Patent ID: 6852822

Claim:
A method for preparing silicic acid polycondensates or silicic acid heteropolycondensates comprising hydrolytically condensing one or more hydrolytically condensable compounds of silicon, said hydrolytically condensable compound optionally comprising one or more elements selected from the group consisting of B, AI, P, Sn, Pb, the transition metals, the lanthanides and the actinides, said condensable compound optionally comprising precondensates of the compound; the reaction optionally comprising one or more of (i) a catalyst, (ii) a solvent, (iii) an ionically polymerizable compound and (iv) a free-radical polymerizable compound; wherein 5 to 100% mol % based on monomeric compounds of the hydrolytically condensable compounds are silanes of the general formula I: B{(A) d —R′—U—R′—SiX a R b } c (I) in which: B is a mono- to tetravalent, straight-chained or branched organic radical with at least one C═C double bond and 4 to 50 carbon atoms; X is hydrogen, halogen, hydroxy, alkoxy, acyloxy, alkylcarbonyl, alkoxycarbonyl or NR″ 2 ; R is alkyl, alkenyl, aryl, alkylaryl or arylalkyl; R′ is alkylene, alkenylene, arylene, arylenealkylene or alkylenearylene having 2 to 10 carbon atoms, these radicals being able to be interrupted by oxygen and sulphur atoms or by amino groups; R′ is hydrogen, alkyl or aryl; U is an inorganically modified organic radical comprising a siloxane or carbosiloxane framework having atoms that are silicon or germanium or a carbosilane framework having at least one atom that is silcon or germanium, said framework having 1 to 15 C atoms and up to 5 additional heteroatoms that are O, S or N; A is C(═O)O, OC(═O)O, C(═O), O, S, C(═O)NR″, OC(═O), or NR″(═O); a = 1, 2 or 3; b = 0, 1 or 2; a + b = 3; c = 1, 2, 3 or 4; and d = 0 or 1.