JPH1017609A - Olefin polymerization catalyst and method for producing polyolefin - Google Patents

Abstract

(57) [Problem] To provide an olefin polymerization catalyst having high catalyst preparation efficiency and high activity. A halide of magnesium, ¹ ₃ (wherein following general formula CpMX, M is Ti, Zr, a Hf, X ¹ is H, halogen, hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group or aryloxy is a group. transition metal compound represented by) in the following general formula AlR _m X ² _3-m (wherein, R represents a hydrocarbon group having 1 to 20 carbon atoms, X ² is a halogen, an alkoxy group, or an aryl group , M is 1 to
3 is a real number. An olefin prepolymerization catalyst formed by prepolymerizing an olefin with a catalyst component comprising an organoaluminum compound represented by the formula (1), an electron donor, and an olefin polymerization catalyst comprising an organoaluminum compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel catalyst and a method for polymerizing an olefin using the same. More specifically, CpTi, which is thought to suppress the formation of clusters between transition metal atoms that are active sites for olefin polymerization,
A catalyst for olefin polymerization, comprising a catalyst component preliminarily polymerized using a complex such as Cl ₃ and a carrier such as magnesium chloride and an organoaluminum compound, an electron donor, and if necessary, an organoaluminum compound, and the catalyst. The present invention relates to a method for polymerizing an olefin using olefin.

[0002]

2. Description of the Related Art Polyolefins are widely used in many fields as general-purpose resins. As a method for producing this polyolefin, a method using a so-called Ziegler catalyst comprising a combination of a transition metal compound and an organometallic compound in olefin polymerization has been known, and many proposals have been made. Among them, there is a method using a catalyst system in which a transition metal compound is supported on MgCl ₂ or the like as a highly active catalyst. On the other hand, as a method for producing polyolefin, it has already been reported by Kaminsky et al. That a catalyst system using metallocene and methylaluminoxane exhibits high activity, and has recently attracted attention. This Kaminsky type catalyst has high copolymerizability,
It is possible to obtain a polymer having a narrow molecular weight distribution, which cannot be obtained with a conventional Ziegler-Natta catalyst. However, the use of expensive methylaluminoxane or boron compound has the disadvantage that the catalyst cost is high.

[0003] By the way, a catalyst system having relatively high activity without using a methylaluminoxane or a boron compound has also been reported (Polymer Preprints,
Japan Vol. 41, No. 2, 1992). This catalyst system is a catalyst supported on MgCl ₂ , and the resulting polymer has a narrow molecular weight distribution and can produce a polymer similar to a Kaminsky catalyst. However, the catalyst preparation efficiency is low because the amount of the complex carried is extremely low, and the activity is not yet sufficient.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been made to solve this problem, and is intended to reduce the cost of a polyolefin that could not be obtained with a conventional Ziegler-Natta catalyst without using a methylaluminoxane or a boron compound. Can be obtained at Furthermore, it is an object of the present invention to provide a polymerization catalyst capable of obtaining a polyolefin with high activity while increasing the catalyst preparation efficiency by performing prepolymerization.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that it is possible to increase the catalyst preparation efficiency and to produce polyolefin with high activity, and completed the present invention. I came to.

That is, the present invention relates to [A] (A-1) a halide of magnesium, (A-
2) In the following general formula CpMX ¹ ₃ (wherein, Cp is a substituted or unsubstituted cyclopentadienyl group, indenyl group or fluorenyl group .M
Is a titanium atom, a zirconium atom or a hafnium atom, and X ¹ is a hydrogen atom, a halogen atom,
2 hydrocarbon groups, alkoxy groups or aryloxy groups. The types of X ¹ may be the same or different. Transition metal compound represented by), (A-3) in the following general formula AlR _m X ² _3-m (wherein, R represents a hydrocarbon group having 1 to 20 carbon atoms, X ² is a halogen atom, an alkoxy group or an aryl group And m is a real number of 1 to 3, and when m is greater than 1, each R may be the same or different, and when n is less than 2, each X ² may be the same or different. An olefin prepolymerization catalyst formed by prepolymerizing an olefin with a catalyst component comprising an organoaluminum compound represented by the following formula: [B] an electron donor, [C] a general formula AlR _m X ² _3-m (wherein, R is a hydrocarbon group having 1 to 20 carbon atoms, X ² is a halogen atom, an alkoxy group or an aryl group, m is a real number of 1 to 3, and when m is greater than 1, , Each R is the same or different Use is good, if n is less than 2, each X ² is the catalyst system and the catalyst system which is based on olefin polymerization catalyst comprising an organic aluminum compound represented by also may be different.) The same And a method for polymerizing olefins.

Hereinafter, the present invention will be described in detail.

First, the olefin polymerization catalyst according to the present invention will be described. The magnesium halide (A-1) used in the present invention is used as a carrier.
Specifically, MgF ₂ , MgCl ₂ , MgBr ₂ , Mg
Examples include I ₂ , CH ₃ MgCl, and Mg (OCH ₃ ) Cl. Of these, MgCl ₂ is suitable for obtaining a polyolefin excellent in stereoregularity with a high yield. These carriers used in the present invention have different properties depending on the type of carrier and the production method, but generally those having an average particle size of 1 to 300 μm are preferred, and those having an average particle size of 10 to 200 μm are preferred.
Fine particles in the range of μm are more preferred. Further, the specific surface area is 10 to 1000 m ² / g,
0 to 800 m ² / g, pore volume is 0.1 to 3 cc / g
Is preferably used.

The transition metal compound (A-2) used in the present invention is represented by the following general formula.

[0010] CpMX ¹ ₃ (wherein, Cp is a substituted or unsubstituted cyclopentadienyl group, indenyl group or fluorenyl group .M
Is a titanium atom, a zirconium atom or a hafnium atom, and X ¹ is a hydrogen atom, a halogen atom,
2 hydrocarbon groups, alkoxy groups or aryloxy groups. The types of X ¹ may be the same or different. In the general formula of the above transition metal compound, examples of the halogen atom include fluorine, chlorine, bromine, and iodine;
Examples of the hydrocarbon group having 1 to 12 carbon atoms include an alkyl group, a cycloalkyl group, an aryl group, and an aralkyl group. Specifically, examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group, examples of the cycloalkyl group include a cyclohexyl group, and examples of the aryl group include a phenyl group and a tolyl group. And examples of the aralkyl group include a benzyl group and a neophyl group. Examples of the alkoxy group include a methoxy group and an ethoxy group, and examples of the aryloxy group include a phenoxy group.

Examples of these specific compounds include transition metal compounds in which M is titanium metal. Cyclopentadienyltitanium trichloride, cyclopentadienyltitanium tribromide, cyclopentadienylmethyltitanium dichloride, cyclopentadienylethyltitanium dichloride, cyclopentadienylphenyltitanium dichloride, cyclopentadienylbenzyltitanium dichloride, cyclopenta Dienyl neopentyl titanium dichloride, cyclopentadienyl dimethyl titanium monochloride, cyclopentadienyl dicyclohexyl titanium monochloride, cyclopentadienyl diphenyl titanium monochloride, cyclopentadienyl dibenzyl titanium monochloride, cyclopentadienyl titanium trimethyl , Cyclopentadienyltitanium triphenyl, cyclopentadienylthi Tribenzyl, cyclopentadienyl titanium methoxy dichloride, cyclopentadienyl titanium ethoxy dichloride, cyclopentadienyl titanium phenoxy dichloride, cyclopentadienyl methyl titanium dibromide, cyclopentadienyl ethyl titanium dibromide, cyclopentadienyl Phenyltitanium dibromide, cyclopentadienylbenzyltitanium dibromide, cyclopentadienyl neopentyltitanium dibromide, cyclopentadienyldimethyltitanium monobromide, cyclopentadienyl diethyltitanium monobromide, cyclopentadienyldicyclohexyltitanium monobromide , Cyclopentadienyldiphenyltitanium monobromide, cyclopentadienyldibe Jill titanium mono bromide,
Cyclopentadienyl titanium trimethyl, cyclopentadienyl titanium triphenyl, cyclopentadienyl titanium tribenzyl, cyclopentadienyl titanium methoxy dibromide, cyclopentadienyl titanium ethoxy dibromide, cyclopentadienyl titanium phenoxy dibromide, Methylcyclopentadienyltitanium trichloride, methylcyclopentadienyltitanium tribromide, methylcyclopentadienyltitanium dichloride monohydride, methylcyclopentadienyltitanium ethoxydichloride, methylcyclopentadienyltitanium bromide hydride, methylcyclopentadi Enyltitanium ethoxydibromide, t-butylcyclopentadienyltitanium trichloride , T-butylcyclopentadienyltitanium tribromide, dimethylcyclopentadienyltitanium trichloride, trimethylcyclopentadienyltitanium trichloride, tetramethylcyclopentadienyltitanium trichloride, pentamethylcyclopentadienyltitanium trichloride, Examples include indenyl titanium trichloride, indenyl titanium tribromide, indenyl titanium dibromide monohydride, and fluorenyl titanium trichloride.

Further, a transition metal compound in which the titanium metal of the above transition metal compound is replaced with zirconium metal or hafnium metal can also be used. Among these transition metals, a titanium compound and a zirconium compound are preferable, and a titanium compound is particularly preferable. Further, these transition metal compounds may be used alone or in combination of two or more.

The organoaluminum compound (A-3) used in the present invention is represented by the following general formula.

[0014] During AlR _m X ² _3-m (wherein, R represents a hydrocarbon group having 1 to 20 carbon atoms, X ² is a halogen atom, an alkoxy group or an aryl group, m is a real number of 1-3, When m is greater than 1, each R may be the same or different, and when n is less than 2, each X ² may be the same or different.) Organoaluminum compound (A-3) May be used alone or in combination of two or more.

Specific examples thereof include trimethylaluminum, triethylaluminum, tri (n-propyl) aluminum, tri (isopropyl) aluminum, tri (n-butyl) aluminum, tri (isobutyl) aluminum and tri (t-butyl) aluminum. )aluminum,
Triamylaluminum, dimethylaluminum chloride, diethylaluminum chloride, diisobutylaluminum chloride, di-t-butylaluminum chloride, diamylaluminum chloride, methylaluminum dichloride, ethylaluminum dichloride, isobutylaluminum dichloride, t-butylaluminum dichloride, amylaluminum dichloride Is used.

Of these, a trialkylaluminum and a combination use of a trialkylaluminum and a dialkylaluminum chloride are particularly preferred.

When m = 1.5, AlR _1.5 X ²
_1.5 . Such compounds are not present in theory, usually carried out in a conventional manner are expressed as sesquicarbonate of Al ^₂ R ₃ X _{2 3,} also includes these compounds.

The prepolymerized catalyst component [A] of the present invention is formed by prepolymerizing an olefin in the presence of the catalyst components (A-1), (A-2) and (A-3). .

This prepolymerization is carried out by using the catalyst component (A-1),
It is possible to prepolymerize using 0.01 to 100 g, preferably 0.1 to 50 g of ethylene or α-olefin having 3 or more carbon atoms per 1 g of the catalyst formed from (A-2) and (A-3). desirable. The condition for contact with the monomer is not particularly limited, but the reaction is carried out without a solvent or under an inert hydrocarbon solvent. As the inert hydrocarbon solvent, any commonly used organic solvent may be used. Specifically, benzene, toluene, xylene, pentane, hexane, methylene chloride, 1,2-dichloroethane and the like can be used as the solvent. . Generally, this prepolymerization is -5
It can be carried out at a temperature range of 0 to 100 ° C., preferably -20 to 60 ° C., more preferably 0 to 50 ° C. under normal pressure or under pressure. In the case where the treatment is performed in a liquid phase, it is preferable to bring the mixture into sufficient contact under stirring. The monomers used for the prepolymerization may be used alone or in combination of two or more. In the case of prepolymerization of two or more, the prepolymerization can be performed sequentially or simultaneously. The amount of the transition metal compound (A-2) per 1 g of the magnesium halide (A-1) during the prepolymerization is 0.005 to 1 mmol, preferably 0.05 to 0.5 mmol, as the amount of the transition metal atom. It is desirable to use them in a ratio, and the amount of Al atoms of the organoaluminum compound (A-3) relative to the transition metal compound (A-2) is 1 to 200 m per 1 mol of transition metal atoms in the transition metal compound.
ol, preferably 15 to 150 mol.

Specific examples of the electron donor [B] used in the present invention include methyl formate, ethyl formate, propyl formate, butyl formate, isobutyl formate, pentyl formate, methyl acetate, ethyl acetate, propyl acetate and acetic acid. Isopropyl, butyl acetate, isobutyl acetate, pentyl acetate, isopentyl acetate, hexyl acetate, cyclohexyl acetate, benzyl acetate, 3-methoxybutyl acetate,
2-ethylbutyl acetate, 3-ethylhexyl acetate, 3-methoxybutyl acetate, methyl propionate, ethyl propionate, butyl propionate, isopentyl propionate, methyl butyrate, ethyl butyrate, butyl butyrate, isopentyl butyrate, isobutyric acid Isobutyl, ethyl isovalerate, isobutyl isovalerate, butyl stearate, pentyl stearate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, isopentyl benzoate, benzyl benzoate, ethyl cinnamate, shu Diethyl acrylate, dibutyl oxalate, dipentyl oxalate, diethyl malonate, dimethyl maleate, diethyl maleate, dibutyl maleate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisobutyl phthalate, triisobutyl phthalate Esters such as Sechin, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, diisopropylamine, butylamine, isobutylamine, dibutylamine, tributylamine, pentylamine, dipentylamine, tripentylamine, 2
Ethylhexylamine, allylamine, aniline, N-
Methylaniline, N, N-dimethylaniline, N, N-
Diethylaniline, toluidine, cyclohexylamine, dicyclohexylamine, pyrrole, piperidine,
Pyridine, picoline, 2,4-lutidine, 2,6-lutidine, 2,6-di (t-butyl) pyridine, quinoline,
Amines such as isoquinoline, diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, dihexyl ether, anisole, phenetole, butylphenyl ether, methoxytoluene, benzylethyl ether, diphenylether, dibenzylether, veratrol, propionoxide, dioxane, Trioxane, furan, 2,5-dimethylfuran, tetrahydrofuran, tetrahydropyran, 1,2
-Diethoxyethane, 1,2-dibutoxyethane, ethers such as crown ether, acetone, methyl ethyl ketone, methyl propyl ketone, diethyl ketone, butyl methyl ketone, methyl isobutyl ketone, methyl pentyl ketone, dipropyl ketone, diisobutyl ketone,
Ketones such as cyclohexanone, methylcyclohexanone, and acetophenone; thioethers such as dimethylsulfide, diethylsulfide, thiophene, and tetrahydrothiophene; tetramethoxysilane, tetraethoxysilane, tetra (n-propoxy) silane, tetraisopropoxysilane, and tetra (n -Butoxy) silane, tetraisopentoxysilane, tetra (n-hexoxy)
Silane, tetraphenoxysilane, tetrakis (2-ethylhexoxy) silane, tetrakis (2-ethylbutoxy) silane, tetrakis (2-methoxyethoxy) silane, methyltrimethoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, isopropyl Trimethoxysilane, n-butyltrimethoxysilane, isobutyltrimethoxysilane, sec-butyltrimethoxysilane, t-butyltrimethoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane, norbornyltrimethoxysilane, cyclohexyltrimethoxysilane , Chloromethyltrimethoxysilane,
3-chloropropyltrimethoxysilane, 4-chlorotrimethoxysilane, triethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, n-propyltriethoxysilane, n-butyltriethoxysilane, phenyltriethoxysilane, vinyltriethoxysilane Ethoxysilane, 3-aminopropyltriethoxysilane, ethyltriisopropoxysilane, isopentyltri (n-
Butoxy) silane, methyltri (n-hexoxy) silane, methyldimethoxysilane, dimethyldimethoxysilane, n-propylmethyldimethoxysilane, n-propylethyldimethoxysilane, di (n-propyl) dimethoxysilane, isopropylmethyldimethoxysilane, diisopropyldimethoxysilane Silane, n-propylisopropyldimethoxysilane, n-butylmethyldimethoxysilane, n-butylethyldimethoxysilane, n-butyl-n-propyldimethoxysilane, n-butylisopropyldimethoxysilane, di (n-butyl) dimethoxysilane, isobutyl Methyldimethoxysilane, diisobutyldimethoxysilane, sec-butylethyldimethoxysilane, di (sec-butyl) dimethoxysilane, t-
Butylmethyldimethoxysilane, t-butyl-n-propyldimethoxysilane, di (t-butyl) dimethoxysilane, t-butyl-n-hexyldimethoxysilane, diisoamyldimethoxysilane, n-hexyl-n-propyldimethoxysilane, n -Decylmethyldimethoxysilane, norbornylmethyldimethoxysilane, cyclohexylmethyldimethoxysilane, methylphenyldimethoxysilane, diphenyldimethoxysilane, dicyclopentyldimethoxysilane, dimethyldiethoxysilane, diethyldiethoxysilane, diisopropyldiethoxysilane, sec-butylmethyl Diethoxysilane, t-butylmethyldiethoxysilane, dimethyldi (n-butoxy) silane, trimethylmethoxysilane, trimethylethoxysilane, Silyl ethers such as methylisopropoxysilane, trimethyl-n-propoxysilane, trimethyl-t-butoxysilane, trimethylisobutoxysilane, trimethyl-n-butoxysilane, trimethyl-n-pentoxysilane, trimethylphenoxysilane, and methylphos Fin, ethyl phosphine, phenyl phosphine, benzyl phosphine, dimethyl phosphine, diethyl phosphine, diphenyl phosphine, methyl phenyl phosphine, trimethyl phosphine, triethyl phosphine, triphenyl phosphine tri (n-butyl) phosphine And phosphines such as ethylbenzylphenylphosphine, ethylbenzylbutylphosphine, trimethoxyphosphine and diethylethoxyphosphine Phosphine oxides such as triphenylphosphine oxide, dimethylethoxyphosphine oxide and triethoxyphosphine oxide; nitriles such as acrylonitrile, cyclohexanedinitrile and benzonitrile; nitro compounds such as nitrobenzene, nitrotoluene and dinitrobenzene; acetone Acetals such as dimethyl acetal, acetophenone dimethyl acetal, benzophenone dimethyl acetal, cyclohexanone dimethyl acetal, carbonates such as diethyl carbonate, diphenyl carbonate, and ethylene carbonate; thioacetals such as 1-ethoxy-1-methylthiocyclopentane; cyclohexanethione And the like, but not limited thereto.

At the time of polymerization, an organoaluminum compound [C] can be used if necessary. At this time, a compound similar to the organic aluminum compound (A-3) can be used, but it is not always necessary to use the same compound.

When an organoaluminum compound is used during the polymerization, the molar ratio of the transition metal atom and the organoaluminum compound [C] in the prepolymerization catalyst is such that the transition metal atom: the organoaluminum compound [C] is 1: 1 to 1: 10000. And preferably in the range of 1:10 to 1: 1000.

Further, the molar ratio of the transition metal atom and the electron donor [B] in the prepolymerization catalyst used in the present invention is not particularly limited, but preferably, the transition metal atom: electron donor [B] is 1: 0. 0.11 to 1: 10000,
Particularly preferably, it is in the range of 1: 0.1 to 1: 1000.

The olefin used in the polymerization reaction of the present invention is ethylene, propylene, 1-butene, 4-methyl-
1-pentene, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-
Linear α-olefins such as tetradodecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2-ethyl- Examples thereof include branched α-olefins such as 1-hexene, conjugated and non-conjugated dienes such as butadiene and 1,4-hexadiene, and cyclic olefins such as styrene and cyclobutene. Polymerization can also be carried out by combining at least two kinds of mixed components. In particular, the catalyst system of the present invention
It is effective for homopolymerization of ethylene or propylene or copolymerization with another α-olefin.

The polymerization method of the olefin in the present invention is not particularly limited, and can be carried out by a known polymerization method such as a liquid phase, a gas phase, and a solution. If the polymerization is performed in the liquid phase, any solvent may be used as long as it is a commonly used organic solvent.Specifically, benzene, toluene, xylene, pentane, hexane, methylene chloride, or the like, or olefin itself is used as a solvent. Can also be used. These solvents may be used alone or in combination of two or more. In the case of propylene, the olefin pressure of the polymerization system is from normal pressure to 50 kg / cm ² G, and the polymerization temperature is not particularly limited, but is preferably in the range of -100 to 300 ° C.

[0026]

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.

The polymerization operation, reaction, and solvent purification were all performed under an inert gas atmosphere. The solvents used for the reaction were all purified, dried and deoxygenated by a known method in advance. The compounds used for the reaction were those synthesized and identified by a known method. In Examples and Comparative Examples, xylene-soluble components, which are indicators of stereoregularity, are measured as follows. After dissolving 4 g of the polymer in 200 ml of xylene, the mixture is left in a constant temperature bath at 25 ° C. for 1 hour, the deposited portion is filtered, the filtrate is recovered, the xylene is almost evaporated, and further dried in vacuo to obtain a xylene-soluble material. A part is collected and determined as a percentage of the original sample.

Example 1 [Preparation of Preliminary Polymerization Catalyst] 9.79 g of MgCl ₂ (surface area: 80 m ^{2 /} g) and 40 ml of toluene were added to a 300 ml glass flask to form a suspension. 20 ml of a toluene solution (0.0485 mol / l) of cyclopentadienyltitanium trichloride was added thereto, and the mixture was added at room temperature.
Stirred for hours. Next, 100 ml of hexane was added, ethylene was introduced at normal pressure, and prepolymerization was performed at 30 ° C. for 1 hour. After the completion of the prepolymerization, the solvent was removed with a bridge filter, washed with toluene, washed three times with 100 ml of hexane, and the solid portion was dried. As a result, 0.289 mmol of titanium, 0.373 mmol of aluminum, and polyethylene 6.
A prepolymerized catalyst containing 9 g was obtained.

[Polymerization] The inside of a stainless steel electromagnetically stirred autoclave having an inner volume of 2 liters was sufficiently replaced with nitrogen, and triisobutylaluminum 1.0 was used as a catalyst component [C].
mmol, ethyl benzoate 0.1 as catalyst component [B]
2 mmol, and the prepolymerized catalyst [A] prepared above
(0.030 milligram atom in terms of titanium atom) was added in order, the internal pressure of the autoclave was adjusted to 0.1 kg / cm ² G, 800 ml of liquid propylene was added, stirring was started, and the temperature was raised to 80 ° C. Polymerized for minutes. After the completion of the polymerization, the stirring was stopped, and at the same time, unreacted propylene in the system was released, and the produced polymer was recovered. As a result, 26 g of a polymer was obtained, and the xylene-soluble matter was 28.6%.

Example 2 [Polymerization] Polymerization was carried out in the same manner as in Example 1 except that the amount of ethyl benzoate was changed to 0.24 mmol. as a result,
7 g of a polymer was obtained, and the xylene-soluble content was 10.0%.
Met.

Comparative Example 1 [Polymerization] Polymerization was carried out in the same manner as in Example 1 except that ethyl benzoate was not used. As a result, 17 g of a polymer was obtained, and the xylene-soluble content was 48.6%.

Comparative Example 2 [Preparation of solid catalyst component]
gCl ₂ (surface area 80 m ^{2 /} g) 4.18 g and toluene 2
0 ml was added to form a suspension. Thereto, a toluene solution of cyclopentadienyl titanium trichloride (0.043
(8 mol / l) 10 ml, and the mixture was stirred at room temperature for 2 hours. Then, after washing with toluene, hexane 100m
The washing was performed three times with 1 l, and the solid portion was dried. As a result, the Ti content was 0.01 g per 1 g of MgCl ₂ .
1 mmol.

[Polymerization] Polymerization was carried out in the same manner as in Example 1 except that ethyl benzoate was not used except that the solid catalyst prepared above was used instead of the prepolymerization catalyst. As a result, 6 g of a polymer was obtained.

[0034]

According to the present invention, the content of the transition metal per MgCl ₂ can be increased by performing the prepolymerization, and the polymer can be produced with relatively high activity.
Also. By adding an external donor even without an internal donor, highly stereoregular polypropylene can be produced.

Claims (3)

[Claims] 1. A [A] (A-1) a halide of magnesium, (A-2) represented by the following general formula CpMX ¹ ₃ (wherein, Cp is a substituted or unsubstituted cyclopentadienyl group, indenyl group or fluorenyl Group.
Is a titanium atom, a zirconium atom or a hafnium atom, and X ¹ is a hydrogen atom, a halogen atom,
2 hydrocarbon groups, alkoxy groups or aryloxy groups. The types of X ¹ may be the same or different. Transition metal compound represented by), (A-3) in the following general formula AlR _m X ² _3-m (wherein, R represents a hydrocarbon group having 1 to 20 carbon atoms, X ² is a halogen atom, an alkoxy group or an aryl group And m is a real number of 1 to 3, and when m is greater than 1, each R may be the same or different, and when n is less than 2, each X ² may be the same or different. An olefin prepolymerization catalyst formed by prepolymerizing an olefin with a catalyst component comprising an organoaluminum compound represented by the following formula: [B] an electron donor, [C] a general formula AlR _m X ² _3-m (wherein, R is a hydrocarbon group having 1 to 20 carbon atoms, X ² is a halogen atom, an alkoxy group or an aryl group, m is a real number of 1 to 3, and when m is greater than 1, , Each R is the same or different At best, if n is less than 2, each of X ² may be the same or different.) Consisting of an organic aluminum compound represented by the olefin polymerization catalyst. Wherein [A] (A-1) a halide of magnesium, (A-2) represented by the following general formula CpMX ¹ ₃ (wherein, Cp is a substituted or unsubstituted cyclopentadienyl group, indenyl group or fluorenyl Group.
Is a titanium atom, a zirconium atom or a hafnium atom, and X ¹ is a hydrogen atom, a halogen atom,
2 hydrocarbon groups, alkoxy groups or aryloxy groups. The types of X ¹ may be the same or different. Transition metal compound represented by), (A-3) in the following general formula AlR _m X ² _3-m (wherein, R represents a hydrocarbon group having 1 to 20 carbon atoms, X ² is a halogen atom, an alkoxy group or an aryl group And m is a real number of 1 to 3, and when m is greater than 1, each R may be the same or different, and when n is less than 2, each X ² may be the same or different. An olefin prepolymerization catalyst formed by prepolymerizing an olefin with a catalyst component comprising an organoaluminum compound represented by the formula (1): [B] an olefin polymerization catalyst comprising an electron donor. 3. A method for producing a polyolefin, comprising polymerizing or copolymerizing an α-olefin in the presence of the olefin polymerization catalyst according to claim 1 or 2.