| 摘要 |
The invention relates to methods for producing a reactive polyurethane composition, wherein in a first method step a monomer-free thermoplastic polyurethane comprising isocyanate-reactive groups is produced by reacting an isocyanate-reactive polymer, or a mixture of isocyanate-reactive polymers, having a content of at least 90 wt % of linear molecules with a polyisocyanate having a molecular weight of < 500 g/mol with a molar deficit of the isocyanate groups of the polyisocyanate relative to the isocyanate-reactive terminal groups of the polymer, or of the mixture of polymers, in a second method step said thermoplastic polyurethane is reacted with a low-monomer isocyanate-terminal prepolymer having a residual monomer content of no more than 0.5 wt % in a mol ratio of the isocyanate-reactive terminal groups of the thermoplastic polyurethane to the isocyanate groups of the prepolymer of 1:1.1 to 1:5 to form the reactive isocyanate group-containing polyurethane composition, wherein the method is carried out adding an inorganic filler component and optionally auxiliary agents, and the filler component contains particles of at least one filler which have a Mohs hardness of at least 6. The invention further relates to reactive polyurethane compositions which can be obtained from such methods, to the use thereof as coating compounds, and to objects containing such compositions as the surfaces.
|
