JP4720589B2 - Electrophotographic photoreceptor and image forming apparatus provided with the photoreceptor - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member, and more particularly, to a technique relating to an electrophotographic photosensitive member having good electrical characteristics.

Electrophotographic technology is widely used in the fields of copiers and various printers because of its immediacy and high quality images. As for the electrophotographic photosensitive member, which is the core of the electrophotographic technology, an electrophotographic photosensitive member using an organic photoconductive material having advantages such as non-pollution, easy film formation, and easy manufacture is used. .
In an organic electrophotographic photoreceptor, it is usual to use an organic photoconductive substance dissolved or dispersed in a binder resin to form a coating film. The coating film is formed by dissolving or dispersing the organic photoconductive substance and the binder resin, followed by coating and drying. Among these, a so-called dispersion type photoreceptor in which photoconductive fine powder is dispersed in a binder resin and a laminate type photoreceptor in which a charge generation layer and a charge transfer layer are laminated are known.

Among them, the laminated type photoreceptor can obtain a highly sensitive photoreceptor by combining a highly efficient charge generating substance and charge transfer substance, respectively, and can obtain a highly safe photoreceptor with a wide range of material selection. Further, it can be easily formed by coating a photosensitive layer, has high productivity, and is advantageous in terms of cost. Therefore, it is the mainstream of photoreceptors, and has been developed and put into practical use.
These electrophotographic photoreceptors are naturally required to have various characteristics such as electrical, mechanical and optical characteristics according to the applied electrophotographic process. In particular, in a photoreceptor that is repeatedly used, electrical and mechanical forces such as charging, exposure, development, transfer, and cleaning are repeatedly applied directly or indirectly, and thus durability against them is required.

In the case of a general photoreceptor not provided with a functional layer such as a surface protective layer, the photosensitive layer is subjected to such a load. The photosensitive layer is usually composed of a binder resin and a photoconductive substance, and the binder resin substantially determines the strength.
In particular, since high-speed, high-quality, and high-stabilization are further required for devices using the electrophotographic process from the present to the future, the binder resin repeatedly maintains high electrical characteristics and high mechanical characteristics. The durability that can be made is particularly necessary.

As the binder resin, various thermoplastic resins or thermosetting resins are used. Among them, polycarbonate resin has a relatively excellent performance, so that it has been developed and put to practical use in the past. However, there is a problem that durability against abrasion in the electrophotographic process described above is insufficient. is there.
On the other hand, polyarylate resin, which is a material excellent in strength, can be used as the binder resin, but the balance between strength and electrical characteristics cannot be said to be good. That is, polyarylate resins are well known as engineering plastics in the use of molded products such as electrical parts and automobile parts, but their use as binder resins for electrophotographic photoreceptors is limited. In view of this, studies have been made to improve the characteristics of the polyarylate resin itself and the characteristics of the electrophotographic photoreceptor (see, for example, Patent Document 1 and Patent Document 2).
JP 2001-59019 A Japanese Patent No. 3537065

However, when this polyarylate resin is used as a binder resin for an electrophotographic photosensitive member, it should be excellent in balance between mechanical properties typified by wear resistance of the electrophotographic photosensitive member and electrical properties. It is still difficult.
The present invention has been made to solve the above-described problems. That is, an object of the present invention is to provide an electrophotographic photoreceptor excellent in electrical characteristics and mechanical characteristics.

As a result of intensive studies, the present inventors have found that in an electrophotographic photosensitive member having a photosensitive layer on a conductive support, the photosensitive layer contains a polyarylate resin produced by a specific production method. The present inventors have found that it is possible to provide an electrophotographic photosensitive member that is excellent in mechanical properties and is excellent in mechanical properties.
That is, the first gist of the present invention is an electrophotographic photosensitive member having a photosensitive layer on a conductive support, wherein the photosensitive layer contains dicarboxylic acid halides represented by the following formula (1) as a total dicarboxylic acid component. a dicarboxylic acid component having 100 mol% containing for the ratio of moles of hydroxide ions (a) the moles of phenolic hydroxyl groups (B) (a / B) is, a / B = 1. An electrophotographic photoreceptor comprising a polyarylate resin produced as a raw material with an alkaline aqueous solution of an aromatic hydroxy compound prepared in the range of 5 to 2.2 . The gist of the present invention resides in an electrophotographic photoreceptor, wherein the aromatic hydroxy compound is a dihydric phenol represented by the following formula (2).

(In Formula (1), R ¹ and R ² are each independently a hydrogen atom or a monovalent substituent, a and b are each independently an integer of 1 to 4, and X is a halogen atom. is there.)

(In formula (2), R ^{3 to} R ⁶ are each independently a hydrogen atom or a monovalent substituent, and c and d are each independently an integer of 1 to 4.)

  According to the present invention, it is possible to provide an electrophotographic photosensitive member having excellent electrical characteristics and excellent wear resistance.

The best mode for carrying out the present invention (hereinafter, an embodiment of the present invention) will be described in detail below. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.
The electrophotographic photoreceptor to which the exemplary embodiment is applied includes a photosensitive layer provided on a predetermined conductive support, and the photosensitive layer includes the polyarylate resin according to the present invention described above. As a specific configuration of the photosensitive layer, for example, a laminate in which a charge generation layer mainly composed of a charge generation material and a charge transport layer mainly composed of a charge transport material and a binder resin are stacked on a conductive support. Type photoreceptor; a dispersion type photoreceptor having a photosensitive layer in which a charge generating substance is dispersed in a layer containing a charge transport substance and a binder resin on a conductive support. The above-described polyarylate resin of the present invention is usually used as a binder resin for a layer containing a charge transport material, and is preferably used as a binder resin for a charge transport layer of a multilayer photoreceptor.

<Polyarylate resin>
The polyarylate resin according to the present invention is obtained by dehydration condensation of dicarboxylic acid halides represented by the following formula (1) and an aromatic hydroxy compound.

In formula (1), R ¹ and R ² are each independently a hydrogen atom or a monovalent substituent, a and b are each independently an integer of 1 to 4, and X is a halogen atom. . As X, a chlorine atom is preferably used.
Examples of monovalent substituents represented by R ¹ and R ² include alkyl groups such as methyl, ethyl and propyl; aryl groups such as phenyl and naphthyl; fluorine, chlorine and bromine And halogen groups such as iodine atom; alkoxy groups such as methoxy group, ethoxy group and butoxy group. These substituents may further have a substituent such as an alkyl group, an aryl group, a halogen group, or an alkoxy group. Among these, considering the solubility in the coating solution for forming a photosensitive layer as the binder resin for the photosensitive layer, the monovalent substituent represented by R ¹ or R ² is preferably an alkyl group, more preferably 1 carbon atom. To an alkyl group having 8 carbon atoms, more preferably an alkyl group having 1 or 2 carbon atoms. a and b are each independently an integer of 0 to 4, but are preferably each independently an integer of 0 to 2, and particularly preferably a = b = 0.

  Specific examples of the dicarboxylic acid halides represented by the formula (1) include, for example, diphenyl ether-2,2′-dicarboxylic acid, diphenyl ether-2,3′-dicarboxylic acid, diphenyl ether-2,4′-dicarboxylic acid, Halides such as diphenyl ether-3,3′-dicarboxylic acid, diphenyl ether-3,4′-dicarboxylic acid, and diphenyl ether-4,4′-dicarboxylic acid are listed. Among these, in consideration of the simplicity of production of dicarboxylic acid halides, halides of diphenyl ether-2,2′-dicarboxylic acid, diphenyl ether-2,4′-dicarboxylic acid, diphenyl ether-4,4′-dicarboxylic acid Are preferred, and diphenyl ether-4,4′-dicarboxylic acid halide is particularly preferred.

The compounds exemplified as the dicarboxylic acid halides represented by the formula (1) can be used in combination of a plurality of compounds in any combination and in any quantitative ratio as necessary. Further, dicarboxylic acid halides other than the dicarboxylic acids represented by the formula (1) can be used in any combination and in any quantitative ratio.
Examples of dicarboxylic acid halides that can be used in addition to the dicarboxylic acid halides represented by formula (1) include adipic acid, suberic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, toluene-2,5-dicarboxylic acid, p-xylene-2,5-dicarboxylic acid, pyridine-2,3-dicarboxylic acid, pyridine-2,4-dicarboxylic acid, pyridine-2,5-dicarboxylic acid, pyridine-2,6-dicarboxylic acid, pyridine-3 , 4-dicarboxylic acid, pyridine-3,5-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-2,3-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, biphenyl-2,2′-dicarboxylic acid And halides such as biphenyl-4,4′-dicarboxylic acid, and among these, adipic acid and sebacic acid are preferable. Halides of phthalic acid, isophthalic acid, terephthalic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, biphenyl-2,2′-dicarboxylic acid, biphenyl-4,4′-dicarboxylic acid Particularly preferred are halides of isophthalic acid and terephthalic acid.

  The polyarylate resin according to the present invention is produced by condensing a dicarboxylic acid halide represented by the formula (1) and an aromatic hydroxy compound, and the aromatic hydroxy compound includes a plurality of hydroxy groups. It is possible to use any aromatic hydroxy compound that can be used as a repeating component of a binder resin for an electrophotographic photoreceptor. Among these, it is preferable to use dihydric phenols represented by the following formula (2) as the aromatic hydroxy compound.

In formula (2), R ^{3 to} R ⁶ are each independently a hydrogen atom or a monovalent substituent, and c and d are each independently an integer of 1 to 4.
Examples of the organic group represented by R ^{3 to} R ⁶ include alkyl groups such as a methyl group, an ethyl group, and a propyl group; aryl groups such as a phenyl group and a naphthyl group; a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Halogen groups such as alkoxy groups such as methoxy, ethoxy and butoxy groups. These substituents may further have a substituent such as an alkyl group, an aryl group, a halogen group, or an alkoxy group. Among these, considering the solubility in the coating solution for forming a photosensitive layer as the binder resin for the photosensitive layer, the monovalent substituent represented by R ^{3 to} R ⁶ is preferably a hydrogen atom or an alkyl group, more preferably. Is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 or 2 carbon atoms. Among these, R ⁶ is preferably a hydrogen atom, and R ⁵ is particularly preferably a methyl group. c and d each independently represent an integer of 0 to 4, preferably each independently represents an integer of 0 to 2, and particularly preferably c = d = 1.

Specific examples of the dihydric phenol represented by the formula (2) include bis (4-hydroxyphenyl) methane, (2-hydroxyphenyl) (4-hydroxyphenyl) methane, bis (2-hydroxyphenyl) methane, Bis (4-hydroxy-3-methylphenyl) methane, bis (4-hydroxy-3,5-dimethylphenyl) methane, bis (4-hydroxy-3-ethylphenyl) methane, 1,1-bis (4-hydroxy) Phenyl) ethane, 1,1-bis (4-hydroxy-3-methylphenyl) ethane, 1,1-bis (4-hydroxy-3,5-dimethylphenyl) ethane, 1,1-bis (4-hydroxy-) 3-ethylphenyl) ethane, 1,1-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxy-3-methylphenyl) Examples include propane, 1,1-bis (4-hydroxy-3,5-dimethylphenyl) propane, 1,1-bis (4-hydroxy-3-ethylphenyl) propane, and among these, bis ( 4-hydroxyphenyl) methane, bis (4-hydroxy-3-methylphenyl) methane, bis (4-hydroxy-3,5-dimethylphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 1, 1-bis (4-hydroxy-3-methylphenyl) ethane is exemplified, and 1,1-bis (4-hydroxyphenyl) ethane and 1,1-bis (4-hydroxy-3-methylphenyl) ethane are particularly preferred. can give.

The compounds exemplified as these dihydric phenols can be used in combination of a plurality of compounds in any combination and in any quantitative ratio as necessary. Moreover, it is also possible to use together aromatic hydroxy compounds other than the dihydric phenol represented by Formula (2) in arbitrary combinations and arbitrary quantity ratios.
The polyarylate resin of the present invention includes a dicarboxylic acid component containing 50 mol% or more of dicarboxylic acid halides represented by the formula (1), the number of moles of hydroxide ions (A) and organic The ratio (A / B) of the number of moles (B) of the hydrophilic hydroxyl group is produced using an alkaline aqueous solution of an aromatic hydroxy compound prepared in the range of A / B = 1.1 to 10 as a raw material. Among electrical characteristics, in particular, A / B = 1.1 to 5.0 is preferable in that the potential after exposure is low, more preferably A / B = 1.1 to 3, particularly Is preferably 1.5 to 2.5.

  Hydroxide ions in an aqueous alkali solution are present by dissolving inorganic hydroxides, such as alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, in the aqueous solution. The number of moles of hydroxide ions varies depending on the degree of dissociation of inorganic hydroxides in the aqueous solution. The number of moles of hydroxide ions in the aqueous alkaline solution in the present invention is the number of moles of the inorganic hydroxide. The number of moles when the substance is completely dissociated, that is, the number of moles of the inorganic hydroxides dissolved in the aqueous solution.

  In the electrophotographic photosensitive member of the present invention, the polyarylate resin according to the present invention and another resin can be used in combination. Examples of other resins used in combination here include vinyl polymers such as polymethyl methacrylate, polystyrene, polyvinyl chloride or copolymers thereof, polyester resins, polyarylate resins, polycarbonate resins, polyester polycarbonate resins, polysulfone resins, phenoxys. Examples thereof include thermoplastic resins such as resins, epoxy resins, and silicone resins, and various thermosetting resins. Among these resins, polyester resins, polyarylate resins, and polycarbonate resins are preferable. Moreover, the mixing ratio of the resin used in combination is not particularly limited, but it is usually preferable to use the resin in a range not exceeding the ratio of the polyarylate resin of the present invention.

The method for producing the polyarylate resin of the present invention is not particularly limited as long as an alkaline aqueous solution of an aromatic hydroxy compound is used, and any known polymerization method can be used.
In the case of production by the interfacial polymerization method, for example, the alkaline aqueous solution of the aromatic hydroxy compound and the halogenated hydrocarbon solution of the dicarboxylic acid component are mixed. At this time, it is preferable that a quaternary ammonium salt or a quaternary phosphonium salt is present as a catalyst for the polymerization reaction. The polymerization temperature is preferably in the range of 0 ° C. to 40 ° C., and the polymerization time is preferably in the range of 2 hours to 20 hours from the viewpoint of productivity. After completion of the polymerization, the water phase and the organic phase are separated, and the polymer dissolved in the organic phase is washed and recovered by a known method to obtain the intended resin. Examples of the halogenated hydrocarbon include dichloromethane, chloroform, 1,2-dichloroethane, trichloroethane, tetrachloroethane, dichlorobenzene, and the like. Examples of quaternary ammonium salts or quaternary phosphonium salts used as catalysts include, for example, salts of tertiary alkylamines such as tributylamine and trioctylamine such as hydrochloric acid, bromic acid and iodic acid; benzyltriethylammonium chloride, benzyltrimethylammonium Examples include chloride, benzyltributylammonium chloride, tetraethylammonium chloride, tetrabutylammonium chloride, tetrabutylammonium bromide, trioctylmethylammonium chloride, tetrabutylphosphonium bromide, triethyloctadecylphosphonium bromide, N-laurylpyridinium chloride, laurylpicolinium chloride It is done.

  Moreover, a molecular weight modifier can be used in the polymerization. Examples of the molecular weight regulator include phenol, o, m, p-cresol, o, m, p-ethylphenol, o, m, p-propylphenol, o, m, p- (tert-butyl) phenol, and pentyl. Monofunctional phenols such as phenol, hexylphenol, octylphenol, nonylphenol, alkylphenols such as 2,6-dimethylphenol derivatives and 2-methylphenol derivatives, o, m, p-phenylphenol; acetic acid chloride, butyric acid chloride, octyl Monofunctional acid halides such as acid chloride, benzoyl chloride, benzenesulfonyl chloride, benzenesulfinyl chloride, sulfinyl chloride, benzenephosphonyl chloride and their substitutes may be present. Among these molecular weight regulators, o, m, p- (tert-butyl) phenol, 2,6-dimethylphenol derivatives, and 2-methylphenol derivatives are preferred because of their high molecular weight controllability and solution stability. is there. Particularly preferred are p- (tert-butyl) phenol, 2,3,6-trimethylphenol, and 2,3,5-trimethylphenol, and a plurality of these can be used in combination.

The viscosity average molecular weight (Mv) of the polyarylate resin according to the present invention is not particularly limited, but is usually 10,000 or more, preferably 15,000 or more, more preferably 20,000 or more, and usually 300,000. Hereinafter, it is preferably 200,000 or less, more preferably 100,000 or less. If the viscosity average molecular weight is excessively small, the mechanical strength of the polyarylate resin is lowered, which is not practical. On the other hand, if the viscosity average molecular weight is excessively large, it is difficult to apply and form the photosensitive layer to an appropriate thickness. In the present invention, the viscosity average molecular weight is, for example, a resin solution in dichloromethane (concentration: 6.00 g / L) at 20.0 ° C. using an Ubbelohde capillary viscometer (dichloromethane flow time t ₀ : 136.16 seconds). ) Is measured and calculated based on the following equation.

η _sp = (t / t ₀ ) −1
a = 0.438 × η _sp +1
b = 100 × (η _sp / C)
C = 6.00 [g / L]
η = b / a
Mv = 3207 × η ^1.205

<Conductive support>
Examples of the material for the conductive support used in the electrophotographic photosensitive member to which this embodiment is applied include metal materials such as aluminum, aluminum alloy, stainless steel, copper, and nickel; metal, carbon, tin oxide, and the like. Resin material that has been given conductivity by adding a conductive powder; resin, glass, paper, etc. with a conductive material such as aluminum, nickel, ITO (indium-tin oxide) deposited or applied on its surface It is done.

Examples of the form of the conductive support include a drum shape, a sheet shape, and a belt shape. Alternatively, a conductive material having an appropriate resistance value may be coated on a conductive support using a metal material for the purpose of controlling conductivity, surface properties, etc. or covering defects.
The surface of the conductive support may be smooth, or may be roughened by using a special cutting method or polishing. Further, it may be roughened by mixing particles having an appropriate particle diameter with the material constituting the support. In order to reduce the cost, it is possible to use the drawing tube as it is without cutting. In particular, when using a non-cutting aluminum substrate such as drawing, impact processing, ironing, etc., it is preferable because the treatment eliminates dirt, foreign matter, and other foreign matters, small scratches, etc., and a uniform and clean substrate can be obtained. .

  Moreover, when using metal materials, such as an aluminum alloy, as an electroconductive support body, you may use, after giving an anodic oxide film. Anodized film is formed, for example, by anodizing in an acidic bath such as chromic acid, sulfuric acid, oxalic acid, boric acid, sulfamic acid, etc. give. In the case of anodic oxidation in sulfuric acid, the sulfuric acid concentration is 100 to 300 g / l, the dissolved aluminum concentration is 2 to 15 g / l, the liquid temperature is 15 to 30 ° C., the electrolysis voltage is 10 to 20 V, and the current density is 0.5 to Although it is preferable to set within the range of 2A / dm2, it is not limited to the above conditions.

If the average film thickness of the anodic oxide coating is too thick, stronger sealing conditions are required due to higher concentration of the sealing liquid and higher temperature / long-time treatment. Accordingly, productivity is deteriorated and surface defects such as spots, dirt, and dusting are easily generated on the coating surface. From such a point, it is preferable that the average film thickness of the anodic oxide coating is usually 20 μm or less, particularly 7 μm or less.
When an anodized film is formed, it is preferable to perform a sealing treatment. The sealing treatment may be performed by a normal method, for example, a low-temperature sealing treatment in which the sealing material is immersed in an aqueous solution containing nickel fluoride as a main component, or a high-temperature sealing in which the sealing treatment is immersed in an aqueous solution containing nickel acetate as a main component. It is preferable to apply a hole treatment.

  In the case of low-temperature sealing treatment, the concentration of the nickel fluoride aqueous solution to be used can be selected as appropriate, but more preferable results are obtained when the concentration is in the range of 3 to 6 g / l. The pH of the aqueous nickel fluoride solution is usually 4.5 or higher, preferably 5.5 or higher, and usually 6.5 or lower, preferably 6.0 or lower. As the pH adjuster, oxalic acid, boric acid, formic acid, acetic acid, sodium hydroxide, sodium acetate, aqueous ammonia and the like can be used. In order to further improve the physical properties of the film, cobalt fluoride, cobalt acetate, nickel sulfate, a surfactant and the like may be added to the nickel fluoride aqueous solution. The treatment temperature is usually in the range of 25 ° C. or higher, preferably 30 ° C. or higher, and usually 40 ° C. or lower, preferably 35 ° C. or lower in order to smoothly proceed with the sealing treatment. The treatment time is preferably in the range of 1 to 3 minutes per 1 μm of film thickness. Subsequently, it is washed with water and dried to finish the low temperature sealing treatment.

  In the case of high-temperature sealing treatment, as the sealing agent, an aqueous metal salt solution such as nickel acetate, cobalt acetate, lead acetate, nickel acetate-cobalt, and barium nitrate can be used, and nickel acetate is particularly preferable. When using nickel acetate aqueous solution, it is preferable to use the density | concentration within the range of 5-20 g / l normally. It is preferable to treat the nickel acetate aqueous solution usually at a pH in the range of 5.0 to 6.0. As the pH regulator, aqueous ammonia, sodium acetate, or the like can be used. In order to improve the physical properties of the film, sodium acetate, organic carboxylic acid, anionic or nonionic surfactant may be added to the aqueous nickel acetate solution. The treatment temperature is usually in the range of 80 ° C. or higher, usually 100 ° C. or lower, preferably 90 ° C. or higher, and preferably 98 ° C. or lower. The treatment time is usually 10 minutes or longer, preferably 20 minutes or longer. Subsequently, it is washed with water and dried to finish the high temperature sealing treatment.

  As a specific configuration of the photosensitive layer used in the electrophotographic photosensitive member to which the exemplary embodiment is applied, for example, in the case of a laminated type photosensitive member, it contains a charge transport material and a binder resin, and retains an electrostatic charge. And a charge transport layer that transports charges generated by exposure, and a charge generation layer that contains a charge generation material and generates charge pairs by exposure. In addition, if necessary, for example, a charge blocking layer for blocking charge injection from the conductive support, a light diffusion layer for diffusing light such as laser light to prevent interference fringes, etc. There is. In the case of a dispersion type photoreceptor, the photosensitive layer has a charge transport material and a charge generation material dispersed in a binder resin.

<Charge generation layer>
When the electrophotographic photosensitive member to which the exemplary embodiment is applied is a laminated type photosensitive member, the charge generating layer constituting the photosensitive layer contains a charge generating substance. Examples of charge generation materials include selenium and its alloys, cadmium sulfide, and other inorganic photoconductive materials; phthalocyanine pigments, azo pigments, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, anthanthrone pigments, benzimidazole pigments And various photoconductive materials such as organic pigments. Among these, organic pigments, phthalocyanine pigments, and azo pigments are particularly preferable. The fine particles of these charge generating materials are, for example, polyester, polyvinyl acetate, polyacrylic acid ester, polymethacrylic acid ester, polycarbonate, polyvinyl acetoacetal, polyvinyl propional, polyvinyl butyral, phenoxy resin, epoxy resin, cellulose ester, cellulose ether. It is used in a form bound with various binder resins. Although the usage-amount of a charge generation substance is not specifically limited, Usually, it is used in 30 weight part-500 weight part with respect to 100 weight part of binder resin. The thickness of the charge generation layer is usually 0.1 μm to 1 μm, preferably 0.15 μm to 0.6 μm.

  When a phthalocyanine compound is used as a charge generation material, specifically, metal-free phthalocyanine, copper, indium, gallium, tin, titanium, zinc, vanadium, silicon, germanium, or other metals or their oxides, halides, etc. Phthalocyanines are used. Examples of the ligand to a trivalent or higher metal atom include an oxygen atom, a chlorine atom, a hydroxyl group, an alkoxy group, and the like. In particular, highly sensitive X-type, τ-type metal-free phthalocyanine, A-type, B-type, D-type titanyl phthalocyanine, vanadyl phthalocyanine, chloroindium phthalocyanine, chlorogallium phthalocyanine, hydroxygallium phthalocyanine, and the like are suitable. Of the crystal forms of titanyl phthalocyanine mentioned here, A type and B type are described in W.W. It has been shown by Heller et al. As phase I and layer II (Zeit. Kristallogr. 159 (1982) 173), respectively, and type A is known as a stable type. The D type is a crystal type showing a clear peak at a diffraction angle 2θ ± 0.2 ° of 27.3 ° in powder X-ray diffraction using CuKα rays. As the phthalocyanine compound, only a single compound may be used, or several mixed states may be used. As the phthalocyanine compound or the mixed state in the crystalline state, the respective constituent elements may be mixed and used later, or mixed in the production / treatment process of the phthalocyanine compound such as synthesis, pigmentation, crystallization, etc. But it ’s okay. As such treatment, acid paste treatment, grinding treatment, solvent treatment and the like are known.

<Charge transport layer>
When the electrophotographic photosensitive member to which this exemplary embodiment is applied is a laminated type photosensitive member, the charge transporting layer constituting the photosensitive layer contains a charge transporting substance. Examples of charge transport materials include aromatic nitro compounds such as 2,4,7-trinitrofluorenone; cyano compounds such as tetracyanoxydimethane; electron-withdrawing materials such as quinones such as diphenoquinone; carbazole derivatives and indoles Heterocyclic compounds such as derivatives, imidazole derivatives, oxazole derivatives, pyrazole derivatives, oxadiazole derivatives, pyrazoline derivatives, thiadiazole derivatives; aniline derivatives, hydrazone compounds, aromatic amine derivatives, stilbene derivatives, butadiene derivatives, enamine compounds or these compounds Or an electron donating substance such as a polymer having a group consisting of these compounds in the main chain or side chain. Among these, a carbazole derivative, a hydrazone derivative, an aromatic amine derivative, a stilbene derivative, a butadiene derivative, and a combination of these derivatives are preferable, and a combination of an aromatic amine derivative, a stilbene derivative, and a butadiene derivative are combined. Is preferred.

  Specific examples of the charge transport material contained in the charge transport layer constituting the photosensitive layer of the electrophotographic photoreceptor to which the exemplary embodiment is applied include, for example, arylamine-based compounds described in JP-A-9-244278. And arylamine compounds described in JP-A-2002-275133. These charge transport materials may be used alone or in combination. The charge transport layer is formed in such a form that these charge transport materials are bound to the binder resin. The charge transport layer may be composed of a single layer, or may be a stack of a plurality of layers having different constituent parts or composition ratios.

The ratio of the binder resin containing the polyarylate resin of the present invention to the charge transport material is usually 30 parts by weight to 200 parts by weight, preferably 40 parts by weight to 150 parts by weight with respect to 100 parts by weight of the binder resin. Used in the range of parts by weight. The film thickness of the charge transport layer is usually 5 μm to 50 μm, preferably 10 μm to 45 μm.
It should be noted that the charge transport layer has well-known plasticizers, antioxidants, ultraviolet absorbers, and electron withdrawing properties in order to improve film forming properties, flexibility, coating properties, stain resistance, gas resistance, light resistance, etc. You may contain additives, such as a substance, dye, a pigment, and a leveling agent. Examples of the antioxidant include hindered phenol compounds and hindered amine compounds. Examples of dyes and pigments include various pigment compounds and azo compounds.

<Dispersed photoconductor>
In the case of a dispersion type photoreceptor, the above-described charge transport material is dispersed in a charge transport medium composed of the above-described binder resin and a charge transport material. The particle size of the charge transport material needs to be sufficiently small, and is preferably 1 μm or less, more preferably 0.5 μm or less. If the amount of the charge generating material dispersed in the photosensitive layer is excessively small, sufficient sensitivity cannot be obtained, and if it is excessively large, there are problems such as a decrease in chargeability and a decrease in sensitivity. The amount of the charge generating material used is preferably in the range of 0.5 wt% to 50 wt%, more preferably 1 wt% to 20 wt%. The film thickness of the dispersion type photosensitive layer is usually 5 μm to 50 μm, more preferably 10 μm to 45 μm. Also in this case, known plasticizers for improving film formability, flexibility, mechanical strength, additives for suppressing residual potential, dispersion aids for improving dispersion stability, coatability A leveling agent or a surfactant, for example, a silicone oil, a fluorinated oil or other additives for improving the viscosity may be added. On the dispersion type photosensitive layer, a protective layer may be provided for the purpose of preventing the wear of the dispersion type photosensitive layer or preventing or reducing the degradation of the dispersion type photosensitive layer due to discharge products generated from a charger or the like. . Further, for the purpose of reducing frictional resistance and wear on the surface of the electrophotographic photosensitive member, the surface layer may contain a fluorine resin, a silicone resin, or the like. Moreover, the particle | grains which consist of these resin, and the particle | grains of an inorganic compound may be included.

<Method for preparing electrophotographic photoreceptor>
The method for preparing the electrophotographic photosensitive member to which the exemplary embodiment is applied is not particularly limited. Usually, for example, the photosensitive layer forming coating solution containing the polyarylate resin of the present invention is immersed on the conductive support. It is formed by coating by a known method such as a coating method, a spray coating method, a nozzle coating method, a barcode coating method, a roll coating method or a blade coating method. Among these, the dip coating method is preferable because of its high productivity.

<Underlayer>
In the electrophotographic photosensitive member to which this exemplary embodiment is applied, an undercoat layer may be provided between the conductive support and the photosensitive layer in order to improve adhesion and blocking properties. As the undercoat layer, for example, a resin, a resin in which particles such as a metal oxide are dispersed, or the like is used. Examples of metal oxide particles used for the undercoat layer include, for example, metal oxide particles containing one metal element such as titanium oxide, aluminum oxide, silicon oxide, zirconium oxide, zinc oxide, iron oxide, calcium titanate, and the like. And metal oxide particles containing a plurality of metal elements such as strontium titanate and barium titanate. As these metal oxide particles, only one type of particles may be used, or a plurality of types of particles may be mixed and used.

  Among these, titanium oxide and aluminum oxide are preferable, and titanium oxide is particularly preferable. The surface of the titanium oxide particles may be treated with an inorganic substance such as tin oxide, aluminum oxide, antimony oxide, zirconium oxide, or silicon oxide, or an organic substance such as stearic acid, polyol, or silicone. As the crystal form of the titanium oxide particles, any of rutile, anatase, brookite, and amorphous can be used. A thing of a several crystalline state may be contained. In addition, various particle diameters of the metal oxide particles can be used. Among these, from the viewpoint of characteristics and liquid stability, the average primary particle diameter is preferably 10 nm or more and 100 nm or less, and particularly preferably 10 nm or more. 50 nm or less.

  The undercoat layer is preferably formed in a form in which metal oxide particles are dispersed in a binder resin. As binder resin used for the undercoat layer, phenoxy, epoxy, polyvinyl pyrrolidone, polyvinyl alcohol, casein, polyacrylic acid, celluloses, gelatin, starch, polyurethane, polyimide, polyamide, etc. are used alone or in a cured form together with a curing agent. Among them, alcohol-soluble copolymerized polyamides, modified polyamides and the like are preferable because they exhibit good dispersibility and coating properties. The compounding composition ratio of the metal oxide particles with respect to the binder resin is not particularly limited, but it is usually preferable in the range of 10% by weight to 500% by weight in terms of stability of the dispersion and coatability. The thickness of the undercoat layer is not particularly limited, but is preferably 0.1 μm to 20 μm in view of the photoreceptor characteristics and applicability. Moreover, you may add a well-known antioxidant etc. to an undercoat layer.

<Image forming apparatus>
Next, an embodiment of an image forming apparatus using the electrophotographic photosensitive member of the present invention (an image forming apparatus of the present invention) will be described with reference to FIG. However, the embodiment is not limited to the following description, and can be arbitrarily modified without departing from the gist of the present invention.

As shown in FIG. 1, the image forming apparatus includes an electrophotographic photosensitive member 1, a charging device 2, an exposure device 3, and a developing device 4, and further, a transfer device 5, a cleaning device 6 and a fixing device as necessary. A device 7 is provided.
The electrophotographic photoreceptor 1 is not particularly limited as long as it is the above-described electrophotographic photoreceptor of the present invention, but in FIG. 1, as an example, a drum in which the above-described photosensitive layer is formed on the surface of a cylindrical conductive support. The photoconductor is shown. A charging device 2, an exposure device 3, a developing device 4, a transfer device 5, and a cleaning device 6 are disposed along the outer peripheral surface of the electrophotographic photosensitive member 1.

  The charging device 2 charges the electrophotographic photosensitive member 1 and uniformly charges the surface of the electrophotographic photosensitive member 1 to a predetermined potential. Examples of the charging device include a corona charging device such as a corotron and a scorotron, a direct charging device (contact type charging device) that charges a direct charging member to which a voltage is applied by contacting the photosensitive member surface, and a contact type charging device such as a charging brush. Often used. Examples of direct charging means include contact chargers such as charging rollers and charging brushes. In FIG. 1, a roller-type charging device (charging roller) is shown as an example of the charging device 2. As the direct charging means, either charging with air discharge or injection charging without air discharge is possible. Moreover, as a voltage applied at the time of charging, it is possible to use only a direct current voltage or to superimpose an alternating current on a direct current.

The type of the exposure apparatus 3 is not particularly limited as long as it can expose the electrophotographic photoreceptor 1 to form an electrostatic latent image on the photosensitive surface of the electrophotographic photoreceptor 1. As a specific example,
Examples include halogen lamps, fluorescent lamps, lasers such as semiconductor lasers and He—Ne lasers, and LEDs. Further, exposure may be performed by a photoreceptor internal exposure method. The light used for the exposure is arbitrary. For example, the exposure may be performed using monochromatic light with a wavelength of 780 nm, monochromatic light with a wavelength slightly shorter than 600 nm to 700 nm, or monochromatic light with a short wavelength of 380 nm to 500 nm. .

  The type of the developing device 4 is not particularly limited, and an arbitrary device such as a dry development method such as cascade development, one-component insulating toner development, one-component conductive toner development, or two-component magnetic brush development, or a wet development method is used. be able to. In FIG. 1, the developing device 4 includes a developing tank 41, an agitator 42, a supply roller 43, a developing roller 44, and a regulating member 45, and has a configuration in which toner T is stored inside the developing tank 41. . Further, a replenishing device (not shown) for replenishing the toner T may be attached to the developing device 4 as necessary. The replenishing device is configured to be able to replenish toner T from a container such as a bottle or a cartridge.

The supply roller 43 is formed from a conductive sponge or the like. The developing roller 44 is made of a metal roll such as iron, stainless steel, aluminum, or nickel, or a resin roll obtained by coating such a metal roll with a silicone resin, a urethane resin, a fluorine resin, or the like. The surface of the developing roller 44 may be smoothed or roughened as necessary.
The developing roller 44 is disposed between the electrophotographic photoreceptor 1 and the supply roller 43 and is in contact with the electrophotographic photoreceptor 1 and the supply roller 43, respectively. The supply roller 43 and the developing roller 44 are rotated by a rotation drive mechanism (not shown). The supply roller 43 carries the stored toner T and supplies it to the developing roller 44. The developing roller 44 carries the toner T supplied by the supply roller 43 and contacts the surface of the electrophotographic photosensitive member 1.

  The regulating member 45 is formed of a resin blade such as silicone resin or urethane resin, a metal blade such as stainless steel, aluminum, copper, brass, phosphor bronze, or a blade obtained by coating such metal blade with resin. The regulating member 45 contacts the developing roller 44 and is pressed against the developing roller 44 side with a predetermined force by a spring or the like (a general blade linear pressure is 5 to 500 g / cm). If necessary, the regulating member 45 may be provided with a function of imparting charging to the toner T by frictional charging with the toner T.

The agitator 42 is rotated by a rotation driving mechanism, and agitates the toner T and conveys the toner T to the supply roller 43 side. A plurality of agitators 42 may be provided with different blade shapes and sizes.
As the toner, in addition to the pulverized toner, chemical toners such as suspension granulation, suspension polymerization, and emulsion polymerization aggregation can be used. In particular, in the case of chemical toners, those having a small particle size of about 4 to 8 μm are used, and those having a shape close to a sphere, and those outside a sphere such as a potato or rugby ball can also be used. . The polymerized toner is excellent in charging uniformity and transferability, and is preferably used for high image quality.

  The type of the toner T is arbitrary, and chemical toners such as suspension granulation, suspension polymerization, and emulsion polymerization aggregation can be used in addition to powdered toner. In the case of chemical toners, those having a small particle size of about 4 to 8 μm are preferable, and the toner particles have various shapes from a nearly spherical shape to a potato shape outside the spherical shape. Can be used. In particular, the polymerized toner is excellent in charging uniformity and transferability, and is suitably used for high image quality.

  The type of the transfer device 5 is not particularly limited, and an apparatus using an arbitrary system such as an electrostatic transfer method such as corona transfer, roller transfer, or belt transfer, a pressure transfer method, or an adhesive transfer method can be used. . Here, it is assumed that the transfer device 5 includes a transfer charger, a transfer roller, a transfer belt, and the like that are disposed to face the electrophotographic photoreceptor 1. The transfer device 5 applies a predetermined voltage value (transfer voltage) having a polarity opposite to the charging potential of the toner T, and transfers the toner image formed on the electrophotographic photosensitive member 1 to a recording paper (paper, medium) P. Is.

  There is no restriction | limiting in particular about the cleaning apparatus 6, Arbitrary cleaning apparatuses, such as a brush cleaner, a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, can be used. The cleaning device 6 is for scraping off residual toner adhering to the photoreceptor 1 with a cleaning member and collecting the residual toner. If there is little or almost no residual toner, the cleaning device 6 may be omitted.

  The fixing device 7 includes an upper fixing member (fixing roller) 71 and a lower fixing member (fixing roller) 72, and a heating device 73 is provided inside the fixing member 71 or 72. FIG. 1 shows an example in which a heating device 73 is provided inside the upper fixing member 71. Each of the upper and lower fixing members 71 and 72 includes a fixing roll in which a metal base tube such as stainless steel or aluminum is coated with silicon rubber, a fixing roll in which Teflon (registered trademark) resin is coated, and a fixing sheet. A member can be used. Further, each of the fixing members 71 and 72 may be configured to supply a release agent such as silicone oil in order to improve releasability, or may be configured to forcibly apply pressure to each other by a spring or the like.

When the toner transferred onto the recording paper P passes between the upper fixing member 71 and the lower fixing member 72 heated to a predetermined temperature, the toner is heated to a molten state and cooled after passing through the recording paper. Toner is fixed on P.
The type of the fixing device is not particularly limited, and a fixing device of any type such as heat roller fixing, flash fixing, oven fixing, pressure fixing, etc. can be provided including those used here.

In the image forming apparatus configured as described above, an image is recorded according to the following method (the image forming method of the present invention).
That is, first, the surface (photosensitive surface) of the photoreceptor 1 is charged to a predetermined potential (for example, −600 V) by the charging device 2. At this time, charging may be performed with a DC voltage, or charging may be performed by superimposing an AC voltage on the DC voltage.

Subsequently, the photosensitive surface of the charged photoreceptor 1 is exposed by the exposure device 3 according to the image to be recorded, and an electrostatic latent image is formed on the photosensitive surface. The developing device 4 develops the electrostatic latent image formed on the photosensitive surface of the photoreceptor 1.
The developing device 4 thins the toner T supplied by the supply roller 43 with a regulating member (developing blade) 45 and has a predetermined polarity (here, the same polarity as the charging potential of the photosensitive member 1) and the negative polarity. ), And conveyed while being carried on the developing roller 44 to be brought into contact with the surface of the photoreceptor 1.

When the charged toner T carried on the developing roller 44 comes into contact with the surface of the photoreceptor 1, a toner image corresponding to the electrostatic latent image is formed on the photosensitive surface of the photoreceptor 1. This toner image is transferred onto the recording paper P by the transfer device 5. Thereafter, the toner remaining on the photosensitive surface of the photoreceptor 1 without being transferred is removed by the cleaning device 6.
After the transfer of the toner image onto the recording paper P, the final image is obtained by passing the fixing device 7 and thermally fixing the toner image onto the recording paper P.

In addition to the above-described configuration, the image forming apparatus may be configured to perform, for example, a static elimination process. The neutralization step is a step of neutralizing the electrophotographic photosensitive member by exposing the electrophotographic photosensitive member, and a fluorescent lamp, an LED, or the like is used as the neutralizing device. In addition, the light used in the static elimination process is often light having an exposure energy that is at least three times that of the exposure light.

The image forming apparatus may be further modified. For example, the image forming apparatus may be configured to perform a pre-exposure process, an auxiliary charging process, or the like, or may be configured to perform offset printing. A full-color tandem system configuration using toner may be used.
The electrophotographic photoreceptor 1 is used alone or in combination with one or more elements of the charging device 2, the exposure device 3, the developing device 4, the transfer device 5, the cleaning device 6, and the fixing device 7. And an integral type cartridge (this is appropriately referred to as an “electrophotographic photosensitive member cartridge”), and the electrophotographic photosensitive member cartridge is detachable from a main body of an image forming apparatus such as a copying machine or a laser beam printer. Also good. In this case, a cartridge case configured to be detachable from the image forming apparatus is used, and the electrophotographic photosensitive member 1 is accommodated and supported by the cartridge case alone or in combination with the above-described elements. It can be. With this configuration, for example, when the electrophotographic photosensitive member 1 and other members deteriorate, the electrophotographic photosensitive member cartridge is removed from the main body of the image forming apparatus, and another new electrophotographic photosensitive member cartridge is mounted on the main body of the image forming apparatus. This facilitates maintenance and management of the image forming apparatus.

Hereinafter, the present embodiment will be described more specifically based on examples. Note that this embodiment is not limited to the examples. In the examples and comparative examples, “parts” and “%” are by weight unless otherwise specified.
(Viscosity average molecular weight (Mv))
Using an Ubbelohde capillary viscometer (dichloromethane flow time t ₀ : 136.16 seconds), the flow time (t) of the resin in dichloromethane (concentration: 6.00 g / L) was measured at 20.0 ° C. Based on the following formula, the viscosity average molecular weight (Mv) of the resin was calculated.

η _sp = (t / t ₀ ) −1
a = 0.438 × η _sp +1
b = 100 × (η _sp / C)
C = 6.00 [g / L]
η = b / a
Mv = 3207 × η ^1.205

(Preparation of photoreceptor)
10 parts by weight of oxytitanium phthalocyanine and 150 parts by weight of 4-methoxy-4-methyl-2-pentanone were mixed, and pulverized and dispersed in a sand grind mill to produce a pigment dispersion. In addition, the used oxytitanium phthalocyanine has a Bragg angle (2θ ± 0.2) of 9.3 °, 10.6 °, 13.2 °, 15.1 °, 15.7 ° in X-ray diffraction by CuKα ray, Strong diffraction peaks were exhibited at 16.1, 20.8, 23.3, 26.3, and 27.1. In this pigment dispersion, 5% by weight of polyvinyl butyral (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name: Denka Butyral # 6000C), 50 parts by weight of 1,2-dimethoxyethane solution, phenoxy resin (manufactured by Union Carbide Co., Ltd., trade name: PKHH) ) 5% by weight, 50 parts by weight of a 1,2-dimethoxyethane solution was mixed, and an appropriate amount of 1,2-dimethoxyethane was further added to prepare a coating solution for forming a charge generation layer having a solid content concentration of 4.0%. . This charge generation layer forming coating solution was applied on a polyethylene terephthalate sheet having aluminum deposited on the surface so that the film thickness after drying was 0.4 μm and dried to provide a charge generation layer.

Next, a coating solution for forming a charge transport layer is applied onto the charge generation layer so that the film thickness after drying is 20 μm, and dried at 125 ° C. for 20 minutes to form a charge transport layer. Photoconductors A1 to I1 shown in Fig. 1 were prepared. The coating solution for forming the charge transport layer has 100 parts by weight of the resin shown in Table 1, 8 parts by weight of an antioxidant (Irganox 1076), 0.03 part by weight of silicone oil as a leveling agent, and the chemical structure shown below. 50 parts by weight of a charge transporting material composed of an isomer mainly composed of the charge transporting material (1) was mixed with 640 parts by weight of a tetrahydrofuran / toluene mixed solvent (80% by weight of tetrahydrofuran, 20% by weight of toluene).

(Electrical characteristics test)
A photoconductor prepared in advance using an electrophotographic characteristic evaluation apparatus compliant with the electrophotographic society measurement standards (basic and applied electrophotographic technology, edited by the Electrophotographic Society, Corona, pages 404 to 405) Affixed to a drum and made into a cylindrical shape, the aluminum drum and the aluminum substrate of the photosensitive sheet are connected to each other, and then the drum is rotated at a fixed number of revolutions. A characterization test was conducted. The initial surface potential was −700 V, the exposure light was 780 nm, the neutralization light was 660 nm, and the surface potential (VL) was measured when the exposure light was irradiated at 2.4 μJ / cm ² . In the VL measurement, the time required from the exposure to the potential measurement was 139 ms. The environmental measurement was performed at a temperature of 25 ° C. and a relative humidity of 50% (hereinafter referred to as NN environment), and at a temperature of 5 ° C. and a relative humidity of 10% (hereinafter referred to as LL environment). The smaller the absolute value of the VL value, the better the response (unit: -V). The results are shown in Table 1.

(Abrasion test)
A photoconductor prepared in advance and cut into a 10 cm diameter circle was prepared to prepare a test piece, which was subjected to a wear test using a Taber abrasion tester (manufactured by Toyo Seiki Co., Ltd.). The test condition is to compare the weight before and after the test after 1000 rotations with no load (wear wheel's own weight) using wear wheel CS-10F in an atmosphere of temperature 23 ° C and relative humidity 50%. It was measured by. The smaller the amount of wear, the better the wear resistance (unit: mg). The results are shown in Table 1.
(Production example of polyarylate resin)
Nine types of polyarylate resins (resin A to resin I) were produced by the following production method.

Comparative Production Example 1 (Resin A)
A polyarylate resin 500 mL beaker produced using an alkaline aqueous solution in which the ratio (A / B) of the number of moles of hydroxide ions (A) to the number of moles of phenolic hydroxyl groups (B) is A / B = 1.1 Sodium hydroxide (8.59 g) and H ₂ O (423 mL) were weighed and dissolved with stirring. This aqueous solution and 1,1-bis (4-hydroxy-3-methylphenyl) ethane (hereinafter referred to as BP-a) (23.01 g) were mixed and stirred to obtain an alkaline aqueous solution of an aromatic hydroxy compound. It was. This alkaline aqueous solution was put into a 1 L reaction vessel, and then benzyltriethylammonium chloride (0.2552 g) and 2,3,5-trimethylphenol (0.6725 g) were sequentially added to the reaction vessel.

Separately, a mixed solution of diphenyl ether-4,4′-dicarboxylic acid chloride (28.20 g) and dichloromethane (211 mL) was transferred into the dropping funnel.
While maintaining the external temperature of the polymerization tank at 20 ° C. and stirring the alkaline aqueous solution in the reaction tank, the dichloromethane solution was dropped from the dropping funnel over 1 hour. After further stirring for 4 hours, dichloromethane (352 mL) was added and stirring was continued for 6 hours. Then, stirring was stopped and the organic layer was separated. This organic layer was washed 4 times with 0.1N hydrochloric acid (424 mL), and further washed twice with H ₂ O (424 mL).

  The organic solvent was removed from the washed organic layer and dried to obtain the desired resin A. The obtained resin A had a viscosity average molecular weight of 40,700. The repeating structure of Resin A is shown below.

Comparative Production Example 2 (Resin B)
A polyarylate resin 500 mL beaker produced using an aqueous alkali solution in which the ratio (A / B) of the number of moles of hydroxide ions (A) to the number of moles of phenolic hydroxyl groups (B) is A / B = 1.2 Sodium hydroxide (9.37 g) and H ₂ O (423 mL) were weighed and dissolved with stirring. This aqueous solution and BP-a (23.01 g) were mixed and stirred to prepare an alkaline aqueous solution of an aromatic hydroxy compound.

The same repeating structure as that of the resin A in the same manner as in Comparative Production Example 1 except that the alkaline aqueous solution of the aromatic hydroxy compound was used instead of the alkaline aqueous solution of the aromatic hydroxy compound used in Comparative Production Example 1. Resin B having a viscosity average molecular weight of 39,400 was obtained.
Comparative Production Example 3 (Resin C)
A polyarylate resin 500 mL beaker produced using an alkaline aqueous solution having a ratio (A / B) of the number of moles of hydroxide ions (A) to the number of moles of phenolic hydroxyl groups (B) (A / B) = 1.3 Sodium hydroxide (10.15 g) and H ₂ O (423 mL) were weighed and dissolved with stirring. This aqueous solution and BP-a (23.01 g) were mixed and stirred to prepare an alkaline aqueous solution of an aromatic hydroxy compound.

The same repeating structure as that of the resin A in the same manner as in Comparative Production Example 1 except that the alkaline aqueous solution of the aromatic hydroxy compound was used instead of the alkaline aqueous solution of the aromatic hydroxy compound used in Comparative Production Example 1. Resin C having a viscosity average molecular weight of 39,300 was obtained.
Production Example 1 (Resin D)
A polyarylate resin produced using an aqueous alkali solution in which the ratio (A / B) of the number of moles of hydroxide ions (A) to the number of moles of phenolic hydroxyl groups (B) is A / B = 1.5
Sodium hydroxide (11.71 g) and H ₂ O (423 mL) were weighed into a 500 mL beaker and dissolved with stirring. This aqueous solution and BP-a (23.01 g) were mixed and stirred to prepare an alkaline aqueous solution of an aromatic hydroxy compound.

The same repeating structure as that of the resin A in the same manner as in Comparative Production Example 1 except that the alkaline aqueous solution of the aromatic hydroxy compound was used instead of the alkaline aqueous solution of the aromatic hydroxy compound used in Comparative Production Example 1. Resin D having a viscosity average molecular weight of 39,200 was obtained.
Production Example 2 (Resin E)
A polyarylate resin produced using an aqueous alkali solution in which the ratio (A / B) of the number of moles of hydroxide ions (A) to the number of moles of phenolic hydroxyl groups (B) is A / B = 1.8
Sodium hydroxide (14.05 g) and H ₂ O (423 mL) were weighed into a 500 mL beaker and dissolved with stirring. This aqueous solution and BP-a (23.01 g) were mixed and stirred to prepare an alkaline aqueous solution of an aromatic hydroxy compound.

The same repeating structure as that of the resin A in the same manner as in Comparative Production Example 1 except that the alkaline aqueous solution of the aromatic hydroxy compound was used instead of the alkaline aqueous solution of the aromatic hydroxy compound used in Comparative Production Example 1. Resin E having a viscosity average molecular weight of 39,800 was obtained.

Production Example 3 (Resin F)
A polyarylate resin produced using an aqueous alkali solution in which the ratio (A / B) of the number of moles of hydroxide ions (A) to the number of moles of phenolic hydroxyl groups (B) is A / B = 2.0
Sodium hydroxide (15.61 g) and H ₂ O (423 mL) were weighed into a 500 mL beaker and dissolved with stirring. This aqueous solution and BP-a (23.01 g) were mixed and stirred to prepare an alkaline aqueous solution of an aromatic hydroxy compound.

The same repeating structure as that of the resin A in the same manner as in Comparative Production Example 1 except that the alkaline aqueous solution of the aromatic hydroxy compound was used instead of the alkaline aqueous solution of the aromatic hydroxy compound used in Comparative Production Example 1. Resin F having a viscosity average molecular weight of 39,600 was obtained.
Production Example 4 (Resin G)
A polyarylate resin produced using an aqueous alkaline solution in which the ratio (A / B) of the number of moles of hydroxide ions (A) to the number of moles of phenolic hydroxyl groups (B) is A / B = 2.2
Sodium hydroxide (17.17 g) and H ₂ O (423 mL) were weighed into a 500 mL beaker and dissolved with stirring. This aqueous solution and BP-a (23.01 g) were mixed and stirred to prepare an alkaline aqueous solution of an aromatic hydroxy compound.

The same repeating structure as that of the resin A in the same manner as in Comparative Production Example 1 except that the alkaline aqueous solution of the aromatic hydroxy compound was used instead of the alkaline aqueous solution of the aromatic hydroxy compound used in Comparative Production Example 1. Resin G having a viscosity average molecular weight of 40,200 was obtained.
Comparative Production Example 4 (Resin H)
A polyarylate resin produced using an aqueous alkali solution in which the ratio (A / B) of the number of moles of hydroxide ions (A) to the number of moles of phenolic hydroxyl groups (B) is A / B = 2.5
Sodium hydroxide (19.51 g) and H ₂ O (423 mL) were weighed into a 500 mL beaker and dissolved with stirring. This aqueous solution and BP-a (23.01 g) were mixed and stirred to prepare an alkaline aqueous solution of an aromatic hydroxy compound.

The same repeating structure as that of the resin A in the same manner as in Comparative Production Example 1 except that the alkaline aqueous solution of the aromatic hydroxy compound was used instead of the alkaline aqueous solution of the aromatic hydroxy compound used in Comparative Production Example 1. Resin H having a viscosity average molecular weight of 39,200 was obtained.
Comparative Production Example 5 (Resin I)
A polyarylate resin produced using an aqueous alkali solution in which the ratio (A / B) between the number of moles of hydroxide ions (A) and the number of moles of phenolic hydroxyl groups (B) is A / B = 3.0
Sodium hydroxide (23.41 g) and H ₂ O (423 mL) were weighed into a 500 mL beaker and dissolved with stirring. This aqueous solution and BP-a (23.01 g) were mixed and stirred to prepare an alkaline aqueous solution of an aromatic hydroxy compound.

The same repeating structure as that of the resin A in the same manner as in Comparative Production Example 1 except that the alkaline aqueous solution of the aromatic hydroxy compound was used instead of the alkaline aqueous solution of the aromatic hydroxy compound used in Comparative Production Example 1. Resin I having a viscosity average molecular weight of 39,900 was obtained.

表１に示す結果から、感光層が本発明に係るポリアリレート樹脂を含む電子写真感光体は、磨耗量が小さく耐摩耗性に優れる上、ＮＮ環境においてもＬＬ環境においても露光後の表面電位が低く、様々な環境下で使用可能で、しかも繰り返し使用するのに適している。

From the results shown in Table 1, the electrophotographic photosensitive member in which the photosensitive layer contains the polyarylate resin according to the present invention has a small amount of wear and excellent wear resistance, and has a surface potential after exposure in both NN and LL environments. It is low, can be used in various environments, and is suitable for repeated use.

  The electrophotographic photosensitive member having the photosensitive layer containing the polyarylate resin according to the present invention has high wear resistance, low surface potential after exposure to changes in temperature and humidity of the usage environment, and less variation due to environmental differences. Have advantages. Therefore, the electrophotographic photosensitive member, the electrophotographic photosensitive member cartridge, and the image forming apparatus of the present invention are preferably used in various fields such as various electrophotographic devices such as copying machines, printers, and fax machines using electrophotographic technology. Can do.

1 is a schematic diagram illustrating a main configuration of an embodiment of an image forming apparatus of the present invention.

Explanation of symbols

1 Photoconductor (Electrophotographic photoconductor)
2 Charging device (charging roller; charging unit)
3 Exposure equipment (exposure section)
4 Development device (development unit)
5 Transfer device 6 Cleaning device (cleaning part)
7 Fixing Device 41 Developing Tank 42 Agitator 43 Supply Roller 44 Developing Roller 45 Regulating Member 71 Upper Fixing Member (Pressure Roller)
72 Lower fixing member (fixing roller)
73 Heating device T Toner P Recording paper (paper, medium)

Claims (5)

On a conductive support an electrophotographic photosensitive member having a photosensitive layer, the photosensitive layer is, the dicarboxylic acid component having 100 mol% containing a dicarboxylic acid halide represented by the following formula (1) relative to the total dicarboxylic acid component And the ratio (A / B) of the number of moles of hydroxide ions (A) to the number of moles of phenolic hydroxyl groups (B) is A / B = 1. An electrophotographic photoreceptor comprising a polyarylate resin produced using a raw material of an alkaline aqueous solution of an aromatic hydroxy compound prepared in the range of 5 to 2.2 .

(In Formula (1), R ¹ and R ² are each independently a hydrogen atom or a monovalent substituent, a and b are each independently an integer of 1 to 4, and X is a halogen atom. is there.) The electrophotographic photoreceptor according to claim 1, wherein the aromatic hydroxy compound is a dihydric phenol represented by the following formula (2).

(In formula (2), R ^{3 to} R ⁶ are each independently a hydrogen atom or a monovalent substituent, and c and d are each independently an integer of 1 to 4.) The electrophotographic photosensitive member according to claim 2, wherein in the dihydric phenol represented by the formula (2), R ⁶ is hydrogen.   An electrophotographic apparatus comprising: the electrophotographic photosensitive member according to claim 1; and a cartridge case that detachably supports the electrophotographic photosensitive member with respect to the image forming apparatus. Photoconductor cartridge.   The electrophotographic photosensitive member according to claim 1, a charging unit that charges the electrophotographic photosensitive member, and an exposure unit that exposes the charged electrophotographic photosensitive member to form an electrostatic latent image. And an image forming apparatus comprising: a developing unit that develops the electrostatic latent image formed on the electrophotographic photosensitive member.

Images