Organic compounds -- part of the class 532-570 series – Organic compounds – Heavy metal containing
Reexamination Certificate
2001-08-31
2003-01-14
Nazario-Gonzalez, Porfirio (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Heavy metal containing
C556S053000, C526S126000, C526S160000, C526S161000, C526S352000, C526S943000, C502S103000, C502S117000, C502S120000
Reexamination Certificate
active
06506919
ABSTRACT:
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention relates to a metallocene compound and the olefin polymerization using the same, particularly to a metallocene containing —CR
1
2
)
a
—O—SiR
b
Y
c
ligand as a part of a ligand, so that the preparation of a supported metallocene catalyst is convenient (wherein each Y, which can be the same as or different from other Y, is a hydrogen, halogen, alkoxy, aryloxy, or amide radical; each R
1
, which can be the same as or different from other R
1
, is a hydrogen radical, or an alkyl, cycloalkyl, aryl, alkenyl, alkylaryl, arylalkyl, or arylalkenyl radical having from 1 to 40 carbon atoms; each R, which can be the same as or different from other R, is an alkyl, cycloalkyl, aryl, alkenyl, alkylaryl, arylalkyl, or arylalkenyl radical having from 1 to 40 carbon atoms, a is an integral number of from 1 to 40, c is 1, 2, or 3, and the sum of b and c is 3). Furthermore, the present invention relates to a supported metallocene catalyst using this metallocene compound and the olefin polymerization using the same.
The metallocene compound in this invention has superior reactivity with support in the preparation of supported metallocene catalyst, so that side reactions can be minimized and the olefin polymerization activity using the catalyst in this invention is excellent. In addition, the olefin polymerization process employing the supported metallocene catalyst of this invention shows no fouling in a reactor and produces polymer with well defined particle size and bulk density.
(b) Description of the Related Art
In 1976, Professor Kaminsky of Germany reported that olefin polymerization could be accomplished using zirconocenedichloride compound as a catalyst with methylaluminoxane (MAO) as a co-catalyst which was obtained through the partial hydrolysis of trimethylaluminum (A. Anderson, J. G. Corde. J. Herwig, W. Kaminsky, A. Merck, R. Mottweiler, J. Pein, H. Sinn, and H, J. Vollmer, Angew. Chem. Int. Ed. Engl. 15, 630, (1976)).
Thereafter, Exxon filed a patent (U.S. Pat. No. 5,324,800) on the olefin polymerization utilizing the metallocene compounds with various substituent groups.
This homogeneous olefin polymerization catalyst shows unique polymerization characteristics which can not be observed by conventional Ziegler-Natta catalysts. That is, the molecular weight distribution of produced polymers is narrow, co-polymerization is easy, and the distribution of the comonomer is uniform. In the case of the propylene polymerization, the tacticity of polymer can be controlled according to the molecular symmetry of catalyst. These unique characteristics not only opened up a way to new polymers which are not obtained by the conventional Ziegler-Natta catalyst, but also provided the way to tailor-made polymers. Accordingly, there have been continuous interests on this catalyst system.
In a gas phase or in a slurry process, the particle morphology and bulk density of a produced polymer should be controlled to enhance the easy transfer of polymer and to increase the throughput per reactor unit volume. Also, the reactor fouling should be avoided for a continuous operation. To solve these problems, the catalyst should be supported on a suitable support.
Described below are conventional preparation methods for supported metallocene catalysts.
In first, a metallocene compound is physisorbed on a support, and then supported by treatment with aluminoxane (W. Kaminsky, Makromol. Chem., Rapid Commun. 14, 239 (1993)).
Secondly, aluminoxane is supported on a support, and then a metallocene compound is supported (K. Soga, Makromol. Chem. Rapid Commun. 13, 221 (1992); U.S. Pat. No. 5,006,500; U.S. Pat. No. 5,086,025).
Thirdly, a metallocene compound is treated with aluminoxane, and then supported on a support (U.S. Pat. No. 5,240,894).
Additionally, anchoring is achieved by a chemical reaction between the ligand of a metallocene compound and a support. In one case, metal is ligated after ligand is supported. (K. Soga, H. J. Kim, T. Shiono, Makromol., Rapid Commun. 15, 139 (1994), Japanese Laid-open Patent No. Heisei 6-56928; U.S. Pat. No. 5,466,766).
In the other case, a metallocene compound with a reactive functional group on a ligand is prepared and then it is anchored by a chemical reaction between the functional group on a ligand and a support. In all cases, the catalyst must be strongly supported on a support surface by a chemical bond. Supported metallocene catalyst obtained by contacting metallocene compound without a reactive ligand with a support such as silica results in reactor fouling due to the leaching of metallocene compound.
The following Reaction Formulae 1 to 5 list chemical reactions which are possible on the support surface:
The above Reaction Formula 1 and Reaction Formula 2 show desirable supporting reactions resulting from the interaction between the functional group of a ligand and the hydroxyl group or reactive oxo functional group on the support surface. The Reaction Formulae 3 to 5 show side reactions.
Additionally, various side reactions involving functional groups on the support surface result in decomposition of the metallocene compounds. Also weakly physisorbed metallocene compounds can be found on the support.
The anchoring of the colorless metallocene compounds on the colorless silica support usually yields brown or dark gray colored supported metallocene compounds. This color change indicates accompanied side reactions described above during the supporting process.
The supported metallocene compounds produced by the side reactions are not activated by co-catalysts and show decreased catalyst activity. The catalyst made by the side reactions, even if activated, will dissolve into a solvent and cause undesirable problems such as reactor fouling or reduced bulk density of the polymer.
These problems due to the side reactions can be overcome by a soxhlet method by which the weakly physisorbed metallocene compounds or decomposed by-products are extracted from the support surface before polymerization process.
More basically, the development of metallocene compounds with suitable ligands which can react with functional groups on the support surface is a solution for this problem. With appropriate ligand systems, reactions described in Reaction Formulae 1 and 2 are maximized, and a supported catalyst can be obtained in a high yield.
Previously reported metallocene compounds with suitable functional groups that can react with support are summarized as follows.
European Patent No. 293,815 A1 discloses a method in which a supported metallocene catalyst is prepared by the reaction of a metallocene compound containing —C—SiR
2
(OR′) functional group (wherein R is a C
1
-C
4
alkyl, C
6
-C
10
aryl, or C
1
-C
4
alkoxy, and OR′ is a C
1
-C
4
alkoxy) with a support containing a hydroxyl group on its surface. Olefin polymerization utilizing this supported catalyst activated by an aluminoxane was presented.
Supported metallocene compounds can be prepared by the reaction of metallocene compound containing an alkoxysilyl functional group similar to that described above with a support containing highly reactive siloxane functionality as presented by these inventors (Korean Patent No. 98-12660).
U.S. Pat. No. 5,767,300 discloses a metallocene compound with —C—ZR
o
Hal
p
(Z is boron, silicon, germanium or tin; each R
o
, which can be the same as or different from other R
o
, is a hydrogen radical or a hydrocarbyl radical having from 1 to 20 carbon atoms; Hal is halogen radical; o is 0, 1, or 2; p is 1, 2 or 3) ligand functional group, preparation of supported metallocene compound, and olefin polymerization process using the supported catalyst.
Additionally, the preparation of a metallocene compound containing at least one —OSiR
3
(R is C
1
-C
20
alkyl, C
3
-C
20
cycloalkyl, C
6
-C
20
aryl, C
7
-C
20
alkenyl, C
7
-C
20
arylalkyl, C
7
-C
20
arylalkenyl or alkylaryl radical.) functional group, preparation of supported metallocene compound, and olefin polymerization process using the supported catalyst are
Lee Bun-Yeoul
Lee Do-Hoon
Lee Joo-Eun
Oh Jae-Seung
Ladas & Parry
LG Chemical Co. Ltd.
Nazario-Gonzalez Porfirio
LandOfFree
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