Catalyst – solid sorbent – or support therefor: product or process – Catalyst or precursor therefor – Plural component system comprising a - group i to iv metal...
Reexamination Certificate
2000-10-09
2002-03-05
Nazario-Gonzalez, Porfirio (Department: 1621)
Catalyst, solid sorbent, or support therefor: product or process
Catalyst or precursor therefor
Plural component system comprising a - group i to iv metal...
C502S114000, C502S120000, C502S154000, C526S160000, C526S943000, C556S006000, C556S027000, C556S053000
Reexamination Certificate
active
06352953
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a novel transition metal which is useful as a catalyst for polymerization of olefins.
2. Prior Art
It is well known to produce ethylene polymers or ethylene-&agr;-olefin copolymers with use of a catalyst composition comprising a zirconium compound, a transition metal compound such as titanocene and hafnocene compounds and an aluminoxane compound. This prior art catalyst is liable to form such a polymers which is of an extremely high catalytic activity and has a narrow molecular weight distribution and modal distribution. Such known transition metal compounds are represented by the formula (cyclopentadienyl)
2
MeRHal wherein R is a cyclopentadienyl or C
1
-C
6
alkyl group or halogen, particularly chlorine, Me is a transition metal, particularly zirconium and Hal is halogen, particularly chlorine. Specific examples are bis(cyclopentadienyl)zirconiumdichloride (Cp
2
ZrCl
2
) and bis(cyclopentadienyl)zirconiummonomethylmonochloride Cp
2
Zr(CH
3
)Cl as disclosed in Japanese Laid-Open Patent Publication No. 58-19309. U.S. Pat. No. 4,404,344 also discloses a zirconium compound represented by the formula Cp
2
MeY
2
wherein Me is zirconium, Y is hydrogen, a C
1
-C
5
alkyl group, a C
1
-C
5
metalalkyl group or a group of such as CH
2
AlR
2
, CH
2
CH
2
AlR
2
and CH
2
CH(AlR
2
)
2
of which each R is a C
1
-C
5
alkyl group or a C
1
-C
5
metalloalkyl group.
Moreover, another compounds are well known from Japanese Patent Publication No. 7-37488 disclosing (C
5
R′
m
)
p
R″
s
(C
5
R′
m
)MeQ
3−p
and R″
s
(C
5
R′
m
)
2
MeQ′ wherein Me is zirconium or hafnium, each (C
5
R′
m
) is a cyclopentadienyl group or a substituted cyclopentadienyl group, R′ each may be the same or different and are one member selected from the group consisting of hydrogen and C
1
-C
20
alkyl, alkenyl, aryl, alkylaryl and arylalkyl groups of which two adjacent members may form 4- through 6-membered condensed rings, R″ is a C
1
-C
4
alkylene group, germanium, silicone, a phosphino group or an amino group which crosslink two rings (C
5
R′
m
), Q each may be the same or different and are a C
1
-C
20
aryl, alkyl, alkenyl, alkylaryl or arylalkyl group or halogen, Q′ is a C
1
-C
20
alkylidene, s=0 or 1, p=1 and, m=4 when s=1 and m=5 when s=0, and at least one of R′ is a hydrocarbon group if m=5.
In recent years, there have been arising various demands for polyolefins in terms of physical properties and characteristics, such demands being directed to the production of polyolefins which are somewhat widened in molecular weight distribution or increased in molecular weight or which are completely free of halogen. It has been found that polyolefins tend to be effectively varied in properties and behaviors such as activity during polymerization depending on the type of a transition metal compound used therefor. Nowadays, a strong demand has been arising for a clean polyolefin free of halogen in view of problems in environment and hygienic.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a novel transition metal compound which is stable in nature and eligible for use of the components of a polymerization catalyst for olefins.
The novel transition metal compound according to the invention is represented by the formula
wherein M
1
is an element of Group IVB in the Periodic Table, M
2
is an element of Group IIIA in the Periodic Table, R
1
and R
2
each are a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group or a substituted indenyl group and may be bonded to each other through a C
1
-C
18
hydrocarbon group and/or silylene group, R
3
and R
4
each are a hydrogen atom or a C
1
-C
18
hydrocarbon group, R
5
and R
6
each are a hydrogen atom or a C
1
-C
18
hydrocarbon group and R
7
and R
8
each are a hydrogen atom or a C
1
-C
18
hydrocarbon group and may be bonded to each other to form one or more cyclic hydrocarbon group.
A typical example of the compound of the above formula (I) is represented by the formula
wherein M
1
is an element of Group IVB in the Periodic Table, M
2
is an element of Group IIIA in the Periodic Table, R
1
and R
2
each are a cyclopentadienyl group, a substituted cyclopentadienyl group, an indenyl group or a substituted indenyl group and may be bonded to each other through a C
1
-C
18
hydrocarbon group and/or silylene group, R
3
and R
4
each are a hydrogen atom or a C
1
-C
18
hydrocarbon group, R
5
, R
6
, R
9
, R
10
, R
11
, R
12
, R
13
and R
14
each are a hydrogen atom or a C
1
-C
18
hydrocarbon group and may be bonded to each other through a hydrocarbon group to form a cyclic hydrocarbon group.
The present invention provides a novel transition metal compound which is capable of becoming a catalyst component exhibiting an excellent catalytic activity when applied to polymerization of olefins. This novel transition metal compound can be synthesized without using a halogen-containing substance as a starting material and is a novel transition metal complex having a 5-membered ring formed by a transition metal compound of Group IVB, two carbons, a metal of Group III and hydrogen and the existence of such a transition metal complex has not ever been known. Furthermore, it has not been known to use this transition metal complex as a component of a catalyst for polymerization of olefins.
The novel transition metal compound of the invention is represented by the above-mentioned formula (I) and one of the features of this compound is exemplified by the metallacycle (5-membered ring) formed through the bond of carbon, carbon, M
2
(an element of Group IIIA in the Periodic Table) and hydrogen to M
1
(an element of Group IVB in the Periodic Table).
It is well known that a zirconocenemonoalkylmonohydride compound of which hydrogen and alkyl are bonded to zirconium forms a divalent zirconocene by reductive elimination reaction caused by the coupling of hydrogen and the hydrocarbon, as reported in “Organozirconium Compounds in Organic Synthesis” written by E. Negishi, T. Takahashi in SYNTHESIS, 1-19, January 1988. Such a zirconocenemonoalkylmonohydride compound is susceptible to the reductive elimination reaction and thus is difficult to stabilize whereas the novel transition metal compound of the invention can suppress the occurrence of the reductive elimination by the formation of a metallacycle (five-membered ring).
The inventive compound is characterized by its stereostructure which is stabilized due to the formation of metaracycle (five-membered ring) containing hydrogen. The five-membered ring of cyclopentadienyl groups or indenyl groups can rotate and thus if two identical ligands are bonded thereto they can not be distinguished. As to Cp
2
ZrCl
2
(Formula A below), it is reported in J. Organomet. Chem., 1964, 2,329 that the 10 hydrogen atoms (H
1
of Formula A) bonding to the cyclopentadienyl group are classified of one single kind by
1
H-NMR. As to Cp
2
Zr(Cl)CH
2
SiMe
3
(Formula B below), it is reported in J. Chem. Soc. Dalton Trans., 1973, 445 that the 10 hydrogen atoms (H
2
of Formula B below) bonding to the cyclopentadienyl group are likewise classified of one single kind by
1
H-NMR. Furthermore, as to Ind
2
ZrCl
2
(Formula C below), Bull. Soc. Chim. Fr., 1966, 3548 describes that the 6 hydrogen atoms (H
3
, H
4
of Formula C) bonding to the 5-membered rings of the indenyl group are observed of two types by
1
H-NMR.
Whereas, as proved in Examples 1 and 2 hereinafter described,
1
H-NMR analysis of the novel compounds as represented by Formulae D and E above, of the invention reveals that the 6 hydrogen atoms in total (H
5
, H
6
, H
7
, H
8
, H
9
and H
10
of Formula D and H
11
, H
12
, H
13
, H
14
, H
15
and H
16
of Formula E) are observed individually.
1
H-NMR data of Examples 1 indicates that these hydrogens are present at a peak of 5.8 ppm, 5.5 ppm, 5.4 ppm, 5.1 ppm, 4.6 ppm, and 4.3 ppm, while
1
H-NMR data of
Sano Akira
Seki Takashi
Shimizu Hiroyuki
Akin Gump Strauss Hauer & Feld L.L.P.
Japan Polyolefins Co., Ltd.
Nazario-Gonzalez Porfirio
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