JP3427488B2 - Novel organic transition metal compound and method for producing polyolefin using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to three types of cyclopentadienyl group, a hetero atom covalently bonded to a transition metal, and a hetero atom capable of coordinatively bonding to a transition metal on the same ligand. The present invention relates to a novel organic transition metal compound having a ligand group, and a method for polymerizing an olefin by using the organic transition metal compound as a main catalyst.

[0002]

2. Description of the Related Art Various catalyst systems and polymerization methods are known for the polymerization of olefins. For example, a Ziegler-Natta catalyst system can be used to produce a high molecular weight polyolefin having a wide molecular weight distribution.

Recently, a catalyst system containing a transition metal compound having a cyclopentadienyl derivative as a ligand (generally called a metallocene compound) has been developed, and in particular, a metallocene composed of a Group 4 transition metal such as titanium, zirconium or hafnium. It is known that a polyolefin such as polyethylene, an ethylene copolymer or polypropylene can be produced with high activity by using a compound as a main catalyst and an aluminoxane as a cocatalyst (for example, JP-A-58-19309). Such).

Further, many studies have been conducted on a catalyst system containing a metallocene compound, and the structural design of the metallocene compound is carried out by introducing various substituents into the cyclopentadienyl group which is a ligand of the metallocene compound. Have revealed that the primary structure such as molecular weight, three-dimensional structure and composition distribution of the produced polymer can be controlled (for example, JP-A-61-26491 and JP-A-6464).
-51408, JP-A-64-66216,
JP-A-1-301704 and J. Am. Che
m. Soc. , 110, 6255-6262, (198
8) etc.).

In addition, Organometallics,
9,867 (1990) and Japanese Patent Application Laid-Open No. 163088/1990, which has a cyclopentadienyl group and a hetero atom such as a nitrogen atom as a ligand, and has a unique structure of a constrained geometric structure. It has been reported that a catalyst system containing a transition metal compound as a constituent exhibits high activity for the polymerization of olefins, and the properties of the resulting polymer are excellent.

However, these organic transition metal compounds and the polymerization active species produced from them are oxygen in the air,
It is easily deactivated by water, impurities in the polymerization system, etc., and easily changes to a chemical species that does not have polymerization activity. Therefore, it is desired to develop a new catalyst that is easy to handle and has excellent polymerization stability.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above problems, and a novel organic transition metal compound which is excellent in stability when used as a catalyst and is easy to handle, and the use thereof Another object of the present invention is to provide a method for polymerizing olefins.

[0008]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a cyclopentadienyl group, a hetero atom covalently bonded to a transition metal, a transition metal and a ligand on the same ligand. A novel organic transition metal compound characterized by having at least three kinds of ligand groups of heteroatoms capable of position bonding, and a catalyst containing this organic transition metal compound is further prepared for olefins. They found that they showed excellent polymerization activity, and completed this discovery.

That is, the present invention provides the following general formula (1)

[0010]

[Chemical 9]

(In the formula, M is a transition metal selected from titanium atom, zirconium atom and hafnium atom,
Cp is the following general formula (2) bonded to the transition metal M,
(3), (4) or (5)

[0012]

[Chemical 10]

(Wherein R ³ is independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms), and X is a nitrogen atom bonded to the transition metal M. Alternatively, it is a phosphorus atom, Y is —OR ⁴ , —SR ⁴ , —NR ⁴ ₂ or —PR ⁴ ₂ and represents an electron-donating ligand group capable of forming a coordinate bond with the transition metal M. However, R
Each of ⁴ is independently a hydrocarbon group having 1 to 20 carbon atoms.
R ¹ represents an alkylene group connecting Cp and X or a substituted silylene group and has a function of bridging Cp and X, R ² represents an alkylene group connecting X and Y or a substituted silylene group, and X and Y are It acts to crosslink. Z may be the same or different and each is a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms or an alkoxy group bonded to the transition metal M. ] It is an organic transition metal compound characterized by being represented by. The present invention also provides the organic transition metal compound, the organic aluminum compound, and the following general formula (6).

[0014]

[Chemical 11]

(Wherein L ¹ is independently a Lewis base, l is 0 <l ≦ 2, M ² is a boron atom, an aluminum atom or a gallium atom, and R ⁵ is independently. A protonic acid represented by a halogen-substituted aryl group having 6 to 20 carbon atoms, represented by the following general formula (7).

[0016]

[Chemical 12]

(In the formula, C is a carbonium cation or tropylium cation, M ² is a boron atom, an aluminum atom or a gallium atom, and R ⁵ is independently a halogen-substituted aryl group having 6 to 20 carbon atoms. A Lewis acid represented by the following general formula (8)

[0018]

[Chemical 13]

(In the formula, M ³ is 1 group, 2 group, 8 of the periodic table
Is a cation of a metal selected from Group 10, Group 9, 10, Group 11 or Group 12, M ² is a boron atom, an aluminum atom or a gallium atom, and R ⁵ are each independently a group having 6 to 20 carbon atoms. It is a halogen-substituted aryl group, L ² is a Lewis base or a cyclopentadienyl group, and m is 0 ≦ m ≦ 2. ) Or an ionized ionic compound represented by the following general formula (9)

[0020]

[Chemical 14]

(Wherein M ² is a boron atom, an aluminum atom or a gallium atom, and R ⁵ is each independently a halogen-substituted aryl group having 6 to 20 carbon atoms), etc. Of the above-mentioned transition metal compound capable of cationization, a catalyst for polymerization comprising one or more compounds as constituent components, or an organic transition metal compound and the following general formula (10) or (11)

[0022]

[Chemical 15]

[0023]

[Chemical 16]

(In the formula, each R ⁶ is independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an arylalkyl group or an alkylaryl group, and q is 2 to 50. It is a polymerization catalyst containing an aluminoxane represented by the formula. Furthermore, the present invention is a method for producing a polyolefin, which comprises polymerizing an olefin using the above-mentioned polymerization catalyst.

The present invention will be described in detail below. The organic transition metal compound of the present invention has a structure of the general formula (1), M is a transition metal of Group 4 of the periodic table selected from titanium atom, zirconium atom and hafnium atom, and Cp
Is a monocyclic or polycyclic hydrocarbon group represented by the general formula (2), (3), (4) or (5) and forming a bond with the transition metal M in the η ⁵ bond mode. Specific examples of Cp include a substituted cyclopentadienyl group such as a cyclopentadienyl group and a tetramethylcyclopentadienyl group, an indenyl group, a tetrahydroindenyl group, a substituted indenyl group such as a 2-methylindenyl group, and a fluorenyl group. Or 2,7-dimethylfluorenyl group, 2,7-di-ter
Examples thereof include substituted fluorenyl groups such as t-butylfluorenyl group and octahydrofluorenyl group. X
Is a nitrogen atom or phosphorus atom covalently bonded to the transition metal M, and Cp and R ¹ , X, and M form one condensed ring system. Y is ^{-OR 4, -SR 4, -NR 4} 2 or -PR ⁴ ₂
Is an electron-donating ligand group capable of forming a coordinate bond with the transition metal M. Here, each R ⁴ is independently a hydrocarbon group having 1 to 20 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a tert-butyl group, and a phenyl group. You can The coordination state of Y changes depending on the type of the ligand group, and Y may form a strong coordination bond with the transition metal M, but may also only weakly interact with the transition metal M. However, the coordination state of Y and the transition metal M is not particularly limited. R ¹ represents an alkylene group connecting Cp and X or a substituted silylene group. Specifically, it has the structure of the following general formula (12) or (13),

[0026]

[Chemical 17]

(In the formula, R ^{7 s} may be the same or different and each is a hydrogen atom, a halogen atom, an alkoxide group, or a hydrocarbon group such as an alkyl group, an aryl group or an aralkyl group, and p is 1 to 3). It is an integer of 1.) The thing which has the effect | action which bridge | crosslinks Cp and X can be mentioned. Further specific examples of R ¹ include a methylene group,
Examples thereof include ethylene group, propylene group, dimethylmethylene group, diphenylmethylene group, dimethylsilylene group, methylphenylsilylene group, diphenylsilylene group and tetramethylethylene group. R ² represents an alkylene group connecting X and Y or a substituted silylene group. Specifically, it has the structure of the following general formula (14) or (15),

[0028]

[Chemical 18]

(In the formula, R ⁸ may be the same or different and each is a hydrogen atom, a halogen atom, an alkoxide group, or a hydrocarbon group such as an alkyl group, an aryl group or an aralkyl group, and r is 1 to 10). It is an integer of 1.) The thing which has the effect | action which bridge | crosslinks X and Y can be mentioned. Further specific examples of R ² include a hydrocarbon group having 1 to 20 carbon atoms such as a methylene group, an ethylene group, a propylene group, a butylene group, a dimethylmethylene group, a tetramethylethylene group, a dimethylsilylene group and a diphenylsilylene group. A substituted silylene group can be mentioned. Z may be the same or different and each is a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms or an alkoxy group bonded to the transition metal M.

The organic transition metal compound represented by the general formula (1) of the present invention can be synthesized, for example, by the following route.

[0031]

[Chemical 19]

Specific examples of the organic transition metal compound represented by the general formula (1) of the present invention include dimethylsilyl (tetramethyl-η ⁵ -cyclopentadienyl) (methoxymethylamido) titanium dichloride and dimethylsilyl. (Tetramethyl- [eta] ⁵ -cyclopentadienyl) (methoxyethylamide) titanium dichloride, dimethylsilyl (tetramethyl- [eta] ⁵ -cyclopentadienyl) (methoxypropylamide) titanium dichloride, dimethylsilyl (tetramethyl- [eta] ⁵ -Cyclopentadienyl)
(Methoxybutyramide) titanium dichloride, dimethylsilyl (tetramethyl-η ⁵ -cyclopentadienyl) (methoxypentylamide) titanium dichloride,
Diphenylsilyl (tetramethyl-η ⁵ -cyclopentadienyl) (methoxymethylamide) titanium dichloride, diphenylsilyl (tetramethyl-η ⁵ -cyclopentadienyl) (methoxyethylamide) titanium dichloride, diphenylsilyl (tetramethyl- η ⁵ -Cyclopentadienyl) (methoxypropylamido) titanium dichloride, diphenylsilyl (tetramethyl-η ⁵
-Cyclopentadienyl) (methoxybutylamido) titanium dichloride, diphenylsilyl (tetramethyl-
η ⁵ -Cyclopentadienyl) (methoxypentylamide) titanium dichloride, dimethylsilyl (tetramethyl-η ⁵ -cyclopentadienyl) (ethoxyethylamide) titanium dichloride, dimethylsilyl (tetramethyl-η ⁵ -cyclopentadiene (Enyl) (isopropoxyethylamide) titanium dichloride, dimethylsilyl (tetramethyl-η ⁵ -cyclopentadienyl) (butylmethoxyethylamide) titanium dichloride, dimethylsilyl (tetramethyl-η ⁵ -cyclopentadienyl) (phenoxy Ethylamide) titanium dichloride,
Dimethylsilyl (tetramethyl-η ⁵ -cyclopentadienyl) (benzoxyethylamide) titanium dichloride, the central metal of the above compound is titanium to zirconium,
An organic transition metal compound in which hafnium is changed, an organic transition metal compound in which a chlorine atom bonded to a metal is changed to a hydrocarbon group, an alkoxy group, or the like, a cyclopentadienyl group which is Cp of the formula (1) is an indenyl group, Examples thereof include organic transition metal compounds having a fluorenyl group and the like, but are not limited thereto.

The present invention also relates to a polymerization catalyst containing the above-mentioned organic transition metal compound as a main catalyst, and a method for producing a polyolefin, which comprises polymerizing an olefin using the catalyst. Here, a protonic acid represented by the general formula (6), a Lewis acid represented by the general formula (7), and an ionized ionicity represented by the general formula (8), which are used as other constituent components of the polymerization catalyst. The compound and the Lewis acidic compound represented by the general formula (9) are compounds capable of converting the above organic transition metal compound into a cationic compound and weakly coordinate and / or interact with the produced cationic compound, It is a compound that provides a counter anion that does not react.

Specific examples of the protonic acid represented by the general formula (6) include diethyloxonium tetrakis (pentafluorophenyl) borate, dimethyloxonium tetrakis (pentafluorophenyl) borate, tetramethyleneoxonium tetrakis (pentafluoro). Phenyl) borate, hydronium tetrakis (pentafluorophenyl) borate, N, N-dimethylammonium tetrakis (pentafluorophenyl) borate, tri-n-butylammonium tetrakis (pentafluorophenyl) borate, diethyloxonium tetrakis (pentafluorophenyl) ) Aluminate, dimethyloxonium tetrakis (pentafluorophenyl) aluminate, tetramethyleneoxonium tetrakis (pentafluorophenyl) Nyl) aluminate, hydronium tetrakis (pentafluorophenyl) aluminate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) aluminate, tri-n-butylammonium tetrakis (pentafluorophenyl) aluminate, etc. You can

Specific examples of the Lewis acid represented by the general formula (7) include trityl tetrakis (pentafluorophenyl) borate, trityl tetrakis (pentafluorophenyl) aluminate, tropylium tetrakis (pentafluorophenyl) borate. , Tropylium tetrakis (pentafluorophenyl) aluminate, and the like, but are not limited thereto.

The ionized ionic compound represented by the general formula (8) is specifically a lithium salt such as lithium tetrakis (pentafluorophenyl) borate or lithium tetrakis (pentafluorophenyl) aluminate, or a salt thereof. Ether complexes, ferrocenium tetrakis (pentafluorophenyl) borate, ferrocenium salts such as ferrocenium tetrakis (pentafluorophenyl) aluminate, silver tetrakis (pentafluorophenyl) borate, silver tetrakis (pentafluorophenyl) aluminate, etc. Examples thereof include, but are not limited to, silver salts.

Further, specific examples of the Lewis acidic compound represented by the general formula (9) include tris (pentafluorophenyl) borane, tris (2,3,5,6-tetrafluorophenyl) borane and tris. (2,3,4,5-
Tetraphenylphenyl) borane, tris (3,4,5)
-Trifluorophenyl) borane, phenylbis (perfluorophenyl) borane, tris (3,4,5-trifluorophenyl) aluminum and the like can be mentioned, but not limited thereto.

Examples of the organoaluminum compound used together with the protonic acid, Lewis acid, ionized ionic compound or Lewis acidic compound include the following general formula (16).
The compound represented by can be mentioned.

[0039]

[Chemical 20]

(In the formula, R ⁹ and R ^{9 ′} R ^{9 ″} may be the same or different and each represents a hydrogen atom, a halogen atom, an amido group, an alkoxide group or a hydrocarbon group, at least one of which is a carbon atom. A hydrogen group.) Examples of such compounds include trimethylaluminum,
Specific examples thereof include triethylaluminum, triisobutylaluminum, dimethylaluminum chloride, diethylaluminum chloride and the like.

The method for preparing the catalyst from the above-mentioned compound and the organic transition metal compound is not particularly limited, and as an example of the preparation method, a solvent inert to each component or a monomer for polymerization is used as a solvent and mixed. And the like. In addition, there is no particular limitation on the order in which these components are reacted, the temperature at which this treatment is performed,
The processing time is also not particularly limited.

The ratio of the organic transition metal compound to the organoaluminum compound at the time of preparing the catalyst is not particularly limited, but the molar ratio of the organic transition metal compound to the organoaluminum compound per metal atom is preferably (the metal of the organic transition metal compound). ):
(Metal of organoaluminum compound) = 100: 1 to 1:
The range is 1,000,000, and particularly preferably 1: 1 to 1.
It is in the range of 100,000.

Further, an organic transition metal compound and a protic acid,
The ratio of the Lewis acid, the ionized ionic compound and / or the Lewis acidic compound is not particularly limited, and the molar ratio of the organic transition metal compound to these compounds is preferably (organic transition metal compound): (protonic acid, Lewis acid, ionized Ionic compound and / or Lewis acidic compound) = 10: 1
˜1: 1000, particularly preferably 1: 1 to 1: 100.

Furthermore, the present invention is a method for producing a polyolefin, characterized in that a polymerization catalyst comprising the organic transition metal compound and an aluminoxane as constituents and an olefin is polymerized using the catalyst. Here, aluminoxane is a compound having a bond between aluminum and oxygen,
It is represented by the general formula (10) or (11). In these general formulas, R ^{6 s} may be the same or different and each represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an alkyl group having 6 to 20 carbon atoms.
Are aryl groups, arylalkyl groups or alkylaryl groups, and specific examples of R ⁶ include methyl group, ethyl group, propyl group, butyl group, hexyl group, phenyl group, tolyl group and cyclohexyl group. it can. Further, q is an integer of 2 to 50.

The method for preparing the catalyst from the aluminoxane and the organic transition metal compound is not particularly limited, but as an example of the preparation method, it is preferable to mix them in a solvent inert to them or using a monomer for polymerization as a solvent. Can be mentioned. There is no particular limitation on the temperature at which this treatment is performed,
The processing time is also not particularly limited.

The ratio of the transition metal compound to the aluminoxane in preparing the catalyst is not particularly limited, but preferably the molar ratio of the transition metal compound to the aluminoxane per metal atom is (the metal of the transition metal compound): (metal of the aluminoxane). = 10
The range is 0: 1 to 1: 1,000,000, and particularly preferably the range is 1: 1 to 100,000.

The olefin polymerization in the present invention can be carried out in the liquid phase or the gas phase. The solvent for carrying out the polymerization in the liquid phase may be any organic solvent that is generally used, and specific examples thereof include benzene, toluene, xylene, pentane, hexane, heptane and methylene chloride. The olefin itself which polymerizes such as propylene, butene-1, octene-1 can also be used as a solvent.

The olefins used for the polymerization in the present invention are α-olefins such as ethylene, propylene, butene-1,4-methylpentene-1, hexene-1, octene-1, styrene, butadiene and 1,4-hexadiene. And the like, and conjugated olefins such as non-conjugated dienes, and cycloolefins such as cyclobutene. The polymerization temperature, the polymerization time, and the concentration of the solvent are not particularly limited, but the polymerization temperature is preferably in the range of -100 to 230 ° C.

[0049]

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

All reactions are carried out under an inert gas atmosphere,
All the solvents used in the reaction were previously purified by a known method,
What was dried or deoxidized was used. ¹ H-NMR (JPX Co., Ltd. GPX-4 was used to identify the organometallic compound.
00 type NMR measuring device).

Example 1 Synthesis of “Dimethylsilyl (tetramethyl-η ⁵ -cyclopentadienyl) (methoxyethylamido) titanium dichloride” Dimethylsilyl (tetramethylcyclopentadienyl) cooled to −78 ° C. under a nitrogen stream. ) (Methoxyethylamine) (3.35 mg, 13 mmol) in THF (7
0 ml), a hexane solution of n-butyllithium (28
(mmol) was slowly added dropwise, and the mixture was stirred at -78 ° C for 1 hour and further at room temperature for 1 hour. After completion of the reaction, the solvent was distilled off under reduced pressure, and the obtained reaction mixture was washed with hexane to give a pale yellow solid. The solid was cooled again to −78 ° C., suspended in diethyl ether (70 ml), and titanium tetrachloride (13 mmo) prepared in advance was added to this suspension.
A reaction solution of 1) and diethyl ether (30 ml) was slowly added. After stirring overnight as it was, the temperature was raised to room temperature, the solvent was distilled off under reduced pressure, the residue was extracted with methylene chloride, and recrystallized with methylene chloride / hexane to obtain a dark green solid.

The ¹ H-NMR spectrum (CDCl ₃ ) of the obtained solid was δ = 4.37 (t, 2H, J = 4.0 Hz, CH ₂ ),
3.47 (t, 2H, J = 4.0 Hz, CH ₂ ), 3.
31 (s, 3H, OMe), 2.26 (s, 6H, Cp
-Me), 2.15 (s, 6H, Cp-Me), 0.6
8 (s, 6H, Si-Me) 2, and this solid is dimethylsilyl (tetramethyl-η
⁵ -cyclopentadienyl) (methoxyethylamide)
It was identified as titanium dichloride (3.44g, 9.3mmol).

Example 2 To a 2-liter autoclave was added 500 ml of toluene,
Methylaluminoxane (Tosoh Akzo Co., Ltd.)
Made, molecular weight 1121) 20m in terms of aluminum atom
mol and 1.85 mg of dimethylsilyl (tetramethyl- [eta] ⁵ -cyclopentadienyl) (methoxyethylamido) titanium dichloride obtained in Example 1 were added. Then, ethylene was supplied to the oclave so that the ethylene content was 20 kg / cm ² G, and ethylene was polymerized at 80 ° C. for 30 minutes to obtain 4.2 g of polyethylene.

Example 3 To a 2 l autoclave was added 500 ml of toluene,
Triisobutylaluminum is added to this at 0.25 mmo
1, dimethylsilyl (tetramethyl-η obtained in Example 1
⁵ -cyclopentadienyl) (methoxyethylamide)
1.85 mg of titanium dichloride and 20.0 mg of N, N-dimethylanilinium tetrakispentafluorophenylborate were added. Then, ethylene was supplied to the oclave so that the ethylene content was 20 kg / cm ² G, and ethylene was polymerized at 80 ° C. for 30 minutes to obtain 3.2 g of polyethylene.

Example 4 500 ml of toluene and 1 in a 2 l autoclave
5 ml of hexene-1 was added, and 20 mmol of methylaluminoxane (produced by Tosoh Akzo Co., Ltd., molecular weight 1121) in terms of aluminum atom and dimethylsilyl (tetramethyl-η ⁵ -cyclopentadienyl) obtained in Example 1 were added. ) (Methoxyethylamide) titanium dichloride (1.85 mg) was added. Then, ethylene was polymerized at 80 ° C. for 30 minutes while supplying ethylene so that the ethylene content was 15 kg / cm ² G into the oclave.
96 g of polymer was obtained. This polymer had a melting point of 128 ° C.

[0056]

INDUSTRIAL APPLICABILITY The organic transition metal compound of the present invention is easy to handle, and when an olefin polymerization catalyst containing the present organic transition metal compound as a main component is used, polyolefin production can be stably carried out, which is extremely valuable industrially. There is.

─────────────────────────────────────────────────── --Continued from the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08F 4/64-4/658 CA (STN)

Claims (4)

(57) [Claims] 1. The following general formula (1): (In the formula, M is a transition metal selected from titanium atom, zirconium atom and hafnium atom, and Cp is the following general formula (2), (3), (4) or (5) in which the transition metal M is bonded. Chemical 2] (In the formula, each R ³ independently represents a hydrogen atom or a carbon number of 1 to
20 hydrocarbon groups. ) Is a hydrocarbon group, X is a nitrogen atom or a phosphorus atom bonded to the transition metal M, and Y is —OR ⁴ , —SR ⁴ , —NR ⁴ ₂ or —PR ⁴ ₂
Is an electron-donating ligand group capable of forming a coordinate bond with the transition metal M. However, each R ⁴ is independently a hydrocarbon group having 1 to 20 carbon atoms. R ¹ represents an alkylene group or a substituted silylene group connecting Cp and X,
It has a function of bridging p and X, R ² represents an alkylene group or a substituted silylene group connecting X and Y, and has a function of bridging X and Y. Z may be the same or different and each is a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms or an alkoxy group bonded to the transition metal M. ) The organic transition metal compound is represented by 2. An organic transition metal compound, an organoaluminum compound according to claim 1, and the following general formula (6): (In the formula, L ¹ is each independently a Lewis base, and l is 0
<L ≦ 2, M ² is a boron atom, an aluminum atom or a gallium atom, and R ⁵ is independently a halogen-substituted aryl group having 6 to 20 carbon atoms. ), A protonic acid represented by the following general formula (7): (In the formula, C is a carbonium cation or tropylium cation, M ² is a boron atom, an aluminum atom or a gallium atom, and R ⁵ is independently a halogen-substituted aryl group having 6 to 20 carbon atoms. ), A Lewis acid represented by the following general formula (8): (In the formula, M ³ is 1 group, 2 group, 8 group, 9 group, or 10 of the periodic table.
Is a cation of a metal selected from Group 11, Group 11 or Group 12, M ² is a boron atom, an aluminum atom or a gallium atom, and R ⁵ are each independently a halogen-substituted aryl group having 6 to 20 carbon atoms. , L ² is a Lewis base or a cyclopentadienyl group, and m is 0 ≦ m ≦ 2. ) Or an ionized ionic compound represented by the following general formula (9): (In the formula, M ² is a boron atom, an aluminum atom or a gallium atom, and R ⁵ are each independently a carbon number of 6 to 20.
Is a halogen-substituted aryl group of. And a catalyst for polymerization containing as a constituent component one or more compounds capable of cationizing the above transition metal compound such as a Lewis acidic compound. 3. The organic transition metal compound according to claim 1 and the following general formula (10) or (11): [Chemical 8] (In the formula, each R ⁶ is independently a hydrogen atom or a carbon number 1 to 20.
Is an alkyl group having 6 to 20 carbon atoms, an arylalkyl group or an alkylaryl group, and q is 2 to
It is an integer of 50. ) A polymerization catalyst comprising an aluminoxane represented by 4. A method for producing a polyolefin, which comprises polymerizing an olefin by using the catalyst for polymerization according to claim 2 or 3.