Patent US2991273A successfully refreshed from Google Patents.
US2991273A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for manufacture of vacuum moulded parts of high molecular weight thermoplastic polycarbonates
Assignee: Bayer AG
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Filing: 1957-07-02
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Granted: 1961-07-04
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Expires: 1977-07-02
Abstract
No abstract record available.
Inventors
- 👤 Hechelhammer Wilhelm
- 👤 Peilstocker Gunter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:04
CPC Classifications
C; C08; C08G; C08G64/00; C08G64/04; C08G64/06; Y; Y10; Y10S; Y10S273/00; Y10S273/01
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
66 words
IN THE PROCESS OF MANUFACTURING FAITHFULLY MOLDED IMPACT-RESISTANT PLASTIC ARTICLES, THE STEPS OF PROVIDING A SHEET OF RESINOUS THERMOPLASTIC LINEAR POLYCARBONATE OF A DI-MONOHYDROXYARYLENE ALKANE, SAID SHEET CONTAINING LESS THAN 0.05% WATER AND SAID POLYCARBONATE HAVING A KVALUE OF AT LEAST 50 MEASURED IN A 0.5% SOLUTION IN METHYLENE CHLORIDE, HEATING THE SHEET UNTIL IT REACHES A MOLDING PLASTICITY, AND THEN VACUUM MOLDING THE HEATED SHEET.
Claim 2
Dependent Claim
66 words
IN THE PROCESS OF MANUFACTURING FAITHFULLY MOLDED IMPACT-RESISTANT PLASTIC ARTICLES, THE STEPS OF PROVIDING A SHEET OF RESINOUS THERMOPLASTIC LINEAR POLYCARBONATE OF A DI-MONOHYDROXYARYLENE ALKANE, SAID SHEET CONTAINING LESS THAN 0.05% WATER AND SAID POLYCARBONATE HAVING A KVALUE OF AT LEAST 50 MEASURED IN A 0.5% SOLUTION IN METHYLENE CHLORIDE, HEATING THE SHEET UNTIL IT REACHES A MOLDING PLASTICITY, AND THEN VACUUM MOLDING THE HEATED SHEET.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-07-03 | 1965-01-02 | 1965-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-07-03 | 1969-01-02 | 1969-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-07-03 | 1973-01-02 | 1973-07-04 | $7700.00 | Window Closed / Lapsed |