JP2012022144A - Photoreceptor, image formation method, image formation device and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoreceptor with good charge stability with respect to the light photoresponsive property and the environment change and with which the generation of image lag can be prevented and to provide an image formation method using the photoreceptor and an image formation device including the photoreceptor and a process cartridge.SOLUTION: A photoreceptor has, on a conductive supporter, an electric charge generator and a photosensitive layer including electric charge transporting agent and a binding resin. The electric charge generator includes a bisazo compound with a fluorenone ring of a specific structure. The electric charge transporting agent includes a heterocyclic compound of a specific structure.

Description

  The present invention relates to a photoreceptor, an image forming method, an image forming apparatus, and a process cartridge.

  2. Description of the Related Art In recent years, with the miniaturization and speeding up of copiers and printers, image forming methods that use a small-diameter photoconductor to increase the peripheral speed are used. As a photoreceptor that can be applied to such an image forming method, a photoreceptor having a photosensitive layer containing a charge generating agent having sensitivity in a long wavelength region is known.

In Patent Document 1, a general formula Ar ¹ —N═N—A—N═N—Ar ² is formed on a conductive support.
(In the formula, Ar ¹ and Ar ² are respectively different coupler residues, and A is triphenylamine, 9-fluorenone, 2,5-diphenyl-1,3,4-oxadiazole, dibenzophenazine, di- Of styrylbenzene, carbazole, N-substituted carbazole, dibenzothiophene, acridone, substituted or unsubstituted biphenyl, xanthone, anthraquinone, naphthalene, α, ω-diphenylpolyene, azobenzene, tetraphenylphenylenediamine, dibenzothiophene dioxide or phenanthrenequinone It is a divalent group.)
An electrophotographic photoreceptor in which a layer containing an asymmetric bisazo pigment represented by the above formula is formed is disclosed.

  However, there is a problem that the photo-responsiveness and the charging stability against environmental fluctuations from high temperature and high humidity to low temperature and low humidity are low. In addition, there is a problem that afterimages are generated due to residual charges on the photoreceptor.

  In view of the above-described problems of the prior art, the present invention is a photoconductor excellent in photoresponsiveness and charging stability against environmental fluctuations and capable of suppressing afterimage generation, an image forming method using the photoconductor, and the photosensitivity. An object of the present invention is to provide an image forming apparatus having a body and a process cartridge.

  The invention according to claim 1 is a photoreceptor having a photosensitive layer containing a charge generator, a charge transport agent and a binder resin on a conductive support, wherein the charge generator is represented by the general formula:

（式中、Ｒ_１及びＲ_２は、それぞれ独立に、置換若しくは無置換のアルキル基、置換若しくは無置換のアルコキシ基、置換若しくは無置換のアリール基又は置換若しくは無置換の複素環基であり、Ｒ_１及びＲ_２は同一ではない。）
で表される化合物を含み、前記電荷輸送剤は、一般式

Wherein R ₁ and R ₂ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, R ₁ and R ₂ are not identical.)
The charge transport agent comprises a compound represented by the general formula:

（式中、Ｒ_３、Ｒ_４、Ｒ_５及びＲ_６は、それぞれ独立に、水素原子、ハロゲン基、置換若しくは無置換の炭素数が１以上６以下のアルキル基、置換若しくは無置換の炭素数が１以上６以下のアルコキシ基である。）
で表される化合物を含むことを特徴とする。

(Wherein R ₃ , R ₄ , R ₅ and R ₆ are each independently a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted carbon number, Are 1 or more and 6 or less alkoxy groups.)
It is characterized by including the compound represented by these.

  According to a second aspect of the present invention, in the photoreceptor according to the first aspect, the charge transfer agent has a chemical formula.

で表される化合物、化学式

A compound represented by the chemical formula

で表される化合物、化学式

A compound represented by the chemical formula

で表される化合物、化学式

A compound represented by the chemical formula

で表される化合物又は化学式

Or a chemical formula represented by

で表される化合物を含むことを特徴とする。

It is characterized by including the compound represented by these.

  According to a third aspect of the present invention, in the photoreceptor according to the first or second aspect, the photosensitive layer includes a charge generation layer including the charge generation agent and a charge transport layer including the charge transfer agent. And

  According to a fourth aspect of the present invention, there is provided the photosensitive member according to the third aspect, wherein the charge transport layer comprises a phenol-based antioxidant, an amine-based antioxidant, a sulfur-based antioxidant, and a benzotriazole-based ultraviolet absorber. It further includes at least one.

  According to a fifth aspect of the present invention, in the image forming method, the step of charging the photosensitive member according to any one of the first to fourth aspects, and exposing the charged photosensitive member to form an electrostatic latent image. A step of developing the photosensitive member on which the electrostatic latent image is formed with toner to form a toner image, and a step of transferring the toner image formed on the photosensitive member to a transfer target. Features.

  According to a sixth aspect of the present invention, in the image forming method according to the fifth aspect, the photosensitive member on which the electrostatic latent image is formed within 100 milliseconds after exposure of the charged photosensitive member is developed with toner. It is characterized by doing.

  According to a seventh aspect of the present invention, in the image forming apparatus, the photosensitive member according to any one of the first to fourth aspects, a charging unit that charges the photosensitive member, and the charged photosensitive member are exposed. An exposure unit that forms an electrostatic latent image, a developing unit that develops the electrostatic latent image formed on the photoconductor with toner to form a toner image, and a toner image formed on the photoconductor It has the transfer means to transfer to.

  According to an eighth aspect of the present invention, in the image forming apparatus according to the seventh aspect, the image forming apparatus is a tandem type having a plurality of the photosensitive member, the charging unit, the developing unit, and the transfer unit.

  According to a ninth aspect of the present invention, in the image forming apparatus according to the seventh aspect of the present invention, the image forming apparatus includes a plurality of the photosensitive member, the charging unit, and the developing unit, and a toner image formed on the photosensitive member is transferred to The transfer unit further includes a first transfer unit that sequentially transfers and superimposes the toner images formed on the plurality of photoconductors to the intermediate transfer member, and the superimposed toner images are transferred to the transfer target. It has the 2nd transcription | transfer means to transcribe | transfer to a body, It is characterized by the above-mentioned.

  According to a tenth aspect of the present invention, in the process cartridge, the photosensitive member according to any one of the first to fourth aspects, a charging unit for charging the photosensitive member, and the charged photosensitive member are exposed to electrostatic force. Exposure means for forming a latent image, developing means for developing the electrostatic latent image formed on the photosensitive member with toner to form a toner image, and transfer for transferring the toner image formed on the photosensitive member to the transfer target And at least one cleaning means for cleaning the photosensitive member to which the toner image has been transferred.

  According to the present invention, a photoconductor excellent in photoresponsiveness and charging stability against environmental fluctuations and capable of suppressing the occurrence of an afterimage, an image forming method using the photoconductor, an image forming apparatus having the photoconductor, and A process cartridge can be provided.

It is sectional drawing which shows an example of the photoreceptor of this invention. It is a figure which shows an example of the image forming apparatus of this invention.

  Next, the form for implementing this invention is demonstrated with drawing.

  FIG. 1 shows an example of the photoreceptor of the present invention. In the photoreceptor 10, a photosensitive layer 12 in which a charge generation layer 12 a and a charge transport layer 12 b are sequentially stacked is formed on a conductive support 11.

  Examples of the material constituting the conductive support 11 include metals such as aluminum, brass, stainless steel, nickel, chromium, titanium, gold, silver, copper, tin, platinum, molybdenum, and indium; alloys of these metals. . Of these, aluminum alloys such as JIS 3000, JIS 5000, and JIS 6000 are preferable.

  Although it does not specifically limit as a shaping | molding method of the electroconductive support body 11, EI (Extension Ironing) method, ED (Extension Drawing) method, DI (Drawing Ironing) method, II (Impact Ironing) method etc. are mentioned. At this time, the surface of the conductive support 11 may be subjected to a surface cutting process such as a diamond cutting tool; a surface treatment such as polishing or anodizing.

  Other materials constituting the conductive support 11 include a resin containing a conductive agent such as metal powder and conductive carbon; a conductive resin; glass whose surface is coated with tin oxide, indium oxide, and aluminum iodide. Etc.

  Although it does not specifically limit as a shape of the electroconductive support body 11, A drum, a sheet | seat, a film, a belt, etc. are mentioned. At this time, the diameter of the drum is usually 60 mm or less, preferably 30 mm or less. Further, the belt may be endless or endless.

  The charge generation layer 12a includes a charge generation agent and a binder resin.

  The charge generating agent has the general formula (I)

（式中、Ｒ_１及びＲ_２は、それぞれ独立に、置換若しくは無置換のアルキル基、置換若しくは無置換のアルコキシ基、置換若しくは無置換のアリール基又は置換若しくは無置換の複素環基であり、Ｒ_１及びＲ_２は同一ではない。）
で表される化合物を含む。このとき、一般式（Ｉ）で表される化合物を二種以上併用してもよい。

Wherein R ₁ and R ₂ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, R ₁ and R ₂ are not identical.)
The compound represented by these is included. At this time, two or more compounds represented by the general formula (I) may be used in combination.

R ₁ and R ₂ are methyl group, ethyl group, n-butyl group, methoxy group, ethoxy group, phenyl group, 2-chlorophenyl group, 3-chlorophenyl group, 4-chlorophenyl group, 2-nitrophenyl group, 3 -Nitrophenyl group, 4-nitrophenyl group, 2-trifluoromethylphenyl group, 3-trifluoromethylphenyl group, 4-trifluoromethylphenyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methyl Phenyl group, 2-methoxyphenyl group, 3-methoxyphenyl group, 4-methoxyphenyl group, 2-cyanophenyl group, 3-cyanophenyl group, 4-cyanophenyl group, 1-naphthyl group, 2-anthraquinolyl group, 3 , 5-bis (trifluoromethyl) phenyl group, 4-pyrazolyl group, 2-thiazolyl group, 4-carboxyl group -2-thiazolyl group, 2-pyridyl, 2-pyrimidyl group, 2-carbazolyl group, 2-quinolyl group and the like.

  The content of the compound represented by the general formula (I) in the charge generation layer 12a is usually 0.2 to 10 parts by mass and 0.3 to 4 parts by mass with respect to 1 part by mass of the binder resin. It is preferable that When the content of the compound represented by the general formula (I) is small, the photosensitivity may be lowered, and when it is large, the adhesiveness may be lowered.

  The charge generator may further contain a charge generator other than the compound represented by the general formula (I) in order to obtain an appropriate photosensitivity wavelength and sensitizing action.

  The charge generator other than the compound represented by the general formula (I) is not particularly limited, but is an azo pigment such as a monoazo pigment, bisazo pigment, trisazo pigment, polyazo pigment, etc .; an indigo pigment; a selenium pigment; a toluidine pigment; a pyrazoline pigment. Perylene pigments; quinacridone pigments; pyrylium salts; phthalocyanine pigments, perylene pigments, and the like.

  The content of the compound represented by the general formula (I) in the charge generating agent is usually 1 to 99% by mass, and preferably 40 to 99% by mass.

  As binder resin, polycarbonate, styrene resin, acrylic resin, styrene-acrylic resin, ethylene-vinyl acetate resin, polypropylene, vinyl chloride resin, chlorinated polyether, vinyl chloride-vinyl acetate resin, polyester, furan resin, nitrile resin , Alkyd resin, polyacetal, polymethylpentene, polyamide, polyurethane, epoxy resin, polyarylate, diarylate, polysulfone, polyethersulfone, polyallylsulfone, silicone resin, ketone resin, polyvinyl butyral, polyether, phenolic resin, EVA (ethylene・ Vinyl acetate) resin, ACS (acrylonitrile / chlorinated polyethylene / styrene) resin, ABS (acrylonitrile / butadiene / styrene) resin, epoxy arylate, etc. Gerare, it may be used in combination of two or more.

  The thickness of the charge generation layer 12a is usually 0.01 to 5 μm, preferably 0.1 to 2 μm.

  The charge generation layer 12a is formed by, for example, applying a coating solution in which a charge generation agent and a binder resin are dispersed or dissolved in a solvent on the conductive support 11, and drying the coating as necessary. can do.

  The solvent is not particularly limited, but alcohols such as methanol, ethanol, n-propanol, i-propanol, and butanol; saturated aliphatic hydrocarbons such as pentane, hexane, heptane, octane, cyclohexane, cycloheptane; toluene, xylene Aromatic hydrocarbons such as dichloromethane; chlorinated hydrocarbons such as dichloromethane, dichloroethane, chloroform, chlorobenzene; ethers such as dimethyl ether, diethyl ether, tetrahydrofuran, dimethoxyethane, methoxyethanol, dioxolane, dioxane, anisole; acetone, methyl ethyl ketone, methyl isobutyl Ketones such as ketone and cyclohexanone; S such as ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, and methyl propionate Le acids; N, N-dimethylformamide; dimethyl sulfoxide and the like, may be used in combination. Among these, ketone solvents, ester solvents, ether solvents or halogenated hydrocarbon solvents are preferable.

  A method for applying the coating solution is not particularly limited, and examples thereof include a dip coating method, a spray coating method, a ring coating method, and a bar coat spinner coating method.

  The charge transport layer 12b includes a charge transport agent and a binder resin.

  The charge transport agent has the general formula (II)

（式中、Ｒ_３、Ｒ_４、Ｒ_５及びＲ_６は、それぞれ独立に、水素原子、ハロゲン基、置換若しくは無置換の炭素数が１以上６以下のアルキル基、置換若しくは無置換の炭素数が１以上６以下のアルコキシ基である。）
で表される化合物を含む。

(Wherein R ₃ , R ₄ , R ₅ and R ₆ are each independently a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted carbon number, Are 1 or more and 6 or less alkoxy groups.)
The compound represented by these is included.

  Although it does not specifically limit as a compound represented by general formula (II), Chemical formula (IIa)

で表される化合物、化学式（ＩＩｂ）

A compound represented by the formula (IIb)

で表される化合物、化学式（ＩＩｃ）

A compound represented by the formula (IIc)

で表される化合物、化学式（ＩＩｄ）

A compound represented by formula (IId):

で表される化合物、化学式（ＩＩｅ）

A compound represented by the formula (IIe)

で表される化合物等が挙げられ、二種以上併用してもよい。

Or a combination of two or more of them may be used.

  The content of the compound represented by the general formula (II) in the charge transport layer 12b is preferably 0.3 to 2 parts by mass with respect to 1 part by mass of the binder resin. When the content of the compound represented by the general formula (II) is small, the residual potential may be increased, and when the content of the compound represented by the general formula (II) is large, the wear resistance is decreased. There is.

  The charge transport agent may further contain a charge transport agent other than the compound represented by the general formula (II) in order to obtain a desired chargeability.

  The charge transport agent other than the compound represented by the general formula (II) is not particularly limited, but polyvinyl carbazole, halogenated polyvinyl carbazole, polyvinyl pyrene, polyvinyl indoloquinoxaline, polyvinyl benzothiophene, polyvinyl anthracene, polyvinyl acridine, polyvinyl Pyrazoline, polyacetylene, polythiophene, polypyrrole, polyphenylene, polyphenylene vinylene, polyisothianaphthene, polyaniline, polydiacetylene, polyheptadiene, polypyridinediyl, polyquinoline, polyphenylene sulfide, polyferrocenylene, polyperinaphthylene, polyphthalocyanine, etc. Conductive polymers: trinitrofluorenone, tetracyanoethylene, tetracyanoquinodimethane, quinone, diphenoxy , Naphthoquinone, anthraquinone and derivatives thereof, polycyclic aromatic compounds such as anthracene, pyrene, phenanthrene, nitrogen-containing heterocyclic compounds such as indole, carbazole, imidazole, fluorenone, fluorene, oxadiazole, oxazole, pyrazoline, hydrazone, Low molecular weight compounds such as triphenylmethane, triphenylamine, enamine, stilbene; polymer solid electrolytes in which polymers such as polyethylene oxide, polypropylene oxide, polyacrylonitrile, polymethacrylic acid are doped with metal ions such as Li ions; tetrathiaful An organic charge transport complex formed of an electron-donating compound such as valene-tetracyanoquinodimethane and an electron-accepting compound may be mentioned, and two or more kinds may be used in combination.

  The content of the compound represented by the general formula (II) in the charge transfer agent is usually 50 to 95% by mass, and preferably 70 to 95% by mass.

  As binder resin, polycarbonate, styrene resin, acrylic resin, styrene-acrylic resin, ethylene-vinyl acetate resin, polypropylene, vinyl chloride resin, chlorinated polyether, vinyl chloride-vinyl acetate resin, polyester, furan resin, nitrile resin , Alkyd resin, polyacetal, polymethylpentene, polyamide, polyurethane, epoxy resin, polyarylate, diarylate, polysulfone, polyethersulfone, polyallylsulfone, silicone resin, ketone resin, polyvinyl butyral, polyether, phenolic resin, EVA (ethylene・ Vinyl acetate) resin, ACS (acrylonitrile / chlorinated polyethylene / styrene) resin, ABS (acrylonitrile / butadiene / styrene) resin, epoxy arylate, etc. Gerare, it may be used in combination of two or more.

  The charge transport layer 12b further includes at least one of a phenol-based antioxidant, an amine-based antioxidant, a sulfur-based antioxidant, and a benzotriazole-based ultraviolet absorber in order to improve the durability of the photoreceptor 10. Is preferred. Of these, amine-based antioxidants are particularly preferable.

  The phenolic antioxidant is not particularly limited, but 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-4-methoxyphenol, 2-tert-butyl-4-methoxyphenol, 2 , 4-Dimethyl-6-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, butylated hydroxyanisole, stearyl propionate-β- (3,5-di-tert-butyl-4- Monophenolic compounds such as hydroxyphenyl), α-tocopherol, β-tocopherol, n-octadecyl-3- (3′-5′-di-tert-butyl-4′-hydroxyphenyl) propionate; 2,2′- Methylenebis (6-tert-butyl-4-methylphenol), 4,4′-butylidenebis- ( -Methyl-6-tert-butylphenol), 4,4'-thiobis (6-tert-butyl-3-methylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butyl) Phenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tetrakis [methylene-3- (3,5-di-) tert-butyl-4-hydroxyphenyl) propionate] polyphenol compounds such as methane, and the like, and two or more of them may be used in combination.

  The content of the phenolic antioxidant in the charge transport layer 12b is usually 1 to 20% by mass with respect to the binder resin.

  The amine antioxidant is not particularly limited, but α, α′-bis (dibenzylamino) -p-xylene, N-phenyl-1-naphthylamine, N-phenyl-N′-isopropyl-p-phenylenediamine. N, N-diethyl-p-phenylenediamine, N-phenyl-N′-ethyl-2-methyl-p-phenylenediamine, N-ethyl-N-hydroxyethyl-p-phenylenediamine, alkylated diphenylamine, N, N′-diphenyl-p-phenylenediamine, N, N′-diallyl-p-phenylenediamine, N-phenyl-1,3-dimethylbutyl-p-phenylenediamine, 4,4′-dioctyl-diphenylamine, 4,4 '-Dioctyl-diphenylamine, 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline 2,2,4-trimethyl-1,2-dihydroquinoline, N-phenyl-β-naphthylamine, N, N′-di-2-naphthyl-p-phenylenediamine, etc. Good.

  The content of the amine-based antioxidant in the charge transport layer 12b is usually 1 to 20% by mass with respect to the binder resin.

  The sulfur-based antioxidant is not particularly limited, but dilauryl-3,3-thiodipropionate, ditridecyl-3,3-thiodipropionate, dimyristyl-3,3-thiodipropionate, distearyl-3. , 3-thiodipropionate, laurylstearyl-3,3-thiopropionate, bis [2-methyl-4- (3-n-alkyl (C12-C14) thiopropionate) -5-t-butyl Phenyl] sulfide, pentaerythritol tetrakis (β-laurylthiopropionate), 2-mercaptobenzimidazole, 2-mercapto-6-methylbenzimidazole and the like, and two or more of them may be used in combination.

  The content of the sulfur-based antioxidant in the charge transport layer 12b is usually 0.1 to 5% by mass with respect to the binder resin.

  Although it does not specifically limit as a benzotriazole type ultraviolet absorber, 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl ] -2H-benzotriazole, 2- (3,5-di-tert-butyl-2-hydroxyphenyl) benzotriazole, 2- (3-tert-butyl-5-methyl-2-hydroxyphenyl) -5-chloro Benzotriazole, 2- (3,5-di-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-tert-amyl-2-hydroxyphenyl) benzotriazole, 2 -(2'-hydroxy-5'-tert-octylphenyl) benzotriazole, etc. It may be use.

  The content of the benzotriazole-based ultraviolet absorber in the charge transport layer 12b is usually 1 to 20% by mass with respect to the binder resin.

  The charge transport layer 12b may further include a radical scavenger, a softener, a curing agent, a cross-linking agent, and the like in order to improve the chargeability, durability, and mechanical properties of the photoconductor 10.

  The thickness of the charge transport layer 12b is usually 3 to 50 μm, preferably 10 to 40 μm.

  For example, the charge transport layer 12b is coated on the charge generation layer 12a with a coating solution in which the charge transport agent and the binder resin are dispersed or dissolved in the solvent in the same manner as the charge generation layer 12a. Then, it can be formed by drying.

  An intermediate layer containing a resin may be formed between the conductive support 11 and the charge generation layer 12a. This improves the adhesion between the conductive support 11 and the charge generation layer 12a, prevents current from flowing from the conductive support 11, and covers defects on the surface of the conductive support 11. be able to.

  Examples of the resin include, but are not limited to, polyethylene, acrylic resin, epoxy resin, polycarbonate, polyurethane, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral, polyamide, nylon resin, alkyd resin, melamine resin, and the like. You may use together.

  The intermediate layer may further contain a metal compound, carbon, silica, resin powder, pigment, electron accepting substance, electron donating substance and the like.

  For the intermediate layer, for example, in the same manner as the charge generation layer 12a, a coating liquid in which a binder resin is dispersed or dissolved in a solvent is coated on the conductive support 11, and dried as necessary. Can be formed.

  The thickness of the intermediate layer is usually 0.1 to 50 μm, preferably 0.5 to 20 μm.

  In order to improve the durability of the photoreceptor 10, a protective layer containing a resin may be formed on the charge transport layer 12b.

  Although it does not specifically limit as resin, Polyvinyl formal, a polycarbonate, a fluororesin, a polyurethane, a silicone resin etc. are mentioned, You may use 2 or more types together.

  The protective layer may be a hydrolyzate of a silane coupling agent.

  The thickness of the protective layer is usually 0.1 to 20 μm.

  Note that the stacking order of the charge generation layer 12a and the charge transport layer 12b may be reversed. Further, a single photosensitive layer may be formed without stacking the charge generation layer 12a and the charge transport layer 12b.

  FIG. 2 shows an example of the image forming apparatus of the present invention. The image forming apparatus 100 includes a charging roller 20 that charges the photosensitive member 10 around the photosensitive member 10, an exposure device 30 that exposes the charged photosensitive member 10 to form an electrostatic latent image, and the photosensitive member 10. The developing device 40 that develops the electrostatic latent image with toner to form a toner image, the transfer roller 50 that transfers the toner image formed on the photoconductor 10 to the transfer target P, and the photoconductor 10 to which the toner image is transferred. A cleaning blade 60 is installed for cleaning. At this time, the image forming apparatus 100 is provided with a fixing device 70 for fixing the toner image transferred to the transfer target P. When the image forming apparatus 100 is used, the photosensitive member 10 on which the electrostatic latent image is formed can be developed with toner within 100 milliseconds after the charged photosensitive member 10 is exposed.

  A voltage is applied to the charging roller 20 from a power source (not shown), and the charging roller 20 is brought into contact with the photoreceptor 10 to be charged positively or negatively.

  Examples of the exposure apparatus 30 include an LED and an LD.

  The developing device 40 may use either a two-component developer or a one-component developer as a developer used when developing the electrostatic latent image formed on the photoreceptor 10 with toner. And non-magnetic.

  Instead of the charging roller 20, a charging brush may be used, or a charging means that does not contact the photoreceptor 10, such as a scorotron or a corotron, may be used.

  Instead of the transfer roller 50, a transfer belt may be used.

  Instead of the cleaning blade 60, a cleaning brush may be used, or a charging unit or a developing unit that can also be used as a cleaning unit may be used. Further, the cleaning blade 60 may be omitted.

  The image forming apparatus 100 may be further provided with a static eliminator that neutralizes the photoreceptor 10.

  Instead of the image forming apparatus 100, an image forming apparatus having a plurality of photosensitive members 10, a charging roller 20, a developing device 40, and a transfer roller 50 may be used.

  Further, instead of the image forming apparatus 100, an image forming apparatus that includes a plurality of photosensitive members 10, a charging roller 20, and a developing device 40, and further includes an intermediate transfer member to which a toner image formed on the photosensitive member 10 is transferred. May be. Such an image forming apparatus includes a first transfer unit that sequentially transfers and superimposes the toner images formed on the plurality of photosensitive members 10 to the intermediate transfer member, and a second that transfers the superimposed toner images to the transfer target P. Transfer means.

  Further, the image forming apparatus 100 has a configuration in which a process cartridge including the photosensitive member 10 and at least one of the charging roller 20, the exposure device 30, the developing device 40, the transfer roller 50, and the cleaning blade 60 is detachably mounted. May be.

  The photoreceptor of the present invention will be described in detail below.

[Example 1]
Alkyd resin Beckolite M-6401-50 (manufactured by DIC) and amino resin Super Becamine G-821-60 (manufactured by DIC) were mixed at a mass ratio of 65:35, and then the mixed resin and titanium oxide CR-EL were mixed. (Ishihara Sangyo Co., Ltd.) was mixed at a mass ratio of 1: 3 and dispersed or dissolved in methyl ethyl ketone to obtain an intermediate layer coating solution.

  An intermediate layer coating solution was applied on a conductive support 11 in the form of an aluminum cylindrical drum having a diameter of 30 mm to form an intermediate layer having a thickness of 1.5 μm.

  Chemical formula (Ia)

で表される化合物３０ｇに、メチルエチルケトン５００ｍｌにポリビニルブチラールＢＨ−５（積水化学工業社製）１０ｇを溶解させた液及びガラスビーズを添加し、サンドミル分散機を用いて２０時間分散させた後、ろ過してガラスビーズを除去し、電荷発生層用塗布液を得た。

To a compound represented by the formula: The glass beads were removed to obtain a charge generation layer coating solution.

  The charge generation layer coating solution was dip-coated on the intermediate layer and then dried to form a charge generation layer 12a having a thickness of 0.2 μm.

  Polycarbonate Panlite TS2050 (manufactured by Teijin Chemicals Ltd.), a compound represented by the chemical formula (IIc) and 2,6-di-tert-butyl-4-methylphenol were mixed at a mass ratio of 1: 1: 0.05. Thereafter, it was dissolved in tetrahydrofuran to obtain a coating solution for a charge transport layer.

  After dip-coating in the charge transport layer coating solution on the charge generation layer 12a, it was dried at 120 ° C. for 60 minutes to form a charge transport layer having a thickness of 25 μm, whereby an electrophotographic photosensitive member was obtained.

[Example 2]
An electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the compound represented by the chemical formula (IIa) was used instead of the compound represented by the chemical formula (IIc).

[Example 3]
An electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the compound represented by the chemical formula (IIb) was used instead of the compound represented by the chemical formula (IIc).

[Example 4]
An electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the compound represented by the chemical formula (IId) was used instead of the compound represented by the chemical formula (IIc).

[Example 5]
An electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the compound represented by the chemical formula (IIe) was used instead of the compound represented by the chemical formula (IIc).

[Example 6]
Instead of the compound represented by the chemical formula (Ia), the chemical formula (Ib)

で表される化合物を用いた以外は、実施例１と同様にして、電子写真感光体を得た。

An electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the compound represented by formula (1) was used.

[Example 7]
Instead of the compound represented by the chemical formula (Ia), the chemical formula (Ic)

で表される化合物を用いた以外は、実施例１と同様にして、電子写真感光体を得た。

An electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the compound represented by formula (1) was used.

[Example 8]
In place of 2,6-di-tert-butyl-4-methylphenol, a semi-riser TPS (manufactured by Sumitomo Chemical Co., Ltd.) of distearyl-3,3′-thiodipropionate was used, and the addition amount was reduced to 1/5. An electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that.

[Example 9]
Example 1 except that Tinuvin-P (manufactured by Geigy) of 2- (2-hydroxy-5-methylphenyl) benzotriazole was used instead of 2,6-di-tert-butyl-4-methylphenol In the same manner as above, an electrophotographic photoreceptor was obtained.

[Example 10]
An electrophotographic photoreceptor in the same manner as in Example 1 except that α, α′-bis (dibenzyl) amino-p-xylene was used in place of 2,6-di-tert-butyl-4-methylphenol. Got.

[Example 11]
Polycarbonate Panlite TS2050 (manufactured by Teijin Chemicals Ltd.), compound represented by chemical formula (IIc), 2,6-di-tert-butyl-4-methylphenol, distearyl-3,3′-thiodipropionate Semirizer TPS (manufactured by Sumitomo Chemical Co., Ltd.) and 2- (2-hydroxy-5-methylphenyl) benzotriazole Tinuvin-P (manufactured by Geigy) were mixed at a mass ratio of 1: 1: 0.05: 0.01: 0. Then, the mixture was dissolved in tetrahydrofuran to obtain a coating solution for a charge transport layer.

  An electrophotographic photoreceptor was obtained in the same manner as in Example 1 except that the obtained charge transport layer coating solution was used.

[Example 12]
An electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that 2,6-di-tert-butyl-4-methylphenol was not added.

[Comparative Example 1]
Instead of the compound represented by the chemical formula (IIc), the chemical formula

で表される化合物を用いた以外は、実施例１と同様にして、電子写真感光体を得た。

An electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the compound represented by formula (1) was used.

[Comparative Example 2]
Instead of the compound represented by the chemical formula (IIc), the chemical formula

で表される化合物を用いた以外は、実施例１と同様にして、電子写真感光体を得た。

An electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the compound represented by formula (1) was used.

[Comparative Example 3]
Instead of the compound represented by the chemical formula (IIc), the chemical formula

で表される化合物を用いた以外は、実施例１と同様にして、電子写真感光体を得た。

An electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the compound represented by formula (1) was used.

[Comparative Example 4]
Instead of the compound represented by the chemical formula (Ia), the chemical formula

で表される化合物を用いた以外は、実施例１と同様にして、電子写真感光体を得た。

An electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the compound represented by formula (1) was used.

[Comparative Example 5]
Instead of the compound represented by the chemical formula (Ia), the chemical formula

で表される化合物を用いた以外は、実施例１と同様にして、電子写真感光体を得た。

An electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the compound represented by formula (1) was used.

[Evaluation of charging stability against environmental fluctuation]
Using an electrophotographic photosensitive member evaluation apparatus (manufactured by Yamanashi Electronics Co., Ltd.), temperature 23 ° C., humidity 50% RH (N / N), temperature 10 ° C., humidity 10% RH (L / L) or temperature 30 ° C., humidity In an environment of 80% RH (H / H), the charging stability of the electrophotographic photoreceptors of Examples 1 to 12 and Comparative Examples 1 to 5 with respect to environmental fluctuations was evaluated.

First, the surface potential (V0) of the electrophotographic photosensitive member charged by flowing a discharge current of 25 μA by the scorotron method was measured. Next, the electrophotographic photosensitive member is charged by supplying a discharge current adjusted to a surface potential of −700 V by the scorotron method, and then irradiated with a semiconductor laser having a wavelength of 650 nm, so that the surface potential is ½ ( The amount of exposure energy when attenuated to −350 V), that is, the amount of half-exposure energy (E1 / 2) was measured. Furthermore, after charging the electrophotographic photosensitive member by supplying a discharge current adjusted to a surface potential of −700 V by the scorotron method, the wavelength is 650 nm so that the exposure energy amount is 1.0 μJ / cm ² . The surface potential when irradiated with the semiconductor laser, that is, the residual potential (VL) was measured.

  The rotational speed of the electrophotographic photosensitive member was 100 rpm, and the time from the irradiation of the semiconductor laser having a wavelength of 650 nm to the electrophotographic photosensitive member until the measurement of the surface potential was 0.06 seconds.

  Table 1 shows the evaluation results of the charging stability against environmental fluctuations.

なお、Ｅ１／２が小さい程、感度に優れ、Ｅ１／２は０．１５μＪ／ｃｍ^２以下であることが好ましい。また、ＶＬが小さい程、画像濃度が大きくなり、ＶＬは１００Ｖ以下であることが好ましい。

The smaller E1 / 2 is, the better the sensitivity is, and E1 / 2 is preferably 0.15 μJ / cm ² or less. Also, the smaller the VL, the higher the image density, and the VL is preferably 100V or less.

  From Table 1, it can be seen that the electrophotographic photoreceptors of Examples 1 to 12 have small changes in V0, E1 / 2, and VL with respect to the environment, and are excellent in charging stability against environmental fluctuations.

[Evaluation of durability]
Using an electrophotographic photosensitive member evaluation apparatus (manufactured by Yamanashi Electronics Co., Ltd.), the electrophotographic photosensitive members of Examples 1 to 12 and Comparative Examples 1 to 5 in an environment of a temperature of 23 ° C. and a humidity of 50% (N / N) The durability was evaluated.

  An operation in which a discharge current of 25 μA is applied by the scorotron method to charge the electrophotographic photosensitive member, followed by irradiation with a semiconductor laser having a wavelength of 650 nm and neutralizing with a light emitting diode (20 μW) having a wavelength of 660 nm is defined as 1 cycle. Repeated 10,000 cycles. The surface potential (V0), half-exposure energy (E1 / 2) and residual potential (VL) of the electrophotographic photosensitive member after 10,000 cycles were measured in the same manner as in the evaluation of charging stability against environmental fluctuations.

  Table 2 shows the durability evaluation results.

表２より、実施例１〜１１の電子写真感光体は、Ｖ０の低下が１０Ｖ以下であることに加え、ＶＬの上昇も２０Ｖ以下であることから、耐久性が優れることがわかる。

From Table 2, it can be seen that the electrophotographic photoreceptors of Examples 1 to 11 have excellent durability because the decrease in V0 is 10 V or less and the increase in VL is 20 V or less.

[Evaluation of photoresponsiveness]
Using the electrophotographic photoreceptor evaluation apparatus (manufactured by Yamanashi Electronics Co., Ltd.), the electrophotographic photoreceptors of Examples 1 to 12 and Comparative Examples 1 to 5 were used in an environment of a temperature of 23 ° C and a humidity of 50% (N / N) Photoresponsiveness was evaluated.

  After charging the electrophotographic photosensitive member by supplying a discharge current adjusted to a surface potential of −700 V by the scorotron method, the exposure energy amount is 5 times the half exposure energy amount (E1 / 2). A semiconductor laser having a wavelength of 650 nm was irradiated, and the surface potential after 100 milliseconds, 50 milliseconds, and 30 milliseconds was measured.

  Table 3 shows the evaluation results of photoresponsiveness.

表３より、実施例１〜１２の電子写真感光体は、露光後の時間を短くしても表面電位の変動が小さく、光応答性が優れることがわかる。

From Table 3, it can be seen that the electrophotographic photoreceptors of Examples 1 to 12 have small variations in surface potential and excellent photoresponsiveness even if the time after exposure is shortened.

[Image Evaluation]
Using a color printer CX-411 (manufactured by Ricoh Co., Ltd.) without an erase exposure device in an environment of a temperature of 23 ° C. and a humidity of 50% (N / N), the transfer current was set to 10 μA, 20 μA, or 30 μA. A solid black image was formed in the first cycle, and the afterimage (ghost) appearing on the subsequent halftone was evaluated. In addition, it was determined that the case where no afterimage occurred was ◯, the case where it was generated was Δ, and the case where it was strongly generated was ×.

  Table 4 shows the evaluation results of the images.

表４より、実施例１〜１２の電子写真感光体は、転写電流を大きくしても、残像の発生を抑制できることがわかる。

From Table 4, it can be seen that the electrophotographic photoreceptors of Examples 1 to 12 can suppress the occurrence of an afterimage even when the transfer current is increased.

DESCRIPTION OF SYMBOLS 10 Photoconductor 11 Conductive support body 12 Photosensitive layer 12a Charge generation layer 12b Charge transport layer 20 Charging roller 30 Exposure apparatus 40 Developing apparatus 50 Transfer roller 60 Cleaning blade 70 Fixing apparatus 100 Image forming apparatus P Transfer object

JP-A-7-70456

Claims (10)

In a photoreceptor having a photosensitive layer containing a charge generator, a charge transport agent and a binder resin on a conductive support,
The charge generating agent has a general formula

Wherein R ₁ and R ₂ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, R ₁ and R ₂ are not identical.)
Including a compound represented by
The charge transfer agent has the general formula

(Wherein R ₃ , R ₄ , R ₅ and R ₆ are each independently a hydrogen atom, a halogen group, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted carbon number, Are 1 or more and 6 or less alkoxy groups.)
A photoreceptor comprising a compound represented by the formula: The charge transport agent has the chemical formula

A compound represented by the chemical formula

A compound represented by the chemical formula

A compound represented by the chemical formula

Or a chemical formula represented by

The photoconductor according to claim 1, comprising a compound represented by the formula:   The photoreceptor according to claim 1, wherein the photosensitive layer has a charge generation layer containing the charge generation agent and a charge transport layer containing the charge transfer agent.   The photoconductor according to claim 3, wherein the charge transport layer further includes at least one of a phenol-based antioxidant, an amine-based antioxidant, a sulfur-based antioxidant, and a benzotriazole-based ultraviolet absorber. . Charging the photoreceptor according to any one of claims 1 to 4,
Exposing the charged photoreceptor to form an electrostatic latent image;
Developing a photoconductor on which the electrostatic latent image is formed with toner to form a toner image;
An image forming method comprising a step of transferring a toner image formed on the photosensitive member to a transfer target.   6. The image forming method according to claim 5, wherein the photosensitive member on which the electrostatic latent image is formed is developed with toner within 100 milliseconds after exposure of the charged photosensitive member. A photoreceptor according to any one of claims 1 to 4,
Charging means for charging the photoreceptor;
Exposure means for exposing the charged photoreceptor to form an electrostatic latent image; and
Developing means for developing the electrostatic latent image formed on the photoreceptor with toner to form a toner image;
An image forming apparatus comprising transfer means for transferring a toner image formed on the photoreceptor to a transfer target.   The image forming apparatus according to claim 7, comprising a plurality of the photosensitive member, the charging unit, the developing unit, and the transfer unit. A plurality of the photoreceptor, the charging unit and the developing unit;
An intermediate transfer member to which a toner image formed on the photosensitive member is transferred;
The transfer unit includes a first transfer unit that sequentially transfers and superimposes toner images formed on a plurality of the photosensitive members to the intermediate transfer member, and a second transfer unit that transfers the superimposed toner images to the transfer target. The image forming apparatus according to claim 7, further comprising a transfer unit. A photoreceptor according to any one of claims 1 to 4,
Charging means for charging the photoreceptor, exposure means for exposing the charged photoreceptor to form an electrostatic latent image, and developing the electrostatic latent image formed on the photoreceptor with toner to form a toner image A process cartridge comprising: developing means; transfer means for transferring a toner image formed on the photoconductor to a transfer target; and at least one of cleaning means for cleaning the photoconductor on which the toner image is transferred.

Images