Patent US2821539A successfully refreshed from Google Patents.
US2821539A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Novel polymethylene glycol carbonates
Assignee: Texaco Inc
•
Filing: 1956-02-24
•
Granted: 1958-01-28
•
Expires: 1976-02-24
Abstract
No abstract record available.
Inventors
- 👤 Stanley R Newman
- 👤 Alpert Norman
- 👤 Robert Y Heisler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:30
CPC Classifications
C; C07; C07D; C07D317/00; C07D317/08; C07D317/10; C07D317/32; C07D317/34; C07D317/36; C07C; C07C69/00; C07C69/96
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
9 words
PENTAMETHYLENE GLYCOL BIS(GLYCOL ETHER CARBONATES) OF THE GENERAL FORMULA
Claim 2
Dependent Claim
9 words
PENTAMETHYLENE GLYCOL BIS(GLYCOL ETHER CARBONATES) OF THE GENERAL FORMULA
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-01-27 | 1961-07-29 | 1962-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-01-27 | 1965-07-29 | 1966-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-01-27 | 1969-07-29 | 1970-01-28 | $7700.00 | Window Closed / Lapsed |