EXPANDABLE STYRENE-BASED RESIN PARTICLE

摘要

PROBLEM TO BE SOLVED: To obtain expandable styrene-based resin particles capable of forming uniform and good cell structure in preliminary foaming particles without adding a special cell-forming agent thereto or applying long-term aging treatment and substantially not changing uniformity of the cells even if resin particles are stored in high-temperature closed vessel. SOLUTION: When a sample in which 100 to 1000 fine pores exist per mm<2> cross section in cut face of resin particles and expandable styrene-based resin particles are packed together with water which is a medium in a glass cell having 10mm thickness is used and absorbance of light which permeates and scatters the interior of sample is measured using a permeation type integration sphere, a relationship represented by the formula (y)>=-0.45X<1/2> +1.39 hold between absorbance (y) of light obtained in spectrum having 660nm wavelength and average particle diameter (x)(mm) of expandable styrene-based resin particles is satisfied.