THERMOPLASTIC POLYURETHANE COMPOSITIONS EXHIBITING IMPROVED UV AND HEAT RESISTANCE

The invention provides thermoplastic polyurethane compositions comprising one or more thermoplastic polyurethanes A) one or more acrylate based rubbers B), and one or more UV and/or heat stabilizers C), wherein the thermoplastic polyurethane composition of A) + B) + C) has a greater UV stability as compared to a thermoplastic polyurethane composition of A) + C), wherein (a.) UV stability is measured as the difference between (1.) Delta E versus white tile after molded, and (2.) Delta E versus white tile after 1000 hours of QUV (b.) increasing stability is indicated by minimization of the difference between (1.) and (2.).More particularly, the instant invention provides thermoplastic polyurethane composition comprising one or more thermoplastic polyurethanes A) comprising the reaction product of (i) polyetherols and (ii) aromatic isocyanates, one or more acrylate based rubbers B) having a core comprised of a partially crosslinked C1-6 alkylacrylate and a shell comprised of a C1-6 alkylmethacrylate, and one or more UV and/or heat stabilizers C) comprising an active ingredient which is 2-(2-hydroxy-3,5,di-tert-amyl-phenyl)-2H-benzotriazole, 1,6-hexanediylbis(3-benzotriazol-N-yl)-4-hydroxy-5-tert-buty l) phenyl propionate, and mixtures thereof, wherein the resulting thermoplastic polyurethane composition of A) + B) + C) has a 50 percent greater UV stability than thermoplastic polyurethane composition of A) + C), when (a.) UV stability is measured as the difference between (1.) Delta E versus white tile after molded and (2.) Delta E versus white tile after 1000 hours of QUV, and (b.) increasing stability is indicated by minimization of the difference between (1.) and (2.). The invention further provides a process of making molded thermoplastic polyurethane articles using the aforementioned thermoplastic polyurethane compositions. La presente invencion proporciona composiciones de poliuretano termoplastico que comprenden uno o más poliuretanos termoplasticos A)uno o más cauchos a base de acrilato B), y uno o más estabilizadores de luz ultravioleta y/o térmico C), en donde la composicion de poliuretano termoplastico de A) + B) + C tiene una estabilidad a la luz ultravioleta mayor en comparacion con una composicion de poliuretano termoplástico de A) + C), en donde (a.) la estabilidad a la luz ultravioleta se mide como la diferencia entre (1.) Delta E versus un mosaico blanco después de moldearse, y (2.) Delta E versus un mosaico blanco después de 1000 horas de QUV