| 摘要 |
PURPOSE:To provide the titled composition having each specific total ray transmittance and compression set with outstanding forming processability and flexibility, suitable for food packaging materials comprising hydrogenated block copolymer of specific molecular weight, a specific resin such as crystalline polypropylene, etc. CONSTITUTION:The objective composition comprising (A) 40-90wt% of a hydro genated block copolymer with a number-average molecular weight 100,000-400,000 made up of (i) block consisting mainly of at least one vinyl aromatic compound (e.g., styrene) and (ii) another block consisting mainly of at least one hydrogenated conjugated diene compound (e.g., butadiene) (B) 5-30wt% of crystalline polypropylene or its copolymer for general forming use and (C) 5-30wt% of an ethylene-acrylate copolymer containing <=5wt% of acrylate; alternatively, 40-85wt% of the component (A), 5-30wt% of the component (B), 5-30wt% of the component (C) and (D) 5-30wt% of crystalline low-molecular weight polypropylene with a number-average molecular weight <=20,000. This composition gives >=70% of total ray transmittance and <=60% permanent compression set. |
