Polyurethane/ureas useful for the production of spandex and a process for their production
AssigneeBayer MaterialScience AG
InventorBruce D. Lawrey
Life of this patent
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Abstract
Segmented polyurethane/ureas useful in the production of spandex are produced by chain extending an isocyanate-terminated prepolymer in the presence of a solvent. The isocyanate-terminated prepolymer is formed by reacting a stoichiometric excess of an isocyanate with an isocyanate-reactive component that includes more than 50 equivalent percent of a high molecular weight polyoxyalkylene diol having an unsaturation level no greater than about 0.015 meq/g and up to about 50 equivalent percent of a polytetramethylene ether glycol.
Claims14
A segmented polyurethane/urea produced by reacting in solution:
- a) an isocyanate-terminated prepolymer having a free isocyanate group content of from about 1.0 to about 3.75% which is the reaction product of
- (1) a stoichiometric excess of at least one diisocyanate with
- (2) an isocyanate-reactive component comprising:
- (i) a diol component which comprises
- (a) at least 50 equivalent percent of at least one polyoxypropylene diol having a molecular weight of at least 1500 Da and an average unsaturation level less than or equal to 0.015 meq/g, and
- (b) up to 50 equivalent percent of at least one polytetramethylene ether glycol having a molecular weight of at least about 600 Da and, optionally,
- (ii) one or more other materials containing at least one functional group that is reactive with an isocyanate group, provided that the sum of the equivalent weight percents of (i) and (ii) is 100 equivalent percent, with
- b) a chain extender in the presence of
- c) a solvent.
A process for the production of spandex fiber comprising spinning a polyurethane/urea which is the reaction product of:
- a) an isocyanate-terminated prepolymer having a free isocyanate group content of from about 1.0 to about 3.75% which is the reaction product of
- (1) a stoichiometric excess of a diisocyanate with
- (2) an isocyanate-reactive component comprising
- (i) a diol component comprising
- (a) at least 50 equivalent percent of at least one polyoxypropylene diol having a molecular weight in excess of about 1500 Da and an average unsaturation level less than or equal to 0.015 meq/g, and
- (b) up to about 50 equivalent percent of at least one polytetramethylene ether glycol having a molecular weight of at least 600 Da;
- and, optionally,
- (ii) one or more other materials containing at least one functional group that is reactive with an isocyanate group, provided that the sum of the equivalent weight percents of (i) and (ii) is 100 equivalent percent, with
- b) a chain extender in
- c) a solvent.
Dependencies are inferred from the claim text.