Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2000-06-08
2002-09-24
Wu, David W. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C526S160000, C526S943000, C526S348000, C526S125100, C502S103000, C502S107000, C502S226000, C502S152000
Reexamination Certificate
active
06455647
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a solid catalyst for olefin polymerization and a method for producing an olefinic polymer using the solid catalyst. More specifically, the invention relates to a solid catalyst for olefin polymerization that does not require deashing treatment because of having high polymerization activity, and provides a polymer having a narrow molecular weight distribution, and a method for producing an olefinic polymer, comprising homopolymerizing or copolymerizing an olefin using the solid catalyst.
BACKGROUND ART
Kaminsky type catalyst that has received attention as a general purpose catalyst for polyolefin production in recent years has the characteristics of, for example, providing a polyolefin that has high activity and a narrow molecular weight distribution and giving a polymer uniform in composition in the case of using the same in copolymerization. However, since this catalyst is a homogeneous catalyst, polymer particles produced are in a form of a fine powder and this makes it difficult to handle and also causes fouling. For this reason, it is practically impossible to apply the catalyst to a slurry polymerization or a gas phase polymerization method, which is a main process in polyolefin production.
An attempt has been made to have a solid carrier carry at least one component of a metallocene compound and an organoaluminum-oxy compound in order to solve those problems.
For example, Japanese Patent Application Laid-open No. Hei 6-256411 discloses a method of using as a carrier various metal salts such as magnesium carbonate, magnesium hydroxide or magnesium sulfate, and Japanese Patent Application Laid-open No. Hei 7-268029 discloses a method of using as a carrier a Lewis acidic solid such as magnesium dichloride or aluminum trichloride. Further, Japanese Patent Application Laid-open No. Hei 8-176225 discloses a method of using as a carrier aluminum- and magnesium-containing solid component obtained by the reaction of a specific magnesium compound with aluminum compound.
However, the on-carrier-catalysts disclosed in those prior arts generally have made improvement in powder properties, fouling and the like, but catalyst activity, particularly polymerization activity per solid catalyst, has not yet been sufficient.
DISCLOSURE OF INVENTION
Accordingly, an object of the present invention is to provide a solid catalyst for olefin polymerization with which polymerization can be made with high activity while maintaining the characteristics of Kaminsky type catalyst, for example, that a polymer produced has narrow molecular weight distribution. Another object of the present invention is to provide a method for producing an olefinic polymer using the solid catalyst for olefin polymerization.
As a result of extensive investigations to achieve the above objects, the present inventors have found that a solid catalyst for olefin polymerization capable of achieving the above objects can be obtained by using as a carrier a magnesium-containing solid component obtained by heat treatment of a specific magnesium compound. The present invention has thus been completed based on this finding.
According to a first aspect of the present invention, there is provided a solid catalyst (D) for olefin polymerization, characterized by comprising a magnesium-containing solid component (A) carrying thereon an organoaluminum-oxy compound (B) and a metallocene compound (C), and the magnesium-containing compound (A) being obtained by heat treating a magnesium compound of the general formula:
MgX
2
.n
H
2
O
where X represents a halogen atom and n is an integer of 1 to 12.
According to a second aspect of the present invention, there is provided a method for producing an olefinic polymer, characterized in that an olefin is polymerized or copolymerized in the presence of the above solid catalyst (D) for olefin polymerization and an organoaluminum compound (E).
A detailed description will now be given of a solid catalyst for olefin polymerization (hereinafter may be abbreviated as a “solid catalyst”) according to the present invention and of the method for producing an olefinic polymer using the catalyst.
A magnesium-containing compound (A) for use in preparation of a solid catalyst (D) for olefin polymerization of the present invention is obtained by heat treating a magnesium compound of the general formula:
MgX
2
.n
H
2
O
where X represents a halogen atom and n is an integer of 1 to 12. The compound represented by the general formula MgX
2
.nH
2
O is a hydrate of magnesium dihalide, and a halogen atom X is chlorine, bromine or iodine. Examples of the compound include MgCl
2
.2H
2
O, MgCl
2
.4H
2
O, MgCl
2
.6H
2
O, MgCl
2
.8H
2
O, MgCl
2
.12H
2
O, MgBr
2
.6H
2
O, MgBr
2
.8H
2
O, MgBr
2
.10H
2
O, MgI
2
.6H
2
O, MgI
2
.8H
2
O and, MgI
2
.10H
2
O. Of those MgCl
2
.2H
2
O, MgCl
2
.4H
2
O, MgCl
2
.6H
2
O and MgBr
2
.6H
2
O are preferably used. Those compounds can be used alone or as mixtures of two or more thereof.
The heat treatment conditions of the magnesium compound are that the temperature is 100 to 500° C., preferably 150 to 300° C., and the heating time is 0.1 to 10 hours, preferably 0.5 to 4 hours. During the heat treatment, air or nitrogen gas is allowed to flow to remove by-products produced. A solid substance thus obtained generally has a composition that a gram atomic ratio of halogen to magnesium (halogen/magnesium) is 0.3 to 1.7, depending on the heating conditions. The solid substance is generally ground with a grinder such as a ball mill before the carrying process. In place of grinding the solid substance, the magnesium compound represented by the general formula MgX
2
.nH
2
O may be used such that an aqueous solution of the magnesium compound is prepared and the aqueous solution is sprayed and dried to form spherical particles.
The organoaluminum-oxy compound (B) used in the preparation of the solid catalyst (D) for olefin polymerization of the present invention is selected from a linear aluminoxane of the following general formula (1) or a cyclic aluminoxane of the following general formula (2):
where R
4
each represents hydrogen atom, a halogen atom or an alkyl group having 1 to 10 carbon atoms, and d is an integer of 2 to 40, provided that when R
4
is a halogen atom all R
4
are not simultaneously halogen atoms;
where R
4
and d are the same as defined in the above general formula (1).
In the case that R
4
in the general formulae (1) and (2) is an alkyl group having 1 to 10 carbon atoms, examples of the alkyl group include methyl group, ethyl group and isobutyl group. Further, in the case that R
4
in the general formulae (1) and (2) is a halogen atom, examples of the halogen atom include chlorine atom and bromine atom. R
4
groups in the compounds represented by the general formulae (1) and (2) may be different from one another. The number d of the repeating unit is selected from a range of 2 to 40 and is preferably selected from a range of 5 to 20. Of the compounds represented by the general formulae (1) and (2), those wherein all R
4
are methyl groups or at least one of R
4
is a methyl group are preferred.
Various known methods can be used to synthesize the organoaluminum-oxy compound (B) of the general formula (1) or (2). For example, the organoaluminum-oxy compound (B) can be prepared by the following methods: a method of dissolving trialkyl aluminum in a hydrocarbon solvent and gradually adding water to the resulting solution in an equivalent amount of trialkyl aluminum in the solvent to hydrolyze trialkyl aluminum; a method of suspending copper sulfate hydrate or aluminum sulfate hydrate in a hydrocarbon solvent and contacting trialkyl aluminum with the resulting suspension in an amount of 1 to 3 times equivalent of water of crystallization of the hydrate in the suspension to slowly hydrolyze trialkyl aluminum; or a method of contacting trialkyl aluminum with an undehydrated silica gel suspended in a hydrocarbon solvent in an amount of 1 to 3 times equivalent of adsorbed water in the silica gel to slowly hydrolyze trialkyl aluminum.
The me
Hane Yukiko
Iijima Minoru
Kamiyama Sakae
Takemori Toshifumi
Yamamoto Shigeharu
Choi Ling-Siu
Maruzen Petrochemical Co. Ltd.
Wu David W.
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