| 摘要 |
PURPOSE:To obtain a resin particle which is excellent in flame retardation, weather resistance, solvent resistance as well as good in the melt adhesiveness of its primary expansion particle impregnated with a foaming agent, by the polymerization of a mixture of a nucleating vinyl chloride resin particle suspended in an aqueous medium and a vinyl aromatic monomer. CONSTITUTION:The 50-80pts.wt. of a nucleating resin particle comprising vinyl chloride polymer is suspended in an aqueous medium, and the suspension is mixed with 50-20pts.wt. of a vinyl aromatic monomer so as to have the monomer absorbed in the aforesaid resin particle and carry out the polymerization in the presence of a catalyst to obtain a flame-retardant thermoplastic resin particle. During or after the polymerization, a gaseous or liquid foaming agent is added with the purpose of obtaining an expansible resin particle. If the amount of the nucleating resin to be used is less than 50wt%, the properties peculiar to vinyl chloride resin are lost, whereas if it exceeds 80wt%, its expansibility becomes worse. |
