| 摘要 |
Thermoplastic moulding composition of the acrylonitrile-butadiene-styrene (ABS) type contains graft polymer(s) (I) and graft polymer(s) (II), both prepared by emulsion polymerisation, and a rubber-free copolymer of styrene and acrylonitrile. The graft polymers are prepared by polymerising styrene and acrylonitrile in the presence of: (i) a mixture of a butadiene polymer lattices (A) and (B), and (ii) butadiene polymer latex (C). These have a particle diameter d50 of (A) ≤ 320, (B) ≥ 370, (C) 110-150 nm; particle size distribution (d90-d10) of (A) 30-100, (B) 50-500, (C) 20-50 nm; and gel content of (A) ≤ 70, (B) ≥ 70, (C) 80-98 wt.%. The weight ratio of graft monomers to butadiene polymer(s) is (I) 25:75 to 70:30, (II) 30:70 to 60:40. Lattices (A), (B) and (C) contain 0-50 wt.% copolymerised vinyl monomer. The styrene and acrylonitrile weight ratio is 90:10 to 50:50 and styrene and/or acrylonitrile may be (partly) replaced by alpha -methylstyrene, methyl methacrylate or N-phenyl maleimide. |
