JP2005139339A - Polycarbonate resin, electrophotographic photoreceptor and image-forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polycarbonate resin having high abrasion resistance; to provide an electrophotographic photoreceptor hardly causing abrasion of a photosensitive layer even after repeated operation; and to provide an image-forming device providing a good image without halation of the image. <P>SOLUTION: The polycarbonate resin having a structural unit represented by general formula (1) (wherein, R<SP>1</SP>to R<SP>5</SP>are each a hydrogen atom, an alkyl group, a fluoroalkyl group, a halogen atom or a phenyl group; R<SP>6</SP>is an alkyl group, a fluoroalkyl group, an alkoxy group, a benzyl group or a phenyl group; and k is an integer of 0 or 1) is contained in the photosensitive layer of the electrophotographic photoreceptor used in the image-forming device. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electrophotographic photosensitive member having a photosensitive layer excellent in wear resistance and gas resistance, and an image forming apparatus such as an electrostatic copying machine, a facsimile, and a laser beam printer using the photosensitive member.

  In the image forming apparatus, various photosensitive members having sensitivity in the wavelength region of the light source of the exposure unit used in the apparatus are used. The photosensitive member is driven in a fixed direction by a driving unit, and an image is formed by a charging unit, an exposure unit, a developing unit, and a transfer unit provided along the driving direction. The toner remaining on the surface of the photoreceptor after the transfer is removed by a cleaning unit as necessary. In this series of image forming operations, the photoconductor is highly sensitive to the wavelength range of the light source of the exposure means, and has excellent wear resistance when the above-mentioned means are in contact with the photoconductor. Is required.

  In particular, with the recent increase in the speed of image forming apparatuses, the number of times the above-described operation of the photosensitive member is repeated tends to increase regardless of whether it is a large machine or a small machine. For this reason, durability of the photosensitive member, that is, suppression of wear during repetitive operation and maintenance of sensitivity are important factors for increasing the speed.

  By the way, as a photosensitive layer of a photoreceptor, a layer in which a compound such as a charge generating agent and a charge transporting agent is dispersed in a binder resin is generally used. Photoreceptors with binder resin layers are easier to manufacture than photoconductors that do not use binder resins, such as a-Si layers and aC layers. It is widely used because it has the advantage that the choice of materials such as the agent and the binder resin is diverse and the degree of freedom in functional design is high.

  Patent Document 1 includes a general formula (5):

An electrophotographic photoreceptor containing a resin having a structural unit represented by the following formula (6) in Patent Documents 2 and 3:

A structural unit represented by the general formula (7):

An electrophotographic photosensitive member containing a copolymerized polycarbonate and a hydrazone derivative with a structural unit represented by the formula: Patent Document 4 discloses an electrophotographic photosensitive member including the copolymerized polycarbonate and a benzidine derivative, and Patent Document 5 discloses the copolymerized above. Electrophotographic photoreceptors containing polycarbonate and butadiene derivatives are described respectively. Although these photoconductors show good sensitivity to some extent, the hardness of the binder resin is low and sufficient wear resistance cannot be obtained.

  Patent Document 6 includes general formula (8):

A photoreceptor using a photosensitive layer containing a binder resin having a structural unit represented by the following (hereinafter referred to as structural unit (8)) and a hydrazone derivative (charge transporting agent) is described. The photoconductor exhibits better wear resistance than those using the binder resins described in Patent Documents 1 and 2 above. However, the binder resin having the structural unit (8) has a problem that the compatibility with the hydrazone derivative is not sufficient and the charge transport property is lowered. For this reason, the photoreceptor could not obtain satisfactory sensitivity.

Further, when the charging means and the transfer means are based on corona discharge, a gas such as NOx is generated along with the discharge. The photoreceptors described in Patent Documents 1 to 3 have a problem that the gas resistance is low, and the electrical characteristics are lowered by long-term use.
JP 59-71057 Japanese Patent Laid-Open No. 5-142798 Japanese Patent Laid-Open No. 5-142799 JP-A-5-142800 Japanese Patent Laid-Open No. 5-142801 JP 63-261267 A

  As described above, the photoreceptors described in Patent Documents 1 to 6 have low wear resistance. For this reason, the photosensitive member has a problem that the photosensitive layer is severely worn when image formation is repeated, and image fogging occurs due to deterioration of electrical characteristics.

  Therefore, an object of the present invention is to solve the above technical problems and provide a polycarbonate resin having high wear resistance.

  Another object of the present invention is to provide an electrophotographic photoreceptor in which the photosensitive layer is less worn even during repeated operations.

  Another object of the present invention is to provide an image forming apparatus capable of obtaining a good image without image fogging.

  The polycarbonate resin of the present invention has the general formula (1):

(Wherein R ^{1 to} R ⁵ represent a hydrogen atom, an alkyl group, a fluoroalkyl group, a halogen atom or a phenyl group, R ⁶ represents an alkyl group, a fluoroalkyl group, a benzyl group or a phenyl group, and k is 0 or Indicates an integer of 1.)
It is characterized by having the structural unit represented by (Hereinafter, it describes as structural unit (1).).

  Further, the polycarbonate resin includes a structural unit represented by the general formula (1) and a general formula (2):

(Wherein R ^{7 to} R ¹⁰ each represent a hydrogen atom, an alkyl group, a halogen atom or a phenyl group, X represents a single bond, an oxygen atom, a sulfur atom, an ethylidene group, —CO—, —COO—, —SO— _{, -SO 2 -, - (CH} 2) 2 -, - CR 11 R 12 -, - SiR 13 R 14 -, - SiR 15 R 16 -O- (R 11 ~R 16 each represent a hydrogen atom, an alkyl group, An aryl group or a trifluoromethyl group, provided that R ¹¹ and R ¹² , R ¹³ and R ¹⁴ and R ¹⁵ and R ¹⁶ may be bonded to each other to form a ring.)
And a structural unit represented by the formula (hereinafter referred to as structural unit (2)) may be copolymerized.

  The polycarbonate resin is more suitable for a binder resin for electrophotography because it has higher abrasion resistance than conventional binder resins and has high compatibility with a charge transport agent.

That is, the electrophotographic photoreceptor of the present invention has a support base and a photosensitive layer on the support base, and the photosensitive layer contains the polycarbonate resin according to claim 1, a charge generator, and a charge transport agent. Furthermore, in the electrophotographic photosensitive member of the present invention, the photosensitive layer may have the following configuration.
(1) The photosensitive layer contains the polycarbonate resin of the present invention, a charge generator and a charge transport agent in the same layer, and the charge transport agent contains a compound having a triarylaminostyryl group which is a hole transport agent.
(2) The photosensitive layer contains a diphenoquinone derivative, a stilbenequinone derivative, a dinaphthoquinone derivative, a naphthoquinone derivative, an azoquinone derivative, a silacyclopentadiene derivative, or a naphthalenetetracarboxylic acid diimide derivative that is an electron transport agent.
(3) The photosensitive layer has a charge generation layer containing a charge generation agent, and a charge transport layer containing a polycarbonate resin of the above basic invention and a compound having a triarylaminostyryl group as a charge transfer agent. The transport layer is provided on the top of the photosensitive layer.

  An image forming apparatus according to the present invention includes the electrophotographic photosensitive member according to the present invention and a driving unit that drives the photosensitive member in a certain direction, and a charging unit, an exposing unit, and a developing unit along the driving direction of the photosensitive member. The means and the transfer means are provided in this order. For this reason, in the image forming apparatus, a good image without image fogging can be obtained even if image formation is repeated.

  Since the electrophotographic photosensitive member of the present invention contains the polycarbonate having the structural unit (1) in the photosensitive layer, the photosensitive layer is less worn even during repeated operations and has excellent durability.

  Since the image forming apparatus of the present invention uses an electrophotographic photosensitive member containing a polycarbonate having the structural unit (1) in the photosensitive layer, a good image free from image fogging can be obtained even when image formation is repeated.

The electrophotographic photoreceptor and image forming apparatus of the present invention will be described in detail.
<Polycarbonate resin>
The polycarbonate resin of the present invention is a polymer having the structural unit (1).

  The binder resin having the structural unit (1) may be copolymerized with another structural unit (for example, a structural unit of a binder resin that can be used by mixing the following). In this case, the structural unit (2) is preferably copolymerized.

  When the total binder resin is 100, the blending ratio of the structural unit (1) is preferably 1 to 100 wt%, particularly preferably 5 to 60 wt%.

  The viscosity average molecular weight of the binder resin is preferably 5,000 to 200,000, more preferably 15,000 to 100,000 in terms of A-type polycarbonate (PCA).

Specific examples of those shown as the substituent group among the groups defined by the substituents R ^{1 to} R ¹⁰ in the general formulas (1) to (2) are as follows.

  Examples of the alkyl group include groups having 1 to 3 carbon atoms such as methyl, ethyl, n-propyl, and isopropyl.

  Examples of the fluoroalkyl group include groups in which the above alkyl group is substituted with a fluorine atom. Here, the number of substitution of fluorine atoms is preferably 1 to 3.

  Examples of the halogen atom include fluorine, chlorine, bromine and iodine.

  Examples of the alkoxy group include groups having 1 to 3 carbon atoms such as methoxy, ethoxy, n-propoxy, and isopropoxy.

Here, from the viewpoint of gas resistance and solubility of the resin in an organic solvent, it is particularly preferable that R ¹ is a methyl group and R ^{2 to} R ⁴ are hydrogen atoms. From the viewpoint of wear resistance, R ⁵ and R ⁶ are preferably small substituents. Specifically, R ⁵ is particularly preferably a hydrogen atom or a methyl group, and R ⁶ is particularly preferably a methyl group or an ethyl group.

Specific examples of the substituents R ^{11 to} R ¹⁶ defined by the general formula (2) are as follows.

  Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, n-heptyl, n-octyl and the like. Group having 1 to 8 carbon atoms. Of these, alkyl groups having 1 to 3 carbon atoms such as methyl, ethyl, n-propyl, and isopropyl are preferable.

  Examples of the aryl group include groups having 6 to 18 carbon atoms in the aryl moiety, such as phenyl, tolyl, xylyl, biphenylyl, o-terphenyl, naphthyl, anthryl, phenanthryl.

  The aryl group may have a substituent, specifically, a hydroxyalkyl group, an alkoxyalkyl group, a monoalkylaminoalkyl group, a dialkylaminoalkyl group, a halogen-substituted alkyl group, an alkoxycarbonylalkyl group, a carboxyalkyl group. , An alkanoyloxyalkyl group, an aminoalkyl group, a halogen atom, an amino group, a hydroxy group, an optionally esterified carboxyl group, a cyano group, and the like, a halogen atom similar to the above, an alkyl group, an alkoxy group, an aryl group And an aralkyl group. The substitution position of these substituents is not particularly limited.

  Examples of the cycloalkylidene group include groups having 5 to 12 carbon atoms such as cyclopentylidene, cyclohexylidene, cycloheptylidene, cyclooctylidene, cyclononylidene, cyclodecylidene, cycloundecylidene, and cyclododecylidene.

  Specific examples of the structural unit (1) include the general formula (1-1):

General formula (1-2):

General formula (1-3):

General formula (1-4):

General formula (1-5):

General formula (1-6):

General formula (1-7):

General formula (1-8):

General formula (1-9):

General formula (1-10):

General formula (1-11):

General formula (1-12):

General formula (1-13):

General formula (1-14):

General formula (1-15):

General formula (1-16):

General formula (1-17):

General formula (1-17):

Etc.

  Of the structural units represented by the structural unit (2), those represented by the following general formula are preferably used.

  As a synthesis method of the binder resin having the structural unit (1), the following method can be used. That is, reaction formula (R-1):

(R ^{1 to} R ⁶ are the same as described above.)
As shown in the above, a bisphenol derivative represented by the general formula (1 ′) is synthesized from a phenol derivative and an oxocarboxylic acid ester derivative using hydrochloric acid as a catalyst and water as a solvent. Then, reaction formula (R-2):

(R ^{1 to} R ⁶ are the same as described above.)
As shown in the above, a solution obtained by dissolving the bisphenol represented by the general formula (1 ′) in an aqueous sodium hydroxide solution is mixed with methylene chloride, and a molecular weight regulator (for example, p-tert-butylphenol) is added thereto. . Next, while stirring the mixed solution vigorously, a triethylamine aqueous solution is added as a catalyst to react with phosgene. After completion of the reaction, the reaction product is diluted with methylene chloride, then washed with water and hydrochloric acid, and the organic layer is poured into methanol and purified by reprecipitation to obtain a binder resin having the structural unit (1). .
<Electrophotographic photoreceptor>
(Binder resin)
In the present invention, a polycarbonate resin having the structural unit (1) is used as a binder resin.

In addition, the binder resin not having the structural unit (1) can be used alone or in combination of two or more within a range not impairing the durability of the photosensitive layer. For example, styrene polymer, styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene-maleic acid copolymer, acrylic polymer, styrene-acrylic copolymer, polyethylene, ethylene-vinyl acetate copolymer , Chlorinated polyethylene, polyvinyl chloride, polypropylene, vinyl chloride-vinyl acetate copolymer, polyester, polyamide, polycarbonate, polyarylate, polysulfone, diallyl phthalate resin, ketone resin, polyvinyl butyral resin, polyether resin, etc. Silicone resin, epoxy resin, phenolic resin, urea resin, melamine resin, unsaturated polyester, alkyd resin, polyurethane, other cross-linkable thermosetting resin, epoxy-acrylate, urethane-acrylate Such as photocurable resins, such bets are available.
(Charge transport agent)
In the electrophotographic photoreceptor of the present invention, among the charge transport agents, examples of the hole transport agent include conventionally known benzidine compounds, phenylenediamine compounds, naphthylenediamine compounds, phenanthrenediamine compounds, oxalates. Diazole compounds [such as 2,5-di (4-methylaminophenyl) -1,3,4-oxadiazole], styryl compounds [such as 9- (4-diethylaminostyryl) anthracene], distyryl compounds Carbazole compounds [eg poly-N-vinylcarbazole etc.], pyrazoline compounds [eg 1-phenyl-3- (p-dimethylaminophenyl) pyrazoline etc.], hydrazone compounds [eg diethylaminobenzaldehyde diphenylhydrazone], tri Phenylamine compounds, indole compounds, oxazole compounds Compound, isoxazole compound, thiazole compound, thiadiazole compound, imidazole compound, pyrazole compound, triazole compound, butadiene compound, pyrene-hydrazone compound, acrolein compound, carbazole-hydrazone compound, quinoline- A hydrazone compound, a stilbene compound, a stilbene-hydrazone compound, a diphenylenediamine compound, an organic polysilane compound, or the like can be used.

  Of the above, in particular the general formula (HT):

(In the formula, Ar represents an aryl group, and ^RHT represents a hydrogen atom, an aryl group or an alkyl group.)
A derivative having a triarylaminostyryl group represented by the formula is preferably used. Specifically, the general formula (HT-1):

(Wherein R ^{h1 to} R ^h5 each represents a hydrogen atom, an alkyl group, an alkoxy group or an aryl group, q represents an integer of 0 to 3, and R ^{h1 to} R ^h5 may each be substituted in plural, In this case, the plural substituted groups may be different from each other or may be bonded to each other to form a saturated or unsaturated hydrocarbon ring.)
General formula (HT-2):

(In the formula, R ^{h6 to} R ^h11 represent a hydrogen atom, an alkyl group, an alkoxy group, or an aryl group. R ^{h6 to} R ^h7 may each be substituted more than once, in which case each of the substituted groups is different. Or may be bonded to each other to form a saturated or unsaturated hydrocarbon ring.)
General formula (HT-3):

(In the formula, R ^{h12 to} R ^h17 represent a hydrogen atom, an alkyl group, an alkoxy group or an aryl group. R ^{h12 to} R ^h17 may each be substituted in plural, and in this case, each of the plural substituted groups is different. Alternatively, they may combine with each other to form a saturated or unsaturated hydrocarbon ring, where Y is a general formula (Y-1):

General formula (Y-2):

Or general formula (Y-3):

Indicates. )
Or general formula (HT-4):

( ^Wherein R ^{h18 to} R ^h25 represent a hydrogen atom, an alkyl group, an alkoxy group, or an aryl group. R ^{h18 to} R ^h25 may each be substituted in plural, and in this case, each of the plural substituted groups is different. Or may be bonded to each other to form a saturated or unsaturated hydrocarbon ring.)
The compound etc. which are represented by these are mentioned.

Specific examples of those shown as the substituent group among the groups defined by the substituents R ^{h1 to} R ^h25 in the general formulas (HT-1) to (HT-4) are as follows.

  Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, n-heptyl, n-octyl and the like. Group having 1 to 8 carbon atoms. Of these, alkyl groups having 1 to 3 carbon atoms such as methyl, ethyl, n-propyl, and isopropyl are preferable.

  Examples of the alkoxy group include groups having 1 to 4 carbon atoms such as methoxy, ethoxy, propoxy, butoxy and the like. Of these, alkyl groups having 1 to 3 carbon atoms such as methoxy, ethoxy, and propoxy are preferable.

  Examples of the aryl group include groups having 6 to 14 carbon atoms in the aryl moiety, such as phenyl, tolyl, xylyl, biphenylyl, o-terphenyl, naphthyl, anthryl, phenanthryl.

  The alkyl group, alkoxy group and aryl group may have a substituent. Specifically, a hydroxyalkyl group, an alkoxyalkyl group, a monoalkylaminoalkyl group, a dialkylaminoalkyl group, a halogen-substituted alkyl group, an alkoxycarbonyl group. Alkyl group, carboxyalkyl group, alkanoyloxyalkyl group, aminoalkyl group, halogen atom, amino group, hydroxy group, carboxyl group which may be esterified, cyano group, etc., halogen atom and alkyl group as described above , Alkoxy groups, aryl groups, aralkyl groups and the like. The substitution position of these substituents is not particularly limited.

Further, the substituents R ^{h1 to} R ^h25 may be substituted in plural on each benzene ring. In that case, each of the plurality of substituted groups may be the same or different, and may be bonded to each other to form a saturated or unsaturated hydrocarbon ring.

  Saturated or unsaturated hydrocarbon rings include cyclic hydrocarbons such as cyclopentane structure, cyclohexane structure, cycloheptane structure, cyclooctane structure, benzene structure, pentalene structure, indene structure, azulene structure, naphthalene structure, heptalene structure, biphenylene structure , Indacene structure, acetylnaphthylene structure, fluorene structure, phenalene structure, phenanthrene structure, anthracene structure, furan structure, thiophene structure, 2H-pyrrole structure, pyrrole structure, oxazole structure, isoxazole structure, thiazole structure, isothiazole structure, imidazole Structure, pyrazole structure, furazane structure, pyran structure, pyridine structure, pyridazine structure, pyrimidine structure, pyrazine structure, indole structure, isoindole structure, 1H-indazole structure, 4H- Men structure, quinoline structure, isoquinoline structure, cinnoline structure, quinazoline structure, quinoxaline structure, phthalazine structure, purine structure, pteridine structure, xanthene structure, carbazole structure, phenanthridine structure, acridine structure, phenazine structure, 1,10-phenanthroline structure , Condensed rings such as a dibenzo [b, d] thiophene structure and a dibenzo [b, d] furan structure. A cyclohexane structure and a benzene structure are particularly preferable.

  The ring may be substituted with the same alkyl group or aryl group as described above.

Of the triarylaminostyryl derivatives represented by the general formulas (HT-1) to (HT-4), those represented by the following general formula are preferably used.
General formula (HT-1-1):

General formula (HT-2-1):

General formula (HT-3-1):

General formula (HT-3-2):

General formula (HT-4-1):

  In addition, the hole transport agent may be used alone or in combination of two or more.

  One or more electron transport agents may be contained in the photosensitive layer of the electrophotographic photoreceptor of the present invention. Specific examples include benzoquinone derivatives, diphenoquinone compounds, naphthoquinone compounds, malononitrile, thiopyran compounds, tetracyanoethylene, 2,4,8-trinitrothioxanthone, fluorenone compounds, dinitrobenzene, dinitroanthracene, dinitroacridine, nitro Anthraquinone, succinic anhydride, maleic anhydride, dibromomaleic anhydride, 2,4,7-trinitrofluorenone imine compound, ethylated nitrofluorenone imine compound, tryptoanthrin compound, tryptoanthrin imine compound, aza Fluorenone compounds, dinitropyridoquinazoline compounds, thioxanthene compounds, 2-phenyl-1,4-benzoquinone compounds, 2-phenyl-1,4-naphthoquinone compounds, 5,12-naphthacenequinone compounds, α- Cyanos Examples thereof include an electron transport agent such as a tilbene compound, a 4'-nitrostilbene compound, and a salt of an anion radical and a cation of a benzoquinone compound.

  In particular, diphenoquinone derivatives, stilbenequinone derivatives, dinaphthoquinone derivatives, naphthoquinone derivatives, azoquinone derivatives, silacyclopentadiene derivatives, or naphthalenetetracarboxylic acid diimide derivatives are publicly used because of their high electron transport properties. Furthermore, even if these electron transporting agents are contained in the same layer as the hole transporting agent, particularly the triarylaminostyryl derivative, it is preferable because the charge transporting property of the photosensitive layer is improved.

  Examples of the diphenoquinone derivative include, for example, the general formula (ET-1):

(Wherein R ^{e1 to} R ^e4 represent a hydrogen atom, an alkyl group, an aryl group, or a cycloalkyl group.)
General formula (ET-2):

(Wherein R ^e5 and R ^e6 represent a hydrogen atom, an alkyl group, an aryl group or a cycloalkyl group.)
The compound etc. which are represented by these are mentioned.

  Examples of stilbene quinone derivatives include general formula (ET-3):

(In the formula, R ^{e7 to} R ^e10 represent a hydrogen atom, an alkyl group, an aryl group, or a cycloalkyl group.)
The compound etc. which are represented by these are mentioned.

  As the dinaphthoquinone derivative, for example, the general formula (ET-4):

( ^Wherein R ^e11 and R ^e12 represent a hydrogen atom, an alkyl group, an aryl group or a cycloalkyl group.)
General formula (ET-5):

( ^Wherein R ^e13 and R ^e14 represent a hydrogen atom, an alkyl group, an aryl group or a cycloalkyl group.)
The compound etc. which are represented by these are mentioned.

  As a naphthoquinone derivative, for example, the general formula (ET-6):

(In the formula, ^Re15 represents a hydrogen atom, an alkyl group, an aryl group or a cycloalkyl group.)
General formula (ET-7):

(In the formula, R ^e16 represents a hydrogen atom, an alkyl group, an aryl group or a cycloalkyl group, and R ^e17 represents an alkyl group, an aryl group or a cycloalkyl group.)
General formula (ET-8)

(In the formula, R ^e18 represents a hydrogen atom, an alkyl group, an aryl group or a cycloalkyl group, and R ^e19 represents an alkyl group, an aryl group or a cycloalkyl group.)
And the like are used.

  As the azoquinone derivative, general formula (ET-9):

( ^Wherein R ^e20 and R ^e21 represent a hydrogen atom, an alkyl group, an aryl group or a cycloalkyl group, and R ^e22 represents a hydrogen atom, an alkyl group, an aryl group, a cycloalkyl group, a halogen atom or a nitro group. ^e22 may be plurally substituted, and in this case, each of the plurally substituted groups may be different.)
General formula (ET-10):

(Wherein, R ^e23 represents a hydrogen atom, an alkyl group, an aryl group or a cycloalkyl group, R ^e24 is a hydrogen atom, an alkyl group, an aryl group, a cycloalkyl group, .R ^e24 indicating a halogen atom or a nitro group more It may be substituted, and in this case, each of a plurality of substituted groups may be different.)
General formula (ET-11):

(In the formula, R ^e25 represents a hydrogen atom, an alkyl group, an aryl group or a cycloalkyl group, and R ^e26 represents a hydrogen atom, an alkyl group, a halogen atom, an aryl group, a cycloalkyl group or a nitro group. R ^e25 and R ^e26 may be plurally substituted, and in this case, the plural substituted groups may be different or may be bonded to each other to form a saturated or unsaturated hydrocarbon ring.)
General formula (ET-12):

(In the formula, R ^{e27 to} R ^e34 represent a hydrogen atom, an alkyl group, an aryl group or a cycloalkyl group. R ^e29 and R ^e32 may be substituted in plural, and in this case, each of the plural substituted groups is different. And may be bonded to each other to form a saturated or unsaturated hydrocarbon ring, and R ^e30 and R ^e31 may be linked to form a ring to form a cycloalkylidene group.)
And the like are used.

  As a silacyclopentadiene derivative, general formula (ET-13):

(In the formula, R ^{e35 to} R ^e42 represent a hydrogen atom, an alkyl group, an alkoxy group, a fluoroalkyl group or an aryl group, and A ¹ and A ² are ═O, ═C (CN), ═C (COOR ^e43 ) _2. (R ^e43 represents an alkyl group) Each of R ^e36 and R ^e42 may be substituted, and in this case, each of the plurality of substituted groups may be different, and R ^{e35 to} R ^e42 And two groups substituted on the same fused ring may combine to form a saturated or unsaturated hydrocarbon ring.)
And the like are used.

  As naphthalene tetracarboxylic acid diimide derivatives, general formula (ET-14):

(In the formula, R ^e43 and R ^e44 represent an alkyl group, an aryl group, or a cycloalkyl group.)
And the like are used.

Specific examples of those shown as the substituent group among the groups defined by the substituents R ^{e1 to} R ^e44 in the general formulas (ET-1) to (ET-14) are as follows.

  Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, n-heptyl, n-octyl and the like. Group having 1 to 8 carbon atoms.

  Examples of the alkoxy group include alkoxy groups having 1 to 6 carbon atoms such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, t-butoxy, pentyloxy, hexyloxy and the like.

  Examples of the aryl group include aryl groups having 6 to 18 carbon atoms in the aryl moiety, such as phenyl, tolyl, xylyl, biphenylyl, o-terphenyl, naphthyl, anthryl, phenanthryl.

  Examples of the fluoroalkyl group include groups in which the above alkyl group is substituted with a fluorine atom. Here, the number of substitution of fluorine atoms is preferably 1 to 3.

  Examples of the halogen atom include fluorine, chlorine, bromine and iodine.

  The alkyl group, alkoxy group and aryl group may have a substituent. Specifically, a hydroxyalkyl group, an alkoxyalkyl group, a monoalkylaminoalkyl group, a dialkylaminoalkyl group, a halogen-substituted alkyl group, an alkoxycarbonyl group. Alkyl group, carboxyalkyl group, alkanoyloxyalkyl group, aminoalkyl group, halogen atom, amino group, hydroxy group, carboxyl group which may be esterified, cyano group, benzyl group, phenylethyl group, etc. The same halogen atom, alkyl group, alkoxy group, aryl group, aralkyl group and the like can be mentioned. The substitution position of these substituents is not particularly limited.

Two or more groups substituted by the same condensed ring or heterocyclic ring among a plurality of R ^e22 , a plurality of R ^e24 , a plurality of R ^e26 , R ^e30 and R ^e31 , R ^{e35 to} R ^e42 are formed by bonding. Cyclic hydrocarbon such as cyclopentane structure, cyclohexane structure, cycloheptane structure, cyclooctane structure, benzene structure, pentalene structure, indene structure, azulene structure, naphthalene structure, heptalene structure, biphenylene structure, indacene structure, acetyl Naphthylene structure, fluorene structure, phenalene structure, phenanthrene structure, anthracene structure, furan structure, thiophene structure, 2H-pyrrole structure, pyrrole structure, oxazole structure, isoxazole structure, thiazole structure, isothiazole structure, imidazole structure, pyrazole structure, Furazane structure, pyran structure, pyridine structure, Dazine structure, pyrimidine structure, pyrazine structure, indole structure, isoindole structure, 1H-indazole structure, 4H-chromene structure, quinoline structure, isoquinoline structure, cinnoline structure, quinazoline structure, quinoxaline structure, phthalazine structure, purine structure, pteridine structure, Examples thereof include condensed rings such as xanthene structure, carbazole structure, phenanthridine structure, acridine structure, phenazine structure, 1,10-phenanthroline structure, dibenzo [b, d] thiophene structure, dibenzo [b, d] furan structure. Among these, a cyclohexane structure and a benzene structure are particularly preferable.

The ring may be substituted with the same alkyl group or aryl group as described above.
(Charge generator)
Examples of the charge generating agent used in the single layer type or multilayer type photosensitive layer include powders of inorganic photoconductive materials such as amorphous inorganic materials (for example, a-silicon, a-carbon, etc.), metal-free phthalocyanines, metals (For example, titanium, copper, aluminum, iron, cobalt, nickel, indium, gallium, tin, zinc, vanadium, etc.) or various phthalocyanines coordinated with metal oxides (such as the above metal oxides such as TiO) Phthalocyanine pigments, azo pigments, bisazo pigments, perylene pigments, ansanthrone pigments, indigo pigments, triphenylmethane pigments, selenium pigments, toluidine pigments, pyrazoline pigments composed of crystals having the following crystal types: And various conventionally known pigments such as quinacridone pigments and dithioketopyrrolopyrrole pigments.

  Of the above, it is preferable to use metal-free phthalocyanine, titanyl phthalocyanine, and hydroxygallium phthalocyanine.

The charge generating agents can be used alone or in combination of two or more so that the photosensitive layer has sensitivity in the exposure wavelength region.
(Photosensitive layer)
The electrophotographic photoreceptor of the present invention has a photosensitive layer containing the above-described charge generator and a binder resin having the structural unit (1).

  The photosensitive layer includes a single-layer type photosensitive layer and a laminated type photosensitive layer, and any of these can be applied to the present invention.

  Of these, the single-layer type photosensitive layer is composed of a single photoconductive layer containing a charge transfer agent (having a hole transfer agent and an electron transfer agent), a charge generation agent and a binder resin in the same layer. is there. The photosensitive layer is formed by dissolving or dispersing a charge generating agent together with a charge transport agent and a binder resin in an appropriate organic solvent to prepare a coating solution, which is applied on a supporting substrate by a means such as coating, and then dried. Is formed.

  In the present invention, when a hole transport agent is used as the charge transport agent, a positively charged type photosensitive layer is formed, and when an electron transport agent is used, a negatively charged type photosensitive layer is formed. Moreover, when using a positive hole transport agent and an electron transport agent together, it becomes a both-charging type.

  The single-layer type photosensitive layer described above has an advantage that it has a simple layer structure and excellent productivity, can suppress film defects when forming a layer, and can improve optical characteristics with few interlayer interfaces. .

  On the other hand, the laminated photosensitive layer is constituted by laminating a charge transport layer containing a charge transport agent and a charge generation layer containing a charge generator on a support substrate. In addition, a photoconductive layer containing a charge transporting agent together with a charge generating agent may be combined with a charge transporting layer and a charge generating layer. Each layer can be formed by a vapor deposition method such as a CVD method or a coating method.

  There are various combinations of the layered photosensitive layer depending on the order of formation of the charge generation layer, the charge transport layer, etc., and the type of the charge transport agent (hole transport agent or electron transport agent) contained in both layers. In the invention, in order to make maximum use of the wear resistance and gas resistance characteristics of the binder resin, the binder resin is preferably formed on the uppermost portion of the photosensitive layer.

Accordingly, preferred examples of the laminated photosensitive layer include the following.
(a) A laminated photosensitive layer in which a charge generation layer or a photoconductive layer is formed on a support substrate, and a charge transport layer containing a binder resin having the structural unit (1) and a charge transport agent is laminated thereon. .
(b) A laminated photosensitive layer in which a charge transport layer is formed on a support substrate, and a charge generation layer containing a binder resin having the structural unit (1) and a charge generator is laminated thereon.

  The photosensitive layer (a) is determined to be positive, negative, or both charged depending on the blending ratio of the hole transport agent and the electron transport agent contained in the charge transport layer.

  Of the above, the charge transport layer and the photoconductive layer are generally much thicker than the charge generation layer. For this reason, when these layers are formed on the outermost surface, even if the photosensitive layer is worn during repeated image formation, the electrical characteristics are unlikely to change. Therefore, in the multilayer photosensitive layer, the configuration (a) is preferable.

  If necessary, a charge generation layer, a charge transport layer, and a photoconductive layer can be added to the layer configurations (a) and (b).

The laminated photoreceptor described above has the advantages that the functions such as charge generation and charge transport are separated in each layer, so that the constituent materials are not wasted and the sensitivity is easily improved.
(Other materials)
In the photosensitive layer, in addition to the above-described components, various conventionally known additives such as an antioxidant, a radical scavenger, a singlet quencher, an ultraviolet absorber, etc., as long as the electrophotographic characteristics are not adversely affected. Deterioration inhibitors, softeners, plasticizers, surface modifiers, extenders, thickeners, dispersion stabilizers, waxes, acceptors, donors, and the like can be blended. In order to improve the sensitivity of the photosensitive layer, a known sensitizer such as terphenyl, halonaphthoquinones, acenaphthylene, etc. may be used in combination with the charge generator.
(Supporting substrate)
As the support substrate on which the photosensitive layer is formed, various materials having conductivity can be used. For example, iron, aluminum, copper, tin, platinum, silver, vanadium, molybdenum, chromium, cadmium, titanium, nickel , Metal alone such as palladium, indium, stainless steel, brass, resin material on which the metal is deposited or laminated, resin material in which conductive filler such as carbon powder is dispersed, conductive polymer material, aluminum iodide, Examples thereof include glass coated with tin oxide, indium oxide and the like.

The shape of the support substrate may be any of a sheet shape, a belt shape, a drum shape, or the like in accordance with the structure of the image forming apparatus to be used. The substrate itself is conductive or the surface of the substrate is conductive. As long as it has. Further, it is preferable that the support substrate has sufficient mechanical strength when used.
(Formation of photosensitive layer)
The photosensitive layer is formed by various conventionally known vapor deposition methods such as chemical vapor deposition methods such as plasma CVD method and photo CVD method, physical vapor deposition methods such as sputtering method, vacuum vapor deposition method and ion plating method, or coating methods. Can be formed.

  Of these, the coating method may be formed as follows.

  In the single-layer type photosensitive layer, the charge generating agent is preferably contained in a proportion of 0.1 to 50 parts by weight, particularly 0.5 to 30 parts by weight, with respect to 100 parts by weight of the binder resin. Moreover, when it contains a hole transport agent, it is preferable to make it contain in the ratio of 5-500 weight part, especially 25-200 weight part, respectively. When the electron transfer agent is contained, it is preferably contained in a proportion of 5 to 100 parts by weight, particularly 10 to 80 parts by weight, based on 100 parts by weight of the binder resin.

  Moreover, when using an electron transport agent and a hole transport agent together, the total amount is 20-500 weight part with respect to 100 weight part of binder resin, Especially 30-200 weight part is preferable.

  The thickness of the single-layer type photosensitive layer is preferably 5 to 100 μm, particularly preferably about 10 to 50 μm.

  In the charge generation layer of the multilayer photosensitive layer, the charge generation agent is preferably contained in an amount of 5 to 1000 parts by weight, particularly 30 to 500 parts by weight, with respect to 100 parts by weight of the binder resin. When the charge generation layer contains a charge transport agent to form a photoconductive layer, 1 to 200 parts by weight, in particular 5 to 100 parts by weight, when the electron transport agent is contained with respect to 100 parts by weight of the binder resin. It is preferable to make it contain in the ratio of a part. When the hole transport agent is contained, the hole transport agent is preferably contained in an amount of 1 to 500 parts by weight, particularly 25 to 200 parts by weight. When the electron transport agent and the hole transport agent are used in combination, the total amount is preferably 10 to 500 parts by weight, particularly 30 to 200 parts by weight, based on 100 parts by weight of the binder resin.

  In the charge transport layer, when 100 parts by weight of the binder resin contains a hole transporting agent, 10 to 500 parts by weight, particularly 25 to 200 parts by weight, when containing an electron transporting agent. The electron transport agent is preferably contained in an amount of 0.1 to 250 parts by weight, particularly 1 to 150 parts by weight.

  When the electron transport agent and the hole transport agent are used in combination, the total amount is preferably 10 to 500 parts by weight, particularly 30 to 200 parts by weight, based on 100 parts by weight of the binder resin.

  The thickness of the laminated photosensitive layer is preferably 0.01 to 5 μm, particularly about 0.1 to 3 μm for the charge generation layer, and 2 to 100 μm, particularly about 5 to 50 μm for the charge transport layer.

  A range that does not impair the characteristics of the photoreceptor between the single-layer or multilayer organic photosensitive layer and the conductive substrate or between the charge generation layer and the charge transport layer constituting the multilayer photosensitive layer. An intermediate layer and a barrier layer may be formed.

  When each layer constituting the photoreceptor is formed by a coating method, the charge generator, charge transport agent, binder resin and the like exemplified above, together with the organic solvent such as tetrahydrofuran described above, a known method, for example, A coating solution may be prepared by dispersing and mixing using a roll mill, ball mill, attritor, paint shaker or ultrasonic disperser, and this may be applied and dried by known means.

  Examples of the organic solvent for preparing the coating liquid include alcohols such as methanol, ethanol, isopropanol and butanol, aliphatic hydrocarbons such as n-hexane, octane and cyclohexane, and aromatic carbonization such as benzene, toluene and xylene. Halogenated hydrocarbons such as hydrogen, dichloromethane, dichloroethane, carbon tetrachloride, chlorobenzene, ethers such as dimethyl ether, diethyl ether, tetrahydrofuran, 1,4-dioxane, 1,3-dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, acetone, 1 type of ketones such as methyl ethyl ketone and cyclohexanone, esters such as ethyl acetate and methyl acetate, dimethylformaldehyde, dimethylformamide and dimethyl sulfoxide 2 or more, and the like.

Furthermore, in order to improve the dispersibility of the charge transport agent or charge generator and the smoothness of the surface of the photosensitive layer, a surfactant, a leveling agent or the like may be added to the coating solution.
<Image forming apparatus>
FIG. 1 schematically shows an example of an image forming apparatus implemented in the present invention. Reference numeral 1 denotes the above-described electrophotographic photosensitive member (the photosensitive layer 11 is formed on the support base 10), and its axis 13 is connected to the driving means 14 via a gear and a pulley in one direction ( It rotates at a constant speed in the direction of arrow A). A main charging unit 2, an exposure unit 3, a developing unit 4, and a transfer unit 5 are provided in this order around the photosensitive member 1 in the driving direction, that is, the rotation direction. Further, as shown in FIG. 1, separation means 6, static elimination means 7, and cleaning means 9 may be provided as necessary.

  Further, the image forming apparatus of the present invention is provided with a fixing unit 12 so that the toner image is fixed to the transfer medium 8 onto which the toner image has been transferred.

  When forming an image, the surface of the photoreceptor 1 is first uniformly charged by the charging means 2. Next, the surface of the photoconductor 1 is exposed along the exposure axis 31 by the exposure means 3, and an electrostatic latent image corresponding to the document image is formed. Since the image forming apparatus uses the above-described electrophotographic photosensitive member, the potential with respect to the ground portion of the photosensitive member 1 (hereinafter referred to as a surface potential) quickly decreases to the value of the bright potential. The non-image area that has not been exposed is stabilized at the dark potential value with almost no decrease in the surface potential.

  Thereafter, the developing means 4 develops the toner by attaching it to the portion corresponding to the electrostatic latent image. Then, the toner image on the surface of the photoreceptor 1 is transferred onto the transfer medium 8 conveyed (in the direction of arrow B) by the transfer means 5. After the transfer, the transfer medium 8 is separated from the photoconductor 1 by the separating unit 6 and then fixed by toner by the fixing unit 12.

  After the transfer, the toner that cannot be transferred onto the transfer medium 8 and remains on the surface of the photoreceptor 1 is removed by the cleaning means 9. Thereafter, the residual potential on the surface of the photosensitive member 1 is removed by the neutralizing light 71 from the neutralizing unit 7 and charged again by the charging unit 2.

  As the charging means 2, a conventionally known method such as a method of applying a high voltage to a charge wire provided close to the surface of the photosensitive member 1 to perform corona discharge, or a charging member such as a conductive roller or a charging brush is used as the photosensitive member 1. A method of applying a charge to the photosensitive member 1 by contacting the surface is applied. In order to keep the surface potential at the main charging portion constant, a method in which a charging member is brought into contact with the surface of the photoconductor 1 or a grid electrode is provided between the charge wire of the main charger and the photoconductor 1 to corona discharge. It is preferable to use the method of performing.

  The main charging voltage applied from the charging unit 2 to the photoconductor 1 varies depending on the characteristics of the photoconductor 1 and toner, development conditions, and the like. For example, in the case of a general positive charge type photoconductor, the grounding portion on the surface of the photoconductor 1 is used. What is necessary is just to set so that the electric potential difference with respect to may be + 300V to + 1000V.

  As the exposure means 3, a laser beam having a wavelength at which the photosensitive member 1 exhibits sensitivity is generally used. Specifically, light having a wavelength that the charge generating agent absorbs may be used. For example, when a phthalocyanine pigment is used as the charge generator, a laser beam having a wavelength of about 600 nm to 850 nm, a perylene pigment of about 400 to 600 nm, and a bisazo pigment of about 400 to 700 nm is used.

  The exposure amount should be set so that the light potential is as low as possible. Specifically, the exposure is performed so that the light potential of the photosensitive member 1 is the same polarity as the potential of the main charged photosensitive member 1 with respect to the ground, and in addition, preferably 0 to 500 V, more preferably 0 to 300 V. The amount should be set.

  As the developing means 4, a conventionally known contact or non-contact developing apparatus can be used, and any of dry and wet methods can be used. The developer used for the developing means 4 may be either a one-component system or a two-component system.

  As the transfer means 5, any conventionally known contact transfer or non-contact transfer method can be applied. Specifically, a transfer voltage is applied to the photoreceptor 1 via the transfer medium 8 by a charger, a roller, a brush, a plate, or the like.

  As the separating means 6, as with the charging means 2, those using a corona discharge with a charge wire, those using a conductive roller, etc. can be used, and those using a corona discharge are preferably used. The separation voltage applied to the photoreceptor 1 by the separation means 6 is generally an alternating current.

  In the case where the static elimination means 7 is provided, a conventionally known static elimination lamp such as an LED array or a fluorescent tube can be used. As the charge eliminating lamp, a lamp that emits a sufficient amount of light to remove residual charges on the surface of the photoconductor 1 at a wavelength with which the photoconductor 1 has sensitivity may be used.

  In the case where the cleaning means 9 is provided, a conventionally known mechanism such as a blade method, a fur brush method, a roller cleaning method, or the like can be used with a simple mechanism and good toner removal efficiency.

  As the fixing means 12, conventionally known methods such as heat fixing, pressure fixing, heat pressure fixing, flash fixing, etc. may be used.

Hereinafter, the present invention will be described based on examples and comparative examples.
(Synthesis Example 1)
Synthesis example of polycarbonate copolymer 1,1-bis (4-hydroxyphenyl) cyclohexane 107.26g (0.40mol) dissolved in 6wt% sodium hydroxide aqueous solution 680ml and methylene chloride 310ml were mixed and stirred While cooling, phosgene gas was blown into the liquid for 20 minutes at a rate of 1.0 liter for 1 second. Subsequently, this reaction liquid was left and separated to obtain a methylene chloride solution of an oligomer having a degree of polymerization of 2 to 4 in the organic layer and having a chloroformate group at the molecular end. Methylene chloride was added to the resulting methylene chloride solution of the oligomer to make a total volume of 560 ml. Thereafter, 45 g (0.15 mol) of bisphenol represented by the above general formula (1-2) was mixed with a solution in 120 ml of a 10 wt% aqueous sodium hydroxide solution, and this was mixed with p-tert-butylphenol 2.0 as a molecular weight regulator. g (0.013 mol) was added. Next, 3 ml of a 6 wt% triethylamine aqueous solution was added as a catalyst while vigorously stirring the mixed solution, and the reaction was performed at 30 ° C. with stirring for 2.0 hours. After completion of the reaction, the reactive organism was diluted with 1.5 liters of methylene chloride, then washed twice with 2.0 liters of water and three times with 1 liter of 0.01N hydrochloric acid, and the organic layer was poured into methanol for reprecipitation purification. General formula (Resin-1):

(Viscosity average molecular weight: PCA conversion 50,100) was obtained.

The polymer thus obtained was a polymer having a viscosity average molecular weight of 50,100 in terms of PCA from the intrinsic viscosity by methylene chloride. Further, this polymer was confirmed to be a polycarbonate copolymer having the following repeating units and copolymer composition by 1H-NMR spectrum analysis.
(Synthesis example 2)
The general formula (Resin-2) is the same as in Synthesis Example 1 except that 40.8 g (0.15 mol) of bisphenol represented by the general formula (1-10) is used instead of the general formula (1-2):

A binder resin represented by the formula (viscosity average molecular weight: 49,900 in terms of PCA) was obtained.
(Synthesis Example 3)
Instead of the general formula (1-2), the general formula (Resin-3) is the same as the synthesis example 1 except that 47.1 g (0.15 mol) of bisphenol represented by the general formula (1-3) is used:

A binder resin represented by the formula (viscosity average molecular weight: 51,100 in terms of PCA) was obtained.
(Synthesis Example 4)
In the same manner as in Synthesis Example 1 except that 112.8 g (0.40 mol) of 1,1-bis (3-methyl-4-hydroxyphenyl) cyclopentane was used instead of 1,1-bis (4-hydroxyphenyl) cyclohexane. General formula (Resin-4):

Was obtained (viscosity average molecular weight: 50,000 in terms of PCA).
(Synthesis Example 5)
In the same manner as in Synthesis Example 1, except that 102.4 g (0.40 mol) of 2,2-bis (3-methyl-4-hydroxyphenyl) propane was used instead of 1,1-bis (4-hydroxyphenyl) cyclohexane. General formula (Resin-5):

(Viscosity average molecular weight: PCA conversion 49,700) was obtained.
(Synthesis Example 6)
Instead of 1,1-bis (4-hydroxyphenyl) cyclohexane, 84.6 g (0.30 mol) of 1,1-bis (4-hydroxyphenyl) cyclohexane and 18.6 g (0.10 mol) of 4,4′-biphenol were used. In addition, the general formula (1-2) was changed to 30 g (0.10 mol), and 4,4′-biphenol 9.3 g (0.05 mol) was used at the same time as in Synthesis Example 1, except that the general formula (Resin-6):

(Viscosity average molecular weight: PCA conversion 50,500) was obtained.
(Synthesis Example 7)
The usage amount of the general formula (1-2) was changed to 30 g (0.10 mol), and 13.4 g (0.05 mol) of 1,1-bis (4-hydroxyphenyl) cyclohexane and the general formula (3 ′):

In the same manner as in Synthesis Example 1 except that 3.9 g (0.0015 mol) of a cyclohexane-containing diphenol represented by general formula (Resin-7):

(In the formula, -A- represents the general formula (3):

Is a structural unit represented by )
A binder resin represented by the formula (viscosity average molecular weight: 47,500 in terms of PCA) was obtained.
(Synthesis Example 8)
In Synthesis Example 6, 16.0 g of 2,7-dihydroxynaphthalene was used instead of 18.6 g of 4,4′-biphenol used in the first reaction with phosgene, and 9.3 g of 4,4′-biphenol used in the latter reaction was used. In the same manner as in Synthesis Example 6 except that 8.0 g of 2,7-dihydroxynaphthalene was used, the general formula (Resin-8):

(Viscosity average molecular weight: PCA conversion 50,500) was obtained.
(Examples 1-28 and Comparative Examples 1-4)
2.5 parts by weight of charge generating agent, 50 parts by weight of hole transporting agent, 35 parts by weight of electron transporting agent, 100 parts by weight of binder resin, and 0.1 weight of dimethyl silicone oil (KF-96-50CS manufactured by Shin-Etsu Chemical Co., Ltd.) as a leveling agent Part (However, in Example 26, 2.5 parts by weight of Pigment Orange 11 together with the above) was dispersed or dissolved in a ball mill for 50 hours together with 750 parts by weight of tetrahydrofuran to prepare a coating solution for a single-layer type photosensitive layer. Then, this coating solution was applied by dipping onto an aluminum base tube as a support substrate, dried with hot air at 140 ° C. for 20 minutes, and Examples and Comparative Examples consisting of a single photosensitive layer with a thickness of 30 μm A single layer type photoreceptor was prepared.

Here, the charge generating agent, hole transporting agent, electron transporting agent and binder resin used in each example are as shown in Table 1. In Table 1, XH ₂ Pc is X-type metal-free phthalocyanine, Y-TiOPc is Y-type titanyl phthalocyanine, α-TiOPc is α-type titanyl phthalocyanine, V-Ga (OH) Pc is V-type hydroxygallium phthalocyanine, II-GaClPc is Type II chlorogallium phthalocyanine, Resin-9:

Resin-10, a binder resin formed by repeating structural units represented by:

The binder resin represented by each is shown.

(Evaluation of photoconductor)
Using a drum sensitivity tester manufactured by GENTEC, an applied voltage was applied to the surface of the photoconductor produced in the above-mentioned Examples and Comparative Examples, and the surface was charged to + 850V. Then, when monochromatic light with a wavelength of 780 nm (half-width 20 nm, light intensity 1.0 μJ / cm ² ) extracted from the white light of the halogen lamp, which is the exposure light source, using a band-pass filter, 0.5 seconds passed from the start of exposure. The surface potential was measured as sensitivity. The lower the absolute value of sensitivity, the higher the sensitivity of the photoreceptor.

  In addition, the photosensitive member obtained in the example and the comparative example was set to off with the electrostatic copying machine (KM-4530 modified machine manufactured by Kyocera Mita Co., Ltd.) with the charging correction by the potential sensor turned off. ), And after initial setting, a single copy was performed for 1200 minutes. Thereafter, the image was output, and the image fogging of the blank paper portion was visually evaluated according to the following criteria.

  A: There was no image fogging.

  ◯: Slight image fogging was observed, but at a level where there was no practical problem.

  (Triangle | delta): The image fog was a level which can be recognized at a glance.

  X: Occurrence of image fogging was remarkable.

  After the image evaluation was completed, the amount of abrasion of the photosensitive layer on the photoreceptor was measured.

The electrostatic copying machine has the following settings.
・ Charging: Scorotron (initial surface potential approx. + 700V)
・ Exposure: Laser light ・ Development: Reversal development (Development bias potential + 50V)
・ Transfer: Transfer charger ・ Cleaning: Cleaning blade method ・ Static elimination: Static elimination lamp (LED)
-Separation: Charge wire-Fixing: Thermal pressure fixing Table 1 shows the measurement results of the amount of photoconductor abrasion and image evaluation.

  From Table 1, the photoconductors of the examples showed good results with a small amount of wear. In addition, a good image without image fog after repeated operations was obtained.

  On the other hand, in the photoreceptors of Comparative Examples 1 and 2 using the binder resin having no structural unit (1), the amount of abrasion of the photosensitive layer was large, and the occurrence of image fog after repeated operations was observed.

1 is a schematic diagram illustrating an example of an image forming apparatus of the present invention.

Claims (6)

General formula (1):

(Wherein R ^{1 to} R ⁵ represent a hydrogen atom, an alkyl group, a fluoroalkyl group, a halogen atom or a phenyl group, R ⁶ represents an alkyl group, a fluoroalkyl group, a benzyl group or a phenyl group, and k is 0 or Indicates an integer of 1.)
A polycarbonate resin having a structural unit represented by: The structural unit represented by the general formula (1) and the general formula (2):

(Wherein R ^{7 to} R ¹⁰ each represent a hydrogen atom, an alkyl group, a halogen atom or a phenyl group, X represents a single bond, an oxygen atom, a sulfur atom, an ethylidene group, —CO—, —COO—, —SO— _{, -SO 2 -, - (CH} 2) 2 -, - CR 11 R 12 -, - SiR 13 R 14 -, - SiR 15 R 16 -O- (R 11 ~R 16 each represent a hydrogen atom, an alkyl group, An aryl group or a trifluoromethyl group, provided that R ¹¹ and R ¹² , R ¹³ and R ¹⁴ and R ¹⁵ and R ¹⁶ may be bonded to each other to form a ring.)
2. The polycarbonate resin according to claim 1, which has a structural unit represented by: 2. An electrophotographic photosensitive member comprising: a supporting substrate; and a photosensitive layer on the supporting substrate, wherein the photosensitive layer contains the polycarbonate resin according to claim 1, a charge generating agent, and a charge transporting agent. The photosensitive layer contains the polycarbonate resin according to claim 1, a charge generator and a charge transport agent in the same layer, and the charge transport agent is a compound having a triarylaminostyryl group which is a hole transport agent, and / or 4. The electrophotographic photosensitive member according to claim 3, comprising a diphenoquinone derivative, a stilbenequinone derivative, a dinaphthoquinone derivative, a naphthoquinone derivative, an azoquinone derivative, a silacyclopentadiene derivative or a naphthalenetetracarboxylic acid diimide derivative which is an electron transport agent. . The photosensitive layer has a charge generation layer containing a charge generation agent, and a charge transport layer containing the polycarbonate resin according to claim 1 and a compound having a triarylaminostyryl group as a charge transfer agent, 2. The electrophotographic photoreceptor according to claim 1, wherein the charge transport layer is provided on the uppermost part of the photosensitive layer. The electrophotographic photosensitive member according to claim 1, and a driving unit that drives the photosensitive member in a certain direction, and the charging unit, the exposing unit, the developing unit, and the transfer unit are arranged along the driving direction of the photosensitive member. An image forming apparatus, which is provided in order.