US3801316A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bicharge zinc oxide
Assignee: Manufacturers Hanover Trust Co
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Filing: 1973-01-29
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Granted: 1974-04-02
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Expires: 1993-01-29
Abstract
Abstract Conventional photoconductive zinc oxide is converted into bicharge photoconductive zinc oxide by heating with selenium in air at about 300*-600*C. Bicharge zinc oxide is particularly useful as the phtoconductive pigment in photocopy papers.
Inventors
- 👤 R Bowman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:59
CPC Classifications
G; G03; G03G; G03G5/00; G03G5/02; G03G5/04; G03G5/08
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
18 words
A method according to claim 1 wherein heating is effected at 400*-500*C in static air for 10-30 minutes.
Claim 2
Independent Claim
60 words
A method for producing bicharge photoconductive zinc oxide which comprises mixing photoconductive zinc oxide with 0.1-1.0 weight percent of selenium in the form of elemental selenium or as an oxide or oxyacid of selenium or a compound of selenium oxidizable or decomposable to an oxidized form of selenium under the process conditions and heating the mixture in air at 400*-500*C.
Claim 3
Independent Claim
50 words
A method for producing bicharge photoconductive zinc oxide which comprises heating selenium in a flowing air stream at 400*-500*C and passing the air stream through a bed of photoconductive zinc oxide at 400*-500*C, the air passed through the bed containing 0.02-2.0 weight percent of selenium based on the zinc oxide.
Claim 4
Dependent Claim
61 words
Colorless bicharge photoconductive zinc oxide produced by heating photoconductive zinc oxide in air at 300*-600*C in the presence of 0.02-2.0 weight percent of selenium based on the zinc oxide in the form of elemental selenium or as an oxide or oxyacid of selenium or a compound of selenium oxidizable or decomposable to an oxidized form of selenium under the process conditions.
Claim 5
Dependent Claim
66 words
Bicharge photoconductive zinc oxide suitable for negative and positive photocopy produced by heating photoconductive zinc oxide in air at 300*-600*C in the presence of 0.02-2.0 weight percent of selenium based on the zinc oxide in the form of elemental selenium or as an oxide or oxyacid of selenium or a compound of selenium oxidizable or decomposable to an oxidized form of selenium under the process conditions.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |