JPH10222008A - Method and device for image forming - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form the image of excellent quality by eliminating inconvenience caused by damages and wear or the like produced on the surface of an electrophotographic photoreceptor and preventing image-flowing or the like caused by the foreign matter of paper power or the like produced from transfer paper and an electric discharge product material or the oxidation of the surface of the photoreceptor by providing grinding and cleaning process in an image forming cycle. SOLUTION: By the image forming cycle, an electrostatic latent image is formed by an electrifying means 2 and latent image writing light 3, and next a toner image is formed by a toner image developing means 4 and the toner image is transferred on a medium 6 to be recorded by a transferring means 5. A roll-like grinding/cleaning means 9 is separated from the electrophotographic photoreceptor 1 during the image forming cycle, and the image forming cycle is interrupted before image defect occurs because of the accumulation of the damage and grinding of the surface of the photoreceptor 1 equal to or above a specified amount and the grinding/cleaning means 9 is automatically brought into contact with the photoreceptor 1, and grinds the surface of the photoreceptor 1 while rotating and also the foreign matter is removed. After this process, operation is returned to the image forming cycle after sticking particulates on the photoreceptor 1 by a particulate imparting means 8.

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 using an electrophotographic method and an apparatus therefor.

[0002]

2. Description of the Related Art FIG. 7 is a conceptual view of a general electrophotographic image forming apparatus represented by a copying machine or a laser printer. Around the electrophotographic photosensitive member 1, charging means 2, latent image writing light 3, toner image developing means 4, transfer and transfer 5, and cleaning means 7 are provided. After the toner is uniformly charged with the toner image, a latent image writing light 3 forms an electrostatic latent image, a toner image developing unit 4 forms a toner image, and the transfer unit 5 transfers the toner image to a recording medium 6 such as paper. Transcribed above. After the transfer, the toner remaining on the electrophotographic photosensitive member 1 is removed and collected by the cleaning unit 7. In this image forming apparatus, the surface of the electrophotographic photosensitive member is strongly rubbed by the cleaning device. As a result, the photoreceptor is worn and damaged as the use of the photoreceptor progresses, so that the life is significantly limited.

In order to avoid the above problem, a cleaner-less system typified by a simultaneous-development cleaning system has been proposed (JP-A-59-133573). FIG.
FIG. 2 is a conceptual diagram of an electrophotographic image forming apparatus employing a simultaneous development and cleaning method. The electrophotographic photosensitive member 1 is uniformly charged by the charging means 2, forms an electrostatic latent image with the latent image writing light 3, forms a toner image with the toner image developing means 4, and transfers the toner image to the transfer means. 5, the image is transferred onto a recording medium 6 such as paper. After the transfer, the toner remaining on the electrophotographic photoreceptor 1 is uniformly charged by the charging means 2, and the toner on the non-image portion which has not been exposed in the developing step is collected in the developing means 4 by electrostatic attraction. Is done.

Further, a cleanerless system has been proposed in which fine particles are adhered to an electrophotographic photoreceptor so that the transfer efficiency of toner is almost 100%, and a cleaning step is omitted (Japanese Patent Application Laid-Open No. 2-157766). However, these cleanerless methods cannot reliably remove deposits on the electrophotographic photoreceptor other than untransferred toner, such as discharge products and paper dust. Problems such as image flow due to the kimono occur. Also, if the electrophotographic photoreceptor, especially the organic photoreceptor is used for a long time without polishing,
It has been found that the surface layer of the electrophotographic photosensitive member is oxidized by a discharge product or the like, and image quality defects such as image deletion easily occur.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention solves the above-mentioned problems and eliminates inconvenience such as scratches and abrasion generated on the surface of an electrophotographic photosensitive member and removes foreign matter such as paper dust generated from transfer paper. It is an object of the present invention to provide an image forming method and an image forming apparatus capable of preventing an image flow caused by oxidation of the surface of an electrophotographic photoreceptor and preventing image flow caused by oxidation of a surface of an electrophotographic photosensitive member.

[0006]

Means for Solving the Problems The present inventors formed a toner image after depositing fine particles on an electrophotographic photoreceptor so that the transfer efficiency of the toner was almost 100% (image forming cycle). During the image forming cycle, a polishing and cleaning process is performed to remove deposits on the electrophotographic photoreceptor and oxidized portions of the electrophotographic photoreceptor surface without constantly contacting the cleaning blade with the photoreceptor. It has been found that the above-mentioned problem can be solved by providing the device periodically or irregularly. The configuration of the present invention is as follows.

(1) After forming a latent image on an electrophotographic photosensitive member,
In an image forming method for forming a toner image using a developer, a step of adhering fine particles before a step of forming a toner image is provided, and the photoconductor is deteriorated in accordance with deterioration of the photoconductor in a process of repeating an image forming cycle. An image forming method comprising a step of polishing and cleaning a surface.

(2) The image forming method according to the above (1), wherein the photoconductor is an organic photoconductor.

(3) An oxidation potential of 0.7 Vv is applied to the photosensitive member.
The image forming method according to the above (1) or (2), further comprising a charge transporting material having sSCE or more.

(4) The image forming method according to the above (3), wherein the charge transporting material is a triarylamine compound represented by the following general formula (1).

[0011]

Embedded image

(Wherein, R ₁ represents a hydrogen atom or a methyl group, k represents 1 or 2. In addition, Ar ₁ and Ar ₂
Represents a substituted or unsubstituted aryl group, and the substituent is a hydrogen atom, a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a substituted amino group, preferably a general formula -NR ₂ (R is an alkyl group having 1 to 4 carbon atoms) selected from the group of amino groups. )

(5) The image forming method according to the above (3) or (4), wherein the antioxidant comprises a hindered phenol compound or a hindered amine compound.

(6) The polishing and cleaning step is provided at a rate of once in ten to one in 10,000 of the image forming cycle.
Item.

(7) In an image forming apparatus provided with a charging unit, an exposing unit, a developing unit, a transferring unit, and a cleaning unit around an electrophotographic photosensitive member, a fine particle attaching unit is provided before the developing unit. An image forming apparatus, comprising: a polishing means for cleaning and cleaning a surface of a photoreceptor provided with a contact / separation means for the photoreceptor at a subsequent stage of the cleaning means.

(8) The image forming apparatus according to the above (7), wherein a polishing apparatus in the form of a roll, brush, film, or pad is used as the polishing and cleaning means.

(9) The above (7) or wherein the polishing and cleaning means is provided with a cleaning means using a liquid detergent.
(8) The image forming apparatus as described in (8).

(10) An intermediate transfer member is provided between the photosensitive member and the transfer means, and means for controlling the rotation speed of the photosensitive member and the intermediate transfer member are provided. (7) The image forming apparatus according to the above (7), wherein a peripheral speed difference between the image forming member and the intermediate transfer member is provided.

(11) There is provided means for detecting scratches and abrasion on the surface of the photoreceptor, and the polishing and cleaning means are operated by a signal from the detecting means.
The image forming apparatus according to any one of (1) to (10).

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, when a toner image is formed using an electrophotographic photoreceptor, fine particles are adhered prior to the formation of the toner image, so that the toner transfer efficiency is almost 100%.
In addition, the surface of the photoreceptor is polished and cleaned in accordance with the deterioration of the photoreceptor with time, and a high-quality image can be formed over a long period of time.

The frequency of the polishing and cleaning is suitably from once in ten to one in 10,000 of the image forming cycle, and the deterioration of the photoreceptor is detected to operate the polishing and cleaning means. You can also do so. If the frequency of polishing and cleaning is more than the above range, it will not be possible to escape from the limitation of the life of the electrophotographic photosensitive member due to abrasion and scratch, while if the frequency of polishing and cleaning is less than the above range, electrophotography The influence of image noise such as image flow due to discharge products and paper dust attached to the surface of the photoreceptor increases.

Further, when the surface of the electrophotographic photosensitive member is oxidized, image defects such as image deletion easily occur. Therefore, in the present invention, the oxidation potential of the electrophotographic photosensitive member surface layer is 0.7 V vs. SCE or more. By using a charge transporting material, preferably an electrophotographic photoreceptor containing a triarylamine compound represented by the above general formula (1), oxidation of the photoreceptor surface is suppressed, and the polishing rate is reduced. Therefore, the life of the electrophotographic photosensitive member can be further extended. Further, when the electrophotographic photoreceptor contains a hindered phenol compound or a hindered amine compound as an antioxidant, the above effect can be further improved.

FIG. 1 is a conceptual diagram showing a configuration example of the image forming apparatus of the present invention. In the image forming cycle, an electrostatic latent image is formed by the charging unit 2 and the latent image writing light 3, and then,
A toner image is formed by the toner image developing means 4. This toner image is transferred onto the recording medium 6 by the transfer means 5. The roll-like polishing and cleaning means 9 is separated from the electrophotographic photosensitive member 1 during the image forming cycle, and the surface of the electrophotographic photosensitive member 1 is scratched or polished more than a certain amount, and the image is formed before an image defect occurs. The forming cycle is interrupted, and the roll-shaped polishing and cleaning means 9 is automatically brought into contact with the electrophotographic photosensitive member 1 to polish the surface of the electrophotographic photosensitive member 1 while rotating, and remove foreign matters. After the polishing and cleaning steps, fine particles are attached to the electrophotographic photoreceptor 11 by the fine particle applying means 8 to improve transferability, and then the process returns to the above-described image forming cycle.

FIG. 2 is a conceptual view showing another example of the structure of the image forming apparatus of the present invention. In the image forming apparatus of FIG. , A cleaning means 10. This apparatus does not have the fine particle applying means shown in FIG. 1, and the fine particles are added in advance to the developer.
Given above.

FIG. 3 is a conceptual view showing another example of the structure of the image forming apparatus of the present invention. In the image forming apparatus shown in FIG. The other structure is the same as that of FIG.

FIG. 4 is a conceptual diagram showing still another example of the structure of the image forming apparatus of the present invention. In the image forming apparatus of FIG. A polishing and cleaning means 12 in the form of a pad impregnated is provided, and the other structure is the same as that of FIG.

FIG. 5 is a conceptual diagram showing another example of the configuration of the image forming apparatus of the present invention. The image forming cycle is
An electrostatic latent image is formed by the charging unit 2 and the latent image writing light 3, and then a toner image is formed by the toner image developing unit 4. After the toner image is transferred to the intermediate transfer body 13,
The image is transferred onto the recording medium 6 by the transfer unit 5. The image forming cycle is interrupted before the image defect occurs, and the rubbing is performed by changing the peripheral speed ratio between the electrophotographic photosensitive member 1 and the intermediate transfer member 13, where the scratches and the polishing on the surface of the electrophotographic photosensitive member 1 accumulate over a certain amount. As a result, the surface of the electrophotographic photosensitive member 1 is polished and foreign matters are removed. After the polishing and cleaning steps, fine particles are attached to the electrophotographic photoreceptor 11 by the fine particle applying means 8 to improve transferability, and then the process returns to the above-described image forming cycle.

FIG. 6 is a schematic view showing a cross section of an electrophotographic photosensitive member used in the image forming apparatus of the present invention. An undercoat layer 15 is applied on the conductive support layer 14, and a charge generation layer 16 and a charge transport layer 17 are formed thereon.

Examples of the conductive support used in the photoreceptor of the present invention include a metal drum or sheet such as aluminum, copper, and stainless steel, a plastic film or paper laminated with a metal foil such as aluminum, and the like. And those obtained by vapor-depositing a metal, and further, those obtained by applying a resin layer in which conductive particles are dispersed on a metal or resin drum. If necessary, the surface of the conductive support may be subjected to a surface roughening treatment for preventing interference fringes.

The undercoat layer used in the photoreceptor of the present invention is provided as necessary to improve the adhesion between the conductive support and the photosensitive layer and to prevent coating defects of the photosensitive layer. Materials for forming the undercoat layer include thermoplastic resins such as polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl methyl ether, polyamide, thermoplastic polyester, phenoxy resin, casein gelatin, nitrocellulose; polyimide, polyethylene imine, epoxy Thermosetting resins such as resins, melamine resins, phenol resins, and polyurethane resins; and organic metal compounds such as titanium coupling agents, zirconium coupling agents, and silane coupling agents are known. These materials can be used alone or
More than one kind can be mixed and used.

The undercoat layer is formed by dissolving and mixing the above-mentioned materials with a solvent, if necessary, diluting the mixture, applying the mixture on a conductive support by spray coating, dip coating, or the like.
It is formed by drying at a temperature of 00 ° C. The thickness of the undercoat layer is arbitrarily set in the range of 0.1 to 10 μm, but is particularly preferably in the range of 0.5 to 2 μm.

Examples of the charge generating material used in the photoreceptor of the present invention include azo dyes such as chlorodiane blue, quinone pigments such as anthantrone and pyrenequinone, quinocyanine pigments, perylene pigments, indigo pigments, bisbenzimidazole pigments, and metal-free pigments. Phthalocyanine pigments such as phthalocyanine, copper phthalocyanine, vanadyl phthalocyanine, titanyl phthalocyanine, and gallium phthalocyanine;
Azurenium salts, squarylium pigments, quinacridone pigments and the like can be used.

Examples of the binder resin for the charge generation layer include polyvinyl butyral, polyarylate (a polymer of bisphenol A and phthalic acid), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, and the like. Insulating resins such as acrylic resin, polyacrylamide, polyamide resin, polyvinyl pyridine, cellulose resin, urethane resin, epoxy resin casein, polyvinyl alcohol, and polyvinylpyrrolidone can be used.

The charge generation layer dissolves the binder resin in a solvent,
The charge generating material is dispersed therein, applied by a spray coating method, a dip coating method, or the like, and then dried, or formed by directly forming a film of the charge generating material by a vacuum evaporation method or the like. The thickness of the charge generation layer is arbitrarily set in the range of 0.01 to 5 μm, but is preferably in the range of 0.1 to 0.5 μm.

When the surface of an electrophotographic photosensitive member is deteriorated by exposure to a discharge gas or the like and causes image defects such as image deletion, the main cause is that a charge transport agent contained in the electrophotographic photosensitive member is
It may be oxidized by a discharge gas or the like. Therefore,
In order to use the electrophotographic photosensitive member with a low wear rate, the electrophotographic photosensitive member surface layer needs to have a certain degree of oxidation resistance.

According to the study by the present inventors, the oxidation resistance of the charge transporting material contained in the surface layer of the electrophotographic photosensitive member has a correlation with its oxidation potential.
An electrophotographic photoreceptor using a charge transport material exhibiting E or more is:
Oxidation of the electrophotographic photoreceptor surface layer can be suppressed, and the rate of polishing can be suppressed low.

The charge transporting material used for the photoreceptor of the present invention comprises:
Polycyclic aromatic compounds such as anthracene, pyrene and phenanthrene, compounds having a nitrogen-containing heterocycle such as indole, carbazole and imidazole, pyrazoline compounds, hydrazone compounds, triphenylmethane compounds, triarylamine compounds, enamine compounds, stilbene compounds, etc. Among them, the oxidation potential (Eox) is 0.7 V vs SCE
The above, preferably 0.75 to 0.85 V vs SC
E can be arbitrarily selected within the range of E, and among them, the triarylamine compound represented by the general formula (1) is particularly effective.

Specific examples of the triarylamine compound represented by the above general formula (1) of the present invention and oxidation potentials thereof are shown in Tables 1 to 3.
It is shown in FIG. The charge transport material used in the present invention is not limited to those described here. These materials can be used alone or in combination of two or more.

[0039]

[Table 1]

[0040]

[Table 2]

[0041]

[Table 3]

[0042]

[Table 4]

The oxidation potential was measured using a dichloromethane solution of the charge transport material (supporting electrolyte, 0.1 M-TBA).
P) CV measurement (Yanagimoto voltammetric analyzer P-1000, manufactured by Yanagi Head Office, working electrode, counter electrode: platinum electrode, reference electrode: saturated calomel electrode).

Further, with respect to oxidation of the charge transport material,
It is also effective to add a hindered phenol compound or a hindered amine compound as an antioxidant. Specific examples of the hindered amine compound used in the present invention include octylated diphenylamine, 4,4 ′
-Bis (α, α′-dimethylbenzyl) diphenylamine, N, N′-diphenyl-P-phenylenediamine,
N-isopropyl-N'-phenyl-P-phenylenediamine, N-1,3-dimethyl-N'-phenyl-P-
Phenylenediamine, N-1-methylheptyl-N′-
Phenyl-P-phenylenediamine, N- (3-methacryloyloxy-2-hydroxypropyl) -N′-phenyl-P-phenylenediamine, 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 6 -Ethoxy-
2,2,4-trimethyl-1,2-dihydroquinoline,
Examples include diphenylamine derivatives, alkylated diphenylamine, and the like.

As a specific example of the hindered phenol compound, triethylene glycol-bis [3-
(3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2 , 4-Bis (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5-triazine, pentaerythrityl-tetrakis [3- (3,5-di -T-butyl-4-hydroxyphenyl) propionate], 2,2
-Thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N , N'-hexamethylenebis (3,5-di-tert-butyl-4-hydroxyhydrocinnamide), 3,5-di-tert-butyl-4-hydroxy-benzylphosphonate-diethyl ester,
1,3,5-trimethyl-2,4,6-tris (3,5
-Di-t-butyl-4-hydroxybenzyl) benzene, bis (3,5-di-t-butyl-4-hydroxybenzylethyl phosphonate) calcium, tris (3,5
-Di-t-butyl-4-hydroxybenzyl) isocyanurate, octylated diphenylamine, 2,4-bis [(octylthio) methyl] -O-cresol, 2,
6-di-t-butyl-4-methylphenol, 2,6-
Di-t-butyl-4-ethylphenol, styrenated phenol, 2,2'-methylenebis (4-methyl-6-
t-butyl-phenol), 2,2′-methylenebis (4-ethyl-6-t-butyl-phenol), 4,
4'-butylidenebis (3-methyl-6-t-butyl-
Phenol), 2,5-di-t-butylhydroquinone,
2,5-di-t-amylhydroquinone, 2-t-butyl-6- (3-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2- [1-
(2-hydroxy-3,5-di-t-pentylphenyl) ethyl] -4,6-di-t-pentylphenyl acrylate, 4,4'-butylidenebis (3-methyl-6
-T-butylphenol), 4,4'-thiobis (3-
Methyl-6-t-butyl-phenol), 4,4′-thiobis (2-methyl-6-t-butylphenol),
3,9-bis {2- [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy]-
1,1-dimethyl {-2,4,8,10-tetraoxaspiro [5,5] undecane, alkylated bisphenol, phenol derivative and the like.

The total amount of the antioxidant added is preferably in the range of 0.07 to 10% by weight of the whole layer to be added. As the binder resin used for the charge transport layer of the photoreceptor, polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer , Vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly Known resins such as -N-vinylcarbazole and polysilane can be used, but are not limited thereto.

The charge transport layer dissolves the binder resin in a solvent,
A solution obtained by adding a charge transport material to the solution is spray-coated,
It is formed by applying a dip coating method or the like, followed by drying. The thickness of the charge transport layer is arbitrarily set in the range of 5 to 40 μm, but is preferably in the range of 15 to 35 μm.

In the present invention, fine particles are used in order to improve the transferability.
Inorganic fine particles such as alumina, silica, barium titanate, calcium titanate, strontium titanate, zinc oxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, chromium oxide, and red iron oxide; Polyacrylate,
Organic fine particles such as polymethacrylate, polymethyl methacrylate, polyethylene, polypropylene, polyvinylidene fluoride, and polytetrafluoroethylene can be used.

In consideration of environmental stability, it is desirable that these fine particles have low hygroscopicity.
Hydrophobic inorganic fine particles such as alumina and silica are used after being subjected to a hydrophobic treatment. In this hydrophobizing treatment, for example, a silane coupling agent such as a dialkylhalogenated silane, a trialkylhalogenated silane, or an alkyltrihalogenated silane, a hydrophobizing agent such as dimethylsilicone oil, or the above-mentioned fine particles at a high temperature. The reaction is carried out. The particle size of the fine particles is preferably smaller, and it is desired to use fine particles having a particle size of 5 μm or less.

The method of attaching fine particles on electrophotography includes a method of attaching mechanically, a method of attaching electrically, and a method of using both together. Examples of the method of mechanically attaching include a method of rubbing with a roll, brush, felt, web, or brush. Examples of the roll shape include a rigid roll formed of a rigid body such as a metal or a hard plastic, and an elastic roll using a material having elasticity such as rubber. Elastic rolls are easier to use because they are easier to adjust. Examples of the brush include a magnetic brush and a fur brush using magnetism. In addition to such a mechanical attachment method, an electric field can be applied to further stabilize the attached state of the fine particles.

As a method of electrically attaching the fine particles, there is a method of dispersing the fine particles in a cloud shape and attaching the fine particles to the image carrier by the force of an electric field. Specifically, a method using mechanical vibration, air, ultrasonic waves, or an alternating electric field, or attaching fine particles to a roll, brush, web, or brush, and rotating, vibrating, or moving them There is a method to make it.

In the present invention, a roll-shaped, brush-shaped, film-shaped or pad-shaped polishing and cleaning means capable of controlling contact and separation with the surface of the electrophotographic photosensitive member is used. These are usually installed separately from the electrophotographic photoreceptor, and if necessary, contact the electrophotographic photoreceptor before polishing, cleaning, Perform

Further, an intermediate transfer member used for forming a multicolor image can be used as polishing and cleaning means. Here, the surface of the electrophotographic photosensitive member is polished and cleaned by sliding while changing the peripheral speed between the electrophotographic photosensitive member and the intermediate transfer member.

As an example of the roll-like polishing and cleaning means used in the present invention, a roll obtained by coating a metal shaft made of stainless steel or the like with a foamed polyurethane, a foamed polypropylene, a foamed polyvinyl chloride, or the like is used. An electrophotographic photoreceptor is brought into contact with a photoreceptor while being rotated to polish and clean the surface of the electrophotographic photoreceptor. The roll may be subjected to a conductive treatment, and a voltage effective in the polishing and cleaning step may be applied.

As the brush-like polishing and cleaning means used in the present invention, those generally used for fur brush cleaning of an electrophotographic image forming apparatus, such as acrylic resin fibers and nylon resin fibers, can be applied. The brush is brought into contact with the electrophotographic photosensitive member while being rotated as necessary, and the surface of the electrophotographic photosensitive member is polished and cleaned. A conductive treatment may be applied to the brush, and a voltage effective in the polishing and cleaning step may be applied.

As an example of the film-like polishing and cleaning means used in the present invention, a fine abrasive such as alumina, silica, silicon carbide and cerium oxide is dispersed in a binder resin on a base film such as polyethylene. The film on which the layer is formed is pressed against an electrophotographic photosensitive member as necessary, and the surface is polished and cleaned while rotating the electrophotographic photosensitive member. The film may be contacted while applying an effective voltage.

As an example of the pad-like polishing and cleaning means used in the present invention, a pad made of foamed polyurethane, foamed polypropylene, foamed polyvinyl chloride or the like is pressed against the electrophotographic photosensitive member as necessary, The surface is polished and cleaned while rotating. A conductive treatment may be applied to the pad, and a voltage effective in the polishing and cleaning step may be applied.

The intermediate transfer member used in the present invention includes:
Examples include a belt-shaped one in which semiconductive treatment is performed on a base film of polyimide or the like, and a drum-shaped one in which semiconductive treatment is similarly performed on a rubber material. It is desirable that the surface of the intermediate transfer member has excellent toner transferability and has irregularities suitable for polishing and cleaning the surface of the electrophotographic photosensitive member. In a normal image forming cycle, the electrophotographic photosensitive member and the intermediate transfer member rotate at substantially the same peripheral speed. In the polishing and cleaning steps, both are rotated at a certain peripheral speed difference. At this time, the surface of the electrophotographic photosensitive member is polished and cleaned by rubbing against the surface of the intermediate transfer member. The difference in peripheral speed is preferably about 1: 2 to 1:10. Also, a band-like polishing and cleaning band having a certain width in the axial direction is provided on a part of the surface of the intermediate transfer member, and in the polishing and cleaning process, the electrophotographic photosensitive member is placed on the band so that the intermediate transfer member is disposed. The surface of the electrophotographic photoreceptor can be polished and cleaned by fixing the electrophotographic photoreceptor and rotating only the electrophotographic photoreceptor.

In the present invention, a method of polishing and cleaning the surface of the electrophotographic photosensitive member using a liquid detergent such as water, an aqueous solution, and an organic solvent which does not deteriorate the electrophotographic photosensitive member is effective. The aqueous solution used for washing preferably contains a surfactant, and the organic solvent is preferably methyl alcohol, ethyl alcohol, isopropyl alcohol and the like. These liquid detergents are contained in a highly absorbent substance such as a sponge, and the above-mentioned roll, brush, film, or pad-like polishing, in combination with cleaning means, polishing while wetting the electrophotographic photosensitive member surface, To clean. This is particularly effective for removing foreign substances such as discharge products and paper powder attached to the surface of the electrophotographic photosensitive member when used for a long period of time.

[0060]

【Example】

[Example 1] 20 parts by weight of acetylacetone zirconium butoxide (Orgatics ZC540, manufactured by Matsumoto Kosho) 2 parts by weight of γ-aminopropyltriethoxysilane (A1100, manufactured by Nippon Yunika) 1.5 parts by weight of polyvinyl butyral resin (Sekisui Chemical) 70 parts by weight of n-butyl alcohol A solution composed of the above components was applied onto an aluminum pipe by dip coating, and then dried at 150 ° C. for 10 minutes to obtain a film having a film thickness of 0.1%.
An undercoat layer of 9 μm was formed.

X-type metal-free phthalocyanine 5 parts by weight Vinyl chloride-vinyl acetate copolymer 5 parts by weight (manufactured by Union Carbide Co., Ltd., VMCH) 200 parts by weight of n-butyl acetate Next, the above-mentioned components were used with glass beads having a diameter of 1 mm. The dispersion obtained by dispersing with a sand mill for 2 hours was dip-coated on the undercoat layer and dried at 100 ° C. for 10 minutes to form a 0.2 μm-thick charge generation layer.

Compound 15 shown in Table 1 (Eox = 0.78) 1 part by weight Binder resin represented by the following structural formula (1) 1 part by weight Monochlorobenzene 6 parts by weight Further, a solution comprising the above-mentioned components was charged into the above-mentioned charge generation. After dip coating on the layer, it was dried at 135 ° C. for 1 hour,
A charge transport layer having a thickness of μm was formed, and an electrophotographic photosensitive member was produced.

[0063]

Embedded image

A digital copying machine Ab manufactured by Fuji Xerox Co., Ltd.
Using a testing machine that was modified from le-1301 to the configuration of FIG.
The above-mentioned electrophotographic photoreceptor is mounted, and poly (methyl methacrylate) fine particles having an average particle diameter of 3 μm are used as fine particles to be adhered to the surface of the electrophotographic photoreceptor. A durability test was carried out by attaching a urethane foam roll as a means for polishing and cleaning.
Polishing was performed at a rate of once every 100 image forming cycles for 10 seconds, and a cleaning roll was operated to perform polishing and remove foreign matters. After 100,000 prints, no image defects such as image defects due to abrasion or scratches on the electrophotographic photosensitive member and no image defects such as image deletion due to the adhesion of foreign matter to the surface of the electrophotographic photosensitive member were observed. In the above-described copying machine, when the cleaning device was stopped and a similar test was performed, no image defect such as a ghost occurred.

Example 2 Example 1 was the same as Example 1 except that a roller brush for polishing and cleaning the copying machine was replaced with a rod brush using nylon fibers as shown in FIG.
A durability test was performed in the same manner as described above. Image forming cycle 1
Polishing was performed once every 0 times for 10 seconds, and a cleaning brush was operated to perform polishing and remove foreign matter. After 100,000 prints, no image defects such as image defects due to abrasion or scratches on the electrophotographic photosensitive member and no image defects such as image deletion due to the adhesion of foreign matter to the surface of the electrophotographic photosensitive member were observed.

Example 3 In Example 1, the charge transporting material of the electrophotographic photoreceptor 31 was changed from Compound 15 to Compound 25 shown in Table 1 to 2,2'-methylenebis (4-methyl-6-t- Butylphenol) was added in an amount of 1 part by weight, and a polishing film prepared by applying an alumina abrasive on a polyethylene base film as shown in FIG. A durability test was performed in the same manner as in Example 1. The surface of the electrophotographic photosensitive member was polished and foreign substances were removed by polishing the film for cleaning for 10 seconds at a rate of once per 100 image forming cycles, and rubbing the film by rotating the electrophotographic photosensitive member. After 100,000 prints, no image defects such as image defects due to abrasion or scratches on the electrophotographic photosensitive member and no image defects such as image deletion due to the adhesion of foreign matter to the surface of the electrophotographic photosensitive member were observed.

Example 4 Example 1 was the same as Example 1 except that a cleaning pad in which foamed polyurethane was impregnated with water was used instead of the polishing and cleaning rolls of the copying machine as shown in FIG. A durability test was performed in the same manner as described above. The surface of the electrophotographic photosensitive member was polished and foreign substances were removed by pressing the cleaning pad and rubbing by rotating the electrophotographic photosensitive member, for 10 seconds at a rate of once every 100 image forming cycles. After 100,000 prints, image defects due to wear and scratches on the electrophotographic photoreceptor,
Also, no image defects such as image deletion due to foreign matter adhering to the surface of the electrophotographic photosensitive member were observed at all.

Example 5 An intermediate transfer drum obtained by subjecting a semiconductive treatment to urethane rubber was used as an intermediate transfer member and mounted on a digital copying machine Able-935 manufactured by Fuji Xerox Co., Ltd. as shown in FIG. A tester equipped with the electrophotographic photosensitive member of Example 1 was used. The same fine particles of polymethyl methacrylate as in Example 1 were used as the fine particles to be adhered to the surface of the electrophotographic photoreceptor.

After repeating the image forming cycle 100 times, the peripheral speed ratio of the electrophotographic photosensitive member and the intermediate transfer drum is automatically changed to 5: 1, and both are slid, and the polishing and cleaning operations are performed for 10 seconds. Then, the surface of the photoreceptor was polished and foreign matters were removed. The intermediate transfer drum to which the foreign matter adhered was removed by a cleaning unit attached to the drum. As a result, after 100,000 prints, no image defects such as image defects due to abrasion or scratches on the electrophotographic photosensitive member and no image defects such as image deletion due to adhesion of foreign matter to the surface of the electrophotographic photosensitive member were observed.

Comparative Example 1 A digital copying machine Able-1301 manufactured by Fuji Xerox Co., Ltd. (FIG. 7) in which a blade cleaning means made of urethane rubber is always in contact with a photosensitive member.
Endurance test was performed using the same device as in Example 1). As a result, after 100,000 prints, fogging of image edges due to abrasion of the electrophotographic photosensitive member and image defects due to scratches were observed.

[Comparative Example 2] Using a test machine obtained by modifying the digital copying machine Able-1301 manufactured by Fuji Xerox Co., Ltd. in Example 1, the polishing and cleaning rolls were constantly brought into contact with the electrophotographic photosensitive member to perform polishing and cleaning. When a durability test was performed while performing the test, after 100,000 prints, fogging of the image end due to abrasion of the electrophotographic photosensitive member and image defects due to scratches were observed.

[Comparative Example 3] An electrophotographic photoreceptor after a transfer process was performed by using a tester in which a digital copying machine Able-1301 manufactured by Fuji Xerox Co., Ltd. was modified into a configuration for performing simultaneous cleaning as shown in FIG. The toner remaining on the top was uniformly charged by the charging means, and was collected in the developing means in the developing step. A durability test was performed in the same manner as in Comparative Example 2. As a result, after 5,000 prints under high temperature and high humidity, image deletion due to foreign matter adhering to the surface of the electrophotographic photosensitive member was observed.

Comparative Example 4 In Example 1, the charge transporting material was changed to the compound 26 shown in Table 5 (Eox = 0.66 Vvs SC
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that E) was replaced. As a result, 1000
After zero printing, image deletion occurred.

[0074]

[Table 5]

Comparative Example 5 In Example 1, the charge transporting material was changed to the compound 27 shown in Table 5 (Eox = 0.64 V vs SC
An electrophotographic photosensitive member was prepared and evaluated in the same manner as in Example 1 except that E) was replaced. As a result, 7000
Image bleeding occurred after printing one sheet.

[0076]

According to the present invention, by employing the above-described structure, it is possible to remove scratches and abrasions generated on the surface of the electrophotographic photosensitive member, and thus image defects caused by scratches and abrasions and transfer defects caused by transfer paper. Image flow due to foreign matter such as paper dust and discharge products can be prevented, and high quality images can be formed.
The life of the electrophotographic photosensitive member has been greatly extended.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a configuration example of an image forming apparatus of the present invention, which is an apparatus using a roll as a polishing and cleaning means.

FIG. 2 is a conceptual diagram showing a configuration example of an image forming apparatus according to the present invention, which is an apparatus using a brush as a polishing and cleaning means.

FIG. 3 is a conceptual diagram showing a configuration example of an image forming apparatus of the present invention, which is an apparatus using a film as a polishing and cleaning means.

FIG. 4 is a conceptual diagram showing a configuration example of an image forming apparatus of the present invention, which is an apparatus using a pad as a polishing and cleaning means.

FIG. 5 is a conceptual diagram showing a configuration example of an image forming apparatus of the present invention, which is an apparatus using an intermediate transfer member as a polishing and cleaning means.

FIG. 6 is a schematic view showing a cross section of an electrophotographic photosensitive member used in the image forming apparatus of the present invention.

FIG. 7 is a conceptual diagram illustrating a configuration example of a conventional image forming apparatus, in which a cleaning unit is always in contact with a photosensitive member.

FIG. 8 is a conceptual diagram illustrating a configuration example of a conventional image forming apparatus, which is an apparatus configured to perform simultaneous development and cleaning instead of a cleaning unit.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03G 21/14 G03G 21/00 372

Claims (10)

[Claims] 1. An image forming method for forming a toner image using a developer after forming a latent image on an electrophotographic photoreceptor, wherein a step of attaching fine particles is provided before the step of forming a toner image; An image forming method, wherein a step of polishing and cleaning a surface of a photoconductor is provided in accordance with deterioration of the photoconductor in a process of repeating an image forming cycle. 2. The image forming method according to claim 1, wherein the photoconductor is an organic photoconductor. 3. An oxidizing potential of the photoconductor is 0.7 V vs.
3. The image forming method according to claim 1, further comprising a charge transporting material having SCE or more. 4. The charge transporting material according to the following general formula (1)
4. The image forming method according to claim 3, wherein the triarylamine compound is represented by the following formula: Embedded image (Wherein, R ₁ represents a hydrogen atom or a methyl group, k represents 1 or 2. Ar ₁ and Ar ₂ represent a substituted or unsubstituted aryl group, and the substituent is a hydrogen atom or a halogen atom. , An alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms and a substituted amino group.) 5. The image forming method according to claim 3, wherein the antioxidant contains a hindered phenol compound or a hindered amine compound. 6. The method according to claim 1, wherein the polishing and cleaning steps are provided at a rate of once in ten to one in 10,000 of the image forming cycle. Image forming method. 7. An image forming apparatus having a charging unit, an exposing unit, a developing unit, and a transferring unit around an electrophotographic photoreceptor, polishing the surface of the photoreceptor having a contacting / separating unit with respect to the photoreceptor. And an image forming apparatus provided with a cleaning unit. 8. An image forming apparatus according to claim 7, wherein said polishing and cleaning means comprises a roll, brush, film or pad polishing device. 9. The polishing and cleaning means is provided with a cleaning means using a liquid cleaning agent.
The image forming apparatus as described in the above. 10. An intermediate transfer member is provided between the photoreceptor and the transfer means, and means for controlling rotation speeds of the photoreceptor and the intermediate transfer member are respectively provided. 8. The image forming apparatus according to claim 7, wherein a peripheral speed difference between the image forming apparatus and the intermediate transfer member is provided.