JPWO2019058789A1 - Electrophotographic photoreceptor - Google Patents

Abstract

The electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer is a single layer. The photosensitive layer contains at least a charge generator and a compound represented by the general formula (1). In the general formula (1), R1 may have an alkyl group having 1 or more and 10 or less carbon atoms, an aryl group having 6 or more and 22 or less carbon atoms, an alkoxy group having 7 or more and 20 or less carbon atoms, and a carbon atom. It represents a cycloalkyl group having a number of 3 or more and 20 or less, an alkoxy group having 1 or more and 6 or less carbon atoms, or an alkyl group having 3 or more and 20 or less carbon atoms which may have -CO-OR3. R3 represents an alkyl group having 1 or more carbon atoms and 8 or less carbon atoms. R2 represents a hydrogen atom, a halogen atom, or a cyano group. [Chemical 1]

Description

The present invention relates to an electrophotographic photoreceptor.

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

The electrophotographic photoreceptor described in Patent Document 1 includes a photosensitive layer. This photosensitive layer contains, for example, a naphthalenetetracarboxylic acid diimide derivative having a structure represented by the chemical formula (E-1) as an electron transporting substance.

JP, 2005-154444, A

However, the inventors of the present invention have found that the electrophotographic photosensitive member described in Patent Document 1 is insufficient in terms of sensitivity characteristics.

The present invention has been made in view of the above problems, and an object thereof is to provide an electrophotographic photoreceptor having excellent sensitivity characteristics.

The electrophotographic photosensitive member of the present invention includes a conductive substrate and a photosensitive layer. The photosensitive layer is a single layer. The photosensitive layer contains at least a charge generating agent and a compound represented by the general formula (1).

In the general formula (1), R ¹ represents an aryl group having 6 to 22 carbon atoms which may have an alkyl group having 1 to 10 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, It represents a cycloalkyl group having 3 to 20 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an alkyl group having 3 to 20 carbon atoms which may have -CO-OR ³ . R ³ represents an alkyl group having 1 to 8 carbon atoms. R ² represents a hydrogen atom, a halogen atom, or a cyano group.

The electrophotographic photoreceptor of the present invention has excellent sensitivity characteristics.

FIG. 3 is a cross-sectional view showing an example of the electrophotographic photosensitive member according to the embodiment of the present invention. FIG. 3 is a cross-sectional view showing an example of the electrophotographic photosensitive member according to the embodiment of the present invention. FIG. 3 is a cross-sectional view showing an example of the electrophotographic photosensitive member according to the embodiment of the present invention.

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. It should be noted that although the description may be omitted as appropriate for the overlapping description, the gist of the invention is not limited.

Hereinafter, a compound and a derivative thereof may be generically referred to by adding "system" after the compound name. Further, when a "system" is added after the compound name to represent the polymer name, it means that the repeating unit of the polymer is derived from the compound or its derivative. Further, the “may have a group” group, the “has a group” group, the “may have a halogen atom” group, and the “has a halogen atom” group are each “substituted by a group”. Means a “optionally substituted” group, a “substituted by a group” group, a “optionally substituted by a halogen atom” group, and a “substituted by a halogen atom” group.

Hereinafter, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 8 carbon atoms, an alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 3 carbon atoms, carbon An alkyl group having 3 to 20 atoms, an alkyl group having 3 to 10 carbon atoms, an alkyl group having 3 to 6 carbon atoms, an alkyl group having 3 or 5 carbon atoms, and an alkyl group having 1 to 6 carbon atoms Alkoxy group, alkoxy group having 1 to 3 carbon atoms, aryl group having 6 to 22 carbon atoms, aryl group having 6 to 14 carbon atoms, aryl group having 6 to 10 carbon atoms, carbon atom Unless otherwise specified, a cycloalkyl group having 3 to 20 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms have the following meanings.

Examples of the halogen atom (halogen group) include a fluorine atom (fluoro group), a chlorine atom (chloro group), a bromine atom (bromo group) and an iodine atom (iodo group).

The alkyl group having 1 to 10 carbon atoms, the alkyl group having 1 to 8 carbon atoms, the alkyl group having 1 to 6 carbon atoms, and the alkyl group having 1 to 3 carbon atoms are each a straight chain. It is in the form of a branched or branched chain and 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, sec-butyl group, tert-butyl group, n-pentyl group and isopentyl group. Group, neopentyl group, 1,2-dimethylpropyl group, straight-chain or branched hexyl group, straight-chain or branched heptyl group, straight-chain or branched octyl group, direct Examples thereof include a linear or branched nonyl group, and a linear or branched decyl group. Examples of the alkyl group having 1 to 8 carbon atoms are groups having 1 to 8 carbon atoms among the groups described as examples of the alkyl group having 1 to 10 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms are groups having 1 to 6 carbon atoms among the groups described as examples of the alkyl group having 1 to 10 carbon atoms. Examples of the alkyl group having 1 to 3 carbon atoms are groups having 1 to 3 carbon atoms among the groups described as examples of the alkyl group having 1 to 10 carbon atoms.

The alkyl group having 3 to 20 carbon atoms, the alkyl group having 3 to 10 carbon atoms, the alkyl group having 3 to 6 carbon atoms, and the alkyl group having 3 or 5 carbon atoms are each linear. Alternatively, it is branched and unsubstituted. Examples of the alkyl group having 3 to 20 carbon atoms include n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, 1 , 2-dimethylpropyl group, straight-chain or branched hexyl group, straight-chain or branched heptyl group, straight-chain or branched octyl group, straight-chain or branched chain Nonyl group, straight chain or branched decyl group, straight chain or branched undecyl group, straight chain or branched dodecyl group, straight chain or branched chain Tridecyl group, straight-chain or branched tetradecyl group, straight-chain or branched pentadecyl group, straight-chain or branched hexadecyl group, straight-chain or branched octadecyl group , A linear or branched nonadecyl group and a linear or branched icosyl group. Examples of the alkyl group having 3 to 10 carbon atoms are groups having 3 to 10 carbon atoms among the groups described as examples of the alkyl group having 3 to 20 carbon atoms. Examples of the alkyl group having 3 to 6 carbon atoms are groups having 3 to 6 carbon atoms among the groups described as examples of the alkyl group having 3 to 20 carbon atoms. Examples of the alkyl group having 3 or 5 carbon atoms are groups having 3 or 5 carbon atoms among the groups described as examples of the alkyl group having 3 or more and 20 or less carbon atoms.

The alkoxy group having 1 to 6 carbon atoms and the alkoxy group having 1 to 3 carbon atoms are linear or branched and unsubstituted. Examples of the alkoxy group having 1 to 6 carbon atoms include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, n-pentoxy group, Examples thereof include an isopentoxy group, a neopentoxy group and a hexyl group. Examples of the alkoxy group having 1 to 3 carbon atoms are groups having 1 to 3 carbon atoms among the groups described as examples of the alkoxy group having 1 to 6 carbon atoms.

The aryl group having 6 to 22 carbon atoms, the aryl group having 6 to 14 carbon atoms, and the aryl group having 6 to 10 carbon atoms are each unsubstituted. Examples of the aryl group having 6 to 22 carbon atoms include a phenyl group, a naphthyl group, an indacenyl group, a biphenylenyl group, an acenaphthylenyl group, an anthryl group, a phenanthryl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthalenyl group, and preyadenyl group. Group, picenyl group, perylenyl group, pentaphenyl group and pentacenyl group. Examples of the aryl group having 6 to 14 carbon atoms include a phenyl group, a naphthyl group, an indacenyl group, a biphenylenyl group, an acenaphthylenyl group, an anthryl group and a phenanthryl group. Examples of the aryl group having 6 to 10 carbon atoms include a phenyl group and a naphthyl group.

The cycloalkyl group having 3 to 20 carbon atoms and the cycloalkyl group having 3 to 10 carbon atoms are each unsubstituted. Examples of the cycloalkyl group having 3 to 20 carbon atoms include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, cycloundecyl group, cyclododecyl group. Group, cyclotridecyl group, cyclotetradecyl group, cyclopentadecyl group, cyclohexadecyl group, cyclooctadecyl group, cyclononadecyl group and cycloicosyl group. Examples of the cycloalkyl group having 3 to 10 carbon atoms are groups having 3 to 10 carbon atoms among the groups described as examples of the cycloalkyl group having 3 to 20 carbon atoms.

The aralkyl group having 7 or more and 20 or less carbon atoms is unsubstituted. Examples of the aralkyl group having 7 to 20 carbon atoms include an alkyl group having 1 to 6 carbon atoms having an aryl group having 6 to 14 carbon atoms.

<Electrophotographic photoreceptor>
This embodiment relates to an electrophotographic photosensitive member (hereinafter, also referred to as a photosensitive member). Hereinafter, the structure of the photoconductor 1 will be described with reference to FIGS. 1A to 1C. 1A to 1C are cross-sectional views showing an example of the photoconductor 1 according to the present embodiment.

As shown in FIG. 1A, the photoconductor 1 includes, for example, a conductive substrate 2 and a photosensitive layer 3. The photosensitive layer 3 is a single layer (one layer). The photoconductor 1 is a single-layer type electrophotographic photoconductor including a single photosensitive layer 3.

As shown in FIG. 1B, the photoreceptor 1 may include a conductive substrate 2, a photosensitive layer 3, and an intermediate layer 4 (undercoat layer). The intermediate layer 4 is provided between the conductive substrate 2 and the photosensitive layer 3. As shown in FIG. 1A, the photosensitive layer 3 may be directly provided on the conductive substrate 2. Alternatively, as shown in FIG. 1B, the photosensitive layer 3 may be provided on the conductive substrate 2 via the intermediate layer 4. The intermediate layer 4 may be a single layer or a plurality of layers.

As shown in FIG. 1C, the photoreceptor 1 may include a conductive substrate 2, a photosensitive layer 3, and a protective layer 5. The protective layer 5 is provided on the photosensitive layer 3. The protective layer 5 may be a single layer or a plurality of layers.

The thickness of the photosensitive layer 3 is not particularly limited as long as the function as the photosensitive layer 3 can be sufficiently exhibited. The thickness of the photosensitive layer 3 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 photoconductor 1 has been described above with reference to FIGS. 1A to 1C. Hereinafter, the photoconductor will be described in more detail.

<Photosensitive layer>
The photosensitive layer contains at least a charge generating agent and a compound represented by the general formula (1). The photosensitive layer may further contain a hole transport material. The photosensitive layer may further contain a binder resin. The photosensitive layer may contain an additive, if necessary.

(Compound represented by the general formula (1))
The photosensitive layer contains a compound represented by the general formula (1) (hereinafter sometimes referred to as compound (1)). The photosensitive layer contains, for example, the compound (1) as an electron transfer agent.

In the general formula (1), R ¹ represents an aryl group having 6 to 22 carbon atoms which may have an alkyl group having 1 to 10 carbon atoms; an aralkyl group having 7 to 20 carbon atoms; carbon It represents a cycloalkyl group having 3 to 20 carbon atoms; an alkoxy group having 1 to 6 carbon atoms; or an alkyl group having 3 to 20 carbon atoms which may have -CO-OR ³ . R ³ represents an alkyl group having 1 to 8 carbon atoms. R ² represents a hydrogen atom, a halogen atom, or a cyano group.

When the photosensitive layer contains the compound (1), the sensitivity characteristics of the photoreceptor can be improved. The reason is presumed as follows.

The compound (1) has a 6-ring condensed ring and has a predetermined chemical structure. Therefore, the compound (1) has a broad conjugated planar structure. Since the compound (1) has a wide conjugated planar structure, the electron transfer distance in the molecule of the compound (1) becomes long, and the electron transfer distance (hopping distance) between the molecules of the compound (1) becomes short. This improves the electron transporting property of the compound (1). In addition, since the compound (1) has a broad conjugated planar structure, the compound (1) is densely stacked with the charge generating agent, and the electron accepting property from the charge generating agent to the compound (1) is improved. The electron transporting property of the compound (1) and the electron accepting property from the charge generating agent to the compound (1) are improved, so that the sensitivity characteristic of the photoreceptor is improved.

Further, in the general formula (1), that one of R ² is with respect to the condensation site of the benzene ring is a benzene ring and the other of R ² that bind to binding, the vertical line (hereinafter referred to as the line Z There is). The compound (1) has an asymmetric structure with respect to the line Z. Specifically, with respect to the line Z, the two carbonyl groups located on the right side and the two carbonyl groups located on the left side do not exist at positions that are line symmetrical. As described above, the compound (1) having an asymmetric structure and a predetermined chemical structure improves the solubility of the compound (1) in the solvent for forming the photosensitive layer. Further, since the compound (1) has an asymmetric structure and a predetermined chemical structure, the compatibility of the compound (1) with the binder resin is improved. By improving the solubility and compatibility of the compound (1), a uniform photosensitive layer can be formed, and the sensitivity characteristics of the photoconductor are improved. It is also possible to suppress crystallization of the photosensitive layer of the photoreceptor.

The aryl group having 6 to 22 carbon atoms represented by R ¹ is preferably an aryl group having 6 to 14 carbon atoms, more preferably an aryl group having 6 to 10 carbon atoms, and further preferably a phenyl group. The aryl group having 6 to 22 carbon atoms represented by R ¹ may have an alkyl group having 1 to 10 carbon atoms as a substituent. As such an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 6 carbon atoms is preferable, an alkyl group having 1 to 3 carbon atoms is more preferable, and a methyl group or an ethyl group is further preferable. preferable. The number of substituents (alkyl group having 1 to 10 carbon atoms) in the aryl group having 6 to 22 carbon atoms is preferably 1 to 5 and is preferably 1 to 3 It is more preferable, and it is still more preferable that the number is 1 or 2. The aryl group having 6 to 22 carbon atoms having an alkyl group having 1 to 10 carbon atoms is preferably an aryl group having 6 to 14 carbon atoms having an alkyl group having 1 to 6 carbon atoms, An aryl group having 6 to 10 carbon atoms having an alkyl group having 1 to 3 carbon atoms is more preferable, a phenyl group having a methyl group and an ethyl group is further preferable, and a 2-ethyl-6-methylphenyl group is particularly preferable. preferable.

The aralkyl group having 7 to 20 carbon atoms represented by R ¹ is preferably an alkyl group having 1 to 6 carbon atoms having an aryl group having 6 to 14 carbon atoms.

The cycloalkyl group having 3 to 20 carbon atoms represented by R ¹ is preferably a cycloalkyl group having 3 to 10 carbon atoms.

The alkoxy group having 1 to 6 carbon atoms represented by R ¹ is preferably an alkoxy group having 1 to 3 carbon atoms.

The alkyl group having 3 to 20 carbon atoms represented by R ¹ is preferably an alkyl group having 3 to 10 carbon atoms, more preferably an alkyl group having 3 to 6 carbon atoms, and more preferably 3 or 5 carbon atoms. Is more preferable, and an isopropyl group or an isopentyl group (that is, a 3-methylbutyl group) is particularly preferable. The alkyl group having 3 to 20 carbon atoms represented by R ¹ may have —CO—OR ³ as a substituent. R in -CO-OR ^{3 3} represents a 1 to 8 alkyl group carbon atoms. As such an alkyl group having 1 to 8 carbon atoms, an alkyl group having 1 to 6 carbon atoms is preferable, an alkyl group having 1 to 3 carbon atoms is more preferable, and a methyl group or an ethyl group is further preferable. preferable. The number of substituents (—CO—OR ³ ) in the alkyl group having 3 to 20 carbon atoms is preferably 1 or more and 3 or less, more preferably 1 or 2, More preferably, it is a piece. The alkyl group having ³ to 20 carbon atoms having -CO-OR ³ has ³ to 10 carbon atoms having -CO-OR ³ (R ³ represents an alkyl group having 1 to 6 carbon atoms). The following alkyl groups are preferable, and an alkyl group having 3 to 6 carbon atoms and having —CO—OR ³ (R ³ represents an alkyl group having 1 to 3 carbon atoms) is more preferable, and —CO—OR ³ An alkyl group having 5 carbon atoms having (R ³ represents a methyl group or an ethyl group) is more preferable, and a 1-(ethoxycarbonyl)-3-methylbutyl group is particularly preferable.

In the case where R ³ represents an alkyl group having 1 to 8 carbon atoms, -CO-OR ³ is an alkoxycarbonyl group having 2 to 9 carbon atoms. When R ³ represents an alkyl group having 1 to 6 carbon atoms, -CO-OR ³ is an alkoxycarbonyl group having 2 to 7 carbon atoms. When R ³ represents an alkyl group having 1 to 3 carbon atoms, -CO-OR ³ is an alkoxycarbonyl group having 2 to 4 carbon atoms. When R ³ represents a methyl group or an ethyl group, -CO-OR ³ represents a methoxycarbonyl group or an ethoxycarbonyl group.

The halogen atom represented by R ² is preferably a chlorine atom or a fluorine atom.

In general formula (1), R ¹ may have an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 22 carbon atoms, or —CO—OR ^3. It is preferable to represent an alkyl group having 3 to 20 carbon atoms. R ³ preferably represents an alkyl group having 1 to 8 carbon atoms.

In general formula (1), R ² preferably represents a hydrogen atom or a cyano group. It is more preferable that R ² represents a cyano group because the cyano group is an electron-accepting group and the sensitivity characteristics of the photoconductor can be improved.

The compound (1) is preferably the compound represented by the chemical formulas (1-1), (1-2), (1-3) and (1-4) since the sensitivity characteristics of the photoreceptor can be improved (hereinafter, Each of them may be referred to as compound (1-1), (1-2), (1-3) and (1-4). As the compound (1), the compounds (1-2), (1-3) and (1-4) are more preferable, and the compound (1-2) is more preferable, because the sensitivity characteristics of the photoreceptor can be further improved.

The photosensitive layer may contain only the compound (1) as an electron transfer agent. In addition to the compound (1), the photosensitive layer may further contain an electron transfer agent other than the compound (1) (hereinafter, may be referred to as other electron transfer agent). Examples of other electron transfer agents include quinone compounds, diimide compounds, hydrazone compounds, thiopyran compounds, trinitrothioxanthone compounds, 3,4,5,7-tetranitro-9-fluorenone compounds, dinitroanthracene compounds. Examples thereof include compounds, dinitroacridine compounds, tetracyanoethylene, 2,4,8-trinitrothioxanthone, dinitrobenzene, dinitroacridine, succinic anhydride, maleic anhydride and dibromomaleic anhydride. Examples of the quinone compound include diphenoquinone compounds, azoquinone compounds, anthraquinone compounds, naphthoquinone compounds, nitroanthraquinone compounds and dinitroanthraquinone compounds.

The photosensitive layer may contain only one type of compound (1) or may contain two or more types. The photosensitive layer may contain, in addition to the compound (1), only one kind of other electron transfer agent, or may contain two or more kinds of other electron transfer agent. The content of the compound (1) is preferably 80% by mass or more, more preferably 90% by mass or more, and particularly preferably 100% by mass, based on the total mass of the electron transport agent.

The content of the compound (1) is preferably 5 parts by mass or more and 100 parts by mass or less, and more preferably 20 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the binder resin. When the content of the compound (1) is 5 parts by mass or more with respect to 100 parts by mass of the binder resin, it is easy to improve the sensitivity characteristics of the photoreceptor. When the content of the compound (1) is 100 parts by mass or less based on 100 parts by mass of the binder resin, the compound (1) is easily dissolved in the solvent for forming the photosensitive layer, and a uniform photosensitive layer is easily formed. ..

Next, a method for producing the compound (1) will be described. If R ² in the general formula (1) represents a hydrogen atom, if R ² in the general formula (1) represents a halogen atom, and R ² in the general formula (1) is divided into the case where a cyano group Explain.

(When R ² represents a hydrogen atom)
First, the case where R ² in the general formula (1) represents a hydrogen atom will be described. General formula (1) in this case is represented by general formula (1a). The compound represented by the general formula (1a) (hereinafter sometimes referred to as the compound (1a)) is, for example, a reaction represented by the following reaction formula (R-1) (hereinafter, reaction (R-1)). May be described) or by a method according thereto. Hereinafter, the compounds represented by the general formulas (A) and (B) represented by the reaction (R-1) are referred to as compounds (A) and (B), respectively. Y in the general formula (A) represents a halogen atom. R ¹ in the general formula (B) R ¹ and the general formula in in (1a) are each the same meaning as R ¹ in the general formula (1).

In the reaction (R-1), 1 molar equivalent of the compound (A) and 2 molar equivalents of the compound (B) are reacted to obtain 1 molar equivalent of the compound (1a). Specifically, the compound (A) and the compound (B) are reacted in the presence of a Lewis acid. Examples of the Lewis acid include aluminum chloride and titanium tetrachloride. The reaction (R-1) may be performed in the presence of a solvent. Examples of the solvent include 1,2-dichlorobenzene, trichlorobenzene and monochlorobenzene. The reaction (R-1) may be performed under an inert gas atmosphere (for example, under a nitrogen gas atmosphere). The reaction temperature of the reaction (R-1) is preferably 150° C. or higher and 200° C. or lower. The reaction time of the reaction (R-1) is preferably 2 hours or more and 15 hours or less. In addition to the reaction (R-1), the method for producing the compound (1a) may further include an appropriate step, if necessary.

(When R ² represents a halogen atom)
Next, the case where R ² in the general formula (1) represents a halogen atom will be described. General formula (1) in this case is represented by general formula (1b). The compound represented by the general formula (1b) (hereinafter sometimes referred to as the compound (1b)) is, for example, a reaction represented by the following reaction formula (R-2) (hereinafter, reaction (R-2)). May be described) or by a method according thereto. X in X ₂ shown in the reaction (R-2) and X in the general formula (1b) represent a halogen atom. R ¹ in the general formula (1b) has the same meaning as R ¹ in the general formula (1).

In the reaction (R-2), 1 molar equivalent of the compound (1a) obtained in the reaction (R-1) and 1 molar equivalent of X ₂ are reacted to obtain 1 molar equivalent of the compound (1b). Specifically, compound (1a) and X ₂ are reacted in the presence of an acid and a catalyst to obtain compound (1b). Examples of the acid include concentrated sulfuric acid and trichloroacetic acid. The acid may act as a solvent. Examples of the catalyst include iodine. Examples of X ₂ include bromine (Br ₂ ) and chlorine (Cl ₂ ). The reaction temperature of the reaction (R-2) is preferably 50° C. or higher and 100° C. or lower. The reaction time of the reaction (R-2) is preferably 3 hours or more and 15 hours or less. In addition to the reaction (R-2), the method for producing the compound (1b) may further include an appropriate step, if necessary.

(When R ² represents a cyano group)
Next, the case where R ² in the general formula (1) represents a cyano group will be described. General formula (1) in this case is represented by general formula (1c). The compound represented by the general formula (1c) (hereinafter sometimes referred to as the compound (1c)) is, for example, a reaction represented by the following reaction formula (R-3) (hereinafter, reaction (R-3)). May be described) or by a method according thereto. R ¹ in the general formula (1c) has the same meaning as R ¹ in the general formula (1).

In the reaction (R-3), 1 molar equivalent of the compound (1b) obtained in the reaction (R-2) and 2 molar equivalents of copper cyanide (CuCN) are reacted to give 1 molar equivalent of the compound (1c). To get Reaction (R-3) may be performed in the presence of a solvent. Examples of the solvent include N,N-dimethylformamide and dimethyl sulfoxide. The reaction temperature of the reaction (R-3) is preferably 100° C. or higher and 200° C. or lower. The reaction time of the reaction (R-3) is preferably 2 hours or more and 10 hours or less. In addition to the reaction (R-3), the method for producing the compound (1c) may further include an appropriate step, if necessary.

After performing the reaction (R-1), the obtained compound (1a) may be purified. In addition, the compound (1b) obtained may be purified after the reaction (R-2). Further, the obtained compound (1c) may be purified after the reaction (R-3). Examples of the purification method include known methods (for example, filtration, silica gel chromatography or crystallization).

(Charge generating agent)
The charge generating agent is not particularly limited as long as it is a charge generating agent for a photoreceptor. Examples of the charge generating agent include phthalocyanine pigments, perylene pigments, bisazo pigments, trisazo pigments, dithioketopyrrolopyrrole pigments, metal-free naphthalocyanine pigments, metal naphthalocyanine pigments, squaraine pigments, indigo pigments, azurenium pigments, cyanines. Pigment, inorganic photoconductive material (for example, selenium, selenium-tellurium, selenium-arsenic, cadmium sulfide or amorphous silicon) powder, pyrylium pigment, anthanthrone pigment, triphenylmethane pigment, slene pigment, toluidine pigment, Examples include pyrazoline-based pigments and quinacridone-based pigments. The charge generating agents may be used alone or in combination of two or more.

Examples of the phthalocyanine-based pigment include metal-free phthalocyanine and metal phthalocyanine. The metal-free phthalocyanine is represented by, for example, a chemical formula (CGM2). Examples of the metal phthalocyanine include titanyl phthalocyanine, hydroxygallium phthalocyanine and chlorogallium phthalocyanine. Titanyl phthalocyanine is represented by a chemical formula (CGM1). The phthalocyanine-based pigment may be crystalline or non-crystalline. The crystal shape of the phthalocyanine-based pigment (for example, α-type, β-type, Y-type, V-type or II-type) is not particularly limited, and phthalocyanine-based pigments having various crystal shapes are used.

Examples of the metal-free phthalocyanine crystals include X-type crystals 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, and Y-type titanyl phthalocyanine).

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 photoconductor having sensitivity in a wavelength region of 700 nm or more. Since it has a high quantum yield in the wavelength region of 700 nm or more, the charge generating agent is preferably a phthalocyanine-based pigment, more preferably metal-free phthalocyanine or titanyl phthalocyanine, and further preferably X-type metal-free phthalocyanine or Y-type titanyl phthalocyanine. , Y-type titanyl phthalocyanine is particularly preferable.

The 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. The main peak in the CuKα characteristic X-ray diffraction spectrum is a peak having the first or second highest intensity in the range where the Bragg angle (2θ±0.2°) is 3° or more and 40° or less.

An example of the 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), and an X-ray tube Cu, a tube voltage of 40 kV, a tube current of 30 mA, and CuKα. An X-ray diffraction spectrum is measured under the condition that the characteristic X-ray wavelength is 1.542Å. The measurement range (2θ) is, for example, 3° or more and 40° or less (start angle 3°, stop angle 40°), and the scanning speed is, for example, 10°/min.

An anthanthrone-based pigment is preferably used as a charge generating agent in a photoreceptor applied to an image forming apparatus using a short-wavelength laser light source (for example, a laser light source having a wavelength of 350 nm or more and 550 nm or less).

The content of the charge generating agent is preferably 0.1 parts by mass or more and 50 parts by mass or less, and 0.5 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the binder resin contained in the photosensitive layer. It is more preferable that the amount is 0.5 part by mass or more and 4.5 parts by mass or less.

(Hole transfer agent)
Examples of the hole transfer agent include triphenylamine derivatives, diamine derivatives (eg, N,N,N′,N′-tetraphenylbenzidine derivatives, N,N,N′,N′-tetraphenylphenylenediamine derivatives, N,N,N',N'-tetraphenylnaphthylenediamine derivative, N,N,N',N'-tetraphenylphenanthrylenediamine derivative or di(aminophenylethenyl)benzene derivative), oxadiazole type 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 compounds (for example, 1-phenyl-3-(p-dimethylaminophenyl)pyrazolin), hydrazone compounds, indole compounds, oxazole compounds, isoxazole compounds, thiazole compounds. Examples thereof include compounds, thiadiazole-based compounds, imidazole-based compounds, pyrazole-based compounds and triazole-based compounds. The hole transport materials may be used alone or in combination of two or more.

The photosensitive layer preferably contains a compound represented by the general formula (10) (hereinafter sometimes referred to as compound (10)). The photosensitive layer preferably contains, for example, the compound (10) as a hole transport material.

In formula (10), R ¹⁰¹ , R ¹⁰² , R ¹⁰³ , R ¹⁰⁴ , R ^105, and R ¹⁰⁶ are each independently an alkyl group having 1 to 6 carbon atoms and an alkoxy group having 1 to 6 carbon atoms. Represents a group or an aryl group having 6 to 14 carbon atoms. a, b, c and d each independently represent an integer of 0 or more and 5 or less. e and f each independently represent an integer of 0 or more and 4 or less.

When a represents an integer of 2 or more and 5 or less, a plurality of R ¹⁰¹ may be the same or different from each other. When b represents an integer of 2 or more and 5 or less, a plurality of R ^{102 s} may be the same or different from each other. When c represents an integer of 2 or more and 5 or less, a plurality of R ¹⁰³ may be the same as or different from each other. When d represents an integer of 2 or more and 5 or less, a plurality of R ¹⁰⁴ may be the same as or different from each other. When e represents an integer of 2 or more and 4 or less, a plurality of R ^{105 s} may be the same as or different from each other. When f represents an integer of 2 or more and 4 or less, a plurality of R ¹⁰⁶ may be the same as or different from each other.

In formula (10), R ¹⁰¹ , R ¹⁰² , R ¹⁰³ , R ¹⁰⁴ , R ¹⁰⁵ and R ¹⁰⁶ each independently preferably represent an alkyl group having 1 to 6 carbon atoms, and 1 carbon atom. More preferably, it represents an alkyl group of 3 or less, and more preferably a methyl group. It is preferable that each of a, b, c and d independently represents 0 or 1, and more preferably 1. Each of e and f independently represents 0 or 1, and more preferably represents 1.

Suitable examples of the compound (10) include a compound represented by the following chemical formula (10-1) (hereinafter sometimes referred to as compound (10-1)).

The photosensitive layer may contain only the compound (10) as a hole transport material. The content of the compound (10) is preferably 80% by mass or more, more preferably 90% by mass or more, and particularly preferably 100% by mass, based on the mass of the hole transport material.

The content of the hole transport agent contained in the photosensitive layer is preferably 10 parts by mass or more and 200 parts by mass or less, and more preferably 10 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the binder resin. More preferable.

(Binder resin)
Examples of the binder resin include thermoplastic resins, thermosetting resins, and photocurable resins. Examples of the thermoplastic resin include polycarbonate resin, polyarylate resin, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-maleic acid copolymer, acrylic acid polymer, styrene-acrylic acid copolymer, Polyethylene resin, ethylene-vinyl acetate copolymer, chlorinated polyethylene resin, polyvinyl chloride resin, polypropylene resin, ionomer resin, vinyl chloride-vinyl acetate copolymer, alkyd resin, polyamide resin, urethane resin, polysulfone resin, diallyl phthalate Examples thereof include resins, ketone resins, polyvinyl butyral resins, polyester resins and polyether resins. Examples of the thermosetting resin include silicone resin, epoxy resin, phenol resin, urea resin and melamine resin. Examples of the photocurable resin include acrylic acid adducts of epoxy compounds and acrylic acid adducts of urethane compounds. The photosensitive layer may contain only one kind of these binder resins, or may contain two kinds or more.

Among these resins, the polycarbonate resin is preferable because it provides a photosensitive layer having an excellent balance of processability, mechanical properties, optical properties, and abrasion resistance. Examples of the polycarbonate resin include bisphenol ZC type polycarbonate resin, bisphenol C type polycarbonate resin, bisphenol A type polycarbonate resin and bisphenol Z type polycarbonate resin. The bisphenol Z type polycarbonate resin is a polycarbonate resin having a repeating unit represented by the following chemical formula (20). Hereinafter, a polycarbonate resin having a repeating unit represented by the chemical formula (20) may be referred to as a polycarbonate resin (20).

(Additive)
Examples of the additives include deterioration inhibitors (for example, antioxidants, radical scavengers, singlet quenchers or ultraviolet absorbers), softeners, surface modifiers, extenders, thickeners, dispersion stabilizers. , Waxes, acceptors, donors, surfactants, plasticizers, sensitizers and leveling agents. Examples of the antioxidant include hindered phenol (for example, di(tert-butyl)p-cresol), hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroindanone or their derivatives, organic sulfur compounds and An organic phosphorus compound is mentioned.

<Conductive substrate>
The conductive substrate is not particularly limited as long as it can be used as the conductive substrate of the photoconductor. At least the surface portion of the conductive substrate may be made of a material having conductivity. An example of the conductive substrate is a conductive substrate formed of a material having conductivity. Another example of the conductive substrate is a conductive substrate coated with a material having conductivity. 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 aluminum alloy is preferable because the transfer of charges 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 and a drum shape. Moreover, the thickness of the conductive substrate is appropriately selected according to the shape of the conductive substrate.

<Middle layer>
The intermediate layer (undercoat layer) contains, for example, inorganic particles and a resin used for the intermediate layer (resin for intermediate layer). It is considered that the presence of the intermediate layer makes it possible to smooth the flow of a current generated when the photosensitive member is exposed and suppress an increase in resistance while maintaining an insulating state to the extent that leakage can be suppressed.

Examples of the inorganic particles include particles of metal (for example, aluminum, iron or copper), particles of metal oxide (for example, titanium oxide, alumina, zirconium oxide, tin oxide or zinc oxide) and non-metal oxide (for example, silica). Particles. These inorganic particles may be used alone or in combination of two or more.

The intermediate layer resin is not particularly limited as long as it can be used as a resin forming the intermediate layer. The intermediate layer may contain an additive. The examples of the additives contained in the intermediate layer are the same as the examples of the additives contained in the photosensitive layer.

<Method for manufacturing photoconductor>
The photoconductor is manufactured as follows, for example. The photoconductor is manufactured by applying a coating solution for a photosensitive layer on a conductive substrate and drying. The coating liquid for the photosensitive layer is produced by dissolving or dispersing in a solvent a charge generating agent, an electron transfer agent, and optionally added components (for example, a hole transfer agent, a binder resin and an additive). ..

The solvent contained in the photosensitive layer coating liquid is not particularly limited as long as it can dissolve or disperse each component contained in the coating liquid. Examples of the solvent include alcohols (for example, methanol, ethanol, isopropanol or butanol), aliphatic hydrocarbons (for example, n-hexane, octane or cyclohexane), aromatic hydrocarbons (for example, benzene, toluene or xylene), Halogenated hydrocarbons (for example, dichloromethane, dichloroethane, carbon tetrachloride or chlorobenzene), ethers (for example, dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether or propylene glycol monomethyl ether), ketones (for example, acetone, Methyl ethyl ketone or cyclohexanone), esters (eg ethyl acetate or methyl acetate), dimethylformaldehyde, dimethylformamide and dimethylsulfoxide. One of these solvents may be used alone, or two or more thereof may be used in combination. A non-halogen solvent (a solvent other than a halogenated hydrocarbon) is preferably used as the solvent in order to improve workability during the production of the photoreceptor.

The coating liquid is prepared by mixing the components and dispersing them in a solvent. For mixing or dispersing, for example, a bead mill, roll mill, ball mill, attritor, paint shaker or ultrasonic disperser can be used.

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

The method for applying the coating liquid for the photosensitive layer is not particularly limited as long as it is a method capable of uniformly applying the coating liquid on the conductive substrate. Examples of the coating method include a blade coating method, a dip coating method, a spray coating method, a spin coating method and a bar coating method.

The method of drying the photosensitive layer coating liquid is not particularly limited as long as the solvent in the coating liquid can be evaporated. For example, a method of heat treatment (hot air drying) using a high temperature dryer or a reduced pressure dryer can be mentioned. 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.

The method for producing the photoreceptor may further include one or both of the step of forming the intermediate layer and the step of forming the protective layer, if necessary. In the step of forming the intermediate layer and the step of forming the protective layer, known methods are appropriately selected.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is in no way limited to the scope of the examples.

<Material for forming photosensitive layer>
As materials for forming the photosensitive layer of the photoreceptor, the following charge generating agent, hole transporting agent, binder resin and electron transporting agent were prepared.

(Charge generating agent)
Y-type titanyl phthalocyanine and X-type metal-free phthalocyanine were prepared as charge generating agents. The Y-type titanyl phthalocyanine was represented by the chemical formula (CGM1) described in the embodiment and was a titanyl phthalocyanine having a Y-type crystal structure. The X-type metal-free phthalocyanine was a metal-free phthalocyanine represented by the chemical formula (CGM2) described in the embodiment and having an X-type crystal structure.

(Hole transfer agent)
The compound (10-1) described in the embodiment was prepared as a hole transport material.

(Binder resin)
As the binder resin, the polycarbonate resin (20) described in the embodiment was prepared. The viscosity average molecular weight of the polycarbonate resin (20) was 50,000.

(Electronic transport material)
Compounds (1-1) to (1-4) described in the embodiment were prepared as electron transfer agents. Each of the compounds (1-1) to (1-4) was synthesized by the following method. In addition, the compounds represented by the chemical formulas (A-1), (B-1), (B-2), (B-3) and (C-1) described below are respectively compound (A-1) , (B-1), (B-2), (B-3) and (C-1). In addition, the yield of each compound was obtained by conversion into molar ratio.

(Synthesis of Compound (1-1))
Compound (1-1) was synthesized according to the reaction represented by reaction formula (r-1) (hereinafter referred to as reaction (r-1)).

In reaction (r-1), compound (A-1) and compound (B-1) were reacted to obtain compound (1-1). Specifically, 0.203 g (0.62 mmol) of compound (A-1) and aluminum chloride (0.491 g, 3.69 mmol) were dissolved in 1,2-dichlorobenzene (10 mL) to prepare 1,2-dichlorobenzene. A chlorobenzene solution was obtained. The 1,2-dichlorobenzene solution was stirred at room temperature (25°C) for 5 minutes under a nitrogen gas atmosphere. To the 1,2-dichlorobenzene solution, 1.05 g (12.4 mmol) of compound (B-1) was added and stirred at 180°C for 12 hours. After stirring for 12 hours, chloroform (150 mL) was added to the 1,2-dichlorobenzene solution and filtered through Celite to obtain a filtrate. The filtrate was evaporated under reduced pressure to give a residue. The residue was purified by silica gel column chromatography using chloroform as a developing solvent. Thereby, the compound (1-1) was obtained. The yield of compound (1-1) was 0.184 g. The yield of the compound (1-1) from the compound (A-1) was 70%.

(Synthesis of Compound (1-3))
The same method as in the synthesis of the compound (1-1) except that the following compound (B-2) 2.00 g (12.4 mmol) was added instead of the compound (B-1) 1.05 g (12.4 mmol). , Compound (1-3) were synthesized. The yield of compound (1-3) was 0.214 g. The yield of the compound (1-3) from the compound (A-1) was 60%.

(Synthesis of Compound (1-4))
The same method as in the synthesis of the compound (1-1) except that the following compound (B-3) 2.29 g (12.4 mmol) was added instead of the compound (B-1) 1.05 g (12.4 mmol). , Compound (1-4) was synthesized. The yield of compound (1-4) was 0.251 g. The yield of the compound (1-4) from the compound (A-1) was 65%.

(Synthesis of Compound (1-2))
Compound (1-2) is synthesized according to the reactions represented by the reaction formulas (r-2) and (r-3) (hereinafter, referred to as reaction (r-2) and reaction (r-3), respectively). did.

In reaction (r-2), compound (1-1) and bromine were reacted to obtain compound (C-1). Specifically, 0.310 g (0.730 mmol) of compound (1-1) was dissolved in 10 mL of concentrated sulfuric acid to obtain a concentrated sulfuric acid solution. 7 mg (0.027 mmol) of iodine was added to the concentrated sulfuric acid solution, and the mixture was stirred at 55°C for 5 hours. After stirring for 5 hours, 0.08 mL (1.63 mmol) of bromine was added to the concentrated sulfuric acid solution, and the mixture was stirred at 85°C for 12 hours. After stirring for 12 hours, water (50 mL) was added to the concentrated sulfuric acid solution to precipitate a solid. The precipitated solid was taken out by filtration to obtain the compound (C-1). The compound (C-1) was used for the reaction (r-3) without purification.

In the reaction (r-3), the total amount of the compound (C-1) obtained in the reaction (r-2) and copper cyanide (0.484 g, 5.4 mmol) were combined with N,N-dimethylformamide ( It was dissolved in DMF (50 mL) to obtain a DMF solution. The DMF solution was stirred at 150° C. for 6 hours under a nitrogen gas atmosphere. After stirring for 6 hours, the resulting solid was taken out by filtration. The extracted solid was purified by silica gel column chromatography using chloroform as a developing solvent. Thereby, the compound (1-2) was obtained. The yield of compound (1-2) was 0.173 g. The two-step yield of compound (1-2) from compound (1-1) was 50%.

Next, with reference to ¹ H-NMR (proton nuclear magnetic resonance spectroscopy), was analyzed by ¹ H-NMR spectrum of the compound (1-1) to (1-4). The magnetic field strength was set to 300 MHz. Deuterated chloroform (CDCl ₃ ) was used as a solvent. Tetramethylsilane (TMS) was used as an internal standard. As typical examples of the compounds (1-1) to (1-4), the chemical shift values of the ¹ H-NMR spectrum of the compound (1-1) are shown below. From the measured ¹ H-NMR spectrum chemical shift value, it was confirmed that the compound (1-1) was obtained. Also for the compounds (1-2) to (1-4), it is confirmed that each of the compounds (1-2) to (1-4) is obtained from the measured chemical shift value of the ¹ H-NMR spectrum. confirmed.

Compound (1-1): ¹ H-NMR (300 MHz, CDCl ₃ ) δ=9.37 (d, 2H), 8.64 (d, 2H), 8.44 (d, 2H), 4.72 ( m, 2H), 1.62 (d, 12H).

A compound represented by the following chemical formula (E-1) (hereinafter referred to as compound (E-1)) was also prepared as an electron transfer agent used in Comparative Examples.

<Manufacture of photoconductor>
Each of the photoconductors (A-1) to (A-8) and (B-1) to (B-2) was manufactured using the material for forming the photosensitive layer.

(Production of Photoreceptor (A-1))
In the container, 2 parts by mass of X-type metal-free phthalocyanine as a charge generating agent, 50 parts by mass of compound (10-1) as a hole transferring material, 30 parts by mass of compound (1-1) as an electron transferring material, and a binder. 100 parts by mass of a polycarbonate resin (20) as a resin and 600 parts by mass of tetrahydrofuran as a solvent were added. The contents of the container were mixed with a ball mill for 12 hours to disperse the material in the solvent. As a result, a photosensitive layer coating liquid was obtained. The photosensitive layer coating solution was applied onto a conductive substrate (aluminum drum-shaped support, diameter 30 mm, total length 238.5 mm) using a blade coating method. The applied photosensitive layer coating solution was dried with hot air at 120° C. for 80 minutes. As a result, a single photosensitive layer (thickness 30 μm) was formed on the conductive substrate. As a result, a photoconductor (A-1) was obtained.

(Production of Photoreceptors (A-2) to (A-8) and (B-1) to (B-2))
Each of the photoconductors (A-2) to (A-8) and (B-1) to (B-2) was produced in the same manner as in the production of the photoconductor (A-1) except that the following points were changed. Was manufactured. In the production of the photoconductor (A-1), X-type metal-free phthalocyanine was used as the charge generating agent, but the photoconductors (A-2) to (A-8) and (B-1) to (B-2) were used. In each of the above, the charge generating agents of the types shown in Table 1 were used. The compound (1-1) was used as an electron transfer agent in the production of the photoconductor (A-1), but the photoconductors (A-2) to (A-8) and (B-1) to (B-2). In each of the preparations (1) to (4), electron transfer agents of the types shown in Table 1 were used.

<Evaluation of sensitivity characteristics>
The sensitivity characteristics of each of the photoconductors (A-1) to (A-8) and (B-1) to (B-2) were evaluated. The evaluation of the sensitivity characteristics was performed in an environment of a temperature of 23° C. and a relative humidity of 50% RH. First, the surface of the photoconductor was charged to +600 V using a drum sensitivity tester (manufactured by Gentec Co., Ltd.). Then, using a bandpass filter, monochromatic light (wavelength 780 nm, half width 20 nm, light energy 1.5 μJ/cm ² ) was extracted from the white light of the halogen lamp. The extracted monochromatic light was applied to the surface of the photoreceptor. The surface potential of the photoreceptor was measured when 50 milliseconds had elapsed after the irradiation was completed. The measured surface potential was used as the potential after exposure ( _VL , unit: +V). The measured post-exposure potential ( _VL ) of the photoconductor is shown in Table 1. It should be noted that the smaller the post-exposure potential ( _VL ) is, the more positive the sensitivity value of the photoconductor (particularly the sensitivity property to exposure light) is.

<Evaluation of the presence or absence of crystallization>
The entire surface (photosensitive layer) of each of the photoconductors (A-1) to (A-8) and (B-1) to (B-2) was visually observed. Then, the presence or absence of a crystallized portion in the photosensitive layer was confirmed. The confirmation results are shown in Table 1.

In Table _{1, CGM, ETM, V L} , X-H 2 Pc, and Y-TiOPc shows each electric charge generating material, electron transferring material, the potential after exposure, X-type metal-free phthalocyanine, and a Y-type titanyl phthalocyanine .. In Table 1, "None" indicates that a crystallized portion was not confirmed in the photosensitive layer, and "Slightly crystallized" indicates that a crystallized portion was slightly confirmed in the photosensitive layer.

The photoconductors (A-1) to (A-8) each had a conductive base and a single-layered photosensitive layer. The photosensitive layer contained at least a charge generating agent and the compound (1). Specifically, the photosensitive layer contained any of the compounds (1-1) to (1-4) included in the general formula (1). Therefore, as is clear from Table 1, in the photoconductors (A-1) to (A-8), the post-exposure potential was a small positive value, and the photoconductors had excellent sensitivity characteristics. In the photoconductors (A-1) to (A-8), no crystallized portion was observed in the photosensitive layer, and crystallization of the photosensitive layer was suppressed.

On the other hand, the photosensitive layers of the photoconductors (B-1) to (B-2) did not contain the compound (1). Specifically, the photosensitive layers of the photoconductors (B-1) to (B-2) contained the compound (E-1), but the compound (E-1) is included in the general formula (1). It wasn't a compound. Therefore, as is clear from Table 1, in the photoconductors (B-1) to (B-2), the post-exposure potential was a large positive value, and the photoconductors had poor sensitivity characteristics. In photoconductors (B-1) to (B-2), some crystallized portions were observed in the photosensitive layer, and crystallization of the photosensitive layer was not suppressed.

From the above, it was shown that the photoreceptor according to the present invention has excellent sensitivity characteristics.

The photoconductor according to the present invention can be used in an image forming apparatus.

Claims (9)

Comprises a conductive substrate and a photosensitive layer,
The photosensitive layer is a single layer,
The photosensitive layer is an electrophotographic photosensitive member containing at least a charge generating agent and a compound represented by the general formula (1).

(In the general formula (1),
R ¹ is an aryl group having 6 to 22 carbon atoms which may have an alkyl group having 1 to 10 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, and an alkyl group having 3 to 20 carbon atoms. A cycloalkyl group, an alkoxy group having 1 to 6 carbon atoms, or an alkyl group having 3 to 20 carbon atoms which may have -CO-OR ³ is represented, and R ³ is 1 to 8 carbon atoms. Represents the following alkyl group,
R ² represents a hydrogen atom, a halogen atom, or a cyano group. ) In the general formula (1), R ¹ may have an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 22 carbon atoms, or —CO—OR ^3. The electrophotographic photosensitive member according to claim 1, wherein a good alkyl group having 3 to 20 carbon atoms is represented, and R ³ is an alkyl group having 1 to 8 carbon atoms. The electrophotographic photosensitive member according to claim 1, wherein R ² in the general formula (1) represents a hydrogen atom or a cyano group. The electrophotographic photosensitive member according to claim 1, wherein in the general formula (1), R ² represents a cyano group. The compound represented by the general formula (1) is a compound represented by the chemical formula (1-1), (1-2), (1-3), or (1-4). The electrophotographic photosensitive member described.

The electrophotographic photoreceptor according to claim 5, wherein the compound represented by the general formula (1) is a compound represented by the chemical formula (1-2). The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer further contains a compound represented by the general formula (10).

(In the general formula (10), R ¹⁰¹ , R ¹⁰² , R ¹⁰³ , R ¹⁰⁴ , R ¹⁰⁵ and R ¹⁰⁶ each independently represent an alkyl group having 1 to 6 carbon atoms, and an alkyl group having 1 to 6 carbon atoms. Represents an alkoxy group or an aryl group having 6 to 14 carbon atoms,
a, b, c and d each independently represent an integer of 0 or more and 5 or less,
e and f each independently represent an integer of 0 or more and 4 or less. ) The electrophotographic photoreceptor according to claim 7, wherein the compound represented by the general formula (10) is a compound represented by the chemical formula (10-1).

The electrophotographic photoreceptor according to claim 1, wherein the photosensitive layer further contains a polycarbonate resin having a repeating unit represented by the chemical formula (20).

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