Claims
- 1. A polyurethane which is the reaction product of
- (a) an oligomeric formal diol made by coupling segments of copolymers of tetrahydrofuran and an alkylene oxide whose ring contains 2 or 3 carbon atoms with formaldehyde, the diol having a number average molecular weight of 1200-12000,
- (b) an organic polyisocyanate, and
- (c) a chain extender.
- 2. The polyurethane of claim 1 in which the polyisocyanate is diphenylmethane-4,4'-diisocyanate or a toluene diisocyanate.
- 3. The polyurethane of claim 1 in which the chain extender is an aliphatic polyamine or an aromatic polyamine.
- 4. The polyurethane of claim 3 in which the chain extender is an aliphatic diol of 2-10 carbon atoms.
- 5. The polyurethane of claim 4 wherein the aliphatic diol is 1,4-butanediol.
- 6. An oligomeric formal diol made by coupling copolyether glycol segments with formaldehyde.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a divisional of copending application Ser. No. 188,877, filed Sept. 19, 1980, now U.S. Pat. No. 4,273,693.
US Referenced Citations (4)
Number |
Name |
Date |
Kind |
2961428 |
Muller et al. |
Nov 1960 |
|
3425999 |
Axelwood et al. |
Feb 1969 |
|
3959227 |
Chang et al. |
May 1976 |
|
4090990 |
Singh et al. |
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|
Foreign Referenced Citations (1)
Number |
Date |
Country |
850178 |
Sep 1960 |
GBX |
Non-Patent Literature Citations (1)
Entry |
Schonfeld, Journal of Polymer Science, vol. 59, pp. 87-92 (1962). |
Divisions (1)
|
Number |
Date |
Country |
Parent |
188877 |
Sep 1980 |
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