Chisso Corporation

Tohru Hanari

Akihiro Sato

Kazutsune Kikuta

Toshihiro Uwai

Kenji Matsuda

Hiromasa Chiba

Takeshi Suzuki

Kinya Mori

Masazumi Miyajima

Ichiro Namiki

Kiyoshi Matsuda

A highly crystalline polypropylene is provided having:

Highly crystalline polypropylene

A preactivated catalyst for producing .alpha.-olefin polymers is provided, which is obtained by the steps which comprises:

Preactivated catalyst for producing .alpha.-olefin polymers

A process for producing terpolymers of propylene (as a main monomer), ethylene and another .alpha.-olefin having superior and well-balanced physical properties, almost without forming soluble polymer is provided. This process is characterized by preliminarily activating a catalyst consisting of a titanium trichloride composition and a specified organoaluminum halide, with a small amount of an .alpha.-olefin of 2 to 12 carbon atoms, a trialkylaluminum and an aromatic ester, and copolymerizing specified amounts of propylene, ethylene and an .alpha.-olefin of 4 to 12 carbon atoms in the presence of the preliminarily activated catalyst obtained above.

Process for producing terpolymers of propylene, ethylene and another .alpha

A process for producing .alpha.-olefin polymers with a controlled stereoregularity and with a higher yield is provided, which process comprises: combining a TiCl.sub.3 -containing composition obtained by reducing TiCl.sub.4, with an organoaluminum compound; thereafter subjecting the composition to a polymerization treatment with an .alpha.-olefin; before, during or after the polymerization treatment, adding an electron donor or/and an electron acceptor or a reaction product of these two; as well as adding a reaction product of a trialkylaluminum with an electron donor having a specified molar ratio of the electron donor to the trialkylaluminum selected in the range of 0.01 to 5; and polymerizing an .alpha.-olefin in the presence of the resulting preactivated catalyst.

Process for producing .alpha.-olefin polymers

A process for producing .alpha.-olefin polymers is provided, which comprises: reacting an organoaluminum compound with an electron donor in a specified ratio in a solvent at a specified temperature to obtain a solid product (I); reacting solid product (I) with TiCl.sub.4 at a specified temperature in a specified ratio of Al/Ti and then removing a liquid portion from the resulting material followed by washing to obtain a solid product (II) having no free TiCl.sub.4 ; reacting solid product (II) with an electron donor and an electron acceptor in a specified ratio at a specified temperature to obtain a solid product (III); and polymerizing .alpha.-olefin(s) in the presence of a catalyst comprising a combination of solid product (III) with an organoaluminum compound. This process provides a catalyst having a high storing and thermal stability and a polymer having a uniform particle size.

A process for producing .alpha.-olefin polymers is provided which comprises:

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Ichiharashi, Japan

Tohru Hanari