US3709864A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyurethanes
Assignee: BASF Corp
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Filing: 1970-04-03
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Granted: 1973-01-09
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Expires: 1990-04-03
Abstract
Abstract MICROPOROUS LEATHER SUBSTITUTES ARE MADE FROM HIGH MOLECULAR WEIGHT LINEAR THERMOPLASTIC ELASTOMERIC POLYURETHANES OF I.V. 0.9-2 WHICH HAVE BEEN PREPARED BY REACTION IN SOLUTON IN DIMETHYLFORMAMIDE ("DMF") SOLVENT WHICH CONTAINS SUBSTANTIALLY NO FREE TERTIARY AMINE. A MONOFUNCTIONAL STRONG MINERAL ACID IS ADDED TO NEUTRALIZE FREE TERTIARY AMINE GROUPS. A HYDROXYL-TERMINATED PREPOLYMER AND A DIOL CHAIN EXTENDER ARE REACTED WITH A SMALL EXCESS OF DIISOCYANATE, UNTIL THE -NCO CONTENT BECOMES CONSTANT, THEN A DIOL CHAIN EXTENDER IN AMOUNT EQUIVALENT TO THE REMAINING -NCO AND REACTION IS CONTINUED, AND THEN TERMINATED WITH AN ALCOHOL AFTER THE HIGH I.V. IS ATTAINED.
Inventors
- 👤 F Loew
- 👤 E Stone
- 👤 F Civardi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:42
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/26; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/0838; C08G18/0842; C08G18/0847; C08G18/0852; C08G18/089; C08G18/10; C08G18/12; C08G18/16; C08G18/18; C08G18/28; C08G18/2805; C08G18/65; C08G18/66; C08G18/6603; C08G18/6607; C08G18/6611; C08G18/6633; C08G18/6637; C08G18/664; C08J9/28; D; D06; D06N; D06N3/00; D06N3/0002; D06N3/0015; D06N3/0025; D06N3/0027; D06N3/12; D06N3/14; C08J2375/00; C08J2375/04
Claims Analysis
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |