Abstract: A molding composition consists of an intimate mixture of:(1) about 25 to about 40 percent calcium carbonate having an average particle size range of from about 450 to about 850 millimicrons and(2) about 60 to about 75 percent star-block copolymer of:(a) about 60 to about 95 percent vinyl aromatic compound and(b) about 40 to about 5 percent conjugated diene, said star-block copolymer having from about 3 to about 20 arms, at least some of the arms comprising random segments substantially free from significant blocks of either monovinyl aromatic component or conjugated diene component.

Abstract: Many reflector beads have been made from plastics more costly then polystyrene. By the present invention, water white, crystal clear polystyrene beads are prepared from styrene by polymerization in an aqueous solution having a concentration of from about 2.5 to about 6 molar inorganic solute, at conditions corresponding to production of uniformly sized polystyrene beads of the type ordinarily used as precursor for expandable polystyrene beads. The thus produced beads are rinsed with water and then dried to provide reflector beads.

Abstract: Several established methods produce precursor beads suitable for subsequent impregnation with a volatile agent for making expandable polystyrene beads. Different methods have led to production of reflector beads of crystal clear polystyrene for use as reflectors in movie screens, signs, and the like. Heretofore it has not been practical to use precursor beads as reflector beads. Many reflector beads have been made from plastics more costly than polystyrene. By the present invention, cloudy precursor beads are dispersed in an aqueous solution having a concentration of from about 1.5 to about 6 molar inorganic solute and heated to a temperature in the range from about 110.degree. to 130.degree. C. for a few minutes. The thus treated beads are rinsed with water and then dried to provide reflector beads.

Abstract: An advantageous blend suitable for compression molding, injection molding, or general molding of plastic articles is prepared by mechanically mixing at an elevated controlled temperature a polyurethane resin and a resin derived from copolymerization maleimide and styrene.

Abstract: An advantageous blend suitable for the molding of plastic articles is prepared by mechanically mixing a polyphenylene ether resin and a resin prepared by conducting the polymerization of a mixture of a rubber, maleimide, and styrene.

Abstract: An advantageous blend suitable for the molding of plastic articles is prepared by mechanically mixing a polyphenylene ether resin and a polymeric resin derived from maleimide and styrene.

Abstract: The invention concerns thermoplastic molding compositions consisting essentially of a blend of:A. From about 40% to about 95% by weight of a interpolymer comprising from about 8 to about 15% block interpolymers prepared in a stereospecific system using from 5% to 35% vinyl aromatic compound and from 65 to 95% conjugated alkadiene, and about 84 to about 92% of a mixture containing from about 88 to about 93% sytrene and from about 7 to about 12% unsaturated dicarboxylic acid anhydride selected from the group consisting of maleic anhydride and citraconic anhydride.B. From about 5% to about 60% of a polyphenylene oxide.

Abstract: Thermoplastic molding compositions consist of:(a) 10-90% by weight copolymer of maleimide and styrene containing about 5-35% maleimide and 60-95% styrene; and(b) 10-90% by weight of a polycarbonate of a dihydric phenol and a derivative of carbonic acid.

Abstract: A molding composition suitable for thermoplastic molding operations consists of a blend of:(a) 10-90% by weight of polymethyl methacrylate; and(b) 10-90% by weight of a copolymer derived by copolymerizing from about 5% to about 35% amino nitrogen derivative of an ethylenically unsaturated dicarboxylic acid, and from about 65% to 95% vinyl aromatic composition.

Abstract: Thermoplastic molding composition consists essentially of a blend of:A. 20-80% by weight of a copolymer comprising methyl methacrylate and styrene containing from 20% to 80% of methyl methacrylate and from 20% to 80% of styrene; andB. from about 20% to about 80% by weight of a copolymer comprising:(aa) an amine nitrogen derivative of an ethylenically unsaturated dicarboxylic acid constituting from 5% to 35% of the copolymer of B; and(bb) vinyl aromatic composition constituting from 60% to 95% of the copolymer of B;each of A and B having as an optional component of said copolymer(cc) a rubbery block polymer prepared in a stereospecific system using from 5 to 35% vinyl aromatic compound and from 65 to 95% conjugated alkadiene, said rubbery block copolymer constituting from 5% to 35% of its copolymer.

Abstract: Thermoplastic molding composition consists essentially of a blend of:A. 20-80% by weight of polymethyl methacrylate; andB. from about 20% to about 80% by weight of a copolymer of three components:(aa) a rubbery block polymer prepared in a stereospecific system using from 5 to 35% vinyl aromatic compound and from 65 to 95% conjugated alkadiene, said rubbery block copolymer constituting from 5% to 35% of the copolymer of three components.(bb) an amine nitrogen derivative of an ethylenically unsaturated dicarboxylic acid constituting from 5% to 35% of the copolymer of three components, and(cc) vinyl aromatic composition constituting from 60% to 90% of the copolymer of three components.