Patent ID: 8871844

Claim:
Composite particles obtained by conversion of a) one or more inorganic oxides having a mean diameter of <1000 nm, b) one or more organopolymers and c) one or more coupling reagents, said inorganic oxides a) and organopolymers b) being joined to one another via units of coupling reagents c), wherein the organopolymers b) used are one or more polymers of α) one or more ethylenically unsaturated monomers selected from the group consisting of vinyl esters of carboxylic acids having 1 to 15 carbon atoms, methacrylic esters or acrylic esters of carboxylic acids with unbranched or branched alcohols having 1 to 15 carbon atoms and olefins, vinylaromatics and vinyl halides, and β) one or more ethylenically unsaturated carboxylic acids having 3 to 11 carbon atoms, and optionally γ) one or more monomers containing at least two ethylenically unsaturated groups and optionally δ) one or more further ethylenically unsaturated monomers, with the provisos that the organopolymers b) contain at least 91% by weight of units of monomers α) and β), and that the organopolymers b) contain units of one or more monomers γ) if the organopolymers b) contain more than 4.9% by weight of units of the ethylenically unsaturated carboxylic acids β), where the figures in % by weight are based in each case on the total weight of the organopolymers b), and the coupling reagents c) are selected from the group consisting of c1) one or more alkylalkoxysilanes whose alkyl groups have at least one amino, epoxy, mercapto or isocyanate group, and c2) one or more unsaturated alkoxysilanes and additionally one or more ethylenically unsaturated organomonomers containing at least one functional group selected from the group consisting of carboxylic acid groups or derivatives thereof, sulfo groups, epoxy groups and hydroxyl groups.