Colloidal metal oxides having blocked isocyanate groups

摘要

The present invention relates to colloidal metal oxides having blocked isocyanate groups, which are based on the reaction product of A) blocked isocyanate group-containing silanes corresponding to formula (I) wherein R represents hydrogen or an organic group having 1 to 40 carbon atoms, X, Y and Z represent identical or different organic groups having 1 to 30 carbon atoms which are inert to isocyanate groups below 100 DEG C., provided that at least one of these groups is a C1-C4-alkoxy group, Q represents an organic group which contains at least one isocyanate group reacted with a blocking agent and n is 2, 3 or 4 with B) colloidal metal oxides selected from Al, Si, Ti, Ta, W, Hf, Zr, Sn and Y. The present invention also relates to the use of modified metal oxides, either alone or in combination with compounds containing at least two isocyanate-reactive groups, for the preparation of optionally expanded polyurethane plastics, lacquers or coating agents.