Patent ID: 8648148

Claim:
A mass polymerized rubber-modified monovinylidene aromatic copolymer composition comprising: (i) a continuous matrix phase comprising a copolymer of a monovinylidene aromatic monomer and an ethylenically unsaturated nitrile monomer and a comonomer that is N-phenyl malelmide having a weight average molecular weight of equal to or less than 150 kg/mole and (ii) a rubber component dispersed as discrete rubber particles in the matrix comprising polybutadiene content of at least 12 weight percent as determined by infrared analysis, wherein the rubber-modified monovinylidene aromatic copolymer has a storage modulus (G′) of between 2,000 to 5,000 Pascals, and has an average rubber particle size between 1.5 to 2 microns as determined by Coulter Counter, wherein when the composition is molded or extruded it exhibits a tensile modulus of at least 1,400 MPa as determined by ISO 527-2, and a notched Charpy at 23° C as determined by DIN 53453 of at least 11 kJ/m 2 , and a delta grain gloss of between 0.3 and 0.9 as determined by 60° Gardner gloss by ISO 2813.