JP2001066811A - Electrostatic latent image developing toner, image forming method and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make formable a stable image over a long period of time with a high durability amorphous silicon photoreceptor as an electrostatic latent image forming body by using a toner obtained by fusing at least resin particles in an aqueous medium. SOLUTION: The electrostatic latent image developing toner is obtained by fusing at least resin particles in an aqueous medium, has 3-9 μm volume average particle diameter and a shape factor of 1.3-2.2 represented by (shape factor)=[((maximum diameter)/2)2×π]/(projected area) and includes >=80% by number of toner particles whose shape factor is 1.5-2.0. When the amorphous silicon photoreceptor used as an electrostatic latent image forming body is obtained, a lower electric charge injection preventing layer is disposed under a photosensitive layer formed on a substrate to prevent the injection of electric charges from the substrate and a surface projecting layer is disposed on the photosensitive layer to enhance durability.

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 latent image, an image forming method using the toner, and an image forming apparatus.

[0002]

2. Description of the Related Art In recent years, image forming techniques such as copying machines, printers, and facsimile machines have been remarkably developed, and the most frequently used one belongs to an electrostatic image forming method represented by an electrophotographic system. It is.

[0003] The reason is that an electrostatic image forming method such as an electrophotographic method can obtain a high-quality image at a high speed, can form not only a monochrome image but also a color image, has a durability that can be used for a long time, Probably because of having stability.

A disadvantage of this method is that consumables such as a photoconductor and a developer are replaced. In order to reduce the replacement cycle, it is necessary to extend the life of the photoconductor and the developer.

As a photoreceptor, an organic photoreceptor and an amorphous silicon photoreceptor have been frequently used in recent years. In particular, an amorphous silicon photoreceptor can be used to extend the life. This photoreceptor has an amorphous silicon-containing layer on its surface, so it has high hardness, is hardly scratched, and hardly wears out, and thus is suitable as a long-life photoreceptor.

However, since the surface of the amorphous silicon photoreceptor has high smoothness and hardness, the surface wear due to cleaning and developer is small, and adhesion of toner and the like is strong. As a result, in high-humidity environments such as high-temperature and high-humidity environments, adhesion of moisture and adhesion of fillers and the like existing in the image support occur, and the insulating property of the photoreceptor surface decreases, and the charged electric charge flows on the surface. This easily causes problems such as image deletion.

As described above, there are many means for effectively using a highly durable amorphous silicon photoreceptor that need to be improved.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an image forming method capable of forming a stable image for a long time by using a highly durable amorphous silicon photoreceptor. Another object of the present invention is to provide an electrostatic latent image developing toner used in the image forming method and an image forming apparatus using the amorphous silicon photoreceptor.

[0009]

The present invention has been attained by the following constitutions.

[0010] 1. An image forming method for developing a latent image formed on an electrostatic latent image forming body with a developer containing a toner for developing an electrostatic latent image, wherein the electrostatic latent image forming body is an amorphous silicon photoreceptor; An image forming method, wherein the toner is obtained by fusing at least resin particles in an aqueous medium.

Preferred embodiments are described below.

The toner for developing an electrostatic latent image is a toner obtained by fusing resin particles and colorant particles in an aqueous medium; and the toner for developing an electrostatic latent image comprises resin particles and release agent particles. The toner is fused in an aqueous medium. The toner for developing an electrostatic latent image has a volume average particle diameter of 3 to 9 μm.
m, and the shape factor represented by the following equation is 1.3 to 2.2.
And the number of toner particles having a shape factor in the range of 1.5 to 2.0 is 80% by number or more.

Shape factor = ((maximum diameter / 2) ² × π) / projected area A latent image formed on an amorphous silicon photoreceptor is developed with a developer containing a toner, and an electrostatic latent image developing toner used in an image forming method for forming an image is formed. A toner for developing an electrostatic latent image, wherein the toner is fused.

Preferred embodiments are described below.

The toner for developing an electrostatic latent image has a volume average particle diameter of 3 to 9 μm, a shape factor represented by the following formula in a range of 1.3 to 2.2, and a shape factor of 1 .5
80% by number or more of toner particles within the range of 2.0 to 2.0.

Shape factor = ((maximum diameter / 2) ² × π) / projected area In an image forming apparatus that develops a latent image formed on an electrostatic latent image forming body with a developer containing a toner for developing an electrostatic latent image to form an image, the latent image forming body is an amorphous silicon photoconductor. And an image forming apparatus wherein the toner is obtained by fusing at least resin particles in an aqueous medium.

The present invention is based on the idea that the problem can be solved by improving the toner used as a means for effectively using the amorphous silicon photoreceptor for a long period of time. That is what led to it.

That is, a so-called pulverized toner widely used as a conventional toner is prepared by melting and kneading components such as a resin and a pigment to disperse the pigment and the like in the resin, and then pulverizing the resin. Therefore, the composition of the surface broken at the time of pulverization is not constant, and the shape cannot be constant. In addition, even if the particles are classified, the dispersion of the particle diameter is large, and the composition and surface state of each toner are not uniform. as a result,
There are toners that have excessive adhesion due to uneven adhesion, and there is fine powder released from the fractured surface, so that adhesion to the photoreceptor is likely to occur. Presumed.

On the other hand, toner particles obtained by suspension polymerization, which has recently attracted attention, have the advantage that the surface composition is uniform since they are prepared by an aqueous polymerization method. However, the shape of the formed toner particles is mainly spherical and the surface is smooth, so the adhesive force is strong, and although there is no generation of fine powder released from the fracture surface, the toner itself adheres to the photoconductor. It is easier to do.

The present invention has been proposed to solve this problem, and is a polymerized toner prepared in a so-called aqueous medium, wherein resin particles and colored particles or resin particles containing colored particles are mixed in an aqueous medium. The above-mentioned problem can be solved by using the toner fused by the method described above.

That is, the toner of the present invention has an irregular shape while maintaining a uniform surface property which is an advantage of the polymerized toner. The toner has fine irregularities and has uniform surface properties as a whole.

In the present invention, the use of a toner formed by fusing resin particles in an aqueous medium makes it possible to keep the adherence constant without excessive accumulation of electric charge, so Adhesion of toner can be suppressed.

The method for producing a polymerized toner is a method in which the toner is prepared in a single step using an aqueous medium. Unlike a conventional pulverized toner, the toner itself is formed by breakage or the like, like a pulverized toner obtained by a pulverization method. Since there is no surface state and a uniform surface can be obtained, it is possible to prepare a toner having a uniform chargeability and a sharp charge amount distribution.

Although the reason for this is not clear, it is made by fusing resin particles, so that the particle diameters are uniform, and fine irregularities are formed on the surface.
It is presumed that since the excessive accumulation of electric charges is dispersed in the unevenness formed on the fine surface, there is no excessive adhesive force and no adhesion to the photoconductor occurs. In particular, by preparing the resin particles by an emulsion polymerization method, the object can be better achieved.

Although the reason for this is not clear, it is presumed that the surfactant used in the emulsion polymerization step remains in a slight amount in the concave portions on the surface, thereby suppressing the charge accumulation.

Hereinafter, the present invention will be described in detail.

[1] Electrostatic Latent Image Forming Body and Toner for Developing Electrostatic Latent Image • Electrostatic Latent Image Forming Body The electrostatic latent image forming body of the present invention is formed by forming a photosensitive layer having amorphous silicon. . That is, an amorphous silicon photoconductor is used.

In the structure of the amorphous silicon photosensitive member used as the electrostatic latent image forming member of the present invention, a lower charge injection preventing layer is provided below the photosensitive layer to prevent the intrusion of charges from the substrate. In order to further improve the durability, a surface protective layer is provided on the photosensitive layer, and an upper charge injection preventing layer for preventing injection of latent image charges from the surface of the electrostatic image carrier is provided on the photosensitive layer.
Alternatively, it can be provided between the surface protective layer and the photosensitive layer.
Further, a layer serving as both a surface protective layer and an upper charge injection preventing layer may be provided on the photosensitive layer. Further, a long-wavelength light layer may be provided to prevent the appearance of interference development of long-wavelength light.

In providing each of these layers, in order to make the properties of each layer suitable for practical use as needed, hydrogen atoms, atoms of Group III of the periodic table such as boron, aluminum and gallium, germanium, tin and the like are used. A group IV atom of the periodic table, nitrogen, phosphorus, arsenic, etc., a group V atom of the periodic table, oxygen, sulfur, selenium, etc., a group VI atom of the periodic table, or a halogen atom such as fluorine, chlorine, bromine alone or Each property can be controlled by being combined and introduced at the time of forming amorphous silicon.

For example, a lower charge injection prevention layer composed of amorphous silicon: hydrogen film doped with phosphorus (P) in hydrogenated amorphous silicon (amorphous silicon: hydrogen), and a photosensitive layer composed of non-doped amorphous silicon: hydrogen film Layer, and an amorphous silicon doped with boron (B): by providing an upper charge injection prevention layer composed of a hydrogen film on the drum substrate in this order, a desired amorphous silicon photosensitive material holding a negatively charged electrostatic image. You can get a body drum.

Similarly, a lower charge injection preventing layer composed of boron-doped amorphous silicon: hydrogen film,
By providing a photosensitive layer composed of non-doped amorphous silicon: hydrogen film and a surface protective layer composed of a silicon film composed of silicon, carbon and hydrogen (that is, amorphous silicon: hydrogen film) on the drum substrate in this order. Thus, it is possible to obtain a desired amorphous silicon photosensitive drum holding positive charges.

In the present invention, such an amorphous silicon photosensitive member can form an electrostatic latent image forming member having a spectral sensitivity from visible light to semiconductor laser light.
By using the electrostatic latent image forming member, a digital latent image at a laser spot from a semiconductor laser or the like can be formed on the electrostatic latent image forming member.

The toner for developing an electrostatic image The toner for developing an electrostatic image of the present invention is obtained by fusing at least resin particles in an aqueous medium.

The toner used in the present invention is obtained through a step of fusing resin particles, and is particularly a toner fused in an aqueous medium.

The toner used in the present invention may be produced by fusing resin particles containing a colorant in an aqueous medium. From the viewpoint of problems and stabilization in toner production,
A toner in which resin particles and colorant particles are fused in an aqueous medium is more preferable. The toner has an irregular shape from the time of toner production, and unlike a conventional suspension polymerization toner having an irregular shape by surface treatment, does not generate fine powder due to friction or impact in a developing device. Also, the toner prepared by the so-called pulverization method has a structure in which the fracture surface is angular, and that part receives mechanical stress such as a developing device,
There is a problem of generating fine powder. However, compared to these, the toner of the present invention whose shape is irregularly formed by fusing in an aqueous medium has no angular portions and is uniformly irregular, so that the toner is crushed due to mechanical stress. And no fine powder adheres to the photoreceptor, so that the contact-type charging member is not contaminated.

Furthermore, since the particles are fused in an aqueous medium, there is little difference in the shape and surface properties between the particles, and as a result, the charge amount distribution is sharp, and the toner is excellent in resolution with little scattering of toner. An image is obtained. Further, the toner used in the present invention has a sharp particle size distribution of the toner, small toner adhesion to the charging member and the surface of the photoreceptor due to the deformation of the toner, and secures high image quality and high durability. Formation can be achieved.

As a method for fusing in an aqueous medium, for example, JP-A-63-186253 and JP-A-63-282749.
And a method described in JP-A No. 7-146583, and a method of forming resin particles by salting out / fusion.

The resin particles have a weight average particle size of 50 to 2000 n.
m is preferred, and these resin particles may be formed by any of granulation polymerization methods such as emulsion polymerization, suspension polymerization, and seed polymerization, but the emulsion polymerization method is most preferably used in the present invention.

Hereinafter, examples of toner materials and manufacturing methods will be described.

[Polymerizable Monomer] As the polymerizable monomer, a radical polymerizable monomer is used as an essential component, and a crosslinking agent can be used if 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.

(Radical Polymerizable Monomer) The radical polymerizable monomer component is not particularly limited, and a conventionally known radical polymerizable monomer can be used.
Further, 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.

Examples of the aromatic vinyl monomer include, 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 monomers such as octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, 2,4-dimethylstyrene, and 3,4-dichlorostyrene, and derivatives thereof. .

(Meth) acrylic ester 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, propyl γ-aminoacrylate, 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-based monomer include ethylene, propylene, isobutylene, 1-butene, 1-pentene, 4-methyl-1-pentene and the like.

The diolefin-based monomer includes butadiene, isoprene, chloroprene and the like.

Examples of the halogenated olefin monomer include:
Vinyl chloride, vinylidene chloride, vinyl bromide and the like.

(Crosslinking Agent) As a 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 those having two or more unsaturated bonds such as divinylbenzene, divinylnaphthalene, divinyl ether, diethylene glycol methacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, and diallyl phthalate.

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

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. 4
Secondary 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 0.1 to 15% of the whole monomer. Preferably, the radical polymerizable cross-linking agent is used in the range of 0.1 to 10% by weight, based on the total radical polymerizable monomer, depending 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 to 90 ° C. is used. However, the polymerization can be performed 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 radical 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.).

Further, a nonionic surfactant can also be used. Specifically, polyethylene oxide, polypropylene oxide, a combination of polypropylene oxide and polyethylene oxide, esters of polyethylene glycol and higher fatty acids, alkylphenol polyethylene oxide, esters of higher fatty acids and polyethylene glycol, esters of higher fatty acids and polypropylene oxide, sorbitan esters And the like.

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 weight with respect to the polymer, preferably 3 to 20 parts by weight.
-15 parts by weight are selected.

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 weight.

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.

The pigments for orange or yellow include
C. I. Pigment Orange 31, C.I. I. Pigment Orange 43, C.I. I. Pigment Yellow 12, C.I.
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 weight with respect to the polymer, preferably 3 to 20 parts by weight.
-15 parts by weight are selected.

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.

To the toner obtained by the present invention, a so-called external additive can be added for the purpose of improving the fluidity and the cleaning property. These external additives are not particularly limited, and various inorganic fine particles,
Organic particulates and lubricants can be used.

Conventionally known inorganic fine particles can be used. Specifically, silica, titanium, alumina fine particles and the like can be preferably used. These inorganic fine particles are preferably hydrophobic. Specifically, as silica fine particles, for example, Nippon Aerosil Co., Ltd.
Commercially available products R-805, R-976, R-974, R-
972, R-812, R-809, HVK-2150, H-200 manufactured by Hoechst Co., Ltd., and commercial products TS-720, TS-530, TS-610, H manufactured by Cabot Co., Ltd.
-5, MS-5 and the like.

Examples of the titanium fine particles include commercially available products T-805 and T-604 manufactured by Nippon Aerosil Co., Ltd., and commercially available products MT-100S and MT-100B manufactured by Teica Co., Ltd.
MT-500BS, MT-600, MT-600SS,
JA-1, commercial product TA-300S manufactured by Fuji Titanium Co., Ltd.
I, TA-500, TAF-130, TAF-510,
TAF-510T, commercial product IT- manufactured by Idemitsu Kosan Co., Ltd.
S, IT-OA, IT-OB, IT-OC and the like.

Examples of the alumina fine particles include commercially available products RFY-C and C-604 manufactured by Nippon Aerosil Co., Ltd., and a commercially available product TTO-55 manufactured by Ishihara Sangyo Co., Ltd.

As the organic fine particles, spherical organic fine particles having a number average primary particle diameter of about 10 to 2000 nm can be used. As this, a homopolymer such as styrene or methyl methacrylate or a copolymer thereof can be used.

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

The most preferred form of the inorganic fine particles, organic fine particles and lubricant has a number average primary particle diameter of about 5 to 500 nm.

The addition amount of these external additives is preferably about 0.1 to 5% by weight based on the toner.

(Toner Production Step) The production step of the polymerized toner usable in the present invention is an emulsion polymerization step of preparing resin particles by emulsion polymerization, and melting the resin particles in an aqueous medium using the resin particle dispersion. A washing step of filtering the obtained particles from an aqueous medium to remove a surfactant and the like,
The method comprises a step of drying the obtained particles, and a step of adding an external additive to the particles obtained by further drying. The resin particles may be colored particles. Further, non-colored particles can be used as resin particles. In this case, colored particles can be obtained by adding a colorant particle dispersion or the like to the resin particle dispersion and then fusing the dispersion in an aqueous medium.

In particular, as a method of fusion, a method of performing salting out using resin particles produced in the polymerization step and performing fusion is preferable. When non-colored resin particles are used, the resin particles and the colorant particles can be salted out and fused in an aqueous medium.

In addition to the colorant, a releasing agent and a charge control agent, which are constituents of the toner, can be added in this step.

Here, the aqueous medium is composed of water as a main component and has a water content of 50% by weight or more. Examples of the solvent other than water include organic solvents that dissolve 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 the 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 a 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 step of salting out / fusing, a salting-out agent comprising an alkali metal salt, an alkaline earth metal salt or the like is added to the water in which the resin particles and the colorant particles are present. And then heating to above the glass transition point of the resin particles to promote salting out and simultaneously fuse. 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,
-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 aqueous medium in the present invention is carried out by salting out / fusion, it is preferable to minimize the time for which the salting-out agent is allowed to stand after addition. Although the reason for this is not clear, the aggregation state of the particles fluctuates depending on the standing time after salting out, causing problems such as instability of the particle size distribution and fluctuation of the surface properties of the fused toner. I do. 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. The reason for this is that 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,
There is a problem that large particles are generated. 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.
４５45 ° C.

In the present invention, it is preferable to employ 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 the mixture is 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 quickly, but the rate of temperature increase is preferably 0.25 ° C./min or more. The upper limit is not particularly clear, but if the temperature is raised instantaneously, salting out will proceed rapidly, and it may be impossible to control the particle size. Thus, the upper limit is preferably 5 ° C./min or less.

Here, the particle diameter of the toner of the present invention obtained by fusing the resin particles 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 TAII, Coulter Multisizer, SLAD110
0 (a laser diffraction particle size analyzer manufactured by Shimadzu Corporation) or the like. Coulter counter TA
In the case of II and Coulter Multisizer, the values measured using an aperture having an aperture diameter of 100 μm and a particle size distribution in the range of 2.0 to 40 μm are shown.

The shape of the toner obtained by fusing is as follows.
It is preferable that the number of toner particles having a shape coefficient represented by the following formula in a range of 1.3 to 2.2 and a shape coefficient in a range of 1.5 to 2.0 is 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 this photograph, SCANNING IMAGE ANALYS
Analyze the photographic image using "ER" (manufactured by JEOL Ltd.). At this time, the shape factor of the present invention is measured by the above formula using 500 toner particles.

If the arithmetic mean value of the shape coefficient is less than 1.3, the shape becomes spherical, so that the adhesion to the photoreceptor is increased, cleaning failure is likely to occur, and the contact type charging member is contaminated. There is a problem that is easy to cause.

On the other hand, when the shape factor exceeds 2.1, the irregular shape becomes high, and when mechanical stress is applied, the toner is crushed and fine powder is liable to be generated. There is a problem that the charging member is easily contaminated.

Further, when the number of toner particles having a shape coefficient 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 period of time.

In the present invention, the standard deviation based on the number is preferably 0.05 or less. Standard deviation is 0.
When the value exceeds 05, the distribution of the shape is enlarged, so that a distribution is generated in the developing property and selective development occurs, so that development over a long period cannot be stabilized. So-called fog and changes in image density occur.

The particle size is measured on a weight basis,
This is a method of measuring a frequency distribution using a scale converted logarithmically using an equivalent circle diameter as an axis.

(Tonerization step) In the tonerization step, the toner particles obtained above may be used as they are, but for the purpose of improving, for example, fluidity, charging properties and cleaning properties, the above-mentioned 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 is used alone,
It may be used as a magnetic or non-magnetic one-component toner,
It may be used as a two-component developer by mixing with magnetic particles such as a carrier.

The toner may contain, in addition to the colorant, a material capable of imparting various functions as a toner material. Specific examples include a fixing property improving agent and a charge control agent. These components are added at the stage of emulsion polymerization of the resin particles, the dispersion is added, the resin particles and the colorant particles are added at the same time in the salting-out / fusion step, and the toner particles are 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 and / or the fixability improving agent particles are added in the form of a dispersion at the stage of the emulsion polymerization of the resin particles, and the method of adding the resin particles and the coloring in the salting out / fusing step described above. A method in which the charge control agent particles and / or the fixability improving agent particles are added together with the agent particles in the form of a dispersion, and then salted out / fused.

As the fixability improving agent, various known ones which can be dispersed in water can be used. Specific examples include olefin waxes such as polypropylene and polyethylene, modified products thereof, natural waxes such as carnauba wax and rice wax, and amide waxes such as fatty acid bisamide.

The charge control agents are also various known ones.
What can be dispersed in water can also 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 particles of the charge control agent and the fixability improving agent have a number average primary particle diameter of 10 to 500 in a dispersed state.
It is preferable to set it to about nm.

[2] Image Forming Method and Image Forming Apparatus In the image forming method of the present invention, a latent image formed on the above-described amorphous silicon photoreceptor is formed by fusing the above-described resin particles in an aqueous medium. It is characterized by developing with a developer containing a toner for developing an electrostatic latent image.

The image forming apparatus (electrophotographic copying machine) used in the present invention comprises an amorphous silicon photosensitive member and a developer containing a toner for developing an electrostatic latent image formed by fusing resin particles in an aqueous medium. It can be applied to electrophotographic devices such as copiers, laser printers, LED printers, liquid crystal shutter printers, etc., and furthermore, displays, records, light printing, plate making, facsimile, etc. applying electrophotographic technology Etc. can be widely applied to such devices.

FIG. 1 is a sectional view of an image forming apparatus having an amorphous silicon photosensitive member and containing a developer containing a toner for developing an electrostatic latent image formed by fusing resin particles in an aqueous medium.

In FIG. 1, reference numeral 10 denotes an amorphous silicon photosensitive member (here, a drum, hereinafter referred to as a photosensitive drum) which is an electrostatic latent image forming member, and a photosensitive layer containing amorphous silicon is coated in a drum shape. , Grounded and driven clockwise. Reference numeral 12 denotes a scorotron charger, which applies uniform charging to the peripheral surface of the photosensitive drum 10 by corona discharge. Prior to charging by the charger 12,
In order to remove the history of the previous image, the charge may be removed from the peripheral surface of the photoconductor by performing exposure by the charge erasing exposure unit 11 using a light emitting diode or the like.

After the photosensitive drum is uniformly charged, the image exposure device 13 performs image exposure based on the image signal. The image exposure device 13 in this figure uses a laser diode (not shown) as a light source. The light on the photosensitive drum is scanned by the light whose optical path is bent by the reflection mirror 132 through the rotating polygon mirror 131 and the fθ lens, and an electrostatic latent image is formed.

Next, the electrostatic latent image is developed by the developing device 14. At the periphery of the photoconductor drum 10, there is arranged a developing device 14 containing a developer composed of toner and carrier such as yellow, magenta, cyan, and black. First, development of one color is performed by a developing sleeve 141 which rotates while holding a developer with a built-in magnet. The developer is, for example, a carrier in which ferrite is used as a core and an insulating resin is coated around the core, and a toner in which a pigment, a charge control agent, silica, and titanium oxide are made of polyester as a main material and the resin particles are added to an aqueous medium. The developer is conveyed to a developing area with a thickness of 100 to 600 μm regulated on a developing sleeve 141 by an image forming means (not shown) to perform development. At this time, normally, DC and AC biases are applied between the photosensitive drum 10 and the developing sleeve 141 to perform the development.

In the color image formation, after the first color toner image is formed, the second color image formation process is started, and uniform charging by the scorotron charger 12 is performed again.
The second color latent image is formed by the image exposure device 13. 3,
The fourth color image is formed in the same manner as the second color, and a visible image of four colors is formed on the peripheral surface of the photosensitive drum 10. On the other hand, in a monochrome electrophotographic apparatus, the developing device 14 is composed of one type of single color toner, and forms an image by one development.

After the image is formed, the recording paper P is fed to the transfer area by the rotation of the paper feed roller 17 when the timing of the transfer is adjusted. In the transfer area, a transfer roller (transfer device) is provided on the peripheral surface of the photosensitive drum 10 in synchronization with the transfer timing.
The recording paper 18 is pressed and pressed, and the fed recording paper P is narrowly attached to transfer the multicolor image at once.

Next, the recording paper P is neutralized by a separation brush (separator) 19 brought into pressure contact with the transfer roller, separated from the peripheral surface of the photosensitive drum 10 and conveyed to the fixing device 20, where the heat roller 201 and the pressure roller After the toner is fused by heating and pressurizing 202, the toner is discharged to the outside of the apparatus via the discharge roller 21. After the transfer roller 18 and the separation brush 19 have passed the recording paper P, they are retracted from the peripheral surface of the photosensitive drum 10 to prepare for the next toner image formation.

On the other hand, after the recording sheet P is separated, the photosensitive drum 10 removes and cleans the residual toner by pressing the blade 221 of the cleaning device 22 and the cleaning roller 222, removes electricity by the exposure unit 11 again, and removes the toner by the charger 12. Prepares for the next image formation by receiving the charge. When a color image is formed by superimposing a toner image on a photoconductor, the blade 221 is cleaned immediately after the photoconductor drum 1 is cleaned.
Retreat from 0 circumference.

Reference numeral 30 denotes a process cartridge in which a photosensitive member, a charging device, a transfer device, a separation device, and a cleaning device are integrated and set detachably.

The image forming apparatus includes a developing device and a cleaning device including a developer containing a toner for developing an electrostatic latent image formed by fusing the above-described amorphous silicon photoreceptor and resin particles in an aqueous medium. The components may be integrally connected as a process cartridge, and this unit may be configured to be detachable from the apparatus main body. A process cartridge is formed by supporting at least one of a charging device, a developing device, an image exposing device, a transfer device, a separating device, and a cleaning device together with a photoreceptor. Alternatively, it may be configured to be detachable by a guide means such as a rail of the apparatus main body.

When the image exposure is used as a copying machine or a printer, the reflected light or transmitted light from the original is irradiated on the photosensitive member, or the original is read by a sensor and converted into a signal.
Irradiation of a laser beam, driving of an LED array, and driving of a liquid crystal shutter array are performed according to this signal, and the photosensitive member is irradiated with light. In the case of a facsimile printer, the image exposure device performs exposure for printing received data.

[0125]

EXAMPLES The present invention will be described below in detail with reference to examples, but embodiments of the present invention are not limited thereto. In the following, "parts" indicates "parts by weight".

Example 1 1. Preparation of Non-Spherical Particles Adeka Hope LS-90 was placed in a 20 l resin container.
0.9% (manufactured by Asahi Denka, sodium n-dodecyl sulfate)
0 kg and 10.0 l of pure water are added and dissolved by stirring. To this solution, 1.20 kg of Regal 330R (carbon black manufactured by Cabot Corporation) is gradually added with stirring, and the mixture is stirred for 1 hour after the addition. Next, the mixture was continuously dispersed for 20 hours using a sand grinder (medium type disperser).

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 weight average diameter was 122 nm. Further, the solid content concentration of the above-mentioned dispersion measured by the weight method by standing drying was 16.6 w / w%. This dispersion is referred to as “colorant dispersion 1”.

Sodium dodecylbenzenesulfonate (manufactured by Kanto Chemical Co., Ltd.) 0.055k in a 10 l stainless steel pot
After adding g, 4.0 l of ion-exchanged water is added and the mixture is stirred and dissolved at room temperature. This is designated as an anionic surfactant solution A.

In a 10 l stainless steel pot, 0.014 kg of Newcol 565C (manufactured by Nippon Emulsifier) is added, 4.0 l of ion-exchanged water is added, and the mixture is stirred and dissolved at room temperature. This is designated as Nonionic Surfactant Solution B.

223.8 g of potassium persulfate (manufactured by Kanto Chemical Co., Ltd.) is placed in a 20 l enamel pot, and 12.0 l of ion-exchanged water is added, followed by stirring and dissolving at room temperature. This is called initiator solution C.

A 100-liter GL (glass-lined) reactor equipped with a temperature sensor, a cooling pipe, and a nitrogen introducing device was charged with W.
3.41 kg of AX emulsion (polypropylene emulsion having a number average molecular weight of 3,000: number average primary particle size = 120 nm / solid content = 29.9%), an anionic surfactant solution A and a nonionic surfactant solution B are added and stirred. To start. Next, 44.0 l of ion-exchanged water is added.

Heating is started, and when the liquid temperature reaches 75 ° C., an initiator solution C is added. Thereafter, the liquid temperature is reduced to 75
12.1 kg of styrene, 2.88 kg of n-butyl acrylate and 1.04 k of methacrylic acid while controlling the temperature to ± 1 ° C.
g and 548 g of t-dodecyl mercaptan.

Further, the temperature of the solution was raised to 80 ° C. ± 1 ° C., and the mixture was heated and stirred for 6 hours. The liquid temperature is cooled to 40 ° C. or less, and the stirring is stopped. The mixture was filtered with a pole filter, and this was used as Latex-A.

Incidentally, the glass transition temperature of the resin particles in the latex-A is 57 ° C., the softening point is 121 ° C., the molecular weight distribution is 12700, and the weight average particle size is 120 nm.
Met.

A new 10 l stainless steel pot was charged with sodium dodecylbenzenesulfonate (Kanto Chemical) 0.0
55 kg is added, and 4.0 l of ion-exchanged pure water is added, and the mixture is stirred and dissolved at room temperature. This is referred to as anionic surfactant solution D.

New call 5 in a 10 l stainless steel pot
After putting 0.014 kg of 65C (manufactured by Nippon Emulsifier),
4.0 l of ion-exchanged pure water is added and the mixture is stirred and dissolved at room temperature.
This is called Nonionic surfactant solution E.

After 200.7 g of potassium persulfate (manufactured by Kanto Chemical Co., Ltd.) is placed in a 20 l enamel pot, 12.0 l of ion-exchanged water is added, and the mixture is stirred and dissolved at room temperature. This is called initiator solution F.

A WAX emulsion (polypropylene emulsion having a number average molecular weight of 3000) was placed in a 100-liter GL reactor (a stirring blade was a Faudler blade) equipped with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a comb baffle. 3.41 kg (solids concentration 29.9%)
, Anionic surfactant solution D and nonionic surfactant solution E, and stirring was started.
Add 0l.

The heating is started, and when the liquid temperature reaches 70 ° C., the initiator solution F is added. At this time, styrene 1
1.0 kg, 4.00 kg of n-butyl acrylate, 1.04 kg of methacrylic acid, and t-dodecyl mercaptan 9.
And a solution obtained by previously mixing 02 g with the mixture.

Thereafter, the mixture was heated and stirred for 6 hours while controlling the liquid temperature at 72 ° C. ± 2 ° C. Further, the liquid temperature is set at 80 ° C ± 2 ° C.
And heated and stirred for 12 hours.

The liquid temperature is cooled to 40 ° C. or less, and the stirring is stopped. The solution was filtered through a Pall filter, and this filtrate was used as Latex-B.

Incidentally, the glass transition temperature of the resin particles in latex-B is 58 ° C., the softening point is 132 ° C., the molecular weight distribution is 245,000, and the weight average particle size is 110 nm.
Met.

5.36 kg of sodium chloride (manufactured by Wako Pure Chemical Industries, Ltd.) as a salting-out agent and 20.0 liters of ion-exchanged water are put into a 35 liter stainless steel pot and dissolved by stirring. This is designated as sodium chloride solution G.

1.00 g of FC-170C (manufactured by Sumitomo 3M, nonionic surfactant) is placed in a 2 liter glass beaker, and 1.00 liter of ion-exchanged water is added and dissolved by stirring. This is designated as nonionic surfactant solution H.

The latex-A prepared above was placed in a 100 l SUS reaction vessel equipped with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a comb baffle (the stirring blade was an anchor blade).
0.0 kg, 5.2 kg of latex-B, 0.4 kg of colorant dispersion 1 and 20.0 kg of ion-exchanged water are added and stirred. Then, the mixture was heated to 40 ° C., and sodium chloride solution G, 6.00 kg of isopropanol (manufactured by Kanto Chemical Co., Ltd.),
The nonionic surfactant solution H is added in this order. Thereafter, the temperature was raised after being left for 10 minutes, and the liquid temperature was 85 ° C.
Temperature in 60 minutes. The mixture is heated and stirred at a liquid temperature of 85 ° C. ± 2 ° C. for 6 hours to cause salting out / fusion. Thereafter, the mixture is cooled to 40 ° C. or lower and the stirring is stopped. The solution is filtered through a sieve having an opening of 45 μm, and this filtrate is used as an association liquid.

Next, the non-spherical particles 1 in the form of a wet cake were collected by filtration from the association liquid using a nutche, and then washed with ion-exchanged water.

The obtained non-spherical particles 1 had a weight average molecular weight of 53,000, a volume average particle diameter of 6.95 μm, and a softening point of 1
29 ° C., glass transition temperature 58 ° C., shape factor 1.69
Those having a shape factor in the range of 1.5 to 2.0 were 90% by number.

[0148] 2. Preparation of Toner and Developer Toner 1 was obtained by adding 1% by weight of hydrophobic silica (primary average particle diameter: 12 nm) to the obtained non-spherical particles 1.

Further, this toner 1 and a ferrite carrier coated with a styrene acrylic resin and having a volume average particle diameter of 45 μm were mixed to prepare a developer 1 having a toner concentration of 6%.

(Evaluation) Digital copy machine 7 manufactured by Konica Corporation
The corona charger of No. 033 was changed to a roller charger, and the copying speed was further modified to A4, 10 sheets / min, and the actual photographing evaluation was performed. The conditions are as shown below. The following laminated amorphous silicon photoconductor was used as the photoconductor. This is a contact development system.

Charging roller core metal; 8 mmφ stainless steel conductive elastic layer; 16 mmφ conductive rubber layer (EPDM)
Resin) Surface layer; Nylon-based resin layer having a thickness of 20 μm Hardness: 57.5 (ASKER-C) Resistance value: 3.0 × 10 ⁷ Ω (measured at 20 ° C., 50%) Charge condition Photoconductor contact pressure: 50 g / Cm DC voltage applied to the charging member; -600 V AC voltage applied to the charging member; 2,000 Vp-p frequency; 150 Hz ・ Photoconductor (production of amorphous silicon photoconductor drum) Amorphous silicon photoconductor drum is high-frequency plasma SiH ₄ , H ₂ , CH ₄ , PH ₃ , B ₂ H ₆ , Ge
It was produced by a glow discharge method using a gas such as H ₄ .

The substrate of the photosensitive drum is 80φ × 3
A 60 mm aluminum cylinder was used. The structure of the amorphous silicon photoreceptor is such that boron-doped amorphous silicon (a lower charge injection preventing layer composed of a hydrogen film) is formed, and 25 μm non-doped amorphous silicon (a photosensitive layer composed of a hydrogen film) is formed thereon. )
And a surface protective layer formed of an amorphous film made of silicon, carbon, and hydrogen (that is, an amorphous silicon: hydrogen film) was provided, thereby forming a photosensitive drum holding positive charges.

(Evaluation) Using the obtained developer, a digital copying machine Konica 7060 manufactured by Konica Corporation was used to evaluate a real image. The conditions are as shown below. A laminated organic photoreceptor was used as the photoreceptor.

Developing conditions DC bias; -500 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 mmφ A method in which untransferred toner remaining on the photoreceptor is cleaned by a blade cleaning method using heat roll fixing is employed.

The transfer paper used was a paper having a basis weight of 55 kg, and an image was formed in the vertical direction. As image forming conditions, 10,000 copies of an original image having a solid black, halftone, and white image were copied in a normal temperature and normal humidity environment (25 ° C./55% RH) and evaluated.

As a result, the 10,000th copy image was clearly reproduced in the black density, halftone and white image portions.
Further, no toner was fixed on the surface of the photoreceptor.

Example 2 In the production of the non-spherical particles 1 of Example 1, 400 g of dodecyl mercaptan in the production of Latex-A was used.
Aspherical particles 2 were obtained in the same manner except that dodecyl mercaptan in Latex-B was not used. Let each latex be latex-A, -B.

The resin particles in Latex-A had a glass transition temperature of 57 ° C., a softening point of 121 ° C., a molecular weight distribution of 155,000, and a weight average particle size of 115 nm.

The glass transition temperature of the resin particles in Latex-B was 59 ° C., the softening point was 136 ° C., the molecular weight distribution was 315,000, and the weight average particle size was 115 nm.

The resin particles of the non-spherical particles 2 had a weight average molecular weight of 75,000, a softening point of 131 ° C., and a glass transition temperature of 5
7 ° C., volume average particle size 7.24 μm, shape factor 1.8
7, and 94% by number had a shape factor in the range of 1.5 to 2.0.

The toner 2 was prepared by adding 1% by weight of hydrophobic silica (primary average particle diameter = 12 nm) to the non-spherical particles 2.
I got

The obtained toner 2 was mixed with the same ferrite carrier as in Example 1 to prepare a developer having a toner concentration of 6%, which was used for printing evaluation. This developer is referred to as a developer 2 corresponding to the toner.

Evaluation was performed under the same evaluation conditions as in Example 1.

As a result, the 10,000th copy image was clearly reproduced in the black density, halftone and white image portions.
Further, no toner was fixed on the surface of the photoreceptor.

Example 3 In the preparation of the non-spherical particles 1 of Example 1, the polymerizable monomer of Latex-B was changed to 13.25 kg of styrene, 3.21 kg of butyl acrylate, and 0.75 kg of acrylic acid. In the same manner, resin particles were obtained. This is designated as Latex-B. The glass transition temperature of the resin particles in the latex-B is 55 ° C, the softening point is 135 ° C, the molecular weight distribution is 231,000, the weight average molecular weight is 10
It was 5 nm.

Then, a latex was prepared in the same manner as in Example 1.
Using A and Latex-B, colored particles were obtained. The non-spherical particles obtained here are referred to as non-spherical particles 3.

The resin particles of the non-spherical particles 3 have a weight average molecular weight of 61,000, a softening point of 125 ° C., and a glass transition temperature of 5
7 ° C., volume average particle size 7.24 μm, shape factor 1.7
9 and 9 when the shape factor is in the range of 1.5 to 2.0.
It was 0 number%.

1% by weight of hydrophobic silica (primary average particle diameter = 20 nm) was added to the non-spherical particles 3 to form a toner 3
I got

The obtained toner 3 was mixed with the same ferrite carrier as in Example 1 to prepare a developer having a toner concentration of 6%, which was used for printing evaluation. This developer is referred to as a developer 3 corresponding to the toner.

Evaluation was performed under the same conditions as in Example 1.

As a result, the 10,000th copy image was clearly reproduced in the black density, halftone and white image portions.
Further, no toner was fixed on the surface of the photoreceptor.

Example 4 Production of non-spherical particles was carried out by preparing a suspension-polymerized toner. After the production of the suspension toner, the toner obtained by fusing colored particles to the surface by a mechanochemical technique to make the surface uneven was used. Manufactured according to That is, 165 g of styrene, n-
35 g of butyl acrylate, phthalocyanine blue 10
g, 2 g of a metal di-t-butylsalicylate, 8 g of a styrene-methacrylic acid copolymer, and 20 g of paraffin wax (mp 70 ° C.) were heated to 60 ° C., and TK homomixer (manufactured by Tokushu Kika Kogyo) at 12,000 rpm. Uniformly dissolved and dispersed. To this, 10 g of 2,2'-azobis (2,4-valeronitrile) as a polymerization initiator was added and dissolved to prepare a polymerizable monomer composition. Next, 450 g of a 0.1 M sodium phosphate aqueous solution was added to 710 g of ion-exchanged water.
Then, 68 g of 1.0 M calcium chloride was gradually added while stirring at 12,000 rpm with a TK homomixer to prepare a suspension in which tricalcium phosphate was dispersed.
The polymerizable monomer composition was added to the suspension, and the mixture was stirred with a TK homomixer at 10,000 rpm for 20 minutes to granulate the polymerizable monomer composition. Then, at 80 ° C, 10
Allowed to react for hours. Tricalcium phosphate was dissolved and removed with hydrochloric acid, followed by filtration, washing and drying to obtain colored particles having a volume average particle size of 7.9 μm. 2.0% by weight of PMMA particles having a number average primary particle diameter of 1.0 μm was added to the colored particles, and a mechanomill treatment was performed for 3 minutes at a peripheral speed of 80 m / sec using a hybridizer manufactured by Nara Machinery Co., Ltd. Then, irregularities were formed on the surface of the colored particles. To this was added 1% by weight of hydrophobic silica (number average primary particle size = 12 nm) to obtain a toner. This is referred to as toner 4. This has a shape factor of 1.19 and a shape factor of 1.5 to 2.0.
In the range of 10% by number.

The same ferrite carrier as in Example 1 was mixed with the toner 4 to prepare a developer having a toner concentration of 6%, which was used for printing evaluation. This developer is referred to as a developer 4 corresponding to the toner.

Example 5 100 parts of styrene acrylic resin, carbon black 10
Parts, low molecular weight polypropylene (number average molecular weight = 300
0) 4 parts were melted, kneaded and pulverized to have a volume average particle size of 6.
9 μm colored particles were obtained. Next, 1% by weight of hydrophobic silica (number average primary particle diameter = 12 nm) was added to the colored particles to obtain a toner. This is referred to as toner 5. This has a shape factor of 2.13 and a shape factor of 1.5 to 2.0.
In the range of 26% by number.

The same ferrite carrier as in Example 1 was mixed with the toner 5 to prepare a developer having a toner concentration of 6%, which was used for printing evaluation. This developer is referred to as a developer 5 corresponding to the toner.

Evaluation was performed in the same manner as in Example 1 for the evaluation conditions.

With the developers 4 and 5, the image of the initial copy was good, but in the 10,000th copy image, black streak-like image stains occurred on the halftone and white image portions, and the white image portions did not. Also had thin fog. Fine toner-like fixation was also observed in the photoreceptor surface observation.

Example 6 The following components were added to a 100-liter GL reactor (a stirring blade was a Faudler blade) equipped with a temperature sensor, a cooling pipe, a nitrogen introducing device, and a comb baffle.

Styrene monomer 60 parts Butyl acrylate 40 parts Acrylic acid 8 parts Water 100 parts Nonionic emulsifier (Emulgen 950) 1 part Anionic emulsifier (Neogen R) 1.5 parts Potassium persulfate 0.5 part The above aqueous solution mixture is stirred. Polymerization was performed at 70 ° C. for 8 hours to obtain an acidic polar group-containing resin emulsion (latex) having a solid content of 50%.

(Preparation of Toner) Latex 120 parts Carbon black (Legal 330R) 5 parts Chromium dye (Bontron-E81) 1 part Water 200 parts While stirring and dispersing the above mixture with a slasher, about 30 parts
C. for 2 hours. Then, with further stirring, 70 ° C
And kept for 3 hours. The liquid dispersion obtained by cooling was subjected to Buchner filtration, washed with water, and vacuum dried at 50 ° C. for 10 hours to obtain non-spherical particles 6. The volume average particle diameter of the non-spherical particles 6 was 10.5 μm, the shape coefficient was 1.96, and 85% by number had a shape coefficient in the range of 1.5 to 2.0.

To the above non-spherical particles 6 was added 1% by weight of hydrophobic silica (primary average particle diameter = 20 nm) to form toner 6
I got

Toner 6 was mixed with the same ferrite carrier as in Example 1 to prepare a developer having a toner concentration of 6%, which was used for printing evaluation. This developer is referred to as a developer 6 corresponding to the toner.

Evaluation was performed in the same manner as in Example 1 for the evaluation conditions.

As a result, the 10,000th copy image was clearly reproduced in the black density, halftone and white image portions.
Further, no toner was fixed on the surface of the photoreceptor.

[0185]

According to the present invention, a stable image can be formed over a long period of time by using a highly durable amorphous silicon photosensitive member.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of an image forming apparatus having an electrophotographic photosensitive member according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 photoconductor drum (or photoconductor) 11 charge erasing exposure section using light emitting diode 12 etc. 12 charger 13 image exposure device 14 developing device 17 paper feed roller 18 transfer roller (transfer device) 19 separation brush (separator) 20 fixing Apparatus 21 Discharge roller 22 Cleaning device 30 Process cartridge

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Makoto Kono 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Co., Ltd. F-term (reference) 2H005 AB03 EA05 EA10 2H068 DA23 FC08 2H077 AD06 AD36 BA09 EA03 EA14 GA13

Claims (7)

[Claims] 1. An image forming method for developing a latent image formed on an electrostatic latent image forming body with a developer containing a toner for developing an electrostatic latent image, wherein the electrostatic latent image forming body is formed of an amorphous silicon photoreceptor. Wherein the toner is formed by fusing at least resin particles in an aqueous medium. 2. The image forming method according to claim 1, wherein the toner for developing an electrostatic latent image is a toner obtained by fusing resin particles and colorant particles in an aqueous medium. 3. The image forming method according to claim 1, wherein the toner for developing an electrostatic latent image is a toner obtained by fusing resin particles and release agent particles in an aqueous medium. 4. The toner for developing an electrostatic latent image has a volume average particle diameter of 3 to 9 μm, a shape factor represented by the following formula in a range of 1.3 to 2.2, and a shape factor of 1.5
The image forming method according to any one of claims 1 to 3, wherein the number of toner particles in the range of from 2.0 to 2.0 is at least 80% by number. Shape factor = ((maximum diameter / 2) ² × π) / projected area 5. An electrostatic latent image developing toner used in an image forming method for forming an image by developing a latent image formed on an amorphous silicon photoreceptor with a developer containing the toner, wherein the toner comprises at least a resin. A toner for developing an electrostatic latent image, wherein particles are fused in an aqueous medium. 6. The electrostatic latent image developing toner has a volume average particle size of 3 to 9 μm, a shape factor represented by the following formula in a range of 1.3 to 2.2, and a shape factor of 1.5
5. The toner for developing an electrostatic latent image according to claim 4, wherein the number of toner particles within the range of from 2.0 to 2.0 is at least 80% by number. Shape factor = ((maximum diameter / 2) ² × π) / projected area 7. An image forming apparatus which develops a latent image formed on an electrostatic latent image forming body with a developer containing toner for developing an electrostatic latent image to form an image, wherein the latent image forming body is amorphous An image forming apparatus, which is a silicon photoreceptor, wherein the toner is formed by fusing at least resin particles in an aqueous medium.