Nippon Petrochemicals Company, Limited

Narumi Ishikawa

Kunimichi Kubo

Shigemitsu Kambe

Tatsuyuki Kamiya

Toshifumi Morimoto

Toshiyuki Miyauchi

Sumio Ikeda

Noboru Ikegami

A branch distribution of a crystalline polymer is determined by melting the polymer at a temperature sufficiently higher than the melting point thereof, then cooling the melted polymer to room temperature in such a manner that isothermal crystallization of the polymer is allowed to take place stepwise at intervals of 3.degree. C. or higher at least from near the upper limit of the melting point of the polymer, then raising the temperature to melt the crystals and determining a branch distribution from the melt behavior, using a thermal analyzer.

Method for determining branch distribution of polymer

A polyethylene composition which has a wide molecular weight distribution and excellent balance among melt elasticity, flow characteristics and mechanical properties, and which is suitable for use in producing large-scaled hollow plastics articles. The composition comprises a higher molecular weight ethylene polymer or copolymer and a lower molecular weight ethylene polymer or copolymer which is specified in view of the content of o-dichlorobenzene and the ratio of the area under the elution temperature-eluate volume curve between 25.degree.to 90.degree. C. to the area under said curve of 90.degree. C. and above in temperature rising elution fractionation.

Polyethylene composition

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Nagareyama, Japan

Narumi Ishikawa