JP6747514B2 - Electrophotographic photoreceptor, process cartridge and image forming apparatus - Google Patents

Description

The present invention relates to an electrophotographic photosensitive member, a process cartridge and an image forming apparatus.

The electrophotographic photosensitive member is used in an electrophotographic image forming apparatus. As the electrophotographic photosensitive member, for example, an electrophotographic photosensitive member having a single photosensitive layer is used. The single photosensitive layer has a charge generating function and a charge transporting function.

The electrophotographic photoreceptor described in Patent Document 1 includes a photosensitive layer. As an example of the resin contained in the photosensitive layer, a polyarylate resin represented by the chemical formula (RD) is disclosed.

JP, 2007-121751, A

However, the electrophotographic photosensitive member including the photosensitive layer containing the polyarylate resin represented by the chemical formula (RD) described in Patent Document 1 has not been improved in abrasion resistance, scratch resistance and filming resistance. There is room for improvement.

The present invention has been made in view of the above problems, and an object thereof is to provide an electrophotographic photoreceptor having excellent wear resistance, scratch resistance, and filming resistance. Further, an object of the present invention is to provide a process cartridge and an image forming apparatus capable of suppressing the occurrence of image defects in a formed image by including such an electrophotographic photosensitive member.

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 a charge generating agent, a hole transfer agent, an electron transfer agent, filler particles, and a binder resin. The filler particles include resin particles. The binder resin contains a polyarylate resin represented by the following general formula (1).

In the general formula (1), kr and kt each independently represent 2 or 3. r and s each independently represent a number of 0 or more and 49 or less. t and u each independently represent a number of 1 or more and 50 or less. r+s+t+u=100. r+t=s+u. X and Y are each independently the following chemical formulas (1-1), (1-2), (1-3), (1-4), (1-5), (1-6) or (1-. It represents a divalent group represented by 7).

A process cartridge of the present invention includes the above-mentioned electrophotographic photosensitive member.

The image forming apparatus of the present invention includes an electrophotographic photosensitive member, a charging section, an exposing section, a developing section, and a transfer section. The charging section charges the surface of the electrophotographic photosensitive member. The exposure unit exposes the charged surface of the electrophotographic photosensitive member to form an electrostatic latent image on the surface of the electrophotographic photosensitive member. The developing unit develops the electrostatic latent image as a toner image. The transfer unit transfers the toner image from the electrophotographic photosensitive member to a transfer target member. The charging section charges the surface of the electrophotographic photosensitive member to a positive polarity. The electrophotographic photoreceptor is the electrophotographic photoreceptor described above.

According to the electrophotographic photoreceptor of the present invention, abrasion resistance, scratch resistance and filming resistance can be improved. Further, according to the process cartridge and the image forming apparatus of the present invention, by including such an electrophotographic photosensitive member, it is possible to suppress the occurrence of image defects in a formed image.

1 is a schematic cross-sectional view showing an example of an electrophotographic photosensitive member according to an exemplary embodiment of the present invention. 1 is a schematic cross-sectional view showing an example of an electrophotographic photosensitive member according to an exemplary embodiment of the present invention. 1 is a schematic cross-sectional view showing an example of an electrophotographic photosensitive member according to an exemplary embodiment of the present invention. FIG. 3 is a diagram showing an example of the configuration of an image forming apparatus, which includes the electrophotographic photosensitive member according to the exemplary embodiment of the present invention. FIG. 8 is a diagram showing another example of the configuration of the image forming apparatus, which includes the electrophotographic photosensitive member according to the exemplary embodiment of the present invention. ^{1 is} a ¹ H-NMR spectrum of a polyarylate resin represented by the chemical formula (R-2). ^{1 is} a ¹ H-NMR spectrum of a polyarylate resin represented by the chemical formula (R-4). ^{1 is} a ¹ H-NMR spectrum of a polyarylate resin represented by the chemical formula (R-5).

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.

Hereinafter, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 5 carbon atoms, an alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 3 carbon atoms, carbon Unless otherwise specified, an alkoxy group having 1 to 6 atoms, an alkoxy group having 1 to 3 carbon atoms, and an aryl group having 6 to 14 carbon atoms have the following meanings.

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

The alkyl group having 1 to 6 carbon atoms, the alkyl group having 1 to 5 carbon atoms, the alkyl group having 1 to 4 carbon atoms and the alkyl group having 1 to 3 carbon atoms are each linear. Alternatively, it is branched and 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, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl. Group, neopentyl group, 1,2-dimethylpropyl group or hexyl group. Examples of the alkyl group having 1 to 5 carbon atoms are groups having 1 to 5 carbon atoms among the groups described as examples of the alkyl group having 1 to 6 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms are groups having 1 to 4 carbon atoms among the groups described as examples of the alkyl group having 1 to 6 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 6 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 14 carbon atoms is, for example, an unsubstituted aromatic monocyclic hydrocarbon group having 6 to 14 carbon atoms, 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 elementary 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.

<Electrophotographic photoreceptor>
This embodiment relates to an electrophotographic photosensitive member (hereinafter referred to as a photosensitive member). The photoconductor of this embodiment has excellent wear resistance, scratch resistance, and filming resistance. The reason is presumed as follows.

The photosensitive layer of the photoreceptor of this embodiment contains resin particles as filler particles. The resin particles form irregularities on the surface of the photosensitive layer. By forming irregularities on the surface of the photosensitive layer, the contact area between the cleaning unit (for example, a cleaning blade) included in the image forming apparatus and the photosensitive layer of the photosensitive member is reduced. As a result, the surface of the photosensitive layer can be smoothly cleaned by the cleaning unit. As a result, scratch resistance and filming resistance of the photoconductor can be improved.

Further, the photosensitive layer of the photoreceptor of the exemplary embodiment contains a polyarylate resin represented by the general formula (1) (hereinafter, also referred to as polyarylate resin (1)) as a binder resin. The polyarylate resin (1) has high hardness. By including both the polyarylate resin (1) having high hardness and the resin particles in the photosensitive layer, it is possible to prevent the photosensitive layer from abrading due to contact with the cleaning portion provided in the image forming apparatus. It is possible to prevent the resin particles from being detached from the photosensitive layer. As a result, the wear resistance, scratch resistance and filming resistance of the photoconductor can be improved.

The structure of the photoconductor 100 will be described below with reference to FIGS. 1A to 1C. 1A to 1C are schematic cross-sectional views each showing an example of the photoconductor 100 according to the present embodiment.

As shown in FIG. 1A, the photoconductor 100 includes, for example, a conductive substrate 101 and a photosensitive layer 102. The photosensitive layer 102 is a single layer. The photoconductor 100 is a so-called single-layer type photoconductor including a single photosensitive layer 102.

As shown in FIG. 1B, the photoreceptor 100 may include a conductive substrate 101, a photosensitive layer 102, and an intermediate layer 103 (undercoat layer). The intermediate layer 103 is provided between the conductive substrate 101 and the photosensitive layer 102. As shown in FIG. 1A, the photosensitive layer 102 may be directly provided on the conductive substrate 101, or as shown in FIG. 1B, the photosensitive layer 102 is indirectly provided on the conductive substrate 101 via the intermediate layer 103. May be provided.

As shown in FIG. 1C, the photoreceptor 100 may include a conductive substrate 101, a photosensitive layer 102, and a protective layer 104. The protective layer 104 is provided on the photosensitive layer 102. When the photoconductor 100 includes the protective layer 104, the protective layer 104 is provided on the photosensitive layer 102. Since the photosensitive layer 102 is excellent in abrasion resistance, scratch resistance, and filming resistance, the photoconductor 100 may not include the protective layer. For the same reason, the photosensitive layer 102 can be provided as the outermost surface layer of the photoreceptor 100.

The thickness of the photosensitive layer 102 is not particularly limited as long as the function as the photosensitive layer can be sufficiently exhibited. The thickness of the photosensitive layer 102 is preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less. In order to improve the sensitivity characteristics of the photoconductor 100, it is preferable to charge the surface of the photoconductor 100 with a positive polarity to form an image. That is, the photoconductor 100 is preferably a positively charged electrophotographic photoconductor.

The structure of the photoconductor 100 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 a charge generating agent, a hole transferring material, an electron transferring material, filler particles and a binder resin. The photosensitive layer may contain an additive, if necessary. The charge generating agent, the hole transporting agent, the electron transporting agent, the filler particles, the binder resin, and a component (for example, an additive) optionally added (in the same layer) are contained in the same layer.

(Binder resin)
The binder resin contains polyarylate resin (1). When the binder resin contains the polyarylate resin (1), the abrasion resistance of the photoconductor can be improved. As the polyarylate resin (1), one type may be used alone, or two or more types may be used in combination.

In the general formula (1), kr and kt each independently represent 2 or 3. r and s each independently represent a number of 0 or more and 49 or less. t and u each independently represent a number of 1 or more and 50 or less. r+s+t+u=100. r+t=s+u. X and Y are each independently the following chemical formulas (1-1), (1-2), (1-3), (1-4), (1-5), (1-6) or (1-. It represents a divalent group represented by 7).

X and Y may be the same as or different from each other. It is preferable that X and Y are different from each other. Further, a preferred example of the divalent group represented by the chemical formula (1-4) is a divalent group represented by the chemical formula (1-4′).

kr and kt may be the same or different from each other. When kr and kt are different from each other, one of kr and kt represents 2, and the other of kr and kt represents 3. kr and kt represent 2 or 3, and preferably represent the same number as each other. More preferably, kr and kt each represent 3.

The polyarylate resin (1) includes a repeating unit represented by the chemical formula (1-a) (hereinafter, also referred to as repeating unit (1-a)) and a repeating unit represented by the general formula (1-b). A unit (hereinafter sometimes referred to as a repeating unit (1-b)), a repeating unit represented by the general formula (1-c) (hereinafter sometimes referred to as a repeating unit (1-c)), and It has a repeating unit represented by the general formula (1-d) (hereinafter sometimes referred to as a repeating unit (1-d)).

In general formulas (1-a) to (1-d), kr, X, kt and Y have the same meanings as kr, X, kt and Y in general formula (1), respectively.

The arrangement of the repeating units (1-a) to (1-d) in the polyarylate resin (1) is not particularly limited as long as the repeating unit derived from the aromatic diol and the repeating unit derived from the aromatic dicarboxylic acid are adjacent to each other. .. The repeating units derived from the aromatic diol are the repeating units (1-a) and (1-c). The repeating units derived from the aromatic dicarboxylic acid are the repeating units (1-b) and (1-d). For example, the repeating unit (1-a) is adjacent to and bonded to the repeating unit (1-b) or the repeating unit (1-d). Further, the repeating unit (1-c) is adjacent to the repeating unit (1-b) or the repeating unit (1-d) and is bonded to each other.

In the general formula (1), r and s each independently represent a number of 0 or more and 49 or less, and t and u each independently represent a number of 1 or more and 50 or less. Examples of the numbers represented by r, s, t, and u include integers and decimals. It is preferable that r represents a number of 0 or more and 25 or less. It is preferable that s represents a number of 0 or more and 25 or less. It is preferable that t represents a number of 25 or more and 50 or less. u preferably represents a number of 25 or more and 50 or less. r and s may be the same or different from each other. r and u may be the same as or different from each other. t and s may be the same or different from each other. t and u may be the same as or different from each other. s and u may be the same as or different from each other. It is preferable that s and u are different from each other.

r is the number of repeating units (1-a), the number of repeating units (1-b), the number of repeating units (1-c) and the repeating units (1-d) contained in the polyarylate resin (1). Represents the percentage of the number of repeating units (1-a) with respect to the total number of s is the number of repeating units (1-a), the number of repeating units (1-b), the number of repeating units (1-c) and the repeating units (1-d) contained in the polyarylate resin (1). It represents the percentage of the number of repeating units (1-b) with respect to the total number. t is the number of repeating units (1-a), the number of repeating units (1-b), the number of repeating units (1-c) and the repeating units (1-d) contained in the polyarylate resin (1). Represents the percentage of the number of repeating units (1-c) with respect to the total number of u is the number of repeating units (1-a), the number of repeating units (1-b), the number of repeating units (1-c) and the repeating units (1-d) contained in the polyarylate resin (1). Represents the percentage of the number of repeating units (1-d) with respect to the total number of Note that r, s, t, and u are not the values obtained from one resin chain, but the number average values obtained from the entire polyarylate resin (1) (a plurality of resin chains) contained in the photosensitive layer. Is.

R, s, t, and u in the general formula (1) satisfy the calculation formula “r+s+t+u=100” and the calculation formula “r+t=s+u”.

r/(r+t) is preferably 0.00, or 0.30 or more and 0.70 or less. r/(r+t) is the ratio (moles) of the number of repeating units (1-a) to the total number of repeating units (1-a) and the number of repeating units (1-c) in the polyarylate resin (1). Fraction). When r/(r+t) is 0.00, r represents 0 and t represents 50.

s/(s+u) is preferably 0.00 or 0.30 or more and 0.70 or less. s/(s+u) is the ratio (moles) of the number of repeating units (1-b) to the total number of repeating units (1-b) and repeating units (1-d) in the polyarylate resin (1). Fraction). When s/(s+u) represents 0.00, s represents 0 and u represents 50.

The total content of the repeating units (1-a), (1-b), (1-c) and (1-d) with respect to the substance amount (mol number) of all the repeating units in the polyarylate resin (1) is It is preferably 80 mol% or more, more preferably 90 mol% or more, and particularly preferably 100 mol%. The total content of the repeating units (1-a), (1-b), (1-c) and (1-d) is 100 mols based on the amount (mole number) of all repeating units in the polyarylate resin (1). %, the polyarylate resin (1) has only repeating units (1-a), (1-b), (1-c) and (1-d) as repeating units.

When r and s are not 0 respectively, X and Y preferably represent the following groups in order to improve the wear resistance, scratch resistance and filming resistance of the photoconductor. One of X and Y represents a divalent group represented by the chemical formula (1-1), and the other of X and Y represents a divalent group represented by the chemical formula (1-2). Alternatively, one of X and Y represents a divalent group represented by the chemical formula (1-1), and the other of X and Y represents a divalent group represented by the chemical formula (1-4). Alternatively, one of X and Y represents a divalent group represented by the chemical formula (1-2), and the other of X and Y represents a divalent group represented by the chemical formula (1-4). Alternatively, one of X and Y represents a divalent group represented by the chemical formula (1-3), and the other of X and Y represents a divalent group represented by the chemical formula (1-4). Alternatively, one of X and Y represents a divalent group represented by the chemical formula (1-5), and the other of X and Y represents a divalent group represented by the chemical formula (1-6).

When r and s are not 0 respectively, it is more preferable that X and Y represent the following groups in order to improve the wear resistance, scratch resistance and filming resistance of the photoconductor. One of X and Y represents a divalent group represented by the chemical formula (1-1), and the other of X and Y represents a divalent group represented by the chemical formula (1-2). Alternatively, one of X and Y represents a divalent group represented by the chemical formula (1-1), and the other of X and Y represents a divalent group represented by the chemical formula (1-4). Alternatively, one of X and Y represents a divalent group represented by the chemical formula (1-2), and the other of X and Y represents a divalent group represented by the chemical formula (1-4). Alternatively, one of X and Y represents a divalent group represented by the chemical formula (1-3), and the other of X and Y represents a divalent group represented by the chemical formula (1-4).

When r and s each represent 0, Y is represented by the chemical formula (1-1) or (1-3) in order to improve the wear resistance, scratch resistance and filming resistance of the photoconductor. It is preferable to represent a divalent group.

When the repeating unit (1-a) has the same chemical structure as the repeating unit (1-c), kr and kt represent the same number. When kr and kt represent the same number, the polyarylate resin represented by the general formula (1) is preferably the polyarylate resin represented by the general formula (1′).

In the general formula (1′), kv represents 2 or 3. Two kv's represent the same number. X and Y are each independently a chemical formula (1-1), (1-2), (1-3), (1-4), (1-5), (1-6) or (1-7). ) Represents a divalent group. v+w=1.00. v/(v+w) is 0.00 or 0.30 or more and 0.70 or less.

The polyarylate resin represented by the general formula (1′) includes a repeating unit represented by the chemical formula (1′-a) (hereinafter, also referred to as a repeating unit (1′-a)), and a general formula It has a repeating unit represented by (1′-b) (hereinafter sometimes referred to as a repeating unit (1′-b)).

In general formula (1′), v represents the ratio (molar fraction) of the number of repeating units (1′-a) to the total number of repeating units (1′-a) and (1′-b). .. w represents the ratio (molar fraction) of the number of repeating units (1'-b) to the total number of repeating units (1'-a) and (1'-b). When v/(v+w) represents 0.00, the polyarylate resin represented by the general formula (1′) does not have the repeating unit (1′-a) but the repeating unit (1′-b). ) Only.

Of the total amount (moles) of repeating units (1′-a) and (1′-b) with respect to the amount (moles) of all repeating units in the polyarylate resin represented by the general formula (1′). The ratio (molar fraction) is preferably 80 mol% or more, more preferably 90 mol% or more, and particularly preferably 100 mol%. Of the total amount (moles) of repeating units (1′-a) and (1′-b) with respect to the amount (moles) of all repeating units in the polyarylate resin represented by the general formula (1′). When the ratio (molar fraction) is 100 mol %, the polyarylate resin represented by the general formula (1′) has only repeating units (1′-a) and (1′-b) as repeating units. Have. The case where the repeating unit (1-a) has the same chemical structure as the repeating unit (1-c) has been described above.

Suitable examples of the polyarylate resin (1) include chemical formulas (R-1), (R-2), (R-3), (R-4), (R-5), (R-6) and (R-6). It is a polyarylate resin represented by R-7) or (R-8). Hereinafter, chemical formulas (R-1), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8). Each of the polyarylate resins represented by the following formulas is a polyarylate resin (R-1), (R-2), (R-3), (R-4), (R-5), (R-6), It may be described as (R-7) and (R-8).

In order to improve the abrasion resistance, scratch resistance and filming resistance of the photoconductor, as well as to improve the solubility of the polyarylate resin (1) in the solvent for forming the photosensitive layer, the general formula (1) is used. Is not 0 and X and Y are different from each other, s/(s+u) is 0.30 or more and 0.70 or less, and one of X and Y is the chemical formula (1-1). It is preferred to represent the divalent radicals represented. A more preferable example of such a polyarylate resin is polyarylate resin (R-4), (R-5) or (R-8).

In order to further improve the abrasion resistance of the photoconductor while improving the scratch resistance and the filming resistance of the photoconductor, r and s in the general formula (1) are not 0 each, and X and Y are Are different from each other, s/(s+u) is 0.30 or more and 0.70 or less, one of X and Y represents a divalent group represented by the chemical formula (1-1), and the other of X and Y. Preferably represents a divalent group represented by the chemical formula (1-2). A more preferable example of such polyarylate resin is polyarylate resin (R-5).

In order to improve the wear resistance, scratch resistance and filming resistance of the photoreceptor, r and s in the general formula (1) each represent 0, t and u each represent 50, and Y represents the chemical formula ( It is also preferable to represent a divalent group represented by 1-3). A more preferable example of such polyarylate resin is polyarylate resin (R-6).

In order to improve the wear resistance, scratch resistance and filming resistance of the photoconductor, r and s in the general formula (1) are not 0 respectively, and X and Y are different from each other, and s/( s+u) is 0.30 or more and 0.70 or less, one of X and Y represents a divalent group represented by the chemical formula (1-3), and the other of X and Y is the chemical formula (1-4). It is preferred to represent the divalent radicals represented. A more preferable example of such a polyarylate resin is polyarylate resin (R-7).

In order to improve the wear resistance, scratch resistance and filming resistance of the photoconductor, r and s in the general formula (1) are not 0 respectively, and X and Y are different from each other, and s/( It is preferable that s+u) is 0.30 or more and 0.70 or less, and s and u represent different numbers. For the same reason, r and s in the general formula (1) are not 0 respectively, X and Y are different from each other, s/(s+u) is 0.30 or more and 0.70 or less, and s and u Represent different numbers, one of X and Y represents a divalent group represented by the chemical formula (1-1), and the other of X and Y represents a divalent group represented by the chemical formula (1-4). Is more preferably represented. A more preferable example of such a polyarylate resin is polyarylate resin (R-8).

The viscosity average molecular weight of the polyarylate resin (1) is preferably 10,000 or more, more preferably 20,000 or more, and further preferably 30,000 or more. When the viscosity average molecular weight of the polyarylate resin (1) is 10,000 or more, the abrasion resistance of the binder resin is increased and the photosensitive layer is less likely to be worn. On the other hand, the viscosity average molecular weight of the binder resin is preferably 80,000 or less, and more preferably 51,000 or less. When the binder resin has a viscosity average molecular weight of 80,000 or less, the polyarylate resin (1) is likely to be dissolved in the solvent for forming the photosensitive layer, and the photosensitive layer tends to be easily formed.

The method for producing the polyarylate resin (1) is not particularly limited. Examples of the method for producing the polyarylate resin (1) include a method of polycondensing an aromatic diol and an aromatic dicarboxylic acid for forming a repeating unit of the polyarylate resin. The synthesis method of the polyarylate resin (1) is not particularly limited, and a known synthesis method (more specifically, solution polymerization, melt polymerization, interfacial polymerization, or the like) can be adopted.

The aromatic dicarboxylic acid for synthesizing the polyarylate resin (1) is a compound represented by the general formulas (1-e) and (1-f). X in the general formula (1-e) and Y in the general formula (1-f) have the same meanings as X and Y in the general formula (1), respectively. The aromatic dicarboxylic acid for synthesizing the polyarylate resin (1) may be used as a derivative of an aromatic dicarboxylic acid derivative. Examples of the aromatic dicarboxylic acid derivative are aromatic dicarboxylic acid dichloride, aromatic dicarboxylic acid dimethyl ester, aromatic dicarboxylic acid diethyl ester or aromatic dicarboxylic acid anhydride. Aromatic dicarboxylic acid dichlorides have two "-C(=O)-Cl" groups.

Specific examples of the compounds represented by the general formulas (1-e) and (1-f), which are aromatic dicarboxylic acids for synthesizing the polyarylate resin (1), include the following chemical formulas (1-g) to (1). -L) and compounds represented by (1-q). Hereinafter, each of the compounds represented by the chemical formulas (1-g) to (1-1) and (1-q) will be referred to as compounds (1-g) to (1-l) and (1-q). Sometimes.

A preferred example of the compound represented by the chemical formula (1-j) which is an aromatic dicarboxylic acid for synthesizing the polyarylate resin (1) is a compound represented by the following chemical formula (1-jj). Hereinafter, the compound represented by the chemical formula (1-jj) may be referred to as the compound (1-jj).

The aromatic diol for synthesizing the polyarylate resin (1) is a compound represented by the chemical formula (1-m) and the general formula (1-n). Kr in the general formula (1-m) and kt in the general formula (1-n) have the same meanings as kr and kt in the general formula (1), respectively. The aromatic diol for synthesizing the polyarylate resin (1) may be used by transforming it into an aromatic diacetate.

Specific examples of the compound represented by the chemical formula (1-m) and the general formula (1-n), which are aromatic diols for synthesizing the polyarylate resin (1), include the following chemical formulas (1-о) or (1 -P) is a compound. Hereinafter, the compounds represented by the chemical formulas (1-o) and (1-p) may be referred to as compounds (1-o) and (1-p), respectively.

The photosensitive layer may contain only the polyarylate resin (1) as a binder resin. Alternatively, the photosensitive layer may further contain, as a binder resin, a binder resin other than the polyarylate resin (1) (hereinafter sometimes referred to as other binder resin) in addition to the polyarylate resin (1). Good. The content of the polyarylate resin (1) 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 binder resin.

Examples of other binder resins include thermoplastic resins, thermosetting resins, and photocurable resins. Examples of the thermoplastic resin include a polycarbonate resin, a polyarylate resin other than the polyarylate resin (1), a styrene-butadiene copolymer, a styrene-acrylonitrile copolymer, a styrene-maleic acid copolymer, an 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, Examples thereof include urethane resin, polysulfone resin, diallyl phthalate resin, ketone resin, polyvinyl butyral resin, polyester resin and polyether resin. Examples of the thermosetting resin include silicone resin, epoxy resin, phenol resin, urea resin and melamine resin. Examples of the photocurable resin include epoxy acrylate (acrylic acid adduct of epoxy compound) or urethane-acrylate (acrylic acid adduct of urethane compound). The other binder resins may be used alone or in combination of two or more.

(Filler particles)
The filler particles include resin particles. Compared with non-resin particles (for example, silica particles or alumina particles), resin particles are less likely to impair the sensitivity characteristics of the photoreceptor. Since the photosensitive layer contains the resin particles as the filler particles, the abrasion resistance, scratch resistance and filming resistance of the photoconductor can be improved while maintaining the sensitivity characteristics of the photoconductor. The resin particles are preferably silicone resin particles.

The volume median diameter (D ₅₀ ) of the resin particles is preferably 0.05 μm or more and 5.00 μm or less, more preferably 0.50 μm or more and 5.00 μm or less, and 0.60 μm or more and 3.00 μm or less Is more preferable, and 0.70 μm or more and 2.00 μm or less is particularly preferable. When the volume median diameter of the resin particles is 0.05 μm or more and 5.00 μm or less, abrasion resistance, scratch resistance and filming resistance of the photoconductor can be further improved. The volume median diameter of the resin particles is measured using, for example, a precision particle size distribution measuring device (“Beckman Coulter Co., Ltd. “Coulter Counter Multisizer 3”). The volume median diameter means the median diameter calculated on the volume basis using the Coulter counter method.

The content of the resin particles is preferably greater than 0.0% by mass and 10.0% by mass or less, and is 0.5% by mass or more and 10.0% by mass or less, based on the mass of the photosensitive layer. It is more preferably 2.5 mass% or more and 10.0 mass% or less, still more preferably 5.0 mass% or more and 9.5 mass% or less. When the content of the resin particles is more than 0.0% by mass and 10.0% by mass or less with respect to the mass of the photosensitive layer, the abrasion resistance of the photoconductor can be further improved. Further, when the content of the resin particles is more than 0.0% by mass and 10.0% by mass or less with respect to the mass of the photosensitive layer, image defects due to irregularities on the surface of the photoconductor (for example, black spots) Dirt does not easily occur.

The resin particles preferably have a spherical shape. The spherical resin particles are less likely to aggregate in the solvent for forming the photosensitive layer than the acicular resin particles. Therefore, the photosensitive layer in which the resin particles are uniformly dispersed tends to be formed. The shape of the resin particles can be confirmed using an electron microscope.

The photosensitive layer may contain only resin particles as the filler particles. Alternatively, the photosensitive layer may further contain filler particles other than the resin particles as the filler particles, in addition to the resin particles. The content of the resin particles 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 filler particles.

(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 represented by the chemical formula (CG-1) or metal phthalocyanine. Examples of the metal phthalocyanine include titanyl phthalocyanine represented by the chemical formula (CG-2), hydroxygallium phthalocyanine, and chlorogallium phthalocyanine. 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, or 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.

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.

(Electronic transport material)
Examples of electron transfer agents include quinone compounds, diimide compounds, hydrazone compounds, thiopyran compounds, trinitrothioxanthone compounds, 3,4,5,7-tetranitro-9-fluorenone compounds, dinitroanthracene compounds. , Dinitroacridine compounds, tetracyanoethylene, 2,4,8-trinitrothioxanthone, dinitrobenzene, dinitroacridine, succinic anhydride, maleic anhydride or dibromomaleic anhydride. Examples of the quinone compound include diphenoquinone compounds, azoquinone compounds, anthraquinone compounds, naphthoquinone compounds, nitroanthraquinone compounds, and dinitroanthraquinone compounds. The electron transfer agents may be used alone or in combination of two or more.

In order to improve the abrasion resistance, scratch resistance and filming resistance of the photoconductor, the compound represented by the general formula (ET1), (ET2), (ET3), (ET4) or (ET5) is used as the electron transfer agent. Compounds are preferred. The compounds represented by the general formulas (ET1), (ET2), (ET3), (ET4) and (ET5) are respectively compound (ET1), (ET2), (ET3), (ET4) and (ET5). May be described as. The compounds (ET1), (ET2), (ET3), (ET4) and (ET5) may be used alone or in combination of two or more.

Formula (ET1), (ET2), (ET3), (ET4) and (ET5) ^{in, R 11, R 12, R} 21, R 22, R 23, R 24, R 31, R 32, R 41, R ⁴² , R ⁴³ , R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ are each independently a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, or 2 to 6 carbon atoms. Represents an alkenyl group, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 14 carbon atoms which may have at least one alkyl group having 1 to 6 carbon atoms.

R< ¹¹ >, R< ¹² >, R< ²¹ >, R< ²² >, R< ²³ >, R< ²⁴ >, R< ³¹ >, R< ³² >, R< ⁴¹ >, R<^42> , R ^<43> , R ^<51> , R ^<52 > in general formulas (ET1) to (ET5). The halogen atom represented by R ⁵³ and R ⁵⁴ is preferably a chlorine atom (chloro group).

R< ¹¹ >, R< ¹² >, R< ²¹ >, R< ²² >, R< ²³ >, R< ²⁴ >, R< ³¹ >, R< ³² >, R< ⁴¹ >, R<^42> , R ^<43> , R ^<51> , R ^<52 > in the general formulas (ET1) to (ET5). The alkyl group having 1 to 6 carbon atoms represented by R ⁵³ and R ⁵⁴ is preferably an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a tert-butyl group or 1,1-dimethylpropyl. Groups are more preferred.

R< ¹¹ >, R< ¹² >, R< ²¹ >, R< ²² >, R< ²³ >, R< ²⁴ >, R< ³¹ >, R< ³² >, R< ⁴¹ >, R<^42> , R ^<43> , R ^<51> , R ^<52 > in the general formulas (ET1) to (ET5). Examples of the alkenyl group having 2 to 6 carbon atoms represented by R ⁵³ and R ⁵⁴ include alkenyl groups having 2 to 4 carbon atoms.

R< ¹¹ >, R< ¹² >, R< ²¹ >, R< ²² >, R< ²³ >, R< ²⁴ >, R< ³¹ >, R< ³² >, R< ⁴¹ >, R<^42> , R ^<43> , R ^<51> , R ^<52 > in the general formulas (ET1) to (ET5). Examples of the alkoxy group having 1 to 6 carbon atoms represented by R ⁵³ and R ⁵⁴ include an alkoxy group having 1 to 3 carbon atoms.

R< ¹¹ >, R< ¹² >, R< ²¹ >, R< ²² >, R< ²³ >, R< ²⁴ >, R< ³¹ >, R< ³² >, R< ⁴¹ >, R<^42> , R ^<43> , R ^<51> , R ^<52 > in the general formulas (ET1) to (ET5). The aryl group having 6 to 14 carbon atoms represented by R ⁵³ and R ⁵⁴ is preferably a phenyl group. The aryl group having 6 to 14 carbon atoms may have at least one (preferably 1 or 2) alkyl group having 1 to 6 carbon atoms. As the alkyl group having 1 to 6 carbon atoms contained in the aryl group having 6 to 14 carbon atoms, an alkyl group having 1 to 3 carbon atoms is preferable, and a methyl group or an ethyl group is more preferable. The 2-ethyl-6-methylphenyl group is preferable as the aryl group having 6 to 14 carbon atoms and having at least one alkyl group having 1 to 6 carbon atoms.

In general formula (ET1), R ¹¹ and R ¹² each preferably represent an alkyl group having 1 to 6 carbon atoms, and more preferably an alkyl group having 1 to 5 carbon atoms. More preferably, it represents a 1,1-dimethylpropyl group. A preferred example of the compound (ET1) is a compound represented by the chemical formula (ET1-1) (hereinafter sometimes referred to as compound (ET1-1)).

In formula (ET2), R ²¹ , R ²² , R ²³ and R ²⁴ each preferably represent an alkyl group having 1 to 6 carbon atoms, and an alkyl group having 1 to 4 carbon atoms. Is more preferable, and a methyl group or a tert-butyl group is more preferable. A preferred example of the compound (ET2) is a compound represented by the chemical formula (ET2-1) (hereinafter sometimes referred to as compound (ET2-1)).

In formula (ET3), R ³¹ and R ³² each independently represent an aryl group having 6 to 14 carbon atoms which may have at least one alkyl group having 1 to 6 carbon atoms. Is preferable, and more preferably represents an aryl group having 6 to 14 carbon atoms which may have one or two alkyl groups having 1 to 6 carbon atoms, and a 2-ethyl-6-methylphenyl group. Is more preferably represented. A suitable example of the compound (ET3) is a compound represented by the chemical formula (ET3-1) (hereinafter sometimes referred to as compound (ET3-1)).

In General Formula (ET4), R ⁴¹ and R ⁴² each preferably represent an alkyl group having 1 to 6 carbon atoms, more preferably an isopropyl group or a tert-butyl group, and a tert-butyl group. Is particularly preferred. R ⁴³ in the general formula (ET4) preferably represents a halogen atom, more preferably a chlorine atom (chloro group). A preferred example of the compound (ET4) is a compound represented by the chemical formula (ET4-1) (hereinafter sometimes referred to as compound (ET4-1)).

In general formula (ET5), R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ each preferably represent an alkyl group having 1 to 6 carbon atoms, and an alkyl group having 1 to 4 carbon atoms. Is more preferable, and a methyl group or a tert-butyl group is more preferable. A suitable example of the compound (ET5) is a compound represented by the chemical formula (ET5-1) (hereinafter sometimes referred to as compound (ET5-1)).

The photosensitive layer may contain only the compound (ET1), (ET2), (ET3), (ET4) or (ET5) as an electron transfer agent. Alternatively, in addition to the compounds (ET1), (ET2), (ET3), (ET4) or (ET5) as the electron transfer agent, the photosensitive layer contains the compounds (ET1), (ET2), (ET3), (ET4). ) And (ET5) may be further contained. The content of the compound (ET1), (ET2), (ET3), (ET4) or (ET5) is preferably 80% by mass or more, and 90% by mass or more based on the total mass of the electron transfer agent. It is more preferable that the amount is 100% by mass, and particularly preferably 100% by mass.

The content of the electron transfer agent contained in the photosensitive layer is preferably 5 parts by mass or more and 100 parts by mass or less, and more preferably 10 parts by mass or more and 80 parts by mass or less with respect to 100 parts by mass of the binder resin. preferable.

(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 (e.g. 2,5-di(4-methylaminophenyl)-1,3,4-oxadiazole), styryl compounds (e.g. 9-(4-diethylaminostyryl)anthracene), carbazole compounds (e.g. , 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 compounds, imidazole compounds, pyrazole compounds and triazole compounds. The hole transport materials may be used alone or in combination of two or more.

In order to improve the wear resistance, scratch resistance and filming resistance of the photoconductor, the hole transport agent is preferably a compound represented by the general formula (HT1), (HT2) or (HT3). The compounds represented by formulas (HT1), (HT2) and (HT3) may be referred to as compounds (HT1), (HT2) and (HT3), respectively. One of the compounds (HT1), (HT2) and (HT3) may be used alone, or two or more thereof may be used in combination.

In formula (HT1), R ¹¹¹ , R ¹¹² and R ¹¹³ are each independently an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an aryl group having 6 to 14 carbon atoms. Represents a group. b ₁ , b ₂ and b ₃ each independently represent an integer of 0 or more and 5 or less.

In formula (HT1), R ^{111 to} R ¹¹³ preferably represent an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and an n-butyl group or an ethoxy group. It is more preferable to represent.

When b ₁ represents an integer of 2 or more and 5 or less, a plurality of R ¹¹¹ may be the same or different from each other. When b ₂ represents an integer of 2 or more and 5 or less, a plurality of R ¹¹² may be the same or different from each other. When b ₃ represents an integer of 2 or more and 5 or less, a plurality of R ¹¹³ may be the same or different from each other. It is preferable that b ₁ , b ₂ and b ₃ each independently represent 0 or 1. More preferably, b ₁ represents 1. More preferably, b ₂ and b ₃ represent 0.

The bonding positions of R ^{111 to} R ¹¹³ are not particularly limited. R ^{111 to} R ¹¹³ may be bonded (positioned) to any of the ortho-position, meta-position and para-position of the phenyl group. R ¹¹¹ is preferably bonded to the ortho position or para position of the phenyl group.

A suitable example of the compound (HT1) is a compound represented by the following chemical formula (HT1-1) or (HT1-2) (hereinafter sometimes referred to as compound (HT1-1) or (HT1-2)). Is.

In formula (HT2), R ¹²¹ , R ¹²² , R ¹²³ , R ¹²⁴ , R ¹²⁵ and R ¹²⁶ each independently represent an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms. Represent d ₁ , d ₂ , d ₅ and d ₆ each independently represent an integer of 0 or more and 5 or less. d ₃ and d ₄ each independently represent an integer of 0 or more and 4 or less.

When d ₁ represents an integer of 2 or more and 5 or less, a plurality of R ¹²¹ may be the same as or different from each other. When d ₂ represents an integer of 2 or more and 5 or less, a plurality of R ¹²² may be the same or different from each other. When d ₃ represents an integer of 2 or more and 4 or less, a plurality of R ¹²³ may be the same or different from each other. When d ₄ represents an integer of 2 or more and 4 or less, a plurality of R ¹²⁴ may be the same or different from each other. When d ₅ represents an integer of 2 or more and 5 or less, a plurality of R ¹²⁵ may be the same or different from each other. When d ₆ represents an integer of 2 or more and 5 or less, a plurality of R ¹²⁶ may be the same or different from each other.

In formula (HT2), R ¹²¹ , R ¹²² , R ¹²³ , R ¹²⁴ , R ¹²⁵ and R ¹²⁶ each independently preferably represent an alkyl group having 1 to 6 carbon atoms and represent a methyl group. Is more preferable. It is preferred that _one of d ₁ and d ₂ represents 1 and the other represents 0. It is preferable that one of d ₅ and d ₆ represents 1, and the other represents 0. It is preferable that d ₃ and d ₄ each represent 0.

A preferred example of the compound (HT2) is a compound represented by the following chemical formula (HT2-1) (hereinafter sometimes referred to as compound (HT2-1)).

In formula (HT3), R ¹³¹ , R ¹³² , R ¹³³ , R ¹³⁴ , R ^135, and R ¹³⁶ each independently represent an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, It represents an aryl group having 6 to 14 carbon atoms or an alkenyl group having 2 to 6 carbon atoms. e ₁ , e ₂ , e ₃ and e ₄ each independently represent an integer of 0 or more and 5 or less. e ₅ and e ₆ each independently represent an integer of 0 or more and 4 or less.

When e ₁ represents an integer of 2 or more and 5 or less, a plurality of R ¹³¹ may be the same or different from each other. When e ₂ represents an integer of 2 or more and 5 or less, a plurality of R ¹³² may be the same or different from each other. When e ₃ represents an integer of 2 or more and 5 or less, a plurality of R ¹³³ may be the same or different from each other. When e ₄ represents an integer of 2 or more and 5 or less, a plurality of R ¹³⁴ may be the same or different from each other. It is preferable that e ₁ , e ₂ , e ₃ and e ₄ each independently represent an integer of 0 or more and 2 or less. More preferably, one of e ₁ and e ₂ represents 2 and the other represents 0 or 1 (preferably 0). More preferably, one of e ₃ and e ₄ represents 2 and the other represents 0 or 1 (preferably 0).

The bonding positions of R ^{131 to} R ¹³⁴ are not particularly limited. R ^{131 to} R ¹³⁴ may be bonded (positioned) to any of the ortho position, the meta position and the para position of the phenyl group. R ^{131 to} R ¹³⁴ are preferably bonded to the ortho position or the para position of the phenyl group.

When e ₅ represents an integer of 2 or more and 4 or less, a plurality of R ¹³⁵ may be the same or different from each other. When e ₆ represents an integer of 2 or more and 4 or less, a plurality of R ¹³⁶ may be the same or different from each other. It is preferable that each of e ₅ and e ₆ represents 0.

The bonding positions of R ¹³⁵ and R ¹³⁶ are not particularly limited. ^R135 and ^R136 may each be bonded (positioned) to either the ortho position or the meta position with respect to the nitrogen atom to which the phenylene group is bonded.

In formula (HT3), R ¹³¹ , R ¹³² , R ¹³³ , R ¹³⁴ , R ^135, and R ¹³⁶ each preferably represent an alkyl group having 1 to 6 carbon atoms, and a methyl group or an ethyl group. It is more preferable to represent. It is preferable that e ₁ , e ₂ , e ₃ and e ₄ each independently represent an integer of 0 or more and 2 or less. It is preferable that each of e ₅ and e ₆ represents 0.

A preferred example of the compound (HT3) is a compound represented by the following chemical formula (HT3-1) (hereinafter, each may be referred to as compound (HT3-1)).

The photosensitive layer may contain only the compound (HT1), (HT2) or (HT3) as a hole transport material. Alternatively, the photosensitive layer further contains, as a hole transfer agent, a hole transfer agent other than the compounds (HT1), (HT2) and (HT3) in addition to the compound (HT1), (HT2) or (HT3). May be. The content of the compound (HT1), (HT2) or (HT3) is preferably 80% by mass or more, more preferably 90% by mass or more, and more preferably 100% by mass based on the total mass of the hole transferring material. It is particularly preferable that the content is% by mass.

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.

(Combination of materials)
In order to improve wear resistance, scratch resistance and filming resistance, it is preferable that the hole transfer agent, the electron transfer agent, the binder resin and the filler particles are any of the following combinations. For the same reason, it is preferable that the hole transfer material, the electron transfer material, the binder resin and the filler particles are any one of the following combinations, and the charge generation agent is Y-type titanyl phthalocyanine. For the same reason, it is also preferable that the hole transferring material, the electron transferring material, the binder resin and the filler particles are any of the following combinations, and the charge generating agent is an X-type metal-free phthalocyanine.

The hole transfer material is the compound (HT1-1), the electron transfer material is the compound (ET1-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer agent is the compound (HT1-2), the electron transfer agent is the compound (ET1-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT2-1), the electron transfer material is the compound (ET1-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT3-1), the electron transfer material is the compound (ET1-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-1), the electron transfer material is the compound (ET2-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-2), the electron transfer material is the compound (ET2-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT2-1), the electron transfer material is the compound (ET2-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer agent is the compound (HT3-1), the electron transfer agent is the compound (ET2-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-1), the electron transfer material is the compound (ET3-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-2), the electron transfer material is the compound (ET3-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer agent is the compound (HT2-1), the electron transfer agent is the compound (ET3-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer agent is the compound (HT3-1), the electron transfer agent is the compound (ET3-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-1), the electron transfer material is the compound (ET4-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer agent is the compound (HT1-2), the electron transfer agent is the compound (ET4-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT2-1), the electron transfer material is the compound (ET4-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT3-1), the electron transfer material is the compound (ET4-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-1), the electron transfer material is the compound (ET5-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-2), the electron transfer material is the compound (ET5-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer agent is the compound (HT2-1), the electron transfer agent is the compound (ET5-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8); Alternatively, the hole transfer material is the compound (HT3-1), the electron transfer material is the compound (ET5-1), the filler particles are the filler particles (F-1), and the binder resin is the polyarylate resin (R-). 1), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8).

The hole transfer material is the compound (HT1-1), the electron transfer material is the compound (ET1-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-2), the electron transfer material is the compound (ET1-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT2-1), the electron transfer material is the compound (ET1-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT3-1), the electron transfer material is the compound (ET1-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-1), the electron transfer material is the compound (ET2-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-2), the electron transfer material is the compound (ET2-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer agent is the compound (HT2-1), the electron transfer agent is the compound (ET2-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer agent is the compound (HT3-1), the electron transfer agent is the compound (ET2-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-1), the electron transfer material is the compound (ET3-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-2), the electron transfer material is the compound (ET3-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT2-1), the electron transfer material is the compound (ET3-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT3-1), the electron transfer material is the compound (ET3-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-1), the electron transfer material is the compound (ET4-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-2), the electron transfer material is the compound (ET4-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT2-1), the electron transfer material is the compound (ET4-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT3-1), the electron transfer material is the compound (ET4-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-1), the electron transfer material is the compound (ET5-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer agent is the compound (HT1-2), the electron transfer agent is the compound (ET5-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer agent is the compound (HT2-1), the electron transfer agent is the compound (ET5-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8); Alternatively, the hole transfer agent is the compound (HT3-1), the electron transfer agent is the compound (ET5-1), the filler particles are the filler particles (F-2), and the binder resin is the polyarylate resin (R- 1), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8).

The hole transfer material is the compound (HT1-1), the electron transfer material is the compound (ET1-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-2), the electron transfer material is the compound (ET1-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT2-1), the electron transfer material is the compound (ET1-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT3-1), the electron transfer material is the compound (ET1-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-1), the electron transfer material is the compound (ET2-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer agent is the compound (HT1-2), the electron transfer agent is the compound (ET2-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT2-1), the electron transfer material is the compound (ET2-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT3-1), the electron transfer material is the compound (ET2-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer agent is the compound (HT1-1), the electron transfer agent is the compound (ET3-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-2), the electron transfer material is the compound (ET3-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT2-1), the electron transfer material is the compound (ET3-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer agent is the compound (HT3-1), the electron transfer agent is the compound (ET3-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-1), the electron transfer material is the compound (ET4-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-2), the electron transfer material is the compound (ET4-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT2-1), the electron transfer material is the compound (ET4-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT3-1), the electron transfer material is the compound (ET4-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-1), the electron transfer material is the compound (ET5-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-2), the electron transfer material is the compound (ET5-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT2-1), the electron transfer material is the compound (ET5-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8); Alternatively, the hole transfer agent is the compound (HT3-1), the electron transfer agent is the compound (ET5-1), the filler particles are the filler particles (F-3), and the binder resin is the polyarylate resin (R- 1), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8).

The hole transfer material is the compound (HT1-1), the electron transfer material is the compound (ET1-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer agent is the compound (HT1-2), the electron transfer agent is the compound (ET1-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT2-1), the electron transfer material is the compound (ET1-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer agent is the compound (HT3-1), the electron transfer agent is the compound (ET1-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-1), the electron transfer material is the compound (ET2-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-2), the electron transfer material is the compound (ET2-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer agent is the compound (HT2-1), the electron transfer agent is the compound (ET2-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT3-1), the electron transfer material is the compound (ET2-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-1), the electron transfer material is the compound (ET3-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-2), the electron transfer material is the compound (ET3-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer agent is the compound (HT2-1), the electron transfer agent is the compound (ET3-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT3-1), the electron transfer material is the compound (ET3-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-1), the electron transfer material is the compound (ET4-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-2), the electron transfer material is the compound (ET4-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT2-1), the electron transfer material is the compound (ET4-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT3-1), the electron transfer material is the compound (ET4-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-1), the electron transfer material is the compound (ET5-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT1-2), the electron transfer material is the compound (ET5-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8);
The hole transfer material is the compound (HT2-1), the electron transfer material is the compound (ET5-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R-1). ), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8); Alternatively, the hole transfer agent is the compound (HT3-1), the electron transfer agent is the compound (ET5-1), the filler particles are the filler particles (F-4), and the binder resin is the polyarylate resin (R- 1), (R-2), (R-3), (R-4), (R-5), (R-6), (R-7) and (R-8).

The suitable combination of the hole transport material, the electron transport material, the binder resin and the filler particles has been described above.

(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 or leveling agents. As the antioxidant, for example, hindered phenol (for example, di(tert-butyl)p-cresol), hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroindanone or their derivatives, organic sulfur compounds or 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 material having conductivity include aluminum, iron, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel or 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 current generated when the photosensitive member is exposed and suppress the increase in resistance while maintaining the insulation 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) or 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 various additives. Examples of the additives are the same as the examples of the additives for the photosensitive layer.

<Method for manufacturing photoconductor>
An example of the method for manufacturing the photoconductor will be described. The photoconductor is manufactured by applying a coating solution for a photosensitive layer on a conductive substrate and drying. The coating solution for the photosensitive layer is prepared by dissolving or dispersing a charge generating agent, a hole transporting agent, an electron transporting agent, filler particles, a binder resin and components (for example, additives) added as necessary in a solvent. Manufactured.

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 or dimethylsulfoxide. These solvents may be used alone or in combination of two or more. 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 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.

<Image forming device>
Next, with reference to FIG. 2, an image forming apparatus 110 including the photoconductor 100 according to this embodiment will be described. FIG. 2 is a diagram showing an example of the configuration of the image forming apparatus 110. The image forming apparatus 110 includes the photoconductor 100 according to this embodiment. The image forming apparatus 110 shown in FIG. 2 adopts a direct transfer system. The image forming apparatus 110 adopting the intermediate transfer method will be described later with reference to FIG.

The image forming apparatus 110 is not particularly limited as long as it is an electrophotographic image forming apparatus. The image forming apparatus 110 may be, for example, a monochrome image forming apparatus or a color image forming apparatus. When the image forming apparatus 110 is a color image forming apparatus, the image forming apparatus 110 adopts a tandem system, for example. Hereinafter, the tandem type image forming apparatus 110 will be described as an example.

The image forming apparatus 110 includes image forming units 40a, 40b, 40c and 40d, a transfer belt 50, and a fixing unit 52. Hereinafter, when it is not necessary to distinguish them, each of the image forming units 40a, 40b, 40c, and 40d is referred to as an image forming unit 40. When the image forming apparatus 110 is a monochrome image forming apparatus, the image forming apparatus 110 includes the image forming unit 40a and the image forming units 40b to 40d are omitted.

The image forming unit 40 includes the photoconductor 100 according to the present exemplary embodiment, a charging unit 42, an exposure unit 44, a developing unit 46, and a transfer unit 48. The photoconductor 100 is provided at the center of the image forming unit 40. The photoconductor 100 is rotatably provided in the arrow direction (counterclockwise). Around the photoconductor 100, a charging unit 42, an exposure unit 44, a developing unit 46, and a transfer unit 48 are provided in order from the upstream side in the rotation direction of the photoconductor 100 with the charging unit 42 as a reference. The image forming unit 40 may further include one or both of a cleaning unit (not shown) and a charge eliminating unit (not shown).

The charging unit 42 positively charges the surface (peripheral surface) of the photoconductor 100. The charging unit 42 is a non-contact type or a contact type. An example of the non-contact type charging unit 42 is a corotron charger or a scorotron charger. An example of the contact type charging unit 42 is a charging roller or a charging brush.

The voltage applied to the photoconductor 100 by the charging unit 42 is not particularly limited. An example of the voltage applied to the photoconductor 100 by the charging unit 42 is a DC voltage, an AC voltage, or a superimposed voltage. The superimposed voltage is a voltage obtained by superimposing an AC voltage on a DC voltage. The charging unit 42 preferably applies a DC voltage to the photoconductor 100. This is because the amount of wear of the photosensitive layer 102 tends to decrease when the charging section 42 applies only a DC voltage. The DC voltage applied to the photoreceptor 100 by the charging unit 42 is preferably 1000 V or more and 2000 V or less, more preferably 1200 V or more and 1800 V or less, and particularly preferably 1400 V or more and 1600 V or less.

The exposure unit 44 exposes the surface of the charged photoconductor 100. As a result, an electrostatic latent image is formed on the surface of the photoconductor 100. The electrostatic latent image is formed based on the image data input to the image forming apparatus 110.

The developing unit 46 supplies toner to the electrostatic latent image formed on the photoconductor 100. As a result, the electrostatic latent image is developed as a toner image. The photoconductor 100 corresponds to an image carrier that carries a toner image. The toner may be used as a one-component developer. Alternatively, the toner may be mixed with a desired carrier and the toner may be used in a two-component developer. When the toner is used as the one-component developer, the developing unit 46 supplies the toner that is the one-component developer to the electrostatic latent image formed on the photoconductor 100. When the toner is used in the two-component developer, the developing unit 46 supplies the toner included in the two-component developer and the carrier to the electrostatic latent image formed on the photoconductor 100.

The transfer belt 50 conveys the recording medium P between the photoconductor 100 and the transfer section 48. The transfer belt 50 is an endless belt. The transfer belt 50 is provided so as to be rotatable in the arrow direction (clockwise direction).

The transfer unit 48 transfers the toner image developed by the developing unit 46 from the photoconductor 100 to the transfer target. When the image forming apparatus 110 adopts the direct transfer method, the transfer target corresponds to the recording medium P. When the image forming apparatus 110 adopts the direct transfer method, the photoconductor 100 is in contact with the recording medium P when the toner image is transferred from the photoconductor 100 to the recording medium P. The transfer unit 48 is, for example, a transfer roller.

Toner images of a plurality of colors (for example, four colors of black, cyan, magenta, and yellow) are sequentially superposed on the recording medium P on the transfer belt 50 by each of the image forming units 40a to 40d.

The fixing unit 52 heats and/or pressurizes the unfixed toner image transferred onto the recording medium P by the transfer unit 48. The fixing unit 52 is, for example, a heating roller and/or a pressure roller. The toner image is fixed on the recording medium P by heating and/or pressing the toner image. As a result, an image is formed on the recording medium P.

The image forming apparatus 110 can also adopt an intermediate transfer method. Hereinafter, the image forming apparatus 110 adopting the intermediate transfer method will be described with reference to FIG. FIG. 3 is a diagram showing another example of the configuration of the image forming apparatus 110. The image forming apparatus 110 includes the photoconductor 100 according to this embodiment. In order to avoid redundancy, the same components as those of the image forming apparatus 110 shown in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted.

When the image forming apparatus 110 adopts the intermediate transfer system, the transfer unit 48 described in the direct transfer system corresponds to the primary transfer unit 54 and the secondary transfer unit 58. When the image forming apparatus 110 adopts the intermediate transfer method, the transfer target corresponds to the intermediate transfer belt 56 and the recording medium P. The primary transfer unit 54 applies a primary transfer bias (specifically, a bias having a polarity opposite to the charging polarity of toner) to the intermediate transfer belt 56. The intermediate transfer belt 56 is an endless belt. The intermediate transfer belt 56 rotates in the arrow (counterclockwise) direction. When the primary transfer bias is applied, the toner image formed on the surface of the photosensitive member 100 is transferred (primary transfer) from the photosensitive member 100 to the intermediate transfer belt 56 between the photosensitive member 100 and the primary transfer portion 54. ..

The secondary transfer unit 58 applies a secondary transfer bias (specifically, a bias having a polarity opposite to that of the toner image) to the recording medium P. As a result, the toner image primarily transferred onto the intermediate transfer belt 56 is transferred (secondary transfer) from the intermediate transfer belt 56 to the recording medium P between the secondary transfer portion 58 and the intermediate transfer belt 56. As a result, the unfixed toner image is transferred to the recording medium P.

The image forming apparatus 110 including the photoconductor 100 according to the present exemplary embodiment has been described above with reference to FIGS. 2 and 3.

<Process cartridge>
Next, with continuing reference to FIGS. 2 and 3, a process cartridge including the photoconductor 100 of the present embodiment will be described. The process cartridge is a cartridge for image formation. The process cartridge corresponds to each of the image forming units 40a-40d. The process cartridge includes a photosensitive member 100 that is unitized. The process cartridge adopts a configuration in which, in addition to the photoconductor 100, at least one selected from the group consisting of the charging unit 42, the exposure unit 44, the developing unit 46, and the transfer unit 48 (or the primary transfer unit 54) is unitized. To be done. The process cartridge may further include one or both of a cleaning unit (not shown) and a charge eliminating unit (not shown). The process cartridge may employ a static elimination-less method. The process cartridge is designed to be removable from the image forming apparatus 110. Therefore, the process cartridge is easy to handle, and when the sensitivity characteristic of the photoconductor 100 is deteriorated, the process cartridge and the photoconductor 100 can be replaced easily and quickly. The process cartridge including the photoconductor 100 according to the present embodiment has been described above with reference to FIGS. 2 and 3.

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, electron transporting agent, filler particles and binder resin were prepared.

(Charge generating agent)
As the charge generating agent, X-type metal-free phthalocyanine represented by the chemical formula (CG-1) described in the embodiment was prepared. Further, as a charge generating agent, Y-type titanyl phthalocyanine represented by the chemical formula (CG-2) described in the embodiment was prepared.

(Hole transfer agent)
The compounds (HT1-1), (HT1-2), (HT2-1) and (HT3-1) described in the embodiment were prepared as hole transport agents.

(Electronic transport material)
The compounds (ET1-1), (ET2-1), (ET3-1), (ET4-1) and (ET5-1) described in the embodiment were prepared as electron transfer agents.

(Filler particles)
As the filler particles, the filler particles (F-1) to (F-6) shown in Table 1 were prepared. In Table 1, D ₅₀ indicates the volume median diameter of the filler particles. Each of the filler particles (F-1) to (F-6) had a spherical shape. Note that “AEROSIL” and “NanoTek” in Table 1 are both registered trademarks.

(Binder resin)
As the binder resin, each of the polyarylate resins (R-1) to (R-8) described in the embodiment was produced.

[Preparation of polyarylate resin (R-2)]
A three-necked flask was used as the reaction vessel. This reaction vessel is a three-necked flask having a capacity of 1 L, equipped with a thermometer, a three-way cock and 200 mL of a dropping funnel. In a reaction vessel, 12.1-g (41.28 mmol) of 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane (compound (1-p) described in the embodiment) and tert-butylphenol 0.062 g ( 0.413 mmol), sodium hydroxide 3.92 g (98 mmol), and benzyltributylammonium chloride 0.120 g (0.384 mmol). Next, the air in the reaction vessel was replaced with argon gas. Then, 300 mL of water was further charged into the reaction vessel. The internal temperature of the reaction vessel was raised to 50°C. While maintaining the internal temperature of the reaction container at 50° C., the content in the reaction container was stirred for 1 hour. Then, the internal temperature of the reaction container was cooled to 10°C. As a result, an alkaline aqueous solution was obtained.

On the other hand, 4.10 g (16.2 mmol) of 2,6-naphthalenedicarboxylic acid dichloride (dicarboxylic acid dichloride of the compound (1-jj) described in the embodiment) and biphenyl-4,4′-dicarboxylic acid dichloride (implementation) 4.52 g (16.2 mmol) of the dicarboxylic acid dichloride of compound (1-h) described in the form was dissolved in 150 mL of chloroform. As a result, a chloroform solution was obtained.

Then, the chloroform solution was slowly added dropwise to the alkaline aqueous solution over 110 minutes using a dropping funnel to start the polymerization reaction. The internal temperature of the reaction vessel was adjusted to 15±5° C., and the contents of the reaction vessel were stirred for 4 hours to allow the polymerization reaction to proceed.

Then, the upper layer (aqueous layer) in the contents of the reaction vessel was removed using a decant to obtain an organic layer. Next, 400 mL of ion-exchanged water was charged into a three-necked flask having a capacity of 1 L, and then the obtained organic layer was charged. Further, 400 mL of chloroform and 2 mL of acetic acid were added. The contents of the three-necked flask were stirred at room temperature (25°C) for 30 minutes. Then, the upper layer (water layer) in the contents of the three-necked flask was removed using a decant, and an organic layer was obtained. The organic layer obtained by using 1 L of water was washed 5 times with a separating funnel. As a result, an organic layer washed with water was obtained.

Next, the organic layer washed with water was filtered to obtain a filtrate. 1 L of methanol was put into an Erlenmeyer flask having a volume of 1 L. The obtained filtrate was slowly dropped into an Erlenmeyer flask to obtain a precipitate. The precipitate was filtered off by filtration. The obtained precipitate was vacuum dried at a temperature of 70° C. for 12 hours. As a result, a polyarylate resin (R-2) was obtained. The yield of the polyarylate resin (R-2) was 12.2 g, and the yield was 77 mol %. The viscosity average molecular weight of the polyarylate resin (R-2) was 46,000.

[Production of Polyarylate Resins (R-1) and (R-3) to (R-8)]
Each of the polyarylate resins (R-1) and (R-3) to (R-8) was produced in the same manner as the polyarylate resin (R-2) except that the following points were changed.

In the preparation of the polyarylate resin (R-1), 2,6-naphthalenedicarboxylic acid dichloride (16.2 mmol) and biphenyl-4,4′-dicarboxylic acid dichloride (16.2 mmol) were used instead of the compound (1 -K) dicarboxylic acid dichloride (16.2 mmol) and compound (1-1) dicarboxylic acid dichloride (16.2 mmol) were used. The viscosity average molecular weight of the obtained polyarylate resin (R-1) was 35300.

In the preparation of the polyarylate resin (R-3), 2,6-naphthalenedicarboxylic acid dichloride (16.2 mmol) and biphenyl-4,4′-dicarboxylic acid dichloride (16.2 mmol) were used instead of the compound (1 -G) of dicarboxylic acid dichloride (32.4 mmol) was used. The viscosity average molecular weight of the obtained polyarylate resin (R-3) was 36600.

In the preparation of the polyarylate resin (R-4), 2,6-naphthalenedicarboxylic acid dichloride (16.2 mmol) and biphenyl-4,4′-dicarboxylic acid dichloride (16.2 mmol) were used instead of the compound (1 -G) of dicarboxylic acid dichloride (16.2 mmol) and compound (1-jj) of dicarboxylic acid dichloride (16.2 mmol) were used. The viscosity average molecular weight of the obtained polyarylate resin (R-4) was 34400.

In the preparation of the polyarylate resin (R-5), instead of the 2,6-naphthalenedicarboxylic acid dichloride (16.2 mmol) and the biphenyl-4,4′-dicarboxylic acid dichloride (16.2 mmol), the compound (1 -G) of dicarboxylic acid dichloride (16.2 mmol) and compound (1-h) of dicarboxylic acid dichloride (16.2 mmol) were used. The viscosity average molecular weight of the obtained polyarylate resin (R-5) was 35600.

In the preparation of the polyarylate resin (R-6), 2,6-naphthalenedicarboxylic acid dichloride (16.2 mmol) and biphenyl-4,4′-dicarboxylic acid dichloride (16.2 mmol) were used instead of the compound (1 -I) dicarboxylic acid dichloride (32.4 mmol) was used. The viscosity average molecular weight of the obtained polyarylate resin (R-6) was 35800.

In the preparation of the polyarylate resin (R-7), 2,6-naphthalenedicarboxylic acid dichloride (16.2 mmol) and biphenyl-4,4′-dicarboxylic acid dichloride (16.2 mmol) were used instead of the compound (1 -I) dicarboxylic acid dichloride (16.2 mmol) and compound (1-jj) dicarboxylic acid dichloride (16.2 mmol) were used. The viscosity average molecular weight of the obtained polyarylate resin (R-7) was 34,000.

In the preparation of the polyarylate resin (R-8), 2,6-naphthalenedicarboxylic acid dichloride (16.2 mmol) and biphenyl-4,4′-dicarboxylic acid dichloride (16.2 mmol) were used instead of the compound (1 -G) dicarboxylic acid dichloride (9.7 mmol) and compound (1-jj) dicarboxylic acid dichloride (22.7 mmol) were used. The viscosity average molecular weight of the obtained polyarylate resin (R-8) was 33600.

Next, using a proton nuclear magnetic resonance spectrometer (manufactured by JASCO Corporation, 300 MHz), ¹ H-NMR spectra of the prepared polyarylate resins (R-1) to (R-8) were measured. CDCl ₃ was used as the solvent. Tetramethylsilane (TMS) was used as an internal standard sample. Of these, polyarylate resins (R-2), (R-4) and (R-5) are listed as typical examples.

4 to 6 show ¹ H-NMR spectra of polyarylate resins (R-2), (R-4) and (R-5), respectively. 4 to 6, the horizontal axis represents chemical shift (unit: ppm) and the vertical axis represents signal intensity (unit: arbitrary unit). ¹ H-NMR spectrum confirmed that polyarylate resins (R-2), (R-4) and (R-5) were obtained. Regarding the polyarylate resins (R-1), (R-3) and (R-6) to (R-8), the polyarylate resins (R-1) and (R-3) were respectively analyzed by ¹ H-NMR spectrum. ) And (R-6) to (R-8) were obtained.

Polycarbonate resins represented by the following chemical formulas (RA) to (RC) (hereinafter, also referred to as polycarbonate resins (RA) to (RC)) were also prepared as binder resins. Further, as the binder resin, a polyarylate resin represented by the following chemical formulas (RD) to (RF) (hereinafter sometimes referred to as polyarylate resin (RD) to (RF)). I also prepared. The viscosity average molecular weights of the polycarbonate resins (RA) to (RC) and the polyarylate resins (RD) to (RF) were 31000, 32500, 33000, 34500, 33200 and 32400, respectively. .. In addition, the subscripts attached to the repeating units in the chemical formulas (RA) to (R-F) are the subscripts for the total amount of substances (total number of moles) of the repeating units contained in the resin. The percentage of the substance amount (mol number) of the unit is shown.

<Manufacture of photoconductor>
Photoconductors (A-1) to (A-22) and (B-1) to (B-9) were produced using the material for forming the photosensitive layer.

(Production of Photoreceptor (A-1))
5 parts by mass of X-type metal-free phthalocyanine as a charge generating agent, 50 parts by mass of a compound (HT1-1) as a hole transferring material, 35 parts by mass of a compound (ET1-1) as an electron transferring material, poly as a binder resin. 100 parts by mass of arylate resin (R-1), 5 parts by mass of filler particles (F-1), and 750 parts by mass of tetrahydrofuran were added to a container of a ball mill. The contents were mixed and dispersed for 50 hours using a ball mill to prepare a coating liquid for the photosensitive layer. The coating liquid obtained by the dip coating method was applied on a conductive substrate to form a coating film on the conductive substrate. The coating film was heated at 100° C. for 40 minutes to remove tetrahydrofuran from the coating film. As a result, a single photosensitive layer (thickness: 35 μm) was formed on the conductive substrate. As a result, a photoconductor (A-1) was obtained.

(Production of Photoreceptors (A-2) to (A-22) and (B-1) to (B-9))
Except for changing the following points (1) to (8), the photoconductors (A-2) to (A-22) and (B-1) to (A-1) were manufactured in the same manner as in the production of the photoconductor (A-1). Each of (B-9) was produced.
(1) Although X-type metal-free phthalocyanine was used as a charge generating agent in the production of the photoconductor (A-1), the photoconductors (A-2) to (A-22) and (B-1) to (B). In the respective productions of -9), the types of charge generating agents shown in Tables 2 and 3 were used.
(2) The compound (HT1-1) was used as the hole transporting agent in the production of the photoconductor (A-1), but the photoconductors (A-2) to (A-22) and (B-1) to In the respective productions of (B-9), hole transfer agents of the types shown in Tables 2 and 3 were used.
(3) The compound (ET1-1) was used as an electron transfer agent in the production of the photoconductor (A-1), but the photoconductors (A-2) to (A-22) and (B-1) to ( In each production of B-9), electron transfer agents of the types shown in Tables 2 and 3 were used.
(4) Although the polyarylate resin (R-1) was used as the binder resin in the production of the photoconductor (A-1), the photoconductors (A-2) to (A-22) and (B-1) to Binder resins of the types shown in Tables 2 and 3 were used in the respective productions of (B-9).
(5) Although the filler particles (F-1) were used in the production of the photoconductor (A-1), the photoconductors (A-2) to (A-22) and (B-1) to (B-9). In the respective productions of 1), filler particles of the types shown in Tables 2 and 3 were used.
(6) In the production of the photoconductor (A-1), 5 parts by mass of the filler particles (F-1) were added, but in the production of the photoconductor (A-20), 10 parts by mass of the filler particles (F-1) were added. Added in parts. Thereby, the content of the filler particles with respect to the mass of the photosensitive layer was changed from 2.6% by mass in the production of the photoconductor (A-1) to 5.0% by mass.
(7) In the production of the photoconductor (A-1), 5 parts by mass of the filler particles (F-1) were added, but in the production of the photoconductor (A-21), 20 parts by mass of the filler particles (F-1) were added. Added in parts. Thereby, the content of the filler particles with respect to the mass of the photosensitive layer was changed from 2.6% by mass in the production of the photoconductor (A-1) to 9.5% by mass.
(8) In the production of the photoconductor (A-1), 5 parts by mass of the filler particles (F-1) were added, but in the production of the photoconductor (A-22), the filler particles (F-1) were added to 23. 5 parts by mass was added. Thereby, the content of the filler particles with respect to the mass of the photosensitive layer was changed from 2.6% by mass in the production of the photoconductor (A-1) to 11.0% by mass.

<Evaluation of wear resistance>
The abrasion resistance was evaluated for each of the photoconductors (A-1) to (A-22) and (B-1) to (B-9). The abrasion resistance was evaluated under the environment of a temperature of 23° C. and a relative humidity of 50% RH. A printer (FS-C5250DN, manufactured by Kyocera Document Solutions Co., Ltd.) was used as an evaluation machine. The evaluation machine was equipped with a charging roller as a charging section. The charging roller was composed of charging rubber (specifically, epichlorohydrin resin in which conductive carbon was dispersed). The charging polarity of the charging section was positive, and the voltage applied to the charging section was DC voltage. In addition, the evaluation machine used an intermediate transfer system.

First, the thickness (T ₁ , unit: μm) of the photosensitive layer of the photosensitive member was measured. Next, the photoconductor was mounted on the evaluation machine, and the image I (character image with a printing rate of 5%) was continuously printed on 50,000 sheets of paper using the evaluation machine. Then, the thickness (T ₂ , unit: μm) of the photosensitive layer of the photosensitive member after printing 50,000 sheets was measured. Then, the wear amount (unit: μm) of the photosensitive layer was obtained from the calculation formula “wear amount of photosensitive layer=T ₁ −T ₂ ”. The thickness of the photosensitive layer was measured with an eddy current film thickness meter (“LH-373” manufactured by Kett Scientific Research Co., Ltd.). The amount of wear of the obtained photosensitive layer is shown in Tables 2 and 3. The smaller the amount of abrasion of the photosensitive layer, the better the abrasion resistance of the photoreceptor.

<Evaluation of scratch resistance and filming resistance>
Each of the photoconductors (A-1) to (A-22) and (B-1) to (B-9) was evaluated for scratch resistance and filming resistance. The evaluator for evaluating scratch resistance and filming resistance was the same as the evaluator for evaluating wear resistance. The photoconductor was mounted on the evaluation machine. Using an evaluation machine, image I (character image with a printing rate of 5%) was continuously printed on 50,000 sheets of paper under a normal temperature and normal humidity environment (temperature 23° C. and relative humidity 50% RH environment). After printing 50,000 sheets of image I, image II (an image including a halftone image and a white background image) was printed on one sheet of paper to obtain an evaluation image in a normal temperature and normal humidity environment. Next, the image I was continuously printed on 50,000 sheets of paper under a low temperature and low humidity environment (environment of temperature 10° C. and relative humidity 20% RH). After printing 50,000 sheets of image I, image II was printed on one sheet of paper to obtain an image for evaluation in a low temperature and low humidity environment.

Then, the photoconductor was taken out from the evaluation machine. The surface of the photoconductor was observed with the naked eye to confirm the occurrence of scratches and filming on the surface of the photoconductor. Further, each of the evaluation image in the normal temperature and normal humidity environment and the evaluation image in the low temperature and low humidity environment was observed to confirm the occurrence of image defects due to scratches and filming. When filming occurs on the surface of the photoconductor, image defects such as stripes and dash marks occur in the formed image. The streak is an image defect in which a black line parallel to the direction in which the image is printed appears. The dash mark is an image defect in which black dots arranged parallel to the direction in which the image is printed appear. When the surface of the photoconductor is scratched, one or both of white streaks and black streaks are generated in the formed image. From the confirmation results, the scratch resistance and the filming resistance of the photoconductor were evaluated according to the following criteria. The evaluation results of the scratch resistance and the filming resistance are shown in Tables 2 and 3.

(Evaluation criteria for scratch resistance and filming resistance)
Evaluation A (especially good): No scratches and filming occurred on the surface of the photoreceptor. Further, no image defects were observed in both the evaluation images in the normal temperature and normal humidity environment and the low temperature and low humidity environment.
Evaluation B (good): At least one of scratches and filming was slightly generated on the surface of the photoreceptor. However, no image defects were observed in both the evaluation images in the normal temperature and normal humidity environment and the low temperature and low humidity environment.
Evaluation C (bad): At least one of scratches and filming occurred on the surface of the photoconductor. Image defects were observed in the evaluation images in the low temperature and low humidity environment. However, no image defect was observed in the evaluation image in the normal temperature and normal humidity environment.
Evaluation D (particularly bad): At least one of scratches and filming occurred on the surface of the photoconductor. In addition, image defects were observed in both the evaluation images in the normal temperature and normal humidity environment and the low temperature and low humidity environment.

In Tables 2 and 3, CGM, HTM, ETM, resin and wt% represent a charge generating agent, a hole transfer agent, an electron transfer agent, a binder resin and mass %, respectively. In Tables 2 and 3, CG-1 and CG-2 represent X-type metal-free phthalocyanine and Y-type titanyl phthalocyanine, respectively. In Tables 2 and 3, the content indicates the content (unit: mass%) of the filler particles with respect to the mass of the photosensitive layer. The content of the filler particles with respect to the mass of the photosensitive layer was calculated from the following formula.
Content of filler particles relative to mass of photosensitive layer=(mass of filler particles)/(mass of charge generation agent+mass of hole transfer agent+mass of electron transfer agent+mass of binder resin+mass of filler particles)

Each of the photoconductors (A-1) to (A-22) was provided with a conductive substrate and a single photosensitive layer. The photosensitive layer contained a charge generating agent, a hole transferring material, an electron transferring material, filler particles and a binder resin. The filler particles contained resin particles. The binder resin contained polyarylate resin (1). Therefore, as is clear from Tables 2 and 3, the photoconductors (A-1) to (A-22) had small wear loss and excellent wear resistance. Further, in the photoconductors (A-1) to (A-22), the evaluation results of the scratch resistance and the filming resistance are A (particularly good) and B (good), which are excellent in the scratch resistance and the filming resistance. Was there.

On the other hand, in the photoconductors (B-1) to (B-6), the binder resin did not contain the polyarylate resin (1). Therefore, as is clear from Table 3, in the photoconductors (B-1) to (B-6), the abrasion loss was large and the abrasion resistance was poor.

In the photoconductors (B-7) and (B-8), the filler particles did not contain resin particles. Specifically, in the photoconductors (B-7) and (B-8), the photosensitive layer contained the filler particles (F-5) or (F-6), but the filler particles (F-5). Neither (F-6) was resin particles. Therefore, as is clear from Table 3, in the photoconductors (B-7) and (B-8), the abrasion loss was large and the abrasion resistance was poor. Further, in the photoconductors (B-7) and (B-8), the evaluation results of the scratch resistance and the filming resistance were D (particularly bad), and the scratch resistance and the filming resistance were poor.

The photosensitive layer of the photoconductor (B-9) did not contain filler particles. Therefore, as is clear from Table 3, in the photoconductor (B-9), the wear loss was large and the wear resistance was poor. Further, in the photoconductor (B-9), the evaluation results of the scratch resistance and the filming resistance were C (defective), and the scratch resistance and the filming resistance were poor.

From the above, it was shown that the photoreceptor according to the present invention is excellent in wear resistance, scratch resistance and filming resistance. Further, it has been shown that the process cartridge and the image forming apparatus according to the present invention can suppress the occurrence of image defects by including such a photoconductor.

The photoconductor according to the present invention can be used in an image forming apparatus. The process cartridge and the image forming apparatus according to the present invention can be used to form an image on a recording medium.

Claims (12)

Comprises a conductive substrate and a photosensitive layer,
The photosensitive layer is a single layer ,
The photosensitive layer contains a charge generating agent, a hole transfer agent, an electron transfer agent, filler particles and a binder resin,
The filler particles include resin particles,
The binder resin is an electrophotographic photoreceptor containing a polyarylate resin represented by the following general formula (1).

(In the general formula (1),
kr and kt each independently represent 2 or 3 ,
r+s+t+u=100,
r+t=s+u,
In the general formula (1), t and u each independently represent a number of 1 or more and 50 or less, r and s each independently represent a number of 0 or more and 49 or less, provided that r and s are Each is not 0, and s/(s+u) is 0.30 or more and 0.70 or less, X and Y are different from each other, and the following chemical formulas (1-1), (1-2), and (1- 3), (1-4), (1-5), (1-6) or a divalent group represented by (1-7), provided that one of X and Y is represented by the chemical formula (1- 1) represents the divalent group represented by the above, or
In the general formula (1), r and s each represent 0, t and u each represent 50, and Y represents the divalent group represented by the chemical formula (1-3), or
In the general formula (1), t and u each independently represent a number of 1 or more and 50 or less, r and s each independently represent a number of 0 or more and 49 or less, provided that r and s are Each is not 0, s/(s+u) is 0.30 or more and 0.70 or less, X and Y are different from each other, and one of X and Y is represented by the chemical formula (1-3). It represents a divalent group, and the other of X and Y represents the divalent group represented by the chemical formula (1-4). )

The electrophotographic photosensitive member according to claim 1, wherein the volume median diameter of the resin particles is 0.05 μm or more and 5.00 μm or less. The electrophotographic photosensitive member according to claim 1, wherein the content of the resin particles is greater than 0.0% by mass and 10.0% by mass or less based on the mass of the photosensitive layer. The electrophotographic photosensitive member according to claim 1, wherein the resin particles have a spherical shape. In the general formula (1), r and s are not 0, X and Y are different from each other, s/(s+u) is 0.30 or more and 0.70 or less, and one of X and Y is It represents the divalent group represented by the formula (1-1), the other of X and Y represents the bivalent group represented by the formula (1-2), according to claim 1 Electrophotographic photoreceptor. In the general formula (1), r and s are not 0, X and Y are different from each other, s/(s+u) is 0.30 or more and 0.70 or less, and s and u are different from each other. The electrophotographic photosensitive member according to claim 1, which represents a number. The polyarylate resin represented by the general formula (1) is represented by the following chemical formula ( R-4), (R-5), (R-6), (R-7) or (R-8). The electrophotographic photosensitive member according to claim 1, which is a polyarylate resin.

The electrophotographic photosensitive member according to claim 1, wherein the electron transfer agent contains a compound represented by the following general formula (ET1), (ET2), (ET3), (ET4) or (ET5).

(In the above general formulas (ET1), (ET2), (ET3), (ET4) and (ET5), R ¹¹ , R ¹² , R ²¹ , R ²² , R ²³ , R ²⁴ , R ³¹ , R ³² , R. ⁴¹ , R ⁴² , R ⁴³ , R ⁵¹ , R ⁵² , R ⁵³ and R ⁵⁴ are each independently a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, or 2 or more carbon atoms. It represents an alkenyl group having 6 or less, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 14 carbon atoms which may have at least one alkyl group having 1 to 6 carbon atoms. ) The electrophotographic photosensitive member according to claim 1, wherein the hole transport material contains a compound represented by the following general formula (HT1), (HT2), or (HT3).

(In the general formula (HT1), R ¹¹¹ , R ¹¹² and R ¹¹³ each independently represent an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or 6 to 14 carbon atoms. Represents an aryl group, and b ₁ , b ₂ and b ₃ each independently represent an integer of 0 or more and 5 or less.)

(In the general formula (HT2), R ¹²¹ , R ¹²² , R ¹²³ , R ¹²⁴ , R ¹²⁵ and R ¹²⁶ are each independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms. Represents a group, d ₁ , d ₂ , d ₅ and d ₆ each independently represent an integer of 0 or more and 5 or less, and d ₃ and d ₄ each independently represent an integer of 0 or more and 4 or less.)

(In the general formula (HT3), R ¹³¹ , R ¹³² , R ¹³³ , R ¹³⁴ , R ¹³⁵ and R ¹³⁶ are each independently an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms. A group, an aryl group having 6 to 14 carbon atoms or an alkenyl group having 2 to 6 carbon atoms, e ₁ , e ₂ , e ₃ and e ₄ each independently represent an integer of 0 to 5; e ₅ and e ₆ each independently represent an integer of 0 or more and 4 or less.) A process cartridge comprising the electrophotographic photosensitive member according to claim 1. An electrophotographic photoreceptor,
A charging unit that charges the surface of the electrophotographic photosensitive member,
An exposure unit that exposes the charged surface of the electrophotographic photosensitive member to form an electrostatic latent image on the surface of the electrophotographic photosensitive member;
A developing unit for developing the electrostatic latent image as a toner image,
An image forming apparatus comprising: a transfer unit that transfers the toner image from the electrophotographic photosensitive member to a transfer target,
The charging unit positively charges the surface of the electrophotographic photosensitive member,
An image forming apparatus, wherein the electrophotographic photosensitive member is the electrophotographic photosensitive member according to claim 1. The image forming apparatus according to claim 11 , wherein the charging unit applies a DC voltage to the electrophotographic photosensitive member.

Images