JPS63309962A - Laminate type positively chargeable electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain superior electrophotographic characteristics and durability by laminating on a conductive supporting body an electric charge transfer layer containing a binder resin and a charge transfer material and a charge generating layer containing a specified azo compound and a charge transfer material. CONSTITUTION:The charge transfer layer formed on the conductive supporting body contains the binder resin and the charge transfer material dispersed in it and the charge generating layer formed on said layer contains the charge transfer material and the azo compound represented by formula I in which X is a biphenyl derivative; each of T and Z is an organic group composed, each in a specified molar proportion, of a mixture of combinations T-T, T-Z, and Z-Z, where each of T and Z is selected from residues of formulae II, III, and IV; in which A is an atomic group necessary to form a hydrocarbon ring or heterocyclic ring; E is benzene ring or heterocyclic ring having N atom at the P-position; G is residue of phenylene diamine groups; J is halogen; and (l) is an integer of 0-4, thus permitting the obtained photosensitive body to be high in photosensitivity the improved in residual potential.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a laminated positively charged electrophotographic photoreceptor.

(Prior Art) In conventional electrophotographic technology, the photosensitive layer of an electrophotographic photoreceptor uses inorganic materials such as selenium and cadmium sulfide.

Although zinc oxide and the like have been widely put into practical use, in recent years, research has been increasingly conducted on the use of organic photoconductive materials as electrophotographic photoreceptors.

Today, inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide are behind the fact that organic photoconductive materials are replacing inorganic photoconductive materials. This is based on the fact that although a photoreceptor using a single body has advantages in terms of basic characteristics for electrophotography such as charging characteristics and photosensitivity residual potential, it also includes various disadvantages. .

Many of the disadvantages are, for example, manufacturing difficulties, pollution of the raw materials, or problems with toxicity during sanitary use. In the case of selenium, in addition to the difficult manufacturing conditions of the selenium vapor deposition film, it is weak in mechanical strength and tends to crystallize selenium on the surface of the photoreceptor.In the case of cadmium sulfide, it is sensitive to temperature and humidity. , there is a pollution problem with cadmium compounds. In addition, in the case of zinc oxide, dispersion stability is a problem when dispersing zinc oxide particles in a resin.
It has problems such as fatal characteristic deterioration due to temperature and humidity.

On the other hand, compared to inorganic photoconductive materials, it is often possible to use resin as a binder for organic photoconductive materials.
Solution acid salts are easy to manufacture and inexpensive in both dispersion and use forms. In addition, the photosensitive layer has excellent flexibility, it is easy to obtain a photosensitive member with various functions depending on the intended use of the photosensitive member, and the photosensitive member can be designed in a variety of ways.

In view of these points, research and development of electrophotographic photoreceptors using organic photoconductors has recently become more active, and electrophotographic photoreceptors using various organic photoconductors have been proposed and industrially implemented. Some have even been put into practical use.

Furthermore, positively charged organic photoreceptors are expected to be able to reduce the cost of copying machines by simply replacing them with amorphous selenium photoreceptors.

However, although various electrophotographic photoreceptors have been proposed, there are still not enough photoreceptors that satisfy the basic characteristics required for a photoreceptor, such as mechanical strength, durability, and storage stability. It has not been done.

(Problems to be Solved by the Invention) As described above, electrophotographic photoreceptors have poor basic characteristics such as photosensitivity, charging characteristics, residual potential characteristics, and durability. There was a problem.

The present invention was made to solve these problems, and an object of the present invention is to provide an electrophotographic photoreceptor having excellent electrophotographic properties and good durability.

[Structure of the Invention] (Means and Effects for Solving the Problems) The present invention has solved the problems with the configuration shown below.

A charge transport layer containing a charge transport material in a binding resin is formed on a conductive support, and a charge transport layer containing an azo compound represented by the general formula: % formula % and a charge transport material is formed on the charge transport layer. This is a laminated positively charged electrophotographic photoreceptor provided with a generation layer.

In particular, it is a laminated positively charged electrophotographic photoreceptor in which the weight ratio of the charge transport material contained in the charge transport layer to the binding resin is 1.5 or more.

In addition, the charge transport material contained in the charge transport layer is CI! ,.

This is a laminated positively charged electrophotographic photoreceptor made of a material shown in the following.

Furthermore, the laminated positively charged electrophotographic photoreceptor according to claim 1 is characterized in that the charge transport material contained in the charge transport layer is a material represented by the following.

The conductive support used in the present invention may be any support that is normally used as a conductive support for electrophotographic photoreceptors, and is not particularly limited. Examples of the body include metal materials such as brass, aluminum, gold, and silver; materials whose surfaces are coated with a thin film of plastic; metal-coated paper, metal-coated plastic sheets, or aluminum iodide, copper iodide, and oxide. Examples include glass coated with a conductive layer such as chromium or tin oxide. These are used as thin cylindrical sheets with appropriate thickness, hardness, and flexibility, and either the support itself is electrically conductive or its surface is electrically conductive, and has sufficient strength when handled. It is preferable that it has the following.

The present photoreceptor can be produced by coating using a solvent together with a polymerizable film-forming binder to form a film.

The polymerizable film-forming binder may be any binder commonly used as a binder, and examples thereof include the following.

Polyester resin, polycarbonate resin, polyarylate resin, butyral resin, polystyrene resin, styrene-butadiene copolymer resin, polyvinyl acetal resin, diallyl phthalate resin, silicone resin, polysulfone resin, acrylic resin, methacrylic resin, vinyl acetate resin.

Polyphenylene oxide resin, alkyd resin.

These include styrene-maleic anhydride copolymer resin, phenol resin, and the like, and these can be used alone or as a copolymer, singly or in combination of two or more.

(Example) Next, Examples of the present invention will be shown, but the present invention is not limited thereto. In addition, as shown in Table 1, the azo compound used in the charge generation layer is represented by the general formula (■). Although the various materials shown are used, other materials may be used.

Example 1 4 parts by weight of Compound V shown below and polyvinyl butyral resin (S-LEC BM-1 were applied like building blocks,
Dry.

Separately, 3 parts by weight of the charge generating agent IV-(a), 7 parts by weight of the charge transporting agent (■), and 10 parts by weight of polyarylate resin (U-100゜Unitika) were dissolved and mixed in 1,2-dichloroethane, and the mixture was ball-milled. After dispersing for 48 hours, this coating solution was applied and dried to a film thickness of 10-
It was applied onto the TLW using a pull-up method.

The electrophotographic properties of the thus obtained photosensitive plate were evaluated using a paper analyzer (Yorojuki@5P-428 model).

As a result, when the corona charge was measured at +6kV,
Initial band 9 with a charge amount of 900v! The charge retention rate after 5 seconds for the amount is 98%, and the tungsten light (151!ux)
The half-decrease exposure amount was 1.3 Qux·sec.

On the other hand, when a drum coated in the same manner was placed on a Toshiba PPC machine and imaged under the same conditions as selenium, a good image with an image density of 1.3 or higher and no fogging was obtained.

Example 2 4 parts by weight of the compound (1) shown below and polyvinyl butyral resin (S-LEC BM-1 were applied like building blocks,
Dry.

On the other hand, 3 parts by weight of the charge generating agent IV-b, 8 parts by weight of the charge transporting agent (2), and polyarylate resin (U-1oo).

Unitika) was dissolved and mixed in 1,2-dichloroethane and dispersed for 48 hours using a ball mill.The coating solution was then applied to the previously coated and dried CTL layer to a film thickness of 9'μs. It was applied using the upward pull method.

The electrophotographic properties of the thus obtained photosensitive plate were evaluated using a paper analyzer (Model FISP-428). As a result, when corona charging was measured at +6 kV, the charge retention rate after 5 seconds with respect to the initial charge amount was 94% at a charge iu:t ssov, and when tungsten light (15
The half-reduced exposure amount for 1.5 Qux・tae
It was c.

On the other hand, when a drum coated in the same manner was placed on a Toshiba PPC machine and imaged under the same conditions as selenium, a good image with an image density of 1.3 or more and no fogging was obtained.

Example 3 6 parts by weight of Compound V shown below and polyvinyl butyral resin (S-LEC BM-1f) were applied in a wet manner and dried.

On the other hand, charge generation agent N-c was added to 3f! 8 parts by weight of charge transport agent V and 10 parts by weight of polyarylate resin (U-100° Unitika) were coated onto the CTL layer which had been dried with 1,2-dichloroethane by a pulling method.

The electrophotographic properties of the thus obtained photosensitive plate were evaluated using a paper analyzer (SP-428 model manufactured by Kawaguchi Denki). As a result, when corona charging was measured at +8 kV, the charge retention rate after 5 seconds with respect to the initial band Wl amount was 98% at a charge amount of 900 V, and tungsten light (151 ux)
The half-decrease exposure amount was 1.2 ff1ux·SeC.

On the other hand, when a drum coated in the same manner was placed on a Toshiba PPC machine and imaged under the same conditions as selenium, a good image with an image density of 1.3 or higher and no fogging was obtained.

(See the margins below) [Effects of the Invention] The structure of the present invention improves charge transport efficiency, prevents white spots caused by secondary aggregation of pigment particles on images, and provides high sensitivity and memory storage. Therefore, a photoreceptor with improved residual potential can be obtained.

Agent: Patent Attorney Noriyuki Chika Same as Mitsuyuki Matsuyama

Claims (4)

[Claims] (1) A charge transport layer containing a charge transport material in a binding resin is formed on a conductive support, and the general formula: T-N=N-X-N=N-Z is formed on the charge transport layer. However, X is a biphenyl derivative, and T and Z are the same or different T-T, T-Z, Z- selected from the general formulas (I), (II), and (III) shown below. It is an organic group in which compounds of the combination of Z are mixed in a molar ratio of T and Z. General formula (I): ▲Mathematical formulas, chemical formulas, tables, etc.▼ [However, A is a group of atoms necessary to complete a substituted or unsubstituted hydrocarbon ring, or a substituted or unsubstituted heterocycle, E is a substituted benzene ring having N at the p-position or a substituted or unsubstituted heterocycle. ] General formula (II): ▲There are mathematical formulas, chemical formulas, tables, etc.▼ General formula (III): ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [However, G is a residue of phenylenediamines, and J is a halogen 1 is a group of integers from 0 to 4 selected from 1. A laminated positively charged electrophotographic photoreceptor comprising a charge generation layer containing an azo compound represented by the formula and a charge transporting material. 〕〕 (2) The laminated positively charged electrophotographic photoreceptor according to claim 1, wherein the weight ratio of the charge transport material contained in the charge transport layer to the binding resin is 1.5 or less. (3) The laminated positive charging electrophotographic photosensitive material according to claim 1, characterized in that the charge transporting material contained in the charge transporting layer is a material represented by ▲A mathematical formula, a chemical formula, a table, etc.▼ body. (4) The laminated positive charging electrophotographic photosensitive material according to claim 1, characterized in that the charge transporting material contained in the charge transporting layer is a material represented by ▲a mathematical formula, a chemical formula, a table, etc.▼ body.