JPS59128550A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve electric characteristics by forming a photoconductive layer on a photoconductive interlayer obtained by dispersing a specified trisazo pigment formed on a conductive substrate. CONSTITUTION:A photoconductive layer made of Se, an Se alloy, or an Se compd. is formed on an interlayer obtained by dispersing fine particles of a trisazo pigment represented by formula I (X is an aromatic ring, such as benzene or naphtalene ring, or a hetero ring, such as indole or carbazole ring, or a substitute of them; Ar1 is an aromatic or hetero ring; Ar2 is an aromatic ring; R1 is H, lower alkyl, or phenyl; and R2 is lower alkyl, COOH, or ester) into an insulating resin. As a result, electric characteristics are stabilized even when dispersion conditions of the dispersed particles are varied or the photoconductive layer is repeatedly used and a sensitizing effect, a crystallization restraining effect, and a flexibility enhancing effect are also obtained by the presence of the interlayer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor having a photoconductive intermediate layer between a support and a selenium-based photoconductive layer.

2. Description of the Related Art Electrophotographic photoreceptors are known in which a conductive support is provided with an intermediate layer in which inorganic or organic fine particles are dispersed as dispersoids in an insulating resin binder, and a selenium-based photoconductive layer is provided thereon. In an electrophotographic photoreceptor having such a layered structure, the purpose of the intermediate layer is to improve the adhesiveness between the support and the photoconductive layer and to improve the electrical properties. Intermediate layers are generally divided into two types, low-resistance interlayers and photoconductive interlayers, depending on the type of particles dispersed in the binder.6 An example of the former is one using carbon as a dispersoid (Unexamined Japanese Patent Publication No. (Japanese Patent Publication No. 126339/1983) and those using metals or chalcogen compounds (Japanese Patent Publication No. 54-3)
No. 6859] An example of the latter is one using phthalocyanine (Japanese Patent Publication No. 44-12671). However, in the former intermediate layer, electrical properties such as charging properties and residual potential of the photoreceptor vary greatly depending on dispersion conditions. Therefore, controlling the dispersion conditions is a challenge. On the other hand, when the dispersoid in the latter intermediate layer is a 7-talocyanine pigment,
A drawback is that the electrical properties, especially the residual potential, fluctuate during repeated use. In addition, other intermediates that do not belong to the above categories! : A resin made of an amorphous resin alone without using a dispersoid is known (Japanese Patent Application Laid-open No. 103742/1983).

The purpose of this intermediate layer is to inhibit crystallization in the photoconductive layer provided thereon, and is different from the above two types of intermediate layers.

The purpose of the present invention is to ensure that the electrical properties of the dispersed particles used in the intermediate Ill are stable even under dispersion conditions, repeated use, and use, and that the sensitizing effect of the intermediate Ill, the crystallization suppressing effect, and the improvement of flexibility are achieved by improving adhesiveness. It is an object of the present invention to provide an electrophotographic photoreceptor having excellent t'L electron properties as well as effects.

That is, the present invention provides an intermediate layer made of fine particles of an organic pigment dispersed in an insulating resin on a conductive support, and a photoconductive layer made of selenium, a selenium alloy, or a selenium compound thereon. In the electrophotographic photoreceptor, the organic pigment has the general formula (where X represents an aromatic ring such as a benzene ring or a naphthalene ring, or a hetero ring such as an indole ring, a carbazole ring, or a benzofuran ring, or a substituted product thereof;
Ar1 represents an aromatic ring such as a benzene ring or a naphthalene ring, a dibenzofuran ring, a heterocycle, or a substituted product thereof; %Arc is a benzene ring, a naphthalene 3!1l
fx represents any aromatic ring or its substituents; slR+
represents hydrogen, a lower alkyl group, a phenyl group, and a symbol represents a substituent thereof; ). ] It is characterized by being a trisazo pigment shown in the following.

In addition, the substituent on the aromatic ring or heterocycle of group, low i dialkylamino group, carxyl group, sulfonic acid group or 7
'( is a salt thereof, etc. Substituents on the aromatic ring of Ar2 include, in addition to the substituent in Arl 171:, an acylamino group, -80, NH2, etc.
Examples of the substituent on the phenyl group of t include halogen.

The present invention thus uses a trisazo pigment represented by the above general formula as a dispersoid in the intermediate layer of an electrophotographic photoreceptor having a conductive support, an intermediate layer, and a photoconductive layer. As a conductive support. is a plate made of metal or metal oxide such as AJ, Ni, stainless steel; AJ, Pd
, synthetic paper coated with metals such as Au, insulating sheets such as plastic films; polymeric quaternary ammonium salts;
Paper or cloth impregnated with a conductive substance such as polystyrene sulfonate is used.

The intermediate layer is mainly composed of a freezing resin and a trisazo pigment of the general formula 1C5. Examples of insulating resins include epoxy resin, acrylic resin, polyimide, and boria ε.
Examples include polyester, zotyral resin, polyester, etc.
Among them, polyester and butyral resins give particularly good results. It is also possible to use two or more types of insulating resins for the purpose of supplementing the unique characteristics of these resins. On the other hand, specific examples of trisazo pigments include the following.

In addition, during the ceremony It is written as

The above trisazo pigment can be easily produced by any reaction according to a known method, for example (X, Arl, Arc *R1 and R3 are the same as above).

The amount of the trisazo pigment thus obtained dispersed in the insulating resin is 1 to 50 weight equivalents.

If the amount of dispersion is too large from the above range, the adhesiveness will be reduced, resulting in a loss of flexibility improvement effect, and if the amount is too small, the residual potential will increase. The thickness of the intermediate layer is suitably 5 microns or less, preferably 1 to 3 microns.

Note that the intermediate theory of the present invention includes other than the above two components.

Other dispersoids may be added to improve and stabilize various properties.

The photoconductive layer is composed of selenium, a selenium alloy, or a selenium compound. As a selenium alloy or selenium compound... is 8
eTe, Aa2Sam, Be-B1 alloy, 5s-8b
Examples include alloys. The thickness of the light guide tNi is suitably 100μ or less, preferably 10 to 70μ.

To make the photoreceptor of the present invention, an insulating resin solution in which the trisazo pigment is dispersed is coated on a conductive support and dried to form an intermediate layer, and selenium, a selenium alloy, or a selenium compound is deposited on the intermediate layer. A photoconductive layer may be formed.

The present invention will be explained below by way of examples.

Example 1 Butyral resin (XYHL manufactured by Union Carbide) 4
Part by weight was dissolved in 11 parts by weight of tetrahytronane in a glass pot, and then the compound, 1 part by weight of trisazo pigment No. 45, and stainless steel Zeel were added thereto, and 7
I gelled for 2 hours. 34 parts by weight of tetrahydrofuran was added to the obtained dispersion liquid to prepare an intermediate layer forming liquid.Next, this liquid was coated on a stainless steel (SUS304) support so that the thickness after drying was 1 μm. An electrophotographic photoreceptor was prepared by drying at ℃ for 1 hour to form an intermediate layer, and then vacuum-depositing selenium on the intermediate layer to form a photoconductive layer of amorphous selenium with a thickness of 60 μm. Shift
-B For comparison, the butyral resin 1 was used as the intermediate layer forming liquid.
1! An electrophotographic photoreceptor was produced in the same manner except that a solution in which the :it part was dissolved in 9 parts by weight of tetrahydrofuran was used.

Next, we tested the electrophotographic characteristics of the above two types of photoreceptors, and obtained the results shown in the table below.

Note) VM: Surface potential when a 5KV corona discharge is applied to the sample surface for 20 seconds.

D, D: Vo/Vt cr) value (Vo is the surface potential when dark decayed for 20 seconds).

E%: After dark decay, the surface is irradiated with light using a tungsten lamp so that the surface illuminance becomes 20 uX, and the amount of exposure required to bring the surface potential to Vo.

■Surface potential after 20 seconds of R two-point light irradiation.

As can be seen from this table, the effect of the intermediate layer in which the trisazo pigment is dispersed in the photoreceptor of the present invention is clear, and in particular, a remarkable effect is observed in reducing the residual potential.

Example 2 Polyester (Dupont Exhibition Polyester Adhesive)
In a glass pot, 9 parts were dissolved in 23 parts by weight of tetrahydrofurine, and 1 part by weight of trisazo pigment of compound 417 and Example 1. ! : The same stainless steel gel was added and heated for 72 hours. Further, 63 parts by weight of tetrahydrofuran was added to the obtained solid dispersion to prepare an intermediate layer forming liquid. Next, this solution was coated on the same support as in Example 1 so that the thickness after drying would be 3μ, and dried at 100°C for 1 hour. -, and then vacuum-deposited a 5e-Te alloy with a Te content of 8 to a thickness of 60
A photoreceptor was prepared by forming a photoconductive layer consisting of amorphous 5e-1'e of fc6. For comparison, β-copper phthalocyanine was substituted for the trisazo pigment in the intermediate layer forming solution. An electrophotographic photoreceptor was produced in the same manner except that .

Next, these photoreceptors are set in a commercially available electrophotographic copying machine,
When a repeated use test was conducted, the initial residual potential of the comparative product increased from 20V to 110V by approximately 90V, whereas no fluctuation in the residual potential was observed in the product of the present invention.

Procedural amendment March 10, 1982 Mr. Kazuo Wakasugi, Commissioner of the Patent Office 1.Display of the incident 1981 Patent Application No. 5124 2. Name of the invention electrophotographic photoreceptor 1-3-6 Nakamagome, Ota-ku, Tokyo (674) Rico Co., Ltd. Representative Takeshi Oue 4. Deputy manager 5. Subject of correction “Detailed description of the invention” column in the specification Contents of correction (1) The compound in question on page 17 " Correct.

Correct to A r t J A r 1 J.

that's all

Claims (1)

[Claims] 1. An intermediate layer formed by dispersing fine particles of an organic pigment in an insulating resin on a conductive support, and further a photoconductor made of selenium, a selenium alloy, or a selenium compound thereon. In the electrophotographic photoreceptor, the organic pigment has a general formula (where X is an aromatic ring such as a benzene ring or a naphthalene ring, or an indole ring, a carbazole ring, a benzofuran ring,
Heterocycles such as prefectures represent their substitution products, and A
r1 represents an aromatic ring such as a benzene 331° naphthalene ring or a hetero ring such as a dibenzofuran ring, or a substituted product thereof 17% Arz represents an aromatic ring such as a benzene ring or a naphthalene ring or a substituted product thereof kRl is hydrogen , a lower alkyl group, a phenyl group or a substituent thereof; R1 represents a lower alkyl group, a phenyl group, a carzexyl group or an ester thereof; ). ] An electrophotographic photoreceptor characterized by being a trisazo pigment represented by the following.