JPH07287403A - Electrophotogpaphic photoreceptor, image forming device with the same and process unit - Google Patents

Abstract

PURPOSE:To provide a long-life electrophotographic photoreceptor capable of always obtaining a good image, and to provide an image forming device equipped with the electrophotographic photoreceptor and a process unit. CONSTITUTION:This electrophotographic photoreceptor 1 is provided with a photosensitive layer having a part of increasing shaving in a direction from the surface to the inside on a support. The image forming device is provided with the electrophotographic photoreceptor 1, an electrostatic charging member 2 for electrostatically charging the photoreceptor 1, an image exposure means for executing image exposure to the electrostatically charged photoreceptor 1 and forming an electrostatic latent image, a developing means 6 for developing the photoreceptor 1 with the electrostatic latent image formed by used of toner and a cleaning means 9 for cleaning the surface of the photoreceptor 1. As for the process unit, at least one of the electrostatic charging member 2, the developing means 6 and the cleaning means 9 is integrally formed with the electrophotographic photoreceptor 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, an image forming apparatus and a process unit equipped with the electrophotographic photosensitive member.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic recording method,
Not only is the electrophotographic photoreceptor smeared with transfer residual toner,
By repeated use, the components of the transfer material and discharge products at the time of charging are gradually contaminated. Contamination of the electrophotographic photosensitive member lowers the electric resistance of the surface and disturbs the electrostatic latent image, or toner is fused to the surface of the electrophotographic photosensitive member, resulting in a marked damage to the image. .

Therefore, a method which has been conventionally practiced is to always obtain a good image by positively polishing the electrophotographic photosensitive member with a cleaning blade or the like and always making the surface of the photosensitive member a new surface. . According to this, since the photoconductor is constantly refreshed, a good image is maintained.

[0004]

However, since contaminants adhering to the surface of the electrophotographic photoconductor become difficult to remove with repeated use of the photoconductor, in the conventional photoconductor, the surface of the photoconductor is not easily removed. From the beginning of use of the photoconductor, polishing was performed more than necessary so that contaminants could be completely removed even when the photoconductor was used for a long period of time. In other words, if it is attempted to completely remove the contaminants, the life of the electrophotographic photosensitive member is shortened accordingly.

As described above, if it is attempted to maintain a stable image, the photosensitive layer of the electrophotographic photosensitive member is shaved too much and the life is shortened. On the contrary, in order to prolong the life, the shading amount of the photosensitive layer is reduced. If it is reduced, there is a problem that a good image cannot be maintained.

On the other hand, a method of detecting the film thickness of the photosensitive layer has been proposed (for example, Japanese Patent Application Laid-Open No. 5-223513).
This is when the charge is removed from the charged state of the photoconductor (or when the charge is removed from the charged state).
Is a method of calculating the film thickness of the photosensitive layer by detecting the current flowing through the capacitor, measuring the capacity of the capacitor from the current.
In this way, the maintenance of the photoconductor can be properly performed.

The present invention has been made in view of the above circumstances, and provides an electrophotographic photosensitive member which always obtains a good image and has a long life, and an image forming apparatus and a process unit equipped with the electrophotographic photosensitive member. The purpose is to

[0008]

The electrophotographic photosensitive member of the present invention has, on a support, a photosensitive layer having a portion whose abradability increases from the surface toward the inside.

In the image forming apparatus of the present invention, the electrophotographic photosensitive member described above, a charging member for charging the electrophotographic photosensitive member, and an electrostatic latent image by performing image exposure on the charged electrophotographic photosensitive member. And an image exposing unit for forming an electrostatic latent image, a developing unit for developing the electrophotographic photosensitive member on which an electrostatic latent image is formed with a toner, and a cleaning unit for cleaning the surface of the electrophotographic photosensitive member.

Further, the process unit of the present invention is one in which at least one of a charging member, a developing means and a cleaning means is integrated with the above electrophotographic photosensitive member.

The electrophotographic photosensitive member of the present invention has a photosensitive layer on the support which is easily scraped in the direction from the surface to the inside. That is, the cleaning means is in contact with the surface of the electrophotographic photosensitive member to polish the surface of the photosensitive member to remove contaminants such as toner on the surface of the photosensitive member. However, it is improved as the polishing progresses. The sharpness of the electrophotographic photosensitive member will be described in detail later.

By doing so, the photosensitive layer is not scraped off more than necessary at the beginning of use of the electrophotographic photosensitive member, and the life of the photosensitive member is extended.

In the present invention, the abrasion resistance of the photosensitive layer was evaluated as follows.

Laser beam printer manufactured by Hewlett-Packard (trade name: Laserjet 4 Plus)
Then, attach the electrophotographic photosensitive member to be evaluated to a temperature of 25 ° C,
Printing was carried out at a humidity of 50% RH, and the sharpness was evaluated by how much the photosensitive layer was scraped when printed on 500 sheets of recording paper. That is, the amount of abrasion of the photosensitive layer from the first recording sheet to the 500th recording sheet is α ₁ , and the 1000th recording sheet after the 501st recording sheet is printed. The amount of scraping before printing on α
₂ , 1500 after printing on 1001st recording paper
The amount of abrasion until printing on the first recording paper is α ₃ , 15
The amount of abrasion from printing on the 01st recording paper to printing on the 2000th recording paper is α ₄ , ..., {500
50 after printing on the (n-1) +1} th recording paper
The amount of abrasion until printing on the 0nth recording paper is α _n ,
As described above, the scraping property was shown by the scraping amount α _n for every 500 sheets of recording paper.

The abrasion resistance is evaluated by the laser jet 4 plus in the one-sheet intermittent mode (printing is performed on one sheet of recording paper, and after the printing is completed, the rotation of the photoconductor is completely stopped, and then the image signal is again reproduced. Was input to print the next print mode. The image pattern at this time was a horizontal line having a thickness of 2 dots. The interval between the horizontal lines was equivalent to 99 dots.

In the present invention, the range in which the sharpness is increased is at least 10 μm, further 25 μm, particularly 30 μm in the depth direction from the surface of the electrophotographic photosensitive member in the unused state.
It is preferable to be up to. Further, the sharpness may be constant from the surface of the electrophotographic photosensitive member in the unused state to a predetermined depth, and thereafter, the sharpness may be increased in the depth direction within a range of 10 μm, further 25 μm, and particularly 30 μm. in this case,
It is preferable that the range of constant sharpness is within a range of 3 to 8 μm from the surface of the electrophotographic photosensitive member in an unused state.

In the electrophotographic photosensitive member of the present invention, the rate of increase in the abrading property is such that the abrading property becomes 1.2 to 3.0 times every 10 μm in the inward direction from the surface of the electrophotographic photosensitive member. preferable.

The electrophotographic photosensitive member of the present invention preferably has an abrasion amount α ₁ of 0.3 to 0.9 μm from an unused state to printing on 500 sheets of recording paper.

The electrophotographic photoreceptor of the present invention has a photosensitive layer on a support. As the photosensitive layer, a layer in which a charge generation layer, a charge transport layer and, if necessary, a protective layer are laminated can be used. The charge generation layer contains a charge generation material that generates charges upon exposure. The charge transport layer contains a charge transport material that transports charges. The charge generation layer and the charge transport layer may be in the order of the charge generation layer and the charge transport layer from the conductive support side, or vice versa.

The charge-generating layer can be formed by vapor-depositing the charge-generating material or by applying a coating composition dispersed with a suitable binder (without a binder).

Examples of the charge generating substance include azo pigments (eg monoazo, bisazo, trisazo, etc.), phthalocyanine pigments (eg metal phthalocyanine, non-metal phthalocyanine), indigo pigments (eg indigo,
Thioindigo etc.), polycyclic quinone pigments (eg anthraquinone, pyrene quinone etc.), perylene pigments (eg perylene anhydride, perylene imide etc.), squalium pigments, pyrylium, thiopyrylium salts, triphenylmethane pigments etc. Can be mentioned. Further, an inorganic material such as selenium, selenium-tellurium, or amorphous silicon can also be used as the charge generation substance.

The binder used in the charge generating layer can be selected from a wide range of insulating resins or organic photoconductive polymers. For example, as the insulating resin, polyvinyl butyral, polyarylate (condensation polymer of bisphenol A and phthalic acid, etc.), polycarbonate (polycarbonate Z, modified polycarbonate, etc.), polyester, phenoxy resin, acrylic resin, polyacrylamide, polyamide, cellulose resin , Urethane resin, epoxy resin,
Examples thereof include casein and polyvinyl alcohol. Examples of the organic photoconductive polymer include polyvinylcarbazole, polyvinylanthracene, polyvinylpyrene and the like.

The thickness of the charge generation layer is 0.01 to 15 μm,
Further, it is preferably 0.05 to 5 μm, and when a binder is used, the weight ratio of the charge generating material to the binder is 10:
1 to 1:20 is preferable.

The organic solvent used for coating the charge generation layer is selected from the solubility and dispersion stability of the resin and charge generation material used, but alcohols, sulfoxides, ethers, esters, and aliphatic halogens. Chemical hydrocarbons or aromatic compounds can be used.

The charge transport layer is formed by dissolving the charge transport material in a binder having a film forming property. Examples of the charge transport material used in the present invention include hydrazone compounds,
Examples thereof include stilbene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds and triarylamine compounds. These charge transport materials are 1
They may be used alone or in combination of two or more.

As the binder used in the charge transport layer,
For example, polyvinyl butyral, polyester, polycarbonate (polycarbonate Z, modified polycarbonate, etc.), nylon, polyimide, polyarylate, polyurethane, styrene-butadiene copolymer, styrene-
Examples thereof include acrylic acid copolymers and styrene-acrylonitrile copolymers. The organic solvent used for coating the charge transport layer is the same as that used for coating the charge generation layer.

The thickness of the charge transport layer is preferably 5 to 50 μm, more preferably 8 to 20 μm, and the weight ratio of the charge transport material to the binder is 5: 1 to 1: 5, further 3: 1 to 1: 3. preferable.

The photosensitive layer may not be divided into two layers of the charge generating layer and the charge transporting layer, but may have a single layer structure containing both the charge generating material and the charge transporting material.

When the photosensitive layer is a single layer, the thickness of the photosensitive layer is 5
˜100 μm is preferable, and further preferably 10 to 60 μm. The single photosensitive layer preferably contains 10 to 70% by weight, and more preferably 20 to 70% by weight of each of the charge generating substance and the charge transporting substance.

The support can be formed using a conductive material such as aluminum, aluminum alloy, stainless steel, or the like. In addition, a support having a conductive surface layer formed on the surface of a support such as plastic, paper or metal can also be used. As the conductive surface layer, a vacuum deposited film of aluminum, an aluminum alloy, an indium oxide-tin oxide alloy, or the like, or a coating film in which conductive particles (for example, carbon black, tin oxide particles, etc.) are mixed in a binder and applied Can be used. The thickness of the conductive surface layer is preferably 1 to 30 μm. The shape of the support is preferably cylindrical, belt-shaped or sheet-shaped.

If desired, an undercoat layer having a barrier function or an adhesive function may be provided between the support or the conductive surface layer and the photosensitive layer. The subbing layer can be formed of, for example, casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyamide, modified polyamide, polyurethane, gelatin, aluminum oxide and the like. The thickness of the undercoat layer is 5 μm or less, further 0.5 to 3 μm.
m is preferred. The undercoat layer preferably has a thickness of 10 ⁷ Ω · cm or more.

If necessary, a protective layer may be provided on the surface of the electrophotographic photosensitive member. For the protective layer, a resin such as polyvinyl butyral, polyester, polycarbonate (polycarbonate Z, modified polycarbonate, etc.), nylon, polyimide, polyarylate, polyurethane, styrene-butadiene copolymer, styrene-acrylic acid copolymer, styrene-acrylonitrile copolymer is used. It can be formed by dissolving in a solvent, coating on the photosensitive layer and drying. The thickness of the protective layer is preferably 0.05 to 20 μm. Further, the protective layer may contain a conductive powder ultraviolet absorber or the like.

In the electrophotographic photosensitive member of the present invention, the material used for the photosensitive layer is combined with vacuum deposition, sputtering, CVD or an appropriate binder resin, and the dip coating method, spray coating method, spinner coating method, roller coating method is used. It can be obtained by forming a film on a support using a coating method such as a Meyer bar coating method or a blade coating method.

In order to obtain an electrophotographic photosensitive member which is easily scraped in the direction from the surface to the inside, for example, the molecular weight or the glass transition point of the component constituting the photosensitive layer may be decreased or increased from the surface to the inside. Also,
The photosensitive layer may contain a fluororesin so that the content of the fluororesin decreases in the direction from the surface of the photoconductor toward the inside. In this way, the coefficient of friction decreases from the surface toward the inside, and it tends to be scraped toward the inside.

An image forming apparatus using the electrophotographic photosensitive member of the present invention will be described with reference to FIG.

The electrophotographic photosensitive member 1 of the present invention comprises a support 1a.
Is grounded and rotates in the direction of the arrow. The charging member 2 comes into contact with the photosensitive layer 1b of the electrophotographic photosensitive member 1, and the charging member 2
As a result, the photoconductor 1 is charged to a predetermined positive or negative voltage.
A positive or negative DC voltage is applied to the charging member 2. The DC voltage applied to the charging member 2 is -2000V-
+ 2000V is preferred. In addition to the DC voltage, an AC voltage may be superimposed on the charging member 2 to apply a pulsating voltage. The AC voltage superimposed on the DC voltage is preferably a peak-to-peak voltage of 4000 V or less.

The charged photoconductor 1 is then transferred to the image exposure means 1
2 receives light image exposure 5 (slit exposure or laser beam scanning exposure). As a result, electrostatic latent images corresponding to the exposed image are sequentially formed on the peripheral surface of the photoconductor. The electrostatic latent image is then toner-developed by the developing unit 6, and the toner-developed image is rotated by the transfer charging unit 8 from a sheet feeding unit (not shown) between the photoconductor 1 and the transfer charging unit 8. And is sequentially transferred onto the surface of the recording material 4 that is fed in synchronization with the above. The recording material 4 which has received the image transfer is separated from the surface of the photoconductor and is introduced into an image fixing means (not shown) to be subjected to the image fixing and printed out of the apparatus.

The surface of the photoconductor 1 after the image transfer is cleaned by the cleaning means 9 to remove the residual toner after transfer, and is repeatedly used for image formation.

The electrophotographic apparatus is constructed by integrally combining a plurality of constituent elements such as the above-mentioned photoconductor and developing means as a process unit, and this unit is configured to be detachable from the apparatus main body. May be. For example, at least the photoconductor 1, the charging member 2, and the developing means 6 are integrated into a process unit 13, and the process unit 1
3 may be configured to be removable by using a guide means such as a rail of the apparatus body. The cleaning means 9 may or may not be provided in the process unit 13. Further, at least the photoconductor 1 and the charging unit 2 are integrated into a first process unit, at least the developing unit 7 is a second process unit, and these first process units are included.
The second process unit may be detachably configured. The cleaning means 9 may or may not be provided in the first process unit.

A voltage is applied to the charging means 2 and the transfer charging means 8 by a power source 10. The power supply 10 is controlled by the control unit 11.

The film thickness detecting means 15 arranged between the charging means 2 and the power source 10 detects the current flowing when the charged photoconductor 1 is discharged to detect the thickness of a predetermined film forming the photosensitive layer. To do. In this way, it is possible to know when to replace the electrophotographic photosensitive member.

[0042]

EXAMPLES The present invention will be described in more detail below with reference to examples. "Parts" shown below means "parts by weight".

Example 1 An aluminum cylinder having an outer diameter of 30 mm and a length of 260 mm was used as a support, and a coating material composed of the following materials was applied to the outer surface of the support by a dipping method, followed by heat curing at 140 ° C. for 30 minutes. To form a conductive layer having a thickness of 15 μm.

Conductive pigment: Tin oxide coated titanium oxide ... 10 parts Resistance adjusting pigment: Titanium oxide ... 10 parts Binder resin: Phenol resin ... 10 parts Leveling material: Silicone oil ... 0.001 part Solvent: Methanol / methyl cellosolve = 1/1 ... 20 copies

A solution obtained by dissolving 3 parts of N-methoxymethylated nylon and 3 parts of copolymerized nylon in a mixed solvent of 65 parts of methanol and 30 parts of n-butanol was applied onto the conductive layer by a dipping method to prepare a coating solution of 0.1. An undercoat layer of 5 μm was formed.

Next, the diffraction angles 2θ ± 0.2 ° in the X-ray diffraction spectrum of CuKα are 9.0 °, 14.2 °, 2
TiOPc having strong peaks at 3.9 ° and 27.1 °
4 parts, polyvinyl butyral (brand name S-REC BM-
2 Sekisui Chemical Co., Ltd.) 2 parts and cyclohexanone 80 parts φ
115 parts of methyl ethyl ketone was added to the dispersion liquid dispersed for 4 hours by a sand mill using 1 mm glass beads to obtain a dispersion liquid for charge generation layer. This dispersion was applied onto the undercoat layer by a dipping method to form a charge generation layer having a thickness of 0.3 μm.

Next, 7 parts of an amine compound represented by the following structural formula (I), 3 parts of an amine compound represented by the following structural formula (II), 10 parts of a bisphenol Z polycarbonate resin having a viscosity average molecular weight of 15,000, 50 parts of monochlorobenzene and It was dissolved in a mixed solvent of 10 parts of dichloromethane to prepare a charge transport layer coating liquid (A).

[0048]

[Outer 1]

A weight average molecular weight of 2 instead of the bisphenol Z polycarbonate resin having a viscosity average molecular weight of 15,000.
A coating liquid (B) for charge transport layer was prepared in the same manner as the coating liquid (A), except that bisphenol Z of 0000 was used for the polycarbonate resin.

Thereafter, as in the case of the coating liquid (B), the coating liquid (C) was prepared using a bisphenol Z polycarbonate resin having a viscosity average molecular weight of 25,000 and a viscosity average molecular weight of 30.
Coating solution (D) using bisphenol Z polycarbonate resin having a viscosity average molecular weight of 35,000 (E)
A coating solution (F) was prepared using bisphenol Z polycarbonate resin having a viscosity average molecular weight of 40,000.

Thus, the coating liquid (A) was first applied on the charge generation layer by the dipping method and dried at 110 ° C. for 20 minutes to form a charge transport layer having a thickness of 4 μm.

After fusing the surface of the charge transport layer with dichloromethane, the coating solution (B) was applied in the same manner as the coating solution (A), and a charge transport layer having a thickness of 4 μm was laminated. . Similarly, coating liquids (C) to (F) are used to form charge transport layers having a thickness of 4 μm in the order of (C) to (F), and finally a charge transport layer having a total film thickness of 24 μm. Was formed. The outermost charge transport layer (formed by the coating liquid (F)) was dried for 40 minutes.

With respect to the electrophotographic photosensitive member of the present invention thus obtained, the viscosity average molecular weight was measured from the surface toward the inside at a thickness of 2 μm. The viscosity average molecular weight was calculated by measurement with an Ostwald viscometer. The results are shown in Table 1.

[0054]

[Table 1]

Further, this electrophotographic photosensitive member was mounted on the laser jet 4 plus of the above-mentioned evaluation machine and printing was carried out to evaluate the durability and the scraping property. The evaluation of the scraping property includes the scraping property from the unused state of the photoconductor to printing on 500 sheets of recording paper (hereinafter, initial scraping property), and the scraping amount when the total scraping amount from the unused state exceeds 10 μm. (Hereinafter referred to as internal scraping property). The evaluation results are shown in Table 2.

Comparative Example 1 An electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the charge transport layer was formed from only the coating liquid (A) of Example 1. The thickness of the charge transport layer was 24 μm. The drying condition of the charge transport layer was 105 ° C. for 1 hour.

The electrophotographic photosensitive member thus obtained was evaluated for durability and abrasion resistance in the same manner as in Example 1. The evaluation results are shown in Table 2.

Comparative Example 2 An electrophotographic photosensitive member was obtained in the same manner as in Comparative Example 1 except that the coating liquid (E) of Example 1 was used instead of the coating liquid (A) used in Comparative Example 1. It was

The electrophotographic photosensitive member thus obtained was evaluated for durability and abrasion resistance in the same manner as in Example 1. The evaluation results are shown in Table 2.

[0060]

[Table 2]

Example 2 Six types of copolymers (1) to (6) were synthesized at the copolymerization ratios shown in Table 3 using the following structural units (A) and (B). Table 3 also shows the glass transition points Tg of the copolymers (1) to (6). The viscosity average molecular weights of the copolymers (1) to (6) were all 20,000.

[0062]

[Outside 2]

[0063]

[Table 3]

Then, the copolymer (1) was used as a binder in place of the bisphenol Z polycarbonate resin in the coating liquid for the charge transport layer used in Example 1, and the others were the same as in the coating liquid of Example 1. To prepare a coating liquid (1) for charge transport layer. Similarly, using the copolymers (2) to (6),
Coating solutions (2) to (6) for charge transport layer were prepared respectively.

The coating liquid (1) thus prepared was used in place of the coating liquid (A) used in Example 1 to obtain the coating liquid (2).
Was used instead of the coating liquid (B), and in the same manner, coating liquids (3) to (6) were used instead of the coating liquids (C) to (F), respectively, and otherwise the same as in Example 1. To obtain the electrophotographic photoreceptor of the present invention. This electrophotographic photosensitive member has a glass transition point increasing from the surface toward the inside.

The electrophotographic photosensitive member thus obtained was evaluated for durability and abrasion resistance in the same manner as in Example 1. The evaluation results are shown in Table 4.

Comparative Example 3 An electrophotographic photosensitive member was obtained in the same manner as in Example 2 except that the charge transport layer was formed from only the coating liquid (3) of Example 2. The thickness of the charge transport layer was 24 μm. The drying condition of the charge transport layer was 105 ° C. for 1 hour.

The electrophotographic photosensitive member thus obtained was evaluated for durability and abrasion resistance in the same manner as in Example 1. The evaluation results are shown in Table 4.

Comparative Example 4 An electrophotographic photosensitive member was obtained in the same manner as in Comparative Example 3 except that the coating liquid (5) of Example 2 was used in place of the coating liquid (3) used in Comparative Example 3. It was

The electrophotographic photosensitive member thus obtained was evaluated for durability and abrasion resistance in the same manner as in Example 1. The evaluation results are shown in Table 4.

[0071]

[Table 4]

Example 3 7 parts of the amine compound of the structural formula (I) used in Example 1,
3 parts of an amine compound represented by the following structural formula (III) and 10 parts of a bisphenol Z polycarbonate resin having a viscosity average molecular weight of 20,000 are dissolved in a mixed solvent of 90 parts of monochlorobenzene and 20 parts of dichloromethane, and 1 part of tetrafluoroethylene powder is further added. Was added to prepare a coating liquid (i).

[0073]

[Outside 3]

A coating liquid (ii) was prepared in the same manner as the coating liquid (i) except that the amount of the tetrafluoroethylene powder was 2 parts. Similarly, the amount of tetrafluoroethylene powder is 3 parts,
4 parts, 5 parts and 6 parts, respectively, coating liquid (ii
i), (iv), (v) and (vi) were created.

A conductive layer, an undercoat layer and a charge generating layer were formed on the same support as in Example 1 in the same manner as in Example 1, and the coating solution (i) was further sprayed on the charge generating layer. Applied.
Next, before the coating film of the coating liquid (i) was dried, the coating liquid (ii) was applied onto the coating film of the coating liquid (i) by a spray method. Hereinafter, in the same manner, coating liquids (iii), (iv),
Each of (v) and (vi) was applied in this order by a spray method, and finally dried at 105 ° C. for 1 hour. Thus, an electrophotographic photosensitive member of the present invention having a 24 μm thick charge transport layer in which the content of the tetrafluoroethylene powder decreases from the surface toward the inside was obtained.

The electrophotographic photosensitive member thus obtained was evaluated for durability and abrasion resistance in the same manner as in Example 1. The evaluation results are shown in Table 5.

Comparative Example 5 An electrophotographic photosensitive member was obtained in the same manner as in Example 3, except that the charge transport layer was formed only from the coating liquid (iii) of Example 3. The thickness of the charge transport layer was 24 μm.

The electrophotographic photosensitive member thus obtained was evaluated for durability and abrasion resistance in the same manner as in Example 1. The evaluation results are shown in Table 5.

[0079]

[Table 5]

[0080]

In the electrophotographic photoreceptor of the present invention, the photosensitive layer is easily scraped in the direction from the surface to the inside, so that the scraping amount of the photosensitive layer is always appropriate, the life is long, and a good image is obtained for a long period of time. To be

[Brief description of drawings]

FIG. 1 is a side view showing an example of an image forming apparatus of the present invention.

[Explanation of reference numerals] 1 electrophotographic photosensitive member 2 charging member 6 developing means 8 transfer charging means 9 cleaning means 10 power supply 11 control section 15 film thickness detection means

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G03G 15/22 101 B 21/10

Claims (9)

[Claims] 1. An electrophotographic photosensitive member comprising a photosensitive layer having, on a support, a photosensitive layer having a portion whose abrasion resistance increases from the surface toward the inside. 2. The electrophotographic photosensitive member according to claim 1, wherein the abradability becomes 1.2 to 3.0 times for every 10 μm in an inward direction from the surface. 3. The electrophotographic photosensitive member according to claim 1, wherein a scraped amount from an unused state to printing on 500 sheets of recording paper is 0.3 to 0.9 μm. 4. The molecular weight of the components constituting the photosensitive layer is
The electrophotographic photosensitive member according to claim 1, wherein the electrophotographic photosensitive member is made smaller in a direction from the surface toward the inside to increase the abrasion resistance. 5. The electrophotographic photosensitive member according to claim 1, wherein a glass transition point of a component forming the photosensitive layer is increased in a direction from the surface to the inside to increase the abrasion resistance. 6. The electrophotographic photosensitive material according to claim 1, wherein the photosensitive layer contains a fluororesin, and the content of the fluororesin is decreased in a direction from the surface to the inside to increase the abrasion resistance. body. 7. The electrophotographic photosensitive member according to claim 1, a charging member that charges the electrophotographic photosensitive member, and image exposure that forms an electrostatic latent image by performing image exposure on the charged electrophotographic photosensitive member. An image forming apparatus comprising: a unit, a developing unit that develops the electrophotographic photosensitive member on which an electrostatic latent image is formed with toner, and a cleaning unit that cleans the surface of the electrophotographic photosensitive member. 8. The image forming apparatus according to claim 7, further comprising a film thickness detection unit that detects a film thickness of a photosensitive layer of the electrophotographic photosensitive member. 9. A process unit, wherein at least one of a charging member, a developing means and a cleaning means is integrated with the electrophotographic photosensitive member according to claim 1.