Patent US3644530A successfully refreshed from Google Patents.
US3644530A
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US
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Process for preparing (2 5-dihydroxy-phenyl) diphenyl phosphine
Assignee: Polaroid Corp
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Filing: 1968-10-30
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Granted: 1972-02-22
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Expires: 1988-10-30
Abstract
Abstract ORGANIC PHOSPHINES CONTAINING A DIHYDROXYPHENYL SUBSTITUENT ARE PREPARED BY REACTING P-BENZOQUINONE AND A PRIMARY OR SECONDARY ORGANIC PHOSPHINE.
Inventors
- 👤 Stanley M Bloom
- 👤 Ronald F Lambert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 15:25
CPC Classifications
C; C07; C07F; C07F9/00; C07F9/02; C07F9/28; C07F9/50; C07F9/5022; G; G03; G03C; G03C1/00; G03C1/005; G03C1/06; G03C1/34; G03C5/00; G03C5/26; G03C5/29; G03C5/30; G03C5/3021
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) | 1975-02-21 | 1975-08-23 | 1976-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-21 | 1979-08-23 | 1980-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-21 | 1983-08-23 | 1984-02-22 | $7700.00 | Window Closed / Lapsed |