JPH02296251A - Electrophotographic sensitive body - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is applicable to copying machines, LED printers, LD printers,
This invention relates to an electrophotographic photoreceptor used in C8 printers and the like.

(Prior art) As electrophotographic photoreceptors, amorphous selenium,
Inorganic photoelectric materials such as cadmium sulfide and zinc sulfide and poIJ-
'Organic photoconductive materials such as N-vinylcarbazole have been used.

In recent years, electrophotographic photoreceptors using amorphous silicon,
A functionally separated organic electrophotographic photoreceptor in which a charge generation section and a charge transport section are separated has been put into practical use.

However, although electrophotographic photoreceptors using amorphous silicon have excellent photosensitivity and printing durability, they have the problems of high film formation cost and poor moisture resistance. On the other hand, functionally separated organic electrophotographic photoreceptors have the advantages of excellent charging properties and flexibility, easy film formation, low film formation cost, and a high degree of freedom in material selection.

The photosensitivity of a functionally separated organic electrophotographic photoreceptor is determined by (-) photocarrier generation efficiency in the charge generation layer, (b) injection efficiency from the charge generation layer to the charge transport layer, and (C) transport efficiency in the charge transport layer. Development activities are being carried out with the goal of improving each efficiency.

(Problems to be Solved by the Invention) Electrophotographic photoreceptors using inorganic photoelectric materials are superior to functionally separated organic electrophotographic photoreceptors in terms of optical carrier generation efficiency and carrier transport efficiency. Sensitivity is also high. For this reason, the electrophotographic photoreceptors installed in high-speed copying machines and printers are mainly those using inorganic photoelectric materials, and the use of functionally separated organic electrophotographic photoreceptors is limited to medium- and low-speed machines. was.

The problem to be solved by the present invention is a high-speed copying machine,
The high light sensitivity required for electrophotographic photoreceptors installed in
An object of the present invention is to provide a functionally separated organic electrophotographic photoreceptor that has high printing durability and excellent cycle stability.

In order to solve the above problems, the present invention provides a functionally separated organic electrophotographic photoreceptor having a charge generation layer and a charge transport layer, in which the charge transport layer contains 100 parts by weight of a charge transport agent. In contrast, benzo l-IJ azole ultraviolet absorber to, 05-0,1
Provided is an electrophotographic photoreceptor containing 5 parts by weight.

Examples of benzotriazole ultraviolet absorbers used in the present invention include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-5'-tart-butylphenyl)pe /citriazole, 2- (2'-hydroxy-3'.

5'-di-tert-butylphenyl)benzotriazole, 2-(2'-hydroquine-3'-tert-butyl-5'-methylphenyl)-5-chloropenztriazole, 2-(2'-hydroxy-3/ , S/
-di-t@rt-butylphenyl)-5-chlorobenzotriazole, 2- (2'-hydroxy-3'15'
-di-tert-amylphenyl)benzotriazole,
Examples include 2-(2/-hydroxy-4'-octoxyphenylbenzotriazole).

Benzo) IJ azole-based external radiation absorbers and charge transport agents are known to absorb harmful ultraviolet rays and have the effect of preventing deterioration of electrophotographic photoreceptors. It has been discovered that a sensitizing effect can be exhibited by adjusting the content of the ultraviolet absorber to 0.05 to 0.15 parts by weight based on 100 parts by weight of the charge transport agent.

Content of benzotriazole ultraviolet absorber is 0.05
If it is less than 0.15 parts by weight, there is no sensitizing effect (but if it is more than 0.15 parts by weight, the photosensitivity tends to decrease, which is not preferable).

Examples of charge transport agents include low molecular weight compounds such as pyrene; N-ethylcarbazole, N-i:/propylcarbazole, N-phenylcarbazole, N-methyl-2;
- Carbazoles such as phenylhydrazino-3-methylidene-9-ethylcarbazole, N,N-diphenylhydrazino-3-methylidene-9-ethylcarbazole:
Hydrazones such as p-N,N-dimethylaminobenzaldehyde diphenylhydrazo/, p-N,N-diethylaminobenzaldehyde diphenylhydrazone, p-N,N-diphenylaminobenzaldehyde diphenylhydrazone; 2,5-bis(p-diethylamino phenyl) -1,3,4-oxadiazole, 1-phe-ru3. -(p-diethylaminostyryl)-5
-Pyrazolines such as (p-diethylaminophenyl) virasolii; triphenylamine, N, N, N', N'-
Nato2phenyl-1,1'-biphenyl-4,4'-diamine, N,N'-diphenyl-N,N'-bis(3-
methylphenyl) -1,1'-biphenyl-4,4'
-diamine etc., and as the polymer compound,
91Ltij:,yf! Examples include IJ-N-vinylcarbazole, halodanated polyN-vinylcarbazole, polyvinylpyrene, polyvinylanthracene, polyvinylacridine, pyrene-formaldehyde resin, ethylcarbazole-formaldehyde resin, triphenylmethane polymer, and polysilane compounds. The charge transport agent is -Senjin (wherein A represents an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent, and R1 and R2 each independently represent a hydrogen atom, a halodane atom or (represents an alkyl group or aryl group which may have a substituent.) When the compound is a hydrazone compound having an indoline ring represented by Because it will be
Particularly preferred.

Examples of the electrophotographic photoreceptor of the present invention include the following 211 functionally separated organic electrophotographic photoreceptors.

(1) vacuum-depositing a charge generating agent on a conductive support;
Alternatively, a dispersion obtained by dispersing fine particles of a charge generating agent in a solvent or a binder resin solution is coated and dried to form a charge generating layer, and a charge transporting agent, a benzotriazole ultraviolet absorber, and a charge generating layer are applied thereon. An electrophotographic photoreceptor that is formed by applying a solution containing Ingu resin and drying it to form a charge transport layer.

(2) A charge transporting agent, a solution containing a benzo-IJ azole external radiation absorbing agent and a binder resin is applied onto a conductive support and dried to form a charge transporting layer, and a charge generating agent is applied on top of the solution. An electrophotographic photoreceptor in which a charge generation layer is formed by vacuum deposition or by coating and drying a dispersion obtained by dispersing fine particles of a charge generation agent in a solvent or a binder resin.

The thickness of the charge generation layer is preferably in the range of 0.01 to 2 μm, and the thickness of the charge transport layer is preferably in the range of 5 to 30 μm.

Various pigments can be used as the charge generating agent, for example,
Azo pigments, quinone pigments, azulenium dyes, sufuuniarium dyes, biryllium dyes, cyanine dyes,
Examples include perylene pigments, indigo pigments, bisbenzimidazole pigments, phthalocyanine pigments, quinacridone pigments, and quinoline pigments.

Examples of the conductive support include metal plates, metal drums, or conductive metals made of metals or alloys such as aluminum, copper, zinc, stainless steel, chromium, titanium, nickel, molybdenum, vanadium, indium, gold, and platinum. ? Examples include paper and plastic films coated with, vapor-deposited, or laminated with conductive compounds such as reamer and indium oxide, and metals or alloys such as aluminum, palladium, and gold.

As the binder resin, it is preferable to use a hydrophobic polymer capable of forming an electrically insulating film. Examples of such polymers include polycarbonate, polyester, methacrylic resin, acrylic resin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, styrene-butadiene copolymer,
Vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol-forma/L/7” human resin, styrene - Alkyd resins, poly-N-vinylcarbazole, polyvinyl butyral, polyvinyl formal, polysulfone, etc., but are not limited to these.

These binder resins can be used alone or as a mixture of two or more.

The solvent that dissolves the binder resin or charge generating agent varies depending on the type of binder, but it is preferable to select one from among those that do not dissolve the lower layer.

Specific examples of organic solvents include methanol,
Alcohols such as ethanol and n-7'ronoyameil:
Ketones such as acetone, methyl ethyl ketone, and cyclohexanone: N, N-methylformamide, N, N-
Amides such as dimethylacetamide; ethers such as tetrahydrofuran, dioxane, and methyl cellosolve; esters such as methyl acetate and ethyl acetate; sulfoxides and sulfones such as trimethyl sulfoxide and sulfolane;
Examples include aliphatic halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, and trichloroethane; and aromatics such as benzene, toluene, xylene, monochlorobenzene, and duchlorpenze.

As the coating method, for example, a dip coating method, a spray coating method, a spinner coating method, a heat coating method, a wire per coating method, a grade coating method, a roller coating method, a curtain coating method, etc. can be used.

(Examples) Hereinafter, the present invention will be specifically explained using Examples, but the present invention is not limited to the Examples. still,
In the examples, "1 part" indicates "part by weight."

・Disperse 2 parts of the benzuzine-based disazo pigment shown in the table in a mixed solvent consisting of 80 parts of dioxane and 20 parts of acetone, and apply this dispersion to an aluminum drum with an outer diameter of 60 μm to a dry coating thickness. It was coated to a thickness of 0.3 μm and dried to form a charge generation layer.

Next, polycarbonate resin (Mitsubishi Gas Chemical Co., Ltd. rZ
-2004) 10 parts of dioxane and 9 parts of the hydrazone compound represented by the formula
5 parts of methylene chloride, and 2-(2'-hydroxy-5
1 part of '-□methylphenyl)penztriazole was added and dispersed. This dispersion was coated on the charge generation layer to a dry coating thickness of 20 μm and dried to form a charge transport layer to obtain an electrophotographic photoreceptor.

Example 2 In Example 1, 1.2-, (2'-hydroxy-5'
-methylphenyl)benzotriazole, 2-
(2'-hydroxy-3'-tart-butyl-5'
An electrophotographic photoreceptor was obtained in the same manner as in Example 1 except that methylphenyl)-5-chlorobenzotriazole was used.

Comparative Examples 1 to 3 In Example 1, 2. - (2'-hydroxy-5
The electrophotographic photoreceptors of Comparative Examples 1, 2, or 3 were prepared in the same manner as in Example 1, except that the amount of IJ azole used was 0 parts, 0.1 parts, or 3 parts. Obtained.

Example 3 A mixture consisting of 1 part of polyvinyl butyral resin (manufactured by Tanezu Kagaku Co., Ltd. [S-LEC BBH-3J), 2 parts of α-type titanyl phthalocyanine, 60 parts of 1,1,2-h dichloroethane, and 40 parts of methylene chloride. The dispersion was dispersed in a solvent, and this dispersion was applied to an aluminum drum having an outer diameter of 60mm to a dry coating thickness of 0.3 μm, and dried to obtain a charge generation layer.

Next, polycarbonate resin (Mitsubishi Gas Chemical Co., Ltd. rZ
-200J), 30 parts of trichloroethane, and 20 parts of methylene chloride.
1 part of 2'-hydroxy-3/,S/-tert-butylphenyl)25-chlorobenztriazole was added and dispersed. This dispersion was coated on the charge generation layer to a dry coating thickness of 20 μm and dried to form a charge transport layer to obtain an electrophotographic photoreceptor.

Comparative example 4 In Example 3, 2-(2'-hydroxy-3'.

An electrophotographic photoreceptor of Comparative Example 4 was obtained in the same manner as in Example 3 except that 5'-di-tert-butylphenyl)-5-chlorobenzotriazole was not added.

Next, each of the electrophotographic photoreceptors obtained in Examples 1 to 3 and Comparative Examples 1 to 4 was installed in a commercially available negative charging type copying machine, and the characteristics of the electrophotographic photoreceptor were measured. The results are shown in Table 1. Indicated. In Table 1, the charging potential represents the surface potential at the development position during non-exposure after corona charging, and the exposure potentials 1, 2, and 3 represent the maximum image density (minimum exposure amount) and the normal (exposure amount), respectively. The residual potential represents the surface potential at the development position at the time of exposure (normal amount) and minimum (maximum exposure amount), and the residual potential represents the surface potential at the development position at the time of irradiation with static eliminating light.

(Effects of the Invention) The electrophotographic photoreceptor of the present invention is excellent in high photosensitivity, high printing durability, and cycle stability, and is therefore useful as an electrophotographic photoreceptor installed in copying machines and printers.

Claims (1)

[Scope of Claims] 1. In an electrophotographic photoreceptor having a charge generation layer and a charge transport layer, the charge transport layer contains, based on 100 parts by weight of the charge transport agent,
0.05 to 0.1 benzotriazole ultraviolet absorber
An electrophotographic photoreceptor containing 5 parts by weight. 2. The electron transport agent has a general formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, A represents an aromatic hydrocarbon group or an aromatic heterocyclic group that may have a substituent, and R^2 each independently represents a hydrogen atom, a halogen atom, or an alkyl group or an aryl group which may have a substituent.) Claim 1 characterized in that it is a hydrazone compound having an indoline ring represented by: The electrophotographic photoreceptor described above.