JPH031158A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain copied images which are stable in development contrast by incorporating a nonionic antistatic agent into an intermediate layer. CONSTITUTION:The intermediate layer 2 is provided on the conductive base 1 and a photosensitive layer 3 having a single layer structure is provided thereon. The intermediate layer 2 contains an org. solvent soluble resin as its constituting component and contains the nonionic antistatic agent. Polyoxyethylene alkyl amine, polyoxyethylene fatty acid amide, etc., are preferably used as the nonionic antistatic agent. The electrophotographic sensitive body having the good repetitive stability of the development contrast is obtd. in this way.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an electrophotographic photoreceptor with an improved intermediate layer.

2. Description of the Related Art Conventionally, electrophotographic copying machines have been developed that are becoming faster and capable of copying a variety of paper sizes year by year.

Along with this, electrophotographic photoreceptors are required to have high photosensitivity and a long lifespan to meet these demands.

In addition, in recent years, functionally separated electrophotographic photoreceptors in which photoreceptor functions are shared among multiple members have improved charge retention, repetition stability, and
Many proposals have been made to improve electrophotographic properties such as photoresponsiveness, spectral properties, and mechanical strength.

These electrophotographic photoreceptors have the following drawbacks:
Lack of repeated development contrast stability and environmental stability; ■ Image defects such as white spots, black spots, roughness, and pinholes are likely to occur; ■ Adhesive strength between the substrate and photosensitive layer is weak, causing the photosensitive layer to fail during use. peels off and is not durable enough,
etc. were known.

As a measure to improve these drawbacks, between the substrate and the photosensitive layer, names vary depending on the intended function, such as intermediate layer, adhesive layer, barrier layer, resin layer, etc., but from several to several dozen layers are added. A device provided with a transparent resin layer is known.

These resin layers include, for example, polyvalaxylene, casein, polyvinyl alcohol, phenolic resin, polyvinyl acetal resin, melamine resin, nitrocellulose,
Ethylene-acrylic acid copolymer, polyamide (nylon 6, nylon 66, nylon 610, copolymerized nylon, alkoxymethylated nylon, etc.), polyurethane, gelatin, polyvinylpyrrolidone, polyvinylpyridine,
Polyvinyl methyl ether or the like is used.

It is also known to add antistatic agents to the intermediate layer. (Unexamined Japanese Patent Publication No. 83-208761, [13-208
No. 762, No. 82-289965, No. 62-2722
79, No. 62-270982) Problems to be Solved by the Invention However, the function of the intermediate layer using the above-mentioned resin is mainly ionic conduction using water as a medium, and it is significantly affected by humidity. Therefore, when the photoreceptor is placed in a low humidity environment and the water content in the resin decreases, the intermediate layer becomes extremely high in resistance, resulting in deterioration of the electrophotographic properties of the photosensitive layer, such as a decrease in development contrast. there were.

In addition, when adding an antistatic agent to the intermediate layer, for example, when the antistatic agent is an ionic type (cationic type, anionic type), a local battery is created with the member of the charge generation layer, the base material, etc.
Alternatively, white spots,
There was a problem in that image quality defects such as black spots occurred. Also, JP-A-63-208761 and JP-A-83-20678
Even when polyethylene glycol ethers or esters were used, as described in No. 2, fully satisfactory results were not obtained.

The present invention has been made with the aim of improving the above-mentioned drawbacks in the conventional technology.

Therefore, an object of the present invention is to provide a laminated photoreceptor that has high photosensitivity, long life, good repeat stability of development contrast and environmental stability, and eliminates white spots, black spots, roughness, and
An object of the present invention is to provide an electrophotographic photoreceptor in which image defects such as pinholes are less likely to occur.

Another object of the present invention is to provide an electrophotographic photoreceptor that is less susceptible to the effects of the surfaces of sequentially laminated substrates and has excellent durability.

Means and Effects for Solving the Problems The above-mentioned object of the present invention is to provide an electrophotographic photoreceptor in which an intermediate layer and a photosensitive layer are successively provided on a conductive substrate, the intermediate layer comprising an organic solvent-soluble resin as a constituent component. This is achieved by an electrophotographic photoreceptor characterized by containing a nonionic antistatic agent.

The present invention will be explained in detail below.

1 and 27 are schematic cross-sectional views of the electrophotographic photoreceptor of the present invention. In FIG. 1, an intermediate layer 2 is provided on a conductive support 1, and a photosensitive layer 3 having a single layer structure is provided thereon. Further, in FIG. 2, the photosensitive layer has a laminated structure, and includes a charge generation layer 31 and a charge transport layer 3.
It is composed of 2.

In the electrophotographic photoreceptor of the present invention, the conductive support is a drum made of metal such as aluminum, copper, iron, zinc, or nickel, and aluminum, copper, gold, silver, platinum, etc. on a sheet, paper, plastic, or glass. Deposit metals such as palladium, titanium, nickel-chromium, stainless steel, copper-indium, or conductive metal compounds (e.g. In2
O3,5b203-3nO2,5n02,Tt O*
) powder, metal powder, etc. are dispersed in a binder resin, and conductive treatment is performed by coating the resin, and the like can be used in the form of a drum, sheet, or plate.

The intermediate layer provided on the conductive support contains a nonionic antistatic agent. This improves the drawbacks of conventional intermediate layers, particularly the humidity dependence of development contrast.

Examples of the nonionic antistatic agent preferably used in the present invention include the following.

('1) Polyoxyethylene alkylamine (2 polyoxyethylene fatty acid amide (3) Glycerin fatty acid ester CH20COR HOH CH,0H (4) Sorbitan fatty acid ester CH20COR ■ Polyoxyethylene sorbitan alkyl ester CH20COR (In the above formula, R is alkyl In the present invention, nonionic antistatic agents other than those mentioned above may be used.

In the present invention, the intermediate layer uses an organic solvent-soluble resin as a main component. As organic solvent soluble resin,
For example, polyvinyl acetal, polyvinyl alcohol, phenolic resin, polyamide, cellulose, polyvinylpyrrolidone, polyvinylpyridine, polyvinyl methyl ether, ethylene-acrylic acid ester copolymer,
Examples include polyester, polycarbonate, polyvinyl butyral, polystyrene, polyurethane, polypropylene, and polyacrylate.

The ratio of the above-mentioned nonionic antistatic agent mixed with these organic solvent-soluble resins is 1:1000 to 1:1000 to resin.
The ratio is 1:2, preferably 1:100 to 1:5. If the addition ratio is less than the above range, the contribution of the nonionic antistatic agent to ion conduction will be small, and the expected effect will not be seen. On the other hand, if the addition ratio is too large than the above range, an electrophotographic photoreceptor that lacks compatibility, repeated stability, or environmental stability may be formed, or the adhesion between the support and the photosensitive layer may deteriorate. They become a middle class with inferior gender.

In order to form an intermediate layer in the present invention, it is necessary to prepare a coating liquid. A nonionic antistatic agent is added to an organic solvent in which the resin is dissolved, and mixed to obtain a coating liquid. When applying this coating liquid, coating methods such as a dip coating method, a spray coating method, a blade coating method, a spinner coating method, a bead coating method, and a curtain coating method can be used. Drying is carried out using a blow dryer at a temperature in the range of 10 to 200°C, preferably 20 to 150°C, for 5 minutes to 5 hours, preferably 10 minutes to 2 hours.
Or it can be carried out under static drying.

The thickness of the intermediate layer is generally preferably in the range of 0.01 to 5 IA.

A photosensitive layer is formed on the intermediate layer, and the photosensitive layer may have a single layer structure or a functionally separated laminated structure.

Examples of single-layer structures include dye-sensitized ZnO photosensitive layers;
Examples include a CdS layer and a photosensitive layer in which a charge-generating substance is dispersed in a charge-transporting substance.

On the other hand, in the case of a functionally separated layered structure, a charge generation layer is formed first, and a charge transport layer is formed thereon.

The charge generation layer is made of a charge generation material or is formed by dispersing a charge generation material in a binder resin.

Examples of charge-generating materials include selenium and selenium alloys; Cd55CdSeSCdSSe.

Inorganic photoconductors such as ZnO and ZnS; metal phthalocyanines and metal-free phthalocyanine pigments; bisazo pigments,
Azo pigments such as trisazo pigments: squarium compounds;
Azulenium compounds; perylene pigments; indigo pigments;
Quinacridone pigments; polycyclic quinone pigments; cyanine dyes;

Examples of the binder resin include well-known ones such as polycarbonate, polystyrene, polyester, polyvinyl butyral, methacrylic acid ester polymer or copolymer, vinyl acetate polymer or copolymer, cellulose ester or ether, polybutadiene, polyurethane, and epoxy resin. etc. are used.

Several types of these may be used in combination.

The thickness of the charge generation layer is 0.01a to 5mm, preferably 0.01a to 5mm.
．． 03/1ffi ~ 2 prisoners. When the film thickness is larger than the above range, problems such as a decrease in chargeability, an increase in dark decay, and a decrease in repetition stability occur, and when it is smaller, the sensitivity decreases.

The charge transport layer provided on the charge generation layer is formed by containing a charge transport material in a suitable binder resin.

The charge transporting material is not particularly limited as long as it is transparent to visible light and has charge transporting ability, and specific examples include imidazole, pyrazoline, thiazole, oxadiazole, Examples include oxazole, hydrazone, ketazine, azine, carbazole derivatives, polyvinylcarbazole and its derivatives, triphenylamine derivatives, stilbene derivatives, and benzidine derivatives.

Examples of the binder resin include known ones such as polycarbonate resin, polyarylate resin, polyester resin, polystyrene resin, styrene-acrylonitrile copolymer, polysulfone, polymethacrylate ester, and styrene-methacrylate ester copolymer. It will be done.

The blending ratio of the charge transport material and the binder resin is 10:1 to 1:1.
5 (weight ratio) is preferred. The thickness of the charge transport material used in the present invention is generally 5 to 50", preferably 10 to 3".
The range is set to 0m+.

The electrophotographic photoreceptor of the present invention has excellent repeat stability of development contrast and environmental stability, and exhibits good electrophotographic properties.The reason for this is that the polyethylene glycol contained in the intermediate layer acts as a wetting agent, It is presumed that this is because moisture is taken in and held in the intermediate layer, thereby improving charge transfer (ion conductivity) in the intermediate layer in a low-humidity environment.

Example The present invention will be explained below with reference to Examples.

Example 1 A polyvinyl acetal resin represented by the following structural formula (1)% (mol%) was used as an organic solvent-soluble resin, and its 5
% n-Propyl alcohol/water mixed solution, add and mix a nonionic antistatic agent represented by the following structural formula (2) /CH2CH20H in an amount of 10 parts by weight per 100 parts by weight of polyvinyl acecool resin solid content. did.

Aluminum pipe (outer diameter 84cm, length 340mm+
) was used as a substrate, and the above coating solution for forming an intermediate layer was applied thereon by dip coating, followed by heating and drying at 100° C. for 5 minutes to form an intermediate layer having a thickness of 0.51IIr1.

On the other hand, 87 parts by weight of granular trigonal selenium and vinyl chloride-vinyl acetate copolymer (trade name: Trusion Vinyl VMC
H. Union Carbide Co.) 13 parts by weight was added to acetic acid n-
A solution dissolved in 200 parts by weight of butyl was dispersed for 24 hours using an attritor. Next, 57 parts by weight of n-butyl acetate was added to 30 parts by weight of this dispersion to dilute it, thereby preparing a dip coating solution.

This dip coating liquid was applied onto an aluminum pipe on which an intermediate layer was formed. That is, 100% in a dip coating bath.
It was pulled up at a speed of mu/min and dried by heating at 100° C. for 5 minutes to form a charge generation layer with a thickness of 0.1 B.

Next, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-[1,1'-biphenylco4.4
10 parts by weight of '-diamine, 10 parts by weight of polycarbonate Z resin
Part by weight was dissolved in 80 parts by weight of monochlorobenzene to prepare a charge transport coating liquid. This liquid was applied onto the charge generation layer and dried with hot air at 100°C for 60 minutes to form a charge transport layer with a thickness of 25a+.

The electrophotographic photoreceptor produced as described above was heated at 24°C.
, 40%R1 (Modified copying machine 5030 manufactured by Fuji Xerox) under the environment of
After adjusting the voltage to 00 V, the bright area potential VL was measured when an exposure of 2 erg/cd was applied. Next, the electrophotographic photoreceptor was subjected to similar measurements in an environment of 10° C. and 5% RH. After that, under the same environment, an endurance test of 10,000 copies was conducted, and the dark potential VD was determined.

Changes in bright area potential VL were measured. At the same time, image evaluation was performed. The results are shown in Table 1.

Example 2 An electrophotographic photoreceptor was prepared in the same manner as in Example 1, except that a compound represented by the following structural formula (3) was used as the nonionic antistatic agent, and the electrophotographic photoreceptor was similarly tested. I did it. The results are shown in Table 1.

Ta.

Example 3 As an organic solvent soluble resin, 8- which is a polyamide resin
10 parts by weight of nylon (trade name: Laccamite 5003, manufactured by Dainippon Ink ■) was dissolved in 80 parts by weight of methanol and 30 parts by weight of Kanobutanol. As a nonionic antistatic agent, 0.5 parts by weight of the compound represented by the structural formula (1) was prepared, and this was added to the polyamide resin solution and mixed to prepare a coating solution for forming an intermediate layer. An electrophotographic photoreceptor was prepared in the same manner as in Example 1, except that the intermediate layer was formed using this coating liquid, and tests were conducted in the same manner. The results are shown in Table 1.

Comparative Example An electrophotographic photoreceptor was prepared in the same manner as in Example 1 except that the nonionic antistatic agent was not added, and the same tests were conducted. The results are shown in Table 1.

Table 1 Effects of the Invention As is clear from the above comparison, the electrophotographic photoreceptor of the present invention contains a nonionic antistatic agent in the intermediate layer, so that the humidity dependence of the electrophotographic properties is reduced. Since the amount is small, a clear copy image with stable development contrast can be obtained.

[Brief explanation of drawings]

1 and 2 are schematic cross-sectional views of the electrophotographic photoreceptor of the present invention, respectively. (2) Conductive substrate, 2 Intermediate layer, 3 Photosensitive layer, 31 Charge generation layer, 32 Charge transport layer. Patent applicant Fuji Xerox Co., Ltd. Agent
Patent Attorney Mold Department Rigidity 1... Conductive substrate 2... Intermediate layer 3... Photosensitive layer 31 Charge generation layer 32... Charge transport layer Figure 2

Claims (2)

[Claims] (1) An electrophotographic photoreceptor comprising an intermediate layer and a photosensitive layer sequentially provided on a conductive support, characterized in that the intermediate layer is composed of an organic solvent-soluble resin and contains a nonionic antistatic agent. An electrophotographic photoreceptor. (2) The electrophotographic photoreceptor according to claim 1, wherein the nonionic antistatic agent is a compound represented by the following general formulas (I) to (V). ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(II) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(III) ▲There are mathematical formulas, chemical formulas, tables, etc.▼( IV) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(V) (In the formula, R represents an alkyl group)