JPH05158272A - Electrophotographic sensitive body and its production - Google Patents

Abstract

PURPOSE:To obtain a high durability electrophotographic sensitive body excellent in environmental stability and cleanability. CONSTITUTION:The surface layer of this electrophotographic sensitive body with a photosensitive layer formed on the electric conductive substrate contains a product obtd. by allowing at least one of silane, titanate and aluminum coupling agents to react with a binder contg. active hydrogen. A coating liq. for the surface layer contg. the coupling agent and the binder contg. active hydrogen is applied and subjected to reaction curing at the time of drying to form the surface layer.

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,
Due to its low compatibility, it has a drawback that the sensitivity is slightly lowered or the residual potential is increased. As described above, the conventional organic photoreceptor containing a silicone-containing polymer has a problem in charging characteristics, and further has a problem in electric characteristics under various environments, and improvement thereof is strongly desired in the art. Further, it has been proposed to improve durability by using a thermosetting resin as a binder (Japanese Patent Laid-Open No. 54-300).
No. 40, etc.). However, in this method, the film of the obtained photosensitive layer is hard, but on the other hand, it is fragile, and as a result, it cannot contribute to the durability. Further, since the compatibility with the photosensitive material is poor, the sensitivity is lowered or the residual potential is increased. It has the drawback.

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 the actual situation, a satisfactory method has not yet been obtained by the method of using or the method of using the thermosetting resin as the binder. 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 characteristics,
It is an object of the present invention to provide a highly durable electrophotographic photosensitive member which is significantly improved in mechanical abrasion properties and cleaning properties and is also excellent in 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 comprises a silane coupling agent, a titanate coupling agent, and an aluminum coupling agent. An electrophotographic photoreceptor containing a reaction product of at least one selected from the group consisting of and an active hydrogen-containing binder, and a silane coupling agent, a titanate coupling agent, and an aluminum coupling agent. A method for producing an electrophotographic photosensitive member, characterized in that a surface layer coating solution containing at least one selected from the group and an active hydrogen-containing binder is applied, and the surface layer is formed by reaction curing when dried. Regarding

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 Any of the above described photoconductors may be used.

In the present invention, the surface layer is a layer containing a reaction product of a coupling agent / a binding agent containing active hydrogen, and is a layer provided on the surface of a photoreceptor. Therefore, in the case of a single-layer type photoreceptor, the photosensitive layer is a 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, which contains the reaction product of the coupling agent / active hydrogen-containing binder. As a means therefor, in the present invention, the surface layer coating liquid contains at least one selected from the group consisting of a silane coupling agent, a titanate coupling agent, and an aluminum coupling agent, and an active hydrogen-containing binder.

Examples of the silane coupling agent used in the present invention include vinyl silane, acryl silane, epoxy silane, amino silane and alkyl silane, and epoxy silane, amino silane and alkyl silane are preferable. As products, KBM303, KBM
403, KBE402, KBM603, KBM602,
KBE903, KBM573, KBM803, KBM7
03, (manufactured by Shin-Etsu Chemical Co., Ltd.) and TSL8186,
TSL8241, TSL8340, TSL8331, T
SL8350 (manufactured by Toshiba Silicone Co., Ltd.) and the like can be mentioned. Examples of titanate coupling agents include isopropyl titanate and tetraoctyl titanate. Products include KR-TTS and KR-38
S, KR-44, KR-46B, KR-55, KR-1
38S, KR-238S, 338X, (Ajinomoto Co., Inc.
Manufactured) etc. Examples of the aluminum-based coupling agent include aluminum diisopropylate. Examples of products include AL-M (manufactured by Ajinomoto Co., Inc.) and the like. The above three types of coupling agents can be used alone or in combination of two or more types. In this case, two or more kinds of coupling agents of the same series may be selected and used, and two or more kinds of silane coupling agents, titanate coupling agents, and aluminum coupling agents may be selected and used. Good.

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, polycarbonate, polyester, polysulfone, polyarylate, epoxy resin, phenol resin and the like are preferably used from the viewpoints of reactivity with a coupling agent and mechanical properties of the obtained surface layer. These may be used alone or in admixture of two or more, and may be used in combination with a commonly used binder. The total content of the coupling agent is 0.05 to 10% by weight with respect to the active hydrogen-containing binder.
And preferably 0.1 to 5% by weight. If the amount of the coupling agent is less than 0.05% by weight, the abrasion resistance is poor and the durability is inferior, and if it is more than 10% 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 thereof include ether solvents such as tetrahydrofuran; alcohol solvents such as ethanol and butanol; dimethylformamide and dimethyl sulfoxide.

When the charge generation layer is a surface layer, a coating method is used, and at least one coupling agent described above is added to the coating liquid containing the charge generation substance and the like, and the main component of the binder is used. A surface layer coating solution is prepared using an active hydrogen-containing 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 coupling agent 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 butadiene 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, etc. are used.

When the charge transport layer serves as a surface layer, a coating method is used in which at least one coupling agent described above is added to the coating liquid containing the above charge transport substance and the like, and the main component of the binder is used. A surface layer coating solution is prepared using an active hydrogen-containing 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 coupling agent 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, a coating liquid for a surface layer is prepared by using the above-mentioned charge generating substance, charge transporting substance, binder, coupling agent, active hydrogen-containing binder, and solvent, The electrophotographic photoreceptor of the present invention is produced by a coating method or the like. At this time, the type of each component is the same as that of the laminated type. Regarding the amount used, the active hydrogen-containing binder is 30 to 80% by weight based on the weight of the photosensitive layer, and the amount of other components such as the weight ratio of the charge generating substance and the charge transporting substance to the binder is used. Is similar to the case of the laminated type. The thickness of the obtained photosensitive layer is 10 to 30 μm.

The electrophotographic photosensitive member of the present invention is produced as described above. In the present invention, the coupling agent and the active hydrogen-containing binder are dried at the time of producing the surface layer and after the coating liquid is applied and dried. It causes reaction hardening with. This allows
The surface layer may contain a reaction product of a coupling agent and an active hydrogen-containing binder. As described above, in the present invention, the mechanical abrasion property of the photoconductor is improved due to the improvement of the surface smoothness and the strength of the photosensitive layer, and the charging property and the like are also improved because the coupling agent is bonded to the binder. ..

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) 20 parts by weight, 0.2 parts by weight of silane coupling agent (TSL8241 manufactured by Toshiba Silicone Co., Ltd.), and 1,
A surface layer coating solution consisting of 168 parts by weight of 2-dichloroethane was applied onto the charge generation layer by dip coating, dried at 100 ° C. for 30 minutes and reacted and cured to form a charge transport layer having a thickness of 20 μm as a surface layer. A laminated photoreceptor was produced.

Example 2 In Example 1, the charge transport layer was a butadiene-based charge transport material and a silane-based coupling agent (K, Shin-Etsu Chemical Co., Ltd.).
BE402) 0.4 parts by weight and polyarylate (Unitika Ltd., U polymer: U-100) 20 parts by weight, which is applied on the charge generation layer by dip coating and then dried at 120 ° C. for 2 hours to be reaction-cured. Then, a laminated type photoreceptor was prepared in the same manner as in Example 1 except that a charge transport layer having a film thickness of 20 μm was formed as a surface layer.

Example 3 In Example 1, the charge transport layer was a butadiene-based charge transport material and a titanate-based coupling agent (KR, KR, manufactured by Ajinomoto Co., Inc.).
-TTS) 1 part by weight and polyester (manufactured by Toyobo Co., Ltd.,
Byron: V-200) 20 parts by weight, which is applied on the charge generation layer by dip coating, dried at 120 ° C. for 2 hours and then cured by reaction to form a charge transport layer having a thickness of 20 μm as a surface layer. A laminated photoreceptor was prepared in the same manner as in Example 1.

Example 4 In Example 1, 0.4 parts by weight of an aluminum-based coupling agent (Ajinomoto Co., AL-M) was used as the charge transport layer and an epoxy resin (AER-664, Asahi Kasei Co., Ltd.) 25. 0.25 parts by weight of imidazole (manufactured by Shikoku Chemicals Co., Ltd., Curezol 2MZ-OK) and 25 parts by weight of a hydrazone-based charge transport material (manufactured by Anan Co., Ltd., CTC-191), on the charge generation layer. After dip coating, the laminate type photoreceptor was prepared in the same manner as in Example 1 except that a charge transport layer having a film thickness of 20 μm was formed as a surface layer by drying at 120 ° C. for 2 hours for reaction curing.

Example 5 In Example 1, the charge generation material was changed from X-type metal-free phthalocyanine to oxytitanyl phthalocyanine, and the charge transport material was changed from a butadiene compound to a tristyryl compound (see the synthesis example of JP-A-2-279767). Synthetic), and the coupling agent from a silane coupling agent to a titanate coupling agent (manufactured by Ajinomoto Co., Inc.,
A multilayer photoreceptor was prepared in the same manner as in Example 1 except that the composition was changed to KR-238S).

Comparative Example 1 A laminated type photoreceptor was prepared in the same manner as in Example 1 except that the silane coupling agent was not added during preparation of the charge transport layer.

Comparative Example 2 In Example 1, except that 0.4 part by weight of a silicone graft polymer (GS-30 manufactured by Toagosei Kagaku Kogyo Co., Ltd.) was added in place of the silane coupling agent in the preparation of the charge transport layer. In the same manner as in Example 1, a multi-layer photosensitive member was manufactured.

Comparative Example 3 A laminated type photoreceptor was prepared in the same manner as in Example 4 except that the aluminum-based coupling agent was not added during preparation of the charge transport layer.

Test Example 1 The photoconductors prepared in Examples 1 to 5 and Comparative Examples 1 to 3 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.

[0029]

[Table 1]

As shown in the results of Table 1, the electrophotographic photoreceptors of Examples 1 to 5 contained the reaction product of the coupling agent and the active hydrogen-containing binder in the surface layer, and therefore, had excellent wear resistance. The image quality was excellent, and the decrease in image density and the increase in residual potential were hardly seen. 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 Examples 1 and 3, and the conventional silicone-containing polymer is contained as in Comparative Example 2, both of the abrasion resistance are caused by the phase separation of the silicone-containing polymer. Inferior in the property, the image density was lowered, the charging was unstable, and the residual potential was increased.

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 decrease in image density was observed under the same conditions as in Test Example 1, and the charging stability and abrasion resistance were good. It was On the other hand, Comparative Examples 1 to 3
In the electrophotographic photosensitive member of No. 3, as in Test Example 1, a decrease in image density and instability of charging properties were observed.

[0032]

As described above, the electrophotographic photoreceptor of the present invention contains the reaction product of the coupling agent and the active hydrogen-containing binder in the surface layer, and the curing reaction is coating and drying. Since this is sometimes done, 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 photoreceptor having a photosensitive layer provided on a conductive substrate, wherein the surface layer of the electrophotographic photoreceptor is selected from the group consisting of a silane coupling agent, a titanate coupling agent, and an aluminum coupling agent. An electrophotographic photoreceptor comprising a reaction product of at least one selected and an active hydrogen-containing binder. 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 photoreceptor having a photosensitive layer provided on a conductive substrate, wherein at least one selected from the group consisting of a silane coupling agent, a titanate coupling agent, and an aluminum coupling agent and active hydrogen. A method for producing an electrophotographic photosensitive member, which comprises applying a surface layer coating liquid containing a contained binder, and reacting and curing it when dried to form a surface layer.