JPS60258549A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an org. photosensitive body having high sensitivity and sensitivity from a long wavelength to a visible light region by laminating an electrostatic charge generating layer contg. the resulted product of reaction of benzopyrilium salt and benzopyran deriv. and electrostatic charge transfer layer contg. an electron donative material. CONSTITUTION:The liquid prepd. by dissolving the resulted product of reaction obtd. by heating the benzopyrilium salt and benzopyran deriv. expressed by formulas I, II (R1 is aliphat. group selected from styryl, p-methoxystyryl, omega- phenyl butadienyl or the arom. group selected from phenyl, p-methoxyphenyl, R2 is H or phenyl, R3 is H or OCH3) for several hours into CHCl3 is coated on a conductive substrate such as Al substrate and is dried to form the charge generating layer. The charge transfer layer contg. the electron donative material is laminated thereon to provide the photosensitive layer. The electrophotographic sensitive body having the high sensitivity from the long wavelength to the visible light region is thus obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to electrophotographic photoreceptors containing organic photoconductive materials.

Conventional Structures and Problems Traditionally, photoreceptors made of inorganic photoconductive materials such as selenium, selenium-tellurium alloy, cadmium sulfide, and zinc oxide have been widely used as electrophotographic photoreceptors. Electrophotographic photoreceptors using conductive substances in the photosensitive layer have been studied, and various proposals have been made.

Compared to inorganic photoreceptors, organic photoreceptors using organic photoconductive substances have advantages such as being easier to form a film, having greater flexibility and freedom in design, being inexpensive and non-polluting. However, they had the disadvantage of being inferior to inorganic photoreceptors in terms of sensitivity and photoreceptor life.

As a solution to this problem, a laminated electrophotographic photoreceptor was proposed in which the photosensitive layer is formed by separating the functions of a charge generation layer and a charge transfer layer, and research is actively progressing and some of them have even been put into practical use. It's arrived.

However, many of these laminated electrophotographic photoreceptors are not satisfactory in terms of sensitivity, repeatability stability, etc., and at present, inorganic photoreceptors such as selenium and cadmium sulfide are still widely used.

Purpose of the Invention The purpose of the present invention is to provide a highly sensitive electrophotographic photoreceptor that is sensitive to long wavelength visible light by using a reaction product of a benzopyrylium salt and a benzobylane derivative in a charge generation layer. It provides:

Structure of the Invention The electrophotographic photoreceptor of the present invention comprises a charge generation layer containing a reaction product obtained by reacting a benzopyrylium salt represented by general formula (1) with a benzopyran derivative represented by general formula (2). It is characterized in that it is formed by laminating a charge transfer layer containing an electron-donating substance on a conductive support. Hereinafter, the electrophotographic photoreceptor of the present invention will be explained in detail.

(In the formula, R1 is an aliphatic group selected from styryl, P-methoxystyryl, and ω-phenylbutadienyl, or an aromatic group selected from phenyl and P-methoxyphenyl), and R2 is hydrogen or a phenyl group. , R3 represents hydrogen or a methoxy group. ) The charge generating substance used in the charge generating layer of the electrophotographic photoreceptor of the present invention has the general formula (1).
) is a reaction product obtained by heating the benzopyran derivative represented by the general formula (2) in a halogenated hydrocarbon for several hours. -25658. Benzopy IJ represented by general formula (1)
Representative examples of lithium salts include 2-(α-inpropyl-ω-butadienyl)penzohyrylium perchlorate, 2-P-methoxystyryl-3-phenylbenrypyrylium perchlorate, and 2-P-methoxystyryl- 3
-P-methoxyphenyl-8-methoxybenzopyrylium perchlorate), 2-P-methoxyphenyl-8-methoxybenzopyrylium perchlorate, and the like;
) Representative examples of benzopyran derivatives are 2-
(α-isopropyl-ω-phenylbutadienyl) = 2
-Methoxybenzobilane, 2-P-methoxysf')-2-methoxy/-3-phenylbenzohy77.2-P-
Me) quinstyryl-3-phenyl-2,8-dimethoxybenzobilane, 2-styryl-2-methoxy-3-phenylbenzobilane, and the like.

To form the charge generation layer of the electrophotographic photoreceptor of the present invention,
The reaction product may be used alone or mixed with a binder resin as needed, dissolved in a suitable solvent, and a coating solution obtained is applied and dried.

The binder resin in this charge generation layer is used as necessary for purposes such as improving adhesion with other layers, improving uniformity of the coating film, and adjusting fluidity during coating. polyvinyl acetate, polyvinyl chloride,
Examples include polyvinyl butyral, acrylic resin, methacrylic resin, polyester, and polycarbonate.

Solvents for preparing the coating solution include ethers of tetrahydrofuranate, chloroform, halogenated hydrocarbons such as 1,2-dichloroethane, dichloromethane, 1,1,2-trichloroethylene, methyl ethyl ketone, acetone, and cyclohexanone. Ketones such as ethyl acetate and butyl acetate, esters such as ethyl acetate and butyl acetate, halogenated aromatics such as chlorobenzene, cellosolves such as ethyl cellosolve and methyl cellosolve, etc., may be used as long as they can dissolve the reaction product. , they can be used alone or in combination. Of course, when using a binder resin, a solvent that can dissolve both is selected.

The coating solution thus prepared is applied by a conventional coating method and dried to form a charge generating layer with a thickness of several micrometers, preferably 0.2 to 2 micrometers.

Examples of electron-donating substances used in the charge transfer layer of the electrophotographic photoreceptor of the present invention include compounds having electron-donating groups such as alkyl groups, alkoxy groups, amino groups, and imide groups, anthracene, pyrene, and phenanthrene. Examples thereof include polycyclic aromatic compounds or derivatives containing them, and heterocyclic compounds such as indole, oxadiazole, carbazole, thiazole, pyrazolino, imidazole, and triazole, and derivatives containing them. Even if these electron-donating substances are low-molecular compounds, the size, volume, IJ-
N-vinyl carbazole may be a polymer compound typified by halogenated poly-N-vinyl carbazole, N-vinyl carbazole acrylic copolymer, polyvinylpyrene, etc. Among them, poly-N-vinyl carbazole , brominated poly-N-vinylcarbazole, and the like are suitable.

These electron-donating substances and binder resin are dissolved in a suitable solvent, coated using a conventional coating method, and dried to form a charge transfer layer. Well-known materials can be used, similar to those used in .

However, when the electron donating substance is a polymeric substance such as BoIJ N-vinylcarbazole, the charge transfer layer may be formed alone without mixing with a binder resin. The thickness of the charge transfer layer is from several μm to several tens of μm, preferably from 6 to 20 μm.

The conductive support used in the electrophotographic photoreceptor of the present invention may be any one having conventionally known conductivity.
Metal plates and drums such as aluminum, tin oxide,
These include plates made of metal oxides such as indium oxide, and various plastic films and papers to which these metals and metal oxides are attached by vapor deposition, spackling, lamination, coating, etc. and treated to make them conductive.

Furthermore, the charge generation layer and charge transfer layer constituting the electrophotographic photoreceptor of the present invention have flexibility of the coating film.

Conventional plasticizers may be added to improve uniformity 2 mechanical strength and the like. Examples of the plasticizer include orthoterphenyl, epoxy compounds, phthalate esters, maleate esters, chlorinated paraffins, chlorinated fatty acid esters, and the like. Further, if necessary, an adhesive layer or barrier layer such as casein, polyvinyl acetate, polyvinyl butyseal, etc. can be provided in the same manner as in ordinary electrophotographic photoreceptors.

The electrophotographic photoreceptor of the present invention, which is formed by laminating a charge generation layer and a charge transfer layer on a conductive support in this manner, has a charge generation layer and a charge transfer layer successively laminated on a conductive support. Alternatively, a charge transport layer and a charge generation layer may be laminated in this order on a conductive support. Since the charge transfer layer is formed by containing an electron-donating substance, the former case is sensitive to negative charges, and the latter is sensitive to positive charges, but from the viewpoint of surface film strength and durability. The former is more promising.

Description of Examples Examples of the present invention will be described below, but the present invention is not limited to the combinations shown in the following examples.

(Example 1) 2-P-meryldistyryl-3-phenylbenzopyrylium perchlorate and 2-styryl-2-methoxy-
The reaction product obtained by heating 3-phenylbenzopyranto in dichloroethane for several hours. ．． 1.9 was dissolved in 5 g of chloroform to prepare a coating solution. This coating liquid was applied onto an aluminum plate using a spinner, and dried at 60°C for 30 minutes, resulting in a coating amount of ○. A charge generation layer of 6Bjj/d was formed.

On top of this, a coating solution prepared by dissolving 3 g of poly-N-vinylcarbazole (trade name Rubican, manufactured by BASF) and 0.9 g of epoxy resin (trade name Epicor 828, manufactured by SHELL) in 3 Jj9 of toluene was applied with a blade at 80°C. After drying for 1 hour, a charge transfer layer with a coating amount of 14.0 gβ was formed to obtain a laminated electrophotographic photoreceptor. Next, this photoreceptor was charged at -eKV using an electrostatic copying paper testing device (Kawaguchi Electric Seisakusho Model 5P42B), and the charging potential v0 (v
), the surface potential is %■ when exposed to 201ux white light.
Exposure amount E% required to attenuate to o (lux-sea
), vo was -960V and E% was 81
It was tlx・Sec.

(Example 2) In Example 1, the chloroform in the coating solution in which the charge generation layer was formed was changed to 1,2-dichloroethane 1°y, and polycarbonate (trade name: Panrai, manufactured by Ryotaisha) K-1300 was further added to the coating solution. ) A photoreceptor was formed in the same manner as in Example 1 except that 0.11 was added. When the V E3A of this photoreceptor was measured in the same manner as in Example 1, the vo was -1085 IV and the E3A was 8.31 ux-sec.

(Example 3) Toluene 36g was added to 0.9g of HoIJ-N-hinylluhasol (BASF Co., Ltd. 5 product name Rubican)!! and epoxy resin (SHELL Co., Ltd. product name Epicoat 82 B).
．． The coating liquid dissolved in No. 9 was applied with a blade onto an aluminum plate, and after drying at 80'C for 1 hour, the coating amount was 15.6j.
A charge transfer layer of 9/r11'' was formed.

Furthermore, on top of this, 0.1 of the reaction product used in Example 1
j; l, 0.1 g of polycarbonate (trade name: Panlite-1300, manufactured by Ryotaisha) was mixed with 10.1 g of methyl ethyl ketone.
After applying the coating liquid obtained by dissolving it in J9 using a spinner, it was dried at 60°C for 30 minutes, and the coating amount was 0.25jj/
/r+1" charge generation layer was formed. This photoreceptor was charged at +6KV and measured in the same manner as in Example 1. ■. was 840V, and E3A was 5+51ux+sec.
Met.

Effects of the Invention The electrophotographic photoreceptor of the present invention has been described in detail above. A photosensitive layer is formed by stacking the charge transfer layer containing the photosensitive material and the photosensitive layer, which is highly sensitive and sensitive to long wavelength visible light.

Furthermore, the charge generation layer of the electrophotographic photoreceptor of the present invention is formed by dissolving the reaction product in a solvent and coating it, so there is no need for processes such as pigment dispersion, and the photosensitive layer has the advantage of being easy to prepare. have

Claims (1)

[Claims] A charge generation layer containing a reaction product obtained by reacting a benzopyrylium salt represented by the following general formula (1) with a benzopyran derivative represented by the following general formula (2), and an electron-donating substance. 1. An electrophotographic photoreceptor, characterized in that it is formed by laminating a charge transfer layer on a conductive support.