US2640044A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat stabilization of polyamides
Assignee: EIDP Inc
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Filing: 1951-05-24
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Granted: 1953-05-26
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Expires: 1971-05-24
Abstract
No abstract record available.
Inventors
- 👤 Gelu S Stamatoff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:37
CPC Classifications
C; C08; C08K; C08K3/00; C08K3/32; C01; C01B; C01B32/00; C01B32/30; C01B32/312; C01B32/336
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
69 words
A SYNTHETIC LINEAR POLYCARBONAMIDE WHICH IS STABILIZED AGAINST DEGRADATIVE EFFECTS OF HEAT AND OXYGEN BY THE ADDITION OF FROM 0.1 TO 1% BY WEIGHT OF A PHOSPHOROUS COMPOUND OF THE CLASS CONSISTING A PHOSPHOROUS ACIDS AND ALKALI METAL SALTS THEREOF AND FROM 0.5 TO 2.5% BY WEIGHT OF AN ALKALI METAL HALIDE, SAID POLYAMIDE BEING ONE HAVING RECURRING CARBONAMIDE GROUPS AS AN INTEGRAL PART OF THE MAIN POLYMER CHAIN.
Claim 2
Dependent Claim
69 words
A SYNTHETIC LINEAR POLYCARBONAMIDE WHICH IS STABILIZED AGAINST DEGRADATIVE EFFECTS OF HEAT AND OXYGEN BY THE ADDITION OF FROM 0.1 TO 1% BY WEIGHT OF A PHOSPHOROUS COMPOUND OF THE CLASS CONSISTING A PHOSPHOROUS ACIDS AND ALKALI METAL SALTS THEREOF AND FROM 0.5 TO 2.5% BY WEIGHT OF AN ALKALI METAL HALIDE, SAID POLYAMIDE BEING ONE HAVING RECURRING CARBONAMIDE GROUPS AS AN INTEGRAL PART OF THE MAIN POLYMER CHAIN.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-05-25 | 1956-11-24 | 1957-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-05-25 | 1960-11-24 | 1961-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-05-25 | 1964-11-24 | 1965-05-26 | $7700.00 | Window Closed / Lapsed |