Sumitomo Chemical Company, Limited

Tadahiro Mitsuno

Yasuro Suzuki

Yuki Iseki

Hiroyuki Shiraishi

Seiichiro Ima

The object of the present invention to provide a method for producing a extruded ethylene copolymer that can provide a film having excellent melt tension and fluidity as well as excellent impact strength and appearance (haze and transmittance). This object is achieved by a method for producing a extruded ethylene copolymer, comprising extruding an ethylene copolymer of ethylene and an &#x3b1;-olefin having 4 to 20 carbon atoms under specific conditions, and obtaining the extrudate.

Method for producing a extruded ethylene copolymer

An object of the present invention is to provide an ethylene-&#x3b1;-olefin copolymer excellent in extrusion molding processability and in the balance between the appearance and impact strength. This object is achieved by a copolymer of ethylene and &#x3b1;-olefin of from 4 to 20 carbon atoms having melt flow rate (MFR; unit is g/10 minutes), melt tension at 190&#xb0; C. (MT; unit is cN), intrinsic viscosity ([&#x3b7;]; unit is dl/g), the chain length A and characteristic relaxation time at 190&#xb0; C. (&#x3c4;; unit is sec) which satisfy the specific relations.

Ethylene copolymer

The invention provides an ethylene-&#x3b1;-olefin copolymer which is superior in extrusion molding processability. The present invention is to provide a copolymer of ethylene and &#x3b1;-olefin of from 4 to 20 carbon atoms, having melt flow rate of from 1 to 100 g/10 min, an activation energy for melt flow of 60 kJ/mol or more, melt tension at 190&#xb0; C. (MT), intrinsic viscosity ([&#x3b7;]) and a chain length A which satisfy the formula (1) to (3), wherein the chain length A is a chain length at peak position of a logarithm normal distribution curve of a component having the highest molecular weight among logarithm normal distribution curves obtained by dividing a chain length distribution curve obtained by gel permeation chromatography measurement into at least two logarithm normal distribution curves.

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Ichihara, Japan

Tadahiro Mitsuno