Mitsubishi Chemical Industries Limited

Hisashi Kitada

Yoshinori Suga

Masayoshi Hasuo

Genjiro Kakogawa

Yumito Uehara

Yasuo Maruyama

Junichi Gotoh

A propylene-ethylene block copolymer in the presence of a catalyst comprises as main components, a solid titanium-containing catalytic component and an organoaluminum compound having the formula

Process for producing propylene-ethylene block copolymer

Propylene is polymerized in the presence of a catalytic system of the type which comprises a solid titanium trichloride-based complex serving as a catalyst, said complex having an atomic ratio of aluminum to titanium in the range of below 0.15:1 and containing a complexing agent, and an organic aluminum compound of the general formula, AlR.sup.1.sub.n Cl.sub.3-n wherein R.sup.1 represents an n-propyl group or an n-hexyl group and n is a value of 1.95-2.10. The catalytic system may further comprise an electron-donor compound as a third catalytic component.

Process for polymerizing propylene

Propylene is polymerized in the presence of a catalytic system of the type which comprises a solid titanium trichloride-based complex serving as a catalyst, said complex having an atomic ratio of aluminum to titanium in the range of below 0.15:1 and containing a complexing agent, and an organic aluminium compound of the general formula, AlR.sub.n.sup.1 Cl.sub.3-n wherein R.sup.1 represents an n-propyl group or an n-hexyl group and n is a value of 1.95-2.10. The catalytic system may further comprise an electron-donor compound as a third catalytic component.

In a process for preparing polyolefin by polymerizing an olefin in the presence of a catalyst system combining an organoaluminum compound and a titanium-containing solid catalytic component prepared by mixing (a) water and/or a hydroxy compound, (b) a Grignard reagent and (c) a titanium tetrahalide, the components (a) (b) or (c) or the reaction mixture of two or three components thereof is contacted with (d) one or more electron donor selected from the group consisting of amines, carboxylic acid amides, phosphines, phosphine oxides, phosphoric esters, phosphorous esters, phosphoric acid amides, ketones and carboxylic esters. The polyolefin having high isotactic index can be obtained.

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Tokyo, Japan

Hisashi Kitada