Patent US3185656A successfully refreshed from Google Patents.
US3185656A
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Preparation of linear polyureas utilizing a cyclic amide solvent
Assignee: WR Grace and Co
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Filing: 1961-03-23
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Granted: 1965-05-25
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Expires: 1981-03-23
Abstract
No abstract record available.
Inventors
- 👤 Gabler Rudolf
- 👤 Muller Helmut
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:02
CPC Classifications
C; C08; C08L; C08L75/00; C08L75/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
79 words
THE PROCESS FOR THE PRODUCTION OF A LINEAR, FIBERFORMING POLYUREA BY THE CONDENSATION OF UREA AND A DIAMINE SELECTED FROM THE GROUP CONSISTING OF A LINEAR ALIPHATIC DIAMINE AND A CYCLOALIPHATIC DIAMINE WHICH COMPRISES DISSOLVING THE REACTANTS IN A SOLVENT, HEATING THE RESULTING SOLUTION AT AN ELEVATED TEMPERATURE BELOW 200*C. UNTIL THE EVOLUTION OF AMMONIA CEASES, AND SUBSEQUENTLY CONTINUING HEATING AT A TEMPERATURE FROM ABOVE 200*C. UP TO ABOUT 260*C., SAID SOLVENT BEING A CYCLIC AMIDE HAVING THE STRUCTURE
Claim 2
Dependent Claim
79 words
THE PROCESS FOR THE PRODUCTION OF A LINEAR, FIBERFORMING POLYUREA BY THE CONDENSATION OF UREA AND A DIAMINE SELECTED FROM THE GROUP CONSISTING OF A LINEAR ALIPHATIC DIAMINE AND A CYCLOALIPHATIC DIAMINE WHICH COMPRISES DISSOLVING THE REACTANTS IN A SOLVENT, HEATING THE RESULTING SOLUTION AT AN ELEVATED TEMPERATURE BELOW 200*C. UNTIL THE EVOLUTION OF AMMONIA CEASES, AND SUBSEQUENTLY CONTINUING HEATING AT A TEMPERATURE FROM ABOVE 200*C. UP TO ABOUT 260*C., SAID SOLVENT BEING A CYCLIC AMIDE HAVING THE STRUCTURE
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-05-24 | 1968-11-23 | 1969-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-05-24 | 1972-11-23 | 1973-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-05-24 | 1976-11-23 | 1977-05-25 | $7700.00 | Window Closed / Lapsed |