US2504049A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of polymethacrylic acid and of polymeric products containing polymethacrylic acid
Assignee: EIDP Inc
•
Filing: 1946-03-04
•
Granted: 1950-04-11
•
Expires: 1966-03-04
Abstract
No abstract record available.
Inventors
- 👤 Lawrence M Richards
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:53
CPC Classifications
C; C08; C08F; C08F8/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
67 words
A PROCESS FOR THE PREPARATION OF POLYMETHACRYLIC ACID WHICH COMPRISES DISSOLVING AN ESTER OF POLYMETHACRYLIC ACID IN AN EXCESS OF SULFURIC ACID OF 90 TO 100% CONCENTRATION, AGING THE RESULTING ACID SOLUTION OF SAID ESTER FOR A PERIOD OF AT LEAST ONE HOUR AT A TEMPERATURE OF 25* TO 100* C., THEN DILUTING THE AGED ACID SOLUTION WITH WATER AND ISOLATING THEREFROM THE POLYMETHACRYLIC ACID SO OBTAINED.
Claim 2
Dependent Claim
67 words
A PROCESS FOR THE PREPARATION OF POLYMETHACRYLIC ACID WHICH COMPRISES DISSOLVING AN ESTER OF POLYMETHACRYLIC ACID IN AN EXCESS OF SULFURIC ACID OF 90 TO 100% CONCENTRATION, AGING THE RESULTING ACID SOLUTION OF SAID ESTER FOR A PERIOD OF AT LEAST ONE HOUR AT A TEMPERATURE OF 25* TO 100* C., THEN DILUTING THE AGED ACID SOLUTION WITH WATER AND ISOLATING THEREFROM THE POLYMETHACRYLIC ACID SO OBTAINED.
References Cited (Backward Citations)
US2205883A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-04-10 | 1953-10-10 | 1954-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-04-10 | 1957-10-10 | 1958-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-04-10 | 1961-10-10 | 1962-04-11 | $7700.00 | Window Closed / Lapsed |