JPS6361259A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To make the preparation of a photosensitive body inexpensive and convenient by using a polymer of a heterocyclic 5-membered compd. and/or a polymer of aniline for a component of a charge generating layer. CONSTITUTION:A charge generating layer of a photosensitive body contains a polymer of (A) heterocyclic 5-membered compd. or a polymer of (B) aniline. Suitable component (A) is thiophene, tellurophene, selenophene or derivs. thereof, and suitable component (B) is aniline or its deriv.; both can be polymerized electrochemically or chemically. These polymers are preferred to be doped with a dopant. Preferred dopant is a divalent anion (e.g. decachloro decaborate anion). It is preferred that the charge transfer layer contains an oxadiazole compd., hydrazone compd., and/or a pyrazoline compd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic photoreceptor. More specifically, the present invention relates to a laminated electrophotographic photoreceptor using an organic photoconductive material.

[Conventional technology]

Conventionally, inorganic photoconductive compounds such as selenium and cadmium sulfide have been used in electrophotographic photoreceptors, but in recent years, electrophotographic photoreceptors have been developed that are highly sensitive, durable, non-polluting, and highly productive. Various methods using electroconductive compounds have been proposed. In particular, various dyes such as phthalocyanine dyes, diazo dyes, and perylene dyes are used in the charge generation layer.
Various laminated electrophotographic photoreceptors have been proposed in which a charge transfer layer is made of oxadiazole, hydrazone, pyrazoline, polyvinylcarbazole, or the like.

[Problem that the invention seeks to solve]

Electrophotographic photoreceptors using the above-mentioned organic photoconductive materials (unfortunately, the dyes used are generally insoluble or sparingly soluble in solvents, and when used, it is necessary to use a polymer or the like as a binder. However, there are problems in that operations such as cleaving the particle size of the dye, mixing it with a binder, and applying it to a substrate, drum, etc. are complicated.

[Means for solving problems]

The present inventors have diligently searched for a new electrophotographic photoreceptor that solves the above problems, and have completed the present invention.

That is, the present invention provides an electrophotographic photoreceptor formed of at least two layers, a charge generation layer and a charge transfer layer, in which a five-membered heterocyclic compound polymer and/or an aniline polymer is used as the charge generation layer. This is a characteristic electrophotographic photoreceptor.

What is important in the present invention is that the charge generation layer is composed of a five-membered heterocyclic compound polymer and/or an aniline polymer.

Here, the 5-membered heterocyclic compound polymer is a polymer of thiophene, pyrrole, furan, tellophene, selenophene, and their derivatives, and the aniline polymer is a polymer of aniline and its derivatives. These polymers can be obtained by electrochemically or chemically polymerizing the monomers according to conventional methods such as those introduced in Kagaku Vol. 40, No. 10, pages 60-61. .

Usually these polymeric layers are formed on a conductive support such as a sheet or drum of aluminum. However, since many of these polymer layers themselves are electrically conductive, an insulating support may also be used.

Moreover, these layers can be formed by polymerizing with a polymer having adhesive properties according to a conventional method in order to strengthen the adhesiveness with the support, if necessary.

In the electrophotographic photoreceptor of the present invention, the five-membered heterocyclic compound polymer or the aniline polymer can be used without being doped with a dopant, but it is preferable to use it in a state where it is doped with a dopant. In particular, when the polymer is produced by the above electrochemical method or chemical method, the polymer is obtained in a doped state with a dopant and can be suitably used as it is. Further, if necessary, it can be used by dedoping, or by doping with another dopant after dedoping.

Examples of dopants include electrolytes used in electrochemical polymerization methods such as lithium borofluoride, dilithium decachlorodecaborate, dilithium dodecachlorododecaborate, and iron chloride (■).
Examples include Lewis acids such as ruthenium (III) chloride and molybdenum chloride (TV), and oxidizing agents used in other chemical polymerization methods.

Furthermore, halogen, halogen compounds, sulfur dioxide, etc. can also be used as separate dopants. Among these dopants, equivalent anions such as decachlorodecaborate anion and dodecachlorododecaborate anion are particularly preferred dopants.

The electrophotographic photoreceptor of the present invention is formed by providing a charge transfer layer overlapping the above-described charge generation layer. As the charge transfer layer, polycyclic aromatic compounds such as anthracene, pyrene, and phenanthrene, nitrogen-containing compounds such as indole, carbazole, oxazole, isoxazole, thiazole, imidazole, pyrazole, oxadiazole, pyrazoline, thiadiazole, triazole, and hydrazone are used. It is formed by dispersing it in a resin with good film-forming properties and forming it into a film.

Examples of compounds used in the charge transfer layer include oxadiazole compounds represented by the following formula (1), hydrazone compounds represented by the following formula (II), and birapurin compounds represented by the following formulas (II) and (IV). This is a particularly preferred compound.

(In the formula, R represents the same or different alkyl group.) (In the formula, R
represent the same or different alkyl groups. ) (In both formulas, R represents the same or different alkyl group, and X represents a pyridyl group, a quinolyl group, or an aryl group.) The resins used in this case include acrylic resin, polyarylate, polyester, and polycarbonate. , polyvinyl butyral, etc.

In the present invention, the charge transfer layer can also contain various additives, such as diphenyl, terphenyl, diphenyl chloride, dibutyl phthalate, dioctyl phthalate, triphenyl phosphoric acid, methylnaphthalene,
Examples of additives include benzophenone and the like.

In the present invention, in order to prevent the injection of free charges from the conductive support to the charge generation layer and further improve the adhesion between the charge generation layer and the conductive support, the charge generation layer and the conductive support are In between, aluminum oxide, indium oxide, tin oxide, polypropylene, acrylic resin, methacrylic resin, vinyl chloride resin, epoxy resin, polyester resin,
A layer made of alkyd resin, polyurethane, polyimide resin, etc. can also be provided.

〔Example〕

The present invention will be explained in more detail with reference to Examples below.

Example-1 Lithium borofluoride (0.5 mol/l) was added as an electrolyte in benzonitrile under a nitrogen atmosphere in a polymerization container with conductive glass (Nesa Glass) attached to the anode and a nickel plate attached to the cathode.
), and after adding thiophene (3 mol/l), I
When an OV voltage was applied for 20 seconds, a blue film was formed on the Nesa glass.

After washing with acetonitrile, a polythiophene layer doped with borofluoride ions and having a thickness of about 1 μm was obtained, which was used as a charge generation layer.

Next, 2,5-bis[4-(diethylamino)phenyl]
1 part by weight of oxadiazole, 1 part by weight of saturated polyester resin (Toyobo Kasai Byron 200), 1 part by weight of chloroform
A solution dissolved to 0 parts by weight was applied onto the charge generation layer by a film applicator method and dried at 80°C for 30 minutes to form a charge transfer layer with a thickness of 10 μm. The laminated electrophotographic photoreceptor thus obtained was statically charged with a corona at +6 KV using Kawaguchi Electric's side electrostatic paper analyzer 8100, and then placed in a dark place for 2 hours.
After holding for a second, it was exposed to light at an illuminance of 10 lux to examine charging characteristics.

Initial potential Vo (V), potential retention rate V2/ in the dark for 2 seconds
Charging characteristics are shown with VO (%) and half-decreased exposure amount of 8% (1ux·sec).

Vo: +613V V2/VO: 90% E IA: 42.5 1ux-sec Example-2 Example-1 except that dilithium decachlorodecaborate was used instead of lithium borofluoride in Example-1.
In the same manner as in Example 1, a polythiophene layer doped with decachlorodecaborate anions and having a thickness of about 1 μm was formed, and this was used as a charge generation layer.

Next, a charge transfer layer was formed in the same manner as in Example 1, except that 4-(diethylamino)benzaldehyde diphenylhydrashene was used as the charge transfer substance.

The charging characteristics of the electrophotographic photoreceptor thus obtained are shown below.

Vo: +516V V2/VO: 91% E'A: 44.0 1ux-sec Example-3 Dissolve 10 parts by weight of iron (III) chloride hexahydrate in 75 parts by weight of water, and add 10% polyvinyl alcohol to this. 20 parts by weight of an aqueous solution was added.

After applying the above solution on a glass plate and drying it, leave it under pyrrole vapor for 5 minutes to obtain a polypyrrole film with a thickness of about 1 μm. This was thoroughly washed with methanol to form a charged native layer.

Next, a charge transfer layer was formed in the same manner as in Example 1, and the charging characteristics of the resulting photoreceptor were examined.

Vo: +909V ■2/■o: 94% EV2: 81 1ux-sec Example-4 Chloroform solution of anhydrous iron (III) chloride (9% by weight)
was applied onto glass in the same manner as in Example 3, and treated under aniline vapor to obtain a polyaniline film. Example-3 except that this polyaniline film was used as a charge generation layer
When the same conditions as above were used, the following charging characteristics were obtained.

"o: +870 V V2/VO: 90% E', 4: 110 1ux-sec [Effects of the Invention] The electrophotographic photoreceptor of the present invention can be used not only in electrophotographic copying machines, but also in laser printers, CRT printers, It can be widely used in electrophotographic application fields such as electrophotographic plate making systems.

The electrophotographic photoreceptor of the present invention can be manufactured easily and inexpensively without using expensive dyes, and has relatively high sensitivity, making it extremely valuable industrially.

Claims (1)

[Scope of Claims] 1) In an electrophotographic photoreceptor formed of at least two layers, a charge generation layer and a charge transfer layer, a five-membered heterocyclic compound polymer and/or an aniline polymer is used as the charge generation layer. An electrophotographic photoreceptor characterized by: 2) The electrophotographic photoreceptor according to claim 1, wherein the charge generation layer is a 5-membered heterocyclic compound polymer and/or an aniline polymer doped with a dopant. 3) The electrophotographic photoreceptor according to claim 2, wherein the dopant is a divalent anion. 4) The electrophotographic photoreceptor according to any one of claims 1 to 3, wherein the charge transfer layer is a layer containing an oxadiazole compound, a hydrazone compound, and/or a pyrazoline compound.