JPS5818637A - Electrophotographic receptor - Google Patents

Abstract

PURPOSE:To obtain a photoreceptor prooving no reduction in chargeability and high in sensitivity, by providing an interlayer containing an organic titanium compound between a photoconductive layer and a protective layer formed on a conductive substrate, and preventing remarkable cycle rise of residual potential by the ordinary Carlson process. CONSTITUTION:A photoconductive layer 3 containing an inorganic photoconductor, such as Se or Se alloy, or an organic photoconductor, such as polyvinycarbazole, is formed on a conductive substrate 4, then, a solution containing at least one selected from a group of organic orthotitanate, polyorthotitanate, and titanium chelate is coated on the layer 3, and dried to form a <=10mum thick interlayer 2. A 10-20mum thick protective layer 1 having low resistance is formed on the layer 2 by adding an electron donor or an electron donor and an electron acceptor to an organic polymer or dispersing a metal or metal oxide having <=0.3mum particle diameter, thus permitting a photoreceptor high sensitivity and durability to be obtained by the ordinary Carlson method because an insulating protective layer is not formed.

Description

DETAILED DESCRIPTION OF THE INVENTION The invention relates to an electrophotographic photoreceptor, and more specifically, to an improvement of an electrophotographic body wash in which a protective layer is provided on the photoconductive layer.

For electrophotographic methods including charging, exposure, s-image processing, etc.
Many types of photoreceptors have been put into practical use (for example, see US Patent No. 2.29''1619). Those provided directly by vapor deposition, etc., those provided with an appropriate organic binder such as the above materials, or those provided with an inorganic photoconductive material such as ZnO, CAS, T101 dispersed in the binder, or amorphous selenium or its alloy. etc., or those in which two or more of the various photoconductive layers listed above are laminated (for example, Japanese Patent Publication No. 5394/1983, Japanese Patent Publication No. 46/1986), etc.
(See No. 3005, Japanese Patent Publication No. 14271/1983). In order to make these photoreceptors compatible with their electrical and optical properties and mechanical properties, or to further improve and stabilize these properties, in some cases, the properties in the process of the developing section are improved. To improve.

It has been proposed to provide a surface layer on the surface of a photoreceptor. this! I! One of the surface layers is called a protective layer and [,
For example, a thin resin film is provided on the surface, and a latent layer is formed by charging and image exposure (Carlson Purseth). However, when using a photoreceptor provided with such a protective layer, a high residual potential and a significant cycle increase are often observed. This high residual potential and cycle increase can be considerably improved by reducing the storage layer to 1 μm or less, but the film tends to peel off and cannot withstand long-term use. The separate female decay 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. 4,041,167). It is something.

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 the former photoreceptor provided with a protective layer, and the present invention relates to a photoreceptor in which a latent image can be formed by a so-called Carlson process without using a special latent image forming process. Previously, people proposed a low-resistance protective layer as a solution to the above-mentioned drawbacks of ICs (%
Reference No. 1854-42118, No. 54-55671, No. 54-65672 and No. 54-5571 II).

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 although high residual potential and large cycle increases 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.

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

The object of the present invention is to provide an electrophotographic photoreceptor comprising a conductive support, a conductive layer, an intermediate layer, and a protective layer laminated in sequence, wherein the intermediate layer contains at least one organic titanium compound. This can be achieved using an electrophotographic photoreceptor.

The structure of the electronic photoreceptor of the present invention is shown in attached figures IiK and 1. In figure 1, organic polymer compound or metal oxide (average particle size α3 μm or less), etc., added with an appropriate organic compound is dispersed. 2 is an organic titanium compound-containing intermediate layer; 3 is a photoconductive layer; 4 is a low-resistance transparent protective layer made of an organic polymer compound;
is a conductive support.

At least the intermediate layer 2 must not be immersed in the solvent used to apply the upper protective layer.

In addition to its role as a layer, this intermediate layer can also function as an adhesive layer between the photoconductor and the protective layer.

Examples of the organic titanium compound suitable for the intermediate layer 2 include organic derivatives of orthotitanic acid such as titanium orthoester, polyorthotitanate ester, and titanium chelate.

Titanium orthoester has the following general formula (11% formula % (in the formula -. Isopropyl group, n-butyl group, isobutyl group, Credit J/
(Cgegyl) group, stearyl group, hexyl group, nonyl group, and cetyl group. ), and the polyorthotitanate ester is represented by the following general formula (ml (wherein, R□, R, R1, and R4 each have the same meaning as in the above formula I). titanium chelate is a compound with the following general formula (l Ti(L)IIX4-n (II (in the formula,
L represents a chelate group, X represents an ester group, and F represents 1 to 4.

) It is a compound with 0 (hydrone) coordination represented by the following, and the ligand species include dalicols such as octylene dalicol and hexanediol; β-diketones such as acetyla heptaton; lactic acid,
Hydroxycarboxylic acids such as malic acid, tartaric acid, and salicylic acid; ketoesters such as acetate monoester; and ketophyl alcohols such as diacene alcohol.

These compounds can be used alone or as a mixture of two or more. Furthermore, for improving adhesion, controlling resistance, and for other reasons, it is also possible to use the above-mentioned organic titanium compounds as a mixture with other organic IIMll compounds.

The thickness of the intermediate layer 2 is set arbitrarily, but it is 10 μm or less,
In particular, the thickness is preferably 1.1 μm or less.

This intermediate layer can be formed by spray coating, dip coating, or knife j1! This can be done by applying with a suitable method such as cloth or a-ru coating.

The photoconductive layer of the photoreceptor of the present invention is 8e, 5a-Te.
metal, 5s-As alloy, or a multilayer vacuum lid film made of an appropriate combination of these, polyvinylcarbazole/2,
4.7-) dinitro-9-fluorenone (PVK4'N
F) Inorganic photoconductor of ZIIO, C, i8 type is dispersed in a binder.

Alternatively, a stack of a charge generation layer and a charge transport layer can be used.

In addition, as a protective layer, a material prepared by adding an appropriate organic compound or an inorganic compound to an organic polymer compound can generally be used. When using an electronically conductive material or an organic polymer with a particle size of 0
．． A remarkable effect can be obtained when using an electronically conductive material in which metals and metal oxides of 3 μm or less are dispersed. That is,
If the particle size is 3 μm or more, it is opaque, but if it is 13 μm or less, it becomes substantially transparent, and light transmission is not hindered.

Specifically, the materials used for such a protective layer include merocene, a compound having one or more metallo-7ane skeletons in its molecular structure; tetrazole, a compound having a small amount (both one) and A compound having a tetrazole skeleton of more than
silver, aluminum.

Metal powders such as iron, copper, and nickel, as well as zinc oxide, titanium oxide, tin oxide, bismis oxide, and indium oxide.

Powders of metal oxides such as antimony oxide; powders containing tin oxide and antimony oxide in single particles, etc.

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

Comparative Example 1 80 parts by weight of polycarbonate and 20 parts by weight of dimethylferrocene
Part by weight was dissolved in dichloromethane, and this solution was dissolved in dichloromethane.
It was coated on Se3 evaporated II (55 μm thick) provided on the substrate and dried to obtain a photoreceptor having a 10 μm thick protective layer.

Before applying the above protective layer, the a3S/3 vapor deposition at was positively charged, the initial potential was 800VKL, and this was 460T3.
The operation of exposing the sample to light having a wavelength of rn was repeated at a rate of 40 times per minute. At this time, the residual potential was stable at Ov. - When the Aasses 11 deposited film provided with the blade protective layer was charged and exposed under the above conditions, the initial potential was 200V and the residual potential was stable at 100V.

Therefore, the Aa2Sel photoreceptor with the protective layer had significantly lower electrostatic contrast than the photoreceptor without the protective layer.

Example 1 A Mug2se3 vapor-deposited film was formed on an An substrate in the same manner as in Comparative Example. Next, 1 part by weight of tetranormaldityl titanate (trade name: Orga Cheek Stem 25, manufactured by Matsumoto Trading Co., Ltd.) and isocarbon A resin solution consisting of 10 parts by weight of bupyl alcohol was applied by dip coating and dried at 100 rK for 2 hours to form an intermediate layer with a thickness of 15 μm.A protective layer similar to that of the comparative example was then provided on this layer with 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 900v, and the residual potential was 105v.

Therefore, the electrostatic contrast was 795V, and its characteristics were significantly improved compared to a photoreceptor with only a protective layer.

The value was similar to that of the photoreceptor without a protective layer.Example 2 An Aa23e3 vapor deposited layer was formed on the Aj substrate using the same method as in Comparative Example 1. A resin solution consisting of 1 part by weight of luzotyl titanate, 71 parts by weight of methyl()rimethoxy)sila, 30 parts by weight of isopropyl alcohol, and 5 parts by weight of n-butylarsul was spray applied,
Hydrolysis was carried out in a high humidity environment of 50 tll' and 80% RH, and then 1 ooc'r°.

After drying for 2 hours, an intermediate layer having a thickness of α3μ was provided.Then, the same protective layer as in Comparative Example 1 was provided thereon to a thickness of 15μ. When this photoreceptor was repeatedly charged and exposed in the same manner as in Comparative Example 1, the initial potential was 93V and the residual potential was 140V. Therefore, the electrostatic charge of this photoreceptor was 795 V, which was the same value as that of a photoreceptor without a protective layer.

Example 3 AJI Tomi 863 was deposited on a muj substrate in the same manner as in Comparative Example 1. Next, 2 parts by weight of diimpropoxy titanium bis(acetylacetonate) is added on top of it.

A solution consisting of 1 part by weight of γ-acryloxyprobyltrimethoxycin (trade name KBM503, manufactured by Shin-Etsu Chemical Co., Ltd.) and 20 parts by weight of n-sitanol was spray applied to give 100%
After drying at t:' for 2 hours, an intermediate layer having a thickness of 6 μm was formed. 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 turned off in the same manner as in Comparative Example 1, the initial potential was 920V and the residual potential was 120V. Therefore, the electrostatic contrast of this photoreceptor was 800 V, which was the same as that of a photoreceptor without a protective layer.

Comparative Example 2 A polyurethane resin (manufactured by Kansai Paint Co., Ltd.) was placed on a two-layer photoconductor consisting of a 5s (50μ thick) vapor deposited film and a 5s-Te alloy vapor deposited @ (1μ thick) provided on an A4 cylinder with a length of 300W. , Rethane 4000) Particle size (L
A resin solution in which 30 parts by weight of tin oxide with a diameter of 1 μm or less was added and dispersed was applied and dried.

The protective layer had a thickness of 10μ. When this photoreceptor was repeatedly charged and exposed in the same manner as in Comparative Example 1, the initial potential was 150V.
The residual potential was 85 V, and the electrostatic contrast was significantly low.

Example 4 2 parts by weight of diisopropoxy and titanium bis(acetyl acetonate) were placed on the S・/S・-To two-layer photosensitive layer similar to Comparative Example 2, and silicone nixy resin (trade name SR2) was added.
115, manufactured by Toshi Silicon Co., Ltd.) 1 part by weight, Suiseki Zotyl 20
A solution consisting of parts by weight was spray applied and dried at 40C for 3 hours to provide an intermediate layer of -c, asP thickness.

Next, the same protective layer as in Comparative Example 2 was provided thereon to a thickness of 20 μm. When this photoreceptor was repeatedly charged and exposed in the same manner as in Comparative Example 2, the initial potential was 1000V, and the residual potential was 200V.
Met. Therefore, the electrostatic contrast of this photoreceptor is 80
0V, which was the same as that of a photoreceptor without a protective layer. When a copy test was conducted using this photoreceptor using a magnetic push development method, an extremely detailed image identical to the exposed pattern was obtained.

[Brief explanation of the drawing]

The drawings show the structure of the electrophotographic photoreceptor of the present invention. Symbols in the figure: 1-11 low resistance protective layer; 2--intermediate layer; 5-m-photoconductive layer; 4--conductive support.

Claims (1)

[Scope of Claims] t. An electrophotographic photoreceptor comprising a photoconductive layer, an intermediate layer, and a protective layer successively laminated on a conductive support. A photographic photoreceptor, wherein the intermediate layer contains at least an Ili compound. 2 The organic titanium compound is titanium orthoester. The electrophotographic photoreceptor according to claim 1, which is a compound selected from the group consisting of polyorthotitanate and titanium chelate.