JP2007219481A - Electrophotographic photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor which has superior sensitivity characteristics by using a charge transport agent excellent in solubility with an organic solvent and compatibility with a binder resin used to form a photosensitive layer. <P>SOLUTION: The electrophotographic photoreceptor having the photosensitive layer containing at least a charge generating agent and the charge transport agent, which is made of a compound expressed by general formula (1), is provided. In the formula, R1 to R6 are the same or different groups and represent hydrogen atoms, 1 to 6C alkyl groups, 1 to 6C alkoxy groups, phenoxy groups, 6 to 20C aryl groups, or aralkyl groups in which carbon number in the alkyl part is 1 to 6 and carbon number in the aryl part is 6 to 20, where (n) is an integer of 0 to 2 and (m) is an integer of 1 to 4. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member containing a charge transporting agent excellent in solubility in an organic solvent and compatibility with a binder resin used for forming a photosensitive layer.

  In an image forming apparatus such as a copying machine, a laser printer, or a facsimile, an organic photoreceptor having sensitivity suitable for a wavelength region of a light source used in the apparatus is used. This organic photoconductor is easier to manufacture than conventional inorganic photoconductors, and there are various options for constituent materials of the photoconductor such as a charge transport agent, a charge generator, and a binder resin. Widely used because of its high cost.

  The organic photoreceptor includes a single-layer photoreceptor in which a charge generator is dispersed in a photosensitive layer containing a charge transport agent, a charge generation layer containing a charge generator, and a charge transport layer containing a charge transport agent. There are laminated type photoconductors in which are separated and laminated. In any of the above photoreceptors, in order to improve the sensitivity characteristic, it is required to use a charge transport agent having a high charge transport property. Therefore, conventionally, various charge transport agents have been proposed, and Patent Document 1 discloses, as a charge transport agent having a predetermined charge mobility among such organic photoreceptor materials, the following general formula HT-12. As shown, a stilbene derivative having two specific triphenylamine structures at the molecular terminals via — (CH═CH) n— (wherein n represents an integer) and electrophotographic sensitivity using the same The body is known.

JP-A-5-105646

However, although the stilbene derivatives disclosed in the above publications are generally excellent in charge transport properties, they have low solubility in organic solvents and low compatibility with the binder resin used to form the photosensitive layer. It is not uniformly dispersed and charge transfer is unlikely to occur. Therefore, although the stilbene derivative itself has a high charge mobility, when it is used as a charge transfer agent for a photoreceptor, the characteristics cannot be sufficiently exhibited, and the photoreceptor is not suitable for long-term use. There is a problem that the residual potential becomes high and the photosensitivity becomes insufficient.
An object of the present invention is to provide an electrophotographic photoreceptor excellent in sensitivity characteristics by using a charge transfer agent excellent in solubility in an organic solvent and compatibility with a binder resin used for forming a photosensitive layer.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor is a compound in which the two substituents substituted with nitrogen of the diphenylamino group at the molecular terminal are different and the whole molecule is asymmetric in the charge transfer agent. In particular, one phenyl group in the diphenylamino group has a substituent, and the other phenyl group is bonded to the benzene ring via one or two double bonds (— (CH═CH) —). When a stilbene amine derivative having a substituent is used, the solubility in organic solvents and the compatibility with the binder resin can be remarkably improved. A new fact that a photoconductor can be obtained has been found, and the present invention has been completed.

（式中、Ｒ₁〜Ｒ₆は、同一または異なる基であって、水素原子、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、フェノキシ基、炭素数６〜２０のアリール基、またはアルキル部分の炭素数が１〜６でアリール部分の炭素数が６〜２０であるアラルキル基を示す。ｎは０〜２の整数を示す。ｍは１〜４の整数を示す。） That is, the electrophotographic photoreceptor using the charge transport agent of the present invention has the following characteristics.
(1) An electrophotographic photosensitive member provided with a photosensitive layer containing at least a charge generating agent and a charge transport agent, wherein the charge transport agent comprises a compound represented by the following general formula (1). Electrophotographic photoreceptor.

(In the formula, R _{1 to} R ₆ are the same or different groups and are a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a phenoxy group, or an aryl having 6 to 20 carbon atoms. Group or an aralkyl group having an alkyl moiety having 1 to 6 carbon atoms and an aryl moiety having 6 to 20 carbon atoms, n represents an integer of 0 to 2, and m represents an integer of 1 to 4.)

  According to the charge transfer agent comprising the general formula (1) of the present invention, the solubility in an organic solvent and the compatibility with a binder resin are remarkably improved, so that the precipitation of crystals in the photosensitive layer is prevented, and the high sensitivity. An electrophotographic photosensitive member can be obtained.

Hereinafter, the present invention will be described in detail. The electrophotographic photoreceptor of the present invention is provided with a photosensitive layer containing at least a charge generating agent and a charge transporting agent, and the charge transporting agent comprises a compound represented by the above general formula (1).
As described above, the charge transfer agent according to the present invention is represented by the general formula (1), and the substituents R in the formula (1) are the same or different groups, and are a hydrogen atom, carbon An alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a phenoxy group, an aryl group having 6 to 20 carbon atoms, or an alkyl moiety having 1 to 6 carbon atoms and an aryl moiety having 6 to 20 carbon atoms A certain aralkyl group is shown. n represents an integer of 0 to 2, and m represents an integer of 1 to 4. That is, the charge transporting agent according to the present invention is a compound in which two substituents substituted with nitrogen of a diphenylamino group at the molecular terminal are different and are asymmetric as a whole molecule, and in particular, substituted with one phenyl group in the diphenylamino group. And the other phenyl group is a stilbeneamine derivative having a substituent formed by bonding to a benzene ring via any one to three double bonds (— (CH═CH) —). is there.

Examples of the alkyl group in R _{1 to} R ₆ include a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, pentyl group, isopentyl group, C1-C6 alkyl groups, such as a neopentyl group and a hexyl group, are mentioned. Examples of the alkoxy group include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, s-butoxy, t-butoxy, pentyloxy, isopentyloxy, neopentyloxy, hexyloxy and the like. Moreover, as an aryl group, C6-C20 aryl groups, such as a phenyl group, a naphthyl group, a tolyl group, a xylyl group, an anthryl group, a phenanthryl group, etc. are mentioned, for example. The aryl group in R may have a substituent, and examples of the substituent include an alkyl group having 1 to 6 carbon atoms and an alkoxy group having 1 to 6 carbon atoms. Examples of the aralkyl group include aralkyl groups having 6 to 20 carbon atoms such as benzyl, α-methylbenzyl, phenethyl, styryl, cinnamyl, 3-phenylpropyl, 4-phenylbutyl, 5-phenylpentyl, 6-phenylhexyl and the like. Is mentioned.

  As described above, the compound represented by the formula (1) is a compound in which two substituents substituted with nitrogen of a diphenylamino group at the molecular terminal are different and are asymmetric as a whole molecule. The other phenyl group is bonded to the benzene ring via any one to three double bonds (— (CH═CH) —). A structure having By taking the structure, it becomes difficult to crystallize due to steric hindrance in the two substituents substituted with nitrogen, and excellent sensitivity is maintained for a long time, and further compatibility with the binder resin is excellent. Moreover, in the said structure, by having-(CH = CH)-in the center location in a molecule | numerator, while intramolecular conjugation can be expanded, as a result, stability and durability are improved, and also for a long time. Excellent sensitivity can be shown.

  Examples of the compound represented by the above formula (1) according to the present invention include HT-1 to 11 shown below. However, the compounds that can be used as the charge transport agent in the present invention are not limited to these. In the following formula, Ph represents a phenyl group.

(Synthesis method)
Any compound included in the formula (1) in the present invention can be synthesized by a known production method. For example, HT-1 can be obtained by the following method using a Wittig reaction and a coupling reaction. That is, first, compound (2) which is a phosphite derivative is subjected to a substitution reaction at a temperature of 0 to 10 ° C., dry THF (tetrahydrofuran) and sodium methoxide are added, and the mixture is stirred for 20 to 50 minutes. To do. Next, the compound (8) which is an aldehyde derivative dissolved in dry THF is added to the obtained reaction solution, and the mixture is stirred at room temperature for 10 to 15 hours. The resulting reaction solution can be extracted with toluene or the like to obtain compound (3).

同様にして、亜リン酸エステル誘導体である化合物（５）を温度０〜１０℃のもとで置換反応を行い、乾燥ＴＨＦ（テトラヒドロフラン）とナトリウムメトキシドとを加えて、２０〜５０分混合攪拌する。次に、得られた反応液に、乾燥ＴＨＦに溶解させたアルデヒド誘導体である化合物（９）を加え、室温で１０〜１５時間攪拌する。得られた反応液をトルエンなどで抽出して化合物（６）を得ることができる。

Similarly, the compound (5) which is a phosphite derivative is subjected to a substitution reaction at a temperature of 0 to 10 ° C., dry THF (tetrahydrofuran) and sodium methoxide are added, and the mixture is stirred for 20 to 50 minutes. To do. Next, the compound (9) which is an aldehyde derivative dissolved in dry THF is added to the obtained reaction solution, and the mixture is stirred at room temperature for 10 to 15 hours. The resulting reaction solution can be extracted with toluene or the like to obtain compound (6).

次に、得られた化合物（６）と式（１０）で表される化合物とを、下記の反応式によりカップリング反応させる。すなわち、前記化合物（６）と化合物（１０）とをｏ−キシレンに加えて、Ｐｄ触媒の存在下で置換反応を行い、１００〜１３０℃で２〜４時間攪拌する。その後室温まで冷却し、得られた反応液をトルエンなどで抽出して化合物（７）を得ることができる。

Next, the obtained compound (6) and the compound represented by the formula (10) are subjected to a coupling reaction according to the following reaction formula. That is, the compound (6) and the compound (10) are added to o-xylene, and a substitution reaction is performed in the presence of a Pd catalyst, followed by stirring at 100 to 130 ° C. for 2 to 4 hours. Thereafter, the mixture is cooled to room temperature, and the resulting reaction solution is extracted with toluene or the like to obtain compound (7).

さらに、同様にして、得られた化合物（７）と化合物（３）とを、下記の反応式によりカップリング反応させる。すなわち、化合物（７）と前記化合物（３）とをｏ−キシレンに加えて、Ｐｄ触媒の存在下で置換反応を行い、１００〜１３０℃で２〜４時間攪拌する。その後室温まで冷却し、得られた反応液をトルエンなどで抽出し、本発明にかかるＨＴ−１が得られる。

Further, similarly, the obtained compound (7) and compound (3) are subjected to a coupling reaction according to the following reaction formula. That is, the compound (7) and the compound (3) are added to o-xylene, and a substitution reaction is performed in the presence of a Pd catalyst, followed by stirring at 100 to 130 ° C. for 2 to 4 hours. Thereafter, the mixture is cooled to room temperature, and the resulting reaction solution is extracted with toluene or the like to obtain HT-1 according to the present invention.

本発明における式（１）に含まれる他の化合物も、前記化合物（２）、（５）、（９）および（１０）等を、所望の基を有する化合物に代えることにより、前記と同様にして合成することができる。

Other compounds included in the formula (1) in the present invention are the same as described above by replacing the compounds (2), (5), (9) and (10) with compounds having a desired group. Can be synthesized.

  As described above, the electrophotographic photoreceptor of the present invention contains a charge transporting agent composed of the compound contained in the formula (1) in the photosensitive layer.

The photosensitive layer is composed of a single layer type photoreceptor in which a charge generator and a charge transport agent are mixed in the same layer, a layer containing a charge generator, and a layer containing a charge transport agent. Each photosensitive layer is obtained by dissolving and dispersing each component such as a charge generating agent and a charge transporting agent in a solvent together with a binder resin and the like. It is formed by applying and drying the resulting coating solution on a conductive substrate.
As described above, the electrophotographic photoreceptor of the present invention contains a compound contained in the formula (1) having good solubility in a solvent and high charge transportability, and therefore, compared with a conventional electrophotographic photoreceptor. And high sensitivity. Moreover, according to the electrophotographic photosensitive member of the present invention, since the compatibility between the compound contained in the formula (1) and the binder resin is good, the long-term stability of the photosensitive layer is improved.

(Charge generator)
Next, examples of the charge generating agent according to the present invention include metal-free phthalocyanine, hydroxygallium phthalocyanine, chlorogallium phthalocyanine, α-titanyl phthalocyanine, Y-titanyl phthalocyanine, and phthalocyanine pigments such as V-hydroxygallium phthalocyanine and perylene pigments. Bisazo pigments, diketopyrrolopyrrole pigments, metal-free naphthalocyanine pigments, metal naphthalocyanine pigments, squaraine pigments, trisazo pigments, indigo pigments, azurenium pigments, cyanine pigments, pyrylium pigments, ansanthrone pigments, triphenylmethane pigments, Organic photoconductors such as selenium pigments, toluidine pigments, pyrazoline pigments, quinacridone pigments, selenium, selenium-tellurium, selenium-arsenic, cadmium sulfide, amorphous silicon Inorganic photoconductive material and the like such emissions. These charge generating agents may be used alone or in combination of two or more.

  In the present invention, a phthalocyanine pigment, particularly a metal-free phthalocyanine (for example, X-type metal-free phthalocyanine), titanyl phthalocyanine, hydroxygallium phthalocyanine and chlorogallium phthalocyanine is used as a charge generator. In view of the electrical characteristics of the photoconductor when red or infrared light of 650 nm or more is used as the exposure light source, etc.

(Hole transport agent)
The charge transport agent used in the electrophotographic photosensitive member of the present invention is a hole transport agent and is composed of a compound included in the formula (1).
In the electrophotographic photoreceptor of the present invention, various conventionally known hole transport agents may be contained in the photosensitive layer in combination with the compound (1). Examples of such other hole transporting agents include bisstilbenediamine derivatives, bistriphenylamine derivatives, triphenylaminostyryl derivatives, stilbeneamine-hydrazone derivatives, and the like.

(Electron transfer agent)
Examples of the electron transporting agent include diphenoquinone derivatives, benzoquinone derivatives, naphthoquinone derivatives, anthraquinone derivatives, malononitrile derivatives, thiopyran derivatives, thioxanthone derivatives (2,4,8-trinitrothioxanthone, etc.), fluorenone derivatives (3,4,5,7). -Tetranitro-9-fluorenone derivatives, etc.), anthracene derivatives, acridine derivatives, dinitrobenzene, dinitroanthracene, dinitroacridine, succinic anhydride derivatives, maleic anhydride derivatives, dibromomaleic anhydride derivatives, etc. Can be mentioned.

(Binder resin)
In the electrophotographic photoreceptor of the present invention, conventionally known various resins can be adopted as the binder resin for forming a layer containing each component such as a charge generator and a charge transport agent. Among them, the use of at least one resin selected from the group consisting of polycarbonate, polyester, polyarylate, polystyrene, and polymethacrylic acid ester as the binder resin is the compound represented by the above formula (1) according to the present invention. From the standpoint of further improving the compatibility, and the properties such as the strength and abrasion resistance of the photosensitive layer. Moreover, the binder resin exemplified above is excellent in compatibility with the charge generating agent and the charge transport agent, and does not have a site in the molecule that interferes with the charge transport property of the charge transport agent. Therefore, by using such a binder resin, an electrophotographic photosensitive member with higher sensitivity can be obtained.

(Dispersion medium)
As a dispersion medium used for preparing a coating solution for forming a photosensitive layer by dispersing and dissolving the charge generating agent, hole transporting agent, electron transporting agent, binder resin and the like exemplified above, a coating solution for forming a photosensitive layer is used. Various organic solvents conventionally used can be used. Specifically, alcohols such as methanol, ethanol, isopropanol and butanol; aliphatic hydrocarbons such as n-hexane, octane and cyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene; dichloromethane, dichloroethane and chloroform , Halogenated hydrocarbons such as carbon tetrachloride and chlorobenzene; ethers such as dimethyl ether, diethyl ether, tetrahydrofuran, dioxane, dioxolane, ethylene glycol dimethyl ether and diethylene glycol dimethyl ether; ketones such as acetone, methyl ethyl ketone and cyclohexanone; ethyl acetate and methyl acetate And esters such as dimethylformaldehyde, dimethylformamide, and dimethyl sulfoxide.

  In addition, although not limited thereto, tetrahydrofuran, dioxane, dioxolane, cyclohexanone, among various organic solvents, are preferable for stably dispersing each component such as a charge generator, a charge transport agent, and a binder resin. It is preferable to use at least one organic solvent selected from the group consisting of toluene, xylene, dichloromethane, dichloroethane and chlorobenzene.

(Additive)
In the coating solution for forming the photosensitive layer, in addition to the above-mentioned components, various conventionally known additives such as an antioxidant, a radical scavenger, a singlet quencher are used as long as they do not adversely affect the electrophotographic characteristics. Deterioration inhibitors such as char and ultraviolet absorbers, softeners, plasticizers, surface modifiers, extenders, thickeners, dispersion stabilizers, waxes, acceptors, donors, and the like can be blended. In order to improve the sensitivity of the photosensitive layer, a known sensitizer such as terphenyl, halonaphthoquinones, and acenaphthylene may be used in combination with the charge generator. Further, a surfactant, a leveling agent or the like may be used in order to improve the dispersibility of the charge transport agent or charge generator and the smoothness of the photosensitive layer surface.

(Conductive substrate)
As the conductive substrate, various conductive materials can be used. For example, iron, aluminum, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel And a simple metal such as brass, a plastic material on which the above metal is deposited or laminated, and glass coated with aluminum iodide, tin oxide, indium oxide, or the like. The conductive substrate is used in the form of a drum or a sheet according to the structure of the image forming apparatus to be used. The conductive substrate preferably has sufficient mechanical strength.
The conductive substrate used in the present invention is not limited to this, but the surface thereof may be subjected to an oxide film treatment or a resin film treatment.

(Manufacture of single layer type electrophotographic photoreceptor)
The single-layer type electrophotographic photosensitive member includes a charge generator, the compound (1) of the present invention (hole transport agent), a binder resin, and an electron transport agent and the above additives as necessary. The photosensitive layer forming coating solution thus obtained is dispersed or dissolved in an appropriate dispersion medium, coated on a conductive substrate, and dried to form a photosensitive layer.

  In the photosensitive layer forming coating solution, the charge generating agent may be blended in an amount of 0.1 to 50 parts by weight, preferably 0.5 to 30 parts by weight with respect to 100 parts by weight of the binder resin. What is necessary is just to mix | blend a hole transport agent in the ratio of 5-200 weight part with respect to 100 weight part of binder resin, Preferably it is 50-150 weight part. What is necessary is just to mix | blend an electron transport agent in the ratio of 5-200 weight part with respect to 100 weight part of binder resin, Preferably it is 10-100 weight part. In the case where the electron transport agent and the hole transport agent are used in combination, the total amount of the electron transport agent and the hole transport agent is 20 to 500 parts by weight, preferably 30 to 200 parts by weight with respect to 100 parts by weight of the binder resin. It is appropriate to do.

The thickness of the photosensitive layer obtained by applying the coating solution for forming the photosensitive layer is preferably set to 5 to 100 μm, particularly 10 to 50 μm.
When preparing a coating solution for forming a photosensitive layer, the above-exemplified charge generator, charge transport agent, insoluble azo pigment, binder resin, etc., together with an appropriate solvent, roll mill, ball mill, attritor, paint shaker, ultrasonic dispersion What is necessary is just to disperse and mix using well-known means, such as a machine.

(Manufacture of multilayer electrophotographic photoreceptors)
In the case of a laminated photoreceptor, a charge generator and a hole transport agent are mixed together with a suitable binder resin and solvent using a roll mill, ball mill, attritor, paint shaker, ultrasonic disperser, etc. What is necessary is just to prepare and apply | coat this dispersion liquid on an electroconductive base | substrate by a well-known means, and to make it dry. The thickness of each layer after drying is 0.01 to 5 μm, preferably 0.1 to 3 μm for the charge generation layer, and 2 to 100 μm, preferably 5 to 50 μm for the charge transport layer.

  In the charge generation layer of the multilayer photoconductor, the charge generation agent is preferably contained in an amount of 5 to 1000 parts by weight, particularly 30 to 500 parts by weight, based on 100 parts by weight of the binder resin. In the charge transport layer, the hole transport agent may be contained in an amount of 10 to 100 parts by weight, particularly 30 to 80 parts by weight with respect to 100 parts by weight of the binder resin. Moreover, when using together a positive hole transport agent and an electron transport agent, it is good to contain the total amount in the ratio of 10-500 weight part with respect to 100 weight part of binder resin, especially 30-200 weight part.

  Between the single layer type photosensitive layer or the multilayer type photosensitive layer and the conductive substrate, or between the charge generation layer and the charge transport layer constituting the multilayer type photosensitive layer, as long as the characteristics of the photosensitive member are not hindered. A layer, a barrier layer, or the like may be formed. Further, a protective layer may be formed on the surface of the photosensitive layer.

  Hereinafter, the electrophotographic photosensitive member of the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited only to the following Examples.

(Synthesis of hole transport agent)
(1) Synthesis of Compound (2) First, the compound represented by Formula (2) was synthesized according to the following reaction formula. That is, 10 g (0.04 mol) of the compound represented by the formula (20) and 6.5 g (0.04 mol) of triethyl phosphite were added to a 200 mL flask, heated at 180 ° C., and stirred for 8 hours. did. Then, after cooling to room temperature, excess phosphorous acid triethyl ester was distilled off under reduced pressure to obtain 12 g of a compound represented by the formula (2) (yield 95%).

(2) Synthesis of Compound (3) Next, the compound represented by the above formula (3) was synthesized according to the above reaction formula (R-1). That is, after adding 15.3 g (0.05 mol) of the compound represented by the formula (2) into a 500 mL two-necked flask, argon gas replacement was performed and 100 mL of dried tetrahydrofuran (THF) was added. % Sodium methoxide 11.6 g (0.06 mol) was added and stirred at 0 ° C. for 30 minutes. Next, 9.3 g (0.05 mol) of the compound represented by the formula (8) was dissolved in 300 mL of dry THF and added to this reaction solution, followed by stirring at room temperature for 12 hours. Thereafter, the reaction solution was poured into ion exchanged water and extracted with toluene, and the organic layer was washed 5 times with ion exchanged water. Next, the organic layer was dried over anhydrous sodium sulfate, and the solvent was distilled off. Thereafter, the residue was purified with a toluene / methanol mixed solvent (toluene / methanol = 20 mL / 100 mL) to obtain a compound represented by the formula (3). Yield 14.3 g (85% yield).

(3) Synthesis of Compound (5) Next, the compound represented by the formula (5) was synthesized according to the following reaction formula. That is, 12.3 g (0.098 mol) of benzyl chloride and 30.0 g (0.18 mol) of triethyl phosphite were added in a 200 mL flask, heated at 180 ° C., and stirred for 8 hours. Then, after cooling to room temperature, excess phosphorous acid triethyl ester was distilled off under reduced pressure to obtain 20 g of a compound represented by the formula (5) (yield 90%).

(4) Synthesis of Compound (6) Next, the compound represented by the above formula (6) was synthesized according to the above reaction formula (R-2). That is, after adding 11.2 g (0.049 mol) of the compound represented by the formula (5) into a 500 mL two-necked flask, argon gas replacement was performed and 100 mL of dried tetrahydrofuran (THF) was added. % Sodium methoxide 10.6 g (0.055 mol) was added and stirred at 0 ° C. for 30 minutes. Next, 9.25 g (0.05 mol) of the compound (9) was dissolved in 300 mL of dry THF and added to this reaction solution, followed by stirring at room temperature for 12 hours. Thereafter, the reaction solution was poured into ion exchanged water and extracted with toluene, and the organic layer was washed 5 times with ion exchanged water. Next, the organic layer was dried over anhydrous sodium sulfate, and the solvent was distilled off. Thereafter, the residue was purified with a toluene / methanol mixed solvent (toluene / methanol = 20 mL / 100 mL) to obtain a compound represented by the formula (6). Yield 10.74 g (85% yield).

(3) Synthesis of Compound (7) Next, the compound represented by the above formula (7) was synthesized according to the above reaction formula (R-3). That is, 19.6 g (0.0755 mol) of compound (6), (2-biphenyl) dicyclohexylphosphine (Pcy) 0.0662 g (0.000189 mol), tris (dibenzylideneacetone) 0.0864 g (0.0000944 mol) of palladium (Pd2 (dba) 3), 7.68 g (0.08 mol) of t-butoxy sodium (t-BuONa), and 9.13 g of the compound represented by the above formula (10) ( 0.0755 mol) and 500 mL of purified o-xylene were added, followed by replacement with argon gas and stirring at 120 ° C. for 5 hours. Then, after cooling to room temperature, the organic layer was washed 3 times with ion exchange water. Next, the organic layer was dried over anhydrous sodium sulfate, further treated with activated clay, and xylene was distilled off under reduced pressure. Thereafter, the residue was purified by column chromatography (developing solvent: chloroform / hexane) to obtain 19.1 g of the compound represented by the formula (7) (yield 85%).

(4) Synthesis of HT-1 Finally, HT-1 was synthesized according to the above reaction formula (R-4). That is, in a 300 mL two-necked flask, 6.12 g (0.0181 mol) of compound (3), 0.0318 g (0.000096 mol) of (2-biphenyl) dicyclohexylphosphine (Pcy), tris (dibenzylideneacetone) di 0.0414 g (0.000045 mol) of palladium (Pd2 (dba) 3), 5.76 g (0.06 mol) of t-butoxy sodium (t-BuONa), 10.8 g (0.036 mol) of compound (7), After adding 200 mL of purified o-xylene, argon gas replacement was performed, and the mixture was stirred at 120 ° C. for 3 hours. Then, after cooling to room temperature, the organic layer was washed 3 times with ion exchange water. Next, the organic layer was dried over anhydrous sodium sulfate, further treated with activated clay, and xylene was distilled off under reduced pressure. Thereafter, the residue was purified by column chromatography (developing solvent: chloroform / hexane) to obtain 11.2 g of the target compound (HT-1) (yield 80%).

(Synthesis of HT-2)
In addition, in the synthesis of HT-1, HT-2 is obtained by replacing the compound (10) with the compound represented by the following formula (12) and further replacing the compound (9) with the following formula (13). Synthesized in the same manner as HT-1.

(Synthesis of HT-3)
HT-3 in the present invention was synthesized in the same manner as HT-1 by replacing the compound (10) described above with the compound represented by the following formula (11) in the synthesis of HT-1.

(Synthesis of HT-4)
HT-4 in the present invention was synthesized in the same manner as HT-1 by replacing the compound (9) with the compound represented by the formula (8) in the synthesis of HT-1.

(Synthesis of HT-5)
HT-5 in the present invention is obtained by replacing the compound (9) with the compound represented by the formula (8) and further replacing the compound (10) with the following formula (14) in the synthesis of the HT-1. And synthesized in the same manner as HT-1.

(Synthesis of HT-6)
In the synthesis of HT-1, HT-6 in the present invention is obtained by replacing the compound (9) with the compound represented by the formula (8) and further replacing the compound (10) with the formula (11). And synthesized in the same manner as HT-1.

(Synthesis of HT-7)
HT-7 in the present invention is obtained by replacing the compound (9) with the compound represented by the formula (8) and further replacing the compound (20) with the following formula (15) in the synthesis of the HT-1. And synthesized in the same manner as HT-1.

(Synthesis of HT-8)
In the synthesis of HT-1, the HT-8 in the present invention is represented by the above formula (9) by replacing the above compound (9) with the compound represented by the above formula (8). The compound (10) was replaced with the compound represented by the formula (14), and the compound (5) was replaced with the following formula (16).

(Synthesis of HT-9)
In the synthesis of HT-1, the HT-9 in the present invention is obtained by replacing the compound (8) with the compound represented by the formula (9) and the compound (10) represented by the formula (11). The compound was synthesized in the same manner as HT-1 by replacing the compound (9) with the compound (8) described above instead of the above compound.

(Synthesis of HT-10)
In the synthesis of HT-1, HT-10 in the present invention is obtained by replacing the compound (8) with the compound (9) described above and further replacing the compound (9) with the compound (8) described above. And synthesized in the same manner as HT-1.

(Synthesis of HT-11)
In the synthesis of HT-1, HT-11 in the present invention is obtained by substituting the compound (8) with the compound (13) and further replacing the compound (9) with the compound (8). And synthesized in the same manner as HT-1.

[Examples 1-33 and Comparative Examples 1-3]
[Manufacture of electrophotographic photosensitive member]
(Hole transport agent)
As the hole transport agent, the above-described HT-1 to 12 were used.

(Electron transfer agent)
As the electron transport agent, the following three types of electron transport agents (ET-1 to ET-3) were used.

Example 1
5 parts by weight of X-type metal-free phthalocyanine as a charge generating agent, 80 parts by weight of HT-1 as a hole transporting agent, 50 parts by weight of ET-1 as an electron transporting agent, and 100 parts by weight of polycarbonate as a binder resin Were mixed and dispersed in a ball mill for 50 hours together with 800 parts by weight of tetrahydrofuran as a solvent to prepare a coating solution for a single-layer type photosensitive layer. Next, this coating solution was applied on a conductive substrate made of an aluminum base tube by dip coating and dried with hot air at 100 ° C. for 30 minutes to produce a single-layer type photoreceptor having a film thickness of 25 μm.
(Examples 2-33, Comparative Examples 1-3)
In the coating solution for the single-layer type photosensitive layer prepared in Example 1, HT-1 to 12 as a hole transport agent, ET-1 to 3 as an electron transport agent, and Y type instead of X type metal-free phthalocyanine A monolayer type photoreceptor was produced in the same manner as in Example 1 using the combinations of titanyl phthalocyanine shown in Table 1.

(Evaluation test and evaluation method)
Any of the electrophotographic photoreceptors of Examples 1 to 33 and Comparative Examples 1 to 3 prepared above was installed in a GENTEC drum sensitivity tester, and an electrical property test and the presence or absence of crystallization on the drum surface were evaluated. It was. In the electrical characteristic test, first, charging was performed so that the initial surface potential V ₀ was + 700V. Next, monochromatic light (light intensity 1.5 μJ / cm ² ) having a wavelength of 780 nm (half-width 20 nm) extracted from the white light of the halogen lamp using a bandpass filter is irradiated on the surface of the photosensitive member for 1.5 seconds to be exposed. The surface potential at the time when 0.5 seconds elapsed from the start was measured, and this was defined as the residual potential V _L (V). This was regarded as one step, and this step was repeated for 500 minutes, and the evaluation at the final repetition time was performed.

  The results are shown in Table 1.

Table 1 As is clear, in the electrophotographic photoreceptor of Comparative Examples 1 to 3 using the HT-12, both high residual potential V _L is, the sensitivity can not be obtained sufficiently, and none in the photosensitive layer Since crystals precipitated, they could not be put to practical use.

On the other hand, in the electrophotographic photoreceptors of Examples 1 to 33 using the HT-1 to 11 of the present invention, the residual potential V _L is low, and the crystal is prevented from being precipitated in the photosensitive layer, thereby achieving high sensitivity. An electrophotographic photosensitive member can be obtained.

Claims (1)

An electrophotographic photosensitive member comprising a photosensitive layer containing at least a charge generating agent and a charge transporting agent, wherein the charge transporting agent comprises a compound represented by the following general formula (1): body.

(In the formula, R _{1 to} R ₆ are the same or different groups and are a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a phenoxy group, or an aryl having 6 to 20 carbon atoms. Group or an aralkyl group having an alkyl moiety having 1 to 6 carbon atoms and an aryl moiety having 6 to 20 carbon atoms, n represents an integer of 0 to 2, and m represents an integer of 1 to 4.)