Mitsui Chemicals, Inc.

Mitsui Petrochemical Industries, Ltd.

Teruhisa Kojima

Ryoichi Yamamoto

Satoru Ohtani

Mamoru Kioka

Satoru Moriya

Shinichi Kojoh

Kenji Sugimura

Shinya Matsunaga

Norio Kaneshige

Hiroshi Nishikawa

Masahiro Kishine

Takahiro Mamyoda

Toshimi Hachimori

Crystalline polypropylene contains components insoluble in 64&deg; C. decane satisfying the characteristics involving intrinsic viscosity; Mz/Mn; pentadvisotacticity, D value and Mw/Mn, are excellent in hardness and rigidity, high in melt tension, and excellent in molding properties. Processes for preparing such crystalline polypropylenes, and polypropylene compositions and thermoformed products that contain such crystalline polypropylenes are also described. The number-average molecular weight Mn of the components insoluble in 64&deg; C. decane is preferably 25000 or more.

Crystalline polypropylenes, process for preparing thereof, polypropylene compositions, and thermoformed products

A method of treating polyolefin comprises (i) a ligand-decomposition step of contacting polyolefin, which is obtained by the use of a transition metal compound containing ligands having cyclopentadienyl skeleton, with a ligand decomposer, such as water, oxygen, alcohol, alkylene oxide or peroxide, to decompose the ligands contained in the polyolefin, and (ii) a ligand-removal step of heating the polyolefin contacted with the ligand decomposer to remove the decomposed ligands from the polyolefin. According to this method, the residual ligands having cyclopentadienyl skeleton, which are contained in the polyolefin produced by the use of a transition metal compound containing ligands having cyclopentadienyl skeleton, are decomposed and removed from the polyolefin, whereby polyolefin diminished in odor development in the molding process can be obtained.

Method of treating polyolefin

Drying of a solid polymer is disclosed in which a solid polymer obtained by polymerization (or a product of modification of the solid polymer) is contacted with a drying gas so that any solvent and/or unreacted polymerization feed materials remaining in the solid polymer are removed to thereby dry the solid polymer, and in which a gaseous polymerization feed material is used as the drying gas and contacted with the solid polymer to thereby dry the solid polymer (step i), and the resultant solid polymer is contacted with a drying gas which contains an inert gas (step ii). The drying gas can be recovered from the step (i) and part thereof can be recycled through a polymerization step as it is or be recycled, after cooling the drying gas to thereby remove any condensed components, to the step (i). Not only can the solid polymer be efficiently dried but also the solvent and unreacted polymerization feed materials recovered from the solid polymer can efficiently be recycled by the disclosed method.

Drying solid polymer apparatus

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Yamaguchi, Japan

Teruhisa Kojima