JP2022069078A - Electrophotographic photoreceptor, process cartridge, and image forming apparatus - Google Patents

Abstract

To provide an electrophotographic photoreceptor that is excellent in wear resistance, filming resistance, and scratch resistance and prevention of transfer memory.SOLUTION: An electrophotographic photoreceptor 1 comprises a conductive substrate 2 and a photosensitive layer 3. The photosensitive layer is a single layer and contains a charge generating agent, a hole transport agent, an electron transport agent, and polyarylate resin. The polyarylate resin includes repeating units represented by specific formulas (1), (2), and (3). The ratio n1/n2 of the number n1 of the repeating unit (1) to the number n2 of the repeating unit (2) is 1.0 or more. The electron transport agent includes a compound represented by a specific formula, and the hole transport agent includes a compound represented by a specific formula.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 the photosensitive layer is a polyarylate resin containing a structure represented by the following formula.

Japanese Patent Application Laid-Open No. 2003-322982

However, according to the studies by the present inventors, it has been found that the electrophotographic photosensitive member described in Patent Document 1 is insufficient in terms of abrasion resistance, filming resistance, scratch resistance, and suppression of transfer memory. ..

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, filming resistance, scratch resistance, and suppression of transfer memory. Another object of the present invention is to provide a process cartridge and an image forming apparatus capable of improving wear resistance, filming resistance, and scratch resistance of an electrophotographic photosensitive member and suppressing transfer memory.

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 a repeating unit represented by the formula (1), a repeating unit represented by the formula (2), and a repeating unit represented by the formula (3). The ratio n ₁ / n ₂ of the number n ₁ of the repeating units represented by the formula (1) to the number n ₂ of the repeating units represented by the formula (2) is 1.0 or more. The electron transporting agent contains a compound represented by the formula (11), (12), (13), or (14). The hole transporting agent contains a compound represented by the formula (20), (21), (22), (23), or (24).

In the above 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, or R ¹ and R ² are represented. Each independently represents 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.

Q ⁵¹ , Q ⁵² , Q ⁵³ , Q ⁵⁴ , Q ⁵⁵ , and Q ⁵⁶ in the formula (11), Q ²¹ , Q ²² , Q ²³ , and Q ²⁴ in the formula (12), the formula (13). ), ^{And Q 41, Q 42 , Q 43} , and Q ⁴⁴ in the above formula (14) ^are independently hydrogen atom, atom, cyano group, carbon atom number 1 or more 6 At least one selected from the group consisting of the following alkyl groups, alkenyl groups having 2 or more and 6 or less carbon atoms, alkoxy groups having 1 or more and 6 or less carbon atoms, or alkyl groups and halogen atoms having 1 or more and 6 or less carbon atoms. Represents an aryl group having 6 or more and 14 or less carbon atoms which may be substituted with one substituent. Y ¹ and Y ² in the above formula (11) independently represent an oxygen atom or a sulfur atom, respectively.

In the above formula (20), R ¹¹ , R ¹² , R ¹³ and R ¹⁴ each independently represent an alkyl group having 1 or more and 6 or less carbon atoms or an alkoxy group having 1 or more and 6 or less carbon atoms. a ₁ , a ₂ , a ₃ , and a ₄ each independently represent an integer of 0 or more and 5 or less. In the above formula (21), R ²¹ , R ²² and R ²³ each independently represent an alkyl group having 1 or more carbon atoms and 6 or less carbon atoms. R ²⁴ , R ²⁵ , and R ²⁶ each independently represent a hydrogen atom or an alkyl group having 1 or more and 6 or less carbon atoms. b ₁ , b ₂ and b ₃ independently represent 0 or 1, respectively. In the above formula (22), R ³¹ , R ³² , and R ³³ each independently represent an alkyl group having 1 or more carbon atoms and 6 or less carbon atoms. R ³⁴ represents an alkyl group or a hydrogen atom having 1 or more and 6 or less carbon atoms. d ₁ , d ₂ , and d ₃ each independently represent an integer of 0 or more and 5 or less. In the above formula (23), R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , R ⁴⁵ , and R ⁴⁶ each independently represent an alkyl group or a phenyl group having 1 or more and 6 or less carbon atoms. R ⁴⁷ and R ⁴⁸ each independently represent a hydrogen atom, an alkyl group having 1 or more and 6 or less carbon atoms, or a phenyl group. e1, e2 _{, e3} , and e4 _each independently represent an integer of 0 or more and ₅ or less. e ₅ and e ₆ each independently represent an integer of 0 or more and 4 or less. e ₇ and e ₈ independently represent 0 or 1, respectively. In the formula (24), R ⁵⁰ and R ⁵¹ each independently represent an alkyl group having 1 or more and 6 or less carbon atoms, an alkoxy group having 1 or more and 6 or less carbon atoms, or a phenyl group. R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁵⁶ , R ⁵⁷ , and R ⁵⁸ are each independently a hydrogen atom, an alkyl group having 1 or more and 6 or less carbon atoms, and an alkoxy having 1 or more and 6 or less carbon atoms. Represents a phenyl group that may be substituted with a group or an alkyl group having 1 or more and 6 or less carbon atoms. f ₁ and f ₂ each independently represent an integer of 0 or more and 2 or less. f ₃ and f ₄ each independently represent an integer of 0 or more and 5 or less.

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

The image forming apparatus of the present invention exposes the image carrier, the charging device that charges the surface of the image carrier, and the surface of the charged image carrier, and electrostatically charges the surface of the image carrier. An exposure device that forms a latent image, a developing device that supplies toner to the surface of the image carrier and develops the electrostatic latent image as a toner image, and a toner image from the image carrier to the transferred object. It is provided with a transfer device for transferring. The image carrier is the electrophotographic photosensitive member.

The electrophotographic photosensitive member of the present invention is excellent in abrasion resistance, filming resistance, scratch resistance, and suppression of transfer memory. Further, the process cartridge and the image forming apparatus of the present invention can improve the wear resistance, the filming resistance, and the scratch resistance of the electrophotographic photosensitive member, and can suppress the transfer memory.

It is a partial cross-sectional view of the electrophotographic photosensitive member which concerns on 1st Embodiment of this invention. It is a partial cross-sectional view of the electrophotographic photosensitive member which concerns on 1st Embodiment of this invention. It is a partial cross-sectional view of the electrophotographic photosensitive member which concerns on 1st Embodiment of this invention. It is a figure which shows an example of the structure of the image forming apparatus which concerns on 2nd Embodiment of this invention. It is a figure which shows an example of the structure of the developing apparatus shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and can be carried out with appropriate modifications within the scope of the object of the present invention. The description may be omitted as appropriate for the parts where the explanations are duplicated, but the gist of the invention is not limited. Hereinafter, the compound and its derivatives 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. In addition, general formulas and chemical formulas are comprehensively described as "formulas". Also, "independently" in the description of the equation means that the same group may be represented or different groups may be represented. Further, as for each component described in the present specification, unless otherwise specified, one kind may be used alone, or two or more kinds may be used in combination. Unless otherwise specified, the viscosity average molecular weight is a value measured according to JIS (Japanese Industrial Standards) K7252-1: 2016.

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 6 carbon atoms, alkyl groups with 1 to 5 carbon atoms, alkyl groups with 1 to 3 carbon atoms, alkyl groups with 2 carbon atoms, and alkyl groups with 3 carbon atoms are , Respectively, linear or branched and unsubstituted, unless otherwise specified. Examples of the alkyl group having 1 or more and 6 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, and 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, n-hexyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 1,1-dimethylbutyl group, 1,2-dimethylbutyl group, 1,3-dimethyl Butyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, 3,3-dimethylbutyl group, 1,1,2-trimethylpropyl group, 1,2,2-trimethylpropyl group, 1-ethylbutyl Examples include groups, 2-ethylbutyl groups, and 3-ethylbutyl groups. Examples of an alkyl group having 1 to 5 carbon atoms, an alkyl group having 1 to 3 carbon atoms, an alkyl group having 2 carbon atoms, and an alkyl group having 3 carbon atoms have 1 to 6 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 6 or less carbon atoms and the alkoxy group having 1 or more and 3 or less carbon atoms are linear or branched and unsubstituted. Examples of the alkoxy group having 1 or more and 6 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, 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-trimethylpropoxy group, 1,2, Examples thereof include a 2-trimethylpropoxy group, a 1-ethylbutoxy group, a 2-ethylbutoxy group, and a 3-ethylbutoxy group. An example of an alkoxy group having 1 or more and 3 or less carbon atoms is a group having a corresponding carbon atom number among the groups described as an example of an alkoxy group having 1 or more and 6 or less carbon atoms.

Unless otherwise specified, each of the aryl group having 6 or more and 14 or less carbon atoms and the aryl group having 6 or more and 10 or less carbon atoms is unsubstituted. Examples of the aryl group having 6 or more carbon atoms and 14 or less carbon atoms include a phenyl group, a naphthyl group, an indasenyl group, a biphenylenyl group, an acenaphthylenyl group, an anthryl group, and a phenanthryl group. Examples of the aryl group having 6 or more and 10 or less carbon atoms include a phenyl group and a naphthyl group.

Unless otherwise specified, alkenyl groups having 2 or more and 6 or less carbon atoms are linear or branched and unsubstituted. An alkenyl group having 2 or more and 6 or less carbon atoms has one or more and three or less double bonds. Examples of the alkenyl group having 2 or more and 6 or less carbon atoms include an ethenyl group, a propenyl group, a butenyl group, a butazienyl group, a pentenyl group, a hexenyl group, a hexadienyl group, and a hexatrinyl group. The substituents used in the present specification have been described above.

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

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 the single-layer photosensitive layer 3.

As shown in FIG. 2, the photoconductor 1 may further include an intermediate layer 4 (undercoat layer) in addition to the conductive substrate 2 and the photosensitive layer 3. 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 photoconductor 1 may further include a protective layer 5 in addition to the conductive substrate 2 and the photosensitive layer 3. The protective layer 5 is provided on the photosensitive layer 3. As shown in FIG. 3, the protective layer 5 may be provided as the outermost surface layer of the photoconductor 1. However, as shown in FIGS. 1 and 2, it is preferable that the photosensitive layer 3 is provided as the outermost surface layer of the photoconductor 1. A wear resistant layer 1 is provided with a photosensitive layer 3 containing a polyarylate resin (PA) described later, a predetermined electron transporting agent described later, and a predetermined hole transporting agent described later as the outermost surface layer. The sex is further improved.

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 structure of the photoconductor 1 has been described above with reference to FIGS. 1 to 3.

Hereinafter, the photoconductor will be further described. The photosensitive layer included in the photoconductor contains a charge generating agent, a hole transporting agent, an electron transporting agent, and a polyarylate resin.

(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, azurenium pigments, and cyanine. Pigments, powders of inorganic photoconductive materials (eg, selenium, selenium-tellu, selenium-arsenic, cadmium sulfide, and amorphous silicon), pyrylium pigments, anthanthrone pigments, triphenylmethane pigments, sulene pigments, toluidin pigments. , Pyrazoline pigments, and quinacridone pigments. The photosensitive layer may contain only one type of charge generator, or may contain two or more types of charge generator.

The phthalocyanine pigment is a pigment having a phthalocyanine structure. Examples of the phthalocyanine pigment include non-metallic phthalocyanine and metallic phthalocyanine. Examples of the metallic phthalocyanine include titanyl phthalocyanine, hydroxygallium phthalocyanine, and chlorogallium phthalocyanine. As the metallic phthalocyanine, titanyl phthalocyanine is preferable. Titanyl phthalocyanine is represented by the formula (CG-1).

The phthalocyanine pigment may be crystalline or amorphous. Examples of the crystal of the non-metal phthalocyanine include an X-type crystal of the non-metal phthalocyanine (hereinafter, may be referred to as an X-type non-metal 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, 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), it is preferable to use a photoconductor having sensitivity in a wavelength region of 700 nm or more. Since it has a high quantum yield in the wavelength region of 700 nm or more, the phthalocyanine pigment is preferable, the metal-free phthalocyanine or the titanyl phthalocyanine is more preferable, the titanyl phthalocyanine is further preferable, and the 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 (titanylphthalocyanine) 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 the 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 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the binder resin.

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

In 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. Alternatively, in 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. show.

Hereinafter, the repeating unit represented by the formulas (1), (2), and (3) may be described as the repeating unit (1), (2), and (3), respectively. Further, 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) includes the repeating unit (1), the repeating unit (2), and the repeating unit (3). A polyallylate resin having a value of 1.0 or more may be referred to as a polyallylate resin (PA).

When the photosensitive layer contains a polyarylate resin (PA), the abrasion resistance, scratch resistance, and filming resistance of the photoconductor can be improved, and the transfer memory can be suppressed. The reason is presumed as follows.

The polyarylate resin (PA) contains a repeating unit (1) and repeating units (2) and (3) having an ether bond (-O-bond), and the ratio n ₁ / n ₂ is 1.0 or more. be. By containing the polyarylate resin (PA) having such a predetermined structure, the strength of the photosensitive layer is increased, and the abrasion resistance and scratch resistance of the photoconductor are improved. Further, by containing the polyarylate resin (PA) having a predetermined structure, the elastic modulus of the photosensitive layer is increased, and it becomes difficult for the toner external agent and the paper dust to get into the photosensitive layer. As a result, the external additive and the paper dust adhering to the photosensitive layer are suitably cleaned, and the filming resistance of the photoconductor is improved. The filming of the photoconductor is a problem in which the external additive and the paper dust remaining on the surface of the photoconductor after cleaning are fused to the surface of the photoconductor. Further, since the polyarylate resin (PA) has a predetermined structure, the transfer memory of the photoconductor is suppressed. Further, since the polyarylate resin (PA) having a predetermined structure has excellent solubility in a solvent for forming a photosensitive layer, a uniform and dense photosensitive layer can be formed. As a result, it is possible to improve the wear resistance of the photoconductor and suppress the transfer memory.

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

Examples of the alkyl group having 2 or 3 carbon atoms represented by R ⁴ in the 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.

As a suitable example of the repeating unit (1), the repeating unit represented by the formulas (1-1), (1-2), (1-3), (1-4), and (1-5) is used. Can be mentioned. Hereinafter, the repeating units represented by the formulas (1-1), (1-2), (1-3), (1-4), and (1-5) are each repeated units (1-1). , (1-2), (1-3), (1-4), and (1-5). In order to improve the wear resistance of the photoconductor, the repeating unit (1) is preferably the repeating unit (1-5).

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 abrasion resistance, the scratch resistance, and the filming resistance of the photoconductor are improved, and the transfer memory is suppressed. In order to improve the abrasion resistance, scratch resistance, and filming resistance of the photoconductor and suppress the transfer memory, the ratio n ₁ / n ₂ is preferably 1.5 or more, and 2.0 or more. Is more preferable. For the same reason, the ratio n ₁ / n ₂ is preferably 10.0 or less, more preferably 9.0 or less, further preferably 6.0 or less, and 5.0 or less. Is particularly preferred. For the same reason, the ratio n ₁ / n ₂ is chosen from 1.0, 1.5, 2.0, 3.0, 4.0, 5.0, 6.0, 9.0, and 10.0. It is also preferable that it is within the range of two values. The ratio n ₁ / n ₂ is characteristic of each repeating unit in the obtained ¹ H-NMR spectrum obtained by measuring the ¹ H-NMR spectrum of the polyarylate resin (PA) using, for example, a proton nuclear magnetic resonance spectrometer. It can be calculated from the ratio of peaks.

As the polyarylate resin (PA), the polyarylate resins (PA-a) to (PA-e) shown in Table 1 below are preferable. As the polyarylate resin (PA), the polyarylate resins (PA-1) to (PA-8) shown in Table 2 below are more preferable. In Tables 1 and 2, "unit (1)", "unit (2)", and "unit (3)" indicate repeating units (1), (2), and (3), respectively. In Tables 1 and 2, "n ₁ / n ₂ " indicates the ratio n ₁ / n ₂ .

The polyarylate resin (PA) is described as a polyarylate resin represented by the formulas (R-1) to (R-8) (hereinafter, each of which is referred to as a polyarylate resin (R-1) to (R-8). May be more preferred). In the formulas (R-1) to (R-8), the number attached to the lower right of each repeating unit is a percentage (%) of the number of each repeating unit 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 formulas (R-1) to (R-8). 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) to (R-8) is 50% (right of the two repeating units (3)). The total of the numbers attached below).

The polyarylate resin (PA) may contain only one type of repeating unit (1), or may contain two or more types of repeating units (1). Further, the polyarylate resin (PA) may contain only the repeating units (1), (2), and (3) as the repeating unit, and may further contain other repeating units. Further, the photosensitive layer may contain only one kind of polyarylate resin (PA), or may contain two or more kinds of polyarylate resin (PA).

In the polyarylate resin (PA), the bisphenol-derived repeating unit and the dicarboxylic acid-derived repeating unit are adjacent to each other. 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). The polyarylate resin (PA) may be, for example, a random copolymer, an alternate copolymer, a periodic copolymer, or a block copolymer.

The viscosity average molecular weight of the polyarylate resin (PA) is preferably 10,000 or more, more preferably 30,000 or more, and further preferably 50,000 or more. When the viscosity average molecular weight of the polyarylate resin (PA) is 10,000 or more, the wear resistance of the photoconductor is improved. On the other hand, the viscosity average molecular weight of the polyarylate resin (PA) is preferably 80,000 or less, 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 the 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 compounds represented by the formulas (BP-1) and (BP-2) (hereinafter, the compounds (BP-1) and (BP-2), respectively). May be described). Examples of the dicarboxylic acid for constituting the dicarboxylic acid-derived repeating unit include a compound represented by the formula (DC-3) (hereinafter, may be referred to as a compound (DC-3)). R ^{1, R 2, R 3, and R 4 in the formula (BP-1) are synonymous with R 1 , R 2 , R 3 , and R 4 in the formula (} 1), respectively. 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).

Bisphenols (eg, compound (BP-1) and compound (BP-2)) may be derived and used as aromatic diacetates. The dicarboxylic acid (for example, compound (DC-3)) may be derivatized and used. Examples of dicarboxylic acid derivatives 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 substituted with "-C (= O) -Cl" groups.

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 photosensitive layer may contain only the polyarylate resin (PA) as the binder resin, or may further contain other binder resins (hereinafter, may be referred to as other binder resins). Examples of other binder resins include thermoplastic resins (more specifically, polyarylate resins other than polyarylate resin (PA), polycarbonate resins, styrene resins, styrene-butadiene copolymers, and styrene-acrylonitrile co-weights. Combined, styrene-maleic acid copolymer, styrene-acrylic acid copolymer, acrylic copolymer, polyethylene resin, ethylene-vinyl acetate copolymer, chlorinated polyethylene resin, polyvinyl chloride resin, polypropylene resin, ionomer, chloride Vinyl-vinyl acetate copolymer, polyester resin, alkyd resin, 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, urea resin, melamine resin, and other crosslinkable thermosetting resins), and photocurable resins (more specifically, epoxy-acrylic acid-based resins). , And urethane-acrylic acid-based copolymer).

(Electronic transport agent)
The electron transporting agent is a compound represented by the formula (11), (12), (13), or (14) (hereinafter, each of which is an electron transporting agent (11), (12), (13), and (14). ) May be included. The photosensitive layer contains an electron transporting agent (11), (12), (13), or (14) together with a polyarylate resin (PA) and a predetermined hole transporting agent described later, whereby the photosensitive layer is resistant to the photoconductor. Abrasion resistance can be improved and transfer memory can be suppressed.

^Q51 to ^Q56 in the formula (11), Q21 to Q24 in the formula ^{( 12} ), Q31 and ^Q32 in the formula ( ¹³ ), and ^Q41 to ^Q44 in the formula (14) are Each independently has a hydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 or more and 6 or less carbon atoms, an alkenyl group having 2 or more and 6 or less carbon atoms, an alkoxy group having 1 or more and 6 or less carbon atoms, or a carbon atom number. Represents an aryl group having 6 or more and 14 or less carbon atoms which may be substituted with at least one substituent selected from the group consisting of 1 or more and 6 or less alkyl groups and halogen atoms. Y ¹ and Y ² in the formula (11) independently represent an oxygen atom or a sulfur atom.

^Q51 to ^Q56 in the formula (11), Q21 to Q24 in the formula ^{( 12} ), Q31 and ^Q32 in the formula ( ¹³ ), and ^Q41 to ^Q44 in the formula (14) are Each may be independently substituted with at least one substituent selected from the group consisting of a hydrogen atom, an alkyl group having 1 or more and 6 or less carbon atoms, or an alkyl group having 1 or more and 6 or less carbon atoms and a halogen atom. It is preferable to represent an aryl group having 6 or more carbon atoms and 14 or less carbon atoms. It is preferable that Y ¹ and Y ² represent an oxygen atom.

Represented by Q ⁵¹ to Q ⁵⁶ in Eq. (11), Q ²¹ to Q ²⁴ in Eq. (12), Q ³¹ and Q ³² in Eq. (13), and Q ⁴¹ to Q ⁴⁴ in Eq. (14). As the alkyl group having 1 or more and 6 or less carbon atoms, an alkyl group having 1 or more and 5 or less carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, a butyl group, or a pentyl group is preferable, and a methyl group, an isopropyl group, and the like. A tert-butyl group or a 1,1-dimethylpropyl group is particularly preferred.

It is represented by Q ⁵¹ to Q ⁵⁶ in the formula (11), Q ²¹ to Q ²⁴ in the formula (12), Q ³¹ and Q ³² in the formula (13), and Q ⁴¹ to Q ⁴⁴ in the formula (14). As the aryl group having 6 or more and 14 or less carbon atoms, an aryl group having 6 or more and 10 or less carbon atoms is preferable, and a phenyl group is more preferable. The aryl group having 6 or more and 14 or less carbon atoms may be substituted with at least one substituent selected from the group consisting of an alkyl group having 1 or more and 6 or less carbon atoms and a halogen atom. As the alkyl group having 1 or more and 6 or less carbon atoms as a substituent, an alkyl group having 1 or more and 3 or less carbon atoms is preferable, and a methyl group or an ethyl group is more preferable. As the halogen atom as the substituent, a fluorine atom, a chlorine atom or a bromine atom is preferable, and a chlorine atom is particularly preferable. When an aryl group having 6 or more and 14 or less carbon atoms is substituted with a substituent, the number of substituents is preferably 1 or more and 5 or less, and more preferably 1 or 2. Examples of the aryl group having 6 or more and 14 or less carbon atoms substituted with at least one substituent selected from the group consisting of an alkyl group having 1 or more and 6 or less carbon atoms and a halogen atom include a chlorophenyl group, a dichlorophenyl group, or an ethyl. A methylphenyl group is preferred, a 4-chlorophenyl group, a 2,5-dichlorophenyl group, or a 2-ethyl-6-methylphenyl group is more preferred.

Preferable examples of the electron transporting agent (11) include compounds represented by the formulas (E-2) and (E-3). Preferable examples of the electron transporting agent (12) include a compound represented by the formula (E-7). Preferable examples of the electron transporting agent (13) include a compound represented by the formula (E-6). Preferable examples of the electron transport agent (14) include a compound represented by the formula (E-8). Hereinafter, the compounds represented by the formulas (E-2), (E-3), (E-6), (E-7), and (E-8) are each used as an electron transporting agent (E-2). , (E-3), (E-6), (E-7), and (E-8).

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 100 parts by mass or less, and 30 parts by mass or more with respect to 100 parts by mass of the binder resin. It is more preferably 70 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. Further, the photosensitive layer further contains an electron transporting agent other than the electron transporting agents (11), (12), (13), and (14) (hereinafter, may be referred to as other electron transporting agents). May be good. 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-based compounds, dinitroacridin-based 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)
The hole transporting agent is a compound represented by the formula (20), (21), (22), (23), or (24) (hereinafter, each of which is a hole transporting agent (20), (21), ( 22), (23), and (24)). The photosensitive layer is photosensitive by containing the hole transporting agent (20), (21), (22), (23), or (24) together with the polyarylate resin (PA) and the above-mentioned predetermined electron transporting agent. The wear resistance of the body can be improved and the transfer memory can be suppressed.

In formula (20), R ¹¹ , R ¹² , R ¹³ and R ¹⁴ each independently represent an alkyl group having 1 or more and 6 or less carbon atoms or an alkoxy group having 1 or more and 6 or less carbon atoms. a ₁ , a ₂ , a ₃ , and a ₄ each independently represent an integer of 0 or more and 5 or less.

In the formula (20), when a ₁ represents an integer of 2 or more and 5 or less, the plurality of R ^11s may represent the same group or different groups. When a ₂ represents an integer of 2 or more and 5 or less, the plurality of R ^12s may represent the same group or different groups. When a ₃ represents an integer of 2 or more and 5 or less, the plurality of R ^13s may represent the same group or different groups. When a ₄ represents an integer of 2 or more and 5 or less, the plurality of R ^14s may represent the same group or different groups.

In formula (20), R ¹¹ , R ¹² , R ¹³ and R ¹⁴ each independently preferably represent an alkyl group having 1 or more carbon atoms and 3 or less carbon atoms, and more preferably a methyl group or an ethyl group. preferable. It is preferable that a ₁ , a ₂ , a ₃ and a ₄ each independently represent an integer of 1 or more and 3 or less, and more preferably 1 is represented.

In formula (21), R ²¹ , R ²² and R ²³ each independently represent an alkyl group having 1 or more carbon atoms and 6 or less carbon atoms. R ²⁴ , R ²⁵ , and R ²⁶ each independently represent a hydrogen atom or an alkyl group having 1 or more and 6 or less carbon atoms. b ₁ , b ₂ and b ₃ independently represent 0 or 1, respectively.

In the formula (21), R ²¹ , R ²² and R ²³ each independently represent an alkyl group having 1 or more and 3 or less carbon atoms, and more preferably a methyl group. R ²¹ , R ²² and R ²³ are preferably attached to the meta position of the phenyl group with respect to the ethenyl group or the butazienyl group. R ²⁴ , R ²⁵ , and R ²⁶ each preferably represent a hydrogen atom. It is preferable that b ₁ , b ₂ and b ₃ all represent 0 or all represent 1.

In formula (22), R ³¹ , R ³² , and R ³³ each independently represent an alkyl group having 1 or more carbon atoms and 6 or less carbon atoms. R ³⁴ represents an alkyl group or a hydrogen atom having 1 or more and 6 or less carbon atoms. d ₁ , d ₂ , and d ₃ each independently represent an integer of 0 or more and 5 or less.

In the formula (22), when d ₁ represents an integer of 2 or more and 5 or less, the plurality of R ^31s may represent the same group or different groups. When d ₂ represents an integer of 2 or more and 5 or less, the plurality of R ^32s may represent the same group or different groups. When d ₃ represents an integer of 2 or more and 5 or less, the plurality of R ^33s may represent the same group or different groups.

In formula (22), R ³⁴ preferably represents a hydrogen atom. It is preferable that d ₁ , d ₂ and d ₃ each represent 0.

In formula (23), R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , R ⁴⁵ , and R ⁴⁶ each independently represent an alkyl group or a phenyl group having 1 or more and 6 or less carbon atoms. R ⁴⁷ and R ⁴⁸ each independently represent a hydrogen atom, an alkyl group having 1 or more and 6 or less carbon atoms, or a phenyl group. e1, e2 _{, e3} , and e4 _each independently represent an integer of 0 or more and ₅ or less. e ₅ and e ₆ each independently represent an integer of 0 or more and 4 or less. e ₇ and e ₈ independently represent 0 or 1, respectively.

In the formula (23), when e ₁ represents an integer of 2 or more and 5 or less, the plurality of R ^41s may represent the same group or different groups. When e ₂ represents an integer of 2 or more and 5 or less, the plurality of R ^42s may represent the same group or different groups. When e ₃ represents an integer of 2 or more and 5 or less, the plurality of R ^43s may represent the same group or different groups. When e ₄ represents an integer of 2 or more and 5 or less, the plurality of R ^44s may represent the same group or different groups. When e ₅ represents an integer of 2 or more and 4 or less, the plurality of R ^45s may represent the same group or different groups. When e ₆ represents an integer of 2 or more and 4 or less, the plurality of R ^46s may represent the same group or different groups.

In the formula (23), R ⁴¹ to R ⁴⁶ each independently preferably represent an alkyl group having 1 or more and 6 or less carbon atoms, and more preferably represent an alkyl group having 1 or more and 3 or less carbon atoms. It is more preferable to represent a methyl group or an ethyl group. R ⁴⁷ and R ⁴⁸ preferably represent a hydrogen atom. It is preferable that e ₁ , e ₂ , e ₃ and e ₄ each independently represent an integer of 0 or more and 2 or less, and e ₁ and e ₂ represent 0 and e ₃ and e ₄ represent 2. More preferred. e ₅ and e ₆ preferably represent 0. It is preferable that e ₇ and e ₈ both represent 0 or 1 respectively.

In the formula (24), R ⁵⁰ and R ⁵¹ each independently represent an alkyl group having 1 or more and 6 or less carbon atoms, an alkoxy group having 1 or more and 6 or less carbon atoms, or a phenyl group. R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁵⁶ , R ⁵⁷ , and R ⁵⁸ are each independently a hydrogen atom, an alkyl group having 1 or more and 6 or less carbon atoms, and an alkoxy having 1 or more and 6 or less carbon atoms. Represents a phenyl group that may be substituted with a group or an alkyl group having 1 or more and 6 or less carbon atoms. f ₁ and f ₂ each independently represent an integer of 0 or more and 2 or less. f ₃ and f ₄ each independently represent an integer of 0 or more and 5 or less.

In formula (24), when f ₃ represents an integer of 2 or more and 5 or less, the plurality of R ^50s may represent the same group or different groups. When f ₄ represents an integer of 2 or more and 5 or less, the plurality of R ^51s may represent the same group or different groups.

In the formula (24), it is preferable that R ⁵⁰ and R ⁵¹ each independently represent an alkyl group having 1 or more and 6 or less carbon atoms. R ⁵² and R ⁵³ preferably represent a phenyl group which may be substituted with a hydrogen atom or an alkyl group having 1 or more and 6 or less carbon atoms, respectively. It is preferable that R ⁵⁴ to R ⁵⁸ each independently represent a hydrogen atom, an alkyl group having 1 or more and 6 or less carbon atoms, or an alkoxy group having 1 or more and 6 or less carbon atoms. It is preferable that f ₁ and f ₂ both represent 0, both represent 1, and both represent 2. It is preferable that f ₃ and f ₄ independently represent 0 or 1, respectively.

As the alkyl group having 1 or more and 6 or less carbon atoms represented by R ⁵⁰ and R ⁵¹ , an alkyl group having 1 or more and 3 or less carbon atoms is preferable, and a methyl group is more preferable. As the phenyl group represented by R ⁵² and R ⁵³ which may be substituted with an alkyl group having 1 or more and 6 or less carbon atoms, a phenyl group or a phenyl group substituted with an alkyl group having 1 or more and 3 or less carbon atoms is preferable. .. As the phenyl group substituted with an alkyl group having 1 or more and 3 or less carbon atoms, a methylphenyl group is preferable, and a 4-methylphenyl group is more preferable. As the alkyl group having 1 or more and 6 or less carbon atoms represented by R ⁵⁴ to R ⁵⁸ , an alkyl group having 1 or more and 4 or less carbon atoms is preferable, and a methyl group, an ethyl group, or an n-butyl group is preferable. As the alkoxy group having 1 or more and 6 or less carbon atoms represented by R ⁵⁴ to R ⁵⁸ , an alkoxy group having 1 or more and 3 or less carbon atoms is preferable, and an ethoxy group is more preferable.

A suitable example of the hole transporting agent (20) is a compound represented by the formula (H-11). Preferable examples of the hole transporting agent (21) include compounds represented by the formulas (H-7) and (H-8). A suitable example of the hole transporting agent (22) is a compound represented by the formula (H-6). Preferable examples of the hole transporting agent (23) include compounds represented by the formulas (H-9) and (H-10). Preferable examples of the hole transporting agent (24) are compounds represented by the formulas (H-1), (H-2), (H-3), (H-4), and (H-5). Can be mentioned. Hereinafter, the compounds represented by the formulas (H-1) to (H-11) may be described as hole transporting agents (H-1) to (H-11), respectively.

The content of the hole transporting agent is preferably 10 parts by mass or more and 200 parts by mass or less, more preferably 30 parts by mass or more and 120 parts by mass or less, and 50 parts by mass with respect to 100 parts by mass of the binder resin. It is more preferably 90 parts by mass or less.

The photosensitive layer may contain only one kind of hole transporting agent, or may contain two or more kinds of hole transporting agents. Further, the photosensitive layer may be described as a hole transporting agent other than the hole transporting agents (20), (21), (22), (23), and (24) (hereinafter, other electron transporting agents). ) May be further contained. Examples of other hole transporting agents include triphenylamine derivatives and diamine derivatives (for example, N, N, N', N'-tetraphenylbenzidine derivatives, N, N, N', N'-tetraphenylphenylenediamine. Derivatives, N, N, N', N'-tetraphenylnaphthylene diamine derivatives, N, N, N', N'-tetraphenylphenanthrylene diamine derivatives, and di (aminophenylethenyl) benzene derivatives), oxa Diazole compounds (eg 2,5-di (4-methylaminophenyl) -1,3,4-oxadiazole), styryl compounds (eg 9- (4-diethylaminostyryl) anthracene), carbazole compounds. Compounds (eg, polyvinylcarbazole), organic polysilane compounds, pyrazoline compounds (eg, 1-phenyl-3- (p-dimethylaminophenyl) pyrazoline), hydrazone compounds, indol compounds, oxazole compounds, isooxazole compounds. , Thiazol-based compounds, thiadiazol-based compounds, imidazole-based compounds, pyrazole-based compounds, and triazole-based compounds.

(Additive)
The photosensitive layer may contain an additive, if necessary. Additives include, for example, UV absorbers, antioxidants, radical scavengers, single quenchers, softeners, surface modifiers, bulking agents, thickeners, waxes, donors, surfactants, plasticizers. , Sensitizers, and leveling agents.

(Combination of materials)
In order to improve the abrasion resistance, filming resistance, scratch resistance, and suppression of transfer memory of the photoconductor, the combination of the electron transporting agent, the hole transporting agent, and the polyarylate resin is the combination No. shown in Table 3. .. Combination Nos. a-1 to a-22, shown in Table 4. The combinations No. b-1 to b-25 and the combinations shown in Table 5 are shown in Table 5. It is preferably each of c-1 to c-25. For the same reason, the combinations of the electron transporting agent, the hole transporting agent, and the polyarylate resin are the combinations No. 2 shown in Table 3. Combination Nos. a-1 to a-22, shown in Table 4. The combinations No. b-1 to b-25 and the combinations shown in Table 5 are shown in Table 5. It is each of c-1 to c-25, and it is more preferable that the charge generator is Y-type titanylphthalocyanine. In Tables 3 to 5, "No." indicates "combination No.", "ETM" indicates "electron transport agent", "HTM" indicates "hole transport agent", and "resin" indicates "resin". "Polyarylate resin" is shown.

(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. Examples of the conductive material include aluminum, iron, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, and brass. Among these conductive materials, aluminum and aluminum alloys are preferable because the charge transfer from the photosensitive layer to the conductive substrate is good.

The shape of the conductive substrate is appropriately selected according to the structure of the image forming apparatus. Examples of the shape of the conductive substrate include a sheet shape and a drum shape. Further, 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. Particles of (eg silica) can be mentioned.

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 satisfactorily form the intermediate layer and the photosensitive layer, 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. Examples of the solvent 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, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, etc.), ketones (more specifically, acetone, methyl ethyl ketone, cyclohexanone, etc.), esters (more specifically, ethyl acetate, methyl acetate, etc.), Included are dimethylformaldehyde, dimethylformamide, and dimethylsulfoxide.

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, a rod-shaped sonic oscillator, 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. As the step of forming the intermediate layer, a known method can be appropriately selected.

<Second Embodiment: Image Forming Device>
Next, the image forming apparatus 100 according to the second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a diagram showing an example of the configuration of the image forming apparatus 100. The image forming apparatus 100 is, for example, a tandem color printer.

As shown in FIG. 4, the image forming apparatus 100 includes a control unit 10, an operation unit 20, a paper feeding unit 30, a transport unit 40, a toner supply unit 50, an image forming unit 60, a transfer device 70, a fixing device 80, and an ejection unit. A unit 90 is provided.

The control unit 10 controls the operation of each unit included in the image forming apparatus 100. The control unit 10 includes a processor (not shown) and a storage unit (not shown). The processor includes, for example, a CPU (Central Processing Unit). The storage unit includes a memory such as a semiconductor memory, and may include an HDD (Hard Disk Drive). The processor controls the operation of the image forming apparatus 100 by executing a control program. The storage unit stores the control program.

The operation unit 20 receives an instruction from the user. When the operation unit 20 receives an instruction from the user, the operation unit 20 transmits a signal indicating the instruction from the user to the control unit 10. As a result, the image forming operation by the image forming apparatus 100 is started.

The paper feed unit 30 has a paper feed cassette 31 and a paper feed roller group 32. The paper cassette 31 can accommodate a plurality of recording media P (for example, paper). The paper feed roller group 32 feeds the recording media P housed in the paper cassette 31 one by one to the transport unit 40.

The transport unit 40 includes a roller and a guide member. The transport unit 40 extends from the paper feed unit 30 to the discharge unit 90. The transport unit 40 transports the recording medium P from the paper feed unit 30 to the discharge unit 90 so as to pass through the image forming unit 60 and the fixing device 80.

The toner supply unit 50 replenishes the image forming unit 60 with toner. The toner supply unit 50 includes a first mounting unit 51Y, a second mounting unit 51C, a third mounting unit 51M, and a fourth mounting unit 51K.

The first toner container 52Y is mounted on the first mounting portion 51Y. Similarly, the second toner container 52C is mounted on the second mounting portion 51C, the third toner container 52M is mounted on the third mounting portion 51M, and the fourth toner container 52K is mounted on the fourth mounting portion 51K.

Toner is contained in the first toner container 52Y, the second toner container 52C, the third toner container 52M, and the fourth toner container 52K, respectively. In the second embodiment, the first toner container 52Y contains the yellow toner. Cyan toner is stored in the second toner container 52C. Magenta toner is housed in the third toner container 52M. Black toner is stored in the fourth toner container 52K.

The image forming unit 60 includes an exposure device 61, a first image forming unit 62Y, a second image forming unit 62C, a third image forming unit 62M, and a fourth image forming unit 62K.

Each of the first image forming unit 62Y to the fourth image forming unit 62K has a charging device 63, a developing device 64, an image carrier 65, a cleaning device 66, and a static elimination device 67.

The configurations of the first image forming unit 62Y to the fourth image forming unit 62K are the same except for the type of toner replenished from the toner replenishing unit 50. Therefore, in FIG. 4, each configuration of the second image forming unit 62C to the fourth image forming unit 62K is shown by omitting a reference numeral.

The image carrier 65 is the photoconductor 1 of the first embodiment. As described in the first embodiment, the photoconductor 1 of the first embodiment is excellent in abrasion resistance, filming resistance, scratch resistance, and suppression of transfer memory. Therefore, the image forming apparatus 100 of the second embodiment can improve the wear resistance, the filming resistance, and the scratch resistance of the photoconductor 1 which is the image carrier 65, and can suppress the transfer memory.

The charging device 63, the developing device 64, the cleaning device 66, and the static elimination device 67 are arranged along the peripheral surface of the image carrier 65. In the second embodiment, the image carrier 65 rotates in the direction (clockwise direction) indicated by the arrow R1 in FIG.

The charging device 63 charges the surface (peripheral surface) of the image carrier 65. The charging device 63 uniformly charges the image carrier 65 to a predetermined polarity by electric discharge. In the second embodiment, the charging device 63 charges the image carrier 65 to a positive polarity. The charging device 63 is, for example, a charging roller.

The exposure apparatus 61 exposes the surface of the charged image carrier 65. Specifically, the exposure apparatus 61 irradiates the surface of the charged image carrier 65 with laser light. As a result, an electrostatic latent image is formed on the surface of the image carrier 65.

Toner is replenished to the developing device 64 from the toner replenishing unit 50. The developing device 64 supplies the toner replenished from the toner replenishing unit 50 to the surface of the image carrier 65. As a result, the electrostatic latent image formed on the surface of the image carrier 65 is developed as a toner image.

In the second embodiment, the developing device 64 included in the first image forming unit 62Y is connected to the first toner container 52Y. Therefore, the developing apparatus 64 included in the first image forming unit 62Y is replenished with yellow toner. Therefore, a yellow toner image is formed on the surface of the image carrier 65 included in the first image forming unit 62Y.

Similarly, the developing device 64 of the second image forming unit 62C, the developing device 64 of the third image forming unit 62M, and the developing device 64 of the fourth image forming unit 62K are the second toner container 52C and the second toner container, respectively. 3 Connects to the toner container 52M and the 4th toner container 52K. Therefore, the developing device 64 of the second image forming unit 62C, the developing device 64 of the third image forming unit 62M, and the developing device 64 of the fourth image forming unit 62K have cyan toner, magenta toner, and cyanide toner, respectively. Black toner is replenished. Therefore, the surface of the image carrier 65 of the second image forming unit 62C, the surface of the image carrier 65 of the third image forming unit 62M, and the surface of the image carrier 65 of the fourth image forming unit 62K are on the surface of the image carrier 65. A cyan toner image, a magenta toner image, and a black toner image are formed, respectively.

The cleaning device 66 has a cleaning member 661. After the transfer by the primary transfer roller 71 described later, the cleaning device 66 collects the toner adhering to the surface of the image carrier 65. Specifically, the cleaning device 66 presses the cleaning member 661 against the surface of the image carrier 65 to recover the toner adhering to the surface of the image carrier 65. The cleaning member 661 is, for example, a cleaning blade.

The static elimination device 67 irradiates the surface of the image carrier 65 with static elimination light to eliminate static electricity on the surface of the image carrier 65.

The transfer device 70 transfers the toner image from the image carrier 65 to the recording medium P which is the transfer target. Specifically, the transfer device 70 superimposes and transfers each toner image formed on the surface of each image carrier 65 included in the first image forming unit 62Y to the fourth image forming unit 62K on the recording medium P. In the second embodiment, the transfer device 70 superimposes and transfers each toner image on the recording medium P by a secondary transfer method (intermediate transfer method). The transfer device 70 includes four primary transfer rollers 71, an intermediate transfer belt 72, a drive roller 73, a driven roller 74, and a secondary transfer roller 75.

The intermediate transfer belt 72 is an endless belt stretched on four primary transfer rollers 71, a drive roller 73, and a driven roller 74. The intermediate transfer belt 72 is driven according to the rotation of the drive roller 73. In FIG. 4, the intermediate transfer belt 72 orbits counterclockwise. The driven roller 74 is rotationally driven in response to the drive of the intermediate transfer belt 72.

The first image forming unit 62Y to the fourth image forming unit 62K are arranged so as to face the lower surface of the intermediate transfer belt 72. In the second embodiment, the first image forming unit 62Y to the fourth image forming unit 62K are the first image forming unit 62Y to the fourth image from the upstream side to the downstream side of the drive direction D of the lower surface of the intermediate transfer belt 72. The forming units 62K are arranged in this order.

Each primary transfer roller 71 is arranged facing each image carrier 65 via an intermediate transfer belt 72 and is pressed toward each image carrier 65. Therefore, the toner image formed on the surface of each image carrier 65 is sequentially transferred to the intermediate transfer belt 72 by each primary transfer roller 71. In the second embodiment, the yellow toner image, the cyan toner image, the magenta toner image, and the black toner image are superimposed and transferred to the intermediate transfer belt 72 in this order. Hereinafter, a toner image in which a yellow toner image, a cyan toner image, a magenta toner image, and a black toner image are superimposed may be referred to as a “laminated toner image”.

The secondary transfer roller 75 is arranged to face the drive roller 73 via the intermediate transfer belt 72. The secondary transfer roller 75 is pressed toward the drive roller 73. As a result, a transfer nip is formed between the secondary transfer roller 75 and the drive roller 73. When the recording medium P passes through the transfer nip, the laminated toner image on the intermediate transfer belt 72 is transferred to the recording medium P by the secondary transfer roller 75. In the second embodiment, the yellow toner image, the cyan toner image, the magenta toner image, and the black toner image are transferred to the recording medium P in this order from the upper layer to the lower layer. The recording medium P on which the laminated toner image is transferred is conveyed toward the fixing device 80 by the conveying unit 40.

The fixing device 80 includes a heating member 81 and a pressurizing member 82. The heating member 81 and the pressurizing member 82 are arranged so as to face each other and form a fixing nip. The recording medium P conveyed from the image forming unit 60 is pressurized while being heated at a predetermined fixing temperature by passing through the fixing nip. As a result, the laminated toner image is fixed on the recording medium P. The recording medium P is conveyed from the fixing device 80 toward the discharging unit 90 by the conveying unit 40.

The discharge unit 90 has a discharge roller pair 91 and a discharge tray 93. The discharge roller pair 91 conveys the recording medium P to the discharge tray 93 via the discharge port 92. The discharge port 92 is formed on the upper part of the image forming apparatus 100.

Next, the configuration of the developing apparatus 64 will be described in detail with reference to FIG. FIG. 5 is a diagram showing an example of the configuration of the developing device 64. Specifically, FIG. 5 shows a developing device 64 included in the first image forming unit 62Y. In FIG. 5, the image carrier 65 is shown by a two-dot chain line for ease of understanding. In the second embodiment, the developing apparatus 64 employs a two-component developing method using a two-component developing agent and a touch-down developing method.

As already described with reference to FIG. 4, the developing container 640 of the developing device 64 is connected to the first toner container 52Y. Therefore, the developing container 640 of the developing device 64 is replenished with yellow toner via the toner replenishing port 640h.

As shown in FIG. 5, the developing apparatus 64 has a developing roller 641, a magnetic roller 642, a first stirring screw 643, a second stirring screw 644, and a blade 645 inside the developing container 640. Specifically, the developing roller 641 is arranged to face the magnetic roller 642. The magnetic roller 642 is arranged to face the second stirring screw 644. The blade 645 is arranged to face the magnetic roller 642.

The developing container 640 is divided into a first stirring chamber 640a and a second stirring chamber 640b by a partition wall 640c. The partition wall 640c extends in the axial direction of the developing roller 641. The first stirring chamber 640a and the second stirring chamber 640b communicate with each other at both ends in the longitudinal direction of the partition wall 640c.

A first stirring screw 643 is arranged in the first stirring chamber 640a. A carrier which is a magnetic material is housed in the first stirring chamber 640a. Toner, which is a non-magnetic material, is replenished to the first stirring chamber 640a via the toner replenishment port 640h. In the example shown in FIG. 5, the first stirring chamber 640a is replenished with yellow toner.

A second stirring screw 644 is arranged in the second stirring chamber 640b. A carrier which is a magnetic material is housed in the second stirring chamber 640b.

The yellow toner is stirred with the carrier by the first stirring screw 643 and the second stirring screw 644. As a result, a two-component developer containing a carrier and yellow toner is formed.

The first stirring screw 643 and the second stirring screw 644 stir between the first stirring chamber 640a and the second stirring chamber 640b while circulating the two-component developer. As a result, the toner is charged to a predetermined polarity due to friction with the carrier. In the second embodiment, the toner is charged to a positive polarity.

The magnetic roller 642 is composed of a non-magnetic rotary sleeve 642a and a magnet body 642b. The magnet body 642b is fixedly arranged inside the rotary sleeve 642a. The magnet body 642b includes a plurality of magnetic poles. The two-component developer is attracted to the magnetic roller 642 by the magnetic force of the magnet body 642b. As a result, a magnetic brush is formed on the surface of the magnetic roller 642.

In the second embodiment, the magnetic roller 642 rotates in the direction indicated by the arrow R3 in FIG. 5 (counterclockwise direction). The magnetic roller 642 rotates to convey the magnetic brush to a position facing the blade 645. The blade 645 is arranged so as to form a gap (gap) with the magnetic roller 642. Therefore, the thickness of the magnetic brush is defined by the blade 645. The blade 645 is arranged on the upstream side in the rotation direction of the magnetic roller 642 with respect to the position where the magnetic roller 642 and the developing roller 641 face each other.

A predetermined voltage is applied to the developing roller 641 and the magnetic roller 642. When a predetermined voltage is applied and a predetermined potential difference is reached between the developing roller 641 and the magnetic roller 642, the yellow toner contained in the two-component developer is transferred to the developing roller 641. As a result, a toner thin layer made of yellow toner is formed on the surface of the developing roller 641.

The developing roller 641 rotates in the direction indicated by the arrow R2 in FIG. 5 (counterclockwise direction). As a result, the toner thin layer formed on the surface is conveyed to a position facing the image carrier 65 and adheres to the image carrier 65. In this way, the developing device 64 supplies the toner charged by friction with the carrier to the surface of the image carrier 65.

As described above, the developing apparatus 64 included in the first image forming unit 62Y has been described with reference to FIG. The configurations of the developing apparatus 64 included in each of the first image forming unit 62Y to the fourth image forming unit 62K are the same except for the type of toner replenished from the toner replenishing unit 50. Therefore, the description of the configuration of the developing apparatus 64 included in the second image forming unit 62C to the fourth image forming unit 62K will be omitted.

Although an example of the image forming apparatus has been described above with reference to FIGS. 4 and 5, the image forming apparatus is not limited to the image forming apparatus 100. The image forming apparatus 100 is 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 has adopted the tandem method, the image forming apparatus may adopt, for example, a rotary method. Although the charging device 63 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). The image forming apparatus 100 has adopted a two-component developing method using a two-component developing agent, but the image forming apparatus may adopt a one-component developing method using a one-component developing agent. The image forming apparatus 100 has adopted a touch-down developing method, but the image forming apparatus adopts a developing method other than the touch-down developing method (for example, a developing method that does not have a developing roller and the magnetic roller also serves as a developing roller). You may. Although the image forming apparatus 100 has adopted the intermediate transfer method, the image forming apparatus may adopt the direct transfer method. When the image forming apparatus adopts the direct transfer method, the toner image is directly transferred from the image carrier 65 to the recording medium P while the image carrier 65 is in contact with the recording medium P. Although the cleaning blade has been described as an example of the cleaning member 661, the cleaning member may be a cleaning roller. Further, the image forming apparatus does not have to include the cleaning apparatus 66. Further, although the first image forming unit 62Y to the fourth image forming unit 62K are provided with a static elimination device, the image forming unit may not be provided with a static elimination device.

<Third Embodiment: Process cartridge>
Next, with reference to FIG. 4, the process cartridge according to the third embodiment of the present invention will be described. The process cartridge of the third embodiment corresponds to each of the first image forming unit 62Y to the fourth image forming unit 62K. The process cartridge comprises an image carrier 65. The image carrier 65 is the photoconductor 1 of the first embodiment. As described in the first embodiment, the photoconductor 1 of the first embodiment is excellent in abrasion resistance, filming resistance, scratch resistance, and suppression of transfer memory. Therefore, the process cartridge of the third embodiment can improve the wear resistance, filming resistance, and scratch resistance of the photoconductor 1 which is the image carrier 65, and can suppress the transfer memory.

In addition to the image carrier 65, the process cartridge further includes at least one (for example, one or more and four or less) selected from the group consisting of the charging device 63, the developing device 64, the cleaning device 66, and the static elimination device 67. Be prepared. The process cartridge may further include a transfer device 70 (particularly, a primary transfer roller 71). The process cartridge may further include an exposure apparatus 61. 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 65 deteriorates, the process cartridge including the image carrier 65 can be easily and quickly replaced. The process cartridge of the third embodiment has been described above 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 generating agent, electron transporting agent, hole transporting agent, and binder resin were prepared as materials for forming the photosensitive layer of the photoconductor.

(Charge generator)
The Y-type titanylphthalocyanine described in the first embodiment was prepared as a charge generator.

(Electronic transport agent)
As the electron transporting agent, each of the electron transporting agents (E-2), (E-3), (E-6), (E-7), and (E-8) described in the first embodiment was prepared. .. Further, as an electron transporting agent used in the comparative example, a compound represented by the formula (EA) was prepared.

(Hole transport agent)
As the hole transporting agent, the hole transporting agents (H-1) to (H-11) described in the first embodiment were prepared. Moreover, as the hole transporting agent used in the comparative example, the compound represented by the formula (HA) was prepared.

(Binder resin)
As the binder resin, the polyarylate resins (R-1) to (R-8) described in the first embodiment were prepared. The viscosity average molecular weight of the polyarylate resins (R-1) to (R-8) was 60,000.

Further, as the binder resin used in the comparative example, polycarbonate resins (RA) to (RC) and polyarylate resins (RD) to (RG) were also prepared. Each of the polycarbonate resins (RA) to (RC) and the polyarylate resins (RD) to (RG) is represented by the following formulas (RA) to (RG). 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 resin. The viscosity average molecular weights of the polycarbonate resins (RA) to (RC) and the polyarylate resins (RD) to (RG) were 60,000.

<Manufacturing of photoconductor>
(Manufacturing of Photoconductor (A-1))
2 parts by mass of Y-type titanylphthalocyanine which is a charge generator, 70 parts by mass of a hole transport agent (H-1), 50 parts by mass of an electron transport agent (E-2), and a polyallylate resin (R-1) which is a binder resin. 100 parts by mass and 500 parts by mass of tetrahydrofuran as a solvent were mixed for 20 minutes using a rod-shaped sonic oscillator to obtain a dispersion liquid. The dispersion liquid was filtered using a filter having an opening of 5 μm 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, and dried with hot air at 120 ° C. for 50 minutes. In this way, a photosensitive layer (thickness 30 μm) was formed on the conductive substrate to obtain a photosensitive member (A-1). In the photoconductor (A-1), a single photosensitive layer was directly provided on the conductive substrate.

(Manufacturing of Photoreceptors (A-2) to (A-22) and (B-1) to (B-9))
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 Tables 6 and 7 were used. -22) and each of (B-1) to (B-9) were produced.

<Evaluation>
Abrasion resistance, filming resistance, and scratch resistance are applied to each of the obtained photoconductors (A-1) to (A-22) and (B-1) to (B-9) by the methods shown below. Sex and suppression of transfer memory were evaluated. Paper (“Askul Multipapper Super Economy +” sold by ASKUL Corporation) was used for these evaluations. Further, as an evaluation machine for performing these evaluations, a modified machine of an image forming apparatus (“FS-C5250DN” manufactured by Kyocera Document Solutions Co., Ltd.) was used. This evaluation machine was equipped with a charging roller made of epichlorohydrin resin in which conductive carbon was dispersed as a charging device. The charging polarity of the charging roller was positive, and the voltage applied to the charging roller was a DC voltage. In addition, this evaluation machine has adopted a two-component development method and an intermediate transfer method. In addition, this evaluation machine was equipped with a cleaning blade and a static eliminator.

<Evaluation of wear resistance>
The wear resistance was evaluated in an environment with a temperature of 23 ° C. and a relative humidity of 50% RH. The film thickness T1 of the photosensitive layer of the photoconductor was measured. Next, the photoconductor was mounted on the evaluation machine. Image I (character image with a printing rate of 5%) was continuously printed on 100,000 sheets of paper using an evaluation machine. After printing, the film thickness T2 of the photosensitive layer of the photoconductor was measured. An eddy current film thickness meter (“LH-373” manufactured by Kett Science Institute Headquarters) was used for measuring the film thicknesses T1 and T2. Then, the wear amount (unit: μm) of the photosensitive layer was obtained from the formula “wear amount = T1-T2”. The obtained wear amounts are shown in Tables 6 and 7. The smaller the amount of wear, the better the wear resistance of the photoconductor.

<Evaluation of filming resistance and scratch resistance>
The photoconductor after evaluating the wear resistance was mounted on the evaluation machine. Image I (character image with a printing rate of 5%) was continuously printed on 100,000 sheets of paper in an environment of a temperature of 23 ° C. and a relative humidity of 50% RH. Next, an image II (an image including a halftone image and a white background image) was printed on one sheet of paper using an evaluation machine, and the obtained image was used as a first evaluation image.

After obtaining the first evaluation image, the photoconductor was taken out from the evaluation machine. The surface of the photoconductor was observed with the naked eye to confirm the presence or absence of scratches and filming on the surface of the photoconductor. After visual observation, the photoconductor was mounted on the evaluation machine again.

Then, in an environment of a temperature of 10 ° C. and a relative humidity of 15% RH, an image I (character image having a printing rate of 5%) was continuously printed on 50,000 sheets of paper using an evaluation machine. Next, an image II (an image including a halftone image and a white background image) was printed on one sheet of paper using an evaluation machine, and the obtained image was used as a second evaluation image.

The first evaluation image and the second evaluation image were observed, and the presence or absence of image defects due to filming was confirmed. Image defects resulting from filming are, for example, dash marks and fog. Dash marks are black dots arranged parallel to the paper transport direction. The larger the area where filming occurs on the surface of the photoconductor, the more fog occurs from the dash mark in the formed image. From the confirmation result of the surface of the photoconductor and the confirmation result of the image defect of the first evaluation image and the second evaluation image, the filming resistance and the scratch resistance were evaluated based on the following criteria. The evaluation results of filming resistance and scratch resistance are shown in Tables 6 and 7.

Evaluation A (particularly good): No scratches or filming occurred on the surface of the photoconductor. In addition, no image defects occurred in both the first evaluation image and the second evaluation image.
Evaluation B (good): At least one of scratches and filming was generated on the surface of the photoconductor. However, no image defect occurred in both the first evaluation image and the second evaluation image.
Evaluation C (defective): At least one of scratches and filming was generated on the surface of the photoconductor. An image defect occurred in the second evaluation image. However, no image defect occurred in the first evaluation image.
Evaluation D (particularly defective): At least one of scratches and filming was generated on the surface of the photoconductor. In addition, image defects occurred in both the first evaluation image and the second evaluation image.

<Evaluation of suppression of transfer memory>
The evaluation of the suppression of the transfer memory was performed in an environment of a temperature of 23 ° C. and a relative humidity of 50% RH. The photoconductor after evaluating the wear resistance, the filming resistance and the scratch resistance was mounted on the evaluation machine. The voltage applied to the charging roller was set so that the charging potential of the photoconductor was +570V. The transfer bias of the primary transfer roller was set to −2.0 kV.

The photoconductor was charged using an evaluator, and the first charging potential V ₁ (unit: + V) was measured. The transfer bias was then applied to the photoconductor without exposure and development. Then, the photoconductor was statically charged, charged again, and the second charging potential V ₂ (unit: + V) was measured. ΔVtc (unit: V) was obtained from the calculation formula “transfer memory potential ΔVtc = V1-V2”. ΔVtc is shown in Tables 6 and 7. The smaller the absolute value of ΔVtc, the more the transfer memory is suppressed.

The meanings of the terms in Tables 6 and 7 are as follows. "CGM" indicates a charge generator. "CG-1" indicates Y-type titanylphthalocyanine. "ETM" refers to an electron transport agent. "HTM" refers to a hole transport agent. "Resin" indicates a binder resin. “N ₁ / n ₂ ” indicates 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). “Filming / scratch” indicates the evaluation result of filming resistance and scratch resistance. “ΔVtc” indicates the transfer memory potential. "-" Indicates that there is no corresponding value.

As shown in Table 6, the photosensitive layers of the photoconductors (A-1) to (A-22) are polyarylate resin (PA) (more specifically, polyarylate resin (R-1) to (R-). 1 of 8)), electron transport agent (11), (12), (13), or (14) (more specifically, electron transport agent (E-2), (E-3), (E-6), (E-7), and (E-8)), and hole transport agents (20), (21), (22), (23), or (24). (More specifically, one of the hole transporting agents (H-1) to (H-11)) was contained. Therefore, the evaluation of the wear resistance of the photoconductors (A-1) to (A-22) shown in Table 6 and the evaluation of the suppression of the transfer memory are performed by the photoconductors (B-1) to (B) shown in Table 7. Compared with these evaluations in -9), it was excellent. Further, the evaluation of the filming resistance and the scratch resistance of the photoconductors (A-1) to (A-22) shown in Table 6 is based on those of the photoconductors (B-1) to (B-6) shown in Table 7. It was excellent compared to the evaluation of.

From the above, the photoconductors according to the present invention including the photoconductors (A-1) to (A-22) are excellent in abrasion resistance, filming resistance, scratch resistance, and suppression of transfer memory. Shown. Further, it is judged that the process cartridge and the image forming apparatus of the present invention provided with such a photoconductor can improve the wear resistance, the filming resistance, and the scratch resistance of the photoconductor, and can suppress the transfer memory.

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 photosensitive member)
2: Conductive substrate 3: Photosensitive layer 61: Exposure device 63: Charging device 64: Developing device 65: Image carrier 66: Cleaning device 67: Static elimination device 70: Transfer device 100: Image forming device P: Recording medium

Claims (12)

With 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 a repeating unit represented by the formula (1), a repeating unit represented by the formula (2), and a repeating unit represented by the formula (3), and is represented by the formula (2). The ratio n ₁ / n ₂ of the number n ₁ of the repeating units represented by the above equation (1) to the number n ₂ of the repeating units represented is 1.0 or more.
The electron transporting agent contains a compound represented by the formula (11), (12), (13), or (14).
The hole transport agent is an electrophotographic photosensitive member containing a compound represented by the formula (20), (21), (22), (23), or (24).

(In the above 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, or
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. )

(Q ⁵¹ , Q ⁵² , Q ⁵³ , Q ⁵⁴ , Q ⁵⁵ , and Q ⁵⁶ in the above formula (11), Q ²¹ , Q ²² , Q ²³ , and Q ²⁴ in the above formula (12), the above formula ( Q31 and ^Q32 in ¹³ ) and ^Q41 , ^Q42 , ^Q43 , and ^Q44 in the above formula (14) are independently hydrogen atom, halogen atom, cyano group, and carbon atom number 1 or more. At least selected from the group consisting of an alkyl group having 6 or less, an alkenyl group having 2 or more and 6 or less carbon atoms, an alkoxy group having 1 or more and 6 or less carbon atoms, or an alkyl group having 1 or more and 6 or less carbon atoms and a halogen atom. Represents an aryl group having 6 or more and 14 or less carbon atoms which may be substituted with one substituent.
Y ¹ and Y ² in the above formula (11) independently represent an oxygen atom or a sulfur atom, respectively. )

(In the above formula (20), R ¹¹ , R ¹² , R ¹³ and R ¹⁴ each independently represent an alkyl group having 1 or more and 6 or less carbon atoms or an alkoxy group having 1 or more and 6 or less carbon atoms. , _{A 1} , a ₂ , a ₃ and a ₄ each independently represent an integer of 0 or more and 5 or less.
In the above formula (21), R ²¹ , R ²² and R ²³ each independently represent an alkyl group having 1 or more and 6 or less carbon atoms, and R ²⁴ , R ²⁵ and R ²⁶ independently represent each of them. Represents a hydrogen atom or an alkyl group having 1 or more and 6 or less carbon atoms, and b ₁ , b ₂ and b ₃ independently represent 0 or 1, respectively.
In the above formula (22), R ³¹ , R ³² , and R ³³ each independently represent an alkyl group having 1 or more and 6 or less carbon atoms, and R ³⁴ is an alkyl group having 1 or more and 6 or less carbon atoms. Representing a hydrogen atom, d ₁ , d ₂ and d ₃ each independently represent an integer of 0 or more and 5 or less.
In the above formula (23), R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , R ⁴⁵ , and R ⁴⁶ each independently represent an alkyl group or a phenyl group having 1 or more and 6 or less carbon atoms, and R ⁴⁷ . And R ⁴⁸ each independently represent a hydrogen atom, an alkyl group having 1 or more and 6 or less carbon atoms, or a phenyl group, and e ₁ , e ₂ , e ₃ , and e ₄ independently represent 0 or more and 5 respectively. The following integers are represented, e ₅ and e ₆ each independently represent an integer of 0 or more and 4 or less, and e ₇ and e ₈ each independently represent 0 or 1.
In the above formula (24), R ⁵⁰ and R ⁵¹ independently represent an alkyl group having 1 or more and 6 or less carbon atoms, an alkoxy group having 1 or more and 6 or less carbon atoms, or a phenyl group, and R ⁵² and R respectively. ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁵⁶ , R ⁵⁷ , and R ⁵⁸ are each independently a hydrogen atom, an alkyl group having 1 or more and 6 or less carbon atoms, an alkoxy group having 1 or more and 6 or less carbon atoms, or carbon. Represents a phenyl group that may be substituted with an alkyl group having 1 or more and 6 or less atoms, f ₁ and f ₂ each independently represent an integer of 0 or more and 2 or less, and f ₃ and f ₄ each independently. , Represents an integer of 0 or more and 5 or less. ) The repeating unit represented by the formula (1) is a repeating unit represented by the formula (1-1), (1-2), (1-3), (1-4), or (1-5). The electrophotographic photosensitive member according to claim 1.

The electrophotographic photosensitive member according to claim 2, wherein the repeating unit represented by the formula (1) is a repeating unit represented by the formula (1-5). The compound represented by the formula (11) is a compound represented by the formula (E-2) or (E-3).
The compound represented by the formula (12) is a compound represented by the formula (E-7).
The compound represented by the formula (13) is a compound represented by the formula (E-6).
The electrophotographic photosensitive member according to any one of claims 1 to 3, wherein the compound represented by the formula (14) is a compound represented by the formula (E-8).

The compound represented by the formula (20) is a compound represented by the formula (H-11).
The compound represented by the formula (21) is a compound represented by the formula (H-7) or (H-8).
The compound represented by the formula (22) is a compound represented by the formula (H-6).
The compound represented by the formula (23) is a compound represented by the formula (H-9) or (H-10).
The compound represented by the formula (24) is a compound represented by the formula (H-1), (H-2), (H-3), (H-4), or (H-5). , The electrophotographic photosensitive member according to any one of claims 1 to 4.

The electrophotographic photosensitive member according to any one of claims 1 to 5, wherein the charge generator contains titanylphthalocyanine. The electrophotographic photosensitive member according to any one of claims 1 to 6, 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 7. With the image carrier,
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 supplies toner to the surface of the image carrier and 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.
The image forming apparatus, wherein the image carrier is the electrophotographic photosensitive member according to any one of claims 1 to 7. The image forming apparatus according to claim 9, further comprising one or both of a cleaning device for collecting the toner adhering to the surface of the image carrier and a static elimination device for eliminating static electricity on the surface of the image carrier. .. The image forming apparatus according to claim 9 or 10, wherein the charging device is a charging roller. The image forming apparatus according to any one of claims 9 to 11, wherein the developing device supplies the toner charged by friction with a carrier to the surface of the image carrier.

Images