Abstract: Surface-modified nanoparticles whose surface is covered completely or near-completely with (A) modifying groups which are attached covalently to the surface via linking functional groups (a) and contain inert spacer groups (b) and contain reactive functional groups (c) which are connected via the groups (b) to the groups (a) and are inert toward the reactive functional groups of the surface to be modified, (B) modifying groups which are attached covalently to the surface via linking functional groups (a) and contain inert groups (d) having a smaller hydrodynamic volume VH than the inert spacer groups (Ab), and (C) modifying groups which are attached to the surface via linking functional groups (a) which contain at least one silicon atom, contain inert groups (e), and have a smaller hydrodynamic volume VH than the modifying groups (A); dispersions comprising the nanoparticles, processes for preparing them, and their use.

Abstract: Transparent coatings with a thickness of at least 30 ?m, a relative elastic resilience to DIN 55676 of at least 70%, and a scratch resistance corresponding to a score of not more than 2 in the steel wool scratch test to DIN 1041 after 10 double strokes; process for producing them, and their use.

Abstract: An aqueous dispersion with a pH of from 2 to 7, comprising (A) at least one swellable polymer or oligomer containing anionic and/or potentially anionic functional groups, (B) surface-modified, cationically stabilized, inorganic nanoparticles of at least one kind, and (C) at least one amphiphile; and its use for producing highly scratch-resistant coatings, moldings, and self-supporting films.