JPS58121045A - Electrophotographic receptor - Google Patents

Abstract

PURPOSE:To obtain a photoreceptor superior in various kinds of potential characteristics in an electrophotographic receptor having a protective layer on a photosensitive layer, by forming an interlayer made of a hardened material contg. a zirconium complex on a photosensitive layer. CONSTITUTION:In an electrophotographic receptor having a photoconductive layer 3 and a surface protective layer 1 on a conductive substrate 4, an interlayer 2 made of a hardened material contg. a zirconium complex and a silane coupling agent is formed between the layers 3, 1, and they are laminated successively to suppress injection of charge from the surface, and to serve as a barrier layer for enhancing electrostatic contrast. As a result, the obtained electrophotographic receptor reduces residual potential and effect of humidity change on charged potential, prevents charge on the surface of the layer 1 from discharging and lowering latent image potential, has various superior potential characteristics, and it can form a defectless image even after long time uses.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic photoreceptor, and an electrophotographic photoreceptor having a protective layer on both sides.

The electrophotographic photoreceptor is made of Se or St gold alloy vapor deposited film, Zo
A photosensitive layer such as a coating film in which inorganic particles such as O or CdS or organic pigments such as azo pigments and cyanine pigments are dispersed in a binder resin is provided on a support, and a static image is formed by charging and exposure. This is used in an electrophotographic method in which a toner image is formed, developed, transferred to transfer paper, and then fixed to obtain a copy.

A photoreceptor with a photosensitive layer on the surface may be scratched during handling, or the toner may become clogged.
This would shorten the life of the photoreceptor. In order to overcome this drawback, attempts have been made to provide a surface layer different from the photosensitive layer on the surface of the photoreceptor. As the surface layer,
On the one hand, an insulating layer is used, and on the other, a protective layer is used. The former insulating layer is a film made of electrically insulating resin or the like provided on the surface of the photoreceptor t1, and is composed of −order charging → secondary charging → image exposure or primary charging → reverse polarity secondary Teiden → uniform exposure. The process forms an electrostatic moat. Although the photoreceptor having this insulating layer has the advantage that the insulating layer can be made thicker and the mechanical strength can be increased, the ag/I! It has the disadvantage that the forming process is special and that it is difficult to remove static electricity. The latter protective layer has a lower resistance than the insulating layer, and forms an electrostatic m-image by the so-called Carlson method of charging→image exposure. Although a photoreceptor having this protective layer can form an m-image by the Carlson method, the residual potential is high, and the film is thinner than an insulating layer and has inferior mechanical strength.

Therefore, attempts have been made to add electrical resistance modifiers such as quaternary ammonium salts to the protective layer to prevent the accumulation of charge on the surface rfJ of the protective layer or inside the protective layer. Although this attempt can reduce the residual potential to some extent, it has the disadvantage that the charged potential changes due to the influence of humidity.

I! This has the drawback that the electrical charge on the surface of the protective layer is injected into the photosensitive layer and discharged until the subsequent image exposure step or development step, resulting in a decrease in the S* potential.

The present invention relates to the improvement of a photoreceptor having this latter protective layer, and an object of the present invention is to provide a photoreceptor that eliminates these conventional drawbacks.

An object of the present invention is to provide an electrophotographic photoreceptor comprising a photoconductive layer, an intermediate layer made of a cured product containing a zirconium complex and a silane coupling agent, and a protective layer, which are sequentially laminated on a conductive support. This can be achieved by

The structure of the electrophotographic photoreceptor of the present invention is shown in the attached circular. In the figure, l is a transparent protective layer, 2 is an intermediate layer made of a cured product containing a zirconium complex and a 7-rank coupling agent, 3 is a photoconductive layer mainly made of S@, and 2.4 is a conductive support. be.

As the protective layer l, an organic polymer compound to which a suitable organic compound or inorganic compound is added can generally be used.
For example, when an electron-donating compound is added to an organic polymer compound (1), an electron-conductive material containing an electron-donating compound and an electron-accepting compound is used, or an organic polymer with an average particle size of 0 is used.
．． Significant effects are obtained when using electronically conductive materials in which metals and metal oxides of 3 μm or less, preferably 0.15 μm or less, are dispersed. That is, when the average particle size is 0.3 μm or more, it is opaque, but when it is 0.3 μm or less, it becomes substantially transparent9, and the original transmission is not hindered. Specifically, it is preferable to include particles having a particle size of 5 μm or more in t-S weight percent or less, and particles having a particle size of 0.03 μm or less in f: 20 weight percent or less. If t-5% by weight or more of particles with a particle size of 5 or more is contained, the dispersibility of the fine powder will be poor, fine irregularities will be formed on the surface of the protective layer, the cleaning properties will be reduced, and the transparency of the protective layer will be reduced. If particles with a particle diameter of 0.03 μm or less are included in a weight tts or more, the residual potential of the photoreceptor increases.

Specifically, materials used for such a protective layer include metallocene and a compound having at least one metallocene skeleton in its molecular structure; tetrazole and a compound having at least one tetrazole skeleton in its molecular structure. Compound; gold, silver, with an average particle size of 0.3# or less
Powders of metals such as aluminum, iron, copper, copper, chloride, etc. 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 in a single particle There are powders etc. that contain it. The amount of metal oxide added to #fat is desirably in the range of 3 to 65% by weight.

A preferred protective layer is a layer in which conductive metal oxide powder is dispersed in a binder resin, and the conductive metal oxide powder is particularly preferably a powder containing tin oxide and antimony oxide in the same particle. Here, the expression "containing tin oxide and antimony oxide in the same particle" means a solid solution or a fused body of tin oxide and antimony oxide.

As the resin for dispersing the above powder, any resin capable of forming a film can be used. Specific Kt
X Polyester resin, polycarbonate resin, fluororesin, polystyrene resin, cellulose resin, vinyl chloride resin, polyurethane resin, acrylic resin, epoxy resin,
7 recon resin, alkyd resin, vinyl chloride vinyl acetate copolymer resin, etc. can be used. The thickness of the metal oxide dispersed layer is preferably between 2 and 30 μm, particularly between 5 and 15 μm. The protective layer is formed using known techniques such as the Sdale method, Davey-Fugu method, and Blade method. This can be done by:

The intermediate layer 2 must have a higher resistance than at least the upper protective layer l, which has low insulation properties.

The intermediate layer of F2 must not be immersed in the solvent used to apply at least the upper protective layer.

In addition to serving as a barrier layer that suppresses charge injection from the surface and increases electrostatic contrast, this intermediate layer can also function as an adhesive layer between the photoconductor and the protective layer.

The intermediate layer is formed from a dried and cured solution of a zirconium complex and a silane coupling agent. These zirconium complexes and silane coupling agents can be mixed in any proportion.

Examples of zirconium complexes suitable for the intermediate layer include acetylacetone complexes such as zirconium acetylacetonate and zirconium trifluoroacetylacetonate. Examples of 7-run coupling agents suitable for the intermediate layer include the following. Vinyltrichlorosilane/, Vinyltriethoxysilane, Vinyltris (β-
methoxyethoxy) 7 runs, γ-glycidoxyglobil trimethoxine 7 runs, r-methacryloxyglobil trimethoxy 7 runs, N-β (aminoethyl) γ-aminoglobil trimethoxine run, N-β (amino ethyl)
r-aminoglobil methyldimethoxy 77ran, r-chloroglobil trimethoxy 7ran, γ-mercagtoglobil trimethoxy 7ran, γ-aminoglobil triethoxysilane, methyltrimethoxy 77ran, dimethyldimethoxy 77 runs in trimethylmonomethoxysilane, diphenyldimethoxysilane 7 runs, diphenyldiethoxy7 silane, -77 runs in monophenyltrimethane.

The thickness of the intermediate layer can be set arbitrarily, but it is preferably 10 μm or more, particularly 1 μm or less. The intermediate layer can be formed by coating by an appropriate method such as gray coating, dip coating, knife coating, roll coating, etc., and then drying and curing by heating to a temperature of 200°C to 200°C.

The photoconductive layer 3 is a layer that has both the ability to generate charges by light irradiation and the ability to transport charges, and may be a single layer or a stack of two or more layers. The photoconductive layer is formed primarily of selenium. For example, inorganic substances such as selenium, selenium-tellurium, selenium-arsenic, selenium-tellurium oxide, zinc oxide, titanium oxide, cadmium sulfide, cadmium selenide, zinc sulfide, amorphous silicon, polyvinyl carbazole and its derivatives, aromatic amines, etc. Examples include organic substances such as azo pigments, phthalocyanines, oxazole, triazole, imidazole, and brompyrene. This photoconductive layer can be formed by a known method such as a vacuum deposition method. The thickness of the photoconductive layer can be set arbitrarily, but S/11
11-200 μm, special K 20-Zoo fiw* are suitable.

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

Comparative Example 1 65 parts by weight of polyacrylic urethane and parts by weight of tin oxide/antimony oxide fine powder with an average particle size of 0.3 μm were added to Ceronlube acetate on an As2Se3 vapor deposited film (60 μm thick) provided on an Al-plated pipe. The mixture was dispersed in a ball mill with butyl acetate, and an appropriate amount of a curing agent was added thereto, and the mixture was coated and dried to obtain a photoreceptor having a 10 μm thick protective layer.

Before applying this protective layer, the A-port Sea vapor deposited film was positively charged to an initial potential of 900 V, and this operation of exposing it to light having a wavelength of t460 was repeated for 5 minutes at a rate of 40 times per minute. At this time, the residual potential was stable at the back Ov. On the other hand, when the As25 vapor-deposited film provided with the protective layer was charged and exposed under the above conditions, the initial potential was 120V and the residual potential was 55V.
It was stable. Therefore, the AsSe3 sensitizer with the protective layer had almost no electrostatic contrast.

Example 1 A vapor deposited film of As25e3 was formed on an aluminum pipe in the same manner as in Comparative Example 1. Next, a solution consisting of 2 parts by weight of zirconium acetylacetonate, 1 part by weight of r-methacryloki 7globyl trimethoxylate, and 20 parts by weight of n-butanol was spray-coated on top, and dried at 100°C for 2 hours. Then, an intermediate layer having a thickness of 0.6 μm was provided. Next, the same protective layer as in Comparative Example 1 was provided on this to a thickness of 10 μm, and charging exposure was repeated in the same manner as in Comparative Example 1, resulting in an initial potential of 960 cm and a residual potential of 55 V. Therefore, the electrostatic contrast of this photoreceptor was 905 V, which was the same value as a photoreceptor without a protective layer. When my father made copies using this photoreceptor, he was able to obtain clear images with no background sK stains. Soyiita power is f tpy ■ h
9. Equivalent to an i photoreceptor without a protective layer. Furthermore, this photoreceptor is heated to high temperature (30℃, 851m1M).
Low temperature and low fi even in the environment (10°C115*RH)
I was able to obtain a good copy 1 with no change in image quality.My father used a blade cleaning device and a paper stripping unit to install a steel photoreceptor that is in constant pressure contact with the photoreceptor. Put a copy taK with a peeling nail 1
After making oooooo copies, it was possible to obtain good image quality without changing the image quality or causing any scratches on the surface of the protective layer.

Comparative Example 2 When the As25 odour-deposited film prepared in the same manner as Comparative Example 1 was electroplated and the original was repeated without providing an intermediate layer or protective lIl, the W period potential was 910 V and the residual potential was 910 V compared to Comparative Example 1. It was stable with OV and C.

Carrying out this photoreceptor? When copying was carried out using the same copying machine as No. 11, a clear -1 image with no background smear was obtained. When copying was continued, a moldy defect was found around the 30,000th copy. In other words, polar (aZ white streaks occurred in solid S), and there were signs that the white streaks increased with the number of copies, but almost no white streaks were seen in the text area.However, after 100,000 copies were made. In this case, a considerable number of fine white streaks were observed in the solid black area, and white streaks were also observed in the text area.Example 2 KAs2Se was applied to an aluminum pipe using the same method as in Comparative Example 1.

1 part by weight of zirconium trifluoroacetylacetonate, 1 part by weight of r-grid xyglobytrimethoxysilane, 1 L, 20 liters of n-butanol.
A solution consisting of parts by weight was spray applied and dried at 100'QK for 2 hours to provide a 0.5 μm thick intermediate layer. Next, the same protective layer as in Comparative Example 1 was provided thereon to a thickness of 10 .mu.m, and exposure was repeated in the same manner as in Comparative Example 1, resulting in an initial potential of 955 V and a residual potential of 55 V. Therefore, the electrostatic contrast of this photoreceptor was 900 V, which was the same value as the h photoreceptor without a protective layer and the photoreceptor of Example 1. Using this photoreceptor, a copy test, an itching test, and a durability test were conducted in the same manner as in Example 10, and similar good results were obtained.

[Brief explanation of drawings]

The drawing shows the structure of the electrophotographic photoreceptor of the present invention.
Photoconductive layer; 4... conductive support. (3 others)

Claims (1)

[Scope of Claims] 1) An electronic device characterized in that a photoconductive layer, an intermediate layer consisting of a cured product containing a zirconium complex and a Clan coupling agent, and a protective layer are formed on a conductive support by KI (secondary lamination). Photographic photoreceptor. 2) The protective layer is a layer in which conductive metal oxide powder is dispersed in a binder resin, and the particle size distribution of the conductive metal oxide fine powder is 5 μm or more in size by weight or less: 5% by weight or less and particle size 0.03μ
Claim 11: The electrophotographic photoreceptor according to claim 11, wherein the weighting amount is less than or equal to m. 3) The electrophotographic photoreceptor according to claim 2, wherein the conductive metal oxide powder is a powder containing tin oxide and antimony oxide in the same particle.