ABS COMPOSITIONS HAVING AN IMPROVED SURFACE FOLLOWING STORAGE IN A WARM-HUMID ENVIRONMENT

摘要

The invention relates to polymer compositions containing A) 0 to 98 parts by weight, relative to the sum of A and B, of one or a mixture of several thermoplastic polymers other than B, and B) 2 to 100 parts by weight, relative to the sum of A and B, of B1) at least one graft polymer produced in an emulsion polymerization process, B2) optionally, at least one graft polymer produced in a bulk polymerization, suspension polymerization, or solution polymerization process, B3) optionally, at least one rubber-free vinyl (co)polymer, and C) 0 to 30 parts by weight of at least one conventional polymer additive, the sum of parts by weight of A and B being 100. The invention is characterized in that (i) the composition contains at least one inorganic salt consisting of a cation selected from the group comprising alkali metals, alkaline earth metals and aluminum, and an anion selected from the group consisting of chloride, sulfate, nitrate, phosphate, acetate and formate at a concentration of 100 to 5000 mg/kg relative to the composition, and (ii) said salt in the composition is provided exclusively in a dissolved form or in the form of amorphous or crystalline inclusions having a size of less than 60 µm. The disclosed polymer compositions are characterized by an improved surface following storage in a warm-humid environment and are suitable in particular for the production of molded articles or molded parts having Class A surface requirements and a high-gloss finish, after being optionally subjected in part or entirely to an additional surface treatment step, for example painting, film insert molding, vacuum metallizing or electroplating.