Patent ID: 7641972

Claim:
Surface-modified nanoparticles comprising metal or semimetal oxides or hydroxides having a covalently bonded modifier on their surfaces, wherein the modifier is a polysiloxane of the following general empirical formula: (R 1 x R 2 3−x SiR 3 ) y R 5 in which x=0-2, y=1-10, R 1 =monovalent organic radical having 1-18 carbon atoms, R 2 =OH group or hydrolysable group consisting of: linear or branched or cyclic alkoxy group having 1-6 carbon atoms, a halogen atom, or a carboxylic acid radical having 1-4 carbon atoms, R 3 =a divalent organic radical consisting of: linear or branched alkylene radical having 1-8 carbon atoms, alkylene ether, alkylene thioether, or alkylene polyether, based on ethylene oxide, propylene oxide or butylene oxide or mixtures thereof, arylene polyether, alkylene polyester, or an organic aliphatic or aromatic or araliphatic group which in addition to ester and/or ether groups also contain urethane and/or urea groups, R 5 =polyvalent organic radical consisting of: polydialkylsiloxane having a number-average molecular weight of 300-5000 daltons, the alkyl substituents on the silicon atom having 1-8 carbon atoms.