JPH05150536A - Electrophotographic sensitive body and its production - Google Patents

Abstract

PURPOSE:To improve an electrostatic charge characteristic and mechanical wear characteristic without degrading sensitivity and increasing a residual potential and to improve environmental stability and cleanability by incorporating the reaction product of epoxy modified silicone and active hydrogen-contg. binder into a surface layer. CONSTITUTION:The surface layer is a layer contg. the reaction product of the epoxy modified silicone and the active hydrogen-contg. binder and is provided on the surface of the photosensitive body. Then, the photosensitive layer is the surface layer in the case of the single layer type photosensitive body and the layer provided on the surface of either a charge generating layer or charge transfer layer is the surface layer in the case of the laminated photosensitive body. The reaction curing of the epoxy modified silicone and the active hydrogen-contg. binder is induced at the time of drying after application of a coating liquid and the reaction product is incorporated into the surface layer at the time of forming the surface layer. Then, the silicone is not liberated, therefore, the mechanical wear characteristic of the photosensitive body is improved. Since the silicone are present in a specified amt. in the surface layer at all times, the electrostatic charge characteristic is improved.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an electrophotographic photoreceptor,
More specifically, the present invention relates to a highly durable electrophotographic photoreceptor having excellent cleaning properties and environmental stability, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, inorganic photoconductive materials such as selenium, .alpha.-silicon, and zinc oxide have been mainly used as photoconductive materials for electrophotographic photoreceptors in terms of sensitivity and durability.
However, these inorganic materials are harmful substances,
It has a drawback that the cost is high due to poor productivity. Therefore, the development of an organic photoreceptor which is pollution-free and whose cost can be easily reduced by mass production by coating has been actively pursued in recent years. Among them, a laminated type photoconductor in which a photosensitive layer is divided into a charge generation layer and a charge transport layer, the functions of which are separated, is currently the mainstream in terms of sensitivity and durability.

[0003]

However, although these organic photoconductors have advantages such as no pollution and low cost, they still have problems in sensitivity, environmental stability, and durability. The advent of organic photoreceptors having excellent stability and durability is strongly desired in the art. Further, the recent demand for higher image quality tends to reduce the toner particle size, and there is a demand for high cleaning performance of the photoconductor corresponding to this demand.

As a method of solving these drawbacks, a method of incorporating a silicone resin (oil) or a silicone-containing polymer into the charge transport layer provided on the surface of the photoconductor has been proposed (JP-A-57-64243). Japanese Patent Laid-Open No. 60-256146, Japanese Patent Laid-Open No. 61-95358.
JP-A-61-132954, JP-A-61-61954
-219047). However, although the method of adding silicone oil initially has a low frictional resistance and is good for durability, the silicone is liberated when a printing durability test is conducted, and as the amount of silicone decreases, the opposite In addition, it has a drawback that mechanical wear resistance is deteriorated. Further, in the method of adding the silicone-containing polymer,
It has a drawback that the sensitivity is slightly lowered or the residual potential is increased. As described above, conventional organic photoreceptors containing silicone-containing polymers have problems in charging characteristics and electrical characteristics under various environments, and improvement thereof is strongly desired in the art.

As described above, the organic photoreceptor contains a conventional silicone resin and the like, although problems such as environmental stability and durability remain and high cleaning property is required. In fact, it is not possible to obtain a satisfactory method by the method. The object of the present invention is exactly at this point, and as a solution to such a problem, there is no decrease in sensitivity and increase in residual potential during use, and charging properties, mechanical abrasion properties, and cleaning properties are greatly improved. It is another object of the present invention to provide a highly durable electrophotographic photoreceptor having excellent environmental stability and a method for producing the same.

[0006]

The present inventors have completed the present invention as a result of intensive studies to solve the above problems. That is, the gist of the present invention is, in an electrophotographic photoreceptor having a photosensitive layer provided on a conductive substrate, the surface layer of the electrophotographic photoreceptor contains a reaction product of an epoxy-modified silicone and an active hydrogen-containing binder. An electrophotographic photoreceptor characterized by containing, and a coating solution for a surface layer containing an epoxy-modified silicone and a binder containing an active hydrogen, is applied, and a surface layer is formed by reaction curing when dried. The present invention relates to a method for producing a characteristic electrophotographic photosensitive member.

The electrophotographic photosensitive member of the present invention has a photosensitive layer provided on a conductive substrate, and examples of the conductive substrate include metals such as aluminum, nickel and stainless, or polyethylene terephthalate and polybutylene terephthalate. A film coated with metal is used. The photosensitive layer is generally composed of a charge-generating substance, a charge-transporting substance (charge-transporting material), and a binder, and in the present invention, a single layer type in which they form the same layer, or a charge-generating layer containing the charge-generating substance. And a charge-transporting layer containing a charge-transporting substance. In the case of a laminated type photoreceptor, a photoreceptor in which a charge generation layer and a charge transport layer are laminated in this order on a conductive substrate, or a charge transport layer and a charge generation layer are laminated in this order on a conductive substrate Either of the photoconductors may be used.

In the present invention, the surface layer means a layer containing a reaction product of an epoxy-modified silicone / a binder containing active hydrogen and provided on the surface of a photoreceptor. Therefore, in the case of a single-layer type photoreceptor, the photosensitive layer is the surface layer, and
In the case of a laminated type photoreceptor, of the charge generation layer or the charge transport layer, the layer provided on either surface is the surface layer,
It contains the reaction product of an epoxy modified silicone / binder containing active hydrogen. As a means for this, in the present invention, the surface layer coating liquid contains an epoxy-modified silicone and an active hydrogen-containing binder.

The epoxy-modified silicone used in the present invention includes, for example, epoxy-modified dimethylpolysiloxane, epoxy-modified phenylmethylpolysiloxane, epoxy-modified diphenylpolysiloxane, etc., and the products are KF100T, KF101, KF102, KF.
103, X-22-163B, X-22-169B, X
-22-173B (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like.
Of these, preferably KF100T, KF102, X-
22-169B, X-22-163B and the like. Moreover, these can be used individually or in mixture of 2 or more types.

Examples of the active hydrogen-containing binder used in the present invention include polycarbonate, polyester, polysulfone, polyarylate, epoxy resin, phenol resin, polyamide, polyether sulfone, polyvinyl butyral and polyvinyl alcohol. .. Of these, especially in terms of reactivity with epoxy groups,
And from the viewpoint of mechanical properties of the resulting surface layer, polycarbonate, polyester, polysulfone, polyarylate,
Epoxy resin and phenol resin are preferably used. These may be used alone or in admixture of two or more, and may be used in combination with a commonly used binder. The content of the epoxy-modified silicone is 0.05 to 10 with respect to the active hydrogen-containing binder.
% By weight, preferably 0.1 to 5% by weight. When the amount of epoxy-modified silicone is less than 0.05% by weight, abrasion resistance is poor and durability is poor.
When it is more than 0% by weight, the sensitivity is lowered, which is not preferable.

The charge generating substance used in the present invention is not particularly limited, and examples thereof include inorganic materials such as selenium, amorphous silicon, and amorphous silicon carbide, and azo pigments, perylene pigments, quinone pigments, metal-free materials. Organic materials such as phthalocyanine pigments, metal phthalocyanine pigments, squarylium pigments, and pyrrole pyrrole pigments are used. Of these, organic materials are preferably used because of their low toxicity and ease of device design.

In the case of the laminated type, the charge generation layer is vapor-deposited, CV
It is desirable that the charge generation layer is formed by coating when the charge generation material is an organic material. Specifically, a charge generating substance and a binder are mainly dispersed and dissolved in a solvent, which is applied and dried. When using a coating method, the means is not particularly limited,
For example, a dip coater, a bar coater, a calendar coater, a gravure coater, a spin coater, or the like can be used as appropriate, and electrodeposition coating, spray coating, or the like can also be used. As the binder, for example, polyester, polystyrene, polyacrylate, polyvinyl butyral, polyvinyl chloride-vinyl acetate, polycarbonate, polysulfone, polyarylate, epoxy resin, phenol resin or the like is used. Examples of the solvent include aromatic solvents such as benzene, toluene and xylene; halogen solvents such as dichloroethane, chloroform and chlorobenzene; ester solvents such as ethyl acetate and propyl acetate; ketone solvents such as methyl ethyl ketone and cyclohexanone; dioxane; Examples include ether solvents such as tetrahydrofuran; alcohol solvents such as ethanol and butanol; dimethylformamide and dimethyl sulfoxide.

When the charge generation layer is the surface layer, a coating method is used, the above-mentioned epoxy-modified silicone is added to the coating liquid, and an active hydrogen-containing binder is used as the main component of the binder. Here, as the active hydrogen-containing binder,
Polycarbonate, polyester, polysulfone, polyarylate, epoxy resin, phenol resin and the like are preferably used. At this time, the amount of the active hydrogen-containing binder used is usually 20 to 70 with respect to the weight of the charge generation layer produced.
%, Preferably 30 to 60% by weight. If the amount is less than 20% by weight, the mechanical strength is lowered and the durability is deteriorated, and if it is more than 70% by weight, the sensitivity is lowered. The solvent is not particularly limited as long as it can dissolve the epoxy-modified silicone and the active hydrogen-containing binder. In any case, the weight ratio of the charge generating substance to the binder is 30:70 to 80:20, and the thickness of the charge generating layer produced by this is about 0.05 to 2 μm.

The charge transport material used in the present invention is not particularly limited, and examples thereof include a hydrazone derivative, a triphenylamine derivative, a stilbene derivative, a pyrazoline derivative, and an oxadiazole derivative. In the case of the laminated type, the charge transport layer is prepared mainly using a charge transport substance, a binder and a solvent in the same manner as the charge generation layer, and the binder is polycarbonate, polyarylate, polystyrene, polyacrylate, polystyrene. -Acrylate, polyester, polysulfone, polyamideimide, epoxy resin, phenol resin, urethane resin and the like are used.

When the charge transport layer is the surface layer, a coating method is used, the above-mentioned epoxy-modified silicone is added to the coating liquid, and an active hydrogen-containing binder is used as the main component of the binder. Here, as the active hydrogen-containing binder,
For example, polycarbonate, polyester, polysulfone, polyarylate, epoxy resin, phenol resin and the like are preferably used. At this time, the amount of the active hydrogen-containing binder used is usually 3 with respect to the weight of the charge transport layer produced.
It is 0 to 70% by weight, preferably 35 to 65% by weight.
If the amount is less than 30% by weight, the mechanical strength is lowered and the durability is deteriorated, and if it is more than 70% by weight, the sensitivity is lowered. The solvent is not particularly limited as long as it can dissolve the epoxy-modified silicone and the active hydrogen-containing binder. In either case, the weight ratio of the charge transport material to the binder is 30:70 to 70:30, and the thickness of the charge transport layer is about 10 to 30 μm.

In the case of a single-layer type photoreceptor, the above-mentioned charge generating substance, charge transporting substance, binder, epoxy-modified silicone,
It is prepared by a coating method or the like using an active hydrogen-containing binder and a solvent. The type and usage amount of each component are similar to those of the laminated type.

The electrophotographic photosensitive member of the present invention is produced as described above. In the present invention, the epoxy-modified silicone and the active hydrogen-containing binder are added to the surface layer during the drying after the coating liquid application. Cause reaction hardening of. Thereby, the reaction product of the epoxy-modified silicone and the active hydrogen-containing binder can be contained in the surface layer. As described above, in the present invention, since the silicone is not liberated, the mechanical abrasion property of the photoconductor is improved, and since the silicone is always present in the surface layer in a fixed amount, the charging property and the like are also improved.

The reaction conditions (drying conditions) at the time of reaction curing are such that the reaction temperature is usually 50 to 150 ° C. If the temperature is lower than 50 ° C, the reaction takes a long time, which is not preferable, and if the temperature is higher than 150 ° C, the photosensitive material is deteriorated, which is not preferable. The reaction time is usually 30 minutes or longer. Three
If it is less than 0 minutes, the reaction becomes insufficient, which is not preferable. Further, in the present invention, an undercoat layer, an adhesive layer or the like may be further provided between the conductive substrate and the photosensitive layer, if necessary. The use of the electrophotographic photosensitive member of the present invention can be carried out by a process such as charging, exposure, phenomenon, etc., similarly to the usual electrophotographic photosensitive member.

[0019]

The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

Example 1 Aluminum drum (outer diameter: 40 mmφ, length 318 m)
m) alcohol-soluble polyamide (manufactured by Toray Industries, Inc.,
A solution of 10 parts by weight of Amilan CM8000) and 190 parts by weight of methanol / butanol (7/3) was applied by dip coating and dried at 100 ° C. for 30 minutes to form an undercoat layer having a thickness of 0.6 μm. Then, 7 parts by weight of X-type metal-free phthalocyanine (manufactured by Dainippon Ink and Chemicals, Inc., 8120B), 7 parts by weight of polyvinyl butyral (manufactured by Sekisui Chemical Co., Ltd., S-REC BM-1), and cyclohexanone 3
A mixture of 36 parts by weight was dispersed by a ball mill to obtain a dispersion liquid. This dispersion is applied by dip coating on the undercoat layer,
It was dried at 100 ° C. for 30 minutes to form a charge generation layer having a film thickness of 0.5 μm. Next, 20 parts by weight of polycarbonate (Upilon E-2000, manufactured by Mitsubishi Gas Chemical Industry Co., Ltd.),
Butadiene-based charge transport material (A-40, T-40
5) A solution consisting of 20 parts by weight, 0.2 parts by weight of epoxy-modified silicone (X-22-169B manufactured by Shin-Etsu Chemical Co., Ltd.), and 168 parts by weight of 1,2-dichloroethane was immersed in the charge generation layer. It was applied, dried at 100 ° C. for 30 minutes and reacted and cured, and a charge transporting layer having a film thickness of 20 μm was formed as a surface layer to prepare a laminated photoreceptor.

Example 2 In Example 1, the charge transport layer consisted of a butadiene-based charge transport material, 0.4 parts by weight of epoxy-modified silicone, and polyarylate (U Polymer: U-100, manufactured by Unitika Ltd.) 2.
0 parts by weight, and after dip coating on the charge generation layer, 1
A laminated type photoreceptor was produced in the same manner as in Example 1 except that the charge transport layer having a film thickness of 20 μm was formed as the surface layer by drying at 20 ° C. for 2 hours for reaction curing.

Example 3 In Example 1, the charge transport layer was a butadiene type charge transport material and an epoxy-modified silicone (manufactured by Shin-Etsu Chemical Co., Ltd.,
1 part by weight of KF100T and polyester (Toyobo Co., Ltd.)
Manufactured by Vylon: V-200) 20 parts by weight, and applied on the charge generation layer by dip coating, dried at 120 ° C. for 2 hours and then reaction-cured to form a charge transport layer having a thickness of 20 μm as a surface layer. A laminated type photoreceptor was prepared in the same manner as in Example 1 except for the above.

Example 4 In Example 1, the charge transport layer was an epoxy-modified silicone (X-22-163B, manufactured by Shin-Etsu Chemical Co., Ltd.)
4 parts by weight and epoxy resin (AER-6 manufactured by Asahi Kasei Corp.)
64) 25 parts by weight and imidazole (Shikoku Chemicals Co., Ltd.)
CURESOL 2MZ-OK) 0.25 parts by weight and hydrazone-based charge transport material (Anan Co., Ltd., CTC-19).
1) 25 parts by weight, which is applied on the charge generation layer by dip coating, dried at 120 ° C. for 2 hours and then reaction-cured to give a film thickness of 20
A laminated type photoreceptor was produced in the same manner as in Example 1 except that the charge transport layer having a thickness of μm was formed as the surface layer.

Example 5 In Example 1, the charge-generating material was changed from X-type metal-free phthalocyanine to oxytitanyl phthalocyanine, and the charge-transporting material was changed from a butadiene compound to a tristyryl compound (see the synthesis example of JP-A-2-279767). A laminated type photoreceptor was produced in the same manner as in Example 1 except that the composition was changed to (synthesis accordingly).

Comparative Example 1 A laminated photoreceptor was prepared in the same manner as in Example 1 except that the epoxy-modified silicone was not added during the preparation of the charge transport layer.

Comparative Example 2 In Example 1, a silicone graft polymer (GS-30, manufactured by Toagosei Kagaku Kogyo Co., Ltd.) 0.4 was used instead of the epoxy-modified silicone added at the time of preparing the charge transport layer.
A multilayer type photoreceptor was prepared in the same manner except that the weight part was added.

Test Example 1 The photoconductors prepared in Examples 1 to 5 and Comparative Examples 1 and 2 were mounted on a laser printer of the reversal development system, and at 20 ° C.
Copying 5000 under the condition of 65% relative humidity (RH)
By repeating 0 times, the presence or absence of defects in the obtained image, the stability of charging, and the abrasion property were evaluated. The results are shown in Table 1.

[0028]

[Table 1]

As shown by the results in Table 1, the electrophotographic photoreceptors of Examples 1 to 5 contained the reaction product of the epoxy-modified silicone and the active hydrogen-containing binder in the surface layer, and therefore, the abrasion resistance was high. The image density was not deteriorated and the residual potential was hardly increased. These performances suggest good cleaning properties of the photoconductor. On the other hand, in the case where the reaction product is not contained as in Comparative Example 1 or the conventional silicone resin is contained as in Comparative Example 2, the abrasion resistance is poor due to phase separation of the silicone resin,
A decrease in image density and an increase in residual potential were observed.

Test Example 2 Temperature and humidity were 10 ° C. and 35% R.V. H. , And 35 ℃, 8
5% R. H. An environmental stability test was conducted in the same manner as in Test Example 1 except that. As a result, in the electrophotographic photosensitive members of Examples 1 to 5, no image defects and image density unevenness were observed under the same conditions as in Test Example 1, and the charging stability and abrasion resistance were also high. It was good. On the other hand, in the electrophotographic photosensitive members of Comparative Examples 1 and 2, the decrease in image density and the instability of the charging property were recognized as in Test Example 1.

[0031]

As described above, the electrophotographic photosensitive member of the present invention contains the reaction product of the epoxy-modified silicone and the active hydrogen-containing binder in the surface layer, and the curing reaction is performed by coating. Since it is carried out during drying, a very homogeneous and smooth surface layer is formed. For this reason, unlike conventional photoreceptors, there is no decrease in sensitivity and rise in residual potential, and charging characteristics and mechanical abrasion properties can be greatly improved, and therefore, a highly durable electrophotographic photosensitive material excellent in environmental stability and cleaning properties. You can get a body.

Claims (3)

[Claims] 1. An electrophotographic photosensitive member having a photosensitive layer provided on a conductive substrate, wherein the surface layer of the electrophotographic photosensitive member contains a reaction product of an epoxy-modified silicone and an active hydrogen-containing binder. An electrophotographic photosensitive member. 2. The electrophotographic photosensitive member according to claim 1, wherein the active hydrogen-containing binder is at least one selected from the group consisting of polycarbonate, polyester, polysulfone, polyarylate, epoxy resin, and phenol resin. 3. A method for producing an electrophotographic photosensitive member having a photosensitive layer provided on a conductive substrate, wherein a surface layer coating liquid containing an epoxy-modified silicone and a binder containing active hydrogen is applied and dried. A method for producing an electrophotographic photosensitive member, which comprises reaction-curing to form a surface layer.