US3179625A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyurethane prepolymer stabilization with acids
Assignee: Armstrong World Industries Inc
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Filing: 1961-08-01
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Granted: 1965-04-20
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Expires: 1981-08-01
Abstract
No abstract record available.
Inventors
- 👤 Wendell A Ehrhart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:23
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/10; C08G18/089
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
107 words
A METHOD OF PREPARING A HEAT-STABLE ISOCYANATOTERMINATED POLYURETHANE PREPOLYMER WHICH COMPRISES HEATING A MIXTURE OF AN EXCESS OF ORGANIC DIISOCYANATE HAVING NO REACTIVE GROUPS ON THE MOLECULE THAN THE ISOCYANATO GROUPS WITH A POLYMER SELECTED FROM THE GROUP CONSISTING OF POLYETHERS AND POLYESTERS TO CAUSE CHAINEXTENTION OF SAID POLYMER AND THE FORMATION OF SAID ISOCYANATO-TERMINATED POLYURETHANE PREPOLYMER, CONTINUING TO HEAT SAID MIXTURE TO ACHIEVE THE DESIRED DEGREE OF BRANCHING AND CROSS-LINKING IN SAID PREPOLYMER, AND SUBSEQUENTLY ADDING TO SAID HEATED MIXTURE TO STOP SUBSEQUENT BRANCHING AND CROSS-LINKING 0.0011-2% BY WEIGHT BASED ON THE WEIGHT OF SAID MIXTURE OF AN ACID HAVING A DSSOCIATION CONSTANT GREATER THAN 1X10**-5.
Claim 2
Independent Claim
107 words
A METHOD OF PREPARING A HEAT-STABLE ISOCYANATOTERMINATED POLYURETHANE PREPOLYMER WHICH COMPRISES HEATING A MIXTURE OF AN EXCESS OF ORGANIC DIISOCYANATE HAVING NO REACTIVE GROUPS ON THE MOLECULE THAN THE ISOCYANATO GROUPS WITH A POLYMER SELECTED FROM THE GROUP CONSISTING OF POLYETHERS AND POLYESTERS TO CAUSE CHAINEXTENTION OF SAID POLYMER AND THE FORMATION OF SAID ISOCYANATO-TERMINATED POLYURETHANE PREPOLYMER, CONTINUING TO HEAT SAID MIXTURE TO ACHIEVE THE DESIRED DEGREE OF BRANCHING AND CROSS-LINKING IN SAID PREPOLYMER, AND SUBSEQUENTLY ADDING TO SAID HEATED MIXTURE TO STOP SUBSEQUENT BRANCHING AND CROSS-LINKING 0.0011-2% BY WEIGHT BASED ON THE WEIGHT OF SAID MIXTURE OF AN ACID HAVING A DSSOCIATION CONSTANT GREATER THAN 1X10**-5.
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) | 1968-04-19 | 1968-10-19 | 1969-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-04-19 | 1972-10-19 | 1973-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-04-19 | 1976-10-19 | 1977-04-20 | $7700.00 | Window Closed / Lapsed |