US3637433A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for improving photoconductive elements
Assignee: International Business Machines Corp
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Filing: 1969-08-21
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Granted: 1972-01-25
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Expires: 1989-08-21
Abstract
Abstract The surface properties of a solvent coated photoconductive element comprising a heat softenable photoconductive insulating layer on an electrically conductive substrate are improved by quickly heating the photoconductive insulating layer above its softening point such as by placing the element in contact with a heated member for a short period of time.
Inventors
- 👤 Jimmy A Sims
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:20
CPC Classifications
G; G03; G03G; G03G5/00; G03G5/02; G03G5/04; G03G5/06; G03G5/07; G03G5/071; G03G5/072; G03G5/073; G03G13/00; G03G5/05; G03G5/0525
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
57 words
A method of improving the properties of a photoconductive element comprising a photoconductive insulating layer supported on a conductive substrate which method comprises heating said element from about 10* to about 70* C. above the softening point of said photoconductive insulating layer for a short period of time, sufficient to evaporate residual solvent from said insulating layer.
Claim 2
Dependent Claim
16 words
The method of claim 2 wherein said layer is heated for from 1 to 60 seconds.
Claim 3
Dependent Claim
21 words
The method of claim 2 wherein said heating is accomplished by placing said substrate in intimate contact with a heated member.
Claim 4
Dependent Claim
18 words
The method of claim 3 wherein heating is accomplished by placing said substrate in contact with a plate.
Claim 5
Dependent Claim
19 words
The method of claim 3 wherein said heating is accomplished by contacting said substrate with a moving heated roll.
Claim 6
Dependent Claim
122 words
A process for improving the properties of a photoconductive element comprising a heat softenable photoconductive insulating layer supported on a substrate, said element having been prepared by coating said substrate with a solvent mixture of the material comprising said layer and evaporating the bulk of said solvent, said process comprising the steps of applying heat to the surface of said substrate opposite said photoconductive insulating layer at a temperature less than about 70* C. above the softening point of said photoconductive insulating layer so as to permit rapid escape of solvent from said layer, continuing said heating for a time sufficient to evaporate the residual solvent from said photoconductive insulating layer, and then cooling said element to resolidify said photoconductive insulating layer.
Claim 7
Dependent Claim
13 words
The process of claim 7 wherein said heating time is from 1-60 seconds.
Claim 8
Dependent Claim
131 words
A process for improving the properties of a photoconductive element comprising a heat softenable photoconductive insulating layer supported on an electrically conductive substrate, said element having been prepared by coating said substraTe with a solvent mixture comprising poly-N-vinyl carbazole and 2,4,7-trinitro-9-fluorenone in tetrahydrofuran and evaporating the bulk of said tetrahydrofuran, said method comprising the steps of applying heat to the surface of said substrate opposite said photoconductive insulating layer to heat said insulating layer to a temperature of from about 160* to 170* C. to soften said photoconductive insulating layer so as to permit rapid escape of solvent from said layer, continuing said heating for from 1 to 10 seconds to evaporate the residual solvent from said photoconductive insulating layer, and then cooling said element to resolidify said photoconductive insulating layer.
Claim 9
Dependent Claim
134 words
A process for improving the properties of a photoconductive element comprising a heat softenable photoconductive insulating layer supported on an electrically conductive substrate, said element having been prepared by coating said substrate with a solvent mixture comprising a copolymer of N-vinyl carbazole and ethylacrylate and 2,4,7-trinitro-9-fluorenone in methylene chloride and tetrachloroethane and evaporating the bulk of said methylene chloride and tetrachloroethane, said method comprising the steps of applying heat to the surface of said substrate opposite said photoconductive insulating layer to a temperature of about 160* C. to soften said photoconductive insulating layer so as to permit rapid escape of solvent from said layer, continuing said heating for from 1 to 10 seconds to evaporate the residual solvent from said photoconductive insulating layer and then cooling said element to resolidify said photoconductive insulating layer.
References Cited (Backward Citations)
US3501330A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-24 | 1975-07-26 | 1976-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-24 | 1979-07-26 | 1980-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-24 | 1983-07-26 | 1984-01-25 | $7700.00 | Window Closed / Lapsed |