Patent ID: 8431198

Claim:
A multilayer film comprising at least 3 layers, a first outer layer, a second outer layer and, between the first and second outer layers, at least one core layer wherein the first and second outer layers each are from 3 to 18 volume percent of the film and each comprises: at least about 75 weight percent 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 25 weight-percent or less of a rubber homopolymer based on the total rubber weight in the HIPS component; (iii) a total rubbery conjugated diene content of one weight percent or more and seven weight percent or less based on total weight of the HIPS component; (iv) less than 10 weight percent gel concentration by methyl ethyl ketone/methanol extraction; (v) an average rubber particle size of less than 1.0 micrometers and of 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; and the at least one core layer comprises from 64 to 94 volume percent of the film and comprises (b) at least about 70 weight percent of at least one styrene block copolymer; and wherein polymers (a), and (b) and optionally (c) at least one general purpose polystyrene (GPPS) having a weight-average molecular weight of more than 200,000 grams per mole and 350,000 grams per mole or less, account for 100 weight percent of the polymers in the film with the exception of optional additives, tie layers or a combination thereof.