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
2000-12-06
2004-01-27
Bell, Mark L. (Department: 1755)
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
active
06683017
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority of China patent Application No. 99125566.6, filed on Dec. 6, 1999.
BACKGROUND OF THE INVENTION
The present invention relates to a catalyst system for the (co)polymerization of olefins.
In recent years, a study of a catalyst for olefinic polymerization has been greatly developed and properties of the catalyst have been greatly improved. Meanwhile, olefinic polymerization catalysts with better properties are desired as the demand for the processability of the polymer product become higher and higher.
U.S. Pat. No. 4,784,983 discloses a catalyst system for olefinic polymerization comprising components (A), (B) and (C). Component (A) is prepared by dissolving a halide of magnesium in a solvent mixture of an organic epoxy compound and an organic phosphorus compound to form a homogeneous solution; mixing the homogeneous solution with a liquid halide of titanium; adding an auxiliary precipitant such as organic carboxylic acid anhydrides, organic carboxylic acids, ethers and ketones to form a precipitate; adding at least one polycarboxylic acid ester when the precipitate appears; and separating the precipitate from the mixture and treating the separated precipitate with the halide of titanium or a mixture of the halide of titanium in an inert diluent. The activity of the catalyst system of the patent is a very high. The resultant polymer using the catalyst system has very high stereospecificity and a narrow particle size distribution.
One main method of adjusting molecular weight of polypropylene is to introduce hydrogen gas into the polymerization system. When the catalyst system of U.S. Pat. No. 4,784,983 is used in the propylene polymerization, sensitivity of adjusting molecular weight of polypropylene with hydrogen gas is not ideal.
CN 1143651A disclosed solid catalyst components and catalyst therefrom. The catalysts comprise the reaction product of: (1) a solid catalyst component containing an internal electron-donor; (2) an Al-alkyl compound, and optionally (3) an external electron-donor. The catalyst obtained by using, as the external-electron donor, cyclopolyenic, 1,3-diethers exhibit in the polymerization of olefins very high balances of activity and stereosepcificity. But, when the catalysts are used in file polymerization of propylene, an external electron-donor must be added in order to obtain the polymer with stereospecificity of greater 99%. If no external electron-donor is used, stereospecificity of the resultant polymer can only be about 98%. However, when an external electron-donor is added in the polymerization of olefins, the sensitivity of active sites of the catalysts to hydrogen gas decreases, hydrogen gas adjustability on the molecular weight of polypropylene becomes bad and activity of the catalysts greatly decreases.
An object of the present invention is to provide a catalyst system for the (co)polymerization of olefins that overcome the above drawbacks in the prior art.
SUMMARY OF THE INVENTION
The present invention provides a catalyst system for the (co)polymerization of olefins, characterized in that it consists of the following components:
(A) A solid catalyst component comprising titanium, magnesium, halogen and a 1,3-diether and prepared by dissolving a halide of magnesium in a solvent system consisting of an organic epoxy compound, an organic phosphorus compound and optionally an inert diluent to form a homogeneous solution; mixing the homogeneous solution with titanium tetrahalide or its derivatives to form a mixture; precipitating a solid from the mixture in the presence of at least one auxiliary precipitant; treating the solid with the 1,3-diether to load the diether on the solid; and treating the diether loaded solid with the titanium tetrahalide or its derivatives and the inert diluent;
(B) An organic aluminum compound; and optionally
(C) An organic silicon compound.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in details as follows.
1. The halide of Magnesium solution
The halide of Magnesium solution herein means a uniform solution obtained by dissolving a halide of magnesium in a solvent system consisting essentially of organic epoxy compounds and organic phosphorus compounds. The solvent system may include inert diluents.
(1) Halide of magnesium
Suitable halide of magnesium includes magnesium halide such as magnesium chloride, magnesium bromide and magnesium iodide; a complex of magnesium halide with water or alcohol; a derivative of magnesium halide wherein a halogen atom is substituted by a hydrocarboxyl or halohydrocarboxyl group; and like.
(2) Organic epoxy compound
Suitable organic epoxy compound includes oxides of aliphatic olefins, aliphatic diolefins, halogenated aliphatic olefins, and halogenated aliphatic diolefins, glycidyl ethers, cyclic ethers and the like having 2-8 carbon atoms. Examples of suitable organic epoxy compounds are ethylene oxide, propylene oxide, butylene oxide, butadiene dioxide, epoxy chloropropane, methylglycidyl ether, diglycidyl ether, tetrahydrofuran, and the like.
(3) Organic phosphorus compounds
Suitable organic phosphorus compounds include hydrocarbon and halohydrocarbon esters of phosphoric acid or phosphorous acid, e.g. trimethyl phosphate, triethyl phosphate, tributyl phosphate, triphenyl phosphate, trimethyl phosphate, triethyl phosphate, tributyl phosphate, triphenyl phosphite and the like.
(4) Preparation of the halide of magnesium solution
The particle size of the halide of magnesium used is preferred to be such that it is easily dissolved with stirring. The dissolution temperature is about 0° C.-100° C., preferably from 30° C.-70° C. Inert diluents such as hexane, heptane, octane, benzene, toluene, xylene, 1,2-dichloroethane, chlorobenzene and other hydrocarbons or halohydrocarbons can be added into the solvent system. The amount of epoxy compounds added is about 0.2-10.0 moles, preferably 0.5-4.0 moles, per mole of halide of magnesium, and the amount of organic phosphorus compounds added is about 0.1-3.0 moles, preferably 0.3-1.0 moles, per mole of halide of magnesium.
2. Precipitation of the solid
The halide of magnesium solution is maixed liquid titanium tetrahalide to form a solid precipitate in the presence of an auxiliary precipitant. 1,3-diether may be added before or after the precipitation of the solid and loaded on the solid.
According to the invention, the auxiliary precipitant can be added either after the halide of magnesium solution is obtained or together with the halide of magnesium. The liquid titanium tetrahalide or its derivatives can be in the pure liquid state, or in a solution of inert diluents.
(1) Titanium tetrahalide or its derivatives
The halide of titanium used in the preparation of the solid catalyst component (A) of the invention is a compound having the formula TiX
n
(OR)
4-n
wherein X is a halogen, each R is independently a hydrocarbyl and n is an integer of from 0 to 4. Examples of the compounds are titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, tetrabutoxy titanium, tetraethoxy titanium, chlorotriethoxy titanium, dichlorodiethoxy titanium, trichloroethoxy titanium and the like.
The halide of magnesium solution and liquid titanium tetrahalide or its derivatives used in the present invention have been disclosed in U.S. Pat. No. 4,784,983 which is incorporated herein by reference.
(2) 1,3-diether
The 1,3-diether used in this invention is selected from the compounds of the general formula:
Where each R is independently hydrogen, halogen, linear or branched C
1
-C
20
alkyl, C
3
-C
20
cycloalkyl, C
6
-C
20
aryl, C
7
-C
20
alkaryl and C
7
-C
20
aralkyl, with the proviso that all R cannot be hydrogen or CH
3
;
Each R
1
is independently hydrogen, halogen, linear or branched C
1
-C
20
alkyl, C
3
-C
20
cycloalkyl, C
6
-C
20
aryl, C
7
-C
20
alkaryl and C
7
-C
20
aralkyl;
Each R
2
is independently hydrogen, halogen, linear or branched C
1
-C
20
alkyl, C
3
-C
20
cycloalkyl, C
6
-C
20
aryl, C
7
-C
20
alkaryl and C
7
-C
20
aralkyl;
Two R can be
Feng Weihua
Gao Mingzhi
Li Zhulan
Yang Juxiu
Yang Yantoo
Bell Mark L.
Brown Jennine
China Petro - Chemical Corporation
Christie Parker & Hale LLP
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