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Abstract

The present invention relates to methods for producing a reactive polyurethane composition, by preparing in a first method step a monomer-free thermoplastic polyurethane having isocyanate-reactive groups from an isocyanate-reactive polymer or from a mixture of isocyanate-reactive polymers having a fraction of at least 90 wt % of linear molecules, by reaction with a polyisocyanate having a molecular weight <500 g/mol, in a molar deficit of the isocyanate groups of the polyisocyanate relative to the isocyanate-reactive end groups of the polymer or of the mixture of polymers, and in a second method step reacting said thermoplastic polyurethane with a low-monomer-content, isocyanate-terminal prepolymer having a residual monomer content of not greater than 0.5 wt %, in a molar ratio of the isocyanate-reactive end groups of the thermoplastic polyurethane to the isocyanate groups of the prepolymer of 1:1.1 to 1:5, to give the polyurethane composition containing reactive isocyanate groups, where the method takes place with addition of an inorganic filler component and optionally of auxiliaries and the filler component comprises particles of at least one filler which have a Mohs hardness of at least 6. The present invention further relates to reactive polyurethane compositions obtainable from such methods, to the use thereof as coating material, and to articles featuring such compositions as their surface.

First Claim