| 摘要 |
Proposed is a process for preparing a reactive polyurethane composition that is characterized in that in a first process stage, from an isocyanate-reactive polymer or mixture of isocyanate-reactive polymers with a fraction of at least 90%, preferably at least 95%, more preferably at least 99% by weight of linear molecules, by reaction with a polyisocyanate having a molecular weight <500, in a molar deficit of the isocyanate groups of the polyisocyanate relative to the isocyanate-reactive end groups of the polymer or mixture of polymers, a monomer-free thermoplastic polyurethane is prepared which in a second process stage is reacted with a low-monomer-content, isocyanate-terminal prepolymer, 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 isocyanate-reactive polyurethane composition. |
