The invention provides copolymers of ethylenically unsaturated monomers and of ethylenically
functionalized nanoparticles in the form of their aqueous
polymer dispersions or water-redispersible
polymer powders, obtainable by means of free-radically initiated
polymerization in an
aqueous medium and, if desired, subsequent
drying of the
resultant polymer dispersion, ofA) one or more monomers from the group consisting of vinyl esters, (
meth)acrylic esters, vinylaromatics, olef ins, 1,3-dienes, vinyl ethers and vinyl halides and, if desired, further monomers copolymerizable therewith, in the presence ofB) at least one particle P having an
average diameter of ≦1000 nm, which is functionalized with ethylenically unsaturated, free-radically polymerizable groups, characterized in thatB2) particles P used are one or more from the group of
metal oxides and
semimetal oxides, and / orB2) particles P used are
silicone resins composed of repeating units of the general formula [R4(p+Z)SiO(4−p−Z) / 2] (II), where for at least 20 mol % of the respective
silicone resin p+z=0, 1 or 3,and where B1) and B2) are each functionalized with one or more α-organosilanes of the general formula (R1O)3−(R2)nSi—(CR32)—X (I), where X is a radical having 2 to 20
hydrocarbon atoms and containing an ethylenically unsaturated group.