JPS5860748A - Electrophotographic receptor - Google Patents

Abstract

PURPOSE:To obtain an electrophotographic receptor superior in acceptance potential and capable of forming an image having sufficient contrast, by laminating a photoconductive layer, an interlayer contg. an organometallic compd., and a protective layer having low resistance on a conductive substrate. CONSTITUTION:A photoconductive layer 3 consisting of Se, Se-Te alloy, Se-As alloy, or the like, an interlayer 2, <=10mum thick contg. an organometallic compd. such as aluminum tris-(acetylacetonate) as a main component, and a low-resistance protective layer 1 formed by dispersing a <=0.3mum particle diameter metal oxide into an org. polymer are laminated on a conductive substrate 4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor having a protective layer.

Many photoreceptors have been put into practical use as photoreceptors used in electrophotography including processes such as charging, exposure, and development (for example, see US Pat. No. 2,297,619).

For example, an organic photoconductive material is directly provided on a suitable conductive substrate by coating or vapor deposition, or the above material is provided together with a suitable organic binder, or Zoo s CdS s Ti4) is provided in the binder.
Used are those in which inorganic photoconductive materials such as z are dispersed, amorphous selenium or its alloys are deposited, or two or more of the various photoconductive layers listed above are laminated ( For example, see Japanese Patent Publication No. 45-5394, Japanese Patent Publication No. 4←3005, and Japanese Patent Publication No. 49-14271). For these photoreceptors, in order to achieve both electrical and optical properties and mechanical properties, or to further improve and stabilize these properties, and in some cases, to improve properties in processes such as development. For this reason, it has been proposed to provide a surface layer on the surface of the photoreceptor. One of these surface layers is called a protective layer, and for example, a thin resin film is provided on the surface and a latent image is formed by charging and image exposure (Carlsson process). However, when a photoreceptor provided with such a protective layer is used, a high residual potential and a significant increase in its cycle are often observed. This high residual potential and cycle increase can be considerably improved by making the protective layer t-1μ or less, but the film becomes easy to peel off and cannot withstand long-term use. Another surface layer is a resin layer with high electrical resistance called an insulating layer, and a latent image is formed by a special method including a static elimination process (for example, see U.S. Pat. No. 3,041,167). It is. However, a photoreceptor having this insulating layer requires a special latent image forming process and requires at least two charging steps, resulting in a problem of complication of the device.

The present invention relates to a photoreceptor provided with the former protective layer, and more particularly, to a photoreceptor on which a latent image can be formed by the so-called Carlson process without using a special a-image forming process.

The present applicant has previously proposed a low resistance protective layer as a solution to the above-mentioned drawbacks (Japanese Patent Application Nos. 54-42118, 54-65671, 54-65672 and 54-65673). reference). However, in these methods, by providing a low-resistance protective layer, it is possible to obtain a protective layer with a thickness of 10 to 20 μm, and high residual potential and large cycle increase can be prevented.

Sometimes, the chargeability of the entire photoreceptor decreases, resulting in the disadvantage that images with sufficient contrast cannot be obtained, and this tendency is particularly noticeable when the photoconductive layer is of high sensitivity. There was found.

The object of the present invention is to provide an electrophotographic photoreceptor that can reliably eliminate these drawbacks.

K: Yes.

The object of the present invention is to provide a photoconductive layer on a conductive support.

This can be achieved by using an electrophotographic photoreceptor formed by sequentially laminating an intermediate layer containing an organometallic compound as a main component and a low-resistance protective layer.

The structure of the electrophotographic photoreceptor of the present invention is shown in the accompanying drawings. In the figure, 1 is a low-resistance transparent protective layer made of an organic polymer compound added with a suitable organic compound, 2 is an intermediate layer containing an organometallic compound, 3 is a photoconductive layer, and 4 is a conductive support.

At least the intermediate layer 2 must not be immersed in the solvent used to apply the upper protective layer. Jin's middle class 4
In addition to its role as a barrier layer, it can also function as an adhesive layer between the photoconductor and the protective layer. Organometallic compounds suitable for this intermediate layer 2 include aluminum tris(acetylacetonate), iron tris(acetylacetonate), cobalt bis(acetylacetonate), copper bis(acetylacetonate), Magnesium bis(acetylacetonate), manganese(
1) Bis-(acetylacetonate), nickel (1)
-Bis(acetylacetonate), vanadium tris-
Metal acetylacetonate compounds such as (acetylacetonate), zinc bis-(acetylacetonate), tin bis-(acetylacetonate), aluminum isopropylate, °mono1ec-ptoxyaluminum diisoglobilate, aluminum 5ec-butyrate , No(Nadium ethylate, Vanadyl globilate,
Mention may be made of metal alcoholade compounds such as vanadium isobutyrate, and compounds such as aluminum di-n-butoxide mono-ethyl acetoacetate, aluminum oxide offtate, aluminum oxide stearate, aluminum oxide acrylate. These compounds can be used alone or as a mixture of two or more. Furthermore, improved adhesion,
For controlling the resistance value and for other reasons, it is also possible to use a mixture of the above-mentioned organometallic compound and another organic resin compound.

The thickness of the intermediate layer 2 is set arbitrarily, but it is 10 μm or less,
49 to 1j#m or less is suitable.

This intermediate layer can be formed by coating by an appropriate method such as spray coating, dip coating, knife coating, roll coating, or the like.

The photoconductive layer of the photoreceptor of the present invention may be a multilayer vacuum-deposited film made of Se%5e-Te alloy%5e-As alloy, or an appropriate combination thereof, or poly-vinylcarsol/2
,4,7-dolinitro-9-fluorenone (PVK/T
Generally, organic photoconductors such as NF), inorganic photoconductors such as ZnO and CdS are dispersed in a binder, or those in which a charge generation layer and a charge transport layer are laminated and an appropriate organic or inorganic compound is added. For example, when using an electron-conductive material in which an electron-donating compound or an electron-donating compound and an electron-accepting compound are added to an organic polymer compound, or when metal oxides with a particle size of 13 μm or less are added to an organic polymer, Significant effects can be obtained when a dispersed, electronically conductive material is used.Specifically, materials used for such a protective layer include metallocene and at least one metallocene skeleton in its molecular structure. Compound; tetrazole and at least one compound in its molecular structure
Compounds with more than one tetrazole skeleton: average particle size of 0.3? Metal powders such as gold, silver, aluminum, iron, copper, and nickel, and powders of metal oxides such as zinc oxide, titanium oxide, tin oxide, bismuth oxide, indium oxide, and antimony oxide; tin oxide and antimony oxide. Examples include powder contained in a single particle.

Next, the electrophotographic photoreceptor of the present invention will be explained with reference to comparative examples and examples.

Comparative Example 1 Parts by weight of polycarbonate and parts by weight of dimethylferro7ine were dissolved in dichloromethane, and this solution was applied to an As25ea vapor deposited film (55μ thick) provided on an M substrate, dried, and a 10μ protective layer was formed. A photoreceptor having the following properties was obtained. Positively charging the Amuses vapor deposited film before applying the above protective layer,
The initial potential is set to '1tsoo v, which is k 460 su
The operation of exposing to light with a wavelength of m was repeated at a rate of φ times per minute. At this time, the residual potential was stable at OV. On the other hand, when the As2Se3 vapor deposited film provided with the protective layer was charged and exposed under the above conditions, the initial potential was 200 V and the residual potential was ioo
It was stable at v.

Therefore, the As2Se3 photoreceptor having a protective layer had significantly lower electrostatic contrast than the photoreceptor having a slanted protective layer.

Example 1 An As2Se3 vapor deposited film was formed on an M substrate in the same manner as in the comparative example. Next, on top of that, ethyl acetoacetate aluminum diisoglovirade ('778 & ALCM
A resin solution consisting of 1 part by weight (manufactured by S Kawaken Fine Chemical Co., Ltd.) and 10 parts by weight of Improvil alcohol was applied by dip coating and dried at 50'0 for 2 hours to form an intermediate layer with a thickness of 0.5 μm. Then, on top of this, the same protective layer ft as in Comparative Example 1 was applied.
It was provided with a thickness of 10μ. When the photoconductor was charged and exposed repeatedly in the same manner as in Comparative Example 1, the initial potential was 910V,
The residual potential was 105v. Therefore, the electrostatic contrast was sos v, which was a significantly improved characteristic compared to a photoreceptor with only a protective layer, and the same value as a photoreceptor without a protective layer.

Example 2 and Comparative Example 1. An As25 vapor deposited film was formed on the M substrate using the same method. Next, on top of that, 2 parts by weight of zinc bis(acetylacetonate) and a silane coupling agent (trade name,
KBM503. A resin solution consisting of 20 parts by weight of TS (manufactured by Shin-Etsu Chemical Co., Ltd.) and 20 parts by weight of n-butyl alcohol was spray applied.

It was dried at 100°C for 30 minutes to provide a 0.5μ thick intermediate layer. Next, the same protective layer as in Comparative Example 1 was provided thereon to a thickness of 10 μm. When this photoreceptor was repeatedly charged and exposed in the same manner as in Comparative Example 1, the initial potential was 900 V and the residual potential was 105 V. Therefore, the electrostatic contrast of this photoreceptor was 795V, which was the same value as that of a photoreceptor without a protective layer.

Example 3 In the same manner as in Comparative Example 1, an As2Se3 vapor deposited film was formed on the M base dye. Next, a solution consisting of 1 part by weight of Kobal (II) acetylacetonate and 10 parts by weight of rope-tyl alcohol was spray-coated on top of the coating, and dried at 50°C for 2 hours to form an intermediate layer with a thickness of 0.3μ. Then, the same protective layer as in Comparative Example 1 was provided thereon to a thickness of 10 μm.

When this photoreceptor was repeatedly charged and exposed in the same manner as in Comparative Example 1, the initial potential was 910 V% and the residual potential was 100 V. Therefore, the electrostatic contrast of this photoreceptor is 810v.
and the electrostatic contrast of the photoreceptor without a protective layer)Y
Further improvements were made.

Comparative Example 2 80 parts by weight of polyarylate resin (trade name, υ Polymer, manufactured by Unitika) and 20 parts by weight of ferrocene? Dissolved in dichloromethane. This solution was deposited on an M cylinder with a length of 300 cm and a Ss''C (50 μ thick) vapor deposited film and a 5e-Te alloy vapor deposited film.
The photoreceptor was coated on a two-layer photoconductor of 1 μm thick and dried to obtain a photoreceptor having a protective layer of 15 μm thick. When this photoreceptor was subjected to repeated charging and exposure using the method of Comparative Example 1, the initial potential was 400 V and the residual potential was stable at 90 V.

On the other hand, the same Se/5e-T4 as above! When a photoreceptor consisting of a two-layer vapor-deposited film was charged and exposed under the above conditions without applying a protective layer, the initial potential was 900 V.

The residual potential was iov. Therefore, Se with a protective layer
The /5e-Te two-layer photoreceptor had significantly lower electrostatic contrast than the photoreceptor without a protective layer.Example 4 In the same manner as Comparative Example 2, A! Se/Se-Te on the cylinder
A photosensitive layer consisting of a two-layer vapor-deposited alloy film was formed.

A solution consisting of 1 part by weight of zinc bis(acetate fk acetonate) and 10 parts by weight of n-butanol was then spray-coated onto the layer and dried at 40°C for 3 hours to form an intermediate layer with a thickness of 0.3μ. . Next, the same protective layer as in Comparative Example 2 was provided thereon to a thickness of 15 μm.

When this photoreceptor was repeatedly charged and exposed in the same manner as in Comparative Example 2, the initial potential was 990V and the residual potential was 100V. Therefore, the electrostatic contrast of this photoreceptor is 890v.
This was the same as a photoconductor without a protective layer. When this photoreceptor was used for copying and manual copying using a magnetic brush development method, an extremely clear image identical to the exposed pattern was produced.

Comparative Example 3 On a photoreceptor made of the same Sc/5e-Tc two-layer vapor deposited film as in Comparative Example 2, a polyurethane resin (Rethane 4000 manufactured by Kansai Paint Co., Ltd.) with a particle size of Q and 1 was applied to a solid content of 70 parts by weight.
A resin solution prepared by adding less than #i weight part of tin oxide was applied and dried to form a 10 μm protective layer.

When this photoreceptor was repeatedly charged and exposed in the same manner as in Comparative Example 1, the initial potential was 150 V and the residual potential was 85 V, resulting in a significantly low electrostatic contrast.

Example 5 1 part by weight of ethyl acetate aluminum diisoglobilate (trade name: ALCH, manufactured by Yoken 7-I/Chemical Co., Ltd.) and n-butanol were placed on the same Se/5e-Te double-layer photosensitive layer as in Comparative Example 2. An intermediate layer having a thickness of α5# was provided by dipping a cloth in a solution consisting of 10 parts by weight. Next, Comparative Example 3 is added on top of this.
The same protective layer was provided to a thickness of 10 μm. When this photoreceptor was repeatedly charged and exposed in the same manner as in Comparative Example 1, it was stable at an initial potential of 990 V and a residual potential of 100 V.

Therefore, the electrostatic contrast was 890 V, which was equivalent to a photoreceptor without a protective layer.

When a copy test was conducted using this photoreceptor using a magnetic brush development method, an extremely clear image identical to the exposed pattern was obtained.

[Brief explanation of drawings]

The drawings show the structure of the electrophotographic photoreceptor of the present invention. Codes in the figure: 1...Low resistance transparent protective layer; 2... Phase intermediate layer;
3.--Photoconductive layer; 4. Conductive support for.

Claims (1)

[Claims] 1. A conductive support, a photoconductive layer, and an intermediate layer containing an organometallic compound as a main component. and a low-resistance protective layer are successively laminated.