Patent ID: 6613867
Filing Date: 2003-09-02
Classification: C08G

Abstract:
A thermoplastic polyurethane or thermoplastic polyurethane/polyurea comprising structural units of:a) a diisocyanate; b) a first chain extender selected from the group consisting of ethylene glycol, diethylene glycol, and 1,3-propanediol; c) a second chain extender selected from the group consisting of i) a diol, ii) a diamine, and iii) an amino alcohol and having a molecular weight of less than 400 Daltons, with the proviso that the first chain extender is different from the second chain extender; and d) ethylene oxide polyol or ethylene oxide-capped propylene oxide polyol; wherein the mole ratio of the first chain extender to the second chain extender is not less than 1:1 and wherein the thermoplastic polyurethane or polyurethane/urea has: (i) a melting point of not less than 120Â° C. and not more than 230Â° C., (ii) a Shore D hardness of not more than 75 or a Tg of less than 25Â° C., (iii) a total optical transmission rate of at least 50 percent and (iv) a tensile strength of at least 800 psi.