Patent ID: 7824773

Claim:
A film composition comprising from 0 to 5 weight percent additives and from 95 to 100 weight percent of a polymer composition consisting essentially of: (a) at least one high impact polystyrene (HIPS) component having: (i) a block copolymer of styrene and a rubbery conjugated diene, wherein the copolymer is grafted to a polystyrene; (ii) optionally, two weight-percent or more and 8 weight percent or less of a rubbery conjugated diene homopolymer based on total rubber weight in the HIPS component; (iii) a total diene-component content from the block copolymer and optional rubbery conjugated diene homopolymer grafted into the polystyrene of the HIPS component, hereinafter rubber component, of one weight percent or more and seven weight percent or less based on total weight of the HIPS component; (iv) less than 10 wt % gel concentration by methyl ethyl ketone/methanol extraction; (v) an average rubber particle size of less than 1.0 micrometers and 0.01 micrometers or more: (vi) about 40 to about 90 volume percent of the rubber particles with diameters of less than about 0.4 microns and from about 10 to about 60 volume percent of the rubber particles with diameters between about 0.4 and about 2.5 microns; (vii) a majority of rubber particles with a core/shell morphology; (viii) that is present at a concentration of at least about 10 weight percent and up to at most about 70 weight percent of the polymers in the composition and accounts for one or more and five or less percent by weight of rubbery diene weight relative to total composition weight; (b) at least one general purpose polystyrene having a weight-average molecular weight of more than 200,000 grams per mole and 350,000 grams per mole or less and that is present at a concentration of at least about 10 weight percent and up to at most 45 weight percent of the polymers in the composition; and (c) at least one styrene butadiene block copolymer having a tensile elongation at break of at least about 200 and a melt flow rate as determined by the procedures of ASTM D1238, Condition G, of at least about 2 g/10 min and that is present at a concentration of at least about 20 weight percent and up to at most about 80 weight percent of the polymers in the composition; wherein, the total combination of (a), (b) and (c) accounts for 100 wt % of the polymer composition.