JP3078028B2 - Method for producing polyolefin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a polyolefin having excellent stereoregularity.

[0002]

2. Description of the Related Art In recent years, as a new Ziegler type olefin polymerization catalyst, a catalyst comprising a complex of a metal from Group IVB of the periodic table and an aluminoxane has been proposed.

[0003] Methods for improving the polymerization activity of the above catalysts are also being studied. For example, JP-A-60-260
JP-A-602 and JP-A-60-130604 disclose aluminoxane and alkylaluminum as co-catalysts in order to improve the catalytic activity of a complex of a metal belonging to Group IVB of the Periodic Table. A method of polymerizing a polyolefin in combination in the range of 3 to 3: 1 is described.

[0004]

However, when the present inventors polymerized propylene according to the above-mentioned method, it was found that the obtained polypropylene had insufficient stereoregularity.

[0005]

Means for Solving the Problems Conventionally, the periodic table IV
It has been considered that aluminoxane is indispensable as a co-catalyst in order to sufficiently exhibit the performance of an α-olefin of a complex of a group B metal as a polymerization catalyst. Therefore, aluminoxane is also used as an essential component in the invention described in the above-mentioned publication.

The present inventors have searched for a co-catalyst for sufficiently exhibiting the performance as a polymerization catalyst of an α-olefin possessed by a complex of a Group IVB metal of the periodic table. As a result, surprisingly, the polymerization of α-olefins proceeds sufficiently even when substantially only alkylaluminum is used as a cocatalyst, and the stereoregularity when polymerization of propylene is performed. They have found that excellent polypropylene can be obtained, and have proposed the present invention.

That is, the present invention provides (A) a carrier component composed of MgCl ₂ , (B) an organoaluminum compound component, and (C) a tetravalent zirconium or hafnium having two cyclopentadienyl groups in one molecule. When polymerizing an α-olefin in the presence of a catalyst component consisting of a complex component consisting of: and a solid catalyst component consisting of: (D) a cocatalyst consisting solely of an alkylaluminum compound, the solid catalyst component comprises (A) Preparation of polyolefin characterized by being prepared by contacting a mixture of component (B) and component (C) or contacting component (A) with component (B) in advance and then contacting with component (C). Is the way.

Hereinafter, the present invention will be described in detail.

The catalyst used in the present invention is a solid catalyst component comprising a tetravalent zirconium or hafnium complex having two cycloalkadienyl groups in one molecule supported on a carrier by a specific method, and an alkylaluminum. It is formed from a co-catalyst consisting of only

The (C) tetravalent zirconium or hafnium complex having two cycloalkadienyl groups in one molecule (hereinafter also simply referred to as a transition metal complex) constituting the solid catalyst component is contained in one molecule. Having two cycloalkadienyl groups, particularly those having the following structures can be preferably used.

[0011]

Embedded image Wherein X ₁ and X ₂ are each a cycloalkadienyl group or a group derived therefrom, and Y ₁ and Y ₂
Is a hydrogen atom, a halogen atom, a hydrocarbon group or an alkoxy group, and M is zirconium or hafnium. In the above formula [I], the group derived from the cycloalkadienyl group represented by X ₁ and X ₂ has at least one hydrogen atom of the cycloalkadienyl group substituted by a halogen atom or a hydrocarbon group. And a group condensed with an aromatic hydrocarbon ring such as a benzene ring or a naphthalene ring or an alicyclic hydrocarbon ring such as a cyclopentane ring, a cyclohexane ring or a cycloheptane ring. Also, X ₁
And a group in which two cycloalkadienyl groups represented by X ₂ are linked by an alkylene group is also included in the group derived from the cycloalkadienyl group in the present invention.

Specific examples of the cycloalkadienyl group represented by X ₁ and X ₂ in the above formula [I] or groups derived therefrom include cyclopentadienyl group, methylcyclopentadienyl group, ethyl A cyclopentadienyl group, a pentamethylcyclopentadienyl group, an indenyl group, a tetrahydroindenyl group and the like.

Next, in the above formula [I], halogen atoms represented by Y ₁ and Y ₂ include fluorine, chlorine,
Examples of each atom of iodine include hydrocarbon groups such as methyl group, ethyl group, and alkyl group such as propyl group; cyclopentyl group, cyclohexyl group, cycloalkyl group such as cycloheptyl group, phenyl group, naphthyl group, phenanthryl group, Aryl groups such as anthryl groups; aralkyl groups such as benzyl group, phenethyl group and phenylpropyl group; and alkoxy groups include methoxy group, ethoxy group and propoxy group. M in the above formula [I] is zirconium or hafnium.

Specific examples of the above transition metal complexes include the following compounds. Bis (cyclopentadienyl) zirconium monochloride monohydride bis (cyclopentadienyl) zirconium monobromide monohydride bis (cyclopentadienyl) methyl zirconium hydride bis (cyclopentadienyl) ethyl zirconium hydride bis (cyclopentadienyl) ) Cyclohexylzirconium hydride bis (cyclopentadienyl) phenylzirconium hydride bis (cyclopentadienyl) benzylzirconium hydride bis (cyclopentadienyl) neopentyl zirconium hydride bis (cyclopentadienyl) zirconium dichloride bis (cyclopentadienyl) ) Zirconium dibromide bis (cyclopentadienyl) methyl zirconium monochloride Do bis (cyclopentadienyl) ethyl zirconium monochloride bis (cyclopentadienyl) cyclohexyl zirconium monochloride bis (cyclopentadienyl) phenyl zirconium monochloride bis (cyclopentadienyl) benzyl zirconium monochloride bis (cyclopentadi (Enyl) zirconium diphenyl bis (cyclopentadienyl) zirconium dibenzyl bis (cyclopentadienyl) methoxy zirconium chloride bis (cyclopentadienyl) ethoxy zirconium chloride bis (cyclopentadienyl) butoxyzirconium chloride bis (cyclopentadienyl) ) 2-Ethylhexoxyzirconium chloride bis (cyclopentadienyl) methylzirconium butoxide bis (cyclopentadiene) Nyl) ethyl zirconium ethoxide bis (cyclopentadienyl) phenyl zirconium methoxide bis (methylcyclopentadienyl) zirconium monochloride monohydride bis (methylcyclopentadienyl) zirconium dichloride bis (indenyl) zirconium monochloride monohydride bis (Indenyl) zirconium dichloride bis (indenyl) zirconium dibromide bis (4,5,6,7-tetrahydroindenyl) zirconium dichloride bis (4,5,6,7-tetrahydroindenyl) zirconium dibromide bis (4,5 , 6,7-Tetrahydroindenyl) methyl zirconium monochloride bis (4,5,6,7-tetrahydroindenyl) ethyl zirconium monochloride bis (4 5,6,7-tetrahydroindenyl) cyclohexyl zirconium monochloride bis (4,5,6,7-tetrahydroindenyl) phenyl zirconium monochloride bis (4,5,6,7-tetrahydroindenyl) benzyl zirconium monochloride Bis (4,5,6,7-tetrahydroindenyl) zirconium diphenyl bis (4,5,6,7-tetrahydroindenyl) zirconium dibenzyl bis (4,5,6,7-tetrahydroindenyl) zirconium dichloride ethylene Bis (4,5,6,7-tetrahydro-1-indenyl) zirconium dibromide ethylenebis (4,5,6,7-tetrahydro-1-indenyl) methylzirconium monochloride ethylenebis (4,5,6,7 -Tetrahydro-1-indene E) Ethyl zirconium monochloride ethylene bis (4,5,6,7-tetrahydro-1-indenyl) cyclohexyl zirconium monochloride ethylene bis (4,5,6,7-tetrahydro-1-indenyl) phenyl zirconium monochloride ethylene bis (4,5,6,7-tetrahydro-1-indenyl) benzylzirconium monochloride ethylenebis (4,5,6,7-tetrahydro-1-indenyl) zirconiumdiphenyl ethylenebis (4,5,6,7-tetrahydro -1-indenyl) zirconium dibenzyl and the like.

In the present invention, a specific carrier for supporting the above transition metal complex is essential. When no carrier is used, almost no polyolefin is produced. By using magnesium chloride as a carrier, a polyolefin yield is good, and a polyolefin having excellent stereoregularity can be obtained.

The above carrier generally has an average particle size of 10 to 10.
300 [mu] m, a further 20 to 200 [mu] m, a specific surface area of 100~1000m ² / g, further 100～600M ²
/ G.

The method for preparing the solid catalyst component is as follows.

1) A method in which a carrier is brought into contact with an organoaluminum compound in advance, and then the resulting carrier is brought into contact with a transition metal complex.

2) A method in which a mixture of an organoaluminum compound and a transition metal complex is brought into contact with a carrier.

The organoaluminum compound used in the supporting methods 1) and 2) is a compound having at least one aluminum-carbon bond, for example, trimethylaluminum, triethylaluminum, tri-n
Propyl aluminum, tri-n-butyl aluminum,
Tri-isobutyl aluminum, tri-n hexyl aluminum, tri-n octyl aluminum, tri-n
Trialkyl aluminums such as decyl aluminum;
Examples thereof include diethylaluminum monohalides such as diethylaluminum monochloride; and alkylaluminum halides such as methylaluminum sesquichloride, ethylaluminum sesquichloride, and ethylaluminum dichloride. Other alkoxy aluminums such as monoethoxy diethyl aluminum and diethoxy monoethyl aluminum can be used. Among them, trialkylaluminums such as trimethylaluminum and triethylaluminum are preferable.

The mixing ratio of the organoaluminum compound or the transition metal complex to the carrier in the above treatment is 0.001 to 10 per gram of the carrier for the organoaluminum compound.
0 mmol, preferably 0.005 to 10 mmol, and for transition metal complexes, 0.001 to 100 mmol, preferably 0.005 to 100 mmol per gram of the carrier.
It is in the range of 10 mmol. It is preferable that the organoaluminum compound and the transition metal complex which are present in excess after the above treatment are removed by filtration, gradient, or the like, or washed with an inert solvent. Examples of the inert solvent include:
Examples include aliphatic hydrocarbons such as pentane, hexane, heptane, and octane; aromatic hydrocarbons such as benzene, toluene, and xylene; alicyclic hydrocarbons such as cyclohexane; chlorobenzene; and halogenated hydrocarbons such as ethylene dichloride. it can. Preferably, aromatic hydrocarbons are good. The temperature of the above treatment is -100 to 150C, preferably -50 to 100C.

The amount of the transition metal complex supported on the carrier is preferably 1 × 10 ⁻⁵ to 1 × 10 mmol, more preferably 1 × 10 ⁻⁵ to 1 × 10 mmol, based on 1 g of the solid catalyst supporting the transition metal complex. ^-4 to 1 × 10 ^-1 mmol is more preferable.

Next, alkyl aluminum is used as a co-catalyst. Among them, trialkylaluminum can be most preferably used. Compounds other than alkylaluminum, for example, aluminum compounds such as trialkoxyaluminum, dialkoxymonohalogenoaluminum, and monoalkoxydihalogenoaluminum, make it difficult to sufficiently achieve the object of the present invention. When a conventionally used aluminoxane is used in combination, a polyolefin having high stereoregularity cannot be obtained.

In the present invention, the use of substantially only alkylaluminum as a cocatalyst does not impair the effects of alkylaluminum, that is, the effect of improving the stereoregularity of the resulting polyolefin, for example,
This means that the alkylaluminum is used in a proportion of 98 mol% or more in the cocatalyst.

The alkyl aluminum preferably used in the present invention includes, for example, trimethyl aluminum, triethyl aluminum, tri-n-propyl aluminum, tri-n-butyl aluminum, tri-iso.
Butyl aluminum, tri-n-hexyl aluminum,
Trialkyl aluminums such as tri-n-octyl aluminum and tri-n decyl aluminum; diethyl aluminum monohalides such as diethyl aluminum monochloride; alkyl aluminum halides such as methyl aluminum sesquichloride, ethyl aluminum sesquichloride, ethyl aluminum dichloride and the like Is exemplified.

The amount of the co-catalyst component used in the present invention is preferably 1 to 10,000 in terms of a molar ratio to the transition metal complex in the solid catalyst component, and more preferably 10 to 10,000.
Preferably it is 1000.

In the present invention, the polymerization of α-olefin is carried out in the presence of a solid catalyst component and a cocatalyst component.
The α-olefin that can be used in the present invention is an α-olefin having 2 to 20 carbon atoms, for example, ethylene, propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-
Dodecene, 1-tetradodecene, 1-hexadecene, 1
-Octadecene, 1-eicosene and the like. In particular, the solid catalyst component and co-catalyst component in the present invention are effective for homopolymerization of propylene and copolymerization of propylene with another α-olefin.

In the present invention, known polymerization methods such as slurry polymerization, gas phase polymerization, and solution polymerization are used without any limitation as the polymerization method and polymerization conditions for the α-olefin. Further, either continuous polymerization or discontinuous polymerization may be used. The olefin pressure of the reaction system is from normal pressure to 50 kg /
cm ² G, and the reaction temperature is in the range of -100 to 120 ° C, preferably -60 to 100 ° C. The reaction time can be appropriately determined, but is usually employed in the range of 1 to 24 hours.

[0029]

According to the present invention, it is possible to obtain a polyolefin in good yield by using substantially only alkylaluminum as a cocatalyst for exhibiting the performance as a polymerization catalyst of an α-olefin of a transition metal complex. A polyolefin having good stereoregularity can be obtained.

[0030]

The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

Example 1 [Preparation of solid catalyst component] 740 m of anhydrous magnesium chloride having an average particle size of 20 μm and a specific surface area of 100 m ² / g in a 50 ml flask under a nitrogen stream.
g, toluene solution of trimethylaluminum (2 mmo
1 / ml) and 10 ml of a toluene solution of ethylenebis (tetrahydroindenyl) zirconium dichloride (0.084 mmol / ml) were added, and the mixture was vigorously stirred at room temperature for 10 minutes. Then, after the solid component was settled and the supernatant was removed, the solid component was washed with 20 ml of toluene to prepare a solid catalyst component. Z contained in this solid catalyst component
r was 0.016 mmol / g. [Polymerization] In a nitrogen stream, 15 ml of toluene, 5 ml of a toluene solution of trimethylaluminum (2 mmol / ml) and 15 ml of a toluene suspension containing 750 mg of the solid catalyst component synthesized above were introduced into a 100 ml stainless steel autoclave (Al / Zr (mol Ratio) = 830). Then, after degassing the inside of the system, 7 L (about 0.31 mmol) of propylene was introduced, and polymerization was carried out at 40 ° C. for 18 hours. After terminating the polymerization with acidic methanol, the precipitated polymer was filtered, sufficiently washed with methanol, and dried at 60 ° C. under reduced pressure for 8 hours. The yield of the polymer was 4.19 g. In addition, the pentad fraction in which four consecutive sequences of monomer units based on propylene were all meso was 91%.

Example 2 The same operation as in Example 1 was performed, except that triethylaluminum was used instead of trimethylaluminum.

The yield of the produced polymer was 1.80 g. The pentad fraction in which four consecutive sequences of monomer units based on propylene were all meso was 91%.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-168408 (JP, A) JP-A-3-56508 (JP, A) JP-A-3-70710 (JP, A) JP-A-3- 197513 (JP, A) JP-A-4-110308 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08F 4/60-4/70

Claims (1)

(57) [Claims] (A) a carrier component composed of MgCl ₂ , (B) an organoaluminum compound component, (C) a tetravalent zirconium or hafnium complex component having two cyclopentadienyl groups in one molecule, When the α-olefin is polymerized in the presence of a solid catalyst component consisting of a solid catalyst component consisting of: (D) a cocatalyst consisting solely of an alkylaluminum compound, the solid catalyst component comprises the above component (A) and the component (B) A method for producing a polyolefin, which comprises preparing a polyolefin by contacting a mixture with the component (C) or pre-contacting the component (A) with the component (B) and then contacting the component (C).