US2857424A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of oxalic acid salts of phenylene diamines
Assignee: Universal Oil Products Co
•
Filing: 1955-08-25
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Granted: 1958-10-21
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Expires: 1975-08-25
Abstract
No abstract record available.
Inventors
- 👤 William L Cox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:45
CPC Classifications
C; C08; C08K; C08K5/00; C08K5/16; C08K5/17; C08K5/18; C10; C10L; C10L1/00; C10L1/10; C10L1/14; C10L1/22; C10L1/222; C10L1/223
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
38 words
IN THE REACTION OF A PHENYLENE DIAMINE WITH OXALIC ACID, THE IMPROVEMENT WHICH COMPRISES EFFECTING THE REACTION IN THE PRESENCE OF A DI-ALKYL KETONE HAVING FROM 1 TO ABOUT 4 CARBON ATOMS IN EACH F THE ALKYL GROUPS.
Claim 2
Dependent Claim
38 words
IN THE REACTION OF A PHENYLENE DIAMINE WITH OXALIC ACID, THE IMPROVEMENT WHICH COMPRISES EFFECTING THE REACTION IN THE PRESENCE OF A DI-ALKYL KETONE HAVING FROM 1 TO ABOUT 4 CARBON ATOMS IN EACH F THE ALKYL GROUPS.
References Cited (Backward Citations)
US1875903A
Cited
US2130947A
Cited
US2130948A
Cited
US2279385A
Cited
GB632997A
Cited
US2632770A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-10-20 | 1962-04-21 | 1962-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-10-20 | 1966-04-21 | 1966-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-10-20 | 1970-04-21 | 1970-10-21 | $7700.00 | Window Closed / Lapsed |