JPH06301220A - Electrophotographic sensitive body and production of electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide an electrophotographic sensitive body having a reverse laminar structure having stable electric characteristics, high sensitivity and excellent durability with which picture images of high quality can be obtd., and to provide the production method of this material. CONSTITUTION:This electrophotographic sensitive body has a charge transfer layer and a charge producing layer containing dispersion of a charge producing material in a binder resin succesively formed on a conductive supporting body. The charge producing layer consists of at least two layers. The charge producing layer nearest to the charge transfer layer has <=0.1mum film thickness and higher proportion of the charge producing material in the binder resin than the proportion of the material in other charge producing layers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoconductor and a method for producing the electrophotographic photoconductor, and particularly to an electrophotographic photoconductor having excellent durability which can be used by positive charging and the production of the electrophotographic photoconductor. It is about the method.

[0002]

2. Description of the Related Art Conventionally, inorganic photoconductive materials such as selenium, selenium-tellurium alloys, arsenic selenide, cadmium sulfide, and amorphous silicon have been used as electrophotographic photoreceptors. In recent years, research and development using an organic photoconductive material in a photosensitive layer have become popular, and in particular, a charge generation layer and a charge that separate the function of absorbing light and generating charge carriers and the function of moving the generated charge carriers are separated. A laminated type photoreceptor having a transport layer has been developed and has become the mainstream of research and development. However, the laminated electrophotographic photoreceptor that has been practically used in the past has a charge transport layer laminated on the charge generation layer,
In addition, since the charge transport layer usually has only a hole transfer function,
It may be negatively charged and cannot be used under positive charging.

On the other hand, in the electrophotographic method, charging of the photosensitive member is usually performed by corona discharge. 1) Since negative corona discharge is more difficult to discharge uniformly in the wire direction than positive corona discharge, charging Is difficult to obtain. 2) Negative corona discharge generates far more ozone than positive corona discharge, which pollutes the use environment, causes sanitary problems, and causes deterioration of the photoreceptor. 3) Since the selenium-based photoconductor, which was the center of the prior art, was positively charged, it is difficult to use the process technology used in this system when it is negatively charged. There are many disadvantages in using the photoreceptor with negative charging.

Therefore, in recent years, the development of a positively charged organic electrophotographic photosensitive member, which is extremely advantageous in terms of charging uniformity and ozone reduction, has been earnestly pursued. The specific layer structure of the positively charged photoreceptor is as follows: A dispersion type photoconductor in which a charge generating substance is dispersed in a layer containing a charge transporting substance and a binder resin on a conductive support to form a single layer. 2. A charge-transporting layer containing a charge-transporting substance and a binder resin as main components and a charge-generating layer containing a charge-generating substance and a binder resin as main components are laminated in this order on a conductive support. .

[0005]

The electrophotographic photosensitive member of the reverse laminated structure is superior to the dispersion type photosensitive member in electrical characteristics such as charging property, sensitivity, and photoresponsiveness, but the charge generating layer. The thickness, the concentration or distribution of the charge generating substance in the charge generating layer have a great influence on the sensitivity, the residual potential, the repeated electric characteristics and the printing durability. Therefore, an electrophotographic photosensitive member having a reverse laminated structure having good stable performance and excellent durability and a method capable of manufacturing the same have been desired.

[0006]

As a result of intensive studies by the present inventors, the concentration of the charge-generating substance in the charge-generating layer in the electrophotographic photosensitive member having the reverse laminated structure is made higher on the charge-transporting layer side than on the surface side. As a result, the present invention has been completed by finding an electrophotographic photosensitive member which has stable electric characteristics, can obtain a high-quality image, is excellent in printing durability, and is very useful for positive charging.

That is, the gist of the present invention is to provide an electrophotographic photoreceptor in which a charge transport layer and a charge generating layer having a charge generating substance dispersed in a binder resin are sequentially laminated on a conductive support. The generation layer is composed of at least two layers, and the layer adjacent to the charge transport layer has a film thickness of 0.1 μm.
The following, on the electrophotographic photosensitive member and the conductive support, characterized in that the ratio of the charge generating substance in the adjacent layer to the binder resin is higher than the ratio in other layers in the charge generating layer. An electrophotographic photoreceptor that forms a charge generation layer by applying a charge generation layer forming dispersion liquid obtained by dispersing a charge generation substance in a solution containing a binder resin and an organic solvent on the provided charge transport layer. In the production method, when the charge generation layer is formed by sequentially applying at least two or more kinds of dispersion liquids for forming a charge generation layer, first, the first dispersion liquid for forming a charge generation layer is applied to form a film having a thickness of 0. A charge generation layer having a thickness of 1 μm or less is formed, and then a charge generation layer-forming dispersion liquid having a ratio of the charge generation substance to the binder resin lower than the ratio in the first charge generation layer-forming dispersion liquid is at least 1%.
A method of manufacturing an electrophotographic photosensitive member is characterized in that a charge generation layer is formed by coating more than one kind.

The present invention will be described in detail below. The electrophotographic photoreceptor produced by the present invention has a structure in which a charge transport layer is provided on a conductive support and a charge generation layer is further laminated. These photosensitive layers are formed on the conductive support by a known method such as roll coating, dip coating or spray coating.

As the conductive support, various known supports can be used. For example, aluminum, copper, nickel,
Drum of metal such as stainless steel; laminated metal foil, vapor-deposited or sputtered metal or conductive oxide, and conductive metal such as fine metal powder, carbon black, copper iodide, tin oxide, titanium oxide, indium oxide, alumina A plastic film that has been subjected to a conductive treatment, such as applying a conductive substance together with a binder if necessary,
Examples include plastic drums, glass drums, and paper.

A well-known barrier layer or organic layer which is usually used may be provided between the conductive support and the photosensitive layer. As the barrier layer, for example, an aluminum anodized film, an inorganic layer such as aluminum oxide or aluminum hydroxide, an organic layer such as polyvinyl alcohol, casein, polyvinylpyrrolidone, polyacrylic acid, celluloses, gelatin, starch, polyurethane, polyimide or polyamide. Is used.

A charge transport layer is provided on these conductive supports. The charge transport layer contains at least a charge transport substance and a binder. As the charge-transporting substance, various known substances used in electrophotographic photoreceptors can be used, and compounds having a heterocycle such as carbazole, indole, imidazole, thiazole, oxadiazole, pyrazole and pyrazoline; phenylamine, diphenylamine and triphenylamine. Examples thereof include aniline derivatives such as phenylamine; hydrazone derivatives; stilbene derivatives; and electron-donating substances such as polymers having a group composed of these compounds in the main chain or side chain. Particularly preferred substances include hydrazone derivatives, aniline derivatives and stilbene derivatives.

Various known resins can be used as the binder resin used with the charge transport material. Thermoplastic resins and curable resins such as polycarbonate resins, polyester resins, polyarylate resins, acrylic resins, methacrylate resins, styrene resins and silicone resins can be used. Particularly preferred are polycarbonate resins, polyacrylate resins, and polyester resins that are less likely to cause wear and scratches. As the bisphenol component of the polycarbonate resin, various known components such as bisphenol A, bisphenol C and bisphenol Z can be used.

The charge transporting material and the binder resin are mixed in a proportion of, for example, 20 to 200 parts by weight, preferably 40 to 150 parts by weight, based on 100 parts by weight of the resin. In order to form the charge transport layer, the above components are dissolved in an appropriate solvent according to a conventional method, and if necessary, a binder resin sensitizing dye, an electron donating compound, an electron accepting compound or a plasticizer, an antioxidant. A coating solution obtained by adding an additive such as an agent, an ultraviolet absorber and a leveling agent can be applied on a conductive support, dried and produced, and the thickness of the charge transport layer is usually 5 to 50 μm. , Preferably 10-4
Used at 0 μm.

In the present invention, the charge generation layer is provided on the charge transport layer provided on the conductive support. The charge generation layer contains at least a charge generation substance and a binder resin. In order to satisfy the electrical characteristics and durability of the electrophotographic photoreceptor, the concentration of the charge generating substance on the surface side of the charge generating layer is made smaller than the concentration of the charge generating substance on the charge transporting layer side to suppress the surface charge injection. However, it is effective to set the film thickness so that the charge generation layer as a whole has sufficient sensitivity and durability. Furthermore, the high concentration region of the charge generation substance on the charge transport layer side of the charge generation layer should be as much as possible. By making it small, good dark attenuation characteristics and stable repeated electric characteristics can be achieved.

Therefore, the charge generation layer is composed of at least two layers, and the ratio of the charge generation substance to the binder resin in layers other than the layer adjacent to the charge transport layer is adjacent to the charge transport layer. The ratio of 0.
2 to 75%, preferably 2% to 40%, more preferably 4% to 25%, and the thickness of the charge generation layer closest to the charge transport layer is 0.1 μm or less, more preferably 0.05.
It is preferably μ or less. The thickness of the charge generation layer as a whole is preferably 0.05 μ to 20 μ, and more preferably 0.5 μ to 10 μ.

As the charge generating substance, particles of various inorganic or organic charge generating substances can be used. For example, as the inorganic charge generating substance, various selenium-based alloy materials such as amorphous selenium, selenium-tellurium alloys, trigonal selenium, and arsenic triselenide; II-VI such as cadmium sulfide and cadmium selenide Group compound semiconductor materials; amorphous silicon,
Known materials such as silicon hydride are used in the form of fine particles. Further, known phthalocyanine pigments, perylene pigments, polycyclic quinones, quinacridone pigments, indigo pigments, squarylium salts, azo pigments and the like can be used as organic charge generating substances. Of these, phthalocyanine pigments and azo pigments can be used as more preferable materials. Examples of the phthalocyanine pigment include those described by the following general formula.

[0017]

[Chemical 1]

Cu, Fe, M as the metal component of the above M
g, Si, Ge, Sn, Pb, In, Ga, Al, Ti
Phthalocyanine containing such atoms, and metal-free phthalocyanine having two hydrogen atoms added. X is a hydrogen atom, a lower alkyl group, a lower alkoxy group,
Examples include nitro group, cyano group, halogen atom, m
Represents an integer from 0 to 4.

Various types of azo pigments can be mentioned, but azo pigments having an aromatic condensed ring such as a naphthalene ring as a coupler component are preferable, and a more preferable material is at least one coupler component represented by the following general formula. Examples thereof include monoazo pigments, bisazo pigments, trisazo pigments and other polyazo pigments.

[0020]

[Chemical 2]

However, in the formula, A represents a divalent group of an aromatic hydrocarbon or a heterocyclic divalent group containing a nitrogen atom in the ring. The charge generating substance is used by being dispersed in a binder resin in the form of fine particles. As the binder resin, polyvinyl acetate, polyacrylic acid ester, methacrylate resin, polyester resin, polycarbonate resin, polyvinyl butyral, polyvinyl formal or other polyvinyl acetal resin, phenoxy resin, cellulose ester, cellulose ether, urethane resin, various binders such as epoxy resin Resin can be used. The composition ratio of the charge generating material and the binder resin is preferably 10: 1 to 1:99 by weight.

The charge generating layer is, for example, an electron-accepting substance such as 2,4,7-trinitrofluorenone or tetracyanoquinodimethane, carbazole, indole, imidazole, oxazole, pyrazole, oxadiazole,
Heterocyclic compounds such as pyrazoline and thiadiazole, aniline derivatives, hydrazone compounds, aromatic amine derivatives,
It may contain an electron donating substance such as a stilbene derivative or a polymer having a group composed of these compounds in the main chain or side chain. The weight ratio of these electron accepting substance or electron donating substance to the charge generating substance is preferably in the range of 50: 1 to 1: 100.

Further, the charge generation layer or the charge transport layer is a known plasticizer for improving film formability, flexibility, mechanical strength, etc., additives for suppressing accumulation of residual potential, dispersion stability. Dispersion aid for improvement, leveling agent for improving coating property, for example, silicone oil, fluorine-based oil, binder resin sensitizing agent, plasticizer, if necessary.
It may contain an antioxidant, an ultraviolet absorber, and other additives.

The charge generation layer is formed by applying a charge generation layer-forming dispersion liquid obtained by dispersing a charge generation substance in a solution containing a binder resin and an organic solvent onto the charge transport layer according to a conventional method. Examples of the method for coating and forming such a charge generation layer include: 1. A method of forming in the charge generation layer coating step by a spray coating method, a spiral coating method or the like. There is a method of sequentially dipping and coating in at least two kinds of dispersion liquids for forming a charge generation layer having different concentrations of the charge generation substance. The method 2 has an advantage that the coating device is simple and the control of the coating process can be stably performed. As a specific second method according to the present invention, for example, a conductive support provided with a charge transport layer is dip-coated in a first dispersion liquid for forming a charge generation layer, and then a binder in the first dispersion liquid is applied. This can be achieved by sequentially dip-coating at least one kind of dispersion liquid for forming a charge generation layer having a concentration lower than the concentration of the charge generation substance with respect to the resin to form the charge generation layer. By this method, it is possible to easily obtain a photoconductor having a charge generation layer in which the charge generation material has a high concentration on the charge transport layer side and a low concentration on the surface side.

As the solvent for preparing the coating solution for the charge transport layer and the charge generating layer, for example, aromatic hydrocarbons such as benzene, toluene, xylene; acetone, methyl ethyl ketone,
Diethyl ketone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, methyl n-propyl ketone,
Ketones such as methyl isopropyl ketone; esters such as n-propyl acetate, isopropyl acetate, methyl acetate, ethyl acetate, methyl propionate; alcohols such as methanol, ethanol, propanol, butanol; tetrahydrofuran, dioxane, dimethoxymethane, dimethoxy Ethers such as ethane and diglyme; halogenated hydrocarbons such as carbon tetrachloride, chloroform, methylene chloride, dichloroethane, trichloroethylene and chlorobenzene; amides such as N, N-dimethylformamide and N, N-dimethylacetamide; dimethyl Sulfoxide; 4-methoxy-4-methylpentanone-2, and alkanol having a hydroxyl group and a functional group containing any one of O, N, and F atoms in the molecule; for example, 2-methoxyethanol, 2-eth Ethylene glycol monoalkyl ethers such as ciethanol, 2-butoxyethanol and tetrahydrofurfuryl alcohol, 2-hydroxyethyl acetate, 2-hydroxyethyl propionate, methyl hydroxyacetate, esters of methyl lactate methyl lactate, etc., diacetone alcohol , 3-hydroxy-3-methyl-2-butanone and other ketone alcohols, dimethylaminoethanol, diethylaminoethanol, CF ₃ CF
₂ CH ₂ OH, F (CF ₂ ) ₄ CH ₂ CH ₂ OH, H
(CF ₂ ) ₄ CH ₂ OH, H (CF ₂ ) ₂ CH ₂ OH,
F (CF ₂ ) ₅ CH ₂ OH, F (CF ₂ ) ₃ CH ₂ O
H, F (CF ₂ ) ₄ CH ₂ OH, methoxyethyl lactate,
Trifluoromethoxyethyl lactate, H (CF ₂ ) ₄ CH
₂ OCH ₂ CH ₂ OH and the like can be mentioned. These solvents mentioned above can be used alone or in combination.

[0026]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

Example 1 An extruded aluminum tube was ironed to a thickness of 0.
An aluminum cylinder having a diameter of 75 mm, an outer diameter of 30 mm and a length of 246 mm was produced. After forming an anodized film having an average film thickness of 10 μm on this aluminum cylinder, it was subjected to a sealing treatment, washed with water and dried. Next, 70 parts by weight of the hydrazone compound represented by the following formula (1) and 1.5 parts by weight of the cyano compound represented by the following formula (2) were used for the aluminum cylinder.

[0028]

[Chemical 3]

And 100 parts by weight of a polycarbonate resin (Novarex 7030A manufactured by Mitsubishi Kasei Co., Ltd.)
A charge transport layer was provided so that the film thickness after dried coating was 17 μm by dipping and coating in a solution dissolved in 1000 parts by weight of 1,4-dioxane. On the other hand, 2 in the X-ray diffraction spectrum
To 10 parts by weight of oxytitanium phthalocyanine having a main peak at 7.3 ° (± 0.2 °), 200 parts by weight of n-propanol was added, and the liquid temperature was cooled to 5 ° C. or lower by ice water cooling, and then 10 times with a sand grind mill. Time pulverization and atomization dispersion treatment were performed. Next, polyvinyl butyral (Denka Butyral # -600, manufactured by Denki Kagaku Kogyo KK)
0) was mixed with a 10% n-propanol solution containing 5 parts by weight to prepare a first dispersion liquid for forming a charge generation layer. Next, a second dispersion liquid for forming a charge generation layer was prepared in the same manner as the first dispersion liquid except that polyvinyl butyral was changed to 57 parts by weight.

Next, in the first dispersion liquid for forming the charge generation layer,
The aluminum cylinder coated with the charge transport layer prepared above was dip-coated, and the charge generation layer was provided so that the film thickness after drying was 0.1 μm. After that, it is further immersed in the second dispersion liquid for forming the charge generation layer, and the total film thickness after drying is 1 μm.
The charge generation layer was provided so that The photoconductor manufactured in this way is mounted on a photoconductor characteristic measuring machine, and the initial 700V
After half-exposure and 780 nm exposure, the half-exposure sensitivity and residual potential were measured. The results are shown in Table 1 together with the values of the subsequent examples. Both sensitivity and residual potential were good. This photosensitive member was attached to a commercially available laser printer PC-406LM (manufactured by NEC Corporation) modified for positive charging and evaluated. As a result, a good image was obtained even after 10,000 sheets (A4 paper) were exceeded.

Example 2 Example 1 was repeated except that the thickness of the charge generation layer formed by the first dispersion liquid for forming the charge generation layer after drying was 0.05 μm.
A photoconductor was prepared in the same manner as above and evaluated in the same manner. As a result, both the sensitivity and the residual potential were good, and a good image was obtained even after exceeding 10,000 sheets (A4 paper).

Example 3 A photoconductor was prepared in the same manner as in Example 1 except that the polyvinyl butyral of the second dispersion liquid for forming the charge generation layer was changed to 90 parts by weight, and the sensitivity and residual potential were evaluated in the same manner. Both were good, and a good image was obtained even after exceeding 10,000 sheets (A4 paper).

Example 4 An epoxy resin (YD-01 manufactured by Tohto Kasei Co., Ltd.) was used as a substitute for polyvinyl butyral in the second dispersion liquid for forming the charge generation layer.
4) was used and a photoconductor was prepared in the same manner as in Example 1 except that methyl isopropyl ketone was used instead of n-propanol, and the sensitivity and residual potential were evaluated in the same manner. Good images were obtained even when the size exceeded (A4 paper).

Example 5 An aluminum cylinder coated with a charge transport layer prepared in the same manner as in Example 1 was dip-coated with the first dispersion liquid for forming a charge generation layer used in Example 1, and the film thickness after drying was applied. Is 0.1μ
The charge generation layer is provided so as to have a thickness of m and then immersed in a second dispersion liquid for forming a charge generation layer similar to that used in Example 1, and 90 wt% of polyvinyl butyral of the dispersion liquid for forming a charge generation layer is further added. Except that the total thickness of the charge generation layer after being immersed in a third dispersion liquid for forming a charge generation layer, which was prepared in the same manner as the first dispersion liquid, was 1.5 μm. A photoconductor was prepared in the same manner as in Example 1 and evaluated in the same manner. As a result, both sensitivity and residual potential were good, and 15,000 sheets (A
Good images were obtained even when the number of sheets exceeded 4 sheets.

Example 6 A photoconductor was prepared in the same manner as in Example 1 except that dichlorotin phthalocyanine was used in place of oxytitanium phthalocyanine, and the same evaluation showed that both sensitivity and residual potential were good. Good images were obtained even when the size exceeded (A4 paper).

Example 7 Oxytitanium phthalocyanine 10 used in Example 1
Instead of 10 parts by weight of the azo compound represented by the formula (3) and 10 parts by weight of the hydrazone compound represented by the above formula (1), the same procedure as in Example 1 was performed for forming the charge generation layer. 1 dispersion was prepared. Next, in the same manner as in the first dispersion, except that polyvinyl butyral was changed to 57 parts by weight,
A second dispersion liquid for forming the charge generation layer was prepared. And
A photoconductor was prepared in the same manner as in Example 1, and the photoconductor characteristics were evaluated by exposure to white light. As a result, both the white light sensitivity and the residual potential were good.

[0037]

[Chemical 4]

Example 8 A photoreceptor was prepared in the same manner as in Example 5 except that 10 parts by weight of the azo compound represented by the formula (4) was used in place of the azo compound represented by the formula (3) used in Example 5. As a result of manufacturing and evaluating the characteristics of the photoconductor by exposure to white light, both the sensitivity to white light and the residual potential were good.

[0039]

[Chemical 5]

Comparative Example 1 The charge generation layer using the second dispersion liquid for forming the charge generation layer was not provided, and the film thickness after drying using the first dispersion liquid was 0.1 μm.
A photoconductor was prepared in the same manner as in Example 1 except that only m charge generation layers were provided. The thus prepared photoconductor was mounted on a photoconductor characteristic measuring machine, charged at an initial 700 V, and the half-exposure sensitivity and residual potential when exposed at 780 nm were measured. Both were good, and the surface potential, the half-exposure dose sensitivity, and the residual potential were measured repeatedly. As a result, the characteristics were good even after 10,000 cycles. This photoreceptor was attached to a commercially available laser printer PC-406LM (manufactured by NEC Corporation) modified for positive charging and evaluated. As a result, when the number of sheets exceeded about 1500 sheets (A4 paper), the number of image defects sharply increased, and extremely. Only an unclear image was obtained. At this time, it was observed that the charge generation layer on the photoconductor disappeared.

Comparative Example 2 A photoconductor was prepared in the same manner as Comparative Example 1 except that only the charge generation layer having a thickness of 0.05 μm after drying was provided using the first dispersion liquid for forming the charge generation layer. did. The photoconductor manufactured in this way is mounted on a photoconductor characteristic measuring machine, and the initial 700V
As a result of measuring the half-exposure sensitivity and residual potential when charged at 780 nm and exposed to 780 nm, both sensitivity and residual potential are good, and the results of repeated measurement of surface potential, half-exposure sensitivity and residual potential The characteristics were good even after 10,000 cycles. As a result of mounting this photoreceptor on a commercially available laser printer PC-406LM (manufactured by NEC Corporation) modified for positive charging, about 500 sheets (A4
When it exceeds the paper size, the number of image defects sharply increases and only an extremely unclear image is obtained. At this time, it was observed that the charge generation layer on the photoconductor disappeared.

Comparative Example 3 A charge generation layer having a thickness of 0.2 μm after drying was provided using the first dispersion liquid for charge generation layer formation, and a second dispersion liquid for charge generation layer formation was provided thereon. A photoconductor was prepared in the same manner as in Example 1 except that the charge generation layer according to 1. was provided and the thickness of the entire charge generation layer was 1 μm. The thus prepared photoconductor was mounted on a photoconductor characteristic measuring machine, charged at an initial 700 V, and the half-exposure sensitivity and residual potential when exposed at 780 nm were measured. Both were good, but as a result of repeatedly measuring the half-dose exposure sensitivity and the residual potential, the surface potential decreased by 300 V after 10,000 times, and it was not practical as a photoreceptor.

[0043]

[Table 1] Dark potential Sensitivity Residual potential Remarks Example 1 700V 0.12μJ / cm ² 50V 10,000 good images even after actual shooting Example 2 700V 0.14μJ / cm ² 70V 10,000 good images even after actual shooting Example 3 700V 0.12 μJ / cm ² 60V 10,000 good images even after actual shooting Example 4 700V 0.13 μJ / cm ² 55V 10,000 good images even after actual shooting Example 5 700V 0.14 μJ / cm ² 75V 15,000 actual images Good image even after the operation Example 6 700V 0.19 μJ / cm ² 80V 10,000 images Good after actual shooting Example 7 700V 2.5lux sec 50V Sensitivity and residual potential are good Example 8 700V 2.0lux sec 50V Sensitivity, residual potential Both are good Comparative example 1 700V 0.17μJ / cm ² 70V 1500 sheets After actual shooting, image defects occur and are extremely unclear Comparative example 2 700V 0.19μJ / cm ² 90V 500 sheets After actual shooting Image defects occur and are extremely unclear Image Comparative example 3 700V 0.16μJ / cm ² 65V Repeated charging and 10,000 exposures caused a large decrease in surface potential.

[0044]

According to the present invention, it is possible to provide an electrophotographic photoreceptor having a reverse laminated structure which has stable electric characteristics, can obtain a high-quality image, has high sensitivity and is excellent in durability, and a method for producing the same.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsuro Saida 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Sanryo Kasei Co., Ltd. (72) Inventor Kaname Makino 1000, Kamoshita-cho, Midori-ku, Yokohama, Kanagawa Ryokasei Co., Ltd.

Claims (2)

[Claims] 1. An electrophotographic photosensitive member comprising a conductive support, a charge transport layer, and a charge generating layer in which a charge generating substance is dispersed in a binder resin, which are sequentially laminated on an electrically conductive support. At least two charge generating layers are provided. The layer formed of the above layers, the layer adjacent to the charge transport layer having a thickness of 0.1 μm or less, and the ratio of the charge generating substance in the layer adjacent to the charge transport layer to the binder resin is An electrophotographic photosensitive member characterized by being higher than the ratio in other layers in the layer. 2. A charge-generating layer-forming dispersion liquid obtained by dispersing a charge-generating substance in a solution containing a binder resin and an organic solvent is applied onto the charge-transporting layer provided on a conductive support. In the method of manufacturing an electrophotographic photosensitive member for forming a charge generation layer, first, when the charge generation layer is formed by sequentially applying at least two kinds of dispersion liquids for forming a charge generation layer,
Of the charge generation layer forming dispersion liquid to form a charge generation layer having a thickness of 0.1 μm or less, and then the ratio of the charge generating substance to the binder resin in the first charge generation layer forming dispersion liquid. A method for producing an electrophotographic photosensitive member, characterized in that at least one kind of dispersion liquid for forming a charge generation layer having a ratio lower than that of the charge generation layer is applied to form a charge generation layer.