Chisso Corporation

The Institute of Physical and Chemical Research

Takaya Mise

Hiroshi Yamazaki

Shinya Miya

Masato Harada

Takashi Yoshimura

A novel transition-metal compound having a bis-substituted cyclopentadienyl ligand of bridged structure (I) and a novel mixture of the compound (I) with an aluminoxane (B), each useful as catalyst component(s) for stereoregular olefin polymerization are provided, which compound (I) is expressed by the formula ##STR1## wherein M is Zr or Hf; Y is Si or Ge; R.sup.1.sub.n -C.sub.5 H.sub.4-n and R.sup.1.sub.q -C.sub.5 H.sub.4-q each represent an unsubstituted or substituted cyclopentadienyl group; n and q each represent an integer of 0 to 4, but cases of n=q=0 and n=q=4 are excluded; R.sup.1 s may be same or different and each represent H, silyl or hydrocarbon radical; R.sup.2 s may be same or different and represent H or hydrocarbon radical; and Xs may be same or different and represent H, halogen or hydrocarbon radical; and which aluminoxane is expressed by the formula (II) or the formula (III) ##STR2## wherein m represents an integer of 4 to 30 and R.sup.3 represents a hydrocarbon radical.

Transition-metal compound having a bis-substituted-cyclopentadienyl

Bis(di-, tri- or tetra-substituted-cyclopentadienyl)zirconium dihalides represented by the following general formula [I] are provided, ##STR1## (wherein R.sup.1 denotes a substituent group on the cyclopentadienyl ring which is an alkyl radical of 1 to 5 carbon atoms; R.sub.2.sup.1 --C.sub.5 H.sub.3 stands for a di-substituted cyclopentadienyl radical; and X is a halogen atom). This compound, when combined with an aluminoxane repesented by the following general formula [VII], gives a high-activity catalyst for the synthesis of polyolefins, ##STR2## (wherein m is an integer of 4 to 20; and R.sup.2 denotes a hydrocarbyl radical).

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Kawagoeshi, Japan

Takaya Mise