JPH0689038A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To prevent occurrence of citron-peel-like patterns without deteriorating characteristics of the photosensitive body by incorporating specified polyarylate, polycarbonate, and dimethylpolysiloxane. CONSTITUTION:The electrophotographic sensitive body is formed by coating a conductive substrate with a composition comprising a photoconductor, a binder resin, and an organic solvent to form a photosensitive layer containing the polyarylate represented by formula I and the polycarbonate represented by formula II and the dimethylpolysiloxane represented by formula III. In formulae I-III, each of l, m, and n is a polymerization degree of 10-5000, 10-5000, and 0-2000, respectively. The photosensitive layer comprises an electric charge generating layer and a charge transfer layer, and the charge transfer layer can also contain these polyarylate, and polycarbonate, and dimethylpolysiloxane.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. 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. A typical example of the inorganic photoconductor is, for example, amorphous selenium (a-S).
e) or amorphous selenium arsenic (a-As ₂ Se)
₃ ) Selenium-based photoreceptors, dye-sensitized zinc oxide (ZnO) or cadmium sulfide (CdS) dispersed in binder resin, and photoreceptors using amorphous silicon (a-Si), etc. There is. However, among the above-mentioned inorganic photoconductors, selenium photoconductors and photoconductors using cadmium sulfide have problems in heat resistance and storage stability, and these photoconductors are toxic to the human body. There is a constraint that it cannot be easily discarded because it contains material and must be recovered. Further, the zinc oxide resin dispersion type photoconductor is hardly used at present because of its low sensitivity and low durability. Further, although the amorphous silicon type photoreceptor has advantages such as high sensitivity and high durability, it has a drawback that image defects are caused due to the complexity of the manufacturing process.

On the other hand, as a typical example of the organic photoconductor, a photoconductor using a charge transfer complex of 2,4,7-trinitro-9-fluorenone (TNF) and polyvinylcarbazole (PVK), , A function-separated type photoreceptor having a charge generation layer and a charge transport layer. These organic photoconductors can produce a photoconductor having no storage stability and toxicity by appropriately selecting a material most suitable for the photoconductor from organic materials that exist in a larger number than inorganic materials, and at low cost. It has been attracting attention as one of the most important photoconductors because it can be manufactured and its durability has been improved in recent years.

Various improvements have been added to the PVK-TNF charge-transfer complex type organic photoconductor, but the present situation is that the photosensitivity has not yet reached sufficient sensitivity. The function-separated type organic photoreceptor is a layer containing a charge generating material that generates charge carriers when irradiated with light (hereinafter, referred to as “charge generating layer”), and a charge generated in the charge generating layer. It has a layered structure with a layer containing a charge-transporting material that receives a carrier and transports it (hereinafter referred to as “charge-transporting layer”), has a relatively excellent sensitivity, and is currently in practical use. It is the mainstream of organic photoconductors. As such a function-separated type organic photoconductor, for example, a thin film formed by coating a charge generation layer with an organic amine solution of chlorodian blue and a photoconductor using a hydrazone compound in the charge transport layer (Japanese Patent Publication No. 55-42380), a photoconductor comprising a charge generation layer containing a disazo compound and a charge transport layer containing a hydrazone compound (JP-A-59-214035), or a charge containing an azurenium salt compound. A photoreceptor (Japanese Patent Laid-Open No. 59-53850) including a generating layer and a charge transport layer containing a hydrazone compound is known. Further, there has been proposed a photoconductor using an anthuron, which is one of pigments, or a quinone compound as a charge generating material (US Pat. No. 3,877,935).

These organic photoreceptors are generally manufactured by forming a photosensitive layer on a sheet-shaped or drum-shaped conductive support. As a method for forming the photosensitive layer on the sheet-shaped conductive support, a method using a baker applicator, a bar coater or the like is known.
Further, in the case of the drum-shaped support, a spray method, a vertical ring method, and a dip coating method are known. Of these, the dip coating method is generally adopted because the device is simple. In the process of forming a photosensitive layer on a conductive support in these methods, the photosensitive layer forming coating liquid is applied on the conductive support to form a coating film, and the coating film is dried to form a photosensitive layer. However, since the solvent contained in the coating film evaporates due to drying in this process, eddy convection occurs in the coating film at this time, resulting in unevenness on the surface after drying and There is a phenomenon that the smoothness is lost, and this is generally called "Yuzu skin".

Conventionally, a method of using a solvent having a slow evaporation rate has been known in order to suppress the generation of this skin damage.
However, when this method is used particularly for a drum-shaped conductive support, the coating film sags during drying to cause unevenness in the upper and lower film thicknesses, and it takes time to dry and productivity is reduced, which is not practical. It cannot be used and is therefore unsuitable for the prevention of scarred skin.

On the other hand, polysiloxane is generally called "silicone oil", and in the field of paints, this silicone oil has been conventionally added to paints in order to obtain surface smoothness. Further, it is known that silicone oil is effective in preventing silking and lettering. Therefore, even in the production of electrophotographic photoreceptors, it is known that the skin damage can be prevented by adding the silicone oil to the coating solution for forming the photosensitive layer (Japanese Patent Publication No. 49-152).
No. 20, JP-A-55-140849, JP-A-57-5050, and JP-A-57-212453), but these are said to cause an increase in residual potential and deterioration of photoreceptor characteristics. There is a problem.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems of the prior art, and to provide an electrophotographic photosensitive member which can surely prevent discolored skin without deteriorating the characteristics of the photosensitive member. It is in.

[0009]

As a result of intensive studies to solve the above-mentioned conventional problems, the inventors of the present invention have achieved the above-mentioned object by combining a specific binder resin for forming a photosensitive layer and a specific silicone oil. Succeeded in obtaining an electrophotographic photosensitive member, and completed the present invention. That is,

The electrophotographic photoreceptor of the present invention is 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. Structural formula (I)

[Chemical 4] Polyarylate and structural formula (II)

[Chemical 5] Polycarbonate and structural formula (III)

[Chemical 6] And a dimethylpolysiloxane represented by The photosensitive layer comprises a charge generation layer and a charge transport layer, and the charge transport layer comprises the polyarylate represented by the structural formula (I), the polycarbonate represented by the structural formula (II), and the structural formula (III). ) And dimethylpolysiloxane represented by

The photoconductor of the present invention has different aspects depending on the form of the photoconductor to be described later, but basically, the photoconductive material, that is, the charge generating material and the charge transporting material, and the above structural formula (I ), A polyarylate represented by the formula, a polycarbonate represented by the structural formula (II) and a binder resin containing dimethylpolysiloxane represented by the structural formula (III) are dissolved or dispersed in an organic solvent to obtain a coating liquid. ,
This coating liquid is applied onto a conductive support and dried to form a photosensitive layer.

The electrophotographic photoreceptor of the present invention is schematically shown in FIGS.
This will be explained in Section 3. FIG. 1 shows a function-separated type photoreceptor in which a photosensitive layer 4 composed of two layers of a charge generation layer and a charge transport layer 3 is formed on a conductive support 1. FIG. 2 shows a photoreceptor in which an undercoat layer 5 is provided between the conductive support 1 and the photosensitive layer 4 of FIG. 1, and the undercoat layer 5 improves coating properties and smoothness of the support. It is provided for improvement, mechanical protection, and stabilization of electrical characteristics. FIG. 3 shows a single-layer type photoreceptor in which the charge generating material 6 is dispersed in the charge transport layer 3 on the conductive support 1 to form the photosensitive layer 4.

The conductive support in the photoconductor of the present invention disclosed in FIGS. 1 to 3 may be one having conductivity, and examples thereof include aluminum, aluminum alloys, copper, zinc, stainless steel, Nickel, a metal having conductivity such as titanium, or plastic or paper on which a conductive metal film such as aluminum, gold, silver, copper, zinc, nickel, titanium, indium oxide, or tin oxide is deposited, Plastic or paper containing conductive particles and plastic containing conductive polymer can be used, and the shape of these supports can be, for example, a drum shape, a sheet shape, or a seamless belt shape.

Next, the photosensitive layer formed on the conductive support will be described for each mode of the photosensitive layer shown in FIGS.
In the function separation type photoreceptor shown in FIG. 1, a charge generating material is contained in the charge generating layer of the photosensitive layer. Examples of the charge generating material include selenium and its alloys, arsenic-selenium, cadmium sulfide, zinc oxide, amorphous silicon, other inorganic photoconductors, phthalocyanines, azo compounds, quinacridones, polycyclic quinones, organic pigments such as perylene, and thiapyrylium. Organic dyes such as salt and squarylium salt are used. Further, in the charge generation layer, an electron accepting material such as tetracyanoethylene, 7, 7,
Cyano compounds such as 8,8-tetracyanoquinodimethane, anthraquinone, quinones such as p-benzoquinone, 2,4,7-trinitrofluorenone, 2,4
A nitro compound such as 5,7-tetranitrofluorenone or a dye such as a xanthene-based dye, a thiazine dye or a triphenylmethane-based dye can be contained as an optical sensitizer.

As a method for forming the charge generation layer, a vapor deposition method such as vacuum vapor deposition, sputtering, CVD or the like can be used. The above charge generation material is dissolved in a solvent, or a ball mill, a sand grinder, a paint shaker, Grind and disperse with an ultrasonic disperser, etc., add a binder resin as needed to make a coating liquid, and use this coating liquid.
When it is applied on a sheet-shaped support, it is applied by a baker applicator, bar coater, casting, spin coating, etc.When it is applied on a drum-shaped support, a spray method, a vertical ring method, dipping The charge generation layer is formed by coating by a coating method.

As the binder resin added as necessary, polyarylate, polyvinyl butyral, polycarbonate, polyester, polystyrene, polymethyl methacrylate, polyvinyl chloride, phenoxy resin,
Epoxy resin, silicone, etc. are used. Examples of the solvent include ketones such as acetone, methyl ethyl ketone and cyclohexanone, esters such as ethyl acetate and butyl acetate, ethers such as tetrahydrofuran and dioxane, aromatic hydrocarbons such as benzene, toluene and xylene, and N, N-dimethyl. An aprotic polar solvent such as formamide or dimethyl sulfoxide can be used. The thickness of the charge generation layer is 0.05 to 5 μm.
m, preferably 0.08 to 1 μm.

The charge transport layer laminated on the charge generation layer comprises:
A charge transport material is included. As the charge transport material,
Polymer compounds such as polyvinylcarbazole and polysilane, low molecular compounds such as hydrazone compounds, pyrazoline compounds, oxadiazole compounds, stilbene compounds, triphenylmethane compounds and triphenylamine compounds are used.

As the method for forming the charge transport layer, the above charge transport material is dissolved in the solvent, and the polyarylate represented by the structural formula (I), the polycarbonate represented by the structural formula (II) and the structural formula (III) are used. A coating solution is prepared by adding a binder resin containing dimethylpolysiloxane shown in the above, and when the coating solution is applied to a sheet-shaped support, it is applied by a baker applicator, a bar coater, casting, spin coating, etc. In the case of applying it to a flat support, the charge transporting layer is formed on the charge generating layer by spraying, vertical ring method or dip coating method. The molecular weight of dimethylpolysiloxane is 200 to 1
It is preferably 10,000, particularly 1,000 to 10,000. Also, the addition amount is based on the binder resin,
0.015 to 1.2% by weight, preferably 0.02 to 0.
8% by weight. The mixing ratio of polyarylate is preferably 10% by weight or more of the total binder resin. Further, the mixing ratio of the polycarbonate is preferably 10% by weight or more of the total binder resin.

As the binder resin, polyester, polystyrene, polymethylmethacrylate, polyvinyl chloride, phenoxy resin, epoxy resin, silicone or the like may be added to a mixture of the above polyarylate and polycarbonate. Examples of the solvent 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,
Ethers such as tetrahydrofuran and dioxane, aromatic hydrocarbons such as benzene, toluene and xylene,
It is also possible to use an aprotic polar solvent such as N, N-dimethylformamide or dimethyl sulfoxide. If a solvent with a slow evaporation rate is used, sagging may occur, so especially dichloromethane, acetone,
It is desirable to use a solvent such as tetrahydrofuran. The thickness of the charge generation layer is 5 to 50 μm, preferably 10 to 40 μm.

An antioxidant may be further added as an additive to the charge generation layer or the charge transport layer. As the antioxidant, vitamin E, hydroquinone, hindered amine, hindered phenol, paraphenylenediamine,
Aryl alkanes and their derivatives, organic sulfur compounds, organic phosphorus compounds and the like are used.

As the undercoat layer shown in FIG. 2, polyvinyl alcohol, polyvinyl butyral, casein, N
-Methoxymethylated nylon is used. Also,
The film thickness is preferably about 0.2 to 10 μm.

The single-layer type photoreceptor shown in FIG. 3 has a photosensitive layer in which the charge generating material and the charge transporting material are dispersed in a charge transporting layer on a conductive support.
To form the single-layer type photosensitive layer, the charge generation material, the charge transport material, the structural formulas (I) and (II),
The binder resin containing the resin represented by (III) or the like is dissolved or dispersed in the solvent to prepare a coating solution, which is applied onto the conductive support by the above-mentioned forming method and dried to produce the coating solution.

The electrophotographic photoreceptor of the present invention is shown in FIGS.
The photoconductor shown in FIG. 3 is not limited to the photoconductor shown in FIG. 3, but may be in various forms. For example, a surface protective layer may be provided on the surface of the photoconductive layer.

[0024]

In the photosensitive layer formed on the conductive support, the polyarylate represented by the structural formula (I), the polycarbonate represented by the structural formula (II) and the dimethylpolysiloxane represented by the structural formula (III) are used. When the components are contained, orange peel is prevented, and the increase in residual potential and the decrease in charging potential are eliminated. This point will be described in more detail in Comparative Examples and the like described later.

[0025]

EXAMPLES Next, the photoreceptor of the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

The photoreceptors obtained in the examples and comparative examples were evaluated as follows. Measurement of sensitivity: Measured with a self-made drum evaluation device. The sensitivity is 10 μW / cm at 550 nm, which is separated by an interference filter.
^It was evaluated by the reciprocal of the light energy required to reduce the charging potential to 1/2 when irradiated with the light of ² . Measurement of charging potential (V _o ) and residual potential (V _r ): The obtained electrophotographic photosensitive member was mounted on a commercially available copying machine (SF8260: manufactured by Sharp Corporation), and after confirming the image, potential fluctuation during repeated use. As a result, the charging potential (V _o ) and the residual potential (V _r ) were measured at the initial stage and after 10,000 times of use. Measurement of scratched skin: The surface of the photosensitive layer was visually evaluated, and those without scratched skin were evaluated as ◯, and those with scratched skin were evaluated as x.
Note that the measurement contents of the sensitivity, the charging potential, and the like of Examples 11, 12, and 14 are slightly different, and therefore the measurement contents will be supplementarily described in each Example section.

Example 1 (Function-separated type photoconductor) As a charge generating material,

[Chemical 7] 2 parts by weight of a polycyclic quinone pigment represented by and 1 part by weight of a phenoxy resin (PKHH: Union Carbide Co.)
12 parts of 4-dioxane and 97 parts by weight of a ball mill disperser
A dispersion liquid was prepared by time-dispersing. This dispersion was filled in a tank, and an aluminum cylindrical support (aluminum drum) having a diameter of 80 mm and a length of 340 mm was dipped in the tank, then pulled up and coated, and dried at room temperature for 1 hour to obtain a film having a thickness of 1 μm. A charge generation layer was formed.

On the other hand, as the charge transport material,

[Chemical 8] 100 parts by weight of a hydrazone compound, 50 parts by weight of polyarylate (U-100: manufactured by Unitika Ltd.) as a binder resin, 50 parts by weight of polycarbonate (Z-200: manufactured by Mitsubishi Gas Chemical Co., Inc.), and dimethyl silicone oil (SH20050cs). : Toray Silicone Co., Ltd.) 0.02
Part by weight and 800 parts by weight of dichloromethane were dissolved to prepare a coating liquid for coating the charge transport layer. The coating solution is applied onto the charge generation layer formed on the support by dip coating and dried at 80 ° C. for 1 hour to form a charge transport layer having a thickness of 20 μm, and the function as shown in FIG. A separation type photoconductor was produced.
The obtained photoreceptor was evaluated as described above, and the results are shown in Table 1.

Examples 2 to 9 (Function-separated type photoconductor) As shown in Table 1, the procedure of Example 1 was repeated except that the ratio of polyarylate to polycarbonate and the amount of dimethyl silicone oil added were changed. A photoreceptor as shown was prepared and evaluated. The results are shown in Table 1.

Comparative Example 1 (Function-separated type photoreceptor containing only dimethyl silicone oil) Example 1 except that dimethyl silicone oil was not added
In the same manner as above, a photoconductor as shown in FIG. 1 was produced and its characteristics were evaluated. The results are shown in Table 1. The photoreceptor had an orange skin on the entire surface of the photosensitive layer, and the obtained image was rough. In addition, almost no increase in residual potential was observed.

Comparative Example 2 (Functionally Separated Photoreceptor Not Containing Only Polyarylate Resin) Polycarbonate (Z-200: manufactured by Mitsubishi Gas Chemical Co., Inc.) 1 without using polyarylate as a binder resin for the charge transport layer.
FIG. 1 is the same as Example 1 except that only 100 parts by weight is used.
A photoconductor as shown in (1) was prepared and its characteristics were evaluated. The results are shown in Table 1. With this photosensitive member, no clean skin was observed on the surface of the photosensitive layer, and a clear image was obtained. However, the residual potential increased after repeated use.

Comparative Example 3 (Function-separated type photoreceptor containing no polycarbonate resin) Polyarylate (U-100: Unitika Ltd.) 100 without using polycarbonate as a binder resin for the charge transport layer.
A photoreceptor as shown in FIG. 1 was produced in the same manner as in Example 1 except that only parts by weight were used, and the characteristics were evaluated. The results are shown in Table 1. The photoconductor has no visible skin on the surface of the photosensitive layer,
A beautiful image was obtained. However, the charge potential decreased after repeated use.

Example 10 (Function-separated type photoconductor) As a charge generating material,

[Chemical 9] 4 parts by weight of chlorodian blue represented by (4) were dissolved in 257 parts by weight of ethylenediamine, and the mixture was stirred for 45 minutes.
Further, 247 parts by weight of n-butylamine was added and stirred for 45 minutes to prepare a coating solution. A tank was filled with this dispersion, and an aluminum cylindrical support having a diameter of 80 mm and a length of 340 mm was dipped in the tank, then pulled up and coated, and dried at room temperature for 1 hour to obtain a charge having a thickness of 0.1 μm. A generator layer was formed.

On the other hand, as the charge transport material,

[Chemical 10] 100 parts by weight of a hydrazone compound, 50 parts by weight of polyarylate (U-100: manufactured by Unitika Ltd.) as a binder, 50 parts by weight of polycarbonate (ZP-128: manufactured by Mitsubishi Gas Chemical Co., Inc.), and dimethyl silicone oil (SH20050cs: Torre Silicone) 0.0
5 parts by weight was dissolved in 800 parts by weight of dichloromethane to prepare a coating liquid for coating the charge transport layer. The coating solution is applied onto the charge generation layer formed on the support by dip coating, and the coating is applied at 80 ° C. for 1 hour.
After drying for an hour, a charge transport layer having a thickness of 20 μm was formed and a photoreceptor as shown in FIG. 1 was prepared and evaluated. The results are shown in Table 1.

Example 11 (Function-separated type photoconductor with an undercoat layer interposed) Copolymerized nylon (Amilan CM8000: manufactured by Toray) 6
47 parts by weight of methyl alcohol and 4 parts by weight of chloroform
Dissolve in 7 parts by weight of mixed solvent, fill the tank,
An aluminum cylindrical support having a diameter of 30 mm and a length of 255 mm is dipped in the tank, and then pulled up to apply a coating at 110 ° C. for 1 hour.
It was dried for 0 minutes to provide an undercoat layer of about 2 μm.

Next, as the charge generating material,

[Chemical 11] 2 parts by weight of X-type metal-free phthalocyanine and polyvinyl butyral (S-REC BMS: manufactured by Sekisui Chemical Co., Ltd.) 1
By weight, 97 parts by weight of dichloroethane were dispersed for 12 hours with a ball mill disperser to prepare a dispersion liquid. A tank was filled with this dispersion, and the aluminum cylindrical support provided with the undercoat layer was dipped in the tank, then pulled up and coated, and dried at room temperature for 1 hour to obtain a charge having a thickness of 0.2 μm. A generator layer was formed.

On the other hand, as the charge transport material,

[Chemical 12] 100 parts by weight of the styryl compound represented by and polyarylate (U-100: Unitika Ltd.) as a binder 7
0 parts by weight, 30 parts by weight of polycarbonate (Z-300: manufactured by Mitsubishi Gas Chemical Co., Inc.) and dimethyl silicone oil (SH
200 50 cs: manufactured by Torre Silicone Co., Ltd.) and 0.03 part by weight were dissolved in 800 parts by weight of chloroform to prepare a coating liquid for coating the charge transport layer. The coating solution is applied onto the charge generation layer formed on the support by dip coating and dried at 100 ° C. for 1 hour to form a charge transport layer having a thickness of 20 μm to prepare a photoreceptor as shown in FIG. did.

This drum is used in a self-made drum evaluation device.
The sensitivity was measured in the same manner as in Example 1 except that 0 nm light was used, and then a commercially available laser beam printer (JX95
00: manufactured by Sharp Corporation). After confirming the image, the charge potential (V _o ) and the residual potential (V _r ) at the initial stage and after 10,000 uses were measured as potential fluctuations during repeated use. The results are shown in Table 1.

Example 12 (single-layer type photoconductor) As a charge generating material,

[Chemical 13] 2 parts by weight of the perylene pigment represented by and 98 parts by weight of 1,2-dichloroethane were dispersed by a paint shaker to prepare a dispersion liquid.

In this dispersion, a charge transport material of the formula

[Chemical 14] 100 parts by weight of a hydrazone compound represented by and polyarylate as a binder (U-100: manufactured by Unitika Ltd.)
50 parts by weight and polycarbonate (ZP-118: manufactured by Mitsubishi Gas Chemical Co., Inc.) 50 parts by weight, dimethyl silicone oil (SH200 20cs: manufactured by Torre Silicone Co., Ltd.) 0.0
A solution prepared by dissolving 3 parts by weight in 700 parts by weight of dichloromethane was added to prepare a coating liquid for coating the photosensitive layer. This coating solution is applied by dip coating on an aluminum cylindrical support having a diameter of 80 mm and a length of 340 mm and dried at 100 ° C. for 1 hour to give a thickness of 1
A photosensitive layer having a thickness of 5 μm was formed to prepare a photosensitive member as shown in FIG.

The sensitivity of this photosensitive member was measured by a self-made drum evaluation device similar to that in Example 1, and then a commercially available copying machine (S
(F8100: manufactured by Sharp Corporation) was mounted on an experimental machine modified for positive charging, and after confirming the image, as potential fluctuations during repeated use, the charged potential (V _o ) and the residual potential (V _o ) after the initial use and after 10,000 uses were used. _r ) and were measured. The results are shown in Table 1.

Example 13 (Function-separated type photoreceptor) As a charge generating material,

[Chemical 15] 2 parts by weight of the bisazo pigment represented by 1 part, 1 part by weight of polyvinyl butyral (XYHL: manufactured by Union Carbide Co.) and 97 parts by weight of cyclohexanone were dispersed in a ball mill to prepare a dispersion liquid. Fill the tank with this dispersion,
An aluminum cylindrical support having a length of 0 mm and a length of 340 mm was dipped in the tank, then pulled up and coated, and dried at 110 ° C. for 10 minutes to form a charge generation layer having a thickness of 0.8 μm.

On the other hand, as a charge transport material,

[Chemical 16] 100 parts by weight of the hydrazone compound represented by the formula and polyarylate as a binder (U-100: manufactured by Unitika Ltd.) 4
0 parts by weight, 40 parts by weight of polycarbonate (Z-200: manufactured by Mitsubishi Gas Chemical Co., Inc.), 20 parts by weight of polyester resin (V290: manufactured by Toyobo Co., Ltd.), and dimethyl silicone oil (S
H200 50cs: manufactured by Torre 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. The coating solution is applied onto the charge generating layer formed on the support by dip coating and dried at 80 ° C. for 1 hour to form a charge transporting layer having a thickness of 20 μm to prepare a photoreceptor as shown in FIG. Then, the evaluation was performed in the same manner as in Example 1. The results are shown in Table 1.

Example 14 (Function-separated type photoconductor) As a charge generating material,

[Chemical 17] 2 parts by weight of a perylene pigment represented by
(KHH: manufactured by Union Carbide Co.) 1 part by weight and 97 parts by weight of 1,4 dioxane were dispersed for 12 hours with a ball mill disperser to prepare a dispersion liquid. This dispersion was applied on a conductive support having an aluminum layer formed on the surface of polyethylene terephthalate by an evaporation method using an applicator and dried at room temperature to form a charge generation layer having a thickness of 1 μm.

On the other hand, as a charge transport material,

[Chemical 18] 100 parts by weight of a hydrazone compound represented by and polyarylate as a binder (U-100: manufactured by Unitika Ltd.)
30 parts by weight of polycarbonate (Z-200: manufactured by Mitsubishi Gas Chemical Company) and 30 parts by weight of polyester resin (V-29)
0: Toyobo Co., Ltd.) 40 parts by weight and dimethyl silicone oil (SH200 50 cs: Torre Silicone Co., Ltd.)
02 parts by weight was dissolved in 800 parts by weight of dichloromethane to prepare a coating liquid for coating the charge transport layer. The coating solution is applied onto the charge generation layer formed on the support with an applicator and dried at 80 ° C. for 1 hour to form a charge transport layer having a thickness of 20 μm to form a photoreceptor as shown in FIG. Was produced.

This photosensitive member has a diameter of 80 mm and a length of 340 mm.
Attach it with a conductive tape on the aluminum cylindrical support of
The sensitivity was measured by a self-made drum evaluation device, and then mounted on a commercially available copying machine (SF8260: manufactured by Sharp Corporation). After confirming the image, the charge potential (V _o ) and the residual potential (V _r ) at the initial stage and after 10,000 uses were measured as potential fluctuations during repeated use. The results are shown in Table 1.

[0047]

[Table 1]

As is clear from the results shown in Table 1, the photoconductors containing the three components of polyarylate, polycarbonate and dimethylpolysiloxane, that is, the photoconductors of Examples 1 to 14, had no rind skin and remained. Almost no increase in potential or decrease in charging potential. On the other hand, Comparative Example 1
As shown in FIGS. 3 to 3, if any one of the above three components is lacking, it causes orange peel skin, an increase in residual potential, and a decrease in charging potential.

[0049]

EFFECT OF THE INVENTION The electrophotographic photosensitive member of the present invention does not have an orange skin and is smooth, has no increase in residual potential or decrease in charging potential, and is excellent in stability even after repeated use.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an electrophotographic photosensitive member whose photosensitive layer has a function separation type.

FIG. 2 is a schematic sectional view showing an electrophotographic photosensitive member with an undercoat layer interposed in FIG.

FIG. 3 is a schematic cross-sectional view showing 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 has the structural formula (I): Chemical 1] Polyarylate represented by and structural formula (II): And a structural formula (III): An electrophotographic photoreceptor containing the dimethylpolysiloxane represented by: 2. The photosensitive layer comprises a charge generation layer and a charge transport layer, and the charge transport layer comprises the polyarylate represented by the structural formula (I), the polycarbonate represented by the structural formula (II), and the structure. The electrophotographic photoreceptor according to claim 1, further comprising dimethylpolysiloxane represented by the formula (III).