US3640992A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Naphthoquinone diazide sulfonic acid ester
Assignee: Kalle GmbH and Co KG
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Filing: 1967-06-05
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Granted: 1972-02-08
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Expires: 1987-06-05
Abstract
Abstract THIS INVENTION RELATEDS TO A LIGHT-SENSITIVE ESTER OF A NAPHTHOQUINONE DIAZIDE SULFONIC ACID AND TO A PROCESS FOR MAKING THE ESTER. THE ESTER HAS EHANCEDSOLUBILITY AND IS USEFUL IN PHOTOMECHANICAL REPRODUCTION PROCESSES.
Inventors
- 👤 Oskar Sus
- 👤 Fritz Uhlig
- 👤 Heinz Schafer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:07
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/022
Claims Analysis
Total Claims: 0
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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) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |