GB1517463A - Extrusion foamed article and process for producing the same - Google Patents

Abstract

1517463 Extruded foamed ionomer resin/ polymer blends ASAHI-DOW Ltd 23 March 1976 [25 March 1975 14 Oct 1975] 11654/76 Heading C3C An extruded foamed article is made by blending (A) 100 parts by wt. of a molten mixture of (i) 10-90 wt. per cent of an ionomer resin of melt index 0À1-50 g./10 min and of general formula where R is G or alkyl, R<1> and R<11> are H or methyl, R<111> is C1-3 alkyl, M is the ion of a metal of valency 1-3 belonging to Groups I-III, IVa or VIII of the Periodic Table, a is at least 50 mol per cent and b, c and d are such that N, which is 60 mol per cent or less, = c/(c+d) x 100, and S, which is 50 mol per cent or more, = (c+d)/(b+c+d), and (ii) 90-10 wt. per cent of a polymer of styrene or its substitution product, with (B) 5-60 parts by wt. of a volatile blowing agent of b.p. of 90‹ C. or less and Kauri-Butanol value of not more than 25 in an extruder at a temperature which is sufficient to melt the resins and at a pressure which is above atmospheric and then extruding the blend into a zone kept at a pressure no higher than atmospheric thereby allowing the extrudate to expand. In the examples twelve ionomer resins which contained units derived from methacrylic acid and optionally methyl methacrylate were blended with polystyrene which optionally contained polybutadiene or a styrene-butadiene copolymer or block copolymer were blended with talc and zinc or barium stearate and the blends were melted and kneaded in extruders in which a blowing agent, viz. dichloro-(mono- or di-) fluoromethane, methylene or methyl chloride, propane, trichloromonofluoromethane, pentane and/or hexane, was injected under pressure into the third zone thereof and the extrudate was allowed to foam in the atmosphere.