To obtain the subject foam excellent in homogeneity and recyclability in a little installation investment by kneading a specific modified resin composition with a thermal decomposition type chemical foaming agent and subsequently thermally foaming the kneaded product.
This method for producing a polyolefin resin foam comprises melt-blending (A) 100 pts.wt. of a polyolefin resin such as polyethylene or polypropylene with (B) 0.05-5 pts.wt. of a dioxime compound (e.g. a p- quinonedioxide compound of formula III) having two groups each comprising an oxime group of formula I or an oxime group of formula II wherein the hydrogen atom of the oxime group is replaced with some other atomic group (mainly hydrocarbon) at a temperature of 170°C to the decomposition temperature of the component A, kneading (C) 100 pts.wt. of the obtained modified resin composition with (D) 1-50 pts.wt. of a thermal decomposition type chemical foaming agent (e.g. azodicarbonamide), if necessary, shaping the obtained foamable resin composition, and subsequently foaming the product at the decomposition temperature of the component D to the decomposition temperature +100°C.
FUKUOKA TAKAMASA
TSUJIMOTO NORITAKA
OKABE MASASHI
