Thermoplastic molding compositions of a polysiloxane block copolycarbonate and a polycarbonate based on certain dihydroxydiphenylcycloalkanes

Abstract

Abstract The invention relates to a thermoplastic molding composition comprising (A) from 10 to 98 parts by weight of a polydiorganosiloxane-polycarbonate block copolymer having a weight average molecular weight of from 10,000 to 200,000 and containing from 75 to 97.5 wt. % of aromatic carbonate structural units and from 25 to 2.5 wt. % of polydiorganosiloxane structural units; (B) from 2 to 90 parts by weight of a thermoplastic, aromatic polycarbonate having a weight average molecular weight of at least 10,000, and containing bifunctional carbonate structural units corresponding to ##STR1## wherein R 1 and R 2 independently represent hydrogen, halogen, C 1 -C 8 alkyl, C 5 -C 6 cycloalkyl, C 6 -C 10 aryl or C 7 -C 12 aralkyl; m represents an integer of from 4 to 7, R 3 and R 4 , which may be selected individually for each X, independently represent hydrogen or C 1 -C 6 alkyl; and x represents carbon, with the proviso that, on at least one atom X, R 3 and R 4 both represent alkyl; and (C) from 0.5 to 30 parts by weight of a rubber having a glass transition temperature of less than -20° C. The composition of the invention is useful for the preparation of injection molded articles having an excellent surface and a particularly good toughness at low temperatures.

Inventors

• 👤 Ulrich Grigo
• 👤 Peter Horlacher
• 👤 Dieter Freitag
• 👤 Karsten-Josef Idel
• 👤 Uwe Westeppe
• 👤 Wolfgang Beer
• 👤 Werner Nouvertne

Bibliographic Details