Polyurethane molding mass that can be processed thermoplastically

A method for producing a thermoplastically processable polyurethane molding mass, free of cyclic oligourethanes capable of migration, and demonstrating light-fastness, comprising the steps of:

• reacting one or more aliphatic polyols having a molecular weight of 450 to 4000 g/mol and an OH number of 20 to 235, selected from the group consisting of polycarbonates, polytetrahydrofurane, and copolymers thereof and mixtures of them, mixtures of either a polycarbonate or a polytetrahydrofurane with either a polyadipate or a polycaprolactone;
• and a mixture of:
• (1) polycaprolactones and copolymers thereof with polycarbonates, polytetrahydrofurans, polypropyleneglycol and polyethylene glycol;
• with (2) a member of the group consisting of polycarbonates, polytetrahydrofurans, polypropyleneglycol and polyethyleneglycol, with 1,6-hexamethylene diisocyanate and a chain lengthening agent selected from the group consisting of 1,5-pentane diol, 1,6-hexane diol, and 1,4-cyclohexane diol, with an equivalence ratio of the 1,6-hexamethylene diisocyanate to the polyol of 1.5:1 to 14.0:1, where the NCO characteristic number, formed from the quotient of the equivalence ratios of isocyanate groups to the sum of the hydroxyl groups of polyol and chain lengthening agent, multiplied by 100, lies in the range of 96 to 105, and wherein the polyol polycaprolactone is not used in combination with 1,6-hexanediol.