JPH02129652A - Organic photosensitive body having laminated structure - Google Patents

Abstract

PURPOSE:To obtain an org. photosensitive body having a laminated structure having also high sensitivity to long wavelength light of semiconductor laser by constituting the photosensitive body of a charge transfer material consisting of a specified styryl compd. and a charge generating material consisting of an X-type metal free phthalocyanine and using a chlorine-contg. resin as binder resin for constituting a charge generating material layer. CONSTITUTION:In an org. photosensitive body having a laminated structure provided with a charge transfer layer and a charge generating layer on an electroconductive base body, an X-type metal free phthalocyanine is incorporated as charge generating material into a charge generating layer incorporating simultaneously a chlorine-contg. resin thereinto as binder resin, and incorporating also a styryl compd. expressed by the formula I into a charge transfer layer as charge transfer material. Thus, an org. photosensitive body having high sensitivity to light having a wavelength of semiconductor laser is obtd., which can be used suitably as photosensitive body for laser beam printer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a layered organic photoreceptor, and more specifically, a charge generating layer containing a charge generating substance and a charge generating layer containing a charge transporting substance on a conductive support. The present invention relates to a laminated organic photoreceptor that has a generation layer, has high sensitivity to the wavelength of a semiconductor laser, and can be suitably used as a photoreceptor for a laser beam printer.

Traditionally, small limb deformities have recently been published in Japanese Patent Publication No. 55-42380 and Special Publication No. 60-3.
As described in Japanese Patent No. 4099, in electrophotographic devices, a layered organic material is used, in which a charge generation layer containing a charge generation substance and a charge generation layer containing a charge transport substance are laminated on a conductive support. A euphotoreceptor has been developed and put into practical use. As shown in FIG. 3, such a laminated organic photoreceptor includes, for example, a charge generation layer 4 and a charge transport layer 5 laminated on a conductive support 3 formed by vapor-depositing aluminum 2 on a polyester film 1. ing.

In these laminated organic photoreceptors, the charge transport layer is
For example, a charge transport material is made into a solution or dispersion with an appropriate organic solvent, a binder, and if necessary a plasticizer, etc., and this is applied onto a conductive support or a charge generation layer thereon, and then dried. It is prepared by forming a film with a thickness of about 5 to 100 μm. Further, the charge transport layer is prepared by dissolving a charge transport substance in a binder and forming a film with the resultant mixture.

Conventionally, a wide variety of charge generating substances have already been known. For example, in Japanese Patent Application Laid-Open No. 62-30255, a styryl compound represented by the following is used as a charge transporting substance, and copper phthalocyanine is used as a charge generating substance. A laminated electrophotographic photoreceptor has been proposed. However, this electrophotographic photoreceptor still does not have satisfactory performance in terms of charging ability, sensitivity, etc.

It has long been known that various metal phthalocyanine compounds and metal-free phthalocyanines, including the copper phthalocyanine mentioned above, have photoconductivity; for example, US Pat.
16.118 describes a single-layer type photoreceptor using X-type metal-free phthalocyanine, but the sensitivity is low.

On the other hand, in recent years, there has been a demand for photoreceptors for laser beam printers that have sensitivity around 780 nm, which is the wavelength of semiconductor lasers, and extensive research and development has been carried out. A photoreceptor used as a charge generating material has low sensitivity to long wavelength light from a semiconductor laser.

As a result of intensive research to obtain an organic photoreceptor that can be used as a photoreceptor for laser beam printers, the present inventors unexpectedly discovered that a specific charge transport material By using a styryl compound, using an X-type metal-free phthalocyanine as a charge generating substance, and using a chlorine-containing resin as a binder resin for forming the charge generating layer, it has high sensitivity at 800 nm. Thus,
The present invention was achieved by discovering that it is possible to obtain a laminated organic photoreceptor having sensitivity around 780 nm, which is the wavelength of a semiconductor laser.

The present invention provides a multilayer organic photoreceptor comprising a charge generation layer and a charge transport layer on a conductive support, wherein the charge generation layer contains an X-type metal-free phthalocyanine as a charge generation substance. In addition, it is characterized in that it contains a chlorine-containing polymer as a binder, and the charge transport layer contains a styryl compound represented by as a charge transport substance.

In the electrophotographic photoreceptor according to the present invention, the charge generating substance is an X-type metal-free phthalocyanine and is represented by the following formula.

In addition, the X-ray diffraction diagram of X-type metal-free phthalocyanine (CuK
(alpha ray, powder method) is shown in Figure 1.

In the layered organic photoreceptor according to the present invention, the charge transporting material is a styryl compound represented by the above-mentioned symbol.

The laminated organic photoreceptor according to the present invention contains a solution or dispersion containing an A charge generation layer is formed by coating on a conductive support and drying.A solution containing the styryl compound, an organic solvent, a binder, and if necessary a plasticizer is coated on this and dried. This can be obtained by forming a charge transport layer. However, the charge generation layer and charge transport layer on the conductive support may be laminated in the reverse order to the above.

The content of the chlorine-containing polymer as a binder in the charge generation layer is preferably as small as possible, but is usually in the range of 5 to 50% by weight. In addition, the thickness of the charge generation layer is usually
It ranges from 0.05 to 20 μm, preferably from 0.1 to 10 μm.

Examples of the chlorine-containing polymer include polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-EV
Vinyl chloride copolymers such as A-graft copolymer and vinyl chloride-vinyl acetate-maleic anhydride copolymer are preferably used. In the case of vinyl chloride copolymers, those having a vinyl chloride content of 20% by weight or more are preferably used.

The content of the styryl compound as a charge transport substance in the charge transport layer is usually 10 to 60% by weight, and the thickness of the charge transport layer is usually 5% to 60% by weight.
~100 μm is suitable.

The binder used to form the charge transport layer must be soluble in an organic solvent and compatible with the charge transport material so that a solution or dispersion of the charge transport material can be stably and easily prepared. It is preferable to use a resin that has a high mechanical strength, a low mechanical strength of its coating, and excellent transparency and insulation properties.

For example, polycarbonate, polystyrene, polyester, polyvinyl chloride resin, styrene-acrylic copolymer, etc. are suitable.

The organic solvent used to form the charge generator layer and the charge transport layer is not particularly limited, but examples include Eva, chloroform, 1.2-dichloroethane, 1.1.2.2-
Tetrachloroethane and tetrahydrofuran are preferably used.

The multilayer organic photoreceptor according to the present invention uses a specific styryl compound as a charge transporting substance, uses an X-type metal-free phthalocyanine as a charge generating substance, and has a structure in which: By using a chlorine-containing polymer as the binder resin, it has a high sensitivity to the wavelength of a semiconductor laser, so it can be suitably used as a photoreceptor for a laser beam printer.

Implementation (2) The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples in any way.

Example 1 Polyvinyl chloride (PVC-3R1 manufactured by Chisso ■, average degree of polymerization 800) was purified by reprecipitation using tetrahydrofuran and n-hexane, and vacuum-dried.

1.6 parts by weight of this polyvinyl chloride and X-type metal-free phthalocyanine as a charge generating substance (Dainippon Ink & Chemicals)
812OB) and 9 parts by weight of tetrahydrofuran.
In addition to 6.2 parts by weight, the mixture was mixed and pulverized in a ball mill for 2 hours to obtain a dispersion. Incidentally, FIG. 1 shows an X-ray diffraction pattern (CuKα ray, powder method) of the above-mentioned X-type metal-free phthalocyanine.

This dispersion was applied onto a polyester film coated with aluminum using a doctor blade, and the film thickness was 0.6 μm.
A charge generation layer of m was formed.

Separately, 10 parts by weight of polycarbonate (Niepilon E-2000, manufactured by Mitsubishi Gas Chemical Co., Ltd.) and 8 parts by weight of the styryl compound as a charge transport substance were dissolved in 82 parts by weight of chloroform, and the resulting solution was poured onto the charge generation layer. The film was coated using a doctor blade (with a gap of 10,100 μm), air-dried at room temperature, and then heated and dried at 70°C for 90 minutes to form a charge-generating layer with a thickness of 20 μm. Made the body.

Example 2 Example 1 was repeated except that a vinyl chloride-vinyl acetate copolymer (manufactured by Nippon Kayaku ■) having an acetic acid content of 15 wt. was used as a binder when forming the charge generation layer. A laminated organic photoreceptor was manufactured in the same manner as described above.

Example 3 In Example 1, a vinyl chloride-EVA graft polymer (Graftomer R-5 manufactured by Nippon Zeon ■) having a mole fraction of vinyl chloride of 50% was used as a binder in forming the charge generation layer. A multilayer organic photoreceptor was manufactured in the same manner as in Example 1 except for this.

Example 4 In Example 1, vinyl chloride-vinyl acetate-maleic acid copolymer (
A laminated organic photoreceptor was produced in the same manner as in Example 1, except that ESLETSUKU MF-10) manufactured by Block Chemical Industry Co., Ltd. was used.

Comparative Example 1 A laminated photoreceptor was produced in the same manner as in Example 2, except that N,N-diethylaminobenzaldehyde diphenylhydrazone was used as the charge transport material.

Comparative Example 2 In Example 1, the same polycarbonate as above was used as the binder when forming the charge generation layer.
A laminated organic photoreceptor was produced in the same manner as in Example 1.

The spectral sensitivity of the photoreceptor produced in Example 1 is shown in FIG. It has been shown to have high sensitivity in the wavelength range of semiconductor lasers.

Next, the electrostatic charging properties of each of the laminated organic photoreceptors obtained as described above were evaluated as follows using an electrostatic charging tester (Model 5P428 manufactured by Kawaguchi Electric Seisakusho ■).

That is, the surface of the photoreceptor was negatively charged by -6 KV corona discharge, and the potential of the surface of the photoreceptor at that time was measured and used as the initial potential. Leave it in the dark for 5 seconds and measure the potential.
The charge retention rate was determined. Next, the surface of the photoreceptor is irradiated with light at an illuminance of 5 lux using a halogen lamp, the time until the surface potential reaches 1/2 is measured, and the amount of exposure E+/z (lux/second) up to that point is calculated as the light intensity. Sensitivity.

In addition, as a measurement of photosensitivity to monochromatic light, the white light from the halogen lamp was converted into monochromatic light of 750 nm by combining a colored glass filter and an interference filter, and the light intensity was set to 0.5 μW/d, and the photoreceptor surface was Similarly, the time taken for the surface potential to reach 1/2 of the initial value is measured, and the exposure amount up to that point E+/z (μ
J/d) was determined as photosensitivity.

In either case, the potential 5 seconds after the light irradiation was measured as the residual potential. The above results are shown in Table 1.

[Brief explanation of drawings]

FIG. 1 shows an X-ray diffraction diagram (CuKα ray, powder method) of X-type metal-free phthalocyanine used as a charge-generating substance in the laminated organic photoreceptor according to the present invention, and FIG. FIG. 3, a wavelength-sensitivity curve showing an example of spectral sensitivity, is a cross-sectional view generally showing a laminated electrophotographic photoreceptor. 3... Conductive support, 4... Charge generating material layer, 5
...layer of charge transport material. Fig. 2 45 length (arm) Fig. 3

Claims (2)

[Claims] (1) In a multilayer organic photoreceptor comprising a charge generation layer and a charge transport layer on a conductive support, the charge generation layer contains an X-type metal-free phthalocyanine as a charge generation substance and contains chlorine as a binder. A laminated organic photoreceptor comprising a polymer and a charge transport layer containing a styryl compound represented by ▲a mathematical formula, a chemical formula, a table, etc.▼ as a charge transport substance. (2) The laminated organic photoreceptor according to claim 1, wherein the chlorine-containing resin is polyvinyl chloride.