PURPOSE: To obtain an ethylene/α-olefin copolymer having no tendency toward decreasing in strength properties, which is characteristic of a linear low-density polyethylene, and having a wide MW distribution and excellent processability, by specifying its physical properties.
CONSTITUTION: A copolymer of ethylene with 0.5W40wt.% 3W18C α-olefin, having a melt flow rate ratio ≥35 and a melt expansion ratio ≤1.35 can be obtained by the following process. Namely, ethylene and 3W18C α-olefins (e.g., those fed through lines 2, 3 and 4) are copolymerized together at a pressure ≥400 bar in the presence of a Ziegler catalyst (poured into monomer lines by pumps 15, 16 and 17) in a reaction system (e.g., reactor 14) comprising at least two reaction zones so that the temperatures in the respective reaction zones may fall in the range of 130W350°C and that the temperature difference between the reaction zones and the ratio between the amounts of the copolymers formed in the respective reaction zones may satisfy specified conditions.
OCHI HIROSHI
KONAKA TSUTOMU
NAITO YUKIO
TANAKA HISAO
CHUMA NAOHIRO
TAKAHARA TORU
TOSOH CORP
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