JP2004059650A5 - - Google Patents

Claims (4)

It consists of at least two types of polyethylene (A) and (B). Polyethylene (A) is a resin produced using a chromium compound-supported catalyst, and polyethylene (B) is a resin prepared using a titanium-based catalyst. Polyethylene (A) is a resin produced by step polymerization, and the polyethylene (A) is an ethylene homopolymer having an MI of 0.01 to 10 g / 10 min and a density of 940 kg / m ³ or more, or ethylene and α having 3 to 20 carbon atoms. -Copolymer with olefin, and polyethylene (B) is obtained by homopolymerizing ethylene or copolymerizing ethylene and an α-olefin having 3 to 20 carbon atoms, and MI is 10 to 300 g / 10 min . after producing the low molecular weight polymer component is 960 kg / m ³ or more, copolymerizing a α- olefin of ethylene and 3 to 20 carbon atoms, 0 relative to the amount of low-molecular weight polymer component. Obtained by producing high molecular weight polymer component of 5 to 1.05 times the weight ratio, MI is 0.03~1g / 10 min, density of 958kg / ^{m 3} or less, ethylene and carbon atoms 3 20 α-olefin copolymer, the amount of (B) in the composition is in the range of 20 to 80% by weight, MI of the composition is 0.01 to 5 g / 10 min, and the density is A polyethylene composition, which is 940 to 960 kg / m ³ .   The polyethylene composition according to claim 1, wherein the polyethylene (A) is produced by a combination of a chromium compound-supported catalyst treated with an organometallic compound and a promoter.   The polyethylene composition according to claim 1 or 2, wherein the low molecular weight polymer component is produced in a solvent containing 0.1 wt% or less of an α-olefin. The polyethylene composition according to any one of claims 1 to 3, wherein the density of the low molecular weight polymer component is 971 kg / m ³ or more.