JPH07301936A - Electrophotographic photoreceptor and its production - Google Patents

Abstract

PURPOSE:To provide an electrophotographic photoreceptor having small frictional resistance of the surface, enough durability for repeated use in which production of defects in the photosensitive layer such as pin holes can be suppressed, and to provide the production method. CONSTITUTION:This electrophotographic photoreceptor has a photosensitive layer containing fluorine-modified silicone oil as the outermost surface layer on a conductive supporting body. The production method of this electrophotographic photoreceptor includes a process to form the outermost surface layer of the photosensitive layer with using a specified coating liquid. The coating liquid used in the process to form the photosensitive layer is such a liquid that a specified amt. of fluorine-modified silicone oil is preliminarily compounded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor and a method for manufacturing the same, and more particularly to an electrophotographic photoreceptor used when an image is formed by an electrophotographic process such as a copying machine, a printer or a facsimile. And a manufacturing method thereof.

[0002]

2. Description of the Related Art Recently, in this type of electrophotographic photoreceptor,
Materials using organic materials, which are advantageous in terms of cost and ease of disposal, have come to be used in many cases. However, these electrophotographic photoconductors have problems such as increased wear or scratches during repeated use when electrophotographic properties such as chargeability and sensitivity are increased, and conversely Attempting to improve the wear resistance causes a problem that the electrophotographic characteristics are deteriorated, such as a decrease in sensitivity or an increase in residual potential, and it is not always sufficient to achieve both electrophotographic characteristics and durability during repeated use. Was not.
Further, in the contact-type charging system in which the number of devices adopted recently has increased, if a pinhole exists in the photosensitive layer, leakage occurs from that portion, and the photosensitive layer is damaged.

To address these problems, there has been proposed a method for reducing the friction of a contacting object such as a cleaning blade that causes wear for durability against repeated use. For example, a technique of dispersing fluororesin powder in a photosensitive layer (Japanese Patent Laid-Open No. 56-126838) or a technique of incorporating a fluorine-based or silicon-based graft polymer (Japanese Patent Laid-Open No. 61-61).
-95358). In order to prevent pinholes and the like, a technique (Japanese Patent Laid-Open No. 2-46938) has been proposed to improve this by including methylphenyl silicone oil in the photosensitive layer.

[0004]

However, although there have been proposals for improving the above-mentioned problems, there have been no proposals for means for simultaneously solving these problems. That is, in the above-mentioned conventional example, even if a measure for reducing wear is taken, the occurrence of pinholes that occur when the photosensitive layer is formed cannot be suppressed at all. Further, even if the generation of pinholes is suppressed, the problem of wear is not solved at all, and therefore a drum having sufficient durability cannot be obtained. Further, when two or more kinds of substances are added to the photosensitive layer in order to solve these problems at the same time, as a result, the amount added to the photosensitive layer is increased and electrophotographic characteristics are deteriorated.

[0005]

It is an object of the present invention to improve the disadvantages of the prior art examples, in particular, the surface has a small frictional resistance, has sufficient durability upon repeated use, and is free from defects such as pinholes in the photosensitive layer. It is an object of the present invention to provide an electrophotographic photoreceptor that can be suppressed and a method for producing the same.

[0006]

In the electrophotographic photoreceptor of the present invention, a conductive support is provided with a photosensitive layer containing a fluorine-modified silicone oil as the outermost surface layer.
Is adopted.

Further, as a method for producing the electrophotographic photoreceptor, a method for producing the electrophotographic photoreceptor includes a step of forming the outermost surface layer of the photosensitive layer of the electrophotographic photoreceptor by using a predetermined coating solution. That is, the constitution is such that a coating liquid containing a predetermined amount of fluorine-modified silicone oil is used as the coating liquid in the photosensitive layer forming step. This aims to achieve the above-mentioned object.

[0008]

[Working] Solving the problem of durability by including fluorine-modified silicone oil in the outermost surface layer of the photosensitive layer, and further adding fluorine-modified silicone oil to the paint forming the outermost surface layer of the photosensitive layer, By using the coating material containing the fluorine-modified silicone oil, the method of forming the outermost surface layer of the photosensitive layer is used to suppress the occurrence of defects such as pinholes.

[0009]

EXAMPLE An example of the present invention will be described below.

In this embodiment, an electrophotographic photosensitive member having a photosensitive layer on a conductive support is used in which a fluorine-modified silicone oil is contained in the outermost surface layer of the photosensitive layer.

Further, in forming the outermost surface layer of the photosensitive layer of the electrophotographic photosensitive member, in the method of manufacturing an electrophotographic photosensitive member including a step of using a predetermined coating solution, a photosensitive layer forming step In order to use the one containing a predetermined amount of fluorine-modified silicone oil as the coating liquid in
A method in which some of the steps are recombined is adopted.

In this case, the fluorine-modified silicone oil contained in the coating solution has a weight ratio of 50 to 1000 [ppm].
It is set to a degree.

More specifically, the fluorine-modified silicone oil used in this embodiment is, for example, FS-1265 manufactured by Toray Dow Corning Co., Ltd., or one having a structure similar thereto. There is. The addition amount can be appropriately selected within a range where the effect is recognized, but it is preferably about 50 to 1000 [ppm] in weight ratio with respect to the elements constituting the film of the outermost surface layer.

In this case, if the addition amount is too small, the effect of addition is not exhibited, and conversely, if the addition amount is too large, the electrophotographic characteristics of the photosensitive layer are likely to be adversely affected. As a method of adding the fluorine-modified silicone oil to the outermost surface layer, it is possible to impregnate it after forming the outermost surface layer, add it to the coating liquid used when forming the outermost surface layer, etc. It is desirable to add it to the coating liquid used for forming.

If the outermost surface layer is formed by this method, pinholes and the like do not occur during manufacturing, and a film having a small surface friction resistance can be obtained.

The electrophotographic photosensitive member used in this embodiment has a photosensitive layer formed on a conductive support. The photosensitive layer is composed of a charge generation layer and a charge transfer layer, or a plurality of layers in which an intermediate layer and a protective layer are further stacked, and further, only the charge generation layer or a charge transfer material in the charge generation layer. And a single layer formed by mixing.

As the conductive support, one having conductivity itself, for example, aluminum, titanium, zinc,
Metals such as copper, chromium and nickel, or alloys thereof are used. In addition to the above, the metal or the metal oxide such as tin oxide or indium oxide as described above may be vapor-deposited or dispersed in a binder resin to form a film on the surface of the plastic so as to have conductivity. Can be used.

In this case, various intermediate layers may be provided between the above-mentioned conductive support and the photosensitive layer.

As the intermediate layer in this case, polyamide,
It can be formed of polyvinyl alcohol, polyurethane, polyacrylic acid, an epoxy resin, a dispersion of conductive fine particles in these resins, or an anodized film such as alumite.

These intermediate layers may be a single layer or a laminate of two or more layers. The thickness of this intermediate layer is 0.1
20 [μm], preferably 0.2 to 10 [μm]
Is appropriate.

The charge generation layer is composed of only the charge generation material, a resin layer in which the charge generation material is dispersed or compatible, or a mixture of the charge generation material and the charge transfer material.

As the charge generating material, known materials such as various phthalocyanine pigments, azo pigments, disazo pigments, indigo pigments and quinacridone pigments are used. Further, these charge generating materials can be used alone or in combination of two or more kinds. When the charge generation layer is formed by using the charge generation material alone without using a resin, a method such as vacuum deposition is used.

When the charge generation layer is formed of resin, the resin may be polyvinyl chloride, polyvinyl acetate, polyester, vinyl chloride-vinyl acetate copolymer,
Polyvinyl butyral, polystyrene, polycarbonate, acrylic resin, phenol resin, etc. are used. These resins may be used alone or as a mixture.

Solvents for the coating liquid used when forming the charge generation layer from these resins include toluene, methylene chloride, monochlorobenzene, methyl alcohol, ethyl alcohol, ethyl acetate, tetrahydrofuran, cyclohexane and the like. These solvents may be used alone or as a mixture. The thickness of the charge generation layer is 0.05 to 5
[Μm], preferably about 0.1 to 2 [μm] is suitable.

The charge transfer layer is formed by making the charge transfer material compatible with the resin.

The charge transfer material includes an electron transfer material and a hole transfer material. Examples of the electron transfer substance include chloroanil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, and the like. There are substances and those obtained by polymerizing them.

As the hole transfer material, pyrene, N-ethylcarbazole, N-isopropylcarbazole, N-
Methyl-N-phenylhydrazino-3-methylidene-9
-Ethylcarbazole, N, N-diphenylhydrazino-3-methylidene-9-ethylcarbazole, N, N-
Diphenylhydrazino-3-methylidene-10-ethylphenothiazine, p-diethylaminobenzaldehyde-N, N-diphenylhydrazone, p-diethylaminobenzaldehyde-N-α-naphthyl-N-phenylhydrazone, 1,3,3, -tritylindo Renin-ω-
Hydrazones such as aldehyde-N, N-diphenylhydrazone, p-pyrrolidinobenzaldehyde-N, N-diphenylhydrazone, p-diethylaminobenzaldehyde-3-methylbenzothiazolinone-2-hydrazone, 2,5-bis (p -Diethylaminophenyl)-
1,3,4-oxadiazole, 1-phenyl-3-
(P-Diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, 1- [quinolyl (2)]
-3- (p-diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, 1- [pyridyl (2)]-3- (p-diethylaminostyryl) -5-
(P-Diethylaminophenyl) pyrazoline, 1- [6
-Methoxypyridyl (2)]-3- (p-diethylaminostyryl) -5- (p-diethylaminophenyl) pyrazoline, 1- [pyridyl (3)]-3- (p-diethylaminostyryl) -5- (p- There are pyrazolines such as diethylaminophenyl) pyrazolin, triarylmethane compounds, oxadiazole compounds, thiazole compounds, triphenylamine, poly-N-vinylcarbazole, and the like, and one or two of these known charge transfer materials can be used.
A combination of two or more species can be used.

As the resin of the charge transfer layer, polystyrene, ketone resin, phenol resin, polyester, polycarbonate, polyvinyl butyral, polyvinyl formal, polyacrylamide, polyamide and the like are used. These resins may be used alone or as a mixture.

Further, various additives usually used for these resins, such as an ultraviolet absorber and an antioxidant, can be appropriately added.

Solvents for the coating solution when forming a charge transfer layer from these resins include tetrahydrofuran, dioxane, cyclohexane, toluene, dichloroethane,
Methylene chloride, monochlorobenzene, etc. can be used. These solvents can also be used alone or as a mixture. The thickness of the charge transfer layer is 5 to 40 [μm], preferably 15 to 25
[Μm] is suitable.

As the coating method for forming the photosensitive layer using the coating liquid, known methods such as a spin coater, an applicator, a spray coater, a bar coater, a dip coater and a doctor blade are used. The applied photosensitive layer is dried by heating with hot air, infrared rays or the like.

[0032]

EXPERIMENTAL EXAMPLES The present invention will be described in detail below with reference to examples.

Experimental Example 1

Diameter (hereinafter “φ” is used) 80 [m
[m] aluminum cylinder on a polyamide resin (CM
-8000, manufactured by Toray Co., Ltd.) as an undercoat layer of about 0.2 [μm], and a coating solution obtained by dispersing and dissolving titanyl phthalocyanine and butyral resin (BX-1, manufactured by Sekisui Chemical Co., Ltd.) in tetrahydrofuran is formed thereon. After dip coating, it was heated and dried to form a charge generation layer of about 0.2 [μm].

Next, a charge transfer material (M) represented by the following structural formula 1 and a polycarbonate resin (Z-200, manufactured by Mitsubishi Gas Chemical Co., Inc.) (B) are used in a weight ratio of M / B = 0.8 and solid content. Dissolve in methylene chloride to a concentration of 25 [wt%], and add fluorine-modified silicone oil (FS-1265, manufactured by Toray Dow Corning) to 500 [pp
m] (weight ratio: the same applies hereinafter) was applied on the charge generation layer by dip coating and then dried by heating to form a charge transfer layer of about 20 μm to prepare an electrophotographic photoreceptor.

[0036]

[Chemical 1]

With respect to the above electrophotographic photoreceptor, the appearance of the photosensitive layer was visually evaluated, and further, it was mounted on a printer (NEC page printer) and continuous printing of 60,000 pages was performed. The amount of change was measured by an interference film thickness meter.

Experimental Example 2 The amount of fluorine-modified silicone oil added was 1000 [pp
[m]] was prepared and evaluated in the same manner as in Experimental Example 1.

Experimental Example 3

The amount of fluorine-modified silicone oil added was 50.
A sample was prepared and evaluated in the same manner as in Experimental Example 1 except that the content was changed to [ppm].

Comparative Example 1

Samples were prepared and evaluated in the same manner as in Experimental Example 1 except that fluorine-modified silicone oil was not added.

Comparative Example 2

The amount of fluorine-modified silicone oil added was 10
A sample was prepared and evaluated in the same manner as in Experimental Example 1 except that the amount was changed to 000 [ppm].

Experimental Example 4

On an aluminum cylinder of 30 [mmφ] having an anodized film of about 10 [μm] on the surface,
Titanyl phthalocyanine and butyral resin (BX-1,
Sekisui Chemical Co., Ltd.) was dispersed in tetrahydrofuran and dissolved, and a coating solution was applied by dip coating and then dried by heating to about 0.2 [μm].
The charge generation layer of was formed.

Next, the charge transfer substance (M) represented by the following structural formula 2 and the polycarbonate resin (Z-200, manufactured by Mitsubishi Gas Chemical Co., Inc.) (B) were used in a weight ratio of M / B = 0.8 and solid content. Dissolve in methylene chloride to a concentration of 25 [wt%], and add fluorine-modified silicone oil (FS-1265, manufactured by Toray Dow Corning) to 500 [pp
m] The applied coating solution was applied onto the charge generation layer by dip coating and then dried by heating to form a charge transfer layer of about 20 μm to prepare an electrophotographic photoreceptor.

[0048]

[Chemical 2]

With respect to the electrophotographic photoreceptor, the appearance of the photosensitive layer was visually evaluated, and further mounted on a laser printer (NEC contact-type brush charging system) to perform continuous printing on 4,800 sheets for image evaluation and The amount of change in film thickness was measured with an interference film thickness meter.

Experimental Example 5

On an aluminum cylinder of 30 [mmφ] having an anodized film of about 10 [μm] on the surface,
An X-type metal-free phthalocyanine (P), a charge transfer substance (M) represented by the following structural formula 3 and a polyester resin (Vylon 200, manufactured by Toyobo) (B) in a weight ratio of P / M / B = 2.
/ 1/2 and a solid content concentration of 25 [wt%] dispersed in a tetrahydrofuran / toluene (1/1) mixed solution and dissolved to give a fluorine-modified silicone oil (FS-126).
5, manufactured by Toray Dow Corning) to solid content of 500
A coating solution containing [ppm] was applied onto the charge generation layer by dip coating, and then dried by heating to form a charge transfer layer of about 20 [μm] to prepare an electrophotographic photoreceptor.

[0052]

[Chemical 3]

The same evaluation as in Experimental Example 4 was performed on the above electrophotographic photosensitive member.

Comparative Example 3

Samples were prepared and evaluated in the same manner as in Experimental Example 4 except that fluorine-modified silicone oil was not added.

Comparative Example 4

Samples were prepared and evaluated in the same manner as in Experimental Example 5 except that the fluorine-modified silicone oil was not added.

Table 1 shows the overall results.

[0059]

[Table 1]

As a result, in the electrophotographic photoreceptors in the above-mentioned examples, the addition of the fluorine-modified silicone oil reduces the frictional resistance of the surface, and the characteristics are not deteriorated by abrasion even after repeated use. It turned out to be durable.

[0061]

As described above, according to the present invention,
By adding the fluorine-modified silicone oil, the frictional resistance of the surface was reduced, and it was possible to obtain an electrophotographic photoreceptor having sufficient durability with little deterioration in characteristics due to abrasion even during repeated use. Further, in the present invention, since the manufacturing method of forming the outermost surface layer of the electrophotographic photoreceptor with a coating liquid containing fluorine-modified silicone oil is adopted, it is possible to prevent the occurrence of defects on the surface of the photosensitive layer, and contact type charging It is possible to provide an unprecedented excellent electrophotographic photoreceptor and a method for producing the same, which does not cause a problem such as a leak caused by a defect on the surface of the photosensitive layer even when applied to an apparatus adopting the method.

Claims (3)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer on a conductive support, wherein the outermost surface layer is a photosensitive layer containing a fluorine-modified silicone oil. 2. A method for producing an electrophotographic photosensitive member, comprising the step of forming the outermost surface layer of the photosensitive layer of the electrophotographic photosensitive member using a predetermined coating liquid, wherein the coating in the photosensitive layer forming step is performed. A method for producing an electrophotographic photosensitive member, characterized in that a liquid containing a predetermined amount of fluorine-modified silicone oil is used as a liquid. 3. The production of an electrophotographic photosensitive member according to claim 2, wherein the fluorine-modified silicone oil contained in the coating liquid is set to a weight ratio of about 50 to 1000 [ppm]. Method.