Patent ID: 8268904

Claim:
An extruded polymeric foam article comprising a polymer matrix with a continuous thermoplastic polymer phase, the polymer matrix defining a multitude of cells therein and the continuous thermoplastic polymer phase having a continuous phase of styrene-acrylonitrile polymer characterized by having: a. an acrylonitrile content of 20 weight-percent or less and five weight-percent or more, with weight-percent based on total styrene-acrylonitrile copolymer weight; b. a mean acrylonitrile comonomer content that exceeds its median acrylonitrile comonomer content; and c. an average copolymerized acrylonitrile comonomer distribution having a breadth at half-height that is greater than 2.5 weight-percent as measured at half peak height of a copolymerized acrylonitrile comonomer distribution curve for the styrene-acrylonitrile copolymer.