US3767735A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dialkyl-3-acetyl-4-hydroxybenzyl phosphonates
Assignee: Buckman Laboratories International Inc
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Filing: 1971-03-24
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Granted: 1973-10-23
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Expires: 1991-03-24
Abstract
Abstract METAL MONO-, BIS-, AND TRIS-DERIVATIVES OF PHOSPHONIC ACID HALF-ESTERS USEFUL AS ULTRAVIOLET LIGHT ABSORBERS ARE PREPARED BY REACTING A DIALKYL-3-ACETYL-4-HYDROXYBENZYL PHOSPHONATE WITH AN ALKALI-METAL HYDROXIDE TO FORM THE ALKALIMETAL DERIVATIVE WHICH IS THEN CONVERTED TO THE BIS- OR TRISDERIVATIVE BY REACTION WITH A BI- OR TRIVALENT METAL CHLORIDE.
Inventors
- 👤 J Fenyes
- 👤 K Flanagan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 09:26
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/49; C08K5/51; C08K5/53; C08K5/5317; C08K5/5333; C07; C07F; C07F9/00; C07F9/02; C07F9/28; C07F9/38; C07F9/40; C07F9/4003; C07F9/4056
Claims Analysis
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |