Abs molding composition for sheet extrusion and thermoforming with high escr, high color and thermal stability and low tendency to delamination

A thermoplastic molding composition comprising components A, B, C, D, and optionally E:

• (A) 15 to 45 wt.-% of at least one graft copolymer (A) consisting of
• 15 to 60 wt.-% of a graft sheath (A2) and
• 40 to 85 wt.-% of a graft substrate (A1), wherein (A1) is an agglomerated butadiene rubber latex and wherein (A1) and (A2) sum up to 100 wt.-%,
• obtained by emulsion polymerization of
• styrene and acrylonitrile in a weight ratio of 95:5 to 65:35 to obtain the graft sheath (A2), wherein the styrene and/or acrylonitrile is optionally replaced partially by alphamethylstyrene, methyl methacrylate, maleic anhydride, or mixtures thereof,
• in the presence of at least one agglomerated butadiene rubber latex (A1) with a median weight particle diameter D50 of 150 to 800 nm;
• wherein the agglomerated butadiene rubber latex (A1) is obtained by agglomeration of at least one starting butadiene rubber latex (S-A1) having a median weight particle diameter D50 of equal to or less than 120 nm, with at least one acid anhydride;
• (B) 40 to 75 wt.-% of at least one copolymer (B) of styrene and acrylonitrile in a weight ratio of from 80:20 to 65:35, wherein the styrene and/or acrylonitrile is optionally replaced partially by methyl methacrylate, maleic anhydride, and/or 4-phenylstyrene;
• wherein copolymer (B) has a weight average molar mass Mw of 150,000 to 300,000 g/mol;
• (C) 2.0 to 5.0 wt.-% of at least one elastomeric block copolymer (C) made from
• 15 to 65 wt.-%, based on (C), of at least one diene, and
• 35 to 85 wt.-%, based on (C), of at least one vinylaromatic monomer,
• wherein block copolymer C comprises
• at least two blocks S which have polymerized units of vinylaromatic monomer, a glass transition temperature Tg above 25° C., and form a hard phase, and at least one elastomeric block B/S (soft phase) which contains both polymerized units of vinylaromatic monomer and diene, has a random structure, a glass transition temperature Tg of from −50 to +25° C., and forms a soft phase,
• and the amount of the hard phase formed from the blocks S accounting for from 5 to 40% by volume, based on the total block copolymer;
• (D) 2.0 to 5.0 wt.-% of a titanium dioxide pigment D comprising at least 95 wt.-% titanium dioxide and 1.7 to 3.3 wt.-% alumina;
• and
• (E) 0 to 7.0 wt.-% of at least one additive and/or processing aid (E) which is different from (D);
• wherein the sum of components (A), (B), (C), (D), and, if present, (E) totals 100 wt.-%.