| 摘要 |
PURPOSE:To increase thermal contraction coefficient and contraction stress of a low-temperature heat-shrink film as well as improve its transparency by forming a low-density ehtylene-alpha-olefin copolymer having two kinds of side chains with 1-10C alkyls. CONSTITUTION:An ethylene-alpha-olefin copolymer (A) having a density of 0.915-0.935g/cm<4> and side chains with 1-10C 3-30 alkyl group per 1,000 carbon atoms in the main chain is mixed with an ethylene-alpha-olefin copolymer (B) having a density of 0.890-0.910g/cm<3> and side chains with 10-60 alkyl group per 1,000 carbon atoms in the main chain. The proportion of the copolymer (B) is 10-60wt% on the basis of sum total of the copolymers (A) and (B). The mixture is melted and molded to obtain a film having improved transparency of a haze value of 5% or less, a thermal contraction coefficient (in m direction at 90 deg.C) of 30% or more, and a contraction stress of 300g/mm<2> or more, showing high thermal contraction coefficientry and high contraction stress. |
