Patent US2315217A successfully refreshed from Google Patents.
US2658055A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Orientable condensation polymers of hydroxypivalic acid and process for preparing them
Assignee: EIDP Inc
•
Filing: 1951-08-24
•
Granted: 1953-11-03
•
Expires: 1971-08-24
Abstract
No abstract record available.
Inventors
- 👤 Alderson Thomas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 00:57
CPC Classifications
C; C08; C08G; C08G63/00; C08G63/02; C08G63/06
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
90 words
A PROCESS FOR PRODUCTION ORIENTABLE POLYMERS OF HYDROXYPIVALIC ACID WHICH COMPRISES HEATING A MEMBER OF THE GROUP CONSISTING OF HYDROXYPIVALIC ACID HAVING A MELTING POINT OF AT LEAST 122% C. AND CORRESPONDING HYDROXPIVALIC ACID ESTERS OF LOW BOILING ALIPHATIC ALCOHOLS AT TEMPERATURES IN THE RANGE OF 150-200* C. UNTIL RAPID EVOLUTION OF BY-PRODUCTS CEASES, AND THEN CONTINUING THE HEATING AT TEMPERATURES IN THE RANGE OF 200-275* C. AND AT LESS THAN 1 MM. OF MERCURY ABSOLUTE PRESSURE UNTIL A POLYMER HAVING AN INTRINSIC VISCOSITY OF AT LEAST 0.5 IS FORMED.
Claim 2
Dependent Claim
90 words
A PROCESS FOR PRODUCTION ORIENTABLE POLYMERS OF HYDROXYPIVALIC ACID WHICH COMPRISES HEATING A MEMBER OF THE GROUP CONSISTING OF HYDROXYPIVALIC ACID HAVING A MELTING POINT OF AT LEAST 122% C. AND CORRESPONDING HYDROXPIVALIC ACID ESTERS OF LOW BOILING ALIPHATIC ALCOHOLS AT TEMPERATURES IN THE RANGE OF 150-200* C. UNTIL RAPID EVOLUTION OF BY-PRODUCTS CEASES, AND THEN CONTINUING THE HEATING AT TEMPERATURES IN THE RANGE OF 200-275* C. AND AT LESS THAN 1 MM. OF MERCURY ABSOLUTE PRESSURE UNTIL A POLYMER HAVING AN INTRINSIC VISCOSITY OF AT LEAST 0.5 IS FORMED.
References Cited (Backward Citations)
US1095205A
Cited
GB550837A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-11-02 | 1957-05-04 | 1957-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-11-02 | 1961-05-04 | 1961-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-11-02 | 1965-05-04 | 1965-11-03 | $7700.00 | Window Closed / Lapsed |