JP2021071564A - Electrophotographic photoreceptor - Google Patents

Abstract

To provide an electrophotographic photoreceptor that is excellent in wear resistance and prevents random lateral stripes in a formed image.SOLUTION: A photosensitive layer included in an electrophotographic photoreceptor includes a charge generating layer and a charge transport layer. The charge transport layer contains a binder resin, metal-free phthalocyanine, and a hole transport agent. The content of metal-free phthalocyanine is 0.1 to 0.5 parts by mass based on 100.0 parts by mass of the binder resin. The binder resin includes a polyarylate resin having one type of first repeating unit, one type of second repeating unit, and an end group. The first repeating unit is represented by the general formula (1). The second repeating unit is represented by the general formula (2). The end group is represented by the general formula (3). In the general formula (3), Rf represents a chain aliphatic group having 1 to 20 carbon atoms and substituted by one or more fluorine atoms.SELECTED DRAWING: None

Description

The present invention relates to an electrophotographic photosensitive member.

The electrophotographic photosensitive member is used as an image carrier in an electrophotographic image forming apparatus (for example, a printer or a multifunction device). The electrophotographic photosensitive member includes a photosensitive layer. As the electrophotographic photosensitive member, for example, a single-layer electrophotographic photosensitive member and a laminated electrophotographic photosensitive member are used. The single-layer electrophotographic photosensitive member includes a single-layer photosensitive layer having a function of generating charges and a function of transporting charges. The laminated electrophotographic photosensitive member includes a photosensitive layer including a charge generating layer having a function of generating charges and a charge transporting layer having a function of transporting charges.

An example of Patent Document 1 describes the production of a polycarbonate copolymer using p-tert-butylphenol as a terminal terminator.

Japanese Unexamined Patent Publication No. 2012-51983

However, the polycarbonate copolymer described in Patent Document 1 is insufficient in terms of wear resistance.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an electrophotographic photosensitive member having excellent wear resistance and further suppressing random horizontal streaks in a formed image.

The electrophotographic photosensitive member of the present invention includes a conductive substrate and a photosensitive layer. The photosensitive layer includes a charge generation layer and a charge transport layer. The charge generating layer contains a charge generating agent. The charge transport layer contains a binder resin, metal-free phthalocyanine, and a hole transport agent. The content of the metal-free phthalocyanine is 0.1 parts by mass or more and 0.5 parts by mass or less with respect to 100.0 parts by mass of the binder resin. The binder resin contains a polyarylate resin having at least one first repeating unit, at least one second repeating unit, and a terminal group. The first repeating unit is represented by the general formula (1). The second repeating unit is represented by the general formula (2). The terminal group is represented by the general formula (3).

In the general formula (1), R ¹ , R ² , R ³ , and R ⁴ each independently represent a hydrogen atom or a methyl group. R ⁵ and R ⁶ each independently represent a hydrogen atom or an alkyl group having 1 or more and 4 or less carbon atoms. R ⁵ and R ⁶ may be combined with each other to represent a divalent group represented by the general formula (X). In the general formula (2), X ¹ represents a divalent group represented by the chemical formulas (2A), (2B), (2C), or (2D). In the general formula (3), R ^f represents a chain aliphatic group having 1 or more and 20 or less carbon atoms substituted with one or more fluorine atoms.

In the general formula (X), t represents an integer of 1 or more and 3 or less. * Represents a bond.

The electrophotographic photosensitive member of the present invention has excellent wear resistance and can suppress random horizontal streaks in a formed image.

It is a partial cross-sectional view of the electrophotographic photosensitive member which concerns on embodiment of this invention. It is a partial cross-sectional view of the electrophotographic photosensitive member which concerns on embodiment of this invention. It is a partial cross-sectional view of the electrophotographic photosensitive member which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments. The present invention can be carried out with appropriate modifications within the scope of the object of the present invention. In addition, although the description may be omitted as appropriate for the parts where the description is duplicated, the gist of the invention is not limited.

In the following description, a compound and its derivatives may be generically referred to by adding "system" after the compound name. When the polymer name is represented by adding "system" after the compound name, it means that the repeating unit of the polymer is derived from the compound or its derivative.

Next, the substituents used in the present specification will be described. Alkyl groups with 1 to 8 carbon atoms, alkyl groups with 1 to 6 carbon atoms, alkyl groups with 1 to 4 carbon atoms, and alkyl groups with 3 to 5 carbon atoms are not specified. As long as it is linear or branched, it is unsubstituted. Examples of the alkyl group having 1 or more and 8 or less carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and 1 -Methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylpropyl group, 2-ethylpropyl group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, 2,2-dimethylpropyl group, 1,2-dimethylpropyl group, n-hexyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 1,1-dimethylbutyl group, 1,2-dimethyl Butyl group, 1,3-dimethylbutyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, 3,3-dimethylbutyl group, 1,1,2-trimethylpropyl group, 1,2,2 Included are -trimethylpropyl group, 1-ethylbutyl group, 2-ethylbutyl group and 3-ethylbutyl group, linear and branched heptyl groups, and linear and branched octyl groups. Examples of alkyl groups having 1 to 6 carbon atoms, alkyl groups having 1 to 4 carbon atoms, and alkyl groups having 3 to 5 carbon atoms are examples of alkyl groups having 1 to 8 carbon atoms, respectively. Among the groups described as an example, it is a group having a corresponding number of carbon atoms.

Unless otherwise specified, the alkoxy group having 1 or more and 8 or less carbon atoms and the alkoxy group having 1 or more and 4 or less carbon atoms are linear or branched and unsubstituted. Examples of the alkoxy group having 1 to 8 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, and an n-pentoxy group. 1-methylbutoxy group, 2-methylbutoxy group, 3-methylbutoxy group, 1-ethylpropoxy group, 2-ethylpropoxy group, 1,1-dimethylpropoxy group, 1,2-dimethylpropoxy group, 2,2- Dimethylpropoxy group, 1,2-dimethylpropoxy group, n-hexyloxy group, 1-methylpentyloxy group, 2-methylpentyloxy group, 3-methylpentyloxy group, 4-methylpentyloxy group, 1,1- Dimethylbutoxy group, 1,2-dimethylbutoxy group, 1,3-dimethylbutoxy group, 2,2-dimethylbutoxy group, 2,3-dimethylbutoxy group, 3,3-dimethylbutoxy group, 1,1,2- Methyl propoxy group, 1,2,2-trimethylpropoxy group, 1-ethylbutoxy group, 2-ethylbutoxy group, 3-ethylbutoxy group, linear and branched heptyloxy groups, and linear and branched Examples include branched octyloxy groups. The examples of the alkoxy groups having 1 or more and 4 or less carbon atoms are the groups having the corresponding carbon atoms among the groups described as examples of the alkoxy groups having 1 or more and 8 or less carbon atoms.

Cycloalkanes having 5 or more and 7 or less carbon atoms are unsubstituted unless otherwise specified. Examples of cycloalkanes having 5 or more and 7 or less carbon atoms include cyclopentane, cyclohexane, and cycloheptane. The substituents used in the present specification have been described above.

<Electrophotophotoreceptor>
The present embodiment relates to an electrophotographic photosensitive member (hereinafter, may be referred to as a photosensitive member). Hereinafter, the structure of the photoconductor 1 of the present embodiment will be described with reference to FIGS. 1 to 3. 1 to 3 show partial cross-sectional views of the photoconductor 1.

As shown in FIG. 1, the photoconductor 1 includes a conductive substrate 2 and a photosensitive layer 3. The photosensitive layer 3 includes a charge generation layer 3a and a charge transport layer 3b. That is, the photosensitive member 1 is provided with a charge generating layer 3a and a charge transporting layer 3b as the photosensitive layer 3. The photoconductor 1 is a laminated electrophotographic photosensitive member.

As shown in FIG. 1, a charge generation layer 3a may be provided on the conductive substrate 2, and a charge transport layer 3b may be provided on the charge generation layer 3a. As shown in FIG. 2, the photoconductor 1 may be provided with a charge transport layer 3b on the conductive substrate 2 and a charge generation layer 3a on the charge transport layer 3b.

As shown in FIG. 3, the photosensitive member 1 may include a conductive substrate 2, a photosensitive layer 3, and an intermediate layer 4 (undercoat layer). The intermediate layer 4 is provided between the conductive substrate 2 and the photosensitive layer 3. As shown in FIGS. 1 and 2, the photosensitive layer 3 may be provided directly on the conductive substrate 2. Alternatively, as shown in FIG. 3, the photosensitive layer 3 (for example, the charge generating layer 3a or the charge transporting layer 3b) may be provided on the conductive substrate 2 via the intermediate layer 4.

The photoconductor 1 may include a conductive substrate 2, a photosensitive layer 3, and a protective layer (not shown). The protective layer is provided on the photosensitive layer 3.

The charge generation layer 3a is, for example, a single layer. The thickness of the charge generation layer 3a is not particularly limited, but is preferably 0.01 μm or more and 5 μm or less, and more preferably 0.1 μm or more and 3 μm or less.

The charge transport layer 3b is, for example, a single layer. The thickness of the charge transport layer 3b is not particularly limited, but is preferably 2 μm or more and 100 μm or less, and more preferably 5 μm or more and 50 μm or less.

As shown in FIGS. 1 and 3, it is preferable that the charge transport layer 3b is a single layer and is provided as the outermost surface layer of the photoconductor 1. The wear resistance of the photoconductor 1 can be further improved by providing the charge transport layer 3b containing the polyarylate resin (PA) described later and the metal-free phthalocyanine described later in the same layer as the outermost surface layer. As shown in FIG. 2, the charge generation layer 3a may be provided as the outermost surface layer of the photoconductor 1. Further, the protective layer may be provided as the outermost surface layer of the photoconductor 1. The structure of the photoconductor 1 has been described above with reference to FIGS. 1 to 3. Hereinafter, the photoconductor will be described in more detail.

[Charge generation layer]
The charge generating layer contains a charge generating agent. The charge generation layer may further contain a base resin, if necessary. The charge generation layer may further contain additives, if necessary.

(Charge generator)
Examples of the charge generator include phthalocyanine pigments, perylene pigments, bisazo pigments, trisazo pigments, dithioketopyrrolopyrrole pigments, metal-free naphthalocyanine pigments, metal naphthalocyanine pigments, squaline pigments, indigo pigments, azulenium pigments, and cyanine. Pigments, powders of inorganic photoconductive materials (eg, selenium, selenium-tellu, selenium-arsenic, cadmium sulfide, and amorphous silicon), pyririum pigments, anthanthrone pigments, triphenylmethane pigments, slen pigments, toluidine pigments , Pyrazoline pigments, and quinacridone pigments. The charge generating layer may contain only one kind of charge generating agent, or may contain two or more kinds of charge generating agents.

The phthalocyanine pigment is a pigment having a phthalocyanine structure. Examples of the phthalocyanine pigment include metal-free phthalocyanine and metal phthalocyanine. Examples of the metallic phthalocyanine include titanyl phthalocyanine, hydroxygallium phthalocyanine, and chlorogallium phthalocyanine. Metal-free phthalocyanines are represented by the chemical formula (CGM-1). Titanyl phthalocyanine is represented by the chemical formula (CGM-2).

The phthalocyanine pigment may be crystalline or amorphous. Examples of the crystal of the metal-free phthalocyanine include an X-type crystal of the metal-free phthalocyanine (hereinafter, may be referred to as an X-type metal-free phthalocyanine). Examples of the crystals of titanyl phthalocyanine include α-type, β-type, and Y-type crystals of titanyl phthalocyanine (hereinafter, they may be referred to as α-type, β-type, and Y-type titanyl phthalocyanine, respectively).

For example, it is preferable to use a photoconductor having sensitivity in a wavelength region of 700 nm or more for a digital optical image forming apparatus (for example, a laser beam printer or a facsimile using a light source such as a semiconductor laser). Since it has a high quantum yield in the wavelength region of 700 nm or more, the phthalocyanine pigment is preferable as the charge generator, metal-free phthalocyanine or titanyl phthalocyanine is more preferable, titanyl phthalocyanine is further preferable, and Y-type titanyl phthalocyanine is particularly preferable. ..

The Y-type titanyl phthalocyanine has a main peak at 27.2 ° of the Bragg angle (2θ ± 0.2 °) in the CuKα characteristic X-ray diffraction spectrum, for example. The main peak in the CuKα characteristic X-ray diffraction spectrum is the peak having the first or second highest intensity in the range where the Bragg angle (2θ ± 0.2 °) is 3 ° or more and 40 ° or less. Y-type titanyl phthalocyanine does not have a peak at 26.2 ° C. in the CuKα characteristic X-ray diffraction spectrum.

The CuKα characteristic X-ray diffraction spectrum can be measured by, for example, the following method. First, a sample (titanyl phthalocyanine) is filled in a sample holder of an X-ray diffractometer (for example, "RINT (registered trademark) 1100" manufactured by Rigaku Co., Ltd.), and an X-ray tube Cu, tube voltage 40 kV, tube current 30 mA, The X-ray diffraction spectrum is measured under the condition that the wavelength of CuKα characteristic X-ray is 1.542 Å. The measurement range (2θ) is, for example, 3 ° or more and 40 ° or less (start angle 3 °, stop angle 40 °), and the scanning speed is, for example, 10 ° / min. The main peak is determined from the obtained X-ray diffraction spectrum, and the Bragg angle of the main peak is read.

The content of the charge generator is preferably 10 parts by mass or more and 300 parts by mass or less, and more preferably 100 parts by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the base resin.

(Base resin)
Examples of the base resin include thermoplastic resins (more specifically, polycarbonate resins, styrene resins, styrene-butadiene copolymers, styrene-acrylonitrile copolymers, styrene-maleic acid copolymers, and styrene-acrylic acids). Copolymers, acrylic copolymers, polyethylene resins, ethylene-vinyl acetate copolymers, chlorinated polyethylene resins, polyvinyl chloride resins, polypropylene resins, ionomers, vinyl chloride-vinyl acetate copolymers, polyester resins, alkyd resins, Polyamide resin, polyurethane resin, polysulfone resin, diallyl phthalate resin, ketone resin, polyvinyl butyral resin, polyvinyl acetal resin, and polyether resin), thermosetting resin (more specifically, silicone resin, epoxy resin, phenol resin, Examples thereof include urea resins, melamine resins, and other crosslinkable thermosetting resins), and photocurable resins (more specifically, epoxy-acrylic acid-based resins and urethane-acrylic acid-based copolymers). ..

(Additive)
Examples of the additive contained in the charge generation layer include an ultraviolet absorber, an antioxidant, a radical scavenger, a singlet quencher, a softener, a surface modifier, a bulking agent, a thickener, and a dispersion stabilizer. , Wax, donor, surfactant, plasticizer, sensitizer, and leveling agent.

[Charge transport layer]
The charge transport layer contains a binder resin, metal-free phthalocyanine, and a hole transport agent. The charge transport layer preferably further contains an electron acceptor compound. The charge transport layer may further contain additives, if desired.

(Binder resin)
The binder resin contains a polyarylate resin having at least one first repeating unit, at least one second repeating unit, and a terminal group. The first repeating unit is represented by the general formula (1). The second repeating unit is represented by the general formula (2). The terminal group is represented by the general formula (3). Hereinafter, at least one kind of first repeating unit represented by the general formula (1), at least one kind of second repeating unit represented by the general formula (2), and a terminal represented by the general formula (3). A polyarylate resin having a group may be referred to as "polyarylate resin (PA)". The first repeating unit represented by the general formula (1) may be described as "repeating unit (1)". The second repeating unit represented by the general formula (2) may be described as "repeating unit (2)". The terminal group represented by the general formula (3) may be described as "terminal group (3)".

In the general formula (1), R ¹ , R ² , R ³ , and R ⁴ each independently represent a hydrogen atom or a methyl group. R ⁵ and R ⁶ each independently represent a hydrogen atom or an alkyl group having 1 or more and 4 or less carbon atoms. R ⁵ and R ⁶ may be combined with each other to represent a divalent group represented by the general formula (X). In the general formula (2), X ¹ represents a divalent group represented by the chemical formulas (2A), (2B), (2C), or (2D). In the general formula (3), R ^f represents a chain aliphatic group having 1 or more and 20 or less carbon atoms substituted with one or more fluorine atoms.

In the general formula (X), t represents an integer of 1 or more and 3 or less. * Represents a bond. Specifically, * represents a bond to the carbon atom to which ^{X 1} is bonded in the general formula (2).

Polyarylate resin (PA) has excellent strength because it has a repeating unit having a specific structure. Since the terminal group (3) of the polyarylate resin (PA) has a fluorine atom and the main chain does not have a halogen atom, the main chains are easily entangled with each other and have excellent strength. Since the polyarylate resin (PA) has a terminal group containing a chain aliphatic group substituted with a fluorine atom, the frictional resistance on the surface of the charge transport layer is reduced. For these reasons, the abrasion resistance of the photoconductor is improved by incorporating the polyarylate resin (PA) in the charge transport layer.

Further, since the polyarylate resin (PA) has a fluorine atom at the terminal group (3) and no halogen atom at the main chain, it has excellent compatibility with metal-free phthalocyanine and a hole transporting agent, which will be described later, and has an electric charge. Crystallization of the transport layer can be suppressed.

The polyarylate resin (PA) has a main chain and a terminal group (3). Hereinafter, the main chain and the terminal group (3) of the polyarylate resin (PA) will be described.

The main chain of the polyarylate resin (PA) contains at least one repeating unit (1) and at least one repeating unit (2).

Hereinafter, the repeating unit (1) will be described. As the alkyl group having 1 or more and 4 or less carbon atoms represented by ^{R 5} and R ⁶ in the general formula (1), a methyl group or an ethyl group is preferable.

As t in the general formula (X), 1 or 2 is preferable, and 2 is more preferable.

^{When R 5} and R ⁶ in the general formula (1) are bonded to each other to represent a divalent group represented by the general formula (X), R ¹ and R ³ represent a methyl group, respectively, and R ² and R It is preferable that each R ^{4 represents a hydrogen atom.}

At least one repeating unit (1) is a repeating unit of at least one of the repeating units represented by the chemical formulas (1-1), (1-2), (1-3), and (1-4). It is preferably a unit. Hereinafter, the repeating units represented by the chemical formulas (1-1), (1-2), (1-3), and (1-4) are referred to as repeating units (1-1) and (1-2), respectively. , (1-3), and (1-4). Of these repeating units, at least one repeating unit (1) is at least one of these repeating units (1-2), (1-3), and (1-4). May be good.

The polyarylate resin (PA) may contain only one type of repeating unit (1), or may contain two or more types (for example, two types) of repeating units (1).

When the polyarylate resin (PA) contains two types of repeating units (1), the ratio of the number of one repeating unit (1) to the total number of the two types of repeating units (1) (hereinafter referred to as ratio r). There is), preferably 0.10 or more and 0.90 or less.

Next, the repeating unit (2) will be described. As the repeating unit (2), the repeating unit represented by the general formulas (2-1) and (2-2) (hereinafter, each of which may be described as the repeating unit (2-1) and (2-2). There is) is preferable. In the following general formula (2-2), X ² represents a divalent group represented by the chemical formula (2A), (2B) or (2D).

At least one repeating unit (2) is one of the repeating units represented by the chemical formulas (2-1C), (2-2A), (2-2B), and (2-2D). It is preferably a unit. Hereinafter, the repeating units represented by the chemical formulas (2-1C), (2-2A), (2-2B), and (2-2D) are referred to as repeating units (2-1C) and (2-2A), respectively. , (2-2B), and (2-2D).

The polyarylate resin (PA) may contain only one type of repeating unit (2), or may contain two or more types (for example, two types) of repeating units (2). When the polyarylate resin (PA) contains one type of repeating unit (2), the repeating unit (2) may be the repeating unit (2-2A), (2-2B), or (2-2D). It is preferably a repeating unit (2-2A), more preferably.

From the viewpoint of further improving the abrasion resistance of the photoconductor, the polyarylate resin (PA) preferably has two or more kinds of repeating units (2), and the repeating unit (2-1) and the repeating unit (2-2). ) And more preferably. From the same viewpoint, it is particularly preferable that the polyarylate resin (PA) has one type of repeating unit (2-1) and one type of repeating unit (2-2) as the repeating unit (2).

When the polyarylate resin (PA) contains two kinds of repeating units (2), it is preferable that the two kinds of repeating units (2) are a repeating unit (2-1C) and a repeating unit (2-2A). It is also preferable that the two types of repeating units (2) are a repeating unit (2-1C) and a repeating unit (2-2B). It is also preferable that the two types of repeating units (2) are a repeating unit (2-1C) and a repeating unit (2-2D).

From the viewpoint of further improving the wear resistance of the photoconductor, the ratio of the number of repeating units (2-1) to the total number of repeating units (2) (hereinafter, may be referred to as ratio p) is 0.05. More than 1.00 is preferable, 0.10 or more and 0.70 or less is more preferable, 0.30 or more and 0.70 or less is further preferable, 0.50 or more and 0.70 or less is further preferable, and 0.60 or more and 0. 70 or less is particularly preferable.

The ratio p and the ratio r already described are not values obtained from one molecular chain, but are derived from the entire polyarylate resin (PA) contained in the charge transport layer (plural molecular chains). It is the average value of the obtained values. The ratio of each repeating unit can be calculated from the ^{1 H-NMR spectrum obtained by measuring the 1} H-NMR spectrum of the polyarylate resin (PA) using a proton nuclear magnetic resonance spectrometer.

Next, the terminal group (3) will be described. The chain aliphatic group substituted with the fluorine atom represented ^{by R f} in the general formula (3) is linear or branched chain. The number of fluorine atoms substituting the chain aliphatic group is preferably 1 or more and 37 or less, and more preferably 1 or more and 17 or less. The terminal group (3) is acyclic. Since the terminal group (3) is not a cyclic group but a chain-like aliphatic group, the abrasion resistance of the photoconductor can be improved. Here, the "chain aliphatic group" is, for example, a monovalent chain hydrocarbon group (particularly an alkyl group) or a group in which -O- is inserted between carbon-carbon bonds of the chain hydrocarbon group. is there.

As the terminal group (3), a terminal group represented by the following general formula (3-1) (hereinafter, may be referred to as a terminal group (3-1)) is preferable. When the polyarylate resin (PA) has a terminal group (3-1), the frictional resistance on the surface of the charge transport layer can be further reduced, and the abrasion resistance of the photoconductor can be further improved.

In the general formula (3-1), Q ¹ represents a linear or branched-chain perfluoroalkyl group having 1 to 6 carbon atoms. Q ² represents a linear or branched chain perfluoroalkylene group having 1 or more and 6 or less carbon atoms. n represents an integer of 0 or more and 2 or less. when n is 2, two Q ² 'may represent the same group together, it may represent a different group.

^{As the perfluoroalkyl group represented by Q 1} in the general formula (3-1), a linear or branched perfluoroalkyl group having 3 to 6 carbon atoms is preferable, and a linear carbon atom is preferable. A perfluoroalkyl group having a number of 3 or more and 6 or less is more preferable, and a heptafluoro n-propyl group or a tridecafluoro n-hexyl group is further preferable.

^{As the perfluoroalkylene group represented by Q 2} in the general formula (3-1), a linear or branched perfluoroalkylene group having 2 or 3 carbon atoms is preferable, and 1-fluoro-1-tri is preferable. A fluoromethyl-methylene group or a 1,1,2-trifluoro-2-trifluoromethyl-ethylene group is more preferred.

From the viewpoint of further improving the wear resistance of the photoconductor, suitable examples of the terminal group (3) are the terminal groups represented by the chemical formulas (M1), (M2), (M3), and (M4) (hereinafter referred to as). , Each of which may be referred to as a terminal group (M1), (M2), (M3), and (M4)).

From the viewpoint of further improving the wear resistance of the photoconductor, the terminal group (3) is more preferably the terminal group (M1), (M3), or (M4). Further, the terminal group (3) has a long carbon chain and has many fluorine atoms, so that the frictional resistance on the surface of the charge transport layer tends to decrease. For this reason, as the terminal group (3), the terminal group (M1) or (M3) is more preferable, and the terminal group (M3) is particularly preferable.

As the polyarylate resin (PA), the polyarylate resins (j-1) to (j-11) shown in Table 1 below are preferable.

The meanings of the terms used in Table 1 and Tables 2 and 3 described later are as follows. "Unit (1)" and "unit (2)" indicate repeating units (1) and (2), respectively. When two repeating units are described in the repeating unit (1) or the repeating unit (2), it indicates that the repeating unit (1) or the repeating unit (2) has both of them. For example, "1-2 / 1-3" in Table 1 indicates that it has both repeating units (1-2) and (1-3). "-" Indicates that there is no corresponding value.

Examples of the polyarylate resin (PA) include the polyarylate resins (R-1-M1) to (R-10-M1) and (R-1-M2) to (R-1-M4) shown in Table 2 below. preferable.

In the polyarylate resin (PA), the repeating unit derived from an aromatic diol and the repeating unit derived from an aromatic dicarboxylic acid are adjacent to each other. The repeating unit derived from the aromatic diol is, for example, the repeating unit (1). The repeating unit derived from the aromatic dicarboxylic acid is, for example, the repeating unit (2). Further, in the polyarylate resin (PA), the terminal group (3) is adjacent to the repeating unit derived from the aromatic dicarboxylic acid and bonded to each other. When the polyarylate resin (PA) is a copolymer, the polyallylate resin (PA) may be, for example, a random copolymer, an alternating copolymer, a periodic copolymer, or a block copolymer. ..

The polyarylate resin (PA) preferably has only the repeating units (1) and (2) as the repeating unit. However, the polyarylate resin (PA) may further have a repeating unit derived from an aromatic diol other than the repeating unit (1), and further has a repeating unit derived from an aromatic dicarboxylic acid other than the repeating unit (2). You may.

The viscosity average molecular weight of the polyarylate resin (PA) is preferably 10,000 or more, more preferably 20,000 or more, further preferably 30,000 or more, and particularly preferably 40,000 or more. When the viscosity average molecular weight of the polyarylate resin (PA) is 10,000 or more, the abrasion resistance of the binder resin can be further improved. On the other hand, the viscosity average molecular weight of the binder resin is preferably 80,000 or less, more preferably 70,000 or less. When the viscosity average molecular weight of the binder resin is 80,000 or less, the polyarylate resin (PA) is easily dissolved in the solvent for forming the charge transport layer, so that the charge transport layer can be preferably formed.

The method for producing the polyarylate resin (PA) is not particularly limited, and for example, an aromatic diol and an aromatic dicarboxylic acid for forming the main chain, and a terminal terminator for forming the terminal group (3). There is a method of polycondensing. As a method for polycondensation, a known synthesis method (more specifically, solution polymerization, melt polymerization, interfacial polymerization, etc.) can be adopted.

The aromatic diol for forming the main chain is represented by, for example, the following general formula (BP-1). The aromatic dicarboxylic acid for forming the main chain is represented by, for example, the following general formula (DC-2). The terminal terminator for forming the terminal group (3) is represented by, for example, the following general formula (T-3). ^{R 1} , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , X ¹ and R ^f in the following general formulas (BP-1), (DC-2) and (T-3) are general. It is synonymous with ^{R 1} , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , X ¹ and R ^{f in the} formulas (1), (2) and (3). Hereinafter, the compounds represented by the following general formulas (BP-1), (DC-2), and (T-3) are used as compounds (BP-1), (DC-2), and (T-3), respectively. ) May be described.

Examples of the compound (BP-1) include compounds represented by the chemical formulas (BP-1-1) to (BP-1--4) (hereinafter, each of which is a compound (BP-1-1) to (BP-1--4). ) May be described as).

The compound (DC-2) is a compound represented by the following chemical formulas (DC-2-1C), (DC-2-2A), (DC-2-2B), and (DC-2-2D) (hereinafter referred to as “compound”). , Each of which may be referred to as compound (DC-2-1C), (DC-2-2A), (DC-2-2B), and (DC-2-2D)).

The compound (T-3) may be described as a compound represented by the following chemical formulas (T-M1) to (T-M4) (hereinafter, each of which is referred to as a compound (T-M1) to (T-M4). ) Is preferable.

The aromatic diol for forming the main chain may be transformed into an aromatic diacetate and used. The aromatic dicarboxylic acid for forming the main chain may be derivatized and used. Examples of the derivative of the aromatic dicarboxylic acid include aromatic dicarboxylic acid dichloride, aromatic dicarboxylic acid dimethyl ester, aromatic dicarboxylic acid diethyl ester and aromatic dicarboxylic acid anhydride. Aromatic dicarboxylic acid dichloride is a compound in which two "-C (= O) -OH" groups of an aromatic dicarboxylic acid are each replaced with a "-C (= O) -Cl" group.

In the polycondensation of the aromatic diol and the aromatic dicarboxylic acid, one or both of the base and the catalyst may be added. The base and catalyst can be appropriately selected from known bases and catalysts. Examples of the base include sodium hydroxide. Examples of the catalyst include benzyltributylammonium chloride, ammonium chloride, ammonium bromide, quaternary ammonium salt, triethylamine, and trimethylamine.

The charge transport layer preferably contains only polyarylate resin (PA) as the binder resin. The charge transport layer may further contain a binder resin other than the polyarylate resin (PA) (hereinafter, may be referred to as other binder resin) as the binder resin. Examples of other binder resins are the same as those of the base resin.

(Metal-free phthalocyanine contained in the charge transport layer)
The charge transport layer contains metal-free phthalocyanine. Since the charge transport layer contains metal-free phthalocyanine, random horizontal streaks in the formed image can be suppressed. In the present specification, the random horizontal stripe means that when an image is formed on paper using an image forming apparatus, a black line perpendicular to the paper transport direction (parallel to the axial direction of the photoconductor) is random. Image defects that occur at various line intervals. Random horizontal stripes are likely to occur when forming a halftone image on paper.

When the photoconductor is charged using a charging device, uneven charging occurs on the surface of the photoconductor in a direction parallel to the axial direction of the photoconductor (hereinafter, may be referred to as axial charging unevenness). Random lateral streaks are thought to be triggered. As the amount of change in the charging potential of the photoconductor increases with respect to the amount of change in the charging current flowing through the charging device, axial charging unevenness of the photoconductor is likely to occur. This is because the charging potential of the photoconductor fluctuates greatly with respect to a slight fluctuation of the charging current flowing through the charging device. Since the charge transport layer contains metal-free phthalocyanine, the amount of change in the charging potential of the photoconductor is reduced with respect to the amount of change in the charging current flowing through the charging device. Therefore, it is possible to suppress the occurrence of axial charging unevenness of the photoconductor, and it is possible to suppress the random horizontal streaks in the formed image.

Here, when the amount of change in the charging potential of the photoconductor is reduced with respect to the amount of change in the charging current flowing through the charging device, the charging current may be set high. When the charging current is set high, the photosensitive layer is easily worn. However, as already described, in the present embodiment, the charge transport layer contains a polycarbonate resin (PA) having excellent wear resistance. Therefore, the photoconductor of the present embodiment can achieve both improvement of wear resistance and suppression of random horizontal streaks in the formed image.

The metal-free phthalocyanine contained in the charge transport layer is represented by the following chemical formula (K1). The chemical formula (K1) is the same as the chemical formula (CGM-1) already described, but for convenience of explanation, the metal-free phthalocyanine contained in the charge generation layer is contained in the chemical formula (CGM-1) and the charge transport layer. The metal-free phthalocyanine produced is described as the chemical formula (K1).

The metal-free phthalocyanine may be crystalline or amorphous. Examples of crystals of metal-free phthalocyanine include X-type metal-free phthalocyanine.

The content of metal-free phthalocyanine is 0.1 parts by mass or more and 0.5 parts by mass or less with respect to 100.0 parts by mass of the binder resin. When the content of the metal-free phthalocyanine is less than 0.1 parts by mass with respect to 100.0 parts by mass of the binder resin, random horizontal stripes are generated in the formed image. If the content of the metal-free phthalocyanine is more than 0.5 parts by mass with respect to 100.0 parts by mass of the binder resin, the wear resistance of the photoconductor is lowered. In order to achieve a good balance between improvement of wear resistance and suppression of random horizontal streaks in the formed image, the content of metal-free phthalocyanine is 0.2 parts by mass or more and 0 parts by mass or more with respect to 100.0 parts by mass of the binder resin. It is preferably 5.5 parts by mass or less, and more preferably 0.2 parts by mass or more and 0.4 parts by mass or less.

(Hole transport agent)
Examples of the hole transporting agent include triphenylamine derivatives and diamine derivatives (for example, N, N, N', N'-tetraphenylbenzidine derivatives, N, N, N', N'-tetraphenylphenylenediamine derivatives, etc. N, N, N', N'-tetraphenylnaphthylene diamine derivative, N, N, N', N'-tetraphenylphenanthrylene diamine derivative, and di (aminophenylethenyl) benzene derivative), oxadiazole Systems compounds (eg, 2,5-di (4-methylaminophenyl) -1,3,4-oxadiazole), styryl compounds (eg, 9- (4-diethylaminostyryl) anthracene), carbazole compounds (eg, 9- (4-diethylaminostyryl) anthracene) For example, polyvinylcarbazole), organic polysilane compounds, pyrazoline compounds (eg, 1-phenyl-3- (p-dimethylaminophenyl) pyrazoline), hydrazone compounds, indol compounds, oxazole compounds, isooxazole compounds, thiazole. Examples thereof include system compounds, thiadiazol system compounds, imidazole system compounds, pyrazole system compounds, and triazole system compounds. The charge transport layer may contain only one type of hole transport agent, or may contain two or more types of hole transport agents.

The hole transporting agent preferably contains a compound represented by the following general formula (10) (hereinafter, may be referred to as a hole transporting agent (10)). When the charge transport layer contains the hole transport agent (10), the wear resistance, charge characteristics, and sensitivity characteristics of the photoconductor can be further improved, and random horizontal streaks in the formed image can be further suppressed.

In the general formula (10), R ¹⁰¹ , R ¹⁰³ , R ¹⁰⁴ , R ¹⁰⁵ , R ¹⁰⁶ , R ¹⁰⁷ , and R ¹⁰⁸ are each independently a hydrogen atom, an alkyl group having 1 or more and 8 or less carbon atoms, and a carbon atom. It represents a phenyl group which may be substituted with an alkyl group having a number of 1 or more and 8 or less, or an alkoxy group having a carbon atom number of 1 or more and 8 or less. Adjacent two of R ¹⁰³ , R ¹⁰⁴ , R ¹⁰⁵ , R ¹⁰⁶ and R ¹⁰⁷ may be bonded to represent a cycloalkane having 5 or more and 7 or less carbon atoms. R ¹⁰² and R ¹⁰⁹ each independently represent an alkyl group having 1 or more and 8 or less carbon atoms, a phenyl group, or an alkoxy group having 1 or more and 8 or less carbon atoms. b ₁ and b ₂ each independently represent an integer of 0 or more and 5 or less.

In the general formula (10), ^{as the alkyl group having 1 to 8 carbon atoms represented by R 101 to} R ¹⁰⁹ , an alkyl group having 1 to 6 carbon atoms is preferable, and an alkyl group having 1 to 4 carbon atoms is preferable. Is more preferable, and an n-butyl group is further preferable.

In the general formula (10), the ^{phenyl group represented by R 101 to} R ¹⁰⁹ may be substituted with an alkyl group having 1 to 8 carbon atoms. As such an alkyl group having 1 to 8 carbon atoms, an alkyl group having 1 to 6 carbon atoms is preferable, an alkyl group having 1 to 4 carbon atoms is more preferable, and a methyl group is further preferable.

In the general formula (10), ^{as the alkoxy group having 1 or more and 8 or less carbon atoms represented by R 101 to} R ¹⁰⁹ , an alkoxy group having 1 or more and 4 or less carbon atoms is preferable, and a methoxy group or an ethoxy group is more preferable.

In the general formula (10), ^{two adjacent two of R 103} , R ¹⁰⁴ , R ¹⁰⁵ , R ¹⁰⁶ and R ¹⁰⁷ may be bonded to each other to represent a cycloalkane having 5 or more and 7 or less carbon atoms. When ^{two adjacent two of R 103} , R ¹⁰⁴ , R ¹⁰⁵ , R ¹⁰⁶ and R ¹⁰⁷ are bonded to each other to form a cycloalkane having 5 or more and 7 or less carbon atoms, the cycloalkane is R ¹⁰³ , R ¹⁰⁴ , It condenses with the phenyl group to which R ¹⁰⁵ , R ¹⁰⁶ and R ¹⁰⁷ are bonded to form a bicyclic condensed ring group. In this case, the condensation site between the cycloalkane and the phenyl group may contain a double bond. Cyclohexane is preferable as the cycloalkane in which two adjacent two of R ¹⁰³ , R ¹⁰⁴ , R ¹⁰⁵ , R ¹⁰⁶ and R ^{107 are represented by binding to each other.}

When b ₁ represents an integer of 2 or more and 5 or less, the plurality of R ¹⁰² may represent the same group or different groups. When b ₂ represents an integer of 2 or more and 5 or less, the plurality of R ^109s may represent the same group or different groups. It is preferable that b ₁ and b ₂ independently represent 0 or 1, respectively.

In the general formula (10), R ¹⁰¹ and R ¹⁰⁸ preferably represent a hydrogen atom. R ¹⁰² and R ¹⁰⁹ preferably represent an alkyl group having 1 to 8 carbon atoms. R ¹⁰³ , R ¹⁰⁴ , R ¹⁰⁶ and R ¹⁰⁷ each preferably represent a hydrogen atom. R ¹⁰⁵ preferably represents an alkyl group having 1 or more carbon atoms and 8 or less carbon atoms, and more preferably an n-butyl group. It is preferable that b ₁ and b ₂ each independently represent 0.

As the hole transporting agent (10), a compound represented by the following chemical formula (HTM-1) (hereinafter, may be referred to as a hole transporting agent (HTM-1)) is preferable.

The charge transport layer preferably contains only the hole transport agent (10) as the hole transport agent, but may further contain a hole transport agent other than the hole transport agent (10).

The content of the hole transporting agent is preferably 10 parts by mass or more and 200 parts by mass or less, and more preferably 20 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the binder resin.

(Electron acceptor compound)
Examples of the electron acceptor compound include quinone compounds, diimide compounds, hydrazone compounds, malononitrile compounds, thiopyran compounds, trinitrothioxanthone compounds, 3,4,5,7-tetranitro-9-fluorenone compounds, and the like. Examples thereof include dinitroanthracene-based compounds, dinitroacridine-based compounds, tetracyanoethylene, 2,4,8-trinitrothioxanthone, dinitrobenzene, dinitroaclydin, succinic anhydride, maleic anhydride, and dibromomaleic anhydride. Examples of the quinone-based compound include a diphenoquinone-based compound, an azoquinone-based compound, an anthraquinone-based compound, a naphthoquinone-based compound, a nitroanthraquinone-based compound, and a dinitroanthraquinone-based compound.

As the electron acceptor compound, a compound represented by the following general formula (20) (hereinafter, may be referred to as an electron acceptor compound (20)) is preferable. When the charge transport layer contains the electron acceptor compound (20), the abrasion resistance, charge characteristics, and sensitivity characteristics of the photoconductor can be further improved, and random horizontal streaks in the formed image can be further suppressed.

In the general formula (20), R ²¹ , R ²² , R ²³ , and R ²⁴ each independently represent an alkyl group having 1 to 6 carbon atoms. It is preferable that R ²¹ , R ²² , R ²³ , and R ²⁴ each independently represent an alkyl group having 3 or more and 5 or less carbon atoms.

As the compound represented by the general formula (20), a compound represented by the following chemical formula (E-1) (hereinafter, may be referred to as an electron acceptor compound (E-1)) is preferable.

The content of the electron acceptor compound is preferably 0.1 part by mass or more and 10 parts by mass or less, and more preferably 0.5 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the binder resin.

The charge transport layer may contain only one type of electron acceptor compound, or may contain two or more types of electron acceptor compounds. The charge transport layer may contain only the electron acceptor compound (20) as the electron acceptor compound, or may further contain an electron acceptor compound other than the electron acceptor compound (20).

(Additive)
The example of the additive contained in the charge transport layer is the same as the example of the additive contained in the charge generation layer described above.

(Combination of materials)
In order to have excellent wear resistance and suppress random horizontal streaks in the formed image, the charge transport layer is made of polyarylate resins (j-1) to (j-11), (R-1-M1) to (R-1-M1) as binder resins. It is preferable to contain one of R-1-M4) and (R-2-M1) to (R-10-M1) and a metal-free phthalocyanine. For the same reason, the charge transport layer is composed of polyarylate resins (j-1) to (j-11), (R-1-M1) to (R-1-M4), and (R-2-M4) as binder resins. It is more preferable to contain one of M1) to (R-10-M1) and X-type acrylate metalless phthalocyanine.

In order to have excellent wear resistance and suppress random horizontal streaks in the formed image, the charge transport layer is composed of polyarylate resins (j-1) to (j-11), (R-1-M1) to (R-1-M1) as binder resins. It is preferable to contain one of R-1-M4) and (R-2-M1) to (R-10-M1), a metal-free phthalocyanine, and a hole transport agent (HTM-1). .. For the same reason, the charge transport layer is composed of polyarylate resins (j-1) to (j-11), (R-1-M1) to (R-1-M4), and (R-2-M4) as binder resins. It is more preferable to contain one of M1) to (R-10-M1), an X-type metal-free phthalocyanine, and a hole transport agent (HTM-1).

In order to have excellent wear resistance and suppress random horizontal streaks in the formed image, the charge transport layer is composed of polyarylate resins (j-1) to (j-11), (R-1-M1) to (R-1-M1) as binder resins. It preferably contains one of R-1-M4) and (R-2-M1) to (R-10-M1), a metal-free phthalocyanine, and an electron acceptor compound (E-1). For the same reason, the charge transport layers are polyarylate resins (j-1) to (j-11), (R-1-M1) to (R-1-M4), and (R-2-) as binder resins. It is more preferable to contain one of M1) to (R-10-M1), an X-type acrylate metalless phthalocyanine, and an electron acceptor compound (E-1).

In order to have excellent wear resistance and suppress random horizontal streaks in the formed image, the charge transport layer is composed of polyarylate resins (j-1) to (j-11), (R-1-M1) to (R-1-M1) as binder resins. R-1-M4), and one of (R-2-M1) to (R-10-M1), metal-free phthalocyanine, hole transporter (HTM-1), and electron acceptor compound (E). -1) and is preferably contained. For the same reason, the charge transport layers are polyarylate resins (j-1) to (j-11), (R-1-M1) to (R-1-M4), and (R-2-) as binder resins. It is more preferable to contain one of M1) to (R-10-M1), an X-type metalless phthalocyanine, a hole transport agent (HTM-1), and an electron acceptor compound (E-1). ..

[Conductive Hypokeimenon]
The conductive substrate is not particularly limited as long as it can be used as the conductive substrate of the photoconductor. The conductive substrate may be made of a material having a conductive surface at least. An example of a conductive substrate is a conductive substrate made of a conductive material. Another example of a conductive substrate is a conductive substrate coated with a conductive material. Materials having conductivity include, for example, aluminum, iron, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, and brass. These conductive materials may be used alone or in combination of two or more (for example, as an alloy). Among these conductive materials, aluminum and aluminum alloys are preferable because the transfer of electric charge from the charge generation 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. 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 the intermediate layer). By the presence of the intermediate layer, it is possible to smooth the flow of the current generated when the photoconductor is exposed and suppress the increase in resistance while maintaining the insulating state to the extent that the occurrence of leakage can be suppressed.

Inorganic particles include, for example, metal (eg, aluminum, iron, and copper) particles, metal oxide (eg, titanium oxide, alumina, zirconium oxide, tin oxide, and zinc oxide) particles, and non-metal oxides. (For example, silica) particles can be mentioned. These inorganic particles may be used alone or in combination of two or more.

The example of the resin for the intermediate layer is the same as the example of the other binder resin described above. In order to form the intermediate layer and the photosensitive layer well, it is preferable that the resin for the intermediate layer is different from the binder resin contained in the photosensitive layer. The intermediate layer may contain additives. Examples of additives contained in the intermediate layer are the same as those of other additives already described.

[Manufacturing method of photoconductor]
Next, an example of a method for manufacturing a photoconductor will be described. The method for producing a photoconductor includes a charge generation layer forming step and a charge transport layer forming step.

In the charge generation layer forming step, a coating liquid for forming the charge generation layer (hereinafter, may be referred to as a charge generation layer forming coating liquid) is prepared. The coating liquid for forming the charge generation layer is applied onto the conductive substrate. Next, at least a part of the solvent contained in the coated liquid for forming the charge generation layer is removed to form the charge generation layer. The coating liquid for forming a charge generating layer contains, for example, a charge generating agent, a base resin, and a solvent. Such a coating liquid for forming a charge generating layer is prepared by dissolving or dispersing a charge generating agent and a base resin in a solvent. The coating liquid for forming the charge generation layer may contain other additives, if necessary.

In the charge transport layer forming step, a coating liquid for forming the charge transport layer (hereinafter, may be referred to as a charge transport layer forming coating liquid) is prepared. A coating liquid for forming a charge transport layer is applied onto the charge generation layer. Next, at least a part of the solvent contained in the coated liquid for forming the charge transport layer is removed to form the charge transport layer. The coating liquid for forming the charge transport layer contains a hole transport agent, a binder resin, an additive, and a solvent. The coating liquid for forming the charge transport layer can be prepared by dissolving or dispersing the hole transport agent, the binder resin, and the metal-free phthalocyanine in a solvent. The coating liquid for forming the charge transport layer may further contain an electron acceptor compound and other additives, if necessary.

The solvent contained in the coating liquid for forming the charge generation layer and the coating liquid for forming the charge transport layer (hereinafter, may be comprehensively referred to as the coating liquid) is not particularly limited. Examples of solvents include alcohols (more specifically methanol, ethanol, isopropanol, butanol, etc.), aliphatic hydrocarbons (more specifically n-hexane, octane, cyclohexane, etc.), aromatic hydrocarbons, etc. Hydrogen (more specifically, benzene, toluene, xylene, etc.), halogenated hydrocarbons (more specifically, dichloromethane, dichloroethane, carbon tetrachloride, and chlorobenzene, etc.), ethers (more specifically, dimethyl ether). , Diethyl ether, tetrahydrofuran, propylene glycol monomethyl ether, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether, etc.), ketones (more specifically, acetone, methyl ethyl ketone, and cyclohexanone, etc.), esters (more specifically, ethyl acetate, and the like). Methyl acetate, etc.), dimethylformaldehyde, dimethylformamide, and dimethylsulfoxide. These solvents may be used alone or in combination of two or more.

The solvent contained in the coating liquid for forming the charge transport layer is preferably different from the solvent contained in the coating liquid for forming the charge generating layer. Further, the binder resin contained in the charge transport layer is preferably different from the base resin contained in the charge generation layer. This is because when the coating liquid for forming a charge transport layer is applied on the charge generating layer, it is preferable that the charge generating layer is not dissolved in the solvent of the coating liquid for forming the charge transport layer.

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

In order to improve the dispersibility of each component or the surface smoothness of each layer formed, the coating liquid may contain, for example, a surfactant or a leveling agent.

The method of applying the coating liquid is not particularly limited as long as it can uniformly apply the coating liquid. Examples of the coating method include a dip coating method, a spray coating method, a spin coating method, and a bar coating method.

The method for removing at least a part of the solvent contained in the coating liquid is not particularly limited as long as it can evaporate the solvent in the coating liquid. Examples of the removing method include heating, depressurization, and combined use of heating and depressurization. More specifically, a method of heat treatment (hot air drying) using a high temperature dryer or a vacuum dryer can be mentioned. The temperature of the heat treatment is, for example, 40 ° C. or higher and 150 ° C. or lower. The heat treatment time is, for example, 3 minutes or more and 120 minutes or less.

The method for producing the photoconductor may further include a step of forming an intermediate layer, if necessary. A known method can be appropriately selected for the step of forming the intermediate layer.

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

(Charge generator, hole transporter, and electron acceptor compound)
The Y-type titanyl phthalocyanine described in the embodiment was prepared as a charge generator to be contained in the charge generating layer. As the hole transporting agent contained in the charge transport layer, the hole transporting agent (HTM-1) described in the embodiment was prepared. As the electron acceptor compound to be contained in the charge transport layer, the electron acceptor compound (E-1) described in the embodiment was prepared.

(Metal-free phthalocyanine)
As the metal-free phthalocyanine contained in the charge transport layer, the X-type metal-free phthalocyanine described in the embodiment was prepared.

(Pigments and dyes used in comparative examples)
Instead of the metal-free phthalocyanine contained in the charge transport layer, as pigments used in Comparative Examples, pigments represented by the chemical formulas (K2), (K4), and (K5) (hereinafter, each of them is a pigment (K2), (K4) and (K5) may be described) were prepared. Further, instead of the metal-free phthalocyanine contained in the charge transport layer, a dye represented by the chemical formula (K3) (hereinafter, may be referred to as a dye (K3)) was prepared as a dye used in the comparative example.

(Binder resin)
As the binder resin, polyarylate resins (R-1-M1) to (R-1-M4), (R-2-M1) to (R-10-M1), (R-1-MA), (R-) 3-MA) and (R-6-MA) were respectively synthesized. Among the polyarylate resins, the polyarylate resins (R-1-M1) to (R-1-M4) and (R-2-M1) to (R-10-M1) are the polyarylates described in the embodiments. It is a polyarylate resin included in the resin (PA). Repeating unit (1), repeating unit (2), each of the polyarylate resins (R-1-M1) to (R-1-M4) and (R-2-M1) to (R-10-M1). And the terminal group and the ratio p are shown in Table 2 above. Repeating unit (1), repeating unit (2), and terminal group of each of the polyarylate resin (R-1-MA), (R-3-MA), and (R-6-MA), and the ratio p. Is shown in Table 3 below. “MA” of the terminal group in Table 3 indicates a group represented by the following chemical formula (MA). The yield of each polyarylate resin in the following description is a molar ratio conversion value.

(Synthesis of polyarylate resin (R-1-M1))
In the synthesis of the polyarylate resin (R-1-M1), a three-necked flask having a capacity of 2 L equipped with a thermometer and a three-way cock was used as a reaction vessel. In a reaction vessel, 20.01 g (82.56 mmol) of compound (BP-1-1), 0.281 g (0.826 mmol) of compound (TM1), 7.84 g (196 mmol) of sodium hydroxide, and 0.240 g (0.768 mmol) of benzyltributylammonium chloride was added. The air in the reaction vessel was replaced with argon gas. Further 600 mL of water was added to the contents of the reaction vessel. The contents of the reaction vessel were stirred at 20 ° C. for 1 hour. Next, the contents of the reaction vessel were cooled until the temperature of the contents of the reaction vessel reached 10 ° C. to obtain an alkaline aqueous solution A.

On the other hand, 9.84 g (38.9 mmol) of 2,6-naphthalenedicarboxylic acid dichloride (dichloride of compound (DC-2-1C)) and 4,4'-oxybis benzoic acid dichloride (compound (DC-2-2A)). ) Dichloride) 11.47 g (38.9 mmol) was dissolved in 300 g of chloroform. As a result, chloroform solution B was obtained.

Chloroform solution B was added to the alkaline aqueous solution A while stirring the alkaline aqueous solution A in the reaction vessel at 10 ° C. As a result, the polymerization reaction was started. While adjusting the temperature (liquid temperature) of the contents of the reaction vessel to 13 ± 3 ° C., the contents of the reaction vessel were stirred for 3 hours to proceed with the polymerization reaction. Next, the upper layer (aqueous layer) in the contents of the reaction vessel was removed with a decant to obtain an organic layer. Next, 500 mL of ion-exchanged water was placed in an Erlenmeyer flask having a capacity of 2 L. The obtained organic layer was further added to this flask. Further 300 g of chloroform and 6 mL of acetic acid were added to this flask. The flask contents were then stirred at room temperature for 30 minutes. Then, the upper layer (aqueous layer) in the flask contents was removed with a decant to obtain an organic layer. The obtained organic layer was washed with 500 mL of ion-exchanged water using a separating funnel. Washing with ion-exchanged water was repeated 8 times to obtain a water-washed organic layer.

Next, the organic layer washed with water was filtered to obtain a filtrate. 1.5 L of methanol was placed in a beaker with a capacity of 3 L. The obtained filtrate was slowly added dropwise to methanol in a beaker to obtain a precipitate. The precipitate was removed by filtration. The removed precipitate was vacuum dried at a temperature of 70 ° C. for 12 hours. As a result, a polyarylate resin (R-1-M1) was obtained (yield 28.6 g, yield 82.9%). The viscosity average molecular weight of the polyarylate resin (R-1-M1) was 50,500.

Polyarylate resins (R-1-M2) to (R-1-M4), (R-2-M1) to (R-10-M1), (R-1-MA), (R-3-MA) , And (R-6-MA) were synthesized by the same method as the synthesis of the polyarylate resin (R-1-M1) except that the following points were changed.

(Synthesis of polyarylate resin (R-2-M1))
In the synthesis of the polyarylate resin (R-2-M1), the dichloride of the compound (DC-2-2A) was changed to 38.9 mmol of the dichloride of the compound (DC-2-2B). The yield of the obtained polyarylate resin (R-2-M1) was 27.8 g, the yield was 82.1%, and the viscosity average molecular weight was 52,200.

(Synthesis of polyarylate resin (R-3-M1))
In the synthesis of the polyarylate resin (R-3-M1), the compound (BP-1-1) was changed to 82.56 mmol of the compound (BP-1-2). The yield of the obtained polyarylate resin (R-3-M1) was 31.0 g, the yield was 80.1%, and the viscosity average molecular weight was 48,100.

(Synthesis of polyarylate resin (R-4-M1))
In the synthesis of the polyarylate resin (R-4-M1), the compound (BP-1-1) was changed to 82.56 mmol of the compound (BP-1-2). Further, in the synthesis of the polyarylate resin (R-4-M1), the amount of dichloride used in the compound (DC-2-1C) was changed to 23.3 mmol, and the dichloride used in the compound (DC-2-2A) was used. The amount was changed to 54.5 mmol. The yield of the obtained polyarylate resin (R-4-M1) was 31.3 g, the yield was 79.6%, and the viscosity average molecular weight was 47,600.

(Synthesis of polyarylate resin (R-5-M1))
In the synthesis of the polyarylate resin (R-5-M1), the compound (BP-1-1) was converted to 8.26 mmol of the compound (BP-1-2) and 74.30 mmol of the compound (BP-1--3). changed. Further, in the synthesis of the polyarylate resin (R-5-M1), the amount of dichloride used in the compound (DC-2-1C) was changed to 7.8 mmol, and the dichloride used in the compound (DC-2-2A) was used. The amount was changed to 70.0 mmol. The yield of the obtained polyarylate resin (R-5-M1) was 31.2 g, the yield was 80.0%, and the viscosity average molecular weight was 49,500. Further, the obtained polyarylate resin (R-5-M1) has two types of repeating units (1-2) and (1-3) as the repeating unit (1), and the molar ratio (repeating unit) thereof. (1-2): The repeating unit (1-3)) was 1: 9.

(Synthesis of polyarylate resin (R-6-M1))
In the synthesis of the polyarylate resin (R-6-M1), the compound (BP-1-1) was changed to 82.56 mmol of the compound (BP-1-2). Moreover, in the synthesis of the polyarylate resin (R-6-M1), the dichloride of the compound (DC-2-2A) was changed to 38.9 mmol of the dichloride of the compound (DC-2-2B). The yield of the obtained polyarylate resin (R-6-M1) was 30.5 g, the yield was 76.8%, and the viscosity average molecular weight was 48,900.

(Synthesis of polyarylate resin (R-7-M1))
In the synthesis of the polyarylate resin (R-7-M1), the compound (BP-1-1) was changed to 82.56 mmol of the compound (BP-1-2). Moreover, in the synthesis of the polyarylate resin (R-7-M1), the dichloride of the compound (DC-2-2A) was changed to 38.9 mmol of the dichloride of the compound (DC-2-2D). The yield of the obtained polyarylate resin (R-7-M1) was 28.9 g, the yield was 78.6%, and the viscosity average molecular weight was 47,600.

(Synthesis of polyarylate resin (R-8-M1))
In the synthesis of the polyarylate resin (R-8-M1), the compound (BP-1-1) was changed to 82.56 mmol of the compound (BP-1--4). The yield of the obtained polyarylate resin (R-8-M1) was 27.8 g, the yield was 80.6%, and the viscosity average molecular weight was 55,100.

(Synthesis of polyarylate resin (R-9-M1))
Dichloride of compound (DC2-1C) was not used in the synthesis of polyarylate resin (R-9-M1). Moreover, in the synthesis of the polyarylate resin (R-9-M1), the amount of dichloride used in the compound (DC-2-2A) was changed to 77.8 mmol. The yield of the obtained polyarylate resin (R-9-M1) was 28.8 g, the yield was 79.7%, and the viscosity average molecular weight was 60,000.

(Synthesis of polyarylate resin (R-10-M1))
In the synthesis of the polyarylate resin (R-10-M1), the compound (BP-1-1) was changed to 82.56 mmol of the compound (BP-1-2). Further, in the synthesis of the polyarylate resin (R-10-M1), the amount of dichloride used in the compound (DC-2-1C) was changed to 54.5 mmol, and the dichloride used in the compound (DC-2-2A) was used. The amount was changed to 23.3 mmol. The yield of the obtained polyarylate resin (R-10-M1) was 30.0 g, the yield was 78.9%, and the viscosity average molecular weight was 49,700.

(Synthesis of polyarylate resin (R-1-M2))
In the synthesis of the polyarylate resin (R-1-M2), the compound (T-M1) was changed to 0.826 mmol of the compound (T-M2). The yield of the obtained polyarylate resin (R-1-M2) was 27.5 g, the yield was 79.7%, and the viscosity average molecular weight was 53,500.

(Synthesis of polyarylate resin (R-1-M3))
In the synthesis of the polyarylate resin (R-1-M3), the compound (T-M1) was changed to 0.826 mmol of the compound (T-M3). The yield of the obtained polyarylate resin (R-1-M3) was 28.6 g, the yield was 82.9%, and the viscosity average molecular weight was 56,100.

(Synthesis of polyarylate resin (R-1-M4))
In the synthesis of the polyarylate resin (R-1-M4), the compound (T-M1) was changed to 0.826 mmol of the compound (T-M4). The yield of the obtained polyarylate resin (R-1-M4) was 28.4 g, the yield was 82.4%, and the viscosity average molecular weight was 54,200.

(Synthesis of polyarylate resin (R-1-MA))
In the synthesis of the polyarylate resin (R-1-MA), the compound (TM1) is referred to as a compound (p-tert-butylphenol, hereinafter referred to as a compound (T-MA)) represented by the following chemical formula (T-MA). Changed to 0.826 mmol (may be described). The viscosity average molecular weight of the polyarylate resin (R-1-MA) was 58,100.

(Synthesis of polyarylate resin (R-3-MA))
In the synthesis of the polyarylate resin (R-3-MA), the compound (BP-1-1) was changed to 82.56 mmol of the compound (BP-1-2). Moreover, in the synthesis of the polyarylate resin (R-3-MA), the compound (TM1) was changed to 0.826 mmol of the compound (T-MA). The viscosity average molecular weight of the polyarylate resin (R-3-MA) was 55,100.

(Synthesis of polyarylate resin (R-6-MA))
In the synthesis of the polyarylate resin (R-6-MA), the compound (BP-1-1) was changed to 82.56 mmol of the compound (BP-1-2). Moreover, in the synthesis of the polyarylate resin (R-6-MA), the dichloride of the compound (DC-2-2A) was changed to 38.9 mmol of the dichloride of the compound (DC-2-2B). Moreover, in the synthesis of the polyarylate resin (R-6-MA), the compound (TM1) was changed to 0.826 mmol of the compound (T-MA). The viscosity average molecular weight of the polyarylate resin (R-6-MA) was 57,700.

<Manufacturing of photoconductor>
Photoreceptors (A-1) to (A-15) using the charge generator, the hole transporter, the electron acceptor compound, the binder resin, and the metal-free phthalocyanine, the pigment, or the dye prepared as described above. ) And (B-1) to (B-10) were produced.

(Manufacturing of photoconductor (A-1))
First, an intermediate layer was formed. Surface-treated titanium oxide (“Prototype SMT-A” manufactured by TAYCA CORPORATION, number average primary particle size 10 nm) was prepared. In SMT-A, the first core (titanium oxide core) is surface-treated with alumina and silica to obtain a second core, and the second core is further surface-treated with methylhydrogenpolysiloxane while being wet-dispersed. Obtained by doing. Next, 2 parts by mass of SMT-A and 1 part by mass of a polyamide resin ("Amilan (registered trademark) CM8000" manufactured by Toray Co., Ltd., polyamide 6, polyamide 12, polyamide 66 and polyamide 610 quaternary copolymerized polyamide resin). , 10 parts by mass of methanol, 1 part by mass of butanol, and 1 part by mass of toluene were mixed for 5 hours using a bead mill to obtain a coating liquid for forming an intermediate layer. The coating liquid for forming the intermediate layer was filtered using a filter having an opening of 5 μm. Then, the coating liquid for forming an intermediate layer was applied to the surface of the conductive substrate by the dip coating method. As the conductive substrate, an aluminum drum-shaped support was used. Subsequently, the applied coating liquid for forming an intermediate layer was dried at 130 ° C. for 30 minutes to form an intermediate layer (thickness 1.5 μm) on the conductive substrate.

Next, a charge generation layer was formed. Specifically, 1.5 parts by mass of Y-type titanyl tetrahydrofuran, which is a charge generator, 1.0 part by mass of polyvinyl acetal resin (“Eslek BX-5” manufactured by Sekisui Chemical Co., Ltd.), which is a base resin, and propylene glycol monomethyl. 40.0 parts by mass of ether and 40.0 parts by mass of tetrahydrofuran were mixed using a bead mill for 12 hours to obtain a coating liquid for forming a charge generation layer. The coating liquid for forming the charge generation layer was filtered using a filter having an opening of 3 μm. The obtained coating liquid for forming a charge generation layer was applied onto the intermediate layer by the dip coating method, and dried at 50 ° C. for 5 minutes. In this way, a charge generation layer (thickness 0.3 μm) was formed on the intermediate layer.

Next, a charge transport layer was formed. Specifically, 45.0 parts by mass of the hole transport agent (HTM-1), 100.0 parts by mass of the polyarylate resin (R-1-M1) which is a binder resin, and 0.3 parts by mass of X-type metal-free phthalocyanine. , 2.0 parts by mass of the electron acceptor compound (E-1), 550.0 parts by mass of tetrahydrofuran, and 150.0 parts by mass of toluene were mixed to obtain a coating liquid for forming a charge transport layer. A coating liquid for forming a charge transport layer was applied onto the charge generation layer by a dip coating method, and dried at 120 ° C. for 40 minutes. In this way, a charge transport layer (thickness 30 μm) was formed on the charge generation layer to obtain a photoconductor (A-1). In the photoconductor (A-1), an intermediate layer was provided on the conductive substrate, a charge generation layer was provided on the intermediate layer, and a charge transport layer was provided on the charge generation layer.

(Manufacturing of Photoreceptors (A-2) to (A-15) and (B-2) to (B-10))
The polyarylate resin shown in Table 4 was used, the type of metal-free phthalocyanine, pigment, or dye shown in Table 4 was used, and the metal-free phthalocyanine, pigment, or dye was added in the amount shown in Table 4. Except for the above, each of the photoconductors (A-2) to (A-15) and (B-2) to (B-10) was produced in the same manner as in the production of the photoconductor (A-1).

(Manufacturing of photoconductor (B-1))
The photoconductor (B-1) was produced by the same method as that for the photoconductor (A-1) except that the X-type metal-free phthalocyanine was not added.

<Evaluation>
Each of the photoconductors (A-1) to (A-15) and (B-1) to (B-10) to be evaluated was evaluated as shown below.

[Evaluation of sensitivity characteristics]
The evaluation environment for the sensitivity characteristics of the photoconductor was an environment with a temperature of 23 ° C. and a relative humidity of 50% RH. The surface of the photoconductor was charged to −550 V using a drum sensitivity tester (manufactured by Gentec Co., Ltd.). Next, monochromatic light (wavelength: 780 nm, exposure amount: exposure amount shown in the following exposure condition A) was taken out from the light of the halogen lamp using a bandpass filter, and the surface of the photoconductor was irradiated. The surface potential of the photoconductor was measured 50 milliseconds after irradiation with monochromatic light. The measured surface potential was defined as the post-exposure potential V _LA (unit: −V) of the photoconductor under the exposure condition A.

Then, the exposure amount as shown in the exposure condition A, except for changing the amount of exposure below exposure condition B, in the same manner as the measurement of the potential after exposure V _LA of the photoconductor at the exposure condition A, the exposure condition B The post-exposure potential V _LB (unit: −V) of the photoconductor was measured.

The measured post-exposure potentials V _LA and V _LB are shown in Table 4. Further, the evaluation criteria of the sensitivity characteristics under the exposure condition A, which are evaluated from the post-exposure potential V _{LA, are shown below.} Further, the evaluation criteria of the sensitivity characteristics under the exposure condition B, which are evaluated from the post-exposure potential V _{LB, are shown below.}

(Exposure condition A)
The exposure amount under the exposure condition A was 1.00 μJ / cm ² . The evaluation criteria under the exposure condition A were as shown below.
Good: _{The absolute value of the potential V LA} after exposure is 90 V or less.
Defective: The absolute value of the _{potential V LA after exposure is over 90 V.}

(Exposure condition B)
The exposure amount under the exposure condition B was 0.18 μJ / cm ² . The evaluation criteria under the exposure condition B were as shown below.
Good: The absolute value of the _{potential V LB after exposure is 280 V or less.}
Defective: The absolute value of the _{potential V LB after exposure is over 280 V.}

The exposure amount under the exposure condition A corresponds to the exposure amount when printing a solid image. Therefore, it is judged that the photoconductor having a good evaluation of the sensitivity characteristic under the exposure condition A can print a solid image well. On the other hand, the exposure amount under the exposure condition B corresponds to the exposure amount when printing a halftone image. Therefore, it is judged that the photoconductor having a good evaluation of the sensitivity characteristic under the exposure condition B can print a halftone image well.

[Evaluation of charging characteristics]
The evaluation environment for the charging characteristics of the photoconductor was an environment with a temperature of 23 ° C. and a relative humidity of 50% RH. The surface of the photoconductor was charged using a drum sensitivity tester (manufactured by Gentec Co., Ltd.) under the measurement conditions shown below. The measurement conditions are that the charging device provided in the drum sensitivity tester is a corotron charger, the charging current flowing through the corotron charger is the charging current shown in charging condition 1, the peripheral speed of the photoconductor is 125 rpm, and static elimination is performed after charging. Was the condition to be implemented. The surface potential of the photoconductor was measured when the photoconductor was rotated 10 times. _{The measured surface potential was defined as} the charging potential I d1 (unit: −V) of the photoconductor under charging condition 1.

Next, the photoconductor under the charging condition 2 is measured by the same method as the measurement _{of the charging potential I d1} of the photoconductor under the charging condition 1 except that the charging current shown in the charging condition 1 is changed to the charging current shown in the charging condition 2 below. The charging potential I _d2 (unit: −V) was measured.

(Charging condition 1)
The charging current under charging condition 1 was -3 μA.

(Charging condition 2)
The charging current under charging condition 2 was -6 μA.

The value obtained by subtracting _{I d1} from the measured charging potential I _{d2 (Id2-} I _d1 ) was defined as the charging potential difference. The absolute value of the charging potential difference is shown in Table 4. Further, the evaluation criteria of the charging characteristics, which are evaluated from the absolute value of the charging potential difference, are shown below.
Good: The absolute value of the charging potential difference is 330V or more and 400V or less.
Defective: The absolute value of the charging potential difference is less than 330V or more than 400V.

[Evaluation of wear resistance]
The evaluation machine used for the evaluation of wear resistance was a color printer (“C711dn” manufactured by Oki Data Corporation). The toner cartridge of the evaluation machine was filled with cyan toner. _{First, the film thickness T 1} of the charge transport layer of the photoconductor was measured. Next, the photoconductor was mounted on the evaluation machine. Then, in a normal temperature and humidity environment (temperature 23 ° C. and relative humidity 50% RH), Image I (pattern image with a printing rate of 1%) was printed on 10,000 sheets of paper using an evaluation machine. Image I was printed on 10,000 sheets of paper using an evaluator in a high temperature and high humidity environment (temperature 32 ° C. and relative humidity 85% RH). Image I was printed on 10,000 sheets of paper using an evaluation machine in a low temperature and low humidity environment (temperature 10 ° C. and relative humidity 15% RH: hereinafter, may be referred to as LL environment). After printing in the LL environment, the evaluation machine was allowed to stand for 2 hours. Next, a solid image (an image having an image density of 100%) was printed on one sheet of paper in an LL environment. _{Then, the film thickness T 2} of the charge transport layer of the photoconductor was measured. Then, the wear amount film of a thickness variation of the printed before and after the charge transport layer (T ₁ -T _2, Unit: [mu] m) was determined. The determined amount of wear is shown in Table 4 below. The smaller the amount of wear, the better the wear resistance of the photoconductor. When the amount of wear was 2.5 μm or less, the wear resistance was evaluated as good, and when the amount of wear was more than 2.5 μm, the wear resistance was evaluated as poor.

[Evaluation of suppression of random lateral muscle]
The evaluation machine used for the evaluation of the random horizontal streaks was a monochrome multifunction device (“MultiXpress SL-K4350LX” manufactured by Samsung Electronics). A photoconductor was mounted on the evaluation machine. In a normal temperature and humidity environment (temperature 23 ° C. and relative humidity 50% RH), a halftone image (image with a printing rate of 30%) is printed on one sheet of paper using an evaluation machine, and the printed image is evaluated. It was made into an image. The evaluation image was visually observed, and the degree of suppression of the random lateral muscle was evaluated according to the following criteria. When the evaluation result of the random horizontal muscle was "A" or "B", it was evaluated that the random horizontal muscle was suppressed, and when it was "C", it was evaluated that the random horizontal muscle was not suppressed.
Evaluation A: No random horizontal streaks were confirmed in the evaluation image.
Evaluation B: Random horizontal streaks were slightly confirmed in the evaluation image, but there was no problem in actual use.
Evaluation C: Random horizontal stripes were clearly confirmed in the evaluation image.

The meaning of each term in Table 4 is as follows. "Resin" refers to a polyarylate resin. “Pigment, etc.” refers to a metal-free phthalocyanine, a pigment, or a dye. "K1" represents an X-type metal-free phthalocyanine represented by the chemical formula (K1). "Sensitivity" indicates an evaluation of sensitivity characteristics. "Charging" indicates an evaluation of charging characteristics. “Id2-Id1” indicates the absolute value of the charging potential difference. "Random lateral muscle" indicates an evaluation of suppression of random lateral muscle. “Part” indicates a mass part.

As shown in Table 4, each of the photoconductors (A-1) to (A-15) had the following configurations. Specifically, the charge generating layer contained a charge generating agent, and the charge transporting layer contained a hole transporting agent, a binder resin, and metal-free phthalocyanine (more specifically, Y-type metal-free phthalocyanine). .. The content of metal-free phthalocyanine was 0.1 parts by mass or more and 0.5 parts by mass or less with respect to 100.0 parts by mass of the binder resin. The charge transport layer is a binder resin such as a polyarylate resin (PA) (more specifically, polyarylate resins (R-1-M1) to (R-1-M4) and (R-2-M1) to ( It contained one of R-10-M1)).

Therefore, the amount of wear of the photoconductors (A-1) to (A-15) was 2.5 μm or less, and the wear resistance of these photoconductors was good. Moreover, the evaluation result of the suppression of the random horizontal streaks of the photoconductors (A-1) to (A-15) was "A" or "B", and the random horizontal streaks were suppressed in the image formed by using these photoconductors. It had been. Since the absolute value of the charging potential difference between the photoconductors (A-1) to (A-15) was 330 V or more and 400 V or less, it was possible to suppress the occurrence of axial charging unevenness of the photoconductor and suppress the random horizontal streaks in the formed image. Judged.

Further, when the photoconductors (A-1) to (A-15) are used, not only the wear resistance is excellent and the random horizontal streaks in the formed image can be suppressed, but also the sensitivity characteristics under both the exposure conditions A and B are exhibited. It was good.

From the above, it was shown that the photoconductor according to the present invention has excellent wear resistance and can suppress random horizontal streaks in the formed image.

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

1: Photoreceptor (electrophotograph photoconductor)
2: Conductive substrate 3: Photosensitive layer 3a: Charge generation layer 3b: Charge transport layer

Claims (11)

It is provided with a conductive substrate and a photosensitive layer,
The photosensitive layer includes a charge generating layer and a charge transporting layer.
The charge generating layer contains a charge generating agent and
The charge transport layer contains a binder resin, metal-free phthalocyanine, and a hole transport agent.
The content of the metal-free phthalocyanine is 0.1 part by mass or more and 0.5 part by mass or less with respect to 100.0 parts by mass of the binder resin.
The binder resin contains at least one first repeating unit, at least one second repeating unit, and a polyarylate resin having a terminal group, and the first repeating unit is represented by the general formula (1). , The second repeating unit is represented by the general formula (2), and the terminal group is represented by the general formula (3).

(In the general formula (1),
R ¹ , R ² , R ³ , and R ⁴ each independently represent a hydrogen atom or a methyl group.
R ⁵ and R ⁶ each independently represent a hydrogen atom or an alkyl group having 1 or more and 4 or less carbon atoms, and R ⁵ and R ⁶ are divalent groups represented by the general formula (X) in which they are bonded to each other. May represent,
In the general formula (2), X ¹ represents a divalent group represented by the chemical formulas (2A), (2B), (2C), or (2D).
In the general formula (3), R ^f represents a chain aliphatic group having 1 or more and 20 or less carbon atoms substituted with one or more fluorine atoms. )

(In the general formula (X),
t represents an integer of 1 or more and 3 or less.
* Represents a bond. )

At least one of the first repeating units is a repeating unit of at least one of the repeating units represented by the chemical formulas (1-1), (1-2), (1-3), and (1-4). The electrophotographic photosensitive member according to claim 1, which is a unit.

The first repeating unit of at least one kind is the repeating unit of at least one kind among the repeating units represented by the chemical formulas (1-2), (1-3), and (1-4). Item 2. The electrophotographic photosensitive member according to Item 2. At least one of the second repeating units is a repeating unit of at least one of the repeating units represented by the chemical formulas (2-1C), (2-2A), (2-2B), and (2-2D). The electrophotographic photosensitive member according to any one of claims 1 to 3, which is a unit.

The electrophotographic photosensitive member according to any one of claims 1 to 4, wherein the terminal group is represented by the general formula (3-1).

(In the general formula (3-1),
Q ¹ represents a linear or branched chain perfluoroalkyl group having 1 or more and 6 or less carbon atoms.
Q ² represents a linear or branched chain perfluoroalkylene group having 1 or more and 6 or less carbon atoms.
n represents an integer of 0 or more and 2 or less. ) The electrophotographic photosensitive member according to any one of claims 1 to 5, wherein the terminal group is represented by a chemical formula (M1), (M2), (M3), or (M4).

The electrophotographic photosensitive member according to any one of claims 1 to 6, wherein the hole transporting agent contains a compound represented by the general formula (10).

(In the general formula (10),
R ¹⁰¹ , R ¹⁰³ , R ¹⁰⁴ , R ¹⁰⁵ , R ¹⁰⁶ , R ¹⁰⁷ , and R ¹⁰⁸ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, and an alkyl having 1 to 8 carbon atoms. It represents a phenyl group that may be substituted with a group, or an alkoxy group having 1 or more and 8 or less carbon atoms ^{, and two adjacent two of R 103} , R ¹⁰⁴ , R ¹⁰⁵ , R ¹⁰⁶ and R ¹⁰⁷ are bonded to carbon. It may represent a cycloalkane having 5 or more and 7 or less atoms.
R ¹⁰² and R ¹⁰⁹ each independently represent an alkyl group having 1 or more and 8 or less carbon atoms, a phenyl group, or an alkoxy group having 1 or more and 8 or less carbon atoms.
b ₁ and b ₂ each independently represent an integer of 0 or more and 5 or less. ) The electrophotographic photosensitive member according to any one of claims 1 to 7, wherein the hole transporting agent contains a compound represented by the chemical formula (HTM-1).

The charge transport layer further contains an electron acceptor compound and
The electrophotographic photosensitive member according to any one of claims 1 to 8, wherein the electron acceptor compound contains a compound represented by the general formula (20).

(In the general formula (20), R ²¹ , R ²² , R ²³ , and R ²⁴ each independently represent an alkyl group having 1 or more and 6 or less carbon atoms.) The electrophotographic photosensitive member according to claim 9, wherein the compound represented by the general formula (20) is a compound represented by the chemical formula (E-1).

The electrophotographic photosensitive member according to any one of claims 1 to 10, wherein the charge transport layer is a single layer and is provided as the outermost surface layer.

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