JP2007086416A - Electrophotographic photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor improved in contamination resistance against toner and cleaning alcohol in the case of replacing a photoreceptor unit. <P>SOLUTION: In the electrophotographic photoreceptor having a photosensitive layer on a conductive substrate, a binder resin containing 0.5 to 5.0 wt.% terminal denatured polycarbonate oligomer, which has a repeating unit expressed by general formula (1), has a group expressed by general formula (2) at one molecule terminal and is <0.20 dl/g in intrinsic viscosity, is used in the photosensitive layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member. More specifically, the present invention relates to an electrophotographic photoreceptor in which a charge transport layer is produced from a binder resin containing a terminal fluoroalkyl-modified polycarbonate oligomer.

  Currently, electrophotographic technology is widely applied to copying machines, laser beam printers (hereinafter abbreviated as LBP), fax machines, and the like due to its high speed and high image quality.

  Conventionally, inorganic photoconductive materials such as selenium, selenium / tellurium alloys, selenium / arsenic alloys and cadmium sulfide have been mainly used as electrophotographic photoreceptors in this electrophotographic technology. However, from the viewpoints of toxicity, safety, price, productivity, and the like, recently, an electrophotographic photoreceptor using an organic photoconductive material has been developed.

  There are two types of electrophotographic photoreceptors using an organic photoconductive material: a laminate type divided into a charge generation layer and a charge transport layer and a single layer type in which both layers are mixed. Yes. For the purpose of retaining a low molecular charge transport agent contained in the charge transport layer, various binder resins are usually used and dissolved in a solvent to form a coating film.

  Binder resins include vinyl polymers such as polymethyl methacrylate, polystyrene, and polyvinyl chloride, and copolymers thereof, various thermoplastic resins such as polycarbonate, polyester, polysulfone, phenoxy resin, epoxy resin, and silicone resin, and thermosetting. Resin has been used. Electrophotographic photoreceptors using these various binder resins can be easily formed into thin films by a cast film forming method, are suitable for mass production, and are relatively inexpensive. Of these various resins, polycarbonate resin has relatively excellent characteristics and is often used (see Patent Document 1).

  Among these, it has been reported that a polycarbonate resin having a specific perfluoroalkyl group at the molecular terminal is effective as a binder resin for an electrophotographic photoreceptor excellent in abrasion resistance (see Patent Document 2).

  On the other hand, with the spread of LBP and digital multi-function peripherals to small-scale offices and general households, various problems due to inadequate maintenance have occurred. Among them, when the photoconductor unit is replaced, dust, fingerprints, oil, cleaning liquid, and a large amount of toner adhere to the surface of the outermost layer of the photoconductor. Cases that cause image degradation have been reported.

For such contamination, the conventional polycarbonate resin is not always sufficient, and there has been a demand for a binder resin with improved initial stain resistance.
Japanese Patent Application Laid-Open No. 60-172044 JP-A-5-306335

  The problem to be solved by the present invention is to improve the initial stain resistance of the electrophotographic photosensitive member.

  As a result of intensive studies to solve the above problems, the present inventors have found that an electrophotographic photosensitive member using a binder resin in which a small amount of a specific terminal fluoroalkyl polycarbonate oligomer is added to a photosensitive layer is a conventional binder resin. To complete the present invention, it has been found that the toner can be easily removed compared to the used electrophotographic photosensitive member, and it is difficult to get wet with alcohol-based cleaning agents, and that the contamination resistance when the photosensitive unit is replaced is improved. It came.

  That is, the present invention provides an electrophotographic photoreceptor having a photosensitive layer on a conductive substrate, the photosensitive layer having a repeating unit represented by the following general formula (1), and represented by the following general formula (2). And a binder resin containing 0.5 to 5.0% by weight of a terminal-modified polycarbonate oligomer having an intrinsic viscosity at least on one molecular end and having an intrinsic viscosity of less than 0.20 dl / g. It is.

（式中、Ｒ_１〜Ｒ_４は、それぞれ、水素、フッ素、塩素、臭素、ヨウ素、炭素数１〜９のアルキル基、炭素数６〜１２のアリール基、炭素数２〜５のアルケニル基、炭素数１〜５のアルコキシ基または炭素数７〜１７のアラルキル基であり、これらの基の炭素に有してもよい置換基は、炭素数１〜５のアルキル基、炭素数２〜５のアルケニル基または炭素数１〜５のアルコキシ基である。Ｘは、

(Wherein R _{1 to} R ₄ are each hydrogen, fluorine, chlorine, bromine, iodine, an alkyl group having 1 to 9 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, It is a C1-C5 alkoxy group or a C7-C17 aralkyl group, The substituent which you may have in carbon of these groups is a C1-C5 alkyl group, C2-C5 An alkenyl group or an alkoxy group having 1 to 5 carbon atoms, X is

であり、ここにＲ_５及びＲ_６は、それぞれ、水素、フッ素、塩素、臭素、ヨウ素、炭素数１〜９のアルキル基、炭素数１〜５のアルコキシ基もしくは炭素数６〜１２のアリール基を表すか、またはＲ_５及びＲ_６が一緒に結合して、炭素環または複素環を形成する基を表し、これらの基の炭素に有してもよい置換基は、炭素数１〜５のアルキル基、炭素数２〜５のアルケニル基、炭素数１〜５のアルコキシ基、またはフッ素、塩素、臭素、ヨウ素から選ばれるハロゲン基である。aは０〜２０の整数を表す。）

Wherein R ₅ and R ₆ are each hydrogen, fluorine, chlorine, bromine, iodine, an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an aryl group having 6 to 12 carbon atoms. Or R ₅ and R ₆ are bonded together to form a carbocyclic or heterocyclic ring, and the substituent that may be present on the carbon of these groups is a group having 1 to 5 carbon atoms An alkyl group, an alkenyl group having 2 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a halogen group selected from fluorine, chlorine, bromine and iodine. a represents an integer of 0 to 20. )

（式中、Ｒ_７は炭素数１〜３０のパーフルオロアルキル基を表す。ｂは０〜８の整数を表す。）

(Wherein, _{R 7} represents an integer of .b 0 to 8 representing a perfluoroalkyl group having 1 to 30 carbon atoms.)

  As an effect of the present invention, the electrophotographic photoreceptor of the present invention uses a binder resin in which a small amount of a specific terminal fluoroalkyl polycarbonate oligomer is added to the photosensitive layer, so that the electrophotographic photoreceptor using a conventional binder resin is used. The toner can be easily removed and it is difficult to get wet with water-based or alcohol-based cleaning agents, and the contamination resistance when the photosensitive unit is replaced is improved. Therefore, it contributes to the stability of the image quality at the initial stage of replacement, and is effective in saving paper and toner, extending the life of the photoreceptor, and improving the replacement workability. Furthermore, since it can be used by adding a small amount of the terminal fluoroalkyl polycarbonate oligomer of the present invention to a conventional binder resin, there is an advantage that it can be produced with almost no change in the electrophotographic photoreceptor production process and materials.

  The electrophotographic photoreceptor of the present invention can be used for either a single-layer photosensitive layer on a conductive support or a laminated type having a functionally separated charge generation layer and a charge transport layer. It is preferable to use it for the charge transport layer of a laminated electrophotographic photosensitive member that can easily exhibit the characteristics of the binder resin holding the substance.

  The conductive support of the present invention is a metal material such as aluminum, stainless steel, nickel or the like, or a polyester film, a phenolic resin, paper having a conductive layer made of aluminum, palladium, tin oxide, indium oxide or the like on the surface. Etc. are used.

  The charge generation layer of the present invention is formed on a conductive support by a known method. As the charge generation material, for example, organic pigments such as azoxybenzene, disazo, trisazo, benzimidazole, polycyclic quinoline, indigoid, quinacridone, phthalocyanine, perylene, and methine can be used. . These charge generation materials are made of fine particles such as polyvinyl butyral resin, polyvinyl formal resin, silicone resin, polyamide resin, polyester resin, polystyrene resin, polycarbonate resin, polyvinyl acetate resin, polyurethane resin, phenoxy resin, epoxy resin, and various celluloses. Used in a form dispersed in a binder resin.

  The charge transport layer of the present invention is formed by dispersing a charge transport material on the charge generation layer by a known method in a binder resin to which the terminal modified polycarbonate oligomer of the present invention is added. Examples of the charge transport material include polytetracyanoethylene; fluorenone compounds such as 2,4,7-trinitro-9-fluorenone; nitro compounds such as dinitroanthracene; succinic anhydride; maleic anhydride; dibromomaleic anhydride; Triphenylmethane compounds; oxadiazole compounds such as 2,5-di (4-dimethylaminophenyl) -1,3,4-oxadiazole; styryl compounds such as 9- (4-diethylaminostyryl) anthracene Carbazole compounds such as poly-N-vinylcarbazole; pyrazoline compounds such as 1-phenyl-3- (p-dimethylaminophenyl) pyrazoline; 4,4 ′, 4 ″ -tris (N, N-diphenylamino); Triphenylamine, N, N′-bis (3-methylphenyl) -N, N′-bi Amine derivatives such as (phenyl) benzidine; conjugated unsaturated compounds such as 1,1-bis (4-diethylaminophenyl) -4,4-diphenyl-1,3-butadiene; 4- (N, N-diethylamino) benzaldehyde Hydrazone compounds such as N, N-diphenylhydrazone; indole compounds, oxazole compounds, isoxazole compounds, thiazole compounds, thiadiazole compounds, imidazole compounds, pyrazole compounds, pyrazoline compounds, triazole compounds, etc. Examples thereof include nitrogen-containing cyclic compounds, condensed polycyclic compounds, etc. The above charge transport materials may be used alone or in combination of two or more.

  The terminal-modified polycarbonate oligomer of the present invention is a known method used in the production of polycarbonate from bisphenol A and a carbonate ester-forming compound, for example, a direct reaction of bisphenols and phosgene (phosgene method), or a bisphenols and bisphenol A method such as a transesterification reaction with an aryl carbonate (a transesterification method) can be employed.

  Specific examples of raw material bisphenols for deriving the repeating unit represented by the general formula (1) used in the production of the terminal-modified polycarbonate oligomer in the present invention include 1,1′-biphenyl-4,4′-. Diol, bis (4-hydroxyphenyl) methane, bis (4-hydroxyphenyl) ether, bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) ketone, 1,1 -Bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A; BPA), 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis ( 4-hydroxy-3-tert-butylphenyl) propane, 1,1-bis (4-hydroxyphenyl) Clopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane (bisphenol Z; BPZ), 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 2,2-bis ( 4-hydroxy-3-allylphenyl) propane, 2,2-bis (4-hydroxyphenyl) hexafluoropropane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, bis (4-hydroxyphenyl) Diphenylmethane, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 4,4 ′-[1,4-phenylenebis (1-methylethylidene) ] Bisphenol, 4,4 '-[1,3-phenylenebis (1-methylethylidene)] bisphenol , 4,4'-butylidene bis (3-methyl -6-t-butylphenol) and the like. Two or more of these may be used in combination. Moreover, among these, it is preferable that it is especially selected from 2,2-bis (4-hydroxyphenyl) propane and 1,1-bis (4-hydroxyphenyl) cyclohexane.

  On the other hand, examples of the carbonate ester-forming compound include phosgene and bisaryl carbonates such as diphenyl carbonate, di-p-tolyl carbonate, phenyl-p-tolyl carbonate, di-p-chlorophenyl carbonate, and dinaphthyl carbonate. Two or more of these compounds can be used in combination.

  In the phosgene method, bisphenols and phosgene are reacted usually in the presence of an acid binder and a solvent. Examples of the acid binder include pyridine and alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and examples of the solvent include methylene chloride and chloroform. Furthermore, in order to accelerate the polycondensation reaction, a tertiary amine such as triethylamine or a quaternary ammonium salt such as benzyltriethylammonium chloride is used. In the present invention, the terminal-modified polycarbonate oligomer of the present invention can be obtained by reacting a monochloroformate having a fluoroalkyl group as a terminal stopper for adjusting the degree of polymerization. If desired, small amounts of antioxidants such as sodium sulfite and hydrosulfite, and branching agents such as phloroglucin, isatin bisphenol and trisphenol ethane may be added. The reaction is usually in the range of 0 to 150 ° C, preferably 5 to 40 ° C. While the reaction time depends on the reaction temperature, it is generally 0.5 min-10 hr, preferably 1 min-2 hr. Further, during the reaction, it is desirable to maintain the pH of the reaction system at 10 or more.

  On the other hand, in the transesterification method, bisphenols, bisaryl carbonate, and alcohol or carbonate having a fluoroalkyl group are mixed and reacted at high temperature under reduced pressure. Even if they are added simultaneously, after reacting bisphenols and bisaryl carbonate first, an alcohol or carbonate having a fluoroalkyl group is added, or a polycarbonate oligomer having a terminal phenolic hydroxyl group obtained in advance by the phosgene method A carbonate having a fluoroalkyl group can be added to the reaction. The reaction is usually carried out under reduced pressure at a temperature of 150 to 350 ° C., preferably 200 to 300 ° C., and the degree of reduced pressure is preferably set to 1 mmHg or less at the end. The derived phenols are distilled out of the system. The reaction time depends on the reaction temperature and the degree of reduced pressure, but is usually about 1 to 10 hours. The reaction is preferably carried out in an inert gas atmosphere such as nitrogen or argon. Moreover, you may react by adding antioxidant and a branching agent as needed.

Specific examples of the compound that derives the general formula (2), which is the terminal group of the terminal-modified polycarbonate oligomer of the present invention, include 1H, 1H-trifluoroethanol, 1H, 1H-pentafluoropropanol, 2- (par Fluorobutyl) ethanol, 6- (perfluorobutyl) hexanol, 2- (perfluorohexyl) ethanol, 2- (perfluorooctyl) ethanol, 6- (perfluorooctyl) hexanol, 2- (perfluorodecyl) ethanol, 2- (perfluorododecanyl) ethanol, 2- (perfluorohexadecanyl) ethanol, 2- (perfluorodocosanyl) ethanol, 6- (perfluoro-1-methylethyl) hexanol, 2- (perfluoro- 3-methylbutyl) ethanol, 2- (perf (Holo-7-methyloctyl) alcohols such as ethanol, 1H, 1H-trifluoroethyl chloroformate, 1H, 1H-pentafluoropropyl chloroformate, 2- (perfluorobutyl) ethyl chloroformate, 6- ( Perfluorobutyl) hexyl chloroformate, 2- (perfluorooctyl) ethyl chloroformate, 6- (perfluorooctyl) hexyl chloroformate, 2- (perfluorodecyl) ethyl chloroformate, 6- (perfluoro Chloroformates such as 1-methylethyl) hexyl chloroformate, 2- (perfluoro-3-methylbutyl) ethyl chloroformate, 2- (perfluoro-7-methyloctyl) ethyl chloroformate, 1H, 1H-trifluoroethyl phenyl carbo 1H, 1H-pentafluoropropyl phenyl carbonate, 2- (perfluorobutyl) ethyl phenyl carbonate, 6- (perfluorobutyl) hexyl phenyl carbonate, 2- (perfluorooctyl) ethyl phenyl carbonate, 6- (per Fluorooctyl) hexylphenyl carbonate, 2- (perfluorodecyl) ethylphenyl carbonate, 6- (perfluoro-1-methylethyl) hexylphenyl carbonate, 2- (perfluoro-3-methylbutyl) ethylphenyl carbonate, 2- ( Perfluoro-7-methyloctyl) ethyl phenyl carbonate, di-1H, 1H-trifluoroethyl carbonate, di-1H, 1H-pentafluoropropyl carbonate, di-2- (perfluorobuty) ) Ethyl carbonate, di-6- (perfluorobutyl) hexyl carbonate, di-2- (perfluorooctyl) ethyl carbonate, di-6- (perfluorooctyl) hexyl carbonate, di-2- (perfluorodecyl) ethyl Carbonates, di-6- (perfluoro-1-methylethyl) hexyl carbonate, di-2- (perfluoro-3-methylbutyl) ethyl carbonate, di-2- (perfluoro-7-methyloctyl) ethyl carbonate, etc. And carbonates. R _{7 in the} general formula (2) is a perfluoroalkyl group having 1 to 30 carbon atoms, but in consideration of the water repellency effect and reactivity, a perfluoroalkyl group having 6 to 20 carbon atoms is preferable, and the carbon number is further increased. 6-12 perfluoroalkyl groups are more preferred. Those having a perfluorooctyl group are particularly preferred because they have the best balance between water repellency and reactivity. Further, phenol, pt-butylphenol, cumylphenol and other phenols, ethanol, propanol, hexanol and other alcohols, ethyl chloroformate, chloroformates such as phenyl chloroformate, etc. It is also possible to use together. When using a general terminal terminator in combination, it is preferably less than 50 mol% with respect to the terminal terminator that derives the general formula (2). By doing in this way, the terminal modified polycarbonate oligomer which has group represented by the said General formula (2) in at least one molecule terminal can be obtained. Otherwise, the effects of the present invention cannot be fully exhibited.
Further, after producing a polycarbonate oligomer having a terminal phenolic hydroxyl group by using the phosgene method or the transesterification method, it is reacted with an alcohol or a carbonate having a fluoroalkyl group in a basic solution to thereby produce the terminal modified polycarbonate oligomer of the present invention. It is also possible to synthesize.

  The terminal-modified polycarbonate oligomer of the present invention has an intrinsic viscosity at 20 ° C. of a 0.5 g / dl solution containing methylene chloride as a solvent of less than 0.2 dl / g, preferably 0.05 to 0.19 dl / g. The average degree of polymerization n calculated from the ratio of the monofunctional compound that derives the general formula (2) to the raw material bisphenol is preferably 1-20.

  The terminal-modified polycarbonate oligomer cannot be used alone as a binder resin, but is added to the binder resin. The addition amount is preferably 0.5 to 5.0% by weight based on the total amount of the binder resin and the terminal-modified polycarbonate oligomer in consideration of the water repellency effect and the film formability.

  After mixing with a charge transporting material using the binder resin of the present invention, an electrophotographic photoreceptor is formed by known wet molding such as a solution casting method, a casting method, a spray method, a dip coating method (dip method), etc. Is possible. In order for the electrophotographic photosensitive member formed by wet forming to obtain a sufficient film strength, the intrinsic viscosity of the binder resin is preferably 0.40 to 1.5 dl / g.

  The mixing ratio of the charge transport material and the binder resin is preferably in the range of 10: 1 to 1:10. The thickness of the charge transport layer is 2 to 100 μm, preferably 5 to 30 μm.

  In the present invention, the binder resin includes vinyl polymers such as polymethyl methacrylate, polystyrene, and polyvinyl chloride, and copolymers thereof, and various heats such as polycarbonate, polyester, polysulfone, phenoxy resin, epoxy resin, and silicone resin. A plastic resin or a thermosetting resin is used, and among them, it is preferable to select a polycarbonate having good compatibility with the terminal-modified polycarbonate oligomer of the present invention.

  When polycarbonate is selected as the binder resin, specifically, 1,1′-biphenyl-4,4′-diol, bis (4-hydroxyphenyl) methane, bis (4-hydroxyphenyl) ether as bisphenols Bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) ketone, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxy) Phenyl) propane (bisphenol A; BPA), 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxy-3-tert-butylphenyl) propane, 1,1-bis ( 4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclo Xan (bisphenol Z; BPZ), 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 2,2-bis (4-hydroxy-3-allylphenyl) propane, 2, 2-bis (4-hydroxyphenyl) hexafluoropropane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, bis (4-hydroxyphenyl) diphenylmethane, 9,9-bis (4-hydroxyphenyl) Fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) fluorene, 4,4 ′-[1,4-phenylenebis (1-methylethylidene)] bisphenol, 4,4 ′-[1,3- Phenylenebis (1-methylethylidene)] bisphenol and 4,4'-butylidenebis (3-methyl-6-t-butychi) Using at least one selected from the group consisting of phenol) and the like, a polycarbonate synthesized by known methods as described above. Further, bisphenols include 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1, Particularly preferred is a polycarbonate synthesized from at least one selected from the group consisting of 1′-biphenyl-4,4′-diol and 1,1-bis (4-hydroxyphenyl) -1-phenylethane.

Prepolymerization 1
913 g (4.00 mol) of 2,2-bis (4-hydroxyphenyl) propane, 805 g (3.76 mol) of diphenyl carbonate, and 3.5 × 10 ⁻⁵ g (4.2 × 10 ⁻⁷ ) sodium hydrogen carbonate Mol) was placed in a 3 liter four-necked flask equipped with a stirrer and a distillation apparatus, heated to 220 ° C. in a nitrogen atmosphere, and the degree of vacuum was adjusted to 0.28 mmHg in 1 hour while stirring. The transesterification reaction was carried out for 4 hours. After completion of the reaction, nitrogen was blown into the reactor to return to normal pressure, and the produced polycarbonate was taken out.

The intrinsic viscosity at 20 ° C. of a 0.5 g / dl concentration solution of this polymer using methylene chloride as a solvent was 0.14 dl / g. Further, the result of measuring the concentration of the terminal hydroxyl group by a titanium tetrachloride color developing method with a spectrophotometer was 1.21% by weight, and the result of gel permeation chromatography was that the remaining amount of monomer was less than 100 ppm. The results obtained polymer was analyzed by infrared absorption spectrum, absorption by carbonyl group at the position in the vicinity of 1770 cm ^-1, observed absorption by ether bond position near 1240 cm ^-1, it is polycarbonate oligomer having a carbonate bond Was confirmed.

Prepolymerization 2
Except for changing 913 g (4.00 mol) of 2,2-bis (4-hydroxyphenyl) propane to 1072 g (4.00 mol) of 1,1-bis (4-hydroxyphenyl) cyclohexane, Similarly, a polycarbonate was produced.

Prepolymerization 3
A polycarbonate was produced in the same manner as in Prepolymerization 1, except that 913 g (4.00 mol) of 2,2-bis (4-hydroxyphenyl) propane was changed to 907 g (3.98 mol).

Synthesis example 1
3 liters of methylene chloride, 267 g of bis (2,4-dinitrophenyl) carbonate and 280 g of 2- (perfluorooctyl) ethanol were put into a 5 liter beaker and mixed with stirring at room temperature. To this mixed solution, a solution obtained by dissolving 73.7 g of triethylamine in 500 ml of methylene chloride was slowly added dropwise over 1.5 hours to cause a stirring reaction. Further, after stirring for 1 hour, a solution prepared by dissolving 500 g of the polycarbonate prepared in Prepolymerization 1 in 3.5 liters of methylene chloride, 73.7 g of triethylamine, and 2.5 g of 4- (dimethylamino) pyridine was added over 2.5 hours. The solution was slowly added dropwise to the reaction solution and stirred. After further stirring for 3 hours, the reaction solution was washed with 3.5 kg of 1N hydrochloric acid, and then washed four times with 3.5 kg of 0.5N caustic soda solution. Finally, the reaction solution was washed with 3.5 kg of 1N hydrochloric acid and further washed with 7.4 kg of pure water.
Methylene chloride was removed from the reaction solution with an evaporator, and the residue was washed with 3 liters of methanol and then with 3 liters of hexane. The washed residue was vacuum dried at 40 ° C. to obtain the desired polymer.

The intrinsic viscosity at 20 ° C. of a 0.5 g / dl concentration solution of this polymer using methylene chloride as a solvent was 0.13 dl / g. Further, the result of measurement of the terminal hydroxyl group concentration by the titanium tetrachloride coloring method by a spectrophotometer was less than 0.01% by weight. The results obtained polymer was analyzed by infrared absorption spectrum, absorption by carbonyl group at the position in the vicinity of 1770 cm ^-1, observed absorption by ether bond position near 1240 cm ^-1, contains further results fluorine atoms XPS analysis It was confirmed that As a result, it was confirmed that this polymer was a polycarbonate oligomer (hereinafter abbreviated as AL1) having the following structure.

Synthesis example 2
3 liters of methylene chloride, 288 g of bis (2,4-dinitrophenyl) carbonate and 324 g of 2- (perfluorooctyl) ethanol were put into a 5 liter beaker and stirred and mixed at room temperature. To this mixed solution, a solution obtained by dissolving 79.6 g of triethylamine in 500 ml of methylene chloride was slowly added dropwise over 1.5 hours to cause a stirring reaction. Further, after stirring for 1 hour, a solution prepared by dissolving 700 g of the polycarbonate prepared in Prepolymerization 2 in 3.5 liters of methylene chloride, 79.6 g of triethylamine, and 2.5 g of 4- (dimethylamino) pyridine was added over 2.5 hours. The solution was slowly added dropwise to the reaction solution and stirred. After further stirring for 3 hours, the reaction solution was washed with 3.5 kg of 1N hydrochloric acid, and then washed four times with 3.5 kg of 0.5N caustic soda solution. Finally, the reaction solution was washed with 3.5 kg of 1N hydrochloric acid and further washed with 7.4 kg of pure water.
Methylene chloride was removed from the reaction solution with an evaporator, and the residue was washed with 3 liters of methanol and then with 3 liters of hexane. The washed residue was vacuum dried at 40 ° C. to obtain the desired polymer.

  The intrinsic viscosity of the obtained polymer is 0.13 dl / g, the terminal hydroxyl group concentration measurement result is less than 0.01% by weight. As a result of infrared absorption spectrum and XPS analysis, this polymer is a polycarbonate having the following structure. It was confirmed to be an oligomer (hereinafter abbreviated as AL2).

Synthesis example 3
The synthesis was performed in the same manner as in Synthesis Example 1 except that 280 g of 2- (perfluorooctyl) ethanol was changed to 220 g of 2- (perfluorohexyl) ethanol.

  The intrinsic viscosity of the obtained polymer is 0.12 dl / g, the terminal hydroxyl group concentration measurement result is less than 0.01% by weight. As a result of infrared absorption spectrum and XPS analysis, this polymer is a polycarbonate having the following structure: It was confirmed to be an oligomer (hereinafter abbreviated as AL3).

Synthesis example 4
3 liters of methylene chloride, 186 g of bis (2,4-dinitrophenyl) carbonate and 279 g of 2- (perfluorododecanyl) ethanol were put into a 5 liter beaker and mixed with stirring at room temperature. To this mixed solution, a solution obtained by dissolving 51.4 g of triethylamine in 500 ml of methylene chloride was slowly dropped over 1.5 hours to cause a stirring reaction. Further, after stirring for 1 hour, a solution prepared by dissolving 500 g of the polycarbonate prepared in Prepolymerization 3 in 3.5 liters of methylene chloride, 51.4 g of triethylamine, and 2.5 g of 4- (dimethylamino) pyridine was added over 2.5 hours. The solution was slowly added dropwise to the reaction solution and stirred. After further stirring for 3 hours, the reaction solution was washed with 3.5 kg of 1N hydrochloric acid, and then washed four times with 3.5 kg of 0.5N caustic soda solution. Finally, the reaction solution was washed with 3.5 kg of 1N hydrochloric acid and further washed with 7.4 kg of pure water.
Methylene chloride was removed from the reaction solution with an evaporator, and the residue was washed with 3 liters of methanol and then with 3 liters of hexane. The washed residue was vacuum dried at 40 ° C. to obtain the desired polymer.

  The intrinsic viscosity of the obtained polymer is 0.19 dl / g, the terminal hydroxyl group concentration measurement result is less than 0.01% by weight. As a result of infrared absorption spectrum and XPS analysis, this polymer is a polycarbonate having the following structure. It was confirmed to be an oligomer (hereinafter abbreviated as AL4).

Example 1
10 g of phthalocyanine titanium oxide (ST10 / 10.1 manufactured by SYNTEC Co.), 5 g of phenoxy resin, 5 g of polyvinyl butyral resin, and 100 g of dimethoxyethane are mixed on a polyethylene terephthalate film on which aluminum is deposited to a thickness of about 50 nm. Then, it was coated using a coating liquid that had been pulverized and dispersed, dried, and a charge generation layer having a thickness of about 0.5 μm was provided.
Next, 50 g of N, N′-bis (3-methylphenyl) -N, N′-bis (phenyl) benzidine (ST16 / 1.2 manufactured by SYNTEC) was added to 2,2-bis (4-hydroxyphenyl) propane. Polycarbonate oligomer (AL1) 0 obtained in Synthesis Example 1 and 49.5 g of a homopolycarbonate derived from the above (Mitsubishi Gas Chemical Co., Ltd., Iupilon E-2000, intrinsic viscosity 0.58 dl / g, hereinafter referred to as PC1) A coating solution prepared by mixing 0.5 g and 350 g of methylene chloride was prepared, applied onto the charge generation layer, air-dried, dried at 100 ° C. for 8 hours, and provided with a charge transport layer having a thickness of about 20 μm. A photographic photoreceptor was prepared.

Evaluation of this electrophotographic photosensitive member film was measured with an EPA-8100 electrostatic charge test device manufactured by Kawaguchi Electric Co., Ltd., and water repellency and wettability by surface contact angle measurement were also evaluated.
Further, the photosensitive drum of a commercially available LBP photosensitive cartridge (LPA3ETC4 manufactured by Epson Corporation) is taken out, the charge transport layer is dissolved in THF, the charge transport agent solution is applied, and a charge transport layer having a thickness of about 20 μm is provided. Thus, a reproduction photosensitive drum was prepared. The toner in the cartridge was evenly sprinkled on the surface of the reproduction photosensitive drum, and the increase in weight due to toner adhesion at the time when the toner no longer fell by shaking was measured. The results are shown in Table 1.

Further, the reproducing photosensitive drum is mounted on the cartridge, mounted on a commercially available LBP (LP-8600FX manufactured by Epson Corporation), and after a part of the toner in the cartridge is evenly sprinkled on the exposed photosensitive drum surface, After shaking the cartridge lightly to visually confirm that the toner no longer spills, the cartridge was mounted on the LBP main body, continuous white printing was performed, and the number of sheets until the black spot with a major axis of 0.5 mm or more disappeared was visually counted. . The results are shown in Table 2.
On the other hand, the regenerative photosensitive drum is mounted on a cartridge and mounted on a commercially available LBP (LP-8600FX manufactured by Epson Corporation). The exposed photosensitive drum surface is lightly rubbed with ethanol-containing absorbent cotton, and further dried absorbent cotton After the ethanol was wiped off, continuous black printing was carried out, and the number of sheets until thin unevenness could not be confirmed visually was counted. The results are shown in Table 2.

Example 2
A coating solution was prepared in the same manner as in Example 1 except that the polycarbonate oligomer (AL1) was changed to 2.4 g and the polycarbonate (PC1) was changed to 47.6 g, and the same experiment as in Example 1 was performed using this coating solution. It was. The results are shown in Tables 1 and 2.

Example 3
A coating solution was prepared in the same manner as in Example 1 except that the polycarbonate oligomer (AL1) was changed to 0.3 g and the polycarbonate (PC1) was changed to 49.7 g, and the same experiment as in Example 1 was performed using this coating solution. It was. The results are shown in Tables 1 and 2.

Example 4
Homopolycarbonate (PC1) derived from 1,1-bis (4-hydroxyphenyl) cyclohexane (Mitsubishi Gas Chemical Co., Ltd., Iupizeta PCZ-200, intrinsic viscosity 0.58 dl / g, hereinafter referred to as PC2). ), The polycarbonate oligomer (AL1) was changed to the polycarbonate oligomer (AL2) of Synthesis Example 2, and the methylene chloride was changed to toluene. A coating solution was prepared in the same manner as in Example 1, and this coating solution was used. The same experiment as in Example 1 was conducted. The results are shown in Tables 1 and 2.

Example 5
Homopolycarbonate (PC1) is converted into 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) propane and 1,1-bis (4-hydroxyphenyl) -1- Copolymerized polycarbonate derived from phenylethane (Mitsubishi Gas Chemical Co., Ltd., Iupizeta FPC-A152, intrinsic viscosity 0.96 dl / g, hereinafter referred to as PC3) was changed to polycarbonate oligomer (AL1). The coating solution was prepared in the same manner as in Example 1 except that the methylene chloride was changed to tetrahydrofuran, and the same experiment as in Example 1 was performed using this coating solution. The results are shown in Tables 1 and 2.

Example 6
Copolycarbonate derived from homopolycarbonate (PC1) from 2,2-bis (4-hydroxyphenyl) propane and 1,1′-biphenyl-4,4′-diol (Tufzette B-300, manufactured by Idemitsu Kosan Co., Ltd.) , Limiting viscosity to 0.72 dl / g, hereinafter referred to as PC4), except that polycarbonate oligomer (AL1) was changed to polycarbonate oligomer (AL2), and methylene chloride was changed to toluene. A liquid was prepared and the same experiment as in Example 1 was performed using this coating liquid. The results are shown in Tables 1 and 2.

Example 7
A coating solution was prepared in the same manner as in Example 1 except that the polycarbonate oligomer (AL1) was changed to the polycarbonate oligomer (AL3) of Synthesis Example 3, and the same experiment as in Example 1 was performed using this coating solution. The results are shown in Tables 1 and 2.

Example 8
A coating solution was prepared in the same manner as in Example 1 except that the polycarbonate oligomer (AL1) was changed to the polycarbonate oligomer (AL4) of Synthesis Example 4, and the same experiment as in Example 1 was performed using this coating solution. The results are shown in Tables 1 and 2.

Comparative Example 1
A coating solution was prepared in the same manner as in Example 1 except that the polycarbonate oligomer (AL1) was not used, and the same experiment as in Example 1 was performed using this coating solution. The results are shown in Tables 1 and 2.

Comparative Example 2
A coating solution was prepared in the same manner as in Example 4 except that the polycarbonate oligomer (AL2) was not used, and the same experiment as in Example 1 was performed using this coating solution. The results are shown in Tables 1 and 2.

Comparative Example 3
A coating solution was prepared in the same manner as in Example 1 except that the polycarbonate oligomer (AL1) was changed to 2.8 g and the homopolycarbonate (PC1) was changed to 47.2 g. Using this coating solution, the same experiment as in Example 1 was conducted. I did it. The results are shown in Tables 1 and 2.

Comparative Example 4
A coating solution was prepared in the same manner as in Example 1 except that the polycarbonate oligomer (AL1) was changed to 0.1 g and the homopolycarbonate (PC1) was changed to 49.9 g. An experiment similar to that in Example 1 was performed using this coating solution. I did it. The results are shown in Tables 1 and 2.

Comparative Example 5
Without using the polycarbonate oligomer (AL1), a homopolycarbonate (PC1) was obtained by terminal-modified polycarbonate having the following structure obtained by the same reaction as in Example 1 of JP-A-5-306335 (ultimate viscosity 0.82 dl / g, below) A coating solution was prepared in the same manner as in Example 1 except that it was changed to PFOE), and an experiment similar to that in Example 1 was performed using this coating solution. The results are shown in Tables 1 and 2.

Comparative Example 6
A coating solution was prepared in the same manner as in Example 1 except that 0.5 g of 2- (perfluorooctyl) ethanol was used instead of the polycarbonate oligomer (AL1), and the same experiment as in Example 1 was performed using this coating solution. Was done. The results are shown in Tables 1 and 2.

[Explanation of table symbols and words]
AL1: Terminal modified polycarbonate oligomer of Synthesis Example 1 AL2: Terminal modified polycarbonate oligomer of Synthesis Example 2 AL3: Terminal modified polycarbonate oligomer of Synthesis Example 3 AL4: Terminal modified polycarbonate oligomer of Synthesis Example 4 PC1: Iupilon E manufactured by Mitsubishi Gas Chemical Co., Ltd. -2000
PC2: Iupizeta PCZ-200 manufactured by Mitsubishi Gas Chemical Company, Inc.
PC3: Iupizeta FPC-A152 manufactured by Mitsubishi Gas Chemical Company, Inc.
PC4: Idemitsu Kosan Co., Ltd. Toughzet B-300
PC5: Polycarbonate PFOE described in Example 1 of JP-A-5-306335: 2- (perfluorooctyl) ethanol Initial potential: room temperature (about 23 ° C.) 50 μA current flows into the photoreceptor film with a DC charger Initial charge amount when adjusted.
Residual potential: Residual potential after 4 seconds after exposing the photosensitive film at room temperature (about 23 ° C.) (static elimination 10 Lux).
Water contact angle: measured with DropMaster 300 manufactured by Kyowa Interface Science Co., Ltd.
Film appearance: judged visually.
JIS wettability: Measured according to the wetting tension test (JIS K6768).
Toner adhesion weight: It was estimated from the increase in film weight after the toner was sprinkled on a 20 cm × 20 cm photosensitive film until the film was no longer visible, and the toner was removed by hand shaking.

  As an application example of the present invention, an electrophotographic photosensitive member that prevents contamination such as washing alcohol or a large amount of toner that is mistakenly attached at the time of replacement or maintenance of the photosensitive member, and quickly returns to a good printing state even if it is contaminated. Application to is possible.

Claims (8)

In an electrophotographic photoreceptor having a photosensitive layer on a conductive substrate, the photosensitive layer has a repeating unit represented by the following general formula (1) and at least one group represented by the following general formula (2). An electrophotographic photoreceptor using a binder resin containing 0.5 to 5.0% by weight of a terminal-modified polycarbonate oligomer having an intrinsic viscosity of less than 0.20 dl / g.

(Wherein R _{1 to} R ₄ are each hydrogen, fluorine, chlorine, bromine, iodine, an alkyl group having 1 to 9 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, It is a C1-C5 alkoxy group or a C7-C17 aralkyl group, The substituent which you may have in carbon of these groups is a C1-C5 alkyl group, C2-C5 An alkenyl group or an alkoxy group having 1 to 5 carbon atoms, X is

Wherein R ₅ and R ₆ are each hydrogen, fluorine, chlorine, bromine, iodine, an alkyl group having 1 to 9 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or an aryl group having 6 to 12 carbon atoms. Or a group in which R ₅ and R ₆ are bonded together to form a carbocycle or a heterocycle, and the substituent that may be present on the carbon of these groups is a group having 1 to 5 carbon atoms An alkyl group, an alkenyl group having 2 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or a halogen group selected from fluorine, chlorine, bromine and iodine. a represents an integer of 0 to 20. )

(Wherein, _{R 7} represents an integer of .b 0 to 8 representing a perfluoroalkyl group having 1 to 30 carbon atoms.) The electrophotographic photoreceptor according to claim 1, wherein R ₇ in the general formula (2) is a C 6-30 perfluoroalkyl group. The electrophotographic photosensitive member according to claim 1, wherein R ₇ in the general formula (2) is a C 6-12 perfluoroalkyl group. The electrophotographic photosensitive member according to claim 1, wherein R ₇ in the general formula (2) is a perfluorooctyl group and b is 2. The repeating unit represented by the general formula (1) is derived from 2,2-bis (4-hydroxyphenyl) propane and / or 1,1-bis (4-hydroxyphenyl) cyclohexane. The electrophotographic photosensitive member described. The electrophotographic photosensitive member according to claim 1, wherein the binder resin contains a polycarbonate resin as a main component. The binder resin is 2,2-bis (4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 1,1 ′ The electrophotographic photoreceptor according to claim 1, which is a polycarbonate resin derived from the group consisting of -biphenyl-4,4'-diol and 1,1-bis (4-hydroxyphenyl) -1-phenylethane. The electrophotographic photosensitive member according to claim 1, wherein the binder resin is used in a charge transport layer of the laminated electrophotographic photosensitive member.