| 摘要 |
In thermoplastic molding compositions containing (A) 20-90 wt.% thermoplastic styrene-acrylonitrile polymer and (B) 10-80 wt.% multiphase, crosslinked graft rubber, (i) polymer A has a solution viscosity of 50-70 ml/g at 23 deg C; and (ii) >= 80% of the rubber particles B have a diameter less than 0.2 mu m. Thermoplastic molding composition contains (A) 20-90, preferably 30-80, especially 40-75 wt.% thermoplastic polymer, derived from (a1) 60-85, preferably 63-81, especially 65-80 wt.% styrene and/or substituted styrene, especially alpha -methylstyrene, (a2) 15-40, preferably 19-37, especially 20-35 wt.% acrylonitrile and (a3) 0-25, preferably 0-20, especially 0-18 wt.% other comonomers; and (B) 10-80, preferably 20-70, especially 25-60 wt.% multiphase, crosslinked graft rubber, derived from (b1) 30-90, preferably 40-70, especially 45-70 wt.% phase produced by emulsion- or mini emulsion polymerization of (b1.1) 80-100, preferably 90-100, especially 95-100 wt.% acrylate and (b1.2) 0-20, preferably 0-10, especially 0-5 wt.% other monomers and (b2) 10-70, preferably 30-60, especially 30-55 wt.% other phase(s), produced by polymerization of (b2.1) 60-85, preferably 70-80 wt.% styrene, (b2.2) 15-35, preferably 20-30 wt.% acrylonitrile and (b2.3) 0-20 wt.% other monomer in the presence of the first phase. The novel features are that (i) polymer A has a viscosity of 50-70, preferably 55-65 ml/g, measured as 0.5% solution in dimethylformamide at 23 deg C; and (ii) >= 80, preferably >= 85, especially >= 90% by number of the rubber particles B in the dispersion have a diameter less than 0.2, preferably less than 0.18, especially less than 0.15 mu m after their production. Independent claims are also included for (a) moldings made by coextrusion of 0.1-50 wt.% of these compositions and 80-98 wt.% second thermoplastic molding composition; and (b) the production of the moldings by co-extrusion.
|
