Use of modified diisocyanates for preparing linear TPU elastomers.

Use of modified diisocyanates for preparing linear TPU elastomers

U.S. patent: 5,013,811 Issued: May 7, 1991 Inventor: Bert A. Ross Assigned: Reeves Brothers, Inc. In the preparation of a linear thermoplastic polyurethane elastomer composition from a polyol component, a diisocyanate compound, a first extender component having a molecular weight of less than about 500 and a second extender component, the improvement which comprises lowering the processing temperature of said polyurethane by reacting the diisocyanate compound with said first extender in a molar ratio of above 2:1 to form a modified diisocyanate component having a functionality of about 2 prior to reacting the modified diisocyanate component with the polyol and second extender components, thus forming a linear thermoplastic polyurethane elastomer composition having lower temperature processing characteristic compared to similar compositions wherein the diisocyanate compound is not modified.