JPH07281458A - Electrophotographic photoreceptor and electrophotographic device using the same - Google Patents

Abstract

PURPOSE:To prevent cracks due to mechanical force and to obtain good images without producing image defects such as contamination of the base even when the photoreceptor is repeatedly used for a long time. CONSTITUTION:The photosensitive layer or a charge transfer layer of a functional separation type photoreceptor shows such a DSC curve of differential scanning calorimetry that has the endothermic peak of the binder included in the photosensitive layer or the charge transfer layer. Or the photosensitive layer or the charge transfer layer contains bisphenol E polycarbonate and/or copolymer polycarbonate as a binder resin. This electrophotographic photoreceptor is mounted on the electrophotographic device.

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 which does not generate cracks due to mechanical force and gives a high quality image even after repeated use for a long period of time, and an electrophotographic apparatus equipped with the same.

[0002]

2. Description of the Related Art Inorganic substances such as selenium, cadmium sulfide, and zinc oxide are used as photoconductive materials for photoconductors used in electrophotographic apparatuses such as electrophotographic copying machines. There are drawbacks in productivity, flexibility, thermal and mechanical impact. There are electrophotographic photoconductors that use various organic substances in order to eliminate the disadvantages of the inorganic substances, and the organic photoconductors are generally excellent in discardability and mass productivity. Since organic photoconductors have low photosensitivity, function-separated photoconductors in which a charge generation layer and a charge transport layer are laminated in order to improve photosensitivity are known.

On the other hand, when the photoconductor is mounted in an electrophotographic apparatus such as a copying machine, it is subjected to corona charging, exposure, development, transfer to paper, cleaning of developer, and the like. These processes cause deterioration of photoreceptor characteristics when repeatedly used. For example, deterioration of ozone during corona charging, light fatigue, scraping of the photosensitive layer during development / transfer to paper / cleaning of the developer, etc. In addition, recently, the number of members such as a developing roller, a cleaning blade, a roller-shaped charging member, and an intermediate transfer belt interposed between transferring a toner image formed on the photosensitive member and directly in contact with the photosensitive member increases. There is a tendency. When an electrophotographic apparatus such as a copying machine is repeatedly used, the photoconductor is always placed in an environment where it comes into direct contact with these members, but the occurrence of cracks that are thought to be due to the contact, Image defects such as scumming have become a new problem. In addition, when a photoconductor is attached to an electrophotographic apparatus, a human hand touches it, and an image defect occurs, which is becoming a problem. As a cause of these, when the photoreceptor is manufactured by applying a photosensitive layer or the like on a conductive substrate by a wet method and then drying the photosensitive layer, the photosensitive layer contacts with the conductive substrate on one side, so that a strong residue is left inside. It can be considered that, in addition to the generation of stress, when a developing roller or the like comes into contact with the stress, some of the constituent materials move and act on the photoconductor, resulting in image defects. In order to suppress the occurrence of such cracks, for example, a photoconductor in which a charge-transporting layer contains a silicone-type comb-type graft polymer has been proposed (JP-A-4-368954).

Further, as the conductive substrate of the organic photoreceptor,
Although a hard cylindrical drum is often used, a flexible belt-shaped conductive substrate is recently adopted for mounting in small printers because of the high degree of freedom in space design. Is becoming. However, since the belt photosensitive member is stressed when being rotated by being supported by a plurality of rollers in addition to the above-mentioned factors causing cracks, cracks are more likely to occur during repeated use. This causes an image defect similarly to the above, and therefore improvement is desired. However, no proposal has been made yet to prevent the occurrence of cracks due to such mechanical force.

[0005]

SUMMARY OF THE INVENTION Therefore, the present invention has been made in view of the above-mentioned circumstances of the prior art. Specifically, no cracks are generated by mechanical force, and even when repeatedly used for a long time It is an object of the present invention to provide an electrophotographic photosensitive member which gives a good image free from image defects such as stains, and an electrophotographic apparatus equipped with the same.

[0006]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made earnest studies on suppression of crack generation in an electrophotographic photosensitive member. As a result, in an electrophotographic photosensitive member having at least a photosensitive layer provided on a conductive substrate, An electron formed by giving an endothermic peak of the binder resin contained in the photosensitive layer to the DSC curve in the differential scanning calorimetry of the layer, or by stacking at least a charge generation layer and a charge transport layer on a conductive substrate. In the photographic photoreceptor, by giving an endothermic peak of the binder resin contained in the charge transport layer to the DSC curve in the differential scanning calorimetry of the charge transport layer, cracks are not generated and a good image is provided. It was found that a photoreceptor was obtained, and the present invention was completed. Further, in an electrophotographic photoreceptor having at least a photosensitive layer provided on a conductive substrate, the photosensitive layer contains a specific bisphenol E-type polycarbonate and / or a specific copolymerized polycarbonate, or on the conductive substrate. In an electrophotographic photosensitive member comprising at least a charge generation layer and a charge transport layer laminated, by incorporating a specific bisphenol E-type polycarbonate and / or a specific copolymerized polycarbonate in the charge transport layer, no crack is generated. It was found that a photoconductor that gives a good image can be obtained, and the present invention has been completed.

That is, according to the present invention, in an electrophotographic photosensitive member comprising a conductive substrate and at least a photosensitive layer provided thereon,
There is provided an electrophotographic photosensitive member characterized in that the DSC curve in the differential scanning calorimetry of the photosensitive layer has an endothermic peak of a binder resin contained in the photosensitive layer, and at least a charge generation layer on a conductive substrate. In an electrophotographic photosensitive member formed by laminating a charge carrying layer, the DSC curve in the differential scanning calorimetry of the charge carrying layer has an endothermic peak of a binder resin contained in the charge carrying layer. A photoreceptor is provided.

Further, according to the present invention, in an electrophotographic photosensitive member comprising at least a photosensitive layer provided on a conductive substrate,
The photosensitive layer has at least a bisphenol E type polycarbonate having a repeating unit represented by the following structural formula (1) and / or a repeating unit represented by the following structural formulas (A) and (B), and (A) And the ratio of (B) is 1: 9
There is provided an electrophotographic photosensitive member comprising a copolycarbonate of 9 to 90:10.

[Chemical 1]

[Chemical 2]

[Chemical 3]

Further, according to the present invention, in an electrophotographic photosensitive member comprising a conductive substrate and at least a charge generation layer and a charge transfer layer laminated on each other, the charge transfer layer has at least the following structural formula (1). A bisphenol E type polycarbonate having a repeating unit represented and / or a repeating unit represented by the following structural formulas (A) and (B), and the ratio of (A) to (B) is 1:99 to. There is provided an electrophotographic photosensitive member comprising a copolymerized polycarbonate of 90:10.

[Chemical 1]

[Chemical 2]

[Chemical 3]

Further, according to the present invention, there is provided the electrophotographic photosensitive member characterized in that the photosensitive member has an endless belt shape, and further, the electrophotographic photosensitive member is mounted. An electrophotographic apparatus is provided.

The present invention will be described in detail below. The electrophotographic photosensitive member is a single layer type in which a photosensitive layer in which a charge generating substance and a charge carrier substance are dispersed in a binder resin is provided on a conductive substrate, and a charge containing a charge generating substance and a binder resin on a conductive substrate. There are two types of layer structure, such as a generation layer, a function separation type in which a charge transfer layer containing a charge transfer material and a binder resin is laminated thereon, and a function separation type in which a charge transfer layer and a charge generation layer are laminated in that order on a conductive substrate. However, the present invention is applicable to any layer structure. In the case of the function separation type, a charge carrier substance may be contained in the charge generation layer. Configuration diagrams for the above cases, and are shown in FIGS. 1, 2, and 3. In the figure, 1 is a conductive substrate, 2 is a single photosensitive layer, 3 is a charge carrier layer, and 4 is a charge generation layer. Of course, an intermediate layer may be provided between the photosensitive layer and the substrate in order to improve the adhesiveness and the charge blocking property, and a protective layer may be provided on the photosensitive body to protect the surface of the photosensitive body. It may be provided. Figure 4 shows the configuration of these cases.
~ 12. In the figure, 5 indicates an intermediate layer and 6 indicates a protective layer, respectively.

The conductive substrate 1 has a volume resistance of 10 ¹⁰ Ω.
Those exhibiting the following conductivity, for example, metals such as aluminum, nickel, chromium, nichrome, copper, silver, gold and platinum,
A belt-shaped or cylindrical plastic, paper, or the like coated with an oxide such as tin oxide or indium oxide by vapor deposition or sputtering, or aluminum, aluminum alloy, nickel, stainless steel, or the like, and D. l. , L. l. It is possible to use a tube whose surface is treated by cutting, superfinishing, polishing or the like after forming the raw tube by a method such as extrusion or drawing. Of these, the present invention is particularly effective when a belt-shaped conductive substrate is used.

Next, the charge generation layer 4 of the function-separated type photoreceptor will be described. The charge generation layer 4 is a layer containing a charge generation material as a main component, and a binder resin may be used if necessary. As the binder resin, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinylcarbazole, polyacrylamide and the like are used. These binder resins are used alone or as a mixture of two or more kinds.

As the charge generating substance, known materials can be used. For example, phthalocyanine-based pigments such as metal phthalocyanine and metal-free phthalocyanine, azurenium salt pigment, squaric acid methine pigment, azo pigment having carbazole skeleton, azo pigment having triphenylamine skeleton, azo pigment having diphenylamine skeleton, dibenzothiophene skeleton Having azo pigment, azo pigment having fluorenone skeleton, azo pigment having oxadiazole skeleton, azo pigment having bisstilbene skeleton, azo pigment having distyryl oxadiazole skeleton, azo pigment having distyryl carbazole skeleton, perylene Series pigments, anthraquinone series or polycyclic quinone series pigments, quinone imine series pigments, diphenylmethane and triphenyl methane series pigments, benzoquinone and naphthoquinone series pigments, cyanine and azomethine series pigments, Jigoido based pigments, and bisbenzimidazole pigments. These charge generating substances can be used alone or as a mixture of two or more kinds. The charge generation layer may contain a charge generation substance.

Next, the charge carrier layer 3 of the function-separated type photoreceptor will be described. The charge carrier layer 3 can be formed by dissolving or dispersing a charge carrier substance and a binder resin in a suitable solvent, and applying and drying the solution. The charge carrier substance includes a hole carrier substance and an electron carrier substance. Examples of the electron carrier substance include chloranil, bromanil, tetracyanoethylene, tetracyanoquinodimethane, 2,
4,7-trinitro-9-fluorenone, 2,4,5,
7-tetranitro-9-fluorenone, 2,4,5,7
-Tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno (1,2-b) thiophen-4one, 1,3,7-trinitrodibenzothiophene-5 And electron-accepting substances such as 5-dioxad. These electron carrier substances can be used alone or as a mixture of two or more kinds.

Examples of the hole-transporting substance include the electron-donating substances shown below, which are preferably used. For example,
Poly-N-vinylcarbazole and its derivatives, poly-
γ-carbazolylethyl gourmet tart and its derivatives,
Pyrene-formaldehyde condensate and its derivative, polyvinylpyrene, polyvinylphenanthrene, oxazole derivative, oxadiazole derivative, imidazole derivative, triphenylamine derivative, 9- (p-diethylaminostyryl) anthracene, styrylpyrazoline, phenylhydrazones, α -Phenylstilbene derivative,
Examples thereof include thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives and thiophene derivatives. These hole-transporting substances can be used alone or as a mixture of two or more kinds.

For the charge carrier layer 3, the resin of the present invention may be mixed with another resin. Specifically, polycarbonate (bisphenol A type, bisphenol Z type, etc.), polyester, methacrylic resin,
Acrylic resin, polyethylene, vinyl chloride, vinyl acetate, polystyrene, phenol resin, epoxy resin, polyurethane, polyvinylidene chloride, alkyd resin, silicone resin, polyvinyl carbazole, polyvinyl butyral, polyvinyl formal, polyacrylate,
Polyacrylamide, phenoxy resin, etc. are used. These binder resins may be used as a mixture of two or more kinds.

Next, the photosensitive layer 2 of the single-layer type photoreceptor will be described. The photosensitive layer 2 can be formed by dissolving or dispersing a charge-generating substance, a charge-transporting substance and a binder resin in a suitable solvent, and applying and drying the solution. As the charge generating substance, the compounds exemplified in the description of the charge generating layer of the function-separated type photoreceptor can be used. As the charge carrier substance, the compounds exemplified in the description of the charge carrier layer of the function-separated type photoreceptor can be used. As the binder resin of the photosensitive layer, the resin of the present invention or the resin exemplified in the description of the charge transport layer of the function-separated type photoreceptor can be used.

The intermediate layer 5 provided between the conductive substrate 1 and the charge generation layer 4 is provided for the purpose of improving the adhesiveness,
The materials include inorganic materials such as SiO ₂ , Al ₂ O ₃ , silane coupling agents, titanium coupling agents, and chromium coupling agents, polyamide resins, alcohol-soluble polyamide resins, water-soluble polyvinyl butyral, polyvinyl butyral, polyvinyl alcohol, etc. A binder resin having good adhesiveness is used. In addition, a binder resin having ZnO, TiO ₂ , ZnS, or the like dispersed therein can be used. As a method for forming the intermediate layer, a method such as sputtering or vapor deposition is used when the inorganic material is used alone, and a usual coating method is used when the organic material is used. The thickness of the intermediate layer is appropriately 5 μm or less.

The protective layer 6 is provided for the purpose of protecting the surface of the photoreceptor, and materials used for this are ABS resin and AC.
S resin, olefin / vinyl monomer copolymer, chlorinated polyether, allyl resin, polyacetal, polyamide, polyamideimide, polyacrylate, polyallylsulfone, polybutylene, polybutylene terephthalate, polycarbonate, polyethersulfone, polyethylene, polyethylene Terephthalate, polyimide, acrylic resin, polymethylpentene, polypropylene, polyphenylene oxide, polysulfone, polystyrene,
Examples thereof include AS resin, butadiene / styrene copolymer, polyurethane, polyvinyl chloride, epoxy resin, fluororesin such as polytetrafluoroethylene, and silicone resin. Among these, the curable materials are
It can be used as a mixture with a curing agent. Further, for the purpose of improving abrasion resistance, a material in which an inorganic material such as tin oxide or potassium titanate is dispersed can be added. As a method for forming the protective layer, a usual coating method can be adopted.

In the case where a photoconductor is prepared by using the above layer structure and substances, the film thickness and the composition ratio of the substances have preferable ranges. In the case of the function separation type, the ratio of the binder resin to the charge generating substance in the charge generating layer is 0 to
It is preferably 500% by weight and the film thickness is 0.1 to 10 μm. In the charge transport layer, the ratio of the charge transport substance to the binder resin is preferably 2 to 200% by weight and the film thickness is preferably 5 to 50 μm. In the case of a single layer type, the ratio of the charge carrier substance and the charge generating substance to the binder resin is preferably 50 to 150% by weight and 0.01 to 50% by weight, respectively, and the film thickness is 5 to 50 μm. Is preferred.

In the photoreceptor of the present invention, the DSC curve in the differential scanning calorimetry of the photosensitive layer in the case of the single layer type and the charge transport layer in the case of the function separated type is the photosensitive layer or the charge. It is characterized by having an endothermic peak of the binder resin contained in the transport layer. As a result, a photosensitive member which does not generate cracks due to mechanical force and gives a good image even when repeatedly used for a long period of time.

Further, in order to have an endothermic peak of the binder resin contained in the photosensitive layer or the charge transport layer in the DSC curve in the differential scanning calorimetry of the photosensitive layer or the charge transport layer, the following binder resin may be used. Structural formula (1)
A bisphenol E type polycarbonate having a repeating unit represented by and / or a repeating unit represented by the following structural formulas (A) and (B), and the ratio of (A) to (B) is 1:99. It is advantageous to use a copolycarbonate which is ˜90: 10.

[Chemical 1]

[Chemical 2]

[Chemical 3] As the bisphenol E type polycarbonate and the copolymerized polycarbonate, those having a specific viscosity of 0.1 to 10 can be used, and those having a specific viscosity of 0.15 to 5.0 are more preferable. The specific viscosity referred to in the present invention is a value obtained by a solution viscosity method in which 0.70 g of a polycarbonate resin is dissolved in 100 ml of methylene chloride and measured at 20 ° C. using an Ostwald viscosity tube.

Next, the structure of an electrophotographic apparatus equipped with the electrophotographic photosensitive member of the present invention will be described. 13 to 18 show schematic configuration diagrams of the peripheral portion of the photoconductor of the electrophotographic apparatus of the present invention, any configuration can be suitably used for the electrophotographic apparatus of the present invention. In the figure, 11a and b are photoconductors, 11a is a drum type, 11b is a belt type,
It is driven to rotate in the direction of the arrow. The photoconductors 11a and 11b are charged in the charging section 12a or 12b while rotating.
Here, 12a is a wire type by indirect charging,
2b is a roller type by direct charging. Next, the exposure unit 13 receives light irradiation corresponding to the image signal to form an electrostatic latent image, the developing unit 14 develops it with electro-detection fine particles (toner), and the transfer unit 15a or b transfers it to the image receiving paper. (15a is a wire type and 15b is a belt type). Here, the detection particles may be directly transferred to the transfer portion 15b and then transferred to the image receiving paper. The image receiving paper on which the electroscopic fine particles are transferred is sent to the image fixing section, heated and pressed, and discharged as a duplicate. Photoreceptor 11a after image transfer
With respect to b and b, the cleaning unit 16 removes the fine particles for detection, and the static elimination unit 17 performs static elimination by light irradiation, and shifts to the next copying process. In the figure, 18 indicates an image fixing unit and 19 indicates an image receiving material.

[0025]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples. All parts used in the examples are parts by weight.

Example 1 As a charge-generating substance, 12 parts of P-1 shown in Table 1 below and 88 parts of tetrahydrofuran were pulverized and mixed in a pot together with a zirconium oxide ball for 2 hours, and then a bisphenol E type polycarbonate resin [Teijin Chemical Co., Ltd., specific viscosity 1.042] 108 parts, and tetrahydrofuran 7
A solution prepared by mixing and dissolving 92 parts was added, and the mixture was ground and mixed for 24 hours. 26.5 parts of D-1 shown in Table 1 below was added as a charge carrier substance to 350 g of the solution thus obtained to obtain a photosensitive layer liquid. This is applied by an immersion coating method on an aluminum surface on a conductive base made of an aluminum vapor-deposited polyester base in the form of an endless belt, and then at 80 ° C. for 5 minutes.
Then, it was dried at 120 ° C. for 15 minutes to form a photosensitive layer having a thickness of about 20 μm, and the photosensitive member of Example 1 was prepared.

The photosensitive layer liquid obtained here is applied to a polyester film by a dip coating method, and the temperature is kept at 80 ° C. for 5 minutes.
Minute, then dried at 120 ° C for 15 minutes, thickness about 20 μm
To form a photosensitive layer. This photosensitive layer was peeled off from the polyester film to prepare a sample for differential scanning calorimetry.

Example 2 In Example 1, except that the bisphenol E-type polycarbonate resin was replaced by a copolymerized polycarbonate resin (specific viscosity 0.861) having a bisphenol E / bisphenol A copolymerization ratio of 1: 1. In the same manner as in Example 1, a photoconductor of Example 2 and a sample for differential scanning calorimetry were prepared.

Example 3 As a charge generating substance, 25 parts of P-1 shown in Table 1 below and 625 parts of a 1.6% cyclohexanone solution of a polyester resin [Vylon 200, manufactured by Toyobo Co., Ltd.] together with balls made of zirconium oxide were used. After pulverizing and mixing in a pot for 24 hours, 550 parts of cyclohexanone and 215 parts of methyl ethyl ketone were further added and pulverized and mixed in a ball mill for 24 hours to obtain a dispersion liquid. This is applied by an immersion coating method onto an aluminum surface on a conductive base made of an aluminum vapor-deposited polyester base in the form of an endless belt.
After drying at 0 ° C. for 10 minutes, a charge generation layer having a thickness of about 1 μm was formed.

On the other hand, as a charge carrier substance, D in Table 1 below is used.
-1 140 parts, bisphenol E type polycarbonate resin [manufactured by Teijin Chemicals, Ltd., specific viscosity 1.042] 200
Parts and 1660 parts of dichloromethane are mixed and dissolved to form a solution, which is then applied onto the charge generation layer by a dip coating method, dried at 80 ° C. for 5 minutes, and then 120 ° C. for 15 minutes to have a thickness of about A charge transport layer having a thickness of 20 μm is formed, and the third embodiment
The photoconductor was created.

Further, as a charge carrier substance, D in Table 1 below is used.
-1 of 140 parts, bisphenol E type polycarbonate resin [manufactured by Teijin Kasei Co., Ltd.], and 1660 parts of dichloromethane were mixed and dissolved to form a solution, which was then applied to a polyester film by a dip coating method.
℃, 5 minutes, then 120 ℃, dried for 15 minutes, thickness about 2
A 0 μm charge transport layer was formed. The charge carrying layer was peeled from the polyester film to prepare a sample for differential scanning calorimetry.

Example 4 In Example 3, except that a bisphenol E-type polycarbonate resin was replaced by a copolycarbonate resin (specific viscosity 0.861) having a bisphenol E / bisphenol A copolymerization ratio of 1: 1. In the same manner as in Example 3, a photoconductor of Example 4 and a sample for differential scanning calorimetry were prepared.

Comparative Examples 1 to 3 Comparative Example 1 was carried out in the same manner as in Example 1 except that the polycarbonate resin shown in Table 2 below was used in place of the bisphenol E type polycarbonate resin.
Sample Nos. 3 to 3 and samples for differential scanning calorimetry were prepared.

Comparative Examples 4 to 6 Comparative Example 4 was carried out in the same manner as in Example 3 except that the polycarbonate resin shown in Table 2 below was used in place of the bisphenol E type polycarbonate resin.
Sample Nos. 6 to 6 and samples for differential scanning calorimetry were prepared.

[0035]

[Table 1]

[0036]

[Table 2] Note) The specific viscosity is determined by a solution viscosity method in which 0.70 g of a polycarbonate resin is dissolved in 100 ml of methylene chloride using an Ostwald viscous tube and the temperature is measured at 20 ° C.

(Evaluation) The prepared photoconductor was mounted in the electrophotographic test apparatus having the structure shown in FIG. 18, and after a printing test was conducted 5000 times, the image quality of the printed matter was evaluated and the presence or absence of cracks was visually confirmed. I went. In addition, on the created photoconductor,
After applying finger oil and leaving it for 48 hours, the presence or absence of cracks was confirmed with a microscope. The differential scanning calorimetry was performed using a differential thermogravimetric simultaneous measurement apparatus DSC220 (manufactured by Seiko Denshi Kogyo Co., Ltd.) under the following conditions. Measurement temperature range: 20 to 240 ° C. Heating rate: 10 ° C./min. The results are shown in Table 3. Table 4 shows the differential scanning calorimetry results of the polycarbonate resin.

[0038]

[Table 3]

[0039]

[Table 4]

[0040]

As described above, the electrophotographic photosensitive member of the present invention is
It has an excellent effect that a crack is not generated by a mechanical force and a good image is provided without causing image defects such as background stain even when it is repeatedly used for a long period of time. An electrophotographic apparatus equipped with the present electrophotographic photosensitive member also exhibits the same effect.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a layer structure of a single-layer type electrophotographic photosensitive member.

FIG. 2 is a schematic cross-sectional view showing the layer structure of a function-separated electrophotographic photosensitive member.

FIG. 3 is a schematic cross-sectional view showing the layer structure of a function-separated electrophotographic photoreceptor.

FIG. 4 is a schematic cross-sectional view showing a layer structure of a single-layer type electrophotographic photosensitive member in which an intermediate layer is provided between a photosensitive layer and a substrate.

FIG. 5 is a schematic cross-sectional view showing a layer structure of a function-separated electrophotographic photosensitive member in which an intermediate layer is provided between a charge generation layer and a substrate.

FIG. 6 is a schematic cross-sectional view showing the layer structure of a function-separated electrophotographic photosensitive member in which an intermediate layer is provided between a charge transport layer and a substrate.

FIG. 7 is a schematic cross-sectional view showing the layer structure of a single-layer type electrophotographic photosensitive member in which a protective layer is provided on the photosensitive layer.

FIG. 8 is a schematic cross-sectional view showing the layer structure of a function-separated electrophotographic photosensitive member in which a protective layer is provided on a charge transport layer.

FIG. 9 is a schematic cross-sectional view showing the layer structure of a function-separated electrophotographic photosensitive member in which a protective layer is provided on a charge generation layer.

FIG. 10 is a schematic cross-sectional view showing a layer structure of a single-layer type electrophotographic photosensitive member in which an intermediate layer is provided between a photosensitive layer and a substrate, and a protective layer is provided on the photosensitive layer.

FIG. 11 is a schematic cross-sectional view showing a layer structure of a function-separated electrophotographic photosensitive member in which an intermediate layer is provided between a charge generation layer and a substrate, and a protective layer is provided on a charge transport layer.

FIG. 12 is a schematic cross-sectional view showing a layer structure of a function-separated electrophotographic photoreceptor in which an intermediate layer is provided between a charge transport layer and a substrate, and a protective layer is provided on the charge generation layer.

FIG. 13 is a schematic cross-sectional view showing an example of an electrophotographic apparatus equipped with the electrophotographic photosensitive member of the present invention.

FIG. 14 is a schematic cross-sectional view showing another example of an electrophotographic apparatus equipped with the electrophotographic photosensitive member of the present invention.

FIG. 15 is a schematic cross-sectional view showing another example of an electrophotographic apparatus equipped with the electrophotographic photosensitive member of the present invention.

FIG. 16 is a schematic cross-sectional view showing another example of an electrophotographic apparatus equipped with the electrophotographic photosensitive member of the present invention.

FIG. 17 is a schematic cross-sectional view showing another example of an electrophotographic apparatus equipped with the electrophotographic photosensitive member of the present invention.

FIG. 18 is a schematic cross-sectional view showing another example of an electrophotographic apparatus equipped with the electrophotographic photosensitive member of the present invention.

[Explanation of symbols]

 1 Conductive Substrate 2 Single Photosensitive Layer 3 Charge Transfer Layer 4 Charge Generation Layer 5 Intermediate Layer 6 Protective Layer 11a Drum Type Photoreceptor 11b Belt Type Photoreceptor 12a Charging Part (Wire Type) 12b Charging Part (Roller Type) 13 Exposure Part 14 developing unit 15a transfer unit (wire type) 15b transfer unit (belt type) 16 cleaning unit 17 charge eliminating unit 18 image fixing unit 19 image receiving material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoshi Mishima 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd. (72) Toshimasa Tokuda 1-6-21 Nishishinbashi, Minato-ku, Tokyo Teijin Kasei Stock company

Claims (6)

[Claims] 1. An electrophotographic photosensitive member comprising a conductive substrate and at least a photosensitive layer provided thereon, wherein a DSC curve in differential scanning calorimetry of the photosensitive layer has an endothermic peak of a binder resin contained in the photosensitive layer. An electrophotographic photoreceptor characterized by: 2. An electrophotographic photoreceptor comprising a conductive substrate and at least a charge generation layer and a charge transport layer laminated on the conductive substrate,
An electrophotographic photosensitive member characterized in that the DSC curve in the differential scanning calorimetry of the charge transport layer has an endothermic peak of the binder resin contained in the charge transport layer. 3. An electrophotographic photosensitive member comprising a conductive substrate and at least a photosensitive layer provided thereon, wherein the photosensitive layer has a bisphenol E-type polycarbonate having at least a repeating unit represented by the following structural formula (1) and / or A copolymerized polycarbonate having repeating units represented by the structural formulas (A) and (B) and having a ratio of (A) to (B) of 1:99 to 90:10. Characteristic electrophotographic photoreceptor. [Chemical 1] [Chemical 2] [Chemical 3] 4. An electrophotographic photosensitive member comprising a conductive substrate and at least a charge generation layer and a charge transport layer laminated on the conductive substrate,
The charge-transporting layer has at least a bisphenol E-type polycarbonate having a repeating unit represented by the following structural formula (1) and / or a repeating unit represented by the following structural formulas (A) and (B), and ( An electrophotographic photoreceptor comprising a copolycarbonate in which the ratio of A) to (B) is 1:99 to 90:10. [Chemical 1] [Chemical 2] [Chemical 3] 5. The electrophotographic photosensitive member according to claim 1, wherein the photosensitive member has an endless belt shape. 6. An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1.