Abstract: The invention relates to surface-modified nanoparticles composed of metal or semimetal oxides or hydroxides and having been reacted on their surface with a modifier, with formation of covalent bonds. The modifier is a polysiloxane. The invention also relates to a process for preparing the nanoparticles, to their use as fillers in coating materials, plastics, foams and nail varnishes, and to dispersions which comprise the nanoparticles.

Abstract: The invention relates to polyester-modified poly-siloxanes of the general formula (I) where A is an alkyl group having 1 to 8 carbon atoms, Z is an aliphatic group having 1 to 14 carbon atoms, R is an aliphatic and/or cycloaliphatic and/or aromatic poly-ester group containing at least 3 and having a weight-average molecular weight of 200 to 4000 g/mol, with no Zerewitinoff hydrogen atoms, Q is a group which contains no Zerewitinoff hydrogen atoms and is free from reactive carbon-carbon multiple bonds, m is 3 to 200 and o+n=2, with both o and n being other than zero. The invention further relates to the use of the compounds of the invention in thermoplastics, moulding compounds and coating materials.