JPH02160248A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance photosensitivity characteristics and photoconductive sensitivity in the wavelength region of semiconductor laser beams by incorporating a specified naphthalocyanine compound in a photosensitive layer. CONSTITUTION:The photosensitive layer formed on a conductive substrate contains as the organic photoconductor one of the naphthalocyanine compounds represented by formulae I and II in which M is one of elements in the groups Ia, IIa, and IIIa of the periodic table or a transition metal atom; each of R<1> and R<2> is H, F, Cl, Br, OH, nitro, straight or branched alkyl, aryl, or aralkyl, optionally substituted by halogen, or polyether; m is a number of R<1> and an integer of 0 - 5; n is a number of R<2> and an integer of 0 - 4; and each of Y and Z is -O- or -NH-, thus permitting the obtained photosensitive body to be superior in photosensitive characteristics and sufficient in photoconductive sensitivity to semiconductor laser beams.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an electrophotographic photoreceptor using an organic photoconductive substance.

(Prior Art) Conventionally, electrophotographic photoreceptors have been made of inorganic photoconductive substances such as selenium, cadmium sulfide, and zinc oxide, organic polymeric photoconductive substances such as poly-N/vinyl carbazole, and polyvinyl anthracene, and carbazole. anthracenes, anthracenes,
Products using organic low-molecular photoconductive substances such as fluorenones, hydrasulfates, pyrazolines, oxadiazoles, phthalocyanine dyes, and quinone dyes have been developed and put into practical use.

Among these, many methods using organic photoconductive substances have been proposed due to their advantages such as low toxicity, wide selection of wavelength ranges, and low cost.

On the other hand, in recent years, laser printers have been proposed as printers for digital copying machines, facsimile machines, word processors, etc., and electrophotographic photoreceptors are also used here.

Further, in order to improve the photosensitive characteristics of the photoreceptor, a laminated type electrophotographic photoreceptor in which a charge generation layer and a charge transport layer are functionally separated is also well known.

(Problems to be Solved by the Invention) As mentioned above, when using an organic photoconductive material for a photoreceptor, it has advantages such as safety, cost, and ease of selection. It is still difficult to say that it is sufficient in terms of characteristics. In addition, there are almost no conventional organic photoconductive substances that have effective photoconductive sensitivity in the oscillation wavelength range of semiconductor lasers and are also excellent in stability.

(Means for Solving the Problems) The present inventors conducted studies to solve the problems set forth in Section L, and discovered an organic photoconductive material that has excellent photosensitivity and stability as an electrophotographic photoreceptor. , applied to electrophotographic photoreceptors.

That is, the present invention provides an electrophotographic photoreceptor comprising a layer containing at least an organic photoconductive substance on a conductive support, wherein the organic photoconductive substance has the following general formula (
This is an electrophotographic photoreceptor characterized by being a naphthalocyanine compound represented by 1) or (2).

Rl and R2 are the same or different and each independently represents a metal atom, a straight chain or branched chain which may be substituted with a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a nitro group, or a halogen atom r. Good alkyl group, aryl group,
Aralkyl group, polyether group, or OA group (in the formula A
represents a hydrogen atom, an alkyl group, an aryl group, an aralkyl group, or a polyether group which may be linear or branched), m and n each independently represent the number of R' and R2, m and n each represents an integer of 0 to 5.0 to 4]; [wherein M is an atom of group Ia or II
A group a atom or a group IIIa atom or transition [wherein,
Y and Z each independently represent 0 or NH; N
R', R2, m and n have the same meanings as above. ]
A compound to which one or two molecules of the naphthalene derivative represented by the formula are added.

Among the naphthalocyanine compounds in the present invention, compounds in which M is copper or zinc are more preferred.

The structure of the electrophotographic photoreceptor in the present invention may be such that a layer containing at least the naphthalocyanine compound of the present invention is provided on a conductive support, but preferably, at least a layer containing the naphthalocyanine compound of the present invention is provided on the conductive support -L. The charge generating layer is composed of a laminated layer and a charge transport layer, and the naphthalocyanine compound of the present invention is the main component of the charge generating layer.

In order to form the naphthalocyanine of the present invention as a charge generation layer, the naphthalocyanine is dissolved or dispersed in a solvent, coated and dried to form a film, or the naphthalocyanine compound and the binder are dispersed or dissolved in a solvent and coated and dried. In addition, a naphthalocyanine compound, a binder, and other organic photoconductive substances may be added as small amounts of components, dispersed or dissolved, and applied and dried.

Binders used at this time include polyvinyl butyral, polyarylate, polycarbonate, polyamide, polyurethane, polyester, polyvinyl acetate,
There are ethyl cellulose, etc., and these! 11. - Also, the use of a mixture of two or more types may be mentioned.

As the charge transport layer forming material used in the present invention, poly-
Examples include, but are not limited to, N-vinyl carbazole, polyvinyl anthracene, carbazoles, fluorenones, hydrazones, triazoles, quinones, and oxazoles. The formation of this charge transport layer is carried out in the same manner as described above for the formation of the charge generation layer, and binders, solvents, etc. may be appropriately selected and used.

Examples of the conductive support in the present invention include an aluminum plate, an aluminum cylinder, an aluminum foil, and a plastic film in which a thin film or foil of a conductive metal such as aluminum is provided on the surface. The electrophotographic photoreceptor of the present invention can be provided with a protective layer on the surface layer of the photoreceptor, if necessary. The present invention will be specifically described below with reference to Examples, but the present invention is not limited thereto.

(Example) Using the A compound and B compound corresponding to each Nα described above, an electrophotographic photoreceptor was prepared by the following method and evaluated.

First, 5 g of Compound A and 5 g of polyvinyl butyral were added to 90 mO of n-butanol on an aluminum plate, mixed in a ball mill for 5 hours, and the solution was bar coated to a dry film thickness of 0.5 μ. It was applied and dried to form a film. Next, 5 g of compound B and 5 g of polymethyl methacrylate were added to 90% of toluene to homogenize the solution,
It was coated on the previously formed film by blade coating so that the dry film thickness was 25 mm, and then dried to form a film.

The electrophotographic photoreceptors on each floor obtained as described above were tested using an electrostatic copying paper tester 5P-428 manufactured by Kawaguchi Electric ■.
The initial surface potential is V by charging with a corona voltage of 5.5 KV.

The surface potential v after being left in the dark for 10 seconds
d, and then irradiated with a semiconductor laser with an oscillation wavelength of 780 nm to obtain half-exposure fit (E station) residual potential Vl? was measured. These measurement results are shown in Table 1 for each positron photoreceptor.

Hereinafter F margin (1)" (Et: ether amount, the same hereinafter) Compound A (Effect of the invention) By incorporating the specific naphthalocyanine compound of the present invention into the photoreceptor layer, the charge generation layer can be improved. It has been found that by incorporating the compound into the electrophotographic photoreceptor, it is possible to obtain an electrophotographic photoreceptor with excellent photosensitivity and also with sufficient photoconductivity sensitivity even for semiconductor lasers.

Claims (1)

[Claims] (1) In an electrophotographic photoreceptor comprising a layer containing at least an organic photoconductive substance on a conductive support, the organic photoconductive substance is represented by the following general formulas (1) and (2). An electrophotographic photoreceptor characterized in that it is a naphthalocyanine compound. ▲There are mathematical formulas, chemical formulas, tables, etc.▼(1) [In the formula, M is an atom of group Ia in the periodic table or II
Represents a group a atom, a group IIIa atom, or a transition metal atom, and R^1 and R^2 are the same or different and each independently represents a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, a nitro group, a halogen A straight-chain or branched alkyl group, aryl group, aralkyl group, polyether group, or OA group that may be substituted with an atom (wherein A is a hydrogen atom, a straight-chain or branched alkyl group) group, aryl group, aralkyl group or polyether group), m
and n each independently represent the number of R^1 and R^2, and m and n each represent an integer of 0 to 5 and 0 to 4.] General formula (2) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (2) [In the formula, Y and Z each independently represent O or NH, and R^1, R^2, m and n have the same meanings as above]. A compound to which one or two molecules of the represented naphthalene derivative are added.