| 摘要 |
The invention describes a process for the preparation of N,o-substituted mono- and/or polyurethanes of formula R1[-NHCOOR2]n, in which R1 is an aliphatic, cycloaliphatic, aromatic, araliphatic, or heterocyclic radical, which may be substituted, R2 is an aliphatic, cycloaliphatic, or araliphatic radical which may be substituted with alkoxy or polyoxyalkylene groups, and n is a whole number from 1 to 5, through the reaction of N-substituted allophanates and/or polyallophanates with alcohols R2OH in the presence or absence of catalysts at temperatures of at least 160 DEG C., preferably from 165 DEG to 250 DEG C.
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