JPS6180158A - Photosensitive body - Google Patents

Abstract

PURPOSE:To improve electrostatic charge retentivity, repeating use characteristics, printing resistance, etc., of a photosensitive body and to obtain a superior image free from fog by forming a resin layer contg. a specified hydrazone compd. as an undercoat layer on a conductive substrate. CONSTITUTION:The undercoat layer formed on the conductive substrate is composed of a resin contg. a hydrazine compd. represented by the formula in which R1 is H, methyl, or phenyl; R2, R3 are each alkyl, aralkyl, or aryl, or both may unite to form a ring; n is 1 or 2; and A is an aromatic or aromatic heterocyclic group. Such an undercoat layer may be formed in a various film thicknesses, and a superior surface smoothness can be obtained, thus permitting the charge retentivity, repeating use characteristics, and printing resistance of the photosensitive body to be improved, and a superior image free from fog to be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application for Business Owners The present invention relates to a photoreceptor having an undercoat layer and a photoconductive layer on a conductive substrate.

As general sliding photoreceptors, those in which a photoconductive layer is formed on a conductive substrate, or those in which a charge transport layer is further laminated thereon are widely known.

In such a photoreceptor, improvements in adhesion between the base and the photoconductive layer, improvement in coating properties of the photoconductive layer, protection of the substrate, covering of defects on the substrate, protection against electrical breakdown of the photoconductive layer,
It is effective to provide an undercoat layer between the substrate and the photoconductive layer in order to improve charge injection from the substrate to the photoconductive layer. Examples include JP-A-58-30757 and JP-A-58-9.
No. 5744 proposes a photoreceptor in which a polyimide resin is used as an undercoat layer.

By the way, the first characteristic required of the undercoat layer is electrical characteristics. Since it is used in an electrophotographic photoreceptor, it is important that the electrophotographic properties are not affected, and for this purpose, it is important that the electrical resistance is low. When the electrical resistance is high, a charged potential is applied to the undercoat layer, and fogging occurs in the image as a so-called residual potential. Therefore, if the undercoat layer is made only of resin, the residual potential will increase and fog will occur.

Furthermore, it is necessary that the electrical resistance of the subbing layer is unaffected by changes in the external environment, in particular by changes in atmospheric humidity. For example, if the electrical resistance increases due to low humidity, fogging will occur. The undercoat layer is required to have various properties as described above, but in the past, it has been difficult to obtain good properties when using only a single resin layer. Therefore, it is recommended to make the resin layer very thin, or if necessary, use conductive powder (e.g., conductive powder, copper, silver, etc.)
■(Dispersed in fat. However, reducing the thickness of the resin layer has the disadvantage that its performance as an undercoat layer is insufficient. On the other hand, undercoat with metal powder dispersed In the layer, since the metal particles were rough, there was a drawback that the surface quality of the undercoating dust was reduced.

-Problems that Ming is trying to address As mentioned above, the undercoat layers that have been proposed so far have insufficient electrical resistance characteristics, resulting in an increase in residual potential. For this reason, it is conceivable to reduce the thickness of the undercoat layer, but the performance of the undercoat layer itself deteriorates. Further, even if the conductive powder is dispersed, there is a drawback that the surface properties of the undercoat layer are deteriorated.

The purpose of the present invention is to provide a photoreceptor that eliminates the above-mentioned drawbacks, and specifically has a smooth surface and an undercoat layer that can be formed thickly, and has excellent overall electrophotographic properties. The purpose is to provide a photoreceptor.

The present invention provides a photoreceptor having an undercoat layer on a conductive substrate, in which the undercoat layer is electrically coated with a resin and contains a hydrazone compound represented by the following general formula (1). The gist is that.

[In the formula, R5 is hydrogen, methyl group or phenyl group, R2
, R1 represents an alkyl group, an aralkyl group or an aryl group, and R2 and R3 may be combined to form a ring.

n is a number of 1 or 2, and A represents an aromatic hydrocarbon group or an aromatic heterocyclic group which may have a substituent. ] As specific examples of the above hydrazone compound, the following can be used.

N-N On the other hand, polyvinyl alcohol, polyvinyl methyl ether, poly-N-viniciimiguzole, ethyl cellulose, methyl cellulose, ethylene-acrylic acid fuborimer, casein, gelatin, polyamide, etc. are conventionally known as resins for electrically sliding the undercoat layer. In addition to using general polyester resins, acrylic resins, vinyl acetate resins, vinyl chloride-vinyl acetate resins, polyvinyl butyral resins, thermoplastic resins or alkyd resins, melamine resins, urethane resins, epoxy resins, silicone resins, 7
Any thermosetting resin such as E7-el resin may be used, and is selected in consideration of adhesion with the substrate, compatibility with hydrazone, etc. Among these, polyester resins and polyvinyl butyl resins are particularly preferred in terms of adhesiveness.

The undercoat layer containing a hydrazone compound together with the above-mentioned resin has excellent surface smoothness and provides a considerable degree of freedom in determining the thickness of the scrap itself. That is, by containing the hydrazone compound, the thickness of the undercoat layer can be approximately 0.1 to 20 microns, preferably 1 to 15 microns. The hydrazone compound can be contained in the undercoat layer in a weight ratio of 0.1 to 70%, preferably 1 to 50%, and may be contained alone or in a weight ratio of 2f!
One or more hydrazone compounds may be used in combination. The inclusion of a hydrazone compound not only gives freedom to the nQ j'7 of the undercoat layer as described above, but also improves the charge retention ability of the photoreceptor and exhibits excellent repeatability and printing durability.

Specifically, the undercoating dust is formed by applying one or more hydrazone compounds dissolved or dispersed in a binder resin solution onto a conductive substrate. The application method is
This can be carried out using a coating method such as a dip coating method, a spray coating method, a spinner coating method, a bead coating method, a wire bar coating method, a Fleid coach ink method, a roller coating method, a curtain coating method, or the like. In addition, as the conductive substrate, a sheet or drum-shaped foil or plate of copper, aluminum, silver, iron, nickel, etc. is used, or these metals are vacuum-deposited or electrolessly deposited on a plastic film, etc. A plated material or a material in which a layer of a conductive compound such as a conductive polymer, indium oxide, or tin oxide is provided on a support such as paper or a plastic film by coating or vapor deposition is used.

As mentioned above, the undercoat layer has a thickness of 0.1 to 20 μm, particularly 1 to 1 μm.
It is desirable that the film thickness be about 5 μm; if the film thickness is too thin, the desired effect cannot be obtained, and if it is too thick, the resistance will increase and residual potential will accumulate. In addition, setting the content of the hydrazone compound to 0.1 to 70 wt% is 0.
．． This is because if it is less than 1%, an increase in residual potential is unavoidable, and if it is more than 70%, the coating film itself may not be homogeneous and crystallization may occur.

When an electron-accepting substance or a low-resistance substance is added to the undercoat layer of the present invention, if necessary, the properties are further improved in all aspects. Examples of the electron-accepting substance to be added include polycyclic or heterocyclic nitro compounds such as trinitroanthracene, trinitrofluorenone, dinitroacridine, and tetrathia/pyrene; These are electron-withdrawing group-substituted compounds such as acid anhydrides dinitrochlorobenzene, tricyanobenzene, chlorochlor, bromarol, tetracyanoethylene, tetracyafuki/dimethane, benzoquinone, and dinitrobiphenyl. Effective low-resistance materials are:
These are metal oxides such as zinc oxide, tin oxide, and titanium oxide, and organic conductive substances such as carbon black and 7-erocene.

A photoconductive layer is formed on the undercoat layer, but it is made of Se or CdS.
organic photoconductive materials such as those coated with a mixture of CdS, ZnO, TiO2 and insulating binder resin, polyvinyl carbazole, anthracene 1.7 lysyanine, etc., either by themselves or mixed with insulating binder resin. It is possible to use a coating coated with. Further, a protective layer or a charge transport layer may be formed on the photoconductive layer.

Effects of the Invention As is clear from the above description, according to the photoreceptor of the present invention, the surface smoothness of the undercoating dust is excellent and the film thickness can be set with a considerable degree of freedom.

As a result, the photoreceptor exhibits excellent charge retention ability, repeatability, and printing durability, and good images without fog can be obtained.

Examples will be described below.

Yuzanran L Polyester Resin Byron 200 (Toyobo Co., Ltd.)
! A solution prepared by dissolving 10 parts by weight of hydrazone compound example (1) and 6 parts by weight of hydrazone compound example (1) in 50 parts by weight of tetrahydro7ran was coated on an aluminum substrate to a thickness of about 3 μm and dried to form an undercoat layer. . Next, 20 parts by weight of ε-type copper phthalocyanine, 40 parts by weight of N-ethylcarbazole-3-aldehyde-methylphenylhydrazone, 40 parts by weight of polyester resin (Vylon 200, manufactured by Toyobo Co., Ltd.) and polycarbonate resin (Panlite) were added. 1300 to
: 40 parts by weight (manufactured by Yodai Kasei Co., Ltd.) were placed in a Pall Mill Bot along with 100 parts by weight of toluene/tetrahydro 7 run (1:9) and mixed for 48 hours to transform the photoconductive paint into TI.
! This paint was coated on the undercoat layer and dried to produce a photoreceptor having a photoconductive layer with a thickness of 10 μm.

Example 2 A solution prepared by dissolving 10 parts by weight of polyester resin Vylon 300 (manufactured by Toyobo Co., Ltd.) and 5 parts by weight of Hydrazone Compound Example (2) in 50 parts by weight of Tetrahydro 7ran was spread on an aluminum base to a thickness of about 5μ. , and dried to form undercoating waste. On top of this undercoat layer, Sc was evaporated to a thickness of 60 μm using a conventional method with an internal vacuum of 1×10’Lon.
A photoreceptor having a thick photoconductive layer was prepared.

Example 3 10 parts by weight of polystyrene resin Dialex 30 (manufactured by Misara Monsanto Kasei Co., Ltd.) and hydrazone compound example (3
) A solution prepared by dissolving 10 parts by weight of xylene in 50 parts by weight of xylene was applied to an aluminum substrate to a thickness of approximately 5μ, dried, and an undercoat layer was formed. As2Se:+ by the usual method at 1×105ton
A photoreceptor having a photoconductive layer with a thickness of 60 μm was prepared by vapor-depositing.

Example 4 Acrylic resin A405 (manufactured by Dainippon Ink Co., Ltd.) 1
0 parts by weight, 5 parts by weight of hydrazone compound example (4), and 3 parts by weight of titanium oxide were placed in a ball mill pot with 50 parts by weight of methyl ethyl ketone and kneaded for 24 hours. was applied and dried to form an undercoat layer.

50 parts by weight of copper phthalocyanine and 0.2 parts by weight of copper tetranitro-copper phthalocyanine are dissolved in 500 parts by weight of 98% concentrated sulfuric acid with thorough stirring, and this is poured into 3000 parts by weight of water to dissolve the light of copper-7-lysocyanine and copper-tetranitro-phthalocyanine. After depositing the conductive material composition, it was filtered, washed with water, and dried at 120° C. under reduced pressure. This photoconductive material composition 15
parts by weight, 20 parts by weight of polyester resin, 20 parts by weight of polycarbonate resin, 20 parts by weight of p-noethylaminobenzaldehyde diphenylhydrazone, 100 parts by weight of Tetrahydro7ran, and kneaded in a ball mill pot for 48 hours to obtain photoconductivity. A photoreceptor was prepared by preparing a photoreceptor and coating it on the undercoat layer so that it had a thickness of 10 μm after drying.

In Example 4, polyvinyl butyral 2000 (Denki Kagaku Co., Ltd.) 10 parts by weight, 3 parts by weight of zinc oxide, and 6 parts by weight of hydrazone compound example (16) were added to polyvinyl butyral for the undercoat layer. A photoreceptor was prepared using the same recipe as in Example 4, except that the composition was put into a ball millbot along with parts by weight and kneaded for 24 hours, and the resulting composition was coated on an aluminum substrate to a thickness of about 5μ. .

A photoreceptor was prepared using the same recipe as in Example 1 except that the side round undercoat layer was not provided.

Comparative Example 2 A photoreceptor was produced using the same formulation as in Example 1 except that the undercoat layer did not contain a hydrazone compound.

Each of the seven types of photoreceptors prepared as in the previous stage was used as a commercially available powder image transfer type electrophotographic copying machine (manufactured by Mi/Rutaka Co., Ltd.).
-350Z) Incorporated as a photoreceptor with +6KV corona discharge, initial surface potential (Vo), initial surface potential is 1/2
The amount of exposure required to achieve (El/2 (Lux 5ec
)) The attenuation rate (DDR, (%)) after 1 second in the dark after being charged to (Vo) and the image quality of the copies were investigated. The results are shown in Table 1, and the photoreceptor of the present invention has improved charge retention ability and can produce good images without deterioration in sensitivity.

Table 1 Table

Claims (1)

[Claims] 1. A photoreceptor having an undercoat layer on a conductive substrate,
A photoreceptor characterized in that the undercoat layer is a resin layer containing a hydrazone compound represented by the following general formula [I]. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [I] [In the formula, R_1 is hydrogen, methyl group or phenyl group, R
_2 and R_3 represent an alkyl group, an aralkyl group, or an aryl group, and R_2 and R_3 may be combined to form a ring. n is a number of 1 or 2, and A may have a substituent. Represents an aromatic hydrocarbon group or an aromatic heterocyclic group. 2. The photoreceptor according to claim 1, wherein the resin of the undercoat layer is polyester or polyvinyl butyral.