The use of dispersing aids in processing aid compositions for vinyl chloride polymer, the production of said compositions and vinyl chloride compositions containing them.

摘要

The dispersability of processing aids for vinyl chloride polymers is improved by the use of a dispersing aid comprising at least one homopolymer and/or copolymer containing at least 50% by weight of units of one or more of the following monomers: (C1-C8)-alkyl acrylates, (C1-C9)-cycloalkyl acrylates, ethylene, propylene, vinyl acetate and butadiene. Preferred processing aid compositions therefor comprise blends of (a) copolymer(s) of methyl methacrylate and, in an amount of less than 50% by weight of the copolymer, (C1-C4)-alkyl acrylate(s) and (b) at least one such dispersing aid homopolymer or copolymer wherein the ratio of (a):(b) is 99.5:0.5 to 90:10. The blend may be prepared by intimately mixing components (a) and (b) as latex polymer and subsequently coisolated.