| 摘要 |
PROBLEM TO BE SOLVED: To provide seed particles capable of further improving impact resistance at a high magnification without greatly decreasing heat resistance and slow-burning properties of a foam molded body.SOLUTION: High density polyethylene resin particles used for seed particles when polymerizing into seeds includes a mixed resin having the seed particles composed of 100 pts.wt. of a high density polyethylene and 20-100 pts.wt. of an ethylene copolymer where the high density polyethylene has a density of 935-960 kg/mand a softening point of 115-130°C, the ethylene copolymer is a copolymer of an ester monomer selected from acrylic acid alkyl ester and aliphatic saturated mono-carboxylic acid vinyl ester with ethylene, has 1-20 wt.% of a constituent derived from the ester monomer, and has a softening point of 75-110°C, the acrylic acid alkyl ester is selected from methyl acrylate and ethyl acrylate, and the aliphatic mono-carboxylic acid vinyl ester is selected from vinyl acetate and vinyl propionate. |
