The curable composition

The invention relates to curable compositions comprising a) an alkoxy- and / or acyloxysilanterminiertes polymer having at least one terminal group of the general formula (I) -A wherein - A represents a divalent linking group, - R is a divalent optionally hetero atom-containing hydrocarbon radical having 1-12 carbon atoms and - X, Y, Z is a C - n represents 0 or 1; and b) hollow microspheres of a copolymer which is obtainable by polymerization of methacrylonitrile and at least one monomer M2 selected from acrylic acid, methacrylic acid, alkyl acrylates and alkyl methacrylates, wherein the copolymer wt .-% of units containing a maximum of 5, back to the incorporation of further monomers and is chlorine-containing units a process for their preparation and their use as a silane-crosslinking adhesives, sealants or coating materials.