Glass fiber-reinforced styrene copolymers

A thermoplastic molding material comprising, based on the sum of A, B, C and D,

• A:
• 30 to 95% by weight of a copolymer A comprising, in each case, based on A
• a.sub.1 :
• 50 to 95% by weight of styrene, .alpha.-methylstyrene, a nuclear-substituted styrene derivative or mixtures of these monomers (a.sub.1) and
• a.sub.2 :
• 5 to 50% by weight of acrylonitrile (a.sub.2)
• B:
• up to 60% by weight of a graft copolymer B
• b.sub.1 :
• prepared either by emulsion polymerization of, based on B, 15 to 85% by weight of a monomer mixture based either on
• b.sub.11 :
• styrene-acrylonitrile in the ratio 9:1 to 4:6, or
• b.sub.12 :
• styrene-acrylonitrile-methyl methacrylate in the ratio 19:1:0 to 8:6:6 on 15 to 85% by weight of a latex, obtained as an emulsion, of an elastomer based on butadiene or acrylic ester as grafting base;
• or by
• b.sub.2 :
• solution polymerization of, based on B, 15 to 85% by weight of a monomer mixture based on
• b.sub.21 :
• styrene-acrylonitrile in the ratio 9:1 to 4:6 or
• b.sub.22 :
• styrene-acrylonitrile-methyl methacrylate in the ratio 19:1:1 to 8:6:6 on 15 to 85% by weight of an elastomer, prepared in solution, based on butadiene or an acrylic ester or an EPDM elastomer as grafting base;
• C:
• 1 to 40% by weight of a reinforcing agent C based on an inorganic glass, and also
• D:
• 0.1 to 10% by weight of a copolymer D of, based on B,
• d.sub.1 :
• 10 to 90% by weight of units of the formula I ##STR4## in which R.sup.1 and R.sup.2 are hydrogen or methyl and R.sup.3 is hydrogen, C.sub.1 -C.sub.8 alkyl, C.sub.5 -C.sub.12 2-cycloalkyl or C.sub.6 -C.sub.16 aryl or C.sub.6 -C.sub.16 aralkyl, and
• d.sub.2 :
• 10 to 90% by weight of units derived from a copolymerizable monomer selected from styrene, .alpha.-methylstyrene, (meth) acrylonitrile or (meth)acrylic acid esters,
• with the proviso that the acid number S of the copolymer D is at least 0.5 meq/g..