Patent ID: 8067522

Claim:
A process for preparing an alkoxysilane-functional prepolymer comprising reacting A) 1.0 equivalent of a polyol component having a number average molecular weight of 3000 g/mol to 20,000 g/mol and comprising one or more polyoxyalkylene polyols or polyoxyalkylene polyol prepolymers with B) 1.05 to 1.50 equivalents of an isocyanate- and alkoxysilane-functional compound of the formula I), wherein X, Y, and Z independently of one another are linear or branched C 1 -C 8 alkyl or C 1 -C 8 alkoxy radicals, wherein at least one of the radicals is a C 1 -C 8 alkoxy group and R is an organic radical having a functionality of at least two, and subsequently further reacting the remaining free NCO groups by allophanatization such that after the further reacting of the remaining free NCO groups, the amount of NCO groups remaining is less than 0.05% by weight, based on the weight of the reaction mixture.