JPH11212289A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain both high mechanical strength and high lubricity even after use over a long period of time by incorporating a polyarylate having specified constituent units, a polycarbonate having specified constituent units, a specified copolymer and a graft polymer. SOLUTION: The surface layer of the electrophotographic photoreceptor contains a polyarylate having constituent units of formula I, a polycarbonate having constituent units of formula II, a copolymer having constituent units of formulae III and IV and fluororesin powder and/or a graft polymer having a polymerizable monomer as constituent having Si atoms in a side chain. In the formulae I-IV, X1 -X3 are each C or a single bond, R1 -R28 are each H, halogen, optionally substd. alkyl or aryl, R5 and R6 may bond to each other to form alkylidene, R27 and R28 may bond to each other to form alkylidene and (n) is a positive integer.

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, and more particularly, to an electrophotographic photosensitive member having a photosensitive layer containing a specific resin on a surface layer, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member. About.

[0002]

2. Description of the Related Art An electrophotographic method is disclosed in U.S. Pat.
As shown in the specification, a photoconductive material is used in which the electric resistance changes according to the irradiation amount received during image exposure and which is made of a support coated with an insulating substance in a dark place. The basic characteristics required of an electrophotographic photoreceptor using this photoconductive material include (1) being able to be charged to an appropriate potential in a dark place, (2) being small in potential dissipation in a dark place, (3) Quickly dissipating the charge by light irradiation, and the like.

Heretofore, as an electrophotographic photoreceptor, an inorganic photoreceptor having a photosensitive layer mainly containing an inorganic photoconductive compound such as selenium, zinc oxide, and cadmium sulfide has been widely used. However, they satisfy the above conditions (1) to (3), but are not always satisfactory in heat stability, moisture resistance, durability, and productivity. In recent years, electrophotographic photoconductors containing various organic photoconductive compounds as main components have been actively developed in order to overcome the disadvantages of inorganic photoconductors. For example, U.S. Pat. No. 3,838,851 discloses a photoreceptor having a charge transporting layer containing triallylpyrazoline, and U.S. Pat. No. 3,871,880 describes a charge generating layer comprising a derivative of perylene pigment, and condensation of 3-propylene and formaldehyde. Photoreceptors and the like comprising a charge transport layer comprising a body are known.

Further, the photosensitive wavelength range of the electrophotographic photosensitive member can be freely selected by the organic photoconductive compound depending on the compound.
The substances disclosed in Japanese Unexamined Patent Publication Nos. 72754 and 56-167759 are disclosed to exhibit high sensitivity in the visible region.
It has been shown that the compound disclosed in 1-228453 has sensitivity up to the infrared region. Among these materials, those exhibiting sensitivity in the infrared region include laser beam printers (hereinafter abbreviated as LBPs) and L
Used in ED printers, their demand frequency is increasing. Electrophotographic photoreceptors using these organic photoconductive compounds are used as function-separated type photoreceptors in which a charge transport layer and a charge generation layer are laminated in order to satisfy both electrical and mechanical properties. Often. On the other hand, as a matter of course, the electrophotographic photoreceptor is required to have sensitivity, electrical characteristics, and optical characteristics according to the applied electrophotographic process. In particular, in the case of an electrophotographic photoreceptor that is repeatedly used, the surface of the electrophotographic photoreceptor is directly subjected to electrical or mechanical external force such as corona or direct charging, image exposure, toner development, transfer process, surface cleaning, and the like. Also, durability for them is required.

[0005] More specifically, electrical deterioration due to ozone and nitrogen oxides during charging, electric discharge during charging, mechanical deterioration in which the surface is worn or scratched due to rubbing of a cleaning member, and electric deterioration. Durability against mechanical deterioration is required. The electrical degradation is particularly problematic in that carriers stay in a portion irradiated with light and an electric difference is generated from a portion not irradiated with light. This occurs as a photo memory. The mechanical deterioration is particularly different from the inorganic photoreceptor, and the organic photoreceptor having many soft materials is inferior in the durability against the mechanical deterioration, and the improvement of the durability is particularly desired. Various attempts have been made to satisfy the durability characteristics required for the photosensitive member as described above.

A polycarbonate resin having bisphenol A as a skeleton has attracted attention as a resin which is often used for the surface layer and has good abrasion and electrical characteristics. However, not all of the above-mentioned problems can be solved. In addition, it has the following problems. (1) It has poor solubility and shows good solubility only in a part of halogenated aliphatic hydrocarbons such as dichloromethane and 1,2-dichloroethane. In addition, since these solvents have a low boiling point, these solvents are used. When the photoreceptor is manufactured using the coating solution prepared in the above, the coated surface is likely to be whitened. It also takes time to control the solid content of the coating liquid. (2) For solvents other than halogenated aliphatic hydrocarbons, it is partially soluble in tetrahydrofuran, dioxane, cyclohexanone or a mixed solvent thereof, but the solution gels in a few days and has a time-dependent property. It is not suitable for photoconductor production. (3) Even if the above (1) and (2) are improved, solvent cracks are liable to occur in the polycarbonate resin having bisphenol A as a skeleton. (4) In addition, in the case of a conventional polycarbonate resin, the photoreceptor is easily damaged because the film formed of the resin does not have lubricity, and the image is not cleaned in a cleaning setting in which the abrasion loss of the electrophotographic photoreceptor is reduced. In some cases, the cleaning blade may be defective, defective cleaning may occur due to early deterioration of the cleaning blade, and toner fusion may occur.

For the solution stability mentioned in the above (1) and (2), a polycarbonate Z resin having a bulky cyclohexylene group as a polymer structural unit is used or copolymerized with bisphenol Z, bisphenol C or the like. It has been solved by

On the other hand, polyarylate has a structure similar to that of polycarbonate, but differs in various properties. For example, although the mechanical strength is excellent, the solubility of Z type having a cyclohexylidene group is low. Also, there are differences in electrophotographic photoreceptor characteristics, and particularly when used as a binder resin for a charge transport layer, each memory, residual potential, and the like are susceptible to change (deterioration) depending on the structure of the charge transport material used.

In addition, since the formed film is harder than conventional polycarbonate resins, the formed film is hard to be scraped off, and the cleaning method using a general rubber blade does not roughen the surface than polycarbonate and increases the contact area, so that the cleaning blade comes in contact with the cleaning blade in the counter direction. In such a case, the phenomenon that the cleaning blade is turned up easily occurs.

[0010] Solvent cracks can also be solved by using silicon-modified polycarbonate and ether-modified polycarbonate as disclosed in JP-A-6-51544 and JP-A-6-75415. . However, compared to conventional polycarbonate resins, these modified polycarbonates have a structure that gives flexibility to internal stress in the polymer in order to prevent solvent cracks, and as a result, the mechanical There was a disadvantage that the strength was reduced.

Further, in recent years, as disclosed in JP-A-57-17826 and JP-A-58-40566, a direct charging method in which a voltage is applied directly to a charging member to apply a charge to an electrophotographic photosensitive member. The method is becoming mainstream. This is a method in which a roller-shaped charging member made of a conductive rubber or the like is directly brought into contact with an electrophotographic photoreceptor to apply a charge, and the amount of generated ozone is significantly smaller than that of a scorotron or the like. While about 80% of the current flowing through the charger flows through the shield and is wasted, direct charging has the advantage that it is very economical without this waste.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problem of having a conventional polycarbonate resin or polyarylate resin as a surface layer, and to improve the mechanical strength and lubricity. An object of the present invention is to provide an electrophotographic photoreceptor which has both of them until the end of the life. Further, an object of the present invention is to provide an electrophotographic photoreceptor having good electrophotographic properties, good coatability at the time of production, and good paint pot life, and which does not turn over even with a general cleaning blade.

[0013]

According to the present invention, there is provided an electrophotographic photosensitive member having a conductive support and a photosensitive layer, wherein the surface layer of the electrophotographic photosensitive member has (A) a structure represented by the following formula (1). A polyarylate having a unit, (B) a polycarbonate having a structural unit represented by the following formula (2),
(C) a copolymer having the structural units represented by the following formulas (3) and (4), and (D) a fluorine-based resin powder and / or a polymerizable monomer having a silicon atom in a side chain. An electrophotographic photoreceptor comprising a graft polymer having a constituent component, a process cartridge for an electrophotographic apparatus in which the electrophotographic photoreceptor is integrally joined together with components of a charging unit, a developing unit and a cleaning unit, and An electrophotographic apparatus including the above process cartridge is provided.

[0014]

Embedded image (X ₁ is a carbon atom or a single bond (R ₅ , R
₆ story), R ₁ to R ₄ is a hydrogen atom, a halogen atom, an optionally substituted alkyl group, an aryl group, R _5,
R ₆ represents a hydrogen atom, a halogen atom, an alkyl group which may be substituted, an aryl group, or an alkylidene group formed by combining R ₅ and R ₆ ;
_{7 to} R ₁₀ each represent a hydrogen atom, a halogen atom, an alkyl group which may be substituted, or an aryl group)

[0015]

Embedded image (X ₂ is a carbon atom or a single bond (in this case, R ₁₅ , R
₁₆ story), R ₁₁ to R ₁₄ is a hydrogen atom, a halogen atom, an optionally substituted alkyl group, an aryl group, R _15,
R ₁₆ represents a hydrogen atom, a halogen atom, an alkyl group which may be substituted, an aryl group, or an alkylidene group formed by combining R ₁₅ and R ₁₆ )

[0016]

Embedded image (R _{17 to} R ₂₂ each represent a hydrogen atom, a halogen atom, an alkyl group which may be substituted, or an aryl group, and n represents a positive integer)

[0017]

Embedded image (X ₃ is a carbon atom or a single bond (in this case, R ₂₇ , R
₂₈ ), R _{23 to} R ₂₆ each represent a hydrogen atom, a halogen atom, an optionally substituted alkyl group or an aryl group, and R ₂₇ and R ₂₈ represent a hydrogen atom, a halogen atom, or an optionally substituted alkyl group, respectively. , An aryl group, or an alkylidene group formed by the bonding of R ₂₇ and R ₂₈ )

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION In the formulas (1) to (4), the halogen atom includes a fluorine atom, a chlorine atom, a bromine atom and the like, and the alkyl group includes a lower alkyl group such as a methyl group, an ethyl group, a propyl group. Group, butyl group and the like,
Examples of the aryl group include a phenyl group and a naphthyl group, and examples of the cycloalkylidene group include a cyclohexylidene group. Examples of the substituent which the alkyl group, the aryl group and the cycloalkylidene group may have include a lower alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group; an aryl group such as a phenyl group and a naphthyl group; Examples thereof include a halogen atom such as a fluorine atom, a chlorine atom and a bromine atom. n represents a positive integer and is preferably 1 to 200.

Table 1 shows specific examples of the structural unit represented by the formula (1), but the present invention is not limited to these.

[0020]

[Table 1]

[0021]

[Table 2]

[0022]

[Table 3]

[0023]

[Table 4] The polymer having a constitutional unit represented by the formula (1) used in the present invention is usually prepared by mixing a mixture of terephthalic acid chloride and isophthalic acid chloride with various bisphenols for controlling solubility and rigidity. It is obtained by interfacial polymerization with stirring in a solvent / water system under an alkali. That is, the formula shown in Table 1 was expressed as a form prepared from a mixed system of terephthalic acid chloride and isophthalic acid chloride.
However, the ratio of terephthalic acid chloride and isophthalic acid chloride is determined in consideration of the solubility of the polymer,
There is no established theory. However, any chloride is 30 mol%
Attention must be paid to the following, since the solubility of the synthesized polymer is extremely reduced. Usually, it is preferable to synthesize at a ratio of 1/1. In the electrophotographic photoreceptor of the present invention,
A monopolymer composed of the same structural unit represented by the formula (1) or a copolymer composed of two or more different types of structural units represented by the formula (1) may be used.

Table 2 shows specific examples of the structural unit represented by the formula (2), but the present invention is not limited to these.

[0025]

[Table 5]

[0026]

[Table 6]

[0027]

[Table 7] Table 3 shows specific examples of the structural unit represented by the formula (3), but is not limited thereto.

[0028]

[Table 8]

[0029]

[Table 9] Since the expression (4) is the same as the expression (2) shown in Table 2, the example of Table 2 is applied to the example of Expression (4).

Specific examples of the fluorine resin powder as the component (D) used in the present invention include ethylene tetrafluoride resin, ethylene trifluoride chloride resin, ethylene tetrafluoride hexafluoropropylene resin, and vinyl fluoride. Resins, vinylidene fluoride resins, ethylene difluoride dichloride resins, and copolymers thereof. Preferred examples include ethylene tetrafluoride resin and vinylidene fluoride resin, and particularly preferred examples include ethylene tetrafluoride resin.

The graft polymer having a polymerizable monomer having a silicon atom in the side chain as the component (D) used in the present invention is a polymer having a silicon atom in the side chain and a polymerizable terminal. Copolymerization of a monomer having a functional group and a polymerizable monomer having no silicon atom or a macromonomer comprising a relatively low molecular weight oligomer having a polymerizable functional group at a terminal and having a molecular weight of about 1,000 to 10,000. And has a structure in which a side chain containing a silicon atom with respect to the main chain hangs in a branch shape. Examples of the polymerizable monomer having a silicon atom in the side chain include the following compounds, but the present invention is not limited to these examples.

[0032]

Embedded image

[0033]

Embedded image

[0034]

Embedded image

[0035]

Embedded image

[0036]

Embedded image R is H or CH ₃ in the above formulas.

One of the polymerizable monomers or macromonomers is selected to have an affinity for the resin to which the above graft polymer is to be added. For example, acrylates, methacrylates, styrene and styrene derivatives Are used. The copolymerization ratio is preferably at least 5 wt% as the content of the polymerizable monomer having a silicon atom in the side chain. The weight average molecular weight of the obtained polymer is preferably from 500 to 100,000, particularly preferably from 1,000 to 5,000.

Although the detailed mechanism has not been fully elucidated, a polyarylate having a structural unit represented by the formula (1), a polycarbonate having a structural unit represented by the formula (2), and a formula (3) And a mixture of copolymers each having a structural unit represented by formula (4),
Further, by containing a fluorine-based resin powder as the D component, surface lubricity, solvent crack resistance, and the like can be stably improved from the initial stage of durability to after the durability. This is because the polyarylate structure, the polycarbonate structure, and the siloxane structure penetrate into each molecular chain, destroying each crystallinity, and further dispersing the fluorine-based resin powder inside the film, so that the fluorine-based Creates innumerable molecular groups and intramolecular orientational order with resin powder as the core,
It is presumed that this makes it possible to improve high surface lubricity and solvent crack resistance until after durability while maintaining high wear resistance.

Further, by containing a graft polymer having a polymerizable monomer having a silicon atom in a side chain as a component thereof as a component (D), surface lubricity and solvent resistance can be stably maintained from the beginning to the end of durability. Cracking properties and the like can be improved. It is known that a graft polymer having a polymerizable monomer having a silicon atom in a side chain as a component has a strong surface migration property. It can be easily understood that the graft polymer as a component will be mostly localized near the film surface and improve the surface lubricity in the early stage of durability, but in the configuration according to the present invention, it is stable from the early stage of durability to after the durability. It is surprising that the surface lubricity is improved. This is because a graft polymer having a polyarylate structure, a polycarbonate structure, and a siloxane structure penetrating between each molecular chain to break down each crystallinity, and further having a polymerizable monomer having a silicon atom in a side chain as a component. By being present not only near the film surface but also inside the film, a molecular group including a graft polymer having a polymerizable monomer having a silicon atom in a side chain as a constituent component inside the film and an intramolecular orientation order are created, It is presumed that this makes it possible to improve high surface lubricity and solvent crack resistance until after durability while maintaining high wear resistance.

This effect is obtained when all the graft polymers having a polyarylate structure, a polycarbonate structure, a siloxane structure, and a polymerizable monomer having a silicon atom in a side chain as constituents of the present invention are provided. Is effectively expressed, and even if one of the constituent elements is missing, the effect is greatly impaired.Therefore, a polymerizable monomer having a conventionally known siloxane structure or a silicon atom in the side chain is formed. It is presumed that a new effect far exceeding the lubricity and solvent crack resistance of the graft polymer possessed as a component is exerted by the interaction between the components of the present invention described above.

Although the detailed mechanism has not been sufficiently elucidated, R ₁ , R ₂ , R ₅ ,
R ₆ is a methyl group and R ₃ , R ₄ , R ₇ , R ₈ , R ₉ ,
A structural unit containing a polyarylate having a structural unit in which R ₁₀ is a hydrogen atom, and wherein R _{11 to} R ₁₄ in the formula (2) are a hydrogen atom, and R ₁₅ and R ₁₆ are a cyclohexylidene group together with X. Wherein R _{17 to} R ₂₀ in the formula (3) are methyl groups, R ₂₁ and R ₂₂ are hydrogen atoms, and R _{23 to} R ₂₃ in the formula (4)
₂₆ is a hydrogen atom, and each of copolymers having a constitutional unit in which R ₂₇ and R ₂₈ are a cyclohexylidene group together with X is mixed and used. Further, as a component (D), a fluororesin powder and / or silicon By containing the graft polymer having an atom in the side chain, surface lubricity and solvent crack resistance can be particularly stably improved from the initial stage of durability to after the durability. This is because in the polyarylate structure, R ₁ , R ₂ , R ₅ , and R ₆ in the formula (1) are methyl groups, and R ₃ , R ₄ , R ₇ , R ₈ , R ₉ , and R ₁₀ are hydrogen atoms. And the polycarbonate structure is represented by R ₁₁ to R ₁₁ in the formula (2).
R ₁₄ is a hydrogen atom, R ₁₅ and R ₁₆ are a cyclohexylidene group together with X, the siloxane structure is a group represented by R _{17 to} R ₂₀ in the formula (3), and R ₂₁ and R ₂₂ are a hydrogen atom R _{23 to} R ₂₆ in the formula (4) are a hydrogen atom, and R ₂₇ and R ₂₈ are closely related to being a cyclohexylidene group together with X, and how to enter each molecular chain, Differences in how each crystallinity is broken, and how the molecular groups including the fluorine resin powder of component (D) and / or the graft polymer having a silicon atom in the side chain and the intramolecular orientational order are formed inside the film. It is presumed that this makes it possible to improve the high surface lubricity and solvent crack resistance until the end of the durability while maintaining the high wear resistance.

Further, a polyarylate having a structural unit represented by the formula (1), a polycarbonate having a structural unit represented by the formula (2), and a formula (3) and a formula (4)
By mixing and dissolving a copolymer having the structural unit represented by in a good solvent, and containing a blend material obtained by reprecipitation with a poor solvent, it is possible to further exert the effects of the present invention. . The method of dissolution-reprecipitation is carried out by a conventional method, for example, a polyarylate having the structural unit represented by the formula (1) in a good solvent such as dichloromethane or chloroform, and a polycarbonate having the structural unit represented by the formula (2); And the copolymer having the structural units represented by the formulas (3) and (4) is sufficiently dissolved. Next, the mixed polymer solution is reprecipitated from a poor solvent such as methanol or water to obtain a flocculent polymer. This is vacuum dried to obtain a blend material. The material thus obtained comprises a polyarylate having a structural unit represented by the formula (1), a polycarbonate having a structural unit represented by the formula (2), and a structure represented by the formulas (3) and (4). The solubility and paint stability are improved compared to a simple blend of a copolymer having units. This method comprises: a polyarylate having any of the structural units represented by Formula (1); and a polycarbonate having any of the structural units represented by Formula (2):
The copolymers having the structural units represented by the formulas (3) and (4) are also effective, but particularly the polycarbonate A type and the polyarylate Z type, which have poor solubility, are effective for improving the properties.

Although the detailed mechanism has not been sufficiently elucidated, each polymer is previously blended in a solution to obtain a polyarylate structure having a structural unit represented by the formula (1), and a polymer represented by the formula (2). The polycarbonate structure having the structural unit represented by the formula (3) and the copolymer structure having the structural unit represented by the formula (3) and the formula (4) can be highly blended, and the obtained blended material enters between the respective molecular chains. Therefore, it is presumed that new characteristics due to interaction with the fluorine resin powder of the component (D) and / or the graft polymer having a silicon atom in the side chain have been easily developed.

First, in the case of polycarbonate A type or polyarylate Z type having low solubility, it is considered that molecules of different structures are blended, thereby deteriorating the crystallinity of each component. It is considered that the solubility was improved, and it is also presumed that gelation during storage and the like could be suppressed. Further, the cause of the decrease in the electrophotographic characteristics is estimated as follows. The phthalate ester structure, which is one of the factors that make polyarylate excellent in mechanical strength, is expected to become one of the carrier trapping factors in combination with the charge transporting material. A) a polycarbonate having a structural unit represented by formula (3) and a copolymer having a structural unit represented by formula (4) are present at a molecular level in the vicinity of a polyarylate having a structural unit represented by formula (1); Therefore, it is presumed that some kind of interaction occurs with the phthalate ester structure, thereby reducing carrier traps caused by the phthalate ester structure. Further, residual impurities (residual monomers, chlorides, etc.) in the polymer are one of the causes of deterioration of various properties. However, in the blend system of the present invention, the level of purification increases due to the improvement in solubility, and the electrophotographic properties deteriorate. Is considered to be suppressed.

Since the blend at the molecular level increases the intramolecular density and has both an amorphous portion and a crystalline portion in the same molecule, the intramolecular stress generated at the time of forming a coating film can be reduced, thereby improving the solvent. It is presumed that the internal stress is maintained and no crack occurs even if a chemical causing the crack enters.

In the present invention, the polyarylate having the structural unit represented by the formula (1), the polycarbonate having the structural unit represented by the formula (2), and the polycarbonate represented by the formula (3) and the formula (4) The viscosity-average molecular weight of the copolymer having the constituent units is preferably 10,000 to 200,000, and particularly 15,000 to 100,000.
00 is preferred. Further, the viscosity average molecular weight (M) of the polyarylate having the structural unit represented by the formula (1)
a), the viscosity average molecular weight (Mc) of the polycarbonate having the structural unit represented by the formula (2), and the viscosity average molecular weight (Ms) of the copolymer having the structural unit represented by the formulas (3) and (4). ) Preferably satisfies Ma ≧ Mc ≧ Ms.

The weight mixing ratio (Wa) of the polyarylate having the structural unit represented by the formula (1), the weight mixing ratio (Wc) of the polycarbonate having the structural unit represented by the formula (2), and the formula (Wc) The weight mixing ratio (Ws) of the copolymer having the structural units represented by 3) and formula (4) is Wa / W
c = 95/5 to 5/95, and Ws /
It is preferable that (Wa + Wc) = 1/99 to 30/70.

Further, the weight mixing ratio (W
f) is Wf / (Wa + Wc + Ws) = 1 / 100-5
It is preferably 0/100. The mixing weight ratio (Wf) of the graft polymer having a silicon atom in the side chain as the component (D) is Wf / (Wa + Wc + Ws) = 0.02 /
It is preferably 100 to 20/100.

Hereinafter, the structure of the electrophotographic photosensitive member used in the present invention will be described.

The electrophotographic photoreceptor in the present invention may be a single layer type in which the photosensitive layer contains a charge transporting material and a charge generating material in the same layer, or a laminated type in which the charge transporting layer and the charge generating layer are separated. Although good, the laminated type is preferable from the viewpoint of electrophotographic characteristics.
In any case, at least the surface layer of the electrophotographic photoreceptor has, as described above, a polyarylate as the component (A) represented by the formula (1), a polycarbonate as the component (B) represented by the formula (2), and a formula It contains a copolymer as the component (C) represented by the formula (3) and the formula (4) and a fluororesin powder or a graft polymer having a silicon atom in a side chain as the component (D).

The conductive support to be used may be any one having conductivity, such as metal such as aluminum and stainless steel, or metal provided with a conductive layer, paper, plastic and the like. And the like.
In particular, when an image input such as LBP is a laser beam, it is preferable to provide a conductive layer for the purpose of preventing interference fringes due to scattering or covering a scratch on the support. This can be formed by dispersing conductive powder such as carbon black and metal particles in a binder resin. The thickness of the conductive layer is suitably 5 to 40 μm, preferably 10 to 30 μm.

An intermediate layer having an adhesive function and a barrier function can be provided thereon as required. Examples of the material of the intermediate layer include polyamide, polyvinyl alcohol, polyethylene oxide, ethyl cellulose, casein, polyurethane, and polyether urethane. These are applied by dissolving in an appropriate solvent. The thickness of the intermediate layer is suitably 0.05 to 5 μm, preferably 0.3 to 1 μm.

In the case of the function separation type, a charge generation layer is formed thereon. Examples of the charge generation material used in the present invention include selenium-tellurium, pyrylium, thiapyrylium dyes, phthalocyanine, anthantrone, dibenzpyrenequinone, trisazo, cyanine, disazo, monoazo, indigo, quinacridone, and asymmetric quinocyanine pigments. No. The charge generation layer uses a homogenizer, an ultrasonic dispersion, a ball mill, a vibrating ball mill, a sand mill, an attritor, a roll mill, a liquid collision type high-speed disperser, and the like with the charge generation material together with a binder resin and a solvent in an amount of 0.3 to 4 times the amount. Well dispersed, apply the dispersion,
It is formed by drying. The thickness of the charge generation layer is 5 μm or less, preferably 0.1 to 2 μm.

The charge transport layer is formed by applying and drying a paint in which a charge transport material and a binder resin are dissolved in a solvent. Examples of the charge transport material used include a triarylamine compound, a hydrazone compound, a stilbene compound, a pyrazoline compound, an oxazole compound, a triallylmethane compound, and a thiazole compound.

These are combined with 0.5 to 2 times the amount of the binder resin, applied and dried to form a charge transport layer. The thickness of the charge transport layer is 5 to 40 μm, preferably 15 to 40 μm.
３０30 μm is appropriate.

When the photosensitive layer is of a single-layer type, the photosensitive layer is formed by dispersing and dissolving the above-described charge generation material and charge transport material in the above-described binder resin, followed by drying and application. The film thickness is 5 to 40 μm, preferably 15 to 3
0 μm is appropriate.

FIG. 1 shows a schematic configuration of an electrophotographic apparatus having a process cartridge having the electrophotographic photosensitive member of the present invention.

In FIG. 1, reference numeral 1 denotes a drum-shaped electrophotographic photosensitive member of the present invention, which is driven to rotate around a shaft 2 in a direction of an arrow at a predetermined peripheral speed. The photoreceptor 1 rotates during the rotation process.
The peripheral surface is uniformly charged with a predetermined positive or negative potential by the primary charging means 3, and then receives image exposure light 4 from an image exposure means (not shown) such as slit exposure or laser beam scanning exposure. Thus, an electrostatic latent image is sequentially formed on the peripheral surface of the photoconductor 1.

The formed electrostatic latent image is then transferred to developing means 5
The toner-developed image developed by the toner image is transferred from a paper supply unit (not shown) between the photoconductor 1 and the transfer unit 6 in synchronization with the rotation of the photoconductor 1 and fed to a transfer material 7 fed therefrom. The image is sequentially transferred by the transfer unit 6.

The transfer material 7 having undergone the image transfer is separated from the surface of the photoreceptor, introduced into the image fixing means 8 and subjected to image fixing, thereby being printed out of the apparatus as a copy.

The surface of the photoreceptor 1 after the image transfer is cleaned and cleaned by removing the untransferred toner by a cleaning blade 9, and further subjected to a static elimination process by a pre-exposure light 10 from a pre-exposure unit (not shown). Later, it is used repeatedly for image formation. When the primary charging unit 3 is a contact charging unit using a charging roller or the like, the pre-exposure is not necessarily required.

In the present invention, a plurality of components such as the above-described electrophotographic photosensitive member 1, primary charging means 3, developing means 5, and cleaning means 9 are integrally connected as a process cartridge. This process cartridge may be configured to be detachable from a main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. For example, at least one of the primary charging unit 3, the developing unit 5, and the cleaning unit 9 is integrally supported together with the photoreceptor 1 to form a cartridge, which can be attached to and detached from the apparatus main body using a guide unit such as a rail 12 of the apparatus main body. Process cartridge 1
It can be 1.

When the electrophotographic apparatus is a copying machine or a printer, the image exposure light 4 is reflected or transmitted from the original, or the original is read by a sensor and converted into a signal. Laser beam scanning,
Light emitted by driving the LED array, driving the liquid crystal shutter array, and the like.

The electrophotographic photosensitive member of the present invention can be used not only for an electrophotographic copying machine but also for a laser beam printer,
RT printer, LED printer, LCD printer,
It can be widely used in electrophotographic applications such as laser plate making.

Hereinafter, description will be made in accordance with embodiments.

The polyarylate having the structural unit represented by the formula (1), the polycarbonate having the structural unit represented by the formula (2), and the structural unit represented by the formulas (3) and (4) used in the present invention. Was synthesized by a conventional method.

A polyarylate having a structural unit represented by the formula (1), a polycarbonate having a structural unit represented by the formula (2), and a copolymer having the structural units represented by the formulas (3) and (4) As a method of blending the coalesced, a method of blending each polymer with a powder, a method of blending while dissolving in a good solvent, and the like are applicable.
In the present invention, a method of dissolving in a good solvent and reprecipitating with a poor solvent and blending is effective. As a procedure, first, each polymer was weighed at an arbitrary mixing ratio and sufficiently dissolved in 10 times (wt) of dichloromethane. Next, 10
The polymer solution was gradually added dropwise while stirring twice the amount (wt) of methanol. A white flocculent blend polymer was obtained in this methanol. This was vacuum dried and used as flakes. [Example 1] An aluminum cylinder having a diameter of 30 mm and a diameter of 254 mm was used as a support, and a coating composed of the following materials was applied to the support by a dipping method, and was thermally cured at 140 ° C for 30 minutes to form a conductive film having a thickness of 15 µm. A layer was formed.

Conductive pigment: SnO ₂ coated barium sulfate 10 parts Resistance adjusting pigment: titanium oxide 2 parts Binder resin: phenol resin 6 parts Leveling material: silicone oil 0.001 parts Solvent: methanol, methoxypropanol 0.2 / 0.8 20 parts Next, on this conductive layer, N-methoxymethylated nylon 3
And a solution of 3 parts of copolymerized nylon in a mixed solvent of 65 parts of methanol and 30 parts of n-butanol were applied by an immersion method to form an intermediate layer having a thickness of 0.5 μm.

Next, the diffraction angle 2 in X-ray diffraction of CuKα
θ ± 0.2 ° is 9.0 °, 14.2 °, 23.9 °, 2
After 4 parts of TiOPc having a strong peak at 7.1 °, 2 parts of polyvinyl butyral (trade name: Eslec BM2, manufactured by Sekisui Chemical) and 60 parts of cyclohexanone were dispersed in a sand mill using φ1 mm glass beads for 4 hours,
100 parts of ethyl acetate was added to prepare a dispersion for a charge generation layer. This was applied by an immersion method to form a charge generation layer having a thickness of 0.3 μm.

Next, in order to form a charge transport layer, a paint for the charge transport layer was prepared. Bisphenol C type (Example 1
-2) 50 parts of polyarylate and bisphenol Z type (Example 2-3) 40 parts of polycarbonate and Example 3-1
And a blend polymer prepared using 10 parts of the modified polycarbonate shown in Example 2-13. 100 parts of this blended polymer, 10 parts of polytetrafluoroethylene (trade name: Lubron L-2, manufactured by Daikin Industries, Ltd.), and fluorine-based graft polymer (trade name: Aron GF300, manufactured by Toagosei Chemical Industry Co., Ltd.) Five parts were dissolved in 500 parts of monochlorobenzene and 500 parts of dichloromethane, and dispersed in a stainless steel ball mill for 48 hours.

To the obtained dispersion, 90 parts of an amine compound having the following structural formula were added.

[0072]

Embedded image 10 parts of amine compound of the following structural formula

[0073]

Embedded image Was dissolved to obtain a paint for a charge transport layer.

This paint was applied by a dipping method and dried at 120 ° C. for 2 hours to form a 25 μm charge transport layer.

Next, the evaluation will be described.

The device is an LBP manufactured by Burette Packard
"Laser jet 4plus" (process speed 7
1 mm / sec). For the remodeling, pre-exposure with a fuse lamp was attached immediately before the charger, and the lamp was used only when the residual potential was measured. For the potential measurement, V
d, the laser beam irradiation part was Vl, and the pre-exposure irradiation part was Vr. The prepared electrophotographic photoreceptor is converted to 23
Paper passing durability was performed at 55 ° C. and 55% RH. The sequence is set to an intermittent mode in which the printing is stopped once for each print, and 1000
After printing the sheet, measure the potential and continue 500
The paper passing durability was reduced to 0 sheets, and the shaved amount of the photoreceptor was measured. In a high temperature and high humidity environment of 32.5 ° C. and 85% RH, 15,000
Endurance of paper passing was performed. The sequence is an intermittent mode that stops once for each print, pauses printing for 500 minutes for 10 minutes, repeatedly inserts and removes cartridges for every 1000 prints, evaluates the turning of the cleaning blade after endurance of 15,000 prints did. It should be noted that the toner was replenished as needed while the printing was suspended for 10 minutes. Further, as for solvent cracking property, finger fat was adhered to the surface, left for 24 hours, and observed with a microscope for the presence or absence of solvent cracking. As an evaluation of the pot life, each charge transport layer paint was allowed to stand in a closed container at room temperature (23 ° C.) for one week, and then the dissolved state was observed. [Example 2] As a blend polymer to be used, bisphenol Z type (Example 1-23) and bisphenol C type (Example 1)
-2) was carried out in the same manner as in Example 1 except that the conditions shown in Table 4 were used, using a polyarylate copolymerized in 1/1. Table 5 shows the results. [Examples 3 to 12] In the same manner as in Example 1 except that the conditions shown in Table 4 were used as the polymer to be used, the fluororesin powder, the mixing ratio, and whether the polymer was used as a blend polymer or each polymer was used separately. went. Table 5 shows the results. [Comparative Examples 1 to 18] In the same manner as in Example 1 except that the conditions shown in Table 4 were used, the polymer to be used, the fluororesin powder, the mixing ratio, and whether the polymer was used as a blend polymer or each polymer was used separately. went. Table 5 shows the results.

[0077]

[Table 10]

[0078]

[Table 11] *: "Re-precipitation" is a blend obtained by dissolution / re-precipitation. "Separate" is one added sequentially during dissolution. **: No cracks = も の Cracks were generated = × *** : Dissolved = ○ Gelled or not dissolved = × ****: Cleaning blade did not turn up = ○ Cleaning blade turned up ×× Cleaning blade did not turn up to 15,000 sheets Unprintable = (O) As described above, by containing the polyarylate, the polycarbonate, the modified polycarbonate, and the fluororesin powder shown in the present invention, excellent mechanical strength and surface lubricity can be obtained after durability. The present invention can provide an electrophotographic photoreceptor having both of the above. Further, it is possible to provide an electrophotographic photoreceptor having good electrophotographic properties, good coatability at the time of production and good paint pot life, and which does not turn up even with a general cleaning blade.

The graft polymers (compound Nos. 4-1 to 4-4) having a polymerizable monomer having a silicon atom in the side chain used as a constituent in the following examples are as shown in the table.

[0080]

[Table 12] Example 13 A conductive layer having a thickness of 15 μm, an intermediate layer having a thickness of 0.5 μm, and a charge generation layer having a thickness of 0.3 μm were formed in the same manner as in Example 1.

Next, in order to form a charge transport layer, a paint for the charge transport layer was prepared. Bisphenol C type (Example 1
A blend polymer prepared using 50 parts of polyarylate-2), 40 parts of a bisphenol Z type (Example 2-3) polycarbonate, and 10 parts of the modified polycarbonate shown in Examples 3-1 and 2-13 was used. 100 parts of the blend polymer, a graft polymer having a polymerizable monomer having a silicon atom in a side chain as a component (Compound N)
o. 4-1) 2 parts, 90 parts of an amine compound having the following structural formula, and

[0082]

Embedded image 10 parts of amine compound of the following structural formula

[0083]

Embedded image Are mixed with 500 parts of monochlorobenzene and 50 parts of dichloromethane.
0 parts to obtain a paint for the charge transport layer. This paint was applied by a dipping method and dried at 120 ° C. for 2 hours to form a 25 μm charge transport layer. Next, Table 7 shows the results of the evaluation performed in the same manner as in Example 1. [Example 14] A polyarylate obtained by copolymerizing bisphenol Z type (Example 1-23) and bisphenol C type (Example 1-2) at 1/1 as the blend polymer to be used was used, except that the conditions shown in Table 6 were used. Performed in the same manner as in Example 1. Table 7 shows the results. [Examples 15 to 24] Tables showing polymers to be used, graft polymers having a polymerizable monomer having a silicon atom in a side chain as a component, mixing ratio, and whether they were used as a blend polymer or each polymer was used separately. 6 was performed in the same manner as in Example 1 except that the conditions shown in FIG. Table 7 shows the results. [Comparative Examples 19 to 36] Tables showing polymers to be used, graft polymers having a polymerizable monomer having a silicon atom in a side chain as a component, mixing ratio, and whether they were used as a blend polymer or each polymer was used separately. 6 was performed in the same manner as in Example 1 except that the conditions shown in FIG. Table 7 shows the results.

[0084]

[Table 13]

[0085]

[Table 14] In the table, *, **, ***, and **** are the same as the remarks in Tables 10 and 11. Thus, the polyarylate, polycarbonate, modified polycarbonate, and polymerization having a silicon atom in the side chain shown in the present invention. An electrophotographic photoreceptor having excellent mechanical strength and surface lubricity until endurance can be provided by containing a graft polymer having a hydrophilic monomer as a constituent component. Further, it is possible to provide an electrophotographic photoreceptor having good electrophotographic properties, good coatability at the time of production and good paint pot life, and which does not turn up even with a general cleaning blade.

[0086]

As described above, the electrophotographic photoreceptor of the present invention has both excellent mechanical strength and surface lubricity until after the endurance, and has good electrophotographic properties. In addition, the improvement in solubility and pot life has expanded the range of choice of materials (constituent units), making it possible to provide an electrophotographic photoreceptor according to the purpose of use.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus having a process cartridge having an electrophotographic photosensitive member of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor of this invention 2 axis 3 Primary charging means 4 Image exposure light 5 Developing means 6 Transfer means 7 Transfer material 8 Image fixing means 9 Cleaning blade 10 Pre-exposure light 11 Process cartridge 12 Rail

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hirotoshi Uesugi 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (9)

[Claims] 1. An electrophotographic photosensitive member comprising a conductive support and a photosensitive layer, wherein the surface layer of the electrophotographic photosensitive member comprises: (A) a polyarylate having a repeating unit represented by the following formula (1): ) A polycarbonate having a repeating unit represented by the following formula (2); (C) a copolymer having a repeating unit represented by the following formulas (3) and (4); and (D) a fluororesin powder and / or An electrophotographic photoreceptor comprising a graft polymer having as a constituent a polymerizable monomer having a silicon atom in a side chain. Embedded image (X ₁ is a carbon atom or a single bond (R ₅ , R
₆ story), R ₁ to R ₄ is a hydrogen atom, a halogen atom, an optionally substituted alkyl group, an aryl group, R _5,
R ₆ represents a hydrogen atom, a halogen atom, an alkyl group which may be substituted, an aryl group, or an alkylidene group formed by combining R ₅ and R ₆ ;
_{7 to} R ₁₀ represent a hydrogen atom, a halogen atom, an alkyl group which may be substituted, and an aryl group, respectively. (X ₂ is a carbon atom or a single bond (in this case, R ₁₅ , R
₁₆ story), R ₁₁ to R ₁₄ is a hydrogen atom, a halogen atom, an optionally substituted alkyl group, an aryl group, R _15,
R ₁₆ represents a hydrogen atom, a halogen atom, an alkyl group which may be substituted, an aryl group, or an alkylidene group formed by the bonding of R ₁₅ and R _16. (R _{17 to} R ₂₂ each represent a hydrogen atom, a halogen atom, an alkyl group which may be substituted, or an aryl group, and n represents a positive integer.) (X ₃ is a carbon atom or a single bond (in this case, R ₂₇ , R
₂₈ ), R _{23 to} R ₂₆ each represent a hydrogen atom, a halogen atom, an optionally substituted alkyl group or an aryl group, and R ₂₇ and R ₂₈ represent a hydrogen atom, a halogen atom, or an optionally substituted alkyl group, respectively. , An aryl group, or an alkylidene group formed by the bonding of R ₂₇ and R ₂₈ ) 2. The method according to claim 1, wherein R ₁ , R ₂ , R
₅ , R ₆ are methyl groups and R ₃ , R ₄ , R ₇ , R ₈ , R
₉ , a polyarylate having a repeating unit in which R ₁₀ is a hydrogen atom, having a repeating unit in which R _{11 to} R ₁₄ in the formula (2) are a hydrogen atom and R ₁₅ and R ₁₆ are a cyclohexylidene group together with X. Polycarbonate, the formula (3)
R _{17 to} R ₂₀ are a methyl group, R ₂₁ and R ₂₂ are hydrogen atoms, and R _{23 to} R ₂₆ in the formula (4) are hydrogen atoms, and R ₂₇ and R ₂₈ are cyclohexylidene together with X. The electrophotographic photosensitive member according to claim 1, further comprising a copolymer having a repeating unit as a group. 3. The fluorine resin powder as the component (D) is a tetrafluoroethylene resin, a trichloroethylene resin,
The resin according to claim 1, wherein the resin is selected from ethylene tetrafluoride hexafluoride propylene resin, vinyl fluoride resin, vinylidene fluoride resin, ethylene difluoride ethylene chloride resin, and a copolymer thereof. 4. Electrophotographic photoreceptor. 4. A graft polymer having a polymerizable monomer having a silicon atom in a side chain as a component (D) as a component, the graft polymer having a silicon atom in a side chain and having a polymerizable functional group at a terminal. 3. The electron according to claim 1, which is obtained by copolymerizing a monomer and a polymerizable monomer having no silicon atom or a macromonomer comprising an oligomer having a polymerizable functional group at a terminal. Photoreceptor. 5. The weight ratio (Wa) of the polyarylate as the component (A), the weight ratio (Wc) of the polycarbonate as the component (B), and the weight ratio (Ws) of the copolymer as the component (C). And the weight ratio (Wf) of the fluororesin of the component (D) satisfies the following relationship: Wa / Wc = 95/5 to 5/95 Ws / (Wa + Wc). ) = 1 / 99-30 / 70 Wf / (Wa + Wc + Ws) = 1 / 100-50 / 10
0 6. The weight ratio (Wa) of the polyarylate as the component (A), the weight ratio (Wc) of the polycarbonate as the component (B), and the weight ratio (Ws) of the copolymer as the component (C). 3. The electrophotographic photoreceptor according to claim 1, wherein the weight ratio (Wf) of the graft polymer containing a silicon atom as a side chain as the component (D) satisfies the following relationship: Wa / Wc = 95 / 5-5 / 95 Ws / (Wa + Wc) = 1 / 99-30 / 70 Wf / (Wa + Wc + Ws) = 0.02 / 100-20
/ 100 7. A polyarylate having a structural unit represented by the formula (1), a polycarbonate having a structural unit represented by the formula (2), and a structural unit represented by the formula (3) and the formula (4) 3. The electrophotographic photoreceptor according to claim 1, further comprising a blend material obtained by dissolving and mixing the copolymer in a good solvent, and reprecipitating the poor solvent. 8. A process cartridge for an electrophotographic apparatus, wherein the photosensitive member is integrally combined with components of a charging unit, a developing unit and a cleaning unit. 9. An electrophotographic apparatus comprising: a process cartridge in which the photosensitive member is integrally combined with components of a charging unit, a developing unit, and a cleaning unit.