JPH0683080A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide a electrophotographic sensitive body of smooth surface, hardly provide a electrophotographic sensitive body raising residual potential and excellent in repetition stability. CONSTITUTION:When a photosensitive layer 4 is formed on an electric conductive substrate 1 by coating with a compsn. consisting of a photoconductive material, a resin binder and an org. solvent to obtain an electrophotographic sensitive body, dimethylpolysiloxane having 1,500-5,000 average mol.wt. is incorporated into the photosensitive layer 4 by 0.015-0.025wt.% of the amt. of the resin binder.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an electrophotographic photoreceptor.

[0002]

2. Description of the Related Art Electrophotographic photoreceptors which have been put into practical use at present are classified into inorganic photoreceptors using an inorganic material and organic photoreceptors using an organic material. Typical examples of the inorganic photoconductor are selenium-based ones made of amorphous selenium (a-Se) or amorphous selenium arsenic (a-As ₂ Se ₃ ), and dye-sensitized zinc oxide (Zn).
O) or cadmium sulfide (CdS) is dispersed in a binder resin, or amorphous silicon (a-Si) is used. However, among the above-mentioned inorganic photoconductors, the selenium photoconductor and the photoconductor using Cds have problems in heat resistance and storage stability. In addition, there is a restriction that it cannot be easily discarded due to its toxicity and must be recovered. The ZnO resin-dispersed photoreceptor has low sensitivity and low durability.
Currently rarely used. Although the a-Si photoconductor has advantages such as high sensitivity and high durability, it has drawbacks such as image defects due to the complexity of the manufacturing process.

On the other hand, a typical organic photoreceptor is 2,4,7-trinitro-9-fluorenone (TN).
Examples thereof include those using a charge transfer complex of F) and polyvinylcarbazole (PVK), and those of a function separation type having a charge generation layer and a charge transport layer. Since various organic materials exist, these organic photoreceptors can be produced with storage stability and no toxicity by appropriately selecting them, and can be produced at low cost, and in recent years, they have improved durability. As a result, it has attracted attention as one of the most important photoconductors. The PVK-TNF charge transfer complex-based organic photoreceptor has been improved in various ways, but has not yet reached a sufficient sensitivity. On the other hand, the above-mentioned function-separated type organic photoreceptor comprises a layer containing a charge generating material that generates a charge carrier when irradiated with light (hereinafter referred to as a charge generating layer) and a charge carrier generated in the charge generating layer. It has a layered structure with a layer containing a charge transport material that receives and transports it (hereinafter referred to as a charge transport layer),
It has a relatively high sensitivity and occupies the mainstream of the organic photoconductors currently in practical use.

As an example of such a function-separated type organic photoreceptor, a thin film formed by coating a charge generation layer with an organic amine solution of chlorodian blue and a charge transport layer using a hydrazone compound ( Japanese Examined Japanese Patent Publication 55-4238
No. 0), a charge generation layer of a disazo compound and a charge transport layer of a hydrazone compound (JP-A-59-21).
No. 4035), a charge-generating layer of an azurenium salt compound and a charge-transporting layer of a hydrazone compound (JP-A-59-53850), and the like. Further, it has been proposed to use ansanthuron, which is one of pigments, or a quinone compound as a charge generating material (US Pat. No. 3,877,935).

This organic photoreceptor is manufactured by coating a photoreceptor layer on a conductive support. When the support is sheet-like, it is applied by a baker applicator, bar coater or the like, and when the support is drum-like, it is applied by a spray method, a vertical ring method or a dip coating method. Generally, the dip coating method is adopted because the device is simple.In such a process of forming the photosensitive layer, eddy convection occurs in the coating film when the solvent evaporates and unevenness occurs on the surface after drying. There is a phenomenon that the smoothness of the surface is lost, and this is called yuzu skin.

[0006] Conventionally, there is a method of using a solvent having a slow evaporation rate in order to suppress the generation of this skin loss. But,
In particular, when using a drum-shaped conductive support to make a photoconductor, if a solvent with a slow evaporation rate is used, the coating film sags during drying, causing unevenness in the upper and lower layers, and it takes a long time to dry. The cost is low and the productivity is low, so that it cannot be practically used. Therefore, this method is unsuitable for the prevention of distressed skin.

On the other hand, polysiloxane is generally called silicone oil, and has been added in the field of paints to obtain smoothness of the surface. Silicone oil is used for yuzu skin,
It is known to be effective in preventing silking and lettering. It is known that even in electrophotographic photoreceptors, the skin damage can be prevented by adding this silicone oil to the coating liquid (Japanese Patent Publication No. 49-15220, Japanese Patent Laid-Open No. 5220/1982).
5-140849, JP-A-57-5050, JP-A-57-212453, etc.), however, they have the drawback of simultaneously increasing the residual potential.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems of the prior art. An object of the present invention is to provide an electrophotographic photosensitive member that does not deteriorate the characteristics of the photosensitive member and does not cause a scratched skin.

[0009]

[Means for Solving the Problems] The present inventors have variously used to prevent unpleasant skin without deteriorating the smoothness of the photosensitive layer of the photoconductor and without deteriorating the photoconductor characteristics such as residual potential. As a result of repeated studies, the inventors have found that the problem can be solved by using a specific amount of a specific dimethylpolysiloxane, and have completed the present invention.

The electrophotographic photoreceptor of the present invention is an electrophotographic photoreceptor having a photosensitive layer prepared by coating a composition comprising a photoconductive material, a binder resin and an organic solvent on a conductive support. Dimethyl polysiloxane having a molecular weight of 1500 to 5000 is added to the binder resin by 0.0
It is characterized by containing 15 to 0.025% by weight.

The dimethylpolysiloxane used in the electrophotographic photosensitive member of the present invention is represented by the following formula.

[0012]

[Chemical 1]

The average molecular weight of this dimethylpolysiloxane is 1500-5000. If the average molecular weight is less than 1500, the effect of preventing the skin damage cannot be imparted even if the amount added is increased. On the other hand, when the average molecular weight exceeds 5,000, it is possible to prevent the skin from getting scratched, but the characteristics of the photoreceptor are greatly deteriorated. If the addition amount is reduced in order to suppress the deterioration of the characteristics of the photoconductor, it becomes impossible to suppress the rough skin, and there is no appropriate addition amount. There is a correlation between the viscosity and the average molecular weight of dimethylpolysiloxane, and those having an average molecular weight of 1500 have a viscosity of about 20 cs and those having an average molecular weight of 5000 have a viscosity of about 10 cs.
It is 0cs. Specific examples of dimethylpolysiloxane include dimethyl silicone oil (SH200: manufactured by Toray Silicone Co., Ltd.).

The amount of dimethylpolysiloxane added is 0.015 to 0.025% by weight with respect to the binder resin. If the addition amount is less than 0.015%, it is not possible to prevent the skin from becoming scratched, and if it is 0.015% or more, the effect of preventing the skin from being damaged is exhibited. On the other hand, regarding the characteristics of the photoconductor, when the addition amount is 0.025% or less, the residual potential is hardly increased,
If it exceeds 0.025%, the residual potential increases sharply and becomes unusable for practical use.

The constitution of the electrophotographic photosensitive member of the present invention is as follows:
As shown in FIG. 1, the photosensitive layer is a function-separated type photoreceptor having a charge generation layer and a charge transport layer, or a single layer type in which a charge generation material is dispersed in the charge transport layer as shown in FIG. As described above, an undercoat layer may be provided between the conductive support and the photosensitive layer.

As the conductive support used in the electrophotographic photosensitive member of the present invention, it is possible to use one whose substrate itself has conductivity such as aluminum, aluminum alloy, copper, zinc, stainless steel, nickel and titanium. In addition, in addition to aluminum, gold, silver, copper, zinc, nickel, titanium, indium oxide, tin oxide vapor deposited plastics and paper, plastics and paper containing conductive particles, plastics containing conductive polymers, etc. It can be used, and those shapes include drum shape, sheet shape,
Seamless belts can be used.

As the charge generating material used in the electrophotographic photoreceptor of the present invention, Se and its alloys, arsenic-selenium, cadmium sulfide, zinc oxide, amorphous silicon, other inorganic photoconductors, phthalocyanines, azo compounds, quinacridone, Organic pigments such as polycyclic quinone and perylene, and organic dyes such as thiapyrylium salt and squarylium salt are used. In the charge generation layer, an electron-accepting material such as tetracyanoethylene, 7,7,8,8- is used as a chemical sensitizer.
Cyano compounds such as tetracyanoquinodimethane, quinones such as anthraquinone and p-benzoquinone, 2,4
Even if a nitro compound such as 7-trinitrofluorenone or 2,4,5,7-tetranitrofluorenone or a dye such as a xanthene dye, a thiazine dye or a triphenylmethane dye is added as an optical sensitizer. Good.

The charge generating layer may be formed by a vapor deposition method such as vacuum vapor deposition, sputtering or CVD, by dissolving the charge generating material, or by crushing and dispersing with a ball mill, sand grinder, paint shaker, ultrasonic disperser or the like. , If necessary, add a binder resin, if the conductive support is a sheet, a baker applicator,
When the support is drum-shaped, such as a bar coater, casting, and spin coating, it is prepared by a spray method, a vertical ring method, or a dip coating method. 0.0 as film thickness
It is 5 to 5 μm, preferably 0.08 to 1 μm. As the solvent for dissolving the charge generating material, acetone, methyl ethyl ketone, ketones such as cyclohexanone, ethyl acetate, esters such as butyl acetate, ethers such as tetrahydrofuran and dioxane, aromatic hydrocarbons such as benzene, toluene and xylene, An aprotic polar solvent such as N, N-dimethylformamide or dimethylsulfoxide can be used.

As the binder resin for the charge generation layer, polyvinyl butyral, polycarbonate, polyester,
Polyarylate, polystyrene, polymethylmethacrylate, polyvinyl chloride, phenoxy resin, epoxy resin, silicone, etc. are used.

Examples of the charge transport material in the charge transport layer include low molecular weight compounds such as high molecular compounds such as polyvinylcarbazole and polysilane, hydrazone compounds, pyrazoline compounds, oxadiazole compounds, stilbene compounds, triphenylmethane compounds and triphenylamine compounds. Molecular compounds are used.

As the method for forming the charge transport layer, the charge transport material is dissolved in a solvent, a binder resin is added, and when the conductive support is in the form of a sheet, a support such as a baker applicator, a bar coater, casting or spin coating is used. In the case of a drum shape, it is produced by a spray method, a vertical ring method, or a dip coating method. 5 to 50 μm as film thickness
And preferably 10 to 40 μm.

Solvents for dissolving the charge transport material include halogen solvents such as dichloromethane and 1,2-dichloroethane, ketones such as acetone, methyl ethyl ketone and cyclohexanone, esters such as ethyl acetate and butyl acetate, tetrahydrofuran and dioxane. The above ethers, aromatic hydrocarbons such as benzene, toluene and xylene, and aprotic polar solvents such as N, N-dimethylformamide and dimethyl sulfoxide can be used.

As the binder resin for the charge transport layer, polycarbonate, polyester, polystyrene, polymethylmethacrylate, polyvinyl chloride, phenoxy resin,
Epoxy resin, silicone, etc. are used.

To prevent deterioration of the electrophotographic photosensitive member of the present invention, an antioxidant may be added as an additive to the charge generation layer or the charge transport layer, if necessary. Antioxidants include vitamin E, hydroquinone, hindered amines,
Hindered phenols, paraphenylenediamines, aryl alkanes and their derivatives, organic sulfur compounds,
An organic phosphorus compound or the like is used.

As the undercoat layer of the photoreceptor as shown in FIG. 2, polyvinyl alcohol, polyvinyl butyral, casein, N-methoxymethylated nylon and the like are used.

[0026]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to the following examples. The electrophotographic photoreceptors obtained in Examples and Comparative Examples were evaluated as follows. Sensitivity: Measured with a self-made drum evaluation device. Sensitivity is 10μW at 550nm or 780nm which is separated by interference filter
It was evaluated by the reciprocal of the light energy required for the charging potential to become 1/2 when irradiated with light of / cm ² . Charge potential V _o (V) and residual potential V _r (V) The obtained electrophotographic photosensitive member was mounted on a commercially available copying machine or a laser beam printer, and after confirming the image, potential fluctuations during repeated use were observed as initial and After using 10,000 times, the charging potential (V _o ) and the residual potential (V _r ) were measured. Damaged skin: The surface of the photosensitive layer was visually evaluated, and those having no damage skin were evaluated as ◯, and those having damage skin were evaluated as x.

Example 1

[Chemical 2]

2 parts by weight of a polycyclic quinone pigment which is a charge generating material represented by 1 part by weight, 1 part by weight of a phenoxy resin (PKHH: manufactured by Union Carbide Co.) and 97 of 1,4-dioxane.
Parts by weight are dispersed by a ball mill disperser for 12 hours to prepare a dispersion liquid, which is filled in a tank and has a diameter of 80 mm and a length of 3
A 40 mm aluminum cylindrical (aluminum drum) conductive support is dipped, pulled up, coated with the dispersion liquid, and dried at room temperature for 1 hour to form a 1 μm-thick charge generation layer. did.

On the other hand, as the charge transport material, the following structural formula is used.

[Chemical 3]

100 parts by weight of a hydrazone compound represented by: 100 parts by weight of polycarbonate (Z-200: manufactured by Mitsubishi Gas Chemical Co., Inc.) as a binder, and dimethyl silicone oil (SH200: manufactured by Torre Silicone Co.)
0.015 parts by weight was dissolved in 800 parts by weight of dichloromethane to prepare a coating liquid for coating the charge transport layer. This coating solution is applied by dip coating on the charge generation layer previously formed, and the coating solution is applied at 80 ° C. for 1 hour.
After drying for an hour, a charge transporting layer having a thickness of 20 μm was formed as a photosensitive layer to prepare an electrophotographic photosensitive member as shown in FIG.

The photosensitive layer was a smooth coating film having no scratched skin. The sensitivity was measured by irradiating with light of 550 nm and 10 μW / cm ² . Next, it was mounted on a commercially available copying machine (SF8260: manufactured by Sharp Corporation), and the charging potential (V _o ) and the residual potential (V _r ) were measured at the initial stage and after 10,000 times of use. The results are shown in Table 1. Almost no increase in residual potential was observed.

Examples 2 to 9 Electrophotographic photoreceptors were prepared and evaluated in the same manner as in Example 1 except that the average molecular weight and addition amount of dimethyl silicone oil were changed. The results are shown in Table 1.

Comparative Example 1 A photoconductor was prepared in the same manner as in Example 1 except that the addition amount of dimethyl silicone oil (SH200 50cs: manufactured by Toray Silicone Co., Ltd.) was 0.005 parts by weight, and the characteristics were evaluated. The results are shown in Table 2. Uneven skin was seen on one side, and the resulting image also looked rough. Almost no increase in residual potential was observed.

Comparative Example 2 A photoconductor was prepared in the same manner as in Example 1 except that the addition amount of dimethyl silicone oil (SH200 50cs: manufactured by Toray Silicone Co., Ltd.) was 0.035 parts by weight, and its characteristics were evaluated. The results are shown in Table 2. No scratched skin was found on the surface of the photoreceptor, and a clean image was obtained. However, the residual potential increased after repeated use.

Comparative Examples 3 to 8 Samples were prepared and evaluated in the same manner as in Example 1 except that the average molecular weight and addition amount of dimethyl silicone oil were changed as shown in Table 2 below.

[0036]

[Table 1]

[0037]

[Table 2]

As shown in Table 1, the results obtained in the examples in which the average molecular weight and the addition amount of the photoconductor of the present invention are in the range are as follows. The comparative examples out of the range cause the generation of discolored skin and an increase in residual potential.

Example 10

[Chemical 4]

4 parts by weight of chlorodian blue, which is the charge generating material represented by the above structural formula, was added to 25 parts of ethylenediamine.
It was dissolved in 7 parts by weight and stirred for 45 minutes. Furthermore n-
247 parts by weight of butylamine was added and the mixture was stirred for 45 minutes to prepare a coating solution, which was filled in a tank, and an aluminum cylindrical conductive support having a diameter of 80 mm and a length of 340 mm was dipped and pulled up to apply this coating on the surface of the support. The liquid was applied and dried at room temperature for 1 hour to form a charge generation layer having a thickness of 0.1 μm.

On the other hand, as the charge transport material, the following structural formula

[Chemical 5]

100 parts by weight of the hydrazone compound represented by: and a polycarbonate (Novarex 7
030A: Mitsubishi Kasei Co., Ltd.) 100 parts by weight, and dimethyl silicone oil (SH200 50cs: Torre Silicone Co., Ltd.) 0.015 parts by weight are added to dichloromethane 800 parts.
It was dissolved in parts by weight to prepare a coating liquid for coating the charge transport layer.
This coating solution is applied by dip coating on the charge generation layer previously formed,
By drying at 80 ° C. for 1 hour, a charge transport layer having a thickness of 20 μm was formed as a photosensitive layer, and an electrophotographic photosensitive member as shown in FIG. 1 was produced. The photosensitive layer was a smooth coating film having no scratched skin.
The sensitivity was measured by irradiating with light of 550 nm and 10 μW / cm ² . Further, it was mounted on a commercially available copying machine (SF8260: manufactured by Sharp Corporation), and the charging potential (V _o ) and the residual potential (V _r ) were measured at the initial stage and after 10,000 times of use. The results are shown in Table 3.
Shown in. A clear image was obtained and almost no increase in residual potential was observed even after repeated use.

Example 11 Copolymerized nylon (Amilan CM8000: manufactured by Toray) 6
47 parts by weight of methyl alcohol and 4 parts by weight of chloroform
Fill a tank with a solution of 7 parts by weight of mixed solvent,
An aluminum cylindrical conductive support having a diameter of 30 mm and a length of 255 mm is dipped and pulled up to coat the solution on the surface of the support 1
It was dried at 10 ° C. for 10 minutes to provide an undercoat layer of about 2 μm.

Next, the following structural formula

[Chemical 6]

2 parts by weight of an X-type metal-free phthalocyanine, which is a charge-generating material represented by, 1 part by weight of polyvinyl butyral (Eslec BMS: manufactured by Sekisui Chemical Co., Ltd.) and 97 parts by weight of dichloroethane were dispersed in a ball mill disperser for 12 hours. A dispersion is prepared, the tank is filled with the dispersion, the conductive support provided with the above-mentioned undercoat layer is dipped and pulled up to apply the dispersion to the surface of the support, and the coating is dried at room temperature for 1 hour to obtain a thickness. A charge generation layer having a thickness of 0.2 μm was formed.

On the other hand, as the charge transport material, the following structural formula

[Chemical 7]

100 parts by weight of the styryl compound represented by the formula, 100 parts by weight of polycarbonate (A-300: made by Idemitsu Petroleum Co., Ltd.) as a binder, and dimethyl silicone oil (SH200 50cs: made by Toray Silicone Co., Ltd.) 0.0
15 parts by weight was dissolved in 800 parts by weight of chloroform to prepare a coating liquid for coating the charge transport layer. This coating solution is applied onto the previously formed charge generating layer by dip coating and dried at 100 ° C. for 1 hour to form a charge transporting layer having a thickness of 20 μm. Was produced.

The photoconductor layer was a smooth coating film without any scratched skin. Sensitivity was measured using light at 780 nm 10 μW / cm ² . Next, a commercially available laser beam printer (JX95
(00: manufactured by Sharp), and the charging potential (V _o ) and the residual potential (V _r ) were measured at the initial stage and after 10,000 times of use. The results are shown in Table 3. A clear image was obtained and almost no increase in residual potential was observed even after repeated use.

Example 12 The following structural formula

[Chemical 8]

A dispersion liquid was prepared by dispersing 2 parts by weight of a perylene pigment, which is a charge generating material represented by, and 98 parts by weight of 1,2-dichloroethane with a paint shaker. As the charge transport material, the following structural formula

[Chemical 9]

100 parts by weight of the hydrazone compound represented by and polycarbonate (S-200
0: Mitsubishi Gas Chemical Co., Ltd.) 100 parts by weight and dimethyl silicone oil (SH200 20cs: Toray Silicone Co., Ltd.) 0.015 parts by weight dissolved in 700 parts by weight of dichloromethane were added to prepare a coating liquid for photosensitive layer coating. Then, this is filled in a tank, immersed in a cylindrical aluminum-made conductive support having a diameter of 80 mm and a length of 340 mm, pulled up to apply the coating solution on the surface of the support, and dried at 100 ° C. for 1 hour. Then, a photosensitive layer having a thickness of 15 μm was formed to prepare an electrophotographic photosensitive member as shown in FIG. The photosensitive layer was a smooth coating film having no scratched skin. The sensitivity was measured by irradiating with light of 550 nm and 10 μW / cm ² . Next, a commercially available copying machine (SF8100:
(Sharp) was installed on an experimental machine modified for positive charging,
The charging potential (V _o ) and the residual potential (V _r ) were measured at the initial stage and after 10,000 times of use. The results are shown in Table 3. A clear image was obtained and almost no increase in residual potential was observed even after repeated use.

Example 13 The following structural formula

[Chemical 10]

2 parts by weight of a bisazo pigment, which is a charge generating material, 1 part by weight of polyvinyl butyral (XYHL: manufactured by Union Carbide Co.) and 97 parts by weight of cyclohexanone are dispersed by a ball mill to prepare a dispersion liquid, which is prepared in a tank. Filled with aluminum, and a cylindrical aluminum-made conductive support having a diameter of 80 mm and a length of 340 mm was dipped and pulled up to apply the dispersion liquid to the support, followed by drying at 110 ° C. for 10 minutes to obtain a thickness of 0.
An 8 μm charge generation layer was formed.

On the other hand, as the charge transport material, the following structural formula

[Chemical 11]

100 parts by weight of the hydrazone compound represented by: 100 parts by weight of polyester (V290: Toyobo Co., Ltd.) as a binder and dimethyl silicone oil (SH2)
(0050cs: manufactured by Toray Silicone Co., Ltd.) 0.02 parts by weight was dissolved in 800 parts by weight of dichloromethane to prepare a coating liquid for coating the charge transport layer. This coating solution is applied onto the previously formed charge generation layer by dip coating and dried at 80 ° C. for 1 hour to form a charge transport layer having a thickness of 20 μm as a photosensitive layer. The body was made. The photosensitive layer was a smooth coating film having no scratched skin. The sensitivity was measured by irradiation with light having a wavelength of 550 nm and 10 μW / cm ² . Next, a commercially available copying machine (SF82
60: manufactured by Sharp Corporation), initial and 10000
After repeated use, the charging potential (V _o ) and the residual potential (V _r ) were measured. The results are shown in Table 3. You get a beautiful image,
Almost no increase in residual potential was observed even after repeated use.

[0056]

[Table 3]

[0057]

EFFECT OF THE INVENTION The electrophotographic photosensitive member of the present invention is a photosensitive member which is smooth and has no scratched surface, and which has a small increase in residual potential and is excellent in repeated stability.

[Brief description of drawings]

FIG. 1 is a function-separated type photoreceptor having two photosensitive layers.

FIG. 2 is a photoreceptor having an undercoat layer between a conductive support and a photosensitive layer.

FIG. 3 is an electrophotographic photosensitive member having a single photosensitive layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conductive support 2 Charge generation layer 3 Charge transport layer 4 Photosensitive layer 5 Undercoat layer 6 Charge generation material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Katayama 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Within Sharp Corporation (72) Inventor Kamo Morita 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka (72) Inventor Satoshi Nishigaki 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) In-house Kazuhiro Enomoto 22-22, Nagaike-cho, Abeno-ku, Osaka-shi, Osaka

Claims (2)

[Claims] 1. An electrophotographic photoreceptor in which a photosensitive layer is prepared by coating a composition comprising a photoconductive material, a binder resin and an organic solvent on a conductive support, and the photosensitive layer is dimethyl having an average molecular weight of 1500 to 5000. An electrophotographic photoreceptor containing polysiloxane in an amount of 0.015 to 0.025% by weight with respect to a binder resin. 2. The photosensitive layer comprises a charge generation layer and a charge transport layer, and the dimethylpolysiloxane is contained in the charge transport layer in an amount of 0.015 to 0.05 relative to the binder resin of the charge transport layer.
An electrophotographic photosensitive member containing 25%.