JPH09329907A - Electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electrophotographic photoreceptor having high sensitivity and high durability by providing the surface of a conductive base with a photosensitive layer contg. a specific arom. polycarbonate resin as an effective component. SOLUTION: The surface of the conductive base is provided with the photosensitive layer contg. the arom. polycarbonate resin consisting of the repeating unit expressed by the formula as the effective component. In the formula, R1 , R2 denote substd. or unsubstd. alkyl groups, substd. or unsubstd. arom. hydrocarbon groups or substd. or unsubstd. heterocyclic groups which may be respectively the same or different. Ar1 denotes the bivalent group of substd. or unsubstd. arom. hydrocarbon; Ar2 denotes the tervalent group of substd. or unsubstd. arom. hydrocarbon and (n) denotes an integer from 2 to 5000. Further, X denotes an aliphat. bivalent group, cyclic aliphat. bivalent group, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photoconductor, and more particularly to a high sensitivity and high durability electrophotographic photoconductor containing a novel aromatic polycarbonate resin as an active ingredient in a photosensitive layer. .

[0002]

2. Description of the Related Art In recent years, organic photoconductors (OPC) have been used in copying machines,
It is often used in printers. As a typical configuration example of the organic photoreceptor, a charge generation layer (CG) is formed on a conductive substrate.
L) and a charge transport layer (CTL) are sequentially laminated. The charge transport layer is a low molecular charge transport material (CT
M) and a binder resin. However,
The inclusion of the low molecular weight charge transport material reduces the mechanical strength originally possessed by the binder resin, which causes abrasion, scratches, cracks, etc. of the photoconductor and impairs the durability of the photoconductor. .

A typical aromatic polycarbonate resin is a polycarbonate resin obtained by reacting 2,2-bis (4-hydroxyphenyl) propane (hereinafter abbreviated as bisphenol A) with phosgene or diphenyl carbonate. Known as one. Polycarbonate resin from such bisphenol A is
Since it has excellent properties in terms of transparency, heat resistance, dimensional accuracy and mechanical strength, it is used in many fields. As one example thereof, various studies have been made as a binder resin for an organic photoconductor used in electrophotography. As a typical configuration example of the organic photoreceptor, there is a laminated photoreceptor in which a charge generation layer and a charge transport layer are sequentially laminated on a conductive substrate. The charge transport layer is formed of a low molecular charge transport material and a binder resin, and many aromatic polycarbonate resins have been proposed as the binder resin. However, the inclusion of the low-molecular charge transport material reduces the mechanical strength originally possessed by the binder resin, which causes deterioration of the photoconductor's wear properties, scratches, cracks, etc., and impairs the durability of the photoconductor. Has become.

On the other hand, as the photoconductive polymer material, polyvinyl anthracene, polyvinyl pyrene, poly-N have long been used.
A vinyl polymer such as vinylcarbazole was investigated as a charge transfer complex type photoreceptor, but it was not satisfactory in terms of photosensitivity. On the other hand, in order to improve the above-mentioned drawbacks of the laminated type photoreceptor, studies have been conducted on a polymer material having a charge transporting ability. For example, an acrylic resin having a triphenylamine structure [M. Stolka et a
L. J. Polym. Sci. , Vol21,
969 (1983)], a vinyl polymer having a hydrazone structure (Japan Hard Copy '89.
P. 67) and a polycarbonate resin having a triarylamine structure (US Pat. Nos. 4,801,517, 4,806,443, 4,806,444, 4,937,165, and 4,959, US Pat. No. 288, No. 5,030,532, No. 5,034,296, No. 5,080,989, JP-A-64-9964
Japanese Patent Laid-Open No. 3-221522, Japanese Patent Laid-Open No. 30445/1990
6, JP-A-4-11627, and JP-A-4-17533.
7, JP-A-4-183719, and JP-A-4-3140.
No. 4, Japanese Patent Laid-Open No. 4-133065).
It has not been put to practical use.

In addition, M. A. Abkowitz et al. Have compared a low molecular weight dispersion type and a polymerized polycarbonate using a tetraarylbenzidine derivative as a model compound, and obtained a result that a polymer system has a drift mobility lower by one digit. Physical Revi
ew B46 6705 (1992)]. Although the cause of this is not clear, it suggests that there are problems in electrical characteristics such as sensitivity and residual potential, although the mechanical strength is improved by polymerizing. Furthermore, an aromatic polycarbonate resin having a benzidine structure (JP-A-64-
Although a photoconductive polymer material such as Japanese Patent No. 9964) has been studied, it has not been put to practical use.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances, and by using a novel aromatic polycarbonate resin having a charge transporting property, high sensitivity and high durability can be obtained. An object is to provide an electrophotographic photoreceptor.

[0007]

According to the present invention, a photosensitive layer containing an aromatic polycarbonate resin comprising a repeating unit represented by the following general formula (1) as an active ingredient is provided on a conductive support. An electrophotographic photosensitive member characterized by the above is provided.

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Further, according to the present invention, the repeating unit is composed of repeating units represented by the following general formulas (2) and (3), and the composition ratio of the repeating units is 0 <k / (k +).
j) A photoreceptor for electrophotography is provided, which is provided with a photosensitive layer containing an aromatic polycarbonate resin of ≦ 1 as an active ingredient.

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Further, according to the present invention, there is provided the electrophotographic photoreceptor, wherein the polycarbonate resin is an aromatic polycarbonate resin comprising a repeating unit represented by the following general formula (4). It

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Furthermore, according to the present invention, the aromatic polycarbonate resin has the following general formulas (5) and (3):
The electrophotographic photosensitive member is characterized in that it is an aromatic polycarbonate resin comprising a repeating unit represented by: and a composition ratio of the repeating unit is 0 <k / (k + j) ≦ 1.

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In the above general formulas (1) to (5), R ₁ ,
R ₂ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon, or a substituted or unsubstituted heterocyclic group, and may be the same or different. n represents an integer of 2 to 5000. X is an aliphatic divalent group, a cycloaliphatic divalent group, or a divalent group represented by the following general formula

Embedded image {In the formula, R ₃ and R ₄ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, or a halogen atom 1, m: each independently an integer of 0 to 4 Y: a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, -O-, -S-, -SO-,
_{-SO 2 -, - CO -,} - CO-O-Z-O-CO-
(In the formula, Z represents an aliphatic divalent group.) Or a divalent group represented by the following general formula.

Embedded image (In the formula, R ₅ and R ₆ are each independently a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic hydrocarbon group, a is an integer of 0 to 20, and b is an integer of 1 to 2000. Represents).

The electrophotographic photoreceptor of the present invention contains an aromatic polycarbonate resin comprising a repeating unit having the above-mentioned specific structure in the photosensitive layer, and the aromatic polycarbonate resin has a charge transporting ability. In addition, since it has high mechanical strength, the photoconductor of the present invention has high sensitivity and high durability.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. As described above, the electrophotographic photoreceptor of the present invention contains the aromatic polycarbonate resin composed of the repeating unit represented by the general formula (I) or the general formulas (2) and (3) in the photosensitive layer. However, this aromatic polycarbonate resin is a novel substance and is produced by the following method.

That is, the aromatic polycarbonate resin having the repeating unit of the above-mentioned specific structure can be produced by the same method as the polymerization of bisphenol and a carbonic acid derivative which is known as a conventional method for producing a polycarbonate resin. First, the aromatic polycarbonate resin composed of the repeating unit represented by the general formula (2) or the general formula (5) has an amino group represented by the following general formula (6) or the general formula (7). Produced by a transesterification method of a diol compound and bisaryl carbonate, a phosgene method by solution or interfacial polymerization with phosgene, or a chloroformate method using a monochloroformate or bischloroformate derived from diol. . At this time, by using together a diol represented by the following general formula (8),
An aromatic polycarbonate resin comprising a repeating unit represented by the general formula (2) and a repeating unit represented by the general formula (3), or a repeating unit represented by the general formula (5) and the general formula An aromatic polycarbonate resin composed of the repeating unit represented by the formula (3) can be produced, and by doing so, an aromatic polycarbonate resin having desired properties can be obtained. Ratio of the repeating unit having an amino group represented by the general formula (2) to the repeating unit represented by the general formula (3), and the repeating unit having an amino group represented by the general formula (5). The ratio of the repeating unit represented by the above general formula (3) can be selected from a wide range depending on desired characteristics. The aromatic polycarbonate resin composed of the repeating unit represented by the general formula (1) or the general formula (4) has an amino group represented by the following general formula (6) or the general formula (7). It can be obtained by interfacial polymerization or solution polymerization of the diol compound having and the bischloroformate derived from the general formula (8). It can also be obtained by polymerizing a bischloroformate derived from a diol compound having an amino group represented by the general formula (6) or the general formula (7) with a diol represented by the general formula (8). .

[0015]

[Chemical 6]

[Chemical 7]

HO-X-OH (8) (The definitions in the formulas (6) to (8) are the same as above).

The aromatic polycarbonate resin will be described in more detail below. The aromatic polycarbonate resin used in the present invention has the general formula (2) or (5) above.
A homopolymer consisting of a repeating unit represented by, or
Alternating copolymers composed of repeating units represented by the general formula (1) or (4), and further represented by the general formulas (2) and (3) or the general formulas (5) and (3). It may be a random or block copolymer having the repeating unit as a constitutional unit. The molecular weight of the aromatic polycarbonate resin used in the present invention is 1,000 to 1,000,000, preferably 5,000 to 500,000 in terms of polystyrene-reduced number average molecular weight.

The above-mentioned general formula () of the raw material which gives each repeating unit represented by the above-mentioned general formulas (1), (2), (4) and (5), which constitutes the aromatic polycarbonate resin used in the present invention, In the diol compound having an amino group and the like represented by 6) and (7), R ₁ , R ₂ , R ₃ , R ₄ and R
_The following can be mentioned as specific examples of the alkyl group in which R ₅ and R ₆ are substituted or unsubstituted. It is a C1 to C5 linear or branched alkyl group, and these alkyl groups further contain a phenyl group substituted with a fluorine atom, a cyano group, a phenyl group or a halogen atom or a C1 to C5 alkyl group. Good. Specifically, methyl group, ethyl group, n-propyl group, i-propyl group, t-butyl group, s-butyl group, n-butyl group, i-butyl group, trifluoromethyl group, 2-cyanoethyl group , Benzyl group,
Examples include 4-chlorobenzyl group and 4-methylbenzyl group.

Further, in the diol compound containing an amino group and the like represented by the general formulas (6) and (7), R ₁ ,
Specific examples of R ₂ , R ₃ , R ₄ , R ₅ , and R _{6 which} are substituted or unsubstituted aromatic hydrocarbon groups include the following. Examples thereof include phenyl group, naphthyl group, biphenylyl group, terphenylyl group, pyrenyl group, fluorenyl group, 9,9-dimethyl-2-fluorenyl group, azulenyl group, anthryl group, triphenylenyl group and chrysenyl group, and these are lower alkyl groups. , A lower alkoxy group and a halogen atom may be substituted. Moreover, the group represented by the following general formula can be mentioned.

Embedded image Wherein, B is -O -, - S -, - SO -, - SO 2 -,
-CO- or the following divalent group is represented.

[Chemical 12]

Embedded image (Here, R ₇ and R ₈ are a hydrogen atom, a substituted or unsubstituted alkyl group, an alkoxy group, a halogen atom, a substituted or unsubstituted aromatic hydrocarbon group, an amino group, a nitro group,
Represents a cyano group, c represents an integer of 1 to 12, and d represents an integer of 1 to 3. )]

Specific examples of R ₇ in the above general formula and R ₈ in the divalent group B are a substituted or unsubstituted alkyl group and a substituted or unsubstituted aromatic hydrocarbon group are the above R ₁ and R 2. It is the same as the definition of ₂ , R ₃ , R ₄ , R ₅ , and R ₆ . Further, specific examples of the amino group include groups represented by the following general formula.

[Chemical 14] (R₉, R_TenIs a substituted or unsubstituted alkyl group,
It represents a substituted or unsubstituted aromatic hydrocarbon group. ) Where R₉, R_TenIn the
Alkyl groups and substituted or unsubstituted aromatic hydrocarbon groups
The specific example is R₁, R₂, R_Three, R_Four, R_Five, R₆Same as
It is like. Also, R₉, R_TenMay jointly form a ring
Yes. In addition, the ring is jointly formed with the carbon atom on the aromatic hydrocarbon group.
You may form. As a concrete example of this, piperidino
Group, morpholino group, and julolidyl group.

Furthermore, when R ₁ and R ₂ are a substituted or unsubstituted heterocyclic group, specific examples of the heterocyclic group are:
Examples thereof include a thienyl group, a benzothienyl group, a furyl group, a benzofuranyl group, and a carbazolyl group. These heterocycles have a substituted or unsubstituted alkyl group defined by R _{1 to} R ₆ and a substituted or unsubstituted aromatic group. It may have a group hydrocarbon group as a substituent.

When R ₃ and R ₄ are halogen atoms,
Specific examples of the halogen atom include fluorine, chlorine and bromine.

Further, in the general formulas (6) and (7), 2
Ar ₁ and Ar ₂ each representing a trivalent or trivalent aromatic hydrocarbon group
As specific examples of, there may be mentioned divalent or trivalent groups derived from the aromatic hydrocarbon groups represented by R _{1 to} R ₆ .

The aromatic hydrocarbon group or the heterocyclic group may have a substituent as described above, and specific examples of the substituent will be given below. (1) Halogen atom, trifluoromethyl group, cyano group, nitro group. (2) Alkyl group; preferably C _{1 to} C _12, especially C ₁
To C ₈ , more preferably a C _{1 to} C ₄ linear or branched alkyl group, and these alkyl groups are furthermore a fluorine atom, a hydroxyl group, a cyano group, a C _{1 to} C ₄ alkoxy group,
It may contain a phenyl group or a phenyl group substituted with a halogen atom, a C ₁ -C ₄ alkyl group or a C ₁ -C ₄ alkoxy group. Specifically, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, a t-butyl group,
s-butyl group, n-butyl group, i-butyl group, trifluoromethyl group, 2-hydroxyethyl group, 2-cyanoethyl group, 2-ethoxyethyl group, 2-methoxyethyl group, benzyl group, 4-chlorobenzyl group Group, 4-methylbenzyl group, 4-methoxybenzyl group and the like. (3) Alkoxy group (-OR ₁₁ ); R ₁₁ represents the alkyl group defined in (2). Specifically, methoxy group, ethoxy group, n-propoxy group, i-propoxy group, t-
Examples thereof include butoxy group, n-butoxy group, s-butoxy group, i-butoxy group, 2-hydroxyethoxy group, 2-cyanoethoxy group, benzyloxy group, 4-methylbenzyloxy group and trifluoromethoxy group.

(4) Aryloxy group; as an aryl group
Examples thereof include a phenyl group and a naphthyl group. This is C₁
~ C_FourAlkoxy group of C₁~ C_FourAlkyl group or
Rogen atoms may be contained as a substituent. Specifically
Is a phenoxy group, a 1-naphthyloxy group, a 2-naphthyl group.
Group, 4-methylphenoxy group, 4-methoxyphenoxy group
Enoxy group, 4-chlorophenoxy group, 6-methyl-2
-A naphthyloxy group etc. are mentioned. (5) Substituted mercapto group or aryl mercapto group;
Specifically, methylthio group, ethylthio group, phenylthio group
Group, p-methylphenylthio group and the like. (6) ; R in the formula₁₂And R₁₃Are each independently defined in (2)
It represents a kill group or an aryl group, and examples of the aryl group are
Examples thereof include a phenyl group and a naphthyl group.
Is C₁~ C_FourAlkoxy group of C₁~ C_FourThe alkyl group of
May contain a halogen atom as a substituent. Also
A ring may be formed in cooperation with the carbon atom on the reel group. Ingredient
Physically, diethylamino group, N-methyl-N-phenyl
Ruamino group, N, N-diphenylamino group, N, N-di
(P-Tolyl) amino group, dibenzylamino group, piperi
Examples thereof include a dil group, a morpholino group, and a julolidyl group. (7) Methylenedioxy group, methylenedithio group, etc.
Alkylenedioxy group or alkylenedithio group, etc.
Is mentioned.

Next, specific examples of the diol represented by the general formula (8) are shown below. 1,3-propanediol,
1,4-butanediol, 1,5-pentanediol,
1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 2-methyl-1,3-
Propanediol, 2,2-dimethyl-1,3-propanediol, 2-ethyl-1,3-propanediol,
Aliphatic diols such as diethylene glycol, triethylene glycol, polyethylene glycol and polytetramethylene ether glycol, and cycloaliphatic diols such as 1,4-cyclohexanediol, 1,3-cyclohexanediol and cyclohexane-1,4-dimethanol are available. Can be mentioned.

As the diol having an aromatic ring,
4,4′-dihydroxydiphenyl, bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 2,2 -Bis (4-hydroxyphenyl) propane, 2,2-bis (3-methyl-4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-
Bis (4-hydroxyphenyl) cyclopentane, 2,
2-bis (3-phenyl-4-hydroxyphenyl) propane, 2,2-bis (3-isopropyl-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (3,5-Dimethyl-4-hydroxyphenyl) propane, 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane, 4,4′-dihydroxydiphenyl sulfone, 4,
4'-dihydroxydiphenylsulfoxide, 4,4 '
-Dihydroxydiphenyl sulfide, 3,3'-dimethyl-4,4'-dihydroxydiphenyl sulfide,
4,4'-dihydroxydiphenyl oxide, 2,2-
Bis (4-hydroxyphenyl) hexafluoropropane, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxyphenyl) xanthene, ethylene glycol-bis (4-hydroxybenzoate), diethylene glycol- Bis (4-hydroxybenzoate), triethylene glycol-bis (4
-Hydroxybenzoate), 1,3-bis (4-hydroxyphenyl) -tetramethyldisiloxane, phenol-modified silicone oil and the like.

The aromatic polycarbonate resin used in the present invention, as described above, has the above general formula (6) or (7).
A diol compound having an amino group or the like represented by and a diol represented by the general formula (8), if necessary, by a transesterification method or a phosgene method, or by the general formula (6), or A method of reacting a diol compound having an amino group or the like represented by (7) with a bischloroformate derived from the diol represented by the general formula (8) in the presence of a solvent and a deoxidizing agent. Can be manufactured by

The above manufacturing method will be described in more detail below. In the transesterification method, a diol compound and a bisaryl carbonate are mixed in the presence of an inert gas, and usually reacted at 120 to 350 ° C under reduced pressure. The degree of reduced pressure is changed stepwise, and finally the phenols produced at 1 mmHg or less are distilled out of the system. The reaction time is usually 1 to
It is about 4 hours. Moreover, you may add a molecular weight regulator and antioxidant as needed. Examples of the bisaryl carbonate include diphenyl carbonate, di-p-tolyl carbonate, phenyl-p-tolyl carbonate and di-p.
-Chlorophenyl carbonate, dinaphthyl carbonate, etc. may be mentioned.

In the phosgene method, the reaction is usually carried out in the presence of a deoxidizing agent and a solvent. As the deoxidizing agent, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, pyridine and the like are used. As the solvent, for example, a halogenated hydrocarbon such as dichloromethane or chlorobenzene is used. In order to accelerate the reaction, for example, a tertiary amine,
A catalyst such as a quaternary ammonium salt can be used,
Examples of the molecular weight regulator include phenol and p-tert.
-It is desirable to use a terminating agent such as butylphenol. The reaction temperature is usually 0 to 40 ° C, and the reaction time is several minutes to
It is 5 hours, and the pH during the reaction is usually preferably maintained at 10 or higher.

When bischloroformate is used, it can be obtained by dissolving a diol compound in a solvent, adding a deoxidizing agent, and adding bischloroformate thereto. Deoxidizing agents include trimethylamine, triethylamine,
Tertiary amines such as tripropylamine and pyridine are used. As the solvent used in the reaction, for example, halogenated hydrocarbons such as dichloromethane, dichloroethane, trichloroethane, tetrachloroethane, trichloroethylene and chloroform, and cyclic ether solvents such as tetrahydrofuran and dioxane are preferable. Further, as the molecular weight modifier, it is desirable to use an end terminating agent such as phenol or p-tert-butylphenol. The reaction temperature is usually 0 to 40 ° C,
The reaction time is several minutes to 5 hours.

Specific examples of the aromatic polycarbonate resin used in the present invention are shown in Table 1 below.

[Table 1- (1)]

[0032]

[Table 1- (2)]

[0033]

[Table 1- (3)]

[0034]

[Table 1- (4)]

Cross-sectional views of the photoconductor of the present invention are shown in FIGS. The photoreceptor of the present invention comprises a photosensitive layer 2 (2 ', 1 or 2 or more of the above aromatic polycarbonate resins.
2 ″, 2 ″ ′ ″, 2 ″ ″ ″, 2 ″ ″ ″ ″), but depending on how these are applied, FIG.
It can be used as shown in FIG. 2, FIG. 3, FIG. 4, FIG. 5 or FIG.

The photosensitive member shown in FIG. 1 comprises a conductive support 1 and a photosensitive layer 2 comprising a sensitizing dye, an aromatic polycarbonate resin, and, in some cases, a binder (binder resin). The aromatic polycarbonate resin here acts as a photoconductive substance, and the generation and transfer of charge carriers required for light attenuation are performed via the aromatic polycarbonate resin. However, since the aromatic polycarbonate resin has almost no absorption in the visible region of light, for the purpose of forming an image with visible light, a sensitizing dye having absorption in the visible region is added for sensitization. There is a need.

The photosensitive member in FIG. 2 has a photosensitive layer 2'wherein a charge generating substance 3 is dispersed on a conductive support 1 in a charge transport medium 4 composed of an aromatic polycarbonate resin alone or in combination with a binder. It is provided. The aromatic polycarbonate resin here alone or in combination with a binder forms a charge transport medium, while the charge generating substance 3
(Charge-generating substances such as inorganic or organic pigments) generate charge carriers. In this case, the charge transport medium 4 is mainly responsible for receiving the charge carriers generated by the charge generating substance 3 and transporting them. In this photoreceptor, the basic condition is that the charge-generating substance and the aromatic polycarbonate resin do not overlap each other mainly in the visible wavelength region. This is because it is necessary to transmit light to the surface of the charge generating substance 3 in order to efficiently generate charge carriers in the charge generating substance 3.
The aromatic polycarbonate resin represented by the general formula (I) has almost no absorption in the visible region, generally absorbs light in the visible region, and when combined with the charge generating substance 3 which generates charge carriers, particularly effectively transports charge. Its characteristic is that it works as a substance. A low molecular weight charge transport material may be used in combination in the charge transport medium 4.

The photosensitive member in FIG. 3 is a photosensitive layer 2 formed by laminating a charge generating layer 5 mainly composed of a charge generating substance 3 on a conductive support 1 and a charge transporting layer 4 containing an aromatic polycarbonate resin. '' Is provided. In this photoreceptor, the light transmitted through the charge transport layer 4 reaches the charge generation layer 5 and the charge carriers are generated in that region, while the charge transport layer 4 receives the charge carriers and carries them. The charge carriers necessary for light attenuation are generated by the charge generating substance 3, and the charge carriers are transported by the charge transport layer 4. Such a mechanism is the same as that explained for the photoconductor shown in FIG. The charge transport layer 4 is formed by using the aromatic polycarbonate resin of the present invention alone or in combination with a binder. Further, the aromatic polycarbonate resin of the present invention may be contained in the charge generation layer 5 in order to increase the charge generation efficiency. For the same purpose, a low molecular weight charge transport material may be used in combination in the photosensitive layer 2 ″. The same applies to the photosensitive layers 2 '"to 2"'"'which will be described later.

The photoreceptor shown in FIG. 4 has a protective layer 6 provided on the charge transport layer 4. In the case of this constitution, the protective layer is formed on the charge transport layer 4 by using the aromatic polycarbonate resin of the present invention or the binder in combination. As a matter of course, it is effective to form it on the low molecular weight dispersion type charge transport layer which has been often used conventionally. A protective layer may be provided on the photosensitive layer 2'shown in FIG.

The photoconductor in FIG. 5 corresponds to the charge generation layer 5 in FIG.
And charge transport layer 4 containing aromatic polycarbonate resin
The stacking order is reversed, and the mechanism of charge carrier generation and transport can be the same as that described above. In this case, in consideration of mechanical strength, the protective layer 6 may be provided on the charge generation layer 5 as shown in FIG.

In order to actually produce the photoreceptor of the present invention, the photoreceptor shown in FIG. 1 is dissolved by dissolving one or more aromatic polycarbonate resins in combination with a binder. A photosensitive layer 2 may be formed by preparing a liquid containing a sensitizing dye, coating the liquid on the conductive support 1, and drying the liquid.

The thickness of the photosensitive layer is 3 to 50 μm, preferably 5 to 20 μm. The amount of the aromatic polycarbonate resin in the photosensitive layer 2 is 30 to 100% by weight,
The amount of the sensitizing dye in the photosensitive layer 2 is 0.1 to 5% by weight, preferably 0.5 to 3% by weight. As the sensitizing dye, there are triarylmethane dyes such as Brilliant Green, Victoria Blue B, Methyl Violet, Crystal Violet, Acid Violet 6B, Rhodamine B, Rhodamine 6G, Rhodamine G Extra, Eosin S, Erythrosine, Rose Bengal, and Fluorescein. Examples include xanthene dyes, thiazine dyes such as methylene blue, and cyanine dyes such as cyanine.

Further, in order to produce the photoreceptor shown in FIG. 2, fine particles of the charge generating substance 3 are dispersed in a solution in which one or more aromatic polycarbonate resins or binders are used in combination and dissolved. Is coated on the conductive support 1 and dried to form the photosensitive layer 2 '.

The thickness of the photosensitive layer 2'is 3 to 50 μm, preferably 5 to 20 μm. The amount of the tertiary amine compound in the photosensitive layer 2'is 40 to 100% by weight, and the amount of the charge generating substance 3 in the photosensitive layer 2'is 0.1 to 10.
It is 50% by weight, preferably 1 to 20% by weight. Examples of the charge generating substance 3 include inorganic pigments such as selenium, selenium-tellurium, cadmium sulfide, cadmium sulfide-selenium, and α-silicon, and examples of organic pigments include CI Pigment Blue 25 (color index CI2118).
0), CI Pigment Red 41 (CI 2120
0), CI Acid Red 52 (CI 4510
0), CI Basic Red 3 (CI4521)
0), an azo pigment having a carbazole skeleton (JP-A-53-53
-95033), an azo pigment having a distyrylbenzene skeleton (JP-A-53-133445), an azo pigment having a triphenylamine skeleton (described in JP-A-53-132347), and dibenzothiophene. Azo pigments having a skeleton (described in JP-A-54-21728), azo pigments having an oxadiazole skeleton (described in JP-A-54-12742), azo pigments having a fluorenone skeleton (JP-A-54). No. 22834), an azo pigment having a bisstilbene skeleton (described in JP-A-54-17733), and an azo pigment having a distyryloxadiazole skeleton (JP-A-54-21).
29), azo pigments having a distyrylcarbazole skeleton (described in JP-A-54-14967).
Azo pigments such as CI Pigment Blue 16
A phthalocyanine-based pigment such as (CI 74100), for example, CIVAT BROWN 5 (CI 73410),
Indigo-based pigments such as CI Eye Bat Dye (CI 73030) and perylene-based pigments such as Argos Scarlet B (manufactured by Bayer) and Indanthren Scarlet R (manufactured by Bayer). These charge-generating substances may be used alone or in combination of two or more.

Further, in order to manufacture the photoreceptor shown in FIG. 3, a charge generating substance is vacuum-deposited on the conductive support 1 or more, or fine particles 3 of the charge generating substance are dissolved in a binder, if necessary. A dispersion liquid dispersed in a different solvent is applied and dried, and if necessary, surface finishing and film thickness adjustment are performed by a method such as buffing to form a charge generation layer 5, and then the charge generation layer 1 is formed thereon. The charge transport layer 4 may be formed by applying a solution in which one or more aromatic polycarbonate resins or binders are used in combination and dissolving, and drying. In addition,
Here, the charge generating material used for forming the charge generating layer 5 is the same as that described for the photosensitive layer 2 '.

The charge generation layer 5 has a thickness of 5 μm or less, preferably 2 μm or less, and the charge transport layer 4 has a thickness of 3 to 50.
μm, preferably 5 to 20 μm is suitable. When the charge generation layer 5 is of a type in which the fine particles 3 of the charge generation layer substance are dispersed in a binder, the proportion of the fine particles 3 of the charge generation substance in the charge generation layer 5 is 10 to 100% by weight, preferably Is about 50 to 100% by weight. The amount of the compound in the charge transport layer 4 is 40 to 100% by weight.

As described above, the photosensitive layer 2 ″ in FIG. 3 may contain a low molecular weight charge transporting substance, and the charge transporting substance used here includes the following. . Oxazole derivatives and oxadiazole derivatives (JP-A-52-139065 and JP-A-52-1)
No. 39066), imidazole derivatives, triphenylamine derivatives (described in JP-A-3-285960), benzidine derivatives (Japanese Patent Publication No. 58-3237).
2), α-phenylstilbene derivatives (described in JP-A-57-73075), and hydrazone derivatives (JP-A-55-154955 and 55-15695).
4, JP-A-55-52063, JP-A-56-81850 and the like), triphenylmethane derivative (described in JP-B-51-10983), anthracene derivative (described in JP-A-51-94829). ), A styryl derivative (JP-A-56-29245 and JP-A-58-19804).
3), carbazole derivatives (JP-A-58)
-58552), pyrene derivatives (JP-A-2
-94812).

To make the photoreceptor shown in FIG.
The protective layer 6 is provided by dissolving and coating the aromatic polycarbonate resin of the present invention, alone or in combination with a binder, on the photoreceptor shown in FIG. The thickness of the protective layer is 0.5
-10 μm is preferred. The amount of the aromatic polycarbonate resin of the present invention in the protective layer 6 is 40 to 100% by weight.

In order to prepare the photoreceptor shown in FIG. 5, a solution in which an aromatic polycarbonate resin or a binder is used in combination and dissolved is coated on the conductive support 1 and dried to form the charge transport layer 4. Then, the charge generation layer 5 is formed on the charge transport layer by coating and drying a dispersion of fine particles of the charge generation layer substance, if necessary, in a solvent in which a binder is dissolved, by a method such as spray coating. Good. The amount ratio of the charge generation layer or the charge transport layer is the same as that described in FIG.
By forming the above-mentioned protective layer 6 on the charge generation layer 5 of the thus obtained photoreceptor, the photoreceptor shown in FIG. 6 can be prepared.

In the production of any of these photoconductors, the conductive support 1 is provided with a metal plate or metal foil such as aluminum, a plastic film on which a metal such as aluminum is vapor-deposited, or a paper subjected to a conductive treatment. Is used. As the binder, polyamide, polyurethane, polyester, epoxy resin, polyketone, condensation resin such as polycarbonate, polyvinyl ketone,
Polystyrene, poly-N-vinylcarbazole, vinyl polymers such as polyacrylamide, etc. are used, but any insulating and adhesive resin can be used. A plasticizer is optionally added to the binder, and examples of such a plasticizer include halogenated paraffin, dimethylnaphthalene, dibutyl phthalate and the like.

Further, the photoreceptor obtained as described above may be provided with an adhesive layer or a barrier layer between the conductive support and the photosensitive layer, if necessary. Materials used for these layers include polyamide, nitrocellulose,
Aluminum oxide and the like, and the film thickness is preferably 1 μm or less.

To make a copy using the photoreceptor of the present invention,
After the photosensitive surface is charged and exposed, it is developed and, if necessary, transferred to paper or the like. The photoreceptor of the present invention has high sensitivity and excellent durability.

[0053]

The present invention will be described below with reference to examples.

[Synthesis of Resin (Compound No. 1 in Table 1) Consisting of Repeating Units Represented by General Formula (1)] 4′-bis (4-methylphenyl) amino-3, under a nitrogen stream.
5-dihydroxystilbene 1.22 g (3.0 mmo
l), triethylamine 0.91 g (9.0 mmol)
Was dissolved in 15 ml of dry tetrahydrofuran and kept at 5 ° C., and 1.10 g (3.0 mmol) of tetramethylene ether glycol bis (chloroformate) was dissolved in 3 ml of dry tetrahydrofuran to give 30
It dripped over minutes. Then, after stirring at room temperature for 3 hours, 0.28 g of a tetrahydrofuran solution of phenol adjusted to 4% was added, and the mixture was further stirred for 1 hour. Then, the precipitated triethylamine hydrochloride is filtered off, and the tetrahydrofuran solution of the filtrate is dropped into methanol,
The precipitated resin was filtered off and dried under reduced pressure. Further, the operation of dissolving the obtained resin in tetrahydrofuran and precipitating it in methanol is repeated twice, dried under reduced pressure and dried to obtain the target aromatic polycarbonate resin represented by the following structural formula (resin No. 1 in Table 1). ) 1.45 g (yield 6
9.0%) was obtained. The Tg of this resin was 44.5 ° C., and the number average molecular weight and weight average molecular weight (in terms of polystyrene) were 13300 and 36000, respectively.

Embedded image The elemental analysis values of the aromatic polycarbonate resin were as follows. C% H% N% Measured value 72.18 7.01 1.84 Calculated value 72.65 6.87 2.00 Infrared absorption spectrum of the above aromatic polycarbonate resin [NaCl liquid film method (cast method)] Is shown in FIG.

Example 1 7.5 parts of a bisazo pigment represented by the following structural formula (A) as a charge generating substance and a polyvinyl butyral resin (UCC)
XYHL) 0.5% tetrahydrofuran solution 5
00 parts were pulverized and mixed in a ball mill, and the resulting dispersion was applied onto an aluminum vapor-deposited polyester film with a doctor blade and air-dried to form a charge generation layer of about 1 μm.

Embedded image On the other hand, as the charge transport material, the compound No. After 2 parts of the aromatic polycarbonate resin of 1 and 8 parts of tetrahydrofuran were mixed and dissolved to form a solution, this was applied onto the charge generation layer using a doctor blade, and 8
Dry at 0 ° C for 2 minutes, then at 120 ° C for 5 minutes to 20μ
m of the electrophotographic photosensitive member of the present invention. 1 was created.

Example 2 In Example 1, the aromatic polycarbonate resin is shown in Table 1.
Compound No. The electrophotographic photoconductor No. 1 of the present invention was operated in the same manner as in Example 1 except that the No. 11 was used. 2 was created.

Example 3 The electrophotographic photosensitive material of the present invention was operated in the same manner as in Example 1 except that the trisazo pigment represented by the following structural formula (B) was used as the charge generating substance used in Example 1. Body No. 3 was created.

Embedded image

Example 4 In Example 3, the aromatic polycarbonate resin was the compound No. 1 in Table 1. Example 3 except that 11 was replaced
The same operation as in No. 1 for electrophotographic photoconductor of the present invention is performed. Created 4.

Example 5 A polyamide resin (CM-8000: manufactured by Toray Industries, Inc.) solution dissolved in a mixed solvent of methanol / butanol was applied onto a 0.2 mm thick aluminum plate with a doctor blade, and naturally dried to a thickness of 0.3 μm. An intermediate layer was provided. The bisazo pigment used in Example 1 was pulverized and dispersed in cyclohexanone, and the resulting dispersion was coated with a doctor blade and dried to form a charge generation layer of about 1 μm. A charge transport layer was formed thereon by the same procedure as in Example 1, and the electrophotographic photosensitive member No. 1 of the present invention was formed. 5 was created.

Examples 6 to 8 The same operations as in Example 5 were carried out except that the aromatic polycarbonate resin and the charge generating substance were changed to those shown in Table 2 in Example 5, respectively. Photoconductor N
o. 6-No. 8 was created.

Next, in order to examine the sensitivity of the thus obtained laminated type electrophotographic photoconductors in the visible region, the electrophotographic photoconductor Nos. Nos. 1 and 2 of the present invention obtained in Examples 1 to 8 were examined. 1 to 8 Electrostatic copying paper tester [SP428 type manufactured by Kawaguchi Electric Co., Ltd.]
After the corona discharge of −6 KV was carried out for 20 seconds in a dark place to charge the battery, the surface potential V was applied after leaving it in the dark for 20 seconds.
po (V) was measured. Then, a tungsten lamp light is irradiated so that the illuminance on the surface of the photoconductor becomes 4.5 lux, and the exposure amount E _1/2 (lu
x · sec) was measured. The results are shown in Table 2.

[0062]

[Table 2]

Further, each of the above photoconductors was charged by using a commercially available electrophotographic copying machine, and then light was irradiated through the original drawing to form an electrostatic latent image, and the latent image was developed using a dry developer. When the obtained image (toner image) was electrostatically transferred onto plain paper and fixed, a clear transferred image was obtained. Even when a wet type developer was used as the developer, a clear transfer image was similarly obtained.

[0064]

The electrophotographic photoreceptor of the present invention contains a novel aromatic polycarbonate resin having a repeating unit of the above-mentioned specific structure in its photosensitive layer, and the aromatic polycarbonate resin has an excellent charge. Since it has transporting ability and excellent mechanical strength, it functions effectively as a photoconductive material as described above, and it is optically or chemically sensitized by a sensitizer such as a dye or Lewis acid. Therefore, the electrophotographic photoreceptor of the present invention has high sensitivity and excellent durability.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a layer structure of an electrophotographic photoreceptor according to the present invention.

FIG. 2 is a schematic cross-sectional view showing another example of the layer structure of the electrophotographic photoreceptor according to the present invention.

FIG. 3 is a schematic cross-sectional view showing another example of the layer structure of the electrophotographic photosensitive member according to the present invention.

FIG. 4 is a schematic cross-sectional view showing another example of the layer structure of the electrophotographic photoreceptor according to the present invention.

FIG. 5 is a schematic cross-sectional view showing another example of the layer structure of the electrophotographic photosensitive member according to the present invention.

FIG. 6 is a schematic cross-sectional view showing another example of the layer structure of the electrophotographic photosensitive member according to the present invention.

FIG. 7 is an infrared absorption spectrum diagram (cast method) of the aromatic polycarbonate resin obtained in Production Example.

[Explanation of symbols]

1 conductive support 2, 2 ', 2'',2''', 2 ''''',
2 ″ ′ ″ ″ ... Photosensitive layer 3 Charge generating substance 4 Charge transport medium or charge transport layer 5 Charge generating layer 6 Protective layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kazuki Nagai 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd. (72) Tomoyuki Shimada 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Chihaya Adachi 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company Ltd. (72) Inventor Akira Katayama 1-3-6 Nakamagome, Ota-ku Tokyo Ricoh Company (72) Inventor Mitsutoshi Anzai 66-2 Horikawa-cho, Sachi-ku, Kawasaki-shi, Kanagawa Hodogaya Chemical Industry Co., Ltd. Industry Co., Ltd.

Claims (4)

[Claims] 1. A photosensitive layer for electrophotography, which comprises a conductive layer and a photosensitive layer containing an aromatic polycarbonate resin comprising a repeating unit represented by the following general formula (1) as an active ingredient. body. Embedded image [Wherein, R ₁ and R ₂ are a substituted or unsubstituted alkyl group,
It represents a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted heterocyclic group, which may be the same or different. Ar ₁ represents a divalent group of a substituted or unsubstituted aromatic hydrocarbon, and Ar ₂ represents a trivalent group of a substituted or unsubstituted aromatic hydrocarbon. n represents an integer of 2 to 5000. X is an aliphatic divalent group, a cycloaliphatic divalent group, or a divalent group represented by the following general formula: {In the formula, R ₃ and R ₄ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, or a halogen atom 1, m: each independently an integer of 0 to 4 Y: a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, -O-, -S-, -SO-,
_{-SO 2 -, - CO -,} - CO-O-Z-O-CO-
(Wherein Z represents an aliphatic divalent group), or a divalent group represented by the following general formula: (In the formula, R ₅ and R ₆ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a is an integer of 0 to 20, and b is an integer of 1 to 2000. Represents.)}. ] 2. An aromatic compound comprising repeating units represented by the following general formulas (2) and (3) on a conductive support, and having a composition ratio of repeating units of 0 <k / (k + j) ≦ 1. An electrophotographic photoreceptor comprising a photosensitive layer containing a polycarbonate resin as an active ingredient. Embedded image Embedded image [Wherein, R ₁ and R ₂ are a substituted or unsubstituted alkyl group,
It represents a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted heterocyclic group, which may be the same or different. Ar ₁ represents a divalent group of a substituted or unsubstituted aromatic hydrocarbon, and Ar ₂ represents a trivalent group of a substituted or unsubstituted aromatic hydrocarbon. X is an aliphatic divalent group, a cycloaliphatic divalent group, or a divalent group represented by the following general formula: {In the formula, R ₃ and R ₄ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, or a halogen atom 1, m: each independently an integer of 0 to 4 Y: a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, -O-, -S-, -SO-,
_{-SO 2 -, - CO -,} - CO-O-Z-O-CO-
(Wherein Z represents an aliphatic divalent group), or a divalent group represented by the following general formula: (In the formula, R ₅ and R ₆ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a is an integer of 0 to 20, and b is an integer of 1 to 2000. Represents.)}. k is an integer of 5 to 5000, j is 0
Represents an integer of 5000. ] 3. The electrophotographic photoreceptor according to claim 1, wherein the polycarbonate resin is an aromatic polycarbonate resin composed of a repeating unit represented by the following general formula (4). Embedded image [Wherein, R ₁ and R ₂ are a substituted or unsubstituted alkyl group,
It represents a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted heterocyclic group, which may be the same or different. n represents an integer of 2 to 5000. X is an aliphatic divalent group, a cycloaliphatic divalent group, or a divalent group represented by the following general formula: {In the formula, R ₃ and R ₄ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, or a halogen atom 1, m: each independently an integer of 0 to 4 Y: a single bond, a linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, -O-, -S-, -SO-,
_{-SO 2 -, - CO -,} - CO-O-Z-O-CO-
(Wherein Z represents an aliphatic divalent group), or a divalent group represented by the following general formula: (In the formula, R ₅ and R ₆ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a is an integer of 0 to 20, and b is an integer of 1 to 2000. Represents.)}. ] 4. The aromatic polycarbonate resin comprises repeating units represented by the following general formulas (5) and (3), and the composition ratio of repeating units is 0 <k / (k + j) ≦.
3. The electrophotographic photoreceptor according to claim 2, which is the aromatic polycarbonate resin of 1. Embedded image Embedded image [Wherein, R ₁ and R ₂ are a substituted or unsubstituted alkyl group,
It represents a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted heterocyclic group, which may be the same or different. X is an aliphatic divalent group, a cycloaliphatic 2
A valent group or a divalent group represented by the following general formula: {In the formula, R ₃ and R ₄ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, or a halogen atom 1, m: an integer of 0 to 4 Y: a single bond A linear, branched or cyclic alkylene group having 1 to 12 carbon atoms, -O-, -S-, -SO-,
_{-SO 2 -, - CO -,} - CO-O-Z-O-CO-
(Wherein Z represents an aliphatic divalent group), or a divalent group represented by the following general formula: (In the formula, R ₅ and R ₆ are each independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a is an integer of 0 to 20, and b is an integer of 1 to 2000. Represents.)}. k is an integer of 5 to 5000, j is 0
Represents an integer of 5000. ]