JPS6069656A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance sensitivity, stability, durability, etc., by vapor depositing a compd. selected from specified naphthalene, tetracene, and fulvalene derivs. to form the photocharge generating layer of a laminate type electrophotographic sensitive body. CONSTITUTION:A photocharge generating layer is formed by depositing on a conductive substrate by the vacuum deposition method, a compd. selected from (A) naphthalene derivs. represented by formula I in which X is S, Se, or Te, (B) tetracene derivs. represented by formula II, and (C) fulvalene derivs. represented by formula III in which R<1>, R<2>, R<3>, R<4> are each H or phenyl or 1-5C alkyl, such as tetrathionaphthalene and tetrathiotetracene. Then, an electrostatic charge transfer layer made of a charge transfer material, such as poly-N-vinylcarbazole, is formed on said layer to obtain an intended electrophotographic sensitive body.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electrophotographic photoreceptor, and more particularly, the present invention relates to an electrophotographic photoreceptor, and more particularly, it has excellent photosensitivity, high stability, a photocharge generating layer that is easy to form, and is durable. The present invention relates to an electrophotographic photoreceptor with excellent electrostatic properties, charging characteristics, and residual potential characteristics.

[Technical background of the invention and its problems]

The photoconductive process of electrophotographic photoreceptors consists of a photocharge generation process and a charge transport process. Conventionally known electrophotographic photoreceptors can be roughly classified into the following two types. That is, there are two types: one in which the above two processes are carried out using one substance, and one in which the two processes are carried out in separate substances.

In the latter type, on a conductive support made of a conductive material such as brass or aluminium,
For example, a laminated structure having a thin layer of a photocharge generating material such as amorphous selenium, and a layer of a charge transporting material such as polyvinylcarbazole on top of the thin layer is well known. This laminated type allows for a wider selection of materials to be used for the photoreceptor, and the resulting photoreceptor has excellent electrophotographic properties such as photosensitivity and acceptance potential, and also produces a photoreceptor with excellent film properties during production. It has the advantage of being able to

However, this photoreceptor is difficult to manufacture from amorphous selenium, which is a photocharge-generating substance, and is therefore expensive to manufacture), and is difficult to process into a belt because it is not flexible. It has its drawbacks.

Further, in this laminated type photoreceptor, a coated layer of a photocharge-generating organic material is well known as a photocharge-generating layer. Examples include a coating layer of chlordiane blue using an organic amine as a solvent, a layer of a carbazole-based diazo pigment, a layer of an oxadiazole-based disazo dye, a layer of perylene derivatives, a layer of phthalocyanines, etc. (U.S. Pat. No. 3,871).
, No. 882, JP-A-52-55643, JP-A-53-
No. 95033, JP-A-56-91237, JP-A-56
-78841 etc.).

Although these organic photocharge generating layers have manufacturing advantages over inorganic ones, they generally have the disadvantage of low photosensitivity. Moreover, the coating layer of Chlordiane Blue uses a toxic and malodorous organic amine as a solvent when forming the layer, resulting in a decrease in workability.

[Purpose of the invention]

The present invention provides a layered electrophotographic photoreceptor in which an organic substance is used for the photocharge generation layer, in which the photocharge generation layer is formed using an organic photocharge generation substance that has excellent stability and can be applied to a vacuum evaporation method. The object of the present invention is to provide an electrophotographic photoreceptor with excellent sensitivity, durability, charging characteristics, and residual potential characteristics.

[Summary of the invention]

The electrophotographic photoreceptor of the present invention comprises an electrically conductive support, a photocharge generation layer laminated on the support, and a charge transport layer further laminated on the generation M. In the X photoreceptor, the photocharge generation layer is a naphthalene derivative represented by (wherein, X represents any one of sulfur, selenium, or tellurium); Atracene auxiliary conductor with 7); (wherein, X has the same meaning as X in formula I, formula
R2, R3, and R4 may be the same or different and each represents a hydrogen atom, a phenyl group, or an alkyl group having 1 to 5 carbon atoms. ) A vacuum-deposited layer of at least one compound selected from the group of fulvalene derivatives represented by t.

The electrophotographic photoreceptor of the present invention is a structure in which a photocharge generation layer and a charge transport layer are laminated in this order on a conductive support.

The conductive support is made of materials such as brass, aluminum, gold, silver, etc., and may be in the form of a sheet, cylindrical material, or cylindrical material having an appropriate thickness, hardness, or flexibility. , may be coated with a thin layer of plastic. It may also be metallized paper, metallized plastic sheet or glass coated with a conductive layer of aluminum iodide, copper iodide or chromium or tin oxide.

It is usually desirable for the support to be itself electrically conductive or to have an electrically conductive surface and to have sufficient strength for handling.

On such a conductive support, photocharge generating materials represented by formulas (1), (2), and (2) are deposited by vacuum deposition to form a photocharge generating layer.

The generation layer may be a single layer of each of the compounds of formula (1), formula (2), or formula (3), a layer in which two or more of them are appropriately mixed and deposited, or a compound of formula (1), formula (2), or formula (2). It may be a layer formed by laminating two or three types of them in random order.

These photocharge generating materials can be easily formed into a layer on a support using a vacuum deposition apparatus used in conventional thin film forming methods. The thickness of the photocharge generating layer to be formed at this time can be adjusted as appropriate by controlling the conditions during vapor deposition. The layer thickness is determined by the charging characteristics required for the electrophotographic photoreceptor to be manufactured, but is usually 0.1 to 5 μm.
It is about m.

The electrophotographic photoreceptor of the present invention is constructed by forming a charge transport layer on this photocharge generation layer.

As the charge transport material used to form the charge transport layer, either a hole-blocking transport material or an electron transport material can be used.

First, examples of hole transport materials include the following. Namely, anthracene, phenanthrene,
Condensed polycyclic compounds such as pyrene and coronene; polymers of condensed polycyclic compounds such as polyvinylpyrene, polyvinylanthracene, and poly-9,-vinylphenylanthracene; diphenylamine, dinaphthylamine, triphenylamine, 4,4' - Aromatic amine compounds such as bis-CN, N-diethylaminocotetraphenylmethane;
4-dimethylaminobenzylidene benzhydrazide, 4
- Acyl hydrazide derivatives such as dimethylaminobenzylidene-2-methylbenzoic acid hydrazide: oxazole derivatives of 2-[4-dimethylaminophenyl-5-phenyl-oxazole, 2-[:4'-diethylaminophenylgobenzoxazole; 4 -Ce-dimethylaminophenyl-5-phenyl-imidazole,
Imidazole derivatives such as 1-ethyl-2-[4'-diethylaminophenyl-6-methyl-benzimidazole, etc.: 2-C4'-diethylaminophenylcortiazole, 2-(4'-dimethylaminophenyl-benzimidazole, etc.) Thiazole derivatives of: 1, 3.
5-triphenylpyrazoline, 1-phenyl-3-(4
'-diethyl7mi/sf IJ le:) -4-methyl-5-C4''-diethylaminophenyl Pyrazoline derivatives such as birapurine: Imidacylone derivatives such as 4,5-diphenylimidasilone: 4,5-diphenyl Imimezothion derivatives such as imidazothion; 2,5
-bis-[4'-dimethylaminophenyl:]-]1.
3.4-Oxadiay /l/, oxadiazole such as 2-(4'-dimethylaminophenyl]-5-[4"-amino-3"-chlorophenyl]-1°3.4-oxadiazole Derivatives; Thiadiazole derivatives such as 2,5-bis-[4'-dimethylaminophenyl]-1,3,4-thiadiazole;2,5-bis-[4'-dimethylaminophenyl]-1,3,4- ) triazole derivatives such as riazole; carbazole derivatives such as carno(zole, N-ethylcarbazole, N-1 soprovircarbazole, N-phenylcarbazole, benzcarbazole); poly-N-vinylcarbazole, nitrated poly-N-vinyl Carbazole, chlorinated poly-N-vinylcarno(sol,!chlorinated poly-N-vinylcarno(zole), chlorinated poly-N-vinylcarno(zole), chlorinated poly-N-vinylcarno(sol), chlorinated poly-N-vinylcarno(sol), chlorinated poly-N-vinylcarno(sol), chlorinated poly-N-vinylcarno(zole), chlorinated poly-N-vinylcarno(sol), chlorinated poly-N-vinylcarno(sol), chlorinated poly-N-vinylcarno(sol), chlorinated poly-N-vinylcarno(sol), chlorinated poly-N-vinylcarno(sol), chlorinated poly-N-vinylcarno(sol), chlorinated poly-N-vinylcarno(sol), chlorinated poly-N-vinylcarno(zol nato novo IJ-N-vinylcarnocarno)”).

Furthermore, examples of electron transporting substances include the following. Namely, chloronyl, promoanil, dichlorodicyano-p-benzoquinone, anthraquinone, dinitroanthraquinone, tetracyanoethylene, tetracyanoquinodimethane, 2.4.7-) dinitro-9-fluorenone, 2°4.5.7-ketone. Nitrofluorenone, 2,4゜7-) IJ nitro-9-dicyanomethylenefluorenone, 2,4,5.7-tetranitroxanthone, 2,4.5-trinidrothioxanthone, etc.
Or these are made into polymers.

'U To form the charge transport layer, a solution prepared by dissolving or dispersing the charge transport substance described above in an organic solvent such as tetrahydrofuran, toluene, methyl ethyl ketone, methylene chloride, etc. is applied by a conventional coating method, such as a spinning method, It may be applied on the p-photocharge generation layer by dipping, four-layer coating, or spray coating, and then dried. Among the above-mentioned charge transport materials, low-molecular ones do not have the ability to form a film, so in this case, various high-molecular compounds may be used in combination and applied in the same manner as above.

The type of such polymer compound is not particularly limited, and examples thereof include known binder materials for electrophotographic photoreceptors, such as polystyrene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer,
Polyvinyl acetate, polyvinyl acetal, phenol resin, epoxy resin, and alkyd resin can be used as appropriate. Further, the polymer compound used itself may have charge transport ability.

The thickness of the charge transport layer is normally 5 to 100 μm. The total thickness of the photoelectric charge generation layer and the charge transport layer is preferably 100 μm or less; if the thickness becomes larger than this, there is a tendency for the photosensitivity to decrease and the flexibility of the entire layer to decrease.

[Embodiments of the invention]

Example 1 On a polyester support with aluminum vapor deposited,
Vacuum degree 2. OX 10=Torr, evaporation source temperature 300~
Tetrathiotetracene (formula 2, where X is S) was deposited at 350° C. for 5 minutes to form a photocharge generating layer with a thickness of 5000 mm.

On top of this, a solution of polyvinylcarbazole dissolved in a solvent with a volume ratio of chlorpene and tetrahydrofuran of 2:1 was spin-coded and dried at 50°C for 3 hours under reduced pressure to form a charge transport layer with a thickness of 4.2 μm. Formed.

Negative charging and attenuation of the photoreceptor thus obtained were examined using an electrostatic paper analyzer. The result is the exposure needle (unit: 1ux-
7.61ux-see with negative charge
This photoreceptor was charged and exposed 5,000 times under the same conditions as above, and as a result, no abnormalities were observed and it was found to have excellent fatigue resistance. Example 2 In the same manner as in Example 1, a photocharge generating layer of tetrathiotetracene having a thickness of 6,200 mm was formed on a polyester support on which aluminum was deposited.

On top of this, a solution of 20t of 2,4.7-) dinitro-9-fluorenone, 5f of polystyrene, otrichloroben7ane, and toluene dissolved in a 1:1 volume ratio of solvent was spin-coded, and the mixture was heated at 55°C under reduced pressure for 4 hours. After drying for a while, a charge transport layer having a thickness of 6.4 μm was formed.

The obtained photoreceptor was positively charged in the same manner as in Example 1, and the half-reduction exposure was measured.8. It was O1ux-see.

This photoreceptor was charged and exposed 5,000 times under the same conditions as above, and as a result, no abnormalities were observed and it was found that the photoreceptor had excellent fatigue resistance. [Effects] As is clear from the above explanation, the electrophotographic photoreceptor of the present invention has: (1) easy formation of a photocharge generation layer and high stability; (2) high photosensitivity, charging characteristics, - Excellent residual potential properties; - Good fatigue resistance and excellent durability; - Workability is good as no harmful solvents are used; - Charge transport material is replaced by hole transport material and electron transport material. By appropriately selecting one of the substances, the surface of the charge transport layer can be charged in either a positive or negative direction, and has great industrial value.

Claims (1)

[Scope of Claims] An electrophotographic photoreceptor comprising an electrically conductive support, a photocharge generation layer laminated on the support, and a charge transport layer further laminated on the generation layer. , the photocharge generating layer is a naphthalene derivative represented by: -X (wherein, X has the same meaning as X in formula I). , ); In formula C, X has the same meaning as X in formula H of formula 11, R1,
R2, R3, and R4 may be the same or different and each represents a hydrogen atom, a phenyl group, or an alkyl group having 1 to 5 carbon atoms, and is selected from the group of fulvalene derivatives represented by An electrophotographic photoreceptor comprising a vacuum-deposited layer of at least a 18+ compound.