JPS62280865A - Organic photosensitive body for electrophotography - Google Patents

Abstract

PURPOSE:To improve the adhesiveness between a photosensitive layer and substrate and to prevent the generation of pinholes in the photosensitive layer by incorporating a mixture composed of the 8-nylon, titanium oxide (IV), tin oxide (II) and antimony into an under coating layer. CONSTITUTION:The mixture composed of the 8-nylon, titanium oxide (IV), tin oxide (II) and antimony is incorporated into the under coating layer. The titanium oxide (IV), tin oxide (II) and antimony are incorporated into the under coating layer in a 1-10pts.wt., more preferably 2-6pts.wt. range per 100pts.wt. 8-nylon. The environmental stability of the org. photosensitive body is debased if the content thereof is below 1pt.wt. The smoothness of the under coating layer is lost; therefore, the smoothness of the photosensitive body is spoiled if the content exceeds 10pts.wt. The tin oxide (II) is incorporated in the under coating layer in a 5-25pts.wt., more preferably 7-20pts.wt. range and the antimony is incorporated therein in a 2-15pts.wt., more preferably 4-12pts.wt. range per 80pts.wt. titanium oxide (IV). The layer thickness of such under coating layer is specified to a 2-40mum, more preferably 5-20mum range.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an organic photoreceptor for electrophotography, and in particular, to an organic photoreceptor that does not generate pinholes due to dielectric breakdown in the photosensitive layer and has good adhesion between the photosensitive layer and the substrate. The present invention relates to an electrophotographic organic photoreceptor in which the residual potential of the photosensitive layer can be effectively removed.

(Conventional technology) In electrophotographic reproduction processes that use organophotoreceptors.

The surface of the photosensitive layer is charged by a certain polar corona discharge or the like. This surface is then subjected to image exposure.

Charges (electrons or holes) are generated in the photosensitive layer.

This transfer of charge to the surface of the photosensitive layer neutralizes the charge on the surface of the photosensitive layer, thereby forming an electrostatic latent image corresponding to the original image.

However, since the adhesion between the substrate and the photosensitive layer is poor, the photosensitive layer is easily peeled off from the substrate. Due to the unevenness of the substrate, pinholes may occur in the photosensitive layer due to dielectric breakdown. Due to the occurrence of pinholes.

The durability of the organic photoreceptor decreases.

In order to solve these drawbacks, attempts have been made to provide an undercoat layer between the substrate and the photosensitive layer to prevent charge from being injected from the substrate into the photosensitive layer. As the undercoat layer, it is also possible to provide an electrically insulating blocking layer on the substrate, but in this case.

Charge is accumulated in the undercoat layer, resulting in a residual potential and causing fog in the image. Furthermore, in order to improve the photoresponsiveness during exposure, it is necessary to quickly release the charges generated in the photosensitive layer to the substrate side. Therefore, the undercoat layer needs to have dual properties of conductivity and insulation.

These subbing layers include, for example, an aluminum oxide (AlzOi) layer formed by anodizing a conductive substrate. However, alumite treatment is complicated.

Therefore, the obtained organic photoreceptor becomes expensive.

On the other hand, although various resins are used for the undercoat layer,
Removal of residual potential is not sufficient. In particular, most of the resins conventionally used for undercoat layers have an ionic conduction mechanism, and undercoat layers using these resins have a higher resistance value at low temperatures and low humidity than at room temperature. Therefore, the residual potential of the photosensitive layer at low temperature and low humidity is higher than the residual potential at room temperature.The undercoat layer also lacks adhesion with the substrate and the photosensitive layer. The adhesion between the photosensitive layer and the substrate is poor.The generation of pinholes in the photosensitive layer cannot be prevented.

(Means for Solving the Problems) The electrophotographic organic photoreceptor of the present invention is an electrophotographic organic photoreceptor having an undercoat layer and a photosensitive layer on a substrate, wherein the undercoat layer has a - contains a mixture of nylon, titanium (IV) oxide, tin (II) oxide and antimony, thereby achieving the above object.

By using a mixture of 8-nylon, titanium oxide (TV), tin (II) oxide, and antimony in the undercoat layer, the generation of pinholes in the photosensitive layer can be particularly effectively prevented. As a result, the durability of the organic photoreceptor is improved.

On the other hand, since titanium oxide (■), tin (II) oxide, and antimony are electronically conductive, by mixing them with ionically conductive 8-nylon, they have the effect of weakening the ionically conductive property of 8-nylon. Therefore, a mixture of 8-nylon, titanium (IV) oxide, tin (II) oxide, and antimony has a small resistance value variation due to temperature change. Therefore, the undercoat layer using this mixture does not have a high resistance value even at low temperature and low humidity. Therefore, in the organic photoreceptor having this undercoat layer, the residual potential of the photosensitive layer at low temperature and low humidity is not higher than the residual potential at room temperature.

Therefore, this organic photoreceptor has excellent environmental stability.

In particular, by adding antimony, the contents of titanium oxide (■) and tin (II) oxide can be reduced, so that the smoothness of the undercoat layer is improved.

Adhesion between the undercoat layer and the photosensitive layer is improved.

Titanium oxide (■), tin oxide (n) and antimony are 1 to 10 parts by weight per 100 parts by weight of 8-nylon,
It is preferably contained in a range of 2 to 6 parts by weight. If it is less than 1 part by weight, it is titanium oxide (■).

The electronic conductivity of tin (n) oxide and antimony is not effectively imparted to 8-nylon, and the resistance value of the obtained Shimohikizaki Aoji fluctuates depending on the temperature. This reduces the environmental stability of the organic photoreceptor. If it exceeds 10 parts by weight, the smoothness of the undercoat layer will be lost, and the smoothness of the photoreceptor will be impaired.

Titanium oxide (IV > 80 parts by weight, tin oxide ([
1) is 5 to 25 parts by weight, preferably 7 to 20 parts by weight.

and antimony is 2 to 15 parts by weight, preferably 4 to 1 part by weight.
It is contained in a range of 2 parts by weight.

The thickness of such an undercoat layer is in the range of 2 to 40 μm, preferably 5 to 20 μm. When it is less than 2 μm,
Charge injection from the substrate to the photosensitive layer cannot be prevented. Pinholes are likely to occur in the photosensitive layer due to the unevenness of the substrate. If it exceeds 40 μm, the residual potential of the photosensitive layer cannot be effectively removed.

The undercoat layer of the present invention comprises 8-nylon and titanium oxide (IV
), tin(II) oxide, and antimony are dissolved and dispersed in a suitable organic solvent, and then this solution is applied onto a conductive substrate. No complicated operations like conventional alumite treatment are required.

Examples of the conductive substrate include aluminum.

Gold, silver, copper, nickel, tin oxide, indinium oxide. Non-metallic conductors such as copper iodide, polyacetylene.

Organic polymers such as polypyrrole are used.

A photosensitive layer is further laminated on the undercoat layer. The photosensitive layer may be a single layer, but in order to improve electrical properties, it is a laminated photosensitive layer that is divided into a charge generation layer that generates charge carriers upon exposure and a charge transport layer that moves the generated charge carriers. Layers are preferred.

As a charge generating pigment used in the charge generating layer.

Any organic or inorganic photoconductive pigments known per se may be used. Among these pigments.

Phthalocyanine pigments, perylene pigments, quinacridone pigments, pyranthrone pigments, disazo pigments 1 It is desirable to use photoconductive organic pigments such as trisazo pigments alone or in combination of two or more. The thickness of the charge generation layer is for a vapor deposited film.

It is preferably in the range of 100 to 5,000 people, and in the case of resin-pigment dispersions, in the range of 3,000 to 30,000 people.

As a charge transport material used in the charge transport layer.

Any hole-transporting or electron-transporting substances known per se may be used for the purposes of the invention. Examples of suitable hole transport materials are poly-N-vinylcarbazole, phenanthrene, N-ethylcarbazole 52.5-diphenyl-1
, 3,4-oxadiazole, 2,5-bis(4-diethylaminophenyl)-1,3,4-oxadiazole, bis(diethylaminophenyl)-1,3,6-oxadiazole, 4,4 ° -bis(diethylamino)-
2,2°-dimethyltriphenylmethane, 2,4°5-
Triaminophenylimidazole, 2,5-bis(4-
diethylaminophenyl)-1,3゜4-triazole, 1-phenyl-3-(4-diethylaminostyryl)
-5-(4-diethylaminophenyl)-2-virapurine, p-diethylaminohentaldehyde (diphenylhydrazone), etc. Examples of suitable electron transport substances are 52-nitro-9-fluorenone, 2,7-sinitro-9 -fluorenone, 2.4.7-trinitro-9-fluorenone, 2.4-. 5.7-Tetranitro-9-fluorenone, 2-nitrobenzothiophene.

2.4.8-trinidrothioxanthone, dinitroanthracene, dinitroacridine, dinitroanthraquinone, etc. The thickness of the charge transport layer is in the range of 1 to 200 μm, preferably 5 to 50 μm.

(Example) The present invention will be described below with reference to examples.

Sosho Plate 8-Nylon (manufactured by Teikoku Kagaku Co., Ltd., Torezin F-30) 10
A mixed solvent of 2.4 parts by weight of heavy titanium oxide (IV), 0.39 parts by weight of tin oxide (n) and 0.21 parts by weight of antimony with 700 parts by weight of 2 methanol and 300 parts by weight of water and stirred for 24 hours to obtain a 10% undercoat layer coating solution. this? The solution is φ7B+nX 230
It was coated on an aluminum pipe with a thickness of 1.5 mm and dried at 100° C. for 30 minutes to form a 5-layer subbing layer with a thickness of 15 μm.

Metal-free phthalocyanine 1S ffi f
Polyester resin (polyester adhesive 49
50 parts by weight (manufactured by DuPont) 10 parts by weight Tetrahydrofuran 50 parts by weight The above formulation was placed in a ball mill and milled using a ceramic ball.
A charge-generating coating liquid was prepared by mixing and dispersing for a period of time. This solution was applied onto the undercoat layer.

It was dried at 100° C. for 1 hour to form a charge generation layer having a thickness of 1 μm.

Polycarbonate (Panlite L-1250, manufactured by Teijin) 20 parts by weight p-diethylaminohenzaldehyde diphenylhydrazone 13 parts by weight dichloromethane 80 parts by weight The above formulation was placed in a ball mill and mixed for 54 hours, followed by 10 parts by weight of cyclohexanone.
Parts by weight were added and mixed for an additional 4 hours to obtain a charge transport coating solution. This solution was applied onto the charge generation layer and heated to 100°C.
This was dried for 1 hour to form a charge transport layer having a thickness of 17 μm.

The sensitivity of the organic photoreceptor thus prepared was measured under first-order conditions.

Measurement mode Static measurement Photoreceptor surface speed 140mm/sec Corona inflow current -40μA Light source
halogen lamp light is temperature
3000K light intensity
As a result of measuring 0.92mW/c, the sensitivity (E
・1/2) was 3.5×10-'mJ/cI11.

Peeling this organic photoreceptor with cellophane tape) (
JIS Z 1522) was conducted, and the adhesion between the substrate and the photosensitive layer was found to be good.

This organic photoreceptor was transferred to a copying machine (manufactured by Sanda Kogyo Co., Ltd., DC-11).
1) and made 1000 copies.

Even when observed under a microscope, no pinholes were observed at all.

Example 2 Example 1 except that the layer thickness of the undercoat layer was 20 μm.
An organic photoreceptor was prepared in the same manner as above.

When this organic photoreceptor was evaluated using the same method as in Example 1, the sensitivity was 3.8 x 10-'+nJ/c.
It was J. Adhesion between the substrate and the photosensitive layer is good;
No pinholes were observed even after 1000 copies were made.

An organic photoreceptor was produced in the same manner as in Example 1, except that the thickness of the undercoat layer was 5 μm.

When this organic photoreceptor was evaluated by the same method as in Example 1, the sensitivity was 3.5×10 −′ mJ/cut. The adhesion between the substrate and the photosensitive layer was good, and no pinholes were observed even after copying 1000 sheets.

Example 1 except that the layer thickness of the undercoat layer was 10 μm.
An organic photoreceptor was prepared in the same manner as above.

When this organic photoreceptor was evaluated by the same method as in Example 1, the sensitivity was 3.5 x 10-'mJ/cIl.
It was l. Adhesion between the substrate and the photosensitive layer is good;
ioo.

No pinholes were observed even after copying the sheets.

wealth 1st life Σ An organic photoreceptor produced in the same manner as in Example 1.

When evaluated in the same manner as in Example 1 at 10°C, 30% R, H (at low temperature and low humidity), the sensitivity was 3.8
It was 10-'mJ/c.

An organic photoreceptor was produced in the same manner as in Example 1, except that titanium (IV) oxide and tin (II) oxide were not used.

When this organic photoreceptor was evaluated using the same method as in Example 1, the sensitivity was 3.6 x 1. It was F'mJ/cut. In addition, this photoreceptor was heated at 10'C, 30%R,H,
When evaluated using the same method as in Example 1 (at low temperature and low humidity), the sensitivity was 5. OX LO-'mJ/ca
1, which caused a decrease in sensitivity at low temperature and low humidity.

A mechanical light body was produced in the same manner as in Example 1 except that a comparative flame main undercoat layer was not formed.

When this organic photoreceptor was evaluated by the same method as in Example 1, the sensitivity was 3.3XIC)-'mJ/cIll. Poor adhesion between the substrate and the photosensitive layer, 100
After copying 0 sheets, pinholes were observed.

(Effect of the invention) The organic photoreceptor for electrophotography of the present invention is thus prepared.

No pinholes are generated in the photosensitive layer, which improves the sensitivity of the photoreceptor. Since the adhesiveness between the substrate and the photosensitive layer is good, the photosensitive layer does not peel off from the substrate. Since the undercoat layer has high smoothness, the generation of pinholes in the photosensitive layer can be effectively prevented.

Adhesion between the substrate and the photosensitive layer is also further improved. Since the residual potential of the photosensitive layer is effectively removed, there is no occurrence of fogging between the two images. In particular, the residual potential of the photosensitive layer at low temperature and low humidity does not become higher than the residual potential at room temperature. Therefore, this organic photoreceptor has excellent environmental stability.

As a result, according to the organic photoreceptor for electrophotography of the present invention, a clear electrophotographic copy image can be provided.

that's all

Claims (1)

[Claims] 1. An organic photoreceptor for electrophotography having an undercoat layer and a photosensitive layer on a substrate, the undercoat layer comprising 8-nylon, titanium (IV) oxide, and tin (II) oxide. ) and antimony. 2. The organic photoreceptor for electrophotography according to claim 1, wherein the undercoat layer has a thickness in the range of 2 to 40 μm. 3. The titanium (IV) oxide, tin (II) oxide, and antimony are contained in an amount of 1 to 10 parts by weight per 100 parts by weight of the 8-nylon.
The organic photoreceptor for electrophotography according to claim 1, wherein the content is within the range of parts by weight. 4. Claim 1, wherein the tin (II) oxide is contained in an amount of 5 to 25 parts by weight, and the antimony is contained in an amount of 2 to 15 parts by weight, relative to 80 parts by weight of the titanium (IV) oxide.
The organic photoreceptor for electrophotography described in Section 1.