US2648593A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Removing salts from polyacrylonitrile
Assignee: Dow Chemical Co
•
Filing: 1952-10-27
•
Granted: 1953-08-11
•
Expires: 1972-10-27
Abstract
No abstract record available.
Inventors
- 👤 George W Stanton
- 👤 Theodore B Lefferdink
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:34
CPC Classifications
D; D05; D05B; D05B1/00; D05B1/08; D05B1/18; D05B1/20; D01; D01F; D01F6/00; D01F6/02; D01F6/18; D01F6/28; D01F6/38; Y; Y10; Y10S; Y10S424/00; Y10S424/06
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
90 words
IN A METHOD FOR MAKING SHAPED ARTICLES BY COAGULATION OF AN AQUEOUS POLYVALENT METAL SALT-CONTAINING SALINE SOLUTION OF A POLYMER CONTAINING AT LEAST 85 PER CENT ACRYLONITRILE IN THE POLYMER MOLECULE, THE IMPROVEMENT WHICH CONSISTS IN IMMERSING THE ARTICLE, BEFORE IT HAS BEEN DRIED, IN AN AQUEOUS SOLUTION OF A WATER-SOLUBLE ALKALI METAL SALT OF A POLYPHOSPHORIC ACID AS A SEQUESTERING AGENT FOR THE POLYVALENT METAL IONS IN THE SALT CONTAINED IN THE COAGULATED ARTICLE, UNTIL THE SALT CONTENT IS REDUCED TO A NEGLIGIBLE VALUE, AND THEN DRYING THE ARTICLE.
Claim 2
Dependent Claim
90 words
IN A METHOD FOR MAKING SHAPED ARTICLES BY COAGULATION OF AN AQUEOUS POLYVALENT METAL SALT-CONTAINING SALINE SOLUTION OF A POLYMER CONTAINING AT LEAST 85 PER CENT ACRYLONITRILE IN THE POLYMER MOLECULE, THE IMPROVEMENT WHICH CONSISTS IN IMMERSING THE ARTICLE, BEFORE IT HAS BEEN DRIED, IN AN AQUEOUS SOLUTION OF A WATER-SOLUBLE ALKALI METAL SALT OF A POLYPHOSPHORIC ACID AS A SEQUESTERING AGENT FOR THE POLYVALENT METAL IONS IN THE SALT CONTAINED IN THE COAGULATED ARTICLE, UNTIL THE SALT CONTENT IS REDUCED TO A NEGLIGIBLE VALUE, AND THEN DRYING THE ARTICLE.
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) | 1956-08-10 | 1957-02-09 | 1957-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-08-10 | 1961-02-09 | 1961-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-08-10 | 1965-02-09 | 1965-08-11 | $7700.00 | Window Closed / Lapsed |