Roscher, C.C.RoscherPopall, M.M.PopallOlsowski, B.E.B.E.Olsowski2022-03-082022-03-082004https://publica.fraunhofer.de/handle/publica/306516Silanes of formula (I) are new. (Z)fSiRaXb (I) In (I): Z = (R'-(Y)e)c+1(C6F4-c)(C6F4)d; R = opt. substd. 1-15 C alk(en)yl, (alkyl)aryl or arylalkyl, opt. with O, S, ester, carbonyl, amido or amino gps. in the chain or ring; R' = I, Br, Cl (if d is not 0), F (if d is not 0), H (if X is not H or R is not Me or e = 1) or a 1-50 C organic gp.; X = H, halogen, OH, alkoxy, acyloxy, alkylcarbonyl, alkoxycarbonyl or NR''2; R'' = H, alkyl or aryl; Y = O, S, NH or NR' with R' = a 1-50 C organic gp.; a = 0, 1 or 2; b and f = 1, 2 or 3; c and e = 0 or 1; d = 0-9; and (a+b+f) = 4. Also claimed is the use of (I) in a process for preparing poly(hetero)silicates. USE - (I) are used in the prepn. of poly(hetero)silicates, bulk materials, composites, adhesives, casting and sealing compsns., coating materials, abrasives, coatings, adhesion promoters, fillers, fibres, films, contact lenses, binders for particles and materials for optical or optoelectronic devices (all claimed). The polycondensates are use ful as scratch-resistant coatings, filling, adhesive and sealing compsns., mouldings or encapsulation materials. ADVANTAGE - (I) are universally used in inorganic-organic composite systems and give poly(hetero)condensates with good adhesion and temp. properties and good optical attenuation. (I) are stable cpds. with relatively high mol. wt. and hence are less volatile than e.g. pure (meth)acrylate monomers, which reduces toxic hazards during processing and application. The polysiloxanes formed by inorganic and/or organic crosslinking are even less volatile and completely eliminate problems of toxicity. The properties, e.g. flexibility, adsorption, refractive index, adhesion etc., of the poly(hetero)condensates can be tailored by using suitable substituents.de608666patent1996-19613650