| 摘要 |
The invention relates to prepolymers (A) with end groups of general formula [1]: -A-CH2-SiR1a(OR2)3- a, where A = a bivalent linking group selected from -O-, -S-, -(R 3)N-, -O-CO-N(R3)-, -N(R3)-CO-O-, -NH-CO-NH-, - N(R4)-CO-NH-, -NH-CO-N(R4)-, -N(R4)-CO-N(R 4)-, R1 = optionally halogenated alkyl, cycloalkyl, alkenyl or aryl with 1-10 C atoms, R2= 1-6 C alkyl or omega-oxaalkyl with 2-10 C atoms in total, R3 = H, optionally halogenated, linear or branched 1-18C alkyl or alkenyl, or 6-18C aryl, R4 = optionally halogenated cyclic, linear or branched 1-18C alkyl or alkenyl, or 6-18C aryl and a = 0, 1 or 2, whereby the prepolymers (A) may be obtained by reaction of isocyanate-functionalised prepolymers (A1) with alkoxysilanes (A2), which have at least one isocyanate-reactive group and optionally further components, with the proviso that the alkoxysilanes (A2) are applied in excess, such that the ratio of isocyanate-reactive groups to isocyanate groups is at least 1.2:1.
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