Idemitsu Petrochemical Co., Ltd.

Takashi Saeki

Tsutomu Onodera

Kazuyoshi Fukada

Shuji Machida

Masaru Nakagawa

Yutaka Obata

Tomio Tatsumi

Yasuhisa Sugita

Kenichi Mitsuhashi

Hiroki Nakashima

Provided are a propylene homopolymer in which a melt tension (MT), a Z average molecular weight (Mz) and a melt index (MI) (g/10 minutes) are specifically related and in which a difference in eluting temperatures and a maximum eluting temperature in programmed temperature fractional chromatography and a propylene copolymer in which a comonomer is specific &agr;-olefin and a content thereof falls in a specific range and in which a melt tension (MT), a Z average molecular weight (Mz) and a melt index (MI) (g/10 minutes) are specifically related. The propylene homopolymer or the propylene copolymer of the present invention has physical properties equivalent to or not lower than those of conventional propylene polymers, and it can be controlled in a melt tension and is suited to foaming molding, sheet molding and blow molding. Further, it is excellent in melt-processing characteristics, molding stability and a recycling property and can be applied to molding methods which are restricted in use in conventional propylene polymers, for example, large size blow molding and extrusion foaming molding.

Propylene homopolymer and propylene copolymer

Provided are a propylene resin composition comprising 100 parts byweight in total of two different types of propylene polymers each having specific properties, from 0 to 50 parts by weight of a specific elastomer, and from 0 to 50 parts by weight of an inorganic filler; and a method for producing it. The production method comprises melting and kneading two polymer groups each comprising one or more propylene polymers. The resin composition in which the viscosity difference between the propylene homopolymer segments to form the base polymer and the amorphous propylene segments to form the disperse phase is small is produced by first melting and kneading one polymer group, then immediately adding the other polymer group thereto, and further kneading and melting the two. For the composition in which the viscosity difference therebetween is large, the polymer groups are separately kneaded in melt, and the resulting melts are further kneaded. The propylene resin composition has high stiffness, high impact resistance and high fluidity, and its moldings have good appearances.

Propylene resin composition and process for producing the same

A process for preparing a styrenic resin is herein disclosed which comprises the step of volatilizing extrudinga styrenic polymer (SPS) powder having a syndiotactic configuration in the presence of water, an alcohol or an antioxidant by the use of an extruder to obtain pellets. According to this process, the operation of volatilization extrusion is done in the presence of water, the alcohol or the antioxidant to stably and efficiently prepare the SPS pellets in which yellowing is inhibited, and the operation of the volatilization extrusion is carried out in the presence of water to stably and efficiently prepare the SPS pellets containing a less amount of a remaining volatile component such as an unreacted monomer.

Process for preparing styrenic resin

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Ichihara, Japan

Takashi Saeki