abstract |
A reactive polyurethane 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. The reactive polyurethane is produced by reacting polyester and/or polyether, which both have at least two functional groups that are reactive with isocyanate 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 with a molecular weight of 62 to 400 daltons and a functionality of 2 to 4; polyamines and/or alkanolamines; compounds with at least one functional group capable of producing anions and at least one functional group that is reactive with isocyanates; polyisocyanates and/or polyisocyanate adducts; blocking agents for the isocyanate groups and neutralizer. Also, a polyurethane dispersion containing the reactive polyurethanes. |