Sekisui Kaseihin Kogyo Kabushiki Kaisha

Sekisui Plastics Co., Ltd.

Mutsuhiko Shimada

Ikuo Morioka

Hiroyuki Yamagata

Yukio Aramomi

A foamed styrene resin material has a density .rho. of 0.02 to 0.008 and a melt tension of the styrene resin of 5 to 40 gf. The relation between an average cell diameter d (.mu.m) and the density .rho. is given by the expression: ##EQU1## and a relation between a thermal conductivity .lambda. (kcal/m.multidot.h.multidot..degree. C.) and the density .rho. given by the expression: ##EQU2## Accordingly, the foamed styrene resin material has a low thermal conductivity and excellent insulating property in spite of a low density (high expansion ratio foam) thereof.

Foamed styrene resin material and heat insulating material using the

A foamed article of styrene type resin, in which base resin particles are styrene type resin particles obtainable by a graft polymerization of a cis-rich polybutadiene with a styrene type monomer, a blowing agent contains n-pentane as its main component and the foamed article shows a density of 0.015-0.040 g/cm.sup.3, an average foam diameter of 60-300 micrometers and a closed cell foam rate of not less than 50%.

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Kyoto, Japan

Mutsuhiko Shimada