JP2001356499A - Electrophotographic photoreceptor and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having electric performance and mechanical performance with excellent photosensitivity characteristics, electrification characteristics and stability for repeated use, good wear resistance and no image failure such as toner filming. SOLUTION: The binder resin 7 of a photosensitive layer 20, 21 containing a carrier generating material 2 and a carrier transfer material 4 consists of two or more kinds of resin, and at least one kind is polycarbonate resin expressed by formula (I) included by 50 wt.% in the resin. In the formula (I), each of R1 to R8 is hydrogen atom, a halogen atom, substituted or unsubstituted aliphatic group or substituted or unsubstituted carbon cyclic group, Z is a group of atoms necessary to form a substituted or unsubstituted carbon ring or substituted or unsubstituted heterocycle, and n is an integer from 10 to 1,000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member used for an electrophotographic apparatus such as a copying machine and a laser printer, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, inorganic materials such as Se, CdS, and ZnO have been used as a photoconductive material for an electrophotographic photoreceptor. Electrophotographic photoreceptors using organic photoconductive materials have been actively developed because of their excellent film-forming properties and wide selection of materials. An electrophotographic photoreceptor using an organic material has a single-layer type in which a carrier-generating substance and, if necessary, a carrier-transporting substance are dispersed in a binder resin, and a laminate in which a carrier-generating layer and a carrier-transporting layer are laminated to separate functions. Type electrophotographic photoreceptors.

The single-layer type photoreceptor has a structure in which a carrier-generating substance and a carrier-transporting substance are co-dispersed, and is easy to produce, low in cost, and used in a process in which ozone, which is a harmful substance, is hardly generated during use. Is possible,
For example, Japanese Patent Publication No. Sho 50-10496,
No. 5961 discloses an electrophotographic photoreceptor using a perylene pigment and a phthalocyanine pigment as a carrier generating pigment. In addition, the multilayer type occupies the mainstream of the organic electrophotographic photosensitive member in that the photosensitive layer can be easily designed, and high sensitivity and high stability can be obtained, and according to Japanese Patent Publication No. 55-42380. Many electrophotographic photoreceptors having a combination of a carrier generation layer containing a specific compound and a carrier transport layer have been filed.

However, the main problem of the organic photoreceptor currently put into practical use is durability, and in particular, the film is abraded during repeated use, and the charge potential decreases and remains due to electrical and chemical changes of the film. There is a problem that characteristic changes such as an increase in potential are likely to occur. In other words, these are latent image creation by charging and exposure, transfer of toner image to transfer paper,
During the image forming process in which the process of removing the toner remaining on the photoreceptor surface with a blade is repeated many times, the printing durability of the photosensitive layer is not sufficient, and light or ozone and nitrogen exposed during the image forming process The main factor is that the organic photoconductive compound in the film is denatured or decomposed by the oxide, and the practical durability is still limited at present.

[0005] The performance required of an electrophotographic photosensitive member in an image forming process is, for example, that when charged, the surface potential is high, the carrier retention is large, the photosensitivity is high, and the characteristics change under any environment. In addition, the film strength is high, the abrasion resistance in repeated use is excellent, the characteristic stability is high throughout the life, and furthermore, in order to improve production efficiency, physically and chemically, A more stable photoreceptor coating solution is required. It can be said that the role of the binder resin serving as the surface layer of the photoreceptor is very important for these requirements.

As a binder resin, a polycarbonate resin is a typical resin. However, a conventional polycarbonate resin has transparency, mechanical properties, compatibility with a carrier transporting substance and a carrier generating substance required for a photoreceptor, and the like. However, particularly when a polycarbonate resin having a high molecular weight is used, there is a problem that electric characteristics greatly fluctuate such as a decrease in surface potential and an increase in residual potential when repeatedly used. Further, when a binder resin having high crystallinity is used, there is a problem that the toner is hardly removed from the surface of the photoreceptor, and filming is easily generated.
Furthermore, when a binder resin other than a polycarbonate resin is used, although the charging characteristics, sensitivity, residual potential, and repetition characteristics are good, the photosensitive member is exposed to light by a contact member such as a cleaning blade, a magnetic brush, and a peeling mask in actual use. It has the disadvantage that the surface of the layer is scratched and the film is greatly scraped. To deal with these issues,
7300 and JP-A-7-199488 propose an improvement by using a specific polycarbonate resin for the carrier transport layer of the organic photoreceptor, but it is practically sufficient in terms of electric characteristics such as potential stability during repeated use. Performance has not yet been obtained.

[0007] From these facts, various binder resins for electrophotographic photoreceptors have been energetically studied for the purpose of further improving the resin material and improving the handling thereof. An effort has been made to obtain an electrophotographic photoreceptor having excellent electrophotographic properties and film strength by combining the above.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrophotographic photoreceptor having excellent photosensitivity, charging characteristics, stability in repeated use, good abrasion resistance, and excellent toner properties. An object of the present invention is to provide an electrophotographic photosensitive member having both practically sufficient electrical performance and mechanical performance without image defects such as filming, and a method of manufacturing the same.

[0009]

That is, the present invention provides a support and a photosensitive layer formed on the support and containing a carrier-generating substance, a carrier-transporting substance and a binder resin, wherein the binder resin is An electrophotographic photoreceptor comprising: a photosensitive layer containing two or more resins, at least one of which contains a polycarbonate resin represented by the following formula (I) in a resin weight ratio of less than 50%. is there.

[0010]

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[In the formula (I), R1 to R8 represent a hydrogen atom, a halogen atom, a substituted or unsubstituted aliphatic group or a substituted or unsubstituted carbocyclic group. Z is a group of atoms necessary to form a substituted or unsubstituted carbon ring or a substituted or unsubstituted heterocyclic ring, and n represents an integer of 10 to 1,000. ]

The present invention also provides a photosensitive layer comprising a support, a carrier generation layer formed on the support and containing a carrier generation material, and a carrier transport layer containing a carrier transport material and a binder resin. The binder resin of the carrier transport layer contains two or more resins, and at least one of them contains a photosensitive layer containing less than 50% by weight of a polycarbonate resin represented by the following formula (I). An electrophotographic photoreceptor characterized by including:

[0013]

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[In the formula (I), R1 to R8 represent a hydrogen atom, a halogen atom, a substituted or unsubstituted aliphatic group or a substituted or unsubstituted carbocyclic group. Z represents a group of atoms necessary to form a substituted or unsubstituted carbon ring or a substituted or unsubstituted heterocyclic ring, and n represents an integer of 10 to 1,000. ]

According to the present invention, as the binder resin used in the photosensitive layer of the electrophotographic photosensitive member, two or more kinds of resins are mixed and used, and the polycarbonate resin represented by the formula (I) is used in an amount of 50% by weight. By containing in a range of less than the conventional polycarbonate resin, the problem of a large variation in electrical characteristics, such as a decrease in surface potential during repeated use, a rise in residual potential, which is a problem of the conventional polycarbonate resin, is solved, and mechanical properties of the film are reduced. The characteristics of improvement in strength and prevention of toner filming can be satisfied at the same time.

When the polycarbonate resin represented by the formula (I) is contained in an amount of 50% or more, a decrease in surface potential and an increase in residual potential upon repeated use become remarkable, which greatly impairs practicality.

Further, according to the present invention, the polycarbonate resin represented by the above formula (I) has a viscosity average molecular weight of 20,000 to 4
The present invention provides an electrophotographic photoreceptor characterized by having a molecular weight of 0,000.

According to the present invention, the viscosity average molecular weight is 20,000
When using a polycarbonate of formula (I) of ~ 40,000,
In particular, excellent stability of the above electrical characteristics can be imparted.

Further, in the present invention, the binder resin is a group consisting of a polycarbonate resin represented by the formula (I), a polycarbonate resin other than the polycarbonate resin represented by the formula (I), a polyarylate resin and a polyester resin. An electrophotographic photoreceptor characterized by containing a resin selected from the group consisting of:

According to the present invention, particularly high mechanical strength can be provided by combining a polycarbonate resin different from the formula (I) as a constituent resin other than the polycarbonate resin represented by the formula (I), Further, by combining with a polyarylate resin or a polyester resin, high electrical characteristics can be stabilized.

Although the detailed reason why good characteristics can be obtained by incorporating a specific type and specific amount of a polycarbonate resin in the photosensitive layer in the present invention is not clear, the physical characteristics are represented by the formula (I). Polycarbonate resin is expected to have low crystallinity, and based on this property, the decrease in surface properties due to the crystalline resin on the surface of the coating film is reduced, and the dispersibility of low molecular compounds such as carrier transport materials is improved. It is considered that the printing durability was improved by the above, and the filming property caused by the adhesion of the toner to the surface defect was suppressed, thereby improving the cleaning property. Further, it is considered that the effect described above becomes more effective when the photosensitive layer contains two or more kinds of binder resins.

With respect to the electrical properties, the polycarbonate resin represented by the formula (I) is photo-electrically inactive, but is asymmetric with respect to the molecular chain, so that the polycarbonate resin is locally incompatible with the carrier transporting substance. In the case where the total resin content ratio in the photosensitive layer is 50% or more, the decrease in surface potential and the increase in residual potential during repetition become remarkably large. Is considered to be dominant, and it has become possible to achieve both physical properties and electrical properties of the photoreceptor surface layer.

Further, the present invention provides an electrophotographic photosensitive member, wherein the carrier generating substance is a titanyl phthalocyanine pigment.

According to the present invention, when a phthalocyanine-based compound, particularly a titanyl phthalocyanine compound, is used as a carrier-generating substance, particularly good sensitivity characteristics, charging characteristics and repetition characteristics can be obtained.

Further, the present invention provides an electrophotographic photoreceptor wherein the composition of the carrier transporting material and the binder resin in the carrier transporting layer is in a range of 10/10 to 10/28 by weight. I do.

According to the present invention, the composition ratio of the carrier transport material and the binder resin in the carrier transport layer is 10/1 by weight.
By setting it in the range of 0 to 10/28, the initial sensitivity and the printing durability can be kept good, and the increase in the residual potential upon repeated use can be suppressed. If the value is larger than 10/10, the initial sensitivity is good, but the printing durability is deteriorated.
When it is less than 8, the printing durability is good, but the initial sensitivity decreases and the residual potential increases after repeated use.

The present invention also relates to a step of forming a photosensitive layer by dissolving or dispersing a carrier transporting substance and a binder resin in a solvent to prepare a coating solution for the photosensitive layer. A step of dissolving a binder resin containing the polycarbonate resin in a range of less than 50% by weight in terms of a resin weight ratio in a solvent, and then dissolving or dispersing a carrier transport material. A manufacturing method is provided.

[0028]

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[In the formula (I), R1 to R8 represent a hydrogen atom, a halogen atom, a substituted or unsubstituted aliphatic group or a substituted or unsubstituted carbocyclic group. Z represents a group of atoms necessary to form a substituted or unsubstituted carbon ring or a substituted or unsubstituted heterocyclic ring, and n represents an integer of 10 to 1,000. ]

Further, the present invention provides a method for producing an electrophotographic photosensitive member, characterized in that in the step of forming the photosensitive layer, the coating solution for the photosensitive layer is applied onto a support by a dip coating method. .

According to the present invention, in which two or more kinds of binder resins are appropriately combined, it is possible to absorb the deviation of the molecular weight of each binder resin depending on the production lot, thereby facilitating the dip coating method excellent in mass productivity and improving the efficiency. Becomes possible. That is, by adjusting the viscosity and the solid content to the same value each time, a photoconductor excellent in coating film uniformity can be efficiently obtained, and an extremely high productivity and inexpensive photoconductor can be manufactured.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view showing a laminated photoreceptor according to an embodiment of the present invention. An undercoat layer 6, a carrier generating layer 3 mainly composed of a carrier generating substance 2, and a carrier transport are provided on a conductive support 1. This is provided with a photosensitive layer 21 composed of a laminate with a carrier transporting layer 5 containing a compound as substance 4. FIG. 2 is a cross-sectional view showing a single-layer type photoreceptor according to an embodiment of the present invention, in which a carrier generating substance 2 and a carrier transporting substance 4 are dispersed in a binder resin 7 (binder) on a conductive support 1. 20
Is provided. The photoreceptor shown in FIG. 1 has a carrier generating substance 2 on an undercoat layer 6 formed on a conductive support 1.
2 is prepared by applying a dispersion obtained by dispersing the particles in a solvent or a binder resin, and applying and drying a solution obtained by dissolving the carrier transport material 4 and the binder resin 7 thereon. Can be prepared by dispersing a carrier-generating substance 2 and a carrier-transporting substance 4 in a solution in which a binder resin is dissolved, applying the dispersion on the conductive support 1, and drying.

In the photoreceptor according to the embodiment shown in FIG. 1, the photosensitive layer 21 comprises the carrier generation layer 3 and the carrier transport layer 5
It is also formed by laminating. When the surface of the photoreceptor provided with such a photosensitive layer 21 is negatively charged by a charger or the like, and the carrier generation layer 3 is irradiated with light having an absorption wavelength, carriers of electrons and holes are generated in the carrier generation layer 3. . Among them, the holes are transferred to the photoreceptor surface by the carrier transporting substance contained in the carrier transporting layer 5 and neutralize the negative charge on the surface. On the other hand, the electrons in the carrier generation layer 3 move to the side of the conductive support 1 where the positive charges are induced, and function as a photoconductor by neutralizing the positive carriers.

The photosensitive member according to the embodiment shown in FIG.
The photosensitive layer 20 is a single-layer photosensitive member, and the formation of the photosensitive layer 20 is not substantially different from the case of the carrier generation layer 3 or the carrier transport layer 5 described above. That is, the carrier generating substance and the carrier transporting substance are dispersed / dissolved in a suitable solvent together with a binder resin, applied to the conductive support 1, dried or cured to form a film. When the surface of the photoconductor provided with the photosensitive layer 20 is positively charged and the carrier generating material 2 is irradiated with light having an absorption wavelength, carriers of electrons and holes are generated near the surface of the photosensitive layer. Among them, the electrons neutralize the positive charges on the surface, while the holes move to the side of the conductive support 1 where the negative charges are induced, and function as a photoreceptor by neutralizing the electrons. You.

The conductive support 1 serves as an electrode of the photoreceptor and serves as a support for the other layers, and may be cylindrical, plate-like, film-like, or belt-like. Examples of the conductive support that can be used include a metal material such as aluminum, stainless steel, copper, and nickel, or a polyester film provided with a conductive layer such as aluminum, copper, palladium, tin oxide, and indium oxide on the surface.
Insulating materials such as phenolic resin pipes and paper tubes. It is preferable that the conductive material has a volume resistance of 10 ¹⁰ Ωcm or less, and the surface may be oxidized for the purpose of adjusting the volume resistance.

The undercoat layer 6 is formed of, for example, polyamide, polyurethane, cellulose, nitrocellulose, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, anodized aluminum film, gelatin, starch, casein, N-methoxymethylated nylon, and the like. You. Further, titanium oxide, tin oxide, and aluminum oxide particles may be dispersed therein. The thickness of the undercoat layer 6 is about 0.1 to about 10 μm.
And a photosensitive layer 21. In addition, it also functions as a barrier layer for preventing carriers from flowing into the photosensitive layer 21 from the conductive support 1. In this manner, the undercoat layer 6 maintains the charging characteristics of the photoconductor, so that the life of the photoconductor itself can be extended.

The carrier generation layer 3 contains a known carrier generation substance. As the carrier-generating substance suitable for the present invention, any of inorganic pigments, organic pigments and organic dyes can be used as long as they absorb visible light to generate free carriers. As inorganic pigments,
Examples include selenium and its alloys, arsenic-selenium, cadmium sulfide, zinc oxide, amorphous silicon, and other inorganic photoconductors. Examples of the inorganic pigment include a phthalocyanine compound, an azo compound, a quinacridone compound, a polycyclic quinone compound, and a perylene compound. Examples of the organic dye include a thiapyrylium salt and a squarylium salt. Among them, preferred quinone-based generators in the present invention are phthalocyanine-based compounds,
It is particularly preferable to use a titanyl phthalocyanine compound. Particularly good sensitivity characteristics, charging characteristics and repetition characteristics are obtained.

In addition to these listed pigments and dyes, electron acceptors such as cyano compounds such as tetracyanoethylene, 7,7,8,8-tetracyanoquinodimethane, anthraquinone, p- Quinones such as benzoquinone, nitro compounds such as 2,4,7-trinitrofluorenone and 2,4,5,7-tetranitrofluorenone, or xanthene dyes and thiazine dye triphenylmethane dyes as optical sensitizers A dye such as a dye may be added to the carrier generation layer 3. In the present invention, the above-mentioned organic photoconductive compounds such as organic pigments and organic dyes are preferably used. The carrier generation layer 3 is formed by dispersing a carrier generation material together with a binder resin in an appropriate solvent, applying the dispersion to the conductive support 1, and drying or curing the film to form a film. The thickness of the carrier generation layer 3 is about 0.
05 to about 5 μm, preferably about 0.1 to about 1 μm. As a method for forming the carrier generation layer 3, generally, a vapor deposition method such as a vacuum evaporation method, a sputtering method, or a CVD method, or a method in which a carrier generation material is pulverized by a ball mill, a sand grinder, a paint shaker, an ultrasonic disperser, or the like, and dispersed in a solvent. If necessary, a binder resin is added, and if the conductive support 1 is a sheet, a baker applicator;
When the conductive support 1 is a drum, a method such as a bar coater, casting, or spin coating, which is applied by a spray method, a vertical ring method, a dip coating method, or the like, is known.

Specific examples of the binder resin used in the carrier generation layer of the present invention include polycarbonate, polyarylate, polyvinyl butyral, polyester,
Examples include resins such as polystyrene, polyvinyl chloride, phenoxy, epoxy, silicone, and polyacrylate. As the solvent used here, isopropyl alcohol, cyclohexanone, cyclohexane, toluene, xylene, acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, dioxolan, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, ethylene glycol dimethyl ether, etc. Is mentioned. Basically, it may be other than those mentioned here, and it may be an alcohol, ketone, amide, ester, ether, hydrocarbon, chlorinated hydrocarbon or aromatic solvent alone or blended. Good. However, taking into account, among other things, sensitivity reduction due to crystal transition at the time of milling and milling of the carrier-generating substance, and property deterioration due to pot life, cyclohexanone, 1,2 which hardly causes crystal transition in both pigments
-It is preferable to use any of dimethoxyethane, methyl ethyl ketone and tetrahydroquinone.

The carrier transport layer 5 contains a known carrier transport material. The carrier transporting material suitable for the present invention may be any organic photoconductive compound that can transport the carriers generated in the carrier generating layer 3. As the carrier transporting substance, hydrazone derivatives, pyrene derivatives, pyrene-formaldehyde condensates and derivatives thereof, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, stilbene derivatives, enamine derivatives, α-phenyl Stilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, anthracene derivatives, pyrazoline derivatives, indene derivatives, butadiene derivatives, polysilane compounds, polygermane compounds, and the like, but the carrier transport material is not limited to these. Absent. Hereinafter, specific examples of the carrier transporting material will be described.

[0042]

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[0043]

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[0044]

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[0045]

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[0046]

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[0047]

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[0048]

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[0049]

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[0050]

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[0051]

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[0052]

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[0053]

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[0054]

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Further, the carrier transporting layer 5 may contain an electron transporting substance. Specifically, as the electron transporting substance, 2,4,7-trinitro-9-fluorenone,
2,4,5,7-tetranitro-9-fluorenone,
Examples include, but are not limited to, 2,4,5,7-tetranitroxanthone, diphenyl derivatives, benzoquinone derivatives and the like.

Further, a stabilizer such as an antioxidant, a leveling agent, and a plasticizer can be added to the carrier transport layer 5 as needed.

As the antioxidant, an antioxidant generally used by being added to a resin or the like can be used as it is. For example, vitamin E, hydroquinone, hindered amine, hindered phenol, paraphenylenediamine, arylalkane and derivatives thereof, organic sulfur compounds, organic phosphorus compounds and the like may be used in combination.

As the leveling agent, silicone oils or polymers or oligomers having a perfluoroalkyl group in the side chain can be used.
0 to 1 part by weight to 0 parts by weight is appropriate.

The binder resin used in the carrier transport layer 5 is the same as the carrier generation layer. The binder resin used for the carrier transport layer 5 is characterized by being composed of two or more kinds of binder resins, and containing less than 50% of the polycarbonate resin represented by the formula (I) in total resin weight ratio. . As the polycarbonate resin represented by the formula (I), specifically, TS-2020, TS-2050 (both manufactured by Teijin Chemicals Ltd.), Z-200, Z-400 (both manufactured by Mitsubishi Gas Chemical Co., Ltd.) ).

The binder resin to be combined with the formula (I) is not substantially different from the binder resin used for the carrier generation layer 3, and includes, for example, polycarbonate, polyarylate, polyester, polyetherketone, epoxy, urethane, Examples include cellulose ethers and copolymers of monomers necessary for constituting these resins. Among these resins, stable electrical properties,
In consideration of the mechanical strength, the production cost of the photoconductor, and the like, the binder resin to be combined with the polycarbonate resin of the formula (I) is preferably a polycarbonate resin, a polyarylate resin, or a polyester resin other than the formula (I).

The polycarbonate resin of the formula (I) has a viscosity average molecular weight of 20,000 to 40,000 in view of electrical characteristics, repetition stability and printing durability of the photosensitive member.
00 is preferred. Viscosity average molecular weight of 20,0
If it is less than 00, the printing durability is significantly reduced, and
When the value is larger than 00, the initial sensitivity decreases and the residual potential increases during repeated use.

The amount of the binder resin is suitably 50 to 300 parts by weight, preferably 100 to 280 parts by weight, per 100 parts by weight of the carrier transporting substance. When the amount is less than 100 parts by weight, the sensitivity characteristics are good, but the charging characteristics and the mechanical strength of the film decrease.
Although the mechanical strength is good, the sensitivity characteristics are significantly reduced.

The thickness of the carrier transport layer 5 is about 10
To about 50 μm, preferably about 10 to about 35 μm.

Next, a suitable solvent for dissolving or dispersing the carrier transporting substance does not substantially differ from the solvent for dissolving or dispersing the carrier generating substance, and can be appropriately selected from the solvents listed for the carrier generating substance. A particularly preferred solvent is tetrahydrofuran.

The carrier transporting layer 5 is formed by dissolving or dispersing a carrier transporting substance together with a binder resin 7 in an appropriate solvent, coating the carrier transporting layer 3 on the conductive support 1 on which the carrier generating layer 3 is formed, and drying or curing. A film is formed. The coating solution for the carrier transport layer measures several or one carrier transport material, a binder resin and an additive,
A method of simultaneously dissolving in a predetermined amount of an organic solvent and producing the same is not problematic, but a method of first dissolving a binder resin in a solvent and then introducing and dissolving a carrier transport material is particularly preferable. According to this method, the molecular dispersibility of the carrier transporting substance in the binder resin is improved, and the potential and local crystallization of the carrier transporting substance in the film is suppressed. Potential stability during use, good image characteristics, and the like are imparted.

The carrier transport layer 5 can be formed by a baker applicator when the conductive support 1 is a sheet,
When the conductive support 1 is a drum, such as a bar coater, casting, or spin coating, a spray method, a vertical ring method, a dip coating method, or the like is used. In particular, dip coating is generally preferred from the viewpoint of productivity and cost.

The method for producing a photoreceptor of the present invention preferably includes a step of drying each layer such as the carrier generation layer 3.
The drying temperature of the photoreceptor is suitably from about 50C to about 130C, and particularly preferably from about 80C to about 130C. If the drying temperature of the photoreceptor is lower than about 80 ° C., the drying time is prolonged. If the drying temperature is higher than about 130 ° C., the electrical characteristics during repeated use deteriorate, and the image obtained using the photoreceptor also deteriorates. I do.

Hereinafter, embodiments of the present invention will be described in more detail with reference to Examples and Comparative Examples, but these do not limit the scope of the present invention. All parts are by weight unless otherwise indicated.

[0069]

【Example】

Example 1 (Single-layer type photoreceptor) Pigment dispersion liquid A was prepared by dispersing 10 parts by weight of titanyl phthalocyanine shown in compound (21) and 190 parts by weight of THF by a ball mill for 48 hours. At the same time, a compound Z-type polycarbonate resin represented by the formula (I) having a viscosity average molecular weight of 21,500 (Z2
00: 45 parts by weight, manufactured by Mitsubishi Gas Chemical Company, 55 parts by weight of a modified polycarbonate resin (B300: manufactured by Idemitsu Kosan Co., Ltd.), 80 parts by weight of the carrier transporting substance of compound (1), and 0.02 parts by weight of silicone oil to 467 parts by weight of THF. To prepare a resin solution B, and mixed and dispersed in a ball mill for 2 hours so that the weight ratio of the pigment dispersion A to the resin solution B was 1: 2 to prepare a photosensitive layer coating solution. The coating solution thus obtained was dip-coated on an aluminum cylindrical support having a diameter of 65 mm and a length of 335 mm, and dried at 120 ° C. for 1 hour to prepare a photoconductor sample having a film thickness image of 30 μm. The evaluation was performed using a commercial copying machine (AR-5) modified for positive charging.
130: manufactured by Sharp Corporation), and an initial charging potential (Vo), an initial residual potential (Vr) under a normal temperature / normal humidity environment,
The change in charge potential (ΔVo) and the change in residual potential (ΔVr) before and after 40,000 continuous copies were measured. Further, the image characteristics and the amount of film reduction (Δd) of these photoconductors at the initial stage and after copying 40,000 sheets were measured. In the column of image characteristics, if there is no problem at all, describe as excellent, if there are slight defects but there is no problem in actual use, describe as good, and if defects such as white spots, streaks, fog occur Described the phenomenon.

[0070]

Examples 2 to 6 The same as Example 1 except that the ratio of the carrier-generating substance and the binder resin in Example 1 was changed.
However, the samples of Examples 5 and 6 were performed using a commercially available analog copier (SF-2027: manufactured by Sharp Corporation) modified for positive charging.

[0071]

Comparative Examples 1 to 6 The same as Example 1 except that the carrier generating material and the binder resin of Example 1 were changed. However, the samples of Comparative Examples 4, 5 and 6 were carried out using a commercial analog copying machine (SF-2027: manufactured by Sharp Corporation) modified for positive charging.

[0072]

[Table 1]

[0073]

[Table 2]

[0074]

Embodiment 7 (Laminated type) Diameter 65 mm, length 335 mm
And a coating solution for an undercoat layer was formed thereon by a dip coating method so as to have a film thickness of 1 μm.
The undercoat layer coating solution was subjected to a dispersion treatment for 10 hours using a paint shaker to prepare an undercoat layer coating solution. Titanium oxide (Al ₂ O ₃ , ZrO ₂ surface-treated dendritic rutile type titanium component 85%) TTO-Ml-1 (manufactured by Ishihara Sangyo) 3 parts by weight CM-800 (manufactured by Toray Industries): 3 parts by weight of alcohol-soluble nylon resin 35 parts by weight of methanol 65 parts by weight of 1,2-dichloroethane

Next, butyral resin (S-LEC BL-
2: Sekisui Chemical Co., Ltd.) 10 parts by weight, methyl ethyl ketone 1
400 parts by weight and 15 parts by weight of titanyl phthalocyanine of the compound (21) were dispersed by a ball mill for 72 hours to prepare a coating liquid for a carrier generating layer. Using this coating solution, a carrier generating layer was formed on an aluminum cylindrical support provided with the undercoat layer so as to have a thickness of 0.2 μm by a dip coating method. Next, 100 parts by weight of the carrier transporting substance of the compound (1) and a viscosity average molecular weight 2
1,500 compound Z-type polycarbonate resin (Z20
0) 45 parts by weight of a modified polycarbonate resin (B30
0) 55 parts by weight of silicon oil and 0.02 parts by weight of TH
F was dissolved in 1,000 parts by weight to prepare a carrier transport layer coating solution. A film was formed on the carrier generation layer by a dip coating method so as to have a thickness of 20 μm, and dried at 120 ° C. for 1 hour to prepare a photoreceptor sample. The evaluation was performed by mounting the photoreceptor sample on a commercially available copying machine (AR-5130: manufactured by Sharp Corporation) and measuring the initial charging potential (V
o), initial residual potential (Vr), change in charged potential (ΔVo) before and after continuous copying of 40,000 sheets, and change in residual potential (ΔVr) were measured. Further, the image characteristics and the amount of film reduction (Δd) of these photoconductors at the initial stage and after copying 40,000 sheets were measured. In the column of image characteristics, if there is no problem at all, describe as excellent, if there are slight defects but there is no problem in actual use, describe as good, and if defects such as white spots, streaks, fog occur Described the phenomenon.

[0076]

Embodiments 8 to 19 are the same as Embodiment 7 except that the kind and composition ratio of the binder resin of Embodiment 7 were changed. Z200: viscosity average molecular weight represented by the formula (I) = 21,
Z-type polycarbonate resin of 500 Z300: viscosity average molecular weight represented by the formula (I) = 32,
Z-type polycarbonate resin of 200 Z400: viscosity average molecular weight represented by the formula (I) = 39,
000 Z-type polycarbonate resin Z800: viscosity average molecular weight represented by the formula (I) = 79,
000 Z-type polycarbonate resin U100: Polyarylate resin (manufactured by Unitika) V209: Polyester resin (manufactured by Toyobo) G400: Modified polycarbonate resin (manufactured by Idemitsu Kosan) C-1400: Bisphenol A-type polycarbonate resin (manufactured by Teijin Chemicals Ltd.) )

[0077]

[Table 3]

[0078]

[Table 4]

Good results were obtained for all the image characteristics.

[0080]

Comparative Examples 7 to 11 The same as Example 7 except that the kind and composition ratio of the binder resin of Example 7 were changed.

[0081]

[Table 5]

[0082]

[Table 6]

[0083]

Embodiments 20 to 28 This embodiment is the same as Embodiment 7 except that the kind of the carrier transporting material, the kind of the binder resin, and the composition ratio are changed.

[0084]

[Table 7]

[0085]

[Table 8]

As for the image characteristics, good results were all obtained. According to the results of Tables 4 and 8, when the weight ratio of the carrier transporting material and the total binder resin is more than 10/10, the initial sensitivity is good, but the printing durability deteriorates,
When the ratio is smaller than 10/28, the printing durability is good, but the initial sensitivity decreases and the residual potential increases after repeated use. It can be said that the composition of the carrier transporting substance and the total binder resin is preferably in the range of 10/10 to 10/28 by weight.

[0087]

Examples 29 to 31, Comparative Examples 12 to 13
Reference numeral 31 denotes the carrier generation layer coating solution of Example 7 in which 2 parts by weight of an azo pigment represented by the compound (23), 1 part of a phenoxy resin (PKHH: manufactured by Union Carbide Co.),
Same as Example 7 except that 97 parts of 4-dioxane was changed to a dispersion liquid dispersed by a ball mill disperser for 12 hours.

Further, Comparative Examples 12 and 13 are the same as Example 29 except that the kind and the composition ratio of the binder resin were changed. The evaluation of the photoreceptor sample was performed using a commercially available analog copying machine (SF-2027: manufactured by Sharp Corporation).
A modified experimental machine was used.

[0089]

[Table 9]

[0090]

[Table 10]

[0091]

Examples 32 to 33 The same as Example 7 except that the carrier-generating substance of Example 7 was changed to the X-type metal-free phthalocyanine represented by the compound (22), and the kind and composition ratio of the binder resin were changed. It is.

[0092]

Comparative Examples 14 and 15 The same as Example 32 except that the kind and composition ratio of the binder resin of Example 32 were changed.

[0093]

[Table 11]

[0094]

[Table 12]

[0095]

Example 34 An undercoat layer and a carrier generation layer were produced in the same manner as in Example 7. In the carrier transport layer,
45 parts by weight of a Z-type polycarbonate resin (Z200) having a viscosity average molecular weight of 21,500 represented by the formula (I), 55 parts by weight of a modified polycarbonate resin (B300), and 0.02 parts by weight of silicone oil are previously dissolved in 1000 parts by weight of THF ( Roll-milling (24 hours) to prepare a resin solution A, and 100 parts by weight of the carrier transporting substance of the compound (1) is added to the resin solution A and dissolved (roll milling for 24 hours) to obtain a coating solution for the carrier transport layer. Produced.
A film was formed on the carrier generation layer by dip coating so that the thickness of the carrier transport layer was 20 μm, and dried at 120 ° C. for 1 hour to prepare a photoconductor sample.

[0096]

Examples 35 to 36

[0097]

[Table 13]

[0098]

[Table 14]

Good results were obtained for all the image characteristics.

[0100]

As described above, according to the electrophotographic photoreceptor of the present invention and the method for producing the same, excellent photosensitivity characteristics, charging characteristics, characteristic stability in repeated use, and good abrasion resistance are obtained. An electrophotographic photoreceptor having both practically sufficient electrical performance and mechanical performance free from image defects such as toner filming can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a laminated function-separated type photoconductor according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing an example of a single-layer type photoconductor according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 conductive support 2 carrier generating substance 3 carrier generating layer 4 carrier transporting substance 5 carrier transporting layer 6 undercoat layer 7 binder resin 20, 21 photosensitive layer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Rikiya Matsuo 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Koichi Toriyama 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka (72) Inventor Tatsuhiro Morita 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka Sharp Corporation (72) Inventor Kazushige Morita 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka Sharp Corporation F term (reference) 2H068 AA13 AA19 AA21 AA35 AA37 BA39 BB23 BB26 BB27 BB52 BB54 EA16

Claims (8)

[Claims] 1. A photosensitive layer formed on the support and containing a carrier-generating substance, a carrier-transporting substance and a binder resin,
The binder resin contains two or more resins, at least one of which contains a photosensitive layer containing less than 50% by weight of a polycarbonate resin represented by the following formula (I). Photoreceptor. Embedded image [In the formula (I), R1 to R8 represent a hydrogen atom, a halogen atom,
Represents a substituted or unsubstituted aliphatic group or a substituted or unsubstituted carbocyclic group. Z represents a group of atoms necessary to form a substituted or unsubstituted carbon ring or a substituted or unsubstituted heterocyclic ring, and n represents an integer of 10 to 1,000. ] 2. A photosensitive layer formed by laminating a support, a carrier generation layer formed on the support and containing a carrier generation material, and a carrier transport layer containing a carrier transport material and a binder resin.
The binder resin of the carrier transport layer contains at least two kinds of resins, at least one of which contains a photosensitive layer containing less than 50% by weight of a polycarbonate resin represented by the following formula (I). An electrophotographic photosensitive member characterized by the following. Embedded image [In the formula (I), R1 to R8 represent a hydrogen atom, a halogen atom,
Represents a substituted or unsubstituted aliphatic group or a substituted or unsubstituted carbocyclic group. Z represents a group of atoms necessary to form a substituted or unsubstituted carbon ring or a substituted or unsubstituted heterocyclic ring, and n represents an integer of 10 to 1,000. ] 3. The electrophotographic photosensitive member according to claim 1, wherein the polycarbonate resin represented by the formula (I) has a viscosity average molecular weight of 20,000 to 40,000. 4. The binder resin is selected from the group consisting of a polycarbonate resin represented by the formula (I), a polycarbonate resin other than the polycarbonate resin represented by the formula (I), a polyarylate resin and a polyester resin. 3. The electrophotographic photoreceptor according to claim 1, wherein said electrophotographic photoreceptor contains a resin. 5. The electrophotographic photoreceptor according to claim 1, wherein the carrier generating substance is a titanyl phthalocyanine pigment. 6. The electrophotograph according to claim 1, wherein the composition of the carrier transporting material and the binder resin in the carrier transporting layer is in a range of 10/10 to 10/28 by weight. Photoconductor. 7. A process for preparing a photosensitive layer by dissolving or dispersing a carrier transporting substance and a binder resin in a solvent to form a photosensitive layer coating solution, wherein the polycarbonate is represented by the following formula (I): A method for producing an electrophotographic photosensitive member, comprising a step of dissolving a binder resin containing a resin in a range of less than 50% by weight of a resin in a solvent and then dissolving or dispersing a carrier transporting substance. Embedded image [In the formula (I), R1 to R8 represent a hydrogen atom, a halogen atom,
Represents a substituted or unsubstituted aliphatic group or a substituted or unsubstituted carbocyclic group. Z represents a group of atoms necessary to form a substituted or unsubstituted carbon ring or a substituted or unsubstituted heterocyclic ring, and n represents an integer of 10 to 1,000. ] 8. The method according to claim 7, wherein in the step of forming the photosensitive layer, the coating solution for the photosensitive layer is applied on a support by a dip coating method.