| 摘要 |
The invention relates to a method for producing dendritic or hyperbranched polyurethanes consisting in 1) reacting diols and polyiols which contain at least one tertiary nitrogen atom, at least two hydroxyl groups provided with a different reactivity to isocyanate groups, with diisocyanates or polyisocyanates for obtaining an addition product, the diols and polyiols and diisocyanates or polyisocyanates being selected in such a way that said addition product contains in average one isocyanate group and several hydroxyl groups, or one hydroxyl group and several isocyanate groups; 2) transforming the addition product obtained at the stage 1) into a polyaddition product by an intermolecular reaction of the hydroxyl groups with isocyanate groups, said reaction can be preliminary carried out with a compound containing at least two hydroxyl, mercapto, amino or isocyanate groups; 3) if necessary, reacting the polyaddition product obtained at the stage 2) with the compound containing at least two hydroxyl, mercapto, amino or isocyanate groups.
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