JPH0962159A - Method and device for electrophotographic image forming - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic image forming method and its device where the deterioration of an image caused by the wear damage of a photoreceptor in the process of repeatedly performing image forming is prevented, and image fogging, spot fault and stripe fault or the like caused by defective cleaning are prevented from occurring. SOLUTION: A stage where a toner image is transferred on transfer material after forming the toner image on the photoreceptor and residual toner on the photoreceptor after transferring is removed is repeated in this method. In this case, the uppermost surface layer of the photoreceptor 10 incorporates inorganic particles whose Mohs hardness is >=5, and the cleaning member used in a cleaning stage is made to be a rubber elastic cleaning blade 211, and the cleaning blade 211 is vibrated at the vibration level of 5-200μm, so that cleaning is performed. The volume-averaged grain sizes of the inorganic particles are made to be 0.05-2.0μm, and resilience factor of the cleaning blade at ordinary temperature is made to be 35-60%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an image using electrophotography and an apparatus used for the method.

[0002]

2. Description of the Related Art Conventionally, in an image forming method using electrophotography, as a method for cleaning residual toner on a photoconductor, a rubber elastic blade is used as a photoconductor because it is simple and has excellent cleaning characteristics. The blade cleaning method in which the cleaning is performed by bringing the cleaning member into contact with the moving direction in the counter direction is most often used.

In this system, it is said that the residual toner on the photosensitive member is cleaned by the reciprocating motion of the cleaning blade tip, that is, the vibration energy accompanying the so-called stick-slip motion.

By the way, in the image forming method using the organic photoconductor, when the cleaning is carried out by the blade cleaning method, the photoconductor surface is abraded or scratched. Against this problem, as a method of increasing the film strength on the surface of the organic photoconductor and preventing abrasion and scratches on the surface of the photoconductor due to cleaning by the blade cleaning method, relatively hard inorganic particles are used as the outermost surface layer of the organic photoconductor. There has been proposed a method of increasing the film strength by containing a compound (Japanese Patent Laid-Open No. 59-223443 and Japanese Patent Laid-Open No. 60-57).
847, JP-A-61-163345, etc.).

[0005]

However, cleaning was carried out by the blade cleaning method using a photoreceptor in which the surface strength of the organic photoreceptor was increased by incorporating inorganic particles in the outermost surface layer as described above. In this case, although the abrasion and abrasion of the surface of the organic photoconductor are certainly improved, the cleaning of the residual toner, which is the core of the photoconductor, is inadequate, often causing image fog, spot defect or streak defect.

As a result of detailed investigation of these phenomena, the present invention uses an organic photoconductor in which the outermost surface layer of the organic photoconductor contains inorganic particles having a Mohs hardness of 5 or more, and uses the blade cleaning method. The cleaning failure that occurs when cleaning the residual toner on the photoconductor is caused by the amplitude of the cleaning blade, more preferably the repulsion elasticity of the cleaning blade, the contact angle (θ) with the photoconductor, and the free length. The inventors have found that the problem can be solved by controlling (l) and the contact load, and completed the present invention.

The present invention is proposed in view of the above circumstances, and an object thereof is to prevent image fogging due to poor cleaning due to no deterioration of electrophotography due to abrasion damage of a photoconductor in the process of repeatedly forming images. An object of the present invention is to provide an image forming method and an apparatus thereof that do not cause a spot defect or a line defect.

[0008]

The above object of the present invention is to form a toner image on an organic photoconductor, transfer the toner image onto a transfer material, and clean residual toner on the photoconductor after the transfer. In the image forming method in which a large number of images are formed by repeating the above-mentioned step, the outermost surface layer of the photoreceptor contains inorganic particles having a Mohs hardness of 5 or more, and the cleaning member used in the developing step is a rubber elastic cleaning blade. , The vibration level of the cleaning blade 5
Image forming method characterized by performing cleaning by vibrating to 200 μm, organic photoreceptor, means for forming a toner image on the photoreceptor, means for transferring the toner image onto a transfer material, and residual after transfer In an image forming apparatus having a means for cleaning toner, wherein the photoreceptor and each means form a large number of images, the photoreceptor contains inorganic particles having a Mohs hardness of 5 or more in the outermost surface layer, and the cleaning is performed. The cleaning blade of the means is a rubber elastic cleaning blade, and the cleaning blade is vibrated to a size of 5 to 200 μm to vibrate to perform cleaning.

Hereinafter, the present invention will be described in detail.

In the image forming method and the image forming apparatus of the present invention, the hardness of the inorganic particles contained in the outermost surface layer of the photoreceptor is 5 or more in Mohs' hardness, and when it is less than 5, the surface of the photoreceptor is sufficiently resistant. Abrasivity cannot be imparted.

If the magnitude of the vibration of the cleaning blade is smaller than 5 μm, the energy of the vibration of the cleaning blade is insufficient and the residual toner cannot be removed from the photoconductor, resulting in poor cleaning, image fog and spot defect. Alternatively, a muscle failure or the like is likely to occur. Further, if the magnitude of the vibration is larger than 200 μm, the energy of the vibration becomes excessive, the tip of the blade bounces on the photosensitive member, and cleaning failure occurs, and horizontal line fog (black streaks) easily occurs.

The magnitude of vibration of the cleaning blade is measured as follows.

Acceleration detector NP-3 manufactured by Ono Sokki Co., Ltd.
The sensor 210 is attached to the center of the cleaning blade (at a position 3 mm from the tip), and the vibration when the photoconductor rotates at a constant speed is read by the sensor for 10 seconds.
The output data from the sensor is "ONO SOKKI
CF6400 4-channel intelligent FF analyzer ”is calculated to obtain an average value of the vibration amplitude, which is taken as the size of the blade.

In the present invention, as a preferable condition of the cleaning blade, the blade is brought into contact with the moving direction of the photoconductor in a counter direction, and the contact angle θ is 15 to 2.
The range of 5 °, the free length of the blade is 8 to 12 mm, and the contact load is 5 to 40 g / cm (see FIG. 2 described later).

As the cleaning blade used in the present invention, an elastic rubber blade is particularly preferable, and an elastic rubber blade made of polyurethane is used, and the repulsion elastic modulus at room temperature is 35 to 60%, and if it is less than 35%, the blade has a repulsive elastic modulus. Vibration energy is not sufficiently expressed and cleaning failure is likely to occur, image fog, spot defects and streak defects are likely to occur. If it is more than 60%, vibration energy tends to be excessive, the blade bounces on the photoconductor, and horizontal line fog occurs. (Black streaks) are likely to occur.

The impact resilience (%) of the rubber elastic blade is measured by the measuring method specified in JIS K7311.

The photoconductor according to the present invention includes a photoconductor having a two-layer structure in which a charge generation layer and a charge transport layer are laminated on a conductive support, and a single layer structure in which a charge generation substance and a charge transport substance are mixed. The photoconductor of, and a photoconductor in which a protective layer is further provided, and the like are included, but a photoconductor in which a plurality of charge transport layers are laminated on a charge generation layer is preferable, and the outermost surface layer of the photoconductor is preferably used. The inorganic particles are contained.

The reason why such a constitution of the photoconductor is selected is that the sensitivity is lowered and the residual charge is reduced in the photoconductor in which the protective layer contains inorganic particles as in the case of Japanese Utility Model Publication No. 55-18843. And the image quality deteriorates in the process of repeated image formation. Further, in the case of a photosensitive member containing colloidal silica fine particles in the photosensitive layer as in JP-A-5-341645, it is difficult to uniformly disperse the photosensitive layer in the photosensitive layer, and abrasion resistance and scratch resistance of the photosensitive member are difficult. Is not enough. Furthermore, in the case of a photoreceptor in which inorganic particles are contained in the entire charge transport layer as in JP-A-6-59501, the light scattering in the photosensitive layer is increased, the resolution is lowered, and image blurring easily occurs. Become. In addition, the content of inorganic particles in the entire photosensitive layer increases, and electrophotographic performance is likely to deteriorate.

Therefore, the charge transport layer is composed of a plurality of constituent layers, and the lower charge transport layer does not contain the inorganic particles.
Even if it contains a trace amount so as not to hinder the resolution and electrophotographic performance, the charge transport layer of the outermost surface layer is a photoreceptor containing inorganic fine particles necessary to ensure sufficient wear resistance. preferable.

FIG. 1 shows a typical example of a photoconductor formed by laminating a plurality of charge transport layers on the charge generation layer. In FIG. 1, 1 is a conductive support, 2 is an intermediate layer (undercoat layer), 3 is a charge generation layer, 4 is a first charge transport layer, 5 is a second charge transport layer, and the inorganic particles are Are contained in the second charge transport layer.

As the conductive support 1, a metal plate of aluminum, stainless steel, iron or the like, or a metal layer of aluminum, palladium, gold or the like is laminated or vapor-deposited on the surface of a flexible support such as paper or plastic film. It is possible to use those provided by the method described above, or those in which a layer containing a conductive compound such as a conductive polymer, indium oxide or tin oxide is applied or vapor-deposited on the surface of a flexible support such as paper or plastic film. .

As the intermediate layer 2 used as required, 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 from 0.1 to 10 μm, particularly preferably from 0.1 to 5 μm.

The charge generating layer 3 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, Indigo 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, polycarbonate resin, 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-acetic acid Vinyl-maleic anhydride resin, silicone resin,
Examples thereof include silicone alkyd resin, phenol formaldehyde resin, polyvinyl acetal resin, polyvinyl butyral resin and the like.

The thickness of the charge generation layer 3 is 0.01-10.
μm is preferred.

Next, the first charge-transporting layer 4 and the second charge-transporting layer 5 are layers containing a charge-transporting substance, and the charge-transporting substance is not particularly limited. For example, an oxazole derivative, Oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazoline derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds, benzidine compounds, pyrazoline derivatives, stilbene compounds, amine derivatives,
Oxazolone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, poly-N-vinylcarbazoles,
Examples thereof include poly-1-vinylpyrenes and poly-9-vinylanthracenes. These are formed singly or in combination and dispersed or dissolved in a resin. As the resin used here, styrene-acrylic resin, polycarbonate resin, polyester resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, styrene resin, polyvinyl acetate, styrene-butadiene resin, vinylidene chloride-acrylonitrile resin, Examples thereof include 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 first charge transport layer 4 is preferably 5 to 50 μm, more preferably 10 to 40 μm, and the thickness of the second charge transport layer 5 is preferably 0.2 to 3 μm.
It is 0 μm, more preferably 0.4 to 20 μm.

The amount of the inorganic particles having a Mohs hardness of 5 or more contained in the second charge transport layer 5 is preferably 0.01 to 100 parts by weight, more preferably 0.1 to 100 parts by weight with respect to 100 parts by weight of the binder resin. 60 parts by weight.

The inorganic particles having a Mohs hardness of 5 or more contained in the outermost surface layer of the photoconductor are preferably those which do not adversely affect the electrophotographic performance.
For example, cerium oxide, chromium oxide, aluminum oxide,
Oxides such as magnesium oxide, silicon oxide, tin oxide, zirconium oxide, iron oxide and titanium oxide; sulfates such as calcium sulfate, barium sulfate and aluminum sulfate; silicates such as calcium silicate and magnesium silicate; boron nitride, titanium Chlorides such as titanium carbide; carbides such as silicon carbide, titanium carbide, boron carbide, tungsten carbide and zirconium carbide; borides such as zirconium boride and titanium boride.
They may be used alone or in combination of two or more.

The inorganic particles according to the present invention preferably have a volume average particle diameter of 0.05 to 2.0 μm, and are preferably substantially spherical particles having a major axis / minor axis ratio of less than 2.0. is there.

If the volume average particle diameter of the inorganic particles according to the present invention is less than 0.05, sufficient mechanical strength of the surface of the photoreceptor cannot be obtained, and the surface area of the particles becomes large, so that the water absorption amount increases and the repetition In the process of image formation, the surface of the photoconductor is worn and damaged and electrophotographic performance is deteriorated. On the other hand, if it exceeds 2.0 μm, the surface roughness of the photoreceptor becomes large, the cleaning blade is worn and damaged, the cleaning characteristics are deteriorated, cleaning failure occurs, and image blurring easily occurs.

The volume average particle size of the inorganic particles is measured by a laser diffraction / scattering type particle size distribution measuring device LA-700 (manufactured by Hikiba Seisakusho).

The inorganic particles according to the present invention are treated with a coupling agent such as a silane coupling agent or a titanium coupling agent or a hydrophobic treatment agent such as a higher fatty acid or a metal salt thereof in order to make the particles hydrophobic. Preferably.

Examples of the titanium coupling agent include tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzene sulfonyl titanate, and bis (dioctyl pyrophosphate) oxyacetate titanate. Further, as the silane coupling agent, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β- (N-vinylbenzylaminoethyl) γ-aminopropyltrimethoxysilane hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltri Examples thereof include methoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane, p-methylphenyltrimethoxysilane.

The polymeric fatty acids include undecyl acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, pentadecanoic acid, stearic acid, heptadecanoic acid, arachidic acid, montanic acid, oleic acid, linoleic acid and arachidonic acid. The long-chain fatty acids of are listed as metal salts of zinc, iron, magnesium, aluminum,
Examples thereof include salts with metals such as calcium, sodium and lithium.

The inorganic particles used in the present invention are preferably coated with a theoretical amount of the hydrophobizing agent, and the theoretical amount means that a monomolecular layer of the hydrophobizing agent is formed on the surface of the inorganic particles. It is the amount required to do so and is calculated by the following formula.

Ws = (Wf × SE) / MCA (Ws: amount of silane coupling agent added (g), Wf: amount of used particles (g), SE: specific surface area of particles (m ² / g), M
CA: Minimum coating area (m ² / g) per 1 g of the silane coupling agent (numerical value determined by the treating agent).

In practice, the hydrophobic treatment agent is added to the inorganic particles in an amount of 1 to 10% by weight, and more preferably 3 to 7% by weight.

As the inorganic particles contained in the outermost surface layer of the photoreceptor used in the present invention, silica particles are particularly preferable. Among the silica particles, there are few hydrophilic groups on the particle surface, and the particles have hygroscopicity. Small ones are preferable, and those obtained by the following production method are preferable.

For example, chemical flame CVD (Chemical Flame)
Those manufactured by the Vapor Deposition method, and among them, those manufactured by introducing metallic silicon powder into a mixed gas for combustion, and burning and reacting explosively are preferable.

Details of this manufacturing method are described in, for example, JP-A-60-
255602, JP-A-5-193908, 5-1.
93909, 5-193910, 5-1939
No. 28, No. 5-196614, and No. 6-107406.

In the production method described in each of the above publications, the raw material silicon metal material is washed with high-purity water a plurality of times in advance to remove dissolved components, and heat-treated to remove gas phase components to obtain high purity. To obtain a fine powder of silicon. Next, a combustible gas such as LPG and a combustion supporting gas such as oxygen gas are introduced into a burner at the head of the manufacturing apparatus to form a fire for ignition, and the high-purity silicon powder is added to the flame for ignition. A carrier gas such as air dispersedly contained is introduced to start ignition and combustion. Then, the combustion-supporting gas is supplied in multiple stages to explosively oxidize and burn the silicon powder to obtain high-purity silica particles.

The developer used in the present invention may be either a one-component developer containing a magnetic toner as a main component or a two-component developer containing a non-magnetic toner and a magnetic carrier.

Examples of the magnetic or non-magnetic toner include carbon black, phthalocyanine blue, benzidine yellow, malachite green, and DuPont oil red in a binder resin such as styrene resin, acrylic resin, polyester, and epoxy resin, and a nigrosine dye. Particles having an average particle size of 5 to 30 μm in which a charge control agent such as the above, an offset preventing agent such as a low molecular weight polyalkylene, and a magnetic powder such as magnetite or ferrite are dispersed and contained as necessary can be used. Further, as the magnetic carrier, particles having an average particle diameter of 30 to 100 μm, which are made of a magnetic material such as magnetite or ferrite, or those whose surface is coated with a resin are used. Further, a resin carrier obtained by dispersing the fine powder of the magnetic material in a resin may be used.

In the above-mentioned one-component type developer, the magnetic toner is less than 0.
01 to 5 wt% of inorganic particles (silica, alumina, titania, etc.) are added and mixed as a fluidizing agent, and in the two-component developer, a magnetic carrier and 3 to 10 wt% of a non-magnetic toner are mixed. Further, 0.01 to
It is obtained by mixing 5 wt%.

Next, the image forming method and the image forming apparatus of the present invention will be described with reference to FIGS. FIG. 2 is a diagram showing a schematic configuration of a specific example of an image forming apparatus for carrying out the image forming method of the present invention, and FIG. 3 is a schematic diagram for explaining a cleaning unit of the present invention.

In the figure, 10 is a photoconductor drum using the organic photoconductor having the above-described structure, which rotates in the direction of the arrow, and a scorotron charger 11, an image exposure incident light 12, a developing device 13, a pre-transfer device are provided on the periphery of the photoconductor drum. A static eliminator (PTL) 14, a transfer electrode 15, a separation electrode 16, a separation claw 18, a cleaning unit 21, a pre-charge static eliminator (PCL) 22, and the like are arranged.

The photosensitive drum 10 is previously uniformly charged by the charger 11, and then imagewise exposed by the incident light 12 of the imagewise exposure to form an electrostatic latent image. One-component system or two-component system development is carried out. A toner image is formed by being developed by the developing device 13 filled with the agent, and this toner image is easily transferred by the pre-transfer charge eliminator 14, and then the timing is adjusted by the timing rollers 17 and 18 by the action of the transfer pole 15. Is transferred onto the transfer paper P that has been conveyed. The transfer paper P on which the toner image has been transferred is separated from the photoconductor surface by the action of the separation pole 16 and the separation claw 18, and is conveyed to the fixing device 20 by the conveyance belt 19 and fixed.

After the transfer, the photosensitive drum 10 is cleaned by the cleaning unit 21 and discharged by the pre-charge neutralizer 22 to prepare for the next image formation.

In the developing device 13, the developer inside the device and the toner replenished from a toner replenishing device (not shown) are sufficiently agitated and mixed by the agitating screws 131 and 132 and the agitating blade 133, and then the magnet body 135 is provided. The outer periphery is attached to a sleeve 134 that rotates in the direction of the arrow and is conveyed to the developing area, and the electrostatic latent image on the photosensitive drum 10 is contact-developed to form a toner image.

In the cleaning section 21, the toner remaining on the photosensitive drum 10 after the transfer is cleaned by the cleaning blade 211, the cleaning toner is guided by the guide roller 212, and the conveying screw 214 is guided through the guide plate 213. And is conveyed to a waste toner container (not shown) by the conveying screw.

Here, the cleaning blade 211 is
It is preferably made of a urethane rubber elastic plate having a rebound resilience of 35 to 60%, and as shown in FIG. 3, it is contacted at an acute angle in the counter direction with respect to the rotating direction of the photosensitive drum 10, and the contact angle θ is preferably 15. The angle is 25 °. Here, the contact angle θ is the cleaning blade 211 deformed by the contact.
It is not the angle between a and the tangent line X, but the angle between the tangent line X and the cleaning blade (depicted by a broken line in FIG. 3) 211b before deformation.

The supporting member 215 for supporting the cleaning blade 211 is rotatably attached to the rotating shaft 216.
The tip A of the cleaning blade 211 is brought into contact with the peripheral surface of the photoconductor drum 10 by urging the vertical portion 215a with a spring 217.

The contact load P of the cleaning blade on the photosensitive drum is preferably 10 to 40 g / cm, and this value is the pressure contact force (force applied from the cleaning blade to the photosensitive drum) P'g / cm. 3, which is the normal direction vector, and can be set by adjusting the strength of the spring 217, the cleaning blade free length 1 and the contact angle θ.

The free length l of the cleaning blade
Is the length from the end B of the support member 215 to the tip A of the cleaning blade before deformation, preferably 8 to 1
2 mm.

The above contact angle θ of the cleaning blade,
The contact load P and the free length 1 are conditions for setting the cleaning blade when the photosensitive drum is stationary, but the present invention is not necessarily limited to this range, and the point is that the cleaning blade is operating while the photosensitive drum is operating. Vibration is 5-200μ
It is an indispensable requirement that the range is m.

With the image forming method having the above constitution, electrophotographic performance is not deteriorated due to abrasion and damage of the photosensitive member in the process of repeatedly forming an image, and the cleaning property is excellent and black spots and background It is possible to stably obtain a high-quality image for a long period of time without generation of fogging or black streaks.

The image forming method of the present invention is applied to various image forming methods using electrophotography such as digital copying machines, LD printers, LED printers, liquid crystal printers, etc., other than analog copying machines, and their apparatuses. .

[0058]

【Example】

Example 1 <Production of Photoreceptor 1> 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. After cooling to room temperature, this solution is used to
mm on a 355.5 mm long aluminum drum,
An intermediate layer having a thickness of 0.5 μm was formed by dip coating.

Next, 5 g of polyvinyl butyral resin S-REC BX-1 (manufactured by Sekisui Chemical Co., Ltd.) was added to MEK100.
After dissolving in 0 ml and further mixing 10 g of the following compound G, dispersion was carried out for 20 hours using a sand mill. Using this solution, a thickness of 0.5μ is obtained by dip coating the above intermediate layer.
m charge generating layer was formed.

[0060]

Embedded image

Then, 100 g of the following compound T and 150 g of BPZ type polycarbonate resin Panlite TS-2050 (manufactured by Teijin Chemicals Ltd.) were added to 1000 ml of dichloromethane.
Dissolved in.

[0062]

Embedded image

Using this solution, a first charge transport layer having a thickness of 20 μm was formed on the charge generation layer by dip coating.

Then, 20 g of compound T and 30 g of BPZ type polycarbonate resin Panlite TS-2050 (manufactured by Teijin Kasei Co., Ltd.) were dissolved in 1000 ml of dichloromethane, and a silica particle having a hardness of 7 and an average particle size of 0.5 μm was prepared (Table 1). 9 g of the inorganic particles A1) were added and dispersed in the ultrasonic dispersion layer for 20 minutes. Using this solution, a circular amount regulating type coating machine was used to form a second layer having a thickness of 5 μm on the first charge transport layer.
Was formed.

Finally, it was heated and dried at 100 ° C. for 1 hour to prepare a photoconductor 1 in which an intermediate layer, a charge generation layer, a first charge transport layer and a second charge transport layer were laminated in this order.

The silica particles Al are hydrophobic silica coated with a theoretical amount of a silane coupling agent of trimethylsilylmethoxysilane.

<Image Evaluation Test> The photoconductor 1 was mounted on a U-BIX 4155 made by Konica, and a polyurethane rubber elastic blade having a repulsion elasticity of 58% was used as a cleaning blade. Contact angle θ is 18 °, free length 1 is 8 mm, contact load P is 20
g / cm, the magnitude of vibration to the photoconductor during rotation is 50
A film thickness loss amount and an image evaluation test were performed using the plurality of modified machines set to have a thickness of μm.

That is, using the above-mentioned modified machine at room temperature and normal humidity,
A B4 original image (coverage: 10%) having solid black, halftone, and white paper portions was used to perform a copy test 100,000 times, and the amount of wear (μm) of the film thickness of the photoconductor was measured by the following method. Table 1 shows the results.

Measurement of film thickness wear amount: The uniform film thickness portion of the photoconductor is measured at 10 points at random, and the average value is taken as the film thickness of the photoconductor. Film thickness meter EDDY 560C (HELMU
Using T FISCHER GMBHT CO) 1
The film thickness was measured after the first time and 100,000 copies, and the difference was taken as the amount of film thickness loss.

[0070]

[Table 1]

Further, the maximum image density, fog, and image defects of the copied image were evaluated by a densitometer and visually through the 100,000 copy test, and the results are shown in Table 2.

[0072]

[Table 2]

Examples 2 to 9 and Comparative Examples 1 to 4 <Preparation of Photoreceptors 2 to 6> The type of inorganic particles and the amount added to the second charge transport layer (outermost surface layer) were changed as shown in Table 1. Others were made to be the same as the photoconductor 1 to obtain photoconductors 2 to 6.

Inorganic silica particles A1, A2, alumina particles A4 and zirconium particles A5 were all hydrophobized with a silane coupling agent in the same manner as in Example 1.

<Image Evaluation Test> In the same manner as in Example 1 except that the photoconductors 2 to 6 shown in Table 1 were installed in the modified machine in the order shown in Table 2 and the blade conditions shown in Table 2 were set in the order shown in Table 2. ,
A copy test was performed 100,000 times to measure the amount of film thickness loss and evaluate the image quality of the copied image. The results are shown in Table 2.

From Table 2, in each of the examples, the amount of film thickness loss of the photoconductor is small, there is no cleaning failure, and a high image quality can be obtained, but in the comparative example, cleaning by the cleaning blade flipping, cleaning blade slippery, etc. It can be seen that black spots, black streaks, background fog, etc. are generated due to a defect or abrasion damage of the photoconductor, which is impractical.

[0077]

According to the present invention, in the process of repeatedly forming an image, there is no deterioration of an electrophotographic image due to abrasion damage of a photoconductor, and an image fog, a spot defect, a streak defect or the like due to poor cleaning does not occur. A forming method and an apparatus therefor are provided.

[Brief description of drawings]

FIG. 1 is a schematic view showing a specific example of the layer structure of an electrophotographic photosensitive member for carrying out the image forming method of the present invention.

FIG. 2 is a schematic diagram showing a specific example of an image forming apparatus of the present invention.

FIG. 3 is a schematic diagram for explaining contact conditions between a photosensitive drum and a cleaning blade in FIG.

[Description of Reference Signs] 1 conductive support 2 intermediate layer 3 charge generation layer 4 first charge transport layer 5 second charge transport layer 10 photoconductor drum 13 developing device 15 transfer electrode 16 separation electrode 21 cleaning unit 211 cleaning blade 212 guide roller 213 guide plate 214 transport screw 215 support member

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Katsumi Matsuura 2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Stock Company

Claims (5)

[Claims] 1. A large number of images are formed by repeating the steps of forming a toner image on an organic photoconductor, transferring the toner image on a transfer material, and cleaning the residual toner on the photoconductor after the transfer. In the image forming method described above, the outermost surface layer of the photoreceptor contains inorganic particles having a Mohs hardness of 5 or more, and the cleaning member used in the developing step is a rubber elastic cleaning blade, and the cleaning blade has a vibration magnitude of 5 to 5. An image forming method characterized by vibrating to 200 μm for cleaning. 2. The volume average particle diameter of the inorganic particles is 0.05.
2. The image forming method according to claim 1, wherein the image forming method is about 2.0 μm. 3. The image forming method according to claim 1, wherein the repulsion elastic modulus of the cleaning blade at room temperature is 35 to 60%. 4. The image forming method according to claim 1, wherein the cleaning blade is brought into contact with the moving direction of the photoconductor in a counter direction. 5. An organic photoreceptor, means for forming a toner image on the photoreceptor, means for transferring the toner image onto a transfer material, and means for cleaning residual toner after transfer, In an image forming apparatus for forming a large number of images by each means, the photoreceptor contains inorganic particles having a Mohs hardness of 5 or more in the outermost surface layer, and the cleaning blade of the cleaning means is a rubber elastic cleaning blade, An image forming apparatus comprising: a cleaning blade that is vibrated to a size of 5 to 200 μm for cleaning.