JPS61296355A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To reduce the cost of starting materials and the cost of production and to improve the flexibility by forming a charge generating layer having a layer of an electron donative org. binder contg. dispersed arsenic selenide particles and a charge transferring layer contg. a specified alpha-phenylstilbene compound. CONSTITUTION:A charge generating layer 2 having a layer of an electron donative org. binder contg. dispersed arsenic selenide particles and a charge transferring layer 3 contg. at least one kind of alpha-phenylstilbene compound represented by the formula as an effective component are formed to obtain an electrophotographic sensitive body. The charge transferring layer 3 is formed by dissolving one or more kinds of compounds represented by the formula preferably by 40-60wt% in an electrically inert org. resin such as polycarbonate or polystyrene as an org. binder. The preferred particle size of the arsenic selenide particles in the charge generating layer 2 is <=1mum, the preferred thickness of the layer 2 is 0.5-2mum, and that of the charge transferring layer 3 is 5-30mum. Thus, the cost of starting materials and the cost of production are reduced, the form of a flexible belt can be provided to the sensitive body, and high sensitivity is obtd. in a short wavelength range.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an electrophotographic photoreceptor. More specifically, a charge generation layer having an electron-donating organic binder layer in which arsenic selenide particles are dispersed and a charge transfer layer containing at least one α-phenylstilbene compound as an active ingredient are laminated together for use in electrophotography. This relates to photoreceptors.

PRIOR ART In the past, many applications have been filed regarding photoreceptors using arsenic selenide. Conventional photoreceptors using arsenic selenide are vacuum-deposited to form a film with a thickness of 20 μm to Zooμm, but with a dispersion type, the film thickness can be approximately 5 μm to 30 μm to maintain the same surface potential. becomes. This is due to the fact that the dielectric constant of arsenic selenide is about four times that of the organic binder. When a dispersion type of arsenic selenide is used as the charge generation layer as in the present invention, there is no need to maintain the surface potential necessary for development in the copying process in the charge generation layer, so the film thickness is reduced to 5 μm or less. Therefore, the amount of arsenic selenide required per unit area of the photoreceptor is 1/10 to 1/100 of that of the conventional vacuum deposition type, which is more economical.

According to the conventional method, a layer of arsenic selenide is formed by vacuum deposition, and the temperature of the conductive substrate during vacuum deposition is 100C.
It is necessary to maintain the temperature at ~300C, and therefore the substrate material is limited to heat-resistant materials such as metal plates and metal drums. However, when using the dispersion type of the present invention, the drying temperature of the dispersion solvent can be maintained at 60C.
Any substrate that can withstand ~120C can be used, so polyester, polyimide, or other plastic films with metals such as aluminum or tin vapor-deposited on the surface, or polycarbonate 2
It is also possible to use a substrate having relatively low heat resistance, such as a material in which conductive particles such as metal particles are dispersed in plastic such as ester or polyester. Nine, because conventional vacuum-deposited arsenic selenide photoreceptors are brittle against mechanical stress,
Although it was not possible to take the form of a flexible belt as a photoreceptor,
The dispersion type of the present invention makes this possible because a flexible material can be used as the organic binder.

Although it is not arsenic selenide, there are conventional techniques as described below regarding photoreceptors in which inorganic photoconductive particles are dispersed. For example, ZnO, Ou-7 talocyanine, amorphous So, Od
JP-A-47-6586 disclosing the use of S, etc.
No. (Special Publication No. 53-31367). Crystal Ss, R2
JP-A-47-18546 discloses a dispersion of phthalocyanine in polyvinyllupazonil. Crystal S
・Special Publication No. 4, which discloses dispersion of ・ in an organic binder.
No. 7-41470. There is also JP-A No. 53-27033 (Japanese Patent Publication No. 59-9049) which discloses α-phenylstilbene compounds.

Regarding photoreceptors using arsenic selenide as a charge generation layer, there are the following conventional techniques. For example, when vacuum-deposited arsenic selenide is used as a charge generation layer and an electron-donating organic binding layer is used as a charge transfer layer, amorphous selenium is used as a charge injection layer between each layer. Japanese Patent Application Laid-Open No. 1983-1987 discloses that a layer must be provided.
-8148 and JP-A-56-85754.

Purpose The present invention has been made to solve the drawbacks of the conventional methods as described above, and the present invention is to reduce the thickness of the charge generation layer containing arsenic selenide by dispersing particles of arsenic selenide. It is an object of the present invention to provide a photoreceptor that is thin, does not require a charge injection layer, has low raw material costs and manufacturing costs, and has good flexibility.

Composition As a result of intensive research to achieve the above object, the present inventor has developed a nine electrophotographic photoreceptor in which a charge generation layer and a charge transfer layer are laminated on a conductive substrate, and the charge generation layer has arsenic selenide particles dispersed therein. The above object can be achieved by providing an electrophotographic photoreceptor having an electron-donating organic binder layer having an electron-donating organic binder layer, and a charge transfer layer containing an α-phenylstilbene compound represented by the following general formula as at least one active ingredient. found that it can be achieved.

(In the formula, R1 is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group, and Bt, 几3 and R4 are hydrogen atoms, substituted or unsubstituted alkyl groups, substituted or represents an unsubstituted aryl group or a substituted or unsubstituted aralkyl group, Ar" represents a substituted or unsubstituted aryl group, Ar" represents a substituted or unsubstituted aryl group,
"represents a substituted or unsubstituted arylene group. Ar" and R1 may jointly form a ring. n is an integer of 0 or 1. ) Examples of electron-donating organic compounds in which the arsenic selenide particles used in the present invention are dispersed include polyvinyl carbazole and its derivatives (for example, halogens such as chlorine and bromine, methyl groups, amino groups, etc. in the carbazole skeleton). (having a substituent of . Further, these compounds may be used in combination. Even when used as a mixture, it is preferable to add other electron-donating organic compounds to the polynylcarnozeta sol and its derivatives. The reason why polyvinylcarbazole and its derivatives are preferable is that they have a large ionization potential compared to other electron-donating organic compounds and the α-phenylstilbene compound contained in the charge transfer layer, and because they are polymers themselves, they can be used in the charge transfer layer. It is mentioned that coating formation can be easily performed.

The charge transport layer of the present invention is an organic inder) and an electrically inert organic resin such as polycarbonate, polystyrene, styrene-butadiene copolymer, acrylic ester or methacrylic ester polymer or copolymer. Combine? About 10 to about 80% by weight, preferably 40 to 60% by weight, of one or more of the exemplified compounds shown in Table 1 below is dissolved in polyester, epoxy resin, urethane resin, silicone resin, alkyd resin, etc. It consists of

Table 1 The present invention will be explained in more detail with reference to the accompanying drawings. FIG. 1 is a sectional view of a representative example of a photoreceptor according to the present invention, in which 1 represents a conductive substrate, 2 represents a charge generation layer, and 3 represents a charge transfer layer.

FIG. 2 is a cross-sectional view of another representative example, and 4 indicates an intermediate layer. The intermediate layer is provided as an adhesive layer and/or a charge injection blocking layer, if necessary.

The photoreceptor of the present invention basically includes a charge generation layer 2 mainly containing arsenic selenide as a charge generation substance on a conductive substrate 1;
Charge transport layer 3 containing α-7 enylstilpene compound
A photosensitive layer consisting of a laminated layer is provided. In this photoreceptor, the surface of the charge transfer layer is negatively charged, an electric field is applied to the charge generation layer 2 and the charge transfer layer 3, and then light is exposed from the charge transfer layer side, so that the light transmitted through the charge transfer layer 3 generates charges. J#2, and in that region, charge carriers are generated, separated, and injected into the electron-donating organic binder, while the charge transfer layer 3 receives the injection of separated charge carriers and transports them. The generation of charge carriers necessary for optical attenuation is performed by arsenic selenide, which is a charge generation substance, and the transport of charge carriers is performed by charge transfer N3 (mainly an α-phenylstilbene compound acts). If a transparent conductive substrate is used as the conductive substrate 1, it is also possible to perform exposure from the side of the conductive substrate 1, and light attenuation depends on the function of each layer as described above.

To create the photoreceptor shown in attached figure-1, conductive substrate 1
A dispersion of arsenic selenide particles dispersed in a suitable solvent containing an electron-donating organic compound is applied onto the surface, dried, and if necessary, the surface is finished by a method such as polishing. The charge generation layer 2 is formed by preparing the film F-J, and a solution containing one or more α-phenylstilbene compounds and an organic compound is applied thereon and dried. The charge transfer layer 3 may be formed using the above steps.

Arsenic selenide particles for charge generation N2 may have a diameter of 5 μm or less, preferably 1 μm or less. 5
If the particle size is larger than μm, the electrophotographic charging ability of the photoreceptor will be lowered, causing partial whiteout of the image.

The thickness of the charge generation layer 2 is 5 μm or less, preferably 0.5 μm.
m to 2 μm, and the thickness of the charge transfer layer 3 is 3 to 50 μm.
1 Preferably, the diameter is 5 to 30 μm. 0 The proportion of the dispersed arsenic selenide particles in the charge generation layer 2 is about 5 to 95% by weight, preferably about 30 to 80% by weight. If there are too few arsenic selenide particles, there will be few charge-generating substances, which will reduce the light decay rate, and if there are too many, the chargeability of the photoreceptor, especially the chargeability of the charge-generating layer 2, will deteriorate, making it difficult to separate the charges generated during exposure. Therefore, the light attenuation speed decreases.

As a binder for the charge generation layer 2, other inert organic resins may be used as long as the electron donating property of the electron donating organic binder is not reduced, such as the organic resins listed above as examples of the organic d-ing for the charge transfer layer 3. can be mixed. The range in which the electron donating property is not reduced is preferably 60% by weight or less in the charge generation layer 2 excluding the charge generation substance.

The conductive substrate 1 is a metal plate or metal foil made of aluminum, tin, nickel, chromium, stainless steel, iron, etc., a metal such as aluminum, tin, nickel, chromium, iron, or a metal oxide such as indium oxide, tin oxide, ITO, etc. A plastic film that has been vapor-deposited, sputtered, or plated, paper that has been subjected to conductive treatment in a similar manner, or a plastic film or drum that has conductive particles such as metal dispersed therein are used.

A plasticizer can be added to the charge generation layer and/or the charge transfer layer, if necessary. Examples of plasticizers include halogenated paraffins, polychlorinated biphenyls, dimethylnaphthalene, and dibutyl phthalate.

Furthermore, as shown in FIG. 2, the photoreceptor obtained in the above manner is provided with an intermediate layer 4 as an adhesive layer and/or a charge injection blocking layer between the conductive substrate 1 and the charge generation layer N2 as necessary. Can be set up.

Materials used for these layers include organic resin thin films such as polyamide, polyester, polyvinyl butyl, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetate, nitrocellulose, phenolic resin, and mixtures of two or more of these, and aluminum oxide. It is preferably an inorganic thin film of silicon oxide or the like, and the film thickness is preferably 1 μm or less.

The present invention will be explained in more detail by the following examples, but the present invention is not limited thereto.

Example 1 The inside of a vacuum tank equipped with an inlet for nitrogen gas (purity 99.999%) was reduced to 10'' with an exhaust pump, and then nitrogen gas was introduced into the vacuum tank to reduce the pressure inside the tank. is maintained at 0.2 to 0.4 torr. As for As! 8・
8 alloy is evaporated. After the alloy has evaporated, the fine powder of arsenic selenide deposited on the inner wall of the tank is brushed off and collected. This fine powder is colored and has a particle size of 0.1 in diameter.
The size was ~1 μm and the shape was spherical.

Next, in a 3 oct. glass sample-bottle, 1.6
Rust (5/8 inch) stainless steel Miria 0Il, arsenic fine powder obtained above 0.5, p, and the following resin solution A
9.519 and milled to obtain an arsenic selenide dispersion.

Resin Ronin Tetrahydro 7ran 45 parts by weight Toluene 45 parts by weight Thereafter, the arsenic selenide dispersion prepared as described above was mixed to a thickness of 0.2
A charge generation layer was formed by applying a blade onto an aluminum plate of M with a gap of 60 .beta.m, and drying with etooC for 10 minutes at room temperature for 30 minutes. The film thickness after drying was 2 μm.

On the thus formed charge generation layer, the following resin solution B was applied with a blade with a gap of 200 μm, dried at room temperature for 5 minutes, and then dried at 100 tll' for 30 minutes to form a charge transfer layer. The film thickness after drying was 20 μm.

Resin liquid B Compound 433 of Table 1 4.5 parts by weight Silicone oil (trade name KF-50) 0.0001 parts by weight Dichloromethane 51 parts by weight The photoreceptor thus prepared was tested using a commercially available electrostatic copying paper tester (
16KV using KK Kawahi Nichi Denki Seisakusho 5P428 type
After performing corona discharge for 20 seconds to charge the photoreceptor, it was left in a dark place for 20 seconds, the surface potential Vpo at that time was measured, and then tungsten lamp light was applied until the illuminance of the photoreceptor surface was 4.5
The exposure amount E% was calculated by determining the time required for Vpo to reach H by irradiating the sample so as to achieve a certain lux. The results are shown below.

Vpo = -390V E3A = 0.54 ly/s, seconds Example 2 The following resin solution C was bladed onto an aluminum-deposited polyester film with a thickness of 100 μm with a gap of 10 μm, and dried at room temperature for 10 minutes to form an intermediate layer. Formed. The film thickness after drying was 0.2 μm.

Resin liquid C Ethyl alcohol 98 parts by weight Thereafter, a charge generation layer and a charge transfer layer were laminated on the intermediate layer in the same manner as in Example 1 to obtain Vp.

was measured and E% was calculated. The results are shown below.

Vpo = -430V E% = 0.71 Lux・sec Example 3 As the α-phenylstilbene compound of the charge transfer layer,
Vpo was measured in the same manner as in Example 2, except that Compound A37 of No. 1 was used, and E3 was calculated.

Vpo = -410V E3/2 = 0.69 Lux・sec Effect Compared to conventional arsenic selenide photoreceptors, the arsenic selenide dispersed type of the present invention has lower raw material costs and manufacturing costs, which is impossible with conventional methods. This made it possible to create a flexible belt-like photoreceptor.

High spectral sensitivity can be obtained at short wavelengths inherent to arsenic selenide.

[Brief explanation of the drawing]

1 and 2 are schematic cross-sectional views of the photoreceptor of the present invention.

Claims (1)

[Claims] 1. In an electrophotographic photoreceptor in which a charge generation layer and a charge transfer layer are laminated on a conductive substrate, the charge generation layer is an electron-donating organic binder layer in which arsenic selenide particles are dispersed. An electrophotographic photoreceptor having a charge transfer layer containing as an active ingredient at least one α-phenylstilbene compound represented by the following general formula. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R^1 is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group, R^2, R^3 and R^4 represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group, Ar^1 represents a substituted or unsubstituted aryl group, and Ar^2 represents a substituted or unsubstituted aryl group. Represents a substituted or unsubstituted arylene group. Ar^1 and R^1 may jointly form a ring. n is an integer of 0 or 1.)