JPH0150323B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved polymerization method using a supported transition metal catalyst, an organoaluminium, and a stereoregularity improver.

Since Japanese Patent Publication No. 39-12105 proposed a method of using a catalyst consisting of a supported transition metal, organoaluminium, and organic acid ester as a polymerization catalyst for α-olefin, many improved catalysts have been proposed. Both the catalytic activity and the stereoregularity of the resulting polymers are significantly improved. However, the activity is insufficient compared to ethylene polymerization catalysts, and it is often difficult to commercialize products without thoroughly removing catalyst residue or performing special treatment. Alternatively, improvement of the polymerization method is desired.

As a result of various studies, the present inventors found that even if the same supported transition metal catalyst is used, the yield per supported transition metal catalyst is large depending on the combination of specific organoaluminiums, and the stereoregularity is also different. The present invention was completed based on the discovery that a poly-α-olefin with high properties can be obtained.

The present invention provides highly active and highly stereoregular polyα-
An object of the present invention is to provide a method for producing olefin. That is, the present invention provides a method for polymerizing α-olefin using a supported titanium catalyst component, an organoaluminum compound, and a stereoregularity improver, in which a titanium halide catalyst supported on magnesium halide, a dialkyl aluminum chloride, an inorganic It relates to a polymerization method characterized by using a catalyst consisting of an ester of an acid or an organic acid and a trialkylaluminum, and also using triethylaluminum and a trialkylaluminum having an alkyl residue of C ₃ or more as the trialkylaluminum.

There are no particular limitations on the method for producing the titanium halide catalyst component supported on magnesium halide used in the present invention, and any method may be used as long as the resulting catalyst provides a highly active and highly stereoregular polyα-olefin. Good. For example, magnesium halides, preferably magnesium chloride and C-O
Alternatively, a complex is prepared with a compound containing a C-N bond, and then a liquid titanium halide is preferably prepared.
Obtained by heat contact treatment with titanium tetrachloride.

This composite of magnesium chloride and a compound containing a C-O or C-N bond is usually produced by co-pulverizing magnesium chloride and a compound containing a C-O bond, or by co-pulverizing magnesium chloride and a compound containing a C-O bond. A method of obtaining SiO ₂ , Al ₂ O ₃ ,
It is also possible to coexist solid compounds such as AlCl ₃ .

Specific examples of the dialkyl aluminum chloride used in the present invention include diethylaluminum chloride, dipropyl aluminum chloride, dibutyl aluminum chloride, dihexyl aluminum chloride, and the like.

Specifically, the inorganic or organic acid esters used in the present invention include aliphatic carboxylic acid esters such as acetic acid ester, aromatic carboxylic acid esters such as benzoic acid ester, and orthocarboxylic acid esters such as orthobenzoic acid ester. , phosphate ester,
Examples include orthosilicate esters, but aromatic carboxylic esters are particularly preferably used.

Examples of the meralkyl aluminum used in the present invention include triethyl aluminum, tributyl aluminum, tripropyl aluminum, tripentyl aluminum, and trihexyl aluminum.

In the present invention, the amount of each of the above components used varies depending on the compound used and polymerization conditions, but usually dialkylaluminum chloride is 1 to 1000 mol, and inorganic acid or organic acid ester is 1 to 1000 mol, per 1 mol of Ti in the supported catalyst. 500 mol, trialkylaluminum is used in an amount of 1 to 2000 mol.

The feature of the present invention is that triethylaluminum and trialkylaluminium having an alkyl residue of C3 _or more are used together as the trialkylaluminum, and propyl, butyl, pentyl, or hexyl is used as the alkyl residue of _C3 or more. Among them, butyl group is preferred.

Regarding methods of combined use, methods of mixed use,
There is a method of charging C ₃ separately to the polymerization system.
An effective method is to polymerize trialkylaluminum having the above alkyl residue and then use triethylaluminum.

By the above method, propylene, butene-
1. By homopolymerizing α-olefins such as pentene-1 or copolymerizing them with ethylene, stereoregular poly-α-olefins can be obtained in high yield per catalyst, and are of industrial value. There is.

A more specific explanation will be given below with reference to Examples.

Examples and Comparative Example A Production of supported transition metal catalyst A vibratory mill equipped with two grinding pots each having an internal volume of 600 ml each containing 80 steel balls with a diameter of 12 mm was prepared.
In this pot under nitrogen atmosphere, 20 g of magnesium chloride, 2 ml of orthoethyl acetate, 1,2-
4 ml of dichloroethane was added and the mixture was ground for 40 hours. 300
20 g of the above pulverized product and 100 ml of titanium tetrachloride were added to a ml round-bottomed flask, and the mixture was stirred at 80° C. for 2 hours, and then the supernatant liquid was removed by decantation. Then n-
After adding 200 ml of heptane and stirring at room temperature for 15 minutes, the washing operation of removing the supernatant liquid by decantation was repeated 7 times, followed by an additional 200 ml of n-heptane.
ml was added to form a slurry of supported transition metal catalyst. We sampled a portion of this slurry and measured Ti per gram of supported transition metal catalyst.
It contained 1.78wt%.

B Polymerization: Thoroughly dried and purged with nitrogen, with an internal volume of 5
50 n-heptane in SUS-32 autoclave
ml of the above-mentioned supported transition metal catalyst, 0.24 ml of diethylaluminum chloride, 0.14 ml of methyl p-toluate, and trialkylaluminium in the amounts shown in the table.
Next, 1.5 kg of liquid propylene was charged, then 1.6 N of hydrogen was charged, and the internal temperature was raised to 75°C by heating the autoclave with hot water.
Polymerized for hours.

After the polymerization was completed, unreacted propylene was discharged to obtain white polypropylene. The obtained polypropylene was dried under reduced pressure at 60°C, weighed, and the yield of polypropylene was calculated as the yield of polypropylene per hour, which was determined as the activity. In addition, the proportion of the polymer remaining after boiling n-heptane extraction of the polypropylene powder (hereinafter abbreviated as Powder II), the bulk specific gravity, and the intrinsic viscosity (in a tetralin solution at 135° C.) were measured, and the results are summarized in the table.

C Results Polymerization was carried out in the same manner as in Example 1, except that the trialkyl aluminum was divided and polymerized under the conditions shown in the table. The results are shown in the table.

Comparing Examples and Comparative Examples, it is clear that even if the amount of trialkyl aluminum used is the same, the activity increases and II improves by using the two types together or separately. .

Comparative Example 4 Polymerization was repeated using the same mole of triisobutylaluminum instead of the triethylaluminum used in the method of Comparative Example 1, and under the same polymerization conditions as in Comparative Example 1.

Polymerization result is activity 3241g/g-cat・hr, amount obtained
10.3Kg/g-cat, 625Kg/g-Ti, η1.59, II95.7
%, and the bulk specific gravity was 0.42.

Example 5 Methyl p-toluate in the method of Example 1
Polymerization was repeated in the same manner as in Comparative Example 1 except that 0.12 ml of tetraethoxysilane was used instead of 0.14 ml, and the other polymerization conditions were the same as in Comparative Example 1.

Polymerization result is activity 4230g/g-cat・hr, amount obtained
12.7Kg/g-cat, 773Kg/g-Ti, η1.32, II95.0
%, and the bulk specific gravity was 0.43.

Comparative Example 5 Polymerization was repeated in exactly the same manner as in Example 5, except that 1.47 mmol of triethylaluminum was used instead of the mixture of triethylaluminum and triisobutylaluminum.

Polymerization result is activity 3600g/g-cat・hr, amount obtained
10.8Kg/g-cat, 657Kg/g-Ti, η1.33, II93.9
%, and the bulk specific gravity was 0.41.

[Brief explanation of drawings]

The drawing shows a flowchart representing the preparation process of the catalyst of the present invention.

【table】

Claims (1)

[Scope of Claims] 1. A method for polymerizing α-olefin using a titanium tetrahalide catalyst supported on magnesium dihalide, a dialkylaluminum chloride, an ester of an inorganic or organic acid, and a catalyst consisting of a trialkylaluminium. A polymerization method characterized in that triethylaluminum and trialkylaluminum having an alkyl residue of C ₃ or more are used together as the trialkylaluminum. 2. The method according to claim 1, wherein the trialkylaluminum having an alkyl residue of _2C3 or more is tripropylaluminum, tributylaluminum, tripentylaluminum, or trihexylaluminum. 3 Claims in which triethylaluminum and trialkylaluminium having an alkyl residue of C3 _or more are used together by polymerizing the trialkylaluminum having a C3 _or more alkyl residue, and then adding triethylaluminum The method described in paragraph 1.