JPH01295262A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance reliability, to extend life, and the lower cost by filling a porous insulating layer with a photosensitive material and preventing deterioration of the mechanical strength of the porous layer and degradation of the performance of the photosensitive material. CONSTITUTION:The porous insulating layer 4 having pores 5 is formed on a barrier layer 3 made of a metal oxide film or a thin organic insulating film or the like formed on a conductive layer 2, and it is necessary that the layer 4 has high hardness in order to ensure high durability and high reliability and the pores 5 are distributed in high density and perpendicular to a support 1, good in straightness, large in diameter, and suitable in form for being filled with the photosensitive material; e.g., the layer 4 has a hardness of >=450Hv, a volume resistivity of 10<9>-10<11>OMEGA.cm, and the pores 5 have each a diameter of >=0.05mum, and an area ratio of >=30%, thus permitting an electrophotographic sensitive body to be enhanced in durability and reliability, and to be easily manufactured at low cost and in a wide allowance of design by filling the pores with the photosensitive material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photoreceptor used in electrophotography Wilt.

[Conventional technology]

Photoreceptors used in conventional electrophotographic devices are a-3e (amorphous selenium), CclS, ZnO, a-
3i-type evil photo and organic photo
oconductor.

Various types are known, but due to problems such as pollution, hygiene, and reliability, recently the A-5I series photosensitive film, which has excellent mechanical strength and high reliability, has been used. body, low cost and high degree of freedom in photoreceptor design.
PC is a typical example.

[Problem to be solved by the invention]

However, the a-3i photoreceptor has disadvantages in that the current technology requires expensive equipment, has low productivity due to slow film formation rate, and is more expensive than other photoreceptors. On the other hand, OPC deteriorates due to mechanical stress and chemical reactions with ozone, etc., and has the disadvantage of being inferior in durability compared to other photoreceptors, and has not yet been sufficiently improved.

The present invention was made to solve the above-mentioned problems of conventional electrophotographic photoreceptors, and is non-polluting, highly reliable, and low-cost, and has a greater degree of freedom in designing photoreceptors than conventional photoreceptors. The object of the present invention is to provide a highly durable electrophotographic photoreceptor having excellent mechanical strength.

[Means and effects for solving the problems] In order to solve the above problems, the present invention provides a support, a conductive layer laminated on the support, a conductive layer laminated on the conductive layer, and a conductive layer laminated on the conductive layer. An electrophotographic photoreceptor is composed of a porous insulating layer filled with an electrophotographic photosensitive material and a porous insulating layer filled with an electrophotographic photosensitive material.

In the electrophotographic photoreceptor constructed in this way, the mechanical strength of the porous insulating layer makes it possible to improve the durability and reliability without impairing the performance of the photosensitive material to be filled. Since it is constructed by filling the holes, it is possible to easily obtain an electrophotographic photoreceptor with a wide degree of freedom in photoreceptor design at low cost.

〔Example〕

The outline of the structure of the electrophotographic photoreceptor according to the present invention will be explained in the first part.
The explanation will be based on the schematic diagram shown in the figure. In the figure, 1 is a support, and 2 is a conductive layer disposed on the support 1. These are not limited to specific shapes, materials, etc., and form an electrophotographic photoreceptor. From the above, you can choose one that best suits your needs. Examples of the material of the support include glass, plastic, paper, and metals such as aluminum, and the conductive layer is preferably an aluminum vapor-deposited film or a tin oxide film. This is a porous insulating layer having pores 5 disposed on the conductive layer 2 via a barrier layer 3 made of a thin film or the like.The important factors of this porous insulating layer 4 are mechanical strength,
Wear resistance and distribution and shape of pores 5. That is, the porous insulating layer 4 is required to have high hardness in order to achieve high durability and high reliability, and the pores are densely distributed, perpendicular to the support 1, and have a large straight diameter. For example, porous ceramics, porous alumite, etc. are used. 6 is a photosensitive material filled in the pores 5 of the porous insulating layer 4. Although various conventional photosensitive materials can be used as the photosensitive material 6, OPC is particularly preferred because of the wide degree of freedom in designing the photoreceptor.

Describing the detailed structure of the porous insulating layer 4, the hardness is 450 Hv (Vickers hardness: load 50 g) or more, the volume resistivity is 109 to 1011 Ω' cm, and the diameter of the pores 5 is 0.05 μm or more. The area ratio needs to be 30% or more. That is, if the hardness of the porous insulating layer 4 is less than 450 Hv, it will not be possible to obtain the same durability as the AszSe:+ photoreceptor, and the volume resistivity will be 109 Ω・
If it is less than 10 cm, the charging potential is low, and if it exceeds 1011 Ωcm, the residual potential becomes high, and in either case, sufficient potential contrast cannot be obtained.Also, if the diameter of the pore 5 is 0.0
If the thickness is less than 5 μm, the filling of the photosensitive material becomes incomplete, creating voids in the pores 5 and inhibiting the movement of charges, resulting in accumulation of residual potential and reduction in sensitivity. Also, the pore area ratio is 3
If it is less than 0%, the original sensitivity of the filled photosensitive material cannot be obtained and the residual potential becomes high. Therefore, the porous insulating layer 4 needs to be configured as described above.

Note that the upper limit of the diameter of the pores 5 is set in relation to the particle size of the toner used. That is, if the diameter of the pores becomes larger than the particle size of 1.s-0, there is a possibility that the toner will affect the photosensitive material filled in the pores.

Therefore, when using toner having a particle size of about 1 μm, the diameter of the pores 5 is set to about 1 μm or less. Further, the upper limit of the pore area ratio is set based on the strength of the material of the porous insulating layer. For example, when porous alumite is used, its strength can be sufficiently maintained up to 50 to 60%, so the upper limit is set to about 70%.

Next, a specific example of an electrophotographic photoreceptor including a porous insulating layer filled with a photosensitive material according to the present invention will be described.

(First Example) A drum formed using an aluminum material of JIS standard A-6063 is prepared, and after mirror-finishing the surface of the drum, it is immersed in trichlorethylene, and then cleaned with its vapor. Next, in order to chemically polish this, H
A chemical polishing solution was prepared by adding 5% concentration of HNO3 to 3POa and adjusting the solution temperature to 100 to 110°C.
The aluminum drum is immersed in this for 30 seconds and then washed with water to perform smut removal treatment.

Next, a slight chemical etching was performed using a NaOH aqueous solution.
After neutralization with an aqueous HN 03 solution and washing with water, a porous alumite film is formed in a previously prepared aluminum anodic oxidation bath. The aluminum anodization conditions were set as follows.

Bath composition: H2C2045% by weight H2SO40.5% by weight Bath temperature: 25±2''C Current density: 2A/dm2 Treatment time: 15 minutes Thickness of produced film: 15 μm Hardness of produced film: 4501 (v) Volume resistivity of produced film: 1. 5 Xl0I0Ω·cm Pore diameter: 005 μm Pore area ratio: 40% Next, vacuum drying is performed at 120° C. for 60 minutes to remove adsorption of water molecules in the pores.

On the other hand, as photosensitive materials, PVK (polyvinylcarbazole') Sg/l, TNF (1-linitrofluorenone)4. g#! Composition of THF (tetrahydrofuran)? 8
Prepare the solution and immerse the anodized drum in it.
After leaving it for 0 to 60 minutes, gradually reduce the degree of vacuum], X 1
The surface is air-dried by exhausting the air to 0-'Torr and leaving it until it reaches atmospheric pressure. Then 120°C
By performing heat treatment for 2 hours, the production of the electrophotographic photoreceptor of the first embodiment is completed.

Next, Comparative Examples (1) to (8) were treated in the same manner as in Example 1 except that the aluminum anodizing conditions were changed as shown in Table 1.
) was produced.

Table 1 further shows that after being treated in the same manner as in Example 1 before the aluminum anodizing process, PVK20g/CTNF16
A THF solution with a composition of g/ff was prepared, and an aluminum drum that was not subjected to anodizing treatment was dipped in this solution and coated to a dry thickness of 10 μm, and then heated at 120°C.
A reference example (1) without a porous insulating layer was heat treated for 2 hours at
) photoreceptor was created.

(Second Example) After performing aluminum anodization treatment on an aluminum drum in the same manner as in the first example, Se○235g/L
In a solution of HgS○42g/β at a liquid temperature of 25±2°C, using carbon as the anode material, secondary electrolysis was performed with an applied voltage of 15μ and a treatment time of 5 minutes, and approximately 0.5μ was deposited at the bottom of the pores.
m of Se is precipitated, thoroughly washed with water, and then vacuum dried at a temperature of 120° C. to remove adsorbed water molecules.

Next, PVK5wt% THF? 20-30 in liquid
After soaking for 20 minutes, it is treated in the same manner as in the first example.
Filled with VK. This was then heated at 230°C and heated to 6
The electrophotographic photoreceptor of Example 2 was prepared by rapidly cooling in silicone oil adjusted to 0°C.

In order to compare with the photoreceptor of the second example, the process up to the aluminum anodizing process was performed in the same manner as in the first example, and then a-5e was vacuum-deposited to a thickness of about 0.5 μm, and then the film thickness after drying was A THFi solution of 20 g/A of PVK was coated so that the thickness of the photoreceptor was 10 μm, and dried to produce a photoreceptor of Reference Example (2) without a porous insulating layer corresponding to the second example.

Table 2 shows the results of measuring the electrophotographic properties of the Examples, Comparative Examples, and Reference Examples prepared as described above using the electrophotographic property testing apparatus shown in FIG.

In addition, in FIG. 2, 11 is a photosensitive drum to be tested, 12
13 is a transmission type surface electrometer for measuring the potential on the surface of the charged photoreceptor drum; 14 is the transmission type surface electrometer 13;
an exposure light source for exposing the photoreceptor drum 11 through;
Reference numeral 15 denotes a static elimination light source for eliminating static electricity from the photoreceptor drum 11 after exposure, and 16 a surface electrometer for measuring the residual potential of the photoreceptor drum 11 after static electricity removal.

Table 2: However, V: Initial charging potential (V) during the first test TI/□-1: Half time of charging potential due to light irradiation during the first test (Iuχ°5eC) VR; Residual potential (V) VO-2: Initial charging potential (V) at the 500th test TI/2-2: Half-life time (lux-sec) of charging potential due to light irradiation at the 500th test As can be seen from Table 2, comparative examples [1,), +2
1° (4) and (5) have relatively high hardness but high residual potential, while comparative examples (3), +6+, (7+,
Although the residual potential of (8) is low, the hardness is insufficient.

On the other hand, the photoreceptors of the first and second embodiments of the present invention are
The reference example (
It was confirmed that the electrophotographic properties were almost the same as those of the standard samples designated as 1, 1, and [21, and that it had sufficient functionality as a photoreceptor.

〔Effect of the invention〕

As explained in detail above, according to the present invention, it is possible to maintain the mechanical strength of a porous insulating layer without impairing the performance of the photosensitive material filled in the porous insulating layer. OPC with wide flexibility in photoconductor design
When used as a filled photosensitive material, the drawbacks of conventional durability are improved and its advantages are maintained, making it possible to obtain a highly reliable, long-life, and low-cost electrophotographic photoreceptor. .

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view schematically showing an electrophotographic photoreceptor according to the present invention, and FIG. 2 is a diagram showing an apparatus for testing characteristics of the electrophotographic photoreceptor. In the figure, 1 is a support, 2 is a conductive layer, 3 is a barrier layer,
4 is a porous insulating layer, 5 is a pore, and 6 is a photosensitive material. Patent applicant Olympus Optical Industry Co., Ltd. Figure 2

Claims (1)

[Claims] 1. Comprising a support, a conductive layer laminated on the support, and a porous insulating layer laminated on the conductive layer, the pores of which are filled with an electrophotographic photosensitive material. An electrophotographic photoreceptor characterized by: 2. The porous insulating layer has a hardness of 450 Hv or more, a volume resistivity of 10^9 to 10^1^1 Ωcm, a pore diameter of 0.05 μm or more, and an area ratio of 30% or more. The electrophotographic photoreceptor according to claim 1, characterized in that: