JPS59127043A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve the electrical characteristics of an electrophotographic sensitive body obtd. by successively forming an intermediate layer contg. fine particles of an org. pigment dispersed in an insulating resin and a photoconductive layer of an Se compound on an electrically conductive support by using a specified disazo pigment as the org. pigment. CONSTITUTION:An intermediate layer contg. fine particles of an org. pigment dispersed in an insulating resin and a photoconductive layer of an Se compound are successively formed on an electrically conductive support. At this time, a disazo pigment represented by formula I [where A is a group represented by formula II, III or IV (where each of X, Ar1 and Ar2 is a benzene ring or the like, R1 is H, lower alkyl or the like, and R2 is lower alkyl or the like)] is used as the org. pigment. The electrically conductive support is made of a metal such as Al or Ni, the oxide thereof, synthetic paper coated with the metal or metallic oxide, or the like. Since the intermediate layer consists essentially of the insulating resin and the disazo pigment represented by the formula I , the adhesive property of the photoconductive layer to the support and the electrical characteristics can be improved.

Description

[Detailed description of the invention] The present invention is between the support and the 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 thermal properties. The interlayer is generally 2' of the low resistance interlayer and the photoconductive interlayer depending on the type of particles dispersed in the binder.
It is broadly classified into mK. Examples of the former include those using carzene as a dispersoid (Japanese Unexamined Patent Publication No. 126339/1983) and those using a whole area or a chalcogen compound (Japanese Patent Publication No. 1983-126339).
36859), and an example of the latter is one using phthalocyanine (Japanese Patent Publication No. 12671/1983). 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 phthalocyanine pigment, there is a drawback that the electrical properties, particularly the residual potential, fluctuate during repeated use. Note that another intermediate layer that does not fall into the above category is known to consist of a non-crystalline resin alone without using a dispersoid (Japanese Patent Application Laid-open No. 103742/1983), but the purpose of this intermediate layer is to This is intended to suppress crystallization in the photoconductive layer provided above, and is different from the above two types of intermediate layers.

The purpose of the present invention is to have stable electrical properties even under the dispersion conditions and repeated use of the dispersed particles used in the intermediate layer, and also to have the effect of increasing flexibility due to the sensitizing effect, suppressing crystallization effect, and improving adhesiveness of the intermediate layer. Another object of the present invention is to provide an electrophotographic photoreceptor having excellent electrophotographic properties.

That is, in the present invention, an intermediate layer formed by dispersing fine particles of an organic pigment in an insulating resin is provided on a conductive support, and a photoconductive layer made of selenium, a selenium alloy, or a selenium compound is further provided 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; Ar represents an aromatic ring such as a benzene ring, a naphthalene ring, an anthracene ring, a hetero ring such as a dibenzofuran ring, a pyrene ring, a pyridine ring, a furan ring, a thiophene ring, a carpaf 4-ring, or a substituted product thereof;
c represents an aromatic ring such as a benzene ring or a naphthalene ring, or a substituted product thereof.

R3 represents hydrogen, a lower alkyl group, a phenyl group, or a substituted product thereof, and R2 represents a lower alkyl group, a phenyl group, a carbyl group, or an ester thereof. ) represents. ] It is characterized by being a disazo pigment shown in the following.

Examples of substituents on the aromatic ring or heterocycle of Examples of substituents on the aromatic ring of Arc include lower alkyl groups, nitro groups, and .logen groups.

The present invention uses the disazo 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 the conductive support, for example, a plate made of a metal such as At, Ni, stainless steel or a metal oxide; A I-,
Insulating sheets such as synthetic paper and plastic films coated with metals such as Pd and Au; paper or cloth impregnated with conductive substances such as polymeric quaternary ammonium salts and polystyrene sulfonates are used.

The intermediate layer is mainly composed of an insulating resin and a disazo pigment of the above general formula. Examples of the insulating resin include epoxy resin, acrylic resin, polyimide, polyamide, butyral resin, and polyester, among which 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 properties of these resins. On the other hand, specific examples of disazo pigments include the following.

The above-mentioned disazo pigment can be easily produced according to a known method, for example, by reaction with (in the formula, X, Ar4.Arc, R, and R2 are the same as above).

The amount of the disazo pigment thus obtained dispersed in the insulating resin is suitably 1 to 50% by weight. If the amount of dispersion is too large than the above range, the adhesion will decrease, resulting in a loss of flexibility improvement effect, and if it is too small, the residual potential will increase. The thickness of the intermediate layer is suitably 5μ or less, preferably 1μ or less.
~3μ. In addition to the above two components, other dispersoids may be added to the intermediate layer of the present invention in order to improve and stabilize various properties.

The photoconductive layer is composed of selenium, a selenium alloy, or a selenium compound. 5eT as a selenium alloy or selenium compound
a, A11Se3.5s-Bt alloy, 5e-8b alloy, etc. The thickness of the photoconductive layer is suitably 100 microns or less, preferably 10 to 70 microns.

K for making the photoreceptor of the present invention is to apply an insulating resin solution in which the disazo pigment is dispersed on a conductive support and dry it to form an intermediate layer, and then deposit selenium, a selenium alloy, or a selenium compound thereon. 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 tetrahydrofuran in a glass pot, and then 1 part by weight of disazo pigment from Compound Shop 2 and stainless steel Zeel were added thereto, followed by milling for 72 hours. 34 parts by weight of tetrahydrofuran was added to the obtained dispersion to prepare an intermediate layer forming liquid.

Next, this liquid was poured into stainless steel (S U 8304,
Coating was applied on a support made of aluminum to a thickness of 1 μm after drying.
An electrophotographic photosensitive member was prepared by drying at 00° C. for 1 hour to form an intermediate layer, and then vacuum-depositing selenium thereon to form a photoconductive layer made of amorphous selenium with a thickness of 60 μm.

For comparison, the butyral resin 1 was used as the intermediate layer forming liquid.
An electrophotographic photoreceptor was produced in the same manner except that a solution in which parts by weight were dissolved in 9M parts of tetrahydrofuran was used.

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

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

D@D: VO/VM flu (Vo is the surface potential when dark decayed for 20 seconds).

E% = After dark decay, light is irradiated with a tungsten lamp so that the surface illuminance becomes 201uxK, and the exposure amount is KW such that the surface potential becomes MK of VO.

■R2 Surface potential after 20 seconds of light irradiation.

As can be seen from this table, the effect of the intermediate layer in which the disazo 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 (Polyester Adhesive manufactured by DuPont)
9 parts by weight were dissolved in 23 parts by weight of tetrahydrofuran in a glass pot, and 1 part by weight of the disazo pigment from Compound Shop 2 and the same cystineless steel alloy as in Example 1 were processed into the solution and milled for 72 hours. Tetrahydrofuran 631 was further added to the obtained 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 was 3μ, and dried at 100°C for 1 hour to form an intermediate layer, and furthermore, the KTe content was 8% by weight. S@-To gold alloy vacuum evaporated to a thickness of 60μ amorphous 5s
An electrophotographic photoreceptor was prepared from -To.

For comparison, an electrophotographic photoreceptor was prepared in the same manner except that β-copper phthalocyanine was used in place of the disazo pigment in the intermediate layer forming solution.

Next, set the photoreceptor in a commercially available photocopying machine,
When repeated use tests were 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 1982 Patent Application No. 2304 2 Name of the invention 1-3-6 Nakamagome, Ota-ku, Tokyo (674) Ricoh Co., Ltd. - Representative Takeshi Oue 4 Agent 5 Subject of amendment Column of “Detailed Description of the Invention” of the Specification Contents of Amendment “X’ J “X” J (3) “Electrophotography from -8s-Te…” on page 23, lines 10 to 11 was changed to “・・Electronic photograph consisting of 5o-To”
Correct.

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 photoconductive layer formed of selenium, a selenium alloy, or a selenium compound thereon. In the electrophotographic photoreceptor, the organic pigment represents an aromatic ring of the general formula or a hetero ring such as an indole ring, a cal, a dizole ring, a benzifudine ring, or a substituted product thereof, and Ar1 is a benzene ring or a naphthalene ring. , represents an aromatic ring such as an anthracene ring, or a hetero ring with a dibenzofuran ring, a pyrene ring, a pyridine ring, a furan ring, a thiophene ring, a carnozole ring, or a substituted product thereof;
4 represents an aromatic ring such as a benzene ring or a naphthalene ring, or a substituted product thereof; R8 represents hydrogen, a lower argyl group, a phenyl group, or a substituted product thereof; and R1 represents a lower alkyl group, a phenyl group, or a substituent thereof; represents a group or its ester. ) represents. ] An electrophotographic photoreceptor characterized by being a disazo pigment represented by