Spandex elastomers
AssigneeArco Chemical Technology, L.P.
InventorsStephen D. Seneker, Bruce D. Lawrey
Life of this patent
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Abstract
Spandex-type segmented polyurethane/urea elastomers having exceptional elongation, hysteresis, recovery, and other physical properties are prepared by the amine chain extension of an isocyanate-terminated prepolymer prepared by the reaction of a stoichiometric excess of isocyanate with a polyol blend comprising a low molecular weight diol having a molecular weight below 750 Da with a high molecular weight glycol which may be a 1500 Da to 20,000 Da molecular weight, ultra-low unsaturation polyoxypropylene glycol with an unsaturation of less than about 0.010 meq/g.
Claims16
An amine-extended, segmented polyurethane/urea spandex elastomer comprising the reaction product of:
- an isocyanate-terminated prepolymer having a free NCO group content of from about 0.5 percent to about 8 percent by weight, said prepolymer comprising the reaction product of:
- a) a stoichiometric excess of an isocyanate component comprising one or more diisocyanates;
- b) a glycol component comprising,
- b) i) a high molecular weight glycol component comprising in major part, one or more ultra-low unsaturation polyoxypropylene glycols individually having a molecular weight of between about 1500 Da and 20,000 Da and an unsaturation less than about 0.010 meq/g, and
- b) ii) a low molecular weight diol having a molecular weight less than 750 Da, such that the average molecular weight of said glycol component is from about 1000 Da to 10,000 Da,
- with
- a chain extender comprising one or more aliphatic diamine and/or cycloaliphatic diamine chain extender(s), wherein prior to reaction with said diamine chain extender, said isocyanate-terminated prepolymer is dissolved in a polar aprotic solvent.
A process for the preparation of an aliphatic diamine and/or cycloaliphatic diamine-extended, segmented polyurethane/urea spandex elastomer, comprising contacting one or more diamine chain extenders comprising one or more aliphatic diamines and/or cycloaliphatic diamines with a solution of an isocyanate-terminated prepolymer in an aprotic solvent, said isocyanate-terminated prepolymer comprising the reaction product of:
- a) a stoichiometric excess of an isocyanate component comprising one or more diisocyananes;
- b) a glycol component comprising,
- b) i) a high molecular weight glycol component comprising in major part, one or more ultra-low unsaturation polyoxypropylene glycols having a molecular weight of between about 1500 Da and 20,000 Da and an unsaturation less than about 0.010 meq/g, and
- b) ii) a low molecular weight diol having a molecular weight less than 750 Da, such that the average molecular weight of said glycol component is from about 1000 Da to 10,000 Da,
- to form a diamine chain extended polyurethane/urea spandex elastomer polymer.
A reaction spinning process for the production of an amine-extended, segmented polyurethane elastomer, comprising:
- a) selecting an isocyanate-terminated prepolymer having a free NCO group content of from about 0.5 percent to about 8 percent by weight, said prepolymer comprising the reaction product of:
- a stoichiometric excess of an isocyanate component comprising one or more diisocyanates;
- with
- a glycol component comprising a high molecular weight glycol component comprising in major part, one or more ultra-low unsaturation polyoxypropylene glycols individually having a molecular weight of between about 1500 Da and 20,000 Da and an unsaturation less than about 0.010 meq/g, and
- a low molecular weight diol having a molecular weight less than 750 Da, such that the average molecular weight of said glycol component is from about 1000 Da to 10,000 Da;
- b) introducing the prepolymer selected in step (a) into a chain extender solution containing one or more aliphatic diamines and/or cycloaliphatic diamines dissolved in a volatile solvent;
- c) withdrawing from said chain extender solution an amine-extended, segmented polyurethane/urea elastomer;
- and
- d) volatilizing any residual volatile solvent contained in said amine-extended, segmented polyurethane elastomer.
Dependencies are inferred from the claim text.