JPS63311257A - Organic photoconductive material for electrophotography - Google Patents

Abstract

PURPOSE:To improve charge transfer efficiency of an electrophotographic org. photoconductive material and to elevate its sensitivity by forming a charge transfer layer contg. a specified pyrazoline deriv. on a charge generating layer contg. X-type nonmetallophthalocyanine. CONSTITUTION:A charge generating layer 2 and a charge transfer layer 3 are formed successively on an electroconductive substrate 1, and a photosensitive layer 4 is constituted of the charge generating layer 2 and the charge transfer layer 3. X-type nonmetallophthalocyanine is contained in the charge generating layer 2, and a pyrazoline deriv. expressed by formula I is contained in the charge transfer layer 3. In formulas I and II, each R1 and R2 is H, aryl group, etc.; R3 is H, aromatic carbocyclic ring, etc. By this constitution, an electrophotographic org. photoconductive material having improved elec trifiability and photosensitivity as well as decreased residual potential is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an organic photoconductive material used for electrophotographic photoreceptors and the like.

[Conventional technology]

As photoconductive materials for electrophotography, those having a photosensitive layer containing as a main component an inorganic photoconductive material such as selenium, zinc oxide, or cadmium sulfide are widely known. However, these are not necessarily satisfactory in terms of properties such as thermal stability and durability, and furthermore, they have problems in production and handling due to their toxicity.

On the other hand, organic photoconductive materials for electrophotography having a photosensitive layer containing an organic photoconductive compound as a main component are relatively easy to manufacture, inexpensive, easy to handle, and are generally selenium-sensitive. It has many advantages, such as superior thermal stability compared to the body, and has attracted a lot of attention in recent years.

As such organic photoconductive materials for electrophotography, those comprising a charge generation layer containing a charge generation substance and a charge transport layer containing a charge transport substance on a conductive support are known. In this case, known charge generating substances contained in the charge generating layer include azo dyes, phthalocyanine dyes, anthraquinone dyes, perylene dyes, cyanine dyes, and thiapyrylium dyes. Known transport substances include amine derivatives, oxazole derivatives, oxadiazole derivatives, and triphenylmethane derivatives. Since many of these charge-generating substances and charge-transporting substances do not have the ability to form a film by themselves, they are dispersed in a binder to form a film.

However, organic photoconductive materials for electrophotography using the above-mentioned organic photoconductive compounds have a drawback in that sufficient sensitivity cannot be obtained compared to those using inorganic photoconductive compounds. For this reason, research is being actively conducted to obtain organic photoconductive compounds with good sensitivity. In such research, X-type metal-free phthalocyanine (X-82PC
) is known to have good photosensitivity.

(Problems to be Solved by the Invention) However, it is generally known that the characteristics of organic photoconductive materials for electrophotography change significantly depending on the combination of a charge-generating substance and a charge-transporting substance. Even when type-free metal phthalocyanine is used, for example, as a charge-generating substance, satisfactory characteristics cannot be obtained unless sufficient consideration is given to the charge-transporting substance to be combined with it. Therefore, at present, an organic photoconductive material for electrophotography using X-type metal-free phthalocyanine that has characteristics satisfying on a practical level has not yet been found.

An object of the present invention is to provide an organic photoconductive material for electrophotography using X-type metal-free phthalocyanine, which has good chargeability and photosensitivity, and has a small residual potential.

[Means for solving problems]

This invention provides an organic photoconductive material for electrophotography comprising a charge generation layer and a charge transport layer on a conductive support, wherein the charge generation layer contains an X-type metal-free phthalocyanine, and the charge transport layer It is characterized in that it contains a pyrazoline derivative represented by the following general formula (1).

(In the formula, R+ and R2 represent hydrogen, aryl, or alkyl, and R3 represents hydrogen, an aromatic carbocyclic ring, or a heterocyclic ring.) In the present invention, as described above, the X-type charge generating substance is Using metal-free phthalocyanine, the general formula (
By using the compound shown in 1), it is possible to obtain an organic photoelectric IX material for electrophotography having excellent properties.

Next, preferred embodiments of the present invention will be described in more detail.

The organic photoconductive material for electrophotography of the present invention is configured as shown in FIG. 1 or 2, for example. In FIG. 1, a charge generation layer 2 and a charge transport layer 3 are sequentially laminated on a conductive support 1, and a photosensitive layer 4 is constituted by the charge generation layer 2 and the charge transport layer 3. has been done. Further, in FIG. 2, a charge transport layer 3 and a charge generation layer 2 are sequentially laminated on a conductive support 1, and a photosensitive layer 4 is constituted by the charge transport layer 3 and the charge generation layer 2. There is.

As the conductive support 1, for example, a thin metal film such as aluminum, palladium, or gold, or a conductive coating such as indium oxide is formed on a metal plate such as # or Cu, or an insulating plate such as a conductive polymer or plastic. The formed one is used.

The charge generation layer 2 is formed by using X-type metal-free phthalocyanine (X-82PC) as a charge generation agent and dispersing it in a binder and applying it. In this case, binders include phenol resin, polyester resin, vinyl acetate resin, polycarbonate resin, polypeptide resin, cellulose resin, polyvinylpyrrolidone, polyethylene oxide, polyvinyl chloride resin, starch, polyvinyl alcohol, acrylic resin, etc. Polymer resins, methacrylic copolymer resins, silicone resins, polyacrylonitrile copolymer resins, polyacrylamide, polyvinyl butyral, and the like are preferably used. Further, the blending ratio of the binder and the charge generating agent is preferably about 1:1. Generally speaking, the thickness of the charge generation layer is preferably about 0.1 to 1 μm.

The charge transport layer 3 is formed by using a compound represented by the general formula (2) as a charge transport agent, and dispersing the compound in a binder and coating the compound. In this case, as a binder or
The same material as the charge generation layer 2 is used. Further, the blending ratio of the binder and the charge transport agent is suitably 1:1.

In the present invention, the X-type metal-free phthalocyanine used as a charge generating agent is disclosed in, for example, US Pat.
It can be easily synthesized from α-type metal-free phthalocyanine according to the method shown in No. 9.

Further, the compound represented by the general formula (1) used as a charge transport agent can be synthesized, for example, according to the method shown in Japanese Patent Publication No. 10366/1983.

Such an organic photoconductive material has good charge mobility in the charge transport layer and has high photosensitivity when used as a photoreceptor.

〔Example〕

Hereinafter, the effects of this invention will be clarified by showing examples.

(Example 1) X-type metal-free phthalocyanine (manufactured by Deuterochrome) was used as a charge generating material, and this and silicone resin rFs1001N were used.
J (trade name, manufactured by Shin-Etsu Chemical) in a weight ratio of 1:1, tetrahydrofuran was dissolved as a solvent, and the mixture was mixed and ground in a centrifugal mill for about 3 hours. This solution was applied to a thickness of about 0.5 μm on a conductive support made of aluminum using a doctor blade, and dried to form a charge generation layer.

In addition, as a charge transporting material, a pyrazoline derivative represented by the following chemical formula (1. 1.0 g of polycarbonate resin [Tubalex] (trade name, manufactured by Mitsubishi Kasei) was dissolved in 7.5 g of dichloromethane together with 1.0 g of a binder to prepare a coating solution.1. Coating and drying on the charge generation layer described in E to form a charge transport layer with a thickness of about 18 μm,
A photoreceptor was obtained.

The electrophotographic properties of this photoreceptor were measured using an electrostatic charging tester (EP).
A-8100, manufactured by YoNichiden Il) was used for evaluation.

After applying an electrostatic voltage of -5 to V to the conductive support and observing dark decay for 4 seconds, the wave fi! When 6GOn was irradiated with 1.10 lux light at 1081rrR and the optical attenuation characteristics were examined, the characteristics shown in FIG. 3 were obtained. Charge potential (vo) is -7
At 00■, the sensitivity (El/2) was 1.5 lux·sec and the residual potential (VR) was Ov, giving good results.

(Comparative Example 1) The procedure was carried out in the same manner as in Example 1 except that ogisazole was used as the charge transport material for forming the charge transport layer. ) was −740 V, the sensitivity (E112) was 2.0 Lux·sec, and the residual potential (VR) was Ov.

(Comparative Example 2) A photoreceptor was prepared in the same manner as in Example 1 except that Ogi diazole was used as the charge transport material for forming the charge transport layer, and the electrophotographic properties were evaluated in the same manner. The sensitivity (El/2) was 3.3 lux·sec, and the residual potential (VR) was -50V.

As described above, the photoreceptor containing the organic photoconductive material of the present invention had significantly higher sensitivity than the conventional comparative example.

〔Effect of the invention〕

As explained above, the organic photoconductive material of the present invention is
Type-free metal ivy [ ] Since a °fif charge transport layer containing a specific pyrazoline derivative is provided on a charge generation layer containing cyanine, the charge transport efficiency is improved and the sensitivity is high.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are both cross-sectional views showing an example of the structure of a structured photoconductive material for electrophotography according to the present invention, and FIG. 3 is a graph showing the electrophotographic characteristics of an example of the present invention. . 1... Conductive support, 2... Charge generation layer, 3... Charge transport layer. Applicant: Alps Electric Co., Ltd. Representative Katsutabe Kataoka Figure 1 Figure 2 Figure 3 Time C5ecJ

Claims (1)

[Scope of Claims] An organic photoconductive material for electrophotography comprising a charge generation layer and a charge transport layer on a conductive support, wherein the charge generation layer contains an X-type metal-free phthalocyanine, and the charge An organic photoconductive material for electrophotography, characterized in that the transport layer contains a pyrazoline derivative represented by the following general formula (1). ▲There are mathematical formulas, chemical formulas, tables, etc.▼...(1) (In the formula, R_1 and R_2 represent hydrogen, aryl, or alkyl, and R_3 represents hydrogen, an aromatic carbocyclic ring, or a heterocyclic ring.)