Styrenic copolymer composition with PMMA and improved weathering resistance

A thermoplastic molding composition (P) comprising:

• (A) at least one thermoplastic polymer composition (A) comprising:
• (A-1) 10 to 50 wt.-%, based on the total weight of the molding composition (P), of at least one graft copolymer (A-1), wherein the graft copolymer (A-1) is a rubber-modified copolymer comprising repeating units of acrylonitrile and styrene,
• (A-2) 1 to 50 wt.-%, based on the total weight of the molding composition (P), of at least one thermoplastic polymer matrix (A-2) based on one or more vinylaromatic copolymers, and
• (A-3) 20 to 50 wt.-%, based on the total weight of the molding composition (P), of at least one polymerized alkyl methacrylate component (A-3) selected from poly(alkyl methacrylate) homopolymers,
• where the sum of (A-1), (A-2), and (A-3) is 83.2 to 99.8 wt.-% based on the total weight of the molding composition (P);
• (B) a hindered amine light stabilizer composition (B), comprising at least two of substances (B-1) to (B-3):
• (B-1) 0 to 0.9 wt.-%, based on the total weight of the molding composition (P), of at least one hindered amine light stabilizer having a dipiperidine structure with at least one alkyl group at each of the 2 and 6 positions of the dipiperidine structure and not containing any saturated or unsaturated C12-C21 ester moieties at one of the 3, 4 or 5 positions of the piperidine structures, wherein the at least one hindered amine light stabilizer having a dipiperidine structure has a molecular weight of 200-550 g/mol,
• (B-2) 0 to 0.9 wt.-%, based on the total weight of the molding composition (P), of a hindered amine light stabilizer mixture having a monopiperidine structure with at least one alkyl group at each of the 2 and 6 positions of the monopiperidine structure and saturated or unsaturated C12-C21 ester moieties at at least one of the 3, 4 or 5 positions of the monopiperidine structures, and
• (B-3) 0 to 2 wt.-%, based on the total weight of the molding composition (P), of at least one hindered amine light stabilizer having a polymeric structure comprising piperidine groups with at least one alkyl group at each of the 2 and 6 positions of the piperidine groups and not containing any saturated or unsaturated C12-C21 ester moieties at one of the 3, 4 or 5 positions of the piperidine groups, wherein the at least one hindered amine light stabilizer having a polymeric structure has a molecular weight of 1000-4000 g/mol,
• provided that the at least one hindered amine light stabilizer composition (B) is present in the molding composition (P) in an amount of at least 0.2 wt.-%, based on the total weight of the molding composition (P);
• (C) 0 to 5 wt.-% of one or more further additives (C), different from (B);
• and
• (D) 0 to 10 wt.-% of colorants, dyes, and/or pigments (D), different from (C);
• wherein the constituents (A) to (D) sum up to 100 wt.-% of the molding composition (P).