Patent US1534758A successfully refreshed from Google Patents.
US3558531A
Expired / Lapsed
US
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Process for closed-cell rigid polyurethane foams
Assignee: United States Atomic Energy Commission
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Filing: 1968-03-28
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Granted: 1971-01-26
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Expires: 1988-03-28
Abstract
Abstract ISOTROPIC LOW-DENSITY CLOSED-CELL RIGID POLYURETHANE FOAMS ARE PREPARED FROM POLYETHER POLYOLS AND POLYISOCYANATES, USING A CYCLOPENTANE-ACETONE MIXTURE AS A PNEUMATOGEN AND FINELY-POWDERED POLYETHYLENE AS A NUCLEATING AGENT.
Inventors
- 👤 Ival O Salyer
- 👤 Robert T Jefferson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 03:42
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/0061; C08J9/04; C08J9/12; C08J9/14; C08J2375/00; C08J2375/04; C08J2375/08; C08J2423/00
Claims Analysis
Total Claims: 0
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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) | 1974-01-25 | 1974-07-27 | 1975-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-25 | 1978-07-27 | 1979-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-25 | 1982-07-27 | 1983-01-26 | $7700.00 | Window Closed / Lapsed |