| 摘要 |
<p>1459666 Foamed grafted ethylene copolymers BASF AG 3 May 1974 [5 May 1973] 19440/74 Heading C3C A resilient flexible foam of an ethylene copolymer grafted with 2-70% by wt. of a vinyl ester of a saturated C 2-5 carboxylic acid is made by mixing the polymer with a volatile expanding agent at a temperature above the m.p. of the polymer and at a pressure preventing foaming and then extruding the mixture into a zone of lower pressure at which foaming takes place. In the examples a copolymer of ethylene and vinyl acetate or n-butyl acrylate which is grafted with vinyl acetate (prior to or during the mixing with expanding agent) is mixed with talc (as nucleating agent) methyl chloride and n-butane and foamed by extrusion, e.g. through a sheeting die.</p> |
