Abstract: A molding composition having good surface gloss, high elongation at break and good thermoplastic processability is disclosed. The composition contains (A) a graft polymer that is obtained by free-radical polymerization of resin-forming vinyl monomers in the presence of rubber in latex form, (B) a copolymer of styrene and acrylonitrile and an optional (C) a resin selected from the group consisting of polycarbonates, polyester-carbonates, polyesters and polyamides. The preparation of the graft polymer is characterized in that (i) before the start of the grafting polymerization reaction the rubber latex is brought to a pH of 9 to 11, (ii) the redox initiator components are employed in amounts of 0.1 to 2.5 wt. % (based on the monomers metered in) and (iii) during the entire grafting polymerization reaction the pH remains constant±0.5 and in the range of 11.0 to 8.8, and (iv) the temperature difference between the start and end of the reaction is at least 10° C.

Abstract: A molding composition containing a graft polymer is disclosed. The graft is a product of a free-radical emulsion polymerization of resin-forming vinyl monomers in the presence of rubber present in latex form having a glass transition temperature of ≦0° C. using an initiator combination comprising a persulfate compound and a redox initiator system. The process for preparing the graft polymer entails adding the persulfate compound at the beginning of the graft polymerization reaction and a later addition of the redox initiator. The composition that features good gloss and flowability is suitable for the preparation of molded articles.

Abstract: The invention provides compositions comprising a graft polymer obtainable by free-radical polymerization, a vinyl (co)polymer and optionally resins chosen from the group consisting of polycarbonates, polyester-carbonates, polyesters and polyamides, characterized in that the preparation of the graft polymer A) is carried out by a procedure in which before the start of the grafting polymerization reaction the rubber latex is brought to a pH of 9 to 11, the redox initiator components are employed in amounts of 0.1 to 2.5 wt. % (based on the monomers metered in) and during the entire grafting polymerization reaction the pH should not exceed a value of 11.0 and should not fall below a value of 8.8 and the pH remains constant during the reaction within a range of variation of ±0.5 units, and the temperature difference between the start and end of the reaction is at least 10° C.