JP2020181009A - Electrophotographic photoreceptor, process cartridge, and image forming apparatus - Google Patents

Abstract

To provide an electrophotographic photoreceptor that is excellent in wear resistance.SOLUTION: An electrophotographic photoreceptor 1 comprises: a conductive substrate 2; and a photosensitive layer 3. The photosensitive layer 3 is a single layer. The photosensitive layer 3 contains a charge generating agent, a hole transport agent, an electron transport agent, a polyarylate resin. The polyarylate resin includes a repeating unit of a specific structure at a specific ratio. The electron transport agent includes a compound represented by a specific structure.SELECTED DRAWING: Figure 1

Description

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

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 charge generating function and a charge transporting layer having a charge transporting function.

Patent Document 1 describes an electrophotographic photosensitive member having a photosensitive layer. The binder resin of this photosensitive layer is a polyarylate resin containing a structure represented by the following chemical formula.

Japanese Unexamined Patent Publication No. 2003-322982

However, according to the studies by the present inventors, it has been found that the image-forming member 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. Another object of the present invention is to provide a process cartridge and an image forming apparatus having excellent durability by providing 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 generator, a hole transport agent, an electron transport agent, and a polyarylate resin. The polyarylate resin contains at least a repeating unit represented by the general formula (1), a repeating unit represented by the chemical formula (2), and a repeating unit represented by the chemical formula (3), and the chemical formula (2). The ratio n ₁ / n ₂ of the number n ₁ of the repeating units represented by the general formula (1) to the number n ₂ of the repeating units represented by) is 1.0 or more. The electron transporting agent contains a compound represented by the general formula (10), (11), or (12).

In the general formula (1), R ¹ and R ² independently represent a hydrogen atom or a methyl group, R ³ represents a methyl group, and R ⁴ represents a hydrogen atom or an alkyl group having 2 or 3 carbon atoms. Represent. Alternatively, R ¹ and R ² represent a methyl group, respectively, and R ³ and R ⁴ bond with each other to represent a cycloalkylidene group having 5 or 6 carbon atoms.

In the general formula (10), Q ^5A and Q ^5B independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a phenyl group, or an alkoxy group having 1 to 8 carbon atoms. Q ^6A and Q ^6B each independently represent an alkyl group having 1 to 8 carbon atoms, a phenyl group, or an alkoxy group having 1 to 8 carbon atoms. m ₁ and m ₂ each independently represent an integer of 0 or more and 4 or less. In the general formula (11), Q ⁷ and Q ⁸ independently represent a hydrogen atom, 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. Q ⁹ represents 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. m ₃ represents an integer of 0 or more and 4 or less. In the general formula (12), Q ¹⁰ and Q ¹¹ each independently represents an alkyl group or a hydrogen atom of 1 to 6 carbon atoms. Q ¹² represents a halogen atom or a hydrogen atom.

The process cartridge of the present invention includes the electrophotographic photosensitive member described above.

The image forming apparatus of the present invention includes an image carrier, a charging apparatus, an exposure apparatus, a developing apparatus, and a transfer apparatus. The charging device charges the surface of the image carrier. The exposure apparatus exposes the surface of the charged image carrier to form an electrostatic latent image on the surface of the image carrier. The developing device develops the electrostatic latent image as a toner image. The transfer device transfers the toner image from the image carrier to the transfer target. The image carrier is the above-mentioned electrophotographic photosensitive member.

The electrophotographic photosensitive member of the present invention has excellent wear resistance. Further, since the process cartridge and the image forming apparatus of the present invention include an electrophotographic photosensitive member having excellent wear resistance, they are excellent in durability.

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. It is sectional drawing which shows an example of an image forming apparatus.

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. Hereinafter, the compound and its derivative may be collectively referred to by adding "system" after the compound name. Further, 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.

First, the substituents used in the present specification will be described. Examples of the halogen atom (halogen group) include a fluorine atom (fluoro group), a chlorine atom (chloro group), a bromine atom (bromo group), and an iodine atom (iodine group).

Alkyl groups with 1 to 8 carbon atoms, alkyl groups with 1 to 6 carbon atoms, alkyl groups with 1 to 3 carbon atoms, alkyl groups with 2 carbon atoms, and alkyl groups with 3 carbon atoms are , Each is linear or branched and unsubstituted, unless otherwise specified. Examples of the alkyl group having 1 or more carbon atoms 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 3 carbon atoms, alkyl groups having 2 carbon atoms, and alkyl groups having 3 carbon atoms have 1 to 8 carbon atoms, respectively. Among the groups described as examples of the following alkyl groups, the group has a corresponding number of carbon atoms.

Unless otherwise specified, the alkoxy group having 1 or more and 8 or less carbon atoms, the alkoxy group having 1 or more and 6 or less carbon atoms, and the alkoxy group having 1 or more and 3 or less carbon atoms are linear or branched, respectively. It is not substituted. Examples of the alkoxy group having 1 or more carbon atoms and 8 or less 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 group, and linear and branched Examples include branched octyloxy groups. Examples of the alkoxy group having 1 or more and 6 or less carbon atoms and the alkoxy group having 1 or more and 3 or less carbon atoms are the corresponding carbons among the groups described as examples of the alkoxy groups having 1 or more and 8 or less carbon atoms, respectively. It is a group having an atomic number. 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 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, for example, a conductive substrate 2 and a photosensitive layer 3. The photosensitive layer 3 is a single layer. The photoconductor 1 is a single-layer electrophotographic photosensitive member including a single-layer photosensitive layer 3.

As shown in FIG. 2, 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 FIG. 1, the photosensitive layer 3 may be provided directly on the conductive substrate 2. Alternatively, as shown in FIG. 2, the photosensitive layer 3 may be provided on the conductive substrate 2 via the intermediate layer 4.

As shown in FIG. 3, the photosensitive member 1 may include a conductive substrate 2, a photosensitive layer 3, and a protective layer 5. The protective layer 5 is provided on the photosensitive layer 3. As shown in FIGS. 1 and 2, it is preferable that the photosensitive layer 3 is provided as the outermost surface layer of the photosensitive member 1. By providing the photosensitive layer 3 containing the polyarylate resin (PA) described later and the specific electron transporting agent described later as the outermost surface layer, it is easy to improve the wear resistance of the photoconductor 1. As shown in FIG. 3, the protective layer 5 may be provided as the outermost surface layer of the photoconductor 1.

The photosensitive layer 3 contains at least a charge generator, a hole transport agent, an electron transport agent, and a polyarylate resin.

The thickness of the photosensitive layer 3 is not particularly limited, but is preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less. The photoconductor 1 has been described above with reference to FIGS. 1 to 3.

(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 photosensitive layer may contain only one type of charge generating agent, or may contain two or more types.

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 non-crystalline. 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, each may be referred to as α-type, β-type, and Y-type titanyl phthalocyanine).

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, 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 0.1 part by mass or more and 50 parts by mass or less, and more preferably 0.5 parts by mass or more and 4.5 parts by mass or less with respect to 100 parts by mass of the binder resin. preferable.

(Binder resin)
The photosensitive layer contains a polyarylate resin as a binder resin. The polyarylate resin contains at least a repeating unit represented by the general formula (1), a repeating unit represented by the chemical formula (2), and a repeating unit represented by the chemical formula (3). The ratio n ₁ / n ₂ of the number n ₁ of the repeating units represented by the general formula (1) to the number n ₂ of the repeating units represented by the chemical formula (2) is 1.0 or more.

In the general formula (1), R ¹ and R ² each independently represent a hydrogen atom or a methyl group, R ³ represents a methyl group, and R ⁴ represents a hydrogen atom or an alkyl group having 2 or 3 carbon atoms. Represent. Alternatively, in the general formula (1), R ¹ and R ² each represent a methyl group, and R ³ and R ⁴ are bonded to each other to represent a cycloalkylidene group having 5 or 6 carbon atoms.

Hereinafter, the repeating unit represented by the general formula (1), the repeating unit represented by the chemical formula (2), and the repeating unit represented by the chemical formula (3) are referred to as a repeating unit (1) and a repeating unit (2), respectively. ), And the repeating unit (3). Further, at least the repeating unit (1), the repeating unit (2), and the repeating unit (3) are included, and the ratio of the number n ₁ of the repeating unit (1) to the number n ₂ of the repeating unit (2) n ₁ / n ₂ A polyallylate resin having a value of 1.0 or more may be referred to as a polyallylate resin (PA).

When the polyarylate resin (PA) is contained in the photosensitive layer, the abrasion resistance of the photoconductor can be improved. The reason is presumed as follows.

First, the polyarylate resin (PA) contains a repeating unit (2) and a repeating unit (3). Thereby, the wear resistance of the photoconductor can be improved.

Second, the polyarylate resin (PA) contains a repeating unit (1). Thereby, the solubility of the polyarylate resin (PA) in the solvent for forming the photosensitive layer can be improved. Further, when the ratio n ₁ / n ₂ of the number n ₁ of the repeating unit (1) to the number n ₂ of the repeating unit (2) is 1.0 or more, the polyarylate resin (PA) to the solvent for forming the photosensitive layer is formed. ) Can be further improved. By improving the solubility of the polyarylate resin (PA), the photosensitive layer can be suitably formed, and the abrasion resistance of the photoconductor can be improved.

The polyarylate resin (PA) is a repeating unit represented by the chemical formula (4) in addition to the repeating units (1), (2) and (3) (hereinafter, may be referred to as a repeating unit (4)). It is preferable to further contain. When the polyarylate resin (PA) contains the repeating unit (4), the abrasion resistance of the photoconductor can be further improved.

Next, the general formula (1) will be described in detail. Examples of the alkyl group having 2 or 3 carbon atoms represented by R ⁴ in the general formula (1) include an ethyl group, an n-propyl group and an isopropyl group. As the alkyl group having 2 or 3 carbon atoms, an ethyl group or an isopropyl group is preferable.

Examples of the cycloalkylidene group having 5 or 6 carbon atoms represented by the bonds of R ³ and R ⁴ in the general formula (1) include a cyclopentylidene group and a cyclohexylidene group. The cyclopentylidene group and the cyclohexylidene group are divalent groups represented by the following chemical formulas (5) and (6), respectively. As the cycloalkylidene group having 5 or 6 carbon atoms, a cyclohexylidene group is preferable.

Preferable examples of the repeating unit (1) include repeating units represented by the chemical formulas (1-1), (1-2), (1-3), (1-4), and (1-5). Can be mentioned. Hereinafter, the repeating units represented by the chemical formulas (1-1), (1-2), (1-3), (1-4), and (1-5) are each repeated unit (1-1). , (1-2), (1-3), (1-4), and (1-5).

In order to improve the abrasion resistance of the photoconductor, the polyarylate resin (PA) further contains a repeating unit (4) in addition to the repeating units (1), (2), and (3), and the repeating unit ( It is preferable that 1) is a repeating unit (1-1).

The polyarylate resin (PA) may contain only one of the repeating units (1). Alternatively, the polyarylate resin (PA) may contain two or more of the repeating units (1).

The ratio n ₁ / n ₂ of the number n ₁ of the repeating units (1) contained in the polyarylate resin (PA) to the number n ₂ of the repeating units (2) contained in the polyarylate resin (PA) is 1.0. That is all. That is, the number n ₁ of the repeating unit (1) is equal to the number n ₂ of the repeating unit (2) or larger than the number n ₂ of the repeating unit (2). When the ratio n ₁ / n ₂ is 1.0 or more, the solubility of the polyarylate resin (PA) in the solvent for forming the photosensitive layer can be improved, and the wear resistance of the photoconductor can be improved. .. In order to improve the abrasion resistance of the photoconductor, the ratio n ₁ / n ₂ is preferably 10.0 or less, and more preferably 5.0 or less. In order to improve the solubility of the polyarylate resin (PA) in the solvent for forming the photosensitive layer and to improve the abrasion resistance of the photoconductor, the ratio n ₁ / n ₂ is 1.0, 2.0, It is also preferably within the range of two values selected from 3.0, 5.0 and 10.0. The ratio n ₁ / n ₂ may be, for example, 1.0 or more and less than 2.0, or 2.0 or more and 5.0 or less. The ratio n ₁ / n ₂ may be, for example, 1.0 or 3.0.

When the polyarylate resin (PA) contains the repeating unit (4), the repeating unit (4) contained in the polyarylate resin (PA) is relative to the number n ₃ of the repeating units (3) contained in the polyarylate resin (PA). The ratio n ₄ / n ₃ of the number n ₄ is preferably larger than 0.0, more preferably 0.1 or more, and further preferably 0.5 or more. The ratio n ₄ / n ₃ is preferably 5.0 or less, more preferably 3.0 or less, and even more preferably 1.5 or less. The ratio n ₁ / n ₂ is also preferably in the range of two values selected from 0.1, 0.5, 1.0, 1.5, 3.0 and 5.0. The ratio n ₄ / n ₃ may be, for example, 1.0.

The ratio n ₁ / n ₂ can be adjusted by changing the amount of the compound (BP-1) and the amount of the compound (BP-2) added when producing the polyarylate resin (PA). .. Further, the ratio n ₄ / n ₃ is adjusted by changing the amount of the compound (DC-3) and the amount of the compound (DC-4) added when producing the polyarylate resin (PA). Can be done. The compound (BP-1), compound (BP-2), compound (DC-3) and compound (DC-4) will be described later.

The ratio n ₁ / n ₂ and the ratio n ₄ / n ₃ are average values of values obtained from the entire polyarylate resin (PA) (plural molecular chains) contained in the photosensitive layer, respectively. Ratio n ₁ / n ₂ and the ratio n ₄ / n ₃ are each ¹ H-NMR spectrum of the polyarylate resin (PA) was determined by proton nuclear magnetic resonance spectroscopy, the resulting ¹ H-NMR spectrum It can be obtained by calculating the ratio of peaks characteristic of each repeating unit in.

Specific examples of the polyarylate resin (PA) include the following polyarylate resins.
Polyarylate resin (polyarylate) containing the repeating units (1-1), (2) and (3), not including the repeating unit (4), and having a ratio n ₁ / n ₂ of 2.0 or more and 5.0 or less. Resin (I) may be described);
It may be described as a polyarylate resin (polyarylate resin (II)) containing repeating units (1-5), (2) and (3) and having a ratio n ₁ / n ₂ of 2.0 or more and 5.0 or less. is there);
With a polyarylate resin (polyarylate resin (III)) containing repeating units (1-1), (2), (3) and (4) and having a ratio n ₁ / n ₂ of 2.0 or more and 5.0 or less. May be described);
It may be described as a polyarylate resin (polyarylate resin (IV)) containing the repeating units (1-2), (2) and (3) and having a ratio n ₁ / n ₂ of 2.0 or more and 5.0 or less. is there);
It may be described as a polyarylate resin (polyarylate resin (V)) containing the repeating units (1-3), (2) and (3) and having a ratio n ₁ / n ₂ of 2.0 or more and 5.0 or less. is there);
It may be described as a polyarylate resin (polyarylate resin (VI)) containing the repeating units (1-4), (2) and (3) and having a ratio n ₁ / n ₂ of 2.0 or more and 5.0 or less. Yes); and polyarylate containing repeating units (1-1), (2) and (3), not including repeating unit (4), and a ratio n ₁ / n ₂ of 1.0 or more and less than 2.0. Resin (sometimes referred to as polyarylate resin (VII)).

More specific examples of the polyarylate resin (PA) include the following polyarylate resins.
A polyarylate resin (polyarylate resin (i)) containing only the repeating units (1-1), (2) and (3) as the repeating unit and having a ratio n ₁ / n ₂ of 2.0 or more and 5.0 or less. (May be described as);
A polyarylate resin (polyarylate resin (ii)) containing only the repeating units (1-5), (2) and (3) as the repeating unit and having a ratio n ₁ / n ₂ of 2.0 or more and 5.0 or less. (May be described as);
A polyarylate resin (polyarylate) containing only the repeating units (1-1), (2), (3) and (4) as the repeating unit and having a ratio n ₁ / n ₂ of 2.0 or more and 5.0 or less. Resin (iii));
A polyarylate resin (polyarylate resin (iv)) containing only the repeating units (1-2), (2) and (3) as the repeating unit and having a ratio n ₁ / n ₂ of 2.0 or more and 5.0 or less. (May be described as);
A polyarylate resin (polyarylate resin (v)) containing only the repeating units (1-3), (2) and (3) as the repeating unit and having a ratio n ₁ / n ₂ of 2.0 or more and 5.0 or less. (May be described as);
A polyarylate resin (polyarylate resin (vi)) containing only the repeating units (1-4), (2) and (3) as the repeating unit and having a ratio n ₁ / n ₂ of 2.0 or more and 5.0 or less. The poly contains only the repeating units (1-1), (2) and (3) as the repeating unit, and the ratio n ₁ / n ₂ is 1.0 or more and less than 2.0. Acrylate resin (sometimes referred to as polyarylate resin (vii)).

As a more specific example of the polyarylate resin (PA), the polyarylate resins represented by the chemical formulas (R-1) to (R-7) (hereinafter, each of them are polyarylate resins (R-1) to (R)). -7)). In the chemical formulas (R-1) to (R-7), the number attached to the lower right of each repeating unit is a percentage (%) of the number of each repeating unit with respect to the total number of repeating units contained in the polyarylate resin. ) Is shown. The total number of repeating units is the sum of the number of bisphenol-derived repeating units and the number of dicarboxylic acid-derived repeating units. Further, for convenience of description, two repeating units (3) are described in each of the chemical formulas (R-1), (R-2) and (R-4) to (R-7). However, the percentage of the number of repeating units (3) to the total number of repeating units contained in each of the polyarylate resins (R-1), (R-2) and (R-4) to (R-7) is It is 50.0% (the sum of the numbers attached to the lower right of the two repeating units (3)).

In order to improve the abrasion resistance of the photoconductor, the repeating unit (1) is preferably the repeating unit (1-5). As the polyarylate resin (PA) in which the repeating unit (1) is the repeating unit (1-5), the polyarylate resin (II) is preferable, the polyarylate resin (ii) is more preferable, and the polyarylate resin (R-2) is preferable. ) Is more preferable.

In order to improve the abrasion resistance of the photoconductor, the repeating unit (1) is preferably the repeating unit (1-1). As the polyarylate resin (PA) in which the repeating unit (1) is the repeating unit (1-1), the polyarylate resins (I) and (III) are preferable, and the polyarylate resins (i) and (iii) are more preferable. , Polyarylate resins (R-1) and (R-3) are more preferred.

In order to further improve the abrasion resistance of the photoconductor, the repeating unit (1) is a repeating unit (1-1), and it is preferable that the repeating unit (4) is further included. As the polyarylate resin (PA) in which the repeating unit (1) is the repeating unit (1-1) and further contains the repeating unit (4), the polyarylate resin (III) is preferable, and the polyarylate resin (iii) is more preferable. , Polyarylate resin (R-3) is more preferable.

In the polyarylate resin (PA), the bisphenol-derived repeating unit and the dicarboxylic acid-derived repeating unit are adjacent to each other. The number of bisphenol-derived repeating units contained in the polyarylate resin (PA) is equal to the number of dicarboxylic acid-derived repeating units. The bisphenol-derived repeating unit is, for example, the repeating units (1) and (2). The repeating unit derived from dicarboxylic acid is, for example, the repeating unit (3). When the polyarylate resin (PA) contains the repeating unit (4), the dicarboxylic acid-derived repeating unit is, for example, the repeating unit (3) and (4).

The polyarylate resin (PA) may be, for example, a random copolymer, an alternating copolymer, a periodic copolymer or a block copolymer. In the polyarylate resin (PA), the arrangement of the repeating units is not particularly limited as long as the repeating units derived from bisphenol and the repeating units derived from dicarboxylic acid are adjacent to each other and bonded to each other. For example, the repeating unit (1) may be combined at both ends of the repeating unit (3). Alternatively, the repeating unit (2) may be bonded to both ends of the repeating unit (3). Alternatively, the repeating unit (1) may be bonded to one end of the repeating unit (3), and the repeating unit (2) may be bonded to the other end of the repeating unit (3).

When the polyarylate resin (PA) does not contain the repeating unit (4), the polyarylate resin (PA) may contain only the repeating units (1), (2) and (3) as the repeating unit. When the polyarylate resin (PA) does not contain the repeating unit (4), the polyarylate resin (PA) is the repeating unit (1), (2) and (3) in addition to the repeating unit (1). ), (2), (3) and (4) may further include repeating units.

When the polyarylate resin (PA) contains the repeating unit (4), the polyarylate resin (PA) contains only the repeating units (1), (2), (3) and (4) as the repeating unit. May be good. When the polyarylate resin (PA) contains a repeating unit (4), the polyarylate resin (PA) is used as a repeating unit in addition to the repeating units (1), (2), (3) and (4). It may further include repeating units other than the units (1), (2), (3) and (4).

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 40,000 or more. Is particularly preferred. When the viscosity average molecular weight of the polyarylate resin (PA) is 10,000 or more, the abrasion resistance of the photoconductor can be improved. On the other hand, the viscosity average molecular weight of the polyarylate resin (PA) is preferably 80,000 or less, and more preferably 70,000 or less. When the viscosity average molecular weight of the polyarylate resin (PA) is 80,000 or less, the polyarylate resin (PA) is easily dissolved in the solvent for forming the photosensitive layer.

The method for producing the polyarylate resin (PA) is not particularly limited. Examples of the method for producing a polyarylate resin (PA) include a method of polycondensing a bisphenol for forming a bisphenol-derived repeating unit and a dicarboxylic acid for forming a dicarboxylic acid-derived repeating unit. For the polycondensation, a known synthesis method (for example, solution polymerization, melt polymerization or interfacial polymerization) can be adopted.

Examples of the bisphenol for constituting the bisphenol-derived repeating unit include a compound represented by the general formula (BP-1) (hereinafter, may be referred to as a compound (BP-1)) and a chemical formula (BP-2). ) (Hereinafter, it may be referred to as a compound (BP-2)). Examples of the dicarboxylic acid for constituting the dicarboxylic acid-derived repeating unit include a compound represented by the chemical formula (DC-3) (hereinafter, may be referred to as a compound (DC-3)). When the polyarylate resin (PA) contains the repeating unit (4), as the dicarboxylic acid, in addition to the compound (DC-3), the compound represented by the chemical formula (DC-4) (hereinafter, the compound (DC-DC-)). 4)) may be further added. R ¹ in the general formula ^{(BP-1), R 2} , R 3 and R ⁴ are each the same meaning as in formula ^{(1) R 1, R 2} , R 3 and R ⁴ in.

Preferable examples of the compound (BP-1) are the compounds represented by the chemical formulas (BP-1-1) to (BP-1-5) (hereinafter, each of the compounds (BP-1-1) to (BP-1). -1-5) may be described).

Bisphenols (eg, compound (BP-1) and compound (BP-2)) may be used as derivatives of aromatic diacetate. Dicarboxylic acids (eg, compound (DC-3) and compound (DC-4)) may be derivatized and used. Examples of derivatives of dicarboxylic acids include dicarboxylic acid dichloride, dicarboxylic acid dimethyl ester, dicarboxylic acid diethyl ester and dicarboxylic acid anhydride. The dicarboxylic acid dichloride is a compound in which the two "-C (= O) -OH" groups of the dicarboxylic acid are each replaced with a "-C (= O) -Cl" group.

In the polycondensation of bisphenol and dicarboxylic acid, one or both of the base and the catalyst may be added. Examples of bases include sodium hydroxide. Examples of catalysts include benzyltributylammonium chloride, ammonium chloride, ammonium bromide, quaternary ammonium salts, triethylamine and trimethylamine. The polyarylate resin (PA) has been described above.

The photosensitive layer may contain only one type of polyarylate resin (PA), or may contain two or more types of polyarylate resin (PA). The photosensitive layer may contain only polyarylate resin (PA) as the binder resin. Further, the photosensitive 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 include thermoplastic resins (more specifically, polycarbonate resins, styrene resins, styrene-butadiene copolymers, styrene-acrylonitrile copolymers, styrene-maleic acid copolymers, and styrene-). Acrylic acid copolymer, acrylic copolymer, polyethylene resin, ethylene-vinyl acetate copolymer, chlorinated polyethylene resin, polyvinyl chloride resin, polypropylene resin, ionomer, vinyl chloride-vinyl acetate copolymer, polyester resin, alkyd Resins, polyamide resins, polyurethane resins, polysulfone resins, diallyl phthalate resins, ketone resins, polyvinyl butyral resins, polyvinyl acetal resins, and polyether resins), thermosetting resins (more specifically, silicone resins, epoxy resins, phenols) Resins, 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) Can be mentioned.

(Electronic transport agent)
The photosensitive layer shall be described as a compound represented by the general formula (10), (11), or (12) as an electron transporting agent (hereinafter, each of which is referred to as a compound (10), (11), and (12), respectively. There is). When the photosensitive layer contains the compound (10), (11), or (12) together with the polyarylate resin (PA), the abrasion resistance of the photoconductor can be improved.

In the general formula (10), Q ^5A and Q ^5B each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a phenyl group, or an alkoxy group having 1 to 8 carbon atoms. Q ^6A and Q ^6B each independently represent an alkyl group having 1 to 8 carbon atoms, a phenyl group, or an alkoxy group having 1 to 8 carbon atoms. m ₁ and m ₂ each independently represent an integer of 0 or more and 4 or less.

When m ₁ represents an integer of 2 or more and 4 or less, a plurality of Q ^6A may be the same as each other or may be different from each other. When m ₂ represents an integer of 2 or more and 4 or less, the plurality of Q ^6Bs may be the same as or different from each other.

In the general formula (10), Q ^5A and Q ^5B each independently preferably represent an alkyl group having 1 or more and 8 or less carbon atoms, and more preferably represent an alkyl group having 1 or more and 6 or less carbon atoms. , 1,1-Dimethylpropyl group is more preferably represented. It is preferable that m ₁ and m ₂ represent 0.

In the general formula (11), Q ⁷ and Q ⁸ independently represent a hydrogen atom, 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. Q ⁹ represents 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. m ₃ represents an integer of 0 or more and 4 or less.

When m ₃ represents an integer of 2 or more and 4 or less, the plurality of Q ^9s may be the same as or different from each other.

In the general formula (11), Q ⁷ and Q ⁸ each independently preferably represent an alkyl group having 1 or more and 8 or less carbon atoms, and more preferably represent an alkyl group having 1 or more and 6 or less carbon atoms. , Tert-Butyl group is more preferred. m ₃ preferably represents 0.

In the general formula (12), Q ¹⁰ and Q ¹¹ independently represent an alkyl group or a hydrogen atom having 1 or more and 6 or less carbon atoms. Q ¹² represents a halogen atom or a hydrogen atom.

In the general formula (12), Q ¹⁰ and Q ¹¹ each independently preferably represent an alkyl group having 1 or more and 6 or less carbon atoms, and more preferably a tert-butyl group. Q ¹² is preferably a halogen atom, more preferably a chlorine atom.

In order to improve the abrasion resistance of the photoconductor, the compound (10) is preferably a compound represented by the chemical formula (10-E1) (hereinafter, may be referred to as a compound (10-E1)). For the same reason, the compound (11) is preferably a compound represented by the chemical formula (11-E3) (hereinafter, may be referred to as compound (11-E3)). For the same reason, the compound (12) is preferably a compound represented by the chemical formula (12-E2) (hereinafter, may be referred to as compound (12-E2)).

The content of the electron transporting agent is preferably 5 parts by mass or more and 150 parts by mass or less, more preferably 10 parts by mass or more and 50 parts by mass or less, and 20 parts by mass or more with respect to 100 parts by mass of the binder resin. It is more preferably 40 parts by mass or less.

The photosensitive layer may contain only one kind of electron transporting agent, or may contain two or more kinds of electron transporting agents. The photosensitive layer may further contain an electron transporting agent other than the compounds (10), (11), and (12) (hereinafter, may be referred to as other electron transporting agents). Examples of other electron transporting agents include quinone compounds, diimide compounds, hydrazone compounds, malononitrile compounds, thiopyran compounds, trinitrothioxanthone compounds, and 3,4,5,7-tetranitro-9-fluorenone compounds. Examples thereof include compounds, dinitroanthracene compounds, dinitroacridin compounds, tetracyanoethylene, 2,4,8-trinitrothioxanthone, dinitrobenzene, dinitroaclydin, succinic anhydride, maleic anhydride, and dibromomaleic anhydride. Examples of the quinone compound include a diphenoquinone compound, an azoquinone compound, an anthraquinone compound, a naphthoquinone compound, a nitroanthraquinone compound, and a dinitroanthraquinone compound.

(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 System compounds (for example, 2,5-di (4-methylaminophenyl) -1,3,4-oxadiazole), styryl compounds (for example, 9- (4-diethylaminostyryl) anthracene), carbazole compounds (for example) 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 photosensitive layer may contain only one kind of hole transporting agent, or may contain two or more kinds of hole transporting agents.

Preferable examples of the hole transporting agent include compounds represented by the general formulas (20), (21), (22), (23), (24), and (25) (hereinafter, each of them is a compound ( 20), (21), (22), (23), (24), and (25) may be described). The photosensitive layer contains the polyarylate resin (PA) and the compounds (10), (11), or (12) which are electron transporting agents, and the compounds (20), (21), (22), which are hole transporting agents. By containing (23), (24), or (25), the wear resistance of the photoconductor can be improved without impairing the sensitivity characteristics of the photoconductor.

In the general formula (20), R ¹⁰ , R ¹¹ , R ¹² , R ¹³ and R ¹⁴ each independently represent an alkyl group or a hydrogen atom having 1 to 6 carbon atoms. a and b each independently represent 0 or 1.

In the general formula (20), R ¹⁰ , R ¹¹ , R ¹² , R ¹³ and R ¹⁴ each independently preferably represent an alkyl group having 1 or more and 6 or less carbon atoms, and preferably has 1 or more carbon atoms and 3 carbon atoms. It is more preferable to represent the following alkyl group, and further preferably to represent a methyl group.

In the general formula (21), R ¹⁵ , R ¹⁶ and R ¹⁷ each independently represent an alkyl group having 1 to 6 carbon atoms. R ¹⁸ represents an alkyl group or a hydrogen atom having 1 or more and 6 or less carbon atoms. r, s, and t each independently represent an integer of 0 or more and 5 or less.

In the general formula (21), when r represents an integer of 2 or more and 5 or less, a plurality of R ^15s may be the same as each other or may be different from each other. When s represents an integer of 2 or more and 5 or less, the plurality of R ^16s may be the same as or different from each other. When t represents an integer of 2 or more and 5 or less, the plurality of R ^17s may be the same as or different from each other.

In the general formula (21), R ¹⁸ preferably represents a hydrogen atom. It is preferable that r, s, and t each represent 0.

In the general formula (22), R ¹⁹ , R ²⁰ , R ²¹ and R ²² each independently represent an alkyl group having 1 to 6 carbon atoms. u, v, w, and x each independently represent an integer of 0 or more and 5 or less.

In the general formula (22), when u represents an integer of 2 or more and 5 or less, a plurality of R ^19s may be the same as each other or may be different from each other. When v represents an integer of 2 or more and 5 or less, the plurality of R ^20s may be the same as or different from each other. When w represents an integer of 2 or more and 5 or less, the plurality of R ^21s may be the same as or different from each other. When x represents an integer of 2 or more and 5 or less, a plurality of R ^22s may be the same as or different from each other.

In the general formula (22), R ¹⁹ , R ²⁰ , R ²¹ and R ²² each independently preferably represent an alkyl group having 1 or more carbon atoms and 3 or less carbon atoms, and may represent a methyl group or an ethyl group. More preferred. u, v, w, and x each independently represent an integer of 1 or more and 3 or less, and more preferably 1.

In the general formula (23), R ²³ and R ²⁴ each independently represent a hydrogen atom, an alkyl group having 1 or more and 8 or less carbon atoms, or an alkoxy group having 1 or more and 8 or less carbon atoms. R ²⁵ and R ²⁶ each independently represent an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or a phenyl group. R ²⁷ , R ²⁸ , R ²⁹ , R ³⁰ , and R ³¹ each independently have a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or a phenyl group. Represent. Adjacent two of R ²⁷ , R ²⁸ , R ²⁹ , R ³⁰ , and R ³¹ may join together to form a ring. d and e each independently represent an integer of 0 or more and 5 or less. f and g independently represent 1 or 2, respectively.

In the general formula (23), when d represents an integer of 2 or more and 5 or less, the plurality of R ^25s may be the same or different from each other. When e represents an integer of 2 or more and 5 or less, the plurality of R ^26s may be the same as or different from each other. If two adjacent two of R ²⁷ , R ²⁸ , R ²⁹ , R ³⁰ , and R ³¹ combine with each other to form a ring, then this ring and R ²⁷ , R ²⁸ , R ²⁹ , R ³⁰ , and R ³¹ The phenyl group to which R ³¹ is bonded is condensed to form a bicyclic fused ring group. In this case, the condensation site between the ring and the phenyl group may contain a double bond.

In the general formula (23), it is preferable that R ²³ and R ²⁴ each represent a hydrogen atom. R ²⁷ , R ²⁸ , R ²⁹ , R ³⁰ , and R ³¹ can independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or an alkoxy group having 1 to 8 carbon atoms. preferable. The alkyl group represented by R ²⁷ , R ²⁸ , R ²⁹ , R ³⁰ , and R ³¹ having 1 to 8 carbon atoms is preferably an alkyl group having 1 to 6 carbon atoms, and is preferably a methyl group, an ethyl group, or an ethyl group. It preferably represents an n-butyl group. As the alkoxy group represented by R ²⁷ , R ²⁸ , R ²⁹ , R ³⁰ , and R ³¹ having 1 or more and 8 or less carbon atoms, an alkoxy group having 1 or more and 6 or less carbon atoms is preferable, and the number of carbon atoms is 1 or more and 3 or less. Alkoxy group is more preferable, and ethoxy group is more preferable. It is preferable that d and e each represent 0.

In the general formula (24), R ³² and R ³³ each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group. R ³⁴ , R ³⁵ , R ⁴⁶ , and R ⁴⁷ each independently represent an alkyl group or a phenyl group having 1 to 8 carbon atoms. R ^{36 to} R ⁴⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group. p and q each independently represent 0 or 1. h and i each independently represent an integer of 0 or more and 5 or less. j and k each independently represent an integer of 0 or more and 4 or less.

In the general formula (24), when h represents an integer of 2 or more and 5 or less, the plurality of R ^34s may be the same as each other or may be different from each other. When i represents an integer of 2 or more and 5 or less, the plurality of R ^35s may be the same as or different from each other. When j represents an integer of 2 or more and 4 or less, the plurality of R ^46s may be the same as or different from each other. When k represents an integer of 2 or more and 4 or less, the plurality of R ^47s may be the same as or different from each other.

In the general formula (24), it is preferable that R ³² and R ³³ each represent a hydrogen atom. It is preferable that R ^{36 to} R ⁴⁵ each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. As the alkyl group having 1 to 8 carbon atoms represented by R ^{36 to} R ⁴⁵ , an alkyl group having 1 to 6 carbon atoms is preferable, an alkyl group having 1 to 3 carbon atoms is more preferable, and a methyl group or an alkyl group having 3 or less carbon atoms is more preferable. Ethyl groups are more preferred. It is preferable that p and q each represent 0. It is preferable that h and i each represent 0. It is preferable that j and k each represent 0.

In the general formula (25), R ⁴⁸ , R ⁴⁹ , and R ⁵⁰ each independently represent an alkyl group having 1 to 8 carbon atoms. R ⁵¹ , R ⁵² , and R ⁵³ each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.

In the general formula (25), R ⁴⁸ , R ⁴⁹ , and R ⁵⁰ each independently preferably represent an alkyl group having 1 or more and 6 or less carbon atoms, and each of them represents an alkyl group having 1 or more and 3 or less carbon atoms. It is more preferable, and it is further preferable to represent a methyl group. R ⁴⁸ , R ⁴⁹ , and R ⁵⁰ are preferably attached to the meta position of the phenyl group with respect to the butadienyl group. R ⁵¹ , R ⁵² , and R ⁵³ each preferably represent a hydrogen atom.

More preferred examples of hole transport agents include chemical formulas (20-H8), (20-H9), (21-H4), (22-H6), (23-H1), (23-H2), ( Compounds represented by 23-H3), (24-H7), and (25-H5) (hereinafter, each of them is compound (20-H8), (20-H9), (21-H4), (22-H3). H6), (23-H1), (23-H2), (23-H3), (24-H7), and (25-H5) may be described).

The compound (20-H8) and (20-H9) are each preferable examples of the compound (20). Compound (21-H4) is a good example of compound (21). Compound (22-H6) is a good example of compound (22). Compounds (23-H1), (23-H2), and (23-H3) are each preferred examples of compound (23). Compound (24-H7) is a good example of compound (24). Compound (25-H5) is a good example of compound (25).

The content of the hole transporting agent is preferably 10 parts by mass or more and 200 parts by mass or less, more preferably 50 parts by mass or more and 90 parts by mass or less, and 60 parts by mass with respect to 100 parts by mass of the binder resin. It is more preferably 80 parts by mass or less.

(Additive)
Additives include, for example, UV absorbers, antioxidants, radical scavengers, singlet quenchers, softeners, surface modifiers, bulking agents, thickeners, dispersion stabilizers, waxes, donors, surfactants. Examples include agents, plasticizers, sensitizers, electron acceptor compounds, and leveling agents.

(Combination of materials)
In order to improve the abrasion resistance of the photoconductor, the combination of the polyarylate resin and the electron transporting agent is a combination No. 1 shown in Table 1. It is preferably each of C-1 to C-27. For the same reason, the combination of the polyarylate resin and the electron transporting agent is the combination No. 1 shown in Table 1. It is each of C-1 to C-27, and it is more preferable that the charge generator is Y-type titanyl phthalocyanine.

In order to improve the wear resistance of the photoconductor, the combination of the polyarylate resin, the hole transporting agent, and the electron transporting agent is a combination No. 2 shown in Table 2. It is preferably each of D-1 to D-51. For the same reason, the combinations of the polyarylate resin, the hole transporting agent, and the electron transporting agent are the combinations No. 2 shown in Table 2. It is each of D-1 to D-51, and it is more preferable that the charge generator is Y-type titanyl phthalocyanine.

In Tables 1 and 2 above, "No." indicates "combination No.", "HTM" indicates "hole transport agent", "ETM" indicates "electron transport agent", and "resin". Indicates "polyarylate resin".

(Conductive substrate)
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 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. 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 (resin for the intermediate layer) used 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. One type of these inorganic particles may be used alone, or two or more types may be used in combination.

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. The example of the additive contained in the intermediate layer is the same as the example of the additive contained in the photosensitive layer.

(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 step of forming a photosensitive layer. In the photosensitive layer forming step, a coating liquid for forming the photosensitive layer (hereinafter, may be referred to as a coating liquid for a photosensitive layer) is prepared. The coating liquid for the photosensitive layer is applied onto the conductive substrate. Next, at least a part of the solvent contained in the coated liquid for the photosensitive layer is removed to form the photosensitive layer. The coating liquid for the photosensitive layer contains, for example, a charge generating agent, a hole transporting agent, an electron transporting agent, a binder resin, and a solvent. The coating liquid for the photosensitive layer is prepared by dissolving or dispersing a charge generating agent, a hole transporting agent, an electron transporting agent, and a binder resin in a solvent.

The solvent contained in the coating liquid for the photosensitive layer is not particularly limited as long as each component contained in the coating liquid for the photosensitive layer can be dissolved or dispersed. Solvents include, for example, 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, etc.) , Diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, etc.), ketones (more specifically, acetone, methyl ethyl ketone, and cyclohexanone, etc.), esters (more specifically, ethyl acetate, methyl acetate, etc.), Included are dimethyl formaldehyde, dimethylformamide, and dimethylsulfoxide. One of these solvents may be used alone, or two or more of these solvents may be used in combination.

The coating liquid for the photosensitive layer 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.

The method for applying the coating liquid for the photosensitive layer is not particularly limited as long as the coating liquid for the photosensitive layer can be uniformly applied. Examples of the coating method include a dip coating method, a spray coating method, a spin coating method, and a bar coating method.

Examples of the method for removing at least a part of the solvent contained in the coating liquid for the photosensitive layer include heating, depressurization, or 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.

<Image forming device>
Next, an image forming apparatus including the photoconductor 1 of the present embodiment will be described. Hereinafter, a tandem color image forming apparatus will be described as an example with reference to FIG. FIG. 4 is a cross-sectional view showing an example of an image forming apparatus.

The image forming apparatus 100 shown in FIG. 4 includes image forming units 40a, 40b, 40c, and 40d, a transfer belt 50, and a fixing device 54. Hereinafter, when it is not necessary to distinguish between them, each of the image forming units 40a, 40b, 40c, and 40d will be referred to as an image forming unit 40.

The image forming unit 40 includes an image carrier 30, a charging device 42, an exposure device 44, a developing device 46, a transfer device 48, and a cleaning member 52. The image carrier 30 is the photoconductor 1 of the present embodiment.

As described above, according to the photoconductor 1 of the present embodiment, the abrasion resistance can be improved. Therefore, by providing the photoconductor 1 as the image carrier 30, the durability of the image forming apparatus 100 can be improved.

The image carrier 30 is provided at the center of the image forming unit 40. The image carrier 30 is rotatably provided in the arrow direction (counterclockwise). Around the image carrier 30, a charging device 42, an exposure device 44, a developing device 46, a transfer device 48, and a cleaning member 52 are arranged in the order described from the upstream side in the rotation direction of the image carrier 30. Provided.

Each of the image forming units 40a to 40d superimposes toner images of a plurality of colors (for example, four colors of black, cyan, magenta, and yellow) on the recording medium P on the transfer belt 50 in order.

The charging device 42 charges the surface (for example, the peripheral surface) of the image carrier 30 to be positive, for example. The charging device 42 is, for example, a charging roller.

The exposure apparatus 44 irradiates the surface of the charged image carrier 30 with exposure light. That is, the exposure apparatus 44 exposes the surface of the charged image carrier 30. As a result, an electrostatic latent image is formed on the surface of the image carrier 30. The electrostatic latent image is formed based on the image data input to the image forming apparatus 100.

The developing device 46 supplies toner to the surface of the image carrier 30 and develops the electrostatic latent image as a toner image. While the surface of the developing device 46 (for example, the peripheral surface) is in contact with the surface of the image carrier 30, the developing device 46 develops the electrostatic latent image as a toner image. That is, the image forming apparatus 100 employs a contact developing method. The developing device 46 is, for example, a developing roller. When the developer is a one-component developer, the developing apparatus 46 supplies toner, which is a one-component developer, to the electrostatic latent image formed on the image carrier 30. When the developer is a two-component developer, the developing device 46 supplies the electrostatic latent image formed on the image carrier 30 with the toner among the toner and the carrier contained in the two-component developer. In this way, the image carrier 30 carries the toner image.

The transfer belt 50 conveys the recording medium P between the image carrier 30 and the transfer device 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).

The transfer device 48 transfers the toner image developed by the developing device 46 from the surface of the image carrier 30 to the transfer target. The transfer target is the recording medium P. Specifically, the transfer device 48 transfers the toner image from the surface of the image carrier 30 to the recording medium P while the recording medium P is in contact with the surface of the image carrier 30. That is, the image forming apparatus 100 employs a direct transfer method. The transfer device 48 is, for example, a transfer roller.

The cleaning member 52 is pressed against the surface of the image carrier 30, and the cleaning member 52 collects the toner adhering to the peripheral surface of the image carrier 30. The cleaning member 52 is, for example, a cleaning blade.

The recording medium P on which the toner image is transferred by the transfer device 48 is conveyed to the fixing device 54 by the transfer belt 50. The fixing device 54 is, for example, a heating roller and / or a pressure roller. The unfixed toner image transferred by the transfer device 48 is heated and / or pressurized by the fixing device 54. When the toner image is heated and / or pressurized, the toner image is fixed on the recording medium P. As a result, an image is formed on the recording medium P.

Although an example of the image forming apparatus has been described above, the image forming apparatus is not limited to the above-mentioned image forming apparatus 100. The image forming apparatus 100 described above was a color image forming apparatus, but the image forming apparatus may be a monochrome image forming apparatus. In this case, the image forming apparatus may include, for example, only one image forming unit. Further, although the image forming apparatus 100 described above has adopted the tandem method, the image forming apparatus may adopt, for example, the rotary method. Although the charging device 42 has been described by taking a charging roller as an example, the charging device may be a charging device other than the charging roller (for example, a scorotron charging device, a charging brush, or a corotron charging device). Although the image forming apparatus 100 described above has adopted the contact developing method, the image forming apparatus may adopt the non-contact developing method. The image forming apparatus 100 described above has adopted the direct transfer method, but the image forming apparatus may adopt an intermediate transfer method. When the image forming apparatus adopts the intermediate transfer method, the transferred body corresponds to the intermediate transfer belt. Although the cleaning blade has been described as an example of the cleaning member 52, the cleaning member may be a cleaning roller. The image forming unit 40 described above did not have a static elimination device, but the image forming unit may further include a static elimination device.

<Process cartridge>
Next, an example of the process cartridge including the photoconductor 1 of the present embodiment will be described with reference to FIG. The process cartridge corresponds to each of the image forming units 40a to 40d. The process cartridge comprises an image carrier 30. The image carrier 30 is the photoconductor 1 of the present embodiment. In addition to the image carrier 30, the process cartridge further includes at least one of a charging device 42 and a cleaning member 52.

As described above, according to the photoconductor 1 of the present embodiment, the abrasion resistance can be improved. Therefore, by providing the photoconductor 1 as the image carrier 30, the process cartridge is excellent in durability.

In addition to the image carrier 30, the charging device 42, and the cleaning member 52, the process cartridge may further include at least one of an exposure device 44, a developing device 46, and a transfer device 48. The process cartridge may be further equipped with a static elimination device (not shown). The process cartridge is designed to be detachably attached to the image forming apparatus 100. Therefore, the process cartridge is easy to handle, and when the sensitivity characteristics of the image carrier 30 deteriorates, the process cartridge including the image carrier 30 can be easily and quickly replaced. As described above, the process cartridge including the photoconductor 1 of the present embodiment has been described with reference to FIG.

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.

First, the following charge generator, electron transport agent, hole transport agent, and binder resin were prepared as materials for forming the photosensitive layer of the photoconductor.

(Charge generator)
As the charge generator, the Y-type titanyl phthalocyanine described in the embodiment was prepared.

(Electronic transport agent)
As the electron transporting agent, each of the compounds (10-E1), (11-E3), and (12-E2) described in the embodiment was prepared.

(Hole transport agent)
As the hole transporting agent, the compounds (20-H8), (20-H9), (21-H4), (22-H6), (23-H1), (23-H2), (23) described in the embodiment. -H3), (24-H7), and (25-H5) were prepared.

(Binder resin)
As the binder resin, each of the polyarylate resins (R-1) to (R-7) described in the embodiment was synthesized.

(Synthesis of polyarylate resin (R-1))
As the reaction vessel, a three-necked flask equipped with a thermometer, a three-way cock, and a dropping funnel was used. In a reaction vessel, compound (BP-1-1) (30.9 mmol), compound (BP-2) (10.3 mmol), p-tert-butylphenol (0.413 mmol), and sodium hydroxide (98 mmol) and benzyltributylammonium chloride (0.384 mmol) were added. The air in the reaction vessel was replaced with argon gas. Water (300 mL) was added to the contents of the reaction vessel. The contents of the reaction vessel were stirred at 50 ° C. for 1 hour. 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.

Next, the dicarboxylic acid dichloride (32.4 mmol) of compound (DC-3) was dissolved in chloroform (150 mL). As a result, chloroform solution B was obtained.

Chloroform solution B was slowly added dropwise to the alkaline aqueous solution A over 110 minutes using a dropping funnel. While adjusting the temperature (liquid temperature) of the contents of the reaction vessel to 15 ± 5 ° C., the contents of the reaction vessel were stirred for 4 hours to proceed with the polymerization reaction. The upper layer (aqueous layer) of the contents of the reaction vessel was removed using a decant to obtain an organic layer. Then, ion-exchanged water (400 mL) was added to the Erlenmeyer flask. The obtained organic layer was further added to the Erlenmeyer flask. Chloroform (400 mL) and acetic acid (2 mL) were further added to the Erlenmeyer flask. The contents of the Erlenmeyer flask were stirred at room temperature (25 ° C.) for 30 minutes. The upper layer (aqueous layer) of the contents of the Erlenmeyer flask was removed using a decant to obtain an organic layer. The obtained organic layer was washed with ion-exchanged water (1 L) using a separating funnel. Washing with ion-exchanged water was repeated 5 times to obtain an organic layer washed with water. Next, the organic layer washed with water was filtered to obtain a filtrate. The obtained filtrate was slowly added dropwise to methanol (1 L) 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) was obtained.

(Synthesis of polyarylate resin (R-2))
By the same method as the synthesis of polyarylate resin (R-1), except that the compound (BP-1-1) (30.9 mmol) was changed to the compound (BP-1-5) (30.9 mmol). A polyarylate resin (R-2) was obtained.

(Synthesis of polyarylate resin (R-3))
The dicarboxylic acid dichloride (32.4 mmol) of compound (DC-3), the dicarboxylic acid dichloride (16.2 mmol) of compound (DC-3) and the dicarboxylic acid dichloride (16.2 mmol) of compound (DC-4) ) Was used to obtain a polyarylate resin (R-3) in the same manner as in the synthesis of the polyarylate resin (R-1).

(Synthesis of polyarylate resin (R-4))
By the same method as the synthesis of polyarylate resin (R-1), except that the compound (BP-1-1) (30.9 mmol) was changed to the compound (BP-1-2) (30.9 mmol). A polyarylate resin (R-4) was obtained.

(Synthesis of polyarylate resin (R-5))
By the same method as the synthesis of polyarylate resin (R-1), except that the compound (BP-1-1) (30.9 mmol) was changed to the compound (BP-1--3) (30.9 mmol). A polyarylate resin (R-5) was obtained.

(Synthesis of polyarylate resin (R-6))
By the same method as the synthesis of polyarylate resin (R-1), except that the compound (BP-1-1) (30.9 mmol) was changed to the compound (BP-1--4) (30.9 mmol). A polyarylate resin (R-6) was obtained.

(Synthesis of polyarylate resin (R-7))
Compound (BP-1-1) (30.9 mmol) and compound (BP-2) (10.3 mmol), compound (BP-1-1) (20.6 mmol) and compound (BP-2). A polyallylate resin (R-7) was obtained by the same method as the synthesis of the polyarylate resin (R-1) except that the content was changed to (20.6 mmol).

Average viscosity of the obtained polyarylate resins (R-1), (R-2), (R-3), (R-4), (R-5), (R-6) and (R-7) The molecular weights were 50500, 51,000, 50,000, 45,000, 47,300, 45,500, and 48,700, respectively.

The ¹ H-NMR spectra of the obtained polyarylate resins (R-1) to (R-7) were measured using a proton nuclear magnetic resonance spectrometer (manufactured by JASCO Corporation, 300 MHz). CDCl ₃ was used as the solvent. Tetramethylsilane (TMS) was used as the internal standard sample. As a representative example of the polyarylate resins (R-1) to (R-7), the chemical shift values of the polyarylate resin (R-7) are shown below. From the chemical shift value, it was confirmed that the polyarylate resin (R-7) was obtained. It was confirmed that the polyarylate resins (R-1) to (R-6) were obtained by the same method for the polyarylate resins (R-1) to (R-6).

Polyarylate resin (R-7): ^{1 1} H-NMR (300 MHz, CDCl ₃ ) δ = 8.21-8.26 (m, 8H), 7.25-7.29 (m, 4H), 7.07 -7.23 (m, 20H), 2.16 (q, 2H), 1.65 (s, 3H), 0.78 (t, 3H).

In addition, polyarylate resins (RA) to (RG) were also prepared as binder resins used in the comparative examples. Each of the polyarylate resins (RA) to (RC) is represented by the following chemical formulas (RA) to (RC). The number attached to the lower right of each repeating unit indicates the percentage (unit:%) of the number of each repeating unit to the total number of repeating units contained in the polyarylate resin.

The polyarylate resin (RD) used in the comparative example contains only the following repeating units (BP-A) and (BP-C) as bisphenol-derived repeating units. The polyarylate resin (RD) contains only the following repeating units (3), (DC-T) and (DC-I) as dicarboxylic acid-derived repeating units. Percentage of the number of repeating units (BP-A), percentage of the number of repeating units (BP-C), and percentage of the number of repeating units (3) to the total number of repeating units contained in the polyarylate resin (RD). , The percentage of the number of repeating units (DC-T), and the percentage of the number of repeating units (DC-I) are 25.0%, 25.0%, 25.0%, 15.0%, respectively. It is 10.0%.

The polyarylate resin (RE) used in the comparative example contains only the following repeating unit (BP-C) as the bisphenol-derived repeating unit. The polyarylate resin (RE) contains only the following repeating units (3), (DC-T) and (DC-I) as the dicarboxylic acid-derived repeating units. Percentage of the number of repeating units (BP-C), percentage of the number of repeating units (3), and percentage of the number of repeating units (DC-T) to the total number of repeating units contained in the polyarylate resin (RE). , And the percentages of the number of repeating units (DC-I) are 50.0%, 25.0%, 15.0%, and 10.0%, respectively.

The polyarylate resin (RF) used in the comparative example contains only the following repeating unit (BP-A) as the bisphenol-derived repeating unit. The polyarylate resin (RF) contains only the following repeating units (3), (DC-T) and (DC-I) as the dicarboxylic acid-derived repeating units. Percentage of the number of repeating units (BP-A), percentage of the number of repeating units (3), and percentage of the number of repeating units (DC-T) to the total number of repeating units contained in the polyarylate resin (RF). , And the percentages of the number of repeating units (DC-I) are 50.0%, 25.0%, 15.0%, and 10.0%, respectively.

The polyarylate resin (RG) used in the comparative example contains only the following repeating unit (BP-Z) as the bisphenol-derived repeating unit. The polyarylate resin (RG) contains only the following repeating units (3), (DC-T) and (DC-I) as dicarboxylic acid-derived repeating units. Percentage of the number of repeating units (BP-Z), percentage of the number of repeating units (3), and percentage of the number of repeating units (DC-T) to the total number of repeating units contained in the polyarylate resin (RG). , And the percentage of the number of repeating units (DC-I) are 50.0%, 25.0%, 15.0%, and 10.0%, respectively.

The viscosity average molecular weights of the polyarylate resins (RA), (RB), (RC), (RD), (RE), (RF) and (RG) Were 45,300, 51,000, 46,700, 46,800, 51,000, 45,000, and 44,400, respectively.

Types of bisphenol-derived repeating units of the prepared polyarylate resins (R-1) to (R-7) and (RA) to (RG), ratios n ₁ / n ₂ , and dicarboxylic acid-derived repeating units. The types are shown in Table 3. "-" In Table 3 indicates that there is no corresponding value.

<Manufacturing of photoconductor>
Photoreceptors (A-1) to (A-17) and (B-1) to (B-7) were produced using the above-mentioned charge generator, electron transport agent, hole transport agent, and binder resin. ..

(Manufacturing of photoconductor (A-1))
3 parts by mass of Y-type titanyl tetrahydrofuranin as a charge generator, 70 parts by mass of a compound (23-H1) as a hole transporting agent, 100 parts by mass of a polyarylate resin (R-1) as a binder resin, and an electron transporting agent. 30 parts by mass of compound (10-E1) and 800 parts by mass of tetrahydrofuran as a solvent were mixed for 50 hours using a ball mill to obtain a coating liquid for a photosensitive layer. A coating liquid for a photosensitive layer was applied onto a conductive substrate (aluminum drum-shaped support) by a dip coating method. The applied coating liquid for the photosensitive layer was dried with hot air at 120 ° C. for 60 minutes. In this way, a photosensitive layer (thickness 28 μm) was formed on the conductive substrate to obtain a photosensitive member (A-1). In the photoconductor (A-1), a single-layer photosensitive layer was directly provided on the conductive substrate.

(Manufacturing of Photoreceptors (A-2) to (A-17) and (B-1) to (B-7))
Photoreceptors (A-2) to (A-) were produced in the same manner as in the production of the photoconductor (A-1), except that the hole transporting agent, the electron transporting agent, and the binder resin shown in Table 4 were used. 17) and each of (B-1) to (B-7) were produced.

<Evaluation of sensitivity characteristics>
The sensitivity characteristics of each of the photoconductors (A-1) to (A-17) and (B-1) to (B-7) were evaluated in an environment of a temperature of 23 ° C. and a relative humidity of 50% RH. .. Specifically, the surface of the photoconductor was charged to + 750 V using a drum sensitivity tester (manufactured by Gentec Co., Ltd.). Next, monochromatic light (wavelength: 780 nm, exposure amount: 0.7 μJ / cm ² ) was taken out from the light of the halogen lamp using a bandpass filter and irradiated to the surface of the photoconductor. The surface potential of the photoconductor was measured when 40 milliseconds had elapsed from the end of irradiation with monochromatic light. The measured surface potential was defined as the post-exposure potential _VL (unit: + V) of the photoconductor. The post-exposure potential _VL of the photoconductor is shown in Table 4. The smaller the absolute value of the post-exposure potential _VL, the better the sensitivity characteristics of the photoconductor.

<Evaluation of wear resistance>
Abrasion resistance was evaluated for each of the photoconductors (A-1) to (A-17) and (B-1) to (B-7). An image forming apparatus (“FS-C5250DN” manufactured by Kyocera Document Solutions Co., Ltd.) was used as an evaluation machine for evaluating wear resistance. The image forming apparatus was provided with a charging roller and a cleaning blade. In addition, this image forming apparatus employs a contact development method and a direct transfer method.

First, the film thickness T1 of the photosensitive 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), 50,000 sheets of paper (“Kyocera Document Solutions Brand Paper VM-A4” sold by Kyocera Document Solutions Co., Ltd.) using an evaluation machine. Image I (pattern image with a printing rate of 1%) was continuously printed on the paper. After printing, the film thickness T2 of the photosensitive layer of the photoconductor was measured. Then, the average wear amount (unit: μm) when 1000 sheets were printed was obtained from the formula “average wear amount = (T1-T2) / 50”. The obtained average wear amount is shown in Table 4. The smaller the average amount of wear, the better the wear resistance of the photoconductor.

In Table 4, the HTM, the resin, the ETM, and the amount of wear show the hole transporting agent, the binder resin, the electron transporting agent, and the average amount of wear when 1000 sheets are printed, respectively. In Table 4, "not dissolved" indicates that the binder resin did not dissolve in the solvent and the photosensitive layer could not be formed during the preparation of the photosensitive layer coating liquid.

As shown in Table 4, the photosensitive layers of the photoconductors (A-1) to (A-17) are a single layer, and are a charge generator, a hole transport agent, an electron transport agent, and a polyarylate resin ( More specifically, it contained any of polyarylate resins (R-1) to (R-7)). Each of the polyarylate resins (R-1) to (R-7) contains at least a repeating unit (1), a repeating unit (2), and a repeating unit (3), and the number n of the repeating units (2). ratio n ₁ / n ₂ number n ₁ of the repeating units to ₂ (1) was 1.0 or more. The photosensitive layer is any of compounds (10), (11), or (12) (more specifically, compounds (10-E1), (11-E3), and (12-E2)) as an electron transporting agent. Or) was contained. The wear loss of the photoconductors (A-1) to (A-17) was 0.07 μm / 1000 sheets or less, and the photoconductors (A-1) to (A-17) were excellent in wear resistance. Further, the post-exposure potential _VL of the photoconductors (A-1) to (A-17) is +129 V or less, and the photoconductors (A-1) to (A-17) have sensitivity characteristics that can be actually used. Was able to be maintained.

From the above, it was shown that the photoconductor according to the present invention has excellent wear resistance. Since the photoconductor according to the present invention is excellent in abrasion resistance, the process cartridge and the image forming apparatus provided with the photoconductor according to the present invention are excellent in durability.

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

1: Photoreceptor (electrophotograph photoconductor)
2: Conductive substrate 3: Photosensitive layer 30: Image carrier 42: Charging device 44: Exposure device 46: Developing device 48: Transfer device 100: Image forming device P: Recording medium

Claims (13)

It is provided with a conductive substrate and a photosensitive layer,
The photosensitive layer is a single layer and
The photosensitive layer contains a charge generator, a hole transport agent, an electron transport agent, and a polyarylate resin.
The polyarylate resin contains at least a repeating unit represented by the general formula (1), a repeating unit represented by the chemical formula (2), and a repeating unit represented by the chemical formula (3), and the chemical formula (2). The ratio n ₁ / n ₂ of the number n ₁ of the repeating units represented by the general formula (1) to the number n ₂ of the repeating units represented by) is 1.0 or more.
The electron transporting agent is an electrophotographic photosensitive member containing a compound represented by the general formula (10), (11), or (12).

(In the general formula (1),
R ¹ and R ² each independently represent a hydrogen atom or a methyl group, R ³ represents a methyl group, R ⁴ represents a hydrogen atom or an alkyl group having 2 or 3 carbon atoms, or
R ¹ and R ² represent a methyl group, respectively, and R ³ and R ⁴ are bonded to each other to represent a cycloalkylidene group having 5 or 6 carbon atoms. )

(In the general formula (10), Q ^5A and Q ^5B each independently represent a hydrogen atom, 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. , Q ^6A and Q ^6B 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, and m ₁ and m ₂ independently represent, respectively. , Represents an atom from 0 to 4
In the general formula (11), Q ⁷ and Q ⁸ independently represent a hydrogen atom, 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. Q ⁹ represents 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, and m ₃ represents an integer of 0 or more and 4 or less.
In the general formula (12), Q ¹⁰ and Q ¹¹ independently represent an alkyl group or a hydrogen atom having 1 or more and 6 or less carbon atoms, and Q ¹² represents a halogen atom or a hydrogen atom. ) The repeating unit represented by the general formula (1) is a repeating unit represented by the chemical formulas (1-1), (1-2), (1-3), (1-4), or (1-5). The electrophotographic photosensitive member according to claim 1, which is a unit.

The electrophotographic photosensitive member according to claim 1 or 2, wherein the polyarylate resin further contains a repeating unit represented by the chemical formula (4).

The polyarylate resin further contains a repeating unit represented by the chemical formula (4), and the repeating unit represented by the general formula (1) is a repeating unit represented by the chemical formula (1-1). Item 2. The electrophotographic photosensitive member according to any one of Items 1 to 3.

The compound represented by the general formula (10) is a compound represented by the chemical formula (10-E1).
The compound represented by the general formula (11) is a compound represented by the chemical formula (11-E3).
The electrophotographic photosensitive member according to any one of claims 1 to 4, wherein the compound represented by the general formula (12) is a compound represented by the chemical formula (12-E2).

The hole transporting agent is any one of claims 1 to 5, which comprises a compound represented by the general formula (20), (21), (22), (23), (24), or (25). The electrophotographic photosensitive member according to the section.

(In the general formula (20), R ¹⁰ , R ¹¹ , R ¹² , R ¹³ and R ¹⁴ each independently represent an alkyl group or a hydrogen atom having 1 to 6 carbon atoms, and a and b are. , Each independently represents 0 or 1,
In the general formula (21), R ¹⁵ , R ¹⁶ and R ¹⁷ each independently represent an alkyl group having 1 or more and 6 or less carbon atoms, and R ¹⁸ is an alkyl group having 1 or more and 6 or less carbon atoms. Or, it represents a hydrogen atom, and r, s, and t each independently represent an integer of 0 or more and 5 or less.
In the general formula (22), R ¹⁹ , R ²⁰ , R ²¹ , and R ²² each independently represent an alkyl group having 1 to 6 carbon atoms, and u, v, w, and x are respectively. Independently represents an integer between 0 and 5
In the general formula (23), R ²³ and R ²⁴ independently represent a hydrogen atom, an alkyl group having 1 or more and 8 or less carbon atoms, or an alkoxy group having 1 or more and 8 or less carbon atoms, respectively, and R ²⁵ and R ^24. R ²⁶ independently represents an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or a phenyl group, and R ²⁷ , R ²⁸ , R ²⁹ , R ³⁰ , and R. ³¹ independently represent a hydrogen atom, an alkyl group having 1 or more and 8 or less carbon atoms, an alkoxy group having 1 or more and 8 or less carbon atoms, or a phenyl group, and represent R ²⁷ , R ²⁸ , R ²⁹ , R ³⁰ , and so on. And two of R ³¹ adjacent to each other may be coupled to each other to represent a ring, where d and e each independently represent an integer of 0 or more and 5 or less, and f and g each independently 1 or Represents 2
In the general formula (24), R ³² and R ³³ independently represent a hydrogen atom, an alkyl group having 1 or more and 8 or less carbon atoms, or a phenyl group, and R ³⁴ , R ³⁵ , R ⁴⁶ , and R, respectively. ⁴⁷ each independently represents an alkyl group or phenyl group having 1 to 8 carbon atoms, and R ^{36 to} R ⁴⁵ independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or phenyl. Representing a group, p and q each independently represent 0 or 1, h and i each independently represent an integer of 0 or more and 5 or less, and j and k each independently represent 0 or more and 4 or less. Represents an integer of
In the general formula (25), R ⁴⁸ , R ⁴⁹ , and R ⁵⁰ each independently represent an alkyl group having 1 to 8 carbon atoms, and R ⁵¹ , R ⁵² , and R ⁵³ independently represent each. , A hydrogen atom or an alkyl group having 1 to 8 carbon atoms. ) The hole transporting agent has chemical formulas (20-H8), (20-H9), (21-H4), (22-H6), (23-H1), (23-H2), (23-H3), and more. The electrophotographic photosensitive member according to any one of claims 1 to 6, which comprises the compound represented by (24-H7) or (25-H5).

The electrophotographic photosensitive member according to any one of claims 1 to 7, wherein the photosensitive layer is provided as the outermost surface layer. A process cartridge comprising the electrophotographic photosensitive member according to any one of claims 1 to 8. Image carrier and
A charging device that charges the surface of the image carrier,
An exposure apparatus that exposes the surface of the charged image carrier to form an electrostatic latent image on the surface of the image carrier.
A developing device that develops the electrostatic latent image as a toner image,
A transfer device for transferring the toner image from the image carrier to the transfer target is provided.
An image forming apparatus in which the image carrier is the electrophotographic photosensitive member according to any one of claims 1 to 8. The transferred body is a recording medium and
The image forming apparatus according to claim 10, wherein the transfer device transfers the toner image from the image carrier to the recording medium while the recording medium is in contact with the surface of the image carrier. The image forming apparatus according to claim 10 or 11, wherein the developing apparatus develops the electrostatic latent image as the toner image while the developing apparatus is in contact with the surface of the image carrier. The image forming apparatus according to any one of claims 10 to 12, wherein the charging device is a charging roller.

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