| 摘要 |
The invention relates to reactive polyurethane (1) with a number average molecular weight Mn of 800 to 14,000 daltons, a branching degree of 0.0 to 3.0 Mol/kg and an isocyanate functionality of 2.0 to 6.0. Said reactive polyurethane is produced by reacting polyester (1.1) and/or polyether (1.2), which both have at least two functional groups that are reactive with isocyanates and which have a molecular weight of 400 to 2,500 daltons and a branching degree of 0 to 3.5 Mol/kg; with at least one polyol (1.3) with a molecular weight of 62 to 400 daltons and a functionality of 2 to 4; polyamines (1.4) and/or alkanolamines (1.5); compounds (1.6) with at least one functional group capable of producing anions and at least one, especially at least two, functional groups that are reactive with isocyanates; polyisocyanates (1.7) and/or polyisocyanate adducts (1.8); blocking agents (1.9) for the isocyanate groups and neutralizers (1.10). The invention further relates to polyurethane dispersions containing the reactive polyurethanes and to their use for producing solvent-free coating substances, especially base coats, clear varnishes or plain coating varnishes.
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