| 摘要 |
PURPOSE:To obtain the subject copolymer having specific physical properties and remarkably improved transparency, heat-sealability, melt elasticity, processability and environmental cracking resistance without deteriorating the properties of conventional straight-chain low-density polyethylene. CONSTITUTION:This copolymer is an ethylene and a >=3C alpha-olefin copolymer. This copolymer has an MFR of 0.001-100g/10min and a density (d) of 0.86-0.94g/cm<3>, satisfies the formula 0.5<=G1/G2<=0.95 [G1 and G2 are intrinsic viscosity rations ([eta]/[eta]1 and [eta]/[eta]2) of the high-molecular weight region and the low-molecular weight region, respectively, and [eta]1 and [eta]2 are the intrinsic viscosities of straight-chain polyethylenes having the same weight- average molecular weights as those of the high-molecular weight region and the low-molecular weight regions, respectively] and satisfies the formula [Ea (0.1) and Ea (100) (kcal/mol) are activation energy values of the loss modulus G'' in the dynamic viscoelasticity measurement at a standard temperature of 190 deg.C at frequency of omega0=0.1 (rad/sec) and omega1=100 (rad/sec), respectively]. |
