JPH0794493B2 - Olefin Polymerization Method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for polymerizing olefins. Specifically, it relates to a method for polymerizing olefins using a catalyst having a magnesium halide obtained by a specific method as a carrier.

[Prior Art] For the polymerization of olefins, it is known to use a catalyst composed of a transition metal catalyst component in which a titanium halide is supported on a carrier such as magnesium halide and an organometallic compound.
Since its disclosure in No. -12105, various improved methods have been proposed, and fairly excellent performances have been obtained.

[Problems to be solved by the invention]

The smaller the amount of the catalyst residue remaining in the polyolefin obtained by polymerizing the olefin, the better, and the larger the bulk specific gravity, the better. Therefore, the development of higher performance catalysts is desired.

[Means for solving problems]

The present inventors diligently studied a method for solving the above problems, found that magnesium halide that can be produced by a specific method is suitable as a carrier, and completed the present invention.

That is, the present invention relates to a Grignard reagent represented by the general formula R ¹ MgX ¹ (wherein R ¹ is a hydrocarbon residue, X ¹ is a bromine or iodine atom) and a general formula R ² _n SiX ² _4- MgX ¹ X ² obtained by the reaction with a chlorinated silicon compound represented by _n (in the formula, R ² is a hydrocarbon residue, X ² is a chlorine atom, and n is an integer of 0 ≦ n ≦ 3). A method for polymerizing olefins is characterized in that a catalyst composed of a transition metal catalyst component obtained by supporting titanium tetrachloride on the substrate and an organoaluminum compound is used.

The present invention is characterized by a method for producing MgX ¹ X ² used as a carrier (wherein X ¹ is bromine or iodine, and X ² is chlorine).
The method for supporting titanium tetrachloride on the obtained carrier is not particularly limited, and various methods can be adopted.
For example, a method in which the carrier is contacted or co-milled with an oxygen-containing compound such as carboxylic acid ester, ether, orthoester, alkoxy silicon, phosphoric acid ester, alcohol or ketone in advance, and then contacted with titanium tetrachloride or co-milled is used. Can be mentioned.

R ² MgX ¹ (wherein R ¹ is a hydrocarbon residue and X ¹ is a bromine or iodine atom) used in the production of magnesium halide represented by MgX ¹ X ² which is important in the present invention is well known in the art. Can be produced by a method, generally R ¹
It can be produced by reacting a halogenated hydrocarbon represented by X ¹ with metallic magnesium. Here, the hydrocarbon residue may be an aliphatic, alicyclic or aromatic hydrocarbon residue and is not particularly limited, but those having about 1 to 20 carbon atoms are used. X ¹ is iodine or bromine atom.

One of the components used in the production of MgX ¹ X ² has the general formula R ² _n SiX ² _4-n (wherein R ² is a hydrocarbon residue, X ² is a chlorine atom, and n is an integer of 0 ≦ n ≦ 3). The chlorinated silicon compound represented by the formula (1) has a saturated or unsaturated hydrocarbon residue having 1 to 20 carbon atoms in addition to hydrogen as the hydrocarbon residue R ^2. Compounds with saturated hydrocarbon residues such as tetrachlorosilane, trichlorosilane, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, ethyltrichlorosilane, diethyldichlorosilane, triethylchlorosilane, or vinyltrichlorosilane, vinylmethyldichlorosilane Compounds having unsaturated hydrocarbon acid groups such as chlorosilane, phenyltrichlorosilane, diphenyltrichlorosilane, and phenylmethyldichlorosilane Is exemplified.

The reaction between the Grignard reagent and the silicon chlorinated compound is extremely fast, and MgX ¹ X ² can be obtained in good yield at room temperature or around the boiling point of the catalyst used.

Examples of the olefin used in the present invention include ethylene, propylene, butene-1, pentene-1, hexene-1, octene-1, styrene and vinylnaphthalene, and their homopolymerization or mutual copolymerization and further with diene. It is used for copolymerization.

In the present invention, for the polymerization of olefins, conventional olefin polymerization methods can be applied other than using the magnesium halide carrier produced by the above method, solution polymerization using a solvent, bulk polymerization using the olefin itself as a medium, or solvent polymerization. Vapor phase polymerization or the like, which does not substantially contain, can be employed.

〔Example〕

 Hereinafter, the present invention will be described with reference to examples.

Example 1 In a 300 ml round bottom flask, 7.4 g of magnesium and 20 ml of diethyl ether were placed, and a mixture of 50 g of cyclohexane bromide and 100 ml of diethyl ether was added dropwise over 2 hours under reflux of ether. After that, the mixture is further stirred for 1 hour under reflux, and C ₆
A solution of H ₁₁ MgBr in ethyl ether was prepared.

Then, under reflux of ethyl ether, 13 g of silicon tetrachloride was added to 50 m.
What was melt | dissolved in n-hexane of 1 was dripped over 3 hours, and also it stirred under reflux for 4 hours.

Then, the mixture was filtered at room temperature, the solid content was washed with ethyl ether, and dried with a nitrogen stream to obtain a solid content of 40 g. The resulting solids were MgBrCl with Mg: Cl: Br approximately 1: 1: 1.

10 g of the above solid content was placed in a 200 ml round bottom flask, 50 ml of titanium tetrachloride and 50 ml of toluene were placed therein, and the mixture was stirred at 90 ° C. for 1 hour and then left to stand to remove the supernatant. Further, 50 ml of titanium tetrachloride and 50 ml of toluene were added, and the mixture was stirred at 90 ° C. for 1 hour, then left standing to remove the supernatant, and the obtained solid content was washed 7 times with toluene to obtain a transition metal catalyst component. . As a result of the analysis, it contained 1.3 wt% of titanium.

Ethylene was polymerized using the transition metal catalyst component obtained by the above operation. N-heptane 1 in an autoclave with an internal volume of 2 l
Then, add 20 mg of the above transition metal catalyst component and 0.5 ml of triethylaluminum, add hydrogen to 2 kg / cm ² gauge, further add ethylene to 6 kg / cm ² gauge, then raise the temperature to 75 ° C., 10 kg / cm ² gauge Polymerization was carried out at 75 ° C. for 2 hours while adding ethylene so that Then, the mixture was cooled, unreacted ethylene was purged, and then filtered to obtain polyethylene powder. The dry weight was 195 g. The powder has an intrinsic viscosity of 3.01 (measured with a 135 ° C tetralin solution), a bulk specific gravity of 0.43, and a particle size of 200 mesh or less.
It was 0.3% and 0.0% of coarse particles of 10 mesh or more. The yield per Ti is 750 kg / g-Ti, and the bulk specific gravity is also good,
The particle size distribution was also relatively sharp.

Example 2 Propylene was polymerized using the transition metal catalyst component obtained in Example 1. To 2l autoclave n- heptane 1 placed, the transition metal catalyst component 30mg, diethylaluminum chloride 0.32 ml, methyl toluate 0.12 ml, triethylaluminum 0.20ml addition, hydrogen 0.1 kg / cm ² gauge, propylene 2 kg / cm ² gauge insertion Then, the internal temperature was raised to 70 ° C., and the polymerization was carried out at a total pressure of 6 kg / cm ² gauge for 2 hours. After completion of the polymerization, unreacted propylene was purged and the slurry was filtered to obtain 149 g of polypropylene powder, and 3.9 g of atactic polypropylene was obtained from the filtrate.

The polypropylene powder had a boiling n-heptane extraction residual ratio of 97.4% (using a Socklesley extractor for 6 hours with boiling n-heptane), an intrinsic viscosity of 2.08, and a bulk specific gravity of 0.42.

Example 3 16.5 g of trichlorovinylsilane instead of 13 g of silicon tetrachloride
Other than that, the same procedure as in Example 1 was carried out to obtain 1.2 wt% titanium
% Transition metal catalyst component was obtained and polymerized in the same manner to obtain 225 g of polyethylene powder. This powder had an intrinsic viscosity of 2.95 and a bulk specific gravity of 0.39.

Comparative Example 1 C ₆ H ₁₁ MgCl was obtained in the same manner as in Example 1 except that 36 g of cyclohexane chloride was used without using cyclohexane bromide, and the same procedure as in Example 1 was carried out except that MgCl ₂ was used. The intrinsic viscosity of the obtained polyethylene is 2.62,
The bulk specific gravity was 0.37, and the yield per Ti was only 136 kg / g-Ti.

Comparative Example 2 The same procedure as in Example 1 was carried out except that C ₆ H ₁₁ MgBr obtained in Example 1 was used and silicon tetrabromide was used instead of silicon tetrachloride to obtain MgBr _2. Viscosity number
2.36, bulk specific gravity is 0.34, yield per Ti is 187 Kg / g
-It was just Ti.

〔The invention's effect〕

By carrying out the method of the present invention, it is possible to produce a polyolefin with high yield, which is industrially valuable.

[Brief description of drawings]

FIG. 1 is a flowchart of the olefin polymerization catalyst.

Claims (1)

[Claims] 1. A Grignard reagent represented by the general formula R ¹ MgX ¹ (wherein R ¹ is a hydrocarbon residue and X ¹ is a bromine or iodine atom) and a general formula R ² _n SiX ² _4-. MgX ¹ X ² obtained by the reaction with a chlorinated silicon compound represented by _n (wherein R ² is a hydrocarbon residue, X ² is a chlorine atom, and n is an integer of 0 ≦ n ≦ 3). A method for polymerizing an olefin, characterized in that a catalyst comprising a transition metal catalyst component obtained by supporting titanium tetrachloride on a substrate and an organoaluminum compound is used.