JPS6059353A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic sensitive body having excellent filming property, mechanical strength, heat resistance, durability, electrifying characteristic and residual potential characteristic by using a thin film formed by vacuum deposition of poly-P-phenylene sulfide as an electric charge transfer material. CONSTITUTION:A film formed by vacuum deposition of poly-P-phenylene sulfide (PPS) is used as an electric charge transfer layer with an electrophotographic sensitive body provided with an electric charge generating material and an electric charge transfer material on a conductive base. The PPS has resistance as high as 10<17>-10<18>OMEGAcm, is an insulator, has excellent heat resistance and mechanical characteristics and is manufactured as an engineering plastic having high functions. The PPS is formed into a thin film by vapor deposition. The vapor deposition device is constituted of a vacuum vessel 1, a supporting base body 2, a shutter 3, an evaporating source 4, a heating power source 5 for the evaporating source, an evacuating system 6, a power source 7 for heating substrate, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to an electrophotographic photoreceptor comprising a layer made of a photocharge generating material and a layer made of a charge transporting material on a conductive support. The present invention relates to an electrophotographic photoreceptor that uses an effective charge transport material and has excellent coating properties, mechanical strength, heat resistance, durability, charging characteristics, and residual potential characteristics.

[Technical background of the invention and its problems]

The photoconductive process of electrophotographic photoreceptors consists of a photocharge generation process and a charge transport process. Conventional electrophotographic photoreceptors include methods in which the above two processes are performed using one material, and methods in which the two processes are performed using separate materials.

Of the two methods described above, the method in which each process is performed using separate materials allows for a wider selection of materials to be used for the photoreceptor, and improves the photoreceptor's sensitivity, acceptance potential, and other photographic characteristics. It has the advantage of being able to produce a photoreceptor with excellent coating properties, etc. when manufacturing a photoreceptor.

Conventionally, photoreceptors using this method include a photoreceptor in which a photocharge-generating layer made of amorphous selenium as a photocharge-generating substance is provided on a conductive support, and a charge transport layer made of polyvinyl carbazole is provided thereon. is well known.

However, the polyvinyl carbazole used for the charge transport layer lacks flexibility, so the formed layer is hard and brittle, and is prone to cracking and peeling, resulting in poor durability as a photoreceptor. be. Therefore, in order to increase the flexibility of polyvinylcarbazole, a method of using it together with a plasticizer has been proposed. However, this method has a major drawback in that residual charges in the charge transport layer increase, resulting in deterioration of electrophotographic properties such as fogging of images.

Furthermore, it has been proposed to use a low molecular weight organic compound as a charge transport material. Some of these low molecular weight organic compounds, such as 2,5-bis(P-diethylaminophenyl)-1,3,4-oxadiazole, have relatively excellent electrophotographic properties. Since it generally does not have the ability to form a film, it is used in combination with a polymeric binder that has the ability to form a film to form a charge transport layer. However, these low molecular weight organic compounds generally have poor compatibility with polymeric binders, even if they have excellent electrophotographic properties.
When a film is formed as a charge transport layer, it tends to crystallize and has poor thermal stability.

[Purpose of the invention]

An object of the present invention is to eliminate the drawbacks of electrophotographic photoreceptors containing the above-mentioned conventional materials, and to improve durability, charging characteristics, and An object of the present invention is to provide an electrophotographic photoreceptor with excellent residual market characteristics.

[Summary of the invention]

As a result of study, the present inventor has found that the above object is to provide an electrophotographic photoreceptor in which a layer consisting of a charge generating substance and a charge transporting substance is provided on a conductive support, and the charge transporting layer is vacuum evaporated with polyP-phenylene sulfide. The inventors have discovered what can be achieved by using membranes, and have completed the present invention.

Poly P-phenylene sulfide (PPS) used as a charge transport material in the present invention is an insulator with a high resistance of 10 to 10 Ωcm, and has excellent heat resistance and mechanical properties.
It is industrially produced as a high-performance engineering plastic technology. This PP8 has been formed by a melting method for some time, but it has recently been discovered that it can be made into a thin film by a vapor deposition method using a vacuum vapor deposition apparatus.

To manufacture the thin film of the charge transport layer of the present invention, the vacuum evaporation apparatus shown in FIG. 1 may be used. In Figure 1, 1 is a vacuum chamber, 2 is a support base, 3 is a shutter, 4 is an evaporation source, and 5
6 is a heating power source for the evaporation source, 6 is an exhaust system, and 7 is a lightning source for heating the substrate.

The thickness of this photoelectric charge generation layer thin film can be easily controlled by adjusting the deposition conditions. One of the features of the present invention is that the charge transport layer can be easily created in this way.

Examples of photocharge generating substances used in the present invention include the following.

(1) CdS and selenium alloys, (2) CdS
, CdSe.

Inorganic photoconductors such as Cd5Se, ZnO and Zn8, (3) phthalocyanine pigments such as metal phthalocyanines and metal-free phthalocyanines, (4) azo dyes such as monoazo dyes and yohysis azo dyes, (5) benylenic anhydride and penylene acid. Benylene thread pigments such as imide,
(6) Indigoid dye, (Kaquinacridone pigment, (8)
) Ant-2 quinones, polycyclic quinones such as pyrenequinones, (9) cyanine dyes, (10) xanthine dyes, (
11) A charge transfer complex consisting of an electron-donating substance such as, for example, poly-N-vinylcarbazole and an electron-accepting substance such as trinitrofluorenone; and (12) a eutectic formed from a pyrylium salt dye and a polycarbonate resin. Complex.

The electrophotographic photoreceptor of the present invention has a layered structure in which a vI charge generation layer and a charge transport layer are provided on a conductive support, but which of the heavy charge generation layer and the charge transport layer is placed as an upper layer depends on the electrode resistance. It depends on whether you choose the streetcar or the streetcar.

That is, since the compound of the present invention has a positive charge transfer predominance, in the case of negative charge, it is advantageous to use the charge transport layer as an upper layer.

The thickness of the coating of the photocharge generating material, the box, and the cargo transporting material in the present invention is determined based on the characteristics required for the electrophotographic photoreceptor during charging, but the thickness of the photocharge generating layer is usually 0.1 to 0.1.
It is appropriate that the thickness of the cargo transport layer is approximately 5 to 100 microns, and the total thickness of both layers is preferably 100 microns or less; It was confirmed that the sense of calendar decreased.

Brass, aluminum, gold, silver, etc. are used as the conductive support of the electrophotographic photoreceptor of the present invention, and these may be in the form of a thin sheet or cylinder having an appropriate thickness, hardness, or flexibility. , may be coated with a thin layer of plastic. It may also be metal-coated paper, metal-coated glass sheet or glass coated with a conductive layer of aluminum iodide, iodide@ or chromium oxide or tin oxide. Desirably, the trace support is itself electrically conductive or has an electrically conductive surface and is sufficiently strong to be handled.

〔Effect of the invention〕

As detailed above, the present invention uses a vacuum-deposited film of polyP-phenylene sulfide as a charge transport material to obtain a charge transport layer with excellent stain transport ability, high mechanical strength, and high thermal stability. Moreover, it has remarkable effects such as being able to obtain an electrophotographic photoreceptor with excellent durable charging characteristics and residual potential characteristics.

[Embodiments of the invention]

Example 1 Copper phthalocyanide was deposited to a thickness of 0.5 μm as a charge generation layer on a polyester support coated with aluminum vapor deposition, and poly P-phenylene sulfide was further applied thereon as a charge transport layer at a vacuum degree of 2×10. torr, substrate temperature 150-170° evaporation source temperature 390-400°0
Vacuum deposition was performed for 30 minutes.

The thickness of this film was 4μ.

The state of charging and attenuation of the photoreceptor thus obtained was investigated using an electrostatic vapor analyzer. The result is the amount of exposure (unit: 1ux-s) required to attenuate the sensitivity to half the initial value of the surface charge.
Expressed as ec), it is 4 at 8.51ux-sec with negative charging. After charging and exposing this photoreceptor 5,000 times under the same conditions as above, almost no abnormality was observed. It was found that it has excellent fatigue resistance.

Example 2 Phthalocyanine fluoride was vacuum-deposited as a charge generation layer on an aluminum-deposited support to a thickness of 0.5μ.

Furthermore, poly P-phenylene sulfide was vacuum-deposited thereon in the same manner as in Example 1. The film thickness was 4.5μ. The resulting photoreceptor was negatively charged in the same manner as in Example 1, and the half-reduction exposure was measured (7.01 ux -sec).

This photoreceptor was repeatedly charged and exposed 5,000 times under the same conditions as above, and as a result, almost no abnormality was observed and it was found that the photoreceptor had excellent fatigue resistance.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view showing one example of a thin film forming apparatus that can be employed in the present invention. DESCRIPTION OF SYMBOLS 1... Vacuum chamber, 2... Support base, 3... Shutter, 4... Evaporation source. Agent Patent attorney Kensuke Chika (and 1 other person) M1 diagram

Claims (1)

[Claims] An electrophotographic photoreceptor comprising a photocharge generating material layer and a charge transporting material layer provided on a conductive support, wherein the charge transporting material is a thin film of polyP-phenylene sulfite tX vapor-deposited. body.