KR100677550B1 - Electrophotographic photoreceptor - Google Patents

Abstract

Conductive support; A charge generating layer formed on the conductive support, the charge generating layer comprising oxo titanyl phthalocyanine, metal phthalocyanine or a mixture thereof dispersed or dissolved in a binder resin as a charge generating material; And a combination of a butadiene-based amine compound and a hydrazone-based compound, or a combination of a first benzidine-based compound and a second benzidine-based compound, dispersed or dissolved in a binder resin as a charge transporting material. Provided is an electrophotographic photosensitive member comprising a charge transport layer comprising 5 to 200 parts by weight based on 100 parts by weight. The electrophotographic photosensitive member according to the present invention is excellent in adhesion and wear resistance while maintaining the electrostatic properties. Therefore, when used in electrophotographic printers, facsimiles, copiers, and plotters, the electrophotographic photosensitive member has a small change in image over time even after long-term use, and has excellent electrophotographic performance without image defects or physical defects caused by wear of the electrophotographic photosensitive drum. An image forming apparatus can be provided.

Description

Electrophotographic photoreceptor

1 is a cross-sectional view of an electrophotographic photosensitive member constructed as an electrophotographic photosensitive member according to a first aspect of the present invention in an order of a lower layer, a charge generating layer, and a charge transport layer on an aluminum drum.

FIG. 2 is a cross-sectional view of an electrophotographic photosensitive member composed of an alumite layer, a charge generating layer, and a charge transport layer on an aluminum drum as an electrophotographic photosensitive member according to a second aspect of the present invention.

3 is a cross-sectional view of an electrophotographic photoconductor composed of an alumite layer, a bottom layer, a charge generating layer, and a charge transport layer on an aluminum drum as an electrophotographic photoconductor according to a third aspect of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member, and more particularly, to an electrophotographic photosensitive member having an excellent electrostatic property as well as interlayer adhesion and wear resistance in an electrophotographic photosensitive member including a conductive support, a charge generating layer, and a charge transporting layer.

The electrophotographic photoreceptor or photoconductor used in printers, copiers, facsimile machines and large plotters is an important part of expressing information by optical signals and consists of several thin layers. In general, a metal oxide film or an insulating polymer is coated on a conductive support such as an aluminum drum, and a charge generation layer is applied thereon, followed by drying, followed by a charge transport layer (dry).

The charge generating layer serves to generate an electrical signal by light, and is composed of a charge generating material, a binder resin, and an additive, and an organic solvent is used in the preparation of the coating solution. As the charge generating material, a photosensitive organic pigment or an inorganic pigment is used, and in particular, organic pigments such as azo, perylene, and phthalocyanine are used. This is because organic crystals are used a lot because of the advantages that can be obtained a variety of crystal structure according to the synthesis method and processing conditions, which can easily change the electrostatic properties of the electrophotographic photosensitive drum. Binder resins disperse the pigment and allow it to adhere evenly on the aluminum drum, and solvents are used as a medium for uniform dispersion of the charge generating material and the binder resin.

The charge transport layer transfers electrical signals generated from the charge generating layer to the surface of the drum. The charge transport layer is composed of a charge transport material, a binder resin, and an additive. As the charge transport material, tertiary amines such as hydrazone-based, oxadiazole-based, butadiene-based and stilbene-based are used, and the binder resin dissolves or disperses the charge-transporting material and attaches to the support or the charge generating layer.

However, in an electrophotographic image forming apparatus such as a printer, it is important for the electrophotographic photosensitive member to maintain the initial photosensitivity even after long time printing. Image blurring or image darkening occurs due to changes in photosensitivity, and in some cases image defects are generated by uneven charging. Therefore, it is important to manufacture an electrophotographic photosensitive member having stable characteristics through the combination of appropriate components in the construction of the electrophotographic photosensitive member. However, the electrophotographic photosensitive member is a place where mechanical friction occurs a lot, and film peeling occurs according to the adhesive strength between the conductive support, the charge generating layer, and the charge generating layer and the charge transport layer, thereby reducing the durability of the photoreceptor and also the wearability of the charge transport layer. This severe case causes a change in photosensitivity and causes a change in image, so that it cannot be used, and many methods for improvement thereof have been proposed.

US Patent No. 5,496,672 discloses an example of using a melamine resin and a benzoguanamine resin in a charge generating layer to enhance adhesion, and US Patent No. 5,976,743 discloses an improvement in wear resistance using a silicone resin. U.S. Patent No. 6,214,502 discloses a combination of oxotitanium phthalocyanine as the charge generating material, polyvinylbutylal as the binder resin and phenolic resol resin or polyvinylbutylalol in the electrophotographic photoconductor laminated in the order of a conductive support, a charge generating layer, and a charge transporting layer. A charge generating layer comprising a combination of phenolic novolac resin or polyhydroxystyrene; An electrophotographic photosensitive member comprising a benzidine-based compound or a hydrazone-based compound as a charge transport material, a bisphenol-Z polycarbonate as a binder resin, and a charge transport layer comprising silicon microspheres is disclosed. However, they have room for improvement in terms of improving interlayer adhesion or wear resistance, and in particular, US Pat. Nos. 5,496,672 and 6,214,502 have a problem that only the durability of the charge generating layer is enhanced. US Pat. No. 5,976,743 is an intermediate layer of silicone curing. There is a more necessary problem.

Accordingly, the present invention is to provide an excellent electrophotographic photosensitive member which is excellent in durability as well as the electrostatic properties including the photosensitivity as well as the adhesion and wear resistance between the conductive support, the charge generating layer and the charge transport layer to solve the above problems. .

The present invention to achieve the above technical problem,

Conductive support;

A charge generating layer formed on the conductive support, the charge generating layer comprising oxo titanyl phthalocyanine, metal phthalocyanine or a mixture thereof dispersed or dissolved in a binder resin as a charge generating material; And

As the charge transport layer formed on the charge generating layer, a combination of a butadiene-based amine compound and a hydrazone-based compound or a combination of a first benzidine-based compound and a second benzidine-based compound dispersed or dissolved in a binder resin as a charge-transporting material is replaced with the binder resin 100 It provides an electrophotographic photosensitive member comprising a charge transport layer comprising 5 to 200 parts by weight based on parts by weight.

The binder resin of the charge transport layer comprises polycarbonate-Z, the charge transport layer is based on 100 parts by weight of the binder resin of the charge transport layer 0.01 to 10 parts by weight of the phosphate compound, phosphine oxide compound or a mixture thereof and the It is preferable to further contain 0.01-1 weight part of silicone oil based on 100 weight part of binder resins of a charge transport layer.

Butadiene-based amine compound as the charge transport material: The combination of the hydrazone-based compound is 100: 5 ~ 250 and the weight mixing ratio of the combination of the first benzidine-based compound: the second benzidine-based compound is preferably 100: 5 ~ 300 .

N, N'-bis- (3-methylphenyl) -N, N'-bis (phenyl) benzidine: N, N, N when a combination of the first benzidine compound and the second benzidine compound is used as the charge transport material ', N'-tetrakis (3-methylphenyl) benzidine, N, N, N', N'-tetrakis (4-methylphenyl) benzidine, N, N'-di (naphthalen-1-yl) -N, N Two different benzidine derivatives selected from the group consisting of '-di (4-methylphenyl) benzidine and N, N'-di (naphthalen-2-yl) -N, N'-di (3-methylphenyl) benzidine desirable.

When the phosphate compound and the phosphine oxide compound are used together in the charge transport layer, the mixed weight ratio of the phosphate compound: phosphine oxide compound is preferably 100: 0.1 to 100.

The conductive support includes a metal support having an alumite layer on its surface; A metal support having a undercoat layer including an inorganic oxide dispersed in a binder resin on a surface thereof; And it may be any one of a metal support having a surface layer containing an anodized layer and an inorganic oxide dispersed in a binder resin on the surface.

The electrophotographic photosensitive member according to the present invention is excellent in adhesion and wear resistance while maintaining the electrostatic properties. Therefore, when used in electrophotographic printers, facsimiles, copiers, and plotters, the electrophotographic photosensitive member has a small change in image over time even after long-term use, and has excellent electrophotographic performance without image defects or physical defects caused by wear of the electrophotographic photosensitive drum. An image forming apparatus can be provided.

Hereinafter, the electrophotographic photosensitive member according to the present invention will be described in more detail.

The electrophotographic photosensitive member according to the present invention has a structure in which a charge generating layer and a charge transport layer are sequentially stacked as a photosensitive layer on a conductive support. The conductive support is not particularly limited as long as it is a conductive material, and examples thereof include plates, disks, sheets, belts, drums, and the like made of metals, conductive polymers, and the like. Examples of the metal include aluminum, vanadium, nickel, copper, zinc, palladium, indium, tin, platinum, stainless steel or chromium. As the polymer, conductive materials such as conductive carbon, tin oxide and indium oxide are dispersed in polyester resin, polycarbonate resin, polyamide resin, polyimide resin, and mixtures thereof, and copolymers of monomers used to prepare the resin. The one which was made. Metal sheets or organic polymer sheets on which metals are deposited or laminated may also be used. In particular, examples of the conductive support used in the present invention include an aluminum support (FIG. 1) provided with an undercoat layer in which a metal oxide powder such as TiO ₂ is dispersed in a binder resin such as polyamide (FIG. 1), and an aluminum support provided with an alumite layer on the surface thereof ( Fig. 2) or an aluminum support (Fig. 3) provided with an undercoat layer on which aluminite layer and a metal oxide powder such as TiO ₂ are dispersed in a binder resin such as polyamide.

In the charge generating layer, a phthalocyanine compound is preferably used as the charge generating material. When it is oxo titanyl phthalocyanine, it shows the crystal form of D-type or Y-type oxo titanyl phthalocyanine having the strongest diffraction peak at 27.1 ° in Bragg angle (2θ ± 0.2 °) in powder X-ray diffraction peak, or Bragg angle Crystalline form of beta-type oxo titanyl phthalocyanine having the strongest diffraction peak at 26.1 ° at (2θ ± 0.2 °) or alpha type oxo titanyl phthalocyanine having the strongest diffraction peak at 7.5 ° at Bragg angle (2θ ± 0.2 °). It is preferable to use. If this is a metal-free phthalocyanine, use a crystal form of X-type metal-free phthalocyanine or tau-type metal-free phthalocyanine having the strongest diffraction peak at 7.5 ° and 9.2 ° with Bragg angle (2θ ± 0.2 °) in powder X-ray diffraction peak. It is preferable. This exhibits the best sensitivity to light in the wavelength range of 780 nm to 800 nm and can be effectively used in the present invention because there is a wide range of sensitivity selection depending on the crystal structure.

As the charge generating substance, a known charge generating substance or a dye or pigment for adjusting the spectral sensitivity may be used in addition to the phthalocyanine pigment as necessary. As a dye or pigment which can be used together in the charge generating layer according to the present invention, an azo compound, a bis azo compound, a triazo compound, a quinone pigment, a perylene compound, an indigo compound, a bisbenzoimidazole pigment, anthra Quinone compounds, quinacridone compounds, azulenium compounds, squarylium compounds, pyrylium compounds, triarylmethane compounds, cyanine compounds, perinone compounds, polycycloquinone compounds, A pyrrolopyrrole compound, a naphthalocyanine compound, etc. can be used together. These may be used alone or in combination with the phthalocyanine-based pigments, or may be used in combination with two or more kinds of phthalocyanine-based pigments.

In the charge generating layer, oxo titanyl phthalocyanine or metal-free phthalocyanine is dispersed by the binder resin. Binder resins that can be used include polyvinyl butyral, polyvinyl acetal, polyester, polyamide, polyvinyl alcohol, polyvinylacetate, polyvinylchloride, polyurethane, polycarbonate, polymethacryl, polyvinylidene chloride, polystyrene, Styrene-butadiene copolymer, styrene-methacrylate methyl copolymer, vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinylacetate copolymer, vinyl chloride-vinylacetate-maleic anhydride copolymer, ethylene-acrylic acid copolymer, Ethylene-vinylacetate copolymer, methyl cellulose, ethyl cellulose, nitrocellulose, carboxymethyl cellulose, polysilicon, silicone-alkyd resin, phenol-formaldehyde resin, cresol-formaldehyde resin, phenoxy resin, styrene-alkyd resin, poly -N-vinylcarbazole resin, polyvinyl cloth Horses, polyhydroxystyrene, polynobornyl, polycycloolefin, polyvinylpyrrolidone, poly (2-ethyl-oxazoline), polysulfone, melamine resin, urea resin, amino resin, isocyanate resin, epoxy resin, etc. Include. These may be used alone or in combination of two or more.

The content of the binder resin is preferably 5 to 350 parts by weight, and more preferably 10 to 200 parts by weight based on 100 parts by weight of the charge generating material. If less than 5 parts by weight, the dispersion of the phthalocyanine pigment is insufficient, the stability of the dispersion is lowered, there is a concern that it is difficult to obtain a uniform charge generating layer when coating on the conductive support, and also the adhesion strength is lowered. If it exceeds 350 parts by weight, it is difficult to maintain the charge potential and a desired image cannot be obtained with insufficient photosensitivity due to the excess binder resin.

The solvent used to prepare the coating liquid for the charge generating layer of the electrophotographic photosensitive member of the present invention may vary depending on the type of binder resin used, and it is preferable to select one that does not affect the adjacent layer when coating the charge generating layer. Examples of the solvent are methyl isopropyl ketone, methyl isobutyl ketone, 4-methoxy-4-methyl-2-pentanone, isopropyl acetate, tertiary butyl acetate, isopropyl alcohol, isobutyl alcohol, acetone, methyl ethyl ketone Cyclohexanone, 1,2-dichloroethane, 1,1,2-trichloroethane, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethane, dichloromethane, tetrahydrofuran, dioxane, Dioxolane, methanol, ethanol, 1-propanol, 1-butanol, 2-butanol, 1-methoxy-2-propanol, ethyl acetate, butyl acetate, dimethylsulfoxide, methylcellosolve, butylamine, diethylamine, on Butylenediamine, isopropanolamine, triethanolamine, triethylenediamine, N, N'-dimethylformamide, 1,2-dimethoxyethane, benzene, toluene, xylene, methylbenzene, ethylbenzene, cyclohexane, anisole and the like do. These may be used alone or in combination of two or more.

The production of a coating liquid for forming a charge generating layer for forming the charge generating layer will be described. First, 100 parts by weight of a phthalocyanine compound such as oxo titanyl phthalocyanine and 5 to 350 parts by weight of a binder resin, more preferably 10 to 200 parts by weight of an appropriate amount of solvent, for example, 100 to 10,000 parts by weight, preferably 500 to 8,000 Mix parts by weight. Glass beads, steel beads, zirconia beads, alumina beads, zirconia balls, alumina balls or steel balls are added to the mixture and dispersed for 2 to 50 hours using a disperser. At this time, a mechanical milling method can be used. Milling devices that can be used include attritors, ball mills, sand mills, van vari mixers, bag mixers, roll mills, three roll mills and nanomechanizers. ， Microfluidizer, stamp mill, planetary mill, vibration mill, kneader, homogenizer, dynomill, micronizer, paint shaker, high speed stirrer, optimizer, ultrasonic grinder, etc. It can be used individually or in combination of 2 or more types.

The coating solution for charge generation layer formation thus prepared is coated on the conductive support described above. Coating methods include dip coating, ring coating, roll coating, spray coating, and the like. Drying the coated support in this manner at 90 ~ 200 ℃ 0.1 ~ 2 hours can form a charge generating layer.

The thickness of the charge generating layer is preferably 0.001 to 10 µm, more preferably 0.01 to 10 µm, still more preferably 0.05 to 3 µm. If the thickness of the charge generating layer is less than 0.001 µm, it is difficult to form the charge generating layer uniformly, and if it exceeds 10 µm, the electrophotographic characteristics tend to be lowered.

A charge transport layer including a charge transport material and a binder resin is stacked on the charge generating layer.

The charge transport material includes a hole transport material for transporting holes and an electron transport material for transporting electrons. When the stacked photosensitive member is used as an auxiliary type, a hole transport material may be used as a charge transport material, and a hole transport material and an electron transport material may be mixed when both positive / negative bipolar properties are required. Examples of the hole transporting material that can be used in the present invention include, for example, hydrazone compounds, butadiene amine compounds, benzidine compounds, pyrene compounds, carbazole compounds, arylmethane compounds, thiazole compounds, styryl compounds, pyrazolines Compounds, styryl compounds, arylamine compounds, oxazole compounds, oxadiazole compounds, kuprazoline compounds, pyrazolone compounds, stilbene compounds, polyaryl alkane compounds, polyvinylcarbazole compounds and derivatives thereof, N-acrylamide methylcarbazole polymer, triphenylmethane polymer, styrene copolymer, polyacenaphthene, polyindene, copolymer of acenaphthylene and styrene, nitrogen-containing cyclic compounds such as formaldehyde-based condensation resin, condensed polycyclic compound And high molecular compounds having these substituents in the main chain or in the side chain thereof.

Electron transport materials that can be used in the present invention include known electron transport materials. Specific examples thereof include benzoquinone compounds, naphthoquinone compounds, anthraquinone compounds, malononitrile compounds, fluorenone compounds, cyanoethylene compounds, cyanoquinomimethane compounds, xanthone compounds, and phenanthra. Quinone compounds, phthalic anhydride compounds, thiopyran compounds, dicyanofluorenone compounds, naphthalenetetracarboxylic acid diimide compounds, benzoquinoneimine compounds, diphenoquinone compounds, steelbenequinone compounds, diiminoqui Electron-accepting low molecular weight compounds, such as a non-type compound, a dioxo tetracedidione compound, and a pyran sulfide type compound.

However, the charge transport material that can be used in the present invention is not limited to the above-described hole transport material or electron transport material, and the charge transport material is not listed above as long as the charge mobility is faster than 10 ⁻⁸ cm 2 / V · sec. Also, the above charge transport material may be used in combination of two or more kinds. The inventors have repeatedly conducted a number of repeated experiments, particularly when a combination of butadiene-based amine compound and hydrazone-based compound, or surprisingly a combination of a first benzidine-based compound and a second benzidine-based compound is used as a charge transport material, resulting in low image temporal change. It has been found that electrophotographic photosensitive members having high photosensitivity can be obtained, which is preferable.

Butadiene-based amine compounds have excellent electrostatic properties, so they have high E _1/2 sensitivity and low residual potential, making them suitable for high sensitivity, but they are expensive and highly susceptible to image change over time, while hydrazone compounds have low E _1/2 sensitivity. Although it is slow and has a high residual potential, it is thought to be used in combination with a butadiene-based amine compound to stabilize the electrophotographic photosensitive member by reducing image aging change. It is also economically advantageous to use them in combination.

When a combination of these two hole transport compounds is used, the mixing amount of the hole transport compounds is not particularly limited, but the weight ratio of the butadiene-based amine compound to the hydrazone compound is 100: It is preferable that it is 5-250, It is more preferable that it is 100: 5-200, It is preferable that the weight ratio of a 1st benzidine type compound: 2nd benzidine type compound is 100: 5-300, It is more preferable that it is 100: 5-200. desirable. When the first and second benzidine-based compounds are used as charge transport materials, N, N, based on 100 parts by weight of N, N'-bis- (3-methylphenyl) -N, N'-bis (phenyl) benzidine N ', N'-tetrakis (3-methylphenyl) benzidine, N, N, N', N'-tetrakis (4-methylphenyl) benzidine, N, N'-di (naphthalen-1-yl) -N, Preference is given to using a combination of two selected from N'-di (4-methylphenyl) benzidine and N, N'-di (naphthalen-2-yl) -N, N'-di (3-methylphenyl) benzidine. . As a result, N, N, N ', N'-tetrakis (4-methylphenyl) benzidine can improve the compatibility with the binder resin while enhancing the photosensitivity of the photoconductor, thereby preventing crystallization on the surface of the drum during coating.

When the charge transport material itself has a film forming ability, a charge transport layer can be formed without a binder resin. However, since a low molecular weight material does not have a film formation ability, a composition for forming a charge transport layer in a solution or dispersion state dissolved or dispersed in a binder resin is prepared. It is then coated on the charge generating layer and dried to form a charge transport layer. The binder resin which can be used for the charge transport layer of the electrophotographic photosensitive member of the present invention is an insulating resin having film forming ability, preferably polyvinyl butyral, polyarylate (such as a condensation polymer of bisphenol A and phthalic acid), polycarbonate, polyester Resin, phenoxy resin, polyvinyl acetate, acrylic resin, polyacrylamide resin, polyamide, polyvinyl pyridine, cellulose resin, urethane resin, epoxy resin, silicone resin, polystyrene, polyketone, polyvinyl chloride, vinyl chloride Insulating resins such as vinyl acid copolymer, polyvinyl acetal, polyacrylonitrile, phenol resin, melamine resin, casein, polyvinyl alcohol, polyvinylpyrrolidone, and poly N-vinylcarbazole, polyvinyl anthracene or Organic photoconductive resins, such as polyvinylpyrene, are also included.

However, the present inventors found that the binder resin for the charge transport layer of the present invention is a polycarbonate resin, and polycarbonate-derived from cyclohexylidene bisphenol than polycarbonate-A derived from bisphenol A or polycarbonate-C derived from methylbisphenol A. It was found that the use of Z is preferable because it can use high glass transition temperature and high wear resistance of this resin. As the usage-amount of this binder resin, it is preferable to set it as the ratio of 5-200 weight part of charge transport materials with respect to 100 weight part of binder resin, and it is more preferable to set it as the ratio of 10-150 weight part.

In the electrophotographic photosensitive member of the present invention, the charge transport layer includes a phosphate compound, a phosphine oxide compound or a mixture thereof and silicone oil in order to improve wear resistance and to impart lubricity (= slip) on the surface of the charge transport layer. Specific examples of phosphate-based compounds that can be used include, but are not limited to, triphenyl phosphate, tricresyl phosphate, trioctyl phosphate, octyldiphenyl phosphate, trichloroethyl phosphate, cresyl diphenyl phosphate, tributyl phosphate, tri-2 Ethylhexyl phosphate. Phosphine oxide compounds that can be used include, but are not limited to, triphenyl phosphine oxide, tricresyl phosphine oxide, trioctyl phosphine oxide, octyldiphenyl phosphine oxide, trichloroethyl phosphine oxide, cresyl diphenyl phosphate Fin oxide, tributyl phosphine oxide, tri-2-ethylhexyl phosphine oxide, and the like.

As described above, the phosphate compound and the phosphine oxide compound may be used by mixing two or more kinds thereof. Its use amount is 0.01-10 weight part with respect to 100 weight part of binder resin of a charge transport layer, Preferably it is 0.1-5 weight part. If it is less than 0.01 parts by weight, the effect on the improvement of adhesion and durability is insignificant, and if it exceeds 10 parts by weight, there is a disadvantage in reducing the electrostatic properties. When the phosphate compound and the phosphine oxide compound are used in combination, the mixed weight ratio thereof is preferably phosphate compound: phosphine oxide compound = 100: 0.1 to 100.

Silicone oil is used to improve the wear resistance of the electrophotographic photosensitive member by enhancing the slip property of the charge transport layer. Silicone oils that can be used include, but are not limited to, polysiloxane oils such as straight silicone oils such as dimethylsilicone oil, methylphenyl silicone oil, methylhydrogen silicone oil; And modified silicone oil having an organic group introduced into at least one of the side chain or the terminal of the straight silicone oil. The said organic group is an amino group, an epoxy group, a carboxyl group, an alcohol group, a mercapto group, an alkyl group, a polyether group, methyl styryl group, a higher fatty acid ester group, an alkyl fluoride group, a (meth) acryl group, an alkoxy group, etc. are mentioned. Specific examples thereof are Shin-Etsu Chemical Co., Ltd., KF96, KF50, KF54, KP301, KP302, KP306, KP321, KP322, KP323, KP324, KP326, KP340, KP341, KP354, KP355, KP356, KP357, KP358, KP359, and KP36. KP363, KP365, KP366, KP368, KP369, KP316, KP360, KP361, KP390, KP391, or KP392.

The usage-amount of silicone oil is 0.01-1 weight part with respect to 100 weight part of binder resin of the said charge transport layer, Preferably it is 0.01-0.5 weight part. If it is less than 0.01 part by weight, the slip-promoting effect is insignificant, and if it is more than 1 part by weight, there is a fear of reducing the adhesive force. When phosphate-based compounds and / or phosphine oxide-based compounds are used in combination with silicone oil, it is expected to improve abrasion resistance through a synergistic effect of slip on the surface of the charge transport layer.

The solvent used to prepare the coating liquid for the charge transport layer of the electrophotographic photosensitive member of the present invention may vary depending on the type of binder resin used, and it is preferable to select one that does not affect the lower charge generation layer. Specifically, benzene, Aromatic hydrocarbons such as xylene, ligroin, monochlorobenzene and dichlorobenzene; Ketones such as acetone, methyl ethyl ketone and cyclohexanone; Alcohols such as methanol, ethanol and isopropanol; Esters such as ethyl acetate and methyl cellosolve; Aliphatic halogenated hydrocarbons such as carbon tetrachloride, chloroform, dichloromethane, dichloroethane and trichloroethylene; Ethers such as tetrahydrofuran, dioxane, dioxolane, ethylene glycol and monomethyl ether; Amides such as N, N-dimethyl formamide and N, N-dimethyl acetamide; And sulfoxides such as dimethyl sulfoxide and the like are selected and may be used alone or in combination of two or more thereof.

The production of the coating liquid for forming the charge transport layer will be described. First, an appropriate amount of solvent, for example, 100 to 100 parts by weight of the binder resin, 5 to 200 parts by weight of the charge transport material, 0.01 to 10 parts by weight of the phosphate compound and / or phosphine oxide compound, and 0.01 to 1 parts by weight of the silicone oil 1,500 parts by weight, preferably 300 to 1,200 parts by weight are mixed and stirred.

The coating solution for charge transport layer formation thus prepared is coated on the charge generation layer already formed. As the coating method, the dip coating method, ring coating method, roll coating method, spray coating method and the like mentioned above can be used in the same manner. In this way, if the support on which the charge transport layer is coated is dried at 90 to 200 ° C. for 0.1 to 2 hours, a charge transport layer may be formed.

The thickness of the charge transport layer is preferably 2 to 100 µm, more preferably 5 to 50 µm, even more preferably 10 to 40 µm. If the thickness of the charge transport layer is less than 2 µm, the thickness is too thin, insufficient durability, and if the thickness exceeds 100 µm, the physical abrasion resistance increases, but the quality of the printed image tends to be lowered.

In addition, in the production of the photoconductor of the present invention, an electron-accepting material may be further added to the charge transport layer and / or charge generation layer for the purpose of improving the sensitivity, reducing the residual potential, or reducing fatigue during repeated use. Such electron-accepting substances include, but are not limited to, succinic anhydride, maleic anhydride, dibromic succinic anhydride, phthalic anhydride, 3-nitro phthalic anhydride, 4-nitro phthalic anhydride, pyromellitic dianhydride, pyromellitic acid, trimellitic acid ， Electronic affinity such as anhydrous trimellitic acid, phthalimide, 4-nitrophthalimide, tetracyanoethylene, tetracyanoquinomimethane, chloranyl, bromanyl, ο-nitro benzoic acid, p-nitro benzoic acid This includes large compounds. The amount of the electron-accepting material added is preferably 0.01 to 100% by weight based on the weight of the charge generating material.

In addition, the photoconductor of the present invention may contain a deterioration inhibitor such as an antioxidant or a light stabilizer in the charge transport layer and / or the charge generating layer for the purpose of improving environmental resistance and stability against harmful light. Examples of the compound include chromatinol derivatives such as tocopherol and etherified or esterified compounds thereof, polyaryl alkane compounds, hydroquinone derivatives and mono and dietherated compounds, benzophenone derivatives, benzotriazole derivatives, sulfide ether compounds and phenyl. Examples thereof include a rendiamine derivative, a phosphonic acid ester, a phosphorous acid ester, a phenol compound, a phenol compound having a stereo hindered structure, a straight chain amine compound, a cyclic amine compound, an amine compound having a stereo hindered structure

The present invention will be described in more detail with reference to the following examples, which are intended to be illustrative only and should not be construed as limiting the invention.

 Example 1

It was ball milled together with 7 parts by weight of oxo titanyl phthalocyanine, 3.5 parts by weight of polyvinyl butyral resin (ESREC BH-3, Sekisui), 100 parts by weight of 1,2-dimethoxyethane, and 300 parts by weight of glass beads. The dispersion was diluted with 400 parts by weight of 1,2-dimethoxyethane and sonicated for 30 minutes to prepare a stable charge generating layer coating solution. The coating solution for the charge generating layer was uniformly coated on the aluminum drum, the surface of which was aluminite-treated using the sedimentation coating method, and then dried at 150 ° C. for 1 hour to form a charge generating layer.

4 parts by weight of 4-dibenzylamino-2-methylbenzaldehyde diphenylhydrazone (CTC-191, TAKASAGO), 1,1-bis- (para-diethylaminophenyl) -4,4-diphenyl-1, 4 parts by weight of 3-butadiene (T-405, TAKASAGO Co.), 11 parts by weight of polycarbonate (PCZ-400, Mitsubishi Gas), n-octadecyl-3- (3,5-dibutylbutyl-4-hydroxy Phenyl) propionate 0.3 parts by weight, trioctyl phosphate 0.04 parts by weight, silicone oil (KF-50, Shin-Etsu Co., Ltd.) 0.004 parts by weight, 60 parts by weight of tetrahydrofuran, 20 parts by weight of toluene are dissolved together and completely charged Coating on the layer to form a charge transport layer. This drum was dried at 150 degreeC for 1 hour. The electrostatic properties and durability of the electrophotographic photosensitive drum thus obtained were measured by the method described below. The results are shown in Table 1.

 Example 2

An electrophotographic photosensitive member was manufactured in the same manner as in Example 1, except that 0.08 parts by weight of trioctyl phosphate was used as the charge transport layer in Example 1, and the evaluation results of the electrostatic properties and durability thereof are shown in Table 1.

 Example 3

2.4 parts by weight of 4-dibenzylamino-2-methylbenzaldehydediphenylhydrazone, 1,1-bis- (para-diethylaminophenyl) -4,4-diphenyl-1,3 in the water transport layer in Example 1 Except for using 2.4 parts by weight of butadiene, an electrophotographic photosensitive member was manufactured in the same manner as in Example 1, and the results of evaluation of the electrostatic characteristics and durability thereof are shown in Table 1.

 Example 4

2.4 parts by weight of 4-dibenzylamino-2-methylbenzaldehydediphenylhydrazone in Example 1, 1,1-bis- (para-diethylaminophenyl) -4,4-diphenyl-1,3-butadiene 2.4 An electrophotographic photosensitive member was manufactured in the same manner as in Example 1, except that parts by weight and 0.08 parts by weight of trioctyl phosphate were used, and the results of evaluating electrostatic properties and durability thereof are shown in Table 1.

 Example 5

An electrophotographic photosensitive member was manufactured in the same manner as in Example 1, except that the metal-free phthalocyanine was used in place of the oxo titanyl phthalocyanine in Example 1, and the evaluation results of the electrostatic properties and durability thereof are shown in Table 1.

 Example 6

An electrophotographic photosensitive member was manufactured in the same manner as in Example 1, except for using metal-free phthalocyanine in place of oxo titanyl phthalocyanine and using 0.08 parts by weight of trioctyl phosphate in the charge transport layer. The evaluation results are shown in Table 1.

 Example 7

Except for using triphenyl phosphate instead of trioctyl phosphate in Example 1 an electrophotographic photosensitive member was prepared in the same manner as in Example 1 and the results of evaluation of the electrostatic properties and durability thereof are shown in Table 1.

 Example 8

Except for using octyldiphenyl phosphate instead of trioctyl phosphate in Example 1 an electrophotographic photosensitive member was prepared in the same manner as in Example 1 and the results of evaluation of the electrostatic properties and durability thereof are shown in Table 1.

 Example 9

Except for using tributyl phosphate instead of trioctyl phosphate in Example 1 an electrophotographic photosensitive member was prepared in the same manner as in Example 1 and the results of evaluation of the electrostatic properties and durability thereof are shown in Table 1.

 Example 10

An electrophotographic photosensitive member was manufactured in the same manner as in Example 1, except that trioctyl phosphate was used instead of trioctyl phosphate in Example 1, and the evaluation results of the electrostatic properties and durability thereof are shown in Table 1.

 Example 11

Except for using octyldiphenyl phosphine oxide instead of trioctyl phosphate in Example 1 an electrophotographic photosensitive member was prepared in the same manner as in Example 1 and the results of evaluation of the electrostatic properties and durability thereof are shown in Table 1.

 Comparative Example 1

Except that trioctyl phosphate was not used in Example 1, an electrophotographic photosensitive member was manufactured in the same manner as in Example 1, and the evaluation results of the electrostatic properties and durability thereof are shown in Table 1.

 Comparative Example 2

An electrophotographic photosensitive member was manufactured in the same manner as in Example 1 except that the silicone oil was not used in Example 1, and the evaluation results of the electrostatic characteristics and durability thereof are shown in Table 1.

 Comparative Example 3

4 parts by weight of 4-dibenzylamino-2-methylbenzaldehydediphenylhydrazone, 1,1-bis- (para-diethylaminophenyl) -4,4-diphenyl-1,3 in the charge transport layer in Example 1 -An electrophotographic photosensitive member was manufactured in the same manner as in Example 1 except that 4 parts by weight of butadiene was used instead of 8 parts by weight of 4-dibenzylamino-2-methylbenzaldehydediphenylhydrazone. Is shown in Table 1.

 Comparative Example 4

4 parts by weight of 4-dibenzylamino-2-methylbenzaldehydediphenylhydrazone, 1,1-bis- (para-diethylaminophenyl) -4,4-diphenyl-1,3 in the charge transport layer in Example 1 Electrons in the same manner as in Example 1, except that 8 parts by weight of 1,1-bis- (para-diethylaminophenyl) -4,4-diphenyl-1,3-butadiene was used instead of 4 parts by weight of butadiene. Photosensitive photoreceptors were manufactured and the evaluation results of the electrostatic characteristics and durability thereof are shown in Table 1.

 Example 12

4 parts by weight of 4-dibenzylamino-2-methylbenzaldehydediphenylhydrazone, 1,1-bis- (para-diethylaminophenyl) -4,4-diphenyl-1,3 in the charge transport layer in Example 1 6 parts by weight of N, N'-bis- (3-methylphenyl) -N, N'-bis (phenyl) benzidine in place of 4 parts by weight of butadiene, and N, N, N ', N'-tetrakis (3- Except for using 2 parts by weight of methylphenyl) benzidine, an electrophotographic photosensitive member was manufactured in the same manner as in Example 1, and the evaluation results of the electrostatic properties and durability thereof are shown in Table 1.

 Example 13

4 parts by weight of 4-dibenzylamino-2-methylbenzaldehydediphenylhydrazone, 1,1-bis- (para-diethylaminophenyl) -4,4-diphenyl-1,3 in the charge transport layer in Example 1 7.6 parts by weight of N, N'-bis- (3-methylphenyl) -N, N'-bis (phenyl) benzidine in place of 4 parts by weight of butadiene, and N, N, N ', N'-tetrakis (3- Except for 0.4 parts by weight of methylphenyl) benzidine, an electrophotographic photosensitive member was manufactured in the same manner as in Example 1, and the results of evaluation of the electrostatic properties and durability thereof are shown in Table 1.

 Example 14

4 parts by weight of 4-dibenzylamino-2-methylbenzaldehydediphenylhydrazone, 1,1-bis- (para-diethylaminophenyl) -4,4-diphenyl-1,3 in the charge transport layer in Example 1 -6 parts by weight of N, N'-bis- (3-methylphenyl) -N, N'-bis (phenyl) benzidine in place of 4 parts by weight of butadiene, and

An electrophotographic photosensitive member was manufactured in the same manner as in Example 1, except that 2 parts by weight of N, N, N ', N'-tetrakis (4-methylphenyl) benzidine was used. Table 1 shows the evaluation results of the electrostatic characteristics and durability. Shown in

 Example 15

The electrophotographic photosensitive member was used in the same manner as in Example 1, except that Example 1 used an aluminum drum having a undercoat layer in which TiO ₂ was dispersed in a polyamide binder resin on the aluminum drum instead of the aluminum drum on which the surface was anodized. Was prepared and the evaluation results of the electrostatic characteristics and durability thereof are shown in Table 1.

 Example 16

Except that in Example 1, an aluminum drum having an undercoat layer in which anodized surface was aluminized on the aluminum drum instead of the aluminum drum on which the surface was anodized, and in which TiO ₂ was dispersed in a polyamide binder resin was used. An electrophotographic photosensitive member was manufactured in the same manner, and the evaluation results of the electrostatic characteristics and durability thereof are shown in Table 1.

 Comparative Example 5

4 parts by weight of 4-dibenzylamino-2-methylbenzaldehydediphenylhydra zone, 1,1-bis- (para-diethylaminophenyl) -4,4-diphenyl-1,3 in the charge transport layer in Example 1 An electrophotographic photosensitive member was prepared in the same manner as in Example 1, except that 8 parts by weight of N, N'-bis- (3-methylphenyl) -N, N'-bis (phenyl) benzidine was used instead of 4 parts by weight of butadiene. Table 1 shows the evaluation results of the electrostatic characteristics and durability thereof.

 Comparative Example 6

4 parts by weight of 4-dibenzylamino-2-methylbenzaldehydediphenylhydrazone, 1,1-bis- (para-diethylaminophenyl) -4,4-diphenyl-1,3 in the charge transport layer in Example 1 7.6 parts by weight of N, N'-bis- (3-methylphenyl) -N, N'-bis (phenyl) benzidine in place of 4 parts by weight of butadiene, N, N, N ', N'-tetrakis (3-methylphenyl Except that 0.4 parts by weight of benzidine and no silicone oil were used, an electrophotographic photosensitive member was manufactured in the same manner as in Example 1, and the evaluation results of the electrostatic properties and durability thereof are shown in Table 1.

 Electrostatic Characteristics: E _1/2   Photosensitive

The electrostatic characteristics (electrophotographic characteristics) of each electrophotographic photosensitive member obtained in the above Examples and Comparative Examples were measured in a drum photosensitive member evaluation device ("PDT-2000" manufactured by QEA Co., Ltd.) at 23 ° C. and humidity of 50%. Measured together.

The measurement conditions were corona voltage of -6.0 kV, charged at the relative speed of 100 mm / sec between the charger and the photoconductor, and irradiated with varying monochromatic light having a wavelength of 780 nm within the range of exposure energy of 0 to 1 μJ / cm 2. The value was recorded and the relationship of energy to surface potential measured. Here, the surface potential of when not irradiated with light with V ₀ (V), followed by the exposure energy at which the initial charging potential to be V _0/2 (V) in E _1/2 (μJ / ㎠).

 Adhesion Measurement

1 mm × 1 mm sized sheath was placed on the surface of the photosensitive drum having a size of 10 mm × 10 mm, and 3M magic tape was attached thereon, and the 1 mm × 1 mm size was peeled off when the magic tape was removed in the direction perpendicular to the length of the photosensitive drum. Based on the number of square photoreceptor surface pieces, the adhesion of the electrophotographic photoreceptor was evaluated as follows.

Good adhesion: Peel off 4 or less

Adhesion Normal: 5 to 10 peels

Poor adhesion: Peel off at least 11.

 Wear Resistance Measurement

After wearing the electrophotographic photosensitive member using a Taber Abrasion Tester (model name: CALIBRASE CS-10), the wear resistance was evaluated by measuring the reduced weight after 5000 seconds. The smaller the reduced weight, the better the wear resistance.

TABLE 1

division E _1/2 (μJ / ㎠) Adhesion Abrasion Resistance (g) Example 1 0.13 Good 0.0030 Example 2 0.13 Good 0.0022 Example 3 0.20 Good 0.0018 Example 4 0.21 Good 0.0012 Example 5 0.19 Good 0.0032 Example 6 0.19 Good 0.0021 Example 7 0.13 Good 0.0031 Example 8 0.13 Good 0.0028 Example 9 0.13 Good 0.0026 Example 10 0.13 Good 0.0028 Example 11 0.13 Good 0.0027 Example 12 0.12 Good 0.0028 Example 13 0.13 Good 0.0031 Example 14 0.12 Good 0.0029 Example 15 0.11 Good 0.0032 Example 16 0.11 Good 0.0030 Comparative Example 1 0.13 usually 0.0033 Comparative Example 2 0.13 usually 0.0036 Comparative Example 3 0.16 usually 0.0034 Comparative Example 4 0.11 usually 0.0037 Comparative Example 5 0.14 Good 0.0035 Comparative Example 6 0.14 Good 0.0036

Referring to Table 1, in the case of the electrostatic characteristic, the photosensitive members of Examples and Comparative Examples had low E _1/2 energy and thus had excellent photosensitivity. However, in the case of adhesive strength and wear resistance, all of these durability parameters were excellent in the examples according to the present invention, but in the case of the comparative example, it can be seen that these durability parameters were not excellent. In the electrophotographic photosensitive member of the embodiment according to the present invention, it is possible to maintain the electrostatic properties by the complex effect of the combination of the binder, hole transport material, phosphate-based compound and / or phosphine oxide-based compound, and silicone oil. The adhesion between the conductive support, the charge generating layer, and the charge transport layer and the film strength of the charge transport layer are increased, and the durability is enhanced to prevent the film peeling phenomenon even when the mechanical friction is severe.

As described above, the electrophotographic photosensitive member according to the present invention is excellent in adhesion and wear resistance while maintaining electrostatic properties. Therefore, when used in electrophotographic printers, facsimiles, copiers, and plotters, the electrophotographic photosensitive member has a small change in image over time even after long-term use, and has excellent electrophotographic performance without image defects or physical defects caused by wear of the electrophotographic photosensitive drum. An image forming apparatus can be provided.

While several embodiments of the present invention have been disclosed and described, those skilled in the art will understand that changes may be made to such embodiments without departing from the spirit and spirit of the invention. For example, in the present specification, an electrophotographic photosensitive member in which a charge transport layer is stacked on a charge generating layer has been described, but its layer structure may be reversed. Therefore, the scope of the present invention is defined by the following claims and their equivalents.

Claims (5)

Conductive support; A charge generating layer formed on the conductive support, the charge generating layer comprising oxo titanyl phthalocyanine, metal phthalocyanine or a mixture thereof dispersed or dissolved in a binder resin as a charge generating material; And As the charge transport layer formed on the charge generating layer, a combination of a butadiene-based amine compound and a hydrazone-based compound dispersed or dissolved in a binder resin as a charge transport material, or a combination of a first benzidine-based compound and a second benzidine-based compound may be used as the binder resin. An electrophotographic photosensitive member comprising a charge transport layer comprising 5 to 200 parts by weight based on 100 parts by weight. The binder resin of claim 1, wherein the binder resin of the charge transport layer comprises a polycarbonate resin derived from cyclohexylidene bisphenol, and the charge transport layer is 0.01 to 10 parts by weight based on 100 parts by weight of the binder resin of the charge transport layer. An electrophotographic photoconductor further comprising 0.01 to 1 part by weight of a silicone oil based on 100 parts by weight of the compound, a phosphine oxide compound or a mixture thereof and the binder resin of the charge transport layer. The weight mixing ratio of the combination of the butadiene-based amine compound of the charge transport material: the hydrazone-based compound is 100: 5 to 250, and the weight of the combination of the first benzidine-based compound and the second benzidine-based compound. The electrophotographic photosensitive member, wherein the mixing ratio is 100: 5 to 300. The compound of claim 1, wherein the first and second benzidine-based compounds are N, N'-bis- (3-methylphenyl) -N, N'-bis (phenyl) benzidine, N, N, N ', N'-tetra Kis (3-methylphenyl) benzidine, N, N, N ', N'-tetrakis (4-methylphenyl) benzidine, N, N'-di (naphthalen-1-yl) -N, N'-di (4- An electrophotographic photosensitive member, characterized in that it is two benzidine derivatives selected from the group consisting of methylphenyl) benzidine, and N, N'-di (naphthalen-2-yl) -N, N'-di (3-methylphenyl) benzidine. According to claim 2, wherein when the phosphate compound and the phosphine oxide compound is used together in the charge transport layer, the mixed weight ratio of phosphate compound: phosphine oxide compound is 100: 0.1 ~ 100 Photoreceptor.

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