Microcellular elastomers with improved processability and properties
AssigneeArco Chemical Technology, L.P.
InventorsDavid J. Ho, William A. Gill, Susan M. Clift, Nigel Barksby
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Abstract
Microcellular polyurethane elastomer shoe sole components have exceptional physical properties may be prepared from isocyanate-terminated prepolymers derived from polyoxypropylene diols having a molecular weight of from about 2000 Da to 8000 Da, an unsaturation less than about 0.02 meq/g, and a random oxyethylene content of from about 5 to about 15 weight percent. The shoe sole components exhibit high tensile strength, elongation, resilience, and in addition have excellent tear strength, particularly 90.degree. angle tear.
Claims14
A microcellular polyurethane shoe sole component, comprising:
- the catalyzed reaction product of
- a) an isocyanate component comprising an isocyanate-terminated prepolymer having an NCO group content of from 12 to 20 weight percent comprising the reaction product of a stoichiometric excess of one or more di- or polyisocyanate with a polyoxypropylene diol, said diol having an unsaturation lower than about 0.02 meq/g, containing from 5 to 15 weight percent random oxyethylene moieties, and having a molecular weight between about 2000 Da and 8000 Da;
- with
- b) a resin component, comprising:
- b)i) an aliphatic or cycloaliphatic diol chain extender having a molecular weight of less than about 400 Da;
- b)ii) optionally, one or more polyol polymer dispersions;
- and
- b)iii) water in an amount effective to provide a microcellular density of from about 0.15 to about 0.60 g/cm.sup.3
- at an isocyanate index of from about 85 to 115.
A method of improving the physical properties of microcellular polyurethane shoe sole components prepared by the reaction of an isocyanate component with a resin component containing a diol chain extender, said method comprising:
- selecting as a major portion of said isocyanate component, an isocyanate-terminated prepolymer having an NCO group content of from about 12 to about 20 weight percent, said prepolymer prepared by reacting a stoichiometric excess of one or more di- or polyisocyanates with a polyoxypropylene diol, said diol having an unsaturation less than about 0.02 meq/g, containing from about 5 to about 15% random oxyethylene moieties, and having a molecular weight of from about 2000 Da to 8000 Da;
- and
- reacting said isocyanate component with a diol chain extender component at an index of from about 75 to about 130 in the presence of an amount of water effective to produce a microcellular elastomer having a density of from about 0.15 g/cm.sup.3 to about 0.60 g/cm.sup.3.
Dependencies are inferred from the claim text.