Patent EP0013172A2 successfully refreshed from Google Patents.
EP0013172A2
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Electrophotographic elements
Assignee: Ricoh Co Ltd
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Filing: 1979-12-21
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Granted: —
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Expires: 1999-12-21
Abstract
Abstract A layered electrophotographic element comprises an electroconductive support bearing a charge generating layer and a charge transfer layer superimposed on the charge generating layer; the charge generating layer containing, as charge generating agent, a disazo pigment of the formula and the charge transfer layer comprises a polycarbonate binder and, as charge transfer agent, a compound of the formula (in which the group -X- represents a ring system fused to benzene ring B and selected from benzene, naphthalene, indole, carbazole and benzofuran ring systems, and substituted derivatives thereof; Ar is a phenyl, naphthyl, dibenzofuranyl or carbazolyl group or a substituted derivative thereof); Ar 2 is a phenyl or naphthyl group or a substituted derivative thereof; R 1 is a hydrogen atom, a lower alkyl group or a phenyl group or substituted derivation thereof; and R 2 is a lower alkyl group or a carbonyl group or alkyl ester thereof); and the charge transfer layer comprises a polycarbonate resin as binder and, as charge transfer agent, a carbazole compound of the formula: (in which R' is a methyl, ethyl, 2-hydroxyethyl or2-chloroethyl group, and R' is a methyl, ethyl, benzyl or phenyl group). The charge generating layer may comprise the charge generating layer alone or in' admixture with a binder. The carbonate binder of the charge transfer layer is preferably which is soluble in lower boiling hydrocarbon halides, ' rbons or alicyclic esters.
Inventors
- 👤 Takamichi Enomoto
- 👤 Tatuya Katoh
- 👤 Akio Kozima
- 👤 Tatsumi Satoh
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 08:50
CPC Classifications
G; G03; G03G; G03G5/00; G03G5/02; G03G5/04; G03G5/06; G03G5/0664; G03G5/0675; G03G5/0679; G03G5/0683
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
185 words
A layered electrophotographic element comprising an electroconductive support bearing a charge generating layer having a charge transfer layer superimposed thereon characterized in that: (i) the charge generating layer contains, as charge generating agent, a disazo compound of the general formula: in which A is a group of the formula: (in which the grouping --X-- represents a ring system fused to benzene ring B and selected from benzene, naphthalene, indole, carbazole and benzofuran ring systems, and substituted derivatives thereof; Ar is a phenyl, naphthyl, dibenzofuranyl or carbazolyl group or a substituted derivative thereof; Ar 2 is a phenyl or naphthyl group or a substituted derivative thereof; R 1 is a hydrogen atom, a lower alkyl group or a phenyl group or substituted denvation thereof; and R 2 is a lower alkyl group or a carbonyl group or alkyl ester thereof); and (2) the charge transfer layer comprises a polycarbonate resin as binder and, as charge transfer agent, a carbazole compound of the formula: (in which R 3 is a methyl, ethyl , 2-hydroxyethyl or 2-chloroethyl group, and R is a methyl, ethyl, benzyl or phenyl group).
Claim 2
Dependent Claim
185 words
A layered electrophotographic element comprising an electroconductive support bearing a charge generating layer having a charge transfer layer superimposed thereon characterized in that: (i) the charge generating layer contains, as charge generating agent, a disazo compound of the general formula: in which A is a group of the formula: (in which the grouping --X-- represents a ring system fused to benzene ring B and selected from benzene, naphthalene, indole, carbazole and benzofuran ring systems, and substituted derivatives thereof; Ar is a phenyl, naphthyl, dibenzofuranyl or carbazolyl group or a substituted derivative thereof; Ar 2 is a phenyl or naphthyl group or a substituted derivative thereof; R 1 is a hydrogen atom, a lower alkyl group or a phenyl group or substituted denvation thereof; and R 2 is a lower alkyl group or a carbonyl group or alkyl ester thereof); and (2) the charge transfer layer comprises a polycarbonate resin as binder and, as charge transfer agent, a carbazole compound of the formula: (in which R 3 is a methyl, ethyl , 2-hydroxyethyl or 2-chloroethyl group, and R is a methyl, ethyl, benzyl or phenyl group).
Claim 3
Dependent Claim
29 words
An electrophotographic element according to claim 1 characterized in that the weight ratio of charge transfer agent to polycarbonate in the charge transfer layer is from 1:10 to 40:10.
Claim 4
Dependent Claim
29 words
An electrophotographic element according to claim 2 characterized in that the weight ratio of charge transfer agent to polycarbonate in the charge transfer layer is from 4:10 to 20:10.
Claim 5
Dependent Claim
36 words
An electrophotographic element according to any one of claims 1-3 characterized in that the charge generating layer is from 0.04 to 20 microns thick, and the charge transfer layer is from 3 to 50 microns thick.
Claim 6
Dependent Claim
33 words
An electrophotographic element according to claim 4 characterized in that the charge generating layer is from 0.05 to 2 microns thick, and the charge transfer layer is from 8 to 25 microns thick.
Claim 7
Dependent Claim
41 words
6 . An electrophotographic element according to any one of claims 1-5 characterized in that the polycarbonate binder in the charge transfer layer is a polycarbonate soluble in a solvent selected from low boiling hydrocarbon halides, aromatic hydrocarbons and alicyclic ethers.
Claim 8
Dependent Claim
27 words
An electrophotographic element according to claim 6 characterized in that the polycarbonate is soluble in a solvent selected from dichloroethane, methylene chloride, toluene, xylene, tetrahydrofuran and dioxan.
Claim 9
Dependent Claim
209 words
An electrophotographic element according to any one of claims 1-7 characterized in that the charge generating agent is a compound of formula (I) in which: the ring system ---- X ---- is selected from benzene, naphthalene, indole, carbazole and benzofuran ring systems and halo-substituted derivatives thereof; Ar l is a phenyl, naphthyl, dibenzofuranyl or carbazolyl group or a substituted derivative thereof substituted with one of more of halogen atoms, C l -C 4 alkyl groups, C l -C 4 alkxy groups, dialkylamino groups (in which each alkyl group is a C l -C 4 alkyl group), cyano groups, carboxyl groups, nitro groups or sulpho groups; Ar 2 is a phenyl or naphthyl group or a substituted derivative thereof substituted with one or more of nitro groups, sulfoamino groups, sulfo groups, halogen atoms, C l -C 4 alkyl groups, C l -C 4 alkyl groups, cyano groups, dialkylamino groups (in which each alkyl group is a C 1 -C 4 alkyl group) or acylamino groups; R 1 is a hydrogen atom, a C 1 -C 4 alkyl group, a phenyl group or a halo-substituted phenyl group; and R 2 is a C 1 -C 4 alkyl group or a carboxyl qroup or a C l -C 4 alkyl ester thereof.
Claim 10
Dependent Claim
62 words
An electrophotographic element according to any one of claims 1-8 characterized in that the charge transfer agent is a compound of formula (I) in which A is: a group (in which Ar 1 is a phenyl, p-methoxy-phenyl, o-methoxyphenyl, o-methylphenyl, p-chlorophenyl, p-(dimethylamino)-phenyl, m-nitro-phenyl, o-nitro-phenyl, 2,5-dimethoxy-phenyl, 2,4-dimethyl-phenyl, 4-chloro-2-methyl-phenyl or 4-chloro-2,5-dimethoxy-phenyl group), or a group (in which Ar 2 is a phenyl or p-nitro-phenyl group).
Claim 11
Dependent Claim
29 words
An electrophotographic element according to any one of claims 1-9 characterized in that the charge generating agent is a Compound of formula (I) in which A is a group
Claim 12
Dependent Claim
38 words
An electrophotographic element according to any one of claims 1-10 characterized in that the charge transfer agent is a compound of formula (II) in which R 3 is an ethyl group and R 4 is a methyl group.
References Cited (Backward Citations)
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