JPH05150464A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To provide high sensitivity and excellent wear resistance by providing an org. photosensitive layer contg. a charge generating material, an electron transfer material and a hole transfer material on a conductive base body and forming a binder resin of a specific compd. CONSTITUTION:The electron transfer material and the hole transfer material are used for the charge transfer material. The electron transfer material is, for example, a diphenoquinone compd., a fluorenone compd., a benzoquinone compd., a dicyanovinyl compd., etc. The binder resin is the resin expressed by formula and the degree of polymn. thereof is 200. The binder resin is usable for forming the respective layers if the org. photosensitive layer is formed of plural layers. The charge generating material is incorporated in the org. photosensitive layer in a range from 0.5 to 15 pts.wt. per 100 pts.wt. binder resin when the org. photosensitive layer is formed as single layer. The electron transfer material is incorporated into the photosensitive layer in a range from 5 to 100 pts.wt. per 100 pts.wt. binder resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoreceptor provided with an organic photosensitive layer on a conductive substrate, and more particularly to an electrophotographic photoreceptor having high sensitivity and excellent abrasion resistance.

[0002]

2. Description of the Related Art Recently, electrophotographic photoreceptors made of various materials have been proposed and used in image forming apparatuses such as copying machines utilizing the so-called Carlson process. One is an inorganic photoreceptor using an inorganic material such as selenium as a photosensitive layer, and the other is an organic photoreceptor using an organic material as a photosensitive layer. Organic photoconductors have many advantages such as being cheaper and higher in productivity than inorganic photoconductors and being non-polluting, and therefore extensive research has been conducted.

Conventionally, bisphenol A has been used as a binder resin.
Type polycarbonate is used.

[0004]

However, since the above-mentioned binder resin has a low glass transition point, there is a problem that the resulting electrophotographic photoreceptor has insufficient abrasion resistance.

The present invention is intended to solve the above problems, and an object thereof is to provide an electrophotographic photosensitive member having high sensitivity and excellent abrasion resistance.

[0006]

The electrophotographic photosensitive member of the present invention is an electrophotographic photosensitive member in which an organic photosensitive layer containing a charge generating material, an electron transporting material and a hole transporting material is provided on a conductive substrate. In the body, the binder resin is a compound represented by the following formula (I), whereby the above-mentioned object can be achieved.

[0007]

[Chemical 2]

The present invention will be described in detail below.

The electrophotographic photosensitive member of the present invention is constituted by providing an organic photosensitive layer containing a binder resin, a charge generating material and a charge transporting material on a conductive substrate. This organic photosensitive layer may be a single layer or may be formed of a plurality of layers (for example, a charge generation layer and a charge transport layer). When the organic photosensitive layer has a plurality of layers, the electron transport material represented by the general formula (I) and the hole transport material represented by the general formula (II) are preferably contained in the same layer. Further, a protective layer may be provided on the organic photosensitive layer, and an intermediate layer may be provided between the organic photosensitive layer and the conductive substrate.

As the charge generating material used in the present invention, conventionally known materials can be used. For example, A-type metal-free phthalocyanine, copper phthalocyanine, oxotitanyl phthalocyanine, 1,4-dithioketo-3,6- Diphenyl-pyrrolo- (3,4-c) pyrrolopyrrole,
2,7-bis (2-hydroxy-3- (2-chlorophenylcarbamoyl) -1-naphthylazo) fluorenone and the like can be mentioned.

In the present invention, an electron transfer material and a hole transfer material are used as the charge transfer material.

As the electron transport material used in the present invention, conventionally known materials can be used, and examples thereof include a diphenoquinone compound, a fluorenone compound, a benzoquinone compound and a dicyanovinyl compound.

As the hole transporting material used in the present invention, conventionally known materials can be used, and examples thereof include compounds represented by the following formula.

[0014]

[Chemical 3]

[0015]

[Chemical 4]

[0016]

[Chemical 5]

[0017]

[Chemical 6]

[0018]

[Chemical 7]

[0019]

[Chemical 8]

(R represents an alkyl group, an alkoxy group, an aryl group or the like, A represents an alkylene group or an arylene group, and B represents a group capable of forming a urethane bond or an ether bond.) Further, In addition to the charge transport material, the following charge transport material may be contained. For example, m-
Phenylenediamine compounds; tetracyanoethylene;
Fluorenone compounds such as 2,4,7, -trinitro-9-fluorenone; nitrated compounds such as dinitroanthracene; succinic anhydride; maleic anhydride; dibromomaleic anhydride; triphenylmethane compounds; 2,5-di Oxadiazole compounds such as (4-dimethylaminophenyl) -1,3,4-oxadiazole; 9- (4
-Styryl compounds such as diethylaminostyryl) anthracene; carbazole compounds such as poly-N-vinylcarbazole; pyrazoline compounds such as 1-phenyl-3- (p-dimethylaminophenyl) pyrazoline;
4 ′, 4 ″,-tris (N, N-diphenylamino)
Amine derivatives such as triphenylamine; 1,1-bis (4-diethylaminophenyl) -4,4-diphenyl-
Conjugated unsaturated compounds such as 1,3-butadiene; 4- (N,
Hydrazone compounds such as N-diethylamino) benzaldehyde-N, N-diphenylhydrazone; indole compounds, oxazole compounds, isoxazole compounds, thiazole compounds, thiadiazole compounds, imidazole compounds, pyrazole compounds, pyrazoline compounds , Nitrogen-containing cyclic compounds such as triazole compounds; condensed polycyclic compounds and the like.

The binder resin used in the present invention is a resin represented by the above formula (I) and has a degree of polymerization of 200. When the organic photosensitive layer is formed of a plurality of layers, the binder resin can be used to form each layer.

Further, in addition to the above-mentioned binder resin, a resin conventionally used in a photoreceptor coating liquid may be used. For example, thermosetting silicone resin, epoxy resin, urethane resin, curable acrylic resin, acrylic modified urethane resin, alkyd resin, unsaturated polyester resin, diallyl phthalate resin, phenol resin, urea resin, benzoguanamine resin, melamine resin, styrene resin Polymers, acrylic polymers, styrene-acrylic polymers, polyethylene, ethylene-vinyl acetate-based polymers, olefin polymers such as chlorinated polyethylene, polypropylene, ionomers; polyvinyl chloride; vinyl chloride-vinyl acetate copolymers; Polyvinyl acetate; Saturated polyester; Polyamide; Thermoplastic urethane resin; Polycarbonate of bisphenol A type, bisphenol Z type, etc .; Polyarylate; Polysulfone; Ketone resin; Polyvinyl butyral resin; Polyether Resin and the like.

When the organic photosensitive layer is formed of a single layer,
The film thickness of the organic photosensitive layer is preferably 10 to 50 μm, more preferably 15 to 30 μm.

When the organic photosensitive layer is formed of a single layer,
The content of the charge generating material is the same as that of the binder resin 1 of the organic photosensitive layer.
The content is preferably 0.5 to 15 parts by weight, more preferably 1 to 10 parts by weight, based on 00 parts by weight. When the content of the charge generation material is less than 0.5 part by weight, the sensitivity of the obtained photoreceptor is lowered. On the other hand, if the content of the charge generation material exceeds 15 parts by weight, the abrasion resistance of the obtained photoreceptor may be reduced.

The content of the electron-transporting material is preferably in the range of 5 to 100 parts by weight, more preferably 20 parts by weight, based on 100 parts by weight of the binder resin in the organic photosensitive layer.
˜50 parts by weight. When the content of the above electron transport material is less than 5 parts by weight, the repeating characteristics of the obtained photoreceptor are deteriorated. On the contrary, when the content of the electron transport material exceeds 100 parts by weight, the abrasion resistance of the obtained photoreceptor may be deteriorated. Further, it is 50 with respect to 100 parts of the charge generation material.
It is preferably contained in an amount of about 100 parts by weight.

The content of the hole transport material is preferably in the range of 10 to 200 parts by weight, more preferably 5 parts by weight, based on 100 parts by weight of the binder resin in the organic photosensitive layer.
It is 0 to 200 parts by weight. When the content of the hole transport material is less than 10 parts by weight, the sensitivity of the resulting photoreceptor becomes poor. On the other hand, when the content of the hole transport material exceeds 200 parts by weight, the abrasion resistance of the obtained photoreceptor may be reduced. Further, it is 5 with respect to 100 parts by weight of the charge generation material.
It is preferably contained in an amount of 50 parts by weight.

The content of the electron transport material is 20 to 70% by weight in the charge transport material, and particularly 2
It is preferably contained in an amount of 0 to 50% by weight. If the content of the electron transporting material in the charge transporting material is less than 20% by weight, the repetitive characteristics of the resulting photoreceptor will be poor. vice versa,
When the content of the electron transporting material exceeds 70% by weight, the sensitivity of the obtained photoreceptor becomes poor.

The content of the hole transport material is 20 to 70% by weight in the charge transport material, and particularly 2
It is preferably contained in an amount of 0 to 50% by weight. When the content of the hole transporting material in the charge transporting material is less than 20% by weight, the repetitive characteristics of the obtained photoreceptor are deteriorated. vice versa,
When the content of the hole transport material exceeds 70% by weight,
The sensitivity of the obtained photoreceptor is poor.

When the organic photosensitive layer is composed of a charge generation layer and a charge transport layer, the thickness of the charge generation layer is 0.01 to.
It is preferably 3 μm, more preferably 0.1 to 2 μm. The thickness of the charge transport layer is preferably 2 to 100 μm,
More preferably, it is 5 to 30 μm.

The content of the charge generation material is preferably 20 to 300 parts by weight, more preferably 50 parts by weight, based on 100 parts by weight of the binder resin in the organic photosensitive layer.
~ 200 parts by weight. When the content of the charge generation material is less than 20 parts by weight, the charge generation efficiency of the resulting photoreceptor is low, and conversely, when the content of the charge generation material exceeds 300 parts by weight, the mechanical strength of the obtained photoreceptor is suitable. May decrease.

The content of the electron transport material is preferably in the range of 5 to 100 parts by weight, more preferably 20 parts by weight, based on 100 parts by weight of the binder resin of the organic photosensitive layer.
˜50 parts by weight. When the content of the above electron transport material is less than 5 parts by weight, the repeating characteristics of the obtained photoreceptor are deteriorated. On the contrary, when the content of the electron transport material exceeds 100 parts by weight, the abrasion resistance of the obtained photoreceptor may be deteriorated. Further, it is 50 with respect to 100 parts of the charge generation material.
It is preferably contained in an amount of about 100 parts by weight.

The content of the hole transport material is preferably 10 to 200 parts by weight, more preferably 5 parts by weight, based on 100 parts by weight of the binder resin of the organic photosensitive layer.
It is 0 to 200 parts by weight. When the content of the hole transport material is less than 10 parts by weight, the sensitivity of the resulting photoreceptor becomes poor. On the other hand, when the content of the hole transport material exceeds 200 parts by weight, the abrasion resistance of the obtained photoreceptor may be reduced. Further, it is 5 with respect to 100 parts by weight of the charge generation material.
It is preferably contained in an amount of 50 parts by weight.

The content of the above electron transport material is 20 to 70% by weight in the charge transport material, and particularly 2
It is preferably contained in an amount of 0 to 50% by weight. If the content of the electron transporting material in the charge transporting material is less than 20% by weight, the repetitive characteristics of the resulting photoreceptor will be poor. vice versa,
When the content of the electron transport material exceeds 70% by weight,
The sensitivity of the obtained photoreceptor is poor.

The content of the hole transport material is 20 to 70% by weight in the charge transport material, and particularly 2
It is preferably contained in an amount of 0 to 50% by weight. When the content of the hole transporting material in the charge transporting material is less than 20% by weight, the repetitive characteristics of the obtained photoreceptor are deteriorated. vice versa,
When the content of the hole transport material exceeds 70% by weight,
The sensitivity of the obtained photoreceptor is poor.

Further, the organic photosensitive layer may contain various additives such as an antioxidant and a quencher.

The conductive substrate used in the present invention is formed in an appropriate shape such as a sheet shape or a drum shape according to the mechanism and structure of the image forming apparatus in which the electrophotographic photosensitive member is incorporated. The conductive substrate may be entirely formed of a conductive material such as metal, or the base material may be formed of a material having no conductivity and the surface thereof may be provided with a material having conductivity. Good. As the conductive material, for example, the surface is alumite-treated, or untreated aluminum,
Examples include copper, tin, platinum, gold, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, brass, etc. Especially, anodic oxidation by sulfuric acid alumite method and sealing with nickel acetate. Treated aluminum is preferably used. In the case of a conductive substrate formed by providing a conductive material on the surface of a base material made of a material having no conductivity, on the surface of a synthetic resin base material or a glass base material, the above-mentioned metal or A thin film made of a conductive material such as aluminum iodide, tin oxide, or indium oxide formed by a known film forming method such as a vacuum deposition method or a wet plating method, or a film of the metal material or the like on the surface of the base material. It is possible to employ, for example, a laminate of the above, a substrate in which a substance that imparts conductivity is injected into the surface of the base material, or the like. The conductive base material may be subjected to a surface treatment with a surface treatment agent such as a silane coupling agent or a titanium coupling agent, if necessary, to enhance the adhesiveness with the organic photosensitive layer.

In the electrophotographic photoreceptor of the present invention, when the organic photosensitive layer is a single layer, at least a binder resin, a charge generating material,
A coating solution prepared by dispersing the electron transporting material and the hole transporting material in dichloromethane or the like as a solvent or a dispersion medium is applied onto a conductive substrate by a usual coating method such as a spray coating method, a dipping method and a flow coating method. It can be prepared by coating to form an organic photosensitive layer. When the organic photosensitive layer has a plurality of layers, at least a binder resin and the above-mentioned binder resin are formed after forming a charge generating layer by applying a coating liquid in which at least a binder resin and a charge generating material are dispersed in a solvent onto a conductive substrate. An electrophotographic photosensitive member can be formed by further applying a coating liquid in which an electron transporting material and the above hole transporting material are dispersed in a solvent to form a charge transporting layer. Alternatively, the charge-transporting layer may be formed first, and then the charge-generating cleaning may be formed.

It is preferable to perform heat treatment in order to reduce the residual amount of dichloromethane contained in the organic photosensitive layer. For example, the conductive substrate coated with the coating solution is heat treated at a temperature of 50 ° C. or more for 60 minutes or more. Preferably. When the heat treatment temperature is lower than the above conditions, the residual amount of dichloromethane may not be sufficiently reduced.

As the solvent or dispersion medium used in the coating liquid, other solvent or dispersion medium can be used alone or in combination with dichloromethane in addition to dichloromethane.

Examples of such a solvent or dispersion medium include the following. Aliphatic hydrocarbons such as n-hexane, octane and cyclohexane; aromatic hydrocarbons such as benzene, xylene and toluene; halogenated hydrocarbons such as carbon tetrachloride and chlorobenzene; methyl alcohol, ethyl alcohol, isopropyl alcohol, allyl alcohol, Alcohols such as cyclopentanol, benzyl alcohol, furfuryl alcohol, diacetone alcohol; dimethyl ether, diethyl ether,
Ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether and tetrahydrofuran; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; esters such as ethyl acetate and methyl acetate; dimethylformamide; dimethyl sulfoxide and the like.

The coating solution is prepared by a conventionally known method, for example, a mixer, a ball mill, a paint shaker, a sand mill,
It can be prepared using an attritor, an ultrasonic disperser or the like. When preparing the above coating liquid, a surfactant, a leveling agent or the like may be added in order to improve dispersibility, coatability and the like.

[0042]

EXAMPLES The present invention will be described below with reference to examples and comparative examples.

Examples 1 to 4 and Comparative Examples 1 to 4 5 parts by weight of metal-free phthalocyanine as a charge generating material, 40 parts by weight of the compound shown in Table 1 as a hole transferring material,
The diphenoquinone compound 40 shown in Table 1 as an electron transfer agent
By weight, 100 parts by weight of the resin shown in Table 1 as a binder resin and 800 parts by weight of dichloromethane as a solvent were mixed and dispersed in a paint shaker to prepare a coating solution for a single-layer type photosensitive layer. The prepared solution was applied onto an aluminum foil with a wire bar and then dried by heating at 60 ° C. for 120 minutes to obtain an electrophotographic photosensitive sheet having a single-layer type photosensitive layer with a film thickness of 15 to 20 μm. Further, the above prepared liquid was applied onto an aluminum cylinder and dried in the same manner as above to obtain an electrophotographic photosensitive drum having a single-layer type photosensitive layer having a film thickness of 15 to 20 μm.

The charging characteristics and photosensitive characteristics of the electrophotographic photosensitive members obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were evaluated according to the following methods, and the results are shown in Table 1.

1) Measurement of initial surface potential V1sp A single layer type electrophotographic photoreceptor sheet was applied with an applied voltage to the obtained photoreceptor using an electrostatic copying tester (Kawaguchi Denki EPA-8100). The surface potential V1 (V) was measured by positively or negatively charging the surface potential.

2) Measurement of half-exposure amount E1 / 2 and residual potential V2 The surface potential V1 of the charged photoreceptor sheet was reduced to 1/2 by using a halogen lamp as an exposure light source of an electrostatic copying tester. Until the half-exposure dose E1 / 2 (l
ux · sec) was calculated. Further, the surface potential after 5 seconds from the exposure was measured and defined as the residual potential V2 (V).

3) Evaluation of abrasion resistance The obtained photosensitive drum was used as a laser printer LP-X2.
It was mounted on (manufactured by Sanda Kogyo Co., Ltd.) and the change in film thickness was measured after a printing durability test of 1,000 sheets was performed.

[0048]

[Table 1]

[0049]

[Chemical 9]

[0050]

[Chemical 10]

[0051]

[Chemical 11]

From Table 1, by using the binder resin of the above formula, an electrophotographic photoreceptor having high sensitivity and excellent abrasion resistance can be formed.

[0053]

As is apparent from the above description, according to the present invention, it is possible to provide an electrophotographic photosensitive member having high sensitivity and excellent abrasion resistance.

Claims (1)

[Claims] 1. An electrophotographic photosensitive member comprising a conductive substrate and an organic photosensitive layer containing a charge generating material, an electron transporting material and a hole transporting material, wherein the binder resin is represented by the following formula (I): An electrophotographic photoreceptor, which is a compound represented by: [Chemical 1]