Acrylic sequential graft copolymer-styrene-acrylonitrile copolymer blends

A thermoplastic composition comprising a blend of 100 parts by weight of an acrylic sequential graft copolymer and from 5 to 35 parts by weight of a copolymer comprising 90 to 50 wt% styrene and 10 to 50 wt% acrylonitrile, wherein said acrylic sequential graft copolymer has a core-shell structure and consists of:

• (a) from 10 to 100 parts by weight of a rigid monomer mixture comprising from 99.9 to 95 wt% of at least one rigid monovinylic monomer and from 0.1 to 5 wt% of a first copolymerizable functional monomer, and 100 parts by weight of a rubbery monomer mixture comprising from 99.9 to 95 wt% of at least one rubbery acrylic monomer and from 0.1 to 5 wt% of a second copolymerizable functional monomer interractive with said first functional monomer;
• and
• (b) said core-shell structure consists of from 10 to 40 wt% of a rigid polymeric core formed of said rigid monomer mixture, from 10 to 50 wt% of rubbery polymeric shell formed of said rubbery monomer mixture and surrounding and at least partially encapsulating said rigid polymeric core, and from 20 to 80 wt% of a copolymeric transition layer intermediate between said core and said shell and formed of said rigid monomer mixture and said rubbery monomer mixture.