JP2017102160A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor that can inhibit crystallization and have excellent electric characteristics at the same time.SOLUTION: An electrophotographic photoreceptor comprises a photosensitive layer. The photosensitive layer has a compound represented by a general formula (1). In the general formula (1), Rrepresents a halogen atom, an alkyl group having 1 or more and 6 or less carbon atoms, or an alkoxy group having 1 or more and 6 or less carbon atoms. Rand Rindependently represent an aryl group having 6 or more and 14 or less carbon atoms which may comprise an alkyl group having 1 or more and 10 or less carbon atoms, an alkyl group having 1 or more and 6 or less carbon atoms, a cycloalkyl group having 3 or more and 10 or less carbon atoms, an alkoxy group having 1 or more and 6 or less carbon atoms, an aralkyl group having 7 or more and 12 or less carbon atoms, or a heterocyclic group. Rand Rare mutually different.SELECTED DRAWING: None

Description

  The present invention relates to an electrophotographic photoreceptor.

  The electrophotographic photosensitive member is used in an electrophotographic image forming apparatus. The electrophotographic photoreceptor includes a photosensitive layer. As the electrophotographic photosensitive member, for example, a multilayer electrophotographic photosensitive member or a single layer type electrophotographic photosensitive member is used. The multilayer electrophotographic photoreceptor includes, as a photosensitive layer, a charge generation layer having a charge generation function and a charge transport layer having a charge transport function. The single layer type electrophotographic photosensitive member includes a single layer type photosensitive layer having a charge generation function and a charge transport function as a photosensitive layer.

  The electrophotographic photosensitive member described in Patent Document 1 includes a photosensitive layer. The photosensitive layer contains, for example, a compound represented by the following chemical formula (E-1).

JP 2005-154444 A

  However, the electrophotographic photosensitive member described in Patent Document 1 cannot achieve both suppression of crystallization and electrical characteristics.

  The present invention has been made in view of the above problems, and an object thereof is to provide an electrophotographic photosensitive member capable of achieving both suppression of crystallization and electrical characteristics.

  The electrophotographic photoreceptor of the present invention includes a photosensitive layer. The photosensitive layer contains a compound represented by the following general formula (1).

In the general formula (1), R ¹ represents a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. R ² and R ³ are each independently an aryl group having 6 to 14 carbon atoms which may have an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 6 carbon atoms, carbon It represents a cycloalkyl group having 3 to 10 atoms, an alkoxy group having 1 to 6 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a heterocyclic group which may have a substituent. The substituent is an aryl group having 6 to 14 carbon atoms, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, Alternatively, it is an aralkyl group having 7 to 12 carbon atoms. R ² and R ³ are different from each other.

  According to the electrophotographic photosensitive member of the present invention, it is possible to achieve both suppression of crystallization and electrical characteristics.

(A), (b) and (c) are schematic sectional views showing examples of the electrophotographic photosensitive member according to the embodiment of the present invention, respectively. (A), (b) and (c) is a schematic sectional drawing which shows another example of the electrophotographic photoreceptor which concerns on embodiment of this invention, respectively.

  Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments. The present invention can be implemented with appropriate modifications within the scope of the object of the present invention. In addition, about the location where description overlaps, although description may be abbreviate | omitted suitably, the summary of invention is not limited.

  Hereinafter, a compound and its derivatives may be generically named by adding “system” after the compound name. In addition, when “polymer” is added after the compound name to indicate the polymer name, it means that the repeating unit of the polymer is derived from the compound or a derivative thereof.

  Hereinafter, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 3 carbon atoms, carbon An alkoxy group having 1 to 6 atoms, an alkoxy group having 1 to 3 carbon atoms, an aryl group having 6 to 14 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, and 3 to 10 carbon atoms Unless otherwise specified, each of the cycloalkyl group and the heterocyclic group has the following meaning.

  As a halogen atom, a fluorine atom, a chlorine atom, or a bromine atom is mentioned, for example.

  An alkyl group having 1 to 10 carbon atoms is a linear or branched alkyl group having 1 to 10 carbon atoms that is unsubstituted. Examples of the alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, s-butyl group, t-butyl group, pentyl group, isopentyl group, A neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, or n-decyl group may be mentioned.

  The alkyl group having 1 to 6 carbon atoms is a linear or branched alkyl group having 1 to 6 carbon atoms that is unsubstituted. Examples of the alkyl group having 1 to 6 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, s-butyl group, t-butyl group, pentyl group, isopentyl group, A neopentyl group or a hexyl group is mentioned.

  The alkyl group having 1 to 4 carbon atoms is a linear or branched alkyl group having 1 to 4 carbon atoms that is unsubstituted. Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, and a t-butyl group.

  The alkyl group having 1 to 3 carbon atoms is a linear or branched alkyl group having 1 to 3 carbon atoms that is unsubstituted. Examples of the alkyl group having 1 to 3 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, and a t-butyl group.

  The alkoxy group having 1 to 6 carbon atoms is a linear or branched alkoxy group having 1 to 6 carbon atoms which is unsubstituted. Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an s-butoxy group, a t-butoxy group, a pentyloxy group, an iso group. A pentyloxy group, a neopentyloxy group, or a hexyloxy group may be mentioned.

  The alkoxy group having 1 to 3 carbon atoms is a linear or branched alkoxy group having 1 to 3 carbon atoms which is unsubstituted. Examples of the alkoxy group having 1 to 3 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, and an isopropoxy group.

  Examples of the aryl group having 6 to 14 carbon atoms include an unsubstituted aromatic monocyclic hydrocarbon group having 6 to 14 carbon atoms and an unsubstituted aromatic condensed bicyclic carbon group having 6 to 14 carbon atoms. A hydrogen group or an unsubstituted aromatic condensed tricyclic hydrocarbon group having 6 to 14 carbon atoms. Examples of the aryl group having 6 to 14 carbon atoms include a phenyl group, a naphthyl group, an anthryl group, and a phenanthryl group.

  The aralkyl group having 7 to 12 carbon atoms is a straight-chain or branched aralkyl group having 7 to 12 carbon atoms which is unsubstituted. Examples of the aralkyl group having 7 to 12 carbon atoms include an alkyl group having 1 to 6 carbon atoms having an aryl group. Examples of the aralkyl group having 7 to 12 carbon atoms include a benzyl group, a phenethyl group, a 3-phenylpropyl group, and a 4-phenylbutyl group.

  Examples of the cycloalkyl group having 3 to 10 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, and a cyclodecyl group.

  As the heterocyclic group, for example, a 5-membered or 6-membered monocyclic heterocyclic group containing 1 or more (preferably 1 to 3) heteroatoms and having aromaticity; Or a heterocyclic group in which such a single ring is condensed with a 5-membered or 6-membered hydrocarbon ring. The hetero atom is at least one selected from the group consisting of a nitrogen atom, a sulfur atom, and an oxygen atom. Specific examples of the heterocyclic group include thiophenyl group, furanyl group, pyrrolyl group, imidazolyl group, pyrazolyl group, isothiazolyl group, isoxazolyl group, oxazolyl group, isoxazolyl group, thiazolyl group, isothiazolyl group, furazanyl group, pyranyl group, pyridyl group. , Pyridazinyl group, pyrimidinyl group, pyrazinyl group, indolyl group, 1H-indazolyl group, isoindolyl group, chromenyl group, quinolinyl group, isoquinolinyl group, purinyl group, pteridinyl group, triazolyl group, tetrazolyl group, 4H-quinolidinyl group, naphthyridinyl group, A benzofuranyl group, a 1,3-benzodioxolyl group, a benzoxazolyl group, a benzothiazolyl group, or a benzimidazolyl group can be mentioned.

[Electrophotographic photoreceptor]
The electrophotographic photoreceptor of the present invention (hereinafter sometimes referred to as a photoreceptor) is provided. Examples of the photoreceptor include a multilayer electrophotographic photoreceptor (hereinafter sometimes referred to as a multilayer photoreceptor) or a single layer electrophotographic photoreceptor (hereinafter referred to as a single layer photoreceptor). ).

<1. Multilayer photoreceptor>
The multilayer photoreceptor includes a charge generation layer and a charge transport layer. Hereinafter, the structure of the photoreceptor when the photoreceptor is a laminated photoreceptor will be described with reference to FIG. FIG. 1 shows the structure of a laminated photoreceptor that is an example of a photoreceptor according to this embodiment.

  As shown in FIG. 1A, the multilayer photoreceptor 1 includes, for example, a conductive substrate 2 and a photosensitive layer 3. The photosensitive layer 3 includes a charge generation layer 3a and a charge transport layer 3b. As shown in FIG. 1B, in the laminated type photoreceptor as the photoreceptor 1, the charge transport layer 3b is provided on the conductive substrate 2, and the charge generation layer 3a is provided on the charge transport layer 3b. Good. However, since the charge transport layer 3b is generally thicker than the charge generation layer 3a, the charge transport layer 3b is less likely to be damaged than the charge generation layer 3a. Therefore, in order to improve the wear resistance of the multilayer photoreceptor, as shown in FIG. 1A, a charge generation layer 3a is provided on the conductive substrate 2, and charge transport is performed on the charge generation layer 3a. A layer 3b is preferably provided.

  As shown in FIG. 1C, the multilayer photoreceptor as the photoreceptor 1 may include a conductive substrate 2, a photosensitive layer 3, and an intermediate layer (undercoat layer) 4. The intermediate layer 4 is provided between the conductive substrate 2 and the photosensitive layer 3. Further, a protective layer 5 (see FIG. 2) may be provided on the photosensitive layer 3.

  The thicknesses of the charge generation layer 3a and the charge transport layer 3b are not particularly limited as long as the functions as the respective layers can be sufficiently expressed. The thickness of the charge generation layer 3a is preferably 0.01 μm or more and 5 μm or less, and more preferably 0.1 μm or more and 3 μm or less. The thickness of the charge transport layer 3b is preferably 2 μm or more and 100 μm or less, and more preferably 5 μm or more and 50 μm or less.

  The structure of the photoconductor 1 when the photoconductor 1 is a multilayer photoconductor has been described above with reference to FIG.

<2. Single-layer type photoreceptor>
Hereinafter, the structure of the photoreceptor 1 when the photoreceptor 1 is a single-layer photoreceptor will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view showing a single-layer type photoreceptor that is another example of the photoreceptor 1 according to the present embodiment.

  As shown in FIG. 2A, the single layer type photoreceptor as the photoreceptor 1 includes, for example, a conductive substrate 2 and a photosensitive layer 3. The single layer type photoreceptor as the photoreceptor 1 includes a single layer type photosensitive layer 3 c as the photosensitive layer 3. The single-layer type photosensitive layer 3 c is a single photosensitive layer 3.

  As shown in FIG. 2B, the single layer type photoreceptor as the photoreceptor 1 may include a conductive substrate 2, a single layer type photosensitive layer 3 c, and an intermediate layer (undercoat layer) 4. . The intermediate layer 4 is provided between the conductive substrate 2 and the single-layer type photosensitive layer 3c. Further, as shown in FIG. 2C, a protective layer 5 may be provided on the single-layer type photosensitive layer 3c.

  The thickness of the single-layer type photosensitive layer 3c is not particularly limited as long as the function as a single-layer type photosensitive layer can be sufficiently expressed. The thickness of the single-layer type photosensitive layer 3c is preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less.

  The structure of the photoreceptor 1 when the photoreceptor 1 is a single-layer photoreceptor has been described above with reference to FIG.

The photoreceptor according to the present embodiment can achieve both suppression of crystallization and electrical characteristics. The reason is guessed as follows. In the photoreceptor according to the exemplary embodiment, the photosensitive layer contains a compound represented by the general formula (1) (hereinafter sometimes referred to as compound (1)). The compound (1) has an asymmetric structure because R ² and R ³ in the general formula (1) are different from each other. For this reason, the compound (1) is easily dissolved in a solvent for forming the photosensitive layer, and the compound (1) is easily dispersed uniformly in the photosensitive layer. As a result, it is considered that the crystallization of the compound (1) is suppressed in the photosensitive layer.

  On the other hand, since the compound (1) is easily dispersed uniformly in the photosensitive layer, it is considered that the carrier mobility in the photosensitive layer is improved and the electrical characteristics (for example, sensitivity characteristics) of the photoreceptor are improved. Furthermore, in the compound (1), the π-conjugated system sandwiched between two imide groups has planarity, and the spatial extent of the π-conjugated system is relatively large. Since compound (1) has such a structure, it is excellent in electron transport property and electron acceptability. Therefore, when the photosensitive layer contains the compound (1), it is considered that the photoreceptor is excellent in electric characteristics (for example, sensitivity characteristics). From the above, it is considered that the photoreceptor according to the present embodiment can achieve both suppression of crystallization and electrical characteristics.

  In the photoreceptor according to the exemplary embodiment, the photosensitive layer contains the compound (1). In the multilayer photoconductor, the charge generation layer contains, for example, a charge generation agent and a binder resin for charge generation agent (hereinafter sometimes referred to as a base resin). The charge transport layer contains, for example, a compound (1) as an electron acceptor compound, a hole transport agent, and a binder resin. In the single layer type photoreceptor, the single layer type photosensitive layer contains, for example, a charge generating agent, a compound (1) as an electron transporting agent, a hole transporting agent, and a binder resin. The charge generation layer, charge transport layer, and single-layer type photosensitive layer may further contain an additive. Hereinafter, a conductive substrate, an electron transport agent, an electron acceptor compound, a hole transport agent, a charge generating agent, a binder resin, a base resin, an additive, and an intermediate layer will be described as elements of the photoreceptor. In addition, a method for manufacturing the photoreceptor will be described.

<3. Conductive substrate>
The conductive substrate is not particularly limited as long as it can be used as the conductive substrate of the photoreceptor. The conductive substrate may be formed of a material having at least a surface portion having conductivity. An example of the conductive substrate is a conductive substrate formed of a conductive material. Another example of the conductive substrate is a conductive substrate coated with a conductive material. Examples of the conductive material include aluminum, iron, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, and brass. These conductive materials may be used alone or in combination of two or more (for example, as an alloy). Among these materials having conductivity, aluminum or an aluminum alloy is preferable because charge transfer from the photosensitive layer to the conductive substrate is good.

  The shape of the conductive substrate is appropriately selected according to the structure of the image forming apparatus. Examples of the shape of the conductive substrate include a sheet shape or a drum shape. The thickness of the conductive substrate is appropriately selected according to the shape of the conductive substrate.

<4. Electron Transfer Agent, Electron Acceptor Compound>
As already described above, in the multilayer photoreceptor, the charge transport layer contains the compound (1) as an electron acceptor compound. In the single layer type photoreceptor, the single layer type photosensitive layer contains the compound (1) as an electron transport agent. When the photosensitive layer contains the compound (1), the photoreceptor according to this embodiment can achieve both suppression of crystallization and electrical characteristics. Compound (1) is represented by general formula (1).

In General Formula (1), R ¹ represents a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. R ² and R ³ are each independently an aryl group having 6 to 14 carbon atoms which may have an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 6 carbon atoms, carbon It represents a cycloalkyl group having 3 to 10 atoms, an alkoxy group having 1 to 6 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a heterocyclic group which may have a substituent. The substituent of the heterocyclic group includes an aryl group having 6 to 14 carbon atoms, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, and 1 to 6 carbon atoms. Or an aralkyl group having 7 to 12 carbon atoms. R ² and R ³ are different from each other.

In the general formula (1), the alkoxy group having 1 to 6 carbon atoms represented by R ¹ is preferably an alkoxy group having 1 to 3 carbon atoms, and more preferably an ethoxy group. The two R ¹ are preferably the same as each other.

In general formula (1), the aralkyl group having 7 to 12 carbon atoms represented by R ² and R ³ is preferably a benzyl group.

In general formula (1), the aryl group having 6 to 14 carbon atoms represented by R ² and R ³ is preferably a phenyl group. The aryl group having 6 to 14 carbon atoms represented by R ² and R ³ may have a substituent. Examples of such a substituent include an alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 4 carbon atoms is preferable, and a methyl group or a t-butyl group is more preferable.

In general formula (1), the heterocyclic group represented by R ² and R ³ is preferably a pyridyl group. The heterocyclic group represented by R ³ may have a substituent.

In the general formula (1), R ¹ represents an alkoxy group having 1 to 3 carbon atoms, and the two R ¹ are preferably the same. R ² and R ³ represent an aryl group having 6 to 14 carbon atoms having an alkyl group having 1 to 4 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a heterocyclic group, and R ² And R ³ are preferably different from each other.

In general formula (1), it is preferable that any one of R ² and R ³ represents a phenyl group, and this phenyl group has a methyl group in at least one of two ortho positions. In the compound (1) having such a structure, due to the steric hindrance between the ortho-position methyl group and the oxygen atom of the imide group, the plane of the phenyl group of R ² or R ³ and the naphthalenetetracarboxylic acid diimide moiety It is easy to be in a state where it is not parallel to the plane. Compound (1) having such a structure is considered to improve the balance between the spatial extent of the π-conjugated system of the naphthalenetetracarboxylic acid diimide moiety and the asymmetry of compound (1). For this reason, it is considered that the balance between the dispersibility in the photosensitive layer and the electron transport property or the electron acceptability is improved, and the suppression of the crystallization of the photoreceptor and the electric characteristics are more easily achieved.

  Specific examples of the compound (1) include compounds represented by the chemical formulas (1-1) to (1-4) (hereinafter sometimes referred to as compounds (1-1) to (1-4)). Can be mentioned.

  When the photoreceptor is a multilayer photoreceptor, the content of the compound (1) is preferably 10 parts by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the binder resin contained in the charge transport layer. More preferably, it is 20 parts by mass or more and 100 parts by mass or less.

  When the photoreceptor is a single layer type photoreceptor, the content of the compound (1) is 10 parts by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the binder resin contained in the single layer type photosensitive layer. Is more preferably 10 parts by mass or more and 100 parts by mass or less, and particularly preferably 10 parts by mass or more and 75 parts by mass or less.

  The charge transport layer may further contain another electron acceptor compound in addition to the compound (1). The single-layer type photosensitive layer may further contain another electron transport agent in addition to the compound (1). Examples of other electron acceptor compounds and electron transport agents include quinone compounds, diimide compounds (diimide compounds other than compound (1)), hydrazone compounds, malononitrile compounds, thiopyran compounds, trinitrothioxanthone compounds. 3,4,5,7-tetranitro-9-fluorenone compound, dinitroanthracene compound, dinitroacridine compound, tetracyanoethylene, 2,4,8-trinitrothioxanthone, dinitrobenzene, dinitroacridine, succinic anhydride , Maleic anhydride, or dibromomaleic anhydride. Examples of quinone compounds include diphenoquinone compounds, azoquinone compounds, anthraquinone compounds, naphthoquinone compounds, nitroanthraquinone compounds, and dinitroanthraquinone compounds. These electron transfer agents may be used alone or in combination of two or more.

  Compound (1) includes, for example, a reaction formula represented by reaction formula (R-1), a reaction formula represented by reaction formula (R-2), and a reaction formula represented by reaction formula (R-3) (hereinafter each represented by a reaction). (May be described as (R-1), reaction (R-2) and reaction (R-3)) or by a method analogous thereto. In addition to these reactions, appropriate steps may be included as necessary. An example of such a process is a purification process. Examples of the purification method include known methods (more specifically, filtration, chromatography, crystal folding, etc.).

In reaction (R-1), R ¹ and R ² are the same meanings as R ¹ and R ² in the general formula (1). R ⁴ represents an alkyl group, and preferably represents an alkyl group having 1 to 3 carbon atoms.

  In the reaction (R-1), 1 equivalent of the compound represented by the chemical formula (A) (hereinafter sometimes referred to as the compound (A)) and 1 equivalent of the compound represented by the general formula (B) A primary amine compound) (hereinafter may be referred to as compound (B)) in the presence of a base, and a compound represented by general formula (C) which is an equivalent of an intermediate (hereinafter, Compound (C)) may be obtained. In reaction (R-1), it is preferable to add 1 mol or more and 2.5 mol or less of compound (B) with respect to 1 mol of compound (A). When 1 mol or more of compound (B) is added to 1 mol of compound (A), the yield of compound (C) can be easily improved. On the other hand, when 2.5 mol or less of compound (B) is added to 1 mol of compound (A), unreacted compound (B) hardly remains after the reaction, and purification of compound (C) becomes easy. . The reaction temperature for reaction (R-1) is preferably 80 ° C. or higher and 150 ° C. or lower. The reaction time for reaction (R-1) is preferably 1 hour or more and 8 hours or less. Reaction (R-1) can be performed in a solvent. Examples of the solvent include dioxane. The base preferably has low nucleophilicity from the viewpoint of improving the yield of the compound (C). Examples of such a base include N, N-diisopropylethylamine (Hunig base).

In reaction (R-2), R ¹ and R ² are the same meanings as R ¹ and R ² in the general formula (1). In reaction (R-2), R ⁴ has the same meaning as R ⁴ in the reaction (R-1).

  In the reaction (R-2), 1 equivalent of the compound (C) is reacted in the presence of an acid, and 1 equivalent of the compound represented by the general formula (D) (hereinafter referred to as the compound (D)). Get). In the reaction (R-2), the ester of the compound (C) is hydrolyzed in the presence of an acid to form a dicarboxylic acid, and then the dicarboxylic acid is closed. As a result, compound (D) is produced. The reaction time for reaction (R-2) is preferably 5 hours or longer and 30 hours or shorter. The reaction temperature for reaction (R-2) is preferably 80 ° C. or higher and 150 ° C. or lower. As the acid, for example, trifluoroacetic acid is preferable. The acid may function as a solvent.

In reaction (R-3), R ^1, R ² and R ³ are the same meanings as R ^1, R ² and R ³ in the general formula (1).

  In the reaction (R-3), 1 equivalent of the compound (D) and 1 equivalent of the compound represented by the general formula (E) (primary amine compound) (hereinafter referred to as the compound (E) may be described. ) In the presence of a base to give 1 equivalent of compound (1). In reaction (R-3), it is preferable to add 1 mol or more and 2.5 mol or less of compound (E) with respect to 1 mol of compound (D). When 1 mol or more of compound (E) is added to 1 mol of compound (D), the yield of compound (1) can be easily improved. On the other hand, when 2.5 mol or less of the compound (E) is added to 1 mol of the compound (D), the unreacted compound (E) hardly remains after the reaction, and the purification of the compound (1) becomes easy. . The reaction temperature for reaction (R-3) is preferably 80 ° C. or higher and 150 ° C. or lower. The reaction time for reaction (R-3) is preferably 1 hour or more and 8 hours or less. Reaction (R-3) can be performed in a solvent. Examples of the solvent include dioxane. The base is preferably low in nucleophilicity from the viewpoint of improving the yield of compound (1). Examples of such a base include N, N-diisopropylethylamine (Hunig base).

<5. Hole transport agent>
When the photoreceptor is a multilayer photoreceptor, the charge generation layer may contain a hole transport agent. When the photoreceptor is a single layer type photoreceptor, the single layer type photosensitive layer may contain a hole transport agent. As the hole transport agent, for example, a nitrogen-containing cyclic compound or a condensed polycyclic compound can be used. Examples of the nitrogen-containing cyclic compound and the condensed polycyclic compound include diamine derivatives (for example, N, N, N ′, N′-tetraphenylphenylenediamine derivatives, N, N, N ′, N′-tetraphenylnaphthyl). Range amine derivatives or N, N, N ′, N′-tetraphenylphenanthrylenediamine derivatives), oxadiazole compounds (for example, 2,5-di (4-methylaminophenyl) -1,3,4- Oxadiazole), styryl compounds (for example, 9- (4-diethylaminostyryl) anthracene), carbazole compounds (for example, polyvinylcarbazole), organic polysilane compounds, pyrazoline-based compounds (for example, 1-phenyl-3- (p-dimethyl) Aminophenyl) pyrazoline), hydrazone compounds, indole compounds, oxazole compounds Isoxazole compounds, thiazole compounds, thiadiazole compounds, imidazole compounds, pyrazole compound, or triazole-based compounds. These hole transport agents may be used alone or in combination of two or more. Of these hole transporting agents, a compound represented by the chemical formula (H-1) (hereinafter sometimes referred to as the compound (H-1)) is preferable.

  When the photoreceptor is a multilayer photoreceptor, the content of the hole transport agent is preferably 10 parts by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the binder resin contained in the charge transport layer. More preferably, it is 20 parts by mass or more and 100 parts by mass or less.

  When the photoreceptor is a single layer type photoreceptor, the content of the hole transport agent is 10 parts by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the binder resin contained in the single layer type photosensitive layer. Is more preferably 10 parts by mass or more and 100 parts by mass or less, and particularly preferably 10 parts by mass or more and 75 parts by mass or less.

<6. Charge generator>
When the photoreceptor is a multilayer photoreceptor, the charge generation layer may contain a charge generation agent. When the photoreceptor is a single layer type photoreceptor, the single layer type photosensitive layer may contain a charge generating agent.

  The charge generator is not particularly limited as long as it is a charge generator for a photoreceptor. Examples of the charge generator include phthalocyanine pigments, perylene pigments, bisazo pigments, trisazo pigments, dithioketopyrrolopyrrole pigments, metal-free naphthalocyanine pigments, metal naphthalocyanine pigments, squaraine pigments, indigo pigments, azurenium pigments, cyanine Pigments, inorganic photoconductive materials (for example, selenium, selenium-tellurium, selenium-arsenic, cadmium sulfide or amorphous silicon), pyrylium pigments, ansanthrone pigments, triphenylmethane pigments, selenium pigments, toluidine pigments, Examples include pyrazoline pigments and quinacridone pigments. A charge generating agent may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of the phthalocyanine pigment include metal-free phthalocyanine represented by the chemical formula (C-1) (hereinafter sometimes referred to as compound (C-1)) or metal phthalocyanine. Examples of the metal phthalocyanine include titanyl phthalocyanine represented by the chemical formula (C-2) (hereinafter sometimes referred to as compound (C-2)), hydroxygallium phthalocyanine, or chlorogallium phthalocyanine. The phthalocyanine pigment may be crystalline or non-crystalline. The crystal shape of the phthalocyanine pigment (for example, α type, β type, Y type, V type or II type) is not particularly limited, and phthalocyanine pigments having various crystal shapes are used.

  Examples of the crystal of metal-free phthalocyanine include an X-type crystal of metal-free phthalocyanine (hereinafter sometimes referred to as X-type metal-free phthalocyanine). Examples of the crystal of titanyl phthalocyanine include α-type, β-type, and Y-type crystals of titanyl phthalocyanine (hereinafter sometimes referred to as α-type, β-type, or Y-type titanyl phthalocyanine). Examples of the crystal of hydroxygallium phthalocyanine include a V-type crystal of hydroxygallium phthalocyanine. Examples of chlorogallium phthalocyanine crystals include chlorogallium phthalocyanine type II crystals.

  For example, in a digital optical image forming apparatus (for example, a laser beam printer or a facsimile using a light source such as a semiconductor laser), it is preferable to use a photoreceptor having sensitivity in a wavelength region of 700 nm or more. Since it has a high quantum yield in a wavelength region of 700 nm or more, the charge generator is preferably a phthalocyanine pigment, more preferably a metal-free phthalocyanine or titanyl phthalocyanine. In order to particularly improve the electrical characteristics of the photoreceptor when the compound (1) is contained in the photosensitive layer, the charge generating agent is more preferably X-type metal-free phthalocyanine or Y-type titanyl phthalocyanine, and Y-type titanyl phthalocyanine. Is particularly preferred.

  Y-type titanyl phthalocyanine has a main peak at 27.2 ° of the Bragg angle (2θ ± 0.2 °) in the CuKα characteristic X-ray diffraction spectrum, for example. The main peak in the CuKα characteristic X-ray diffraction spectrum is a peak having the first or second highest intensity in a range where the Bragg angle (2θ ± 0.2 °) is 3 ° or more and 40 ° or less.

(Measuring method of CuKα characteristic X-ray diffraction spectrum)
An example of a method for measuring the CuKα characteristic X-ray diffraction spectrum will be described. A sample (titanyl phthalocyanine) is filled in a sample holder of an X-ray diffractometer (for example, “RINT (registered trademark) 1100” manufactured by Rigaku Corporation), an X-ray tube Cu, a tube voltage 40 kV, a tube current 30 mA, and CuKα. An X-ray diffraction spectrum is measured under the condition of a characteristic X-ray wavelength of 1.542 mm. The measurement range (2θ) is, for example, 3 ° to 40 ° (start angle 3 °, stop angle 40 °), and the scanning speed is, for example, 10 ° / min.

  For the photoreceptor applied to the image forming apparatus using the short wavelength laser light source, Ansanthrone pigment is preferably used as the charge generating agent. The wavelength of the short wavelength laser light is, for example, not less than 350 nm and not more than 550 nm.

  When the photoreceptor is a multilayer photoreceptor, the content of the charge generating agent is preferably 5 parts by mass or more and 1000 parts by mass or less with respect to 100 parts by mass of the base resin contained in the charge generation layer. More preferably, it is at least 500 parts by mass.

  When the photoreceptor is a single layer type photoreceptor, the content of the charge generating agent is 0.1 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the binder resin contained in the single layer type photosensitive layer. It is preferably 0.5 parts by mass or more and 30 parts by mass or less, and more preferably 0.5 parts by mass or more and 4.5 parts by mass or less.

<7. Binder resin>
Examples of the binder resin include a thermoplastic resin, a thermosetting resin, and a photocurable resin. Examples of the thermoplastic resin include polycarbonate resin, polyarylate resin, styrene-butadiene resin, styrene-acrylonitrile resin, styrene-maleic acid resin, acrylic acid resin, styrene-acrylic acid resin, polyethylene resin, and ethylene-vinyl acetate resin. , Chlorinated polyethylene resin, polyvinyl chloride resin, polypropylene resin, ionomer resin, vinyl chloride-vinyl acetate resin, alkyd resin, polyamide resin, urethane resin, polysulfone resin, diallyl phthalate resin, ketone resin, polyvinyl butyral resin, polyester resin or A polyether resin is mentioned. As a thermosetting resin, a silicone resin, an epoxy resin, a phenol resin, a urea resin, or a melamine resin is mentioned, for example. Examples of the photocurable resin include an epoxy-acrylic acid resin (more specifically, an acrylic acid derivative adduct of an epoxy compound) or a urethane-acrylic resin (acrylic acid derivative adduct of a urethane compound). Can be mentioned. These binder resins may be used individually by 1 type, and may be used in combination of 2 or more type.

  Among these resins, a polycarbonate resin is preferable because a single-layer type photosensitive layer and a charge transport layer excellent in balance of workability, mechanical properties, optical properties, and abrasion resistance can be obtained. Examples of the polycarbonate resin include a bisphenol Z-type polycarbonate resin represented by the following chemical formula (Resin-1) (hereinafter sometimes referred to as Z-type polycarbonate resin (Resin-1)), a bisphenol ZC-type polycarbonate resin, and bisphenol. C-type polycarbonate resin or bisphenol A-type polycarbonate resin may be mentioned. Z-type polycarbonate resin (Resin-1) is preferable from the viewpoint of good compatibility with the compound (1) and improvement in dispersibility of the compound (1) in the photosensitive layer.

  The viscosity average molecular weight of the binder resin is preferably 40,000 or more, and more preferably 40,000 or more and 52,500 or less. When the viscosity average molecular weight of the binder resin is 40,000 or more, it is easy to improve the wear resistance of the photoreceptor. When the viscosity average molecular weight of the binder resin is 52,500 or less, the binder resin is easily dissolved in a solvent during formation of the photosensitive layer, and the viscosity of the charge transport layer coating solution or single layer type photosensitive layer coating solution is increased. Not too much. As a result, it becomes easy to form a charge transport layer or a single-layer type photosensitive layer.

<8. Base resin>
When the photoreceptor is a multilayer photoreceptor, the charge generation layer contains a base resin. The base resin is not particularly limited as long as it is a base resin applicable to the photoreceptor. Examples of the base resin include a thermoplastic resin, a thermosetting resin, and a photocurable resin. Examples of the thermoplastic resin include styrene-butadiene resin, styrene-acrylonitrile resin, styrene-maleic acid resin, styrene-acrylic acid resin, acrylic resin, polyethylene resin, ethylene-vinyl acetate resin, chlorinated polyethylene resin, poly Vinyl chloride resin, polypropylene resin, ionomer, vinyl chloride-vinyl acetate resin, alkyd resin, polyamide resin, urethane resin, polycarbonate resin, polyarylate resin, polysulfone resin, diallyl phthalate resin, ketone resin, polyvinyl butyral resin, polyether resin or A polyester resin is mentioned. Examples of the thermosetting resin include silicone resin, epoxy resin, phenol resin, urea resin, melamine resin, and other crosslinkable thermosetting resins. Examples of the photocurable resin include an epoxy-acrylic acid resin (more specifically, an acrylic acid derivative adduct of an epoxy compound) or a urethane-acrylic acid resin (more specifically, an acrylic acrylic resin). Acid derivative adducts, etc.). A base resin may be used individually by 1 type, and may be used in combination of 2 or more type.

  The base resin contained in the charge generation layer is preferably different from the binder resin contained in the charge transport layer. This is because the charge generation layer is not dissolved in the solvent of the charge transport layer coating solution. In the production of a layered photoreceptor, it is common to form a charge generation layer on a conductive substrate and form a charge transport layer on the charge generation layer. This is because when forming the charge transport layer, a charge transport layer coating solution is applied onto the charge generation layer.

<9. Additives>
The photosensitive layer (charge generation layer, charge transport layer or single layer type photosensitive layer) of the photoreceptor may contain various additives as required. Additives include, for example, deterioration inhibitors (for example, antioxidants, radical scavengers, quenchers or ultraviolet absorbers), softeners, surface modifiers, extenders, thickeners, dispersion stabilizers, waxes, Examples include donors, surfactants, plasticizers, sensitizers, and leveling agents. Antioxidants include, for example, hindered phenols (eg, di (tert-butyl) p-cresol), hindered amines, paraphenylenediamine, arylalkanes, hydroquinones, spirochromans, spirodanone or derivatives thereof, organic sulfur compounds or An organic phosphorus compound is mentioned.

<10. Intermediate layer>
The intermediate layer (undercoat layer) contains, for example, inorganic particles and a resin (intermediate layer resin) used for the intermediate layer. The presence of the intermediate layer is considered to suppress the increase in resistance by smoothing the flow of current generated when the photosensitive member is exposed while maintaining an insulating state capable of suppressing the occurrence of leakage.

  Examples of the inorganic particles include metal (for example, aluminum, iron or copper), metal oxide (for example, titanium oxide, alumina, zirconium oxide, tin oxide or zinc oxide) particles or non-metal oxide (for example, silica). Particles. These inorganic particles may be used individually by 1 type, and may use 2 or more types together.

  The resin for the intermediate layer is not particularly limited as long as it can be used as a resin for forming the intermediate layer. The intermediate layer may contain various additives. The additive is the same as the additive for the photosensitive layer.

<11. Photoconductor manufacturing method>
When the photoreceptor is a multilayer photoreceptor, the multilayer photoreceptor is manufactured, for example, as follows. First, a charge generation layer coating solution and a charge transport layer coating solution are prepared. A charge generation layer is formed by applying a coating solution for charge generation layer onto a conductive substrate and drying. Subsequently, the charge transport layer coating liquid is applied on the charge generation layer and dried to form the charge transport layer. Thereby, a laminated photoreceptor is manufactured.

  The charge generation layer coating solution is prepared by dissolving or dispersing the charge generation agent and components added as necessary (for example, base resin and various additives) in a solvent. The coating solution for the charge transport layer is prepared by dissolving or dispersing the electron acceptor compound and components added as necessary (for example, a binder resin, a hole transport agent, and various additives) in a solvent.

  Next, when the photoconductor is a single layer type photoconductor, the single layer type photoconductor is manufactured, for example, as follows. The single-layer type photoreceptor is manufactured by applying a coating solution for a single-layer type photosensitive layer onto a conductive substrate and drying it. The coating solution for a single-layer type photosensitive layer is obtained by dissolving or dispersing an electron transport agent and components added as necessary (for example, a charge generator, a hole transport agent, a binder resin, and various additives) in a solvent. Manufactured by.

  The solvent contained in the coating solution for charge generation layer, the coating solution for charge transport layer or the coating solution for single layer type photosensitive layer (hereinafter sometimes referred to as coating solution) dissolves each component contained in the coating solution. Or as long as it can disperse | distribute, it does not specifically limit. Examples of solvents include alcohols (eg, methanol, ethanol, isopropanol or butanol), aliphatic hydrocarbons (eg, n-hexane, octane or cyclohexane), aromatic hydrocarbons (eg, benzene, toluene or xylene), Halogenated hydrocarbons (eg dichloromethane, dichloroethane, carbon tetrachloride or chlorobenzene), ethers (eg dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether or propylene glycol monomethyl ether), ketones (eg acetone, Methyl ethyl ketone or cyclohexanone), esters (eg ethyl acetate or methyl acetate), dimethylformaldehyde, dimethylform Amide or dimethyl sulfoxide. These solvents are used alone or in combination of two or more. In order to improve the workability during the production of the photoreceptor, it is preferable to use a non-halogen solvent (a solvent other than the halogenated hydrocarbon) as the solvent.

  The coating solution is prepared by mixing each component and dispersing in a solvent. For mixing or dispersing, for example, a bead mill, a roll mill, a ball mill, an attritor, a paint shaker, or an ultrasonic disperser can be used.

  The coating liquid may contain, for example, a surfactant in order to improve the dispersibility of each component.

  The method for applying the coating solution is not particularly limited as long as the coating solution can be uniformly applied onto the conductive substrate. Examples of the coating method include a dip coating method, a spray coating method, a spin coating method, and a bar coating method.

  The method for drying the coating solution is not particularly limited as long as the solvent in the coating solution can be evaporated. For example, the method of heat-processing (hot-air drying) is mentioned using a high-temperature dryer or a vacuum dryer. The heat treatment conditions are, for example, a temperature of 40 ° C. or higher and 150 ° C. or lower and a time of 3 minutes or longer and 120 minutes or shorter.

  In addition, the manufacturing method of a photoreceptor may further include one or both of a step of forming an intermediate layer and a step of forming a protective layer as necessary. A known method is appropriately selected in the step of forming the intermediate layer and the step of forming the protective layer.

  The photoreceptor according to this embodiment has been described above. According to the photoreceptor of this embodiment, the electrical characteristics of the photoreceptor can be improved.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the scope of the examples.

<1. Photosensitive Material>
The following electron transporting agent, hole transporting agent, charge generating agent, and binder resin were prepared as materials for forming the single-layered photosensitive layer of the single-layered photoreceptor.

<1-1. Electron transport agent>
Compounds (1-1) to (1-4) were prepared as electron transport agents. Compounds (1-1) to (1-4) were produced by the following methods, respectively.

<1-1-1. Production of Compound (1-1)>
Reactions represented by reaction formulas (R-4), (R-5) and (R-6) (hereinafter referred to as reaction (R-4), reaction (R-5), and reaction (R-6), respectively) Compound (1-1) was prepared according to (may be described).

  In the reaction (R-4), 1.0 g (2.3 mmol) of the compound (1A), 0.27 g (2.6 mmol) of the compound (1B) (benzylamine), and 0.33 g (2. 6 mmol) and 50 mL of dioxane were charged into a flask to prepare a dioxane solution. The temperature of the flask contents was raised to 100 ° C. and maintained at 100 ° C., and the flask contents were stirred for 2 hours. After the reaction, dioxane was removed to obtain a residue. The obtained residue was purified by silica gel column chromatography using ethyl acetate / hexane (volume ratio V / V = 1/2) as a developing solvent. This obtained the intermediate product (1C). The yield of intermediate product (1C) was 1.05 g, and the yield of intermediate product (1C) from compound (1A) in reaction (R-4) was 88 mol%.

  In the reaction (R-5), 1.04 g (2.0 mmol) of the intermediate product (1C) and 15 mL of trifluoroacetic acid were charged into a flask to prepare a trifluoroacetic acid solution. The temperature of the flask contents was raised to 80 ° C. and maintained at 80 ° C., and the flask contents were stirred for 24 hours. After the reaction, trifluoroacetic acid was removed to obtain a residue. The obtained residue was purified by silica gel column chromatography using ethyl acetate / hexane (volume ratio V / V = 1/4) as a developing solvent. This obtained the intermediate product (1D). The yield of the intermediate product (1D) was 0.85 g, and the yield of the intermediate product (1D) from the intermediate product (1C) in the reaction (R-5) was 95 mol%.

  In the reaction (R-6), 1.02 g (2.3 mmol) of the intermediate product (1D), 0.28 g (2.6 mmol) of the compound represented by the chemical formula (1E) (o-toluidine), Diisopropylethylamine 0.33 g (2.6 mmol) and dioxane 50 mL were put into a flask to prepare a dioxane solution. The temperature of the flask contents was raised to 100 ° C. and maintained at 100 ° C., and the flask contents were stirred for 2 hours. After the reaction, dioxane was removed to obtain a residue. The obtained residue was purified by silica gel column chromatography using ethyl acetate as a developing solvent. This obtained the compound (1-1). The yield of compound (1-1) was 1.11 g, and the yield of compound (1-1) from compound (1D) in reaction (R-6) was 90 mol%.

<1-1-2. Production of Compounds (1-2) to (1-4)>
Compounds (1-2) to (1-4) were produced in the same manner as in the production of compound (1-1) except that the following points were changed. In addition, each raw material used in manufacture of compound (1-2)-(1-4) was added by the same mole number as the mole number of the corresponding raw material used in manufacture of compound (1-1).

  First, in order to manufacture a compound (1-4), the raw material was manufactured. Specifically, an intermediate product (2C) was produced. The intermediate product (2D) was manufactured using the obtained intermediate product (2C). The intermediate product (2D) was used as a raw material for producing the compound (1-4). In the production of the intermediate product (2C), the compound (1B) used in the reaction (R-4) was changed to the compound (2B) (4-aminopyridine). As a result, in the reaction (R-4), an intermediate product (2C) was obtained instead of the intermediate product (1C). Table 1 shows compound (A), compound (B), and intermediate product (C) in reaction (R-4).

  Table 1 shows the yield and yield of the intermediate product (C). The compound (2B) is represented by the following chemical formula (2B). The intermediate product (2C) is represented by the following chemical formula (2C).

  Next, an intermediate product (2D) was produced. Table 2 shows the intermediate product (C) and the intermediate product (D) in the reaction (R-5). The intermediate product (1C) used in the reaction (R-5) was changed to the intermediate product (2C). As a result, in the reaction (R-5), either the intermediate product (2D) was obtained instead of the intermediate product (1D).

  Table 2 shows the yield and yield of the intermediate product (D). In Table 2, the compound (2D) is represented by the following chemical formula (2D).

  Next, compounds (1-2) to (1-4) were produced. Table 3 shows the intermediate product (D) and compound (1) in the reaction (R-6). In reaction (R-6), intermediate product (1D) or intermediate product (2D) was used as intermediate product (D). The compound (1E) used in the reaction (R-6) was converted into the compound (2E) (4-t-butylaniline), the compound (3E) (4-aminopyridine), and the compound (4E) (2,6-dimethylaniline). ). As a result, in the reaction (R-6), any one of the compounds (1-2) to (1-4) was obtained instead of the compound (1-1).

  Table 3 shows the yield and yield of compound (1). In Table 3, compounds (2E) to (4E) are represented by the following chemical formulas (2E) to (4E), respectively.

Next, ¹ H-NMR spectra of the produced compounds (1-1) to (1-4) were measured using a proton nuclear magnetic resonance spectrometer (manufactured by JASCO Corporation, 300 MHz). CDCl ₃ was used as the solvent. Tetramethylsilane (TMS) was used as an internal standard sample. Of these, compounds (1-2) and (1-3) are given as representative examples. The chemical shift values of the compounds (1-2) and (1-3) are shown below.
Compound (1-2): ¹ H-NMR (300 MHz, CDCl ₃ ) δ = 8.47 (s, 1H), 8.45 (s, 1H), 7.59-7.51 (m, 4H), 7.35-7.26 (m, 3H), 7.22 (d, 2H), 5.38 (s, 2H), 4.54-4.4 (m, 4H), 1.64 (t, 3H), 1.57 (s, 3H), 1.37 (s, 9H).
Compound (1-3): ¹ H-NMR (300 MHz, CDCl ₃ ) δ = 8.84 (d, 2H), 8.33 (s, 1H), 8.31 (s, 1H), 7.51 ( d, 2H), 7.43 (d, 2H), 7.37-7.19 (m, 3H), 5.33 (s, 2H), 4.42 (q, 4H), 1.64 (t , 3H), 1.57 (s, 3H).

^{From the 1} H-NMR spectrum and the chemical shift value, it was confirmed that the compounds (1-2) and (1-3) were obtained. In the same manner for other compounds (1-1) and (1-4), the compounds (1-1) and (1-4) were obtained from the ¹ H-NMR spectrum and chemical shift value, respectively. confirmed.

<1-1-3. Preparation of Compound (E-1)>
As an electron transport agent, a compound represented by the chemical formula (E-1) (hereinafter sometimes referred to as compound (E-1)) was prepared.

<1-2. Hole transport agent>
The compound (H-1) already described was prepared as a hole transport agent.

<1-3. Charge generator>
As the charge generator, the compounds (C-1) and (C-2) described above were prepared. The compound (C-1) was a metal-free phthalocyanine (X-type metal-free phthalocyanine) represented by the chemical formula (C-1). The crystal structure of the compound (C-1) was X type.

  The compound (C-2) was titanyl phthalocyanine (Y-type titanyl phthalocyanine) represented by the chemical formula (C-2). Moreover, the crystal structure of the compound (C-2) was Y type.

<1-4. Binder resin>
As a binder resin, a Z-type polycarbonate resin (Resin-1) (“Panlite (registered trademark) TS-2050” manufactured by Teijin Ltd., viscosity average molecular weight 50,000) was prepared.

<2. Manufacture of single layer type photoreceptor>
Using the material for forming the photosensitive layer, single layer type photoreceptors (A-1) to (A-8) and single layer type photoreceptors (B-1) to (B-2) were produced.

<2-1. Production of Single Layer Type Photosensitive Member (A-1)>
In the container, 5 parts by mass of the compound (C-1) as a charge generating agent, 80 parts by mass of the compound (H-1) as a hole transporting agent, 40 parts by mass of the compound (1-1) as an electron transporting agent, 100 parts by mass of Z-type polycarbonate resin (Resin-1) as a binder resin and 800 parts by mass of tetrahydrofuran as a solvent were added. The contents of the container were mixed for 50 hours using a ball mill to disperse the material in the solvent. This obtained the coating liquid for single layer type photosensitive layers. The single layer type photosensitive layer coating solution was coated on an aluminum drum-shaped support (diameter: 30 mm, total length: 238.5 mm) as a conductive substrate using a dip coating method. The applied coating liquid for single layer type photosensitive layer was dried with hot air at 100 ° C. for 30 minutes. As a result, a single-layer type photosensitive layer (thickness 30 μm) was formed on the conductive substrate. As a result, a single layer type photoreceptor (A-1) was obtained.

<2-2. Production of Single Layer Type Photoconductors (A-2) to (A-8) and Single Layer Type Photoconductors (B-1) to (B-2)>
Except for the following changes, the single-layer photoconductors (A-2) to (A-8) and the single-layer photoconductors ( B-1) to (B-2) were produced. The compound (C-1) as the charge generating agent used in the production of the single layer type photoreceptor (A-1) was changed to the type of charge generating agent shown in Table 4. The compound (1-1) as the electron transport agent used for the production of the single layer type photoreceptor (A-1) was changed to the type of electron transport agent shown in Table 4. Table 4 shows configurations of the photoconductors (A-1) to (A-8) and the photoconductors (B-1) to (B-2). In Table 4, CGM, HTM, and ETM represent a charge generator, a hole transport agent, and an electron transport agent, respectively. In Table 4, x-H ₂ Pc and Y-TiOPc in the CGM column indicate X-type metal-free phthalocyanine and Y-type titanyl phthalocyanine, respectively. H-1 in the HTM column represents the compound (H-1). 1-1 to 1-4 and E-1 in the ETM column represent the compounds (1-1) to (1-4) and the compound (E-1), respectively.

<3. Evaluation of electrical characteristics of single-layer type photoreceptor>
The electrical characteristics of each of the produced single layer type photoreceptors (A-1) to (A-8) and single layer type photoreceptors (B-1) to (B-2) were evaluated. The electrical characteristics were evaluated in an environment with a temperature of 23 ° C. and a humidity of 60% RH. First, using a drum sensitivity tester (manufactured by Gentec Co., Ltd.), the surface of the single layer type photoreceptor was charged to positive polarity. The charging conditions were set to a rotation speed of 31 rpm of the single layer type photoreceptor and a current flowing into the single layer type photoreceptor +8 μA. The surface potential of the single-layer type photoreceptor immediately after charging was set to + 700V. Next, monochromatic light (wavelength 780 nm, half-value width 20 nm, light energy 1.5 μJ / cm ² ) was extracted from the white light of the halogen lamp using a bandpass filter. The surface of the monolayer type photoreceptor was irradiated with the extracted monochromatic light. The surface potential of the single-layer photoreceptor was measured after 0.5 seconds had elapsed from the end of irradiation. The measured surface potential was defined as a sensitivity potential (V _L , unit V). Table 4 shows the measured sensitivity potential (V _L ) of the single-layer type photoreceptor. Note that the smaller the absolute value of the sensitivity potential (V _L ), the better the electrical characteristics of the single layer type photoreceptor.

<4. Evaluation of Suppression of Crystallization of Single Layer Type Photoreceptor>
The surface of the photoreceptor is visually observed for each of the produced single-layer photoreceptors (A-1) to (A-8) and single-layer photoreceptors (B-1) to (B-2). Crystallization was confirmed. From the observation results obtained, the suppression of crystallization of the single layer type photoreceptor was evaluated according to the following criteria.
A (good): Crystallization was not confirmed.
B (Normal): Slight crystallization was confirmed.
C (Poor): Crystallization was clearly confirmed.

  As shown in Table 4, in the photoreceptors (A-1) to (A-8), the photosensitive layer contains any one of compounds (1-1) to (1-4) as an electron transport agent. It was. These compounds (1-1) to (1-4) were compounds represented by the general formula (1). In the photoreceptors (A-1) to (A-8), the sensitivity potential was +97 V or more and +108 V or less, and no crystallization was confirmed on the photoreceptor surface.

  As shown in Table 4, in the photoreceptors (B-1) to (B-2), the photosensitive layer contained the compound (E-1) as an electron transport agent. Compound (E-1) was not Compound (1). In the photoreceptors (B-1) to (B-2), the sensitivity potential was +130 V or more and +135 V or less, and crystallization was slightly confirmed on the surface of the photoreceptor.

  It is clear that the photoconductors (A-1) to (A-8) can achieve both suppression of crystallization and electrical characteristics as compared with the photoconductors (B-1) to (B-2).

  From the above, it was shown that the photoreceptor provided with the photosensitive layer containing the compound represented by the general formula (1) can achieve both suppression of crystallization and electrical characteristics.

  As shown in Table 4, in the photoreceptors (A-2), (A-4), (A-6) and (A-8), the photosensitive layer contains Y-type titanyl phthalocyanine as a charge generator. The sensitivity potentials were + 97V, + 102V, + 100V, and + 103V, respectively.

  As shown in Table 4, in the photoreceptors (A-1), (A-3), (A-5), and (A-7), the photosensitive layer contains X-type metal-free phthalocyanine as a charge generator. The sensitivity potentials were + 101V, + 107V, + 104V, and + 108V, respectively.

  Photoconductors (A-2), (A-4), (A-6) and (A-8) are photoconductors (A-1), (A-3), (A-5) and (A), respectively. It is clear that the electrical characteristics are superior to -7).

  From the above, it was shown that in the photoreceptor, the photosensitive layer containing Y-type titanyl phthalocyanine as a charge generating agent has superior electrical characteristics as compared to the photosensitive layer containing X-type metal-free phthalocyanine as a charge generating agent.

  The compound according to the present invention can be used for a photoreceptor. The photoreceptor according to the present invention can be used in an image forming apparatus.

DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor 3 Photosensitive layer 3a Charge generation layer 3b Charge transport layer 3c Single layer type photosensitive layer

Claims (4)

An electrophotographic photoreceptor having a photosensitive layer,
The photosensitive layer is an electrophotographic photosensitive member containing a compound represented by the following general formula (1).

In the general formula (1),
R ¹ represents a halogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms,
R ² and R ³ are each independently an aryl group having 6 to 14 carbon atoms which may have an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 6 carbon atoms, carbon A cycloalkyl group having 3 to 10 atoms, an alkoxy group having 1 to 6 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a heterocyclic group which may have a substituent;
The substituent is an aryl group having 6 to 14 carbon atoms, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, Or an aralkyl group having 7 to 12 carbon atoms,
R ² and R ³ are different from each other. In the general formula (1),
R ¹ represents an alkoxy group having 1 to 3 carbon atoms,
The two R ¹ are identical to each other,
R ² and R ^{3 each} represents an aryl group having 6 to 14 carbon atoms having an alkyl group having 1 to 4 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a heterocyclic group. 2. The electrophotographic photosensitive member according to 1. The photosensitive layer is a single-layer type photosensitive layer,
The single-layer type photosensitive layer further contains a charge generating agent,
The electrophotographic photosensitive member according to claim 1, wherein the charge generating agent includes X-type metal-free phthalocyanine or Y-type titanyl phthalocyanine.   The electrophotographic photosensitive member according to claim 3, wherein the charge generating agent includes Y-type titanyl phthalocyanine.

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