The present invention relates to core/shell vinyl polymers wherein an at least partially crosslinked core is formed from a monovinyl monomer and/or a di/tri/ or higher multivinyl monomer wherein the degree of crosslinking in the core ranges from slight to high depending on the ratio of monovinyl and/or di/tri/ or higher multivinyl monomers, and wherein the outer shell is formed from a monovinyl and/or a di/tri/ or higher multi-vinyl monomer that optionally may be crosslinked, and wherein the outer shell has on its surface linear or branched C.sub.3-C.sub.30 alkyl chains formed from substituted vinyl monomers.