Moulding compound for mouldings with high weather resistance

A molding compound comprises a copolymer (I)a), produced by polymerization of 90-100% by weight methylmethacrylate, styrene and malic acid anhydride, and optionally 0-10% by weight additional monomers which can be copolymerized with methylmethacrylate, a (co)polymer (II)b), produced by polymerization of 80-100% by weight methylmethacrylate and optionally 0-20% by weight additional monomers which can be copolymerized with methylmethacrylate, and has a solution viscosity in chloroform at 25° C. (ISO 1628 Part 6) of 50 to 55 ml/g, as well as c) optional conventional additives, auxiliary agents and/or fillers. The molding compound is characterized in that the copolymer (I) has a solution viscosity in chloroform at 25° C. (ISO 1628 Part) of 55 ml/g or less. Also disclosed are moldings produced by thermoplastic processing of the molding compound and their uses.