Cationic paper sizes

摘要

The object was to develop cationic polymeric surface sizes (sizing agents) for paper having improved sizing capacity which do not separate out any of their constituents and thus do not impair papermaking. The problem is solved by 5 to 35% aqueous dispersions of A terpolymers of a) from 6 to 25% of dimethylaminoethyl methacrylate, b) from 30 to 75% of styrene and c) from 5 to 45% of acrylonitrile, and containing d) from 0.5 to 5% of PE wax oxidate which is partially in free-radical grafted form, or B terpolymers as in A in which free-radical emulsion polymerisations of styrene and alkyl acrylates have been carried out, where from 20 to 30% of A has been converted into B The dispersions have no tendency to separate out wax, so that undesired slipping does not occur in the paper sized on the surface therewith.