| 主权项 |
1. A composition, comprising an olefinically functionalized siloxane oligomer having not more than one olefinic radical on a silicon atom thereof,
wherein the olefinically functionalized siloxane oligomer has a Si—O-crosslinked structural element which forms catenary, cyclic, crosslinked or optionally three-dimensionally crosslinked structures, with a structure of formula I,
(R1O)[(R1O)1-x(R2)xSi(A)O]a[Si(Y)2O]c[Si(B)(R4)y(OR3)1-yO]bR3 (I), the structural elements are derived from alkoxysilanes, wherein A is an olefinic radical selected from a linear, branched or cyclic alkenyl- or cycloalkenyl-alkylene-functional group having in each case 2 to 16 C atoms, and B is a saturated hydrocarbon radical selected from a linear, branched or cyclic alkyl radical having 1 to 16 C atoms, Y is OR3 or, in crosslinked and optionally three-dimensionally crosslinked structures, independently at each occurrence, OR3 or O1/2, where R1 independently at each occurrence is a linear, branched or cyclic alkyl radical having 1 to 4 C atoms or H, R3 independently at each occurrence is a linear, branched or cyclic alkyl radical having 1 to 4 C atoms or H, R2 independently at each occurrence is a linear, branched or cyclic alkyl radical having 1 to 15 C atoms, and R4 independently at each occurrence is a linear, branched or cyclic alkyl radical having 1 to 15 C atoms, a, b, c, x and y are each independently an integer, wherein 1≦a, 0≦b, 0≦c, x independently at each occurrence is 0 or 1, y independently at each occurrence is 0 or 1, and (a+b+c)≧2, where the structural elements [(R1O)1-x(R2)xSi(A)O]a, [Si(B)(R4)y(OR3)1-yO]b and [Si(Y)2O]c, in relation to all silicon atoms of formula I, are present at less than or equal to 80% and greater than or equal to 30% as M structure, a weight-average molecular weight (Mw) is greater than or equal to 315 g/mol, and an amount of residues of the acid catalyst during preparation is less than or equal to 250 mg/kg of composition. |
