JP2994732B2 - Electrophotographic method using polysilane electrophotographic photoreceptor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electrophotographic method, and more particularly, to an electrophotographic method using a photosensitive layer containing a polysilane compound.

[Description of Prior Art]

As a copying process (method) using an electrophotographic photosensitive member, a Carlson method, an NP method (JP-B-42-23910, etc.) and the like are known.

In the photoconductor of the Carlson type copying process,
A series of processes of primary charging, image exposure, toner development, transfer to transfer paper, kneading, and static elimination are repeatedly performed.
Further, in addition to the above-described processes, pre-transfer exposure, charge removal exposure, and the like may be performed.

When repeating such a series of processes,
In order to form an image having a constant image density and no background smear, the sensitivity of the photoconductor and the stability of the dark portion potential and the bright portion potential are important.

In order to increase the sensitivity of the photoconductor, it is necessary to speed up the charge transfer in the photosensitive layer and not to increase the charge traps in the photosensitive layer. Therefore, it has been proposed to use a high mobility type charge transport agent in the photosensitive layer. When using a photosensitive layer composed of an organic photoconductor, a layer having a laminated structure in which the photosensitive layer is functionally separated into a charge generation layer and a charge transport layer has been proposed. It has lower mobility and larger potential fluctuation than conductors (amorphous Si, Se, As ₂ Se ₃ etc.).

For the purpose of remedying such drawbacks, it has been proposed to use a polysilane compound as an organic photoconductor (US Pat. No. 4,618,551, US Pat. No. 4,772,525, JP-A-62-26996).
Four). By using a polysilane compound as the charge transport material, it is said that the mobility is considerably higher than that of a conventional organic charge transport material, whereby it is possible to provide a highly sensitive electrophotographic photoreceptor. .

However, an electrophotographic photoreceptor using the above-mentioned polysilane compound as a charge transport material has a good initial sensitivity, but it is difficult to obtain stable potential characteristics and image quality with respect to repeated durability. .

For example, when a photoreceptor using a polysilane compound as a charge transporting material is repeatedly used in a durable manner, a bright portion potential and a residual potential increase, and fog occurs in a copied image. When such a photoreceptor is used in an electrophotographic printer that performs reversal development, there are problems that the density of an image becomes low and a copy having a constant image quality cannot be obtained.

[Object of the invention]

An object of the present invention is to eliminate the above-described conventional problems that occur when performing image formation using an electrophotographic photoreceptor having a photosensitive layer containing a polysilane compound, and perform image formation repeatedly for a long time. It is an object of the present invention to provide an improved electrophotographic method for stably obtaining a desired copied image, that is, an image forming method by an electrophotographic method.

Another object of the present invention is to use an electrophotographic photosensitive member having a photosensitive layer containing a polysilane compound, and to exhibit stable potential characteristics even when the photosensitive member is repeatedly used for a long time.
It is an object of the present invention to provide an improved electrophotographic method which can stably provide a high quality copy image.

[Structure and effect of the invention]

The present inventors have eliminated the above-mentioned problems in a conventional electrophotographic method using an electrophotographic photoreceptor containing a polysilane compound, and have conducted intensive studies to achieve the above object. Was. That is, in an image forming method by electrophotography using an electrophotographic photoreceptor having a photosensitive layer containing a polysilane compound, when light not including a wavelength of 400 nm or less is used as irradiation light to the photoreceptor, the above-described conventional method is used. It has been found that the problems in the art have been solved and the object of the present invention has been achieved.

It was also found that when the air near the photoconductor was replaced for a certain period of time during the image forming process or after the image formation was repeatedly performed, a high-quality copied image could be obtained stably and constantly.

The present invention has been completed based on these findings, and the gist thereof is as described below.

That is, in an image forming process by an electrophotographic method using an electrophotographic photosensitive member having a photosensitive layer containing a polysilane compound on a conductive support, using light not containing a wavelength of 400 nm or less as irradiation light to the photosensitive layer. An electrophotographic method, wherein air near the photoconductor is ventilated for a certain period of time during or at the end of the image forming process.

According to the electrophotographic method of the present invention, even when the photoreceptor is used repeatedly for a long time, a bright potential and a residual potential do not increase as in the related art, and stable potential characteristics are exhibited. A copy image is stably provided.

The configuration of the electrophotographic photoreceptor used in the present invention may be either a lamination type photoreceptor or a single-layer type photoreceptor.

In the case of a laminated photoreceptor, as shown in FIGS. 1 to 4, a configuration in which a charge generation layer 2 or 6 and a polysilane layer 1 are laminated on a conductive support 5 can be employed. The photoreceptor having the configuration shown in FIGS. 1 and 3 uses primary charge negatively. The photoreceptor having the structure shown in FIGS.
The primary charging is positive and used. The charge generation layer 6 or 2 is formed by depositing the charge generation material 6 or
Is dispersed in the binder resin 4 and applied.

Dispersion of the charge generating substance is performed by charging the charge generating substance 3 and the binder resin 4 in an organic solvent, and using a ball mill, a sand mill,
A dispersion is prepared using a disperser such as an attritor. The dispersion of the charge generating substance is applied by wire bar coating, doctor blade coating, spray coating, roll coating, bead coating, and dried. The thickness of the charge generation layer is
In the case of the figure, it is preferably 0.1 μm or more and 5 μm or less.
In the case of FIG. 2, it is preferably 1 μm or more and 10 μm or less, and in the case of FIG.
In the case of the drawing, it is preferably 3 μm or less.

The binder resin for dispersing the charge generating substance is selected from a wide range of insulating resins or organic photoconductive polymers, but includes polyvinyl butyral, polyvinyl benzal, polyarylate, polycarbonate, polyester, phenoxy resin, cellulosic resin, and acrylic resin. Resins, polyurethane and polysilane compounds are preferred,
The amount used is 80% by weight or less, preferably 40% by weight or less 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 charge transporting amount and the undercoat layer described below.

Specifically, tetrahydrofuran, ethers such as 1,4-dioxane, cyclohexanone, ketones such as methyl ethyl ketone, amides such as N, N-dimethylformamide, methyl acetate, esters such as ethyl acetate, toluene, xylene, Aromatics such as chlorobenzene, alcohols such as methanol, ethanol and 2-propanol, chloroform, methylene chloride, dichloroethylene,
Examples thereof include aliphatic halogenated hydrocarbons such as carbon tetrachloride and norichloroethylene.

The polysilane layer (charge transport layer) 1 is obtained by dissolving a polysilane compound in an organic solvent, applying this solution to a wire bar,
It is formed by coating using a coating method such as dip coating, doctor blade coating, spray coating, roll coating, or bead coating, and then drying.

The thickness of the polysilane layer 1 is preferably 4 μm or more and 30 μm.
m, more preferably 7 μm or more and 20 μm or less. Organic solvents used to dissolve the polysilane compound when forming the polysilane layer (charge transport layer) 1 include aromatic solvents such as benzene, toluene, and xylene; halogen solvents such as dichloromethane, dichloroethane, and chloroform; and tetrahydrofuran. , Dioxane is used.

In the case of the single-layer type photoreceptor shown in FIG. 5, the photoreceptor comprises a conductive support 5 and a photosensitive layer 8 provided on the support.
In this case, the photosensitive layer 8 is made of a polysilane 7
It is composed of those dispersed in The primary charge of the photoreceptor shown in FIG. 5 may be either positive or negative.

The photosensitive layer 8 is formed as follows. That is, a charge generating substance and an organic solvent are charged and dispersed using a disperser such as a ball mill, a sand mill, and an attritor. Next, a polysilane compound is added to this dispersion and dissolved to prepare a polysilane solution in which a charge generating substance is dispersed. This solution is formed by applying the solution to the surface of the support 5 by means of wire bar coating, dip coating, doctor blade coating, spray coating, roll coating, bead coating or the like, and drying.
The layer thickness of the photosensitive layer 8 is preferably 4 μm or more and 30 μm or less, more preferably 7 μm or more and 20 μm or less.

As the organic solvent to be used, aromatic solvents such as benzene, toluene and xylene, halogen-based solvents such as dichloromethane, dichloroethane and chloroform, tetrahydrofuran and dioxane are used.

Examples of the above-described charge generating substances include inorganic charge generating substances such as Se, SeTe, and SeAs, and pyrylium and thiapyrylium dyes.
Organic charge generating substances such as phthalocyanine pigments, anthantrone pigments, dibenzopyrene quinone pigments, pyranthrone pigments, trisazo pigments, disazo pigments, azo pigments, indigo pigments, quinacridone pigments, asymmetric quinocyanines, quinocyanines and the like can be used.

The polysilane compound used in the present invention is the journal of organometallic chemistry 198pp C27
(1980) or The Journal of Polymer Science, Polymer Chemistry Edition Vol.22 1
59-170 pp (1984).

A particularly preferred polysilane compound used in the present invention is a polysilane compound represented by the following general formula (I).

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 polysilane compound of the general formula (I) used in the present invention can be synthesized as follows. That is, under a high-purity inert atmosphere without oxygen and moisture, a dichlorosilane monomer is brought into contact with a condensation catalyst comprising an alkali metal to perform halogen elimination and polycondensation to synthesize an intermediate polymer, and the obtained polymer is obtained. Is separated from an unreacted monomer, and the polymer is reacted with a predetermined halogenated organic reagent in the presence of a condensation catalyst comprising an alkali metal to condense an organic group to the polymer terminal.

In the above synthesis operation, the starting materials dichlorosilane, the intermediate polymer, the halogenated organic reagent, and the alkali metal condensation catalyst all have high reactivity with oxygen and moisture, so these oxygen and moisture are present. Under the atmosphere, the desired polysilane compound described above cannot be obtained.

Therefore, the above operation for obtaining the polysilane compound needs to be performed in an atmosphere in which neither oxygen nor moisture exists. 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 a reaction container, vacuum suction and argon gas replacement are performed in a blow box so that moisture and oxygen are not adsorbed in 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 subjected to distillation under reduced pressure using the above-described deoxidized argon gas, and then further dehydrated with metallic sodium.

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 to prevent oxidation.

The starting dichlorosilane monomer used in producing the polysilane compound represented by the general formula (I) is a silane compound represented by the general formula: R ₁ R ₂ SiC ₂ or a silane compound represented by the general formula: R ₃ A silane compound represented by R ₄ SiC ₂ is 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 a general formula: A'-X (where X is C or B
An appropriate compound represented by r) in the specific examples described later is selectively used.

The dichlorosilane monomer represented by the general formula: R ₁ R ₂ SiC ₂ or the general formula: R ₃ R ₄ SiC ₂ used in synthesizing the above-mentioned intermediate polymer 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, n-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 and 130 ° C.

One preferred embodiment of the method for producing the polysilane compound represented by the general formula (I) described above is described below.

That is, the above-mentioned method for producing a polysilane compound comprises the steps of (a)
It comprises a step of producing an intermediate polymer and (b) a step of introducing substituents A and A 'into the terminal of the intermediate polymer.

The step (a) is performed as follows. That is, the inside of the reaction system of the reaction vessel is completely controlled by argon while keeping oxygen and moisture completely removed and maintained at a predetermined internal pressure, an oxygen-free paraffin-based solvent and an oxygen-free condensation catalyst are added, and then the oxygen-free gas is added. 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.

As a specific reaction procedure, 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.

Simple confirmation of polymerization can be determined 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 monomer.

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.

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 to 100 ° C. for 1 hour to perform a desired reaction.

After the reaction, to cool and remove the alkali metal of the catalyst,
Add methanol. Next, the polysilane is extracted with toluene and purified with a silica gel column. Thus, a desired polysilane compound is obtained.

X and Y in the above structure each represent a monomer polymerization unit. The copolymer shows random.

Examples of the conductive support 5 include aluminum,
Aluminum alloy, copper, zinc, stainless steel, titanium, nickel, indium, gold, platinum and the like are used. In addition, plastics (for example, polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate,
A support in which conductive particles (eg, carbon black, silver particles, etc.) are coated on a plastic or metal substrate with an appropriate binder resin, or a support in which conductive particles are impregnated in plastic or paper is used. be able to.

In the above-mentioned photoreceptor used in the present invention, an undercoat layer having a barrier function and an adhesive function may be provided between the conductive support 5 and a layer provided directly on the support.

The undercoat layer can be formed of casein, polyvinyl alcohol, nitrocellulose, polyamide (nylon 6, nylon 66, nylon 610, copolymer nylon, alkoxymethylated nylon, etc.), polyurethane, aluminum oxide, or the like.

The thickness of the undercoat layer is 5 μm or less, preferably 0.1 to 3 μm.
Is appropriate.

The electrophotographic method of the present invention uses an electrophotographic photosensitive member containing a polysilane compound, and 400 nm or less, preferably 450 nm
Image exposure with light that does not include the following wavelengths, performing static elimination exposure,
In addition, by changing the atmosphere of the photosensitive member for a certain period of time during driving of the electrophotographic process and after the charging of the electrophotographic process is stopped, the potential stability and the image density stability due to repetition of durability are remarkably improved. Although the mechanism of this development has not yet been sufficiently elucidated, it is estimated that the following phenomena have occurred.

That is, irradiating a photoreceptor containing polysilane with a wavelength of 400 nm or less has adverse effects. When the polysilane compound is irradiated with light having a wavelength of less than 350 nm, the main chain of the polysilane is cut, radicals are generated, and finally, they react with oxygen or moisture in the air to be modified into siloxane bonds. This photolysis reaction is based on the Journal of Organometallic
Chemistry 300, 327, 1986. When polysilane undergoes photodecomposition in the photoconductor and is converted into siloxane, the charge transporting ability of the polysilane is lost, resulting in a significant decrease in sensitivity. For this reason, if the photoreceptor is subjected to endurance repetition while performing exposure at a wavelength of less than 350 nm, the residual charge and the light-area potential increase with photolysis of the polysilane.

However, it was found that when exposure was performed at a wavelength of 350 nm or more and less than 400 nm, the photodegradation of polysilane was not so much recognized, but the electrophotographic characteristics were significantly deteriorated. This is presumably because the polysilane is excited by exposure to light of 350 nm or more and less than 400 nm, so that the charge generated by the charge generating substance in the photoconductor is trapped by the excited polysilane. For this reason, when exposure is performed at a wavelength of 350 nm or more and less than 400 nm, the sensitivity of the polysilane photoreceptor decreases, and the residual charge and the light portion potential increase.

In the electrophotographic method of the present invention, a step of charging the photoreceptor is performed. This charging is generally performed by corona discharge, and O ₃ and NO _x are generated with the discharge. Charger to several 10ppm by O ₃ immediately below, the concentration of 0.01~0.1ppm is measured in NO _x. When these strongly acceptor substances are adsorbed on the surface of the polysilane photoreceptor, oxidative decomposition of the polysilane compound occurs. Irradiation with ultraviolet rays promotes these reactions. Usually, when the electrophotographic process is driven, even if these acceptor corona products are adsorbed on the photoreceptor surface, they are removed by the cleaner and the polysilane compound is hardly deteriorated. When a large amount of an object is filled in the vicinity of the photoreceptor, it penetrates into the photoreceptor over time, deteriorating the polysilane compound, and causing image defects.

In addition, even when the electrophotographic process is driven, when used for a long time, the concentration of the corona product in the vicinity of the photoreceptor becomes extremely high, so that it is considered that the above-described action causes image defects.

However, in the present invention, exposure to the polysilane photoreceptor is performed using light that does not include light having a wavelength of 400 nm or less, and by ventilating the air near the photoreceptor for a certain period of time during driving of the electrophotographic process and after stopping the electrophotographic process. The stabilization of the potential as the electrophotographic photosensitive member is achieved. For polysilane photoreceptors, avoid exposure to light with a wavelength of 400 nm or less and reduce the concentration of acceptor corona products in the photoreceptor atmosphere to prevent siloxane formation by photolysis of polysilane. And trapping due to optical excitation can be prevented. Due to these effects, even when a polysilane photoreceptor is used, the residual charge and the rise in the light portion potential are reduced by repeated durability, and an electrophotographic method with a stable light portion potential can be provided.

Examples of the light source having a wavelength larger than 400 nm include a semiconductor laser, a gas laser, a light emitting diode (hereinafter, referred to as an LED), and electroluminescence (hereinafter, referred to as EL). Examples of the semiconductor laser include gallium, arsenic-based lasers, indium, and phosphorus-based lasers.

Examples of the gas laser include an argon laser, a helium laser, and an argon-helium laser.

Examples of the LED include gallium, arsenic LED, gallium-phosphorous-indium LED, indium-phosphorus LED, and the like. Examples of EL include a zinc sulfide EL, a manganese EL, and a tungsten oxide EL.

In the present invention, these light sources are used as light that does not include a wavelength of 400 nm or less to perform image exposure, static elimination exposure, and other exposure necessary for the process.

A light source containing light having a wavelength of 400 nm or less is used by using a filter that absorbs light having a wavelength of 400 nm or less. A light source having a wavelength greater than 400 nm can be used as it is. As a light source including light having a wavelength of 400 nm or less, there are a dangsten lamp, a xenon lamp, a neon lamp, an argon lamp, a fluorescent lamp, and the like. UV-absorbing filters (SC
-42, made by Fuji Film) and colored glass filter (Y-4
3, Toshiba).

The electrophotographic method of the present invention can be widely used not only for electrophotographic copying machines but also for electrophotographic applications such as laser beam printers, CRT printers, LED printers, liquid crystal printers, and laser plate making.

(Production example of polysilane compound used in the present invention)

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 thereto, and argon gas was passed through a bypass pipe of the dropping funnel. .

100 g of dehydrated dodecane and 0.3 mol of metal sodium 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 with stirring, and the mixture was 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 measured by developing with THF by GPC (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 from 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. Next, 0.1 mol of dichloromethylcyclohexylsilane monomer (manufactured by Chisso Corporation) was dehydrated with n-
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 while stirring, and the mixture was 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.

Production Examples 3 to 5 Polysilane compound No. 3 was produced in the same manner as in Production Example 2. Polysilane compounds Nos. 4 and 5 were produced in the same manner as in Production Example 1.

Table 1 shows the above polysilane compounds Nos. 1 to 5.

〔Example〕

Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples.

In the following description, “parts” means “parts by weight”.

Example 1 A photoreceptor to be used was prepared as follows. That is, 10 parts by weight of chloroaluminum phthalocyanine (hereinafter, referred to as
Parts) and 5 parts of polyvinyl butyral were ball-dispersed in 190 parts of MEK to prepare a dispersion for a charge generation layer. The dispersion was dip-coated on an aluminum cylinder (φ30 mm × 260 mm) and dried to form a 0.2 μm thick charge generation layer. A solution of polysilane compound No. 1 in toluene was applied by dip coating on the surface of the formed charge generation layer, and dried to form a polysilane layer having a thickness of 11 μm. Thus, photoreceptor No. 1 was prepared. No. 1 electrophotographic photoreceptor produced in this way
Was attached to a copying machine in which a charge-image exposure-development-transfer-cleaning-discharge exposure process was repeated in a cycle of one or two seconds.

For both image exposure and charge removal exposure, a white fluorescent lamp having a wavelength of 450 nm or less and a filter having a transmittance of 0% was used.
An exhaust fan was attached to the copier, and it was modified so that air near the photoconductor could be ventilated at 10 / min. Under these process conditions, a series of 1000 images were produced.
As shown in ( ₁ ), there was no change in the dark area potential (V _d ) and no deterioration in sensitivity (E1 / 2), and an extremely stable image was obtained.

Comparative Example 1 A photoconductor was prepared in the same manner as in Example 1, and the wavelength cut filter of 450 nm or less for image exposure and static elimination used in Example 1 was removed, and modification was performed to stop the exhaust fan. A similar test was performed. As shown in Table 2, on the 1000th sheet, the sensitivity was significantly deteriorated, and the electrophotographic photosensitive member was unsuitable.

Further, the same test as in Example 1 was performed except that the modification was made to stop only the exhaust fan. Further, the same test as in Example 1 was performed except that only the wavelength cut filter of 450 nm or less was removed. As a result, as in the above two examples, significant deterioration in sensitivity occurred.

Examples 2 to 5 A charge generation layer was formed in the same manner as in Example 1, and a polysilane layer was formed thereon using polysilane compounds Nos. 2 to 5, thereby producing photoconductors Nos. 2 to 5. Each of the obtained photoconductors was evaluated in the same manner as in Example 1. Table 2 shows the obtained results.

Comparative Example 2 The same photoconductor as No. 2 used in Example 2 was evaluated in the same manner as in Comparative Example 1. Table 2 shows the obtained results.

Comparative Examples 3 to 5 Photoconductors were prepared in the same manner as in Examples 3 to 5. For each of the obtained photoconductors, the image exposure used in Example 1 was performed.
The filter for the charge removal exposure has a transmittance of 0 for wavelengths of 350 nm or less.
The same durability test as in Example 1 was performed except that the filter was replaced with a% filter. As shown in Table 2, on the 1000th sheet, the sensitivity was significantly deteriorated, and the electrophotographic photosensitive member was unsuitable.

Example 6 A photoconductor was prepared in the same manner as in Example 1, and the image exposure and static elimination filters used in Example 1 were replaced with filters having a transmittance of 0% at a wavelength of 410 nm or less. A similar durability test was performed. As shown in Table 2, a very stable image was obtained.

Comparative Example 6 In Example 6, the cycle in which the exhaust fan was stopped, ten images were continuously output, and the image was paused for 5 minutes was repeated 100 times. As shown in Table 2, at the 1000th sheet, the sensitivity was deteriorated.

[Outline of Effects of the Invention] As described above, in an electrophotographic method using an electrophotographic photoreceptor containing a polysilane compound, the photosensitive layer in the process uses light that does not include light having a wavelength of 400 nm or less as irradiation light. In addition, the synergistic effect of ventilating the air near the photoreceptor for a certain period of time during the operation of the electrophotographic process and for a certain period after the charging of the electrophotographic process is stopped prevents a rise in the light portion potential and the residual potential when the photoconductor is repeatedly used This is particularly effective, and has an effect on image stability during durable use.

[Brief description of the drawings]

1 to 4 are schematic cross-sectional views of a laminated electrophotographic photosensitive member used in the present invention. FIG. 5 is a schematic sectional view of a single-layer type electrophotographic photosensitive member used in the present invention. In the figure, 1 ... polysilane layer (charge transport layer), 2,6
... Charge generating layer, 3 ... Charge generating substance, 4 ... Binder resin, 5 ... Conductive support, 7 ... Polysilane compound, 8 ... Photosensitive layer.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G03G 15/04-15/04 120 G03G 5/07 103

Claims (5)

(57) [Claims] An electrophotographic method for forming an image by electrophotography using an electrophotographic photosensitive member having a photosensitive layer containing a polysilane compound on a conductive support, wherein the photosensitive layer is irradiated with light of 400 nm or less. Using light that does not contain the wavelength of
An electrophotographic method, wherein air near the photoreceptor is ventilated for a certain time during or after the image forming step. 2. The electrophotographic method according to claim 1, wherein after the image forming step is completed, the photoconductor is rotated at least one cycle or more, and the air near the photoconductor is ventilated during the rotation. 3. A light source between the light source of the irradiation light and the photoreceptor.
The electrophotographic method according to claim 1, wherein the image formation is performed by providing a filter that cuts light having a wavelength of 0 nm or less. 4. The electrophotographic method according to claim 1, wherein the image formation is performed by using a laser beam having a wavelength longer than 400 nm as a light source of the irradiation light. 5. An LED having a wavelength longer than 400 nm as a light source of the irradiation light.
The electrophotographic method according to claim 1, wherein the image is formed using light.