Patent ID: 6979745

Claim:
A process for preparing organosilicon compounds which contain isocyanate groups and are comprised of units of the formula (Ia) R a (R 1 O) b X c SiO (4-a-b-c)/2 (Ia), said process comprising heating organosilicon compounds comprised of units of the formula (Ib) R a (R 1 O) b Y c SiO (4-a-b-c)/2 (Ib), where X is an SiC- or SiOC-bonded radical of the general formula (IIa) —(O) g —Z—NCO (IIa), Y is an SiC- or SiOC-bonded radical of the general formula (IIb) —(O) g —Z—NH—C(O)OR 2 (IIb), g is 0 or 1, Z is a divalent, optionally substituted hydrocarbon radical spacer which can be interrupted by O, S, N or P, R, R 1 , and R 2 are each independently a monovalent, SiC-bonded, optionally substituted hydrocarbon radical which can be interrupted by O, S, N or P, a and b are each independently 0, 1, 2 or 3, and c is 0, 1, 2, 3 or 4, with the provisos that the sum a+b+c≦4, that the organosilicon compounds comprising units of the formula (Ia) contain at least one radical X, that the organosilicon compounds comprising units of the formula (Ib) contain at least one radical Y, and that the organosilicon compounds comprising units of the formula (Ib) also contain halide, but in a content of not more than 10,000 ppm by weight.