JP3467665B2 - Image forming method and apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method and apparatus using an electrophotographic organic photoconductor, and more specifically,
The present invention relates to an image forming method and an apparatus for stably obtaining an image with high durability and high resolution.

[0002]

2. Description of the Related Art Conventionally, in an image forming method using electrophotography, a blade cleaning method using an elastic rubber blade is most often used as a method for cleaning residual toner on a photosensitive member because of its simple means. .

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

In an image forming method using an organic photoconductor, when cleaning is performed by a blade cleaning method, not only the residual toner on the photoconductor is removed but also the surface of the photoconductor is abraded or scratched. Therefore, a method of increasing the film strength by increasing the film strength of the surface of the photoconductor and containing relatively hard inorganic particles in the outermost surface layer of the photoconductor has been proposed as a method of preventing abrasion and scratches by the cleaning blade. There is. For example, JP-A-59-223
No. 443, a photoreceptor having inorganic particles contained in a protective layer; JP-A-60-57847, a photoreceptor having colloidal silica fine particles contained in the photosensitive layer;
No. 1-163345 proposes a photoconductor in which inorganic particles such as silica particles are contained in the entire charge transport layer of a photosensitive layer including a charge generation layer and a charge transport layer.

On the other hand, in the electrophotographic industry, there is a demand for higher image quality, and therefore, the atomization of toner in the developer is being investigated. For example, JP-A-60-131551 discloses that a toner having an average particle diameter of 10 μm or less is used.

However, when the photoreceptor having the surface layer of the photoreceptor containing the inorganic particles having the Mohs hardness of 5 or more is cleaned by the blade cleaning method as described above, the abrasion and damage of the photoreceptor surface are certainly improved. Often, poor cleaning occurs, resulting in increased image fog and spot or streak failure. Particularly when the toner in the developer used for development is fine particles, the image quality is significantly deteriorated due to the cleaning failure.

[0007]

In contrast to the above problems, an object of the present invention is to provide high durability without image deterioration due to abrasion damage of the organic photoconductor in the process of repeatedly forming an image, Also, without causing cleaning failure, image fog,
An object of the present invention is to provide an image forming method and an apparatus thereof which can stably obtain an image with high resolution without a spot defect and a muscle defect.

[0008]

The above object of the present invention can be achieved by the following means.

In an image forming method of forming a large number of images by repeating the steps of charging, image exposing, developing, transferring and cleaning using an cleaning blade on an electrophotographic photosensitive member, the photosensitive member is an organic photosensitive member. In addition, by including inorganic particles having a Mohs hardness of 5 or more in the outermost surface layer thereof, the ten-point average surface roughness Rz of the organic photoreceptor is 0.05 to
1.0 μm, the volume average particle diameter of the toner contained in the developer used in the developing step is 2 to 9 μm, and the cleaning blade used in the cleaning step is brought into contact with the photoconductor in the counter direction to prevent vibration. Size 1
An image forming method characterized in that cleaning is performed by vibrating to 0 to 200 μm.

The organic photoconductor is formed by laminating a charge generation layer and a plurality of charge transport layers on a conductive support, and a charge transport layer forming the outermost surface layer of the organic photoconductor among the plurality of charge transport layers. The image forming method as described in the above item, wherein the inorganic particles are contained in.

The image forming method as described in the above item 1 or 2, wherein the repulsion elasticity of the cleaning blade at room temperature is 35 to 60%.

In an image forming apparatus having means for charging, image exposure, development, transfer, and cleaning using a cleaning blade on the outer periphery of an electrophotographic organic photoreceptor, and forming a large number of images by the means, The organic photoconductor is a photoconductor containing inorganic particles having a Mohs hardness of 5 or more in the outermost surface layer and a ten-point average surface roughness Rz of 0.05 to 1.0 μm. Particle size 2-9
The cleaning blade, which is a developer containing a toner of μm and used in the cleaning means, comes into contact with the photoconductor in the counter direction, and the magnitude of vibration is 10 to 2
An image forming apparatus characterized in that cleaning is performed by vibrating it to 00 μm.

The present invention will be described in detail below.

As a result of a detailed study of the above-mentioned problems in cleaning, the present inventors have used an organic photoreceptor having an inorganic particle having a Mohs hardness of 5 or more in the surface layer, and a developer containing a fine particle toner as a developer. The cleaning failure that occurs when the blade is used and is cleaned by the blade cleaning method is caused by the ten-point average surface roughness R of the organic photoreceptor.
It has been found that this can be solved by controlling z (μm) and the magnitude of vibration of the cleaning blade, and more preferably by controlling the repulsion elasticity of the cleaning blade, the contact angle with the organic photoconductor, the free length and the contact load. The present invention has been completed.

In the present invention, the organic photoconductor is one in which an organic compound is used as at least one of the charge-generating substance and the charge-transporting substance constituting the organic photoconductor.

In the above-mentioned items 1 and 4, when the Mohs hardness of the inorganic particles contained in the outermost surface layer of the organic photoconductor is less than 5, desired abrasion resistance can be imparted to the surface of the organic photoconductor. If the ten-point average surface roughness Rz of the organic-organic photoconductor is smaller than 0.05 μm, the cleaning blade is likely to cause the blade to be turned over, resulting in image fog. If the Rz is larger than 1.0 μm, the blade is damaged. As a result, poor cleaning occurs, and a phenomenon of the blade bouncing occurs, which easily causes a linear streak failure.

If the volume average particle diameter of the toner in the developer is smaller than 2 μm, image fog is apt to occur due to the abrasion of the toner during cleaning. On the other hand, if it is larger than 9 .mu.m, the image is distorted, the resolution is lowered and a sharp image cannot be obtained.

The volume average particle diameter of the toner in the developer is measured by a Coulter counter manufactured by Coulter.

If the magnitude of vibration of the cleaning blade is less than 10 μm, the vibration energy of the cleaning blade is small and the toner cannot be removed from the organic photoconductor, resulting in image fog, streak failure, and spot failure. easy. On the other hand, if it is larger than 200 μm, the vibration energy of the blade is large and the blade bounces on the organic photosensitive member, resulting in poor cleaning and horizontal line fog (black streaks).

The magnitude of vibration of the cleaning blade was measured as follows. The sensor of the acceleration detector NP-3210 manufactured by Ono Sokki Co., Ltd. was attached to the center of the cleaning blade (3 mm from the tip), and the vibration of the organic photoconductor when it rotated at a constant speed was measured by the sensor.
Read for 2 seconds, output data from the sensor is "ON"
O SOKKI CF6400 4-channel intelligent FF analyzer ”is calculated to obtain an average value of the vibration amplitude, which is taken as the magnitude of the vibration of the cleaning 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 organic photoreceptor in a counter direction, and the contact angle θ is an acute angle in the range of 15 to 25 °. Contact load is 10-40g /
cm, the free length of the blade is 8 to 12 mm (see below,
Further, the cleaning blade used in the present invention is preferably a polyurethane elastic blade, and its repulsion elastic modulus is 35 to 60% at room temperature. When the impact resilience is less than 35%, the energy of vibration of the blade is insufficient and the cleaning effect is not exhibited, resulting in poor cleaning and easily causing image fog, spot defect, or streak defect. When the repulsion elastic modulus is more than 60%, the vibration energy becomes excessive and the blade bounces on the organic photoconductor, which easily causes horizontal line fog (black streak).

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

[Structure of Organic Photoreceptor] The organic photoreceptor according to the present invention includes an organic photoreceptor having a two-layer structure in which a charge generating layer and a charge transport layer are laminated on a conductive support, a charge generating substance and a charge. A single-layered organic photoconductor in which a transport substance is mixed, and an organic photoconductor in which a protective layer is further provided, and the like are included, but preferably, an organic organic film in which a plurality of charge transport layers are laminated on a charge generation layer. A photoreceptor is desirable, and the inorganic particles are contained in the outermost surface layer of the organic photoreceptor.

The reason why such a constitution of the organic photoconductor is selected is that the sensitivity is lowered in the photoconductor in which the protective layer contains inorganic particles as in the case of the above-mentioned JP-A-59-223443. The residual charge rises, and the image quality deteriorates in the process of repeated image formation. Further, the above-mentioned JP-A-60-57.
In the case of a photoconductor in which colloidal silica fine particles are contained in the photoconductive layer as in the case of No. 847, it is difficult to uniformly disperse it in the photoconductive layer, and it cannot be said that the photoconductor has sufficient abrasion resistance and scratch resistance. Furthermore, in the case of a photoreceptor in which inorganic particles are contained in the entire charge transport layer as in JP-A-61-163345, light scattering in the photosensitive layer is increased, and a blurred image with reduced resolution is obtained. .

On the other hand, in the organic photoreceptor in which a plurality of charge transport layers are provided on the charge generation layer and the uppermost charge transport layer contains inorganic particles, all of the above problems are cleared, and the repeating process is repeated. This is because high image quality can be obtained stably.

FIG. 1 shows a typical example of an organic photoconductor formed by laminating a plurality of charge transport layers on the charge generation layer. 1 in the figure
Is a conductive support, 2 is an intermediate 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 contained in the second charge transport layer. It

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 0.1 to 10 μm, particularly preferably 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 phthalocyanine pigments, polycyclic quinone pigments, azo pigments, perylene pigments, 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.

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. Diazole derivative, thiazole derivative, thiadiazole derivative, triazole derivative, imidazole derivative, imidazolone derivative, imidazoline derivative, bisimidazolidine derivative, styryl compound, hydrazone compound, benzidine compound, pyrazoline derivative, stilbene compound, amine derivative,
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. It is formed by dispersing or dissolving these in a resin alone or in combination. 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 5 to 50 μm.
m, preferably 10 to 40 μm, and the thickness of the second charge transport layer 5 is 0.2 to 30 μm, preferably 0.4 to 2
It is 0 μm.

The amount of the inorganic particles contained in the second charge transport layer 5 is 0.01 to 100 parts by weight of the binder resin.
It is 50 parts by weight, preferably 0.1 to 60 parts by weight.

The inorganic particles contained in the outermost surface layer of the organic photoreceptor are hard inorganic fine particles having a Mohs hardness of 5 or more, and do not adversely affect electrophotographic performance. Examples of such inorganic particles include oxides such as cerium oxide, chromium oxide, aluminum oxide, magnesium oxide, silicon oxide, tin oxide, zirconium oxide, iron oxide, and titanium oxide; calcium sulfate, barium sulfate, aluminum sulfate, and the like. Sulfates; silicates such as calcium silicate and magnesium silicate; nitrides such as boron nitride and titanium nitride; silicon carbide, titanium carbide, boron carbide,
Carbides such as tungsten carbide and zirconium carbide; borides such as zirconium boride and titanium boride may be mentioned, and one or more of these may be used in combination.

The inorganic particles have a volume average particle size of 0.05-2.
The particles are substantially spherical and have a major axis / minor axis ratio of less than 2.0. The volume average particle size of the inorganic particles is 0.
If it is less than 05, sufficient mechanical strength of the surface of the organic photoconductor cannot be obtained, and the surface area of the particles becomes large, so that the amount of water absorption increases, and the surface of the organic photoconductor is worn and damaged during repeated image formation. Electrophotographic performance deteriorates. On the other hand, if it exceeds 2.0 μm, the surface roughness of the organic 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 particle size distribution measuring device LA-700 (manufactured by Horiba Ltd.). Further, the inorganic particles are preferably 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. .

Titanium coupling agents include tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzene sulfonyl titanate, bis (dioctyl pyrophosphate) oxyacetate titanate and the like. 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 Methoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane,
Examples thereof include o-methylphenyltrimethoxysilane and p-methylphenyltrimethoxysilane.

The fatty acids and metal salts thereof 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, long-chain fatty acids such as arachidonic acid and the like, metal salts thereof, zinc, iron, magnesium, aluminum, calcium, Examples thereof include salts with metals such as 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 is necessary to form a monomolecular layer of the hydrophobizing agent on the surface of the inorganic particles. It is the amount and is calculated by the following formula.

[0039]

[Equation 1]

Ws: amount of silane coupling agent added (g), Wf: amount of particles used (g), SE: specific surface area of particles (m ² / g), MCA: minimum coating area (m) per 1 g of silane coupling agent ² / g) In practice, 1 to 10% by weight of the hydrophobizing agent is added to the inorganic particles for coating, and more preferably 3 to 7% by weight is added for coating.

As the inorganic particles contained in the outermost surface layer of the organic photoconductor used in the present invention, silica particles are particularly preferable. Among the silica particles, there are few hydrophilic groups on the surface of the particles, 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)
It is produced by the Vapor Deposition method, but among them, it is preferable to introduce the metal silicon powder into a mixed gas for combustion and to explosively combust and react.

Details of this manufacturing method are described in, for example, JP-A-60-2.
55602, JP-A-5-193908 and 5-19.
No. 3909, No. 5-193910, No. 5-19392
No. 8, No. 5-196614, and No. 6-107406.

In the manufacturing 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 treatment is performed to remove gas phase components and increase the temperature. A fine silicon powder is obtained. Next, a combustible gas such as LPG and a supporting gas such as oxygen gas are introduced into a burner at the head of the manufacturing apparatus to form a flame 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. After that, the combustion-supporting gas is supplied in multiple stages to explosively oxidize and burn the silicon powder to obtain high-purity silica particles.

[Developer] 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. . The magnetic or non-magnetic toner, carbon black in the binder resin such as styrene resin, acrylic resin, polyester, epoxy resin, phthalocyanine blue, benzidine yellow, malachite green, colorant such as DuPont oil red, charged with nigrosine dye etc. A particle having an average particle size of 5 to 30 μm is obtained by dispersing and containing a control agent, an offset preventive agent such as low molecular weight polyalkylene, and magnetic powder such as magnetite and ferrite, if necessary. As the magnetic carrier, an average particle size of 30 to 30 made of a magnetic material such as magnetite or ferrite is used.
100 μm particles or those having a resin coating on the surface are used. Further, a resin carrier formed by dispersing 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.
Obtained by adding and mixing 01 to 5 wt% of inorganic particles (silica, alumina, titania, etc.) as a fluidizing agent. In the two-component developer, 3 to 10 wt% of a non-magnetic toner is mixed with a magnetic carrier. In addition, the fluidizing agent is added to 0.0
It is obtained by mixing 1 to 5 wt%.

[Image Forming Method] FIG. 2 is a schematic configuration diagram for explaining the image forming method of the present invention. In FIG.
Reference numeral 0 denotes, for example, the organic photosensitive drum shown in FIG. 1, which rotates in the direction of the arrow, and 11 denotes a charger for uniformly charging the organic photosensitive drum, such as a corona discharge charger, a roller charger, or a magnet. It may be a brush charger. Reference numeral 12 is an analog image exposure or a digital image exposure using an LED, an LBD or the like, and an electrostatic latent image is formed on the organic photoconductor by the image exposure. This electrostatic latent image is developed in a contact or non-contact manner by a developing device 13 containing a one-component or two-component developer to form a toner image on the organic photoconductor, and the toner image is adjusted in timing. Transfer device (transfer device by corona discharge or roller transfer device) on the transferred transfer agent P
It is electrostatically transferred by 14, is separated by the separation electrode 15, and is conveyed and fixed to the fixing device 17 by the conveying means 16.

The surface of the organic photoconductor after the transfer is destaticized by the destaticizer 18, and then the cleaning blade 1 according to the present invention.
The organic photoconductor 10 is abutted against the organic photoconductor 10 in a counter direction for cleaning, and then the charge is removed by the charge removal lamp 20 to prepare for the next image formation.

The cleaning blade 19 is made of a urethane rubber elastic plate having a repulsion elasticity of 35 to 60% as described above. FIG. 3 is an explanatory view of the cleaning mechanism. As shown in FIG. 3, the cleaning mechanism is brought into contact with the organic photoconductor drum 10 in the counter direction, and when the organic photoconductor drum rotates in the arrow direction, the coefficient of friction is changed according to the mutual friction coefficient. Although it moves to the dotted line 19a, the repulsive elasticity of the blade causes a step slip to the dotted line 19b, and the step slip causes the toner 19c to slip.
Are removed from the drum surface and cleaned.

In the present invention, when the step slip is performed, the magnitude of vibration K ₁ based on the measurement method is 10 to 20.
It is set to 0 μm. In the measuring method, as shown in FIG. 3, the blade vibration acceleration is read by the piezo sensor 30 set at a position of about 3 mm from the blade tip, and the obtained acceleration signal is input to the calculator 31 to be processed to perform the blade calculation. The amplitude of the vibration (amplitude of the blade at the sensor set position) K ₂ μm is output. By comparing this data with the proper value K ₁ , it is determined whether the blade condition is suitable or not. If not,
The blade conversion or blade contact load Pg / cm, contact angle θ, free length 1 mm, etc. are corrected to perform image formation under appropriate conditions.

In the present invention, the contact load P of the cleaning blade on the organic photoreceptor, the contact angle θ, and the free length 1 are preferably P = 15 to 20 g / cm and θ = 1.
5 to 25 °, and l = 8 to 12 mm.

FIG. 4 is an explanatory view of the cleaning mechanism. The free length 1 represents the length from the end B of the support member 191 to the tip of the blade before deformation as shown in FIG. The contact load P is a vector value in the normal direction of the pressure contact force P'when the blade 19 is brought into contact with the organic photosensitive drum 10. The contact angle θ represents the angle between the tangent line X and the blade before deformation (shown by the dotted line in the drawing) at the contact point A of the organic photoreceptor.

[0053]

【Example】

(Example 1) <Production of Organic Photoreceptor 1> Polyamide resin "CM-800"
0 "(manufactured by Toray Industries, Inc.) 30 g of methanol 900 ml
And 1-butanol 100ml in a mixed solvent,
It melt | dissolved by heating at 50 degreeC. After cooling to room temperature, this solution was used to form an intermediate layer having a thickness of 0.5 μm by dip coating on an aluminum drum having an outer diameter of 80 mmφ and a length of 355.5 mm.

Next, 5 g of polyvinyl butyral resin S-REC BX-1 (manufactured by Sekisui Chemical Co., Ltd.) was dissolved in 1000 ml of methyl ethyl ketone, and further mixed with 10 g of the charge generating substance G1 having the following structure, followed by dispersion with a sand mill for 20 hours. I went. This solution was applied onto the intermediate layer by dip coating to form a 0.5 μm thick charge generation layer.

Then, a charge transport material T 10 having the following structure
0 g and 100 g of BPZ type polycarbonate resin "Panlite TS-2050" (manufactured by Teijin Chemicals Ltd.) as binder resin B1 were dissolved in 1000 ml of dichloromethane. Using this solution, a first charge transport layer having a thickness of 20 μm was formed on the charge generation layer using a circular amount regulation type coating machine.

[0056]

[Chemical 1]

Then, 20 g of the charge transport material T and B
PZ type polycarbonate resin Panlite TS-2050
30 g (manufactured by Teijin Chemicals Ltd.) of dichloromethane 100
A liquid dissolved in 0 ml has a hardness of 7 and a volume average particle diameter of 0.5 μ.
9 g of silica particles of m (inorganic particles A1 in Table 1),
It was dispersed for 20 minutes in an ultrasonic dispersion tank. Using this solution, a second charge-transporting layer having a thickness of 5 μm was formed on the first charge-transporting layer using the same circular amount regulating coating machine.

Finally, an organic photoreceptor 1 was obtained by heating and drying at 100 ° C. for 1 hour, and laminating an intermediate layer, a charge generating layer, a first charge transporting layer and a second charge transporting layer in this order.

<Preparation of Organic Photoreceptors 2-5> Organic Photoreceptor 1
In the same manner as the organic photoreceptor 1, except that the inorganic particles A2 to A5 in Table 1 were changed in place of the inorganic particles A1 and the addition amount to the binder resin was changed as shown in Table 1.
Got 5.

Each of the inorganic particles A1 to A5 is coated with a theoretical amount of trimethylsilylmethoxysilane to be hydrophobized.

<Production of Organic Photoreceptor 6> An organic photoreceptor 6 was obtained in the same manner as the organic photoreceptor 1 except that the inorganic particles A1 of the organic photoreceptor 1 were removed.

The ten-point average plane roughness Rz (μm) of the organic photoconductors 1 to 6 obtained as described above was measured, and the results are shown in Table 1. The surface roughness Rz is Jis B0601.
(Reference length 0.25 mm) and is measured by the surface roughness measurement amount (SE-30H) of Kosaka Laboratory.

[0063]

[Table 1]

<Preparation of Developer 1> Carbon black 1 was added to 100 parts by weight of a polyester resin as a binder resin.
0 parts by weight and low molecular weight polypropylene (Mn = 250
0) 3 parts by weight are mixed, melted, kneaded, pulverized and classified to obtain colored particles having a volume average particle diameter of 5 μm.
A part of hydrophobic silica "Aerosil R-972" (manufactured by Nippon Aerosil Co., Ltd.) was externally added to obtain a toner. 5 parts by weight of the toner and 95 parts by weight of a carrier obtained by coating ferrite particles having a volume average particle diameter of 80 μm with a fluororesin made of a copolymer of 2,2,2-trifluoroethyl methacrylate and styrene (1: 1). A developer 1 was obtained by mixing.

<Production of Developers 2 to 5> The volume average particle diameter of the toner of Developer 1 is 8 μm, 3 μm, 10 μm and 1 μm.
Developers 2 to 5 were obtained in the same manner as the developer 1 except that.

<Image Evaluation> Organic Photoreceptors 1 to 6, Developer 1
~ 5 and 1-3 different urethane rubber cleaning blades with different impact resilience (Konic)
aU-BIX4155 was installed in the order shown in Table 2, and the blade conditions of the cleaning blade (contact angle to organic photoconductor drum, contact load, free length and magnitude of vibration of blade) were used. A change was made as shown in Table 2 and a live-action test of 100,000 copies was conducted.

Note that the above-mentioned real-life test was conducted at room temperature and normal humidity under the condition of solid black, halftone, and B4 original image with a blank portion (coverage 1
0%) to reduce the thickness loss of the organic photoreceptor (μ
m), the number of image resolving power / mm, and the quality of cleaning were evaluated, and the results are shown in Table 2.

The measurement of the amount of film thickness loss was 10
Film thickness measuring device "EDDY 560C" (HELMUT FISCH)
ERGMBHT CO.), And the amount of film thickness loss was obtained from the difference in the average value of the film thicknesses.

For the measurement of the resolution R, a chart of the resolution of 1 line / mm to 10 lines / mm was copied, the resolution was visually judged, and the results are shown in Table 2.

[0070]

[Table 2]

From the results shown in Table 2, 10 according to the present invention.
The amount of film thickness consumption at the time of 10,000 copies is small, and the resolution is good,
Moreover, it can be seen that there are few failures and the cleaning property is good.

[0072]

As is apparent from the above description, according to the image forming method and apparatus of the present invention, abrasion damage of the organic photoreceptor is reduced during repeated image formation, and therefore electrophotographic performance is not deteriorated. Even when it is developed using a developer containing fine particle toner, the cleaning property is excellent, and it is possible to obtain a stable image with high resolution without causing fog, spot defect, streak defect, and the like.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a structure of an organic photoreceptor in which a plurality of charge transport layers according to the present invention are laminated.

FIG. 2 is a schematic configuration diagram illustrating an image forming method of the present invention.

FIG. 3 is an explanatory view of a cleaning mechanism.

FIG. 4 is an explanatory diagram of a cleaning mechanism.

[Explanation of symbols]

1 Conductive support 2 Middle class 3 Charge generation layer 4 First charge transport layer 5 Second charge transport layer 10 Organic photoconductor drum 11 charger 12 image exposure 13 Developer 14 Transfer device 15 Separated electrode 16 Transport means 18 Static eliminator 19 cleaning blade 20 Static elimination lamp 30 piezo sensor 31 arithmetic unit p Transfer material l Free length P contact load

Continuation of the front page (56) Reference JP-A-6-130711 (JP, A) JP-A-3-172856 (JP, A) JP-A-1-295290 (JP, A) JP-A-62-100765 (JP , A) JP 5-142792 (JP, A) JP 6-138687 (JP, A) JP 59-223443 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB) Name) G03G 21/00 G03G 21/10-21/12

Claims (4)

(57) [Claims] 1. An image forming method for forming a large number of images by repeating the steps of charging, imagewise exposing, developing, transferring and cleaning a electrophotographic photosensitive member using a cleaning blade, wherein the photosensitive member is an organic material. It is a photoconductor, and the outermost surface layer thereof contains inorganic particles having a Mohs hardness of 5 or more, and the ten-point average surface roughness Rz of the organic photoconductor is 0.05 to
1.0 μm, the volume average particle diameter of the toner contained in the developer used in the developing step is 2 to 9 μm, and the cleaning blade used in the cleaning step is brought into contact with the photoconductor in the counter direction to prevent vibration. Size 1
An image forming method characterized in that cleaning is performed by vibrating to 0 to 200 μm. 2. The organic photoconductor is formed by laminating a charge generation layer and a plurality of charge transport layers on a conductive support, and the charges forming the outermost surface layer of the organic photoconductor among the plurality of charge transport layers. The image forming method according to claim 1, wherein the transport layer contains the inorganic particles. 3. The image forming method according to claim 1, wherein the impact resilience of the cleaning blade at room temperature is 35 to 60%. 4. An image forming apparatus comprising an electrophotographic organic photoconductor on the outer periphery of which means for charging, image exposure, development, transfer and cleaning using a cleaning blade, and which forms a large number of images by each means. The organic photoreceptor contains inorganic particles having a Mohs hardness of 5 or more in the outermost surface layer and has a ten-point average surface roughness Rz of 0.05 to 1.0 μm, and the developer used in the developing means is Volume average particle size 2-9
The cleaning blade, which is a developer containing a toner of μm and used in the cleaning means, comes into contact with the photoconductor in the counter direction, and the magnitude of vibration is 10 to 2
An image forming apparatus characterized in that cleaning is performed by vibrating it to 00 μm.