 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 2.5mm, free length 9mm polyurethane elastic rubber blade with contact angle 20
At 180 ° in the counter direction to the rotation of the photoreceptor with a pressing force of 180 mN / cm by the 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 columnar 2 mm thick aluminum alloy having a heater built in the center and having a diameter of 30 mm and a total width of 310 mm, the surface of which is coated with a tetrafluoroethylene-perfluoroalkylvinyl ether copolymer (PFA). And a sponge-like silicone rubber whose surface is coated with a tetrafluoroethylene-perfluoroalkyl ether copolymer (PFA) (Asker C hardness = 4).
8: 8 mm in thickness). The nip pressure is 100 kPa (total load = 1
94N) and the nip width was 5.5 mm.

As a cleaning mechanism for 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 60%, a character image with a pixel rate of 1% (an 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 divided into quarters) 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 reduction in image density due to the adhesion of the free release agent to the developing sleeve and the presence or absence of image defects due to poor cleaning were 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 2. (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) Image Defects The presence or absence of image defects due to poor cleaning was visually determined for the images after 50,000 sheets. The criteria are as follows.

Rank A: No image defect, Rank B: Black spots with a diameter of 0.5 mm or less were added to the solid white image.
Rank C: 0.5% or less black spots on solid white image
Rank D: 5 black spots with a diameter of 0.5 mm or more on the solid white image
More than one.

(3) Fixing rate The image density of the patch portion of the fixed image is measured by a Macbeth reflection densitometer (RD-918) using the first image of the image formation. 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 the rubbing, the image density of the measurement portion was measured, and the density ratio before and after the rubbing was defined as a fixing ratio.

If the fixing rate is 80% or more, it can be said that there is no practical problem. (4) Presence or absence of fixing offset After an A4 image having a 5 mm wide solid band image in the vertical direction with respect to the transport direction is transported and fixed for 10,000 sheets in a longitudinal feed, a halftone image having a 20 mm width perpendicular to the transport direction. The A4 image having the following is transported continuously by 10,000 sheets in the horizontal direction, and temporarily stopped. After the machine was stopped overnight, the machine was started up again, and the presence or absence of stain on the image due to the fixing offset phenomenon occurring on the first sheet and the state of stain on the pad were visually evaluated. The evaluation criteria are as follows. Evaluation rank Rank A: There is no stain on the image, and the pad has almost no stain. Rank B: There is no stain on the image, but stain is accumulated on the pad. Rank C: Extreme on the image Minor stains occur (no problem in practical use). Rank D: Minor stains occur on the image (slight problem in practical use). Rank E: Stain on the image, which is not suitable for practical use.

[0167]

[Table 2]

Although the toners 1 to 4 of the present invention are excellent in all properties, it is understood that the comparative toners 1 to 5 have a problem particularly in properties after long-term use.

[0169]

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 Continued on the front page (72) Inventor Makoto Shikino 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation F-term (reference) 2H005 AA01 AA06 AB03 CA13 DA06 EA06

Claims (2)

[Claims] 1. A toner for developing an electrostatic image formed by salting out / fusing at least resin particles, colorant particles and release agent particles, wherein the resin constituting the resin particles is at least GPC.
A low molecular weight component having a peak or shoulder in the range of 1,500 to 20,000 in the molecular weight distribution measured in
The release agent is a low molecular weight polyolefin polymer having a high molecular weight component having a peak or a shoulder in the range of 000 to 500,000, and the release agent has a molecular weight distribution (Mw / Mn) of 1.1. A toner for developing an electrostatic image, wherein 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 consisting of a low molecular weight component having a peak or shoulder in the range of 1,500 to 20,000 and a resin consisting of a high molecular weight component having a peak or shoulder in the range of 50,000 to 500,000, and having a molecular weight of A method for producing a toner for developing an electrostatic charge image, comprising salting out / fusing with release agent particles which are low molecular weight polyolefin polymers having a distribution (Mw / Mn) of 1.1 to 2.5.