JP2623144B2 - Electrophotographic photoreceptor having photoreceptive layer containing polysilane and ultraviolet absorber - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electrophotographic photoconductor using polysilane. More specifically, the present invention relates to an electrophotographic photoreceptor having a light-receiving layer containing a polysilane and an ultraviolet absorber, and capable of stably giving a desired copied image without deterioration during repeated use.

[Description of Prior Art]

Conventionally, various organic photoconductive polymers including polyvinyl carbazole have been proposed as a photoconductive material used in an electrophotographic photoreceptor. Despite their superiority in film-forming properties and lightness compared to inorganic photoconductive materials, these polymers have been difficult to put to practical use until today because they still have sufficient film-forming properties. And is inferior to inorganic photoconductive materials in terms of sensitivity, durability and stability due to environmental changes. Other than these photoconductive materials, hydrazone compounds according to U.S. Pat.No. 4,150,987, triarylpyrazoline compounds according to U.S. Pat.No. 3,837,851, JP-A-51-94828, JP-A-51-94829 For example, a low-molecular organic photoconductor such as a 9-styrylanthracene compound has been proposed. Such a low-molecular organic photoconductor can eliminate the drawback of film formation, which has been a problem in the field of organic photoconductive polymers, by appropriately selecting a binder to be used, but has a high sensitivity. However, there is a disadvantage that this is not sufficient.

For this reason, a laminated structure in which a photosensitive layer is functionally separated into a charge generation layer and a charge transport layer has been proposed. The photoreceptor for electrophotography having such a laminated structure as a photosensitive layer shows improvements in sensitivity to visible light, charge retention, surface strength, and the like. Such electrophotographic photoconductors are described, for example, in U.S. Pat. Nos. 3,837,851 and 3,871,8
No. 82, and the like.

However, since any electrophotographic photoreceptor has a charge transport layer formed by mixing a low-molecular organic photoconductor with a binder resin, the sensitivity and characteristics are not necessarily the main cause of the binder resin. In addition to the problem of not being sufficient, there are problems that the mobility of the charge is reduced, the fluctuation of the light portion potential and the dark portion potential is large in repeated charging and exposure, and the durability is not sufficient.

By the way, in addition to the organic photoconductor materials described above, since it has been reported that polysilane compounds have properties as an optical semiconductor capable of transferring charges by σ-bonds in the main chain, their application to electrophotographic photoreceptors has been reported. There has been attracting attention is expected [physical review (physical review), B 3
5 , page 2818 (1987)].

As for polysilane compounds, various synthesis methods and various polysilane compounds have been reported. That is,
It has been reported that polysilane compounds of low molecular weight have a structure in which all Si groups are substituted with organic groups [The Journal of American Chemical Society (Journa)
l of American Chemical Society 94 (11) 3806pp (197
2), JP-B-63-38033). The former publication has a structure in which a terminal group of dimethylsilane is substituted with a methyl group, and the latter publication has a structure in which a terminal group of dimethylsilane is substituted with an alkoxy group. Also have a degree of polymerization of 2 to 6 and do not exhibit the characteristics of a polymer.
That is, because of its low molecular weight, it has no film forming ability as it is, and is difficult to use industrially. A high-molecular-weight polysilane compound having a structure in which all Si groups are substituted with organic groups has recently been reported [Nikkei New Materials August 15, 46
Page (1988)]. However, since such a polysilane compound passes through a special reaction intermediate, the synthesis yield is expected to decrease, and industrial mass production is difficult.

U.S. Pat. No. 4,618,551 describes an electrophotographic photoreceptor using the above-described polysilane compound. However, the electrophotographic photoreceptor employs an abnormally high surface potential (-) of 1000 V, which is generally 500 to 800 V in a general electrophotographic copying machine, with respect to the absolute value of the surface potential. This is considered to be because at a normal potential, a defect occurs in the electrophotographic photosensitive member due to a structural defect of the polysilane, and a spot-like abnormal phenomenon on an image disappears. In addition, JP
In -269964, an electrophotographic photoreceptor is prepared using the above-described polysilane compound, and the photosensitivity is measured.However, the photosensitivity is slow, and compared to conventionally known selenium photoreceptors and organic photoreceptors. Has no advantage.

As described above, the conventional polysilane compounds have many problems and are poor in practicality when they are used as electronic materials, particularly as constituent materials of electrophotographic photoreceptors.

For these reasons, application of polysilane to photoconductors for electrophotography is expected.However, in order to obtain desired electrophotographic photoconductors that can be practically used by using polysilane as a photoconductive material, the following polysilanes are used. It is required to satisfy at least such requirements. That is, the requirements are (i) not only solvent-soluble and film-forming ability, but also formation of a film without fine defects and formation of a film with high homogeneity, (ii) electrophotographic Since fine defects are not allowed in the photoreceptor, the structure of the substituent is clear and the photoreceptor must be of high quality which does not cause an abnormality in film formation.

[Object of the invention]

The present inventors have found a specific polysilane compound satisfying the above requirements, and have already filed an application (Japanese Patent Application No. 63-335617).
No.).

The present inventors have further studied on an electrophotographic photosensitive member having a photoreceptive layer containing the polysilane compound, and found that an electrophotographic photosensitive member using the polysilane compound for a charge transport layer was produced. In some cases, it has been found that, when charging and exposure are repeatedly performed, the light portion potential may increase.

Before the electrophotographic photosensitive member is used, that is, before it is mounted on a copying machine, the photosensitive member is left under a light beam containing external ultraviolet rays. It was found that the bright part gradually rose, and the resulting image gradually became an image with a large fog.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrophotographic photoreceptor which eliminates the above-mentioned drawbacks of the electrophotographic photoreceptor containing a polysilane compound and provides a desired copy image stably without deterioration during repeated use. .

Another object of the present invention is to provide an electrophotographic photoreceptor which prevents the occurrence of irreversible photochemical reactions caused by the action of light rays incident on the electrophotographic photoreceptor, that is, the occurrence of decomposition of polysilane molecules. Is to do.

[Structure and effect of the invention]

The present inventors have conducted intensive studies to solve the above-described problems, and in the above-described electrophotographic photoreceptor, the polysilane used as the charge transport material decomposes by absorbing light in the ultraviolet region, Since the decomposition products trap and accumulate the charge carriers injected from the charge generation material, it has been inferred that the light potential gradually rises when used repeatedly.

The present inventors have conducted intensive studies based on the findings, and found that the surface layer containing polysilane of the electrophotographic photoreceptor containing the polysilane compound has an ultraviolet absorber having a maximum absorption in the range of 280 to 360 nm. By containing
It has been found that the above problems can be solved and the above object can be achieved.

Therefore, the electrophotographic photoreceptor provided by the present invention is represented by the following general formula (I) and has a weight average molecular weight of 60
An electrophotographic photoreceptor having a photoreceptive layer formed by using a polysilane compound of from 00 to 200,000, wherein the surface layer containing the polysilane compound has an ultraviolet absorption having a maximum absorption in the range of 280 to 360 nm. It is characterized by containing an agent.

Wherein R ₁ is an alkyl group having 1 or 2 carbon atoms, R ₂ is an alkyl group having 3 to 8 carbon atoms, a cycloalkyl group, an aryl group or an aralkyl group, and R ₃ is an alkyl group having 1 to 4 carbon atoms. And the group R ₄ represents an alkyl group having 1 to ₄ carbon atoms. A and A 'each represent an alkyl group having 4 to 12 carbon atoms;
It is a cycloalkyl group, an aryl group or an aralkyl group, both of which may be the same or different. n and m are molar ratios indicating the ratio of the number of each monomer to the total monomers in the polymer, and n + m = 1,
0 <n ≦ 1 and 0 ≦ m <1. The configuration of the electrophotographic photoconductor of the present invention is preferably a laminated photoconductor. Such a laminated photoreceptor includes, for example, a charge generation layer 2 on a conductive support 1 as shown in FIG.
And a charge transport layer 3 containing a polysilane compound.

The charge transport layer 3 in the present invention is formed by applying an ultraviolet absorber to a solution obtained by dissolving the above-mentioned polysilane compound with an appropriate organic solvent, applying the mixture on the charge generation layer 2, and drying the mixture.

The ultraviolet absorber has a very small molecular weight as compared with the polysilane compound, and after drying, it is shifted to the surface side of the charge transport layer 3-1 as shown in FIG. However, in reality, the charge transport material has a three-layer structure as shown in FIG. 1, and the polysilane layer 3-1 as the charge transport material is completely protected from ultraviolet rays. The thickness of the charge transport layer 3 is preferably 5 to 40 μm.
m, optimally in the range of 10-30 μm.

The content of the ultraviolet absorber in the charge transport layer 3 is 0.1
〜60 wt%, preferably 0.1-30 wt%.

As the ultraviolet absorber having a maximum absorption in the range of 280 to 360 nm used in the present invention, benzotriazoles, thiazolidones, acrylonitriles, benzophenones,
Ogizanilides, formamidines, aryl esters and the like can be used. Specific UV absorbers are as follows.

The fact that the polysilane compound represented by the general formula (I) used in the present invention is objectively distinguished from known polysilane compounds will be described below.

That is, conventionally known polysilane compounds are generally obtained by using a dichlorosilane monomer as a starting material, performing halogen elimination from the monomer using a Na catalyst, and polymerizing the monomer, as described above. For this reason, most of them have a halogen residue at the terminal.

When a conventional polysilane compound having such a halogen residue is used as a constituent material of a photoreceptor layer of an electrophotographic photoreceptor, the obtained electrophotographic photoreceptor has the following problems. It is not worthy of practical use. That is, in the electrophotographic photoreceptor having a light receiving layer composed of the conventional polysilane compound,
When an image is formed by using this, the halogen residue serves as a trap for charge transfer, resulting in a residual potential. In addition, when performing repetitive charging and exposure, the residual potential increases, and accordingly the bright portion potential increases, resulting in poor durability. In addition to these issues, there are other issues as well. That is, when the halogen residue of the conventional polysilane compound having a halogen residue interposed therein constituting the photoreceptor is a Cl group, if there is water, the Cl group reacts with the water to react with hydrogen chloride gas (HCl ) Occurs, and as a result, a conductive portion in contact with the light receiving layer of the base of the electrophotographic photoreceptor is corroded to cause poor conduction, thereby causing an image defect.

On the other hand, the polysilane compound used in the present invention is:
It is represented by the above-mentioned general formula (I), which has a weight average molecular weight of 6,000 to 200,000 and has no halogen group, and is specified by a side reaction like the above-mentioned conventional polysilane compound. It is characterized by its distinctive features such as no dissolution, easy dissolution in organic solvent and complete dissolution without turbidity, and excellent film-forming ability to make the resulting film transparent without local defects. It is something that can be done.

The present inventors have made a polysilane compound having a weight average molecular weight of 6000 to 200,000 and having no halogen residue, which is represented by the above general formula (I), a constituent material of a photoreceptive layer of an electrophotographic photoreceptor. It was examined through experiments whether or not it was suitable. As a result, the following was found.

That is, the following was found about the polysilane compound itself. (I) It is stable without any side reaction under the use environment: (ii) It is easily soluble in an organic solvent and can be completely dissolved without turbidity: and (iii) It has excellent film-forming ability: (iv) The resulting film is in a transparent state without local defects: and (v) has excellent charge transport ability and very fast charge mobility is observed.

Then, when the polysilane compound was applied to the photoreceptive layer of the electrophotographic photoreceptor, it was found that the crossing occurred. That is, (a) a photoreceptor for electrophotography which provides a high-sensitivity, defect-free and high-quality image: (b) no trap is generated, and the residual potential upon exposure is extremely small: (c) excellent charge A transport layer can be realized: and (d) when the polysilane compound is used in combination with a charge generating substance, it becomes possible to provide an electrophotographic photoreceptor having excellent electrophotographic properties.

As described above, the present invention provides a polysilane compound having a halogen-free polysilane compound represented by the above general formula (I) and having a weight-average molecular weight of 6000 to 200,000, comprising a light-receiving layer of an electrophotographic photoreceptor. It is based on the finding that an electrophotographic photoreceptor having a light-receiving layer formed by using the polysilane compound has various advantages described above. .

Polysilane compound used in the present invention and its production method The polysilane compound represented by the aforementioned general formula (I) and having a weight average molecular weight of 6000 to 200,000 used in the present invention has a chloro group or a side reaction product group. It does not have any, and all Si groups are substituted with a specific organic group having no oxygen, has no toxicity, aromatic solvents such as toluene, benzene, xylene, dichloromethane, dichloroethane,
It is easily soluble in halogenated solvents such as chloroform and carbon tetrachloride, and other solvents such as tetrahydrofuran (THF) and dioxane, and has excellent film forming ability.
The film formed of the polysilane compound has a uniform and uniform film thickness, has excellent heat resistance, is rich in hardness, and is rich in toughness.

The polysilane compound represented by the general formula (I) used in the present invention has a weight average molecular weight of 6,000 to 200,000 as described above, but has a solubility in a solvent and a film forming ability. More preferred from the viewpoint of the weight average molecular weight is 8000 to 120,000,
Most preferred are those having a weight average molecular weight of 10,000 to 80,000.

Those having a weight average molecular weight of 6000 or less do not exhibit the characteristics of a polymer and have no film forming ability. On the other hand, when the amount is more than 200,000, the solubility in a solvent is poor, and it is difficult to form a desired film.

The above-mentioned polysilane compound represented by the above general formula (I) used in the present invention may have terminal groups A and A ′ when the film to be formed is particularly tough.
Is preferably a group selected from the group consisting of an alkyl group having 5 to 12 carbon atoms, a cycloalkyl group having 5 to 12 carbon atoms, an aryl group, and an aralkyl group. In this case, the most preferred polysilane compound used in the present invention is a compound in which the terminal groups A and A 'are groups selected from an alkyl group having 5 to 12 carbon atoms and a cycloalkyl group having 5 to 12 carbon atoms. It is.

The above-mentioned polysilane compound used in the present invention can be synthesized as follows. That is, under a high-purity inert atmosphere free of oxygen and moisture, a dichlorosilane monomer is brought into contact with a condensation catalyst composed of an alkali metal to carry out halogen elimination and polycondensation to synthesize an intermediate polymer. The polymer is synthesized by separating the unreacted monomer from the unreacted monomer, reacting the intermediate polymer with a predetermined halogenated organic reagent in the presence of a condensation catalyst comprising an alkali metal, and condensing an organic group at the terminal of the polymer. You.

In the above-mentioned synthesis operation, the dichlorosilane monomer, the intermediate polymer, the halogenated organic reagent, and the alkali metal condensation catalyst, which are the starting materials, all have high reactivity with oxygen and moisture, and therefore these oxygen and moisture are present. The desired polysilane compound described above cannot be obtained under an atmosphere in which the heat treatment is performed.

Therefore, the above-mentioned operation for obtaining the above-mentioned polysilane compound used in the present invention needs to be performed in an atmosphere in which neither oxygen nor moisture is present. For this reason, it is necessary to pay attention to all of the reaction vessels and the reagents used so that neither oxygen nor moisture is present in the reaction system. For example, for the reaction vessel,
Vacuum suction and argon gas replacement are performed in a blow box to prevent moisture and oxygen from adsorbing into the system. In any case, the argon gas to be used is dehydrated by passing through a silica gel column in advance and then deoxidizing by passing the copper powder through a column heated to 100 ° C.

The dichlorosilane monomer, which is a starting material, is introduced into the reaction system after vacuum distillation using the above-described degassed argon gas immediately before introduction into the reaction system. The halogenated organic reagent for introducing a specific organic group and the solvent to be used are also introduced into the reaction system after being subjected to a deoxygenation treatment in the same manner as the dichlorosilane monomer. In the deoxidizing treatment of the solvent, the solvent is distilled under reduced pressure using the above-described deoxygenated argon gas, and then further dehydrated with metallic sodium.

When the above-mentioned condensation catalyst is used in the form of a wire or chip, the wire or chip is used in an oxygen-free paraffin-based solvent so as not to cause oxidation.

The dichlorosilane monomer as a starting material used in producing the polysilane compound represented by the above general formula (I) used in the present invention is a silane compound represented by a general formula: R ₁ R ₂ SiCl ₂ or This and a silane compound represented by the general formula: R ₃ R ₄ SiCl ₂ are selectively used.

As the above-mentioned condensation catalyst, an alkali metal which causes a condensation reaction by elimination of halogen is desirably used, and specific examples of the alkali metal include lithium, sodium and potassium, and among them, lithium and sodium are preferable.

The above-mentioned halogenated organic reagent is for introducing a substituent represented by A and A ', and comprises an alkyl halide compound, a cycloalkyl halide compound, an aryl halide compound and an aralkyl halide compound. A suitable compound selected from the group, i.e. the general formula: A
-X and / or general formula: A'-X (where X is Cl or Br)
And an appropriate compound in the specific examples described later is selectively used.

The general formula used in synthesizing the above-mentioned intermediate polymer: R ₁ R ₂ SiCl ₂ or a dichlorosilane monomer represented by the general formula: R ₃ R ₄ SiCl ₂ is dissolved in a predetermined solvent to form a reaction system. As the solvent, a paraffinic non-polar hydrocarbon solvent is desirably used. Preferred examples of the solvent include n-hexane, n-octane, and n-hexane.
-Nonane, n-dodecane, cyclohexane and cyclooctane.

Since the resulting intermediate polymer is insoluble in these solvents, it is convenient to separate the intermediate polymer from unreacted dichlorosilane monomer. The separated intermediate polymer is then reacted with the above-mentioned halogenated organic reagent. At this time, both are dissolved in the same solvent and used for the reaction. As the solvent in this case, an aromatic solvent such as benzene, toluene and xylene is preferably used.

In order to obtain a desired intermediate by condensing the above-mentioned dichlorosilane monomer using the above-mentioned alkali metal catalyst, the polymerization degree of the obtained intermediate polymer can be appropriately controlled by adjusting the reaction temperature and the reaction time. However, the reaction temperature at that time is desirably set between 60 ° C and 130 ° C.

One preferred embodiment of the method for producing the above-mentioned polysilane compound represented by the general formula (I) used in the present invention described above will be described below.

That is, the above-mentioned method for producing a polysilane compound used in the present invention comprises (i) a step of producing an intermediate polymer, and (ii) a step of introducing substituents A and A 'into the terminal of the intermediate polymer. .

The step (i) is performed as follows. That is, the inside of the reaction system of the reaction vessel was completely removed of oxygen and moisture, maintained at a predetermined internal pressure controlled by argon, charged with an oxygen-free paraffin-based solvent and an oxygen-free condensation catalyst. The chlorosilane monomer is charged, and the whole is heated to a predetermined temperature while stirring to condense the monomer. At this time, the degree of condensation of the dichlorosilane monomer is
The reaction temperature and reaction time are adjusted so that an intermediate polymer having a desired degree of polymerization is produced.

In this reaction, as shown in the following reaction formula (i), the chloro group of the dichlorosilane monomer and the catalyst cause a desalination reaction, and the Si groups repeatedly condense to form an intermediate polymer. I do.

The specific reaction procedure in this case is that a condensation catalyst (alkali metal) is charged in a paraffinic solvent, and a dichlorosilane monomer is added dropwise while stirring under heating. The degree of polymerization is confirmed by sampling the reaction solution.

A simple confirmation of polymerization can be made by volatilizing the sampling liquid to form a film. As the condensation proceeds and the polymer is formed, it becomes a white solid and precipitates from the reaction system. Here, the mixture is cooled, and the solvent containing the monomer is separated from the reaction system by decantation to obtain an intermediate polymer.

Next, the step (b) is performed. That is, the chloro group of the terminal group of the obtained intermediate polymer is subjected to desalting condensation using a halogenated organic agent and a condensation catalyst (alkali metal) to replace the polymer terminal group with a predetermined organic group. The reaction at this time is represented by the following reaction formula (ii).

Here, specifically, an aromatic solvent is added to and dissolved in the intermediate polymer obtained by condensation of the dichlorosilane monomer. Next, a condensation catalyst (alkali metal) is added, and a halogenated organic agent is added dropwise at room temperature. At this time, a halogenated organic agent is added in an amount of 0.01 to 0.1 times the amount of the starting monomer in order to compete with the condensation reaction between the polymer end groups. The mixture is gradually heated, and heated and stirred at 80 ° C to 100 ° C for 1 hour to perform a desired reaction.

After completion of the reaction, the mixture is cooled, and methanol is added to remove the alkali metal of the catalyst. Next, the produced polysilane compound is extracted with toluene and purified with a silica gel column.
Thus, the desired polysilane compound used in the present invention is obtained.

Examples of preferred polysilane compounds used in the present invention are shown below.

X and Y in the above structural formula each represent a monomer polymerization unit. The copolymer indicates a random polymer.

The charge generation layer 2 in the present invention is formed by depositing a charge generation substance or dispersing the charge generation substance in a binder resin to prepare a dispersion, and applying the dispersion.

The dispersion of the charge generating substance used in the present invention is prepared by charging the charge generating substance and a binder resin in an appropriate organic solvent and using a disperser such as a ball mill, a sand mill, and an attritor.

The thus prepared dispersion liquid of the charge generating substance is applied by means of wire bar coating, dip coating, doctor blade coating, spray coating, roll coating, beat coating, and the like, and dried.

The thickness of the charge generation layer is preferably 0.1 μm to 5 μm
Range.

The charge generating substance used in the present invention is a pigment,
Even a dye soluble in a solvent can be used by selecting a solvent and forming particles.

Examples of the charge generating substance include inorganic charge generating substances such as Se, SeTe, and SeAs; phthalocyanine pigments, anthantrone pigments, dibenzpyrene pigments, pyranthrone pigments, azo pigments, indigo pigments, quinacridone pigments, cyanine dyes, and squarylium pigments Dyes, azulhenium salt compounds,
Pyrylium, thiopyrylium dye, xanthene dye, quinone imine dye, triphenylmethane dye,
Organic charge generating substances such as styryl dyes are exemplified. For dispersion of the charge generating substance, a charge generating substance and a binder resin are charged into an organic solvent, and a dispersion is prepared using a dispersing machine such as a ball mill, a sand mill, and an attritor.

The binder resin used to disperse the charge generating material is selected from a wide range of insulating resins or organic photoconductive polymers. Preferable examples thereof include polyvinyl butyral, polyvinyl benzal, polyarylate, polycarbonate, polyester, phenoxy resin, cellulosic resin, acrylic resin, polyurethane, and polysilane compound. The amount of use is preferably not more than 80% by weight, more preferably not more than 40% by weight in terms of the content in the charge generation layer.

The solvent used is preferably selected from those which dissolve the resin and do not dissolve the adhesive layer.

Specific examples thereof include tetrahydrafuran, 1,4
Ethers such as dioxane; ketones such as cyclohexanone and methyl ethyl ketone; amides such as N, N-dimethylformamide; esters such as methyl acetate and ethyl acetate; aromatics such as toluene, xylene and chlorobenzene; methanol and ethanol Alcohols such as, 2-propanol; chloroform, methylene chloride,
Examples thereof include aliphatic halogenated hydrocarbons such as dichloroethylene, carbon tetrachloride, and trichloroethylene.

As the conductive support used in the present invention, for example, aluminum, aluminum alloy, copper, zinc, stainless steel, titanium, nickel, indium, gold and platinum are used. In addition, a plastic (eg, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, acrylic resin, etc.) obtained by forming a film of such a metal or alloy by a vacuum evaporation method, or conductive particles (eg, carbon black, silver particles, etc.) with an appropriate binder A support coated on a plastic or metal substrate together with a resin, a support in which conductive particles are impregnated in plastic or paper, or the like can be used.

In the present invention, an adhesive layer (not shown) may be provided between the conductive support 1 and the charge generation layer 2.

In that case, the adhesive layer can be formed using casein, polyvinyl alcohol, nitrocellulose, polyamide (nylon 6, nylon 66, nylon 610, copolymerized nylon, alkoxymethylated nylon, etc.), polyurethane, aluminum oxide, or the like.

The thickness of the adhesive layer is preferably 5 μm or less, more preferably in the range of 0.1 to 3 μm.

Specific examples of the charge generation substance used in the present invention are as follows.

Charge generation materials (1) Amorphous silicon (2) Selenium-tellurium (3) Selenium-arsenic (4) Cadmium sulfide As the organic solvent used to form the polysilane layer containing an ultraviolet absorber, aromatic solvents such as benzene, toluene, and xylene, halogen solvents such as dichloromethane, dichloroethane, and chloroform, tetrahydrofuran, and dioxane are used. Can be

The electrophotographic photoreceptor of the present invention can be applied to general electrophotographic devices such as copiers, LBPs (laser beam printers), LED printers, LCD printers (liquid crystal shutter printers), and micro reader printers. Display, record, light print,
It can be widely applied to devices such as plate making and facsimile.

Hereinafter, production examples of the polysilane compound used in the present invention will be described.

Production Example 1 A three-necked flask was prepared in a blow box in which vacuum suction and argon substitution were performed, and a reflux condenser, a thermometer, and a dropping funnel were attached to the flask, and argon gas was passed through a bypass pipe of the dropping funnel.

100 g of dehydrated dodecane and 0.3 mol of metal wire were charged into the three-necked flask, and heated to 100 ° C. with stirring. Next, 0.1 mol of dichloromethylphenylsilane monomer (manufactured by Chisso Corporation) was added to dehydrated dodecane 3
The solution was dissolved in 0 g, and the prepared solution was slowly dropped into the reaction system.

After the dropwise addition, a white solid was precipitated by condensation polymerization at 100 ° C. for 1 hour. After cooling, decant the dodecane and add 100 grams of dehydrated toluene to dissolve the white solid.
01 mole was added. Next, a solution prepared by dissolving 0.01 mol of n-hexyl chloride (manufactured by Tokyo Kasei) in 10 ml of toluene was slowly added dropwise to the reaction system while stirring, and then added.
Heated at 100 ° C. for 1 hour. Thereafter, the mixture was cooled, and 50 ml of methanol was slowly added dropwise to treat excess metal sodium. This produced a suspension layer and a toluene layer.

Next, the toluene layer was separated, concentrated under reduced pressure, and developed and purified by silica gel column and chromatography to obtain polysilane compound No. 1 (b-1). The yield was 65%.

The weight average molecular weight of this polysilane compound was 75,000 as determined by developing with THF using a GPC method (polystyrene was used as a standard).

Production Example 2 A three-necked flask was prepared in a blow box in which vacuum suction and argon substitution were performed, and a reflux condenser, a thermometer, and a dropping funnel were attached to the flask, and argon gas was passed through a bypass pipe of the dropping funnel.

100 g of dehydrated n-hexane and 0.3 mol of 1 mm square metal sodium were charged into the three-necked flask and heated to 80 ° C. with stirring, and 0.1 mol of dichloromethylcyclohexylsilane monomer (manufactured by Chisso Corporation) was dehydrated. −
A solution prepared by dissolving in hexane was slowly dropped into the reaction system. After the dropping, condensation polymerization was carried out at 80 ° C. for 3 hours to precipitate a white solid. Thereafter, the mixture was cooled, n-hexane was decanted, and 100 g of dehydrated toluene was added to dissolve the white solid, and 0.01 mol of metallic sodium was added. Next, a solution prepared by dissolving 0.01 mol of n-hexyl chloride (manufactured by Tokyo Kasei) in 10 ml of toluene was slowly added dropwise to the reaction system with stirring, and heated at 80 ° C. for 1 hour. Thereafter, the mixture was cooled, and 50 ml of methanol was slowly added dropwise to treat excess metal sodium. This produced a suspension layer and a toluene layer.

Next, the toluene layer was separated, concentrated under reduced pressure, and developed and purified by silica gel column and chromatography to obtain polysilane compound No. 2 (b-10). The yield was 58% and the weight average molecular weight was 120,000.

 Polysilane No. 3 was produced in the same manner as in Production Example 2.

 Polysilane Nos. 4 and 5 were produced in the same manner as in Production Example 1.

 Table 1 shows the obtained polysilane compounds.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

The expression "parts" in the following examples means parts by weight unless otherwise specified.

Example 1 Two parts (parts by weight, hereinafter the same) of a copolymerized nylon resin (trade name: Amilan CM8000, manufactured by Toray) and 8 parts of a copolymerized nylon resin (trade name: Toresin EF-30T manufactured by Teikoku Chemical Co., Ltd.) were placed on an aluminum sheet. It was dissolved in a mixed solution of 60 parts of methanol and 40 parts of butanol, and applied with a wire bar so that the film thickness after drying was 1.0 μm, followed by drying to form an undercoat layer.

Next, 10 parts of chloraluminum phthalocyanine and 5 parts of polyvinyl butyral were dispersed in 90 parts of MEK by a ball mill,
A charge generation layer having a thickness of 0.3 μm after drying by wire bar coating was formed.

Next, 10 parts of polysilane (c-1), 0.1 part of ultraviolet absorber (UV-1) and 80 parts of toluene are dissolved in 80 parts of toluene, and a wire bar is applied on the charge generation layer. Is 10
A μm charge transport layer was formed.

The electrophotographic photoreceptor sheet was corona-charged at −5 kV in a static manner using an electrostatic copying paper tester Model EPA-8100 manufactured by Kawaguchi Electric Co., Ltd., and held for 1 second in a dark place. Exposure was performed in seconds, and the charging characteristics were examined.

As the charging characteristics, a surface potential (V _o ), a dark portion potential _Vd and a bright portion potential _Vl (exposure amount of 2.5 lux · sec) when dark attenuated for 1 second were measured. In addition, the above modes were
Repeated 000 times, it was measured and the light portion potential V _l of this time, the value of the difference △ V _l of the initial light portion potential. The results are shown in Table 2.

Comparative Example 1 On the other hand, the V _d and V _l when a cycle test in another is exactly the same method omitting the use of the UV absorber of the charge transport layer was used when producing the above-mentioned photosensitive member as a comparative test △
The value of _Vl was measured. Table 2 also shows the results.

Examples 2 to 6 Instead of the ultraviolet absorber used in Example 1, an ultraviolet absorber
Five types of electrophotographic photoreceptors were prepared in the same manner as in Example 1 except that UV-3, UV-6, UV-9, UV-13 and UV-15 were used, respectively.

By these electrophotographic photoreceptor same manner as in Example 1, the initial E1 / 2 and 10000 iterations V _l after the durability test, is the difference between the initial light potential and V _l △ V _l were measured. Table 2 shows the results.

Examples 7 to 10 Polysilane N used for producing the photoreceptor of Example 1
Four types of electrophotographic photoreceptors were produced in the same manner as in Example 1 except that No. 2, No. 3, No. 4, and No. 5 were used instead of o.1, respectively.

These electrophotographic photoreceptors were subjected to the dark part potential _Vd and the light part potential (exposure amount 2.5 lux.
Sec.) And repeated 10,000 times, after the durability V _l and the initial light portion potential and the V
ΔV _l , which is the difference between _l, was measured. Table 2 shows the results.

[Summary of Effects of the Invention] As described above, at least a polysilane-containing surface layer in an electrophotographic photoreceptor containing polysilane contains an ultraviolet absorber having a maximum absorption in the range of 280 to 360 nm. There is an advantage that it is possible to provide an electrophotographic photoreceptor which does not cause an increase in the light-area potential even after repeated charging and exposure.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a laminated type photoreceptor in the present invention. In the figure, 1 ... a conductive support, 2 ... a charge generation layer, 3 ... a charge transport layer, 3-1 ... a charge transport layer region, 3-2 ... a UV absorber containing region.

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Claims (2)

(57) [Claims] 1. An electrophotographic photoreceptor having a light-receiving layer containing a polysilane compound represented by the following general formula (I) and having a weight average molecular weight of 6000 to 200,000 on a conductive support. Surface layer containing polysilane compound is 280-3
An electrophotographic photoreceptor comprising an ultraviolet absorber having a maximum absorption within a range of 60 nm. Wherein R ₁ is an alkyl group having 1 or 2 carbon atoms, R ₂ is an alkyl group having 3 to 8 carbon atoms, a cycloalkyl group, an aryl group or an aralkyl group, and R ₃ is an alkyl group having 1 to 4 carbon atoms. And the group R ₄ represents an alkyl group having 1 to ₄ carbon atoms. A and A 'each represent an alkyl group having 4 to 12 carbon atoms;
It is a cycloalkyl group, an aryl group or an aralkyl group, both of which may be the same or different. n and m are molar ratios indicating the ratio of the number of each monomer to the total monomers in the polymer, and n + m = 1,
0 <n ≦ 1 and 0 ≦ m <1. ] 2. An electron containing a polysilane compound according to claim 1, wherein in the general formula (I), A and A 'are each an alkyl group having 5 to 12 carbon atoms or a cycloalkyl group. Photoreceptor.