Patent US2891996A successfully refreshed from Google Patents.
US2891996A
Expired / Lapsed
US
⏱️ 0.0 years remaining
2, 4-dihydroxy benzophenone derivatives
Assignee: Dow Chemical Co
•
Filing: 1956-04-23
•
Granted: 1959-06-23
•
Expires: 1976-04-23
Abstract
No abstract record available.
Inventors
- 👤 Gerald A Clark
- 👤 Carl B Havens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:30
CPC Classifications
C; C07; C07C; C07C45/00; C07C45/45; C07C45/46; C07C49/00; C07C49/76; C07C49/82; C07C49/83; C08; C08K; C08K5/00; C08K5/04; C08K5/13; C08K5/132
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
12 words
AS A NEW ORGANIC COMPOUND, A BENZOPHENONE DERIVATIVE HAVING THE GENERAL FORMULA:
Claim 2
Dependent Claim
12 words
AS A NEW ORGANIC COMPOUND, A BENZOPHENONE DERIVATIVE HAVING THE GENERAL FORMULA:
References Cited (Backward Citations)
US2693492A
Cited
US2794052A
Cited
US2264291A
Cited
US2613209A
Cited
US2659709A
Cited
US2686812A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-06-22 | 1962-12-22 | 1963-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-06-22 | 1966-12-22 | 1967-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-06-22 | 1970-12-22 | 1971-06-23 | $7700.00 | Window Closed / Lapsed |