| 摘要 |
PURPOSE:To provide a molded foam having the amount of a foaming agent remaining in the molded foam and the molding ratio satisfying a specific relationship and good in physical properties of moldings without containing a flame retardant by molding a styrene-modified polyethylene with a combustible foaming agent at a specific molding ratio. CONSTITUTION:The flame retardant molded foam is obtained by adding pure water, magnesium pyrophosphate and sodium dodecylbenzenesulfonate into an autoclave, providing an aqueous medium, suspending polythylenic resin particles therein, adding a polymerization catalyst and a styrenic monomer thereto, carrying out the polymerization while heating the resultant mixture, affording a styrene-modified polyethylenic resin, then dispersing the resin particles in water containing the sodium dodecylbenzensulfonayte in the autoclave, heating the prepared dispersion at 70 deg.C, pressing a combustible foaming agent such as butane thereinto, impregnating the resin particles therewith, providing expandable resin particles, subsequently preexpanding the resin particles with steam and then expansion molding the preexpanded resin particles with a molding machine. This molded foam has 35 times or less molding ratio and the molding ratio (Y) (times) and the amount of the residual combustible foaming agent (X) (wt.%) satisfy a relationship of the formula X<2>.Y<=5. |
