| abstract |
A vinyl polymer is obtainable by polymerizing vinyl monomers in at least two stages by a procedure in which, in a first stage, from 5 to 95% by weight of vinyl monomers are polymerized in an organic solvent or in the absence of a solvent and, in the second stage, from 5 to 95% by weight of the vinyl monomers are polymerized in the presence of the vinyl polymer obtained in the first stage, likewise in an organic solvent or in the absence of a solvent, with the proviso that the polymerization in the second stage is carried out under conditions under which an average molecular weight Mn, which is at least 1,000 higher compared with that of the vinyl polymer, the first stage of results for the vinyl monomers of the second stage in the absence of the vinyl polymer obtained in the first stage. |