Polystyrene serial resin extruded foam plate and its producing method

Abstract

A polystyrene resin extruded foam plate is obtained by extruding a foamable molten resin mixture comprising a mixed blowing agent containing the isobutane (except a chlorofluorocarbon and / or a fluorocarbon) and a polystyrene resin from a high-pressure zone to a low-pressure zone and has >=10 mm thickness and 25-60 kg / m3 apparent density. The residual amount of the isobutane in the foam plate is 0.45-0.80 mol based on 1 kg of the foam plate. Furthermore, the foam plate has 0.05-0.18 mm average cell diameter in the thickness direction and 0.7-1.2 cell deformation ratio (the average cell diameter in the thickness direction / the average cell diameter in the horizontal direction) and satisfies type 3 of the flammability standard of the polystyrene extruded foam heat insulating plate described in JIS A9511(1995) and further has <=0.028 W / mK thermal conductivity of the foamed plate.

Description

technical field [0001] The present invention relates to a polystyrene-based resin extruded foam board used as a heat insulating material for a wall, a floor, a roof, etc. of a building, or as a mat core material, and a method for producing the same. Background technique [0002] In the past, polystyrene-based resin foam has been widely used as a plate-shaped heat insulating material because of its excellent heat insulating properties and suitable mechanical strength. It is known that such a foam board is produced by adding a foam regulator to a polystyrene-based resin material, heating, melting and kneading, adding a physical foaming agent, and extruding the mixture from a high-pressure zone to a low-pressure zone. manufacturing method. [0003] As the blowing agent used in the manufacture of the above-mentioned foam boards, chlorofluorocarbons (hereinafter referred to as CFCs) such as dichlorodifluoromethane have been widely used in the past. However, since CFCs have a hig...

AI Technical Summary

Problems solved by technology

[0008] However, although the thermal conductivity of isobutane in a gaseous state is lower than that of air, compared with conventionally used CFC, HCFC, and HFC, the thermal conductivity in a gaseous state is larger, and it is difficult to obtain the same thermal insulation properties as HFC, etc.

Moreover, isobutane itself is highly flammable, so it is extremely difficult to impart flame retardancy to the resulting foam

Images