JP2005213150A - New quinone compound, electrophotographic photoreceptor and electrophotographic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compound having an excellent electron transport ability useful for applications of an electrophotographic photoreceptor and a positively charged type electrophotographic photoreceptor for highly sensitive copiers and printers and to provide an electrophotographic apparatus using the same. <P>SOLUTION: The new quinone compound has a structure represented by general formula (I) (wherein, R<SP>1</SP>to R<SP>4</SP>are each the same or different and denote each a hydrogen atom or a 1-6C alkyl group which may have a substituent; R<SP>5</SP>and R<SP>6</SP>are each the same or different and denote each a hydrogen atom, a 1-6C alkyl group which may have a substituent, an aryl group which may have a substituent or a heterocyclic group which may have a substituent; and the substituent denotes a fluorine atom, an alkyl group, an alkoxy group, a fluorinated alkyl group, an aryl group or a heterocyclic group). The electrophotographic photoreceptor and electrophotographic apparatus use the new quinone compound. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a novel quinone compound, and more particularly to a novel quinone compound useful as a charge transport material such as an electrophotographic photoreceptor (hereinafter also simply referred to as “photoreceptor”). The present invention also relates to an electrophotographic photoreceptor and an electrophotographic apparatus. More specifically, the present invention relates to an electrophotographic photosensitive member used in an electrophotographic printer, a copying machine, or the like, in which a photosensitive layer containing an organic material is provided on a conductive substrate. The present invention relates to a body and an electrophotographic apparatus using the body.

  Conventionally, a photosensitive layer of an electrophotographic photosensitive member in which an inorganic photoconductive substance such as selenium or a selenium alloy or an inorganic photoconductive substance such as zinc oxide or cadmium sulfide is dispersed in a resin binder is used. Has been. In recent years, research on electrophotographic photoreceptors using organic photoconductive materials has progressed, and some have been put into practical use with improved sensitivity and durability.

  In addition, the photoreceptor must have a function of retaining surface charges in the dark, a function of receiving light to generate charges, and a function of receiving light and transporting charges. Functionally separated into a so-called single-layer type photoconductor that combines these functions with a layer, and a layer that mainly contributes to charge generation and a layer that contributes to the maintenance of surface charge in the dark and charge transport during photoreception. There is a so-called multi-layer photoreceptor in which the above are laminated.

  For example, the Carlson method is applied to image formation by electrophotography using these photoreceptors. In this method, the image is formed by charging the photoconductor in the dark by corona discharge, forming an electrostatic latent image such as text or a picture of an original on the charged photoconductor surface, and forming a static image. The electrostatic latent image was developed by toner and the developed toner image was fixed on a support such as paper. The photoconductor after the toner image was transferred was subjected to charge removal, residual toner removal, and light charge removal. Later, it is used again.

  Organic photoreceptors in practical use have advantages such as flexibility, film formation, low cost, and safety compared to inorganic photoreceptors, and further improvements in sensitivity and durability are possible due to the variety of materials. It is being advanced.

  Most of the organic photoreceptors are stacked organic photoreceptors in which functions are separated into a charge generation layer and a charge transport layer. In general, in a multilayer organic photoreceptor, a charge generation layer containing a charge generation material such as a pigment or a dye and a charge transport layer containing a charge transport material such as hydrazone or triphenylamine are sequentially formed on a conductive substrate. In view of the nature of the electron-donating charge transport material, it is a hole transfer type and has sensitivity when the surface of the photoreceptor is negatively charged. However, in the negatively charged type, corona discharge used for charging is unstable compared to the positively charged type, and in order to generate ozone, nitrogen oxides, etc., these are adsorbed on the surface of the photoconductor, There is a problem that it is easy to cause chemical deterioration and further deteriorates the environment. From this point of view, the positively charged type photoconductor having a higher degree of freedom of use conditions is more advantageous as the photoconductor than the negatively charged type photoconductor.

  Thus, for use in the positively charged type, a method has been proposed in which a charge generation material and a charge transport material are simultaneously dispersed in a resin binder and used as a single photosensitive layer, and some have been put into practical use. However, the single-layer type photoreceptor is not sufficiently sensitive to be applied to a high-speed machine, and further improvement is required from the viewpoint of repeatability.

  In addition, in order to achieve a function separation type laminated structure for the purpose of increasing sensitivity, a method of forming a photoconductor by laminating a charge generation layer on a charge transport layer and using it in a positively charged type is also considered. However, since the charge generation layer is formed on the surface, problems such as corona discharge, light irradiation, mechanical wear, and the like occur in stability during repeated use. In this case, it has been proposed to further provide a protective layer on the charge generation layer. However, although mechanical wear is improved, problems such as a decrease in electrical characteristics such as sensitivity have not been solved.

  Furthermore, a method of forming a photoconductor by laminating an electron transporting charge transport layer on a charge generation layer has also been proposed.

  As an electron transporting charge transporting material, for example, 2,4,7-trinitro-9-fluorenone is known. However, since this substance has carcinogenicity, there is a safety problem. In addition, quinone compounds and the like are proposed in Patent Documents 1 to 6 and the like.

The present inventors have also proposed various photoreceptors containing substances having excellent electron transport properties (for example, described in Patent Documents 7 to 11).
JP-A-1-206349 JP-A-3-290666 JP-A-8-278743 JP-A-9-190002 JP-A-9-190003 JP 2001-222122 A JP 2000-143607 A JP 2000-199979 A JP 2002-62673 A JP 2003-228185 A JP 2003-238561 A

  However, due to the recent demand for a high-sensitivity photoconductor, it has been required to realize a high-performance photoconductor by using a new charge transport material having better electron transport properties.

  Accordingly, an object of the present invention is to provide a compound having excellent electron transport ability useful for electrophotographic photoreceptor applications, and by using such a novel organic material as a charge transport material in a photosensitive layer, It is an object of the present invention to provide a positively charged electrophotographic photoreceptor for high-sensitivity copying machines and printers and an electrophotographic apparatus using the same.

  As a result of intensive studies on various organic materials to achieve the above object, the present inventors have used a compound having a specific electron transport property represented by the following general formula (I) as a charge transport material. The inventors have found that a high-sensitivity photoreceptor that can be used with positive charging can be obtained, and have completed the present invention.

（式（Ｉ）中、Ｒ¹、Ｒ²、Ｒ³およびＲ⁴は、同一または異なって、水素原子、または置換基を有してもよい炭素数１〜６のアルキル基を表し、Ｒ⁵およびＲ⁶は、同一または異なって、水素原子、置換基を有してもよい炭素数１〜６のアルキル基、置換基を有してもよいアリール基、または置換基を有してもよい複素環基を表し、置換基は、フッ素原子、アルキル基、アルコキシ基、フッ化アルキル基、アリール基、または複素環基を表す）で示される構造を有することを特徴とするものである。 That is, in order to solve the above problems, the novel quinone compound of the present invention has the following general formula (I)

(In the formula (I), R ¹ , R ² , R ³ and R ⁴ are the same or different and each represents a hydrogen atom or an optionally substituted alkyl group having 1 to 6 carbon atoms, R ⁵ And R ⁶ may be the same or different and each may have a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, an aryl group which may have a substituent, or a substituent. It represents a heterocyclic group, and the substituent has a structure represented by a fluorine atom, an alkyl group, an alkoxy group, a fluorinated alkyl group, an aryl group, or a heterocyclic group.

（式（Ｉ）中、Ｒ¹、Ｒ²、Ｒ³およびＲ⁴は、同一または異なって、水素原子、または置換基を有してもよい炭素数１〜６のアルキル基を表し、Ｒ⁵およびＲ⁶は、同一または異なって、水素原子、置換基を有してもよい炭素数１〜６のアルキル基、置換基を有してもよいアリール基、または置換基を有してもよい複素環基を表し、置換基は、フッ素原子、アルキル基、アルコキシ基、フッ化アルキル基、アリール基、または複素環基を表す）で示される化合物の少なくとも一種を含有することを特徴とするものである。 The electrophotographic photosensitive member of the present invention is an electrophotographic photosensitive member in which a photosensitive layer containing a charge generating substance and a charge transporting substance is provided on a conductive substrate, and the photosensitive layer has the following general formula (I): ,

(In the formula (I), R ¹ , R ² , R ³ and R ⁴ are the same or different and each represents a hydrogen atom or an optionally substituted alkyl group having 1 to 6 carbon atoms, R ⁵ And R ⁶ may be the same or different and each may have a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, an aryl group which may have a substituent, or a substituent. Represents a heterocyclic group, and the substituent contains at least one compound represented by a fluorine atom, an alkyl group, an alkoxy group, a fluorinated alkyl group, an aryl group, or a heterocyclic group) It is.

  Furthermore, the electrophotographic apparatus of the present invention comprises the above-described electrophotographic photoreceptor of the present invention, and is characterized in that a charging process is performed by a positive charging process.

  According to the present invention, a compound having excellent electron transportability can be obtained, and by applying this compound to an electronic device using an organic compound such as an electrophotographic photoreceptor, electrical characteristics and the like can be improved. Is possible. Further, according to the present invention, by using this compound as a charge transport material in a photosensitive layer provided on a conductive substrate, it is possible to obtain a photoreceptor having high sensitivity and excellent electrical characteristics in positive charging. became. The charge generation material can be selected according to the type of exposure light source. By using a phthalocyanine compound, a squarylium compound, a bisazo compound, etc., a photoconductor that can be used in a semiconductor laser printer or a copying machine can be obtained. Can be obtained. Furthermore, it is possible to improve durability by installing a coating layer on the surface as necessary.

はｔ−ブチル基を表す。 Specific examples of the compound represented by the general formula (I) are shown by the following structural formulas (I-1) to (I-20). However, the present invention is not limited to these compounds. .
In the following specific examples

Represents a t-butyl group.

  The compound of the present invention can be synthesized, for example, according to the following reaction formulas (1) to (3). That is, first, as shown in the following reaction formula (1), a compound represented by the structural formula (D) is synthesized from a compound represented by the structural formula (E). Next, as shown in the following reaction formula (2), the compound represented by the structural formula (C) and the compound represented by the structural formula (D) and / or (D ′) are converted into an appropriate organometallic reagent (for example, n -By reacting with butyllithium or the like, the compound represented by the structural formula (B) is synthesized. Furthermore, as shown in the following reaction formula (3), the compound represented by the structural formula (A) and / or (A ′) and the compound represented by the structural formula (B) are combined with an appropriate organometallic reagent (for example, n -Butyllithium, etc.), and then removing the protecting group (TMS: trimethylsilyl group) and dehydrating and condensing it with a suitable catalyst (for example, p-toluenesulfonic acid (p-TsOH), etc.) A compound represented by the formula (I) can be synthesized. In addition, TBAF in the following reaction formula (3) represents tetrabutylammonium fluoride.

反応式（２）

反応式（３）

Reaction formula (1)

Reaction formula (2)

Reaction formula (3)

Hereinafter, embodiments of the electrophotographic photoreceptor of the present invention will be described in detail with reference to the drawings.
1 and 2 are schematic cross-sectional views showing various configuration examples of the photoreceptor.
FIG. 1 shows an example of the structure of a so-called single-layer type photoreceptor, in which a single-layer photosensitive layer in which a charge generation material and a charge transport material are dispersed in a resin binder (binder) on a conductive substrate 1. 2 is further provided, and a coating layer (protective layer) 6 is laminated as necessary. This single-layer type photoreceptor can be produced by dispersing a charge generating substance in a solution in which a charge transporting substance and a resin binder are dissolved, and applying this dispersion onto a conductive substrate. Furthermore, the covering layer 6 can be applied and formed for necessary lifting.

  FIG. 2 shows an example of the structure of a so-called multilayer photoreceptor, in which a charge generation layer 3 mainly composed of a charge generation material and a charge transport layer 4 containing a charge transport material are formed on a conductive substrate 1. A photosensitive layer 5 that is sequentially laminated is provided. This layered type photoreceptor generates charge by vacuum-depositing a charge generation material on a conductive substrate, or by applying and drying a dispersion obtained by dispersing charge generation material particles in a solvent or resin binder. A layer can be formed, and then a solution in which a charge transport material and a resin binder are dissolved is applied thereon and dried to form a charge transport layer.

  Although not shown, an undercoat layer can be provided between the conductive substrate and the photosensitive layer in any type of photoreceptor. The undercoat layer can be provided as necessary for the purpose of preventing injection of unnecessary charges from the conductive substrate to the photosensitive layer, covering defects on the substrate surface, and improving the adhesion of the photosensitive layer. It consists of a layer as an ingredient and an oxide film such as alumite.

  In addition, any type of the photoreceptor of the present invention contains at least one of the compounds having an electron transporting property according to the present invention represented by the general formula (I) as a charge transport material.

  Hereinafter, a preferred embodiment of the photoreceptor of the present invention will be described with reference to the multilayer photoreceptor shown in FIG. 2, but the present invention is not limited to the following specific examples.

  The conductive substrate 1 serves as a support for each of the other layers as well as serving as an electrode of the photoreceptor, and may be any of a cylindrical shape, a plate shape, and a film shape, and materials such as aluminum, stainless steel, nickel, etc. A metal, glass, resin, or the like subjected to a conductive treatment can be used.

  The charge generation layer 3 is formed by applying a material in which particles of a charge generation material are dispersed in a resin binder as described above, or by vacuum deposition, and generates charge by receiving light. . In addition, the injection efficiency of the generated charges into the charge transport layer 4 is important at the same time as the charge generation efficiency is high, the electric field dependency is small, and it is desirable that the injection is good even at low electric charge.

  As the charge generation material, phthalocyanine compounds such as metal-free phthalocyanine and titanyl phthalocyanine, pigments or dyes such as various azo, quinone, indigo, cyanine, squarylium, azurenium and pyrylium compounds, selenium or selenium compounds, etc. are used for image formation. A suitable substance can be selected according to the light wavelength region of the exposure light source used for the above. Since the charge generation layer only needs to have a charge generation function, the thickness thereof is determined by the light absorption coefficient of the charge generation material, and is generally 5 μm or less, and preferably 2 μm or less. Further, the charge generation layer can be used mainly with a charge generation material added with a charge transport material.

  As the resin binder for the charge generation layer 3, a polycarbonate, polyester, polyamide, polyurethane, vinyl chloride, phenoxy resin, polyvinyl butyral, diallyl phthalate resin, a polymer and a copolymer of methacrylic acid ester, and the like may be used in appropriate combination. Is possible.

  The charge transport layer 4 is a coating film in which a charge transport material is dispersed in a resin binder. The charge transport layer 4 retains the charge of the photoreceptor as an insulator layer in the dark, and transports the charge injected from the charge generation layer when receiving light. Demonstrate the function to do. As described above, in the present invention, as the charge transport material, it is necessary to contain at least one kind of the compound having an electron transport property represented by the general formula (I) according to the present invention. A charge transport material may be included. The preferred addition amount of the compound according to the present invention is preferably 10 to 60% by weight, more preferably 15 to 50% by weight, based on the entire material contained in the charge transport layer 4.

  As the resin binder for the charge transport layer 4, a polymer, a copolymer, or the like of polycarbonate, polyester, polystyrene, and methacrylic acid ester can be used.

  Further, for the purpose of preventing ozone deterioration, which is an obstacle to use when using a photoreceptor, an antioxidant such as amine, phenol, sulfur, phosphite, or phosphorus is added to the charge transport layer 4. It is also possible to contain.

The coating layer 6 shown in FIG. 1 has a function of receiving and holding the electric charge of corona discharge in a dark place, and has a capability of transmitting light sensitive to the photosensitive layer, and transmits light during exposure. Thus, it is necessary to reach the photosensitive layer and neutralize and extinguish the surface charge upon receiving the generated charge injection. As a material for the covering layer, organic insulating film forming materials such as polyester and polyamide can be applied. These organic materials can be used by mixing glass, inorganic materials such as SiO _2, and materials that reduce electrical resistance such as metals and metal oxides. As the inorganic material, a film formed by a vapor deposition method such as an amorphous silicon-carbon (SiC) composite film coating layer can be used. As described above, the material of the coating layer is preferably as transparent as possible in the wavelength region of the light absorption maximum of the charge generation material.

  The film thickness of the coating layer itself depends on the blend composition of the coating layer, but can be arbitrarily set within a range where no adverse effect such as an increase in residual potential occurs when it is repeatedly used continuously.

  Even in the case of the single layer type photoreceptor shown in FIG. 1, it is necessary that the photosensitive layer 2 contains at least one kind of the compound having the electron transporting property represented by the general formula (I) according to the present invention. However, the other materials and the like can be the same as those of the above-described laminated photoreceptor, and are not particularly limited. Preferably, a hole transport material is contained together with the compound of the general formula (I) as a charge transport material. As the hole transport material, a benzidine derivative, a triphenylamine derivative, or the like is preferable. In this case, these preferred addition amounts are preferably 10 to 60% by weight, more preferably 15 to the compound according to the present invention with respect to the entire material contained in the photosensitive layer forming coating film. It is 50% by weight, and the hole transport material is preferably 10 to 60% by weight, and more preferably 20 to 50% by weight.

  Also, silicone oil can be added or lubricated as a leveling material to the surface layer of the photoreceptor (the coating layer when a coating layer is provided, or the outermost layer when no coating layer is provided). For the purpose of imparting properties, it is possible to contain silicon or fluorine-containing polymers such as silicone oil, fluororesin fine particles such as tetrafluoroethylene, silicone resin fine particles, and fluorine-based comb-type graft polymers.

Examples of the present invention will be described below.
Synthesis Example 1: Synthesis of Compound of Specific Example (I-7) According to the following reaction formulas (1-1) to (3-1), the compound represented by the specific example (I-7) in the previous period was synthesized.

反応式（２−１）

反応式（３−１）

Reaction formula (1-1)

Reaction formula (2-1)

Reaction formula (3-1)

(1) In a three-necked flask, 4-chlorobenzoyl chloride (structural formula (E-1)) 300 mmol (52.5 g), N, O-dimethylhydroxylamine hydrochloride 330 mmol (32.2 g), and dichloromethane were added. In addition, 690 mmol (54.6 g) of pyridine was added dropwise under a nitrogen atmosphere. Thereafter, 100 ml of water was added to complete the reaction, and the organic layer was extracted and distilled under reduced pressure to obtain 4-chlorobenzenecarboxamide (structural formula (D-1)) in a yield of 53.1 g (88.7%). It was.

(2) Ethylenedioxythiophene (structural formula (C-1)) 40 mmol (5.7 g) and tetramethylethylenediamine 88 mmol (10.2 g) are added to a three-necked flask, and 0 ° C. (ice bath), nitrogen atmosphere Below, 88 mmol (55 ml) of 1.6 M n-butyllithium hexane solutions were added dropwise, and then heated to reflux. Then, it cooled at -78 degreeC and tetrahydrofuran was added, and 88 mmol (17.6g) of compounds shown by the said structural formula (D-1) were added. Thereafter, an aqueous ammonium chloride solution was added dropwise, and after concentration, a compound represented by the structural formula (B-1) was obtained as a crude product in a yield of 5.1 g (yield 30.4%).

(3) To a solution of 4-bromo-2,6-di-t-butyl-1- [trimethylsilyl] benzene (structural formula (A-1)) 36 mmol (12.9 g) in tetrahydrofuran (THF) at −78 ° C., Under a nitrogen atmosphere, 40 mmol (25 ml) of 1.6M n-butyllithium hexane solution was added dropwise. Thereafter, 12 mmol (5.0 g) of the compound represented by the structural formula (B-1) was added and stirred at room temperature. An aqueous ammonium chloride solution and then 36 mmol (36 ml) of 1.0 M tetrabutylammonium fluoride THF solution (TBAF) were added dropwise, and a small amount of p-toluene sulfonic acid monohydrate (p-TsOH) was added, followed by heating to reflux. The compound represented by Structural Formula (I-7) was obtained by distilling off the solvent and recrystallizing the solid content with a mixed solvent of chloroform and hexane. The yield was 7.2 g (yield 75.4%) and MS m / z 794 (M +). The IR spectrum of the compound of this specific example (I-7) is shown in FIG. 3, and the ¹ H-NMR spectrum is shown in FIG.

  4-Bromo-2,6-di-tert-butyl-1- [trimethylsilyl] benzene (formula (A-1)) can be obtained by a known method described in, for example, JP-A-2001-222122. Can be synthesized.

Photoconductor Example 1
An undercoat layer solution of 3 parts by weight of soluble nylon (Amilan CM8000: manufactured by Toray Industries, Inc.) and 97 parts by weight of a mixed solvent of methanol / methylene chloride (5/5) is dip coated on the aluminum plate and the aluminum base tube. Then, it was dried at 100 ° C. for 60 minutes to form an undercoat layer having a thickness of 0.3 μm.

で示されるスチリル化合物 ８重量部
（特開２０００−３１４９６９号公報中の（ＨＴ１−１０１））
電子輸送物質：前記式（Ｉ−７）で示される化合物 ３重量部
酸化防止剤：３，５−ジ−ｔｅｒｔ−４−ヒドロキシトルエン（ＢＨＴ）
（東京化成工業（株）製） １重量部
シリコーンオイル：ＫＦ−５０（信越化学工業（株）製） ０．０１重量部
樹脂バインダ：ビスフェノールＺ型ポリカーボネート樹脂
（パンライトＴＳ２０２０：帝人化成（株）製） ９重量部
（特開２０００−３１４９６９号公報中の（ＢＤ１−１））
塩化メチレン １００重量部
以上のようにして電子写真用感光体を作製した。 Next, a single layer type photosensitive layer dispersion having the following composition was dip coated and dried at 100 ° C. for 60 minutes to form a single layer type photosensitive layer having a film thickness of 25 m.
Charge generation material: X-type metal-free phthalocyanine 0.3 part by weight (see FIG. 2 in JP-A No. 2001-228637)
Hole transport material: Structural formula below (HT1-101),

8 parts by weight of a styryl compound represented by the formula ((HT1-101) in JP-A No. 2000-314969)
Electron transport material: Compound represented by the above formula (I-7) 3 parts by weight Antioxidant: 3,5-di-tert-4-hydroxytoluene (BHT)
(Tokyo Chemical Industry Co., Ltd.) 1 part silicone oil: KF-50 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0.01 part resin binder: bisphenol Z-type polycarbonate resin (Panlite TS2020: Teijin Chemicals Ltd.) 9 parts by weight ((BD1-1) in JP 2000-314969 A)
An electrophotographic photoreceptor was prepared in the amount of 100 parts by weight or more of methylene chloride.

Photoconductor Example 2
Of the composition of the photosensitive layer dispersion used in Photoreceptor Example 1, 3 parts by weight of the compound represented by the structural formula (I-7) as an electron transporting material is represented by the structural formula (I-5). A single-layer type photoreceptor was produced in the same manner as in photoreceptor Example 1 except that the amount was changed to 3 parts by weight of the compound.

Photoconductor Example 3
Of the composition of the photosensitive layer dispersion used in Photoreceptor Example 1, 3 parts by weight of the compound represented by the structural formula (I-7) as an electron transporting material is represented by the structural formula (I-9). A single-layer type photoreceptor was produced in the same manner as in photoreceptor Example 1 except that the amount was changed to 3 parts by weight of the compound.

で示されるスチリル化合物（特開２０００−３１４９６９号公報中の（ＨＴ２−２））８重量部に変えた以外は感光体実施例１と同様にして、単層型感光体を作製した。 Photoconductor Example 4
Of the composition of the photosensitive layer dispersion used in Photoreceptor Example 1, 8 parts by weight of the styryl compound represented by the structural formula (HT1-101) as a hole transporting substance was replaced by the following structural formula (HT2-2),

A single layer type photoreceptor was produced in the same manner as in photoreceptor example 1 except that the amount was changed to 8 parts by weight ((HT2-2) in JP 2000-314969 A).

で示されるベンジジン誘導体（特開２０００−３１４９６９号公報中の（ＨＴ−１１））８重量部に変えた以外は感光体実施例１と同様にして、単層型感光体を作製した。 Photoconductor Example 5
Of the composition of the photosensitive layer dispersion used in Photoreceptor Example 1, 8 parts by weight of the styryl compound represented by the structural formula (HT1-101) as a hole transporting substance was replaced by the following structural formula (HT-11),

A single-layer type photoreceptor was produced in the same manner as in photoreceptor Example 1 except that the amount was changed to 8 parts by weight ((HT-11) in JP 2000-314969 A).

Photoconductor Example 6
Of the composition of the photosensitive layer dispersion used in Photoreceptor Example 1, 0.3 part by weight of X-type phthalocyanine as a charge generating material was added to Y-type titanyl phthalocyanine (see FIG. 4 in JP-A-2001-228637). A single-layer type photoreceptor was produced in the same manner as in photoreceptor example 1 except that the content was changed to 0.2 parts by weight.

Photoconductor Example 7
Of the composition of the photosensitive layer dispersion used in Photoreceptor Example 1, 0.3 part by weight of X-type phthalocyanine as a charge generating substance was added to amorphous titanyl phthalocyanine (see FIG. 5 in JP-A-2001-228637). A single layer type photoreceptor was produced in the same manner as in photoreceptor example 1 except that the amount was changed to 2 parts by weight.

で示されるビスアゾ顔料に変えた以外は感光体実施例１と同様にして、単層型感光体を作製した。 Photoconductor Example 8
Of the composition of the photosensitive layer dispersion used in Photoreceptor Example 1, 0.3 part by weight of X-type phthalocyanine as a charge generating material is represented by the following formula (CG1-1),

A single-layer type photoconductor was produced in the same manner as in Photoconductor Example 1 except that the bisazo pigment represented by the formula (1) was used.

Evaluation of Photoconductor Examples 1 to 8 For evaluation of electrical characteristics, evaluation was performed using an electrostatic copying paper test apparatus EPA-8100 manufactured by Kawaguchi Electric Co., Ltd. using a plate-like photoconductor.
First, in an environment of a temperature of 23 ° C. and a humidity of 45%, the surface potential was charged to be about +600 V in a dark place, and the retention rate of the surface potential for 5 seconds until the exposure was obtained from the following formula.
Retention rate V _k5 (%) = (V ₅ / V ₀ ) × 100
V ₀ : Surface potential immediately after charging
V ₅ : Surface potential after 5 seconds (at the start of exposure)

Next, similarly, the surface potential is set to +600 V, and 1.0 μW / cm ² monochromatic light obtained by separating the light of the halogen lamp to 780 nm with a filter is exposed for 5 seconds until the surface potential is reduced to half (+300 V). Was determined as sensitivity E _1/2 (μJ / cm ² ), and the surface potential 5 seconds after exposure was determined as residual potential V _r (V).
The evaluation results are shown in Table 1 below.

※）感光体実施例８のみは露光光５５０ｎｍを用いた。

*) Photoreceptor Example 8 used exposure light of 550 nm.

  A drum-shaped photoconductor (30 mmφ) was used as an evaluation of durability by actual printing. The drum-shaped photoreceptor was mounted on a laser printer HL-1240 manufactured by Brother Industries, Ltd., and a black solid image, a white solid image, and a halftone image were printed in an environment of a temperature of 22 ° C. and a humidity of 44%. Subsequently, 5,000 images with a printing rate of about 5% were printed, and then a black solid image, a white solid image, and a halftone image were printed again, and image evaluation after printing 5,000 sheets was performed.

  As a result, the photoreceptors of photoreceptor examples 1 to 8 obtained good images in both the initial image and the image after printing 5,000 sheets.

  The photoreceptor of Example 8 was not suitable for this laser printer because it did not have sufficient sensitivity in the laser wavelength range (near 780 nm) of the laser printer used.

It is a conceptual sectional view showing a single layer type electrophotographic photoreceptor. 1 is a conceptual cross-sectional view showing a laminated electrophotographic photoreceptor. It is IR spectrum of the compound of specific example (I-7). It is a ¹ H-NMR spectrum of a compound of specific example (I-7).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Conductive base | substrate 2 Photosensitive layer 3 Charge generation layer 4 Charge transport layer 5 Photosensitive layer (lamination | stacking)
6 Coating layer

Claims (4)

The following general formula (I),

(In the formula (I), R ¹ , R ² , R ³ and R ⁴ are the same or different and each represents a hydrogen atom or an optionally substituted alkyl group having 1 to 6 carbon atoms, R ⁵ And R ⁶ may be the same or different and each may have a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, an aryl group which may have a substituent, or a substituent. A novel quinone compound having a structure represented by a heterocyclic group, wherein the substituent represents a fluorine atom, an alkyl group, an alkoxy group, a fluorinated alkyl group, an aryl group, or a heterocyclic group. In the electrophotographic photoreceptor in which a photosensitive layer containing a charge generation material and a charge transport material is provided on a conductive substrate, the photosensitive layer has the following general formula (I),

(In the formula (I), R ¹ , R ² , R ³ and R ⁴ are the same or different and each represents a hydrogen atom or an optionally substituted alkyl group having 1 to 6 carbon atoms, R ⁵ And R ⁶ may be the same or different and each may have a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, an aryl group which may have a substituent, or a substituent. An electron having a heterocyclic group, and the substituent contains at least one compound represented by a fluorine atom, an alkyl group, an alkoxy group, a fluorinated alkyl group, an aryl group, or a heterocyclic group) Photoconductor for photography.   3. The electrophotographic photoreceptor according to claim 2, wherein the photosensitive layer is a single layer type photosensitive layer.   An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 2 and performing a charging process by a positive charging process.

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