JPS6292961A - Laminated electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain the titled body having a high sensitivity by laminating an electrostatic charge generating layer contg. a specific benzopyrilium salt and a brominated poly-N-vinylcarbazole, and an electrostatic charge transfer layer contg. a poly-N-vinylcarbazole on a substrate body. CONSTITUTION:The titled body having a high sensitivity is obtd. by laminating the electrostatic generating layer contg. the benzopyrilium salt having a monomethine structure and shown by the formula and the brominated poly-N- vinylcarbazole, and the electrostatic charge transfer layer contg. the poly-N- vinylcarbazole on a conductive substrate. In the formula, R1 is a hydrogen atom, a phenyl or an ethynyl group such as a styril, a p-methoxystyril or a alpha-phenyl-p-methoxystyril group, R2 is a hydrogen atom or a phenyl group, R3 is a hydrogen atom or a p-methoxyphenyl group, X1 and X2 are each an oxygen atom or a sulfur atom, Y is an anionic functional group.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a laminated electrophotographic photoreceptor containing an organic photoconductive substance.

2. Description of the Related Art Photoreceptors made of inorganic photoconductive substances such as selenium, selenium-tellurium alloy, cadmium sulfide, and zinc oxide have been widely used as electrophotographic photoreceptors. In recent years, research has been progressing on organic photoconductive substances that are easy to synthesize and have the ability to select compounds that exhibit photoconductivity in an appropriate wavelength range.

An electrophotographic photoreceptor using an organic photoconductive substance in the photosensitive layer is
It has advantages such as easy film formation, flexibility (high degree of design freedom), low cost, and non-polluting properties, making it possible to use electrophotography that is not possible with photoreceptors made of inorganic photoconductive materials. process (eg, using a belt-shaped photoreceptor).

Among these, in order to improve sensitivity and photoreceptor life, a laminated electrophotographic photoreceptor has been proposed in which the functions are separated into a charge generation layer and a charge transport layer to form a photoreceptor layer. Research is being actively carried out, including improvements to the method and development of sensitization methods (for example, in the proceedings of the 16th Electrophotography Society Conference).

Problems to be Solved by the Invention However, at present, the above-mentioned organic photoreceptors do not fully satisfy the requirements for various electrophotographic photoreceptors. Therefore, it is desired to develop a highly sensitive electrophotographic photoreceptor that fully satisfies the characteristics required for an electrophotographic photoreceptor by taking advantage of the advantages of organic photoconductive materials.

Means for Solving the Problems In view of the above-mentioned problems, the present invention provides a charge generation layer containing a henovirylium salt having a monomethine structure represented by the structural formula (1) and a brominated poly-N-ruvinylcarbazole. and a charge transport layer containing poly-N-vinylcarbazole are laminated on a conductive support to provide a highly sensitive electrophotographic photoreceptor.

(In the formula, R1 is hydrogen, phenyl group, styryl, p
- an ethynyl group such as methoxystyryl, α-quenylstyryl, α-phenyl to p-methoxystyryl,
R2 is hydrogen or phenyl group, R3 is hydrogen or p
-methoxyphenyl group, Xl, x2 represent oxygen or sulfur atoms, Y represents an anionic functional group).

Function The laminated electrophotographic photoreceptor of the present invention will be explained in detail below.

The charge generation layer of the laminated electrophotographic photoreceptor of the present invention comprises a henzobyrylium salt having a monomethine structure and a brominated polyamide.
It can be obtained by adding N-vinylcarbazole or a suitable binder resin, dispersing or dissolving it, and coating it on a conductive support. Specifically, hendpyrylium salts having a monomethine structure include:
2-[(2'-phenyl-4'-hensohyranyritene)
Methyl-phenylbenzopyrylium perchlorate, 2-((2'-styryl-4'-hensohyranylidene)methyl]-3-phenylbenzopyrylium perchlorate, 2-((2'-p -Metkinstyril-4゛-
benzopyranilidene)methyl]henzobilylium perchlorate, 2-((2'-p-methoxystyryl-4'
-henzobyranylidene)methyl]-3-phenylhenzobilylium perchlorate, 1-((4'-henzothiapyranylidene)methyl2-3-phenylbenzobilylium perchlorate, 2-((2'-αα -phenylsunarylu-4'-henzovilanylidene)methyl-3-phenylbenzobilylium verchlorate, 2-((2'-
α-phenyl-p-methoxystyryl-4'-henzopyranylidene) methylcy 3-phenylhenzobilylium verchlorate, 2-C(2'-phenyl-4'-henzothiapyranylidene) methyl 3- Phenylbenzopyrylium verchlorate, 2-((2'-phenyl-4
'-Benzothiapyranylidene)methyl)-4-p-methoxyphenylhenzthiapyrylium verchlorate, 2
-((2'-phenyl-4'-henzothiapyranylidene)methyl]-3-phenyl-4-p-methoxyphenylhenzothiapyrylium verchlorate can be used. Brominated poly-N-vinylcarbazole is One carbazole ring is substituted with 0.5 to 2 bromines, and poly-N-vinylcarbazole is prepared in a mixed solvent of chloroheme-benzene in the presence of a small amount of hendiyl peroxide. It can be easily synthesized by treating with an equivalent amount of N-bromsuccinimide, heating, and then dissolving in methanol. Brominated poly-N-vinylcarbazole can be prepared in a proportion of 0 to 1 part by weight of benzopyrylium salt. .1 to 5 parts by weight, preferably 0.5 to 1 part by weight.Furthermore, although brominated poly-N-vinylcarbazole alone has film-forming properties, it also improves the adhesion between the charge generation layer and other layers. A binder resin can be used as necessary for the purpose of improving the uniformity of the coating film, adjusting fluidity during coating, etc.

Specifically, polyvinyl butyral, polyvinyl acetate,
Examples include polyvinyl chloride, polycarbonate, acrylic resin, methacrylic resin, and copolymers of these resins. The amount of binder resin used is preferably 50% by weight or less of the weight of the charge generation layer. Also, brominated poly-N
- Solvents that dissolve vinyl carbazole and binder resin are limited to brominated poly-N-vinyl carbazole, but specifically include halogenated hydrocarbons such as chloroform, methylene chloride, and ethylene dichloride, and chlorohemein. Halogenated aromatics and the like can be used. The coating liquid thus dispersed and prepared is applied by a normal coating method and dried by heating to form a charge generation layer with a thickness of several μm, preferably 0.12 to 2 μm. Good.

The charge transport layer of the laminated electrophotographic photoreceptor of the present invention can be obtained by coating the charge generation layer with a coating liquid in which poly N-vinylcarbasol is dissolved as a charge transport agent. Specifically, aromatic hydrocarbons such as toluene and xolene can be used as the solvent for preparing the coating liquid.

The thus prepared coating solution is applied by a conventional coating method and dried by heating to form a charge transport layer having a thickness of several μm to several tens of μm, preferably 5 to 25 μm.

The conductive support used in the laminated electrophotographic photoreceptor of the present invention may be any conventionally known conductive support, including metal plates and drums made of aluminum, aluminum alloy, tin oxide, tin oxide, etc. These include plates made of metal oxides such as indium, or various plastic films made by attaching such metals and metal oxides by vacuum evaporation, sputtering, lamination, coating, etc. and treated to make them conductive.

Furthermore, the charge generation layer and the charge transport layer constituting the laminated electrophotographic photoreceptor of the present invention have flexibility, uniformity,
In order to improve mechanical strength, etc., plasticizers such as 0-terphenyl, epoxy compounds, phthalic esters, maleic esters, and chlorinated halaffins may be added. Further, as in a typical electrophotographic photoreceptor, an adhesive layer or barrier layer of casein, polyvinyl alcohol, polyvinyl butyral, etc. can be provided between the conductive layer and the charge generation layer.

The electrophotographic photoreceptor of the present invention, which is formed by laminating the charge generation layer and the charge transport layer on the conductive support in this way,
A charge generation layer and a charge transport layer may be sequentially laminated on a conductive support, or a charge transport layer and a charge generation layer may be sequentially laminated on a conductive support. The former has sensitivity when charged negatively, and the latter has sensitivity when charged positively, but the former is more desirable in terms of surface film strength and durability.

EXAMPLES The present invention will be explained below using examples, but the present invention is not limited to the combinations shown in the examples below.

[Example 1] 1 part by weight of brominated poly-IJ-N-vinyl Rubadur and 0.05 part by weight of vinyl chloride-vinyl acetate copolymer (manufactured by Union Carbide Co., trade name: VMCH)
2-phenyl-4'-benzobylanylidene)methyl]-
1 part by weight of 3-phenylbenzobilylium verchlorate was dissolved in 100 parts by weight of ethylene dichloride. This coating liquid was spin-coated onto an aluminum plate at 300 rpm and heated to 80'C.
The mixture was dried for 1 hour to form a charge generation layer with a thickness of 0.3 μm.

Next, 1 part by weight of PoIJ-N-vinyl hydrazur (manufactured by Anan Koryo ■, trade name: Ambikol #210) and 0.3 mi part of 0-terphenyl were dissolved in 10 ffl parts of toluene. Apply this solution onto the charge generation layer with a blade and heat it to 80°C.
The mixture was dried for 1 hour to form a charge transport layer with a thickness of 15 μm.

The surface potential v0 when the thus obtained laminated electrophotographic photoreceptor was charged at -5.5 KV using an electrostatic copying paper testing device (EPA-8100 manufactured by Kawaguchi Electric Seisakusho ■)
(V), surface potential V when left in a dark place for 1 second
, (V), 5] ux, the exposure amount E% (
lux −5ec) were measured. The measurement results are shown in Table 1.

[Example 2] 2-[(2'-α- phenyl-p
-Methoxystyryl-4'-henzobyranylidene)methyl]-3-phenylbendupyrylium perkate was used, but a photosensitive plate was prepared and its properties were measured using the same composition and method as in Example 1. I did it. The results are shown in Table 1.

[Example 3] 2-((2'-phenyl -4'-
A photosensitive plate was prepared using the same composition and method as in Example 1, except that benzothiapyranylidene)-4-p-methoxyphenylbenzothiapyrylium perchlorate was used.
Characteristics were measured. The results are shown in Table 1.

[Example 4] In place of 2-((2'-phenyl-4'-benzohyranylidene)methyl]-3-phenylhenzovirylium perkate in Example 1, 2-((2'-phenyl- 4'-
Henzothiapyranylidene)methyl]-3-phenyl-4
A photosensitive plate was prepared and its properties were measured using the same composition and method as in Example 1, except that -p-methoxyphenylbenzothiapyrylium perchlorate was used. The results are shown in Table 1.

[Example 5] For comparative experiments, brominated poly-N-
A sample was prepared with a composition that did not contain vinyl carbazole.

1 part by weight of vinyl chloride-vinyl acetate copolymer (manufactured by Union Carbide, trade name VMCH) and 2-((2'-
Phenyl-4'-benzobylanylidene)methyl]-3-
Fenylbenzvirylium Hari o L/r 1
7 parts by weight of 100 parts by weight of ethylene dichloride were dissolved.

A charge generation layer was formed using this coating liquid in the same manner as in Example 1. Further, the charge transport layer was also formed using the same composition and method as in Example 1.

The measurement results of the laminated electrophotographic photoreceptor thus obtained are shown in Table 1.

(Leaving space below) Table 1 Effects of the Invention As above, the laminated electrophotographic photoreceptor of the present invention has been explained in detail. Poly-N
- a charge generation layer containing vinylcarbazole, and a charge transport layer containing poly-N-vinylcarbazole,
High sensitivity was achieved by laminating the film on a conductive support.

Claims (2)

[Claims] (1) A charge generation layer containing a benzopyrylium salt having a monomethine structure represented by the following structural formula (I) and a brominated poly-N-vinylcarbazole;
A laminated electrophotographic photoreceptor characterized by being formed by laminating a charge transport layer containing vinyl carbazole on a conductive support ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (I) (in the formula, R_1 is hydrogen, phenyl group or styryl,
Ethenyl groups such as p-methoxystyryl, α-phenylstyryl, α-phenyl-p-methoxystyryl, R_2 is hydrogen or phenyl group, R_3 is hydrogen or p-methoxyphenyl group, and X_1 and X_2 are oxygen or sulfur atoms. and Y represents an anionic functional group). (2) The laminated type according to claim 1, wherein the brominated poly-N-vinylcarbazole is substituted with 0.5 to 2 bromines per carbazole ring. Electrophotographic photoreceptor.