JP2631413B2 - Selentellur photoconductor for electrophotography - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a selentellurium photoreceptor for electrophotography, and more particularly to an improvement in its environmental resistance.

(Prior Art and Problems Thereof) A charge transfer layer (2) made of selenium-tellurium-chlorine is formed on a function-separated selenium telluride photoconductor, for example, a conductive substrate (1) as shown in FIG. Selenium on it
A selenium telluride photoreceptor formed with a tellurium charge generation layer (3) has excellent photosensitivity and is still widely used in electrophotographic devices even today.

However, as is well known, the selentellur photoconductor has drawbacks in terms of so-called environmental preservation, such as high temperature resistance and high humidity resistance, which are significantly inferior to organic photoconductors and other photoconductors. Further, if foreign matter adheres or comes into contact with the surface of the photoreceptor, there is a disadvantage that the state easily transitions from the amorphous state to the crystalline state, and the characteristics of the photoreceptor cannot be maintained.

In order to improve the above drawbacks, attempts have been made to add arsenic to the charge generation layer (3) or to the whole layer in FIG. 1, but this method increases dark decay and increases residual potential. Invite. Therefore, it is necessary to consider the limitation of the arsenic addition concentration, the limitation of the thickness of the arsenic addition layer, and the like, and the effect of sufficiently improving the environmental preservation cannot be exhibited. In addition, even when the photoreceptor does not contain arsenic, even at high temperatures (especially 35
(° C. or more), which increases the dark decay, and further increase in the dark decay due to the addition of the arsenic significantly promotes a decrease in surface potential and deteriorates electrical characteristics.

(Object of the Invention) The present invention has been made for the purpose of realizing a photoreceptor in which a decrease in surface potential is small even by addition of arsenic.

(Means of the Present Invention for Solving the Problems) In the function-separated type photoreceptor, charge is injected from the conductive substrate to the charge generation layer to change the surface potential. Varies by amount. Therefore, if the injection of charges from the conductive substrate as described above can be controlled by some means, it is possible to limit the decrease in the surface potential due to the addition of arsenic. The present invention has been conceived from the above, and the features of the present invention are as follows. That is, as shown in FIG. 2, a resin insulating layer (4) is formed on a conductive substrate (1), and the charge generation layer (3) is converted from the conductive substrate (1) by selecting the material thickness and the like.
It is characterized in that the amount of electric charge injected into the substrate is limited, so that the decrease in surface potential due to the influence on the electrical characteristics due to the addition of arsenic is limited.

In this way, the decrease in surface potential due to the addition of arsenic in addition to the significant decrease in surface potential due to an increase in dark decay due to deterioration at high temperatures is limited. Therefore, it is possible to obtain a selentellur photoconductor excellent in both electrical characteristics and environmental preservation.

 Hereinafter, the present invention will be described specifically with reference to Examples.

(Example) PVK (polyvinyl carbazole) dissolved in benzene was used as a material for forming the resin insulating layer (4) in FIG.
A resin insulating layer (4) of 0.5 and 1.0 μm is formed, and a charge transfer layer (2) made of selenium-tellurium-chlorine (tellurium 4%, chlorine 30 ppm) and selenium-tellurium-arsenic (tellurium 12) are formed thereon.
% And 1% of arsenic), and evaluation samples 1 to 4 in which charge generation layers (3) each composed of layers were sequentially laminated were produced. At the same time, even if arsenic was added, Comparative Example 1 having no resin insulating layer (4) (thickness: 0) and a resin-free insulating layer, comprising selenium-tellurium-chlorine (tellurium 4%, chlorine 30 ppm) Comparative Example 2 having no charge of arsenic, provided with a charge transfer layer (2) made of and a charge generation layer (3) made of selenium-tellurium (tellurium 12%).

These photoreceptors were mounted on a normal electrophotographic apparatus, and various electric characteristics such as residual potential and surface potential reduction were measured and an image test of 100 sheets was performed. The results shown in Table 1 were obtained. .

As is clear from Table 1, the residual potential of the photoreceptor provided with the resin insulating layer is slightly higher than that of the normal selentelluric photoreceptor shown in Comparative Example 2, but for example, Sample No. 3
And Comparative Example 2 By appropriately selecting the film thickness, the decrease in the surface potential can be reduced.

After 100 image tests, a standing test was performed in an environment of 50 ° C. and 60% RH. As a result, the surface of the comparative example 2 without arsenic was clouded and the photosensitive characteristics were lost. It was clarified that the added evaluation samples 1 to 4 and Comparative Example 1 did not change in both appearance and electrical characteristics.

The charge transfer layer is selenium-tellurium-chlorine, the tellurium concentration is 2 to 8%, the chlorine concentration is 10 to 100 ppm, the charge generation layer is selenium-tellurium-arsenic, and the tellurium concentration is 5 to 5%.
Even when the present invention was applied to a photoreceptor having an arsenic concentration of 20% and an arsenic concentration of 0.1% to 5%, it was confirmed that environmental resistance could be improved while obtaining practically required electrical characteristics.

An experiment was performed using PC (polycarbonate) in addition to the above PVK as the material of the resin insulating layer (2), and equivalent results were obtained.

(Effects of the Invention) As is clear from the above, according to the present invention, an excellent effect that environmental resistance characteristics can be improved by adding arsenic while substantially maintaining the electrical characteristics required for a photoreceptor is obtained. As a result, the utility of the electrophotographic apparatus such as a copying machine in the market is extremely high.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a conventional photoreceptor, and FIG. 2 is an explanatory view of a photoreceptor of the present invention. (1) ... conductive substrate, (2) ... charge transfer layer, (3) ... charge generation layer, (4) ... resin insulation layer.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-250357 (JP, A) JP-A-61-204637 (JP, A) JP-A-61-20046 (JP, A) JP-A 61-204 273550 (JP, A) JP-A-61-52651 (JP, A) JP-A-62-49357 (JP, A)

Claims (1)

(57) [Claims] 1. An electrophotographic selentellurium photoreceptor having a charge transfer layer and a charge generation layer sequentially laminated on a conductive substrate, wherein a resin insulating layer is provided between the conductive substrate and the charge transfer layer, and the film thickness is provided. The charge transfer layer is selenium-tellurium-chlorine, the tellurium concentration is 2-8%, the chlorine concentration is 10-100 ppm, and the charge generation layer is selenium-tellurium-arsenic, and the tellurium concentration is Is 5 to 20% and the arsenic concentration is 0.1 to 5%.