High-temperature resistant polymerizable metal oxide particles

High temperature resistant polymerizable metal oxide particles having a glass transition temperature of ≧100° C. and having a core A comprising at least one oxide of a metal or semimetal from main groups three to six, transition groups one to eight of the periodic system, or the lanthanides and having at least one side-chain group —(B)w—X, which is bonded covalently to the core by way of one or more oxygen atoms of the oxide, w being 0 or 1 and B being a radical of the formulae

• —(MeO)xMe(O)y1—(R)y2— or —R(O)z—
• in which x is from 0 to 100, y1, y2 and z independently of one another are 0 or 1, and Me is a metal or semimetal from main groups three to six or transitions groups three to eight of the periodic system, the free valences of Me representing a bond to a further oxygen atom of the core A and/or a bond via an oxygen atom to an Me in another group B or and/or a bond to an oxygen atom of another core A and/or being satisfied by H, an organic radical and/or a trialkylsilyloxy radical;
• R is divalent alkyl, cycloalkyl, aryl, arylalkyl, alkylaryl, alkoxy, acyl, acyloxy or a radical remaining following the removal of two phenolic hydrogen atoms from a phenol compound having at least two phenolic hydrogen atoms from a phenol compound having at least two phenolic hydroxyl groups, it being possible for R to be substituted, if desired, by 1, 2, or 3 radicals selected independently of one another from hydroxy, alkoxy, halogen and also, in the case of aryl or cycloalkyl radicals, alkyl, and/or interrupted in the chain by one or two oxygen atoms, and
• X is a reactive functional group or a radical containing a reactive functional group, and
• whereby X may be attached to B through link Z, where Z is either O, NR2, where R2 is either H, C1-C4 alkyl, OCO, COO, NHCO, or CONH, and
• wherein the group or groups —(B)w—X account for at least 10% by weight, based on overall weight of the particles.