KR19990062682A - Electrophotographic photosensitive member, manufacturing method thereof, process cartridge and electrophotographic apparatus - Google Patents

Abstract

An electrophotographic photosensitive member having an aluminum substrate and a photosensitive layer is disclosed. The substrate comprises aluminum, oxygen and titanium, or aluminum, oxygen and zirconium at the surface portion on the side of the photosensitive layer. Also disclosed is a method of manufacturing an electrophotographic photosensitive member, and a process cartridge and an electrophotographic apparatus using the photosensitive member.

Description

Electrophotographic photosensitive member, manufacturing method thereof, process cartridge and electrophotographic apparatus

The present invention relates to an electrophotographic photosensitive member, a method for producing an electrophotographic photosensitive member, and an electrophotographic apparatus having a process cartridge and a photosensitive member.

The electrophotographic photosensitive member is basically composed of a photosensitive layer in which a latent image is formed thereon by electrostatic charging and exposure, and a substrate provided with the photosensitive layer.

On the other hand, electrophotographic photosensitive members are required to have sensitivity, electrical properties and optical properties depending on the electrophotographic process applied.

They are also required to have sufficient environmental stability to satisfactorily perform their performance in any environment from low temperature / low humidity to high temperature / high humidity.

Imaging defects are typically digital copiers and laser beam printers in which exposure is performed using image lines, black spots in white areas, white spots in black areas, background fog in white areas, and short wavelength light sources. In the case of such a device, it is represented by interference fringes caused by factors such as the surface shape of the substrate of the photoconductor and the uneven layer thickness.

As a factor having a great influence when such an image defect occurs, the surface state of the substrate can be given.

Substrates that have not been processed at all after the mold usually do not necessarily have a surface state as is best suited for the photoreceptor. Thus, a problem caused by the surface condition may occur in many cases.

In order to solve this problem, as described in Japanese Patent Application Laid-Open Nos. 54-12733 and 57-62056 so far, a method of forming a chromated chemical conversion coating by chromate treatment on the surface of an aluminum substrate; A method of forming a boehmite coating on the surface of an aluminum substrate as disclosed in Japanese Patent Application Laid-Open Nos. 58-14841 and 64-29852; And as disclosed in Japanese Patent Application Laid-Open No. 57-29051, an approach such as that represented by a method of forcibly oxidizing the surface of an aluminum substrate by high temperature treatment to form an oxidized film has been proposed.

In a chromate treatment method etc., the board | substrate which has some performance can be obtained. However, since the treatment solution contains chromium, it is very difficult to treat the waste liquid, which is also undesirable from the viewpoint of environmental safety.

In the boehmite treatment, the crystal state of the surface cannot be said to be suitable for the substrate of the electrophotographic photosensitive member. This may be effective to some extent in terms of electrophotographic performance, but satisfactory picture quality has not been achieved because the surface structure and shape are inadequate with respect to the image. Thus, under the present circumstances, all of the above satisfactory performances have not been obtained.

The surface treatment aims to prevent the film formed on the surface of the substrate from causing any non-uniformity in electrophotographic performance and image due to the charge locally injected from the substrate into the photosensitive layer.

As a method for preventing the above local charge injection in order not to cause an image defect, a method of providing an aluminum oxide layer by anodizing the surface of an aluminum substrate can be used (for example, Japanese Patent Application Laid-open No. 2-7070 and 5-34964).

This method is a good way to achieve this purpose. However, in order to form the layer uniformly without causing any non-uniform layer thickness on the substrate surface, the layer must be formed to some large thickness, the thickness being about 5 to 6 microns or more under its usual forming conditions. to be. Therefore, the cost increases because the layer must be formed to be substantially larger than the thickness substantially required as the charge injection blocking layer.

Accordingly, it is an object of the present invention to facilitate the electrophotographic photosensitive member having excellent electrophotographic characteristics, which can cause no image defects and also cause dislocation fluctuations under any environment from low temperature / low humidity to high temperature / high humidity, the electrophotographic photosensitive member being easy. And a process cartridge and an electrophotographic apparatus capable of having the photoreceptor, which can be produced at low cost and stably.

1 schematically illustrates a structural example of an electrophotographic apparatus having a process cartridge having an electrophotographic photosensitive member of the present invention.

Fig. 2 is a graph showing the composition ratio of elements constituting the surface portion of the substrate having the electrophotographic photosensitive member of the present invention.

Explanation of symbols for the main parts of the drawings

Drum type electrophotographic photosensitive member: 1 axis: 2

First charging means: 3 Light: 4

Developing Means: 5 Transfer Means: 6

Transfer material: 7 Image fixing means: 8

Cleaning means: 9 Preliminary exposure light: 10

Process cartridge: 11 Guide means: 12

As a result of the research conducted to solve the problems discussed above, the present inventors have applied a specific chemical conversion treatment to the surface of a substrate, that is, an aluminum substrate used in an electrophotographic photosensitive member without using any electrical external force and It has been found that it is a very efficient means to form insoluble coatings or coatings having a specific composition on a substrate by chemical reaction between acid aqueous solutions containing specific metal elements. This means is effective in that an electrophotographic photosensitive member with excellent properties can be obtained, can have a very small adverse effect on cost and environment, and further, the production apparatus can be manufactured more simply in anodizing. .

That is, the present invention provides an electrophotographic photosensitive member comprising aluminum, oxygen and titanium, or an aluminum substrate comprising aluminum, oxygen and zirconium, and a photosensitive layer provided on the substrate, at its surface portion on the side of the photosensitive layer. .

The invention also

Chemically converting the aluminum substrate using an aqueous acid solution containing titanium salt or zirconium salt; And

Forming a photosensitive layer

It provides a method for producing an electrophotographic photosensitive member comprising a.

The present invention still further provides a process cartridge and an electrophotographic apparatus having the above-mentioned electrophotographic photosensitive member.

The electrophotographic photosensitive member of the present invention has an aluminum substrate and a photosensitive layer provided thereon, the substrate containing aluminum, oxygen and titanium, or aluminum, oxygen and zirconium at its surface portion on the side of the photosensitive layer.

The electrophotographic photoconductor may be obtained by chemically converting an aluminum substrate using an acid aqueous solution containing a titanium salt or a zirconium salt to form a photosensitive layer.

The chemical conversion treatment referred to in the present invention is a treatment in which the substrate is contacted with a specific solution to form a coating having a specific composition on the substrate without applying any electrical external force as in the anodization treatment.

Metals of the metal salts used in the present invention are titanium and zirconium. An aluminum substrate having the chemical conversion treatment coating of the present invention, wherein any one of titanium and zirconium is present with aluminum and oxygen, has very good properties as a substrate for electrophotographic photosensitive members.

Titanium salts and zirconium salts may preferably be fluorine compounds. Titanium salts may include titanium hydrofluoric acid, its sodium salt, potassium salt or ammonium salt, and titanium sulfate. Zirconium salts may include zirconium potassium fluoride and zirconium sulfate.

The aqueous acid solution may preferably comprise metal salts at a concentration of 0.01 to 2 g / liter as the weight of the metal.

The aqueous acid solution may also contain fluorine ions, preferably at concentrations ranging from 0 to 10 g / liter. Within this range, the etching reaction can suitably occur on the substrate and a uniform coating can easily be formed.

The aqueous acid solution of the present invention may preferably have a pH adjusted within the range of 1.0 to 5.5 using ammonia or sodium hydroxide. If the pH is below 1.0, the etching reaction may be violent and it may be difficult to obtain a good coating. If the pH is above 5.5, the coating can be formed at a low speed where only a thin coating can be obtained, making it difficult to achieve the excellent results of the present invention.

In the present invention, in view of the fact that the reaction occurs stably, when the acid aqueous solution is used, the acid aqueous solution can preferably be heated to 30 to 90 ° C.

As a method for contacting the substrate with an aqueous acid solution, dipping or spraying can be used. Deposition is preferred in terms of production efficiency.

Chemically converted substrates are used after washing and drying them.

The composition of the substrate surface portion in the present invention is measured by Auger electron beam spectroscopy and is defined as the composition within the range from the outermost surface to a depth of 50 x (5 x 10 ^-3 microns).

In the present invention, titanium or zirconium may be included in amounts ranging from 4 to 100 atomic percent.

The titanium or zirconium containing chemical conversion treatment coating formed on the substrate surface may preferably have a total layer thickness of 1 micron or less, more preferably 50 kPa (5 × 10 ⁻³ microns) or more. If the layer thickness of the coating is greater than 1 micron, the charge tends to barely escape in the excessive state, leading to an increase in residual potential or to ghosting. If the layer thickness is 50 kPa (5 x 10 ^-3 microns) or less, the excellent results of the present invention can barely be obtained.

In the present invention, in view of the corrosion resistance and adhesion of the coating film, the aqueous acid solution may preferably further include phosphoric acid, phosphate, tannin or tannic acid.

Phosphoric acid and phosphate salts can include phosphoric acid or its sodium, potassium or ammonium salts, and pyrophosphoric acid, tripolyphosphoric acid, hexametaphosphate or its sodium or potassium salts. Furthermore, by using propyl acid, nitro diethanol ethylene phosphonic acid, 2-hydroxyethyl methacryl-1-acid phosphonic acid, 2-ethylhexyl acid phosphonic acid and ethane-1-hydroxy-1,1-diphosphonic acid Representative organophosphate compounds can be used.

Phosphoric acid or phosphate in aqueous acid solution may preferably be present at a concentration of 0.05 to 50 g / liter with respect to phosphate ions. Within this range, particularly uniform and good chemical conversion treatment coatings can be formed, and the treatment solution can also have particularly good stability.

Tannins or tannic acids may include kebracho tannins, depth tannins, Chinese tannins, Turkish tannins, hamellitanic acid, chebulinic acid, sumactanine, Chinese gallotanine, and ellagitannin.

Tannin or tananoic acid in the aqueous acid solution may preferably be at a concentration of 0.1 to 10 g / liter.

In the present invention, the aqueous acid solution may preferably include hydrofluoric acid, boric fluoride acid, hydrofluoric acid or any salt thereof. These compounds have the ability to etch the substrate surface when chemically converting the substrate to form a very uniform chemical conversion treatment coating.

From the foregoing, the chemical conversion treatment coating of the present invention preferably contains phosphorus or fluorine.

Special limitations on aluminum substrates as long as aluminum substrates can include pure aluminum and Al-Mn, Al-Mg, Al-Cu, Al-Si, Al-Mg-Si and Al-Cu-Si type aluminum alloys There is no. More specifically, 6000 aluminum type such as JIS A6063 and 3000 aluminum type such as JIS A3003 may be used. There is also no particular limitation on its shape. It may be present in drum form.

The photosensitive layer of the electrophotographic photosensitive member used in the present invention will be described below.

The photosensitive layer of the present invention is roughly divided into a single layer type in which a charge generating material and a charge transporting material are contained in the same layer, and a multilayer type having a charge generating material containing charge generating material and a charge transporting material containing charge transporting material. .

An electrophotographic photosensitive member having a multilayer photosensitive layer will be described below.

The photosensitive layer may be configured in such a way that the charge generating layer and the charge transport layer are stacked on the substrate in this order or vice versa.

The charge transport layer forms a nitrogen-containing cyclic compound, a hydrazone compound, or a styryl compound such as a polycyclic aromatic compound having a biphenylene, anthracene, pyrene or phenanthrene structure, indole, carbazole, oxadiazole or pyrazoline It is formed by coating a coating solution prepared by dissolving in a resin having a resin and then drying.

The film-forming resin may include polyesters, polycarbonates, polystyrenes, polymethacrylates, and polyacrylates.

The charge transport layer may preferably have a layer thickness of 5 to 40 microns, preferably 10 to 30 microns.

The charge generating layer comprises azo pigments such as Sudan red or dian blue, quinone pigments such as pyrene, quinone or anthrone, quinocyanine pigments, indigo pigments such as perylene pigments, indigo or thioindigo, or phthalocyanine pigments. The dispersion prepared by dispersing in a resin such as Ral, polystyrene, polyvinyl acetate or polyvinyl acrylate is coated and then dried or formed by vacuum deposition of the pigment.

The charge generating layer may preferably have a layer thickness of 5 microns or less, more preferably 0.1 to 3 microns.

The monolayer photosensitive layer is formed by coating and then drying a coating fluid prepared by dispersing and dissolving a charge generating material and a charge transporting material in a resin.

The photosensitive layer may have a layer thickness of preferably 5 to 40 microns, more preferably 10 to 30 microns.

In the present invention, a subbing layer having a function as a barrier and an adhesive function can be provided between the support and the photosensitive layer. The serving layer is formed by coating and then drying a solution prepared by dissolving casein, polyvinyl alcohol, nitro cellulose, ethylene-acrylic acid copolymer, alcohol soluble polyamide, polyurethane or gelatin.

The serving layer may preferably have a layer thickness of 0.1 to 3 microns.

In the present invention, a protective layer may be provided on the photosensitive layer.

The protective layer is polyester, polyacrylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, polyamide-imide, polysulfone, polyacrylic acid ether, polyacetal, phenol, acrylic acid , Silicone, epoxy, urea, allyl, alkyd, butyral, phenoxy, phosphazene, acrylic modified epoxy, acrylic modified urethane and acrylic modified polyester resin.

The protective layer may preferably have a layer thickness of 0.2 to 10 microns.

In each of these layers, lubricants such as polytetrafluoroethylene, polyvinylidene fluoride, fluorine graft polymers, silicone graft polymers, fluorine block polymers, silicone block polymers or silicone oils are incorporated to provide cleaning performance and Wear resistance can be improved.

Additives such as antioxidants may be further added for the purpose of improving weather resistance.

In the protective layer, conductive powder such as conductive tin oxide or conductive titanium oxide can be dispersed for the purpose of resistance control.

1 schematically illustrates the structure of an electrophotographic apparatus having a process cartridge having an electrophotographic photosensitive member of the present invention.

In Fig. 1, reference numeral 1 denotes the drum-type electrophotographic photosensitive member of the present invention, which is rotatably driven around the axis 2 in the direction of the arrow at a predetermined peripheral speed. The photosensitive member 1 is uniformly electrostatically charged on its periphery through the first charging means 3 at a predetermined positive or negative potential. The photosensitive member thus charged is then exposed to light 4 emitted from exposure means (not shown) for slit exposure or laser beam scanning exposure. In this way, an electrostatic latent image is formed continuously on the periphery of the photosensitive member 1.

The electrostatic latent image thus formed is immediately developed by the toner by the operation of the developing means 5. The toner developing image formed by the development is then transferred from the paper feeding section (not shown) to the surface of the transfer material 7 supplied in such a manner as to occur simultaneously with the rotation of the photosensitive member 1 between the photosensitive member 1 and the transfer means 6. It is continuously transferred by the operation of the means 6.

The transfer material 7 containing the image is separated from the surface of the photosensitive member, passes through the image fixing means 8, and is printed out from the apparatus as a copy (copy) in which the image is fixed.

The surface of the photosensitive member 1 to which the image is transferred is passed through the cleaning means 9 to remove the toner remaining after the transfer. Therefore, the surface of the photoconductor is cleaned, and the charge is removed by the preexposure light 10 emitted from the preliminary exposure means (not shown), and then repeatedly used for image formation. When the first charging means 3 is a contact charging means using a charging roller, it does not necessarily require preliminary exposure.

In the present invention, the apparatus includes the electrophotographic photosensitive member 1, the first charging means 3, and the developing means 5 so that the process cartridge can be detachably installed on the body of an electrophotographic apparatus such as a copier or a laser beam printer. And a combination of a plurality of components integrally connected as a process cartridge among the components such as the cleaning means 9. For example, at least one of the first charging means 3, the developing means 5 and the cleaning means 9 together with the photoreceptor 1 are integrally supported in the cartridge and provided with a rail 12 provided in the body of the apparatus. Through the same guide means it is possible to form a process cartridge 11 which can be detachably installed in the body of the device.

When the electrophotographic apparatus is used as a copying machine or a printer, the exposure light 4 reads the original from the reflected light and transmitted light from the original, or the sensor, and scans the laser beam according to a signal obtained by signaling the information, It is light irradiated by driving of an LED array or driving of a liquid crystal shutter array.

The electrophotographic photosensitive member of the present invention is widely applied not only in the copier of electrophotographic but also in the field where electrophotography is applied, for example, laser beam printer, CRT printer, LED printer, liquid crystal printer and laser beam engraver. .

The invention will be described in more detail in the following examples.

Example 1

An aluminum cylinder having an outer diameter of 29.92 mm, an inner diameter of 28.5 mm, and a length of 254 mm was manufactured.

Aqueous acid solution containing titanium hydrofluoric acid and titanium ammonium fluoride as the organic phosphoric acid and titanium ammonium fluoride (trade name: PALCOAT 3753, Nihon Parkerizing Co., Ltd.), pH: 3.8 Maintained at a temperature of ℃, the aluminum cylinder was immersed in the acid aqueous solution, subjected to chemical conversion for 1 minute, washed with pure water and then air dried. The layer thickness of the chemical conversion treatment coating thus formed was 200 mm 3.

Next, 4 parts by weight of oxytitanium phthalocyanine, 2 parts by weight of polyvinyl butyral resin (trade name: BX-1, Sekisui Chemical Company, commercially available) and 34 parts by weight of cyclohexanone were dispersed in a sand mill for 8 hours. 60 parts by weight of tetrahydrofuran was added to prepare a charge generating layer coating dispersion.

The dispersion was deposited-coated onto a chemically converted aluminum cylinder and then dried while heating at 95 ° C. for 10 minutes to form a charge generating layer having a layer thickness of 0.2 micron.

Next, a solution prepared by dissolving 50 parts by weight of the triarylamine compound represented by the following formula and 50 parts by weight of the bisphenol-Z polycarbonate resin in 400 parts by weight of monochlorobenzene was deposited-coated on the charge generation layer. Drying while heating at 110 ° C. for 1 hour gave a charge transport layer having a layer thickness of 20 microns.

evaluation

While argon ion etching was performed from the outermost surface in the depth direction of the substrate, the surface portion of the substrate which had been chemically converted, washed and dried was tested by elemental analysis using a scanning auger electron beam spectrometer. As a result, aluminum, titanium and oxygen were detected as main constituent elements. This is shown graphically in FIG. 2. In this embodiment, the relationship between the depth and the sputtering time is 110 mW / min for SiO ₂ . This value can be changed as appropriate.

The composition ratio of the elements at the deepest surface of the substrate and at a depth of 50 mm from the outermost surface is shown in Table 1 as a percentage of the elements considering the amount of aluminum element as 100.

As can be seen from these results, the chemical conversion coating on the substrate surface includes an oxidized aluminum coating in which titanium is incorporated. As a result of the analysis, nitrogen, fluorine, phosphorus and the like are detected as other containing elements. These elements are considered to be elements that were originally contained in the fluorine compound and phosphoric acid in the acid aqueous solution used in the chemical conversion treatment and were incorporated into the chemical conversion treatment coating.

Next, the obtained electrophotographic photosensitive member was subjected to 48 hours in an environment of normal temperature / normal humidity (23 ° C., 60% RH), high temperature / high humidity (32.5 ° C., 85% RH), or low temperature / low humidity (15 ° C., 10% RH). After being left for a while, it was installed in a commercially available laser laser printer of an inverse developing system to reproduce solid white images in each environment.

The state of the background fog in the solid white image thus formed was visually evaluated. The results are shown in Table 2.

At the same time, dark potential and sinus potential were measured in each environment. The results are shown in Table 2.

Example 2

Electrophotographic photosensitive member, except using a solution containing zirconium fluoride and zirconium sulfate (trade name: PALCOAT 3756, Nihon Parkerizing Co., Ltd .; pH: 3.2) as a salt of tannic acid, ammonium salt and metal. Was produced in the same manner as in Example 1. Similarly evaluation was performed. The results are shown in Table 1 and Table 2. The chemical conversion treatment coating had a layer thickness of 150 mm 3.

Example 3

An electrophotographic photosensitive member was used except that a solution containing zirconium hydrofluoric acid and zirconium ammonium fluoride (trade name: PALCOAT 3753T, Nihon Parkerizing Co., Ltd .; pH: 3.2) as the phytic acid-containing and metal salt was used as an aqueous acid solution for chemical conversion treatment. Produced in the same manner as in Example 1. Evaluation was done similarly. The results are shown in Table 1 and Table 2. The chemical conversion treatment coating had a layer thickness of 180 mm 3.

Example 4

The electrophotographic photosensitive member was used as a metal salt, except that a solution containing phosphoric acid and zirconium fluoride and zirconium hydrofluoric acid (trade name: ALUSURF 301N-1, Nihon Paint Co., Ltd .; pH: 4.0) was used as an aqueous acid solution for chemical conversion treatment. Produced in the same manner as in Example 1. Evaluation was done similarly. The results are shown in Table 1 and Table 2. The chemical conversion treatment coating had a layer thickness of 300 GPa.

Comparative Example 1

An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that no chemical conversion treatment was performed. Evaluation was done similarly. The results are shown in Table 2.

Comparative Example 2

Ammonia water having a concentration of 0.3% was prepared and heated to 95 ° C.

In the heated ammonia water, the same aluminum cylinder as used in Example 1 without chemical conversion treatment was immersed and subjected to surface treatment, followed by drying to form a boehmite coating on the cylinder surface.

An electrophotographic photosensitive member was produced in the same manner as in Example 1 except for using the aluminum cylinder instead. Evaluation was done similarly. The results are shown in Table 2.

Comparative Example 3

The aluminum cylinder was immersed for 1 minute in a chemical conversion treatment chromium phosphate solution (trade name: ALUCHROME 3701, manufactured by Nihon Parkerizing Co., Ltd.) maintained at 30 ° C. containing no titanium or zirconium instead of the aqueous acid solution of the present invention. Chemical conversion treatment was performed to form a chromate type chemical conversion treatment coating on the surface of the cylinder.

An electrophotographic photosensitive member was produced in the same manner as in Example 1 except for using the aluminum cylinder instead. Similar evaluation was made. The results are shown in Table 2.

Percentage of atomic number of each element to atomic number of aluminum Measuring element aluminum titanium zirconium Oxygen nitrogen Fluoride sign carbon Example 1 Outermost surface 100 32.8 - 470 80.3 7.2 14.8 503.1 50Å depth 100 64.2 - 389.6 63.4 6.7 13.4 - Example 2 Outermost surface 100 - 23.3 422.1 - 10.5 66.3 541.9 50Å depth 100 - 10 185 - 8.8 9.1 - Example 3 Outermost surface 100 - 29.3 356.6 53.5 6.1 - 453.5 50Å depth 100 - 51.6 320.7 43.1 4.8 - - Example 4 Outermost surface 100 - 59 232.7 100 34 100 394.7 50Å depth 100 - 95 916.7 20.8 8.3 45.8 - Measuring device: ULVAC-PHI. 670xi type scanning auger electron spectrometer manufactured by INC .; Electron probe diameter: 0.1 micron or less. Argon ion gun is used for etching.

Fog rating Measurement potential (-V) Normal temperature / normal humidity High temperature / high humidity Low / low humidity Normal temperature / normal humidity High temperature / high humidity Low / low humidity Dark list Dark list Dark list Example One A A A 700 170 700 170 700 175 2 A A A 705 170 700 170 705 180 3 A A A 695 170 695 165 700 175 4 A A A 700 170 700 165 700 180 Comparative example One C B C 700 170 690 150 700 220 2 C B C 700 170 695 165 700 180 3 B B C 700 170 695 160 705 180 Evaluation: A: Excellent, B: Good, C: Poor

As described above, in the present invention, an electrophotographic photosensitive member having excellent electrophotographic characteristics that do not cause image defects under any circumstances, and which can cause less potential fluctuation, the electrophotographic photosensitive member is easily and at low cost, and A method that can be produced stably is possible.

Claims (24)

An electrophotographic photosensitive member comprising an aluminum substrate containing aluminum, oxygen and titanium or aluminum, oxygen and zirconium at the surface portion of the substrate on the side of the photosensitive layer and a photosensitive layer provided on the substrate. The electrophotographic photosensitive member according to claim 1, wherein the content of titanium or zirconium in the surface portion on the side of the photosensitive layer is 4 atomic% to 100 atomic% based on the aluminum content. The electrophotographic photosensitive member according to claim 1, wherein the surface portion on the side of the photosensitive layer further comprises phosphorus. The electrophotographic photosensitive member according to claim 1 or 3, wherein the surface portion on the side of the photosensitive layer further contains fluorine. The electrophotographic photosensitive member according to claim 1, wherein the surface portion on the side of the photosensitive layer is a coating formed by chemical conversion treatment. 6. An electrophotographic photosensitive member according to claim 5, wherein the coating has a layer thickness of 1 micron or less. Chemically converting the aluminum substrate using an aqueous acid solution containing titanium salt or zirconium salt, and Forming a photosensitive layer Method for producing an electrophotographic photosensitive member comprising a. The method according to claim 7, wherein the titanium salt and zirconium salt are fluorine compounds. The method of claim 7, wherein the pH of the aqueous acid solution is 1.0 to 5.5. The method of claim 7, wherein the temperature of the acid aqueous solution is 30 ℃ to 90 ℃. 8. The method of claim 7, wherein said acid aqueous solution further comprises at least one compound selected from the group consisting of phosphoric acid, phosphate, tannin and tannic acid. 8. The method of claim 7, wherein said acid aqueous solution further comprises one or more compounds selected from the group consisting of hydrofluoric acid, boric fluoride acid, hydrofluoric acid, and any salts thereof. An electrophotographic photosensitive member and at least one means selected from the group consisting of charging means, developing means and cleaning means, wherein said electrophotographic photosensitive member and at least one said means can be detachably installed on a main body of an electrophotographic apparatus; Supported as a unit, The electrophotographic photosensitive member comprises an aluminum substrate and a photosensitive layer provided thereon, The substrate comprises aluminum, oxygen and titanium, or aluminum, oxygen and zirconium at the surface portion of the substrate on the side of the photosensitive layer. Process cartridge. The process cartridge according to claim 13, wherein the content of titanium or zirconium in the surface portion on the side of the photosensitive layer reaches 4 atomic% to 100 atomic% based on the aluminum content. The process cartridge of claim 13, wherein the surface portion on the side of the photosensitive layer further comprises phosphorus. The process cartridge according to claim 13 or 15, wherein the surface portion on the side of the photosensitive layer further comprises fluorine. The process cartridge according to claim 13, wherein the surface portion on the side of the photosensitive layer is a coating formed by chemical conversion treatment. 18. The process cartridge of claim 17, wherein the coating has a layer thickness of 1 micron or less. The electrophotographic photosensitive member comprises an aluminum substrate and a photosensitive layer provided thereon, Wherein the substrate comprises aluminum, oxygen and titanium, or aluminum, oxygen and zirconium at the surface portion of the substrate on the side of the photosensitive layer, And an electrophotographic photosensitive member, a charging means, an exposure means, a developing means, and a transfer means. 20. The electrophotographic apparatus according to claim 19, wherein the content of titanium or zirconium in the surface portion on the side of the photosensitive layer is 4 atomic% to 100 atomic% based on the content of aluminum. An electrophotographic apparatus according to claim 19, wherein the surface portion on the side of the photosensitive layer further comprises phosphorus. The electrophotographic apparatus according to claim 19 or 21, wherein the surface portion on the side of the photosensitive layer further comprises fluorine. An electrophotographic apparatus according to claim 19, wherein the surface portion on the side of the photosensitive layer is a coating formed by chemical conversion treatment. 20. The electrophotographic apparatus of claim 19, wherein the coating has a layer thickness of 1 micron or less.