JPH05301919A - Olefin polymerization catalyst and olefin polymerization method - Google Patents

Abstract

PURPOSE:To provide the subject highly active catalyst useful for producing polyolefins excellent in physical properties and processability, composed of a metallocene compound, organoaluminum compound and Lewis acid. CONSTITUTION:The objective catalyst composed of (A) a metallocene compound of formula I [Cp<1> and Cp<2> are each (substituted)cyclopentadienyl; R<1> is 1-4C alkylene, dialkylsilicon, etc., acting so as to cross-link Cp<1> and Cp<2>; m is 0 or 1; M is titanium, zirconium, etc.; X is F, Cl, etc.] [e.g. bis(cyclopentadienyl) titanium dichloride], (B) an organoaluminum compound of formula II (R<2> is halogen, H, alkyl, etc., at least one R<2> being alkyl) (e.g. trimethylaluminum), and (C) a Lewis acid having acidity enough to accept paired electrons (pref. magnesium chloride) at the molar ratios A/C of pref. (1:0.2) to (1:200) and A/B of (1:1) to (1:10000).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an olefin polymerization catalyst comprising a metallocene compound, an organoaluminum compound and a Lewis acid, and a method for producing a polyolefin using this olefin polymerization catalyst.

[0002]

As an olefin polymerization catalyst, JP-A-3-197513 discloses that ethylene is polymerized by using a metallocene compound and an organoaluminum compound as a catalyst, and JP-A-3-2904.
No. 08 discloses a method of obtaining a polyethylene or ethylene copolymer by using a zirconocene compound, an organoaluminum compound and an organomagnesium compound as a catalyst. However, according to the above publication, although polyethylene and ethylene copolymers can be produced, they are not satisfactory in terms of activity and the like regarding propylene polymerization.

Further, it is possible to produce a highly active olefin polymer containing propylene by a catalyst using metallocene and methylaluminoxane. JP-A-58-1930
As is known from JP-A-9, etc., methylaluminoxane is relatively expensive and it is necessary to use a large amount of this methylaluminoxane at the time of polymerization, so that there is a problem of residual aluminum.

Recently, a catalyst showing high activity in the polymerization of olefins including propylene by adding an organoaluminum compound to an ionic metallocene catalyst has been disclosed in JP-A-3-179.
005 publication. However, according to the above specification, the ionic metallocene catalyst, which is the main catalyst, is generally converted from the chloride of the metallocene compound into a methyl derivative of the metallocene compound by using a methylating reagent such as methyllithium or methylmagnesium chloride. It is disclosed that it must be prepared by reacting the derivative with a Lewis acid. The ionic metallocene catalysts shown in the above specification are often unstable, and many steps are required for the synthesis.
There were many problems such as reproducibility in preparation, storage, and deactivation during transfer to a polymerization container.

[0005]

The present invention has been made in order to solve this problem, and uses a stable metallocene compound, an organoaluminum compound and an olefin polymerization catalyst comprising a Lewis acid, and an olefin polymerization catalyst. It is an object of the present invention to provide a method for producing a polyolefin.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to solve the above-mentioned problems, and as a result, by using a metallocene compound, an organoaluminum compound and a Lewis acid, they have high activity and physical properties and processability. It was found that an excellent polyolefin can be efficiently produced, and the present invention has been completed.

That is, the present invention comprises (A) a metallocene compound, (B) an organoaluminum compound and (C) a Lewis acid, and the metallocene compound (A) is represented by the general formula (1).

[0008]

[Chemical 3] [Wherein Cp ¹ and Cp ² are each independently a cyclopentadienyl or substituted cyclopentadienyl group, R ¹ is an alkylene group having 1 to 4 carbon atoms, a dialkylsilicon group,
A dialkylgermanium group, an alkylphosphine group and an alkylamine group, R ¹ acts to crosslink Cp ¹ and Cp ² , m is 0 or 1, M is titanium, zirconium or hafnium, X is fluorine, chlorine, bromine or iodine], and the organoaluminum compound (B) has the general formula (2).

[0009]

[Chemical 4] [Wherein R ² is a halogen, hydrogen, alkyl, alkoxy or aryl group, each R ² may be the same or different, and at least one R ² is an alkyl group]
And a Lewis acid (C) is a substance having a sufficient acidity to accept an electron pair, and an olefin is polymerized in the presence of the above-mentioned olefin polymerization catalyst. It is a method for producing a polyolefin.

The present invention will be described in detail below.

The metallocene compound (A) used in the present invention is represented by the general formula (1), and specific compounds include bis (cyclopentadienyl) titanium dichloride and bis (cyclopentadienyl). ) Zirconium dichloride, bis (cyclopentadienyl)
Hafnium dichloride, bis (methylcyclopentadienyl) titanium dichloride, bis (methylcyclopentadienyl) zirconium dichloride, bis (methylcyclopentadienyl) hafnium dichloride,
Bis (butylcyclopentadienyl) titanium dichloride, bis (butylcyclopentadienyl) zirconium dichloride, bis (butylcyclopentadienyl) hafnium dichloride, ethylene bis (indenyl) titanium dichloride, ethylenebis (indenyl) zirconium dichloride, ethylene Bis (indenyl) hafnium dichloride, isopropylidene (cyclopentadienyl-1-fluorenyl) titanium dichloride, isopropylidene (cyclopentadienyl-1-fluorenyl) zirconium dichloride, isopropylidene (cyclopentadienyl-1-fluorenyl) hafnium Dichloride, dimethylsilylbis (2,4,5-trimethylcyclopentadienyl) titanium dichloride, dichloride Chirushirirubisu (2,4-dimethyl cyclopentadienyl) titanium dichloride, dimethylsilyl bis (3-methylcyclopentadienyl) titanium dichloride, dimethylsilyl bis (4-t-butyl, 2-methylcyclopentadienyl)
Titanium dichloride, dimethylsilylbis (2,
4,5-trimethylcyclopentadienyl) zirconium dichloride, dimethylsilylbis (2,4-dimethylcyclopentadienyl) zirconium dichloride,
Dimethylsilylbis (3-methylcyclopentadienyl) zirconium dichloride, dimethylsilylbis (4-t-butyl, 2-methylcyclopentadienyl)
Zirconium dichloride, dimethylsilylbis (2,
4,5-Trimethylcyclopentadienyl) hafnium dichloride, dimethylsilylbis (2,4-dimethylcyclopentadienyl) hafnium dichloride, dimethylsilylbis (3-methylcyclopentadienyl) hafnium dichloride, dimethylsilylbis (4 -T-
Butyl, 2-methylcyclopentadienyl) hafnium dichloride, diethylsilylbis (2,4,5-trimethylcyclopentadienyl) titanium dichloride, diethylsilylbis (2,4-dimethylcyclopentadienyl) titanium dichloride, diethyl Silylbis (3-methylcyclopentadienyl) titanium dichloride, diethylsilylbis (4-t-butyl, 2
-Methylcyclopentadienyl) titanium dichloride, diethylsilylbis (2,4,5-trimethylcyclopentadienyl) zirconium dichloride, diethylsilylbis (2,4-dimethylcyclopentadienyl) zirconium dichloride, diethylsilylbis ( 3-Methylcyclopentadienyl) zirconium dichloride, diethylsilylbis (4-t-butyl, 2-
Methylcyclopentadienyl) zirconium dichloride, diethylsilylbis (2,4,5-trimethylcyclopentadienyl) hafnium dichloride, diethylsilylbis (3-methylcyclopentadienyl) hafnium dichloride, diethylsilylbis (4-t -Butyl, 2-methylcyclopentadienyl) hafnium dichloride and the like can be exemplified.

The organoaluminum compound (B) is represented by the general formula (2), and specific compounds include trimethylaluminum, triethylaluminum, tributylaluminum, triisopropylaluminum, diisopropylaluminum chloride and isopropyl. Aluminum dichloride, triisobutyl aluminum, diisobutyl aluminum chloride, isobutyl aluminum dichloride, tri-t-butyl aluminum, di-t-butyl aluminum chloride, t
-Butyl aluminum dichloride, triamyl aluminum, diamyl aluminum chloride, amyl aluminum dichloride and the like can be exemplified.

The Lewis acid (C) used in the present invention
Is a substance having a sufficient acidity to accept an electron pair, and specific examples thereof include tris (pentafluorophenyl) borane and magnesium chloride.

In the practice of this invention, the metallocene compound (A) and the organoaluminum compound (B) are mixed with an olefin and the mixture is contacted with a Lewis acid (C). Metallocene compound (A) and Lewis acid (C)
The molar ratio of the metallocene compound (A): Lewis acid (C) is preferably 1: 0.0.
It is in the range of 1 to 1: 1000, particularly preferably 1:
It is in the range of 0.2 to 1: 200. The preferred concentration of the organoaluminum compound (B) used here is 1
It is × 10 ⁻⁵ to 1 × 10 ⁻³ mol / l. further,
The mol ratio of the metallocene compound (A) and the organoaluminum compound (B) is not particularly limited, but the mol ratio of the metallocene compound (A): the organoaluminum compound (B) is preferably in the range of 1: 1 to 1: 10,000. is there.

The olefins used in the polymerization reaction of the present invention are ethylene, propylene, 1-butene, 4-methyl-
Α-olefins such as 1-pentene and 1-hexene, conjugated and non-conjugated dienes such as butadiene and 1,4-hexadiene, cyclic olefins such as styrene and cyclobutene, and a mixture of two or more kinds of these components may be polymerized. it can.

The olefin polymerization in the present invention can be carried out in a liquid phase or in a gas phase, but if the polymerization is carried out in a liquid phase, any solvent can be used as long as it is a commonly used organic solvent. Include benzene, toluene, xylene, pentane, hexane, methylene chloride and the like, or the olefin itself can be used as a solvent.

The polymerization temperature is not particularly limited, but it is from -100 to
It is preferably carried out in the range of 230 ° C.

[0018]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 The polymerization operation, reaction and solvent purification were all carried out under an inert gas atmosphere. All the solvents and the like used in the reaction were previously purified, dried and / or deoxygenated by a known method. The compounds used in the reaction were those synthesized and identified by known methods.

500 ml of toluene in a 2 liter autoclave
1 and then triethylaluminum 0.66 mmo
1 was added and stirred for 10 minutes. 5 μmol of ethylenebis (indenyl) zirconium dichloride synthesized by a known method was added to this solution as a 1 ml toluene solution, and this mixed solution was stirred for 20 minutes. 500 ml of propylene was inserted into this and stirred for 10 minutes. Then, 221 μmol of tris (pentafluorophenyl) borane was injected into the autoclave by using 10 ml of toluene,
Polymerization was carried out at 40 ° C. for 1 hour. As a result, 125 g of isotactic polypropylene was obtained.

Comparative Example 1 To a 2-liter autoclave, 500 ml of toluene was added, and then 0.66 mmol of triethylaluminum was added, and 1
Stir for 0 minutes. To this, 500 ml of propylene was added, and the mixture was further stirred for 10 minutes. A solution of 221 μmol of tris (pentafluorophenyl) borane in 10 ml of toluene was added with a solution of 5 μmol of ethylenebis (indenyl) zirconium dimethyl in 10 ml of toluene, and the mixture was stirred for 10 minutes and then charged into an autoclave for polymerization at 40 ° C. for 1 hour. As a result, 31 g of isotactic polypropylene was obtained.

Example 2 The procedure of Example 1 was repeated using 5 μmol of isopropylidene (cyclopentadienyl-1-fluorenyl) zirconium dichloride instead of 5 μmol of ethylenebis (indenyl) zirconium dichloride.
As a result, 105 g of syndiotactic polypropylene was obtained.

Comparative Example 2 Ethylenebis (indenyl) zirconium dimethyl 5 μm
isopropylidene (cyclopentadienyl-1-fluorenyl) zirconium dimethyl 5 μm instead of mol
The method of Comparative Example 1 was repeated using ol. As a result, 15 g of syndiotactic polypropylene was obtained.

[0024]

EFFECTS OF THE INVENTION According to the present invention, the catalyst using the above-mentioned mixture of metallocene compound and organoaluminum compound and Lewis acid has a high polymerization activity without producing a metallocene compound having an unstable ion pair, Each component can be stored stably. Further, by using this catalyst, complicated steps of catalyst synthesis can be omitted, and a polyolefin having excellent physical properties and processability can be efficiently produced.

Claims (2)

[Claims] 1. A metallocene compound (A), an organoaluminum compound (B) and a Lewis acid (C), wherein the metallocene compound (A) is represented by the following general formula (1): [Wherein Cp ¹ and Cp ² are each independently a cyclopentadienyl or substituted cyclopentadienyl group, R ¹ is an alkylene group having 1 to 4 carbon atoms, a dialkylsilicon group,
A dialkylgermanium group, an alkylphosphine group and an alkylamine group, R ¹ acts to crosslink Cp ¹ and Cp ² , m is 0 or 1, M is titanium, zirconium or hafnium, X is fluorine, chlorine, bromine or iodine], and the organoaluminum compound (B) is represented by the following general formula (2): [Wherein R ² is a halogen, hydrogen, alkyl, alkoxy or aryl group, each R ² may be the same or different, and at least one R ² is an alkyl group]
And a Lewis acid (C) is a substance having a sufficient acidity to accept an electron pair, and a catalyst for olefin polymerization. 2. A method for producing a polyolefin, which comprises polymerizing an olefin in the presence of the catalyst for olefin polymerization according to claim 1.