Transition metal compound, catalyst component for olefin...

Details Transition metal compound, catalyst component for olefin... Transition metal compound, catalyst component for olefin...

1999-06-08

2001-04-17

Nazario-Gonzalez, Porfirio (Department: 1621)

Organic compounds -- part of the class 532-570 series

Organic compounds

Heavy metal containing

C556S011000, C556S028000, C556S042000, C556S053000, C556S058000, C526S127000, C526S160000, C526S943000, C502S103000, C502S117000, C502S152000

Reexamination Certificate

active

06218558

ABSTRACT:

FIELD OF THE INVENTION
The present invention relates to a novel transition metal compound, a catalyst component for &agr;-olefin polymerization comprising the transition metal compound and a process for the preparation of an &agr;-olefin polymer in the presence of the catalyst component. More particularly, the present invention relates to a highly active catalyst component which allows the preparation of a high molecular and high melting &agr;-olefin polymer, a polymerization catalyst comprising such a catalyst component and a process for the preparation of an &agr;-olefin polymer in the presence of such a catalyst.
BACKGROUND OF THE INVENTION
A so-called Kaminsky catalyst well known as uniform catalyst for olefin polymerization exhibits a high polymerization activity and thus allows the preparation of a polymer having a sharp molecular weight distribution.
As transition metal compounds for use in the preparation of an isotactic polyolefin in the presence of a Kaminsky catalyst there are known ethylenebis(indenyl)zirconium dichloride and ethylenebis(4,5,6,7-tetrahydroindenyl)zirconium dichloride (as in JP-A-61-130314 (The term “JP-A” as used herein means an “unexamined published Japanese patent application”)). However, the preparation of a polyolefin in the presence of such a catalyst is normally disadvantageous in that the resulting polyolefin has a small molecular weight and, if low temperature polymerization is effected to obtain a polymer having an increased molecular weight, the catalyst exhibits a reduced polymerization activity.
Further, for the purpose of preparing a high molecular polyolefin, a method has been proposed involving the use of a hafnium compound instead of the foregoing zirconium compound (Journal of Molecular Catalysis, 56 (1989), pp. 237-247). However, this proposed method is disadvantageous in that the catalyst used exhibits a low polymerization activity.
Moreover, dimethylsilylene bis-substituted cyclopentadienyl zirconium dichloride has been proposed (as in JP-A-1-301704, Polymer Preprints, Japan 39 (1990), pp. 1,614-1,616, JP-A-3-12406). Dimethylsilylene bis(indenyl) zirconium dichloride has been proposed (as in JP-A-63-295007, JP-A-1-275609). The use of these compounds allows the preparation of a polymer having a high steric regularity and a high melting point in a relatively low temperature polymerization process but provides a polymer having a low steric regularity, melting point and molecular weight under high temperature polymerization conditions which are economical. On the other hand, a catalyst comprising a transition metal compound comprising halogen atoms introduced into substituents on the atoms crosslinking ligands and a co-catalyst has been proposed (as in JP-A-4-366106). However, such a catalyst is disadvantageous in that it provides a polymer having a low molecular weight and steric regularity as compared with similar catalysts free of halogen atoms.
Further, a compound has been known having enhanced isotacticity and increased molecular weight provided by adding substituents to indenyl group which is part of ligands (as in JP-A-4-268307, JP-A-6-157661). Moreover, a transition metal compound has been known wherein a subring containing two adjacent carbon atoms constituting a conjugated 5-membered ring has members other than 6 (as in JP-A-4-275294, JP-A-6-239914, JP-A-8-59724).
However, the foregoing compounds exhibit an insufficient catalytic action under high temperature polymerization conditions that are economical. Further, these compounds give a catalyst system soluble in the reaction medium in most cases. Accordingly, the resulting polymer has an amorphous grain form and a small bulk density and contains much fine powder and thus exhibits extremely poor grain properties. Accordingly, these compounds have many production disadvantages. For example, if these compounds are used in slurry polymerization or gas phase polymerization, continuous stable operation can be hardly conducted.
In order to solve these problems, on the other hand, a catalyst comprising a transition metal compound and/or organic aluminum compound supported on an inorganic oxide (e.g., silica, alumina) or organic material has been proposed (as in JP-A-61-108610, JP-A-60-135408, JP-A-61-296008, JP-A-3-74412, JP-A-3-74415). However, polymers prepared in the presence of such a catalyst contain much fine powder or coarse grains. Further, these polymers exhibit insufficient grain properties, e.g., low bulk density. Moreover, such a catalyst exhibits a low polymerization activity per unit solid component. Further, such a catalyst provides a polymer having a relatively low molecular weight and steric regularity than a catalyst system free of carrier. The present invention has been worked out under these circumstances.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a novel transition metal compound which can form a catalyst component for &agr;-olefin polymerization capable of producing a high molecular and high melting olefin polymer that can be extruded or injection-molded in a high yield.
Another object of the present invention is to provide a catalyst for &agr;-olefin polymerization comprising the foregoing catalyst component and a process for the preparation of an &agr;-olefin polymer in the presence of such a catalyst component.
A further object of the present invention is to provide a novel catalyst component which is little liable to deterioration of performance when used supported on a carrier to improve its process applicability.
A first aspect of the present invention lies in a novel transition metal compound represented by the following general formula (I):
In the general formula (I), R
1
, R
2
, R
4
and R
5
each independently represent a hydrogen atom, C
1-10
hydrocarbon group, C
1-18
silicon-containing hydrocarbon group or C
1-18
halogenated hydrocarbon group.
R
3
and R
6
each independently represent a C
3-10
saturated or unsaturated divalent hydrocarbon group which is condensed with the 5-membered ring, with the proviso that at least one of R
3
and R
6
has from 5 to 8 carbon atoms and hence forms a 7- to 10-membered condensed ring.
R
7
and R
8
each independently represent a C
1-20
hydrocarbon group, C
7-30
oxygen-containing aryl group, C
7-30
nitrogen-containing aryl group or C
7-30
sulfur-containing aryl group, with the proviso that at least one of R
7
and R
8
is a C
7-30
oxygen-containing aryl group, C
7-30
nitrogen-containing aryl group or C
7-30
sulfur-containing aryl group.
The suffixes m and n each independently represent an integer of from 0 to 20, with the proviso that m and n are not 0 at the same time and if m or n is an integer of not less than 2, R
7
's or R
8
's may be connected to each other in arbitrary positions to form a new cyclic structure.
Q represents a divalent C
1-20
hydrocarbon group, halogenated hydrocarbon group or silylene, oligosilylene or germylene group which may have C
1-20
hydrocarbon or C
1-20
halogenated hydrocarbon group, which group connects the two 5-membered rings.
X and Y each independently represent a hydrogen atom, halogen atom, C
1-20
hydrocarbon group, C
1-20
silicon-containing hydrocarbon group, C
1-20
halogenated hydrocarbon group, C
1-20
oxygen-containing hydrocarbon group, amino group or C
1-20
nitrogen-containing hydrocarbon group.
M represents a transition metal element belonging to the groups 4 to 6 in the periodic table.
A second aspect of the present invention lies in a novel transition metal compound represented by the following general formula (II):
In the foregoing general formula (II), R
1
and R
4
each independently represent a C
1-6
hydrocarbon group, C
1-6
silicon-containing hydrocarbon group or C
1-6
halogenated hydrocarbon group.
R
2
and R
5
each independently represent a hydrogen atom or C
1-6
hydrocarbon group.
Q, N, X and Y are as defined in the general formula (II)
R
9
, R
10
, R
11
, R
12
, R
13
, R
14
, R
15
an R
16
each independently represent a hydrogen atom or C
1-20
hydrocarbon group.
Ar
1
and Ar
2
each indepe

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