Impact modifier combination for polymers

摘要

An improved impact modifier for polymers, such as PBT and blends thereof, is disclosed. The impact modifier is a blend of (A) a core/shell additive having a core based on alkyl acrylate, on a polyorganosiloxane rubber or a blend thereof and a shell based on poly(alkyl methacrylate), or on a styrene-acrylonitrile copolymer grafted onto the core; and (B) a linear copolymer which contains from 50 to 85 parts of units derived from ethylene, from 5 to 40 parts of units derived from (meth)acrylic esters, and from 2 to 10 parts of a copolymerizable monomer containing an epoxy group. The impact strength provided by the impact modifier blend is unexpectedly higher than the impact strength provided by each individual component of the blend.