KR100696075B1 - Coating Composition for Forming Charge Generation Layer of Electrophotographic Photoconductor - Google Patents

Abstract

The present invention relates to a coating liquid composition for generating charge of an electrophotographic photosensitive member.

The present invention provides a coating liquid composition for forming a charge generating layer of an electrophotographic photosensitive member including a charge generating material, a binder resin, a solvent, and an additive, wherein the solvent is mixed with tetrahydrofuran and methanol. A coating liquid composition for forming a charge generating layer of an electrophotographic photosensitive member is provided.

According to the present invention, dispersion stability is maintained due to no sedimentation or liquid separation even when stored for a long time in the state of the charge generating coating liquid for forming the electrophotographic photosensitive member, and the sensitivity and sensitivity when manufacturing the electrophotographic photosensitive member using the coating liquid Not only is stability improved, but also excellent electrical characteristics such as electrostatic characteristics and dislocation characteristics can provide excellent image quality.

Electrophotographic photosensitive member, charge generating material, methanol, tetrahydrofuran

Description

Coating composition for charge generation of electrophotographic photosensitive member {Coating Composition for Forming Charge Generation Layer of Electrophotographic Photoconductor}

1 is a cross-sectional view of an electrophotographic photosensitive member according to a preferred embodiment of the present invention;

2 is an X-ray diffraction spectrum of Y-type oxo titanyl phthalocyanine used in a preferred embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

110: conductor support layer 112: charge generating layer

114: charge transport layer

The present invention relates to a coating liquid composition for generating charge of an electrophotographic photosensitive member. More specifically, the present invention relates to a coating solution composition for charge generation of an electrophotographic photosensitive member using a charge generating material as a mixture of solvent tetrahydrofuran and methanol to enhance dispersion stability and to prevent precipitation and separation of solids even during long-term storage. .

Carlson's electrophotographic method described in US Pat. No. 2,297,691 is widely applied to copiers, printers, and facsimile machines. In particular, electrophotographic lasers using semiconductor lasers or LEDs suitable as digital light sources for high-speed and high-speed information processing. Widely applied to printers or digital copiers. Accordingly, there is a growing demand for an organic photoconductor (OPC) suitable for signal processing and an electrophotographic photoconductor that responds with high sensitivity to semiconductor lasers or LEDs and has sufficient sensitivity to highly reliable long wavelength light.

Electrophotographic photosensitive members generally include a charge generation layer and a charge transport layer formed on a conductor support layer, and sometimes an insulating layer between the conductor support layer and the charge generation layer. Or a protective layer on the charge transport layer. The photosensitive layer is a charge generating layer that functions to generate carriers when light is irradiated with a thin film, and a relatively thick film thereon that transfers carriers generated from the charge generating layer to the drum surface and supports the charging potential of the photosensitive member. And a charge transport layer that functions to maintain physical strength. The charge generating layer is formed by coating a charge generating material of an inorganic pigment or an organic pigment and a binder resin together or applying a vacuum deposition method, and the charge transport layer is formed by applying a charge transfer material and a binder resin together on the charge generating layer. The structure of these layers may be used when there is only a charge generating layer and a charge transporting layer, the case where the charge generating layer and the charge transporting layer are composed of one layer, and a charge generating layer is applied on the charge transporting layer.

At this time, the charge generating material used in the formation of the charge generating layer is an important material for generating carriers and an afterimage of data by optical signals, such as zinc oxide (ZnO), cadmium sulfide (CdS), and amorphous silicon (a-Si). Inorganic compounds, such as these, and an organic compound using organic pigments, such as an azo (Azo) system, a bis azo system, an indigo system, a perylene system, and a phthalocyanine system, are distinguished. In recent years, charge generation materials of inorganic compounds have tended to be refrained from use because they have disadvantages such as environmental pollution, human hazards, and processing difficulty, whereas the electrostatic properties of photosensitive drums can be easily changed and manufactured. Accordingly, organic charge generating materials using organic pigments, which have an advantage of manufacturing drums with various characteristics, have been in the spotlight.

Among the organic charge generating materials described above, phthalocyanine-based compounds having high sensitivity are attracting attention in the long wavelength region, which is the oscillation wavelength region of a semiconductor laser, and these phthalocyanine-based compounds are chemically and physically so that they are widely used as blue pigments such as inks and paints. Because of its stability, extensive studies have been made on using it as a charge generating material of an electrophotographic photosensitive member.

In general, phthalocyanine compounds have different compounds depending on the type of the central metal atom of the phthalocyanine molecular structure, and even though they have the same central metal atom, UV-visible absorption spectrum or electrical characteristics are different according to the crystal form or particle size. The characteristics as the charge generating material for electrophotography also vary.

Phthalocyanine compounds include copper phthalocyanine, metal-free phthalocyanine, chloro aluminum phthalocyanine, chloro indium phthalocyanine, chloro gallium phthalocyanine, chloro germanium phthalocyanine, oxovanadyl phthalocyanine, oxotinanyl phthalocyanine, hydroxy gelatinin and hydroxy gelatinin, depending on the type of the central metal atom. Roxygallium phthalocyanine and the like are known.

The above-mentioned phthalocyanine compounds are each classified by various crystalline forms. Specifically, the copper phthalocyanine has an ε-type crystalline form, and as the metal-free phthalocyanine, the X-type crystalline form of U.S. Patent No. 3,357,989, and the τ form of Japanese Patent Publication No. Crystalline form, τ′-form crystalline form of Japanese Patent Application Laid-Open No. 60-87,332, high-purity X-type crystalline form with different crystal walls of Japanese Patent Laid-Open Publication No. 60-243,089, crystalline form of Japanese Patent Application Laid-open No. 62-47,054, and crystalline form of Japanese Patent Application Laid-open No. Hei 2-233,769 Examples of the oxo titanyl phthalocyanine include α-form crystalline form of Japanese Patent Application Laid-Open No. 61-239,248, V-form crystalline form of Japanese Patent Application Laid-open No. Hei 1-17,066, A-form crystal form of Japanese Patent Publication No. 62-67,094, and Japanese Patent Application Publication. Type C crystalline form of 63-364 and Japanese Patent Publication No. 63-366, 결정 crystal form of Japanese Patent Publication No. 61-23,9248, and Japanese Patent Publication No. 63-198,067 The like-type crystal form, and Japanese Patent Publication No. 1-123868 arc gave amorphous has been suggested as a charge generating material of the photoconductor for electrophotography.

On the other hand, simple mixtures or mixed crystal compositions of two or more phthalocyanine compounds may be used as the charge generating material for electrophotography. Japanese Patent Application Laid-Open No. 62-194,257 discloses an example in which a mixture of oxo titanyl phthalocyanine and a metal-free phthalocyanine is used as a charge generating substance, and Japanese Patent Laid-Open No. 2-270,2067 discloses an oxo titanyl phthalocyanine and a metal-free phthalocyanine. The X-type metal-free phthalocyanine-based mixed crystal composition of the present invention is a mixed composition of oxo titanyl phthalocyanine and oxovanadil phthalocyanine in Japanese Patent Application Laid-Open No. 5-2,278, and gallium phthalocyanine halide in Japanese Patent Laid-Open No. 6-234,937. A mixed crystal composition of metal-free phthalocyanine, and Japanese Patent Application Laid-open No. Hei 8-176,455 propose a phthalocyanine composition containing oxo titanyl phthalocyanine and a halogenated metal phthalocyanine having a trivalent metal. In addition, Japanese Patent Laid-Open No. 2000-212,462 and Japanese Patent Laid-Open No. 60-95,441 propose a hybrid composition of a phthalocyanine compound and a phthalocyanine derivative.

BACKGROUND OF THE INVENTION Electrophotographic printers, copiers, and facsimiles are becoming faster, smaller, and less energy consumptive as technology advances in print media. Therefore, high sensitivity of the photosensitive member is essential. Although the sensitivity of the Y-type oxo titanyl phthalocyanine is known to be the fastest among the known organic charge generating materials, the crystal form of the Y-type oxo titanyl phthalocyanine is not stable due to the unstable structure, so that charge generation for producing an electrophotographic photosensitive member is possible. After preparing the coating liquid, there is a problem that the sensitivity is not maintained for a long time without maintaining the crystalline form in the coating liquid state, and there is a problem in that the precipitation phenomenon easily separates the solid content and the solvent because of the lack of dispersion stability.

In order to solve the above problems, an object of the present invention is not only to maintain high sensitivity when manufacturing an electrophotographic photoconductor, but also to generate dispersion stability during long-term storage in a coating liquid state for preparing a photoconductor, a binder resin, The present invention provides a coating liquid composition for forming a charge generating layer of an electrophotographic photosensitive member, comprising a solvent and an additive and mixing tetrahydrofuran and methanol as a solvent.

It is another object of the present invention to provide an electrophotographic photosensitive member having improved electrical properties such as electrostatic and dislocation characteristics by improving sensitivity and stability by using the above-described coating liquid composition.

In order to achieve the above object, in the coating liquid composition for forming a charge generating layer of an electrophotographic photosensitive member comprising a charge generating material, a binder resin, a solvent and an additive according to the present invention, tetrahydrofuran as the solvent And a coating liquid composition for forming a charge generating layer of an electrophotographic photosensitive member, characterized in that a mixture of methanol is used.

The coating solution for the charge generating layer of the present invention is composed of a charge generating material, a binder resin, a solvent, and an additive, and may be used alone or in combination of two or more.

In the present invention, Y-type oxo titanyl phthalocyanine is used as the charge generating material. As the binder resin, vinyl acetate, vinylpyrrolidine, acrylic, polyurethane, polycarbonate, polyester, polyamide, epoxy, polyvinyl butyral, polyvinyl acetal, phenoxy resin, silicone resin, vinyl chloride resin, vinyl chloride It may be used without limitation, such as, but not limited to, such as a lithium resin, a formal resin, a cellulose resin or a copolymer thereof, or a halide, a cyanoethyl compound, or the like thereof.

As a solvent, tetrahydrofuran and methanol are mixed and used as mentioned above, but methanol is added as a main solvent. At this time, 0.01 to 5% by weight methanol may be added based on the weight of tetrahydrofuran. Preferably the weight ratio of methanol is 0.1 to 3% by weight based on the weight of tetrahydrofuran. Tetrahydrofuran may also be used as a main solvent by mixing water with methanol. In this case, the weight ratio of water is 0.5% by weight or less based on the weight of tetrahydrofuran, preferably 0.05 to 0.5% by weight. At this time, the mixing ratio of water and methanol is 1:25 to 1: 3 and preferably 1:20 to 1: 5. As described above, by using tetrahydrofuran and methanol as a solvent, dispersion stability and storage property of the coating liquid composition for charge generating layer can be improved.

When using an additive, it is preferable to use a dispersing agent, an antifoamer, surfactant, etc.

The electrophotographic photosensitive member of the present invention is manufactured by the following method.

1 is a cross-sectional view of an electrophotographic photosensitive member according to a preferred embodiment of the present invention. The electrophotographic photosensitive member according to the preferred embodiment of the present invention is formed by sequentially stacking the charge generation layer 112 and the charge transport layer 114 on the conductor support layer 110.

First, as a support of the conductor support layer 110, a metal, such as aluminum, an aluminum alloy, nickel or stainless steel, or a material formed by conducting a conductive treatment on glass or a resin film or the like in a plate shape, a cylindrical shape, or a film shape may be used. Can be.

The structure which forms an insulating layer on the surface of the support body of these conductor support layers 110 is also possible. In this case, the insulating layer is formed on the surface of the support of the conductor support layer 110 to have uniformity and good adhesion. This insulating layer is formed by forming an oxide film layer or a resin film layer on a metal surface. As the material of the resin coating layer, insulating polymers such as casein, polyvinyl alcohol, polyamide, polyimide, melamine, cellulose, or conductive polymers such as polythiophene, polypyrrole and polyaniline, or metal oxide powders are added to these polymers. Is used.

The coating solution for the charge generating layer of the present invention is coated on the aforementioned conductor support layer, and then dried at a high temperature for a predetermined time to form the charge generating layer 112. In coating, conventional coating apparatuses such as a dip coater, spray coater, wire bar coater, applicator, doctor blade, roller coater, bead coater and the like can be used.

Next, the charge transport layer 114 is laminated on the above-described charge generating layer 112. The charge transport layer 114 is formed by applying a coating liquid composition for a charge transport layer composed of a charge transport material, a binder resin, an organic solvent, and an additive on the charge generating layer 112, and then drying at a high temperature for a predetermined time.

The charge transport material serves to transfer charges generated in the charge generating layer 112 to the drum surface. Specifically, 1,1-bis- (para-diethylaminophenyl) -4,4-diphenyl-1 , 3-butadiene, N, N'-bis (olso, para-dimethylphenyl) -N, N'-diphenylbenzidine, 3,3'-dimethyl-N, N, N'N'-tetrakis-4- Methylphenyl- (1,1'-biphenyl) -4,4'-diamine, N-ethyl-3-carbozolylaldehyde-N, N'-diphenylhydrazone, 4- (N, N-bis (para- Toluyl) amino) -betaphenylstilbene, N, N, N ', N'-tetrakis (3-methylphenyl) -1,3-diaminobenzene, N, N-diethylaminobenzaldehydediphenyl-hydrazone , N, N-dimethylaminobenzaldehydediphenyl-hydrazone, 4-dibenzylamino-2-methylbenzaldehydediphenylhydrazone, 2,5-bis (4-aminophenyl)-[1,3,4] oxadia Sol, (2-phenylbenzo [5,6-b] -4H-thiopyran-4-ylidene) -propanedinitrile-1,1-dioxide, 4-bromo-triphenylamine, 4,4'- (1,2-ethanediylidene) -bis (2,6 -Dimethyl-2,5-cyclohexadien-1-one), 3,4,5-triphenyl-1,2,4-triazole, 2- (4-methylphenyl) -6-phenyl-4H-thiopyran 4-ylidene-propanedinitrile-1,1-dioxide, 4-dimethylamino-benzaldehyde-N, N-diphenylhydrazone, 9-ethylcarbazole-3-aldehyde-N-methyl-N-phenylhydra Zone, 5- (2-chlorophenyl) 3- [2- (2-chlorophenyl) ethenyl "-1-phenyl-4,5-dihydro-1H-pyrazole, 4-diethylamino-benzaldehyde-N , N-diphenylhydrazone, N-biphenylyl-N-phenyl-N- (3-methylphenyl) amine, 9-ethylcarbazole-3-aldehyde-N, N-diphenylhydrazone, 3,5- Bis (4-tert-butylphenyl) -4-phenyl triazole, 3- (4-biphenylyl) -4-phenyl-5-tert-butylphenyl-1,2,4-triazole, 4-diphenyl Amino-benzaldehyde-N, N-diphenylhydrazone, 5- (4-diethylaminophenyl) -3- [2- (4-diethylaminophenyl) -ethenyl] -1-phenyl-4,5- Dihydro-1H-pyrazole, N, N'-di (4-methylphenyl) -N, N'-diphenyl-1,4-phenylenediamine, 4-dibenzylaminobenzaldehyde-N, N-diphenylhydrazone, 4-dibenzylamino-3-methylbenzaldehyde-N, N-diphenylhydrazone, 4,4'-bis (carbazol-9-yl) biphenyl, N, N, N ' , N'-tetraphenylbenzidine, N, N'-bis (4-methylphenyl) -N, N'-bis (phenyl) -benzidine, N, N'-bis (3-methylphenyl) -N, N'-bis (Phenyl) benzidine, N, N, N ', N'-tetrakis (4-methylphenyl) benzidine, N, N, N', N'-tetrakis (3-methylphenyl) benzidine, di (4-dibenzylamino Phenyl) ether, N, N'-di (naphthalen-2-yl) -N, N'-diphenylbenzidine, N, N'-di (naphthalen-1-yl) -N, N'-diphenylbenzidine, 1,3-bis (4 (4-diphenylamino) phenyl-1,3,4-oxadiazol-2-yl) benzene, N, N'-di (naphthalen-2-yl) -N, N ' -Di (3-methylphenyl) benzidine, N, N'-di (naphthalen-1-yl) -N, N'-di (4-methylphenyl) benzidine, N, N'-di (naphthalen-2-yl) -N, N'-di (3-methylphenyl) benzidine, 1,1-bis (4-bis (4-methylphenyl) aminophenyl) cyclohexane, 4,4 ', 4 "-tris (carbazol-9-yl ) -Triphenylamine, 4,4 ', 4 "-tris (N, N-diphenylamino) -triphenylamine, N, N'-bis (biphenyl-1-yl) -N, N'-bis (naphth-1-yl) benzidine, 4,4 ', 4 "-tris (N-3-methylphenyl-N-phenyl Amino) triphenylamine, N, N, N ', N'-tetrakis (biphenyl-4-yl) benzidine, 4,4', 4 "-tris (N- (1-naphthyl) -N-phenyl Amino) triphenylamine, 4,4 ', 4 "-tris (N- (2-naphthyl) -N-phenylamino) triphenylamine, 4,4'4" -bis (4,4-diphenyl- 1,3-butadienyl) triphenylamine, 4,4'4 "-tris (4,4-diphenyl-1,3-butadienyl) triphenylamine, 4,4'4" -bis (4 , 4-di (4-methoxyphenyl) -1,3-butadienyl) triphenylamine, 4,4'4 "-tris (4,4-di (4-methoxyphenyl) -1,3- Butadienyl) trifenylamine, 4,4'4 "-bis (4,4-di (3-methoxyphenyl) -1,3-butadienyl) triphenylamine, 4,4'4"- Tris (4,4-di (3-methoxyphenyl) -1,3-butadienyl) triphenylamine, 4,4'4 "-bis (4,4-di (2-methoxyphenyl) -1 , 3-butadienyl) triphenylamine, 4,4'4 "-tris (4,4-di (2-methoxyphenyl) -1,3-butadienyl) triphenylamine, N, N'- Bis (3-methylphenyl ) -N, N'-bis (2-naphthalene)-[1,1'-biphenyl] -4,4'-diamine etc. can be used individually or in mixture of 2 or more types.

As the binder resin, polyvinyl butyl al resin, polyvinyl alcohol resin, polyamide resin, polyvinylacetate resin, polyvinyl chloride resin, polyacrylic resin, polyurethane resin, polycarbonate resin, polymethacryl resin, polyvinylidene Chloride resin, polystyrene resin, styrene-butadiene copolymer resin, styrene-methyl methacrylate resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinylacetate-maleic anhydride Copolymer resin, ethylene-acrylic acid copolymer resin, ethylene-vinylacetate copolymer resin, methyl cellulose, nitrocellulose, polysilicon resin, silicone-alkyd resin, phenol-formaldehyde resin, cresol-formaldehyde resin, styrene-alkyd resin, Poly-N-vinylcarbazole resin, poly Nilformal resin, polyhydroxystyrene resin, polynorbornyl resin, polycycloolefin resin, polyvinylpyrrolidone resin, poly (2-ethyl-oxazoline) resin, melamine resin, urea resin, amino resin, isocyanate resin And epoxy resins can be used alone or in combination of two or more thereof.

Organic solvents usable in the present invention include methyl isopropyl ketone, methyl isobutyl ketone, 4-methoxy-4-methyl-2-pentanone, isopropyl acetate, isobutyl acetate, tertiary butyl acetate, isopropyl Alcohol, isobutyl alcohol, acetone, methyl ethyl ketone, cyclohexanone, 1,2-dichloroethane, 1,2-dichloropropane, 1,1,2-trichloroethane, 1,1,1-trichloroethane, Trichloroethylene, tetrachloroethane, dichloromethane, tetrahydrofuran, dioxane, methanol, ethanol, 1-propanol, 1-butanol, 2-butanol, 1-methoxy-2-propanol, ethyl acetate, butyl acetate, dimethyl Sulfoxide, methyl cellosolve, butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, triethylenediamine, N, N'-dimethylformamide, benzene, toluene, xylene, methylbenzene, ethylbenzene, cyclohexane Back alone or 2 Or more may be mixed.

The additive may include an antioxidant, an antifoaming agent, and the like.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments. In the description of the present invention, when the detailed description of the related well-known technology is obvious to those skilled in the art or it may be determined that the subject matter of the present invention may be obscured, the detailed description thereof will be omitted.

[Production example]

Preparation Example 1

1.0 weight part of Y type oxo titanyl phthalocyanine (ST10 / 10.2: Syntec Corporation make), 1.0 weight part of polyvinyl butyral resins (XYHL: UCC make), 18.0 weight part of tetrahydrofuran solvents, and 1.98 weight part of zirconia balls ( 1 mm? (Manufactured by Toray Corporation) for 24 hours using a ball mill to prepare a dispersion. This dispersion was diluted with 180 parts by weight of tetrahydrofuran solvent and injected for 30 minutes by ultrasound to prepare a stable coating solution.

Preparation Example 2

Preparation of Coating Liquid for Charge Generation Layer A coating liquid was prepared in the same manner as in Preparation Example 1, except that methanol in Example 1 was changed from 1.98 parts by weight to 0.198 parts by weight.

Preparation Example 3

Preparation of Coating Liquid for Charge Generation Layer A coating liquid was prepared in the same manner as in Preparation Example 1, except that methanol in Example 1 was changed from 1.98 parts by weight to 5.94 parts by weight.

Preparation Example 4

Preparation of the coating solution for charge generation layer The same as in Production Example 1 except that the Y-type oxo titanyl phthalocyanine (ST10 / 10.2: manufactured by Syntec Co., Ltd.) was changed to Y-type oxo titanyl phthalocyanine (TIPC-500 (manufactured by Japan Corporation)). To prepare a coating solution.

Preparation Example 5

1.0 part by weight of Y-type oxo titanyl phthalocyanine (ST10 / 10.2 manufactured by Syntec), 1.0 part by weight of polyvinyl butyral resin (BX-1: manufactured by Integra Chemical Co., Ltd.), 18.0 parts by weight of tetrahydrofuran solvent, 1.98 parts by weight of methanol, and A dispersion was prepared by milling for 24 hours using a ball mill with 0.099 parts by weight of ion-exchanged water together with a zirconia ball (1 mm? Manufactured by Toray Corporation). This dispersion was diluted with 180 parts by weight of tetrahydrofuran solvent and injected for 30 minutes by ultrasound to prepare a stable coating solution.

Preparation Example 6

Preparation of Coating Solution for Charge Generation Layer A coating solution was prepared in the same manner as in Preparation Example 5, except that methanol in Example 5 was changed from 1.98 parts by weight to 4.95 parts by weight and ion exchanged water was changed from 0.099 parts by weight to 0.99 parts by weight.

compare Production Example  One

1.0 weight part of Y type oxo titanyl phthalocyanine (ST10 / 10.2: the Syntec company make), 1.0 weight part of polyvinyl butyral resin (XYHL: UCC make), 18.0 weight part of tetrahydrofuran solvent, a zirconia ball (1mm To 24 hours using a ball mill to prepare a dispersion. This dispersion was diluted with 180 parts by weight of tetrahydrofuran solvent and injected for 30 minutes by ultrasound to prepare a stable coating solution.

Comparative Production Example 2

Preparation of Coating Liquid for Charge Generation Layer A coating liquid was prepared in the same manner as in Preparation Example 1, except that methanol in Example 1 was changed from 1.98 parts by weight to 7.92 parts by weight.

Comparative Production Example 3

A coating solution was prepared in the same manner as in Comparative Preparation Example 1 except that 0.99 parts by weight of ion-exchanged water was added to Comparative Preparation Example 1 of the coating solution for the charge generating layer.

Comparative Production Example 4

A coating solution was prepared in the same manner as in Preparation Example 3, except that 1.12 parts by weight of ion-exchanged water was added to Preparation Example 3 of the coating solution for charge generating layer.

EXAMPLE

Example 1

After primary processing on the conductive cylindrical support (24 mmФ), the coating liquid for charge generation layer prepared in Preparation Example 1 was uniformly coated with 0.3 µm by using a dip coating method on an aluminite-treated aluminum drum at 120 ° C. Hot air drying was performed for 30 minutes to form a charge generating layer. Then, N, N'-bis (3-methylphenyl) -N, N'-bis (2-naphthalene)-[1,1'-biphenyl] -4,4'-diamine (DPND: manufactured by Hitachi Chemical Co., Ltd.) ) 8.4 parts by weight, polycarbonate resin (PCX-500: manufactured by Mitsubishi Gas Kagaku Co., Ltd.), 11 parts by weight, 55.7 parts by weight of tetrahydrofuran, and 24 parts by weight of toluene were completely dissolved together, followed by a dip coating method on the charge generation layer. It was coated with, and hot air dried at 120 ° C. for 30 minutes to obtain a photosensitive member having a thickness of 16.5 μm. The prepared photosensitive drum was corona charged with -6 KV to -7 KV with an electrostatic checker tester to charge the potential of the drum surface to about -800 V, and then the light of 780 nm wavelength was injected into the drum to halve the charge potential. The energy E1 / 2 per unit area was measured, and the potential Vr was measured after erasing the potential of the drum surface with a red LED light source. And the dark attenuation DD1 and DD5 which hold | maintain the electric potential after 1 second and 5 second in the dark after the charging were measured, respectively.

Afterwards, the black potential, 300 dpi, and 600 dpi were measured using a self-made JIG using a Samsung printer (ML-1210), and again, the black density and 600 were measured using a Samsung printer (ML-1210). The dpi concentration was measured with a densitometer (manufactured by Macbeth Co., Ltd.).

Example 2

In the formation of the charge generating layer, Example 1 was coated and evaluated in the same manner as in Example 1 except that the charge generating layer coating solution of Preparation Example 2 was used instead of the charge generating layer coating solution of Preparation Example 1.

Example 3

In the formation of the charge generating layer, Example 1 was coated and evaluated in the same manner as in Example 1 except that the charge generating layer coating solution of Preparation Example 3 was used instead of the charge generating layer coating solution of Preparation Example 1.

Example 4

In the formation of the charge generating layer, Example 1 was coated and evaluated in the same manner as in Example 1 except that the charge generating layer coating solution of Preparation Example 4 was used instead of the charge generating layer coating solution of Preparation Example 1.

Example 5

In the formation of the charge generating layer, Example 1 was coated and evaluated in the same manner as in Example 1 except that the charge generating layer coating solution of Preparation Example 5 was used instead of the charge generating layer coating solution of Preparation Example 1.

Example 6

In the formation of the charge generating layer, Example 1 was coated and evaluated in the same manner as in Example 1 except that the charge generating layer coating solution of Preparation Example 6 was used instead of the charge generating layer coating solution of Preparation Example 1.

Comparative Example 1

After primary processing on the conductive cylindrical support (24 mmФ), the charge generating coating solution prepared in Comparative Preparation Example 1 was uniformly coated with 0.3 µm using a dip coating method on an aluminite-treated aluminum drum at 120 ° C. Hot air drying was performed for 30 minutes to form a charge generating layer. Then, N, N'-bis (3-methylphenyl) -N, N'-bis (2-naphthalene)-[1,1'-biphenyl] -4,4'-diamine (DPND: manufactured by Hitachi Chemical Co., Ltd.) ) 8.4 parts by weight, polycarbonate resin (PCX-500: manufactured by Mitsubishi Gas Kagaku Co., Ltd.), 11 parts by weight, 55.7 parts by weight of tetrahydrofuran, and 24 parts by weight of toluene were completely dissolved together, followed by a dip coating method on the charge generation layer. It was coated with, and hot air dried at 120 ° C. for 30 minutes to obtain a photosensitive member having a thickness of 16.5 μm. The prepared photosensitive drum was corona charged with -6 KV to -7 KV with an electrostatic checker tester to charge the potential of the drum surface to about -800 V, and then the light of 780 nm wavelength was injected into the drum to halve the charge potential. The energy E1 / 2 per unit area was measured, and the potential Vr was measured after erasing the potential of the drum surface with a red LED light source. And the dark attenuation DD1 and DD5 which hold | maintain the electric potential after 1 second and 5 second in the dark after the charging were measured, respectively.

Afterwards, the black potential and 600 dpi potential were measured using a JIG manufactured by Samsung Electronics (ML-1210), and the black density and 600 dpi concentration were measured again using a Samsung printer (ML-1210). Each was measured with an image density meter (model name: RD918, manufactured by Macbeth).

Comparative Example 2

In the formation of the charge generating layer, Comparative Example 1 was coated and evaluated in the same manner as in Comparative Example 1 except that the charge generating layer coating solution of Comparative Preparation Example 2 was used instead of the charge generating layer coating solution of Comparative Preparation Example 1.

Comparative Example 3

In the formation of the charge generating layer, Comparative Example 1 was coated and evaluated in the same manner as in Comparative Example 1 except that the charge generating layer coating solution of Comparative Preparation Example 3 was used instead of the charge generating layer coating solution of Comparative Preparation Example 1.

Comparative Example 4

In the formation of the charge generating layer, Comparative Example 1 was coated and evaluated in the same manner as in Comparative Example 1 except that the charge generating layer coating solution of Comparative Preparation Example 4 was used instead of the charge generating layer coating solution of Comparative Preparation Example 1.

Evaluation by coating liquid storage period

The coating solution prepared in Preparation Examples 1 to 6 and Comparative Examples 1 to 4 were placed in a 50 ml vial bottle, sealed, and stored immediately in the unstirred state for one month and three months after the preparation, and then the coating solution dispersion stability was evaluated. For particle measurement, particles were measured using a particle size and a ZETA potential measuring device (ELS-8000: Otsuka Electronics). In addition, the solutions prepared in Preparation Examples 1 to 6 and Comparative Examples 1 to 4 were placed in a 50 ml vial bottle, sealed, and stored in an unstirred state for one month and three months after preparation, and then Examples 1 to 6 and Comparative Examples. The electrostatic, potential and image characteristics were evaluated in the same manner as in 1 to 4.

TABLE 1

Coating Dispersion Stability Results

  division Methanol weight ratio to tetrahydrofuran (% by weight)   Water: Methanol Mixing Ratio Weight ratio of water to tetrahydrofuran (% by weight)   Particle Size (nm)  Liquid dispersion stability Immediately after liquid 1 month after manufacture 3 months after manufacture Preparation Example 1 One - - 280 ○ ○ ○ Preparation Example 2 0.1 - - 290 ○ ○ ○ Preparation Example 3 3 - - 320 ○ ○ ○ Preparation Example 4 One - - 300 ○ ○ ○ Preparation Example 5 One 1:20 0.05 360 ○ ○ ○ Preparation Example 6 2.5 1: 5 0.5 400 ○ ○ ○ Comparative Production Example 1 - - - 330 ○ ○ △ Comparative Production Example 2 4 - - 280 ○ △ × Comparative Production Example 3 - - 0.5 550 ○ × × Comparative Production Example 4 3 1: 5 0.6 650 ○ × ×

※ liquid dispersion stability degree

○: little precipitation or liquid separation

△: small amount of precipitation or liquid separation

X: A large amount of precipitation or severe liquid separation

TABLE 2

Immediately after coating liquid

delete

TABLE 3

[표 4] 1 month after coating liquid

TABLE 4

delete

delete

이상의 설명은 본 발명의 기술 사상을 예시적으로 설명한 것에 불과한 것으로서, 본 발명이 속하는 기술분야에서 통상의 지식을 가지는 자라면 본 발명의 본질적인 특성에서 벗어나지 않는 범위에서 다양한 수정 및 변형이 가능할 것이다. 따라서, 본 발명에 개시된 실시예들은 본 발명의 기술사상을 한정하기 위한 것이 아니라 설명하기 위한 것에 불과하고, 이러한 실시예에 의하여 본 발명의 기술사상의 범위가 한정되는 것은 아니다. 본 발명의 보호범위는 아래의 청구범위에 의하여 해석되어야 하며, 그와 동등한 범위 내에 있는 모든 기술사상은 본 발명의 권리범위에 포함되는 것으로 해석되어야 할 것이다. 3 months after coating liquid

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

delete

delete

When the present invention is used, not only high sensitivity is maintained during the preparation of the electrophotographic photosensitive member, but even when stored for a long period of time in the state of a charge generating coating liquid for manufacturing the photosensitive member, no precipitation or liquid separation occurs and dispersion stability is maintained. In the manufacturing of the electrophotographic photosensitive member, not only the sensitivity and stability are improved, but also excellent electrical characteristics such as electrostatic characteristics and potential characteristics can provide excellent image quality.

Claims (7)

In the coating liquid composition for forming a charge generating layer of an electrophotographic photosensitive member comprising a charge generating material, a binder resin and a solvent, Tetrahydrofuran, water and methanol are used as the solvent, but the weight ratio of the water and the methanol is 1:20 to 1: 5 coating liquid composition for forming a charge generating layer of the electrophotographic photosensitive member. . delete delete delete The method of claim 1, The coating liquid composition for forming a charge generating layer of the electrophotographic photosensitive member, characterized in that the weight ratio of the water based on the weight of the tetrahydrofuran is 0.05 to 0.5% by weight. delete An electrophotographic photosensitive member comprising a charge generating layer prepared using the coating liquid composition of claim 1.

Images