US3718619A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ucring polyurethane prepolymers with liquid extender comprising 4,4{40 -methylenebis(2-chloroaniline) and ethylene oxide capped bisphenol a
Assignee: Qo Chemicals Inc
•
Filing: 1971-08-27
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Granted: 1973-02-27
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Expires: 1991-08-27
Abstract
Abstract This invention relates to the curing of isocyanate terminated polyurethane prepolymers with a liquid extended consisting of 4,4''-methylenebis(2-chloroaniline) and ethylene oxide capped bisphenol A.
Inventors
- 👤 N Rustad
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:24
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/10
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
16 words
The method of claim 1 wherein the heating is at a temperature between 70*C. and 90*C.
Claim 2
Dependent Claim
21 words
The method of claim 1 wherein the number of equivalents of the polyurethane prepolymer and the liquid extender are substantially equal.
Claim 3
Dependent Claim
16 words
The method of claim 1 wherein the polyurethane prepolymer has an NCO/OH ratio of about 2/1.
Claim 4
Dependent Claim
19 words
The method of claim 1 wherein the ethylene oxide capped 4,4''-isopropylidenediphenol has an average molecular weight of about 500.
References Cited (Backward Citations)
US3316220A
Cited
US3583926A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-27 | 1976-08-28 | 1977-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-27 | 1980-08-28 | 1981-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-27 | 1984-08-28 | 1985-02-27 | $7700.00 | Window Closed / Lapsed |