Basf Aktiengesellschaft

Claus Bernhard

Johann Swoboda

Juergen Hambrecht

Rudolf Stephan

Burghard Schmitt

Georg Wassmuth

Adolf Echte

Franz Brandstetter

Gerhard Lindenschmidt

Josef Schwaab

Heinz-Juergen Overhoff

The invention relates to a thermoplastic molding material of an elastomeric polymer A, a shell B grafted to the polymer A, and a copolymer C as rigid matrix. The amount of polymer A is 1 to 25 percent by weight based on the weight of A+B+C. It has a glass transition temperature, Tg, of less than 0.degree. C. and an average particle size of 200 to 750 nanometers (d.sub.50 value of the integral mass distribution) and is composed of: 50 to 99.9 percent by weight of at least one alkylacrylate with 1 to 8 carbon atoms in the alkyl radical and 0.1 to 5 percent by weight of a polyfunctional monomer which has a crosslinking action. Grafting shell B represents 5 to 40 percent by weight based on A+B+C and is composed of at least one of the monomers of the group of

Thermoplastic molding material

Thermoplastic molding materials contain a copolymer A and a graft copolymer B. The copolymer A is a hard component comprising one or more copolymers of styrene and/or .alpha.-methylstyrene with from 20 to 40% by weight of acrylonitrile. The graft copolymer B comprises one or more crosslinked acrylate polymer with a mean particle size of 0.5-0.8 .mu.m (d.sub.50 value of the cumulative mass distribution), a particle distribution, expressed by the ratio ##EQU1## in the range Q.gtoreq.0.6, and a glass transition temperature Tg below 0.degree. C. A mixture of styrene and acrylonitrile in a weight ratio from 88:12 to 65:35 is grafted onto this rubber.

Thermoplastic molding materials

Mixtures which essentially consist of a graft copolymer (A), a graft copolymer (B) and a hard component (C), the latter consisting of copolymers of stryrene and/or .alpha.-methylstyrene with acrylonitrile. The graft copolymers (A) and (B) are each based on a crosslinked acrylic ester rubber onto which is grafted a mixture of styrene and acrylonitirle. They differ only slightly in chemical composition, but differ substantially in the particle size of the acrylic ester base used for grafting. The weight ratio of the grafting bases can be from 90:10 to 35:65, and the proportion of the two grafting bases together, based on the total mixture, is from about 10 to 35 percent by weight. Mixtures of the above 3 components are weathering-resistant, exhibit a high impact strength, and are easy to color. The use of such mixtures by conventional thermoplastic processing methods, eg. extrusion or injection molding, gives, especially after the material has been colored, vitrually no difference in hue in the vicinity of a gate or of a weld line, so that a great variety of moldings for daily use or for leisure purposes can be produced.

Weathering-resistant, high-impact, easily colored thermoplastic

Growing community of inventors

Eisenberg, Germany

Claus Bernhard