JPH06222578A - Electrophotographic sensitive body and its production - Google Patents

Abstract

PURPOSE:To prevent image defects such as white spots, black spots, irregular density, etc., by incorporating silicone oil into a carrier producing layer on a flexible belt-type or sheet-type conductive base body. CONSTITUTION:This electrophotographic sensitive body is produced by forming a carrier producing layer 3 containing silicone oil 2, and a carrier transfer layer 4 on a flexible belt or sheet-type conductive base body 1. The silicone oil 2 may be incorporated into the carrier transfer layer 3. As for the coating liquid to form the carrier producing layer 3 on the conductive base body 1, a coating liquid containing silicone oil 2 by 0.01-5.0wt.% solid content of the layer is used. With the silicone oil 2 compounded in the layer, affinity between the flexible conductive base body 1 such as metal and the carrier producing layer 3 is significantly increased, and thereby, excellent products are obtd. without producing irregular images.

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, and in particular, it is of a function separation type in which a carrier generating layer and a carrier transporting layer are sequentially laminated on a flexible belt-shaped or sheet-shaped conductive substrate. It exists in the improvement of the photoreceptor and the manufacturing method thereof, in particular, by eliminating the coating defect of the carrier generation layer,
The present invention relates to a photoreceptor having good image characteristics without white spots and image unevenness.

[0002]

2. Description of the Related Art The basic structure of a photosensitive member is usually one in which a carrier generating layer and a carrier transporting layer are sequentially laminated on a conductive support. Conventionally, an inflexible cylindrical conductive substrate is used. However, from the viewpoint of productivity and use, a flexible belt-shaped or sheet-shaped conductive substrate has been developed.

[0003]

When a thin carrier generating layer is coated on a flexible belt-like or sheet-like conductive substrate as described above, a coating for the conductive substrate and the carrier generating layer is obtained. Since there is no affinity for the coating liquid, the phenomenon of "repelling" of the coating liquid occurs, there are areas where the carrier generation layer is not applied, and the thickness of the coating layer is not uniform, resulting in "uneven coating". There is a problem that it occurs. When an image is obtained using such a photoconductor, the repelling portions become white spots or black spots, and the "coating unevenness" portions become image density unevenness as they are. That is, the coating defect as described above becomes an image density unevenness as it is, which causes a serious problem of causing an image defect. In particular, a belt-shaped or sheet-shaped substrate having flexibility as compared with an inflexible cylindrical conductive substrate has a considerably high coating speed and has flexibility, so The above-mentioned problem of image defect generation due to "working unevenness" is further highlighted.

Conventionally, in order to solve these problems, an intermediate layer is provided between the electroconductive substrate and the carrier generating layer to increase the affinity between the electroconductive substrate and the carrier generating layer coating liquid, and to apply the coating liquid. By improving the workability and coating the carrier generation layer thickly, the image defect caused by the "uneven coating" was not recognized. However, in these methods, the number of working steps is increased by one step, the manufacturing cost is increased due to the increase of the coating amount, and the flexibility is reduced and the image characteristics are sufficiently improved by carrying out these methods. There was a problem such as no. The present invention solves such a problem, and in an electrophotographic photoreceptor in which a thin sheet carrier generation layer is applied to a flexible sheet-shaped or belt-shaped conductive substrate by coating, white spots, black spots, and density unevenness are obtained. It is an object of the present invention to provide an electrophotographic photosensitive member that does not cause image defects such as.

[0005]

SUMMARY OF THE INVENTION The present invention is summarized on a flexible belt-shaped or sheet-shaped conductive substrate.
An electrophotographic photoreceptor comprising a carrier generating layer and a carrier transporting layer, which are laminated in this order, at least an electrophotographic photoreceptor containing silicone oil in the carrier generating layer, and for forming the carrier generating layer on a conductive substrate. In the method for producing an electrophotographic photosensitive member, a coating liquid containing 0.01 to 5.0% by weight of silicone oil in the solid content of the layer is used for coating. According to the present invention, the affinity of the conductive base material such as a flexible metal and the carrier generation layer is dramatically increased by the silicone oil blended in the same layer, the image unevenness is not generated, and the silicone oil is not generated. By setting the concentration of 0.01 to 5.0% by weight based on the solid content as described above, an excellent product could be obtained extremely easily.

An example of the structure of the electrophotographic photosensitive member of the present invention is shown in FIG.
The carrier generating layer 3 containing the silicone oil 2 and the carrier transporting layer 4 are sequentially provided on the flexible belt-shaped or sheet-shaped conductive substrate 1,
It constitutes an electrophotographic photoreceptor. The silicone oil 2 may also be contained in the carrier transport layer 3 described above.

Next, specific materials for the electrophotographic body of the present invention will be described. The conductive substrate in the present invention is a sheet-shaped or belt-shaped flexible material such as aluminum,
A sheet of metal such as nickel, copper or brass, or a plastic film of polyester or the like having a metal such as aluminum vapor-deposited on the surface thereof, a sheet of belt such as paper, synthetic paper or non-woven fabric, or a belt is used.

A known photoconductive substance is used as the carrier generating material used in the carrier generating layer. As an example, phthalocyanine pigments, azo pigments, quinone pigments, perylene pigments, quinacridone pigments, indigo pigments, pyrrole pigments, anthanthrone pigments and the like can be used. The carrier generating layer is formed by applying and drying a coating solution prepared by dispersing and dissolving a carrier generating material and a suitable binder such as polyester, polymethylmethacrylate, polystyrene, polyvinyl butyral and polycarbonate in an organic solvent. At this time, by adding silicone oil to the coating solution, the affinity with the conductive substrate can be increased and the occurrence of "uneven coating" can be prevented.

As the organic solvent used for forming the coating liquid for the carrier generating layer, aromatic hydrocarbons such as benzene, toluene and xylene, methylene chloride, chloroform,
1,1-dichloroethane, 1,2-dichloroethane,
Examples thereof include halogenated hydrocarbons such as 1,1,2-trichloroethane, 1,1,2,2-tetrachloroethane and chlorobenzene, and cyclic ethers such as tetrahydrofuran and 1,4-dioxane.

Examples of the silicone oil used in the present invention include general silicone oils such as methyl silicone oil, dimethyl silicone oil and methylphenyl silicone oil. Modified silicone oil obtained by modifying such silicone oil with other substances, for example, higher fatty acid, alkyl, alkylaralkyl, polyether, amino group, polysiloxane, polyoxyalkylene, epoxy, alkyd, urethane, acrylic, polyester, alcohol, carboxyl Silicone oil modified with fluoroalkyl or the like is used. An appropriate amount of these silicone oils may be added to the carrier generation layer coating liquid, but 0.01 to 5.0% by weight in all solid components (carrier generation material and binder) of the layer. % Is preferred. In this case, if the amount of silicone oil added is less than 0.01% by weight, the affinity between the carrier generation layer coating liquid and the conductive substrate such as metal cannot be increased, and coating defects occur, and the problems cannot be improved. On the contrary, when the amount of silicone oil added is more than 5.0% by weight, the coating defects of the carrier generation layer are eliminated and a good coating surface can be obtained, but when the carrier transport layer is laminated, the carrier generation layer and the carrier transport layer are not transported. The affinity between layers is weakened, unevenness is generated on the surface of the carrier transport layer, the surface is not smooth, and a good coated surface of the carrier transport layer is not formed. Good results are obtained when the coating thickness of these carrier generation layers is 0.01 to 5 μm, preferably 0.05 to 1 μm.

As the material of the carrier transport layer, known materials such as hydrazone, butadiene derivative, polyvinylcarbazole, pyrazoline, oxadiazole, oxazole, triphenylmethane, amine derivative, fluorenone derivative, diphenoquinone derivative and the like can be used. The carrier transport layer is a carrier transport material and a suitable binder, for example, polycarbonate, polymethacrylates, polyarylate, polystyrene, polyester,
Polysulfone, styrene-methyl methacrylate copolymer and the like, a suitable organic solvent, for example, aliphatic hydrocarbons such as cyclohexane, aromatic hydrocarbons such as toluene, hydrogen halides such as dichloromethane, dichloroethane, ethers such as tetrahydrofuran, acetone Ketones, etc.
It is dissolved in an ester such as acetic acid ester, dimethylformamide, etc., and applied by a method such as bar coating, roll coating, spray coating or blade coating. The coating thickness of the carrier transport layer is 5 to 40 μm, preferably 10 to 3
It is about 0 μm.

[0012]

EXAMPLES Next, as examples and comparative examples of the present invention, the coating step of the carrier generating layer will be described.

Example 1 On a 100 μm thick aluminum vapor-deposited polyester film, a coating solution in which a composition having the following composition was dispersed for 4 hours by a dispersion device using glass beads was applied using a bar coater. , Dry at 100 ℃ for 10 minutes,
A carrier generation layer having a thickness of 0.5 μm after drying was provided. -X type metal-free phthalocyanine pigment: 2 parts by weight-Polyvinyl butyral (solid content): 1 part by weight (trade name "# 4000-1" manufactured by Denki Kagaku Kogyo Co., Ltd.)-Silicone oil: 0.03 Parts by weight (Epoxy-modified silicone oil manufactured by Shin-Etsu Chemical Co., Ltd., trade name "ES-1001N") ・ Dichloroethane ……… 96.97 parts by weight The above sample is visually repelled (with a diameter of 0.1 mm or more) and uneven coating. confirmed. The results are shown in Table 1.

Next, a coating solution for the carrier transport layer was prepared with the following composition.・ Hydrazone 10 parts by weight

[Chemical 1] -Polycarbonate 10 parts by weight (Teijin Kasei's trade name "Panlite L1250")-Dichloroethane 80 parts by weight The above composition is mixed and dissolved to form a coating solution for the carrier transport layer, and this coating solution is applied on the carrier generation layer. Apply with a roll coater and dry at 100 ° C for 10 minutes to a thickness of 20 μm.
The carrier transporting layer was formed to obtain the electrophotographic photosensitive member of the present invention. In this way, the obtained electrophotographic photosensitive member was wrapped around a tube of a commercially available laser beam printer to perform image evaluation, and white spots of solid black and image unevenness of halftone were visually evaluated. The results are shown in Table 2.

Example 2 The same as Example 1 except that the silicone oil of the carrier generating layer coating solution shown in Example 1 was replaced with a silicone oil of dimethyl silicone oil trade name "TSF400" manufactured by Toshiba Silicone Co., Ltd. An electrophotographic photoreceptor of the present invention was obtained.

Example 3 An electrophotographic photosensitive member of the present invention was obtained and evaluated in the same manner as in Example 1 except that the composition of the carrier generation layer coating liquid shown in Example 1 was changed to the following composition. -Titanyl phthalocyanine pigment 2.5 parts by weight-Polyvinyl butyral (solid content) 1.0 parts by weight (product name "# 4000-1" manufactured by Denki Kagaku Kogyo Co., Ltd.)-Silicone oil 0.14 parts by weight (Toshiba Silicone Poly Oxyalkylene-modified silicone oil, trade name "YF3860")-Dichloroethane 96.36 parts by weight

Example 4 An electrophotographic photosensitive member of the present invention was obtained and evaluated in the same manner as in Example 1 except that the composition of the carrier generation layer coating liquid shown in Example 1 was changed to the following composition. -Titanyl phthalocyanine pigment 3.0 parts by weight-Polyvinyl butyral (solid content) 1.0 parts by weight (Product name "# 4000-1" manufactured by Denki Kagaku Kogyo Co., Ltd.)-Silicone oil 0.02 parts by weight (Modified by Shin-Etsu Chemical Co., Ltd. Silicone oil, trade name "KR-211")-Dichloroethane 95.98 parts by weight

Comparative Example 1 An electrophotographic photosensitive member for comparison was obtained in the same manner as in Example 1 except that the composition of the carrier generation layer coating liquid shown in Example 1 was changed to the following composition. The work surface was uneven, and a smooth and good surface was not formed. -X type metal-free phthalocyanine pigment 2 parts by weight-Polyvinyl butyral (solid content) 1 part by weight (product name "# 4000-1" manufactured by Denki Kagaku Kogyo Co., Ltd.)-Dichloroethane 97 parts by weight

Table 1 shows the coating defects of the carrier generation layer for each of the examples and comparative examples.

[0020]

[Table 1]

Further, the image evaluation after the carrier transport layer is further provided is shown in each of Examples and Comparative Examples.
It is as follows.

[0022]

[Table 2]

[0023]

According to the present invention, since the silicone oil is contained in the carrier generation layer on the flexible belt-shaped or sheet-shaped conductive substrate, the surface of the carrier generation layer becomes flat, It is possible to provide an electrophotographic photosensitive member that does not cause "coating unevenness" and is free from image defects such as black spots, white spots, and image unevenness.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of the present invention.

[Explanation of symbols]

 1 Flexible Conductive Substrate 2 Silicone Oil 3 Carrier Generation Layer 4 Carrier Transport Layer

Claims (2)

[Claims] 1. An electrophotographic photosensitive member comprising a flexible belt-shaped or sheet-shaped conductive substrate and a carrier-generating layer and a carrier-transporting layer sequentially laminated on the conductive substrate, and at least the carrier-generating layer contains silicone oil. An electrophotographic photosensitive member characterized by being squeezed. 2. As a coating liquid for forming a carrier generation layer on a conductive substrate, 0.01 to 5.0% by weight based on the solid content of the layer.
2. The method for producing an electrophotographic photosensitive member according to claim 1, wherein coating is performed using the silicone oil added.