Sumitomo Chemical Company, Limited

Yuji Shigematsu

Toshio Sasaki

Hiroyuki Shiraishi

Hirofumi Johoji

Kohzoh Miyazaki

Yufu Sato

Hiroyuki Harada

Toshiyuki Kokubo

Fumio Ishibashi

Toshimi Sato

Yuji Kanda

Kohji Kubo

Akio Uemura

Shoichi Nezu

A novel ethylene-.alpha.-olefin copolymer and a molded article formed therefrom, wherein (A) a density is 0.870 to 0.945 g/cm.sup.3, (B) a relation between an activation energy of flow Ea (J/mole K) obtained by measurement of viscoelasticity at at least three temperatures in the molten state and a melt flow rate MFR (g/10 min) satisfies the following equation (1):

Ethylene-.alpha.-olefin copolymer and molded article thereof

An ethylene-.alpha.-olefin copolymer having;

Ethylene-.alpha.-olefin copolymer and a molded article therefor

A resin composition for extrusion molding which has a melt flow rate (MFR) of from 0.5 to 30 g/10 min., having (A) 1 to 80 parts by weight of an ethylenic polymer which gives an endothermic peak in a temperature range of from 80.degree. to 120.degree. C. in a temperature rise thermogram as measured by a differential scanning calorimeter, has a melt flow rate (MFR) of from 0.5 to 50 g/10 min., and is prepared by high-pressure radical polymerization, (B) 5 to 80 parts by weight of a copolymer of ethylene and an .alpha.-olefine containing 3 to 12 carbon atoms which gives at least one endothermic peak in a temperature range of from 110.degree. to 130.degree. C. in the temperature rise thermogram as described above, has a melt flow rate (MFR) of from 0.5 to 30 g/10 min. and a density of from 0.900 to 0.935 g/cm.sup.3 and (C) 5 to 70 parts by weight of the copolymer of ethylene and an .alpha.-olefin containing 3 to 12 carbon atoms which has a melt flow rate (MFR) of from 0.5 to 30 g/10 min. and a density of from 0.870 to 0.920 g/cm.sup.3 in an unannealed state, and gives no endothermic peak at temperatures above 110.degree. C. in the temperature rise thermogram as described above, and in which a ratio of a main component is not less than 80%; which gives a packaging material having significantly improved properties such as heat sealability at low temperature, heat-sealing strength, hot tacking property and bag breaking strength, and exhibits an excellent extrusion processability such as film forming property and extrusion loading.

Resin composition for extrusion molding

A process for polymerizing ethylene at a high temperature under high pressure, which comprises contacting ethylene alone or along with an .alpha.-olefin at a temperature of 120.degree. C. or more at a pressure of 350 kg/cm.sup.2 or more with a catalyst consisting essentially of (A) a reaction product of (A1) a titanium compound having at least one titanium-nitrogen bond with (A2) an organometallic compound of an element of Groups I to III of the Periodic Table and (B) an organoaluminum compound. Said process enables the production of an ethylene polymer or copolymer having a narrow composition distribution and a high molecular weight and being excellent in weather resistance, color development, transparency, corrosiveness and mechanical properties.

Process for polymerizing ethylene at high temperature under high pressure

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Ichihara, Japan

Yuji Shigematsu