Patent US2438520A successfully refreshed from Google Patents.
US2438520A
Expired / Lapsed
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Polymers of unsaturated oxysilicols
Assignee: Unifrax I LLC
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Filing: 1943-03-15
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Granted: 1948-03-30
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Expires: 1963-03-15
Abstract
No abstract record available.
Inventors
- 👤 Norman P Robie
- 👤 Fred E Sheibley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:00
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/04; C08G77/20
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1809755A
Cited
DE528988C
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US2027931A
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US2160942A
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US2329632A
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US2253128A
Cited
US2276094A
Cited
US2318959A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-03-30 | 1951-09-29 | 1952-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-03-30 | 1955-09-29 | 1956-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-03-30 | 1959-09-29 | 1960-03-30 | $7700.00 | Window Closed / Lapsed |