JP2660575B2 - Electrophotographic photoreceptor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electrophotographic photoreceptor having a photoconductive layer comprising a charge generation material, a charge transport material, and a sensitizer provided on a conductive support. It is.

"Conventional technology" An electrophotographic photosensitive member having photosensitivity to visible light is used in copiers,
It has been developed for application to optical printers and the like. As such an electrophotographic photosensitive member, a photosensitive member mainly containing an inorganic photoconductive substance such as selenium, zinc oxide, and cadmium sulfide has been widely used. However, such an inorganic photoreceptor has performance required for an electrophotographic photoreceptor such as a copying machine, for example, photosensitivity, heat stability, moisture resistance,
It does not always satisfy characteristics such as durability.

For example, the selenium photoreceptor crystallizes due to heat or stains on fingerprints when touched by hand, and thus the above-described characteristics required as an electrophotographic photoreceptor are likely to deteriorate.

Further, an electrophotographic photosensitive member using cadmium sulfide is inferior in moisture resistance and durability, and an electrophotographic photosensitive member using zinc oxide has a problem in durability such as film strength. In addition, selenium and cadmium sulfide are toxic, and therefore have great restrictions on production or handling.

In recent years, electrophotographic photoreceptors using various organic substances have been studied and developed to eliminate the disadvantages of photoreceptors using these inorganic substances, and some of them have been put to practical use. For example, an electrophotographic photoreceptor comprising poly-N-vinylcarbazole and 2,4,7-trinitrofluoren-9-one (U.S. Pat.
No. 484,237), those obtained by sensitizing poly-N-vinyl carbazole with a pyrylium salt dye (Japanese Patent Publication No. 48-25658),
Electrophotographic photoreceptor containing an organic pigment as a main component (JP-A-47-37)
No. 543), and an electrophotographic photoreceptor having a eutectic complex comprising a dye and a resin as a main component (JP-A-47-10785).

However, although these photoconductors have improved the disadvantages of the inorganic photoconductors to some extent, they generally have low photosensitivity, are not suitable for repeated use, and do not sufficiently satisfy the requirements as electrophotographic photoconductors.

In order to remedy such drawbacks, an electrophotographic photoreceptor having a function-separated type photoconductive layer in which the charge generation function and the charge transport function are individually assigned to different substances has been proposed. Has become. The function-separated type electrophotographic photoreceptor expands the selection range of materials, thereby improving the sensitivity, durability, and other characteristics of the electrophotographic photoreceptor. It has the advantage that it can be selected from a wide range.

Various organic dyes and organic pigments have been developed as effective organic charge generating substances used in the charge generation layer of such a function-separated type electrophotographic photoreceptor. For example, azo pigments and perylene pigments having various structures have been developed. And polycyclic quinone pigments, square methine dyes, and the like.

However, these pigments show relatively good sensitivity in the short wavelength or middle wavelength range, but have low sensitivity in the long wavelength range, and can be used for laser printers using semiconductor laser light sources that are expected to have high reliability. It was difficult.

[Problems to be Solved by the Invention] The gallium-aluminum-arsenic-based light-emitting device widely used as a semiconductor laser has an oscillation wavelength of 75 or more.
0 nm or more. In order to obtain an electrophotographic photosensitive member having high sensitivity to such long-wavelength light, many studies have hitherto been made. For example, a method of adding a sensitizer for newly increasing the wavelength to light-sensitive materials such as Se and CdS having high sensitivity in the visible light region has been considered, but as described above, Se and CdS have temperature,
Insufficient environmental resistance to humidity etc. As described above, the sensitivity of many known organic photoconductive materials is usually limited to the visible light region of 700 nm or less, and few materials have sufficient sensitivity in the longer wavelength region.

Of these, the phthalocyanine-based compound, which is one of the organic photoconductive materials, is known to have a sensitivity range expanded to longer wavelengths compared to the pigments, dyes, and the like. Insufficient electrophotographic characteristics such as properties are observed. In order to improve these drawbacks, various types of phthalocyanine having different central metals or various crystal forms have been developed. In the process of converting an unstable α-form phthalocyanine into a stable β-form crystal form, various crystal forms of phthalocyanine have been found. For example, ε-type copper phthalocyanine,
X-type metal-free phthalocyanine and m-type titanyl phthalocyanine are known. These phthalocyanines have sensitivity in the long wavelength region, but are insufficient in sensitivity for copiers and optical printers, and have drawbacks such as insufficient potential stability or large residual potential in repeated use. However, it could not be put to practical use.

On the other hand, as a method for improving the sensitivity of an electrophotographic photoreceptor containing a phthalocyanine pigment, the addition of a charge transporting compound such as a hydrazone compound or an oxazole compound, or the addition of an electron withdrawing compound such as tetranitrofluorene or trinitrofluorene. Has been tried, but although the sensitizing effect is recognized, the effect is insufficient,
Alternatively, these additives have adverse effects such as a decrease in chargeability, a decrease in potential stability upon repeated use, a decrease in sensitivity, an increase in residual potential, and the like. The electron-withdrawing compound is toxic and cannot be put to practical use.

However, in general, in an electrophotographic photoreceptor, a charge transporting substance that is effective for a specific charge generating substance is not always effective for other charge generating substances. It cannot be said that a charge-generating substance that is effective is also effective against other charge-transporting substances.

As described above, an appropriate combination is necessary for the charge generating substance and the charge transporting substance, and although this combination has some rules, it does not apply to all the substances.

For example, it has been proposed to use the ionization potential as a guide in selecting a charge transporting substance to be combined with a charge generating substance, but this is the result for specific homogeneous materials.
Lack of generality, it has not been possible to clearly explain the electrophotographic characteristics between different types of materials.

As described above, as to the combination of the charge generation material and the charge transport material, various combinations have been examined by trial and error.

As can be understood from the above description, the electrophotographic photoreceptor has high sensitivity, particularly high sensitivity to light having a long wavelength of 750 nm or more, has high potential stability in repeated use, and has little decrease in residual potential and sensitivity. The development of was desired.

"Object of the Invention" The object of the present invention is to provide high sensitivity, especially sufficient sensitivity to long wavelength light such as a semiconductor laser, and in repeated use, high potential stability, small residual potential, and durability. It is to provide a high electrophotographic photosensitive member.

"Means for Solving the Problems" As a result of intensive studies, we have found that the compounds represented by the general formulas (I) to (VI) sensitize phthalocyanine pigments. ) ~
The photoreceptor using the compound represented by the formula (VI) and the compound represented by the general formula (VII) is superior in the potential stability and the residual potential characteristic in repeated use as compared with the photoreceptor using other pigments. The inventors have found that the present invention has been achieved.

General formula (I) General formula (II) General formula (III) General formula (IV) General formula (V) General formula (VI) General formula (VII) In the general formulas (I) to (VII), Z represents a sulfur atom or an oxygen atom.

R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ each represent a hydrogen atom, an alkyl group or an aryl group, and may be the same or different. R ¹ and R ² or R ³ and R ⁴ may be connected to each other. In the general formula (I), R ¹ , R ² , R ³ and R ⁴ may be linked to form a bridged ring as a whole. R ⁷ is 2
Represents a divalent arylene group, aralkylene group, polymethylene group or branched alkanediyl group.

R ⁸ represents an alkyl group, an alkoxy group, a monocyclic or bicyclic fused aryl group, or a monocyclic or bicyclic fused aryloxy group. In the general formula (V), two R ^{8 's} may be the same or different.

R ⁹ and R ¹⁰ represent an alkyl group, an aryl group or an aralkyl group, and R ⁹ and R ¹⁰ may be the same or different groups.

R ¹¹ represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group. Ar ₁ and R ¹¹ may form a ring.

R ¹² and R ¹³ represent an alkyl group or a hydrogen atom.

 These may be the same or different from each other.

R ¹⁴ represents a hydrogen atom or an alkyl group.

R ¹⁵ represents an alkyl group.

X ¹ is Or a methylene group which may be substituted.

X ₂ represents an atom group necessary for forming benzene.

 n represents an integer of 0 or 1.

Ar ₁ and Ar ₂ represent a monovalent aromatic hydrocarbon group or a monovalent heterocyclic group.

That is, the present invention provides: (1) an electrophotographic photosensitive member having a photoconductive layer provided on a conductive support, wherein the photoconductive layer is a) a phthalocyanine pigment;
b) a printer for a copier or an optical printer, characterized by containing at least one of the compounds represented by the general formulas (I) to (VI) and c) at least one of the compounds represented by the general formula (VII). Electrophotographic photoreceptor.

(2) The electrophotographic photoreceptor for a copying machine or a printer according to the above (1), wherein the light source of the copying machine and the optical printer is a laser beam.

According to the present invention, the composition is highly sensitive and shows good characteristics in repeated use. An electrophotographic photosensitive member having high durability can be obtained.

(Specific structure and effect of the present invention) As the phthalocyanine pigment used in the photoconductive layer of the electrophotographic photoreceptor of the present invention, those having different central metals, those having different crystal forms, and those having a substituent on the benzene ring are used. Various phthalocyanine pigments can be used. For example, Japanese Patent Publication No. 44-14106, Japanese Patent Publication No. 45-8102, Japanese Patent Publication No. 46-42511, Japanese Patent Publication No. 46-41212, Japanese Patent Publication No. 49-4338, JP-A-58-182639, JP-A-62-47054, etc. Metal phthalocyanine, JP-A-50-38543, JP-A-50-95852, JP-A-51-108847, Copper phthalocyanine described in JP-A-51-109841, etc., JP-A-59-49544, JP-A-59-166959, JP 62
-275272, JP 62-286059, JP 62-67094, JP 63-364, JP 63-365, JP 63-37163, JP 6
3-57670, JP-A-63-80263, JP-A-63-116158, JP-A-63-198067, etc., titanyl phthalocyanine, JP-A-57-90058, JP-A-62-163060, JP-A-62-163060 133462,
JP-A-62-177069, JP-A-63-73529, JP-A-63-43155
Aluminum phthalocyanine described in JP-A-57-14
6255, JP-A-57-144761, JP-A-57-148747, etc., vanadyl phthalocyanine, JP-A-59-44053, JP-A-59-44053
-128544, JP-A-59-133550, JP-A-59-133551, JP-A-59-174846, JP-A-59-174847, JP-A-60-59354,
JP-A-60-560054, JP-A-60-220958, JP-A-62-2292
54, JP-A-63-17457, JP-A-59-155851, JP-A-63-2
7562, and halogenated metal phthalocyanines described in JP-A-63-56564, but are not limited thereto, and various known phthalocyanines can be used.

As representative phthalocyanine central metals, various metals such as copper, nickel, iron, vanadium, aluminum, gallium, indium, silicon, titanium, magnesium, cobalt, platinum, germanium and the like, as well as non-metallic phthalocyanines are known. Have been.

The crystal form is confirmed by X-ray crystal diffraction for each metal phthalocyanine and non-metal phthalocyanine. For example, in copper phthalocyanine, α-type, β-type, γ
Polymorphs such as type, δ type, ε type, η type, ρ type, and in metal-free phthalocyanine, α type, β type, χ type, τ type and other polymorphs, and in titanyl phthalocyanine, α type, β type Type, m
Molds and other polymorphs are each known. Further, substituted phthalocyanines in which the benzene ring of phthalocyanine is substituted with a halogen atom such as fluorine, chlorine, or bromine, or an alkyl group, a carboxyl group, an amide group, a sulfonyl group, or other substituents are also known.

Further, phthalocyanine pigments used in the present invention include JP-A-63-233886, JP-A-63-186251, and JP-A-63-186251.
63-72761, germanium naphthalocyanine described in JP-A-63-55556, silicon naphthalocyanine described in JP-A-63-141070, JP-A-63-186251, JP-A-64-2061, etc. Suzuna phthalocyanine described in
63-72761, various metal naphthalocyanines described in JP-A-63-231355 and the like can also be mentioned.

These have different absorption wavelengths and are used as appropriate depending on the application, but when used in a laser beam printer or the like using a semiconductor laser as a light source, 780 nm to 830 nm
Phthalocyanine pigments having an absorption in water are preferred.

Next, the compounds represented by the general formulas (I) to (VI) for improving the photoconductivity of the photoconductive layer using a phthalocyanine pigment will be described.

In the general formulas (I) to (VI), Z represents a sulfur atom or an oxygen atom.

When any ^{one of} R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ is an alkyl group, the alkyl group is a straight-chain or branched unsubstituted or substituted alkyl having 1 to 22 carbon atoms. Group.

Examples of the substituent bonded to the alkyl group include a halogen atom (a chlorine atom, a bromine atom, and a fluorine atom), a cyano group, a nitro group, a phenyl group, a tolyl group, and a trifluoromethyl group. From three to three.

When any ^{one of} R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ is an aryl group, a substituted or unsubstituted phenyl group as the aryl group;
Examples include a substituted or unsubstituted naphthyl group and a substituted or unsubstituted anthranyl group. Examples of the substituent include a halogen atom (a chlorine atom, a bromine atom, and a fluorine atom), a cyano group, a nitro group, a trifluoromethyl group, a linear or branched alkyl group having 1 to 5 carbon atoms, a carboxyl group, An alkoxycarbonyl group, a cyano group, a nitro group or a halogen atom (a chlorine atom, a bromine atom, a fluorine atom)
A straight or branched alkyl group having 1 to 5 carbon atoms, and a carbon atom having 1 to 5 carbon atoms, each of which may be the same or different from each other. A straight-chain or branched alkoxy group having the number of 1 to 5; the number of the substituents is 1 to 3; and when the number of the substituents is 2 or 3, they may be the same or different. Is also good.

When R ¹ and R ² , or R ³ and R ⁴ are linked,
Examples thereof include trimethylene, tetramethylene, pentamethylene, and oxydiethylene groups (—CH ₂ —CH ₂ —O—
CH ₂ —CH ₂ —) and one to three hydrogen atoms of these divalent groups are a halogen atom (a chlorine atom, a bromine atom, a fluorine atom), a cyano group, a nitro group, a phenyl group, a tolyl group, a benzyl group And a divalent group substituted by a linear or branched alkyl having 1 to 5 carbon atoms. Further, the constituent part of these divalent groups may be a part of an aryl ring or a hetero ring.

When R ⁷ is a divalent arylene group, specific examples thereof include p
-Phenylene group, m-phenylene group, o-phenylene group, 1,4-naphthylene group, 2,3-naphthylene group, 4,4'-
And a biferrylene group. In the case of a polymethylene group, a polymethylene group having 1 to 22 carbon atoms can be used.
In the case of a branched alkanediyl group, a propylene group, a butylene group, a pentylidene group, a 1,2-dimethylethylene group, a 1,3
-Dimethyltrimethylene group, 1,4-dimethyltetramethylene group, 1,5-dimethylpentamethylene group, 1,6-dimethylhexamethylene group, 1-ethylethylene group, and 1,2-diethylethylene group.

Aralkylene group Is raised.

The arylene group and the aralkylene group may be substituted with a substituent. As the substituent, a halogen atom,
Cyano group, nitro group, trifluoromethyl group, carbon number 1
And 5 to 5 alkyl groups.

When R ⁸ is an unsubstituted or substituted alkyl group or aryl group, it represents the same group as the unsubstituted or substituted alkyl group or aryl group of R ¹ described above.

When R ⁸ is an alkoxy group or a substituted alkoxy group, examples thereof include the aforementioned alkoxy group or substituted alkoxy group having an alkyl group or a substituted alkyl group.

When R ⁸ is a substituted or unsubstituted monocyclic or bicyclic fused aryloxy group, examples thereof include the above-mentioned aryloxy group having a substituted or unsubstituted monocyclic or bicyclic fused aryl group. be able to.

R ⁹ and R ¹⁰ represent an alkyl group which may have a substituent, an aryl group which may have a substituent, or an aralkyl group which may have a substituent. When these groups are substituted, examples of the substituent include an alkyl group,
Cyano group, hydroxy group, carboxyl group, nitro group,
Halogen atoms such as chlorine, fluorine and bromine, amino groups, alkoxy groups, aryl groups, aryloxy groups, alkoxycarbonyl groups, acyloxy groups, amino groups substituted by alkyl groups or aryl groups or aralkyl groups, trifluoromethyl groups, etc. Can be given.

Specific examples of R ⁹ and R ¹⁰ include a methyl group, an ethyl group, n
-Propyl group, iso-propyl group, n-butyl group, sec-
Butyl group, n-hexyl group, 2-ethylhexyl group, fluoromethyl group, chloromethyl group, trifluoromethyl group, perfluoroalkyl group, methoxymethyl group, linear alkyl group such as cyanomethyl group, branched alkyl group, A substituted alkyl group, a phenyl group, a p-trifluoromethylphenyl group, an o-trifluoromethylphenyl group, a p-cyanophenyl group, an o-cyanophenyl group,
p-nitrophenyl group, o-nitrophenyl group, p-bromophenyl group, o-bromophenyl group, p-chlorophenyl group, o-chlorophenyl group, p-fluorophenyl group, o-fluorophenyl group, N, N-dimethylamide group, N, N-diethylamide group, p-carboxylphenyl group, p-methoxyphenyl group, o-methoxyphenyl group, N, N-diethylaminophenyl group, N, N-diphenylaminophenyl group, N, N-dibenzylaminophenyl group, N, N-dimethylphenyl group, naphthyl group, methoxynaphthyl group, N, N-diethylaminonaphthyl group, benzyl group, p-bromobenzyl group, p-cyanobenzyl group,
p-nitrobenzyl group, p-trifluoromethylbenzyl group, o-bromobenzyl group, o-cyanobenzyl group,
o-nitrobenzyl group, phenylethyl group, 3-phenylpropyl group, p-chlorobenzyl group, aryl group such as naphthylmethyl group, substituted aryl group, aralkyl group,
And substituted aralkyl groups. R ⁹ and R ¹⁰ may be the same or different groups.

R ¹¹ represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, or an aralkyl group which may have a substituent. Among these, when the alkyl group, the aryl group or the aralkyl group is substituted, examples of the substituent include the same substituents as those described for R ⁹ and R ¹⁰ . R ⁹
And specific examples of R ¹⁰ include a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, an n-hexyl group, a 2-ethylhexyl group, and a fluoromethyl group. Group, chloromethyl group, trifluoromethyl group, perfluoroalkyl group, methoxymethyl group, linear alkyl group such as cyanomethyl group, branched alkyl group, substituted alkyl group and phenyl group, p
-Trifluoromethylphenyl group, o-trifluoromethylphenyl group, p-cyanophenyl group, o-cyanophenyl group, p-nitrophenyl group, o-nitrophenyl group, p-bromophenyl group, o-bromophenyl group , P
-Chlorophenyl group, o-chlorophenyl group, p-fluorophenyl group, o-fluorophenyl group, N, N-dimethylamide group, N, N-diethylamide group, p-carboxylphenyl group, p-methoxyphenyl group, o-methoxyphenyl group, N, N-diethylaminophenyl group, N, N-
Diphenylaminophenyl group, N, N-dibenzylaminophenyl group, N, N-dimethylaminophenyl group, naphthyl group, methoxynaphthyl group, cyanonaphthyl group, nitronaphthyl group, chloronaphthyl group, bromonaphthyl group, fluoronaphthyl group , Trifluoromethylnaphthyl group, N,
N-diethylaminonaphthyl group, benzyl group, phenylethyl group, 3-phenylpropyl group, p-chlorobenzyl group, p-bromobenzyl group, p-cyanobenzyl group,
p-nitrobenzyl group, p-trifluoromethylbenzyl group, o-bromobenzyl group, o-cyanobenzyl group,
Examples include an aryl group such as an o-nitrobenzyl group and a naphthylmethyl group, a substituted aryl group, an aralkyl group, and a substituted aralkyl group.

Ar ₁ represents a monovalent aromatic hydrocarbon group which may have a substituent or a monovalent heterocyclic group which may have a substituent. In this case, as the aromatic hydrocarbon group or the heterocyclic group, phenyl group, naphthyl group, anthranyl group, furan, pyrrole, thiophene, indole, benzofuran, benzothiofuran, oxazole, imidazole, thiazole, isoxazole, pyridine, Quinoline, isoquinoline, pyridazine, pyrimidine, pyrazine, phthalazine and derivatives thereof, for example, 2-
Thio-4-thiazolidinone, 3-pyrazolidinone, 5-
Isoxazolone, 2-oxazolidone, 2,4-thiazolidinedione, 2-thiophenone, 2-furanone, 4-
Pyrimidon and the like. When these have a substituent, examples of the substituent include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, an n-hexyl group, a 2-ethylhexyl group, and a fluoro group. A linear alkyl group such as a methyl group, a chloromethyl group, a trifluoromethyl group, a perfluoroalkyl group, a methoxymethyl group, a cyanomethyl group, a branched alkyl group, a substituted alkyl group, and a phenyl group, p-trifluoromethylphenyl Group, o-cyanophenyl group, p-nitrophenyl group, p-bromophenyl group, o-bromophenyl group, o-chlorophenyl group, p-fluorophenyl group,
p-methoxyphenyl group, N, N-diethylaminophenyl group, N, N-dimethylaminophenyl group, naphthyl group, methoxynaphthyl group, cyanonaphthyl group, chloronaphthyl group, benzyl group, phenylethyl group, 3-phenylpropyl Group, p-chlorobenzyl group, p-cyanobenzyl group, p-nitrobenzyl group, p-trifluoromethylbenzyl group, o-bromobenzyl group, o-cyanobenzyl group, o-nitrobenzyl group, naphthylmethyl group, etc. Aryl group, substituted aryl group, aralkyl group, substituted aralkyl group, cyano group, hydroxy group, carboxyl group, nitro group, chlorine, fluorine, halogen atom such as bromine, -NH
A group represented by COR ¹⁷ (R ¹⁷ represents a substituted or unsubstituted alkyl group, aryl group, or aralkyl group), —NHSO ₂ R ¹⁷
(R ¹⁷ is as defined above), SOR ¹⁷ (R ¹⁷ is as defined above), -S
O ₂ R ¹⁷ (R ¹⁷ is as defined above), —COR ¹⁷ (R ¹⁷ is as defined above), (R ¹⁸ and R ¹⁹ may be the same or different from each other, and represent a hydrogen atom, a substituted or unsubstituted alkyl group, an aryl group,
Represents an aralkyl group. ), (R ¹⁸ and R ¹⁹ are as defined above), a sulfonic acid group, an amino group,
Examples include an alkoxy group, an aryl group, an aryloxy group, an alkoxycarbonyl group, an acyloxy group, an amino group and an amide group substituted with an alkyl group or an aryl group or an aralkyl group, and a trifluoromethyl group. As these substituents, substituents that are more electron withdrawing than hydrogen atoms are preferably used.

Next, the compound represented by formula (VII) will be described in more detail.

R ¹² and R ¹³ include an alkyl group with or without a substituent, which is the same as the group represented by R ¹ described above. Other hydrogen atoms may be used.

Specific examples of R ¹⁴ include a hydrogen atom and an alkyl group having 1 to 4 carbon atoms (eg, a methyl group, an ethyl group, a propyl group, a butyl group, etc.).

R ¹⁵ is an alkyl group having or not having a substituent, and is the same as the unsubstituted or substituted alkyl group represented by R ¹² and R ¹³ described above.

Ar ₂ is an aromatic hydrocarbon group such as phenyl, naphthyl, anthryl, or a 2-furyl group, a 2-thienyl group,
-Methyl-2-pyrrolyl group, 5-methyl-2-thienyl group, 2-pyridyl group, 2-benzo [d] thienyl group, 2
-Naphtho [2,3-b] thienyl group, 9-ethylcarbazol-2-yl group, dibenzothiophen-2-yl group,
Represents a heterocyclic group such as a 2-phenoxathiinyl group, a 10-ethylphenoxazin-3-yl group, and a 10-ethylphenothiazin-3-yl group.

These may have a substituent, and as the substituent, an alkyl group, an alkoxy group, an aralkyloxy group, There is a substituted amino group represented by

Specific examples of the substituent of Ar ₂ include an alkyl group having 1 to 12 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, and a hexyl group, and an alkoxy group or an aralkyloxy group having 1 to 1 carbon atoms. There are 12 alkoxy groups and aralkyloxy groups having 12 carbon atoms, and specific examples thereof include methoxy, ethoxy, propoxy, butoxy, octyloxy and benzyloxy groups.

The substituent of Ar ₂ is In the case of a substituted amino group represented by, as R ¹⁶ and R ¹⁷ , an alkyl group having 1 to 12 carbon atoms having no substituent such as a methyl group, an ethyl group, a propyl group, a butyl group, or a substituent such as the following And an alkyl group having 1 to 12 carbon atoms having Represents a substituted or substituted phenyl group, and R ¹⁶ and R ¹⁷ may be linked to form a heterocyclic ring.

Examples of the substituent of the alkyl group having a substituent represented by R ¹⁶ and R ¹⁷ include an alkoxy group having 1 to 4 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, a hydroxy group, and a 6 to 6 carbon atoms.
There are 12 aryl groups, cyano groups and halogen atoms.

Specific examples of the alkyl group having a substituent represented by R ¹⁶ and R ¹⁷ include an alkoxyalkyl group (for example, a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group,
Ethoxyethyl group, ethoxypropoxy group, methoxybutyl group, propoxymethyl group, etc.), aryloxyalkyl group (for example, phenoxymethyl group, phenoxyethyl group, naphthoxymethyl group, phenoxypentyl group, etc.),
Hydroxyalkyl groups (eg, hydroxymethyl group, hydroxypropyl group, hydroxyoctyl group, etc.), aralkyl groups (eg, benzyl group, phenethyl group, ω, ω-
Diphenylalkyl group, etc.), cyanoalkyl group (for example, cyanomethyl group, cyanoethyl group, cyanopropyl group,
Preferred are, for example, a cyanobutyl group and a haloal group (for example, a chloromethyl group, a bromomethyl group, a chloroethyl group, a bromopentyl group, a chlorooctyl group, and the like).

The phenyl group represented by R ¹⁶ and R ¹⁷ may have a substituent. Specific examples of the substituent in the case of the substituted phenyl group include an alkyl group having 1 to 12 carbon atoms, Substituted with an alkoxy group having 4 to 6, an aryloxy group having 6 to 7 carbon atoms, an acyl group having 2 to 8 carbon atoms, an alkoxycarbonyl group having 2 to 5 carbon atoms, a halogen atom, and an alkyl group having 1 to 4 carbon atoms. Monoalkylamino group, having 1 to 1 carbon atoms
Examples include a dialkylamino group substituted with an alkyl group of 4, an amide group having 2 to 4 carbon atoms, and a nitro group.

As an alkyl group having 1 to 12 carbon atoms, a methyl group, an ethyl group, a linear or branched propyl group, a butyl group, a pentyl group, a hexyl group, a methoxy group, an ethoxy group as an alkoxy group having 1 to 4 carbon atoms, Propoxy, butoxy, phenoxy as aryloxy, o-, m-
Or an acetyl group, a propionyl group, a benzoyl group, an o-, m- or p-toluoyl group as a p-tolyloxy group or an acyl group, a methoxycarbonyl group, an ethoxycarbonyl group, or a propoxycarbonyl group as an alkoxycarbonyl group having 2 to 5 carbon atoms. Group, butoxycarbonyl group, chlorine atom, bromine atom, fluorine atom as halogen atom, monoalkylamino group substituted with alkyl group having 1 to 4 carbon atoms, methylamino group, ethylamino group, butylamino group, carbon number A dimethylamino group, a diethylamino group, a dipropylamino group, a dibutylamino group, an N-methyl-N-ethylamino group as a dialkylamino group substituted with 1 to 1 alkyl group, an acetamido group, a propionamido group as an amide group, Nitro group as other substituent A.

Specific examples of the substituted amino group represented by R ¹⁶ and R ¹⁷
May be linked to form a heterocyclic ring, in which case, examples of the heterocyclic ring include a pyrrolidino ring, a morpholino ring, an N-methylpiperazino ring, and a julolidino ring.

Next, specific examples of the compounds represented by the general formulas (I) to (VI) are shown below, but the present invention is not limited to these compounds.

Next, specific examples of the compound represented by the general formula (VII) are shown below.

The urea and thiourea compounds represented by the general formula (I) or (II) in the present invention are both "J. chem, So
c. " 1955 , 1573-1581.

The amide and thioamide compounds represented by the general formulas (III) to (IV) are all referred to as “Bailsteins Handbuchder O
rganichen Chemie ”, Vol. 12, page 265, can be easily synthesized.

Further, (thio) barbituric acid compounds represented by the general formula (VI) are described in "Organic Reactions" Vol.
The Knoevenagel condensation method described on page 599 catalyzes the corresponding aldehyde or ketone with tubbituric acid or thiobarbituric acid using an alkali (eg, NaOH, KOH, ammonia, amine (eg, diethylamine, triethylamine, piperidine, etc.)) Can be easily produced by dehydration condensation.

Further, the hydrozone compound represented by the general formula (VII) can be easily synthesized by the method described in JP-A-57-148749.

It is known that an electrophotographic photoreceptor using a phthalocyanine pigment has an induction effect that causes a delay in the decay of the surface potential immediately after irradiation with light, which causes a reduction in sensitivity. Although the cause has not been clarified, it is considered that a carrier trap exists on the surface of the phthalocyanine particles, and carriers generated by light irradiation are captured by the carrier trap. Have been. The compound of the present invention is considered to be a sensitizer for reducing the induction effect, shortening the time during which the surface potential does not decay (induction period), and consequently improving the sensitivity.

The general formulas (I) to (V)
Use of the compound represented by I) is described in JP-A-58-10223.
No. 9, 58-102240, JP-A-58-65438, 58-6543
9, JP-A-56-149462 and JP-A-57-29650. However, these claim the invention as a sensitizer for further sensitizing the dye-sensitized organic photoconductor, and sensitize the photoreceptor without dye sensitization as in the present invention. No sensational effects are described. Also,
The above specification does not disclose the use of a phthalocyanine pigment which is a photoconductive pigment in the present invention. In addition, regarding the use of a photoconductive material, there is a description of using ZnO which is an inorganic photoconductive pigment, but these are also known to be effective when an inorganic photoconductor such as ZnO is dye-sensitized. The effect of reducing the induction effect specific to phthalocyanine pigments as in the present invention was completely unexpected.

Also, JP-A-58-102239, JP-A-58-102240, JP-A-58-102240
-65438, 58-65439, JP-A-56-149462, 57
The electrophotographic photoreceptor described in No. 29650 shows good electrophotographic characteristics in one-time use, but by repeating several times, a remarkable decrease in charging potential, reduction in sensitivity, and increase in residual potential are observed. It occurs and cannot be used as a photoreceptor for very repetitive copiers and optical printers.

Also, when various additives such as tetranitrofluorene and tetracyanoethylene are added for the purpose of increasing the sensitivity of phthalocyanine, the chargeability is reduced and the charge potential is reduced and the residual potential is increased upon repeated use. Is generated.

However, the compounds represented by the general formulas (I) to (VI) of the present invention sensitize phthalocyanine without causing the deterioration of the above-mentioned repetition characteristics, so that copying requiring high sensitivity and good repetition characteristics is required. Suitable for use in photoreceptors for printing machines and optical printers.

The electrophotographic photoreceptor of the present invention has a photoconductive layer containing the phthalocyanine pigment described above, at least one of the compounds represented by formulas (I) to (VI), and the compound represented by formula (VII). Various types of electrophotographic photoreceptors are known, and the electrophotographic photoreceptor of the present invention may be any type of photoreceptor. Usually, the electrophotographic photoreceptor of the present invention is used in a layer constitution type exemplified below.

(1) A single-layer photoconductive layer containing a phthalocyanine pigment and one of the compounds represented by formulas (I) to (VI) and the compound represented by formula (VII) is provided on a conductive support. Things.

(2) A charge generation layer containing a phthalocyanine pigment and compounds represented by formulas (I) to (VI) is provided on a conductive support, and a charge containing a compound represented by formula (VII) is further provided thereon. With a transport layer.

(3) A charge transport layer containing a compound represented by the general formula (VII) is provided on a conductive support, and a charge containing a phthalocyanine pigment and a compound represented by the general formulas (I) to (VI) is provided thereon. Those with a generation layer.

To prepare an electrophotographic photoreceptor of the type (1), a compound represented by the general formulas (I) to (VI) and a compound represented by the general formula (VI)
The phthalocyanine pigment may be dispersed in a solution in which the compound represented by the formula (I) and the binder are dissolved, and this may be coated on a conductive support and dried. Alternatively, a coating solution may be prepared by dispersing a phthalocyanine pigment in a binder solution and then dissolving the compounds represented by formulas (I) to (VI) and the compound represented by formula (VII) in the solution. .

At this time, the thickness of the photoconductive layer is 3 to 50 μm, preferably 5 to 50 μm.
30μ is good.

To prepare an electrophotographic photoreceptor of the type (2), first, a phthalocyanine and a compound of the formula (I) are placed on a conductive support.
The compound represented by the formulas (VI) to (VI) is dispersed in a suitable solvent or, if necessary, a solvent in which a binder is dissolved, and then coated and dried to form a charge generation layer. Alternatively, the coating liquid may be prepared by dispersing the phthalocyanine pigment in a solvent or a solvent in which a binder is dissolved, and then dissolving the compounds represented by the general formulas (I) to (VI). Thereafter, a solution containing the charge transport compound represented by the general formula (VII) and a binder is applied thereon and dried to provide a charge transport layer.
At this time, the thickness of the charge generation layer is 4 μm or less, particularly 0.1 to 2 μm.
It is preferable that the thickness of the charge transport layer is 3 to 50 μm, particularly 5 to 30 μm.
μ is preferred.

The charge generation layer of the present invention is provided with a thin layer containing a compound represented by any one of the general formulas (I) to (VI) between the charge generation layer and the conductive support. A method of providing a charge generating layer of a phthalocyanine pigment by vapor deposition, and then diffusing a solvent for coating the upper layer, thereby containing the phthalocyanine pigment and the compounds represented by the general formulas (I) to (VI); It can be prepared by a method in which a pigment is vapor-deposited, a solution containing the compounds represented by the general formulas (I) to (VI) is applied thereon, and the solution is made to coexist with a phthalocyanine pigment. In this case, the thickness of the deposited phthalocyanine pigment is preferably from 0.001 μm to 1 μm, particularly preferably from 0.01 μm to 0.5 μm.

The type (3) electrophotographic photoreceptor is prepared by reversing the stacking order of the type (2) charge generation layer and the charge transport layer.

The type (1) photoreceptor of the present invention has relatively good repetition characteristics because phthalocyanine itself has a charge transfer ability as compared to azo pigments and the like, but the type (2) and (3) photoreceptors Compared to the body, the feeling is low, and the charge potential decreases and the residual potential increases slightly due to repeated use.

Therefore, types (2) and (3) are preferable as the use form of the present invention. In this form, the sensitivity is extremely high, the charge potential does not change much in repeated use, the residual potential is low, and the printing durability is high. Thus, a highly durable electrophotographic photosensitive member can be obtained.

(1) The phthalocyanine pigment used in the photoreceptors of the types (2) and (3) is pulverized and dispersed by a known dispersing machine, for example, a hole mill, a sand mill, a vibration mill or the like. Below, preferably 0.
Used after crushing to 1 to 2μ.

If the amount of the phthalocyanine pigment used in the electrophotographic photoreceptor of the type (1) is too small, the sensitivity is poor. If the amount is too large, the chargeability is deteriorated, or the strength of the electrophotographic photosensitive layer is reduced. The ratio of the phthalocyanine pigment in the layer is 0.01 to 2 times by weight, preferably 0.05 to 1 time by weight, relative to the binder.

The ratio of the charge transporting compound represented by the general formula (VII) is 0.1 to 2 times by weight, preferably 0.3 to 1.3 times by weight of the binder.
The weight range is good.

The content of the compounds represented by the general formulas (I) to (VI) is suitably in the range of 0.01 to 1 times by weight, preferably 0.02 to 0.4 times by weight based on the phthalocyanine pigment.

In the case where the phthalocyanine compound-containing layer serving as the charge generation layer is formed by coating on the electrophotographic photoreceptors of types (2) and (3), the amount of the phthalocyanine pigment used is preferably 0.1 to 50 times by weight, and more preferably less than the weight of the binder resin. Sufficient photosensitivity cannot be obtained. The ratio of the charge transporting compound represented by the general formula (VII) in the charge transporting medium is preferably 0.01 to 10 times, more preferably 0.2 to 2 times, the weight of the binder.

Also in this case, the content of the compounds represented by the general formulas (I) to (VI) is 0.01 to 0.01 with respect to the phthalocyanine pigment.
1 part by weight, preferably in the range of 0.02 to 0.4 times by weight is appropriate.

In addition, the photosensitive members of the types (2) and (3)
60-196767, JP-A-60-254045, JP-A-60-262159
As described in the respective specifications, a charge transport compound such as a hydrazone compound and an oxime compound may be added to the charge generation layer.

Examples of the conductive support used in the electrophotographic photoreceptor of the present invention include a metal plate such as aluminum, copper, zinc, and stainless steel, a metal drum, a sheet of plastic, paper, or the like, or aluminum or oxide oxide on a cylindrical substrate. Paper made by depositing or dispersing a conductive material such as Jum, SnO ₂ , or carbon, or by providing a conductive polymer, or paper that has been conductively treated with an inorganic salt such as sodium chloride or calcium chloride or an organic quaternary ammonium salt. ,
A paper tube, a phenol resin drum molded by injecting carbon and a bakelite drum are used.

The binder used in the charge generation layers of the type (2) and the type (3) of the present invention can be selected from a wide range of insulating resins, for example, polyester resin, cellulose resin, acrylic resin, polyamide resin, polyvinyl butyral resin, Phenoxy resin, polyvinyl formal resin, polycarbonate resin, styrene resin, polybutadiene resin, polyurethane resin, epoxy resin, silicone resin, vinyl chloride resin, vinyl chloride-vinyl acetate resin and the like, but are not limited thereto. Absent.

As the binder used for the charge transport layer, it is preferable to use a film-forming high molecular polymer that is hydrophobic, has a high dielectric constant, and is electrically insulating.

Examples of such a high-molecular polymer include, for example, the following, but are not limited thereto.

Polycarbonate, polyester, methacrylic resin,
Acrylic resin, polyvinyl chloride, polyvinylidene chloride,
Polystyrene, polyvinyl acetate, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicon-alkyd resin, Phenol-formaldehyde resin, styrene-alkyd resin, poly-N-
Vinyl carbazole and the like.

The binder for the photoconductive layer of the type (1) can be appropriately selected from the binders for the charge generation layer and the charge transport layer.

These binders can be used alone or as a mixture of two or more.

When preparing the electrophotographic photoreceptor of the present invention, an additive such as a plasticizer or a sensitizer may be used together with the binder.

As a plasticizer, biphenyl, biphenyl chloride, o-terphenyl, p-terphenyl, dibutyl phthalate,
Dimethyl glycol phthalate, dioctyl phthalate, triphenyl phosphate, methyl naphthalene, benzophenone, chlorinated paraffin, polypropylene, polystyrene, dilauryl thiodipropionate, 3,5-dinitrosalicylic acid, dimethyl phthalate, dibutyl phthalate, diisobutyl adipate, dimethyl sebacate , Dibutyl sebacate, butyl laurate, methylphthalylethyl glycolate, various fluorohydrocarbons and the like.

In addition, to improve the surface properties of the electrophotographic photoreceptor,
Silicon oil or the like may be added.

Examples of the sensitizer include chloranil, tetracyanoethylene, methyl violet, rhodamine B, cyanine dye, merocyanine dye, pyrylium dye, thiapyrylium dye, JP-A-58-65439, JP-A-58-102239, and JP-A-58-1.
Compounds described in Nos. 29439 and 62-71965 can be exemplified.

Examples of the coating solvent include alcohols (eg, methanol, ethanol, isopropanol, etc.), ketones (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), and amides (eg, N,
N-dimethylformamide, N, N-dimethylacetamide, etc.), esters (for example, methyl acetate, ethyl acetate,
Butyl acetate, etc.), ethers (eg, tetrahydrofuran, dioxane, monoglyme, diglyme, etc.), halogenated hydrocarbons (eg, methylene chloride, chloroform, methyl chloroform, carbon tetrachloride, monochlorobenzene, dichlorobenzene, etc.) alone Alternatively, they can be used as a mixture.

The application can be performed using a general-purpose coating method such as spraying, roller coating, spinner coating, blade coating, and dip coating.

In the present invention, an adhesive layer or a barrier layer can be provided between the conductive support and the photoconductive layer, if necessary. Materials used for these layers include high molecular weight polymers used for the binder, gelatin,
Casein, polyvinyl alcohol, ethyl cellulose,
Carboxy-methylcellulose, vinylidene chloride based polymer described in JP-A-59-84247, polymer latex,
Styrene-butadiene polymer latex or aluminum oxide described in JP-A-59-114544, and the thickness of these layers is preferably 0.1 to 5 μm.

In the present invention, an overcoat layer can be provided on the photoconductive layer if necessary. The overcoat layer may be a mechanically matted one or a resin layer containing a matting agent. In this case, as the matting agent, silicon dioxide, glass particles, alumina, starch, titanium oxide, zinc oxide, polymethyl methacrylate, polystyrene, polymer particles such as phenolic resin, and U.S. Pat.Nos. 2,701,245 and 2,992,101 Matting agents described in the book are included. These are 2
More than one species can be used in combination.

The resin used for the overcoat layer can be selected from various known resins in addition to the resin used for the photoconductive layer.

Although the present invention has been described in detail above, the electrophotographic photoreceptor of the present invention is an electrophotographic photoreceptor having excellent sensitivity, a small change in the charging potential in repeated use, a small residual potential, and high printing durability and high durability. is there.

The present invention can be widely applied to the field of the electrophotographic photoreceptor of the present invention and a photoreceptor of a printer using a laser or a cathode ray tube as a light source as well as an electrophotographic copying machine. Particularly, since it has high sensitivity up to a long wavelength range, it is suitable for a laser beam printer using a semiconductor laser, a He-Ne laser, or the like as a light source.

Next, the present invention will be specifically described with reference to examples, but the present invention is not limited to the examples. In the examples, “parts” means “parts by weight”.

Example 1 ε-type copper phthalocyanine (Riophoton EPPC: manufactured by Toyo Ink Co., Ltd.) 0.5 part Exemplary compound 0.05 part Polyester resin (Byron 200: manufactured by Toyobo Co., Ltd.) 3.0 parts Exemplary compound (73) 3.0 parts Tetrahydrofuran 100 parts The glass beads were placed in a 500 ml glass container together with the glass beads, and dispersed for 60 minutes with a paint shaker (Toyo Seiki Seisaku-sho, Ltd.). Then, the glass beads were filtered off to obtain a dispersion for a photoconductive layer.

Next, this dispersion liquid for a photoconductive layer is coated on a conductive support (a 75 μm polyethylene terephthalate film having an aluminum vapor-deposited film provided on the surface thereof with a surface resistance of 10 ³ Ω) using a wire round rod, and dried. Thus, an electrophotographic photosensitive member having a photoconductive layer of 20 μm was obtained.

Next, the electrical characteristics of the created electrophotographic photoreceptor were measured using EPA-810.
Using 0 (manufactured by Kawaguchi Electric Co., Ltd.), the measurement was performed under the condition that corona charging was performed at ± 8.0 kv by a static method and monochromatic light of 780 nm was exposed at a light intensity of 1 mw / m ² . The surface potential immediately after charging (V ₀ ), the ratio of the surface potential 10 seconds after charging to V ₀ , is the charge retention ratio (DD ₁₀ ). exposure amount becomes (E ₅₀₎ and 1/10 exposure (E _90), an exposure amount 100μ as residual potential (V _R)
When the surface potential at J / cm ² was examined, it was V ₀ +667 V E ₅₀ 2.1 μJ / cm ² E ₉₀ 4.8 μj / cm ² DD ₁₀ 76% V _R +19 V.

Comparative Example 1 From the coating solution for photoconductive layer of Example 1, Exemplified Compound (1)
An electrophotographic photoreceptor was prepared in exactly the same manner as in Example 1 except for the above. When the electrical characteristics of this electrophotographic photosensitive member were measured under the same conditions as in Example 1, it was V ₀ +695 V E ₅₀ 2.7 μJ / cm ² E ₉₀ 8.1 μJ / cm ² DD ₁₀ 79% V _R +41 V.

Example 2 A solution prepared by dissolving 3 parts of ε-type copper phthalocyanine (Riophoton EPPC), 0.3 part of the exemplary compound (1), and 3 parts of a polyester resin (Vylon 200) in 100 parts of tetrahydrofuran was dispersed by a pole mill for 20 hours, and then dispersed in a wire. Using a round rod, conductive support (Al vapor-deposited film described above)
The resultant was coated and dried to obtain a charge generation layer having a thickness of 0.5 μm.

Next, on the charge generation layer, 10 parts of Exemplified Compound (70) and a polycarbonate of bisphenol A were used as charge transport materials.
A solution prepared by dissolving 10 parts in 50 parts of dichloromethane was applied using a wire round rod, and dried to form a 20 μm-thick charge transport layer, thereby producing an electrophotographic photoreceptor.
The electrical characteristics of this electrophotographic photoreceptor were measured under the same conditions as in Example 1 except that corona charging was performed at −8 kv. V ₀ −753 V E ₅₀ 1.5 μJ / cm ² E ₉₀ 2.8 μJ / cm ² DD ₁₀ 73% V _R -20V. Thereafter, the two steps of charging and exposure were repeated 10,000 times, and the electrical characteristics were examined. As a result, there was almost no change from the characteristics before the repetition.

Comparative Example 2 Example 2 was the same as Example 2 except that the exemplified compound (1) was omitted.
An electrophotographic photoreceptor was prepared in exactly the same manner as described above. The electrical characteristics of this electrophotographic photosensitive member were measured under the same conditions as in Example 2. The result was V ₀ −767 V E ₅₀ 2.3 μJ / cm ² E ₉₀ 6.5 μJ / cm ² DD ₁₀ 79% V _R −33 V.

Comparative Examples 3 and 4 An electrophotographic photosensitive member was prepared in exactly the same manner as in Example 2 except that the following comparative compound was used in place of Exemplified Compound (70) as a charge transporting substance, and electric characteristics were measured.

 The results are shown in Table 1.

Example 3 The ε-type copper phthalocyanine of Example 2 (Riophoton EP
PC) to X-type metal-free phthalocyanine (Dainippon Ink Co., Ltd.)
An electrophotographic photoreceptor was prepared in exactly the same manner as in Example 2 except that Fastogen Blue 8120 was used. As a result of measuring the electric characteristics of this electrophotographic photosensitive member under the same conditions as in Example 2, it was V ₀ -745 V E ₅₀ 0.7 μJ / cm ² E ₉₀ 1.8 μJ / cm ² DD ₁₀ 75% V _R -13 V. Thereafter, the two steps of charging and exposure were repeated 10,000 times, and the electrical characteristics were examined. As a result, there was almost no change from the characteristics before the repetition.

Comparative Example 5 Example 3 was the same as Example 3 except that the exemplified compound (1) was omitted.
An electrophotographic photoreceptor was prepared in exactly the same manner as described above. When the electrical characteristics of this electrophotographic photosensitive member were measured under the same conditions as in Example 2, it was V ₀ −756 V E ₅₀ 1.0 μJ / cm ² E ₉₀ 3.5 μJ / cm ² DD ₁₀ 80% V _R −32 V.

Example 4 The ε-type copper phthalocyanine of Example 2 (Riophoton EP
PC) to α-type titanyl copper phthalocyanine (manufactured by Toyo Ink)
An electrophotographic photoreceptor was prepared in exactly the same manner as in Example 2 except that the above was replaced. As a result of measuring the electrical characteristics of this electrophotographic photosensitive member under the same conditions as in Example 2, it was V ₀ -723 V E ₅₀ 0.6 μJ / cm ² E ₉₀ 1.7 μJ / cm ² DD ₁₀ 73% V _R -14 V. Thereafter, the two steps of charging and exposure were repeated 10,000 times, and the electrical characteristics were examined. As a result, there was almost no change from the characteristics before the repetition.

Comparative Example 6 Example 3 was repeated except that Exemplified compound (1) of Example 4 was omitted.
The electrical characteristics of the electrophotographic photoreceptor were determined in exactly the same manner as in Example 2.
As a result of measurement under the same conditions as those described above, V ₀ −758 V E ₅₀ 1.0 μJ / cm ² E ₉₀ 2.9 μJ / cm ² DD ₁₀ 78% V _R −20 V

Examples 5 to 25 As sensitizers, the exemplified compounds of Table 2 in place of the exemplified compound (1) of Example 3, and as the charge transporting substance, the compounds of Table 2 in place of the exemplified compound (70) of Example 3 An electrophotographic photosensitive member was prepared in exactly the same manner as in Example 3 except that the exemplified compound was used. Table 2 shows the electrical characteristics of this electrophotographic photosensitive member. The measurement of the electrical characteristics was performed under the same conditions as in Example 3.

Example 1 and Comparative Example 1, Examples 2, 5 to 25 and Comparative Examples 2 to 4,
Comparing Example 3 with Comparative Example 5 and Example 4 with Comparative Example 6, the compound containing the compound represented by the general formula (VII) and the compound represented by the general formula (I) to (VI) were added. The electrophotographic photoconductor obtained was 1.
5 to 2 times higher sensitivity. In addition, it can be seen that there is no large difference between the charged product, the dark decay, and the residual potential, and good electrophotographic characteristics are maintained. Further, in Examples 2, 3, and 4, it was confirmed that the electrical characteristics after repeated use of 10,000 times hardly changed from the initial characteristics.

As described above, the electrophotographic photoreceptor shown in the examples satisfies the object of the present invention "an electrophotographic photoreceptor having high sensitivity, high potential stability in repeated use, small residual potential, and high durability". It turns out to be something.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location G03G 5/06 370 G03G 5/06 370 (56) References JP-A-61-20951 (JP, A JP-A-58-102239 (JP, A) JP-A-58-102240 (JP, A) JP-A-56-149462 (JP, A)

Claims (2)

(57) [Claims] 1. An electrophotographic photoreceptor having a photoconductive layer provided on a conductive support, wherein the photoconductive layer comprises at least one of a) a phthalocyanine pigment and b) at least one of the compounds represented by formulas (I) to (VI). An electrophotographic photoreceptor for a copier or an optical printer, which comprises one kind and c) at least one kind of the compound represented by the general formula (VII). General formula (I) General formula (II) General formula (III) General formula (IV) General formula (V) General formula (VI) General formula (VII) In the general formulas (I) to (VII), Z represents a sulfur atom or an oxygen atom. R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ each represent a hydrogen atom, an alkyl group or an aryl group, and may be the same or different. R ¹ and R ² or R ³ and R ⁴ may be connected to each other. In the general formula (I), R ¹ , R ² , R ³ and R ⁴ may be linked to form a bridged ring as a whole. R ⁷ represents a divalent arylene group, an aralkylene group, a polymethylene group or a branched alkanediyl group. R ⁸ represents an alkyl group, an alkoxy group, a monocyclic or bicyclic fused aryl group, or a monocyclic or bicyclic fused aryloxy group. In general formula (V), two
R ⁸ may be the same or different. R ⁹ and R ¹⁰ represent an alkyl group, an aryl group or an aralkyl group, and R ⁹ and R ¹⁰ may be the same or different groups. R ¹¹ represents a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group. Ar ₁ and R ¹¹ may form a ring. R ¹² and R ¹³ represent an alkyl group or a hydrogen atom. These may be the same or different from each other. R ¹⁴ represents a hydrogen atom or an alkyl group. R ¹⁵ represents an alkyl group. X ¹ is Or a methylene group which may be substituted. X ² represents an atom group necessary for forming benzene. n represents an integer of 0 or 1. Ar ₁ and Ar ₂ represent a monovalent aromatic hydrocarbon group or a monovalent heterocyclic group. 2. The electrophotographic photosensitive member for a copying machine or an optical printer according to claim 1, wherein the light source of the copying machine or the optical printer is a laser beam.