Moisture-curing alkoxysilane-terminated polyurethanes

Claim 1

Moisture-curing alkoxysilane-terminated polyurethanes obtained by preparing polyurethane prepolymers having an average NCO functionality of at least 1 and less than 2 in a first step by a) reaction of OH-terminated polyols with diisocyanates to form NCO-terminated polyurethane prepolymers having an average NCO functionality of at least 2 and subsequent partial reaction of the remaining NCO groups with monoalkyl polyether alcohols, with linear or branched aliphatic monofunctional alcohols containing 1 to 18 carbon atoms, or with both monoalkyl polyether alcohols and linear or branched aliphatic monofunctional alcohols or by a') reaction of OH-terminated polyols with a mixture of mono- and diisocyanates and, in a second step, reaction of substantially all the free NCO groups in the polyurethane prepolymers obtained in a), a'), or both with alkoxysilanes corresponding to the following general formula: ##STR5## in which X=NHR 2 , or (NH--CH 2 --CH 2 ) m --NHR 2 R=--CH 3 , --CH 2 CH 3 or OR 1 R 1 =an aliphatic, cycloaliphatic and/or aromatic hydrocarbon radical containing 1 to 10 carbon atoms R 2 =H and/or an aliphatic, cycloaliphatic and/or aromatic hydrocarbon radical containing 1 to 10 carbon atoms n=2 to 6 m=1 or 2.