Patent US3881922A successfully refreshed from Google Patents.
US3881922A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photoconductor and process for the preparation thereof
Assignee: Hoechst AG
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Filing: 1973-04-19
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Granted: 1975-05-06
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Expires: 1993-04-19
Abstract
Abstract WHEREIN X1 and X2 are selected from the group consisting of hydrogen, alkyl or alkoxy with 1 to 4 carbon atoms each, or halogen, X3 and X4 are selected from the group consisting of alkyl or alkoxy with 1 to 4 carbon atoms each, or halogen, and N IS AN INTEGER BETWEEN ABOUT 6 AND 10. SAID PRODUCT BEING SOLUBLE IN TETRAHYDROFURAN AT ROOM TEMPERATURE. This invention relates to a photoconductive polymeric condensation product of formaldehyde or para-formaldehyde and at least one multi-nuclear, carbocyclic aromatic compound, composed of recurrent, non cross-linked units of at least one of the following formulae
Inventors
- 👤 Bernd Lohr
- 👤 Heinz Hermann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:44
CPC Classifications
C; C08; C08G; C08G16/00; C08G16/02; C08G16/0212; C08G16/0218; C08G10/00; C08G10/02; G; G03; G03G; G03G5/00; G03G5/02; G03G5/04; G03G5/06; G03G5/07; G03G5/075; G03G5/076
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
26 words
A FORMALDEHYDE OR PARA-FORMALDEHYDE AND AT LEAST ONE MULTINUCLEAR, CORBOCYCLIC AROMATIC COMPOUND, COMPOSED OF RECURRENT, NON CROSS-LINKED UNITS OF AT LEAST ONE OF THE FOLLOWING FORMULAE
Claim 2
Dependent Claim
26 words
A FORMALDEHYDE OR PARA-FORMALDEHYDE AND AT LEAST ONE MULTINUCLEAR, CORBOCYCLIC AROMATIC COMPOUND, COMPOSED OF RECURRENT, NON CROSS-LINKED UNITS OF AT LEAST ONE OF THE FOLLOWING FORMULAE
Claim 3
Dependent Claim
21 words
A product according to claim 1 containing at least one derivative of fluorenone, fluorene, pyrene, fluoranthene or perylene as an activator.
Claim 4
Dependent Claim
29 words
A product according to claim 1 which contains at least one of mono-, di-, tri- and tetra-nitro-fluoreneone, 9-dicyanomethylene-fluorene, 9-dicyanomethylene-mononitro-fluorene, 9-dicyanomethylene-dinitro-fluorene, 9-dicyanomethylene-trinitro-fluorene, trinitro-bromopyrene, tetranitro-pyrene, trintiro-fluoranthene or tetranitro-perylene as an activator.
Claim 5
Dependent Claim
22 words
A product according to claim 1 containing up to 200 percent by weight of binder, calculated on the weight of the photoconductor.
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) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |