JP3152057B2 - Photoconductor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small-diameter photosensitive member used for electrophotography, which has a photosensitive layer having a particularly large thickness.
The present invention relates to a photoconductor having excellent wear resistance and electrical characteristics.

[0002]

2. Description of the Related Art A photosensitive layer of a layered function-separated type photoreceptor is constituted by laminating a charge generating layer containing a charge generating material, a charge transporting material, and a charge transporting layer containing a binder resin. The photosensitive layer of the dispersion-type function-separated type photosensitive member is composed of a layer in which a charge generation material and a charge transport material in a binder resin are dispersed.

[0003] Such a function-separated laminated photoreceptor is
A wide range of materials can be selected, and the best materials can be combined in electrophotographic characteristics such as charging characteristics, sensitivity, residual potential, and repetition characteristics, whereby a high-performance photoconductor can be provided. In addition, since the photosensitive member can be produced by coating, an extremely high productivity and an inexpensive photosensitive member can be provided, and the photosensitive wavelength region can be freely controlled by appropriately selecting the charge generating material.

However, the photoreceptor generally has low mechanical strength and poor durability, and abrasion of the photosensitive layer occurs due to a practical load in the apparatus such as friction with toner or paper, friction with a cleaning member, and the like. The film thickness decreases. Although the amount of film reduction due to abrasion differs depending on the material and the process, it is usually about 0.2 to 1 μm in a 10,000-sheet copying process. Further, a decrease in the film thickness causes a decrease in chargeability. If this decrease exceeds an allowable range, the photoreceptor reaches its end of life, resulting in poor press life. Therefore, as one of the methods for improving the sensitivity and durability of the photoconductor, a technique of increasing the thickness of the photoconductive layer and extending the life of the photoconductor has been studied. For example, JP-A-3-11353
And JP-A-3-63653 describe a technique in which the thickness of a photosensitive layer is made thicker than in the past.

On the other hand, in recent years, from the viewpoint of saving space, it has been demanded to reduce the size of electrophotographic devices such as copiers and printers used in offices. Generally, an electrophotographic apparatus is provided with a charging device, a developing device, a transfer device, a cleaning device, a charge removing device, and the like around a photoreceptor. For this reason, the size of an electrophotographic apparatus largely depends on the diameter of a photoconductor incorporated in the apparatus. That is, in order to reduce the size of the apparatus, it is necessary to reduce the diameter of the photoconductor disposed at the center thereof, and a proposal for a photoconductor having a small diameter has been demanded.

[0006]

By the way, when a photosensitive layer having a large thickness is formed, the life of the photosensitive member can be certainly prolonged, but the internal stress in the photosensitive layer becomes large, so that the adhesive property is increased. Is worse. The adhesiveness of the photosensitive layer tends to decrease as the thickness of the photosensitive layer increases and as the diameter of the cylindrical support decreases. Accordingly, when the diameter of the photosensitive member described in the above publication is simply reduced, the photosensitive layer is peeled off with repeated use. This tendency is particularly remarkable in a photoreceptor having a diameter of 60 mm or less.

Conventionally, methods for improving the adhesiveness include roughening the surface of the support, providing an adhesive layer between the photosensitive layer and the support, and increasing the adhesiveness of the charge generating layer in the case of lamination. However, there are many adverse effects such as adversely affecting electrostatic characteristics or photosensitive characteristics, and the printing durability of the photosensitive member has not been improved.

Accordingly, a first object of the present invention is to solve a manufacturing problem caused by increasing the thickness of a photosensitive layer and to provide a highly sensitive small-diameter photosensitive member having excellent adhesiveness. .

A second object of the present invention is to provide a small-diameter photosensitive member which prevents image noise from being generated even when used repeatedly and has excellent resolution.

[0010]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, when reducing the diameter of a photosensitive member having a thick charge transport layer, the photosensitive layer is particularly constituted. By setting the glass transition temperature (Tg) of the charge transport layer to be in a specific range, there is no such a problem as observed in a conventional electrophotographic photoreceptor,
Coating property is improved at the time of production of photoreceptor, adhesion is good,
In addition, the inventors have found that high sensitivity and excellent mechanical properties and electrophotographic properties are maintained over a long period of use, and the present invention has been completed based on this finding.

That is, according to the present invention, there is provided a photoreceptor having a photosensitive layer comprising a charge generation layer and a charge transport layer provided on a conductive support, wherein the conductive support has a cylindrical shape having a diameter of 60 mm or less; The charge generation layer may be an organic pigment as a charge generation material.
Or an organic dye, wherein the charge transport layer is
A charge transport material and poly
A charge transport layer containing a carbonate resin,
The glass transition temperature (Tg) of the charge transport layer is 55 to 67.
And a film thickness of 27 μm or more.

By making the photoreceptor of the present invention a small diameter of 60 mm or less, it can be sufficiently mounted on a small electrophotographic apparatus. By setting the glass transition temperature of the charge transport layer itself in a specific range, a photosensitive member having excellent adhesion can be provided even when the thickness of the charge transport layer is increased.

The charge-transporting layer of the photoreceptor has a glass transition temperature of 6
When the temperature is higher than 7 ° C., the adhesiveness is deteriorated, and there is a possibility of peeling due to friction of a handling or a blade.
Since the temperature of the photoconductor rises to about 50 ° C. in the copying machine, when the glass transition temperature of the charge transport layer is lower than 55 ° C., the charge transport layer is deteriorated, and the sensitivity is reduced and image noise is generated. Accordingly, in the present invention, the glass transition temperature of the charge transport layer is 55 ° C to 67 ° C, more preferably 55 ° C to 67 ° C.
Set to 65 ° C.

The glass transition temperature of the binder resin used in the electrophotographic photoreceptor is usually about 100 to 200 ° C. In the present invention, the charge transporting material contained in the charge transporting layer, the antioxidant or the plasticizer The glass transition temperature (Tg) of the charge transport layer is adjusted by appropriately adjusting the amount of
Is adjusted to a temperature considerably lower than the glass transition temperature of the binder resin to improve the adhesiveness.

For example, a charge transporting material having high solubility in a resin solution, for example, having a molecular weight of 100 to 500
In the case of using a charge transporting material having a high degree, it is possible to lower the glass transition temperature and adjust the glass transition temperature to a desired value by including only a charge transporting material in the charge transporting layer in a higher content than usual. The content varies depending on the type of the charge transporting material or the resin solution and cannot be specified unconditionally,
Desirably, about 120 to 150 parts by weight with respect to 100 parts by weight of the resin. Further, when additives such as an antioxidant and a plasticizer are added to the charge transport layer in addition to the charge transport material,
The charge transport material is added in a smaller amount than the above, that is, 80 to 12
The glass transition temperature can be sufficiently reduced to a desired value also by adding about 10 to 100 parts by weight of an additive to about 0 parts by weight and further making the total amount of both about 115 to 160 parts by weight. . On the other hand, when the charge transporting material has a molecular weight of about 500 to 1,000, crystals are precipitated due to an increase in the content thereof, so that the charge transporting material alone may not be able to sufficiently lower the glass transition temperature. Accordingly, the amount of the charge transporting material is generally about 40 to 100 parts by weight with respect to 100 parts by weight of the resin, and the amount of the additive is 20.
The glass transition temperature can be reduced to a desired value by containing the mixture in an amount of from about 100 to about 100 parts by weight, preferably from about 35 to about 80 parts by weight, and a total amount of from 60 to 200 parts by weight, preferably from 80 to 160 parts by weight. . Further, when the melting point of the charge transporting material, the plasticizer, and the antioxidant is high, crystals are precipitated due to the increase in the content, and the glass transition temperature does not sufficiently decrease to a desired value. It is preferable to use various materials.

As described above, the desired glass transition temperature in the present invention can be obtained, and the adhesion of the charge transport layer can be improved.

Further, the charge transporting material having a large molecular weight itself is hard, and the charge transporting layer containing the material has poor film-forming properties. Therefore, the photosensitive material having a small diameter of 60 mm or less tends to be easily peeled off. Therefore, when used in combination with a plasticizer, the film formability can be improved and the adhesiveness can be effectively improved.

The glass transition temperature (Tg) of the charge transporting layer in the present invention is all measured by a differential scanning calorimeter (DSC2).
20, Seiko Denshi Kogyo Co., Ltd.).

[0019] The form of the photosensitive member of the present invention are those having a structure in which a charge transport layer and a charge generating layer on the conductive support
Is applicable . For example, a function separation type lamination in which a charge generation layer 2 containing a charge generation material and a charge transport layer 3 containing a charge transport material are laminated in this order on a conductive support 1 as shown in FIG. A photoreceptor having a surface protective layer 4 provided on the surface of the photoreceptor as shown in FIG. 2 or an intermediate layer 5 provided between the conductive support 1 and the charge generation layer 2 as shown in FIG. May be used.

The photoreceptor according to the present invention will now be described, for example, according to the present invention in which a charge generating layer and a charge transport layer containing the polycarbonate resin of the present invention are laminated on a conductive support as shown in FIG. The case of forming the photoconductor will be specifically described. The laminated photoreceptor of the present invention shown in FIG. 1 is obtained by laminating a charge generating material on a conductive support by vapor deposition or plasma polymerization, or dispersing the charge generating material in a solution in which a suitable resin is dissolved. After forming the charge generation layer by coating the prepared dispersion on a conductive support and drying, a solution containing a charge transport material and a polycarbonate resin is coated thereon and dried to form a charge transport layer. It is made. The application of the coating solution can be performed by a known coating method such as a dip coating method, a spray coating method, a spinner coating method, a blade coating method, a roller coating method, and a wire bar coating method.

The thickness of the charge generation layer in the photoreceptor of the present invention is adjusted to 0.01 to 2 μm, preferably 0.05 to 1 μm. If the amount of the charge generating material used is too small, the sensitivity is deteriorated.If the amount is too large, the chargeability is deteriorated and the mechanical strength is reduced. It is desirable that the amount is 0.1 to 10 parts by weight, preferably 0.2 to 5 parts by weight, based on 1 part by weight of the resin.

Examples of the charge generating material used in the charge generating layer include bisazo pigments, triarylmethane dyes, thiazine dyes, oxazine dyes, xanthene dyes, cyanine dyes, styryl dyes, pyrylium dyes, and the like. Organic pigments and dyes such as azo pigments, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, bisbenzimidazole pigments, indathrone pigments, squarylium pigments, and phthalocyanine pigments
Fees and the like.

Examples of the resin used together with the charge generating material include a saturated polyester resin, a polyamide resin, an acrylic resin, an ethylene-vinyl acetate copolymer, an ion-crosslinked olefin copolymer (ionomer), and a styrene-butadiene block. Copolymer, polyarylate, polycarbonate, vinyl chloride-vinyl acetate copolymer, cellulose ester, polyimide, styrene resin, polyacetal resin, thermoplastic binder such as phenoxy resin, epoxy resin, urethane resin, silicone resin, phenol resin Use of thermosetting binders such as melamine resin, xylene resin, alkyd resin, thermosetting acrylic resin, photocurable resin, photoconductive resin such as poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthracene Can

The above charge generation material is used together with these resins together with alcohols such as methanol, ethanol and isopropanol, ketones such as acetone, methyl ethyl ketone and cyclohexanone, N, N-dimethylformamide, N, N-dimethylacetamide and the like. Amides of
Sulfoxides such as dimethyl sulfoxide; ethers such as tetrahydrofuran, dioxane and ethylene glycol monomethyl ether; esters such as methyl acetate and ethyl acetate; and aliphatic halogens such as chloroform, methylene chloride, dichloroethylene, carbon tetrachloride, and trichloroethylene. A photosensitive coating solution prepared by dispersing or dissolving in a hydrocarbon solvent or an organic solvent such as aromatics such as benzene, toluene, xylene, ligroin, monochlorobenzene, and dichlorobenzene is coated on the conductive support described above. Then, it is dried to provide a charge generation layer.

The conductive support has a diameter of 60 m.
m or less. For example, copper, aluminum,
A drum or a foil of iron, nickel or the like is used. In addition, these metals are vacuum-deposited or electroless-plated on a plastic film or the like, or those obtained by applying or depositing a layer of a conductive compound such as a conductive polymer, indium oxide, or tin oxide on paper or a plastic film. Can be used. Generally, cylindrical aluminum is used.Specifically, for example, after extrusion, a drawn aluminum pipe is cut, and its outer surface is cut to a diameter of about 0.2 mm using a cutting tool such as a diamond tool. Impacts on aluminum discs (DI pipes), which have been cut and finished by cutting 2 to 0.3 mm (cutting pipes), deep-drawn aluminum discs into cups, and then ironed on the outer surface (DI pipes). After processing into a cup, the outer surface is finished by ironing (EI tube), after extrusion, after cold drawing
(ED tube) and the like. Further, those obtained by further cutting these surfaces may be used.

On the charge generation layer formed on the conductive support as described above, a coating solution obtained by dissolving the charge transport material and the above-mentioned polycarbonate resin of the present invention in an appropriate solvent is applied and dried to form a film. The thickness is 27 to 70 μm, preferably 3
The charge transport layer is provided so as to have a thickness of 0 to 60 μm.

Examples of the charge transport material used for forming the charge transport layer include hydrazone compounds, pyrazoline compounds, styryl compounds, triphenylmethane compounds, oxadiazole compounds, carbazole compounds, stilbene compounds,
Various compounds such as an enamine compound, an oxazole compound, a triphenylamine compound, a tetraphenylbenzidine compound, and an azine compound can be used. Specifically, for example, p-diphenylaminobenzaldehyde-N,
N-diphenylhydrazone, 2-methyl-4-N, N-
Diphenylamino-β-phenylstilbene, α-phenyl-4-N, N-diphenylaminostilbene, α-
Phenyl-4-N-phenyl, Np-tolylvinylphenylaminostilbene, 1,1,4,4-bisdiethylaminotetraphenylbutadiene and the like can be mentioned. Also, JP-A-3-13657 and JP-A-4-364
No. 153, a charge transport material such as a compound, and an organic glass such as polysilane can also be used. These charge transporting materials may be used alone or as a mixture of two or more kinds, and the mobility of the charge in the charge transporting layer is 2 × 10 ⁵ V electric field.
In addition, a photoreceptor with higher sensitivity can be obtained by selecting the combination so as to be 5 × 10 to ⁶ cm ² / V · sec or more under the condition of / cm.

As the binder resin used together with the charge transport material, a polycarbonate resin is used from the viewpoints of sensitivity, repetition characteristics, film formability, coating film strength, abrasion resistance and the like.

Here, as the polycarbonate resin, a linear polymer containing one or more kinds of repeating units represented by the following general formula [I] can be used.

[0030]

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Wherein R _{1 to} R ₄ are each independently
Represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group, or a cycloalkyl group.

Specific examples of R _{1 to} R ₄ include, for example, halogen atoms such as fluorine atom, chlorine atom and bromine atom, methyl group, ethyl group, n-propyl group, isopropyl group, n-
Butyl, 1-methylpropyl, 2-methylpropyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, isohexyl, phenyl, cyclohexyl, etc. . Note that R _{1 to} R ₄ may be the same group or different groups. X is a single bond,-
_{(R 5) C (R 6} ) - ( wherein, R ₅ and R ₆ are a hydrogen atom, -C
F _3, represents an alkyl group or an aryl group), - (CH _{2) q}
-( _Q represents an integer of 1 to 10), -O-, -S-,-
SO- or -SO ₂ - represent. R ₅ and R ₆ may be combined to form a ring. _P represents an integer of 20 or more.

Specific examples of R ₅ and R ₆ in — (R ₅ ) C (R ₆ ) — include a hydrogen atom, a trifluoromethyl group, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, n-butyl group, 1-methylpropyl group, 2-methylpropyl group, tert-butyl group, n-pentyl group, isopentyl group, n-hexyl group, isohexyl group, phenyl group, tolyl group, xylyl group, trimethylphenyl group , An ethylphenyl group, a naphthyl group, a methylnaphthyl group, a biphenyl group and the like. Among these, a methyl group and a phenyl group are particularly preferred. Note that R ₅ and R ₆ may be the same group or different groups. Further, specific examples of the case where R ₅ and R ₆ form a ring include, for example, 1,1-cyclopentylidene group, 1,1-cyclohexylidene group, 1,1-cyclooctylidene group and the like. . Among these, a 1,1-cyclohexylidene group is particularly preferred. The - (CH _{2) q} - can be obtained by, for example, methylene group, dimethylene group, trimethylene group, tetramethylene group, hexamethylene group, octamethylene group, etc. decamethylene group.

The polycarbonate resin represented by the general formula [I] is, for example, a general polycarbonate resin obtained by reacting one or more dihydric phenols represented by the following general formula [II] with phosgene. It can be produced by a synthetic method.

[0035]

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Specific examples of the dihydric phenols represented by the above general formula [II] include, for example, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 1,2- Bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane,
2,2-bis (3-methyl-4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) butane,
2,2-bis (4-hydroxyphenyl) octane, 4,4
-Bis (4-hydroxyphenyl) heptane, 1-phenyl-1,1-bis (4-hydroxyphenyl) ethane, 4,
4'-dihydroxytetraphenylmethane, 1,1-bis
(4-hydroxyphenyl) -1-phenylethane, 1,
1-bis (4-hydroxyphenyl) -1-phenylmethane, bis (4-hydroxyphenyl) ether, bis (4
-Hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (3- Methyl-
4-hydroxyphenyl) propane, 2- (3-methyl-
4-hydroxyphenyl) -2- (4-hydroxyphenyl) -1-phenylethane, bis (3-methyl-4-hydroxyphenyl) sulfide, bis (3-methyl-4-hydroxyphenyl) sulfone, bis (3- Methyl-4-hydroxyphenyl) methane, 1,1-bis (3-methyl-
4-Hydroxyphenyl) cyclohexane, 4,4'-dihydroxybiphenyl, 2,2-bis (2-methyl-4-
(Hydroxyphenyl) propane, 1,1-bis (2-butyl-4-hydroxy-5-methylphenyl) butane,
1-bis (2-tert-butyl-4-hydroxy-3-methylphenyl) ethane, 1,1-bis (2-tert-butyl-4-hydroxy-5-methylphenyl) propane,
1-bis (2-tert-butyl-4-hydroxy-5-methylphenyl) butane, 1,1-bis (2-tert-butyl-4-hydroxy-5-methylphenyl) isobutane,
1,1-bis (2-tert-butyl-4-hydroxy-5-
Methylphenyl) heptane, 1,1-bis (2-tert-butyl-4-hydroxy-5-methylphenyl) -1-phenylmethane, 1,1-bis (2-tert-amyl-4-hydroxy-5- Methylphenyl) butane, bis (3-chloro-4-hydroxyphenyl) methane, bis (3,5-dibromo-4-hydroxyphenyl) methane, 2,2-bis
(3-chloro-4-hydroxyphenyl) propane, 2,
2-bis (3-fluoro-4-hydroxyphenyl) propane, 2,2-bis (3-bromo-4-hydroxyphenyl) propane, 2,2-bis (3,5-difluoro-4-hydroxyphenyl) propane 2,2-bis (3,5-dichloro-4-hydroxyphenyl) propane, 2,2-bis
(3,5-dibromo-4-hydroxyphenyl) propane, 2,2-bis (3-bromo-4-hydroxy-5-chlorophenyl) propane, 2,2-bis (3,5-dichloro-4-hydroxyphenyl) ) Butane, 2,2-bis (3,5-dibromo-4-hydroxyphenyl) butane, 1,1-bis
(3-fluoro-4-hydroxyphenyl) -1-phenylethane, bis (3-fluoro-4-hydroxyphenyl) ether, 3,3′-difluoro-4,4′-dihydroxybiphenyl, 1,1-bis ( 3-cyclohexyl-4
-Hydroxyphenyl) cyclohexane, 2,2-bis
(4-hydroxyphenyl) hexafluoropropane,
2,2-bis (3-phenyl-4-hydroxyphenyl)
Propane, 1-phenyl-1,1-bis (3-phenyl-
4-hydroxyphenyl) ethane, 1,1-bis (3-phenyl-4-hydroxyphenyl) cyclohexane, 9,
9-bis (4-hydroxyphenyl) fluorene, 1,3
-Bis (3-phenyl-4-hydroxyphenyl) pentane, bis (3-phenyl-4-hydroxyphenyl) sulfone, 3,3'-diphenyl-4,4'-dihydroxybiphenyl, bis (3-phenyl-4- Hydroxyphenyl)
Methane, 1-phenyl-1,1-bis (3-phenyl-4
-Hydroxyphenyl) methane, 1,1-bis (3-phenyl-4-hydroxyphenyl) ethane, 1,2-bis
(3-phenyl-4-hydroxyphenyl) ethane, 1,
3-bis (3-phenyl-4-hydroxyphenyl) propane, 2,2-bis (3-phenyl-4-hydroxyphenyl) butane, 1,4-bis (3-phenyl-4-hydroxyphenyl) butane, , 1-bis (3-phenyl-4
-Hydroxyphenyl) -1-phenylbutane, 2,2-
Bis (3-phenyl-4-hydroxyphenyl) octane, 1,8-bis (3-phenyl-4-hydroxyphenyl) octane, bis (3-phenyl-4-hydroxyphenyl) ether, bis (3-phenyl-4 -Hydroxyphenyl) sulfide, 1,1-bis (3-phenyl-4-
(Hydroxyphenyl) cyclopentane and the like. Among these, 2-bis (4-hydroxyphenyl) propane, 1-phenyl-1,1-bis (4-hydroxyphenyl) ethane, and 4,4′-dihydroxy are particularly preferred in view of electrophotographic characteristics and solubility. Tetraphenylmethane, bis (4-hydroxyphenyl) sulfone, 1,1-
Bis (4-hydroxyphenyl) cyclohexane, 2,2
-Bis (3-methyl-4-hydroxyphenyl) propane, 4,4'-dihydroxybiphenyl, 2,2-bis (3
-Phenyl-4-hydroxyphenyl) propane, 1-
Phenyl-1,1-bis (3-phenyl-4-hydroxyphenyl) ethane, 1,1-bis (3-phenyl-4-hydroxyphenyl) cyclohexane, 9,9-bis (4-
(Hydroxyphenyl) fluorene, bis (3-phenyl-
4-Hydroxyphenyl) sulfone and the like are preferably used.

Specific examples of the solvent used for forming the charge transport layer include, for example, aromatic solvents such as benzene, toluene, xylene and chlorobenzene, ketones such as acetone, methyl ethyl ketone and cyclohexanone, methanol, ethanol and the like. Alcohols such as isopropanol, ethyl acetate, esters such as ethyl cellosolve, carbon tetrachloride, carbon tetrabromide, chloroform, dichloromethane,
Examples include halogenated hydrocarbons such as tetrachloroethane, ethers such as tetrahydrofuran and dioxane, dimethylformamide, dimethylsulfoxide, and diethylformamide. These solvents may be used alone or in combination of two or more.

Further, the charge transport layer of the present invention contains a plasticizer to lower the glass transition temperature as described above. Specific examples of the plasticizer include halogenated paraffin,
Polychlorinated biphenyl, dimethylnaphthalene, O-terphenyl, m-terphenyl, P-terphenyl, diethylbiphenyl, hydrogenated terphenyl, diisopropylbiphenyl, benzylbiphenyl, diisopropylnaphthalene, dibenzofuran, 9,10-dihydroxyphenanthrene and the like. Can be These have an effect of adjusting the glass transition temperature and improving film formability, flexibility, and the like.

As the antioxidant added to the charge generating layer, hindered phenol, hindered amine, paraphenylenediamine, hydroquinone, spirochroman,
Examples include spiroidanone, hydroquinoline and derivatives thereof, organic phosphorus compounds, organic sulfur compounds and the like. These can adjust the glass transition temperature of the charge generation layer to a desired value similarly to the plasticizer, and can effectively prevent ozone deterioration.

In addition, electron-withdrawing sensitizers such as chloranil, tetracyanoquinodimethane, tetracyanoethylene, trinitrolenolenone, dicyanobenzoquinone, tetrachlorophthalic anhydride, 3,5 dinitrobenzoic acid, cyanovinyl compounds, etc. Sensitizers such as violet, rhodamine B, cyanine dyes, pyrylium salts and thiapyrylium salts can be used. The sensitizer is added in an amount of 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight, and more preferably 0.5 to 8 parts by weight, based on 100 parts by weight of the charge transporting material. Further, a well-known additive such as an additive for suppressing accumulation of residual potential may be contained.

As shown in FIG. 2, the photosensitive member of the present invention may have an intermediate layer between the conductive support and the photosensitive layer. As a result, it is possible to improve adhesion, improve coating properties, protect the support, and suppress charge injection from the support side into the photosensitive layer. As a material used for the intermediate layer, polyimide, polyamide, nitrocellulose, polyvinyl butyral, a polymer such as polyvinyl alcohol as it is, or a dispersion of a low-resistance compound such as tin oxide or indium oxide, or aluminum oxide, A vapor-deposited film of zinc oxide, silicon oxide, or the like is appropriate, and is desirably formed to have a thickness of 1 μm or less.

Further, as shown in FIG. 3, the photoreceptor of the present invention may be provided with a surface protective layer. As a material used for the surface protective layer, a polymer such as an acrylic resin, a polyaryl resin, a polycarbonate resin, or a urethane resin as it is, or a material in which a low-resistance compound such as tin oxide or indium oxide is dispersed is suitable. Further, a protective layer using an organic plasma polymerized film may be used. This organic plasma polymerized film may contain oxygen, nitrogen, halogen,
It may contain atoms of Groups 3 and 5 of the periodic table. The thickness of the surface protective layer is desirably 5 μm or less.

The photoreceptor of the present invention obtained as described above can be used in addition to an electrophotographic copying machine, a laser and a light emitting diode (LE).
D), which can be suitably used in various electrophotographic application fields as a photoconductor of a printer or a facsimile using a light source such as an LED shutter or a cathode ray tube.

Hereinafter, the present invention will be described more specifically with reference to experimental examples, but the present invention is not limited thereto unless it exceeds the gist thereof. In the following, “parts” means “parts by weight” unless otherwise specified.

Examples 1 to 3 On a small-diameter aluminum drum having a diameter of 60 mm and a length of 300 mm, 1 part of a trisazo pigment represented by the following chemical formula and a phenoxy resin (PKHH; manufactured by Union Carbide)
0.5 part and polyvinyl butyral resin (BX-1;
0.5 part of a trisazo compound dispersed with 0.5 part of cyclohexanone together with 500 parts of cyclohexanone using a sand mill for 24 hours is diluted with 500 parts of 1,4-dioxane to a dry film thickness of about 0.2 μm. And then dried to form a charge generation layer.

[0046]

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Further, 35 parts of a diamino compound represented by the following formula:

[0048]

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Bisphenol Z-type polycarbonate 65
Part, 1 part of a dicyano compound having the following structure,

[0050]

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A solution prepared by dissolving 7 parts of di-tert-butylhydroxytoluene and 18 parts of m-terphenyl in 500 parts of dichloromethane is applied to a dry film thickness of 35 μm, and dried to form a charge transport layer. A photoreceptor was prepared.

Examples 2 to 3 In Example 1, the thickness of the charge transport layer was set to 40 μm and 45 μm.
A laminated photoconductor was produced in exactly the same manner as in Example 1 except that the thickness was changed to μm.

Example 4 0.5 part of m-type titanyl phthalocyanine and 0.5 part of a polyvinyl butyral resin (6000C; manufactured by Denki Kagaku Kogyo KK) were dispersed together with 500 parts by weight of tetrahydrofuran (THF) by a sand mill for 4 hours. The obtained dispersion was placed on a small-diameter aluminum drum having an anodized film on a surface having a diameter of 35 mm and a length of 340 mm to a dry film thickness of about 0.1.
After coating so as to have a thickness of 5 μm, it was dried to form a charge generation layer.

On top of this, the distyryl compound 50
Department,

[0055]

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Bisphenol C type polycarbonate 60
Part, 1.5 parts of a dicyano compound having the following structure,

[0057]

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7.5 parts of an antioxidant (Irganox 565, manufactured by Ciba Geigy) and 20 parts of diethylbiphenyl were dissolved in 500 parts of 1,4-dioxane. This solution was applied to a dry film thickness of 30 μm and dried to form a charge transport layer. In this way, a laminated photoreceptor having two photosensitive layers was prepared.

Examples 5 to 6 In the above Example 4, the thickness of the charge transport layer was 40 μm.
A laminated photoconductor was produced in exactly the same manner as in Example 4 except that the thickness was changed to 50 μm.

Example 7 A solution prepared by dispersing 100 parts of conductive fine powder of tin oxide containing antimony oxide in 230 parts of xylene together with 75 parts of acrylic polyol and 6 parts of isocyanate on a plastic drum having a diameter of 50 mm and a length of 280 mm was dried. 3μ thickness
m and thermally cured to form a conductive layer. Next, a polyamide resin (CM8000: manufactured by Toray Industries, Inc.)
Two parts of triisopropoxyaluminum was added to a coating solution prepared by dissolving 10 parts of butanol in 100 parts, and applied onto the conductive layer by adding 2 parts of triisopropoxyaluminum.

Next, disazo pigment 1 represented by the following chemical formula:
Department,

[0062]

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0.5 parts of a polyester resin (Byron 200; manufactured by Toyobo Co., Ltd.) and 0.5 parts of a polyvinyl butyral resin (BX-1; manufactured by Sekisui Chemical Co., Ltd.) were dispersed together with 500 parts of cyclohexanone using a sand mill for 24 hours. The dispersion of the trisazo compound thus obtained is mixed with 1,4-dioxane 50
The mixture was diluted with 0 part, coated so as to have a dry film thickness of about 0.3 μm, and dried to form a charge generation layer.

Next, on the obtained charge generating layer, 50 parts of a diamino compound represented by the following formula:

[0065]

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Bisphenol Z-type polycarbonate 50
Parts, 2 parts of a dicyano compound having the following structure,

[0067]

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And an antioxidant (Irganox 101
0: Ciba-Geigy) 10 parts together with 15 parts of P-benzylbiphenyl 120 parts of tetrahydrofuran, 1,4-
A solution dissolved in 120 parts of dioxane was dried to a film thickness of 40.
By dip coating to a thickness of μm, a laminated photoreceptor was prepared.

Example 8 A laminated photoreceptor was produced in the same manner as in Example 6 except that the thickness of the charge transport layer was changed to 50 μm.

Example 9 One part of a disazo pigment represented by the following chemical formula was placed on a small-diameter aluminum drum having a diameter of 30 mm and a length of 200 mm.

[0071]

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1 part of a polyvinyl butyral resin (BX-1; manufactured by Sekisui Chemical Co., Ltd.) was dispersed together with 500 parts of cyclohexanone using a sand mill for 24 hours. The resulting dispersion of the disazo compound was diluted with 500 parts of 1,4-dioxane, and applied so that the dry film thickness was about 0.2 μm.
After drying, a charge generation layer was formed.

Further, 50 parts of a styryl compound represented by the following formula:

[0074]

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Bisphenol Z type polycarbonate resin 50 parts, dicyano compound of the following structural formula 1 part

[0076]

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A solution prepared by dissolving 5 parts of di-ter-butylhydroxytoluene and 5 parts of diisopropylbiphenyl in 500 parts of dichloromethane was applied by dip coating so as to have a dry film thickness of 30 μm to prepare a laminated photoreceptor.

Example 10 A photoconductor was prepared by the same way as that of Example 9 except that the addition amount of di-ter-butylhydroxytoluene used in the charge transport layer was changed to 15 parts.

Example 11 Example 9 was repeated except that the amount of diisopropyldiphenyl used in the charge transport layer was changed to 15 parts.
A photoreceptor was produced in exactly the same manner as described above.

Comparative Examples 1 to 3 In Examples 1 to 3, the di-ter-
Photoconductors were prepared in exactly the same manner as in Examples 1 to 3, except that butylhydroxytoluene (antioxidant) and m-terphenyl (plasticizer) were not added.

Comparative Example 4 A photoconductor was prepared by the same way as that of Example 4 except that the diethyl biphenyl (plasticizer) used for the charge transport layer was not added.

Comparative Example 5 A photoconductor was prepared in the same manner as in Example 1, except that the addition amount of m-terphenyl used in the charge transport layer was changed to 40 parts.

Comparative Example 6 A photoconductor was prepared in the same manner as in Example 1, except that the m-terphenyl used for the charge transport layer was not added.

Comparative Example 7 A photoconductor was prepared by the same way as that of Example 1 except that 30 parts of terphenyl hydride was added instead of m-terphenyl.

Comparative Example 8 A photoconductor was prepared by the same way as that of Example 9 except that the addition amount of dipropylbiphenyl (plasticizer) used in the charge transport layer was changed to 40 parts.

Comparative Example 9 A photoconductor was prepared in the same manner as in Example 1, except that no antioxidant and a plasticizer were added to the charge transport layer and the thickness of the charge transport layer was changed to 15 μm. Produced.

Comparative Example 10 In Comparative Example 1, the conductive support of the photosensitive member had a diameter of 9 mm.
A photoconductor was prepared in exactly the same manner as the comparative example except that an aluminum drum having a length of 0 mm and a length of 300 mm was used.

Comparative Example 11 In Example 9, the charge transporting layer formed on the charge generating layer was replaced with 100 parts of N-methylcarbazole-3-aldehydediphenylhydrazone, bisphenol A polycarbonate resin (K-1300, manufactured by Teijin Chemicals Ltd.). A photoconductor was prepared in the same manner as in Example 9 except that a solution obtained by dissolving 100 parts and 8 parts of dibutylhydroxytoluene in 1,4-dioxane was provided by dip coating so as to have a dry film thickness of 40 μm. .

The obtained photosensitive member was evaluated by a differential scanning calorimeter (DSC22).
0: manufactured by Seiko Instruments Inc.), and the glass transition temperature (Tg) of the charge transport layer was measured.
The glass transition temperature (Tg) was measured by DSC as shown in FIG.
The temperature at the intersection of the tangent 1 to the endothermic peak of the curve and the baseline m. Further, each of the obtained photoconductors was evaluated using a photoconductor tester shown in FIG. While rotating the photoreceptor (11) at a peripheral speed of 200 mm / sec, the initial surface potential V ₀ (V) when the applied voltage of the charger (10) was corona-charged at −5 KV was measured by the potential probe (7). ,
Further, an exposure amount (hereinafter referred to as a half reduction exposure amount) E _1/2 (lux · sec) necessary for the surface potential to attenuate to half of the initial surface potential due to the exposure (6), and a case where the device is left in the dark for 1 second The decay rate DDR ₁ (%) of the initial potential and the residual potential V _R (V) after erasing (50 lux · sec) by the eraser (8) were measured. The results are shown in Table 1. Example 1, Comparative Examples 1 and 5
After repeating the charging-exposure-erase process 10,000 times while rotating at a peripheral speed of 200 mm / sec using the photoreceptor tester shown in FIG.
₀ ′ (V), half-exposure amount E _1/2 ′ (lux · sec), dark decay rate DDR ₁ ′ (%), residual potential V _R ′ (V) were measured,
The results are shown in Table 2.

Further, the adhesiveness of each photoreceptor was measured by a grid test. The measurement method is JIS-K-5400.
Performed according to the method of No. 15. The results are shown in Table 1. The evaluation of the score in the grid test is as shown in Table 3.

[0091]

[Table 1]

[0092]

[Table 2]

[0093]

[Table 3]

As is clear from the results shown in Tables 1 and 2, the laminated photoreceptor according to the example of the present invention is superior in sensitivity and adhesiveness to those of the comparative example, and has a small diameter. It was also confirmed that this could be used without any practical problems. Further, a commercial copying machine (EP-3150; manufactured by Minolta Camera Co., Ltd.) was remodeled using the photoconductors of Example 1 and Comparative Example 1 of the present invention, and a 5,000-sheet actual shooting test was performed while rotating at a peripheral speed of 200 mm / sec. went. The photoreceptor of Example 1 showed a good image with little decrease in surface potential even after copying 5,000 sheets. However, the photoreceptor of Comparative Example 1 had a large frictional resistance with the blade and caused the blade to be turned up. Peeled off.

[0095]

As described in detail above, in the present invention,
By setting the glass transition temperature of the charge transport layer in a specific range, the adhesion of the charge transport layer having a particularly large thickness is improved, and the small-diameter photoconductor having excellent durability, high sensitivity and stable electrophotographic characteristics is provided. Can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a photoconductor according to the present invention in which a charge generation layer and a charge transport layer are laminated on a conductive support.

FIG. 2 is a schematic cross-sectional view of a photoconductor according to the present invention in which a surface protective layer is provided on the surface of a laminated photoconductor.

FIG. 3 is a schematic cross-sectional view of a photoreceptor according to the present invention in which an intermediate layer is provided between a conductive support and a charge generation layer.

FIG. 4 is a schematic explanatory diagram of glass transition temperature measurement.

FIG. 5 is a schematic configuration diagram of a photoconductor tester.

[Explanation of symbols]

1: conductive support 2: charge generation layer 3: charge transport layer 4: surface protection layer 5: intermediate layer 6: exposure 7: potential probe 8: eraser 9: potential probe 10: charger 11: photoreceptor θ: 45 °

Claims (1)

(57) [Claims] 1. A conductive consisting on the support and the charge generation layer and a charge transport layer photosensitive layer provided photoreceptor, the conductive support forms a 60mm diameter less cylindrical, the electrocoating
Organic pigments or organic dyes as charge generation material
Wherein the charge transport layer is on the charge generation layer.
Formed at least a charge transport material and polycarbonate
A charge transporting layer containing a resin and having a glass transition temperature (Tg) of 55 to 67 ° C. and a film thickness of 27.
a photoreceptor having a thickness of at least μm.