Jsp Corporation

Teruyuki Akiyama

Naochika Kogure

Masato Naito

Daisuke Imanari

Noritoshi Nishiyama

A process for an extruded resin foam, comprising extruding a foamable composition comprising a melted polystyrene resin and a physical blowing agent through a die to obtain a polystyrene resin foam having a thickness of at least 10 mm and a transverse cross-sectional area of at least 50 cm, wherein said extrusion is performed so that the ratio Mz/Mn of a Z average molecular weight Mz of the polystyrene resin foam to a number average molecular weight Mn of the polystyrene resin foam, each measured by gel permeation chromatography, is 8.0 or more.

Process for producing polystyrene resin foam by extrusion

The present invention relates to a hollow molded foam article in which a plurality of polypropylene resins are used as the base resin, and to a process for the production of this hollow molded foam article. More particularly, the present invention relates to a polypropylene resin hollow molded foam article having a foam layer, in which the base resin comprises (a) a polypropylene resin with a melt tension of at least 98 mN and a melt flow rate of 0.5 to 15 g/10 minutes, (b) a polypropylene resin with a melt tension of less than 30 mN (excluding O) and a melt flow rate of 2 to 30 g/10 minutes, and (c) a polypropylene resin with a melt tension of at least 30 mN and less than 98 mN and a melt flow rate of 2 to 15 g/10 minutes, formed by positioning in a mold a softened cylindrical foam having a foam layer obtained by extruding from the die of an extruder a foamable molten resin composition containing a foaming agent, wherein the melt tension at 230&#xb0; C. of the polypropylene resin that forms the foam layer is at least 10 mN and less than 49 mN, and the apparent density of the foam layer is no more than 0.3 g/cm.

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Utsunomiya, Japan

Teruyuki Akiyama