JP2022054799A - Electrophotographic photoreceptor, process cartridge, and image forming apparatus - Google Patents

Abstract

To provide an electrophotographic photoreceptor that can be satisfactorily positively electrified even when positive electrification and negative electrification are repeated and is excellent in storage property in a high temperature environment.SOLUTION: An electrophotographic photoreceptor comprises a conductive substrate and a photosensitive layer. The photosensitive layer is a single layer and contains a charge generating agent, an electron transport agent, a hole transport agent, and an addition agent having a specific structure. The electron transport agent includes a compound represented by the general formula (1).SELECTED DRAWING: None

Description

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

The electrophotographic photosensitive member is used as an image carrier in an electrophotographic image forming apparatus (for example, a printer or a multifunction device). The electrophotographic photosensitive member includes a photosensitive layer. The electrophotographic photosensitive member included in the image forming apparatus described in Patent Document 1 contains a bisphenol Z-type polycarbonate resin which is a binder resin at least in the photosensitive layer which is the surface layer thereof.

Japanese Unexamined Patent Publication No. 8-234538

However, according to the study by the present inventors, the electrophotographic photosensitive member included in the image forming apparatus described in Patent Document 1 has a positive charge property when positive charge and a negative charge are repeated, and a storage property in a high temperature environment. Turned out to be inadequate.

The present invention has been made in view of the above problems, and an object thereof is an electrophotographic photosensitive member which can be satisfactorily positively charged even when positive charging and negative charging are repeated and has excellent storage stability in a high temperature environment. Is to provide. Another object of the present invention is to provide a process cartridge and an image forming apparatus capable of forming a good image by providing such an electrophotographic photosensitive member.

The electrophotographic photosensitive member of the present invention includes a conductive substrate and a photosensitive layer. The photosensitive layer is a single layer and contains a charge generator, an electron transporting agent, a binder resin, a hole transporting agent, and an additive. The electron transporting agent contains a compound represented by the general formula (1). The additive includes a compound represented by the general formula (31), (32), or (33).

In the general formula (1), R ¹ and R ² are each independently substituted with one or more and five or less substituents selected from the group consisting of a halogen atom, an alkyl group, and an alkoxy group. Represents a good aryl group, hydrogen atom, alkyl group, heterocyclic group, alkoxy group, aralkyl group, or allyl group.

In the general formula (31), R ³¹¹ , R ³¹² , and R ³¹³ independently represent an alkyl group having 1 or more and 6 or less carbon atoms, or an alkoxy group having 1 or more and 6 or less carbon atoms, and r1 ,. r2 and r3 each independently represent an integer of 0 or more and 5 or less. In the general formula (32), R ³²¹ 、 R ³²² 、 R ³²³ 、 R ³²⁴ 、 R ³²⁵ 、 R ³²⁶ 、 R ³²⁷ 、 R ³²⁸ 、 R 329 and R ³²⁹ are independently each of a hydrogen atom, a hydroxy group and a halogen atom. Alternatively, it represents an alkyl group having 1 or more and 6 or less carbon atoms. In the general formula (33), R ³³¹ , R ³³⁵ , R ³³⁶ , and R ³⁴⁰ are each independently substituted with a hydrogen atom and an aryl group having 6 or more and 14 or less carbon atoms, and the number of carbon atoms is 1. Representing an alkyl group or nitro group of 6 or less, R ³³² , R ³³³ , R ³³⁴ , R ³³⁷ , R ³³⁸ , and R ³³⁹ are independently hydrogen atoms and aryl groups having 6 or more and 14 or less carbon atoms, respectively. It represents an alkyl group having 1 or more and 6 or less carbon atoms, an aryl group having 6 or more and 14 or less carbon atoms, or a nitro group which may be substituted with.

The process cartridge of the present invention includes at least one selected from the group consisting of a charging device, an exposure device, a developing device, a transfer device, a cleaning member, and a static elimination device, and the electrophotographic photosensitive member described above.

The 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 positively. The exposure apparatus exposes the surface of the charged image carrier to form an electrostatic latent image on the surface of the image carrier. The developing device develops the electrostatic latent image as a toner image. The transfer device transfers the toner image from the image carrier to the transfer target. The image carrier is the electrophotographic photosensitive member already described.

The electrophotographic photosensitive member of the present invention can be satisfactorily positively charged even when positively charged and negatively charged repeatedly, and is excellent in storage in a high temperature environment. Further, according to the process cartridge and the image forming apparatus of the present invention provided with such an electrophotographic photosensitive member, a good image can be formed.

It is a partial cross-sectional view which shows an example of the electrophotographic photosensitive member which concerns on 1st Embodiment of this invention. It is a partial cross-sectional view which shows an example of the electrophotographic photosensitive member which concerns on 1st Embodiment of this invention. It is a partial cross-sectional view which shows an example of the electrophotographic photosensitive member which concerns on 1st Embodiment of this invention. It is sectional drawing which shows an example of the image forming apparatus which concerns on 2nd Embodiment of this invention. It is a figure which shows the image carrier and a cleaning member shown in FIG. 4, and a control device. It is a time chart diagram which shows the control of the cleaning member in a print mode and a cleaning mode. It is a flowchart which shows the control of the image forming apparatus shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and can be carried out with appropriate modifications within the scope of the object of the present invention. Hereinafter, the compound and its derivatives may be collectively referred to by adding "system" after the compound name. Further, when the polymer name is represented by adding "system" after the compound name, it means that the repeating unit of the polymer is derived from the compound or its derivative. "Independently" in the description of the general formula means that they may be the same or different. As each component described in the specification, one kind may be used alone, or two or more kinds may be used in combination.

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

Alkyl groups with 1 to 8 carbon atoms, alkyls with 1 to 6 carbon atoms, alkyl groups with 1 to 4 carbon atoms, and alkyl groups with 1 to 3 carbon atoms are all unless otherwise specified. , Linear or branched and unsubstituted. Examples of the alkyl group having 1 or more and 8 or less carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, and an n-pentyl group, and 1 -Methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylpropyl group, 2-ethylpropyl group, 1,1-dimethylpropyl group, 1,2-dimethylpropyl group, 2,2-dimethylpropyl group, n-hexyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, 1,1-dimethylbutyl group, 1,2-dimethylbutyl group, 1,3-dimethyl Butyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, 3,3-dimethylbutyl group, 1,1,2-trimethylpropyl group, 1,2,2-trimethylpropyl group, 1-ethylbutyl Examples include groups, 2-ethylbutyl and 3-ethylbutyl groups, linear and branched heptyl groups, and linear and branched octyl groups. Examples of alkyl groups having 1 or more and 6 or less carbon atoms, alkyl groups having 1 or more and 4 or less carbon atoms, and alkyl groups having 1 or more and 3 or less carbon atoms have alkyl atoms having 1 or more and 8 or less carbon atoms. Among the groups mentioned as an example of the group, it is a group having a corresponding number of carbon atoms.

Unless otherwise specified, the alkoxy groups having 1 or more and 8 or less carbon atoms, the alkoxy groups having 1 or more and 6 or less carbon atoms, and the alkoxy groups having 1 or more and 3 or less carbon atoms are linear or branched, respectively. It is not substituted. Examples of the alkoxy group having 1 or more and 8 or less carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group and an n-pentoxy group. 1-methylbutoxy group, 2-methylbutoxy group, 3-methylbutoxy group, 1-ethylpropoxy group, 2-ethylpropoxy group, 1,1-dimethylpropoxy group, 1,2-dimethylpropoxy group, 2,2- Dimethylpropoxy group, n-hexyloxy group, 1-methylpentyloxy group, 2-methylpentyloxy group, 3-methylpentyloxy group, 4-methylpentyloxy group, 1,1-dimethylbutoxy group, 1,2- Dimethylbutoxy group, 1,3-dimethylbutoxy group, 2,2-dimethylbutoxy group, 2,3-dimethylbutoxy group, 3,3-dimethylbutoxy group, 1,1,2-trimethylpropoxy group, 1,2, 2-trimethylpropoxy group, 1-ethylbutoxy group, 2-ethylbutoxy group, and 3-ethylbutoxy group, linear and branched heptyloxy groups, and linear and branched octyloxy. The group is mentioned. Examples of alkoxy groups having 1 or more and 6 or less carbon atoms and examples of alkoxy groups having 1 or more and 3 or less carbon atoms are the corresponding carbons among the groups described as examples of alkoxy groups having 1 or more and 8 or less carbon atoms. It is a group having an atomic number.

Aryl groups having 6 to 14 carbon atoms and aryl groups having 6 to 10 carbon atoms are unsubstituted unless otherwise specified. Examples of the aryl group having 6 or more carbon atoms and 14 or less carbon atoms include a phenyl group, a naphthyl group, an indasenyl group, a biphenylenyl group, an acenaphthylenyl group, an anthryl group, and a phenanthryl group. Examples of the aryl group having 6 or more and 10 or less carbon atoms include a phenyl group and a naphthyl group.

Unless otherwise specified, the aralkyl group having 7 or more and 20 or less carbon atoms and the aralkyl group having 7 or more and 13 or less carbon atoms are unsubstituted, respectively. The aralkyl group having 7 or more and 20 or less carbon atoms is, for example, an alkyl group having 1 or more and 6 or less carbon atoms substituted with an aryl group having 6 or more and 14 or less carbon atoms. The aralkyl group having 7 or more and 13 or less carbon atoms is, for example, an alkyl group having 1 or more and 3 or less carbon atoms substituted with an aryl group having 6 or more and 10 or less carbon atoms.

Unless otherwise specified, the 5-membered or more-14-membered heterocyclic group and the 5-membered or 6-membered heterocyclic group are unsubstituted, respectively. The 5-membered or 14-membered heterocyclic group is, for example, a 5- or 6-membered monocyclic heterocyclic group containing 1 or more and 3 or less heteroatoms in addition to the carbon atom; such a monocyclic heterocycle. Heterocyclic group fused with 2; a heterocyclic group fused with such a monocyclic heterocycle and a 5- or 6-membered monocyclic hydrocarbon ring; 3 such monocyclic heterocycles Condensed heterocyclic group; a heterocyclic group in which two such monocyclic heterocycles and one 5- or 6-membered monocyclic hydrocarbon ring are fused; or such a monocyclic heterocycle 1 Examples thereof include a heterocyclic group in which two 5- or 6-membered monocyclic hydrocarbon rings are condensed. Specific examples of the 5-membered or 14-membered heterocyclic group include a piperidinyl group, a piperazinyl group, a morpholinyl group, a thiophenyl group, a furanyl group, a pyrrolyl group, an imidazolyl group, a pyrazolyl group, an isothiazolyl group, an isooxazolyl group, an oxazolyl group and an isooxazolyl group. Group, thiazolyl group, isothiazolyl group, frazanyl group, pyranyl group, pyridyl group, pyridadinyl group, pyrimidinyl group, pyrazinyl group, indyl group, 1H-indazolyl group, isoindryl group, chromenyl group, quinolinyl group, isoquinolinyl group, prynyl group, pteridinyl Group, triazolyl group, tetrazolyl group, 4H-quinolidinyl group, naphthyldinyl group, benzofuranyl group, 1,3-benzodioxolyl group, benzoxazolyl group, benzothiazolyl group, benzimidazolyl group, carbazolyl group, phenanthridinyl group , Acridinyl group, phenazinyl group, and phenanthrolinyl group. The 5-membered or 6-membered heterocyclic group is a group having a corresponding number of ring members among the groups described as an example of a 5-membered or more than 14-membered heterocyclic group. The substituents used in the present specification have been described above.

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

As shown in FIG. 1, the photoconductor 1 includes a conductive substrate 2 and a photosensitive layer 3. The photosensitive layer 3 is a single layer. The photoconductor 1 is a single-layer electrophotographic photosensitive member including the single-layer photosensitive layer 3.

As shown in FIG. 2, the photoconductor 1 may further include an intermediate layer 4 (undercoat layer) in addition to the conductive substrate 2 and the photosensitive layer 3. The intermediate layer 4 is provided between the conductive substrate 2 and the photosensitive layer 3. As shown in FIG. 1, the photosensitive layer 3 may be provided directly on the conductive substrate 2. Alternatively, as shown in FIG. 2, the photosensitive layer 3 may be provided on the conductive substrate 2 via the intermediate layer 4.

As shown in FIG. 3, the photoconductor 1 may further include a protective layer 5 in addition to the conductive substrate 2 and the photosensitive layer 3. The protective layer 5 is provided on the photosensitive layer 3. As shown in FIGS. 1 and 2, the photosensitive layer 3 may be provided as the outermost surface layer of the photosensitive member 1. Alternatively, as shown in FIG. 3, the protective layer 5 may be provided as the outermost surface layer of the photoconductor 1.

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

Hereinafter, the photoconductor will be described in more detail. The photosensitive layer contains a charge generator, an electron transporting agent, a binder resin, a hole transporting agent, and an additive. The photosensitive layer may contain an additive, if necessary. Hereinafter, the charge generator, the electron transport agent, the binder resin, the hole transport agent, and the additive will be described.

(Charge generator)
Examples of the charge generator include phthalocyanine pigments, perylene pigments, bisazo pigments, trisazo pigments, dithioketopyrrolopyrrole pigments, metal-free naphthalocyanine pigments, metal naphthalocyanine pigments, squaline pigments, indigo pigments, azurenium pigments, and cyanine. Pigments, powders of inorganic photoconductive materials (eg, selenium, selenium-tellu, selenium-arsenic, cadmium sulfide or amorphous silicon), pyrylium pigments, anthanthrone pigments, triphenylmethane pigments, sulene pigments, toluidin pigments, Examples thereof include pyrazoline pigments and quinacridone pigments.

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

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

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

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

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

The content of the charge generator is preferably 0.1 part by mass or more and 50 parts by mass or less, and more preferably 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the binder resin.

(Electronic transport agent)
The electron transporting agent includes a compound represented by the general formula (1) (hereinafter, may be referred to as an electron transporting agent (1)).

In the general formula (1), R ¹ and R ² may be independently substituted with one or more and five or less substituents selected from the group consisting of a halogen atom, an alkyl group, and an alkoxy group. Represents an aryl group; a hydrogen atom; an alkyl group; a heterocyclic group; an alkoxy group; an aralkyl group; or an allyl group.

Since the photosensitive layer contains the electron transporting agent (1), the photoconductor can be satisfactorily positively charged even when the photoconductor is repeatedly positively and negatively charged. Such a photoconductor is particularly preferably applicable to the image forming apparatus of the second embodiment described later. Specifically, in the printing mode, the charging device charges the surface of the photoconductor positively, and a negative first voltage (voltage having a polarity opposite to the charging polarity of the toner) is applied to the cleaning member. It is particularly preferably applicable to an image forming apparatus. When the photoconductor is provided in such an image forming apparatus, the surface of the photoconductor is positively charged by the charging device in the printing mode, and the cleaning member to which the negative electrode primary voltage is applied is used. The potential of the photoconductor is repeatedly lowered to the negative electrode due to the contact. Therefore, the photoconductor is repeatedly positively charged and negatively charged. As described above, the photoconductor of the first embodiment is satisfactorily positively charged even when positively charged and negatively charged are repeated. Therefore, the photoconductor of the first embodiment can be suitably charged to a desired positive electrode potential in the charging step of image formation even when the photoconductor of the first embodiment is provided in the image forming apparatus of the second embodiment.

Further, in the photosensitive layer, in addition to the charge transporting agent (1), the compound represented by the general formula (31), (32), or (33), which is an additive (hereinafter, each of which is an additive (31), (32) and (33) may be described). Hereinafter, the "additive (31), (32), or (33)" may be referred to as a "predetermined additive". By containing the charge transporting agent (1) and the predetermined additive in the photosensitive layer, the positive charge property of the photoconductor when positive charge and negative charge are repeated can be particularly improved. Further, since the photosensitive layer contains the charge transporting agent (1) and the predetermined additive, the photosensitive layer is deteriorated even in a high temperature environment and comes into contact with a member (for example, a cleaning member) of the image forming apparatus. Deformation of the photosensitive layer due to the above is suppressed. An image forming apparatus provided with such a photoconductor is unlikely to cause a problem even when it is transported, stored, or installed in a high temperature environment.

The aryl group represented by R ¹ and R ² in the general formula (1) is, for example, an aryl group having 6 or more carbon atoms and 14 or less carbon atoms. As the aryl group having 6 or more and 14 or less carbon atoms, a phenyl group or a naphthyl group is preferable. As the naphthyl group, a 1-naphthyl group or a 2-naphthyl group is preferable.

The aryl group represented by R ¹ and R ² may be substituted with 1 or more and 5 or less substituents selected from the group consisting of a halogen atom, an alkyl group and an alkoxy group. As the halogen atom as a substituent, a chlorine atom or a bromine atom is preferable. As the alkyl group as the substituent, an alkyl group having 1 or more and 6 or less carbon atoms is preferable, an alkyl group having 1 or more and 3 or less carbon atoms is more preferable, and a methyl group is further preferable. As the alkoxy group as the substituent, an alkoxy group having 1 or more and 6 or less carbon atoms is preferable, an alkoxy group having 1 or more and 3 or less carbon atoms is more preferable, and a methoxy group is further preferable. The group consisting of a halogen atom, an alkyl group, and an alkoxy group is preferably a group consisting of a halogen atom, an alkyl group having 1 or more and 6 or less carbon atoms, and an alkoxy group having 1 or more and 6 or less carbon atoms, and a halogen atom. , A group consisting of an alkyl group having 1 or more and 3 or less carbon atoms and an alkoxy group having 1 or more and 3 or less carbon atoms is more preferable, and a group consisting of a chlorine atom, a bromine atom, a methyl group and a methoxy group. Is particularly preferred. The number of substituents of the aryl group represented by R ¹ and R ² is preferably 1 or 2.

The alkyl group represented by R ¹ and R ² is, for example, an alkyl group having 1 or more carbon atoms and 6 or less carbon atoms. As the alkyl group having 1 or more and 6 or less carbon atoms, an alkyl group having 1 or more and 4 or less carbon atoms is preferable, and a methyl group, an n-propyl group, or a tert-butyl group is more preferable.

The heterocyclic group represented by R ¹ and R ² is, for example, a heterocyclic group having 5 or more members and 14 or less members. As the heterocyclic group having 5 or more and 14 or less members, a heterocyclic group having 5 or more and 14 or less members containing at least one heteroatom other than the carbon atom is preferable, and a 5-membered group containing at least one heteroatom other than the carbon atom is preferable. A heterocyclic group having 6 or more members is more preferable, and a monocyclic heterocyclic group having 5 or more and 6 or less members containing at least one heteroatom other than a carbon atom is further preferable. The hetero atom is preferably at least one selected from the group consisting of a nitrogen atom, a sulfur atom and an oxygen atom, and more preferably at least one selected from the group consisting of a sulfur atom and an oxygen atom. It is more preferably a sulfur atom or an oxygen atom. As the heterocyclic group having 5 or more and 14 or less members, a thiophenyl group or a furanyl group is more preferable, and a 2-thiophenyl group or a 2-furanyl group is particularly preferable.

The alkoxy group represented by R ¹ and R ² is, for example, an alkoxy group having 1 or more carbon atoms and 6 or less carbon atoms. As the alkoxy group having 1 or more and 6 or less carbon atoms, an alkoxy group having 1 or more and 3 or less carbon atoms is preferable, and a methoxy group is more preferable.

The aralkyl group represented by R ¹ and R ² is, for example, an aralkyl group having 7 or more and 20 or less carbon atoms. As the aralkyl group having 7 or more and 20 or less carbon atoms, an aralkyl group having 7 or more and 13 or less carbon atoms is preferable, and a benzyl group, a phenylethyl group or a naphthylmethyl group is more preferable.

The allylic group represented by R ¹ and R ² is represented by the chemical formula "CH ₂ = CH-CH _2- ".

In order to improve the positive chargeability when positive charge and negative charge are repeated and the storage stability in a high temperature environment, R ¹ and R ² in the general formula (1) are independently halogen atoms and carbon atoms, respectively. It may be substituted with 1 or more and 5 or less substituents selected from the group consisting of an alkyl group having 1 or more and 6 or less and an alkoxy group having 1 or more and 6 or less carbon atoms. Aryl group; an alkyl group having 1 or more and 6 or less carbon atoms; or a heterocyclic group having 5 or more and 14 or less members is preferable. For the same reason, in the general formula (1), R ¹ represents an aryl group having 6 or more and 14 or less carbon atoms; an alkyl group having 1 or more and 6 or less carbon atoms; or a heterocyclic group having 5 or more and 14 or less members. , R ² is substituted with one or two substituents selected from the group consisting of halogen atoms, alkyl groups having 1 or more and 6 or less carbon atoms, and alkoxy groups having 1 or more and 6 or less carbon atoms. It is more preferable to represent an aryl group having 6 or more and 14 or less carbon atoms; or an alkyl group having 1 or more and 6 or less carbon atoms.

In order to improve the positive chargeability when positive charge and negative charge are repeated and the storability in a high temperature environment, R ¹ and R ² are independently one or two in the general formula (1). It is preferable to represent an aryl group having 6 or more and 14 or less carbon atoms which may be substituted with the halogen atom of the above; or an alkyl group having 1 or more and 6 or less carbon atoms. For the same reason, in the general formula (1), R ¹ represents an aryl group having 6 or more and 14 or less carbon atoms; or an alkyl group having 1 or more and 6 or less carbon atoms, and R ² represents one or two. It is more preferable to represent an aryl group having 6 or more and 14 or less carbon atoms which may be substituted with a halogen atom; or an alkyl group having 1 or more and 6 or less carbon atoms.

In order to improve the positive chargeability when positive charge and negative charge are repeated and the storage stability in a high temperature environment, suitable examples of the electron transporting agent (1) are represented by the chemical formulas (ETM1) to (ETM31). Examples thereof include compounds to be used (hereinafter, each of which may be referred to as an electron transporting agent (ETM1) to (ETM31)).

In order to improve the positive charge property when positive charge and negative charge are repeated and the storage property in a high temperature environment, more preferable examples of the electron transport agent (1) are the electron transport agent (ETM1) and (ETM2). ), (ETM6), (ETM7), (ETM8), (ETM9), (ETM19), (ETM22), (ETM23), (ETM24), (ETM28), and (ETM29).

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 80 parts by mass or less, and 20 parts by mass or more with respect to 100 parts by mass of the binder resin. It is more preferably 60 parts by mass or less.

The photosensitive layer may contain only the electron transporting agent (1) as the electron transporting agent. Further, the photosensitive layer may further contain other electron transporting agents as the electron transporting agent in addition to the electron transporting agent (1). Examples of the electron transporting agent other than the electron transporting agent (1) include quinone-based compounds, diimide-based compounds, hydrazone-based compounds, marononitrile-based compounds, thiopyran-based compounds, trinitrothioxanthone-based compounds, 3, 4, 5, 7-. Tetranitro-9-fluorenone compounds, dinitroanthracene compounds, dinitroacridin compounds, tetracyanoethylene, 2,4,8-trinitrothioxanthone, dinitrobenzene, dinitroaclysine, succinic anhydride, maleic anhydride, and maleylan anhydride. Acid is mentioned. Examples of the quinone compound include a diphenoquinone compound, an azoquinone compound, an anthraquinone compound, a naphthoquinone compound, a nitroanthraquinone compound, and a dinitroanthraquinone compound.

(Binder resin)
Examples of the binder resin include thermoplastic resins (more specifically, polycarbonate resins, polyarylate resins, styrene resins, styrene-butadiene copolymers, styrene-acrylonitrile copolymers, styrene-maleic acid copolymers, etc. Styline-acrylic acid copolymer, acrylic copolymer, polyethylene resin, ethylene-vinyl acetate copolymer, chlorinated polyethylene resin, polyvinyl chloride resin, polypropylene resin, ionomer, vinyl chloride-vinyl acetate copolymer, polyester resin , Alchid resin, polyamide resin, polyurethane resin, polysulfone resin, diallyl phthalate resin, ketone resin, polyvinyl butyral resin, and polyether resin), thermosetting resin (more specifically, silicone resin, epoxy resin, phenol resin, Examples thereof include urea resins, melamine resins, and other crosslinkable thermosetting resins), and photocurable resins (more specifically, epoxy-acrylic acid-based resins and urethane-acrylic acid-based copolymers). ..

Among these resins, a polycarbonate resin is preferable as the binder resin because the photosensitive layer 3 having an excellent balance of processability, mechanical properties, optical properties, and abrasion resistance can be obtained. Examples of the polycarbonate resin include a polycarbonate resin having a repeating unit represented by the chemical formula (R1) (hereinafter, may be referred to as a polycarbonate resin (R1)) and a polycarbonate having a repeating unit represented by (R2). Examples thereof include a resin (hereinafter, may be referred to as a polycarbonate resin (R2)).

The viscosity average molecular weight of the binder resin is preferably 10,000 or more, more preferably 30,000 or more, and particularly preferably 50,000 or more. When the viscosity average molecular weight of the binder resin is 10,000 or more, the wear resistance of the photoconductor is 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.

(Hole transport agent)
Examples of the hole transporting agent include oxadiazole compounds (for example, 2,5-di (4-methylaminophenyl) -1,3,4-oxadiazole) and styryl compounds (for example, 9- (4). -Diethylaminostyryl) anthracene), carbazole compounds (eg, polyvinylcarbazole), organic polysilane compounds, pyrazoline compounds (eg, 1-phenyl-3- (p-dimethylaminophenyl) pyrazoline), hydrazone compounds, indol compounds, oxazole. Examples thereof include a system compound, an isooxazole system compound, a thiazole system compound, a thiadiazole system compound, an imidazole system compound, a pyrazole system compound, and a triazole system compound.

In order to improve the positive charge property when positive charge and negative charge are repeated and the storage property in a high temperature environment, the hole transport agent is a general formula (21), (22), (23), (24). , (25), (26), or (27) is preferably contained. Hereinafter, the compounds represented by the general formulas (21) to (27) may be described as hole transporting agents (21) to (27), respectively.

In the general formula (21), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ each independently represent an alkyl group or a phenyl group having 1 or more and 8 or less carbon atoms. R ¹⁷ and R ¹⁸ each independently represent a hydrogen atom, an alkyl group having 1 or more carbon atoms and 8 or less carbon atoms, or a phenyl group. b1, b2, b3, and b4 each independently represent an integer of 0 or more and 5 or less. b5 and b6 each independently represent an integer of 0 or more and 4 or less. d and e independently represent 0 or 1, respectively.

In the general formula (21), when b1 represents an integer of 2 or more and 5 or less, the plurality of R ^11s may represent the same group or different groups. When b2 represents an integer of 2 or more and 5 or less, the plurality of R ^12s may represent the same group or different groups. When b3 represents an integer of 2 or more and 5 or less, the plurality of R ^13s may represent the same group or different groups. When b4 represents an integer of 2 or more and 5 or less, the plurality of R ^14s may represent the same group or different groups. When b5 represents an integer of 2 or more and 4 or less, the plurality of R ^15s may represent the same group or different groups. When b6 represents an integer of 2 or more and 4 or less, the plurality of R ^16s may represent the same group or different groups.

In the general formula (21), it is preferable that R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ each independently represent an alkyl group having 1 or more and 8 or less carbon atoms, and the number of carbon atoms is preferably 8. It is more preferable to represent an alkyl group of 1 or more and 3 or less, and further preferably to represent a methyl group or an ethyl group. R ¹⁷ and R ¹⁸ preferably represent a hydrogen atom. b1 and b2 preferably represent 0. b3 and b4 preferably represent 2. b5 and b6 preferably represent 0. It is preferable that d and e represent 0.

In the general formula (22), R ²⁰ is substituted with a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkyl group having 1 to 8 carbon atoms. Represents a optionally phenyl group. R ²¹ , R ²² and R ²³ each independently represent an alkyl group having 1 or more and 8 or less carbon atoms, or an alkoxy group having 1 or more and 8 or less carbon atoms. f1, f2, and f3 each independently represent an integer of 0 or more and 5 or less. f4 represents 0 or 1.

In the general formula (22), when f1 represents an integer of 2 or more and 5 or less, the plurality of R ^21s may represent the same group or different groups. When f2 represents an integer of 2 or more and 5 or less, the plurality of R ^22s may represent the same group or different groups. When f3 represents an integer of 2 or more and 5 or less, the plurality of R ^23s may represent the same group or different groups.

In the general formula (22), R ²⁰ preferably represents a phenyl group. R ²¹ , R ²² and R ²³ each independently preferably represent an alkyl group having 1 or more and 8 or less carbon atoms, more preferably an alkyl group having 1 or more and 3 or less carbon atoms, and a methyl group. Is more preferable. It is preferable that f1 and f2 represent 1. f3 preferably represents 0. As already mentioned, f4 represents 0 or 1.

In the general formula (23), R ³¹ , R ³² , R ³³ , R ³⁴ , and R ³⁵ each independently contain an alkyl group having 1 or more and 8 or less carbon atoms or an alkoxy group having 1 or more and 8 or less carbon atoms. show. g1, g2, g3, g4, and g5 each independently represent an integer of 0 or more and 5 or less.

In the general formula (23), when g1 represents an integer of 2 or more and 5 or less, the plurality of R ^31s may represent the same group or different groups. When g2 represents an integer of 2 or more and 5 or less, the plurality of R ^32s may represent the same group or different groups. When g3 represents an integer of 2 or more and 5 or less, the plurality of R ^33s may represent the same group or different groups. When g4 represents an integer of 2 or more and 5 or less, the plurality of R ^34s may represent the same group or different groups. When g5 represents an integer of 2 or more and 5 or less, the plurality of R ^35s may represent the same group or different groups.

In the general formula (23), R ³¹ , R ³² , R ³³ , R ³⁴ , and R ³⁵ each independently represent an alkyl group having 1 or more and 8 or less carbon atoms, preferably 1 or more and 3 carbon atoms. It is more preferable to represent the following alkyl group, and further preferably to represent a methyl group. It is preferable that g1, g2, g3, g4, and g5 represent 1.

In the general formula (24), R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , R ⁴⁵ , and R ⁴⁶ each independently have an alkyl group having 1 or more and 8 or less carbon atoms, a phenyl group, or 1 carbon atom. Represents an alkoxy group of 8 or more and 8 or less. h1, h2, h4, and h5 each independently represent an integer of 0 or more and 5 or less. h3 and h6 each independently represent an integer of 0 or more and 4 or less.

In the general formula (24), when h1 represents an integer of 2 or more and 5 or less, the plurality of R ^41s may represent the same group or different groups. When h2 represents an integer of 2 or more and 5 or less, the plurality of R ^42s may represent the same group or different groups. When h4 represents an integer of 2 or more and 5 or less, the plurality of R ^44s may represent the same group or different groups. When h5 represents an integer of 2 or more and 5 or less, the plurality of R ^45s may represent the same group or different groups. When h3 represents an integer of 2 or more and 4 or less, the plurality of R ^43s may represent the same group or different groups. When h6 represents an integer of 2 or more and 4 or less, the plurality of R ^46s may represent the same group or different groups.

In the general formula (24), it is preferable that R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , R ⁴⁵ , and R ⁴⁶ each independently represent an alkyl group having 1 or more and 8 or less carbon atoms, and the number of carbon atoms is preferably 8. It is more preferable to represent an alkyl group of 1 or more and 3 or less, and further preferably to represent a methyl group or an ethyl group. It is preferable that h1, h2, h4, and h5 each independently represent an integer of 0 or more and 2 or less. h3 and h6 preferably represent 0.

In the general formula (25), R ⁷¹ , R ⁷² , R ⁷³ , and R ⁷⁴ each independently represent an alkyl group having 1 or more carbon atoms and 8 or less carbon atoms. j1, j2, j3, and j4 each independently represent an integer of 0 or more and 5 or less.

In the general formula (25), when j1 represents an integer of 2 or more and 5 or less, the plurality of R ^71s may represent the same group or different groups. When j2 represents an integer of 2 or more and 5 or less, the plurality of R ^72s may represent the same group or different groups. When j3 represents an integer of 2 or more and 5 or less, the plurality of R ^73s may represent the same group or different groups. When j4 represents an integer of 2 or more and 5 or less, the plurality of R ^74s may represent the same group or different groups.

In the general formula (25), R ⁷¹ , R ⁷² , R ⁷³ , and R ⁷⁴ each independently preferably represent an alkyl group having 1 or more carbon atoms and 3 or less carbon atoms, and may represent a methyl group or an ethyl group. More preferred. It is preferable that j1, j2, j3, and j4 independently represent 0 or 1, respectively.

In the general formula (26), R ⁸¹ , R ⁸² , and R ⁸³ each independently represent an alkyl group having 1 or more and 8 or less carbon atoms, a phenyl group, or an alkoxy group having 1 or more and 8 or less carbon atoms. R ⁸⁴ and R ⁸⁵ are each independently substituted with an alkyl group having 1 or more and 8 or less carbon atoms, a phenyl group, a hydrogen atom, an alkyl group having 1 or more and 8 or less carbon atoms, or 1 or more carbon atoms. Represents 8 or less alkoxy groups. k1, k2, and k3 each independently represent an integer of 0 or more and 5 or less. k4 and k5 independently represent 1 or 2, respectively.

In the general formula (26), when k1 represents an integer of 2 or more and 5 or less, the plurality of R ^81s may represent the same group or different groups. When k2 represents an integer of 2 or more and 5 or less, the plurality of R ^82s may represent the same group or different groups. When k3 represents an integer of 2 or more and 5 or less, the plurality of R ^83s may represent the same group or different groups.

In the general formula (26), R ⁸¹ , R ⁸² , and R ⁸³ each independently preferably represent an alkoxy group having 1 or more and 8 or less carbon atoms, and each of them represent an alkoxy group having 1 or more and 6 or less carbon atoms. It is more preferable, and it is further preferable to represent an ethoxy group. R ⁸⁴ and R ⁸⁵ preferably represent a hydrogen atom. It is preferable that k1 and k2 represent 0. k3 preferably represents 1. k4 and k5 preferably represent 1.

In the general formula (27), R ⁶¹ , R ⁶² , and R ⁶³ each independently represent an alkyl group having 1 or more and 8 or less carbon atoms. R ⁶⁴ , R ⁶⁵ , and R ⁶⁶ each independently represent a hydrogen atom or an alkyl group having 1 or more and 8 or less carbon atoms.

In the general formula (27), R ⁶¹ , R ⁶² , and R ⁶³ each independently preferably represent an alkyl group having 1 or more and 8 or less carbon atoms, and each represent an alkyl group having 1 or more and 3 or less carbon atoms. It is more preferable, and it is further preferable to represent a methyl group. R ⁶⁴ , R ⁶⁵ , and R ⁶⁶ preferably represent a hydrogen atom.

As a more preferable example of the hole transporting agent, compounds represented by the chemical formulas (HTM1) to (HTM10) (hereinafter, each may be referred to as a hole transporting agent (HTM1) to (HTM10)) are used. Can be mentioned.

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

(Additive)
Additives include the predetermined additives already mentioned. As described above, since the photosensitive layer contains both the electron transporting agent (1) and the predetermined additive, the positive charge property of the photoconductor when positive charge and negative charge are repeated, and the photosensitivity in a high temperature environment. Improves body storage. The general formulas (31), (32), and (33) are shown below, respectively.

In the general formula (31), R ³¹¹ , R ³¹² , and R ³¹³ independently represent an alkyl group having 1 or more and 6 or less carbon atoms, or an alkoxy group having 1 or more and 6 or less carbon atoms. r1, r2, and r3 each independently represent an integer of 0 or more and 5 or less.

When r1 represents an integer of 2 or more and 5 or less, the plurality of R ^311s may represent the same group or different groups. When r2 represents an integer of 2 or more and 5 or less, the plurality of R ^312s may represent the same group or different groups. When r3 represents an integer of 2 or more and 5 or less, the plurality of R ^313s may represent the same group or different groups. The bonding positions of R ³¹¹ , R ³¹² , and R ³¹³ are not particularly limited. R ³¹¹ may be located at any of the ortho-position, meta-position and para-position of the phenyl group, and is preferably located at the para-position. R ³¹² may be located at any of the ortho-position, meta-position and para-position of the phenyl group, and is preferably located at the para-position. R ³¹³ may be located at any of the ortho-position, meta-position and para-position of the phenyl group, and is preferably located at the para-position.

In the general formula (31), R ³¹¹ , R ³¹² , and R ³¹³ each preferably represent an alkyl group having 1 or more and 6 or less carbon atoms, and each of them may represent an alkyl group having 1 or more and 3 or less carbon atoms. It is more preferable to represent a methyl group. R1, r2, and r3 preferably represent 0 or 1, respectively.

In the general formula (32), R ³²¹ , R ³²² , R ³²³ , R ³²⁴ , R ³²⁵ , R ³²⁶ , R ³²⁷ , R ³²⁸ , and R ³²⁹ are independently each of a hydrogen atom, a hydroxy group, a halogen atom, or Represents an alkyl group having 1 or more carbon atoms and 6 or less carbon atoms.

Chlorine atoms are preferable as the halogen atoms represented by R ³²¹ , R ³²² , R ³²³ , R ³²⁴ , R ³²⁵ , R ³²⁶ , R ³²⁷ , R ³²⁸ and R ³²⁹ in the general formula (32).

The alkyl group having 1 or more and 6 or less carbon atoms represented by R ³²¹ , R ³²² , R ³²³ , R ³²⁴ , R ³²⁵ , R ³²⁶ , R ³²⁷ , R ³²⁸ and R ³²⁹ in the general formula (32) is a carbon atom. Alkyl groups having a number of 1 or more and 4 or less are preferable, and methyl groups or tert-butyl groups are more preferable.

In the general formula (32), R ³²¹ , R ³²² , R ³²³ , R ³²⁴ , R ³²⁵ , R ³²⁶ , R ³²⁷ , R ³²⁸ , and R ³²⁹ are independently each of a hydrogen atom, a hydroxy group, a halogen atom, or It is preferable to represent an alkyl group having 1 or more and 4 or less carbon atoms.

In the general formula (33), R ³³¹ , R ³³⁵ , R ³³⁶ , and R ³⁴⁰ are each independently substituted with a hydrogen atom and an aryl group having 6 to 14 carbon atoms and having 1 or more carbon atoms. Represents an alkyl group of 6 or less, or a nitro group. R ³³² , R ³³³ , R ³³⁴ , R ³³⁷ , R ³³⁸ , and R ³³⁹ may each be independently substituted with a hydrogen atom and an aryl group having 6 or more and 14 or less carbon atoms. It represents the following alkyl group, aryl group having 6 or more carbon atoms and 14 or less carbon atoms, or nitro group.

As the aryl group having 6 or more and 14 or less carbon atoms represented by R ³³² , R ³³³ , R ³³⁴ , R ³³⁷ , R ³³⁸ and R ³³⁹ in the general formula (33), a phenyl group is preferable.

As the alkyl group having 1 or more and 6 or less carbon atoms represented by R ³³¹ to R ³⁴⁰ in the general formula (33), an alkyl group having 1 or more and 3 or less carbon atoms is preferable, and a methyl group is more preferable. The alkyl group having 1 or more and 6 or less carbon atoms may be substituted with an aryl group having 6 or more and 14 or less carbon atoms.

In the general formula (33), it is preferable that R ³³¹ , R ³³⁵ , R ³³⁶ , and R ³⁴⁰ each represent a hydrogen atom. R ³³² , R ³³³ , R ³³⁴ , R ³³⁷ , R ³³⁸ , and R ³³⁹ each independently have a hydrogen atom, an alkyl group having 1 or more and 3 or less carbon atoms, or an aryl group having 6 or more and 10 or less carbon atoms. It is preferable to represent it.

The additive (31) is represented by the chemical formula (AD1) or (AD6) in order to improve the positive chargeability of the photoconductor when positive charge and negative charge are repeated and the storage property in a high temperature environment. Compounds are preferred. As the additive (32), a compound represented by the chemical formula (AD2) or (AD3) is preferable. As the additive (33), a compound represented by the chemical formula (AD4) or (AD5) is preferable. Hereinafter, the compounds represented by the chemical formulas (AD1) to (AD6) may be described as additives (AD1) to (AD6), respectively.

The melting point of the predetermined additive is preferably 90 ° C. or higher and 300 ° C. or lower, more preferably 100 ° C. or higher and 200 ° C. or lower, and further preferably 117 ° C. or higher and 173 ° C. or lower. Usually, when a low molecular weight compound such as an additive and a binder resin are mixed, the glass transition point of the obtained mixture tends to be lower than the glass transition point of the binder resin itself. However, when the melting point of the predetermined additive is 90 ° C. or higher and 300 ° C. or lower, it is possible to suppress a decrease in the glass transition point of the obtained mixture. Therefore, when the photosensitive layer contains a predetermined additive having a melting point of 90 ° C. or higher and 300 ° C. or lower and a binder resin, it is possible to suppress a decrease in the glass transition point of the photosensitive layer. As a result, deterioration and deformation of the photosensitive layer can be particularly suppressed even in a high temperature environment, and the storability of the photoconductor in a high temperature environment is improved. The melting point of the predetermined additive is measured using, for example, a differential scanning calorimeter (“DSC7020” manufactured by Hitachi High-Tech Science Corporation). The starting point of the measured melting peak is defined as the melting point.

The content of the predetermined additive is preferably larger than 0.0 part by mass and more preferably 0.5 part by mass or more with respect to 100.0 parts by mass of the binder resin. The content of the predetermined additive is preferably 50.0 parts by mass or less, more preferably 30.0 parts by mass or less, based on 100.0 parts by mass of the binder resin.

The additive may contain only a predetermined additive. Further, the additive may further contain an additive other than the predetermined additive described above. Additives other than the prescribed additives include, for example, radical scavengers, singlet scavengers, softeners, surface modifiers, bulking agents, thickeners, dispersion stabilizers, waxes, donors, surfactants, and plasticizers. Agents, sensitizers, electron acceptor compounds, and leveling agents.

(Combination of materials)
In order to improve the positive chargeability when positive charge and negative charge are repeated and the storability in a high temperature environment, the combination of the predetermined additive and the electron transporting agent is the combination No. 1 shown in Table 1. Each of F1 to F19 is preferable. For the same reason, the combination of the predetermined additive and the electron transporting agent is the combination No. 1 shown in Table 1. Each of F1 to F19, and the binder resin is preferably a polycarbonate resin (R1). For the same reason, the combination of the predetermined additive and the electron transporting agent is the combination No. 1 shown in Table 1. Each of F1 to F19, and the binder resin is preferably a polycarbonate resin (R2). For the same reason, the combination of the predetermined additive and the electron transporting agent is the combination No. 1 shown in Table 1. Each of F1 to F19, and the charge generator is preferably Y-type titanylphthalocyanine.

In order to improve the positive chargeability when positive charge and negative charge are repeated and the storage stability in a high temperature environment, the combination of the predetermined additive, the hole transport agent, and the electron transport agent is the combination shown in Table 2. No. Each of G1 to G40 is preferable. For the same reason, the combinations of the predetermined additives, hole transporting agents, and electron transporting agents are the combinations No. 2 shown in Table 2. Each of G1 to G40, and the binder resin is preferably a polycarbonate resin (R1). For the same reason, the combinations of the predetermined additives, hole transporting agents, and electron transporting agents are the combinations No. 2 shown in Table 2. Each of G1 to G40, and the binder resin is preferably a polycarbonate resin (R2). For the same reason, the combinations of the predetermined additives, hole transporting agents, and electron transporting agents are the combinations No. 2 shown in Table 2. Each of G1 to G40, and the charge generator is preferably Y-type titanylphthalocyanine.

The meanings of each term in Tables 1 and 2 below are as follows. "No." is the combination No. Is shown. "HTM" refers to a hole transport agent. "ETM" refers to an electron transport agent.

(Conductive hypokeimenon)
The conductive substrate is not particularly limited as long as it can be used as the conductive substrate of the photoconductor. The conductive substrate may be made of a material having a conductive surface at least. An example of a conductive substrate is a conductive substrate made of a conductive material. Another example of a conductive substrate is a conductive substrate coated with a conductive material. Examples of the conductive material include aluminum, iron, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel, palladium, indium, stainless steel, and brass. These conductive materials may be used alone or in combination of two or more (for example, as an alloy). Among these conductive materials, aluminum and aluminum alloys are preferable because the transfer of electric charges from the photosensitive layer to the conductive substrate is good.

The shape of the conductive substrate is appropriately selected according to the structure of the image forming apparatus. Examples of the shape of the conductive substrate include a sheet shape and a drum shape. Further, the thickness of the conductive substrate is appropriately selected according to the shape of the conductive substrate.

(Middle layer)
The intermediate layer (undercoat layer) contains, for example, inorganic particles and a resin (resin for the intermediate layer) used for the intermediate layer. The presence of the intermediate layer makes it possible to smooth the flow of current generated when the photoconductor is exposed and suppress the increase in resistance while maintaining an insulating state to the extent that leakage generation can be suppressed.

Inorganic particles include, for example, metal (eg, aluminum, iron, and copper) particles, metal oxide (eg, titanium oxide, alumina, zirconium oxide, tin oxide, and zinc oxide) particles, and non-metal oxides. Particles of (eg silica) can be mentioned.

The example of the resin for the intermediate layer is the same as the example of the base resin. In order to satisfactorily form the intermediate layer and the photosensitive layer, it is preferable that the resin for the intermediate layer is different from the base resin and the binder resin contained in the photosensitive layer. The intermediate layer may contain additives. The example of the additive contained in the intermediate layer is the same as the example of the additive contained in the photosensitive layer.

(Manufacturing method of photoconductor)
An example of a method for manufacturing a photoconductor will be described. The method for producing a photoconductor includes a step of forming a photosensitive layer. In the photosensitive layer forming step, a coating liquid for forming the photosensitive layer (hereinafter, may be referred to as a coating liquid for a photosensitive layer) is prepared. The coating liquid for the photosensitive layer is applied onto the conductive substrate. Next, at least a part of the solvent contained in the coated liquid for the photosensitive layer is removed to form the photosensitive layer. The coating liquid for the photosensitive layer contains, for example, a charge generating agent, an electron transporting agent, a hole transporting agent, a binder resin, a predetermined additive, and a solvent. The coating liquid for the photosensitive layer is prepared by dissolving or dispersing a charge generating agent, an electron transporting agent, a hole transporting agent, a binder resin, and a predetermined additive in a solvent. The coating liquid for the photosensitive layer may further contain additives other than the predetermined additives, if necessary.

The solvent contained in the coating liquid for the photosensitive layer is not particularly limited, but is, for example, alcohol (more specifically, methanol, ethanol, isopropanol, butanol, etc.), aliphatic hydrocarbons (more specifically, n). -Hexans, octane, cyclohexane, etc.), aromatic hydrocarbons (more specifically, benzene, toluene, and xylene, etc.), halogenated hydrocarbons (more specifically, dichloromethane, dichloroethane, carbon tetrachloride, etc.), and Chlorobenzene, etc.), ethers (more specifically, dimethyl ether, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, etc.), ketones (more specifically, acetone, methyl ethyl ketone, cyclohexanone, etc.), esters (more specifically). Examples thereof include ethyl acetate, methyl acetate and the like), dimethylformaldehyde, dimethylformamide, and dimethylsulfoxide.

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

The method for applying the coating liquid for the photosensitive layer is not particularly limited, and examples thereof include a dip coating method, a spray coating method, a spin coating method, and a bar coating method.

Examples of the method for removing at least a part of the solvent contained in the coating liquid for the photosensitive layer include heating, depressurization, or combined use of heating and depressurization. More specifically, a method of heat treatment (hot air drying) using a high temperature dryer or a vacuum dryer can be mentioned. The temperature of the heat treatment is, for example, 40 ° C. or higher and 150 ° C. or lower. The heat treatment time is, for example, 3 minutes or more and 120 minutes or less.

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

[Second Embodiment: Image Forming Device]
Next, the image forming apparatus 110, which is an example of the image forming apparatus according to the second embodiment of the present invention, will be described with reference to FIG. FIG. 4 is a cross-sectional view of the image forming apparatus 110.

The image forming apparatus 110 shown in FIG. 4 includes a control device 10 (see FIG. 5), a feeding unit 20, a conveying unit 30, image forming units 40Y, 40M, 40C, and 40K, a transfer unit 60, and a belt. A cleaning unit 70, a fixing unit 80, and a paper ejection unit 90 are provided. The belt cleaning unit 70 will be described in detail in the following description of <printing mode and cleaning mode>.

The control device 10 includes each part of the image forming apparatus 110 (more specifically, a feeding unit 20, a conveying unit 30, an image forming unit 40Y, 40M, 40C, and 40K, a transfer unit 60, a belt cleaning unit 70, and a fixing unit). The operation of the 80 and the paper ejection unit 90) is controlled. The control device 10 is arranged at an appropriate position in the main body housing. The control device 10 includes, for example, a Central Processing Unit (CPU), a Random Access Memory (RAM), a Read Only Memory (ROM), and an input / output interface (not shown). The control device 10 executes control by performing each arithmetic processing based on the detection results of various sensors and a preset program.

The feeding unit 20 includes a cassette 22. The cassette 22 accommodates a plurality of recording media P. The feeding unit 20 feeds the recording medium P from the cassette 22 to the transport unit 30. The recording medium P is, for example, a sheet made of paper, cloth, or a synthetic resin.

The transport unit 30 transports the recording medium P to the image forming units 40Y, 40M, 40C, and 40K.

The image forming units 40Y, 40M, 40C, and 40K have corresponding image carriers 100Y, 100M, 100C, and 100K, charging devices 42Y, 42M, 42C, and 42K, and exposure devices 44Y, 44M, 44C, respectively. And 44K, developing devices 46Y, 46M, 46C, and 46K, cleaning devices 48Y, 48M, 48C, and 48K, and static elimination devices 50Y, 50M, 50C, and 50K. Hereinafter, when it is not necessary to distinguish between them, the subscripts of "Y", "M", "C", and "K" attached to each member of the image forming apparatus 110 will be omitted. For example, when it is not necessary to distinguish, each of the image forming units 40Y, 40M, 40C, and 40K is referred to as an image forming unit 40.

The transfer unit 60 includes four transfer devices 62Y, 62M, 62C, and 62K, a drive roller 64, an endless transfer belt 66, a driven roller 67, and a tension roller 68. The transfer devices 62Y, 62M, 62C, and 62K are arranged on the inner peripheral side of the transfer belt 66, respectively, and face the image carriers 100Y, 100M, 100C, and 100K via the transfer belt 66. The transfer belt 66 is hung on the drive roller 64, the driven roller 67, and the tension roller 68. The transfer belt 66 rotates in the arrowhead direction (clockwise in FIG. 4) due to the rotation of the drive roller 64.

The image carrier 100 is provided at the center of the image forming unit 40. The image carrier 100 is rotatably provided in the arrow direction (counterclockwise direction in FIG. 4). Around the image carrier 100, a charging device 42, an exposure device 44, a developing device 46, a transfer device 62, a cleaning device 48, and the like, are arranged in the order described from the upstream side in the rotation direction of the image carrier 100. A static eliminator 50 is provided.

The image carrier 100 is the photoconductor 1 of the first embodiment. As described above, the photoconductor 1 of the first embodiment can be satisfactorily positively charged even when positively charged and negatively charged are repeated, and is excellent in storage in a high temperature environment. Therefore, by providing such a photoconductor 1 as the image carrier 100, the image forming apparatus 110 can form a good image on the recording medium P.

The charging device 42 charges the surface (for example, the peripheral surface) of the image carrier 100 positively. The charging device 42 is, for example, a scorotron charging device.

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

The developing device 46 supplies toner to the surface of the image carrier 100 and develops the electrostatic latent image as a toner image. The toner is a positively charged toner. The developing device 46 is in contact with the surface of the image carrier 100. That is, the image forming apparatus 110 adopts a contact developing method. The developing device 46 is, for example, a developing roller.

When the developer is a one-component developer, the developer 46 supplies toner, which is a one-component developer, to the electrostatic latent image formed on the image carrier 100. When the developer is a two-component developer, the developing device 46 supplies the electrostatic latent image formed on the image carrier 100 with the toner among the toner and the carrier contained in the two-component developer. The image carrier 100 supports the toner image formed by the supplied toner.

The transfer belt 66 conveys the recording medium P between the image carrier 100 and the transfer device 62. The transfer device 62 transfers the toner image developed by the developing device 46 from the surface of the image carrier 100 to the recording medium P which is the transfer target. At the time of transfer, the surface of the image carrier 100 and the recording medium P are in contact with each other. That is, the image forming apparatus 110 employs a direct transfer method. The transfer device 62 is, for example, a transfer roller.

The image forming unit 40Y and the transfer device 62Y, the image forming unit 40M and the transfer device 62M, the image forming unit 40C and the transfer device 62C, and the image forming unit 40K and the transfer device 62K each put the image forming unit 40K and the transfer device 62K on the recording medium P on the transfer belt 66. Toner images of a plurality of colors (for example, four colors of yellow, magenta, cyan, and black) are sequentially superimposed to form an unfixed toner image.

The cleaning devices 48Y, 48M, 48C, and 48K include corresponding housings 481Y, 481M, 481C, and 481K, as well as cleaning members 482Y, 482M, 482C, and 482K, respectively. The cleaning member 482 is arranged in the housing 481. The cleaning member 482 is in contact with the surface of the image carrier 100. The cleaning member 482 polishes the surface of the image carrier 100 and collects the toner adhering to the surface of the image carrier 100 into the housing 481. In this way, the cleaning device 48 collects the toner adhering to the surface of the image carrier 100. The cleaning member 482 is, for example, a cleaning roller.

The static elimination device 50 eliminates static electricity on the surface of the image carrier 100.

The recording medium P on which the unfixed toner image is formed is conveyed to the fixing unit 80. The fixing portion 80 includes a pressurizing member 82 and a heating member 84. The recording medium P is pressurized and heated by the pressing member 82 and the heating member 84, and the unfixed toner image is fixed to the recording medium P.

The recording medium P on which the toner image is fixed is discharged from the paper ejection unit 90.

<Print mode and cleaning mode>
Next, in addition to FIG. 4, the operation of the image forming apparatus 110 executed in the print mode and the cleaning mode will be described with reference to FIGS. 5 and 6. FIG. 5 is a diagram showing the image carrier 100 and the cleaning member 482 shown in FIG. 4, and the control device 10. FIG. 6 is a time chart showing the control of the cleaning member 482 in the print mode and the cleaning mode. The horizontal axis in FIG. 6 indicates time, and the vertical axis indicates the voltage applied to the cleaning member 482. In FIG. 6, "+" indicated by the vertical axis indicates that a positive voltage is applied, "0" indicates that no voltage is applied, and "-" indicates that a negative voltage is applied. Show that it is.

As already described with reference to FIG. 4, the image forming apparatus 110 includes a control device 10 and a belt cleaning unit 70. Further, as shown in FIG. 5, the image forming apparatus 110 further includes voltage applying devices 200Y, 200M, 200C, and 200K, and contact / detachment mechanisms 300Y, 300M, 300C, and 300K. As already described, when it is not necessary to distinguish between them, the subscripts of "Y", "M", "C", and "K" attached to each member of the image forming apparatus 110 are omitted. I will explain.

The control device 10 controls the voltage applied to the cleaning member 482 by controlling the voltage application device 200.

The belt cleaning unit 70 collects the toner that has moved from the image carrier 100 to the transfer belt 66 in the cleaning mode. The belt cleaning unit 70 includes a belt cleaning roller 72, a toner recovery container 74, and a backup roller 76. The belt cleaning unit 70 is provided below the transfer belt 66. The belt cleaning roller 72 is in contact with the surface (for example, the outer peripheral surface) of the transfer belt 66. The backup roller 76 is arranged so as to sandwich the transfer belt 66 with the belt cleaning roller 72. The belt cleaning roller 72 polishes the surface of the transfer belt 66 (the outer peripheral surface which is the contact surface), and collects the toner adhering to the surface of the transfer belt 66 into the toner collection container 74.

The voltage applying devices 200Y, 200M, 200C, and 200K are connected to cleaning members 482Y, 482M, 482C, and 482K, respectively. The voltage application device 200 applies a voltage to the cleaning member 482.

The contact / detachment mechanisms 300Y, 300M, 300C, and 300K contact or separate the corresponding developing devices 46Y, 46M, 46C, and t with respect to the image carriers 100Y, 100M, 100C, and 100K, respectively.

(Print mode)
Hereinafter, the control by the control device 10 in the print mode and the operation of the image forming device 110 will be described. When a print job including image data is input from an external device (not shown, for example, a personal computer), the control device 10 executes the print mode. In the print mode, the image is printed on the recording medium P.

Specifically, as shown in FIG. 6, at the time t11 when printing in the print mode is started, the control device 10 controls the voltage application device 200 to apply a negative primary voltage to the cleaning member 482. Apply. Further, at time t11, the control device 10 starts the rotational drive of the image carrier 100, the cleaning member 482, and the transfer belt 66. The toner (positively charged toner) remaining on the image carrier 100 after transfer is electrostatically recovered by the cleaning member 482 to which the negative electrode primary voltage is applied.

Specifically, in the print mode, the control device 10 applies a positive voltage to the charging device 42. Then, the charging device 42 charges the surface of the image carrier 100 positively. Therefore, the positively charged toner is electrostatically moved from the surface of the positively charged image carrier 100 to the cleaning member 482 to which the negative voltage is applied, and is recovered.

While continuing to collect toner by the cleaning member 482 to which the negative electrode primary voltage is applied, the control device 10 charges the image carrier 100 that is rotationally driven by the charging device 42, exposes it by the exposure device 44, and develops it. Development by the device 46, transfer by the transfer device 62, and static elimination by the static elimination device 50 are performed. Then, after the unfixed toner image is transferred to the recording medium P conveyed between the image carrier 100 and the transfer device 62, the control device 10 causes the fixing unit 80 to fix the unfixed toner image. An image, which is a fixing toner image, is formed on the recording medium P.

At the time when the image formation of all the image data included in the print job is completed, that is, at the time t12 when the print mode ends, the control device 10 controls the voltage application device 200 to have a negative electrode property on the cleaning member 482. 1 Stop the application of voltage. Further, at time t12, the control device 10 stops the rotational drive of the image carrier 100, the cleaning member 482, and the transfer belt 66. This ends the print mode.

As described in the first embodiment, the photoconductor 1 which is the image carrier 100 is satisfactorily positively charged even when positive charging and negative charging are repeated. Therefore, in the print mode, the surface of the image carrier 100 is charged positively by the charging device 42, and the image carrier 100 is brought into contact with the cleaning member 482 to which the first negative voltage is applied. Even when the potential is repeatedly lowered to the negative electrode property, the photoconductor 1 as the image carrier 100 is suitably charged to a desired positive electrode property in the charging step. As a result, the image forming apparatus 110 including the photoconductor 1 as the image carrier 100 can form a good image even when positive charging and negative charging are repeated.

(Cleaning mode)
Hereinafter, the control by the control device 10 in the cleaning mode and the operation of the image forming device 110 will be described. When the print mode ends, the control device 10 executes the cleaning mode. In the cleaning mode, the toner adhering to the cleaning member 482 is collected after the end of the printing mode.

Specifically, in the first predetermined time T1 (time t12 to t13) of the cleaning mode, the control device 10 controls the contact / detachment mechanism 300 to separate the developing device 46 from the image carrier 100 in the separation direction D1. .. The separation direction D1 is a direction in which the developing device 46 is separated from the image carrier 100.

After the developing device 46 is separated, at time t13 in the cleaning mode, the control device 10 controls the voltage applying device 200 to generate a positive second voltage (voltage having the same polarity as the charging polarity of the toner) of the cleaning member 482. Is applied to. Further, at time t13, the control device 10 starts the rotational drive of the image carrier 100, the cleaning member 482, and the transfer belt 66. As a result, the toner (positively charged toner) adhering to the cleaning member 482 is electrostatically transferred from the cleaning member 482 to which the positive second voltage is applied to the image carrier 100. The toner that has moved to the image carrier 100 moves to the transfer belt 66 as the image carrier 100 rotates. The toner that has moved to the transfer belt 66 is collected by the belt cleaning unit 70 as the transfer belt 66 rotates.

At the second predetermined time T2 (time t13 to t14) in the cleaning mode, a positive second voltage is applied to the cleaning member 482. After that, at time t14, the control device 10 controls the voltage application device 200 to stop the application of the positive electrode second voltage to the cleaning member 482.

In the second predetermined time T2 (time t13 to t14) of the cleaning mode, the control device 10 may not apply a voltage to the charging device 42, or may apply a positive voltage to the charging device 42. good. When a positive voltage is applied to the charging device 42, the positive voltage applied to the charging device 42 is preferably lower than the positive second voltage applied to the cleaning member 482. This is because the positively charged toner is electrostatically and suitably moved from the cleaning member 482 to the charging device 42.

In the third predetermined time T3 (time t14 to t15) of the cleaning mode, the control device 10 continues to rotationally drive the image carrier 100, the cleaning member 482, and the transfer belt 66. Further, at the third predetermined time T3, the control device 10 controls the contact / detachment mechanism 300 to move the developing device 46 in the approaching direction D2. The approach direction D2 is the direction in which the developing device 46 approaches the image carrier 100. Then, at time t15, the control device 10 brings the developing device 46 into contact with the image carrier 100. Further, at time t15, the control device 10 stops the rotational drive of the image carrier 100, the cleaning member 482, and the transfer belt 66. At time t15, the toner that had moved from the cleaning member 482 to the image carrier 100 immediately before stopping the application of the positive electrode secondary voltage moved from the image carrier 100 to the transfer belt 66, and from the transfer belt 66 to the belt. It can be the time when the time until it is collected by the cleaning unit 70 has elapsed. The cleaning mode ends when the rotation drive of the image carrier 100, the cleaning member 482, and the transfer belt 66 is stopped.

As described in the first embodiment, the photoconductor 1 which is the image carrier 100 is satisfactorily positively charged even when positive charging and negative charging are repeated. Such an image carrier 100 is not easily affected by fluctuations in the surface potential. Therefore, even when the potential of the photoconductor rises to the positive electrode due to contact with the cleaning member to which the second positive voltage is applied, when the print mode is executed again after the cleaning mode ends, the print mode is executed again. The image carrier 100 can be suitably charged to a desired positive electrode potential.

The control by the control device 10 in the print mode and the cleaning mode and the operation of the image forming device 110 have been described above. Hereinafter, the control by the control device 10 in the print mode and the cleaning mode will be described in more detail with reference to FIG. 7. FIG. 7 is a flowchart showing the control of the image forming apparatus 110 shown in FIG.

The control device 10 repeatedly executes the process of the flowchart shown in FIG. 7. Specifically, the control device 10 determines whether or not a print job has been input (S101). If no print job is input (No in S101), the processing of the flowchart shown in FIG. 7 ends. When a print job is input (Yes in S101), the print mode is executed. In the print mode, the control device 10 controls the voltage application device 200 to apply a negative first voltage to the cleaning member 482 (S102). At this time, as already described, the positively charged toner remaining on the image carrier 100 is recovered by the cleaning member 482 to which the first negative voltage is applied.

After exiting the print mode, the cleaning mode is executed. In the cleaning mode, the control device 10 separates the developing device 46 from the image carrier 100 (S103). Next, the control device 10 controls the voltage application device 200 to apply a positive second voltage to the cleaning member 482 (S104). At this time, as already described, the positively charged toner adhering to the cleaning member 482 moves to the image carrier 100. Next, the toner transferred to the image carrier 100 is collected by the belt cleaning unit 70 via the transfer belt 66. Next, the control device 10 returns the position of the developing device 46 to bring the developing device 46 into contact with the image carrier 100 (S105). Then, the control device 10 ends the processing of the flowchart shown in FIG. 7.

(Modification example)
The image forming apparatus 110 already described can be changed as shown in the following modification. In the multicolor printing mode for printing a multicolor image, the printing mode and the cleaning mode already described are executed.

On the other hand, unlike the multicolor printing mode, the monochrome printing mode for printing a monochrome image can be executed as follows. In the monochrome printing mode (time t11 to t12 in FIG. 6), the control device 10 controls the voltage application device 200K (black voltage application device) to apply the negative electrode primary voltage to the cleaning member 482K (for black). Apply to the cleaning member). In the monochrome printing mode (time t11 to t12 in FIG. 6), the control device 10 controls the voltage application devices 200Y, 200M, and 200C (voltage application devices for yellow, magenta, and cyan) to have positive positive properties. The third voltage of is applied to the cleaning members 482Y, 482M, and 482C (cleaning members for yellow, magenta, and cyan). The negatively charged recording medium P minute components (for example, paper dust) adhere to the image carriers 100Y, 100M, and 100C (image carriers for yellow, magenta, and cyan) that are not used in the monochrome printing mode. Sometimes. Therefore, by applying a third voltage (positive electrode voltage) to the cleaning members 482Y, 482M, and 482C, the minute components of the negatively charged recording medium P are electrostatically recovered by the cleaning members 482Y, 482M, and 482C. To.

Further, in the second predetermined time T2 (time t13 to t14 in FIG. 6) of the cleaning mode after the monochrome printing mode, the control device 10 controls the voltage application device 200K to obtain a positive second voltage. It is applied to the cleaning member 482K. As a result, the positively charged toner adhering to the cleaning member 482K moves onto the image carrier 100K (black image carrier). In the second predetermined time T2 (time t13 to t14 in FIG. 6) of the cleaning mode after the monochrome printing mode, the control device 10 controls the voltage application devices 200Y, 200M, and 200C to obtain a negative electrode fourth voltage. Is applied to the cleaning members 482Y, 482M, and 482C. As a result, the minute components of the negatively charged recording medium P adhering to the cleaning members 482Y, 482M, and 482C move onto the image carriers 100Y, 100M, and 100C. Next, the toner transferred onto the image carrier 100K and the minute components of the recording medium P transferred onto the image carriers 100Y, 100M, and 100C are collected by the belt cleaning unit 70 via the transfer belt 66. The modified example has been described above.

Although an example of the image forming apparatus has been described above, the image forming apparatus is not limited to the image forming apparatus 110, and for example, the following points can be further changed. The image forming apparatus 110 was a color image forming apparatus, but the image forming apparatus may be a monochrome image forming apparatus. In this case, the image forming apparatus may include, for example, only one image forming unit. Further, although the image forming apparatus 110 has adopted the tandem method, the image forming apparatus may adopt, for example, a rotary method. Although the Scorotron charging device has been described as an example of the charging device 42, the charging device may be a charging device other than the Scorotron charging device (for example, a charging roller, a charging brush, or a Corotron charging device). Although the image forming apparatus 110 has adopted the contact developing method, the image forming apparatus may adopt the non-contact developing method. Although the image forming apparatus 110 has adopted the direct transfer method, the image forming apparatus may adopt an intermediate transfer method.

[Third Embodiment: Process cartridge]
Next, with reference to FIG. 4, the process cartridge of the third embodiment of the present invention will be described. The process cartridge of the third embodiment corresponds to each of the image forming units 40Y, 40M, 40C, and 40K. The process cartridge comprises an image carrier 100.

The image carrier 100 is the photoconductor 1 of the first embodiment. As described above, the photoconductor 1 of the first embodiment can be satisfactorily positively charged even when positively charged and negatively charged are repeated, and is excellent in storage in a high temperature environment. Therefore, by providing such a photoconductor 1 as the image carrier 100, the process cartridge of the third embodiment can form a good image on the recording medium P.

In addition to the image carrier 100, the process cartridge further comprises at least one selected from the group consisting of a charging device 42, an exposure device 44, a developing device 46, a transfer device 62, a cleaning member 482, and a static elimination device 50. You may. The process cartridge is designed to be detachably attached to the image forming apparatus 110. Therefore, the process cartridge is easy to handle, and when the sensitivity characteristics of the image carrier 100 are deteriorated, the process cartridge including the image carrier 100 can be easily and quickly replaced. The process cartridge of the third embodiment has been described above with reference to FIG.

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

First, the following charge generators, electron transport agents, hole transport agents, binder resins, and additives were prepared as materials for forming the photosensitive layer of the photoconductor.

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

(Electronic transport agent)
As the electron transporting agent, the electron transporting agent (ETM1), (ETM2), (ETM6), (ETM7), (ETM8), (ETM9), (ETM19), (ETM22), (ETM23) described in the first embodiment. , (ETM24), (ETM28), and (ETM29) were prepared. Further, as the electron transporting agent used in the comparative example, the compounds represented by the following chemical formulas (ETM32-C) to (ETM37-C) (hereinafter, each of them is referred to as an electron transporting agent (ETM32-C) to (ETM37-C). May be described) was prepared.

(Hole transport agent)
As the hole transporting agent, the hole transporting agents (HTM1) to (HTM10) described in the first embodiment were prepared.

(Binder resin)
As the binder resin, the polycarbonate resins (R1) and (R2) described in the first embodiment were prepared. The viscosity average molecular weights of the polycarbonate resins (R1) and (R2) were both 35,000.

(Additive)
As the additives, the additives (AD1) to (AD6) described in the first embodiment were prepared. Further, as an additive used in the comparative example, a compound represented by the following chemical formula (AD7-C) (hereinafter, may be referred to as an additive (AD7-C)) was prepared. The melting points (unit: ° C.) of each additive are shown in Tables 3 and 4.

<Manufacturing of photoconductor>
Photoconductors (A-1) to (A-28) and (B-1) to (B-8) are prepared by using the above charge generator, electron transport agent, hole transport agent, binder resin, and additive. Manufactured.

(Manufacturing of Photoconductor (A-1))
3 parts by mass of Y-type titanyl phthalocyanine as a charge generator, 70 parts by mass of a hole transport agent (HTM1), 100 parts by mass of a polycarbonate resin (R1) as a binder resin, 35 parts by mass of an electron transport agent (ETM1), an additive ( AD1) 18 parts by mass and 800 parts by mass of tetrahydrofuran as a solvent were mixed for 50 hours using a ball mill to obtain a coating liquid for a photosensitive layer. A coating liquid for a photosensitive layer was applied onto a conductive substrate (aluminum drum-shaped support) by a dip coating method. The applied coating liquid for the photosensitive layer was dried with hot air at 120 ° C. for 60 minutes. In this way, a photosensitive layer (thickness 30 μm) was formed on the conductive substrate to obtain a photosensitive member (A-1). In the photoconductor (A-1), a single photosensitive layer was provided directly on the conductive substrate.

(Manufacturing of Photoreceptors (A-2) to (A-28) and (B-1) to (B-8))
The photoconductor (A-2) was produced by the same method as that for the photoconductor (A-1), except that the additives, hole transport agents, electron transport agents, and binder resins shown in Tables 3 and 4 were used. Each of (A-28) and (B-2) to (B-8) was produced. Further, the photoconductor (B-1) was manufactured by the same method as that for the photoconductor (A-1) except that no additive was used.

<Evaluation of positive chargeability when positive charge and negative charge are repeated>
The positive chargeability of the photoconductor was evaluated when positive charge and negative charge were repeated in an environment of a temperature of 25 ° C. and a relative humidity of 50% RH. A drum sensitivity tester (manufactured by Gentech) was used for this evaluation. The photoconductor was set in the drum sensitivity tester. The drum sensitivity tester was provided with a first charging device, a probe, a second charging device, and a static elimination device from the upstream side in the rotation direction of the photoconductor. The first charging device charges the surface of the photoconductor positively. The first charging device was a scorotron charging device, and the grid voltage was set to + 700V. The probe is provided at the developing position and measures the surface potential of the photoconductor. The second charging device is provided at the cleaning position and charges the surface of the photoconductor negatively. The second charging device was a Corotron charging device, and the applied voltage was set to -5 kV. The static eliminator removes static electricity from the surface of the photoconductor.

The photoconductor was rotated 10 times at a rotation speed of 200 mm / sec with the first charging device for positive charging turned on, the static elimination device turned on, and the second charging device for negative charging turned off. In this way, the positive charge and static elimination of the photoconductor were repeated. The surface potential of the photoconductor was continuously measured using a probe while rotating 10 times. The average value of the surface potentials of the photoconductors for 10 rounds was defined as the charging potential V1 (unit: + V) of the photoconductors before repeating positive charging and negative charging.

Next, the photoconductor was rotated 200 times at a rotation speed of 200 mm / sec with all of the first charging device for positive charging, the static elimination device, and the second charging device for negative charging turned on. In this way, positive charging, static elimination, and negative charging of the photoconductor were repeated. Using a probe, the surface potential of the photoconductor for 10 laps from the 191st lap to the 200th lap was continuously measured. The average value of the surface potentials of the photoconductors for 10 rounds was defined as the charging potential V2 (unit: + V) of the photoconductors after repeating positive charging and negative charging.

Then, from the formula "charge potential decrease amount = V1-V2", the charge potential decrease amount (unit: V) of the photoconductor before and after repeated positive charging and negative charging was calculated. From the amount of decrease in charging potential, it was evaluated whether or not the photoconductor could be satisfactorily positively charged when positive charging and negative charging were repeated based on the following criteria. Tables 3 and 4 show the measured amount of decrease in charging potential and the evaluation results of positive charging property when positive charging and negative charging are repeated.

(Evaluation criteria for positive charge when positive charge and negative charge are repeated)
Evaluation A: The amount of decrease in charging potential is less than 90V.
Evaluation B: The amount of decrease in charging potential is 90 V or more and less than 110 V.
Evaluation C: The amount of decrease in charging potential is 110 V or more.

<Evaluation of high temperature storage>
In an environment of a temperature of 50 ° C. and a relative humidity of 80% RH, a cleaning roller coated with 0.1 g of horse oil was pressed against the photoconductor and stored for 3 days. After storage, horse oil on the surface of the photoconductor was wiped off with ethanol, and the surface of the photoconductor was observed with the naked eye. Then, the presence or absence of cracks and dents on the surface of the photoconductor was confirmed. The high temperature storage property of the photoconductor was evaluated based on the following criteria based on the presence or absence of cracks and dents. The evaluation results of the high temperature storage property are shown in Tables 3 and 4.

(Evaluation criteria for high temperature storage)
Evaluation A: No cracks or dents are observed.
Evaluation B: At least one of cracks and dents was slightly observed, but there was no problem in actual use.
Rating C: At least one of the cracks and dents is clearly observed.

The meanings of each term in Tables 3 and 4 are as follows. "HTM" refers to a hole transport agent. "ETM" refers to an electron transport agent. "Resin" indicates a binder resin. The "value" in the "V1-V2" column indicates the amount of decrease in the charging potential (unit: V) of the photoconductor before and after repeated positive charging and negative charging. "Evaluation" in the "V1-V2" column indicates the evaluation result of the positive chargeability when positive charge and negative charge are repeated. "Evaluation" in the "High temperature storage" column indicates the evaluation result of the high temperature storage property.

As shown in Table 4, the photosensitive layer of the photoconductor (B-1) did not contain any additive. Therefore, as shown in Table 4, the positive chargeability and the high temperature storage property of the photoconductor (B-1) when the positive charge and the negative charge are repeated were both evaluated as C and were poor.

As shown in Table 4, the photosensitive layer of the photoconductor (B-2) contained an additive (AD7-C), but the additive (AD7-C) was not a predetermined additive. Therefore, as shown in Table 4, the positive charging property and the high temperature storage property of the photoconductor (B-2) when the positive charging and the negative charging were repeated were both evaluated as C and were poor.

As shown in Table 4, the photosensitive layers of the photoconductors (B-3) to (B-8) did not contain the electron transporting agent (1). Therefore, as shown in Table 4, the positive chargeability of the photoconductors (B-3) to (B-8) when the positive charge and the negative charge were repeated was evaluated as C, which was poor.

On the other hand, as shown in Table 3, the photosensitive layers of the photoconductors (A-1) to (A-28) are the electron transporting agent (1) (more specifically, the electron transporting agent (ETM1), (ETM2). , (ETM6), (ETM7), (ETM8), (ETM9), (ETM19), (ETM22), (ETM23), (ETM24), (ETM28), or (ETM29)), and predetermined additives (more specifically). In particular, it contained one of the additives (AD1) to (AD6)). Therefore, as shown in Table 3, the positive chargeability of the photoconductors (A-1) to (A-28) when positive and negative charges are repeated, and the storability in a high temperature environment are all evaluated. It was A or B, which was good.

From the above, the photoconductor according to the present invention including the photoconductors (A-1) to (A-28) can be satisfactorily positively charged even when positively charged and negatively charged repeatedly, and has a high temperature. It was shown to be excellent in storage in the environment. Further, it is judged that the process cartridge and the image forming apparatus according to the present invention provided with such a photoconductor can form a good image.

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

1: Photoreceptor (electrophotograph photosensitive member)
2: Conductive substrate 3: Photosensitive layer 10: Control device 42Y, 42M, 42C, 42K: Charging device 44Y, 44M, 44C, 44K: Exposure device 46Y, 46M, 46C, 46K: Developing device 50Y, 50M, 50C, 50K : Static eliminator 62Y, 62M, 62C, 62K: Transfer device 100Y, 100M, 100C. 100K: Image carrier 110: Image forming apparatus 482Y, 482M, 482C, 482K: Cleaning member

Claims (14)

With a conductive substrate and a photosensitive layer,
The photosensitive layer is a single layer and contains a charge generator, an electron transporting agent, a binder resin, a hole transporting agent, and an additive.
The electron transporting agent contains a compound represented by the general formula (1) and contains.
The additive is an electrophotographic photosensitive member containing a compound represented by the general formula (31), (32), or (33).

(In the general formula (1),
R ¹ and R ² are each independently substituted with one or more and five or less substituents selected from the group consisting of a halogen atom, an alkyl group, and an alkoxy group, an aryl group, a hydrogen atom, and an alkyl. Represents a group, a heterocyclic group, an alkoxy group, an aralkyl group, or an allyl group. )

(In the general formula (31), R ³¹¹ , R ³¹² , and R ³¹³ each independently represent an alkyl group having 1 or more and 6 or less carbon atoms, or an alkoxy group having 1 or more and 6 or less carbon atoms, and r1. , R2, and r3 each independently represent an integer of 0 or more and 5 or less.
In the general formula (32), R ³²¹ 、 R ³²² 、 R ³²³ 、 R ³²⁴ 、 R ³²⁵ 、 R ³²⁶ 、 R ³²⁷ 、 R ³²⁸ 、 R 329 and R ³²⁹ are independently each of a hydrogen atom, a hydroxy group and a halogen atom. Or, it represents an alkyl group having 1 or more and 6 or less carbon atoms.
In the general formula (33), R ³³¹ , R ³³⁵ , R ³³⁶ , and R ³⁴⁰ are each independently substituted with a hydrogen atom and an aryl group having 6 or more and 14 or less carbon atoms, and the number of carbon atoms is 1. Representing an alkyl group or nitro group of 6 or less, R ³³² , R ³³³ , R ³³⁴ , R ³³⁷ , R ³³⁸ , and R ³³⁹ are independently hydrogen atoms and aryl groups having 6 or more and 14 or less carbon atoms, respectively. It represents an alkyl group having 1 or more and 6 or less carbon atoms, an aryl group having 6 or more and 14 or less carbon atoms, or a nitro group which may be substituted with. ) In the general formula (1), R ¹ and R ² are independent of each other.
A carbon atom which may be substituted with 1 or more and 5 or less substituents selected from the group consisting of a halogen atom, an alkyl group having 1 or more and 6 or less carbon atoms, and an alkoxy group having 1 or more and 6 or less carbon atoms. Aryl groups of 6 or more and 14 or less,
The electrophotographic photosensitive member according to claim 1, which represents an alkyl group having 1 or more and 6 or less carbon atoms or a heterocyclic group having 5 or more and 14 or less carbon atoms. The compounds represented by the general formula (1) are chemical formulas (ETM1), (ETM2), (ETM6), (ETM7), (ETM8), (ETM9), (ETM19), (ETM22), (ETM23), and so on. The electrophotographic photosensitive member according to claim 1 or 2, which is a compound represented by (ETM24), (ETM28), or (ETM29).

In the general formula (31), R ³¹¹ , R ³¹² , and R ³¹³ each represent an alkyl group having 1 or more and 3 or less carbon atoms, and r1, r2, and r3 represent 0 or 1, respectively.
In the general formula (32), R ³²¹ 、 R ³²² 、 R ³²³ 、 R ³²⁴ 、 R ³²⁵ 、 R ³²⁶ 、 R ³²⁷ 、 R ³²⁸ 、 R 329 and R ³²⁹ are independently each of a hydrogen atom, a hydroxy group and a halogen atom. Or, it represents an alkyl group having 1 or more and 4 or less carbon atoms.
In the general formula (33), R ³³¹ , R ³³⁵ , R ³³⁶ , and R ³⁴⁰ represent hydrogen atoms, respectively, and R ³³² , R ³³³ , R ³³⁴ , R ³³⁷ , R ³³⁸ , and R ³³⁹ , respectively, respectively. The electrophotographic photosensitive member according to any one of claims 1 to 3, which independently represents a hydrogen atom, an alkyl group having 1 or more and 3 or less carbon atoms, or an aryl group having 6 or more and 10 or less carbon atoms. The compound represented by the general formula (31) is a compound represented by the chemical formula (AD1) or (AD6).
The compound represented by the general formula (32) is a compound represented by the chemical formula (AD2) or (AD3).
The electrophotographic photosensitive member according to any one of claims 1 to 4, wherein the compound represented by the general formula (33) is a compound represented by the chemical formula (AD4) or (AD5).

The electrophotographic photosensitive member according to any one of claims 1 to 5, wherein the additive has a melting point of 90 ° C. or higher and 300 ° C. or lower. The hole transporting agent comprises the compound represented by the general formula (21), (22), (23), (24), (25), (26), or (27), claims 1 to 6. The electrophotographic photosensitive member according to any one of the above.

(In the general formula (21), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ each independently represent an alkyl group or a phenyl group having 1 or more and 8 or less carbon atoms. R ¹⁷ and R ¹⁸ each independently represent a hydrogen atom, an alkyl group having 1 or more and 8 or less carbon atoms, or a phenyl group, and b1, b2, b3, and b4 independently represent 0 or more and 5 or less, respectively. B5 and b6 each independently represent an integer of 0 or more and 4 or less, and d and e each independently represent 0 or 1.
In the general formula (22), R ²⁰ is substituted with a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or an alkyl group having 1 to 8 carbon atoms. R ²¹ , R ²² , and R ²³ each independently represent an alkyl group having 1 or more and 8 or less carbon atoms, or an alkoxy group having 1 or more and 8 or less carbon atoms, and f1. , F2, and f3 each independently represent an integer of 0 or more and 5 or less, and f4 represents 0 or 1.
In the general formula (23), R ³¹ , R ³² , R ³³ , R ³⁴ , and R ³⁵ each independently have an alkyl group having 1 or more and 8 or less carbon atoms or an alkoxy group having 1 or more carbon atoms and 8 or less carbon atoms. , G1, g2, g3, g4, and g5 each independently represent an integer of 0 or more and 5 or less.
In the general formula (24), R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , R ⁴⁵ , and R ⁴⁶ each independently have an alkyl group, a phenyl group, or a carbon atom number of 1 to 8 carbon atoms. Represents an alkoxy group of 1 or more and 8 or less, h1, h2, h4, and h5 each independently represent an integer of 0 or more and 5 or less, and h3 and h6 each independently represent an integer of 0 or more and 4 or less. ,
In the general formula (25), R ⁷¹ , R ⁷² , R ⁷³ , and R ⁷⁴ each independently represent an alkyl group having 1 or more and 8 or less carbon atoms, and j1, j2, j3, and j4, respectively. Independently represents an integer between 0 and 5
In the general formula (26), R ⁸¹ , R ⁸² , and R ⁸³ each independently represent an alkyl group having 1 or more and 8 or less carbon atoms, a phenyl group, or an alkoxy group having 1 or more and 8 or less carbon atoms. , R ⁸⁴ and R ⁸⁵ are each independently substituted with an alkyl group having 1 or more and 8 or less carbon atoms, a hydrogen atom, an alkyl group having 1 or more and 8 or less carbon atoms, or 1 carbon atom. 8 or more and 8 or less alkoxy groups are represented, k1, k2, and k3 each independently represent an integer of 0 or more and 5 or less, and k4 and k5 each independently represent 1 or 2.
In the general formula (27), R ⁶¹ , R ⁶² , and R ⁶³ each independently represent an alkyl group having 1 or more carbon atoms and 8 or less carbon atoms, and R ⁶⁴ , R ⁶⁵ , and R ⁶⁶ independently represent each. , A hydrogen atom or an alkyl group having 1 or more and 8 or less carbon atoms. ) The hole transporting agent is represented by the chemical formulas (HTM1), (HTM2), (HTM3), (HTM4), (HTM5), (HTM6), (HTM7), (HTM8), (HTM9), or (HTM10). The electrophotographic photosensitive member according to any one of claims 1 to 7, which comprises the compound to be used.

The electrophotographic photosensitive member according to any one of claims 1 to 8, wherein the charge generator contains a Y-type crystal of titanylphthalocyanine. At least one selected from the group consisting of a charging device, an exposure device, a developing device, a transfer device, a cleaning member, and a static eliminator.
A process cartridge comprising the electrophotographic photosensitive member according to any one of claims 1 to 9. With the image carrier,
A charging device that positively charges the surface of the image carrier,
An exposure apparatus that exposes the surface of the charged image carrier to form an electrostatic latent image on the surface of the image carrier.
A developing device that develops the electrostatic latent image as a toner image, and
A transfer device for transferring the toner image from the image carrier to the transfer target is provided.
The image forming apparatus, wherein the image carrier is the electrophotographic photosensitive member according to any one of claims 1 to 9. A cleaning member that comes into contact with the surface of the image carrier and collects toner adhering to the surface of the image carrier.
Further equipped with a control device for controlling the voltage applied to the cleaning member, the cleaning member is further provided with a control device.
The image forming apparatus according to claim 11, wherein the control device applies a first negative voltage to the cleaning member in a print mode. The image forming apparatus according to claim 12, wherein the control device applies a positive second voltage to the cleaning member in a cleaning mode. The image forming apparatus according to any one of claims 11 to 13, further comprising a static elimination device for statically eliminating the surface of the image carrier.

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