CN112051716A - Photoreceptor, image forming apparatus, and method for manufacturing photoreceptor - Google Patents

Abstract

The invention provides a photoreceptor, an image forming apparatus, and a method for manufacturing the photoreceptor. An electrophotographic photoreceptor includes a conductive substrate and a photosensitive layer. A monolayer of the photosensitive layer. The photosensitive layer contains a charge generator, a hole transporting agent, an electron transporting agent, and a binder resin. The hole transport agent contains a first hole transport agent and a second hole transport agent. The first hole transporting agent is a compound represented by the general formula (1). The second hole transporting agent is a compound represented by the general formula (2). The electron transport agent contains a compound represented by general formula (10), (11) or (12). [ CHEM 1 ]

[ CHEM 2 ]

Description

Photoreceptor, image forming apparatus, and method for manufacturing photoreceptor

Technical Field

The present invention relates to a photoreceptor (electrophotographic photoreceptor), an image forming apparatus, and a method for manufacturing a photoreceptor (electrophotographic photoreceptor).

Background

Electrophotographic photoreceptors are used as image carriers in electrophotographic image forming apparatuses (e.g., printers or multifunction machines). The electrophotographic photoreceptor includes a photosensitive layer. Examples of the electrophotographic photoreceptor include a single-layer type electrophotographic photoreceptor and a laminated type electrophotographic photoreceptor. The single-layer electrophotographic photoreceptor has a single photosensitive layer having a charge generating function and a charge transporting function. The photosensitive layer in the laminated electrophotographic photoreceptor contains a charge generation layer having a charge generation function and a charge transport layer having a charge transport function.

For example, an image forming device having a charge transport layer containing a diamine compound having a specific structure is known.

Disclosure of Invention

However, the present inventors have found through their studies that the above-mentioned imaging element is not sufficient in terms of crack resistance and suppression of crystallization.

The present invention has been made in view of the above problems, and an object thereof is to provide an electrophotographic photoreceptor having excellent crack resistance and capable of suppressing crystallization. Still another object of the present invention is to provide an image forming apparatus having excellent durability and capable of forming a high-quality image by including the electrophotographic photoreceptor. Still another object of the present invention is to provide an electrophotographic photoreceptor which can simplify the production process of a hole transporting agent, has excellent crack resistance, and can suppress crystallization.

The electrophotographic photoreceptor 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 transporting agent, an electron transporting agent, and a binder resin. The hole transport agent contains a first hole transport agent and a second hole transport agent. The first hole transporting agent is a compound represented by general formula (1). The second hole transporting agent is a compound represented by general formula (2). The electron transport agent contains a compound represented by general formula (10), (11) or (12).

[ CHEM 1 ]

In the general formula (1), R^1A、R^2A、R^3A、R^4A、R^5A、R^6A、R^7A、R^8A、R^9AAnd R^10AIndependently of one another, represents a hydrogen atom, a C1-C8 alkyl group, a C1-C8 alkoxy group or a C6-C14 aryl group. R in the general formula (1)^1BAnd R in the general formula (2)^1CIs a group represented by the formula (1) and R^1AThe same group. R in the general formula (1)^2BAnd R in the general formula (2)^2CIs a group represented by the formula (1) and R^2AThe same group. R in the general formula (1)^3BAnd R in the general formula (2)^3CIs a group represented by the formula (1) and R^3AThe same group. R in the general formula (1)^4BAnd R in the general formula (2)^4CIs a group represented by the formula (1) and R^4AThe same group. R in the general formula (1)^5BAnd R in the general formula (2)^5CIs a group represented by the formula (1) and R^5AThe same group. R in the general formula (1)^6BAnd R in the general formula (2)^6CAnd R^6DIs a group represented by the formula (1) and R^6AThe same group. R in the general formula (1)^7BAnd R in the general formula (2)^7CAnd R^7DIs a group represented by the formula (1) and R^7AThe same group. R in the general formula (1)^8BAnd R in the general formula (2)^8CAnd R^8DIs a group represented by the formula (1) and R^8AThe same group. R in the general formula (1)^9BAnd R in the general formula (2)^9CAnd R^9DIs a group represented by the formula (1) and R^9AThe same group. R in the general formula (1)^10BAnd R in the general formula (2)^10CAnd R^10DIs a group represented by the formula (1) and R^10AThe same group. Y in the general formula (1) is a divalent group represented by the chemical formula (Y2).

[ CHEM 2 ]

[ CHEM 3 ]

In the general formula (10), Q^5AAnd Q^5BEach independently represents a hydrogen atom, a C1-C8 alkyl group, a phenyl group or a C1-C8 alkoxy group. Q^6AAnd Q^6BIndependently of one another, represents C1-C8 alkyl, phenyl or C1-C8 alkoxy. m is₁And m₂Each independently represents an integer of 0 to 4. In the general formula (11), Q⁷And Q⁸Each independently represents a hydrogen atom, a C1-C8 alkyl group, a phenyl group or a C1-C8 alkoxy group. Q⁹Represents a C1-C8 alkyl group, a phenyl group or a C1-C8 alkoxy group, m₃Represents an integer of 0 to 4 inclusive. In the general formula (12), Q¹⁰And Q¹¹Each independently represents a C1-C6 alkyl group or a hydrogen atom. Q¹²Represents a halogen atom or a hydrogen atom.

An image forming apparatus of the present invention includes an image carrier, a charging device, an exposure device, a developing device, and a transfer device. The charging device charges the surface of the image carrier to a positive polarity. The exposure device exposes the surface of the charged image carrier, and forms an electrostatic latent image on the surface of the image carrier. The developing device develops the electrostatic latent image into a toner image. The transfer device transfers the toner image from the image bearing member to a transfer object. The image bearing member is the electrophotographic photoreceptor.

The method for producing an electrophotographic photoreceptor of the present invention includes a hole transporting agent production step and a photosensitive layer formation step. In the hole transporting agent production step, the hole transporting agent is produced. In the photosensitive layer forming step, a coating solution containing the charge generating agent, the hole transporting agent, the electron transporting agent, the binder resin, and a solvent is applied to the conductive substrate, and then at least a part of the solvent contained in the coating solution is removed, thereby forming the photosensitive layer. The hole transport agent production step includes a first stirring step and a second stirring step. In the first stirring step, a mixed solution containing a compound represented by the general formula (a) and a compound represented by the general formula (B) is subjected to first stirring. In the second stirring step, a compound represented by general formula (C) is further added to the mixed solution, and the mixed solution is subjected to second stirring. After the first stirring step, the second stirring step is performed without purifying the mixed solution. And obtaining the hole transporting agent containing the first hole transporting agent and the second hole transporting agent after the first stirring step and the second stirring step.

[ CHEM 4 ]

R in the general formula (A)¹、R²、R³、R⁴And R⁵Are respectively connected with R in the general formula (1)^1A、R^2A、R^3A、R4^AAnd R^5AAre the same radicals. R in the general formula (B)⁶、R⁷、R⁸、R⁹And R¹⁰Are respectively connected with R in the general formula (1)^6A、R^7A、R^8A、R^9AAnd R^10AAre the same radicals. Z in the general formula (B)¹Represents a halogen atom. Y in the general formula (C) is the same group as Y in the general formula (1). Z in the general formula (C)²And Z³Represents a halogen atom.

The electrophotographic photoreceptor of the present invention has excellent crack resistance and can suppress crystallization. Further, the image forming apparatus of the present invention has excellent durability and can form a high-quality image because it includes an electrophotographic photoreceptor having excellent crack resistance and capable of suppressing crystallization. Further, according to the method for manufacturing a photoreceptor of the present invention, it is possible to manufacture a photoreceptor having excellent crack resistance and capable of suppressing crystallization while simplifying the process for manufacturing a hole transporting agent.

Drawings

FIG. 1 is a partial sectional view of an electrophotographic photoreceptor according to an embodiment of the present invention.

FIG. 2 is a partial sectional view of an electrophotographic photoreceptor according to an embodiment of the present invention.

FIG. 3 is a partial sectional view of the electrophotographic photoreceptor according to the embodiment of the present invention.

Fig. 4 is a cross-sectional view of an example of an image forming apparatus.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments in any way. The present invention can be implemented by appropriately changing the range of the object. Note that, although the description thereof may be omitted as appropriate, the gist of the present invention is not limited thereto. Hereinafter, the compound and its derivatives may be collectively referred to by adding "class" to the compound name. When a "class" is added to a compound name to indicate a polymer name, the repeating unit indicating the polymer is derived from the compound or a derivative thereof.

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

Unless otherwise indicated, C1-C8 alkyl, C1-C6 alkyl, C1-C4 alkyl, C2-C4 alkyl are all linear or branched and unsubstituted. Examples of the C1-C8 alkyl group include: methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylpropyl group, 2-ethylpropyl group, 1-dimethylpropyl group, 1, 2-dimethylpropyl group, 2, 2-dimethylpropyl group, 1, 2-dimethylpropyl group, n-hexyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 1-dimethylbutyl group, 1, 2-dimethylbutyl group, 1, 3-dimethylbutyl group, 2, 2-dimethylbutyl group, 2, 3-dimethylbutyl group, 3-dimethylbutyl group, 1, 2-trimethylpropyl group, 1, 2, 2-trimethylpropyl group, 1-ethylbutyl, 2-ethylbutyl and 3-ethylbutyl, straight-chain and branched heptyl and straight-chain and branched octyl. Examples of C1-C6 alkyl, C1-C4 alkyl and C2-C4 alkyl are the radicals having the corresponding number of carbon atoms in the examples of C1-C8 alkyl, respectively.

Unless otherwise indicated, C1-C8 alkoxy, C1-C6 alkoxy and C1-C3 alkoxy are all straight-chain or branched-chain and unsubstituted. Examples of the C1-C8 alkoxy group include: methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, n-pentoxy, 1-methylbutoxy, 2-methylbutoxy, 3-methylbutoxy, 1-ethylpropoxy, 2-ethylpropoxy, 1-dimethylpropoxy, 1, 2-dimethylpropoxy, 2-dimethylpropoxy, 1, 2-dimethylpropoxy, n-hexoxy, 1-methylpentoxy, 2-methylpentoxy, 3-methylpentoxy, 4-methylpentoxy, 1-dimethylbutoxy, 1, 2-dimethylbutoxy, 1, 3-dimethylbutoxy, 2-dimethylbutoxy, 2, 3-dimethylbutoxy, 3-dimethylbutoxy, n-butoxy, 2-methylbutoxy, 3-methylpropoxy, 2-methylpropoxy, 1, 2-dimethylbutoxy, 1, 2-dimethylbut, 1, 1, 2-trimethylpropoxy, 1, 2, 2-trimethylpropoxy, 1-ethylbutoxy, 2-ethylbutoxy, 3-ethylbutoxy, linear and branched heptyloxy and linear and branched octyloxy. Examples of C1-C6 alkoxy and C1-C3 alkoxy are the radicals having the corresponding number of carbon atoms in the case of C1-C8 alkoxy, respectively.

Unless otherwise indicated, both the C6-C14 aryl and the C6-C10 aryl are unsubstituted. Examples of the C6-C14 aryl group include: phenyl, naphthyl, indacenyl, biphenylene, acenaphthylene, anthryl and phenanthryl. Examples of the C6-C10 aryl group include: phenyl and naphthyl. As described above, the substituents used in the present specification are illustrated.

< electrophotographic photoreceptor >

The present embodiment relates to an electrophotographic photoreceptor (hereinafter, may be referred to as a photoreceptor). The photoreceptor 1 of the present embodiment will be described below with reference to fig. 1 to 3. Fig. 1 to 3 are each a partial sectional view of the photoreceptor 1.

As shown in fig. 1, the photoreceptor 1 includes, for example, a conductive substrate 2 and a photosensitive layer 3. Of a single layer of the photosensitive layer 3. The photoreceptor 1 is a single-layer electrophotographic photoreceptor having a single photosensitive layer 3.

As shown in fig. 2, the photoreceptor 1 may also include a conductive substrate 2, a photosensitive layer 3, and an intermediate layer 4 (undercoat layer). The intermediate layer 4 is between the conductive substrate 2 and the photosensitive layer 3. As shown in fig. 1, the photosensitive layer 3 may be directly on the conductive substrate 2. Alternatively, as shown in fig. 2, the photosensitive layer 3 may be provided on the conductive substrate 2 with the intermediate layer 4 interposed therebetween.

As shown in fig. 3, the photoreceptor 1 may include a conductive substrate 2, a photosensitive layer 3, and a protective layer 5. The protective layer 5 is on the photosensitive layer 3. As shown in fig. 1 and 2, the photosensitive layer 3 is preferably an outermost surface layer of the photoreceptor 1. By using the photosensitive layer 3 containing a predetermined hole transporting agent and a predetermined electron transporting agent, which will be described later, as the outermost surface layer, the photosensitive layer 3 is less likely to crack even if the cleaning agent remains on the surface of the photoreceptor 1 during maintenance. As shown in fig. 3, the protective layer 5 may be an outermost surface layer of the photoreceptor 1.

The photosensitive layer 3 contains at least a charge generator, a hole transporting agent, an electron transporting agent, and a binder resin. The photosensitive layer 3 may further contain additives as necessary.

The thickness of the photosensitive layer 3 is not particularly limited, but is preferably 5 μm to 100 μm, and more preferably 10 μm to 50 μm. As described above, the photoreceptor 1 is described with reference to fig. 1 to 3.

(Charge generating agent)

Examples of the charge generating agent include: phthalocyanine pigments, perylene pigments, disazo pigments, trisazo pigments, dithione-pyrrolopyrrole (dithioketo-pyrrozole) pigments, metal-free naphthalocyanine pigments, metal naphthalocyanine pigments, squaric acid pigments, indigo pigments, azulene pigments, cyanine pigments, powders of inorganic photoconductive materials (e.g., selenium-tellurium, selenium-arsenic, cadmium sulfide, and amorphous silicon), pyran pigments, anthanthrone pigments, triphenylmethane pigments, threne pigments, toluidine pigments, pyrazoline pigments, and quinacridone pigments. The photosensitive layer may contain only 1 kind of charge generating agent, or may contain 2 or more kinds.

The phthalocyanine-based pigment is a pigment having a phthalocyanine structure. Examples of the phthalocyanine pigments include: metal-free phthalocyanines and metal phthalocyanines. Examples of the metal phthalocyanine include: oxytitanium phthalocyanine, hydroxygallium phthalocyanine and chlorogallium phthalocyanine. The metal-free phthalocyanine is represented by the chemical formula (CGM-1). The oxytitanium phthalocyanine is represented by the chemical formula (CGM-2).

[ CHEM 5 ]

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

For example, in a digital optical image forming apparatus (for example, a laser printer or a facsimile machine using a light source such as a semiconductor laser), it is preferable to use a photoreceptor having sensitivity in a wavelength region of 700nm or more. The charge generating agent is preferably a phthalocyanine-based pigment, more preferably a metal-free phthalocyanine or oxytitanium phthalocyanine, still more preferably oxytitanium phthalocyanine, and particularly preferably Y-type oxytitanium phthalocyanine, from the viewpoint of having a high quantum yield in a wavelength region of 700nm or more.

The Y-type oxytitanium phthalocyanine has a main peak at 27.2 ° of the bragg angle (2 θ ± 0.2 °) in the CuK α characteristic X-ray diffraction spectrum, for example. The main peak in the CuK α characteristic X-ray diffraction spectrum means a peak having a first or second large intensity in a range where the bragg angle (2 θ ± 0.2 °) is 3 ° or more and 40 ° or less. In the CuK α characteristic X-ray diffraction spectrum, the Y-type oxytitanium phthalocyanine has no peak at 26.2 ℃.

The CuK α characteristic X-ray diffraction spectrum can be measured, for example, by the following method. First, a sample (oxytitanium phthalocyanine) was filled in a sample holder of an X-ray diffraction apparatus ("RINT (Japanese registered trademark) 1100" manufactured by Rigaku Corporation) at X-ray tube Cu, tube voltage 40kV, tube current 30mA and CuK α characteristic X-ray wavelength

The X-ray diffraction spectrum was measured. MeasuringThe range (2 θ) is, for example, 3 ° to 40 ° (start angle 3 ° and stop angle 40 °), and the scanning speed is, for example, 10 °/min. And determining a main peak according to the obtained X-ray diffraction spectrum, and reading the Bragg angle of the main peak.

The content of the charge generating agent 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.

(hole transport agent)

The hole transport agent contains a first hole transport agent and a second hole transport agent. The first hole transporting agent is a compound represented by the general formula (1). The second hole transporting agent is a compound represented by the general formula (2). Hereinafter, the compounds represented by the general formulae (1) and (2) may be referred to as hole transporters (1) and (2), respectively.

[ CHEM 6 ]

In the general formula (1), R^1A、R^2A、R^3A、R^4A、R^5A、R^6A、R^7A、R^8A、R^9AAnd R^10AIndependently of one another, represents a hydrogen atom, a C1-C8 alkyl group, a C1-C8 alkoxy group or a C6-C14 aryl group. R in the general formula (1)^1BAnd R in the general formula (2)^1CIs a group represented by the formula (1) R^1AThe same group. R in the general formula (1)^2BAnd R in the general formula (2)^2CIs a group represented by the formula (1) R^2AThe same group. R in the general formula (1)^3BAnd R in the general formula (2)^3CIs a group represented by the formula (1) R^3AThe same group. R in the general formula (1)^4BAnd R in the general formula (2)^4CIs a group represented by the formula (1) R^4AThe same group. R in the general formula (1)^5BAnd R in the general formula (2)^5CIs a group represented by the formula (1) R^5AThe same group. R in the general formula (1)^6BAnd R in the general formula (2)^6CAnd R^6DIs a group represented by the formula (1) R^6AThe same group. R in the general formula (1)^7BAnd R in the general formula (2)^7CAnd R^7DIs a general formula(1) R in (1)^7AThe same group. R in the general formula (1)^8BAnd R in the general formula (2)^8CAnd R^8DIs a group represented by the formula (1) R^8AThe same group. R in the general formula (1)^9BAnd R in the general formula (2)^9CAnd R^9DIs a group represented by the formula (1) R^9AThe same group. R in the general formula (1)^10BAnd R in the general formula (2)^10CAnd R^10DIs a group represented by the formula (1) R^10AThe same group. Y in the general formula (1) is a divalent group represented by the formula (Y2).

[ CHEM 7 ]

By incorporating both the hole-transporting agents (1) and (2) in the photosensitive layer, the photoreceptor can be provided with crack resistance and crystallization of the photoreceptor can be suppressed. The cracking resistance of the photoreceptor means the following characteristics: even if the cleaning agent remains on the surface of the photoreceptor 1 during maintenance, cracking of the photosensitive layer 3 can be suppressed. Wherein the hole transporting agent (2) is a by-product generated during the synthesis of the hole transporting agent (1) as a final product. Generally, the by-products are removed by purification, thereby obtaining the final product. However, the present inventors have found that when the hole transporting agent (2) is intentionally mixed into the hole transporting agent (1) without completely removing the hole transporting agent (2) as a by-product by purification, the crack resistance of the photoreceptor is improved. Further, the present inventors have found that the hole transporting agent (2) inhibits aggregation of the hole transporting agent (1) and crystallization of the photoreceptor is inhibited. The photoreceptor of the present embodiment has a photosensitive layer which has excellent sensitivity characteristics and contains the hole transporting agent (1). Therefore, the crack resistance of the photoreceptor can be improved and the crystallization of the photoreceptor can be suppressed without impairing the sensitivity characteristics of the photoreceptor.

R in the general formula (1)^1A、R^2A、R^3A、R^4A、R^5A、R^6A、R^7A、R^8A、R^9AAnd R^10AThe C1-C8 alkyl group represented is preferably a C1-C6 alkyl group,more preferably a C1-C3 alkyl group, and still more preferably a methyl group or an ethyl group.

R in the general formula (1)^1A、R^2A、R^3A、R^4A、R^5A、R^6A、R^7A、R^8A、R^9AAnd R^10AThe C1-C8 alkoxy group is preferably a C1-C6 alkoxy group, more preferably a C1-C3 alkoxy group, and still more preferably a methoxy group.

R in the general formula (1)^1A、R^2A、R^3A、R^4A、R^5A、R^6A、R^7A、R^8A、R^9AAnd R^10AThe C6-C14 aryl group represented is preferably a C6-C10 aryl group.

In order to improve the crack resistance of the photoreceptor and suppress crystallization, it is preferable that: in the general formula (1), R^1A、R^2A、R^3A、R^4A、R^5A、R^6A、R^7A、R^8A、R^9AAnd R^10AAt least 2 of (a) represent a group other than a hydrogen atom, R^1A、R^2A、R^3A、R^4A、R^5A、R^6A、R^7A、R^8A、R^9AAnd R^10AThe remainder of (A) represents a hydrogen atom. The total number of carbon atoms of the groups other than hydrogen atoms is preferably 3 or more. In the general formula (1), R^1A、R^2A、R^3A、R^4A、R^5A、R^6A、R^7A、R^8A、R^9AAnd R^10AThe group other than the hydrogen atom is a C1-C8 alkyl group, a C1-C8 alkoxy group or a C6-C14 aryl group.

In the general formula (1), R is R for improving the crack resistance of the photoreceptor and suppressing crystallization^3APreferably represents a C1-C8 alkoxy group.

In order to improve the crack resistance of the photoreceptor and suppress crystallization, it is preferable that: in the general formula (1), R^1A、R^3AAnd R ^5A1 or 2 of (A) represent a C1-C8 alkyl group or a C1-C8 alkoxy group, R^1A、R^3AAnd R^5AWherein the remainder represent a hydrogen atom, R^2AAnd R^4ABoth represent hydrogen atoms.

In order to improve the crack resistance of the photoreceptor and suppress crystallization, it is preferable that: in the general formula (1), R^8ARepresents a hydrogen atom or a C1-C8 alkyl group, R^6A、R^7A、R^9AAnd R^10ARepresents a hydrogen atom.

In order to improve the crack resistance of the photoreceptor and suppress crystallization, it is preferable that: the hole-transporting agent (1) is a compound represented by the formula (HTM-1), and the hole-transporting agent (2) is a compound represented by the formula (HTM-A). In view of the same, it is preferable that: the hole-transporting agent (1) is a compound represented by the formula (HTM-2), and the hole-transporting agent (2) is a compound represented by the formula (HTM-B). In view of the same, it is preferable that: the hole-transporting agent (1) is a compound represented by the formula (HTM-3), and the hole-transporting agent (2) is a compound represented by the formula (HTM-C). In view of the same, it is preferable that: the hole-transporting agent (1) is a compound represented by the formula (HTM-4), and the hole-transporting agent (2) is a compound represented by the formula (HTM-D). Hereinafter, the compounds represented by the chemical formulas (HTM-1) to (HTM-4) may be referred to as hole-transporting agents (HTM-1) to (HTM-4), respectively. The compounds represented by the chemical formulas (HTM-A) to (HTM-D) may be referred to as hole-transporting agents (HTM-A) to (HTM-D), respectively.

[ CHEM 8 ]

The content of the hole-transporting agent (2) is preferably 1.0 mass% or more and 30.0 mass% or less, more preferably 1.0 mass% or more and 10.0 mass% or less, and still more preferably 2.0 mass% or more and 5.0 mass% or less, based on the total mass of the hole-transporting agents (1) and (2). When the content of the hole-transporting agent (2) is 1.0 mass% or more with respect to the total mass of the hole-transporting agents (1) and (2), the crack resistance of the photoreceptor can be further improved, and the crystallization of the photoreceptor can be further suppressed. When the content of the hole transporting agent (2) is 30.0% by mass or less with respect to the total mass of the hole transporting agents (1) and (2), the sensitivity characteristics of the photoreceptor can be improved. The method for adjusting the content of the hole-transporting agent (2) with respect to the total mass of the hole-transporting agents (1) and (2) will be described later in < method for producing a photoreceptor >.

The total content of the hole transporting agents (1) and (2) is preferably 10 parts by mass or more and 200 parts by mass or less, more preferably 50 parts by mass or more and 90 parts by mass or less, and further preferably 60 parts by mass or more and 80 parts by mass or less, with respect to 100 parts by mass of the binder resin.

In the photosensitive layer, the hole-transporting agent may contain only the hole-transporting agents (1) and (2). Alternatively, the photosensitive layer may contain a hole-transporting agent other than the hole-transporting agents (1) and (2) (hereinafter, sometimes referred to as another hole-transporting agent) in addition to the hole-transporting agents (1) and (2). Other hole-transporting agents are, for example: triphenylamine derivatives, diamine derivatives (e.g., N ' -tetraphenylbenzidine derivatives, N ' -tetraphenylphenylenediamine derivatives, N ' -tetraphenylnaphthalenediamine derivatives, N ' -tetraphenylphenylenediamine (N, N ' -tetraphenylphenylenediamine) derivatives and bis (aminophenylvinyl) benzene derivatives), oxadiazole compounds (e.g., 2, 5-bis (4-methylaminophenyl) -1, 3, 4-oxadiazole), styrene compounds (e.g., 9- (4-diethylaminostyryl) anthracene), carbazole compounds (e.g., polyvinylcarbazole), organic polysilane compounds, pyrazoline compounds (e.g., 1-phenyl-3- (p-dimethylaminophenyl) pyrazoline), hydrazone compounds, indole compounds, oxazole compounds, isoxazole compounds, thiazole compounds, thiadiazole compounds, imidazole compounds, pyrazole compounds and triazole compounds.

(Electron transport agent)

The electron-transporting agent contains a compound represented by general formula (10), (11) or (12) (hereinafter, sometimes referred to as electron-transporting agents (10), (11) and (12), respectively). By containing the hole-transporting agents (1) and (2) and the electron-transporting agents (10), (11), or (12) in the photosensitive layer, the cracking resistance of the photoreceptor can be improved and the crystallization of the photoreceptor can be particularly suppressed.

[ CHEM 9 ]

In the general formula (10), Q^5AAnd Q^5BEach independently represents a hydrogen atom, a C1-C8 alkyl group, a phenyl group or a C1-C8 alkoxy group. Q^6AAnd Q^6BIndependently of one another, represents C1-C8 alkyl, phenyl or C1-C8 alkoxy. m is₁And m₂Each independently represents an integer of 0 to 4.

m₁When it represents an integer of 2 to 4, several Q^6AMay be the same or different from each other. m is₂When it represents an integer of 2 to 4, several Q^6BMay be the same or different from each other.

In the general formula (10), Q^5AAnd Q^5BEach independently preferably represents a C1-C8 alkyl group, more preferably represents a C1-C6 alkyl group, and still more preferably represents a1, 1-dimethylpropyl group. m is₁And m₂Preferably represents 0.

In the general formula (11), Q⁷And Q⁸Each independently represents a hydrogen atom, a C1-C8 alkyl group, a phenyl group or a C1-C8 alkoxy group. Q⁹Represents a C1-C8 alkyl group, a phenyl group or a C1-C8 alkoxy group. m is₃Represents an integer of 0 to 4 inclusive.

m₃When it represents an integer of 2 to 4, several Q⁹May be the same or different from each other.

In the general formula (11), Q⁷And Q⁸Each independently preferably represents a C1-C8 alkyl group, more preferably a C1-C6 alkyl group, and still more preferably a tert-butyl group. m is₃Preferably represents 0.

In the general formula (12), Q¹⁰And Q¹¹Each independently represents a C1-C6 alkyl group or a hydrogen atom. Q¹²Represents a halogen atom or a hydrogen atom.

In the general formula (12), Q¹⁰And Q¹¹Each independently preferably represents a C1-C6 alkyl group, more preferably a tert-butyl group. Q¹²Preferably represents a halogen atom, more preferably a chlorine atom.

The electron-transporting agent (10) is preferably a compound represented by the formula (E-1) in order to improve the crack resistance of the photoreceptor and to suppress crystallization. In the same sense, the electron transporting agent (11) is preferably a compound represented by the formula (E-2). In the same sense, the electron transporting agent (12) is preferably a compound represented by the formula (E-3). Hereinafter, the compounds represented by the chemical formulas (E-1), (E-2) and (E-3) may be referred to as electron transporters (E-1), (E-2) and (E-3), respectively.

[ CHEM 10 ]

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

The photosensitive layer may contain only 1 kind of electron-transporting agent, or may contain 2 or more kinds of electron-transporting agents. The photosensitive layer may further contain an electron-transporting agent (hereinafter, sometimes referred to as another electron-transporting agent) other than the electron-transporting agents (10), (11), and (12). Other electron transport agents are for example: quinone compounds, imide compounds, hydrazone compounds, malononitrile compounds, thiopyran compounds, trinitrothioxanthone compounds, 3, 4, 5, 7-tetranitro-9-fluorenone compounds, dinitroanthracene compounds, dinitroacridine compounds, tetracyanoethylene, 2, 4, 8-trinitrothioxanthone, dinitrobenzene, dinitroacridine, succinic anhydride, maleic anhydride and dibromomaleic anhydride. Examples of the quinone compound include: diphenoquinone compounds, azoquinone compounds, anthraquinone compounds, naphthoquinone compounds, nitroanthraquinone compounds and dinitroanthraquinone compounds.

(Binder resin)

Examples of the binder resin include: thermoplastic resins, thermosetting resins, and photocurable resins. Examples of the thermoplastic resin include: polyarylate resins, polycarbonate resins, styrene-butadiene copolymers, styrene-acrylonitrile copolymers, styrene-maleic acid copolymers, acrylic polymers, styrene-acrylic acid copolymers, polyethylene resins, ethylene-vinyl acetate copolymers, chlorinated polyethylene resins, polyvinyl chloride resins, polypropylene resins, ionomer resins, vinyl chloride-vinyl acetate copolymers, alkyd resins, polyamide resins, polyurethane resins, polysulfone resins, diallyl phthalate resins, ketone resins, polyvinyl butyral resins, polyester resins, polyvinyl acetal resins, and polyether resins. Examples of the thermosetting resin include: silicone resins, epoxy resins, phenolic resins, urea-formaldehyde resins and melamine resins. Examples of the photocurable resin include: acrylic acid adducts of epoxy compounds and acrylic acid adducts of urethane compounds. The photosensitive layer may contain only 1 kind of binder resin, or may contain 2 or more kinds of binder resins.

The viscosity average molecular weight of the binder resin is preferably 10,000 or more, more preferably 20,000 or more, further preferably 30,000 or more, and particularly preferably 40,000 or more. When the viscosity average molecular weight of the binder resin is 10,000 or more, the abrasion resistance of the photoreceptor can be improved. On the other hand, the viscosity average molecular weight of the binder resin is preferably 80,000 or less, more preferably 70,000 or less. When the viscosity average molecular weight of the binder resin is 80,000 or less, the binder resin is easily dissolved in the solvent for forming the photosensitive layer.

The binder resin is preferably a polyarylate resin or a polycarbonate resin, and more preferably a polyarylate resin. The polyarylate resin and the polycarbonate resin will be described in this order.

First, a polyarylate resin will be described. In order to further improve the crack resistance of the photoreceptor and to suppress crystallization, preferred examples of the polyarylate resin are, for example: a polyarylate resin comprising at least 1 repeating unit represented by the general formula (10) and at least 1 repeating unit represented by the general formula (11). Hereinafter, a polyarylate resin containing at least 1 repeating unit represented by the general formula (10) and at least 1 repeating unit represented by the general formula (11) may be referred to as a polyarylate resin (PA). The repeating units represented by the general formulae (10) and (11) may be referred to as repeating units (10) and (11), respectively.

[ CHEM 11 ]

In the general formula (10), R¹¹And R¹²Each independently represents a hydrogen atom or a methyl group. In the general formula (10), W is a divalent group represented by the general formula (W1), the general formula (W2) or the chemical formula (W3).

[ CHEM 12 ]

In the general formula (W1), R¹³Represents a hydrogen atom or a C1-C4 alkyl group, R¹⁴Represents a C1-C4 alkyl group. In the general formula (W2), t represents an integer of 1 to 3.

In the general formula (11), X is a divalent group represented by the formula (X1), the formula (X2) or the formula (X3).

[ CHEM 13 ]

R in the formula (W1)¹³The C1-C4 alkyl group represented is preferably methyl. R in the formula (W1)¹⁴The C1-C4 alkyl group represented is preferably a C2-C4 alkyl group, more preferably an ethyl group. T in the general formula (W2) preferably represents 2.

In the general formula (10), R¹¹And R¹²Preferably represents a methyl group. In the general formula (10), W is preferably a divalent group represented by the general formula (W2). In the general formula (11), X is preferably a divalent group represented by the chemical formulae (X1) and (X3).

Preferred examples of the repeating unit (10) are, for example: repeating units represented by the formulae (10-1), (10-2) and (10-3). Hereinafter, the repeating units represented by chemical formulae (10-1), (10-2) and (10-3) may be described as repeating units (10-1), (10-2) and (10-3), respectively.

[ CHEM 14 ]

Preferred examples of the repeating unit (11) are, for example: a repeating unit represented by the formulae (11-X1), (11-X2) and (11-X3). Hereinafter, the repeating units represented by chemical formulae (11-X1), (11-X2) and (11-X3) may be described as repeating units (11-X1), (11-X2) and (11-X3), respectively.

[ CHEM 15 ]

The polyarylate resin (PA) may contain only 1 kind of repeating unit (10), or may contain 2 or more kinds of repeating units (10). The polyarylate resin (PA) may contain only 1 kind of repeating unit (11), or may contain 2 or more kinds of repeating units (11). The polyarylate resin (PA) preferably contains at least 1 repeating unit (10) and at least 2 repeating units (11), and more preferably contains 1 repeating unit (10) and 2 repeating units (11).

Preferred examples of the polyarylate resin (PA) are, for example: a polyarylate resin (hereinafter, sometimes referred to as polyarylate resin (I)) containing the repeating units (10-2), (11-X1) and (11-X3).

Further preferable examples of the polyarylate resin (PA) are, for example: a polyarylate resin represented by the formula (R-1) (hereinafter, may be referred to as polyarylate resin (R-1)). In addition, in the chemical formula (R-1), the right subscript number of each repeating unit represents: the percentage (%) of the number of each repeating unit with respect to the total number of repeating units contained in the polyarylate resin. The total number of repeating units is the sum of the number of repeating units derived from the bisphenol and the number of repeating units derived from the dicarboxylic acid.

[ CHEM 16 ]

The polyarylate resin (PA) may be, for example, a random copolymer, an alternating copolymer, a periodic copolymer, or a block copolymer. In the polyarylate resin (PA), the arrangement of the repeating units is not particularly limited as long as the repeating units derived from bisphenol and the repeating units derived from dicarboxylic acid are adjacent to each other and are bonded to each other. The repeating unit derived from bisphenol is, for example, the repeating unit (10). The repeating unit derived from a dicarboxylic acid is, for example, the repeating unit (11).

In the polyarylate resin (PA), the repeating units may be only the repeating units (10) and (11). Alternatively, the polyarylate resin (PA) may further contain a repeating unit other than the repeating units (10) and (11) in addition to the repeating units.

The method for producing the polyarylate resin (PA) is not particularly limited. The method for producing the polyarylate resin (PA) is, for example: a method for polycondensation of bisphenol (constituting repeating units derived from bisphenol) and dicarboxylic acid (constituting repeating units derived from dicarboxylic acid). The polycondensation may employ a well-known synthesis method (for example, solution polymerization, melt polymerization, or interfacial polymerization).

Examples of the bisphenol (used to constitute the repeating unit derived from bisphenol) include: a compound represented by the general formula (BP-10). Examples of dicarboxylic acids (used to form the repeating units derived from dicarboxylic acids) include: a compound represented by the formula (DC-11). R in the general formulae (BP-10) and (DC-11)¹¹、R¹²W and X are respectively related to R in general formulas (10) and (11)¹¹、R¹²W and X have the same meaning.

[ CHEM 17 ]

A derivatized aromatic diacetate salt of bisphenol (constituting a repeating unit derived from bisphenol) may be used. Derivatives of dicarboxylic acids (used to form repeat units from dicarboxylic acids) may also be used. Examples of derivatives of dicarboxylic acids are: dicarboxylic acid dichlorides, dicarboxylic acid dimethyl esters, dicarboxylic acid diethyl esters and dicarboxylic acid anhydrides. The dicarboxylic acid dichloride is a compound in which each of the 2 "— C (═ O) -OH" groups possessed by the dicarboxylic acid is substituted with a "— C (═ O) -Cl" group.

In the polycondensation of bisphenol and dicarboxylic acid, one or both of a base and a catalyst may be added. An example of a base is sodium hydroxide. Examples of catalysts are: benzyl tributyl ammonium chloride, ammonium bromide, quaternary ammonium salts, triethylamine and trimethylamine. As described above, the polyarylate resin is explained.

Next, a polycarbonate resin will be described. Examples of the polycarbonate resin are: bisphenol ZC type polycarbonate resin, bisphenol C type polycarbonate resin, bisphenol a type polycarbonate resin, and bisphenol Z type polycarbonate resin. The bisphenol Z-type polycarbonate resin has a repeating unit represented by the formula (R-2). Hereinafter, a polycarbonate resin having a repeating unit represented by the formula (R-2) may be referred to as a polycarbonate resin (R-2). As described above, the polycarbonate resin is explained.

[ CHEM 18 ]

(additives)

Examples of additives include: uv absorbers, antioxidants, radical scavengers, singlet quenchers, softeners, surface modifiers, extenders, thickeners, dispersion stabilizers, waxes, donors, surfactants, plasticizers, sensitizers, electron acceptor compounds, and leveling agents.

(combination of materials)

In order to improve the crack resistance of the photoreceptor and suppress crystallization, the combination of the hole transporting agents (1) and (2) and the electron transporting agent is preferably each of combination Nos. F-1 to F-8 in Table 1. In view of the same, more preferred are: the combination of the hole transporting agents (1) and (2) and the electron transporting agent is each of combination Nos. F-1 to F-8 in Table 1, and the charge generating agent is Y-type oxytitanium phthalocyanine.

[ TABLE 1 ]

No.	HTM(1)	HTM(2)	ETM
				F-1	HTM-1	HTM-A	E-1
F-2	HTM-1	HTM-A	E-2
				F-3	HTM-1	HTM-A	E-3
F-4	HTM-2	HTM-B	E-1
				F-5	HTM-2	HTM-B	E-2
F-6	HTM-2	HTM-B	E-3
				F-7	HTM-3	HTM-C	E-1
F-8	HTM-4	HTM-D	E-1

In order to improve the crack resistance of the photoreceptor and suppress crystallization, the combination of the hole transport agents (1) and (2), the electron transport agent, and the binder resin is preferably each of combination Nos. G-1 to G-17 in Table 2. In view of the same, more preferred are: the combination of the hole transporting agents (1) and (2), the electron transporting agent and the binder resin is each of combination Nos. G-1 to G-17 in Table 2, and the charge generating agent is Y-type oxytitanium phthalocyanine.

[ TABLE 2 ]

In tables 1 and 2, the term "No." means a combination No., "HTM (1)" means a hole transporting agent (1), "HTM (2)" means a hole transporting agent (2), "ETM" means an electron transporting agent, and "resin" means a binder resin. "I" in the column of "resin" is a polyarylate resin (I). "R-1" in the column of "resin" is a polyarylate resin (R-1). The "R-2" in the column of "resin" is a polycarbonate resin (R-2).

(conductive substrate)

The conductive substrate is not particularly limited as long as it can be used as a conductive substrate of a photoreceptor. The conductive substrate may be formed of a conductive material at least on the surface portion. 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. These conductive materials may be used alone, or 2 or more kinds (for example, as an alloy) may be used in combination. Among these conductive materials, aluminum and aluminum alloys are preferable from the viewpoint of good charge transfer from the photosensitive layer to the conductive substrate.

The shape of the conductive substrate is appropriately selected according to the structure of the image forming apparatus. The shape of the conductive substrate is, for example: sheet and drum. The thickness of the conductive substrate is appropriately selected according to the shape of the conductive substrate.

(intermediate layer)

The intermediate layer (undercoat layer) contains, for example, inorganic particles and a resin (resin for intermediate layer) used in the intermediate layer. It can be considered that: the presence of the intermediate layer makes it possible to smoothly flow a current generated when the photoreceptor is exposed while maintaining an insulating state to such an extent that the occurrence of electric leakage can be suppressed, thereby suppressing an increase in electric resistance.

Examples of the inorganic particles include: particles of metals (e.g., aluminum, iron, and copper), particles of metal oxides (e.g., titanium dioxide, aluminum oxide, zirconium oxide, tin oxide, and zinc oxide), and particles of non-metal oxides (e.g., silicon dioxide). These inorganic particles may be used alone or in combination of 2 or more.

Examples of the resin for the intermediate layer are the same as those of the binder resin described above. In order to form the intermediate layer and the photosensitive layer well, the resin for the intermediate layer is preferably different from the binder resin contained in the photosensitive layer. The intermediate layer may also contain additives. Examples of the additive contained in the intermediate layer are the same as those of the additive contained in the photosensitive layer.

< method for producing photoreceptor >

The method for manufacturing the photoreceptor includes a hole transporting agent manufacturing step and a photosensitive layer forming step.

(Process for producing hole transporting agent)

In the hole transporting agent production step, a hole transporting agent is produced. The hole transporting agent production step includes a first stirring step and a second stirring step. In the first stirring step, the mixed solution (hereinafter, may be abbreviated as "solution") is subjected to first stirring. The solution contains a compound represented by the general formula (A) and a compound represented by the general formula (B). In the second stirring step, the compound represented by the general formula (C) is further added to the solution obtained in the first stirring step, and the solution is subjected to second stirring. After the first stirring step, the second stirring step is performed without purifying the solution. After the first stirring step and the second stirring step, a hole transporting agent containing both the first hole transporting agent and the second hole transporting agent (i.e., a mixture of the hole transporting agents (1) and (2)) is obtained. The obtained mixture of the hole transport agents (1) and (2) is used as a hole transport agent in the photosensitive layer forming step. Hereinafter, the compounds represented by the general formulae (a), (B) and (C) may be referred to as compounds (a), (B) and (C), respectively.

[ CHEM 19 ]

R in the formula (A)¹、R²、R³、R⁴And R⁵Are respectively connected with R in the general formula (1)^1A、R^2A、R^3A、R4^AAnd R^5AAre the same radicals. R in the formula (B)⁶、R⁷、R⁸、R⁹And R¹⁰Are respectively connected with R in the general formula (1)^6A、R^7A、R^8A、R^9AAnd R^10AAre the same radicals. Z in the general formula (B)¹Represents a halogen atom. Y in the general formula (C) is the same group as Y in the general formula (1). Z in the general formula (C)²And Z³Represents a halogen atom.

As shown in the following reaction equation (r-1), 1 molar equivalent of the hole transporting agent (2) is obtained by reacting 1 molar equivalent of the compound (a) with 2 molar equivalents of the compound (B). In the first stirring step, the reaction represented by the reaction equation (r-1) proceeds. In addition, not only in the first stirring step but also in the second stirring step, the reaction represented by the reaction equation (r-1) may proceed.

[ CHEM 20 ]

Further, as shown in the following reaction equations (r-2) and (r-3), 2 molar equivalents of the compound (A), 2 molar equivalents of the compound (B) and 1 molar equivalent of the compound (C) were reacted to obtain 1 molar equivalent of the hole transporting agent (1). Specifically, as shown in the reaction equation (r-2), 2 molar equivalents of the compound (a) and 2 molar equivalents of the compound (B) are reacted to obtain 2 molar equivalents of the compound represented by the chemical formula (D) (hereinafter, sometimes referred to as the compound (D)). Compound (D) is an intermediate product. Then, as shown in reaction equation (r-3), 2 molar equivalents of compound (D) and 1 molar equivalent of compound (C) are reacted to obtain 1 molar equivalent of hole transporting agent (1). In the first stirring step, the reaction represented by the reaction equation (r-2) proceeds, and in the second stirring step, the reaction represented by the reaction equation (r-3) proceeds. In addition, not only in the first stirring step but also in the second stirring step, the reaction represented by the reaction equation (r-2) may proceed.

[ CHEM 21 ]

In the raw materials of the hole transporting agents (1) and (2), the compound (A) is common, and therefore R in the general formula (A) is¹And R in the general formula (1)^1AAnd R^1BAnd R in the general formula (2)^1CAre the same radicals. Such as R¹Then, R in the general formula (A)²～R⁵The same substituents as those in the general formulae (1) and (2) are also the same. In the raw materials of the hole transporting agents (1) and (2), the compound (B) is common, and therefore R in the general formula (B)⁶And R in the general formula (1)^6AAnd R^6BAnd R in the general formula (2)^6CAnd R^6DAre the same radicals. Such as R⁶Then, R in the general formula (B)⁷～R¹⁰The same substituents as those in the general formulae (1) and (2) are also the same.

The palladium catalyst may be added to the solution subjected to the first stirring in the first stirring step and the solution subjected to the second stirring in the second stirring step. Examples of the palladium catalyst include: palladium (II) acetate, palladium (II) chloride, sodium hexachloropalladium (IV) tetrahydrate, and tris (dibenzylideneacetone) dipalladium (0).

The ligand may be added to the solution subjected to the first stirring in the first stirring step and the solution subjected to the second stirring in the second stirring step. Examples of ligands include: 2-dicyclohexylphosphine-2 ', 4 ', 6 ' -triisopropylbiphenyl, (4-dimethylaminophenyl) di-tert-butylphosphine, tricyclohexylphosphine, triphenylphosphine and diphenylmethylphosphine.

The solution to be subjected to the first stirring in the first stirring step and the solution to be subjected to the second stirring in the second stirring step may be added with an alkali. Examples of bases are: sodium tert-butoxide, tripotassium phosphate and cesium fluoride.

The solvent may be added to the solution subjected to the first stirring in the first stirring step and the solution subjected to the second stirring in the second stirring step. Examples of the solvent include: xylene, toluene, tetrahydrofuran and dimethylformamide.

The temperature of the solution subjected to the first stirring in the first stirring step and the temperature of the solution subjected to the second stirring in the second stirring step are preferably 80 ℃ to 140 ℃. The time of the first stirring is preferably 1 hour to 10 hours, more preferably 5 hours to 10 hours. The time of the second stirring is preferably 1 hour to 10 hours, more preferably 1 hour to 4 hours. The first stirring and the second stirring may also be performed under an atmosphere of an inert gas (e.g., nitrogen or argon).

In the hole transporting agent production step, the solution is not purified after the first stirring step. Therefore, the manufacturing process of the hole transporting agent can be simplified. Further, the hole-transporting agents (1) and (2) were obtained simultaneously in a mixture state through the first stirring step and the second stirring step. Since the positive hole transporting agent (1) and the negative hole transporting agent (2) are obtained in a mixed state, the operations of separately metering the positive hole transporting agents (1) and (2) and mixing the positive hole transporting agents (1) and (2) can be omitted in the preparation of the coating liquid in the photosensitive layer forming step.

In the hole transporting agent production step, the hole transporting agent (2) remains in the hole transporting agent obtained in the second stirring step. By not completely removing the hole transporting agent (2) as a by-product but rather intentionally leaving the hole transporting agent (2), the photosensitive layer can contain both the hole transporting agents (1) and (2). Therefore, the crack resistance of the photoreceptor can be improved, and the crystallization of the photoreceptor can be suppressed. Alternatively, the hole transporting agent (2) may be purified after the second stirring step so as not to be completely removed. In addition, purification may be performed after the second stirring step so that the hole transporting agent (1) is not completely removed. Examples of the purification method after the second stirring step include: activated clay treatment, recrystallization, and combinations thereof.

The content of the hole-transporting agent (2) relative to the total mass of the hole-transporting agents (1) and (2) can be adjusted by, for example, changing the ratio (B/a) of the amount of the additive substance of the compound (B) to the amount of the additive substance of the compound (a). The ratio (B/A) is a molar ratio conversion value. The higher the ratio (B/A), the higher the content of the hole-transporting agent (2) with respect to the total mass of the hole-transporting agents (1) and (2). The ratio (B/a) is preferably 1.05 to 1.45, more preferably 1.05 to 1.25.

The content of the hole-transporting agent (2) relative to the total mass of the hole-transporting agents (1) and (2) can be adjusted by, for example, changing the ratio (a/C) of the amount of the additive substance of the compound (a) to the amount of the additive substance of the compound (C). The ratio (A/C) is a molar ratio conversion value. The higher the ratio (A/C), the higher the content of the hole-transporting agent (2) with respect to the total mass of the hole-transporting agents (1) and (2). The ratio (a/C) is preferably 2.30 to 3.30, and more preferably 2.30 to 2.60.

The content of the hole transporting agent (2) relative to the total mass of the hole transporting agents (1) and (2) can be adjusted by, for example, purifying between the second stirring steps so as not to completely remove the hole transporting agent (2) and changing the purification conditions. In addition, in order to adjust the content of the hole transporting agent (2) with respect to the total mass of the hole transporting agents (1) and (2), one or both of the hole transporting agents (1) and (2) may be further added to the hole transporting agent obtained through the first stirring step and the second stirring step.

(photosensitive layer Forming step)

In the photosensitive layer forming step, a coating liquid (specifically, a coating liquid for forming a photosensitive layer) is applied to a conductive substrate, and at least a part of a solvent contained in the coating liquid is removed, thereby forming a photosensitive layer. The coating liquid contains a charge generating agent, a hole transporting agent, an electron transporting agent, a binder resin, and a solvent.

The solvent contained in the coating liquid is not particularly limited as long as it can dissolve or disperse each component contained in the coating liquid. Examples of the solvent include: alcohols (more specifically, methanol, ethanol, isopropanol, butanol, and the like), aliphatic hydrocarbons (more specifically, n-hexane, octane, cyclohexane, and the like), aromatic hydrocarbons (more specifically, benzene, toluene, xylene, and the like), halogenated hydrocarbons (more specifically, dichloromethane, dichloroethane, carbon tetrachloride, chlorobenzene, and the like), ethers (more specifically, dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and the like), ketones (more specifically, acetone, methyl ethyl ketone, cyclohexanone, and the like), esters (more specifically, ethyl acetate, methyl acetate, and the like), dimethyl formaldehyde, dimethyl formamide, and dimethyl sulfoxide. These solvents may be used alone or in combination of two or more.

The coating liquid 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. In the dissolving or dispersing operation, for example, a bead mill, a roll mill, a ball mill, an attritor, a paint shaker, or an ultrasonic disperser can be used.

Examples of the method of coating with the coating liquid include: dip coating, spray coating, spin coating, and bar coating.

Examples of a method for removing at least a part of the solvent contained in the coating liquid include: heating, reducing pressure, and a combination of heating and reducing pressure. More specifically, a method of performing heat treatment (hot air drying) using a high-temperature dryer or a reduced-pressure dryer is given. The temperature of the heat treatment is, for example, 40 ℃ to 150 ℃. The time for the heat treatment is, for example, 3 minutes to 120 minutes.

The method for producing the photoreceptor may further include a step of forming an intermediate layer and a protective layer, if necessary. The step of forming the intermediate layer and the protective layer can be performed by appropriately selecting a known method.

< image Forming apparatus >

Next, an image forming apparatus including the photoreceptor 1 of the present embodiment will be described. Hereinafter, a tandem color image forming apparatus will be described as an example with reference to fig. 4. Fig. 4 is a cross-sectional view of an example of an image forming apparatus.

The image forming apparatus 100 in fig. 4 includes image forming units 40a, 40b, 40c, and 40d, a transfer belt 50, and a fixing device 54. Hereinafter, the image forming units 40a, 40b, 40c, and 40d are each described as the image forming unit 40 without distinction.

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

As described above, since the photoreceptor 1 of the present embodiment has excellent crack resistance, the durability of the image forming apparatus 100 can be improved by using the photoreceptor 1 as the image carrier 30. As described above, since the photoreceptor 1 of the present embodiment can suppress crystallization, the image forming apparatus 100 can form a high-quality image by using the photoreceptor 1 as the image carrier 30.

The image carrier 30 is disposed at the center of the image forming unit 40. The image carrier 30 is provided to be rotatable in the arrow direction (counterclockwise direction). Around the image carrier 30, a charging device 42, an exposure device 44, a developing device 46, a transfer device 48, and a cleaning member 52 are provided in this order from the upstream side in the rotational direction of the image carrier 30.

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

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

The exposure device 44 exposes the surface of the charged image carrier 30. Thereby, an electrostatic latent image is formed on the surface of the image carrier 30. Based on image data input into the image forming apparatus 100, an electrostatic latent image is formed.

The developing device 46 supplies toner to the surface of the image carrier 30 to develop the electrostatic latent image into a toner image. When the developing device 46 develops the electrostatic latent image into a toner image, the surface of the image carrier 30 and the surface (for example, the circumferential surface) of the developing device 46 are in contact with each other. That is, the image forming apparatus 100 employs the contact development system. The developing device 46 is, for example, a developing roller. In the case where the developer is a one-component developer, the developing device 46 supplies toner as the one-component developer to the electrostatic latent image formed on the image carrier 30. In the case where the developer is a two-component developer, the developing device 46 supplies toner contained in the two-component developer and toner in the carrier to the electrostatic latent image formed on the image bearing member 30. Thereby, the image bearing member 30 bears the toner image.

The transfer belt 50 conveys the recording medium P between the image carrier 30 and the transfer portion 48. The transfer belt 50 is an endless belt. The transfer belt 50 is provided to be rotatable in an arrow direction (clockwise direction).

After the developing section 46 develops the toner image to obtain a toner image, the transfer section 48 transfers the toner image from the surface of the image bearing member 30 to the transfer object. The transferred body is a recording medium P. Specifically, when the recording medium P comes into contact with the surface of the image carrier 30, the transfer device 48 transfers the toner image from the surface of the image carrier 30 onto the recording medium P. That is, the image forming apparatus 100 employs the direct transfer system. The transfer device 48 is, for example, a transfer roller.

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

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

As described above, although an example of the image forming apparatus is described, the image forming apparatus is not limited to the image forming apparatus 100 described above. The image forming apparatus 100 described above is a color image forming apparatus, but the image forming apparatus may be a monochrome image forming apparatus. In such a case, the image forming apparatus may include only 1 image forming unit, for example. Although the image forming apparatus 100 described above employs a tandem system, the image forming apparatus may employ a Rotary system (Rotary system), for example. The charging device 42 is described by taking a charging roller as an example, but the charging device may be a charging device other than the charging roller (for example, a grid corotron charger, a charging brush, or a corotron charger). The image forming apparatus 100 described above employs a contact development system, but the image forming apparatus may employ a non-contact development system. The image forming apparatus 100 described above employs a direct transfer system, but the image forming apparatus may employ an intermediate transfer system. When the image forming apparatus employs the intermediate transfer system, the intermediate transfer belt corresponds to a transfer target. The cleaning member 52 is described by taking a cleaning blade as an example, but the cleaning member may be a cleaning roller. The image forming unit 40 described above does not include an electrostatic charge eliminating device, but the image forming unit may include an electrostatic charge eliminating device.

[ examples ] A method for producing a compound

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

The following charge generating agent, electron transporting agent, hole transporting agent, and binder resin were prepared as materials for forming a photosensitive layer of the photoreceptor.

(Charge generating agent)

The Y-type oxytitanium phthalocyanine described in the embodiment was prepared as a charge generating agent.

(Electron transport agent)

Each of the electron-transporting agents (E-1), (E-2) and (E-3) described in the embodiments was prepared as an electron-transporting agent. Further, a compound represented by the formula (E-4) (hereinafter, referred to as an electron transporting agent (E-4)) was prepared as an electron transporting agent used in the comparative example.

[ CHEM 22 ]

(Binder resin)

Each of the polyarylate resin (R-1) and the polycarbonate resin (R-2) described in the embodiment was prepared as a binder resin. The viscosity average molecular weight of the polyarylate resin (R-1) was 47,500. The viscosity-average molecular weight of the polycarbonate resin (R-2) was 50,000.

(hole transport agent)

Samples (M-A1) to (M-A4) which were mixtures of the hole transport agents (1) and (2) were synthesized by the following methods. The samples (M-B1) to (M-B5) used in the comparative examples were synthesized by the following methods. The compositions of the samples (M-A1) to (M-A4) and (M-B1) to (M-B5) are shown in Table 3. The technical terms in table 3 are as follows. The "HTM (1)" and the "HTM (2)" in the "type" column represent the type of the hole-transporting agent (1) and the type of the hole-transporting agent (2), respectively. The "HTM (1)" in the "content" column indicates: the content ratio (unit: mass%) of the hole transporting agent (1) relative to the total mass of the hole transporting agent (1) and the hole transporting agent (2). The "HTM (2)" in the "content" column indicates: the content ratio (unit: mass%) of the hole-transporting agent (2) relative to the total mass of the hole-transporting agent (1) and the hole-transporting agent (2). "-" indicates that the hole transporting agent was not contained in the sample.

[ TABLE 3 ]

In the following description of the synthesis methods of the respective samples, the compounds represented by the following chemical formulae (A-1) to (A-4), (B-1) to (B-2), and (C-1) may be referred to as compounds (A-1) to (A-4), (B-1) to (B-2), and (C-1), respectively.

[ CHEM 23 ]

(preparation of sample (M-A1))

The preparation of the sample (M-A1) was carried out according to the following reaction equation (r-a).

[ CHEM 24 ]

Specifically, tris (dibenzylideneacetone) dipalladium (0.0366g, 0.040mmol), 2-dicyclohexylphosphine-2 ', 4 ', 6 ' -triisopropylbiphenyl (0.0763g, 0.016mmol), and sodium tert-butoxide (9.669g, 100.7mmol) were placed in a 500mL three-necked flask equipped with a elephant trunk. The degassing and nitrogen replacement in the flask were repeated 2 times to replace the air in the flask with nitrogen.

Then, 2-ethylaniline (Compound (A-1), 8.45g, 69.8mmol), 4-chlorotoluene (Compound (B-1), 10.13g, 80.0mmol) and xylene (45g) were further added to the flask. The solution in the flask was heated to 130 ℃ and refluxed. Further, the temperature of the solution was raised while evaporating off tert-butanol generated during the temperature raising. While the solution was refluxed, the solution was kept at 130 ℃ and stirred for 2 hours (equivalent to the first stirring). Then, the solution in the flask was cooled to 50 ℃.

Then, sodium t-butoxide (7.680g, 80.0mmol), 4 '-dibromop-terphenyl (compound (C-1), 11.60g, 30.0mmol), palladium (II) acetate (0.0168g, 0.075mmol), 2-dicyclohexylphosphine-2', 4 ', 6' -triisopropylbiphenyl (0.1425g, 0.299mmol) and xylene (32g) were further added to the solution in the flask. The solution in the flask was heated to 130 ℃ and refluxed. Further, the temperature of the solution was raised while evaporating off tert-butanol generated during the temperature raising. While the solution was refluxed, the solution was kept at 130 ℃ and stirred for 3 hours (equivalent to the second stirring).

Then, the solution in the flask was cooled to 90 ℃. The solution in the flask at 90 ℃ was filtered to remove insoluble substances in the solution, thereby obtaining a filtrate. The filtrate was subjected to 2 times of activated clay treatment. The activated clay treatment is a treatment in which activated clay (SA-1, 8g, manufactured by Nippon activated clay Co., Ltd.) was put into the filtrate and the mixture was filtered again at 110 ℃ for 15 minutes to recover the filtrate. The filtrate after 2 times of activated clay treatment was concentrated under reduced pressure to obtain a concentrated solution. To the concentrate, isohexane (about 50g) in an amount to make the concentrate slightly turbid was added, followed by addition of methanol (50 g). The concentrate was cooled to 5 ℃ and the precipitated crystals were removed by filtration. The crystals were placed in xylene (100g) and heated to 110 ℃ to dissolve the crystals in xylene to obtain a solution. The solution was subjected to the above activated clay treatment 5 times. The filtrate after 5 times of activated clay treatment was concentrated under reduced pressure to obtain a concentrated solution. To the concentrate, isohexane (about 50g) in an amount to make the concentrate slightly turbid was added, followed by addition of methanol (50 g). The concentrate was cooled to 5 ℃ and the precipitated crystals were removed by filtration. The resulting crystals were dried at 70 ℃ for 24 hours under vacuum to obtain a sample (M-A1). The sample (M-A1) was a mixture containing a hole-transporting agent (HTM-1) and a hole-transporting agent (HTM-A). The yield of the sample (M-A1) was 16.3 g. The yield of the hole transporting agent (HTM-1) contained in the sample (M-A1) relative to the compound (C-1) was 84%.

(preparation of sample (M-A2))

A sample (M-A2) was obtained by following the method for preparing a sample (M-A1) except that 69.8mmol of the compound (A-1) was changed to 69.8mmol of the compound (A-2). Sample (M-A2) was a mixture containing a hole transporting agent (HTM-2) and a hole transporting agent (HTM-B).

(preparation of sample (M-A3))

A sample (M-A3) was obtained by following the method for preparing a sample (M-A1) except that 69.8mmol of the compound (A-1) was changed to 69.8mmol of the compound (A-3). Sample (M-A3) was a mixture containing a hole-transporting agent (HTM-3) and a hole-transporting agent (HTM-C).

(preparation of sample (M-A4))

A sample (M-A4) was obtained in accordance with the preparation method of sample (M-A1) except that 69.8mmol of compound (A-1) was changed to 69.8mmol of compound (A-4) and 80.0mmol of compound (B-1) was changed to 80.0mmol of compound (B-2). Sample (M-A4) was a mixture containing a hole transporting agent (HTM-4) and a hole transporting agent (HTM-D).

(preparation of sample (M-B1))

The sample (M-A1) was purified by silica gel column chromatography using a mixed solvent of toluene and isohexane (volume ratio 50/50) as a developing solvent. Thereby, a component containing the hole transporting agent (HTM-1) was separated. The mixture was concentrated under reduced pressure until the separated solution (component) was slightly turbid, whereby a concentrated solution was obtained. Isohexane and methanol were added to the concentrate. The concentrated solution was cooled to 5 ℃ and the precipitated crystals were removed by filtration to obtain a sample (M-B1). The sample (M-B1) contained only the hole transporting agent (HTM-1) and no hole transporting agent (HTM-A).

(preparation of sample (M-B2))

A sample (M-B2) was obtained in accordance with the preparation method of sample (M-B1) except that the sample (M-A1) was changed to sample (M-A2). The sample (M-B2) contained only the hole transporting agent (HTM-2) and no hole transporting agent (HTM-B).

(preparation of sample (M-B3))

A sample (M-B3) was obtained in accordance with the preparation method of sample (M-B1) except that the sample (M-A1) was changed to sample (M-A3). The sample (M-B3) contained only the hole transporting agent (HTM-3) and no hole transporting agent (HTM-C).

(preparation of sample (M-B4))

A sample (M-B4) was obtained in accordance with the preparation method of sample (M-B1) except that the sample (M-A1) was changed to sample (M-A4). The sample (M-B4) contained only the hole transporting agent (HTM-4) and no hole transporting agent (HTM-D).

(preparation of sample (M-B5))

The sample (M-A1) was purified by silica gel column chromatography using a mixed solvent of toluene and isohexane (volume ratio 50/50) as a developing solvent. Thereby, a component containing the hole transporting agent (HTM-A) was separated. The mixture was concentrated under reduced pressure until the separated solution (component) was slightly turbid, whereby a concentrated solution was obtained. Isohexane and methanol were added to the concentrate. The concentrated solution was cooled to 5 ℃ and the precipitated crystals were removed by filtration to obtain a sample (M-B5). The sample (M-B5) contained only the hole transporting agent (HTM-A) and no hole transporting agent (HTM-1).

(measurement of content ratio of hole-transporting agent (1) and hole-transporting agent (2))

With respect to each sample prepared, the content ratio of the hole transporting agent (1) was measured with respect to the total mass of the hole transporting agent (1) and the hole transporting agent (2). The content ratio of the hole-transporting agent (1) is the content ratio of the hole-transporting agents (HTM-1) to (HTM-4) contained in the general formula (1). Further, with respect to each sample prepared, the content of the hole transporting agent (2) was measured with respect to the total mass of the hole transporting agent (1) and the hole transporting agent (2). The content ratio of the hole-transporting agent (2) is the content ratio of the hole-transporting agents (HTM-a) to (HTM-D) contained in the general formula (2). The measurement method is as follows.

Specifically, 2.0mg of each of samples (more specifically, samples (M-A1) to (M-A4) and (M-B1) to (M-B5) was dissolved in 670mg of tetrahydrofuran to obtain a tetrahydrofuran solution, wherein tetrahydrofuran containing no stabilizer was used, the obtained tetrahydrofuran solution was analyzed by High Performance Liquid Chromatography (HPLC), specifically, the tetrahydrofuran solution as a sample was analyzed by the following analysis apparatus and analysis conditions to obtain an HPLC chart, the content of the hole transporting agent (1) in the sample was determined from the peak area of the hole transporting agent (1) in the HPLC chart, the content of the hole transporting agent (2) in the sample was determined from the peak area of the hole transporting agent (2) in the HPLC chart, the content of the hole transporting agent (1) and the content of the hole transporting agent (2) were determined, the content of the hole-transporting agent (1) and the content of the hole-transporting agent (2) were calculated. The calculation results are shown in the column "content" in table 3.

(analysis apparatus and analysis conditions)

An analysis device: "Lachrom ELITE" manufactured by Hitachi High-Technologies Corporation "

Detection wavelength: 254nm

Column chromatography: manufactured by GL Sciences Inc. "Inertsil (registered trademark in Japan) ODS-3" (inner diameter: 4.6 mm; length: 250mm)

Column temperature: 40 deg.C

Developing agent: acetonitrile

Flow rate: 1 mL/min

Sample injection amount: 1 μ L

< production of photoreceptor >

Photoreceptors (PA-1) to (PA-9) and (PB-1) to (PB-10) were produced using the charge generating agent, the electron transporting agent, the hole transporting agent, and the binder resin prepared as described above.

(production of photoreceptor (PA-1))

A coating solution was obtained by mixing 3 parts by mass of Y-type oxytitanium phthalocyanine as a charge generator, 70 parts by mass of a sample (M-A1) (specifically, a mixture of 67 parts by mass of a hole transporting agent (HTM-1) and 3 parts by mass of a hole transporting agent (HTM-A)), 100 parts by mass of a polyarylate resin (R-1) as a binder resin, 30 parts by mass of an electron transporting agent (E-1), and 800 parts by mass of tetrahydrofuran as a solvent for 50 hours using a ball mill. Coating of the coating liquid was performed on a conductive substrate (aluminum drum support) by a dip coating method. The coating liquid applied was dried with hot air at 120 ℃ for 60 minutes. Thus, a photosensitive layer (film thickness: 28 μm) was formed on the conductive substrate, and a photoreceptor (PA-1) was obtained. In the photoreceptor (PA-1), a single photosensitive layer is directly formed on a conductive substrate.

(production of photoreceptors (PA-2) to (PA-9) and (PB-1) to (PB-10))

Photoreceptors (PA-2) to (PA-9) and (PB-1) to (PB-10) were produced according to the production method of photoreceptor (PA-1) except that the samples of the types shown in Table 4, electron transport agent and binder resin were used.

< evaluation >

For each of the photoreceptors (PA-1) to (PA-9) and (PB-1) to (PB-10) to be evaluated, the sensitivity characteristics, the cracking resistance, and whether or not crystallization was suppressed were evaluated in the following manner.

< evaluation of sensitivity characteristics >

The evaluation environment of the sensitivity characteristics of the photoreceptor is an environment at a temperature of 23 ℃ and a relative humidity of 50% RH. The surface of the photoreceptor was charged to +750V using a drum sensitivity tester (manufactured by GENTEC corporation). Then, monochromatic light (wavelength: 780 nm; exposure amount: 0.7. mu.J/cm) was extracted from the light of the halogen lamp using a band-pass filter²) And irradiated onto the surface of the photoreceptor. After the irradiation of the monochromatic light was completed, the surface potential of the photoreceptor was measured at a point of time of 40 milliseconds. Using the measured surface potential as the post-exposure potential V of the photoreceptor_L(unit: + V). Post-exposure potential V of photoreceptor_LShown in table 4. The potential V after exposure_LThe photoreceptor having a voltage of +150V or less was evaluated to have good sensitivity characteristics.

< evaluation of crack resistance >

The evaluation environment of the crack resistance of the photoreceptor is an environment of a temperature of 23 ℃ and a relative humidity of 50% RH. The photoreceptor was immersed in an isoparaffinic solvent ("Isopar L" manufactured by ExxonMobil) for 24 hours in a region of 40mm lower in length. After 24 hours of immersion, the number of cracks generated on the surface of the photoreceptor was confirmed. The crack resistance was evaluated based on the number of cracks according to the following criteria. The evaluation results are shown in table 4.

Evaluation a (particularly good): the number of cracks was 20 or less.

Evaluation B (good): the number of cracks is 21 to 100.

Evaluation C (poor): the number of cracks was 101 or more.

< evaluation of crystallization inhibition >

The entire photosensitive layer of the photoreceptor was visually observed to confirm the presence or absence of crystallized portions on the photosensitive layer. From the results of the confirmation, whether or not the crystallization of the photoreceptor was suppressed was evaluated according to the following criteria. The evaluation results are shown in table 4.

Evaluation a (good): the occurrence of crystallized portions was not confirmed.

Evaluation B (poor): it was confirmed that a crystallized portion occurred.

In Table 4The terms of the above-mentioned techniques have the following meanings. "HTM" means a hole transporting agent. "HTM (1)" represents the hole-transporting agent (1). "HTM (2)" represents the hole-transporting agent (2). "ETM" means an electron transport agent. "resin" means a bonding resin. ' V_L"indicates the post-exposure potential. "crack" represents the result of evaluation of crack resistance of the photoreceptor. "crystallization" indicates the evaluation result of whether or not the crystallization of the photoreceptor is suppressed. "-" indicates the absence of the component.

[ TABLE 4 ]

As shown in Table 4, the photosensitive layers of the photoreceptors (PA-1) to (PA-9) were single-layered and contained a charge generating agent, a hole transporting agent, an electron transporting agent, and a binder resin. In the photosensitive layer, the hole-transporting agent contains both the hole-transporting agents (1) and (2) (more specifically, the hole-transporting agents (HTM-1) and (HTM-A), the hole-transporting agents (HTM-2) and (HTM-B), the hole-transporting agents (HTM-3) and (HTM-C), or the hole-transporting agents (HTM-4) and (HTM-D)). In the photosensitive layer, the electron transporting agent contains the electron transporting agent (10), (11) or (12) (more specifically, the electron transporting agent (E-1), (E-2) or (E-3)). The photoreceptors (PA-1) to (PA-9) were evaluated for crack resistance A or B, and these photoreceptors were excellent in crack resistance. Evaluation of inhibition of crystallization of photoreceptors (PA-1) to (PA-9) was A, and crystallization of these photoreceptors was inhibited. The post-exposure potentials V of the photoreceptors (PA-1) to (PA-9)_LIs +150V or less, and these photoreceptors achieve an improvement in cracking resistance and suppression of crystallization without impairing sensitivity characteristics.

As described above, the photoreceptor according to the present invention exhibits excellent crack resistance and can suppress crystallization. Further, since the photoreceptor according to the present invention is excellent in crack resistance and can suppress crystallization, it can be judged that an image forming apparatus provided with such a photoreceptor is excellent in durability and can form a high-quality image. Further, according to the method for manufacturing a photoreceptor of the present invention, it is possible to manufacture a photoreceptor having excellent crack resistance and capable of suppressing crystallization while simplifying the process for manufacturing a hole transporting agent.

Claims (10)

1. An electrophotographic photoreceptor is provided with a photosensitive layer containing a photosensitive compound,

comprises a conductive substrate and a photosensitive layer,

the photosensitive layer is a single layer of a photosensitive material,

the photosensitive layer contains a charge generator, a hole transporting agent, an electron transporting agent and a binder resin,

the hole-transporting agent contains a first hole-transporting agent which is a compound represented by general formula (1) and a second hole-transporting agent which is a compound represented by general formula (2),

the electron transport agent contains a compound represented by general formula (10), (11) or (12),

[ CHEM 1 ]

In the general formula (1), R^1A、R^2A、R^3A、R^4A、R^5A、R^6A、R^7A、R^8A、R^9AAnd R^10AIndependently of one another, represents a hydrogen atom, a C1-C8 alkyl group, a C1-C8 alkoxy group or a C6-C14 aryl group,

r in the general formula (1)^1BAnd R in the general formula (2)^1CIs a group represented by the formula (1) and R^1AThe same group or groups are used as the base group,

r in the general formula (1)^2BAnd R in the general formula (2)^2CIs a group represented by the formula (1) and R^2AThe same group or groups are used as the base group,

r in the general formula (1)^3BAnd R in the general formula (2)^3CIs a group represented by the formula (1) and R^3AThe same group or groups are used as the base group,

r in the general formula (1)^4BAnd R in the general formula (2)^4CIs a group represented by the formula (1) and R^4AThe same group or groups are used as the base group,

r in the general formula (1)^5BAnd R in the general formula (2)^5CIs a group represented by the formula (1) and R^5AThe same group or groups are used as the base group,

r in the general formula (1)^6BAnd R in the general formula (2)^6CAnd R^6DIs a group represented by the formula (1) and R^6AThe same group or groups are used as the base group,

r in the general formula (1)^7BAnd R in the general formula (2)^7CAnd R^7DIs a group represented by the formula (1) and R^7AThe same group or groups are used as the base group,

r in the general formula (1)^8BAnd R in the general formula (2)^8CAnd R^8DIs a group represented by the formula (1) and R^8AThe same group or groups are used as the base group,

r in the general formula (1)^9BAnd R in the general formula (2)^9CAnd R^9DIs a group represented by the formula (1) and R^9AThe same group or groups are used as the base group,

r in the general formula (1)^10BAnd R in the general formula (2)^10CAnd R^10DIs a group represented by the formula (1) and R^10AThe same group or groups are used as the base group,

y in the general formula (1) is a divalent group represented by the formula (Y2),

[ CHEM 2 ]

[ CHEM 3 ]

In the general formula (10), Q^5AAnd Q^5BEach independently represents a hydrogen atom, a C1-C8 alkyl group, a phenyl group or a C1-C8 alkoxy group, Q^6AAnd Q^6BEach independently represents C1-C8 alkyl, phenyl or C1-C8 alkoxy, m₁And m₂Each independently represents an integer of 0 to 4 inclusive,

in the general formula (11), Q⁷And Q⁸Each independently of the other, representHydrogen atom, C1-C8 alkyl, phenyl or C1-C8 alkoxy, Q⁹Represents a C1-C8 alkyl group, a phenyl group or a C1-C8 alkoxy group, m₃Represents an integer of 0 to 4 inclusive,

in the general formula (12), Q¹⁰And Q¹¹Each independently represents a C1-C6 alkyl group or a hydrogen atom, Q¹²Represents a halogen atom or a hydrogen atom.

2. The electrophotographic photoreceptor according to claim 1,

the compound represented by the general formula (1) is a compound represented by the chemical formula (HTM-1), and the compound represented by the general formula (2) is a compound represented by the chemical formula (HTM-A),

alternatively, the compound represented by the general formula (1) is a compound represented by the chemical formula (HTM-2), and the compound represented by the general formula (2) is a compound represented by the chemical formula (HTM-B),

alternatively, the compound represented by the general formula (1) is a compound represented by the chemical formula (HTM-3), and the compound represented by the general formula (2) is a compound represented by the chemical formula (HTM-C),

alternatively, the compound represented by the general formula (1) is a compound represented by the chemical formula (HTM-4), and the compound represented by the general formula (2) is a compound represented by the chemical formula (HTM-D),

[ CHEM 4 ]

3. The electrophotographic photoreceptor according to claim 1 or 2,

the compound represented by the general formula (10) is a compound represented by the chemical formula (E-1),

the compound represented by the general formula (11) is a compound represented by the chemical formula (E-2),

the compound represented by the general formula (12) is a compound represented by the chemical formula (E-3),

[ CHEM 5 ]

4. The electrophotographic photoreceptor according to claim 1 or 2,

the binder resin comprises a polyarylate resin,

the polyarylate resin having at least 1 repeating unit represented by the general formula (10) and at least 1 repeating unit represented by the general formula (11),

[ CHEM 6 ]

In the general formula (10), R¹¹And R¹²Each independently represents a hydrogen atom or a methyl group, W is a divalent group represented by the general formula (W1), the general formula (W2) or the chemical formula (W3),

in the general formula (11), X is a divalent group represented by the formula (X1), the formula (X2) or the formula (X3),

[ CHEM 7 ]

-O- (W3)

In the general formula (W1), R¹³Represents a hydrogen atom or a C1-C4 alkyl group, R¹⁴Represents a C1-C4 alkyl group,

in the general formula (W2), t represents an integer of 1 to 3 inclusive,

[ CHEM 8 ]

5. The electrophotographic photoreceptor according to claim 4,

the polyarylate resin having repeating units represented by chemical formulas (10-2), (11-X1) and (11-X3),

[ CHEM 9 ]

6. The electrophotographic photoreceptor according to claim 1 or 2,

the photosensitive layer is the outermost surface layer.

7. An image forming apparatus includes:

an image bearing body;

a charging device for charging the surface of the image carrier to a positive polarity;

an exposure device that exposes the surface of the charged image carrier to form an electrostatic latent image on the surface of the image carrier;

a developing device that develops the electrostatic latent image into a toner image; and

a transfer device for transferring the toner image from the image bearing member to a transfer object,

the image bearing member is the electrophotographic photoreceptor according to any one of claims 1 to 6.

8. The image forming apparatus according to claim 7,

the transferred body is a recording medium,

the transfer device transfers the toner image from the image carrier onto the recording medium while the recording medium contacts the surface of the image carrier.

9. The image forming apparatus according to claim 7,

the surface of the image carrier is in contact with the developing device.

10. A method for manufacturing a composite material includes the steps of,

producing the electrophotographic photoreceptor according to any one of claims 1 to 6,

the manufacturing method comprises a hole transporting agent manufacturing step and a photosensitive layer forming step,

in the hole transporting agent producing step, the hole transporting agent is produced,

in the photosensitive layer forming step, a coating solution containing the charge generating agent, the hole transporting agent, the electron transporting agent, the binder resin, and a solvent is applied to the conductive substrate, and then at least a part of the solvent contained in the coating solution is removed to form the photosensitive layer,

the hole transporting agent production step includes a first stirring step and a second stirring step,

in the first stirring step, a mixture solution containing a compound represented by the general formula (A) and a compound represented by the general formula (B) is subjected to first stirring,

in the second stirring step, a compound represented by the general formula (C) is further added to the mixed solution, and the mixed solution is subjected to second stirring,

performing the second stirring step after the first stirring step without purifying the mixed solution,

obtaining the hole transporting agent containing the first hole transporting agent and the second hole transporting agent after the first stirring step and the second stirring step,

[ CHEM 10 ]

R in the general formula (A)¹、R²、R³、R⁴And R⁵Are respectively connected with R in the general formula (1)^1A、R^2A、R^3A、R^4AAnd R^5AAre the same group of atoms,

r in the general formula (B)⁶、R⁷、R⁸、R⁹And R¹⁰Are respectively connected with R in the general formula (1)^6A、R^7A、R^8A、R^9AAnd R^10AAre the same group, Z in the general formula (B)¹Represents a halogen atom, and is a halogen atom,

y in the general formula (C) is the same group as Y in the general formula (1), and Z in the general formula (C)²And Z³Represents a halogen atom.

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