JPH08334909A - Image forming method - Google Patents

Abstract

PURPOSE: To provide an image forming method capable of forming stable images free from the occurrence of image defects, such as fogging and black dots, over a long period of time. CONSTITUTION: This image forming method comprises developing the images by using toners prepd. by adding fine particles to colored particles consisting of at least a resin and coloring agents on an org. electrophotographic photoreceptor constituted by providing the surface of a conductive base l with a photosensitive layer. The extreme surface layer of the photoreceptor contains spheroidal inorg. particles having Mohs hardness of >=5. The film strength of the photosensitive layer is 0.1 to 1μm in the depth of flaws when a perpendicular load of 200g is applied on the photosensitive layer by using a diamond needle having a tip radius of 0.3mm. The toner particles to be added to the toners are at least inorg. fine particles having a BET surface area of 4 to 30m<2> /g or resin fine particles having a number average primary grain size of 0.1 to 2.0μm or composite fine particles fixedly attaching inorg. fine particles having a number average primary grain size of 5 to 100μm on their surfaces and inorg. fine particles having a BET surface area of 40 to 400m<2> /g.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a toner obtained by adding fine particles to colored particles composed of at least a resin and a colorant on an organic electrophotographic photosensitive member having a photosensitive layer provided on a conductive support. The present invention relates to an image forming method of developing by developing.

[0002]

2. Description of the Related Art In an image forming method by electrophotography, after an electrostatic latent image is formed on a photoconductor, it is developed with a toner composed of so-called resin and colorant to form a visible image. The method of fixing is performed by transferring the image onto paper or the like and further applying heat or the like. This photoconductor is used for image formation after removing residual toner in a cleaning process after the transfer process. On the other hand, in the fixing step, as a method of fixing by heat, a method of heat roll fixing in which a roll-shaped heating member is passed is generally used. In this method, in order to prevent heat adhesion of the toner to the heat roll member,
A material called a release agent is included in the toner to prevent the toner from adhering to a heat roll, so-called offset phenomenon.

In recent years, as an electrophotographic photosensitive member, an inorganic photosensitive member such as selenium, which has a problem in disposal, is being replaced with an organic photosensitive member in consideration of prevention of environmental pollution. As the organic photoconductor, a multi-layered organic photoconductor which is composed of a charge generation layer and a charge transport layer on a conductive support with an undercoat layer as needed is often used. This charge transport layer is usually composed of a binder resin containing a charge transport substance, and is easily scratched by friction or the like during repeated use in a cleaning process for removing toner, a developing process, a transfer process and the like. However, there was a problem in long-term use due to film thickness loss.

In order to solve this problem, Japanese Patent Laid-Open No. 2-1
No. 18667 discloses an organic photoreceptor having a coating layer in which hydrophobic silica is dispersed, and JP-A No. 57-30846 discloses a protective layer containing metal or metal oxide fine particles having an average particle diameter of 0.3 μm or less. Configuration, JP-A-1-205
Japanese Patent No. 171 discloses a photoconductor having a protective layer containing an inorganic filler and the like. All of them are methods of adding various fine particles to the surface layer of the photoconductor to improve the abrasion resistance of the photoconductor, which is intended to improve the printing durability of the photoconductor.

However, although the abrasion resistance of the photoconductor itself is improved, since the film strength of the photoconductor is increased and the surface of the photoconductor is less likely to be scraped, it is difficult to remove the toner or the like which has strongly adhered to the photoconductor. As a result, an insulating film is formed on the surface of the photoconductor, and the potential of the photoconductor surface does not decrease,
The problem of so-called fog generation and friction with the fine powder exposed on the surface causes abrasion and deterioration of the cleaning blade, resulting in poor cleaning, so that the toner component on the photoconductor can be completely scraped off. However, there is a problem that image defects such as black spots occur.

As described above, a stable image cannot be formed for a long period of time in the image forming method using a photoreceptor having a highly durable protective layer having a wear resistance function on the surface. .

[0007]

An object of the present invention is to provide an image forming method capable of forming a stable image without causing image defects such as image blurring, black spots, and fog over a long period of time.

[0008]

According to the present invention, (1) fine particles are added to colored particles composed of at least a resin and a colorant on an organic electrophotographic photosensitive member having a photosensitive layer provided on a conductive support. In the image forming method of developing with the toner as described above, the outermost surface layer of the photosensitive member contains spherical inorganic particles having a Mohs hardness of 5 or more, and the film strength of the photosensitive layer has a tip radius of 0.
An organic electrophotographic photosensitive member having a scratch depth of 0.1 to 1 μm when a vertical load of 200 g is applied using a 3 mm diamond stylus, and the fine particles added to the toner have at least a BET specific surface area of 4 to 30m ² / g of inorganic fine particles and 4
An image forming method characterized by being 0 to 400 m ² / g of inorganic fine particles, (2) Item (1) characterized in that the inorganic particles have a number average particle diameter of 0.01 to 2 μm. Image forming method, (3) developing using a toner obtained by adding fine particles to colored particles composed of at least a resin and a colorant on an organic electrophotographic photosensitive member having a photosensitive layer provided on a conductive support. In the image forming method, the outermost surface layer of the photoconductor contains Mohs hardness of 5 or more and contains spherical inorganic particles, and the film strength of the photoconductive layer is 200 g vertical load using a diamond needle having a tip radius of 0.3 mm. An organic electrophotographic photosensitive member having a scratch depth of 0.1 to 1 μm when applied, wherein fine particles added to the toner are resin fine particles having a number average primary particle diameter of at least 0.1 to 2.0 μm. BET specific surface area is 4
An image forming method characterized by being 0 to 400 m ² / g of inorganic fine particles, (4) Item (3) characterized in that the inorganic particles have a number average particle diameter of 0.01 to 2 μm. Image forming method, (5) developing with a toner obtained by adding fine particles to colored particles composed of at least a resin and a colorant on an organic electrophotographic photosensitive member having a photosensitive layer provided on a conductive support. In the image forming method, the outermost surface layer of the photoconductor contains Mohs hardness of 5 or more and contains spherical inorganic particles, and the film strength of the photoconductive layer is 200 g vertical load using a diamond needle having a tip radius of 0.3 mm. An organic electrophotographic photosensitive member having a scratch depth of 0.1 to 1 μm when applied, and the fine particles added to the toner are resin fine particles having a number average primary particle diameter of at least 0.1 to 2.0 μm. No number average primary particle size of 5-100 nm on the surface Image forming method, wherein the composite particles and the BET specific surface area obtained by fixing the fine particles are inorganic fine particles of 40 to 400 ² / g, number average particle diameter of the (6) the inorganic particles 0.01~2μm It can be achieved by any of the image forming methods described in the item (5).

That is, as a result of intensive investigations by the present inventors, in order to clean a surface layer having high film strength and abrasion resistance on the surface, the so-called abrasive fine particles are contained in the toner with appropriate film strength of the photosensitive layer. It has been found that it is necessary to include That is, the surface layer of the photosensitive member contains spherical inorganic particles having a Mohs hardness of 5 or more, and the film strength of the photosensitive layer is 200 g using a diamond needle having a tip radius of 0.3 mm.
The depth of scratches when a vertical load is applied is 0.1 to 1 μm, and the fine particles added to the toner are at least BE.
Inorganic fine particles having a T specific surface area of 4 to 30 m ² / g and 40 to 4
The fine particles added to the toner are at least 100 m ² / g, or the fine particles added to the toner have a BET specific surface area of 40 or more with resin particles having a number average primary particle diameter of 0.1 to 2.0 μm.
To 400 m ² / g, or the fine particles added to the toner have a number average primary particle diameter of 5 to 5 on the surface of resin fine particles having a number average primary particle diameter of at least 0.1 to 2.0 μm. The present inventors have found that the present invention can solve the problems by using composite fine particles formed by fixing 100 nm inorganic fine particles and inorganic fine particles having a BET specific surface area of 40 to 400 m ² / g, and completed the invention. is there.

When the depth of the scratch is 0.1 μm or less, the rubber elastic cleaning blade is significantly worn and deteriorated, and it is difficult to obtain a stable cleaning property for a long period of time. On the other hand, if the scratch depth is greater than 1, the film strength of the photoconductor is insufficient, the film wear due to repeated use becomes large, and the photoconductor surface is easily scratched due to contact with peripheral members.

Regarding the fine particles to be added to the toner, the surface of the photoconductor having a high film strength used in the present invention cannot be abraded by only the fine particle fluidization-imparting agent which is usually added, and the fine fluidizing agent is used in a high humidity environment. It is not possible to remove the deposits that adsorb the generated water.

Therefore, in the present invention, in order to effectively polish the photoconductor having the surface layer having high film strength, the polishing effect can be achieved by imparting the polishing effect to the external additive itself of the toner. is there.

That is, fluidity is imparted by using inorganic fine particles having a small particle size such as commonly used hydrophobic silica.
In the second aspect of the invention, the problem is solved by adding these and the inorganic fine particles having a large particle size, and in the third and fourth aspects of the invention, the problem is solved by adding these and the resin fine particles. Further, in the inventions of claims 5 and 6, these problems are solved by adding so-called composite fine particles in which inorganic fine particles are fixed to the surface of these and the resin fine particles.

Further, in the inventions of claims 3 to 6, in order to achieve a more stable effect, it is preferable that the resin particles or the composite particles and the colored particles have the same charging polarity. The reason for this is that the resin fine particles or the composite fine particles are in a state of being attached to the colored particles, not in a state of being attached thereto, so that the polishing property for the photoconductor can be enhanced. On the other hand, the inorganic fine particles having a small particle diameter can impart an effect such as fluidity in a state of being attached to the toner. From these viewpoints, it is preferable that the inorganic fine particles having a small particle size have high chargeability, and the resin fine particles or the composite fine particles have low chargeability. That is, the chargeability of the small-sized inorganic fine particles is 5 to 2 times that of the resin fine particles or the composite fine particles.
It is preferably 0 times. When the chargeability of the small-sized inorganic fine particles is less than 5 times the chargeability of the composite fine particles, the small-sized inorganic fine particles are in a free state, and the effect of imparting fluidity decreases. On the other hand, when the chargeability exceeds 20 times, the inorganic fine particles having a small particle size adhere to the resin fine particles or the composite fine particles, and the chargeability of the resin fine particles or the composite fine particles is changed to reduce the intended effect. Causes a problem.

[Structure of the Invention] Structure of Photoreceptor The photoreceptor of the present invention comprises a charge generation layer and a charge transport layer which are laminated on the surface of a conductive substrate with an undercoat layer, if necessary, or a charge generation substance and a charge transport layer. It is a photoreceptor having a photosensitive layer mixed with a substance and containing inorganic particles in the outermost surface layer.

As the conductive substrate, a metal plate of aluminum, stainless steel, iron or the like, a metal layer of aluminum, palladium, gold or the like is provided on the surface of a flexible support such as paper or plastic film by laminating or vapor deposition. It is possible to use a material having a layer containing a conductive compound such as a conductive polymer, indium oxide or tin oxide applied or vapor-deposited on the surface of a flexible support such as paper or plastic film.

As an undercoat layer used as necessary, casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyvinyl butyral, phenol resin, polyamides (nylon 6, nylon 66, alkoxymethylated) Nylon etc.), polyurethane, gelatin and aluminum oxide are used. The thickness of the undercoat layer is preferably 0.1 to 10 μm, and particularly preferably 0.1 to 5 μm.

The charge generating layer is a layer containing a charge generating substance, and the charge generating substance is not particularly limited, and examples thereof include a phthalocyanine pigment, a polycyclic quinone pigment, an azo pigment, a perylene pigment and an indigo pigment. Pigments, quinacridone pigments, azurenium pigments, squarylium dyes, cyanine dyes, pyrylium dyes, thiopyrylium dyes, triphenylmethane dyes, styryl dyes and the like can be used, and these are formed alone or dispersed in a resin. The resin used here is styrene-
Acrylic resin, bisphenol A type polycarbonate,
Bisphenol Z type polycarbonate, polyester resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, styrene resin, polyvinyl acetate, styrene-butadiene resin, vinylidene chloride-acrylonitrile resin, vinyl chloride-vinyl acetate resin, vinyl chloride-vinyl acetate -Maleic anhydride resin, silicone resin,
Examples thereof include silicone alkyd resin, phenol formaldehyde resin, polyvinyl acetal resin, polyvinyl butyral resin and the like.

The charge-transporting layer is a layer containing a charge-transporting substance, and the charge-transporting substance is not particularly limited. For example, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives,
Triazole derivative, imidazole derivative, imidazolone derivative, imidazoline derivative, bisimidazolidine derivative, styryl compound, hydrazone compound, benzidine compound, pyrazoline derivative, stilbene compound, amine derivative, oxazolone derivative, benzothiazole derivative, benzimidazole derivative, Quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, poly-N-vinylcarbazoles, poly-1-vinylpyrenes, poly-
9-vinyl anthracenes and the like can be mentioned. It is formed by dispersing or dissolving these in a resin alone or in combination. As the resin used here, styrene-acrylic resin, bisphenol A type polycarbonate, bisphenol Z type polycarbonate, polyester resin,
Acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, styrene resin, polyvinyl acetate, styrene-butadiene resin, vinylidene chloride-acrylonitrile resin, vinyl chloride-vinyl acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin , Silicone alkyd resin, phenol formaldehyde resin, polyvinyl acetal resin, polyvinyl butyral resin and the like. The thickness of the charge transport layer is 5 to 50 μm, preferably 10 to 40 μm.

In the case of a photoreceptor layer composed of a mixture of a charge transport substance and a charge generating substance, the above charge transport substance and the charge generating substance are appropriately mixed and dispersed in the resin shown above. It is obtained by forming a layer later. in this case,
The layer thickness is from 5 to 50 μm, preferably from 10 to 40 μm.

The inorganic particles used in the layer containing the inorganic particles according to the present invention are not particularly limited, but those having a Mohs hardness of 5 or more are preferable. Specifically, oxides such as titanium oxide, silica, zirconium oxide and alumina, carbon nitride, aluminum nitride, nitrides such as silicon nitride, carbides such as silicon carbide, strontium titanate and titanate compounds such as barium titanate. And so on.

The Mohs hardness of the inorganic particles means the Mohs hardness of the substance having the material. What is Mohs hardness?
The talc is set to 1 and the diamond is set to 10, and the hardness is sequentially defined by standard materials, and the relative hardness is evaluated by the presence or absence of scratches using these standard materials.

The shape of the inorganic particles is preferably spherical. The spherical inorganic particles referred to here may be true spherical or ellipsoidal, but when expanded to a size in which the particle shape and the surface shape of the particles can be discriminated by an electron microscope or the like (diameter about 1 to 10 mm). That is, the particles have a smooth curved surface with few irregularities in the surface shape. Quantitatively,
It is preferable that the difference between the irregularities is at most 1/10 of the diameter. These inorganic particles have a number average primary particle diameter of 0.0
It is preferably 1 to 2 μm. More preferably 0.05
˜1 μm. When this particle size is large, the surface layer itself becomes brittle and the desired improvement in durability cannot be exhibited,
Further, the presence of the inorganic particles may damage the cleaning mechanism. When the particle size is small, the hardness is not improved due to the presence of the inorganic particles, and the durability is not improved.

Furthermore, the volume resistance of these inorganic particles themselves is 1
0 ⁸ or more Ωcm is preferable. If this resistance is lower than this range, the resistance of the surface is lowered, the charge retaining function is lowered, and the problem of causing image defects is induced.

Such spherical inorganic particles may be formed by chemical flame CVD (Chemical Vapor Deposi), for example.
However, among them, a method in which metallic silicon powder is put into a mixed gas for combustion to explosively burn and react is disclosed in JP-A-60-255620 and JP-A-5-193908. It is disclosed in JP-A-5-193909 and JP-A-5-193910.

The surface layer can be formed by dispersing the above-mentioned inorganic particles in a resin and coating the resin. The constituent resin is not particularly limited, but for example, styrene-acrylic resin, bisphenol A type polycarbonate, bisphenol Z type polycarbonate, polyester resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, styrene resin, Polyvinyl acetate, styrene-butadiene resin, vinylidene chloride-acrylonitrile resin, vinyl chloride-vinyl acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone alkyd resin, phenol formaldehyde resin, polyvinyl acetal resin, polyvinyl butyral resin Etc. can be mentioned.

The content of the inorganic particles in these resins is 0.1 to 200 parts, preferably 5 parts with respect to 100 parts of the resin.
~ 100 copies. If the amount is less than 0.1 part, the amount of the inorganic particles present is too small to exert the effect of improving the hardness. If the amount exceeds 200 parts, the hardness is improved.
Excessive amount of inorganic particles causes light scattering during exposure, which causes image defects.

Further, the surface layer of the present invention has a thickness of 0.2 to 10 μm.
m, preferably 0.4 to 5 μm. When this layer is thin, the effect of improving durability of the present invention is not exerted, and
When the film thickness is large, the effect of improving durability is exhibited, but image defects due to light scattering and a problem of sensitivity decrease occur.

The layer containing the inorganic particles of the present invention preferably contains a charge transporting substance. That is,
Since the specific surface layer is not formed by containing the charge transport substance, the charge is uniformly transported, and the charge distribution according to the image can be stably formed.
The content ratio of this charge transport substance in the surface layer is 30 to 300 parts, preferably 50 to 200 parts, relative to 100 parts of the resin constituting the protective layer.

Examples of resin fine particles The composition of the resin fine particles used in the inventions of claims 4 to 6 is not particularly limited. Generally, vinyl-based organic fine particles are preferable. This is because
This is because it can be easily produced by a production method such as an emulsion polymerization method or a suspension polymerization method.

Specifically, styrene / methylstyrene /
Styrene or styrene derivative such as chlorostyrene / phenylstyrene / methacrylic acid ester derivative such as methyl methacrylate / ethyl methacrylate / isobutyl methacrylate / dimethylaminoethyl methacrylate / methyl acrylate / ethyl acrylate isobutyl acrylate / acryl An acrylic acid ester derivative such as dimethylaminoethyl acid salt can be used as a material for forming the organic fine particles. These can be used alone or in combination.

Further, as materials for constituting other vinyl-based resin fine particles, olefins such as ethylene, propylene and isobutylene, halogen-based vinyls such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride, Vinyl esters such as vinyl propionate / vinyl acetate, vinyl ethers such as vinyl methyl ether / vinyl ethyl ether, vinyl ketones such as vinyl methyl ketone / vinyl ethyl ketone / vinyl hexyl ketone,
N-Vinylcarbazole / N-Vinylindole / N-
There are vinyl compounds such as vinylpyrrolidone, vinyl compounds such as vinylnaphthalene and vinylpyridine, and acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, acrylamide, and N-butylacrylamide. These vinyl monomers can also be used alone or in combination.

Structure of Inorganic Fine Particles The inorganic fine particles used in claims 1 to 6 of the present invention have a BET specific surface area of 40 to 400 m ² / g. Further, those having a number average primary particle diameter of 10 to 500 nm can be preferably used.

Various inorganic oxides, nitrides, borides and the like are preferably used as the material forming the inorganic fine particles.
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, Examples thereof include boron oxide, silicon carbide, boron carbide, titanium carbide, silicon nitride, titanium nitride and boron nitride. Further, the inorganic fine particles may be subjected to a hydrophobic treatment.
When the hydrophobic treatment is performed, it is preferable to perform the hydrophobic treatment with a so-called coupling agent such as various titanium coupling agents and silane coupling agents, and further higher fatty acids such as aluminum stearate, zinc stearate and calcium stearate. Hydrophobic treatment with a metal salt is also preferably used.

Structure of Composite Fine Particles The composite fine particles used in claims 5 and 6 of the present invention are those in which inorganic fine particles are fixed on the surface of resin fine particles.

The composite fine particles are prepared by adding inorganic fine particles to resin fine particles and mixing them. Next, after forming an ordered mixture and electrostatically adhering the inorganic fine particles to the surface of the resin fine particles, mechanical energy is applied to fix the inorganic fine particles to the surface of the resin fine particles. Here, the sticking is a sticking rate described in JP-A-5-11500, which is 2
Shows a state of 5% or more.

Structure of Developer such as Toner The toner used in the present invention contains a binder resin, a colorant, and other additives used as necessary, and its average particle size is a volume average particle size. Is usually 1 to 30 μm, preferably 5 to 20 μm. The binder resin that constitutes the toner is not particularly limited, and various conventionally known resins can be used. For example, styrene resin, acrylic resin, styrene / acrylic resin, polyester resin, etc. may be mentioned. The colorant forming the toner is not particularly limited,
Various conventionally known materials are used. Examples thereof include carbon black, nigrosine dye, aniline blue, calcoil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, and rose bengal. Examples of other additives include charge control agents such as salicylic acid derivatives and azo metal complexes. Further, when a magnetic toner is obtained, magnetic particles are added to the colored particles as an additive. As the magnetic particles, particles such as ferrite magnetite having an average primary particle diameter of 0.1 to 2.0 μm are preferably used. The addition amount of the magnetic particles is preferably 20 to 70% by weight in the colored particles.

From the viewpoint of imparting fluidity, inorganic fine particles may be added. As the inorganic fine particles, inorganic oxide particles such as silica / titania / alumina are preferable, and further,
These inorganic fine particles are preferably hydrophobized with a silane coupling agent, a titanium coupling agent, or the like.

The toner is mixed with a carrier and used as a two-component developer or, in the case of a magnetic toner, only the magnetic toner is used as a one-component developer. As a carrier constituting the two-component developer, iron
Either an uncoated carrier composed only of magnetic material particles such as ferrite or a resin coated carrier in which the surface of the magnetic material particles is coated with a resin may be used. The volume average particle diameter of the carrier is preferably 30 to 150 μm.

Structure of Cleaning Mechanism The mechanism for cleaning the toner remaining on the photosensitive member used in the present invention is not particularly limited, and a blade cleaning system, a magnetic brush cleaning system,
A known cleaning mechanism such as a fur brush cleaning method can be used. A blade cleaning method using a so-called blade is preferable as the cleaning mechanism.

As this structure, any of the structures shown in FIGS. 1 and 2 can be used. 1 and 2 show a configuration in which the cleaning blade 1 is held by the holder 3.
The number of photoconductors is 2. The angle formed by the holder and the photoconductor is 10 to 90 ° in both of FIGS. 1 and 2.
It is preferably 15 to 75 °. An elastic body such as silicone rubber or urethane rubber can be used as a material forming the cleaning blade itself. in this case,
A rubber hardness of 30 to 90 ° is preferable. Thickness is 1.5 ~
5 mm, and the length outside the holder is preferably 5 to 20 mm.
The pressure contact force with respect to the photoconductor is preferably 5 to 50 gf / cm.

[0042]

Embodiments First, embodiments of claims 1 and 2 of the present invention will be described.

Examples of Inorganic Fine Particles The charge amounts shown in Table 1 below are at room temperature and normal humidity (20 ° C./50%).
RH) A blow-off charge amount after 20 minutes of shaking by adding the spherical iron powder carrier at a mixing ratio of 1% by weight under an environment.

[0044]

[Table 1]

Colored Particle Production Example Colored Particle Production Example 1 100 parts of polyester resin, 8 parts of carbon black and 3 parts of low molecular weight polypropylene were mixed, kneaded, pulverized and classified according to a conventional method to give a volume average particle diameter of 8.9 μm. Colored particles were obtained. This was designated as "colored particle 1".

Colored Particle Production Example 2 Colored particles having a volume average particle size of 8.2 μm were obtained in the same manner as in Colored Particle Production Example 1 except that styrene-acrylic resin was used in place of the polyester resin. this,
This is “colored particle 2”.

Colored Particle Production Example 3 In the same manner as in Colored Particle Production Example 1, except that 55 parts of magnetite having a number average primary particle diameter of 0.3 μm was used in place of carbon black, the volume average particle diameter was 8.3 μm. Colored particles were obtained. This is designated as "colored particle 3".

Colored Particle Production Example 4 Colored particles having a volume average particle size of 8.1 μm were obtained in the same manner as in Colored Particle Production Example 3 except that styrene-acrylic resin was used in place of the polyester resin. this,
This is “colored particle 4”.

Preparation Example of Developer The above-mentioned fine particles were added to the above colored particles and mixed with a Henschel mixer (manufactured by Mitsui Miike Kakoki Co., Ltd.) to obtain a toner of the present invention. The amount of fine particles added is shown in Table 2 below.

Further, a ferrite carrier having a volume average particle diameter of 60 μm was mixed with these toners to prepare a developer having a toner concentration of 6% and used.

[0051]

[Table 2]

Preparation Example of Photoreceptor 30 g of polyamide resin CM-8000 (manufactured by Toray Industries, Inc.) was placed in a mixed solvent of 900 ml of methanol and 100 ml of 1-butanol and heated and dissolved at 50 ° C. This liquid is φ8
No. 0 aluminum drum, and a 0.5 μm thick intermediate layer was formed.

Next, 2 g of polyvinyl butyral resin S-REC BX-1 (manufactured by Sekisui Chemical Co., Ltd.) was dissolved in a mixed solvent of 700 ml of methyl ethyl ketone and 300 ml of cyclohexanone, and 3 g of CGM (exemplified compound G-1) was mixed therein and a sand mill was used. Dispersed for 10 hours. This solution was applied onto the intermediate layer to form a charge generation layer having a thickness of 0.3 μm. The structure of the exemplified compound G-1 is as shown in the following chemical formula 1.

[0054]

Embedded image

Next, CTM (Exemplified Compound T-1) 150
g and polycarbonate resin Iupilon Z-200 (manufactured by Mitsubishi Gas Chemical Co., Inc.) and 1,2-dichloroethane 10 g
It was dissolved in 00 ml. Using this solution, coating was performed on the charge generation layer to form a 20 μm thick charge transport layer.
The structure of the exemplified compound T-1 is shown below.

[0056]

Embedded image

Further, 50 g of CTM (exemplified compound T-1)
And polycarbonate resin Iupilon Z-200; 50g
Was dissolved in 1000 ml of 1,2-dichloroethane, and the amount of the inorganic particles shown in Table 3 below was mixed and dispersed in a sand mill for 2 hours. After drying at 60 ° C. for 60 minutes, a protective layer having a thickness of 2 μm was formed.

In this way, a photoreceptor sample comprising an intermediate layer, a charge generation layer, a charge transport layer and a protective layer as shown in Table 3 below was obtained.

[0059]

[Table 3]

The film strength of the photoconductor was measured as follows. Using a HEIDON-18 type surface property measuring instrument (manufactured by Shinto Kagaku Co., Ltd.), a vertical load of 200 g is applied to the surface of the photoconductor through a diamond needle (hemispherical with a tip radius of 0.3 mm), and the needle is 10 mm / sec. It was moved at a speed to scratch the surface of the photoreceptor. The depth of this scratch was measured using a laser microscope (manufactured by Lasertec), and the scratch depth was defined as the film strength.

Evaluation Evaluation was carried out using Konica U-Bix4155 (equipped with a urethane cleaning blade) manufactured by Konica, using the above-mentioned photoreceptor and the above-mentioned toner.

The evaluation itself was carried out at high temperature and high humidity (33 ° C./80% R
In H), a 100,000-copy actual copying test was performed using a B4 size original image (10% coverage) having solid black, halftone, and white paper portions. At this time, a blank sheet was printed every 5,000 copies, and image defects such as black spots and streaks on the image were evaluated. Also, the amount of wear was evaluated by measuring the film thickness of the photosensitive layer before and after the actual copying test. Table 4 below shows these results.

[0063]

[Table 4]

As described above, it becomes possible to maintain a copy without image defects for a long time without wearing the photoreceptor surface so much as compared with the conventional case.

Next, examples of claims 3 and 4 of the present invention will be described.

Preparation Example of Resin Fine Particles Preparation Example 1 of Resin Fine Particles 90 parts of methyl methacrylate and 10 parts of styrene were added to 300 parts of distilled water, and 5 × of redox type polymerization initiator composed of potassium persulfate and sodium thiosulfate was used as a polymerization initiator. 10 ⁻³ mol / l, 2.5 × copper sulfate as a promoter
It was added to 10 ^-5 mol / l, and it was added under nitrogen stream to 6
The reaction was carried out at 5 ° C for 2 hours. Then, after cooling, ultrafiltration and drying were performed to obtain resin fine particles having a number average primary particle diameter of 0.3 μm. This is designated as "resin fine particle 1". The Tg of the "resin fine particles 1" was 100 ° C.
The charge amount of "resin fine particles 1" was a value measured by a blow-off method in which 1% by weight was added to a spherical iron powder carrier and shaken at room temperature and normal humidity (20 ° C / 50% RH environment) for 20 minutes. Was 15 μC / g.

Resin Fine Particle Preparation Example 2 In the same manner as in Preparation Example 1, except that 0.2 part of polyvinyl alcohol was added, the number average primary particle diameter was 0.8 μm.
Resin fine particles of This is referred to as "resin fine particle 2".
The Tg of the “fine resin particles 2” is 100 ° C. and the charge amount is 14
It was C / g.

Preparation Example 3 of Resin Fine Particles In the same manner as in Preparation Example 1, except that the composition was changed to 85 parts of styrene and 15 parts of n-butyl methacrylate instead of methyl methacrylate, the number average primary particle diameter was 1.1 μm. Resin fine particles of This is designated as "resin fine particle 3". The Tg of the "resin fine particles 3" was 78 ° C, and the charge amount was -8 µC / g.

Preparation Example 4 of Resin Fine Particles Resin fine particles having a number average primary particle diameter of 1.2 μm were obtained in the same manner as in Preparation Example 1, except that 10 parts of 2-ethylhexyl acrylate was used instead of styrene. This is referred to as "resin fine particle 4". Tg of this "resin particle 4"
Was 65 ° C. and the charge amount was 18 μC / g.

Next, an example of producing comparative resin fine particles used for comparison is shown.

Comparative Resin Fine Particle Preparation Example 1 Resin particles having a number average primary particle diameter of 0.02 μm were obtained in the same manner as in Preparation Example 1, except that 0.2 part of sodium dodecylbenzenesulfonate was added. This is designated as "Comparative Resin Fine Particle 1". The “Comparative Resin Fine Particles 1” had a Tg of 100 ° C. and a charge amount of 21 μC / g.

Comparative Resin Microparticle Preparation Example 2 1.0 part of polyvinyl alcohol was added to 300 parts of distilled water, and then 1.0 part of benzoyl peroxide was added and dissolved in 75 parts of styrene and 25 parts of 2-ethylhexyl acrylate. Add solution and stir. Then at 70 ° C 6
The reaction was carried out for a period of time, followed by filtration and drying to obtain resin fine particles having a number average primary particle diameter of 3.0 μm. This is designated as “Comparative Resin Fine Particle 2”. Tg of this "Comparative Resin Fine Particles 2"
Was 57 ° C. and the charge amount was −12 μC / g.

Comparative Resin Fine Particle Preparation Example 3 In the same manner as in Comparative Resin Fine Particle Preparation Example 1, except that 75 parts of styrene and 25 parts of 2-ethylhexyl acrylate were used in place of methyl methacrylate and styrene, the number average primary particle diameter was 0. Resin fine particles of 0.07 μm were obtained.
This is designated as "Comparative Resin Fine Particle 3". The Tg of “Comparative Resin Fine Particles 3” was 59 ° C., and the charge amount was −9 μC / g.

Examples of Inorganic Fine Particles As the inorganic fine particles, those shown in Table 5 below were used.

[0075]

[Table 5]

Preparation Example of Colored Particles About this, the same ones as those used in the examples of claims 1 and 2 were used.

Preparation Example of Developer The above-mentioned fine particles were added to the above colored particles and mixed with a Henschel mixer (manufactured by Mitsui Miike Kakoki Co., Ltd.) to obtain a toner of the present invention. Table 6 below shows the addition amount of fine particles and the like.

Further, a ferrite carrier having a volume average particle diameter of 60 μm was mixed with these toners to prepare a developer having a toner concentration of 6% and used.

[0079]

[Table 6]

Preparation Example of Photoreceptor The same thing as that used in the examples of claims 1 and 2 was used.

Evaluation Evaluation was carried out using Konica U-Bix4155 (equipped with a urethane cleaning blade) manufactured by Konica, using the above-mentioned photoreceptor and the above-mentioned toner.

The evaluation itself was carried out at high temperature and high humidity (33 ° C./80% R
In H), a 100,000-copy actual copying test was performed using a B4 size original image (10% coverage) having solid black, halftone, and white paper portions. At this time, a blank sheet was printed every 5,000 copies, and image defects such as black spots and streaks on the image were evaluated. Also, the amount of wear was evaluated by measuring the film thickness of the photosensitive layer before and after the actual copying test. Table 7 below shows these results.

[0083]

[Table 7]

As described above, it becomes possible to maintain a copy having no image defect for a long time without so much wear on the surface of the photoreceptor as compared with the conventional case.

Next, examples of claims 5 and 6 of the present invention will be described.

Preparation Example of Resin Fine Particles The same thing as that used in the embodiments of claims 3 and 4 was used. In addition, the same example as that used in claims 3 and 4 was used for the preparation example of the comparative resin fine particles used for comparison.

Preparation Example of Composite Fine Particles Preparation Example “Resin fine particles 4” was used as the resin fine particles, and titanium oxide (number average primary particle diameter = 15 nm) that had been hydrophobized with octyltrimethoxysilane was used as the inorganic fine particles. . 1 part of inorganic fine particles to 100 parts by weight of resin fine particles
Add 7 parts by weight, OM Dizer (Nara Machinery Co., Ltd.)
And mixed to form an ordered mixture. Then, this ordered mixture was put into a hybridizer (manufactured by Nara Machinery Co., Ltd.) and treated to obtain composite fine particles of the present invention. This is referred to as "composite fine particle 1".

Further, resin fine particles and inorganic fine particles were used as shown in Table 8 below to prepare composite fine particles 2 to 8 and comparative composite fine particles 1 to 2 in the same manner.

[0089]

[Table 8]

The charge amounts shown in Table 8 above were added to the spherical iron powder carrier at a mixing ratio of 1% by weight under a normal temperature and normal humidity (20 ° C./50% RH) environment, and after shaking for 20 minutes. Shows the blow-off charge amount of. Thereafter, the value of the charge amount is in accordance with the measurement method conditions. As the inorganic fine particles in Table 8 above, those shown in Table 9 below were used.

[0091]

[Table 9]

Examples of Inorganic Fine Particles As the inorganic fine particles, those shown in Table 10 below were used, which are the same as those shown in Table 5 used in claims 1 to 4.

[0093]

[Table 10]

Preparation Example of Colored Particles The same particles as those used in Examples 1 to 4 were used.

Developer Preparation Example The above-mentioned fine particles were added to the above colored particles and mixed with a Henschel mixer (manufactured by Mitsui Miike Kakoki Co., Ltd.) to obtain the toner of the present invention. Table 11 below shows the addition amount of fine particles and the like.

Further, a ferrite carrier having a volume average particle diameter of 60 μm was mixed with these toners to prepare a developer having a toner concentration of 6% and used.

[0097]

[Table 11]

Preparation Example of Photoreceptor The same thing as that including Table 4 used in Examples of Claims 1 to 4 was used.

Evaluation Evaluation was carried out using Konica U-Bix4155 (equipped with a urethane cleaning blade) manufactured by Konica, using the above photoreceptor and the above toner.

The evaluation itself was carried out at high temperature and high humidity (33 ° C./80% R
In H), a 100,000-copy actual copying test was performed using a B4 size original image (10% coverage) having solid black, halftone, and white paper portions. At this time, a blank sheet was printed every 5,000 copies, and image defects such as black spots and streaks on the image were evaluated. Also, the amount of wear was evaluated by measuring the film thickness of the photosensitive layer before and after the actual copying test. Table 12 below shows these results.

[0101]

[Table 12]

As described above, it is possible to maintain a copy having no image defect for a long time without significantly depleting the surface of the photoconductor as compared with the conventional case.

[0103]

According to the image forming method of the present invention, the life until now is maintained without increasing the wear of the organic photoconductor, and the image defects which have occurred in a relatively short period until now are eliminated. As a result, it has become possible to form a stable image over a long period of time without causing image defects such as fog, black spots, and blurring.

[Brief description of drawings]

FIG. 1 is an explanatory view showing one cleaning mode of a cleaning unit.

FIG. 2 is an explanatory view showing another cleaning mode of the cleaning means.

[Explanation of symbols]

 1 Cleaning blade 2 Photoconductor 3 Holder

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Yamazaki 2970 Ishikawacho, Hachioji City, Tokyo Konica Stock Company

Claims (6)

[Claims] 1. An image forming method in which an organic electrophotographic photosensitive member having a photosensitive layer provided on a conductive support is developed with a toner obtained by adding fine particles to colored particles composed of at least a resin and a colorant. When the outermost surface layer of the photoreceptor contains spherical inorganic particles having a Mohs hardness of 5 or more and the photosensitive layer has a film strength of 200 g when a vertical load is applied using a diamond needle having a tip radius of 0.3 mm. Depth of scratch is 0.1-1μ
m is an organic electrophotographic photosensitive member, and the fine particles added to the toner have a BET specific surface area of at least 4 to 30 m ^2.
/ G of inorganic fine particles and 40 to 400 m ² / g of inorganic fine particles. 2. The number average particle diameter of the inorganic particles is 0.01 to
The image forming method according to claim 1, wherein the image forming method is 2 μm. 3. An image forming method in which an organic electrophotographic photosensitive member having a photosensitive layer provided on a conductive support is developed with a toner prepared by adding fine particles to colored particles composed of at least a resin and a colorant. When the outermost surface layer of the photoreceptor contains spherical inorganic particles having a Mohs hardness of 5 or more and the photosensitive layer has a film strength of 200 g when a vertical load is applied using a diamond needle having a tip radius of 0.3 mm. Depth of scratch is 0.1-1μ
m is an organic electrophotographic photoreceptor, and the fine particles added to the toner have at least a number average primary particle diameter of 0.1 to 2.
Resin fine particles of 0 μm and BET specific surface area of 40 to 400 m
An image forming method characterized by comprising ² / g of inorganic fine particles. 4. The number average particle diameter of the inorganic particles is from 0.01 to
The image forming method according to claim 3, wherein the image forming method is 2 μm. 5. An image forming method comprising developing on a organic electrophotographic photosensitive member having a photosensitive layer provided on a conductive support with a toner prepared by adding fine particles to colored particles composed of at least a resin and a colorant. When the outermost surface layer of the photoreceptor contains spherical inorganic particles having a Mohs hardness of 5 or more and the photosensitive layer has a film strength of 200 g when a vertical load is applied using a diamond needle having a tip radius of 0.3 mm. Depth of scratch is 0.1-1μ
m is an organic electrophotographic photoreceptor, and the fine particles added to the toner have at least a number average primary particle diameter of 0.1 to 2.
The number average primary particle size is 5 to 10 on the surface of the resin fine particles of 0 μm.
BET with composite fine particles formed by fixing 0 nm inorganic fine particles
An image forming method, which is an inorganic fine particle having a specific surface area of 40 to 400 m ² / g. 6. The number average particle diameter of the inorganic particles is from 0.01 to
The image forming method according to claim 5, wherein the thickness is 2 μm.