JPH09179323A - Electrophotographic photoreceptor and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease leaking of charges even when a photoreceptor is used for an electrophotographic process using a contact electrification electrophotographic method and to improve environmental dependence of the photoreceptor. SOLUTION: This electrophotographic photoreceptor is produced by forming a photosensitive layer on a base body comprising aluminum or aluminum alloy. On the surface of the base body, a coating film is formed by using an acid treating liquid comprising phosphoric acid, chromic acid and hydrofluoric acid. As for the base body, an aluminum or aluminum alloy tube which is not machined or has a roughened surface is used. A base coating layer containing an org. metal compd. and a silane coupling agent may be formed on the coating film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor using a base material made of aluminum or an aluminum alloy and an image forming method using the photoreceptor.

[0002]

2. Description of the Related Art In recent years, organic photoconductors have become the mainstream as photoconductors used in electrophotographic (xerographic) copying machines and optical printers from the viewpoints of safety, low cost and high productivity. The organic photoreceptor is composed of a conductive support and an organic photosensitive layer coated thereon. Aluminum and its alloys are widely used as the conductive support. In this case, rather than forming the photosensitive layer directly on the support, the adhesiveness between the photosensitive layer and the support is improved, the coatability of the photosensitive layer is improved, the support is protected, the defects on the support are covered, It is effective to provide an undercoat layer in order to protect the photosensitive layer from electrical breakdown and to improve the charge injection property of the photosensitive layer. As a material for forming the undercoat layer, it is known to use organic resins such as polyurethane, polyamide, polyvinyl alcohol, ethylene-acrylic acid copolymer, ethylene-vinyl acetate copolymer, casein, methyl cellulose, and nitrocellulose. Has been. However, the undercoat layer formed by using these resins has a problem that the environmental sustainability, particularly the sensitivity is apt to decrease under low humidity. As a solution to this problem, Japanese Patent Laid-Open No. 58-930
No. 62, an organometallic compound, JP-A-61-9405.
No. 7 discloses an organic zirconium compound, and JP-A-2
No. 189559 discloses a cured film of zirconium compound and silane coupling, and further, JP-A-3-73962.
The publication discloses the preferred degree of curing and the like.
As disclosed in these, the undercoat layer is formed of an inorganic cured film. However, when an inorganic undercoating layer is provided, if the film thickness is made to be 5 μm or more, cracks are generated and charges are trapped in the film thickness to increase the residual potential, which is not preferable.

Further, when an organic photosensitive layer is formed on aluminum and its alloy, the charge potential is lowered due to charge injection from a support, and therefore it is known to provide an undercoat layer having charge injection inhibiting property, For example, a system in which powder is dispersed in a binder is provided (Japanese Patent Publication No. 3-42665), a layer made of zirconium alkoxide and an organic silicon compound is provided (Japanese Patent Publication No. 2-7054), and hydration is performed. An aluminum oxide film is provided (Japanese Patent Laid-Open No. 64-29852).
Japanese Laid-Open Patent Publication No. 5-3496).
No. 4) is known.

On the other hand, in the recent charging method, a contact charger is used to reduce the amount of ozone generated, to reduce the cost by not requiring a high-voltage power source, and to downsize the charger.
With respect to the photoconductor combined with such a contact charger, the charge leak due to the protrusion of the support causes a defect in the image quality of the copied image, and therefore it is desired to prepare a photoconductor in which the protrusion does not cause an image defect. ing. An image defect which causes a problem due to contact charging occurs when the protrusion of the support has a height of about 5 μm or more.

By the way, when an aluminum cylindrical substrate is manufactured, a method of performing extrusion processing after extrusion (ED
Pipe) and a method of performing ironing after extrusion (EI
Tubes, etc., but in both cases, minute projections having a width of 2 to 5 μm and a height of 5 to 20 μm are present on the surface when cutting is not performed. In order to render such protrusions harmless, at least an undercoating layer having a charge injection blocking property of 15 μm or more is provided, or the protrusion itself is changed to an insulator.
A method of mechanically removing it by means of mirror cutting or the like can be considered.

In order to render the projections harmless, a method of providing an undercoating layer having a charge injection inhibiting property, for example, a layer in which powder is dispersed in a binder (Japanese Patent Publication No. 3-42665), zirconium alkoxide and organic When the method of providing a layer made of a silicon compound (Japanese Patent Publication No. 2-7054) is used, it is 5 μm.
With the above thickening of the film, cracks are generated and charges are trapped in the thick film, resulting in unfavorable properties such as an increase in residual potential.

As a method of removing the fine projections, a method of providing a hydrated aluminum oxide film (Japanese Patent Laid-Open No. 64-2985).
In Japanese Patent Laid-Open No. 2), there is a problem that it takes about 1 hour to process the film to have a thickness of 1 μm or more, and it is difficult to further increase the film thickness and the effect of preventing charge leakage due to the protrusions is small. It was Further, the anodic oxide coatings found in JP-A 1-312553 and JP-A 5-34964,
It is generally known that the film is formed to have a film thickness of 5 to 6 μm, and that it is effective when the entire protruding portion, which is a problem with this film thickness, is made into an insulator. However, since the anodic oxide film is a porous film, sealing treatment is required, and the treatment time is as long as about 20 minutes. Therefore, the surface treatment cost is large. there were. Also, Japanese Patent Application Laid-Open
The chemical conversion coating formed by the treatment liquid containing phosphoric acid, sodium fluoride and chromic acid, which is described in Japanese Patent Publication No. 81964, can form a stable coating at low cost.
As with the hydrated aluminum oxide film, the film thickness was insufficient, so the effect of preventing charge leakage was insufficient.

Further, as a method for mechanically removing the protrusions, there are a wet honing treatment disclosed in Japanese Patent Laid-Open No. 3-64762, a centerless polishing treatment and the like, which are effective as a surface treatment method for preventing interference fringes. But extruded
Extraction pipe (ED pipe) or extrusion / ironing pipe (EI
When such a treatment is applied to an aluminum-based support such as a pipe), it is possible to remove the originally existing fine projections, but in the case of wet honing treatment, the width is 5 to 15
μm, height about 2 to 10 μm, and in the case of centerless grinding, another minute protrusion with a width of about 10 to 50 μm and a height of about 10 to 20 μm is newly generated, so it is effective as a method to remove the minute protrusion after all. Was not.

Another method for mechanically removing the protrusions is cutting work. In this case, there is an aluminum-based support such as an extruded / drawn pipe (ED pipe) or an extruded / ironing pipe (EI pipe). It is possible to completely remove the fine projections that are formed, and it does not cause formation of new fine projections as seen in the wet honing process or the centerless grinding process. Therefore, it is an effective method for removing the projections. However, there is a problem that the productivity is inevitably low and the processing cost is high due to the reasons that the work needs to be detached and attached individually during processing, the processing time is long, and an expensive diamond tool is required. I couldn't meet the demand for low cost. Further, as the thickness of the material becomes thin, the dimensional accuracy of the shape deteriorates, so it has been difficult to meet the demand for higher accuracy and lighter weight.

[0010]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above-mentioned various problems in an electrophotographic photosensitive member using a support made of aluminum and its alloy. That is, it is an object of the present invention to provide an inexpensive electrophotographic photosensitive member that has less charge leakage even when used in a contact charging type electrophotographic method and has improved environmental dependency. Another object of the present invention is to provide an image forming method which adopts the contact charging method and does not cause image defects.

[0011]

The electrophotographic photoreceptor of the present invention comprises a support made of aluminum or an aluminum alloy and a photosensitive layer provided on the support. The support has phosphoric acid, chromic acid and It is characterized in that it has a film formed by an acidic treatment liquid containing hydrofluoric acid. The support to be treated in the present invention is preferably roughened in order to prevent interference fringes generated on the photoreceptor. Further, the average roughness Ra of the roughened support is 0.5 to
It is preferably 4.0 μm. Also. The support may be a non-cutting tube made of aluminum or an aluminum alloy. Further, in the electrophotographic photosensitive member of the present invention, the support has a coating film formed on the surface by an acidic treatment liquid consisting of phosphoric acid, chromic acid and hydrofluoric acid, and further at least an organometallic compound on the coating film. An undercoat layer containing a silane coupling agent and a silane coupling agent may be provided.

The image forming method of the present invention comprises the steps of charging an electrophotographic photoreceptor, exposing it to an image, developing it, and transferring and fixing it. The electrophotographic photoreceptor is used as the electrophotographic photoreceptor. Then, in the charging step, the charging device to which a voltage is applied is brought into contact with the surface of the electrophotographic photosensitive member to be charged.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. In the present invention, the support made of aluminum or aluminum alloy (hereinafter referred to as “aluminum-based support”) may be a non-cutting tube. That is,
Extrusion process (Extru
Sion) and drawing process (Drawing) in sequence, or an ED tube or an extrusion process and an ironing process (Iron).
ing) can be used. The material of aluminum is 1000 series pure aluminum such as JIS1050 and 3000 series Al-Mn such as JIS3003.
6000 series Al-Mg-Si such as alloy, JIS6063
An alloy or the like is used, but if the post-treatment described below is not performed, the surface property obtained is JIS 30.
A 3000 series Al-Mn alloy such as 03 is most desirable. Further, from the viewpoint of dimensional accuracy, 3000 series Al-Mn alloys such as JIS3003 are also most desirable.

When the photosensitive drum is used in a laser printer, the surface of the support has a center line average roughness Ra in order to prevent interference fringes generated when the laser beam is irradiated.
It is preferable to roughen the surface to 0.04 μm to 0.5 μm. As a roughening method, wet honing performed by suspending an abrasive in water and spraying it on a support, or centerless grinding in which a support is pressed against a rotating grindstone and grinding is performed continuously is preferable. . Ra is 0.04
If it is less than μm, it becomes close to a mirror surface, so that the interference preventing effect cannot be obtained, and if Ra is more than 0.5 μm, the image quality becomes rough even if the coating film of the present invention is formed, which is not suitable.

The uncut or roughened aluminum-based support is treated with an acidic treatment liquid containing phosphoric acid, chromic acid and hydrofluoric acid. The mixing ratio of phosphoric acid, chromic acid and hydrofluoric acid in the acidic treatment liquid is such that phosphoric acid is in the range of 10 to 11% by weight, chromic acid is in the range of 3 to 5% by weight, and hydrofluoric acid is in the range of 0.5 to 2% by weight. Range of
The total concentration of these acids is preferably in the range of 13.5 to 18% by weight. The treatment temperature is 42 to 48 ° C., but by keeping the treatment temperature high, it is possible to form a thicker film faster.

On the surface of the aluminum-based support obtained as described above, fine projections originally present in the ED tube, EI tube, etc., as well as wet honing processing and centerless grinding processing for preventing interference are newly added. Although there are micro-protrusions generated on the surface, the treatment with an acid treatment solution consisting of phosphoric acid, chromic acid and hydrofluoric acid results in the action of hydrofluoric acid while the aluminum or aluminum alloy is being etched. A coating film is formed, whereby any protrusions existing on the surface of the support are made insulating.

The treatment with the acidic treatment liquid consisting of phosphoric acid, chromic acid and hydrofluoric acid in the present invention can be performed to a deeper depth because aluminum or aluminum alloy is etched, and it can be used without cutting. Can be used without problems. Further, it becomes possible to form a thicker film than that in the case of treating with a treatment liquid comprising phosphoric acid and chromic acid in the related art, and it becomes possible to perform surface treatment quickly.
Further, there is an advantage that the projection can be made into an insulator, which cannot be achieved by a conventional hydrated aluminum oxide film or a film formed by using phosphoric acid, chromic acid and sodium fluoride. Moreover, since electricity is not required for processing, the processing cost can be made extremely low.

The support made of aluminum or its alloy surface-treated as described above optionally forms an undercoat layer containing at least an organometallic compound and a silane coupling agent on the formed film. be able to. Examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane. , Β
-(3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, β- (3,3 4-epoxycyclohexyl) ethyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethylmethoxysilane, N,
Examples thereof include N-bis (β-hydroxyethyl) -γ-aminopropylethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and γ-chloropropyltrimethoxysilane. Among these, particularly preferably used silane compounds are vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3,4- Epoxycyclohexyl) ethyltrimethoxysilane, N-β-
(Aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, Examples include γ-mercaptopropyltrimethoxysilane and γ-chloropropyltrimethoxysilane.

On the other hand, examples of the organic metal compound include organic zirconium compounds, organic titanium compounds, organic aluminum compounds and the like. Among these, examples of organic zirconium compounds include zirconium butoxide, ethyl zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl zirconium butoxide acetoacetate, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, Examples thereof include zirconium octanoate, zirconium naphthenate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, and isostearate zirconium butoxide.

The undercoat layer is formed by mixing and applying both the organometallic compound and the silane coupling agent, and heating the mixture. In that case, the organometallic compound, for example, the zirconium compound and the silane coupling agent are used. React to form an inorganic cured film. This undercoat layer has chemically very stable physical properties and contributes to the formation of a photoreceptor having stable properties such as environmental dependence. Further, a thermoplastic resin such as polyvinyl butyral resin may be used in combination in the undercoat layer as long as the curability is not excluded.

A photosensitive layer is formed on a support made of aluminum or an alloy thereof, which has been surface-treated as described above or further provided with an undercoat layer. The photosensitive layer may have either a single layer structure or a laminated structure in which the charge generating layer and the charge transporting layer are functionally separated, but the latter is preferable because it is superior in terms of repeated stability and environmental changes. Further, it is possible to form a surface protective layer if necessary.

The charge generation layer is formed by vacuum deposition of the charge generation material or by dispersing the charge generation material in an organic solvent together with a binder resin and applying the dispersion. As a charge generation material,
Amorphous selenium, crystalline selenium, selenium-tellurium alloy, selenium-arsenic alloy, other selenium compounds and selenium alloys, zinc oxide, inorganic photoconductors such as titanium oxide, metal-free phthalocyanine, titanyl phthalocyanine, copper phthalocyanine, Various phthalocyanine pigments such as tin phthalocyanine and gallium phthalocyanine, various organic pigments and dyes such as squarylium-based, anthanthrone-based, perylene-based, azo-based, anthroquinone-based, pyrene-based, pyrylium salts and thiapyrylium salts are used. In addition, these organic pigments generally have several types of crystal, and in particular, various crystal types such as α and β are known for phthalocyanine pigments, but pigments that provide sensitivity suitable for the purpose If any, any crystal type may be used.

Further, in the present invention, it is particularly preferable to use a gallium phthalocyanine compound as the charge generating material. When a gallium phthalocyanine compound is used as the charge generation material, it is better to form the charge generation layer directly on the aluminum-based support treated with the acidic treatment liquid than to form it through the undercoat layer. It is preferable in terms of simplifying the process and maintaining high sensitivity. Examples of the gallium phthalocyanine compound include chlorogallium phthalocyanine (see, for example, JP-A-5-98181) and hydroxyphthalocyanine (for example, JP-A-5-98181).
263007) and the like.

Examples of the binder resin in the charge generation layer include the following. That is, polycarbonate resin such as bisphenol A type or bisphenol Z type, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer resin, vinylidene chloride-acrylonitrile copolymer Resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N-vinylcarbazole and the like. These binder resins can be used alone or in combination of two or more. The mixing ratio (weight ratio) of the charge generation material and the binder resin is preferably in the range of 10: 1 to 1:10.
The thickness of the charge generation layer is generally 0.01 to 5 μm.
m, preferably 0.05 to 2.0 μm.

On the other hand, the charge transport layer is composed of a charge transport material and a binder resin. Examples of the charge transport material include those shown below. Oxadiazole derivatives such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, 1,3,5-triphenyl-pyrazoline, 1- [pyridyl- (2)]-3 Pyrazoline derivatives such as-(p-diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazoline, aromatic tertiary amino compounds such as triphenylamine and dibenzylaniline, N, N'-diphenyl-N, N ' -Bis (3-methylphenyl)-[1,1-biphenyl] -4,4'-
Aromatic tertiary diamino compounds such as diamine, 3- (4 '
1,2,2, such as dimethylaminophenyl) -5,6-di- (4'-methoxyphenyl) -1,2,4-triazine
4-triazine derivatives, hydrazone derivatives such as 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone, quinazoline derivatives such as 2-phenyl-4-styryl-quinazoline, 6-hydroxy-2,3-di (p-
Benzofuran derivatives such as methoxyphenyl) -benzofuran, α-stilbene derivatives such as p- (2,2-diphenylvinyl) -N, N-diphenylaniline, enamine derivatives, carbazole derivatives such as N-ethylcarbazole, poly-N- Hole-transporting substances such as vinylcarbazole and its derivatives; quinone compounds such as chloranil, bromoanil, anthraquinone, tetracyanoquinodimethane compounds, 2,4,7-trinitrofluorenone, 2,
Examples include fluorenone compounds such as 4,5,7-tetranitro-9-fluorenone, xanthone compounds, electron transporting substances such as thiophene compounds; and polymers having a group consisting of the above compounds in the main chain or side chain. To be
These charge transport materials can be used alone or in combination of two or more.

The binder resin used in the charge transport layer is acrylic resin, polyarylate, polyester resin, bisphenol A type or bisphenol Z.
Polycarbonate resin, polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-
Examples thereof include butadiene copolymer, polyvinyl butyral, polyvinyl formal, polysulfone, polyacrylamide, polyamide, chlorinated rubber and other insulating resins, and polyvinyl carbazole, polyvinyl anthracene, polyvinyl pyrene and other organic photoconductive polymers. The compounding ratio of the charge transport material and the polycarbonate resin is
It is preferably 10: 1 to 1: 5. The thickness of the charge transport layer is generally set in the range of 5 to 50 μm, preferably 10 to 40 μm.

The electrophotographic photosensitive member of the present invention can be used in electrophotographic devices such as laser beam printers, digital copying machines and laser facsimiles. For the electrophotographic photosensitive member of the present invention, a one-component or two-component regular developer or reversal developer can be used. In addition, the electrophotographic photosensitive member of the present invention can obtain good characteristics with less current leakage in the contact charging method using a charging roll, a charging brush or the like. If the aluminum-based support is roughened, it is possible to obtain an image in which no interference fringes are generated even in the halftone portion.

Next, the image forming method of the present invention will be described. FIG. 1 shows an example of a printer apparatus using the electrophotographic photosensitive member of the present invention, and the image forming method of the present invention is carried out as follows. That is, the surface of the photosensitive drum 1 is charged by a charger 3 to which a voltage in the range of 50 to 2000 V is applied from a power source 2 provided outside the apparatus. Next, an electrostatic latent image is formed by exposure with light from an image input device 4 such as an optical system for irradiating a document image or a laser or LED. The formed electrostatic latent image is visualized as toner by the developing device 5 and converted into a toner image. In this case, a magnetic brush method can be used for development. Then, the toner image is transferred onto the sheet 7 by the pressure transfer device or the electrostatic transfer device 6 and fixed by the fixing device 8. On the other hand, the toner remaining on the surface of the photosensitive drum 1 after the transfer is removed by the cleaner mechanism 9 using a blade, and the electric charge slightly remaining on the surface of the photosensitive drum 1 is erased by the deexposure device 10. Although a charging roll is shown as the charging device, a charging member such as a semi-conductive charging roll, a charging blade, a charging brush or the like can be used. For charging, a direct current or a superimposed voltage of direct current and alternating current is applied.

[0029]

【Example】

Example 1 A mixed solution of phosphoric acid and chromic acid (Alsurf 401,
3% made by Nippon Paint Co., Ltd. and hydrofluoric acid (Alsurf 4)
(5, made by Nippon Paint Co., Ltd.) An acid treatment liquid consisting of ion-exchanged water containing 0.3% was kept at 45 ° C., and extruded / pulled out of 3003 aluminum alloy having an outer diameter of 30 mmφ and a length of 253 mm degreased with alkali. Tube (ED tube)
(Showa Aluminum Tube) was immersed for 10 minutes. After the treatment, it was washed with deionized water. The ED tube treated in this manner had a cloudy surface state showing a greenish white color. On top of this ED tube, 50 of tributoxyzirconium acetylacetonate (ZC540, manufactured by Matsumoto Trading Co., Ltd.)
% Toluene solution 100 parts, γ-aminopropyltriethoxysilane (A1100, manufactured by Nippon Unicar Co., Ltd.) 10 parts and n-butanol 130 parts were mixed to obtain a coating solution,
It was applied by a ring coater and heated at 140 ° C. for 10 minutes to form a cured undercoat layer having a thickness of 0.1 μm. By this heating, the zirconium compound and the silane compound were reacted to form an inorganic cured film. Then, a 2% cyclohexanone solution of polyvinyl butyral resin (BM-S, manufactured by Sekisui Chemical Co., Ltd.) was mixed with a hydroxygallium phthalocyanine pigment (described in JP-A-5-263007) in a PB ratio of 2: 1. Dispersion was performed in a sand mill for 3 hours. The obtained dispersion was further diluted with n-butyl acetate and applied on the undercoat layer to form a charge generation layer having a thickness of 0.05 μm. Then, N, N'-diphenyl-N, N '
A solution of 4 parts of bis (m-tolyl) benzidine and 6 parts of polycarbonate Z resin dissolved in 36 parts of monochlorobenzene is applied by dip coating on the charge generating layer and dried at 115 ° C. for 60 minutes, An 18 μm-thickness charge transport layer was formed to produce an organic photoconductor (OPC) drum.

The obtained OPC drum is a commercially available laser printer (Laser Writer Sele sold by Apple Computer Inc.).
ct, a contact charging method using a charging roll is adopted), DC of voltage -360V, AC of peak voltage 1600V, and frequency AC of 400Hz are superimposed and applied to the charging roll to perform contact charging, and continuous by character image. A copy test was performed up to 10,000 sheets. As a result, it was possible to stably obtain a copied image of good quality. In addition, ED produced at the same time
Select 10 tubes from the tubes and use them as a dimensional accuracy evaluation table rotary type roundness measuring device (rondcom 52B-550, manufactured by Tokyo Seimitsu Co., Ltd.) without forming a photosensitive layer.
The cylindricity was measured by. The results are shown in Table 1 below.

Comparative Example 1 Alkali-degreased 3 having an outer diameter of 30 mmφ and a length of 253 mm
On the ED tube (Showa aluminum tube) made of 003 aluminum alloy, without surface treatment with an acidic treatment solution,
An undercoat layer, a charge generation layer and a charge transport layer were formed in the same manner as in Example 1. The obtained OPC drum was mounted on the same laser printer as in Example 1, and a copying test was conducted in the same manner using a character image up to 10,000 copies. Black spots due to leaks were found in 2,000 copies from the initial stage. Three dots occur, and after copying 10,000 sheets, the number of black dots increases to five,
The black spots of 0.2 mmφ initially generated increase in size due to subsequent continuous copying, and become 0.
It grew to a size of 6 mmφ. Ten ED tubes of the same lot used at this time were selected, and the cylindricity was measured by the same method as in Example 1. The results are shown in Table 1 below.

Example 2 An extruding / ironing tube (EI tube) made of a 3003 aluminum alloy having an outer diameter of 30 mmφ and a length of 253 mm was used in Example 1.
The same treatment with the same acidic treatment solution as above was performed in the same manner to form a chromium phosphate oxide conversion coating. A charge generation layer and a charge transport layer were formed thereon in the same manner as in Example 1. Obtained OPC
The drum is mounted on the same laser printer as in Example 1,
In the same manner, when a copying test was continuously performed on 10,000 copies of a character image, a copied image of good quality could be stably obtained. In addition, 10 out of the EI tubes produced at the same time
A book was selected and the cylindricity was measured in the same manner as in Example 1.
The results are shown in Table 1 below.

Example 3 A silicon carbide abrasive having a particle size of 25 μm was suspended in water and the surface of the same ED tube as in Example 1 was subjected to honing at a spraying speed of 50 m / sec to give Ra of 0.18 μm. The surface is made flat (for honing processing, Japanese Patent Laid-Open No. 2-3
7358). This ED tube was similarly treated with the same acidic treatment liquid as in Example 1 to form a chromium phosphate oxide conversion film. A charge generation layer and a charge transport layer were formed thereon in the same manner as in Example 1. The obtained OPC drum was mounted on the same laser printer as in Example 1, and a copying test was conducted on up to 10,000 sheets of images containing halftone densities. As a result, it was possible to stably obtain copied images of good quality. It was Since the surface of the ED tube was roughened, no interference fringe pattern was generated even in the halftone portion. Further, ten tubes were selected from the ED tubes produced at the same time, and the cylindricity was measured by the same method as in Example 1. The results are shown in Table 1 below.

Comparative Example 2 Honing-processed ED produced in the same manner as in Example 3
An undercoat layer, a charge generation layer and a charge transport layer were formed on the tube in the same manner as in Example 1 above, without treatment with the acidic treatment liquid. The obtained OPC drum was mounted on the same laser printer as in Example 1, and continuous 1 was performed with images including halftone density.
When a copy test was conducted up to 10,000 copies, there were no interference fringe patterns, but four black spots due to leaks were found in the initial 6,000 copies. Even after copying 10,000 sheets, the number of occurrences did not change and four black dots remained. No interference fringe pattern was generated in the halftone portion.

Example 4 An ED tube made of a 3003 aluminum alloy having an outer diameter of 30.2 mmφ and a length of 253 mm was subjected to centerless grinding at a peripheral speed of 1500 m / min using a centerless grinder set with a # 1200 grindstone. went. The surface roughness after processing was Ra 0.26 μm and Rmax 2.5 μm. The ED tube thus produced was degreased with alkali, and then treated in the same manner as in Example 1 with the same acid treatment liquid to form a chromium phosphate oxide conversion coating. A charge generation layer and a charge transport layer were formed thereon in the same manner as in Example 1. Obtained O
A PC drum was mounted on the same laser printer as in Example 1, and a copying test was conducted on up to 10,000 sheets of images containing halftone densities. As a result, it was possible to stably obtain copied images of good quality. No interference fringe pattern was generated in the halftone portion. Also, ten ED tubes were selected from the centerless ground ED tubes produced at the same time, and the cylindricity was measured by the same method as in Example 1. The results are shown in Table 1 below.

Comparative Example 3 An undercoat layer, a charge generation layer, and a charge transport layer were prepared in the same manner as in Example 1 above, except that the centerless grinding-processed ED tube produced in the same manner as in Example 4 was not treated with an acidic treatment solution. Layers were formed. The obtained OPC drum was mounted on the same laser printer as in Example 1, and continuous copying was performed using images containing halftone densities. No interference fringe pattern was generated, but there were leaks from the initial 1000 copies. 1 black dot due to
Five occurred. Therefore, the subsequent tests were stopped.

Comparative Example 4 An ED tube made of a 6063 aluminum alloy having an outer diameter of 30 mmφ and a length of 253 mm was mirror-cut, and then an undercoat layer, a charge generation layer and a charge transport layer were formed in the same manner as in Example 1 above. Formed. The obtained OPC drum was mounted on the same laser printer as in Example 1, and a copying test was conducted in the same manner using a character image up to 10,000 sheets. As a result, a copied image of good quality could be stably obtained. . Also,
Ten tubes were selected from the mirror-cut ED tubes produced at the same time, and the cylindricity was measured by the same method as in Example 1. The results are shown in Table 1 below.

Comparative Example 5 A mirror-finished ED tube manufactured in the same manner as in Comparative Example 4 was
Honing was performed in the same manner as in Example 3 above to obtain Ra.
The surface was roughened to 0.18 μm. An undercoat layer, a charge generation layer and a charge transport layer were formed on this ED tube in the same manner as in Example 1. The obtained OPC drum was mounted on the same laser printer as in Example 1, and a copying test was conducted in the same manner using a character image up to 10,000 sheets continuously. As a result, a copied image of good quality could be stably obtained. . Further, no interference fringe pattern was generated even in the halftone portion. Also,
E which was made at the same time and was subjected to honing after mirror surface cutting
Ten tubes were selected from the D tubes, and the cylindricity was measured by the same method as in Example 1. The results are shown in Table 1 below.

The results of Examples 1 to 4 and Comparative Examples 1 to 5 are summarized in Table 1. In the table, ○ in the leak black spot column means good, × means bad, and ○ in the halftone interference fringe column.
Means not to occur.

[0040]

[Table 1]

Comparative Example 6 The same evaluation was performed on the OPC drum produced in Comparative Example 1 by a laser printer which was charged to −360 V using a corona discharger. As a result, two black dots having a size of 0.2 mm were generated when copying 10,000 sheets, but Comparative Example 1
The problem was smaller than the case.

Example 5 An ED tube made of a 6063 aluminum alloy having an outer diameter of 30 mmφ and a length of 253 mm was mirror-cut, and then a silicon carbide abrasive having a particle size of 25 μm was used to spray at a speed of 5
Wet honing treatment was performed at 0 m / sec. A surface treatment was performed with an acidic treatment liquid in the same manner as in Example 1 except that the ED tube treated as described above was used, and an undercoat layer, a charge generation layer and a charge transport layer were formed in the same manner. The obtained OPC drum was mounted on the same laser printer as in Example 1, and a copying test was conducted in the same manner using a character image up to 10,000 sheets. As a result, a copied image of good quality could be stably obtained. .

Comparative Example 7 E made of the same 6063 aluminum alloy as in Example 5
After the mirror-cutting process was performed on the D tube, the wet honing process was similarly performed. After washing with water without treatment with the acidic treatment liquid, an undercoat layer, a charge generation layer and a charge transport layer were formed in the same manner as in Example 1 above. The obtained OPC drum was used in Example 1.
When mounted on the same laser printer as above and evaluated in the same manner, three black spots due to the leak were generated in 6,000 copies from the initial stage. Even after copying 10,000 sheets, the number of occurrences did not change.

Comparative Example 8 E made of 6063 aluminum alloy as in Example 5
After the mirror-cutting process was performed on the D tube, the wet honing process was similarly performed. Then 126 parts phosphoric acid, 1 chromic acid
4.5 parts, sodium fluoride 8 parts, ion-exchanged water 900
The mixed solution consisting of 10 parts is kept at 30 ° C.
The D tube was immersed for 1 minute. After the treatment, it was washed with deionized water. An undercoat layer, a charge generation layer and a charge transport layer were formed on the treated ED tube in the same manner as in Example 1. The OPC drum thus obtained was mounted on the same laser printer as in Example 1 and evaluated in the same manner.
Three black spots were generated due to leaks on 1,000 copies.
Even with 10,000 copies, the number did not change.

Example 6 An extrusion / single draw tube (ED tube) made of 3003 aluminum alloy having an outer diameter of 30 mmφ and a length of 253 mm was used, and a through feed centerless processing machine (manufactured by Micron Seimitsu Co., Ltd.) was used for 1.5 m / min. Processed at a speed of 29.
Cutting was performed up to 97 mmφ. A mixed solution of phosphoric acid and chromic acid (Alsurf 4
01, manufactured by Nippon Paint Co., Ltd.) and hydrofluoric acid (Alsurf 45, manufactured by Nippon Paint Co., Ltd.) 0.3% were used to perform an immersion treatment at 45 ° C. for 10 minutes using an acidic treatment liquid composed of ion-exchanged water. After the treatment, it was washed with deionized water. The treated ED tube had a cloudy surface condition with a greenish white color. The obtained OPC drum was mounted on a commercially available laser printer in the same manner as in Example 1 and a copying test was conducted up to 10,000 sheets continuously. As a result, it was possible to stably obtain a copied image with extremely good image quality.

Comparative Example 9 An OPC drum was produced in the same manner as in Example 6 except that the surface treatment with the acidic treatment liquid was not carried out.
The obtained OPC drum was evaluated in the same manner as in Example 1. As a result, black spots were generated in the copies from the initial stage to 800 sheets, and after that, in the copying test of 10,000 sheets, the number of black spots was increased to 24.

Example 7 An OPC drum was prepared in the same manner as in Example 1 except that the thickness of the cured undercoat layer was 0.2 μm, and the OPC drum was mounted in the same laser printer as in Example 1 and placed in a high temperature environment. Lower (30
C.) and under a low temperature environment (10.degree. C.), a copying test was conducted up to 10,000 sheets with character images, respectively. As a result, it was possible to stably obtain a copied image of good quality.

Example 8 An ED tube made of 6063 aluminum alloy (Kobe Steel Co., Ltd., outer diameter 30 mmφ, length 253 mm) was mirror-cut with a precision lathe using a diamond cutting tool, and the surface was Ra 0.04 μm. After being processed so as to have a diameter of 25 μm, a wet honing treatment was performed at a spraying speed of 50 m / sec using a silicon carbide abrasive having a particle diameter of 25 μm.
Center line average roughness Ra 0.2μ obtained as described above
An ED tube of about m is composed of ion-exchanged water containing 3% of a mixed solution of phosphoric acid and chromic acid (Alsurf 401, manufactured by Nippon Paint Co., Ltd.) and 0.3% of hydrofluoric acid (Alsurf 45, manufactured by Nippon Paint Co., Ltd.). Immersion treatment was performed in the same manner as in Example 1 using the acidic treatment liquid. After the treatment, it was washed with deionized water. On the treated ED tube, 100 parts of the same zirconium compound as in Example 1, 10 parts of silane compound, 10 parts of polyvinyl butyral resin (BM-S, manufactured by Sekisui Chemical Co., Ltd.) and 130 parts of n-butanol were mixed, and ring coating was performed. Machine applied and heated at 140 ° C. for 15 minutes to form a 1.0 μm undercoat layer. The polyvinyl butyral resin is added to increase the liquid viscosity and increase the film thickness. Then, a charge generation layer and a charge transport layer were formed in the same manner as in Example 1. The obtained OPC drum was mounted on the same laser printer as in Example 1, and a copy test was performed up to 10,000 sheets continuously with an image including a halftone under a high temperature environment (30 ° C.) and a low temperature environment (10 ° C.). As a result, it was possible to stably obtain a copied image of good quality. Since the surface of the ED tube was roughened, no interference fringe pattern was generated even in the halftone portion.

COMPARATIVE EXAMPLE 10 The ED tube of Example 8 was subjected to wet honing treatment, and then washed without surface treatment with an acidic treatment liquid,
An undercoat layer, a charge generation layer and a charge transport layer were formed in the same manner as in Example 1. When the obtained OPC drum was evaluated in the same manner as in Example 1, three black spots due to leaks were generated in 6,000 copies from the initial stage. Even after copying 10,000 sheets, the number of occurrences did not change.

Example 9 An ED tube made of 1050 aluminum alloy (manufactured by Sumitomo Light Metal Industries, Ltd., outer diameter 30 mmφ, length 253 mm) was cut by a lathe using a polycrystalline diamond cutting tool having irregularities at the tip, Surface centerline average roughness Ra
The surface was roughened to a rough surface of about 0.3 μm. Next, a mixed solution of phosphoric acid and chromic acid (Alsurf 40
The dipping treatment was performed in the same manner as in Example 1 using an acidic treatment liquid composed of ion-exchanged water containing 3% of 1) (manufactured by Nippon Paint Co., Ltd.) and 0.3% of hydrofluoric acid (Alsurf 45, manufactured by Nippon Paint Co., Ltd.). After the treatment, it was washed with deionized water. An undercoat layer, a charge generation layer and a charge transport layer were formed on this ED tube in the same manner as in Example 1. The obtained OPC drum was mounted on the same laser printer as in Example 1, and a copy test was performed up to 10,000 sheets continuously with an image including a halftone under a high temperature environment (30 ° C.) and a low temperature environment (10 ° C.). As a result, it was possible to stably obtain a copied image of good quality. Since the surface of the ED tube was roughened, no interference fringe pattern was generated even in the halftone portion.

Comparative Example 11 The ED tube of Example 9 was washed without surface treatment with an acidic treatment solution, and then an undercoat layer was formed in the same manner as in Example 1.
A charge generation layer and a charge transport layer were formed. OP obtained
When the C drum was evaluated in the same manner as in Example 1, two black spots due to the leak were generated in 5,000 copies from the initial stage. After copying 10,000 sheets, the number of sunspots increased to 24.

Example 10 A mixed solution of phosphoric acid and chromic acid (Alsurf 401,
3% made by Nippon Paint Co., Ltd. and hydrofluoric acid (Alsurf 4)
(5, made by Nippon Paint Co., Ltd.) An acid treatment liquid consisting of ion-exchanged water containing 0.3% was kept at 45 ° C., and extruded / pulled out of 3003 aluminum alloy having an outer diameter of 30 mmφ and a length of 253 mm degreased with alkali. Tube (ED tube)
(Showa Aluminum Tube) was immersed for 10 minutes. After the treatment, it was washed with deionized water. The ED tube thus treated had a cloudy surface state showing a greenish white color, and a chemical conversion film having a film thickness of about 2 μm was formed. on the other hand,
Polyvinyl butyral resin (BM-S, Sekisui Chemical Co., Ltd.)
2% cyclohexanone solution was mixed with a hydroxygallium phthalocyanine pigment (described in JP-A-5-263007) so that the PB ratio was 2: 1, and the mixture was dispersed in a sand mill for 3 hours. The obtained dispersion was further diluted with n-butyl acetate and directly applied onto the ED tube to form a charge generation layer having a thickness of 0.06 μm. Then N,
A solution prepared by dissolving 4 parts of N'-diphenyl-N, N'-bis (m-tolyl) benzidine and 6 parts of polycarbonate Z resin in 36 parts of monochlorobenzene is applied onto the charge generation layer by dip coating, It was dried at 115 ° C. for 40 minutes to form a charge transport layer having a film thickness of 18 μm, and an OPC drum was produced. A commercially available laser printer (Apple Computer In) was used for the obtained OPC drum.
c. Laser Writer S for sale from
Elect, a contact charging method using a charging roll) and tested up to 10,000 sheets continuously with a character image, a good printed image could be stably obtained.
It should be noted that this example was superior in sensitivity as compared with the case of Example 1 in which the undercoat layer was applied.

Comparative Example 12 In Example 10, Example 1 was performed without treating the surface of the ED tube.
When the coating liquid for forming the charge generation layer was applied in the same manner as in No. 0, the coating liquid was repelled on the surface of the ED tube and the coating could not be performed satisfactorily, and the coating film could not be formed. Comparative Example 13 In Example 10, a treatment liquid was used in which sodium fluoride was used instead of hydrofluoric acid, and the liquid temperature was kept at 30 ° C. to perform the surface treatment of the ED tube. After the treatment, the surface of the ED tube became a slightly dull glossy surface. The ED tube was washed with ion-exchanged water, and the other treatments were performed in the same manner to form a charge generation layer and a charge transport layer, to prepare an OPC drum. When this drum was tested in the same manner as in Example 10, three black spots due to the leak were generated on 2,000 sheets. This is because the phosphoric acid chromic acid film formed by this method is as thin as 0.1 μm, and the leak preventing effect is weak.

Example 11 A silicon carbide abrasive having a particle size of 25 μm was suspended in water, and the same ED tube surface as in Example 10 was subjected to honing at a spraying speed of 50 m / sec to give a rough surface of Ra 0.18 μm. Turned into This ED tube was treated in the same manner as in Example 10 to form a phosphoric acid chromate film. When mounted on the same laser printer and continuously tested with an image containing an intermediate density up to 10,000 sheets, a good printed image could be stably obtained. Since the surface of the ED tube was roughened, no interference fringe pattern was generated in the middle portion.

Comparative Example 14 In Example 11, after performing the honing process and applying the coating liquid for forming a charge generation layer in the same manner as in Example 11 without surface treatment, the surface of the ED tube was not repelled. However, the unevenness of the film thickness was large. A charge transport layer was formed on this by coating to obtain an OPC drum. When this was mounted on a laser printer and the printed image was examined, it was found that fogging occurred. This is probably because the surface of the ED tube did not have a film corresponding to the undercoat layer, and the chargeability of the drum decreased. Comparative Example 15 The same as in Example 11, except that the treatment liquid used was sodium fluoride in place of hydrofluoric acid, the liquid temperature was maintained at 30 ° C., and the surface treatment of the ED tube was performed. Then, the charge generation layer and the charge transport layer L were formed to prepare an OPC drum. When the obtained OPC drum was tested in the same manner as in Example 10, two black spots caused by the leak were generated at 1,000 sheets, and five at 2,000 sheets. This is because the ED tube surface is roughened,
It is presumed that this is because the chromium phosphate oxide conversion film formed by this method was very thin, so that leaks were very likely to occur.

Example 12 An ED tube (manufactured by Sumitomo Light Metal Industries, Ltd., outer diameter 30 mm, length 253 mm) made of JIS6063 aluminum alloy was used, and the surface was Ra0 on a lathe using a polycrystalline diamond bite having irregularities at the tip. The rough surface was cut to about 3 μm. OP is performed using this ED tube in the same manner as in Example 11.
When a C drum was produced and evaluated in the same manner, it was possible to stably obtain a copied image with similarly good image quality.

[0057]

As described above, according to the present invention, the support made of aluminum or aluminum alloy is treated with an acidic treatment liquid containing phosphoric acid, chromic acid and hydrofluoric acid.
A sufficiently thickened chromium phosphate oxide conversion film is formed on the surface of a support made of aluminum or an aluminum alloy. Therefore, as a result of the chemical conversion treatment of the fine projections existing on the support, the ED tube or EI which cannot be used without cutting because of the presence of the fine projections has hitherto been available.
The tube can be used as it is to prepare an electrophotographic photoreceptor applicable to the electrophotographic method of the charging contact system. In addition, even when performing high-speed cutting such as centerless grinding, and aluminum-based supports that have been roughened by wet honing to prevent interference fringes due to laser light, the projections caused by these cutting operations and the wet honing The minute projections specifically generated by the above are rendered harmless by the treatment with the acidic treatment liquid. Furthermore, since a thick chemical conversion film is formed more quickly than in the case of treatment with a treatment liquid consisting of phosphoric acid, chromic acid and sodium fluoride, it is possible to make the protrusions into insulators that could not be achieved by the conventional method. It will be possible. Further, in the case of forming an undercoat layer made of a cured film using an organometallic compound and a silane coupling agent,
Improves adhesion between photosensitive layer and support, improves coatability of photosensitive layer, protects support, covers defects on support, protects photosensitive layer from electrical breakdown, and injects carrier into photosensitive layer Will be improved.

Therefore, the electrophotographic photosensitive member of the present invention is
When it is used in a contact charging type electrophotographic method, charge leakage due to the protrusions of the support is eliminated, and an image of good quality can be formed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an electrophotographic apparatus used in an image forming method of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Photosensitive drum, 2 ... Power supply, 3 ... Charging device, 4 ... Image input device, 5 ... Developing device, 6 ... Pressure transfer device or electrostatic transfer device, 7 ... Paper, 8 ... Fixing device, 9 ... Cleaner mechanism 1
0 ... Exposing device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Toru Asahi, 1600 Takematsu, Minamiashigara-shi, Kanagawa, Fuji Xerox Co., Ltd. (72) Masahiko Hozumi, 1600, Takematsu, Minamiashigara, Kanagawa, Fuji Xerox Co., Ltd.

Claims (6)

[Claims] 1. An electrophotographic photosensitive member comprising a support made of aluminum or an aluminum alloy and a photosensitive layer provided on the support, wherein the support has a film formed by an acidic treatment liquid containing phosphoric acid, chromic acid and hydrofluoric acid on the surface. An electrophotographic photosensitive member comprising: 2. The electrophotographic photosensitive member according to claim 1, wherein the support is a non-cutting tube made of aluminum or an aluminum alloy. 3. The electrophotographic photosensitive member according to claim 1, wherein the surface-treated support is a surface-roughened substrate. 4. An electrophotographic photosensitive member comprising a support made of aluminum or an aluminum alloy and a photosensitive layer provided on the support, wherein the support has a coating film formed on its surface by an acidic treatment liquid containing phosphoric acid, chromic acid and hydrofluoric acid. Wherein the photosensitive layer comprises a charge generation layer containing a gallium phthalocyanine compound as a charge generation material and a charge transport layer, and the charge generation layer is formed directly on the coating film. Item 1. The electrophotographic photosensitive member according to item 1. 5. An electrophotographic photosensitive member comprising a support made of aluminum or an aluminum alloy and a photosensitive layer provided on the support, wherein the support has a surface formed by an acidic treatment liquid containing phosphoric acid, chromic acid and hydrofluoric acid. And an undercoat layer containing at least an organometallic compound and a silane coupling agent on the coating film. 6. An image forming method comprising the steps of charging, imagewise exposing, developing, and transferring and fixing an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member according to claim 1 is used as the electrophotographic photosensitive member. In the step, the image forming method is characterized in that a charging device to which a voltage is applied is brought into contact with the surface of the electrophotographic photosensitive member to be charged.