JPS62273550A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To obtain the titled body having a very small dark attenuation of the electrostatic charge potential by constituting a photoconductive layer from a p-type semiconductor which comprises an amorphous silicon contg. hydrogen atom as a main component, and also boron atom as an impurity, and by constituting an intermediate layer from a dried curing material of a solution contg. at least one kind of an org. titanium compd. CONSTITUTION:The intermediate layer is laminated on a conductive substrate, and the conductive layer composed of the amorphous silicon is coated on the intermediate layer. The dried curing material of the solution contg. at least one kind of the org. titanium compd. is used as the intermediate layer. The p-type semiconductor which contains the amorphous silicon contg. hydrogen atom as the main component, and also contains boron atom and at least one kind of carbon atom, nitrogen atom and oxygen atom as an impurity is used the photoconductive layer. The org. titanium compd. is further preferably exemplified by a titanium complex and a titanium alkoxide. Thus, the high mechanical strength, the high durability, the high heat-resisting property and the high photosensitivity of the titled body are maintained, and the high electric charge holding power of the titled body is obtd., without being affected by the surroundings of an outside and the number of using, thereby obtaining the picture image having excellent quality.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention Industrial Field of Application The present invention relates to a photoreceptor for electrophotography, and in particular to a photoreceptor for electrophotography using amorphous silicon in the photosensitive layer. Regarding.

In conventional electrophotography, an electrostatic latent image is formed by charging a photoreceptor and exposing it to light, and after developing this latent image with a developer called toner, the toner image is transferred to transfer paper. This is a method of fixing and obtaining copies.The basic structure of the photoreceptor used in this electrophotography is a photosensitive layer laminated on a conductive substrate. The materials include inorganic photosensitive materials such as selenium or selenium alloys, cadmium sulfide, and zinc oxide, and mFF photomaterials such as polyvinylcarbazole, trinitrofluorenone, bisazo pigments, phthalonanine, pyrazoline, and hydrazone. It is used with 1 representing the soil layer or layer.

Problems to be Solved by the Invention However, these conventionally used photosensitive layers have problems in durability, heat resistance, photosensitivity, etc. that still need to be solved.

In recent years, photoreceptors using amorphous silicon as the photosensitive layer have been known, and various attempts have been made to improve them. This photoreceptor using amorphous silicon has an amorphous silicon film formed on a conductive substrate using a glow discharge decomposition method using 7-run (SI84) gas. Hydrogen atoms are incorporated into the material to exhibit photoconductivity. This amorphous silicon photoreceptor has a photosensitive layer that has a high surface hardness, is resistant to scratches, is resistant to friction, has high heat resistance, and has excellent mechanical strength.

Furthermore, amorphous silicon has a wide spectral sensitivity range and has excellent photosensitivity, such as high photosensitivity. However, on the other hand, photoreceptors using amorphous silicon have the disadvantage that dark decay is large and a sufficient charging potential cannot be obtained even when charged. That is, when an amorphous silicon photoreceptor is charged, imagewise exposed to form an electrostatic latent image, and then developed, the surface charge on the photoreceptor is not irradiated with light until the imagewise exposure step or the development step. Even the charge on the parts that are not affected is attenuated, making it impossible to obtain the charging potential necessary for development. This attenuation of the charging potential is likely to change depending on the influence of environmental conditions, and in particular, the charging potential decreases significantly in a high temperature and high humidity environment.

Furthermore, when an amorphous silicon photoreceptor is used repeatedly, its charging potential gradually decreases. If a copy is made using a photoreceptor with such a large dark attenuation of the charged potential, the copy will have low image density and poor reproducibility of halftones.

An object of the present invention is to provide an electrophotographic photoreceptor that eliminates the above-mentioned drawbacks of photoreceptors using amorphous silicon.

Furthermore, the object of the present invention is to use amorphous silicon, and
An object of the present invention is to provide an electrophotographic photoreceptor in which the dark decay of the charged potential is extremely small.

Another object of the present invention is to provide an electrophotographic photoreceptor whose charging characteristics are not affected by changes in the cloud surroundings of the external environment.

Another object of the invention is to provide an electrophotographic photoreceptor with improved image quality even after repeated use. An object of the present invention is to provide an electrophotographic photoreceptor having excellent electrophotographic properties such as light sensitivity and photosensitivity.

Means for Solving the Problems As a result of extensive research, the inventor of the present invention laminated an intermediate layer on a conductive substrate, coated it with a photoconductive layer made of amorphous silicon, and It has been found that the above object can be achieved by using, as the intermediate layer, a dried and cured product of a solution containing at least one organic titanium compound.

The photoconductive layer is mainly made of amorphous silicon containing hydrogen atoms, contains boron atoms as impurities, and further contains at least one of carbon atoms, nitrogen atoms, and oxygen atoms.
A p-type semiconductor containing p-type semiconductors is used.

Thus, according to the present invention, in an electrophotographic photoreceptor in which an intermediate layer and a photoconductive layer are sequentially laminated on a conductive substrate, the photoconductive layer is mainly made of amorphous silicon containing hydrogen atoms. Contains a boron atom as an impurity, and further,
The intermediate layer is made of a p-type semiconductor containing at least one of carbon atoms, nitrogen atoms, and oxygen atoms, and the intermediate layer is
There is provided an electrophotographic photoreceptor characterized by being made of a dried and cured product of a solution containing at least one type of organic titanium compound.

Although various organic titanium compounds can be used to form the intermediate layer of the electrophotographic photoreceptor of the present invention, titanium complexes and titanium alkoxides are particularly preferred. Preferred examples of these include diisopropoxy titanium bis(acetylacetone).
), polytitanium acetylacetonate, bis(acetylacetonate) titanium oxide, titanium tetramethoxide, titanium tetraethoxide, titanium tetra-n-propoxide, titanium tetra-iso-propoxide, titanium tetrabutoxide, titanium tetra -iso-butoxide,
etc.

In order to obtain the electrophotographic photoreceptor of the present invention, a solution of one or more of the above organic titanium compounds dissolved in a suitable solvent is coated.

Further, at this time, a solution obtained by mixing these organic titanium compounds with an organic silicon compound may be used.

Compounds generally called silane coupling agents are suitable as this organosilicon compound, such as vinyltrichlorosilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, r-glycidoxypropyltrimethquine, etc. Silane, γ-methacryloxypropyltrimethoxysilane, N-β(aminoethyl>r-aminopropyltrimethoxysilane, N-β(
(aminoethyl) T-aminopropylmethyldimethoxysilane, r-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, methyltrimethoxysilane,
Examples include dimethyldimethoxysilane, trimethylmonomethoxysilane, diphenyldimethoxysilane, diphenyljethoxysilane, and monophenyltrimethoxysilane.

When such silane coupling agents are mixed and used, it is preferable that the silane coupling agents account for 5 to 50% of the total solid weight.

Thus, a solution containing an organotitanium compound and optionally an organosilicon compound is applied onto a conductive substrate.
The electrophotographic photoreceptor of the present invention can be obtained by coating by spray coating, dip coating, knife coating, roll coating, or the like, drying and curing, and laminating a photoconductive layer thereon.

The drying and curing temperature can be set at any temperature between 100 and 400°C. The thickness of the intermediate layer that is finally removed can be set arbitrarily, but it is preferably 0.1 to 10 μm.

The photoconductive layer mainly composed of amorphous silicon is SiH,,s
i2Hg, S i:Hs, S i<H+. , etc., or a mixture thereof, as a raw material, and is formed on the intermediate layer by a method such as a glow discharge method, a sputtering method, an ion blasting method, or a vacuum evaporation method. Among them, plasma CVD (Chemical V
A method (glow discharge method) in which silane (SiH4) gas or the like is decomposed by glow discharge using an apor deposition method is preferable from the viewpoint of controlling the hydrogen content in the film. Further, in this case, in order to more efficiently contain hydrogen, hydrogen (H2) gas may be separately introduced into the plasma CVD apparatus at the same time as the silane gas or the like. Furthermore, from the viewpoint of film growth rate, it is preferable to use SiH, Si□H6.

The photoconductive layer of the electrophotographic photoreceptor of the present invention is made of a p-type semiconductor mainly composed of amorphous silicon containing hydrogen atoms and containing phosphorus atoms as impurities;
It contains at least one type of carbon atom, nitrogen atom, or oxygen atom. The inclusion of such atoms is particularly preferable from the viewpoint of increasing the dark resistance of the photosensitive layer film, increasing the photosensitivity, and further increasing the charging ability (charging potential per unit film thickness). Ciborane (B2 Hs) gas is usually used as a raw material for adding boron (B) atoms to the layer. In this case, the amount of B atoms added is 10 to 100 ppm
This is the extent of

Furthermore, it is also possible to add an element such as germanium (Ge) to the photoconductive layer film for the purpose of increasing the sensitivity of the photoreceptor in the long wavelength region. Further, by adding halogen atoms, it is also possible to increase the dark resistance.

Thus, in order to prepare the photoconductive layer of the electrophotographic photoreceptor of the present invention, silicon hydride gas, which is the main raw material, and hydrogen gas, if desired, are used in a plasma CVD apparatus, and together with these gases, Glow discharge decomposition may be performed by introducing a gaseous compound containing the necessary elements. As mentioned above, effective discharge conditions for forming a photoconductive layer made of amorphous silicon by the plasma CVD method include, for example, in the case of AC discharge, the frequency is usually 0.1 to 33 MHz, and the degree of vacuum during discharge. is 0.1~5 Torr, substrate heating temperature is 100~
The temperature is 400°C. Therefore, the film thickness of the photoconductive layer mainly composed of amorphous silicon is 1 to 100 μm, particularly 10 to 50 μm.
It is preferable to set it to m.

As the conductive substrate, a metal such as aluminum, nickel, chromium, stainless steel, or brass, a plastic sheet or glass having a conductive film, or paper treated to be conductive can be used. Moreover, the shape of the conductive substrate can be any shape such as a cylindrical shape, a flat plate shape, an endless belt shape, or the like.

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

Comparative Example 1: A cylindrical Al substrate was installed at a predetermined position in the reaction chamber of a capacitively coupled plasma CVD apparatus, the substrate temperature was maintained at a predetermined temperature of 250°C, and 100% silane (Si) was placed in the reaction chamber.
Hl) gas at 120cc per minute.

100 CN9m Cibolaf (B'2H3) diluted with hydrogen
33cc of gas per minute, 15cc of ethylene (C2H,) gas, and 75cc of 100% hydrogen (N2) gas per minute were introduced into the reaction tank, and the inside of the reaction tank was heated to Q, 5 Tor.
After maintaining the internal pressure at r, high-frequency power of 13.57 MHz is applied to generate glow discharge, and the high-frequency power supply a
The power was maintained at 85W. In this way, the cylindrical A1
A photoreceptor was obtained having a 25 μm thick photoconductive layer on a substrate made of a p-type semiconductor mainly composed of amorphous silicon, containing boron atoms as impurities, and further containing hydrogen and carbon.

When the photoreceptor thus obtained was placed in a copying machine and the image quality was evaluated using a positive corona charging method, an image density that was acceptable for practical use could not be obtained.

Example 1: On one cylindrical A substrate having the same shape as Comparative Example 1, 1 part by weight of diisobutoxy titanium pis (acetylacetonate),
Applying a solution consisting of 20 parts by weight of n-butanol by dip coating,
It was dried in an oven at 250° C. for 2 hours to provide a 0.4 μm thick intermediate layer. Next, on this intermediate layer, a photoconductive layer mainly made of amorphous silicon having the same content as in Comparative Example 1 was provided by the same method as in Comparative Example 1, and with almost the same thickness as in Comparative Example 1. The photoconductive layer thus obtained had properties similar to ceramics, and had the same surface hardness, abrasion resistance, and heat resistance that are the inferior properties of amorphous silicon.

When the photoreceptor thus obtained was placed in a copying machine and the image quality was evaluated using a positive corona charging method, an image density that was acceptable for practical use was obtained at the initial stage. Further, although the copying operation was repeated 50,000 times, no decrease in image density was observed.

Comparative Example 2: A cylindrical A1 substrate was installed at a predetermined position in the reaction chamber of a capacitively coupled plasma CVD apparatus, the substrate temperature was maintained at a predetermined temperature of 250°C, and 100% silane (Si) was placed in the reaction chamber.
H,) gas at 12 Qcc per minute.

Hydrogen diluted 1000 ppm Siboraf (B2H3) gas was introduced at 30 cc per minute, 100% nitrogen (N2) gas was introduced at 9 Qcc per minute, and 100% hydrogen (N2) gas was introduced at IQcc per minute. After maintaining the internal pressure at 5 Torr, high frequency power of 13.56 MHz was applied to generate glow discharge, and the output of the high frequency power source was maintained at 85 W. In this way, a photoreceptor having a 25 μm thick photoconductive layer made of a p-type semiconductor mainly composed of amorphous silicon and containing boron as impurities and further hydrogen and nitrogen was obtained on a cylindrical Af substrate. .

When the photoreceptor thus obtained was placed in a copying machine and the image quality was evaluated using a positive corona charging method, the image density was not acceptable for practical use.

Example 2: A solution consisting of 1 part by weight of tetraethylorthotitanate and 30 parts by weight of isopropyl alcohol was dip-coated onto a cylindrical A1 substrate having the same shape as in Comparative Example 2, and dried in an oven at 250° C. for 2 hours. A .3 μm thick intermediate layer was provided. Next, on this intermediate layer, a photoconductive layer mainly composed of amorphous silicon having the same contents as in Comparative Example 2 was formed by the same method as in Comparative Example 2.
The film thickness was approximately the same as that of Comparative Example 2.

When the photoreceptor thus obtained was placed in a copying machine and the image quality was evaluated using a positive corona charging method, an image density that was acceptable for practical use was obtained at the initial stage. Further, although the copying operation was repeated 50,000 times, no decrease in image density was observed.

Comparative Example 3: A cylindrical A1 substrate was installed at a predetermined position in the reaction chamber of a capacitively coupled plasma CVD apparatus, the substrate temperature was maintained at a predetermined temperature of 250°C, and 100% silane (Si) was placed in the reaction chamber.
H,) gas at 120cc/min, hydrogen dilution at 1000ρp
m Siboraf (B2 H3) gas was introduced at 3 Qcc per minute, 100% oxygen (02) gas was introduced at 1.0 cc per minute, and 100% hydrogen (H2) gas was introduced at 39 cc per minute to bring the inside of the reaction vessel to 0.0 cc per minute. After maintaining an internal pressure of 5 Torr, 1
High frequency power of 3.56 MHz was applied to generate glow discharge, and the output of the high frequency power source was maintained at 85W. In this way, a cylindrical photoreceptor having a photoconductive layer having a thickness of 25 μm and consisting of a p-type semiconductor mainly composed of amorphous silicon and containing boron as impurities and further hydrogen and oxygen was obtained on one cylindrical substrate. Ta.

When the photoreceptor thus obtained was placed in a copying machine and image quality was evaluated using a positive corona charging method, an image density that could withstand practical use was not obtained.

Example 3: On a cylindrical Afl substrate having the same shape as Comparative Example 3, 1 part by weight of tetrabutyl orthotitanate, 1 part by weight of T-acryloxypropyltrimethoxysilane, and 1 part by weight of methyl alcohol were added.
A solution consisting of 0 parts by weight and 20 parts by weight of isopropyl alcohol was applied by dip coating and dried in an oven at 250° C. for 2 hours to form an intermediate layer with a thickness of 0.3 μm. Next, on this intermediate layer, a photoconductive layer mainly composed of amorphous silicon having the same contents as in Comparative Example 3 was provided by the same method as in Comparative Example 3 and having almost the same thickness as in Comparative Example 3.

When the photoreceptor thus exposed was placed in a copying machine and the image quality was evaluated using a positive corona charging method, an image density that was acceptable for practical use was obtained at the initial stage. Further, although the copying operation was repeated 50,000 times, no decrease in image density was observed.

Effects of the Invention The electrophotographic photoreceptor of the present invention retains the excellent properties of a photoreceptor made of amorphous silicon, such as high mechanical strength, high durability, high heat resistance, and high light sensitivity. B It has a high charge retention ability without being affected by the environment or the number of times of use, and can provide images of excellent quality.

Claims (1)

[Scope of Claims] An electrophotographic photoreceptor comprising an intermediate layer and a photoconductive layer sequentially laminated on a conductive substrate, wherein the photoconductive layer is mainly composed of amorphous silicon containing hydrogen atoms as an impurity. The intermediate layer is made of a p-type semiconductor containing a boron atom, and further contains at least one type of carbon atom, nitrogen atom, or oxygen atom, and the intermediate layer is drying and curing a solution containing at least one type of organic titanium compound. An electrophotographic photoreceptor characterized by being made of a material.