Patent ID: 7588707

Claim:
A process for making a multilayer tube comprising: providing a hard aliphatic polyurethane selected from the group consisting of polyether polyurethane and polycarbonate polyurethane having a Shore hardness from about 95A to about 85D as measured according to ASTM D2240, with the proviso that if said aliphatic polyurethane is a polycarbonate polyurethane, said Shore hardness of said hard aliphatic polyurethane is from about 70A to about 80D, and a soft aliphatic polyether polyurethane having a Shore hardness from about 40A to about 95A as measured according to ASTM D2240; coextruding said soft aliphatic polyurethane and said hard aliphatic polyurethane to form a multilayer tube; wherein both of said soft aliphatic polyurethane and said hard aliphatic polyurethane are biocompatible and biostable.