Melt Processable Thermoplastic Polyurethane-Urea Elastomers

Abstract

The present invention relates to a melt processable thermoplastic polyurethane-urea composition formed by a continuous bulk process without the presence of solvent using a polyol component, an isocyanate component, and chain extender component comprising a hindered aromatic diamine.

1 . A thermoplastic polyurethane-urea elastomer comprising the reaction product of:
 (1) a polyol component;   (2) an isocyanate component; and   (3) a chain extender component, said chain extender component comprising hindered aromatic diamine   
       wherein the composition is made in a one-shot reaction process without using solvent in a continuous reactive extrusion wherein the composition comprises less than 20 mol % urea. 
     
     
         2 . (canceled) 
     
     
         3 . The thermoplastic polyurethane-urea elastomer of  claim 1 , wherein the thermoplastic polyurethane-urea elastomer is melt processable. 
     
     
         4 . The thermoplastic polyurethane-urea elastomer of  claim 1 , wherein the chain extender comprises diethyltoluenediamine. 
     
     
         5 . The thermoplastic polyurethane-urea elastomer of  claim 1  wherein the polyol component comprises a polycaprolactone polyol. 
     
     
         6 . The thermoplastic polyurethane-urea elastomer of  claim 1  wherein the chain extender component further comprises 1,4-butanediol. 
     
     
         7 . The thermoplastic polyurethane-urea elastomer of  claim 1  wherein the composition has a Shore A Hardness of about 60 A to about 95 A. 
     
     
         8 . (canceled) 
     
     
         9 . A process for making a melt-processable thermoplastic polyurethane-urea elastomer composition comprising:
 (1) adding a reaction mixture to a heated extruder, said reaction mixture comprising (a) a polyol component, (b) an isocyanate component; and (c) a chain extender component, said chain extender component comprising a hindered aromatic diamine;   (2) reacting said polyol component, said isocyanate component, and said chain extender component in a one-shot polymerization process in said heated extruder to form a thermoplastic polyurethane-urea elastomer composition, wherein the composition comprises less than 20 mol % urea;   (3) cooling said polyurethane-urea elastomer composition; and   (4) processing said polyurethane-urea elastomer composition.   
     
     
         10 . The process of  claim 9 , wherein said processing step includes forming pellets of polyurethane-urea elastomer composition. 
     
     
         11 . (canceled) 
     
     
         12 . The process of  claim 9  wherein the reaction mixture is substantially free of solvent. 
     
     
         13 . The process of  claim 9  wherein the chain extender component comprises diethyltoluenediamine. 
     
     
         14 . The process of  claim 9  wherein the polyol component comprises a polycarbonate polyol. 
     
     
         15 . A process for making a molded article from a thermoplastic polyurethane-urea composition comprising:
 (1) adding a reaction mixture to a heated extruder, said reaction mixture comprising (a) a polyol component, (b) an isocyanate component; and (c) a chain extender component, said chain extender component comprising diethyltoluenediamine;   (2) reacting said polyol component, said isocyanate component, and said chain extender component in a one-shot polymerization process in said heated extruder to form a thermoplastic polyurethane-urea elastomer composition, wherein the composition comprises less than 20 mol % urea;   (3) cooling said polyurethane-urea elastomer composition;   (4) processing said polyurethane-urea elastomer composition;   (5) melting said polyurethane-urea elastomer composition;   (6) molding the melted polyurethane-urea elastomer composition into an article.   
     
     
         16 . The process of  claim 15 , wherein said processing step includes forming pellets of polyurethane-urea elastomer composition. 
     
     
         17 . (canceled) 
     
     
         18 . The process of  claim 15  wherein the reaction mixture is substantially free of solvent. 
     
     
         19 . (canceled) 
     
     
         20 . The process of  claim 15  wherein the polyol component comprises a polycarbonate polyol.