NUCLEATING AGENT FOR COMPACT THERMOPLASTIC POLYURETHANES

The present invention relates to a process for producing a composition (I) at least comprising a compact thermoplastic polyurethane (P1), comprising the providing of at least one compact thermoplastic polyurethane (P1) or a reaction mixture for production of a compact thermoplastic polyurethane (R-P1), the adding of at least one compound (N) that has a conjugated, nitrogen-containing aromatic structure as nucleating agent to the at least one thermoplastic polyurethane (P1) or to the reaction mixture for production of a compact thermoplastic polyurethane (R-P1), wherein the compound (N) is a solid; and the mixing of the nucleating agent and the thermoplastic polyurethane (P1) or the reaction mixture (R-P1) to obtain a composition (I). The nucleating agent is used here in an amount in the range from 0.01% by weight to 2.0% by weight, based on the thermoplastic polyurethane (P1) or the reaction mixture (R-P1). Further relates the present composition comprising at least one compact thermoplastic polyurethane and at least one compound (N) that has a conjugated, nitrogen-containing aromatic structure as nucleating agent, wherein the compound (N) is a solid, and the use of the compounds mentioned as nucleating agents for a compact thermoplastic polyurethane.