US4220697A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic recording material
Assignee: Hoechst AG
•
Filing: 1978-07-27
•
Granted: 1980-09-02
•
Expires: 1998-07-27
Abstract
Abstract This invention relates to an improvement in an electrophotographic recording material comprising an electrically conductive support, optionally an insulating intermediate layer, and a photoconductive layer composed of at least one layer comprising charge carrier-producing and charge transporting compounds, a binder, and conventional additives, the improvement that the recording material comprises a 75 to 250 mu m thick support, and, in the form of a photoconductor web, is sufficiently flexible that it is not prone to the formation of hairline cracks when repeatedly conducted over rollers of at least 12 mm diameter, said binder being a cellulose nitrate with a viscosity of 400+/-25 cPoises at concentrations between about 4 and 12 percent in a 5 percent aqueous acetone solution, according to DIN 53 179 (standard type 4-12).
Inventors
- 👤 Wolfgang Wiedemann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:32
CPC Classifications
G; G03; G03G; G03G5/00; G03G5/02; G03G5/04; G03G5/05; G03G5/0528; G03G5/0557; G03G5/0585; G03G5/10; G03G5/102
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
149 words
In an electrophotographic recording material comprising an electrically conductive support, optionally an insulating intermediate layer, and a photoconductive layer composed of at least one layer comprising charge carrier-producing and charge transporting compounds, a binder, and conventional additives, the improvement that the recording material comprises a 75 to 250 μm thick support, and, in the form of a photoconductor web, is sufficiently flexible that it is not prone to the formation of hairline cracks when repeatedly conducted over rollers of at least 12 mm diameter, said binder being a cellulose nitrate with a viscosity of 400±25 cPoises at concentrations between about 4 and 12 percent by weight in a 5 percent aqueous acetone solution, according to DIN 53 179 (standard type 4-12), the proportion of cellulose nitrate to charge transporting compound being in the range of about 20 to 60 parts by weight to 40 to 80 parts by weight.
Claim 2
Dependent Claim
149 words
In an electrophotographic recording material comprising an electrically conductive support, optionally an insulating intermediate layer, and a photoconductive layer composed of at least one layer comprising charge carrier-producing and charge transporting compounds, a binder, and conventional additives, the improvement that the recording material comprises a 75 to 250 μm thick support, and, in the form of a photoconductor web, is sufficiently flexible that it is not prone to the formation of hairline cracks when repeatedly conducted over rollers of at least 12 mm diameter, said binder being a cellulose nitrate with a viscosity of 400±25 cPoises at concentrations between about 4 and 12 percent by weight in a 5 percent aqueous acetone solution, according to DIN 53 179 (standard type 4-12), the proportion of cellulose nitrate to charge transporting compound being in the range of about 20 to 60 parts by weight to 40 to 80 parts by weight.
Claim 3
Dependent Claim
39 words
A recording material according to claim 1 in which the cellulose nitrate has a viscosity of 400±25 cPoises at concentrations between about 4 and 9 percent in 5% aqueous acetone solution, according to DIN 53 179 (standard type 4-9).
Claim 4
Dependent Claim
76 words
A recording material according to claim 1 comprising a sequence of layers of a 75 to 250 μm thick electrically conductive support of an aluminum-vaporized polyester film, a charge-producing dyestuff layer of 0.005 to 2 μm thickness, and a 2 to 20 μm thick charge transport layer composed of about 40 to 80 parts by weight of a monomeric organic charge transporting substance and 20 to 60 parts by weight of cellulose nitrate as the binder.
Claim 5
Dependent Claim
68 words
A recording material according to claim 3 comprising a 75 to 250 μm thick electrically conductive support of aluminum-vaporized polyester film, a charge-producing dyestuff layer of 0.005 to 1 μm thickness, and a 3 to 10 μm thick charge transport layer comprising about 50 to 70 parts by weight of a monomeric organic charge-transporting substance and 30 to 50 parts by weight of cellulose nitrate as the binder.
Claim 6
Dependent Claim
16 words
A recording material according to claim 1 in which the charge carrier-producing layer contains cellulose nitrate.
Claim 7
Dependent Claim
28 words
A recording material according to claim 1 in which the photoconductive layer contains at least one monomeric or polymeric aromatic or heterocyclic compound as the charge transporting substance.
Claim 8
Dependent Claim
26 words
A recording material according to claim 6 in which the photoconductive layer comprises a monomeric heterocyclic compound which is substituted by at least one dialkylamino group.
Claim 9
Dependent Claim
15 words
A recording material according to claim 6 in which the heterocyclic compound is an oxadiazole.
Claim 10
Dependent Claim
14 words
A recording material according to claim 8 in which the heterocyclic compound is 2,5-bis-(4'-diethylaminophenyl)-oxadiazole-1,3,4.
Claim 11
Dependent Claim
19 words
A recording material according to claim 6 in which the photoconductive layer comprises a relatively highly condensed aromatic compound.
Claim 12
Dependent Claim
24 words
A recording material according to claim 10 in which the relatively highly condensed aromatic compound employed is a condensation product of formaldehyde and 3-bromopyrene.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-09-02 | 1984-03-03 | 1984-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-02 | 1988-03-03 | 1988-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-02 | 1992-03-03 | 1992-09-02 | $7700.00 | Window Closed / Lapsed |