JP2002182410A - Electrophotographic photoreceptor and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor excellent in photosensitivity characteristics and electrification characteristics even after repeated use, having good wear resistance, not causing image defects due to active species such as ozone and NOx generated in an electrification process and having practically satisfactory electrical, physical and chemical performances. SOLUTION: The top of an electrically conductive substrate 1 is coated by a dip coating method with a photosensitive layer or an electric charge transferring layer 5 containing a specified butadiene compound as an electric charge transferring material 4, a binder resin comprising two or more resins and containing <50 wt.% polycarbonate resin having a specified structural unit and a phenol compound having a specified hindered phenol structural unit to produce the objective electrophotographic photoreceptor.

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, as a photoconductive material of an electrophotographic photoreceptor (hereinafter, also simply referred to as "photoreceptor"), Se,
Inorganic materials such as CdS and ZnO have been used, but due to their problems in toxicity and the like, in recent years, organic photoconductive materials that are non-polluting, have excellent film forming properties, and have a wide selection range of materials have been used. Electrophotographic photoreceptors using the same have been actively developed. An organic electrophotographic photoreceptor using the organic photoconductive material includes a single-layer type in which a charge generation material, which is an organic photoconductive material, and a charge transport material, if necessary, are dispersed in a binder resin. The charge generation layer and the charge transport layer containing a conductive material can be roughly classified into a stacked type in which functions are separated by stacking.

[0003] The single-layer type photoreceptor has a configuration in which a charge generation material and a charge transport material are co-dispersed.
It has been put to practical use because of its low cost and its ability to be used in processes that do not easily generate ozone as a harmful substance. Laminated photoreceptors occupy the mainstream of organic electrophotographic photoreceptors because the photosensitive layer can be easily designed and high sensitivity and high stability can be obtained.

[0004] In these currently used organic photoreceptors, the main problems are durability and stability, especially due to film scraping during repeated use and electrical or chemical change of the film. There is a problem that characteristic changes such as a decrease in charged potential and a rise in residual potential are likely to occur. These problems are latent image creation by charging and exposure,
In the image forming process in which the process of transferring the toner image to the transfer paper and removing the residual toner on the surface of the photoreceptor with a blade or the like is repeated many times, the printing durability of the photosensitive layer is not sufficient. The main factor is that the organic photoconductive compound in the film is denatured or decomposed by the light exposed inside and the ozone and the nitrogen oxide. At present, practically sufficient durability is not ensured in the organic photoreceptor.

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 charge retention rate is high, the photosensitivity is high, and these electrophotographic photoconductors can be used in any environment. The characteristic variation is small. Further, it is required that the film strength is high, the abrasion resistance in repeated use is excellent, and the stability of electrical characteristics throughout life is high. Further, in order to improve the production efficiency of the electrophotographic photoreceptor, it is required that the electrophotographic photoreceptor be prepared with a photoreceptor coating solution that is physically and chemically more stable. In response to these requirements, the roles of the binder resin and the charge transporting material contained in the charge transporting layer, which is also the surface layer of the photoreceptor, are very important.

As the binder resin, a polycarbonate resin is a typical resin. However, the conventional polycarbonate resin has transparency, mechanical properties, compatibility with a charge transport material and a charge generation material required for a photoreceptor, and the like. However, when a polycarbonate resin having a high molecular weight is used, there is a problem in that the electrical characteristics fluctuate greatly, such as a decrease in surface potential and an increase in residual potential when used repeatedly. 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 photoconductor. Furthermore, when a binder resin other than the polycarbonate resin is used, although charging characteristics, sensitivity, residual potential and repetition characteristics are good,
Due to contact members such as a cleaning blade, a magnetic brush, and a peeling mask in practical use, the surface of the photosensitive layer is easily scratched, and has a disadvantage that the film is largely scraped. In order to solve these problems, various improvements by using a specific polycarbonate resin for the charge transport layer of the organic photoreceptor have been proposed in JP-A-7-199488 and JP-A-8-6267. Regarding problems in electrical characteristics such as potential stability during use, sufficient performance for practical use has not yet been obtained.

As described above, the light exposed during the image forming process and the charge products such as ozone and nitrogen oxides cause the organic photoconductive compound in the film to be denatured or decomposed. Therefore, when used repeatedly for a long period of time, problems such as a decrease in chargeability, an increase in residual potential and a decrease in sensitivity occur. To eliminate these disadvantages from the equipment perspective,
A charging system that does not generate a charge product such as ozone, a system that decomposes the generated ozone, and a system that exhausts ozone in the apparatus are required, and there is a problem that the entire process and the system are complicated. An attempt to eliminate the above-mentioned disadvantages from the photoreceptor is disclosed in JP-A-61-1.
JP-A-56052 proposes to add a specific antioxidant, and JP-A-2-59759 proposes a combination of a butadiene-based compound and an antioxidant, but it is not yet sufficient. .

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a photosensitive material having excellent photosensitivity and charging characteristics even after repeated use.
Has good abrasion resistance and does not cause image defects due to active species such as ozone and NOx generated in the charging process.
An object of the present invention is to provide an electrophotographic photosensitive member having practically sufficient electrical, physical and chemical properties.

[0009]

According to the present invention, there is provided an electrophotographic method having a photosensitive layer containing a charge generating material, a charge transport material, a binder resin mixed with the charge transport material, and a phenol compound on a conductive substrate. A photoreceptor, wherein the charge transport material is a butadiene-based compound represented by the following general formula (I); the binder resin is composed of two or more resins; Wherein the compound is a phenol compound having a hindered phenol structural unit represented by the following general formula (III), containing less than 50% by weight of a polycarbonate resin having a structural unit represented by the following formula: It is a photoconductor.

[0010]

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(In the formula, R1 to R4 represent an aryl group which may have a substituent or an aralkyl group which may have a substituent.)

[0012]

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(Wherein R5 to R12 represent a hydrogen atom, a halogen atom, a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted carbocyclic group. Z is a substituted or unsubstituted carbocyclic or substituted or unsubstituted carbocyclic group. Represents an atomic group necessary for forming an unsubstituted heterocyclic ring, and n is 10 to 1000.)

[0014]

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(Wherein, R13 represents a branched alkyl group; R14 to R16 each represent a hydrogen atom, a hydroxy group,
Represents an alkyl group or an aryl group, and at least two of R14 to R16 may be mutually connected to form a ring; )

According to the present invention, a specific polycarbonate resin is used in a photosensitive layer of a single-layer type photosensitive member or a charge transporting layer of a laminated type photosensitive member using a butadiene-based charge transport material.
By containing the resin constituting the layer in an amount of less than 50% by weight with respect to the total amount of the resin, fluctuations in electrical characteristics such as a decrease in surface potential and an increase in residual potential during repeated use, which are problems of the polycarbonate resin, are caused. And the ozone and NO generated in the charging process
An electrophotographic photoreceptor can be provided which solves the problem that image defects occur due to active species such as x and also improves the mechanical strength of the film. That is, with respect to physical properties, the specific polycarbonate resin is expected to have low crystallinity, and based on this property, a decrease in surface properties of the coating film surface due to the crystalline resin is reduced, and low properties such as charge transport materials are reduced. It is considered that the film properties such as printing durability and crack resistance were improved by improving the dispersibility of the molecular compound. Regarding the electrical properties, the specific polycarbonate resin is photo-electrically inactive, but has a high probability of becoming a trap site locally with the charge transport material because it is asymmetric with respect to the molecular chain. When the total resin content ratio in the photosensitive layer or the charge transporting layer is 50% by weight or more, the decrease in surface potential and the increase in residual potential during repetition become remarkably large, but when it is less than 50% by weight, the properties of the host binder resin dominate. It is thought that these can be reduced by being targeted. As for the chemical properties, the combination of high chemical stability of the specific charge transport material and high gas barrier properties of the specific polycarbonate resin causes active species such as ozone and NOx generated in the charging process and charge transport. It is speculated that image degradation (HT white spots) and the like caused by a chemical reaction with the layer are suppressed.

Further, by containing a phenol compound having a hindered phenol structural unit in combination with the above-mentioned specific resin, an action of suppressing a reaction between a photoconductor constituting material such as a charge transport material and an externally attacking substance is provided. As a result, the occurrence of image defects due to the above-mentioned active species can be suppressed, and longer and long-term repeated use becomes possible.

Further, when the photosensitive layer or the charge transporting layer contains two or more kinds of binder resins, the effect of improving the dispersibility of the charge transporting material, which is a low molecular compound, becomes more effective, and each of them depends on the production lot. The displacement of the molecular weight of the binder resin can be absorbed, and the dip coating method excellent in mass productivity can be easily and efficiently performed. 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.

Further, the present invention is characterized in that the photosensitive layer is formed by laminating a charge generating layer containing a charge generating material and a charge transporting layer containing the charge transporting material, the binder resin and the compound. And

According to the present invention, the charge transport layer of the laminated photoreceptor contains less than 50% by weight of a specific butadiene compound and a polycarbonate resin having a specific structural unit and composed of two or more resins. By containing a binder resin and a phenolic compound having a specific phenolic structural unit, ozone generated in the charging process is excellent in abrasion resistance in addition to excellent photosensitivity and charging characteristics even after repeated use. In addition, it is possible to provide a laminated electrophotographic photosensitive member which does not cause image defects due to active species such as NOx and has practically sufficient electrical, physical and chemical performance.

The present invention is further characterized in that the polycarbonate resin having the structural unit represented by the general formula (II) has a viscosity average molecular weight of 20,000 to 40,000.

According to the present invention, the viscosity average molecular weight is 20,
When a polycarbonate resin having a structural unit represented by the general formula (II) of 000 to 40,000 is used, excellent stability of the electric characteristics can be imparted.

Further, the present invention is characterized in that the binder resin contains a polycarbonate resin other than the polycarbonate resin having the structural unit represented by the general formula (II).

According to the present invention, particularly high mechanical strength and high resistance can be obtained by combining a polycarbonate resin having a different structure as a constituent resin other than the polycarbonate resin having the structural unit represented by the general formula (II). It is possible to impart film characteristics with excellent cracking properties.

Further, the present invention provides a compound A having a phenol structural unit represented by the general formula (III) and a butadiene compound B represented by the general formula (I) having a content ratio A / B of: The weight ratio is in the range of 3/97 to 20/80.

According to the present invention, the ratio of the phenol compound having a hindered phenol structural unit is prevented from being too small to cause image deterioration, or from being too large to increase the residual potential upon repeated use. can do.

Further, the present invention is characterized in that the charge generating material is a titanyl phthalocyanine pigment.

According to the present invention, particularly good sensitivity characteristics, charging characteristics and repetition characteristics can be obtained by combining with the butadiene-based charge transporting material.

Further, the present invention is characterized in that the content ratio E / F of the charge transport material E to the binder resin F is in the range of 1/2 to 1 in weight ratio.

According to the present invention, the ratio of the binder resin is
Despite being too small and having good sensitivity characteristics, the charging characteristics, the mechanical strength of the film, and the image stability against ozone and NOx generated in the charging process are reduced, or the charging characteristics are too large and conversely charged Although the characteristics, mechanical strength, and image stability are good, it is possible to avoid a remarkable decrease in the sensitivity characteristics.

The present invention comprises a butadiene compound represented by the following general formula (I) as a charge transporting material and two or more resins formed on a conductive support by a dip coating method. Single-layer type containing a binder resin containing less than 50% by weight of a polycarbonate resin having a structural unit represented by (II) and a phenol compound having a hindered phenol structural unit represented by the following general formula (III) A method for producing an electrophotographic photoreceptor, comprising forming a photosensitive layer of a photoreceptor or a charge transport layer of a laminated photoreceptor.

[0032]

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(In the formula, R1 to R4 represent an aryl group which may have a substituent or an aralkyl group which may have a substituent.)

[0034]

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(Wherein R5 to R12 represent a hydrogen atom, a halogen atom, a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted carbocyclic group. Z is a substituted or unsubstituted carbocyclic or substituted or unsubstituted carbocyclic group. Represents an atomic group necessary for forming an unsubstituted heterocyclic ring, and n is 10 to 1000.)

[0036]

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(Wherein, R13 represents a branched alkyl group; R14 to R16 each represent a hydrogen atom, a hydroxy group,
Represents an alkyl group or an aryl group, and at least two of R14 to R16 may be mutually connected to form a ring; )

According to the present invention, the photosensitivity and charging characteristics are excellent even after repeated use, and the abrasion resistance is good.
An electrophotographic photoreceptor having practically sufficient electrical, physical and chemical performances without causing image defects due to active species such as ozone and NOx generated in the charging process can be provided.

[0039]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described 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. A photosensitive layer comprising a subbing layer 6, a charge generating layer 3 mainly containing a charge generating material 2, and a charge transporting layer 5 containing a compound as a charge transporting material 4 on a conductive support 1. This is a laminated photoconductor provided with a layer 21. In the laminated photoconductor, the photosensitive layer 21 is formed by laminating the charge generation layer 3 and the charge transport layer 5. When the surface of the photoreceptor provided with the photosensitive layer 21 is negatively charged by a charger or the like and the charge generation layer 3 is irradiated with light having an absorption wavelength, charges of electrons and holes are generated in the charge generation layer 3. . The holes are transferred to the photoreceptor surface by the charge transport material 4 contained in the charge transport layer 5 to neutralize the negative charge on the surface, and the electrons in the charge generation layer 3 are transferred to the conductive support on which the positive charges are induced. By moving to the side of the body 1 and neutralizing the positive charge, the laminated photoreceptor functions.

FIG. 2 is a sectional view showing a single-layer type photosensitive member according to another embodiment of the present invention. This is a single-layer photoconductor in which a photosensitive layer 20 in which a charge generation material 2 and a charge transport material 4 are dispersed in a binder resin 7 serving as a binder is provided on a conductive support 1. When the surface of the photoconductor provided with the photosensitive layer 20 is positively charged and the charge generating material 2 is irradiated with light having an absorption wavelength, charges of electrons and holes are generated near the surface of the photosensitive layer 20. The electrons neutralize the positive charges on the surface, and the holes move to the side of the conductive support 1 where the negative charges are induced,
By neutralizing the electrons, the single-layer type photoconductor functions.

In the laminated photoreceptor shown in FIG. 1, particles of the charge generating material 2 are dispersed in a solvent or a binder resin on an undercoat layer 6 formed on the conductive support 1. The charge transport layer 5 can be formed by applying the obtained dispersion and applying and drying a solution in which the charge transport material 4 and the binder resin 7 are dissolved on the formed charge generation layer 3 to form a charge transport layer 5. In the single-layer type photoreceptor as shown in FIG. 2, the charge generating material 2 and the charge transporting material 4 are dispersed in a solution in which a binder resin 7 is dissolved, and this dispersion is coated on the conductive support 1. , And dried to form the photosensitive layer 20. Therefore, the formation of the photosensitive layer 20 is not substantially different from the case of the charge generation layer 3 or the charge transport layer 5 in FIG.

The conductive support 1 functions not only as an electrode of the photoreceptor but also as a support for other layers, and may have any of a cylindrical shape, a plate shape, a film shape and a belt shape. Examples of the material of the conductive support 1 include a metal material such as aluminum, stainless steel, copper and nickel, a polyester film provided with a conductive layer such as aluminum, copper, palladium, tin oxide and indium oxide, and a phenol resin pipe. And insulating materials such as paper tubes. It is preferable that the conductive material has a volume resistivity of 10 ¹⁰ Ω · cm 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. In these, particles of titanium oxide, tin oxide or aluminum oxide may be dispersed. The thickness of the undercoat layer 6 is about 0.1 to 10 μm. Such an undercoat layer 6 serves as an adhesive layer between the conductive support 1 and the photosensitive layer 21, and additionally, a barrier layer that suppresses charge from flowing from the conductive support 1 into the photosensitive layer 21. Also acts as. 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 charge generation layer 3 includes a conventionally known charge generation material 2. In the embodiment of the present invention, as the appropriate charge generation material 2, any of inorganic pigments, organic pigments, and organic dyes can be used as long as they absorb visible light and generate free charges. Inorganic pigments include selenium and its alloys, arsenic-selenium, cadmium sulfide, zinc oxide, amorphous silicon, and other inorganic photoconductors. Examples of the organic 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, phthalocyanine-based compounds are preferable, and it is particularly preferable to use titanyl phthalocyanine compounds. Particularly good sensitivity characteristics, charging characteristics and repetition characteristics can be obtained by combining with a butadiene compound represented by the following general formula (I).

In addition to the pigments and dyes listed above, a chemical sensitizer or an optical sensitizer may be added to the charge generation layer 3. As the chemical sensitizer, electron accepting materials such as cyano compounds such as tetracyanoethylene and 7,7,8,8-tetracyanoquinodimethane, quinones such as anthraquinone and p-benzoquinone, and 2,4 , 7-trinitrofluorenone and 2,
Nitro compounds such as 4,5,7-tetranitrofluorenone are exemplified. Examples of the optical sensitizer include dyes such as xanthene dyes, thiazine dyes, and triphenylmethane dyes. As the charge generation material 2 in the embodiment of the present invention, preferably, the organic photoconductive compound such as an organic pigment and an organic dye is used.

The charge generation layer 3 is formed by dispersing the above-described charge generation material 2 together with a binder resin in an appropriate solvent, applying the dispersion on the conductive support 1 or the undercoat layer 6, and then drying or curing. Film and form.

As the binder resin, specifically, polyarylate, polyvinyl butyral, polycarbonate,
Polyester, polystyrene, polyvinyl chloride, phenoxy resin, epoxy resin, silicone, polyacrylate and the like are used.

As the solvent, isopropyl alcohol,
Examples include cyclohexanone, cyclohexane, toluene, xylene, acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, dioxolan, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, and ethylene glycol dimethyl ether. Solvents other than these may be used, and any of alcohol-based, ketone-based, amide-based, ester-based, ether-based, hydrocarbon-based, chlorinated hydrocarbon-based and aromatic solvent systems may be used alone or in combination. You may. However, in consideration of a decrease in sensitivity due to crystal transition during pulverization and milling of the charge generation material 2 and a decrease in characteristics due to pot life, cyclohexanone, 1,2-dimethoxyethane, methyl ethyl ketone, and tetraethyl are less likely to cause crystal transition in both pigments. It is preferable to use any of hydroquinone.

As a method for forming the charge generation layer 3, a vapor deposition method such as a vacuum evaporation method, a sputtering method, and a CVD method, and a coating method are generally applied. The coating method is as follows. The charge generating material 2 is pulverized by a ball mill, a sand grinder, a paint shaker, an ultrasonic disperser, or the like, dispersed in a solvent, and if necessary, a coating liquid containing a binder resin is electrically conductive by a known method. It is applied on the support 1. For example, when the conductive support 1 is a sheet, it is applied by a baker applicator, a bar coater, casting and spin coating, and when the conductive support 1 is a drum, it is applied by a spray method, a vertical ring method, a dip coating method, or the like. I do. The thickness of the charge generation layer 3 is preferably about 0.05 to 5 μm, more preferably about 0.1 to 1 μm.

The charge transport layer 5 comprises a butadiene compound represented by the following general formula (I), a binder resin containing less than 50% of a polycarbonate resin having a structural unit represented by the following general formula (II), A phenol compound having a hindered phenol structural unit represented by the general formula (III).

[0052]

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[0053]

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[0054]

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The charge transport layer 5 is composed of two or more types of binder resins and is made of a polycarbonate resin having a structural unit represented by the general formula (II) in a total binder resin ratio of 5%.
One feature is that the content is less than 0% by weight.

A butadiene compound represented by the general formula (I) is used as the charge transporting material 4, and the compound represented by the general formula (I)
By containing the polycarbonate resin having the structural unit represented by I) in an amount of less than 50% by weight based on the total amount of the binder resin of the charge transport layer 4, satisfactory electrophotography in electrical properties, chemical properties, and physical properties is obtained. A photoreceptor can be provided. That is, there are large fluctuations in electrical characteristics, such as a decrease in surface potential and an increase in residual potential during repeated use, which are problems with polycarbonate resins, and image defects are caused by active species such as ozone and NOx generated in the charging process. In addition to solving the problem of occurrence, the improvement of the mechanical strength of the film can be satisfied. The content of the polycarbonate resin having the structural unit represented by the general formula (II) is adjusted to 50% of the binder resin.
When the content is not less than% by weight, the reduction of the surface potential and the increase of the residual potential upon repeated use become remarkable, which greatly impairs practicality.

As described above, the detailed reason why good properties can be obtained by the inclusion of the specific kind of the charge transporting material 4 and the specific amount of the polycarbonate resin is not clear, but with respect to the physical properties, the general formula (II) The polycarbonate resin having the structural unit represented by is expected to have low crystallinity, and based on this property, the surface property of the coating film surface is less likely to be reduced by the crystalline resin, and the low molecular compound such as the charge transport material 4 It is considered that the film properties such as printing durability and crack resistance are improved by improving the dispersibility of. Regarding the electrical characteristics, the general formula (II)
Polycarbonate resin having a structural unit represented by
Although it is photo-electrically inactive, since it is asymmetric with respect to the molecular chain, the probability of becoming a trap site locally with the charge transporting material 4 is high. Therefore, the charge transport layer 5
When the content ratio in the total binder resin is 50% by weight or more, the decrease in surface potential and the increase in residual potential during repetition become extremely large, but when the content ratio is less than 50% by weight, the properties of the host binder resin are dominant. As a result, a decrease in surface potential and an increase in residual potential during repetition are suppressed. It is presumed that compatibility between the physical properties and the electrical properties of the charge transport layer 5, which is the photoreceptor surface layer, has thus been made possible.
Further, regarding chemical characteristics, that is, image degradation caused by a chemical reaction between the active species such as ozone and NOx generated in the charging process and the charge transport layer 5, for example, characteristics such as halftone (HT) white spots, etc. The combination of the high chemical stability of the butadiene compound represented by the general formula (I), which is the charge transport material 4, and the high gas barrier property of the polycarbonate resin having the structural unit represented by the general formula (II) Presumed to be effective.

With respect to the molecular weight of the polycarbonate resin having the structural unit represented by the general formula (II), the viscosity average molecular weight is preferably in the range of 20,000 to 40 in view of the electrical properties, repetition stability and printing durability of the photosensitive member. It is preferably 2,000. When the viscosity average molecular weight is less than 20,000,
Eliminating image degradation such as HT white spots and black bands due to ozone and NOx generated in the charging process,
When the image stability is improved, the printing durability is significantly reduced. When it is larger than 40,000, the printing durability is improved, but the initial sensitivity is reduced, the residual potential is increased upon repeated use, and the image stability is reduced. The drop is greater.

The binder resin to be combined with the polycarbonate resin having the structural unit represented by the general formula (II) does not substantially differ from the binder resin used for the charge generation layer 3 and includes, for example, polycarbonate, polyarylate, and the like. Examples include polyesters, polyether ketones, epoxy resins, urethanes, cellulose ethers, and copolymers of monomers required to constitute these resins. Among these resins, a polycarbonate resin other than the general formula (II) is preferable in consideration of stable electric characteristics, mechanical strength, manufacturing cost of the photoreceptor, and the like. As the binder resin, general formula (I
A polycarbonate having a structural unit represented by I),
By using in combination with a polycarbonate resin having a structure other than the general formula (II), it is possible to impart film properties with particularly high mechanical strength and excellent crack resistance.

By appropriately combining two or more kinds of binder resins in this way, it is possible to absorb the deviation of the molecular weight of each binder resin depending on the production lot, thereby facilitating and improving the efficiency of the dip coating method excellent in mass productivity. Becomes possible. That is, since the coating solution used for the dip coating method can be adjusted to the same viscosity and solid content every time, a photosensitive member having excellent coating uniformity can be efficiently obtained, and extremely high productivity and low cost can be obtained. It is possible to manufacture a photosensitive member. In addition, it can be inferred that the effect of improving the dispersibility of the charge transport material 4, which is a low-molecular compound, becomes more effective when the charge transport layer 5 contains two or more binder resins. In addition,
In the case of a single-layer type photoreceptor, the above-described binder resin is used in the photosensitive layer 20.

As the polycarbonate resin having a structure other than the general formula (II), bisphenol A type polycarbonate resin is most commonly used. But,
A commercially available bisphenol A type polycarbonate resin that is generally used has high symmetry with respect to the molecular chain and is easily crystallized. For this reason, if the charge transport material contains a large amount of the charge transport material or the charge transport material has high crystallinity, the charge transport material and the bisphenol A-type polycarbonate resin are phase-separated, and the coating film is not uniform in morphology and composition. It tends to be. Further, since the coating solution for the photosensitive layer using the bisphenol A type polycarbonate resin is easily gelled, it is difficult to store the coating solution for a long period of time. Therefore, a polycarbonate resin having structural units represented by the following structural formulas (IV) and (V), which have low symmetry with respect to the molecular chain and are difficult to crystallize and hardly gel, is converted into a compound represented by the general formula (II)
It is preferable to use in combination with a polycarbonate resin having a structural unit represented by Further, the structural formula (V)
When a polycarbonate resin having the structural unit represented by is used, the surface resistance of the photoreceptor is reduced because Si is contained in the molecular chain, and film scraping can be reduced, and a longer life can be provided.

[0062]

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[0063]

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The amount of the binder resin used in the charge transport layer 5 is 50 to 3 with respect to 100 parts by weight of the charge transport material.
00 parts by weight is preferred. More preferably 100 to 20
0 parts by weight. When the amount is less than 100 parts by weight, the sensitivity characteristics are good, but the image stability due to charging characteristics, mechanical strength of the film, and image deterioration such as HT white spots and black bands caused by ozone and NOx generated in the charging process. Decrease. Conversely, when the amount exceeds 200 parts by weight, the charging characteristics, mechanical strength and image stability are good,
The sensitivity characteristics are significantly reduced.

Another feature of the charge transport layer 5 is that it contains a phenol compound having a hindered phenol structural unit represented by the general formula (III).

In the general formula (III), R13 represents a branched alkyl group, R14 to R16 each represent a hydrogen atom, a hydroxy group, an alkyl group or an aryl group;
At least two of-16 may be mutually connected to form a ring. The R13 is a terpolymer having 3 to 40 carbon atoms.
A t- or sec-alkyl group is preferred. R14-1
6 is preferably an alkyl group having 1 to 40 carbon atoms, and examples of the aryl group include a phenyl group, a naphthyl group and a pyridyl group. When at least two of R14 to R16 are mutually connected to form a ring, a chroman group is preferable. Although the mechanism of action of these compounds is not clear, self-oxidation causes the charge transport material 4
Is considered to be able to suppress the oxidation of, and prevent image deterioration such as HT white spots over a long period of use.
In particular, the phenol compound (III-1) having a hindered phenol structural unit represented by the following structural formula has a low molecular weight and therefore has excellent self-oxidizing ability and can prevent oxidation of the charge transport material 4 for a long period of time.

In addition to the binder resin, the charge transport layer 5
In addition, by containing the phenol compound having the hindered phenol structural unit, image defects due to active species such as ozone and NOx generated in the charging process can be improved, and a longer life can be provided. It becomes possible. With the above-described binder resin alone, HT caused by a chemical reaction between the charge transport layer 5 and active species such as ozone and NOx generated in the charging process.
It is insufficient for image deterioration such as white spots. In order to improve these, when the charge transport layer 5 contains a phenol compound having a hindered phenol structural unit in combination with the above-mentioned binder resin, image deterioration such as HT white spots and the like can be observed even for a long-term repeated use. Will not be caused. This has the effect of suppressing the reaction between the photoreceptor constituting material such as the charge transport material 4 and an external attacking substance.
HT caused by the above-mentioned ozone and NOx
It is considered that image deterioration such as white spots can be prevented.

In the charge transport layer 5, the constitutional ratio A / of the phenolic compound A having a hindered phenol structural unit represented by the general formula (III) and the butadiene compound B represented by the general formula (I) B is 3/97 to 20 by weight.
/ 80 is preferable. If it is less than 3/97, there is no effect on image degradation, and if it exceeds 20/80, the residual potential increases during repeated use, which is a practical problem.

Next, typical specific examples of the compounds represented by the general formulas (I), (II) and (III) are shown in Tables 1 to 3.
Although shown in No. 4, the compound examples in the present invention are not limited to these.

[0070]

[Table 1]

[0071]

[Table 2]

[0072]

[Table 3]

[0073]

[Table 4]

The solvent for dissolving or dispersing the charge transport material 4 does not substantially differ from the solvent for dispersing the charge generation material 2 in the formation of the charge generation layer 3, and may be any of the solvents listed for the charge generation material 2. You can choose from.
A particularly preferred solvent is tetrahydrofuran.

The charge transport layer 5 may optionally contain a plasticizer and a leveling agent. As the leveling agent, silicone oils, polymers or oligomers having a perfluoroalkyl group in the side chain can be used.
0 to 1 part by weight with respect to parts by weight is appropriate.

The charge transport layer 5 may be formed by, for example, a baker applicator, a bar coater, casting or spin coating when the conductive support 1 is a sheet, a spray method when the conductive support 1 is a drum, or the like. A vertical ring method and a dip coating method are used. In particular, dip coating is generally preferred from the viewpoint of productivity and cost. By the dip coating method, the charge transport layer 5 is formed by applying a coating solution obtained by dissolving or dispersing the charge transport material 4 together with the binder resin 7 in an appropriate solvent to the conductive support 1 on which the charge generation layer 3 is formed. It is formed by applying, drying or curing. The coating liquid for the charge transport layer is generally prepared by a method in which several or one kind of the charge transport material 4, the binder resin and the additive are weighed and simultaneously dissolved in a predetermined amount of an organic solvent. Although there is no problem with this method, a method in which the charge transport material 4 is charged and dissolved after dissolving the binder resin in the solvent is particularly preferable. According to this method, the molecular dispersibility of the charge transport material 4 in the binder resin is improved, and the potential and local crystallization of the charge transport material 4 in the film is suppressed, thereby improving the initial sensitivity. In addition, potential stability at the time of repeated use and good image characteristics are imparted.

The thickness of the charge transport layer 5 is about 10 to 50 μm
And more preferably about 10 to 35 μm.

In the method for producing a photoreceptor according to the present invention,
Preferably, a drying step of each layer such as the charge generation layer 3 is included. The drying temperature of the photoreceptor is suitably from about 50 to 140C, and particularly preferably from about 70 to 130C.
If the drying temperature of the photoreceptor is lower than about 70 ° 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 deteriorates. Tend to.

The embodiments of the present invention will be further described below 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.

[0080]

The electrophotographic photosensitive member according to the present invention will be described in more detail with reference to the following examples.

Example 1 (Single-Layer Photoreceptor) 10 parts by weight of titanyl phthalocyanine represented by the structural formula (VI) and 190 parts by weight of tetrahydrofuran (THF) were dispersed by a ball mill for 48 hours. Prepared. At the same time, 45 parts by weight of a Z-type polycarbonate resin having a viscosity average molecular weight of 21,500 (Z200: manufactured by Mitsubishi Engineering-Plastics Corporation) having a structural unit represented by Structural Formula (II-1) and a structural unit represented by Structural Formula (V) 55 parts by weight of a modified polycarbonate resin having the following formula (G400: manufactured by Idemitsu Kosan Co., Ltd.), 80 parts by weight of a charge transporting material represented by Structural Formula (I-1), 10 parts by weight of a compound represented by Structural Formula (III-1), 0.02 parts by weight of silicone oil and T
It was dissolved in HF467 parts by weight to prepare a resin solution D. The mixture was mixed and dispersed by a ball mill for 2 hours so that the weight ratio C: D of the pigment dispersion C to the resin solution D was 1: 2, to prepare a coating solution for a photosensitive layer. The coating solution thus obtained was applied onto a cylindrical aluminum support having a diameter of 65 mm and a length of 335 mm by dip coating, dried at 120 ° C. for 1 hour, and then performed in a single-layer type as shown in FIG. A photoconductor sample of Example 1 was produced. The thickness was 27 μm.

[0082]

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(Examples 2 to 10) Examples 2 to 10 were carried out in the same manner as in Example 1 except that the charge transport materials, binder resins, and additives of the types and composition ratios shown in Table 5 were used.
A photoreceptor sample was prepared.

(Comparative Examples 1 to 15) The charge transport materials, binder resins, and additives of the types and composition ratios shown in Table 5 were used, and in Comparative Examples 14 and 15, the charge generating materials were the following compounds [IX] and Photoconductor samples of Comparative Examples 1 to 15 were produced in the same manner as in Example 1 except that [X] was set.

[0085]

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[0086]

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[0087]

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[0088]

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[0089]

[Table 5]

Z200: a Z-type polycarbonate resin having a viscosity average molecular weight of 21,500 having a structural unit represented by the structural formula (II-1) (manufactured by Mitsubishi Engineering-Plastics Corporation) Z300: a structure represented by the structural formula (II-1) Z-type polycarbonate resin having a viscosity average molecular weight of 32,200 units (manufactured by Mitsubishi Engineering-Plastics Corporation) Z400: Z-type polycarbonate resin having a viscosity average molecular weight of 39,000 having a structural unit represented by Structural Formula (II-1) (Mitsubishi Engineering Plastics Co., Ltd.) Z800: Z-type polycarbonate resin having a viscosity average molecular weight of 79,000 having a structural unit represented by Structural Formula (II-1) (Mitsubishi Engineering Plastics Co., Ltd.) C1400: Bisphenol A-type polycarbonate resin (Manufactured by Teijin Chemicals Limited) 300: Modified polycarbonate resin represented by structural formula (IV) (manufactured by Idemitsu Kosan) G400: Modified polycarbonate resin represented by structural formula (V) (manufactured by Idemitsu Kosan) U100: Polyarylate resin (manufactured by Unitika) V290: Polyester resin (Toyobo)

(Evaluation 1) Examples 1 to 10 and Comparative Example 1
About 14 photoreceptor samples, commercial copying machines (AR
-F330: manufactured by Sharp Corporation) was mounted on a remodeled machine that was remodeled for positive charging.
A commercially available analog copying machine (SF-2027: manufactured by Sharp Corporation) was mounted on a modified machine modified for positive charging and evaluated.
The evaluation was made based on the initial charging potential (V
o) and residual potential (Vr), change in charged potential (ΔVo) and residual potential (ΔV) before and after continuous copying of 100,000 sheets
r), and the film loss (Δd) of each of these photoreceptors at the initial stage and after copying 100,000 sheets was measured. The image characteristics are as follows: 50,000 copies of the copied image (halftone) after stopping for 1 hour after actual shooting, and 50,000 copies after copying, ie, 100,000 copies of actual copying, that is, the copied image after stopping for 1 hour (halftone) The evaluation was made by examining the occurrence of image defects such as white spots or black bands on the drum portion adjacent to the charging charger serving as the charging device. The evaluation was excellent when there were no image defects at all, good when there was some defect but there was no problem in actual use, and it was not when there was a clear defect. In addition, at the initial stage and after copying 100,000 sheets, the results of copying solid black and white solid paper were examined as other image characteristics other than the image defects (white spots / black bands). When there was no image defect, it was evaluated as excellent. When there was a slight defect but there was no problem in actual use, it was evaluated as good. Table 6 shows the results.

[0092]

[Table 6]

As is clear from Table 6, from Examples 1 and 2 and Comparative Example 1, if the charge transporting material is not a butadiene compound represented by the general formula (I), an image due to white spots or black bands appears. It can be seen that the defects are significantly worsened.

From Examples 1 and 3 and Comparative Examples 2 to 4,
A mixture of two or more binder resins, and a compound represented by the general formula (II):
It can be seen that when the polycarbonate resin having the structural unit represented by the formula below is contained in the binder resin in an amount of less than 50% by weight, both the electrical characteristics and the image characteristics are satisfied. Specifically, if the polycarbonate resin having the structural unit represented by the general formula (II) is not contained, the image characteristics (white spots / black bands) deteriorate, and the polycarbonate resin is contained at 50% by weight or more of the total binder resin. In this case, ΔVr increases, causing a decrease in density.

Examples 1, 4 and 5 and Comparative Examples 5 and 6
From the above, since the polycarbonate resin is contained as a binder resin other than the polycarbonate resin having the structural unit represented by the general formula (II), the electrical characteristics and the image characteristics (white spots / black bands) are maintained for a long time. It turns out that it is favorable. Among them, compared to C1400 which is the bisphenol A type polycarbonate resin of Example 5,
G40 which is the modified polycarbonate resin of Examples 1 and 4
It can be seen that 0 and B300 are excellent in all aspects of electrical characteristics, image characteristics and film loss.

From Example 6 and Comparative Example 7, the general formula (I
If the viscosity average molecular weight of the polycarbonate resin having the structural unit represented by I) is not 20,000 to 40,000, the image characteristics (white spots / black bands) are not good.

From Examples 7 and 8 and Comparative Examples 8 and 9, the charge transport material E in the charge transport layer and the binder resin F
If the composition ratio E / F is not in the range of 1/2 to 1 in terms of the weight ratio, it is understood that both the electrical characteristics and the image characteristics cannot be satisfied. Specifically, if the density is less than 1/2, the density is insufficient, and if it exceeds 1, the image characteristics particularly in long-term use (white spots / black bands)
Is not good.

From Examples 9 and 10 and Comparative Examples 10 to 13, the phenolic compound A having a hindered phenol structural unit represented by the general formula (III) is contained and represented by the general formula (I). It can be seen that when the composition ratio A / B with the butadiene-based compound B is in the range of 3/97 to 20/80 by weight, both the electrical characteristics and the image characteristics can be improved over a long period of time. Specifically, 3/9
If it is less than 7, the image characteristics (white spots / black bands) are not good,
If it exceeds / 80, the concentration will be reduced.

From Comparative Examples 14 and 15, it can be seen that if the charge generating material is not a titanyl phthalocyanine pigment, the concentration will be insufficient from the beginning.

(Example 11) (Laminated photoreceptor) 3 parts by weight of titanium oxide (Al ₂ O ₃ and ZrO ₂ surface-treated dendritic rutile type, 85% titanium component) (TTO-MI-1: manufactured by Ishihara Sangyo) And 3 parts by weight of an alcohol-soluble nylon resin (CM-8000: manufactured by Toray Industries, Inc.), 35 parts by weight of methanol, and 65 parts by weight of 1,3-dioxolane are subjected to a dispersion treatment with a paint shaker for 10 hours. A coating solution was prepared. The prepared coating solution for the undercoat layer was coated with a diameter of 6
A film was formed by dip coating on an aluminum cylindrical support having a length of 5 mm and a length of 335 mm so as to have a thickness of 1 μm to form an undercoat layer. Next, butyral resin (SL)
ECBL-2: manufactured by Sekisui Chemical Co., Ltd.) 10 parts by weight, 1,400 parts by weight of dimethoxyethane, and 15 parts by weight of titanyl phthalocyanine represented by the structural formula (VI) were subjected to a ball mill for 72 hours.
The mixture was dispersed for a time to prepare a coating solution for a charge generation layer. Using this coating solution, a charge-generating layer was formed on an aluminum cylindrical support having an undercoat layer by dip coating to a thickness of 0.2 μm. Next, the structural formula (I-
100 parts by weight of the charge transporting material shown in 1) and the structural formula (II)
-1) A viscosity average molecular weight of 21,5 having a structural unit shown in
70 parts by weight of a Z-type polycarbonate resin (Z200: manufactured by Mitsubishi Engineering-Plastics Corporation) and a modified polycarbonate resin (G400:
90 parts by weight (made by Idemitsu Kosan Co., Ltd.), 10 parts by weight of the compound represented by the structural formula (III-1), and 0.02 parts by weight of silicone oil were dissolved in 1000 parts by weight of THF to prepare a coating solution for a charge transport layer. Using a charge transport layer coating solution, a film was formed on the previously formed charge generation layer by dip coating so that the film thickness was 25 μm, and dried at 120 ° C. for 1 hour to form a charge transport layer. Thus, a laminated photoconductor sample of Example 11 as shown in FIG. 1 was produced.

(Examples 12 to 30) Example 12 was repeated in the same manner as in Example 11 except that the charge transporting materials, binder resins, and additives having the types and composition ratios shown in Table 7 were used.
To 30 photoreceptor samples were prepared. The charge transport material was 97 parts by weight in Examples 27 and 29, and
The same amounts as in Example 11 were used, except that 8 and 30 were 80 parts by weight.

(Comparative Examples 16 to 41) The charge transport materials, binder resins, and additives of the types and constitutional ratios shown in Table 7 were used, and in Comparative Examples 40 and 41, the charge generating materials were compounds [IX] and [IX], respectively. X], and photoreceptor samples of Comparative Examples 16 to 41 were produced in the same manner as in Example 11. The charge transport materials were used in the same amounts as in Example 11 except that the charge transport materials were 80 parts by weight in Comparative Examples 37 and 39.

[0103]

[Table 7]

(Evaluation 2) The photoreceptor samples of Examples 11 to 30 and Comparative Examples 16 to 40 were mounted on a commercially available copying machine (AR-F330: manufactured by Sharp Corporation).
For the sample No. 1, a commercially available analog copying machine (SF
-2027: manufactured by Sharp Corporation). The evaluation measures the initial charging potential (Vo) and the residual potential (Vr) in a normal temperature / humidity environment, and changes in the charging potential (ΔVo) and residual potential (ΔVr) before and after continuous copying of 100,000 sheets. Then, the film loss (Δd) of each of these photoconductors at the initial stage and after copying 100,000 sheets was also measured and performed. The image characteristics are as follows: 50,000 copies of the copied image (halftone) after stopping for 1 hour after actual shooting, and further 50,000 copies after copying, ie, 100,000 copies of actual copying, and the copied image after stopping for 1 hour (halftone) The evaluation was made by examining the occurrence of image defects such as white spots or black bands on the drum portion adjacent to the charging charger serving as the charging device. The evaluation was excellent when there were no image defects at all, good when there was some defect but there was no problem in actual use, and it was not when there was a clear defect. Also, the initial and 1
The image defects (white spots / black bands) after copying 100,000 sheets
As other image characteristics other than the above, the results of copying black and white solid paper were also examined. When there was no image defect, it was evaluated as excellent. When there was a slight defect but there was no problem in actual use, the result was evaluated as good. Table 8 shows the results.

[0105]

[Table 8]

As apparent from Table 8, Examples 11 and 1
5 and 16 and Comparative Examples 16 to 18, it can be seen that, unless the charge transporting material is a butadiene-based compound represented by the general formula (I), image defects due to white spots or black bands significantly deteriorate.

From Examples 11 to 16 and Comparative Examples 19 to 24, two or more binder resins were mixed, and the compound represented by the general formula (I)
It can be seen that if the polycarbonate resin having the structural unit represented by I) is contained in less than 50% by weight of the total binder resin, it satisfies both the electrical characteristics and the image characteristics. Specifically, if the polycarbonate resin having the structural unit represented by the general formula (II) is not contained, the image characteristics (white spots / black bands) are deteriorated, and the content is not less than 50% by weight of the total binder resin. In this case, ΔVr increases, causing a decrease in density.

From Examples 11 to 18 and Comparative Examples 27 to 30, the binder represented by the general formula (I) was used as a binder resin other than the polycarbonate resin having the structural unit represented by the general formula (II).
It can be seen that by containing a polycarbonate resin other than the polycarbonate resin having the structural unit represented by I), the electrical characteristics and the image characteristics (white spots / black bands) are good over a long period of time. Among them, C140 which is the bisphenol A type polycarbonate resin of Example 13
Compared to 0, G400 and B300, which are the modified polycarbonate resins of Examples 11 and 12, are superior in all of electrical characteristics, image characteristics (white spots / black bands), and film loss.

From Examples 11, 20 and 22 and Comparative Examples 25 and 26, the polycarbonate resin having the structural unit represented by the general formula (II) has a viscosity average molecular weight of 20,
If it is not 000 to 40,000, the image characteristics (white spots / black bands) are not good.

Examples 23 to 26 and Comparative Examples 31 and 32
From the above, it can be seen that unless the composition ratio E / F of the charge transport material E and the binder resin F in the charge transport layer is in the range of 1/2 to 1 in weight ratio, both the electrical characteristics and the image characteristics cannot be satisfied. I understand. Specifically, if the concentration is less than 1/2, the concentration is insufficient.
If it exceeds 1, image characteristics (white spots,
Black belt) is not good.

From Examples 11, 17, 18, 27 to 30 and Comparative Examples 33 to 39, a phenolic compound A having a hindered phenol structural unit represented by the general formula (III) was contained, and The composition ratio A / B with the butadiene compound B represented by I) is from 3/97 to 20 /
It can be seen that when the ratio is in the range of 80, both the electrical characteristics and the image characteristics can be improved over a long period of time.
Specifically, if less than 3/97, image characteristics (white spots / black bands)
Is not good, and if it exceeds 20/80, the concentration is reduced.

From Comparative Examples 40 and 41, it can be seen that the initial concentration is insufficient if the charge generating material is not a titanyl phthalocyanine pigment.

[0113]

According to the present invention, a specific butadiene-based charge transport material and two or more resins are used in a photosensitive layer of a single-layer type photoreceptor or a charge transport layer of a laminated type photoreceptor. By containing a binder resin containing less than 50% by weight of a polycarbonate resin having a structural unit and a phenol compound having a specific hindered phenol structural unit, the photosensitive resin has excellent photosensitivity characteristics and charging characteristics even after repeated use. A laminated electrophotographic photosensitive material that has good abrasion resistance, does not cause image defects due to active species such as ozone and NOx generated in the charging process, and has practically sufficient electrical, physical and chemical performance. Body can be provided.

Further, according to the present invention, the dip coating method
A specific butadiene-based charge transport material, a binder resin composed of two or more resins and containing less than 50% by weight of a polycarbonate resin having a specific structural unit, and a phenol compound having a specific hindered phenol structural unit. By forming a photosensitive layer or a charge transporting layer containing the same, it is possible to provide a method for producing the electrophotographic photosensitive member.

[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 charge generating material 3 load generating layer 4 charge transporting material 5 charge transporting layer 6 undercoating layer 7 binder resin 20, 21 photosensitive layer

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) G03G 5/06 373 G03G 5/06 373 (72) Inventor ▲ Kaku ▼ Mikio 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka, Japan No. Sharp Corporation (72) Inventor Rikiya Matsuo 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Sharp Corporation (72) Inventor Sayaka 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Sharp shares In-company F term (reference) 2H068 AA13 AA16 AA19 AA20 AA31 AA34 AA35 BA12 BA13 BA39 BB26 BB52 EA16 FA02

Claims (8)

[Claims] 1. An electrophotographic photoreceptor having a photosensitive layer containing a charge generating material, a charge transport material, a binder resin mixed with the charge transport material, and a phenol compound on a conductive substrate, The transport material is a butadiene-based compound represented by the following general formula (I), and the binder resin is composed of two or more resins and has a structural unit represented by the following general formula (II) An electrophotographic photoreceptor containing less than 50% by weight of a polycarbonate resin, wherein the phenol compound is a phenol compound having a hindered phenol structural unit represented by the following general formula (III). Embedded image (In the formula, R1 to R4 represent an aryl group which may have a substituent or an aralkyl group which may have a substituent.) (Wherein, R 5 to R 12 represent a hydrogen atom, a halogen atom, a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted carbocyclic group. Z represents a substituted or unsubstituted carbocyclic or substituted or unsubstituted Represents an atom group necessary for forming a heterocyclic ring, and n is 10 to 1000.) (Wherein, R13 represents a branched alkyl group.
R16 represents a hydrogen atom, a hydroxy group, an alkyl group or an aryl group, and at least two of R14 to R16 may be mutually connected to form a ring. ) 2. The photosensitive layer according to claim 1, wherein the photosensitive layer is formed by laminating a charge generating layer containing a charge generating material and a charge transporting layer containing the charge transporting material, the binder resin and the compound. Item 8. The electrophotographic photosensitive member according to Item 1. 3. The polycarbonate resin having the structural unit represented by the general formula (II) has a viscosity average molecular weight of 2
3. The electrophotographic photoreceptor according to claim 1, wherein said electrophotographic photoreceptor has a molecular weight of from 000 to 40,000. 4. The binder resin according to the general formula (I)
3. The electrophotographic photosensitive member according to claim 1, further comprising a polycarbonate resin other than the polycarbonate resin having the structural unit represented by I). 5. A phenol compound A having a hindered phenol structural unit represented by the general formula (III)
And a butadiene compound B represented by the general formula (I)
3. The electrophotographic photoreceptor according to claim 1, wherein the content ratio A / B with respect to the weight ratio is in the range of 3/97 to 20/80. 6. The electrophotographic photoreceptor according to claim 1, wherein said charge generation material is a titanyl phthalocyanine pigment. 7. The electrophotograph according to claim 1, wherein the content ratio E / F between the charge transport material E and the binder resin F is in a range of 1/2 to 1 by weight. Photoconductor. 8. A butadiene compound represented by the following general formula (I) as a charge transporting material and two or more resins formed on a conductive substrate by a dip coating method, Of a single-layer photoreceptor containing a binder resin containing less than 50% by weight of a polycarbonate resin having a structural unit represented by the following formula: and a phenol compound having a hindered phenol structural unit represented by the following general formula (III): A method for producing an electrophotographic photosensitive member, comprising forming a photosensitive layer or a charge transport layer of a laminated photosensitive member. Embedded image (In the formula, R1 to R4 represent an aryl group which may have a substituent or an aralkyl group which may have a substituent.) (Wherein, R 5 to R 12 represent a hydrogen atom, a halogen atom, a substituted or unsubstituted aliphatic group, or a substituted or unsubstituted carbocyclic group. Z represents a substituted or unsubstituted carbocyclic or substituted or unsubstituted Represents an atom group necessary for forming a heterocyclic ring, and n is from 10 to 1000.) (Wherein, R13 represents a branched alkyl group.
R16 represents a hydrogen atom, a hydroxy group, an alkyl group or an aryl group, and at least two of R14 to R16 may be mutually connected to form a ring. )