| 摘要 |
PROBLEM TO BE SOLVED: To provide an ethylene/vinyl acetate copolymer suitable for a hot-melt adhesive composition having both heat resistance and cold resistance. SOLUTION: The ethylene/vinyl acetate copolymer satisfies the following requirements (a)-(c): (a) the melt flow index (MI) is 0.5-5,000 g/10 min and the vinyl acetate (VAc) content is 2-25 mol%; (b) the branch number (B: mol%) expressed in terms of the sum of the mol% of the vinyl acetate content and the mol% of alkyl branches having a carbon number of two or more satisfies formula (1); and (c) when the branch number of the component having a weight average molecular weight Mw of not less than 100,000 g/mol contained in the ethylene/vinyl acetate copolymer is measured, the branch number (Bh: mol%) in the high-molecular weight range expressed in terms of the sum of the mol% of the vinyl acetate content and the mol% of alkyl branches having a carbon number of two or more satisfies formula (2): 1+(100-Bh)/Bh>100/([VAc]+0.4). COPYRIGHT: (C)2006,JPO&NCIPI
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