Resinous composition with improved resistance to plate-out formation, and method

A composition comprising:

• (i) a rubber modified thermoplastic resin comprising a discontinuous elastomeric phase comprising structural units derived from butyl acrylate dispersed in a rigid thermoplastic phase comprising structural units derived from styrene and acrylonitrile or from styrene, acrylonitrile, and methyl methacrylate, wherein at least a portion of the rigid thermoplastic phase is grafted to the elastomeric phase;
• and (ii) additives comprising a plurality of glass beads;
• at least one fluoropolymer;
• ethylene bis-stearamide;
• at least one homopolymer comprising structural units derived from at least one (C1-C12)alkyl(meth)acrylate monomer;
• a silicone oil;
• and a linear low density polyethylene;
• wherein said composition has a critical shear rate value of greater than about 50 reciprocal seconds as measured at 190° C. in a capillary rheometer with 10 mm length and 1 mm diameter.

A method for reducing or eliminating plate-out during extrusion of a composition comprising a rubber modified thermoplastic resin comprising a discontinuous elastomeric phase comprising structural units derived from butyl acrylate dispersed in a rigid thermoplastic phase comprising structural units derived from styrene and acrylonitrile or from styrene, acrylonitrile, and methyl methacrylate, wherein at least a portion of the rigid thermoplastic phase is grafted to the elastomeric phase;

• which comprises adding to the composition at least two additives selected from the group consisting of a plurality of glass beads;
• at least one fluoropolymer;
• ethylene bis-stearamide;
• at least one homopolymer comprising structural units derived from at least one (C1-C12)alkyl(meth)acrylate monomer;
• a silicone oil;
• and a linear low density polyethylene.

A composition comprising:

• (i) a rubber modified thermoplastic resin comprising a discontinuous elastomeric phase comprising structural units derived from butyl acrylate dispersed in a rigid thermoplastic phase comprising structural units derived from styrene and acrylonitrile or from styrene, acrylonitrile, and methyl methacrylate, wherein at least a portion of the rigid thermoplastic phase is grafted to the elastomeric phase;
• and (ii) additives comprising ethylene bis-stearamide;
• at least one fluoropolymer;
• at least one homopolymer comprising structural units derived from at least one (C1-C12)alkyl(meth)acrylate monomer;
• and a mixture of at least one metal salt of a fatty acid and at least one amide;
• wherein said composition has a critical shear rate value of greater than about 50 reciprocal seconds as measured at 190° C. in a capillary rheometer with 10 mm length and 1 mm diameter.

A method for reducing or eliminating plate-out during extrusion of a composition comprising a rubber modified thermoplastic resin comprising a discontinuous elastomeric phase comprising structural units derived from butyl acrylate dispersed in a rigid thermoplastic phase comprising structural units derived from styrene and acrylonitrile or from styrene, acrylonitrile, and methyl methacrylate, wherein at least a portion of the rigid thermoplastic phase is grafted to the elastomeric phase;

• which comprises adding to the composition at least two additives selected from the group consisting of ethylene bis-stearamide;
• at least one fluoropolymer;
• at least one homopolymer comprising structural units derived from at least one (C1-C12)alkyl(meth)acrylate monomer;
• and a mixture of at least one metal salt of a fatty acid and at least one amide.