JPH0453964A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain high-quality copied images which are stable over a long period of time by incorporating a metal compd. and silane coupling agent into an intermediate layer and incorporating amorphous carbon into a surface protective layer. CONSTITUTION:An As2Se3 layer, the intermediate layer and the surface protective layer are successively provided on a conductive base and the metal oxide and the silane coupling agent are incorporated into the intermediate layer. In addition, the amorphous carbon is incorporated into the surface protective layer. The mixture composed of the metal compd. and silane coupling agent used in the intermediate layer have not only the effect of enhancing the adhesiveness of the As2Se3 photosensitive layer and the protective layer consisting of the amorphous carbon but also prohibit the implantation of, for example, positive charges to the photosensitive layer. On the other hand, the mixture has the function to facilitate the bonding of the carriers formed by the implantation of light and the positive charges in the front layer and to stably maintain the electrostatic characteristic of the photosensitive body after repetitive use. The electrophotographic sensitive body which has a high sensitivity, affords the high-quality images stable over a long period of time and has the excellent durability is obtd. in this way.

Description

[Detailed Description of the Invention] [Prior Art] Electrophotographic photoreceptors are broadly classified into inorganic and organic types, but at present, the former is superior in terms of electrophotographic properties. For this reason, many inorganic electrophotographic photoreceptors are in practical use.

By the way, such inorganic electrophotographic photoreceptors include Se, 5e-Te, 5e-As, and 5e-5.
So-called Se-based photoreceptor such as b-based; a (amorphous)
-5iC:H.

a-5iFI:H, a-5iCO:H, a-5iCF:
So-called amorphous silicon (a-5i) such as
type photoreceptors are known.

Among them, 5e-As photoconductors, especially As2Se□ photoconductors, have a printing durability of 200,000 sheets or more, have good image quality, and
The manufacturing cost is lower than that of the a-5i photoreceptor, so it is currently the most commonly used photoreceptor.

However, since the As, Se3 photoreceptor is seriously inadequate in terms of durability and also has insufficient charging ability, a blocking layer made of arsenic oxide is usually provided on the photosensitive layer.

However, since this blocking layer is formed with an extremely thin thickness of several tens of layers, if it comes into contact with solid matter such as toner, dust, or talc contained in copy paper, it may deteriorate or be damaged, causing damage to the copied image. There is a problem that abnormal images such as white stripes occur.

In order to overcome these drawbacks, a method has been proposed in which a protective layer is provided on the surface of the Se-based photosensitive layer to improve its durability against mechanical loads received inside and outside the copying machine.

For example, a method of providing an organic film on the surface of a photosensitive layer (
Japanese Patent Publication No. 38-015446), a method of providing an inorganic oxide (Japanese Patent Publication No. 43-014517), a method of laminating an insulating layer after providing an adhesive layer (Japanese Patent Publication No. 43-027591), or a plasma CVD method. a-5 by photo-CVD method etc.
Method of laminating i layer, a-5i:N:6 layer, a-5i:O:6 layer, etc. (JP-A-57-179859, JP-A-59-
058437) etc. have been disclosed.

It has been recognized that these methods have some effect on improving the mechanical durability of organic and Se-based photoreceptors. However, when laminating an organic film, it is necessary to use a solvent (which does not affect the organic photoreceptor), so there is less freedom in selecting materials, and silicone-based protective layers require 01 etc. as mentioned above. However, there are many problems that still need to be solved in practical use.

Against this background, the application of carbon or highly hard thin films mainly composed of carbon as a protective layer material for photoreceptors has been active in recent years.

For example, one in which a protective layer made of amorphous carbon or hard carbon is provided on the photosensitive layer (JP-A-6O-249155), one in which a diamond-like carbon protective layer is provided on the outermost surface (JP-A-6L-255352), A high-hardness insulating layer mainly composed of carbon is formed on a photosensitive layer (Japanese Patent Application Laid-Open No. 61-264)
355) Or nitrogen atoms, oxygen atoms,
Those provided with a protective layer consisting of a plasma organic polymer film containing at least atoms such as halogen atoms and alkali metal atoms (
JP-A No. 63-97961-4), a protective layer made of an amorphous hydrocarbon generated by glow discharge containing at least atoms such as chalcogen atoms, group II atoms, group II atoms, group II atoms, etc., on an organic photosensitive layer. (Japanese Unexamined Patent Publication No. 63-2201
66-9), etc.

In all of these proposals, a highly hard thin film mainly composed of carbon or I± carbon (i-carbon It belongs to what is collectively called a diamond-like carbon film.)
was formed.

In these methods, the protective layer is obtained by a film forming process that does not use a solvent and has high hardness.

Furthermore, since the film itself has a characteristic of being resistant to oxidizing atmospheres such as Ol, it has been recognized that it has an excellent effect in improving the durability of organic or Se-based photoreceptors.

However, even if such a material is used, if it is used repeatedly over a long period of time during the electrophotographic process, the photosensitive layer will be affected by plasma etc., causing structural deterioration, and if used repeatedly over a long period of time, the weather resistance will deteriorate. This causes a problem in that the properties and durability deteriorate, making it impossible to obtain stable and high-quality copied images.

[Problem to be solved by the invention]

The present invention has been made in view of the above-mentioned state of the prior art, and provides an electrophotographic photoreceptor that does not deteriorate in durability or weather resistance even after repeated use and provides stable and high-quality copied images over a long period of time. The purpose is to provide

[Means to solve the problem]

As a result of intensive studies to solve the above problems, the present inventors found that in an electrophotographic photoreceptor in which a surface protective layer consisting of As, a Sea layer, an intermediate layer, and amorphous carbon are provided in order from the conductive support side, the intermediate layer The present invention has been completed based on the discovery that the above object can be achieved when a specific material is contained in the conductive support.
e. An electrophotographic photoreceptor in which a layer, an intermediate layer and a surface protective layer are sequentially provided, wherein the intermediate layer contains a metal compound and a silane coupling agent, and the surface protective layer contains amorphous carbon. An electrophotographic photoreceptor is provided.

The mixture of metal compound and silane coupling agent used in the intermediate layer in the present invention not only has the effect of increasing the adhesion between As, Se, and the photosensitive layer and the protective layer made of amorphous carbon, but also has the effect of increasing the adhesion between the photosensitive layer and the protective layer made of amorphous carbon. A function that prevents injection into the layer and facilitates the combination of carriers generated by force tip injection with positive charges in the surface layer, stably maintaining the electrostatic properties of the photoreceptor after repeated use. has.

Therefore, the electrophotographic photoreceptor of the present invention has high sensitivity and excellent durability and weather resistance.

The present invention will be explained in more detail below.

The conductive support used in the present invention may be a conductor or an insulator treated for conductivity, such as AQ, Ni, F
In addition to metals such as e, Cu, and Au, or their alloys, thin films of metals such as AQ, Ag, and Au, or conductive materials such as In2O, and SnO□ are deposited on insulating substrates such as polyester, polycarbonate, polyimide, and glass. It is possible to use paper that has been formed or has been treated with electrical conductivity.

There are no particular restrictions on the shape of the conductive support, and any of the shapes of a plate, drum, or belt can be used.

As described above, the intermediate layer according to the present invention is composed of a metal compound and a silane coupling agent.

Examples of metal compounds that can be used include zirconium tetrakisacetylacetonate, diisopropoxytitanium bisacetylacetonate, etc. (metal complex systems)
, zircodium n-butyrate.

Titanium n-butyrate (metal alcoholade type) may be mentioned.

Examples of the silane coupling agent to be mixed include γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and γ-mercaptopropyltrimethoxysilane.

By coating the surface of the As, Se, and Se layers with these metal compounds, a high-quality blocking layer (cubic-shaped As2Se) is formed on the As2Se layer to prevent positive charges from being injected into the photosensitive layer. This greatly improves the charging characteristics of the photoreceptor. Moreover, the adhesion between the photosensitive layer and the protective layer is improved by the action of the silane coupling agent, and an electrophotographic photoreceptor with improved durability can be obtained.

The thickness of this intermediate layer is 400 to 5000, preferably 80.
0 to 2000 people. If the film thickness is less than 400, pinholes are likely to occur in the intermediate layer, causing abnormal images. Moreover, if the film thickness exceeds 5,000 layers, the residual potential will increase, which is not desirable.

To create the intermediate layer, for example, the metal compound and silane coupling agent described above are diluted with a suitable solvent such as butanol, and the resulting solution is then applied to the photosensitive layer (AszSea).
layer) and dry it.

The photosensitive layer according to the present invention is As2Se based. This As
2Se is a highly sensitive photosensitive material used in 20 to 50 cp copiers, and has excellent crystallization resistance, so it is relatively free from solvents and can be used at temperatures below the melting temperature of As2Se ( 150° C. or lower), no problem will occur even if the film is heated during film formation.

^52Se refers to Se containing 38.7 wt% As, and in terms of electrical properties, 35 to 36 wt% is of good quality.

Therefore, in the present invention, the As content is 35 to 36 wt.
% of As2Se is preferably used.

In the present invention, the protective layer provided on the outermost surface of the photosensitive layer via the intermediate layer is mainly composed of amorphous carbon, and preferably has a Vickers hardness of 600 to 2500.
Kg/Sono 1, ratio resistance ([i! low resistance 1 x 10'
It is formed of a thin film having a value of ~9XIO''Ω·C and having a translucency of 70% or more even at a wavelength of 460n.

Such films are generally produced by sputtering or plasma CVD.
, formed by glow discharge decomposition method, photo-CVD method, etc.
Although the film forming method is not particularly limited, a protective layer having good properties can be obtained by forming the film using a plasma CVD method with a sputtering effect.

In order to obtain amorphous carbon, raw materials include high-purity hydrocarbon gases such as C2H4, C, H, , C3H, and, if necessary, NF, NH, C, F, and B.
, )l, etc. Such a mixed gas may be fed into the apparatus, high frequency (13.56 MHz) may be applied, and a film may be formed by means such as plasma. Amorphous carbon is a colored film, but by selecting raw materials and manufacturing methods, it is possible to produce a film that can obtain a transmittance of 80% or more even at 460 nm.

The specific resistance and film thickness of the protective layer of the present invention are determined by factors such as resolution, residual potential, its accumulation property, and transmittance. It may be within the range of, preferably 5X10”-IXIPaΩ
・CII range is desirable.

When the resistivity is low, image deletion occurs, and when it is high, fogging and image deletion occur.

The thickness of the protective layer should be in the range of 1000 to 2 voices.

Preferably it is 4000 people to 1 μs.

Additionally, additives such as fluorine, nitrogen, phosphorus, and boron can be added to the protective layer of the present invention as needed, and the concentration thereof is uniform in the depth direction of the film. There is no problem even if there is a gradient. Further, this protective layer does not need to be a single layer, and may have a multilayer structure in which the presence or absence of additives, types, etc. are controlled.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 On an aluminum drum (JIS 3003 series) having a diameter of 80mm, a length of 340mm, and a thickness of 3mm, a layer of As, Se, and 35.5% by weight of As was vacuum-deposited at about 60% by vacuum evaporation.

Next, on this As2Se layer, γ-methacryloxypropyltrimethoxysilane (KBM 503, manufactured by Shin-Etsu Chemical Co., Ltd.), zirconium tetrakis acetylacetonate (manufactured by Matsumoto Bunbu Co., Ltd.) and n-BuOH were added in a weight ratio of 1:2.
The mixture was mixed and stirred at a ratio of :40 and then applied by a spray method, and then stirred at 120° C. for 2 hours to form an intermediate layer of about 1200 people.

Next, this was set in a plasma CVD apparatus, and after exhausting to 5 X 10-'' Torr or less with an exhaust pump, 15 SCCM and 1.5 SCCN of C2H4 and NF were introduced as material gases for the protective layer, respectively, and the exhaust valve was closed. The vacuum chamber pressure was controlled at 0.08 Torr. Then, a power of 13.56 MHz, 25 W was applied between the RF electrodes, and a reaction was carried out for 50 minutes to form a surface protective layer made of amorphous carbon.

The thickness of the protective layer formed in this way is approximately 8,000 mm, Vickers hardness is 1,340 Kg/am, and specific resistance is 9.5
The amount of C was 10”Ω・C.The transmittance was 7 at 460μm.
8%, and 98% at 780 m.

Example 2 An As, Se3 photoreceptor with an intermediate layer formed using the same manufacturing method as Example 1 was set in a plasma CVD apparatus, and after being evacuated to below 5 x 10''GTorr with an exhaust pump,
C2H4155 (1:CM) was introduced as a material gas for the protective layer, and the vacuum chamber pressure was adjusted to 0.06 Torr by operating the exhaust valve.
was controlled. Next, 13.56MH between the RF electrodes
A power of z25V was applied and the reaction was carried out for 90 minutes to form a surface protective layer.

The thickness of the protective layer thus formed was approximately 6,500 mm, Vickers hardness was 1,400 Kg/mm, and specific resistance was 1.
It was 10'Ω・C Otori. Also, the transmittance is 460μm
It was 78% at 780 m and 98% at 780 m.

Comparative Example 1 As2Se formed up to the intermediate layer by the same manufacturing method as Example 1,
The photoreceptor has a styrene-Aa A-2HEMA ratio of 2:5:
SnO to urethane cross-linked styrene-HMA resin
□Add 58 wt% of fine particles (S-1, manufactured by Mitsubishi Metals), add a solvent containing toluene, cellosolve acetate, and methyl isobutyl ketone in a ratio of 3:4:3, and sand mill for 60 minutes. Dispersed. Then, fatty acid polyisocyanate (Sumidur HT, Sumitomo Bayer) was added, further dispersed, and then applied by spraying and dried at 130° C. for 30 minutes to form a protective layer of about 3 to form a photoreceptor. .

Comparative Example 2 As2Se3 formed up to the intermediate layer using the same manufacturing method as Example 1
The photoreceptor was set in a plasma CVD apparatus different from that in Example 1, and an amorphous silicon layer (
About 1200 people deposited a-5uC:N:B:H). Hardness is approximately 1360 Kg/am", transmittance at 460 m is 9
0%, and 100% at 780 m.

[Experimental conditions]

Support rotation speed: 10 rρ Support temperature: 140°C Reaction gas pressure: 0.8 Torr back pressure
: I X 10-' Torr discharge power:
150 (o, 1/aJ) Flow rate ratio (SCCM; in air): 5iH4 (20%
): 100Co2 (100%): 16 N, (100%) = 20 BJG (100 pp garden): 12 The electrostatic properties and image quality of the electrophotographic photoreceptors of Examples and Comparative Examples obtained above were evaluated. The results are shown in Table-1.

The electrostatic properties and image quality were measured as follows.
evaluated.

[Electrostatic properties]

Each electrophotographic photoreceptor was set on the measuring drum, +5.5 KV was applied to the corona discharger, and the potential Vm after 50 seconds was
20 seconds dark decay ratio Vo/Vm, rooov 2 charged 1
200 when irradiated with light with a light intensity of 2μtr/ffl
The sensitivity El 15 when light is attenuated to volt and the residual potential v2° after 20 seconds of light attenuation were measured.

[Image quality]

Each of the above electrophotographic photoreceptors was used in a copying machine manufactured by Ricoh, FT-6550.
The image characteristics of the initial image, after 10,000 sheets, after 20,000 sheets, after 50,000 sheets, and after 100,000 sheets were visually evaluated.

O: A high quality image can be obtained without image deterioration.

0: Image quality is good although there is some image deterioration.

×: Image deterioration is significant and image quality is not good.

-: Image is not displayed.

From the results shown in Table 1, the electrophotographic photoreceptor of the present invention has more stable electrostatic properties after repeated use than that of the comparative example, and has high quality even after repeated image production of more than 10,000 sheets. It can be seen that a duplicate image is given.

〔Effect of the invention〕

The electrophotographic photoreceptor of the present invention is highly sensitive and extremely durable, providing stable and high-quality images over a long period of time.

Patent applicant Rico Co., Ltd.

Claims (2)

[Claims] (1) In an electrophotographic photoreceptor in which As_2Se_3 layers, an intermediate layer, and a surface protective layer are sequentially provided on a conductive support, the intermediate layer contains a metal compound and a silane coupling agent, and the surface protective layer contains amorphous carbon. An electrophotographic photoreceptor comprising: (2) The thickness of the intermediate layer is 400 to 5000 Å, and the thickness of the surface protective layer is 1000 Å to 2 μm, and the specific resistance is 1 × 10^■ to 9 × 10^1^2 (Ω cm
) The electrophotographic photoreceptor according to claim (1).