| 摘要 |
<p>Compsn. based on copolymers of acrylonitrile-butadiene-styrene or derivs. is produced as in parent patent by (1) polymerising butadiene, or its alkyl homo logues or halogen derivatives, with 1-30 wt.% water-(in)-soluble vinyl cpd., e.g. (meth)acrylonitrile, acrylic acid, 1-4C-alkyl acrylates, vinyl ether, styrene and/or alpha-methylstyrene, in aqs. emulsion in presence of 0.1-0.4 wt. % catalyst and is not >0.2% emulsifier w.r.t. diene and vinyl cpd. at -20 to +100 degrees C., to from elastomeric copolymer; (2) graft polymerising this with vinyl monomer, e.g. (alpha-methyl)styrene and opt. acrylic acid, 1-4C-alkyl acrylate or (meth)acrylonitrile at 0-100 degrees C. in aqs. emulsion in presence of catalyst; and (3) mixing with copolymer of vinyl cpds. of stage (2). Improvement comprises carrying out stages (1) and (2) at pH 8-9. Using this optimum pH ensures good surface gloss, notched impact strength and processibility. Compn. also has good elastic limit and hardness.</p> |
