TWI867101B - Transition metal compound, catalyst composition containing the same, and method for preparing olefin polymer using the same - Google Patents

Abstract

Provided are a transition metal compound, a catalyst composition containing the same, and a method for preparing an olefin polymer using the same, and the transition metal compound may have high solubility and catalytic activity by introducing a specific functional group at a specific position, and the method for preparing an olefin polymer using the same may easily prepare an olefin polymer having excellent physical properties by a simple process.

Description

Transition metal compound, catalyst composition containing the same, and method for preparing olefin polymer using the same [Cross-reference to related applications]

This application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2019-0159015 filed with the Korean Intellectual Property Office on December 3, 2019 and Korean Patent Application No. 10-2020-0160173 filed with the Korean Intellectual Property Office on November 25, 2020, the disclosures of which are incorporated herein by reference in their entirety.

The following disclosure relates to a transition metal compound, a catalyst composition comprising the transition metal compound, and a method for preparing an olefin polymer using the same, and more specifically, to a transition metal compound having improved solubility by introducing a controlled specific functional group, a catalyst composition comprising the transition metal compound, and a method for preparing an olefin polymer using the same.

Conventionally, the so-called Ziegler-Natta catalyst system consisting of a main catalyst component of a titanium or vanadium compound and a co-catalyst component of an alkyl aluminum compound has been generally used to prepare ethylene homopolymers or copolymers of ethylene and α-olefins.

The Ziegler-Natta catalyst system exhibits high activity for ethylene polymerization. However, its disadvantage is that the resulting polymers generally have a broad molecular weight distribution due to heterogeneous catalytic active sites, and specifically, the composition distribution of copolymers of ethylene and α-olefins is not uniform.

Recently, a so-called metallocene catalyst system has been developed, which is composed of metallocene compounds of transition metals of Group 4 in the periodic table, such as titanium, zirconium, and einsteinium, and methylaluminoxane as a cocatalyst. Since the metallocene catalyst system is a homogeneous catalyst with a single catalyst active site, its characteristic is that, compared with the existing Ziegler-Natta catalyst system, the metallocene catalyst system can produce polyethylene with a narrow molecular weight distribution and a uniform component distribution.

As a specific example, polyethylene with a narrow molecular weight distribution (Mw _{/ Mn} ) can be prepared by activating metallocene compounds such as _{Cp2TiCl2 , Cp2ZrCl2 , Cp2ZrMeCl} , _Cp2ZrMe2 , ( _IndH4 ) _2ZrCl2 , etc. with a cocatalyst methylaluminoxane to polymerize ethylene with high activity.

However, it is difficult to obtain high molecular weight polymers in metallocene catalyst systems. Specifically, when the catalyst system is applied to a solution polymerization process at a high temperature of 100°C or above, the polymerization activity decreases rapidly and the β-dehydrogenation reaction is dominant, so it is not suitable for preparing high molecular weight polymers with a high weight average molecular weight (Mw).

Meanwhile, it is known that as a catalyst capable of preparing a polymer having high catalyst activity and high molecular weight by homopolymerizing ethylene or copolymerizing ethylene and α-olefin under solution polymerization conditions at 100°C or above, a so-called geometrically constrained ANSA-type metallocene-based catalyst in which a transition metal is linked in a ring form can be used. Compared with the metallocene catalyst, the ANSA-type metallocene-based catalyst has significantly improved octene injection and high temperature activity. However, most of the previously known ANSA-type metallocene-based catalysts include a Cl functional group or a methyl group, and thus have problems with being improved for solution processes.

Since the substituted Cl functional groups on the catalyst may cause corrosion etc. depending on the materials used in the process, ANSA-type metallocene-based catalysts substituted with dimethyl groups are studied to avoid the corrosion problem caused by Cl. However, ANSA-type metallocene-based catalysts are also difficult to inject into the polymerization process due to their poor solubility. Toluene or xylene can be used to dissolve such catalysts with poor solubility, but the use of aromatic solvents such as toluene or xylene can cause problems in the production of products that may come into contact with food.

Therefore, there is an urgent need to develop competitive catalysts with characteristics such as good solubility, high temperature activity, reactivity with high-order α-olefins, and the ability to produce high molecular weight polymers.

[Prior Art Literature] [Patent Literature]

Patent document 1: European Patent Application Publication No. 320,762.

Patent document 2: European Patent Application Publication No. 372,632.

One embodiment of the present invention aims to provide a transition metal compound that introduces a controlled specific functional group and a catalyst composition containing the transition metal compound to improve the above-mentioned problem.

Another embodiment of the present invention is to provide a method for preparing olefin polymers using the transition metal compound of the present invention as a catalyst.

In one general aspect, a transition metal compound represented by the following formula 1 is provided, which has significantly improved solubility in non-aromatic hydrocarbons by introducing a specific functional group:

wherein M is a transition metal of Group 4 in the Periodic Table of the Elements; A is C or Si; Ar is a substituted aryl group; and the substituent of the aryl group of Ar is selected from one or more of the following groups: (C1-C20)alkyl, (C3-C20)cycloalkyl, (C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl, (C1-C20)alkoxy, (C6-C20)aryloxy, (C1-C20)alkylamino, (C6-C20)arylamino, (C1-C20)alkylthio and (C6-C20)arylthio and has 14 or more carbon atoms; R is (C1-C20)alkyl, (C1-C20)alkoxy, (C6-C20)aryl or (C6-C20)aryloxy; _R1 to R R ₁₁ to R ₁₈ are _each independently hydrogen, (C1-C20)alkyl, (C1-C20)alkoxy, (C3-C20)cycloalkyl, (C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl, (C1-C20)alkyl(C6-C20)aryl, (C1-C20)alkylsilyl or (C6-C20)arylsilyl, or each substituent may be linked to an adjacent substituent via a (C3-C12)alkylene or (C3-C12)alkenylene group which may or may not have a condensed ring to form an alicyclic ring or a monocyclic or polycyclic aromatic ring.

R ₂₁ and R ₂₂ are each independently (C6-C20) aryl; and R is an alkyl, alkoxy, aryl or aryloxy group, R ₁₁ to R ₁₈ are an alkyl, alkoxy, cycloalkyl, aryl, aralkyl, alkaryl, alkanyl, aromatic silyl, alicyclic ring or aromatic ring, and R ₂₁ and R The aryl group of ₂₂ may be further substituted by one or more substituents selected from the group consisting of a (C1-C20)alkyl group, a (C3-C20)cycloalkyl group, a (C6-C20)aryl group, a (C6-C20)aryl(C1-C20)alkyl group, a (C1-C20)alkoxy group, a (C6-C20)aryloxy group, a (C3-C20)alkylsiloxy group, a (C6-C20)arylsiloxy group, a (C1-C20)alkylamino group, a (C6-C20)arylamino group, a (C1-C20)alkylthio group, a (C6-C20)arylthio group, a (C1-C20)alkylphosphine group, and a (C6-C20)arylphosphine group.

Preferably, in Formula 1 according to an exemplary embodiment of the present invention, Ar may be a (C6-C20)aryl group substituted with an alkyl group having 8 or more carbon atoms; R may be a (C1-C20)alkyl group, a (C1-C20)alkyl(C6-C20)aryloxy group or a (C6-C20)aryl(C1-C20)alkyl group, and more preferably, M may be titanium, zirconium or eum; each R may independently be a (C1-C4)alkyl group, a (C8-C20)alkyl(C6-C12)aryloxy group or a (C6-C12)aryl(C1-C4)alkyl group; _R1 to _R4 may each independently be hydrogen or a (C1-C4)alkyl group; and _R11 to _R18 may be hydrogen.

Preferably, the transition metal compound of Formula 1 according to the exemplary embodiment of the present invention can be represented by the following Formula 2 or Formula 3: [Formula 2]

wherein M is titanium, zirconium or euryl; _Ar1 and _Ar2 are each independently a substituted (C6-C20)aryl group; and the substituent of the (C6-C20)aryl group of _Ar1 and _Ar2 is a (C1-C20)alkyl group, a (C3-C20)cycloalkyl group, a (C6-C20)aryl group, a (C6-C20)aryl group, a (C6-C20)aryl (C1-C20)alkyl group, a (C1-C20)alkoxy group, a (C6-C20)aryloxy group, a (C1-C20)alkylamino group, a (C6-C20)arylamino group, a (C1-C20)alkylthio group or a (C6-C20)arylthio group and has 14 or more carbon atoms; A is C or Si; _R1 to _R4 are each independently hydrogen or a (C1-C4)alkyl group; _R21 and R _{R 22} are each independently (C6-C20)aryl or (C6-C20)aryl substituted by (C1-C4)alkyl; and R ₃₁ is (C1-C20)alkyl or (C1-C20)alkyl(C6-C20)aryl.

Specifically, the transition metal compound of the present invention can be selected from the following compounds:

Preferably, the transition metal compound according to the exemplary embodiment of the present invention may have a solubility of 1 wt% or more at 25°C (solvent: methylcyclohexane).

In another general aspect, a transition metal catalyst composition for preparing an ethylene homopolymer or a copolymer of ethylene and an α-olefin is provided, the composition comprising a transition metal compound according to the present invention, wherein the transition metal catalyst composition according to the present invention contains a transition metal compound represented by Formula 1; and a co-catalyst.

The co-catalyst contained in the transition metal catalyst composition according to the present invention may be an aluminum compound co-catalyst, a boron compound co-catalyst or a mixture thereof.

In addition, the present invention provides a method for preparing an olefin polymer using the transition metal compound according to the present invention.

In another general aspect, the method for preparing an olefin polymer according to the present invention comprises: obtaining an olefin polymer by solution polymerizing a transition metal compound represented by Formula 1, a cocatalyst, and one or two or more monomers selected from ethylene and comonomers in the presence of a non-aromatic hydrocarbon solvent.

The solubility of the transition metal catalyst composition according to the exemplary embodiment of the present invention in a non-aromatic hydrocarbon solvent (solvent: methylcyclohexane) at 25°C can be 1 wt% or more.

Preferably, in the method for preparing an olefin polymer according to the present invention, the cocatalyst may be an aluminum compound cocatalyst, a boron compound cocatalyst or a mixture thereof, and specifically, the boron compound cocatalyst may be a compound represented by the following formula 11 to formula 14, and the aluminum compound cocatalyst may be represented by the following formula 15 to formula 19: [Formula 11] BR ²¹ ₃

[Formula 12] [R ²² ] ⁺ [BR ²¹ ₄ ] ^-

[Formula 13][R ²³ _p ZH] ⁺ [BR ²¹ ₄ ] ^-

wherein B is a boron atom; R ²¹ is a phenyl group, and the phenyl group may be further substituted by 3 to 5 substituents selected from the group consisting of a fluorine atom, a (C1-C20)alkyl group, a (C1-C20)alkyl group substituted by a fluorine atom, a (C1-C20)alkoxy group, or a (C1-C20)alkoxy group substituted by a fluorine atom; R ²² is a (C5-C7)aromatic group, a (C1-C20)alkyl(C6-C20)aryl group, or a (C6-C20)aryl(C1-C20)alkyl group; Z is a nitrogen or phosphorus atom; R ²³ is a (C1-C20)alkyl group or a phenylammonium group substituted by two (C1-C10)alkyl groups and a nitrogen atom; R ²⁴ is a (C5-C20)alkyl group; R ²⁵ is (C5-C20)aryl or (C1-C20)alkyl (C6-C20)aryl; and p is an integer of 2 or 3, [Formula 15] -AlR ²⁶ -O- _m

[Formula 17] R ²⁸ _r AlE _3-r

[Formula 18] R ²⁹ ₂ AlOR ³⁰

[Formula 19] R ²⁹ AlOR ³⁰ ₂

wherein R ²⁶ and R ²⁷ are each independently (C1-C20) alkyl, m and q are integers from 5 to 20; R ²⁸ and R ²⁹ are each independently (C1-C20) alkyl; E is a hydrogen atom or a halogen atom; r is an integer between 1 and 3; and R ³⁰ is (C1-C20) alkyl or (C6-C30) aryl.

Preferably, the solution polymerization according to the exemplary embodiment of the present invention can be carried out at a reactor pressure of 6 atm to 150 atm and a polymerization temperature of 100°C to 200°C.

Preferably, the olefin polymer according to the exemplary embodiment of the present invention may have a weight average molecular weight of 5,000 g/mol to 200,000 g/mol, a molecular weight distribution (Mw/Mn) of 1.0 to 10.0, and an ethylene content of 30 wt% to 99 wt%.

The advantages, features and aspects of the present invention will become apparent by referring to the following description of the embodiments with reference to the drawings listed below. However, the present invention can be implemented in many different forms and should not be construed as being limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. The terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the exemplary embodiments. As used herein, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to include the plural forms as well. It will be further understood that the term "comprises and/or comprising" when used in this specification stipulates the existence of the stated features, integers, steps, operations, elements and/or components, but does not exclude the existence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.

Hereinafter, the present invention will describe the transition metal compound according to the present invention, the catalyst composition containing the transition metal compound, and the method for preparing olefin polymers using the same, but unless otherwise defined, the technical terms and scientific terms used herein have the general meanings understood by those skilled in the art to which the present invention belongs, and the description of known functions and configurations that obscure the present invention will be omitted in the following description.

Unless specifically limited to carbon atoms, the term "alkyl" as used herein refers to a saturated, straight or branched, non-cyclic hydrocarbon having 1 to 20 carbon atoms. "Lower alkyl" refers to a straight or branched alkyl having 1 to 6 carbon atoms. Representative saturated straight-chain alkyl groups include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl and n-decyl, while saturated branched-chain alkyl groups include isopropyl, sec-butyl, isobutyl, t-butyl, isopentyl, 2-methylhexyl, 3-methylbutyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2-methylhexyl, 3-methylhexyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, 2,3-dimethylbutyl, 2,3-dimethylpentyl, 2,4-dimethylpentyl, 2,3-dimethylhexyl , 2,4-dimethylhexyl, 2,5-dimethylhexyl, 2,2-dimethylpentyl, 2,2-dimethylhexyl, 3,3-dimethylpentyl, 3,3-dimethylhexyl, 4,4-dimethylhexyl, 2-ethylpentyl, 3-ethylpentyl, 2-decylhexyl, 3-ethylhexyl, 4-ethylhexyl, 2-methyl-2-ethylpentyl, 2-methyl-3-ethylpentyl, 2-methyl-4-ethylpentyl, 2-methyl-2-ethylhexyl, 2-methyl-3-ethylhexyl, 2-methyl-4-ethylhexyl, 2,2-diethylpentyl, 3,3-diethylhexyl, 2,2-diethylhexyl and 3,3-diethylhexyl.

In this specification, "C1-C20" means the number of carbon atoms is 1 to 20. For example, (C1-C20) alkyl refers to an alkyl group having 1 to 20 carbon atoms.

In addition, the term "substituted aryl group having 14 or more carbon atoms" used herein means that the sum of the carbon atoms of the aryl group and the carbon atoms of the substituent substituted on the aryl group is 14 or more. Preferably, in the present specification, Ar is a substituted aryl group, and the substituted aryl group of Ar may be an aryl group having one or more substituents selected from the group consisting of (C1-C20) alkyl, (C1-C20) alkoxy, (C3-C20) cycloalkyl, (C6-C30) aryl, (C6-C30) aryl (C1-C20) alkyl, (C1-C20) alkyl (C6-C30) aryl, (C1-C20) alkylsilyl and (C6-C30) aromatic silyl, wherein the substituent is The sum of the carbon atoms of Ar and the carbon atoms of the aryl group is 14 or more, and more preferably, the substituted aryl group of Ar may be a (C6-C30)aryl group having one or more substituents selected from the group consisting of a (C8-C20)alkyl group, a (C6-C20)alkoxy group, a (C8-C20)cycloalkyl group, a (C-C30)aryl group, a (C6-C30)aryl group (C1-C20)alkyl group and a (C8-C20)alkyl (C6-C30)aryl group, having a total carbon atom of 14 or more. For example, in a (C6-C30)aryl group having a substituent, the substituent is one or more selected from the following: (C8-C20)alkyl, (C6-C20)alkoxy, (C8-C20)cycloalkyl, (C-C30)aryl (C6-C30)aryl (C1-C20)alkyl and (C8-C20)alkyl (C6-C30)aryl, wherein the sum of the carbon atoms of the aryl group and the carbon atoms of the substituent group substituted on the aryl group is 14 or more.

Substituents other than the substituted aryl group of Ar of the present invention refer to the number of carbon atoms excluding the substituents. As a specific example, in Formula 1 of the present invention, when R is a (C1-C20) alkyl group, it does not include the number of carbon atoms of the substituents that can be substituted on the alkyl group.

The term "alkoxy" as used herein refers _to -O-alkyl _groups including _-OCH3 , _{-OCH2CH3 , -OCH22CH3 , -OCH23CH3} , _-OCH24CH3 , _-OCH25CH3 and the like, wherein alkyl _is as defined above.

The term "lower alkoxy" as used herein refers to -O-lower alkyl, wherein lower alkyl is as defined above.

As used herein, "aryl" refers to a carbocyclic aromatic group containing 5 to 10 ring atoms. Representative examples of aryl are phenyl, tolyl, xylyl, naphthyl, tetrahydronaphthyl, anthracenyl, fluorenyl, indenyl, azulenyl, etc., but aryl is not limited thereto. The carbocyclic aromatic group may be substituted as appropriate.

As used herein, the term "aryloxy" is RO-, and R is an aryl group as defined above. The term "arylthio" is RS-, and R is an aryl group as defined above.

The term "cycloalkyl" as used herein refers to a monocyclic or polycyclic saturated ring having carbon and hydrogen atoms and no carbon-carbon multiple bonds. Examples of cycloalkyl include, but are not limited to, (C3-C10)cycloalkyl, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl. The cycloalkyl may be substituted as appropriate. In one embodiment, the cycloalkyl is a monocyclic or bicyclic ring.

As used herein, the term "substituted" means that a portion of the hydrogen atoms are substituted, such as an alkyl, aryl, heteroaryl, heterocyclic or cycloalkyl group replaced by a substituent. In one embodiment, each carbon atom of the substituted group is not substituted by two or more substituents. In another embodiment, each carbon atom of the substituted group is not substituted by one or more substituents. In the case of a keto substituent, two hydrogen atoms are replaced by oxygens connected to the carbon by a double bond. Unless otherwise specified with respect to the substituent, the substituents of the present invention which may be substituted may be one or more selected from the group consisting of: halogen, hydroxyl, lower alkyl, halogen alkyl, mono- or di-alkylamino, (C1-C20) alkyl, (C1-C20) alkoxy, (C3-C20) cycloalkyl, (C6-C30) aryl, (C6-C30) aryl (C1-C20) alkyl, (C1-C20) alkyl (C6-C30) aryl, (C1-C20) alkyl silyl , (C6-C30) aromatic silyl, (C6-C20) aromatic oxy, (C3-C20) alkyl silyl, (C6-C20) aromatic silyl, (C1-C20) alkylamino, (C6-C20) aromatic amine, (C1-C20) alkylthio, (C6-C20) aromatic thio, (C1-C20) alkylphosphine and (C6-C20) aromatic phosphine, and preferably, the alkyl group may be (C1-C20) alkyl or (C8-C20) alkyl, and the aryl group may be C6 to C12.

The term "olefin polymer" used herein refers to a polymer prepared using an olefin within the range that can be recognized by a person skilled in the art. Specifically, the olefin polymer includes both olefin homopolymers and olefin copolymers, and refers to olefin homopolymers or copolymers of olefins and α-olefins.

The present invention provides a transition metal compound represented by the following formula 1, which can be very useful in olefin polymerization because the solubility can be increased and the thermal stability can be improved by introducing a functional group having one or more controlled specific carbon atoms:

wherein M is a transition metal of Group 4 in the Periodic Table of the Elements; A is C or Si; Ar is a substituted aryl group; and the substituent of the aryl group of Ar is selected from one or more of the following groups: (C1-C20)alkyl, (C3-C20)cycloalkyl, (C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl, (C1-C20)alkoxy, (C6-C20)aryloxy, (C1-C20)alkylamino, (C6-C20)arylamino, (C1-C20)alkylthio and (C6-C20)arylthio and has 14 or more carbon atoms; R is (C1-C20)alkyl, (C1-C20)alkoxy, (C6-C20)aryl or (C6-C20)aryloxy; _R1 to R _{R 4} is each independently hydrogen or (C1-C20) alkyl; R ₁₁ to R ₁₈ are each independently hydrogen, (C1-C20) alkyl, (C1-C20) alkoxy, (C3-C20) cycloalkyl, (C6-C20) aryl, (C6-C20) aryl (C1-C20) alkyl, (C1-C20) alkyl (C6-C20) aryl, (C1-C20) alkylsilyl or (C6-C20) aromatic silyl, or each substituent may be linked to an adjacent substituent via a (C3-C12) alkylene or (C3-C12) alkenylene group which may or may not have a condensed ring to form an alicyclic ring or a monocyclic or polycyclic aromatic ring; R ₂₁ and R ₂₂ are each independently (C6-C20) aryl; and R is an alkyl, alkoxy, aryl or aryloxy group, R ₁₁ to R ₁₈ are an alkyl, alkoxy, cycloalkyl, aryl, aralkyl, alkaryl, alkanyl, aromatic silyl, alicyclic ring or aromatic ring, and R ₂₁ and R The aryl group of ₂₂ may be further substituted by one or more substituents selected from the group consisting of a (C1-C20)alkyl group, a (C3-C20)cycloalkyl group, a (C6-C20)aryl group, a (C6-C20)aryl(C1-C20)alkyl group, a (C1-C20)alkoxy group, a (C6-C20)aryloxy group, a (C3-C20)alkylsiloxy group, a (C6-C20)arylsiloxy group, a (C1-C20)alkylamino group, a (C6-C20)arylamino group, a (C1-C20)alkylthio group, a (C6-C20)arylthio group, a (C1-C20)alkylphosphine group, and a (C6-C20)arylphosphine group.

The transition metal compound according to the exemplary embodiment of the present invention is represented by Formula 1, and by introducing an intentionally controlled substituted aromatic group having 14 or more carbon atoms into Ar of Formula 1, it can have significantly improved solubility and extremely high catalytic activity in non-aromatic hydrocarbon solvents, and the olefin polymer can be prepared by an environmentally friendly simple process.

Specifically, the transition metal compound of the present invention as the ANSA-type catalyst of the present invention can increase the solubility in non-aromatic hydrocarbon solvents and maintain the catalytic activity by introducing a functional group with a controlled number of carbon atoms at a specific position, and at the same time, it is easy to prepare olefin polymers by a solution process.

Preferably, in Formula 1 according to the exemplary embodiment of the present invention, Ar may be a (C6-C20)aryl group substituted by an alkyl group having 8 or more carbon atoms; and R may be a (C1-C20)alkyl group, a (C1-C20)alkyl (C6-C20)aryloxy group or a (C6-C20)aryl (C1-C20)alkyl group.

In Formula 1 according to an exemplary embodiment of the present invention, Ar may be a (C6-C20) aryl group substituted with an alkyl group having 8 to 20 carbon atoms.

In Formula 1 according to the exemplary embodiment of the present invention, Ar may be a phenyl group, a naphthyl group, an anthracenyl group, a pyrenyl group, a phenanthrenyl group, a tetrasenyl group or a tetraphenyl group substituted with an alkyl group having 8 or more carbon atoms.

In Formula 1 according to an exemplary embodiment of the present invention, Ar may be a (C6-C20)aryl group substituted by an alkyl group having 8 or more carbon atoms; and R may be a (C1-C20)alkyl group, a (C1-C20)alkyl group (C6-C20)aryloxy group, or a (C6-C20)aryl group (C1-C20)alkyl group. Preferably, Ar may be a (C6-C12)aryl group substituted by an alkyl group having 8 or more carbon atoms; and R may be a (C1-C10)alkyl group, a (C1-C10)alkyl group (C6-C12)aryloxy group, or a (C6-C12)aryl group (C1-C10)alkyl group.

More preferably, in Formula 1 according to an exemplary embodiment of the present invention, M may be titanium, zirconium or einsteinium; each R may be independently (C1-C7)alkyl, (C8-C20)alkyl(C6-C12)aryloxy or (C6-C12)aryl(C1-C7)alkyl; _R1 to _R4 may be each independently hydrogen or (C1-C7)alkyl; and _R11 to _R18 may be hydrogen, and more preferably, M may be titanium; each R may be independently (C1-C4)alkyl, (C8-C15)alkyl(C6-C12)aryloxy or (C6-C12)aryl(C1-C4)alkyl; and _R1 to _R4 may be each independently hydrogen or (C1-C4)alkyl.

Preferably, the transition metal compound represented by Formula 1 according to the present invention can be represented by the following Formula 2 or Formula 3:

[Formula 3]

wherein M is titanium, zirconium or euryl; _Ar1 and _Ar2 are each independently a substituted (C6-C20)aryl group; and the substituent of the (C6-C20)aryl group of _Ar1 and _Ar2 is a (C1-C20)alkyl group, a (C3-C20)cycloalkyl group, a (C6-C20)aryl group, a (C6-C20)aryl group, a (C6-C20)aryl (C1-C20)alkyl group, a (C1-C20)alkoxy group, a (C6-C20)aryloxy group, a (C1-C20)alkylamino group, a (C6-C20)arylamino group, a (C1-C20)alkylthio group or a (C6-C20)arylthio group and has 14 or more carbon atoms; A is C or Si; _R1 to _R4 are each independently hydrogen or a (C1-C4)alkyl group; _R21 and R _{R 22} are each independently (C6-C20)aryl or (C6-C20)aryl substituted by (C1-C4)alkyl; and R ₃₁ is (C1-C20)alkyl or (C1-C20)alkyl(C6-C20)aryl.

In order to make the transition metal compound have excellent solubility, in Formula 2 or Formula 3, M may be titanium, zirconium or eurium; _Ar1 and _Ar2 may each independently be a (C6-C20)aryl group substituted by an alkyl group having 8 or more carbon atoms; and R may be a (C1-C20)alkyl group, a (C1-C20)alkyl(C6-C20)aryloxy group or a (C6-C20)aryl(C1-C20)alkyl group.

Preferably, in Formula 2 or Formula 3, M may be titanium, zirconium or arsenic; _Ar1 and _Ar2 may each independently be (C8-C20)alkyl(C6-C20)aryl; and R may be (C1-C7)alkyl, (C8-C20)alkyl(C6-C12)aryloxy or (C6-C12)aryl(C1-C7)alkyl, and more preferably, M may be titanium; _Ar1 and _Ar2 may each independently be (C8-C15)alkyl(C6-C12)aryl; and R may be (C1-C4)alkyl, (C8-C15)alkyl(C6-C12)aryloxy or (C6-C12)aryl(C1-C4)alkyl.

Preferably, in Formula 2 or Formula 3, _Ar1 and _Ar2 may each independently be a (C6-C20)aryl group substituted by an alkyl group having 8 or more carbon atoms; and R may be a (C1-C20)alkyl group, and more preferably, _Ar1 and _Ar2 may each independently be a (C6-C20)aryl group substituted by a (C8-C20)alkyl group; and R may be a (C1-C4)alkyl group.

In Formula 2 or Formula 3 according to the exemplary embodiment of the present invention, _Ar1 and _Ar2 may be (C6-C20)aryl groups substituted with an alkyl group having 8 or more carbon atoms, and preferably are phenyl, naphthyl, anthracenyl, pyrene, phenanthrenyl, tetraenyl or tetraphenyl groups substituted with a (C8-20)alkyl group.

Preferably, in Formula 2 or Formula 3 according to the exemplary embodiment of the present invention, the alkyl group substituted by Ar ₁ and Ar ₂ may be a straight chain (C1-C20) alkyl group rather than a branched chain (C1-C20) alkyl group, more preferably a straight chain (C8-C20) alkyl group, and even more preferably a straight chain (C8-C15) alkyl group.

Preferably, the transition metal compound according to the exemplary embodiment of the present invention can be represented by the following formula 4 or formula 5:

wherein M is titanium, zirconium or eurium; A is C or Si; R is (C1-C20) alkyl; _R1 to _R4 are each independently hydrogen or (C1-C4) alkyl; _R11 to R4 are each independently hydrogen or (C1-C4) alkyl; _{R 18} are each independently hydrogen, (C1-C20) alkyl, (C1-C20) alkoxy, (C3-C20) cycloalkyl, (C6-C30) aryl, (C6-C30) aryl (C1-C20) alkyl, (C1-C20) alkyl (C6-C30) aryl, (C1-C20) alkylsilyl or (C6-C30) aromatic silyl, or each substituent may be linked to an adjacent substituent via a (C3-C12) alkylene or (C3-C12) alkenylene group with or without a condensed ring to form an alicyclic ring or a monocyclic or polycyclic aromatic ring; R ₂₁ and R _{R 22} is each independently (C6-C20)aryl or (C6-C20)aryl substituted by (C1-C4)alkyl; and R ₃₁ to R ₄₀ are each independently (C1-C20)alkyl or (C6-C20)aryl.

Preferably, in Formula 4 according to the exemplary embodiment of the present invention, R ₃₁ to R ₄₀ may each independently be a (C1-C20) alkyl group, more preferably a linear (C1-C20) alkyl group, and even more preferably a linear (C8-C20) alkyl group.

The transition metal compound according to the exemplary embodiment of the present invention has high solubility in non-aromatic hydrocarbon solvents, and thus has good polymerization reactivity with other olefins while maintaining catalytic activity. It can prepare high molecular weight polymers in high yields and is more advantageous in a solution process that is very easy to commercialize.

Preferably, in Formula 4 and Formula 5 according to the exemplary embodiment of the present invention, M may be titanium, zirconium or euryl; A may be C; R may be each independently a (C1-C4)alkyl group; R ₁ to R ₄ may be each independently a hydrogen group or a C1-C4 alkyl group; R ₁₁ to R ₁₈ may be each independently a hydrogen group, a (C1-C20)alkyl group, a (C1-C20)alkoxy group or a (C6-C30)aryl group; R ₂₁ and R ₂₂ may be each independently a (C6-C12)aryl group or a (C6-C12)aryl group substituted with a C1-C4 alkyl group; and R ₃₁ to R ₄₀ may be each independently a (C1-C20)alkyl group.

In order to make the transition metal compound have better solubility, catalytic activity and reactivity with olefins, preferably, in Formula 4 and Formula 5 according to the exemplary embodiments of the present invention, R ₃₁ to R ₄₀ can each independently be a (C1-C20) alkyl group, and more preferably a linear (C1-C20) alkyl group, and specifically, R ₃₁ to R ₄₀ can be n-octyl, n-nonyl, n-decyl, n-undecyl or n-dodecyl.

Specifically, the transition metal compound according to the exemplary embodiment of the present invention can be a compound selected from the following structures, but is not limited thereto:

In addition, the present invention provides a transition metal catalyst composition for preparing olefin polymers, which comprises a transition metal compound according to the present invention and a co-catalyst.

According to the exemplary embodiment of the present invention, the co-catalyst may be a boron compound co-catalyst, an aluminum compound co-catalyst and a mixture thereof.

In addition, the present invention provides a method for preparing an olefin polymer using the transition metal compound according to the present invention, and the method for preparing an olefin polymer according to the present invention comprises: in the presence of a non-aromatic hydrocarbon solvent, a transition metal compound represented by the following formula 1, a cocatalyst, and one or two or more monomers selected from ethylene and comonomers are subjected to solution polymerization to obtain an olefin polymer:

wherein M is a transition metal of Group 4 in the Periodic Table of the Elements; A is C or Si; Ar is a substituted aryl group; and the substituent of the aryl group of Ar is selected from one or more of the following groups: (C1-C20)alkyl, (C3-C20)cycloalkyl, (C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl, (C1-C20)alkoxy, (C6-C20)aryloxy, (C1-C20)alkylamino, (C6-C20)arylamino, (C1-C20)alkylthio and (C6-C20)arylthio and has 14 or more carbon atoms; R is (C1-C20)alkyl, (C1-C20)alkoxy, (C6-C20)aryl or (C6-C20)aryloxy; _R1 to R _{R 4} is each independently hydrogen or (C1-C20) alkyl; R ₁₁ to R ₁₈ are each independently hydrogen, (C1-C20) alkyl, (C1-C20) alkoxy, (C3-C20) cycloalkyl, (C6-C20) aryl, (C6-C20) aryl (C1-C20) alkyl, (C1-C20) alkyl (C6-C20) aryl, (C1-C20) alkylsilyl or (C6-C20) aromatic silyl, or each substituent may be linked to an adjacent substituent via a (C3-C12) alkylene or (C3-C12) alkenylene group which may or may not have a condensed ring to form an alicyclic ring or a monocyclic or polycyclic aromatic ring; R ₂₁ and R _R21 to R18 are each independently (C6-C20) aryl; and R22 is an alkyl group, an alkoxy group, an aryl group or an aryloxy group, _R11 to _R18 are an alkyl group, an alkoxy group, a cycloalkyl group, an aryl group, an aralkyl group, an alkaryl group, an alkanyl group, an aromatic silyl group, an alicyclic ring or an aromatic ring, and _R21 and R The aryl group of ₂₂ may be further substituted with one or more substituents selected from the group consisting of a (C1-C20)alkyl group, a (C3-C20)cycloalkyl group, a (C6-C20)aryl group, a (C6-C20)aryl(C1-C20)alkyl group, a (C1-C20)alkoxy group, a (C6-C20)aryloxy group, a (C3-C20)alkylsiloxy group, a (C6-C20)arylsiloxy group, a (C1-C20)alkylamino group, a (C6-C20)arylamino group, a (C1-C20)alkylthio group, a (C6-C20)arylthio group, a (C1-C20)alkylphosphine group and a (C6-C20)arylphosphine group.

Preferably, the method for preparing an olefin polymer according to an exemplary embodiment of the present invention can easily prepare an olefin polymer while maintaining high activity by using a transition metal compound having high solubility in a non-aromatic hydrocarbon solvent as a catalyst.

The solubility of the transition metal compound according to the exemplary embodiment of the present invention at 25°C may be 1 wt% or more (solvent: methylcyclohexane), and preferably 1.2 wt% to 40 wt% at 25°C (solvent: methylcyclohexane).

Preferably, the non-aromatic hydrocarbon solvent according to the exemplary embodiment of the present invention may be, but is not limited to, one or two or more selected from the group consisting of: methylcyclohexane, cyclohexane, n-heptane, n-hexane and n-pentane, and preferably a mixed solvent of one or two or more selected from the group consisting of: methylcyclohexane, cyclohexane, n-heptane and n-hexane.

Preferably, the solubility of the non-aromatic hydrocarbon solvent according to the exemplary embodiment of the present invention at 25°C may be 1 wt% or more (solvent: methylcyclohexane), and more preferably 1.2 wt% to 40 wt% at 25°C (solvent: methylcyclohexane).

The co-catalyst according to the exemplary embodiment of the present invention may be an aluminum compound co-catalyst, a boron compound co-catalyst or a mixture thereof, and may be contained in a molar ratio of 0.5 to 10,000 per 1 mole of the transition metal compound.

Examples of the boron compound that can be used as the cocatalyst in the present invention include the boron compounds known in U.S. Patent No. 5,198,401, and specifically can be selected from the compounds represented by the following Formulae 11 to 14: [Formula 11] BR ²¹ ₃

[Formula 12] [R ²² ] ⁺ [BR ²¹ ₄ ] ^-

[Formula 13][R ²³ _p ZH] ⁺ [BR ²¹ ₄ ] ^-

wherein B is a boron atom; R ²¹ is a phenyl group, and the phenyl group may be further substituted by 3 to 5 substituents selected from the group consisting of a fluorine atom, a (C1-C20)alkyl group, a (C1-C20)alkyl group substituted by a fluorine atom, a (C1-C20)alkoxy group, or a (C1-C20)alkoxy group substituted by a fluorine atom; R ²² is a (C5-C7)aromatic group, a (C1-C20)alkyl(C6-C20)aryl group, or a (C6-C20)aryl(C1-C20)alkyl group; Z is a nitrogen or phosphorus atom; R ²³ is a (C1-C20)alkyl group or a phenylammonium group substituted by two (C1-C10)alkyl groups and a nitrogen atom; R ²⁴ is a (C5-C20)alkyl group; R ²⁵ is (C5-C20)aryl or (C1-C20)alkyl (C6-C20)aryl; and p is an integer of 2 or 3.

Preferred examples of the boron-based co-catalyst include trityl tetrakis(pentafluorophenyl)borate, tris(pentafluorophenyl)borane, tris(2,3,5,6-tetrafluorophenyl)borane, tris(2,3,4,5-tetrafluorophenyl)borane, tris(3,4,5-trifluorophenyl)borane, tris(2,3,4-trifluorophenyl)borane, phenylbis(pentafluorophenyl)borane, tetrakis(pentafluorophenyl)borate, tetrakis(2,3,5,6-tetrafluorophenyl)borate, tetrakis(2,3,4,5-tetrafluorophenyl)borate, tetrakis(3,4,5-trifluorophenyl)borate, tetrakis(2,2,4-trifluorophenyl)borate, phenylbis(pentafluorophenyl)borate or tetrakis(3,5-bis(trifluoromethylphenyl)borate. In addition, examples of specific combinations of boron-based co-catalysts include tetrakis(pentafluorophenyl)ferrocene borate, tetrakis(pentafluorophenyl)boric acid 1,1'-dimethylferrocene, tetrakis(pentafluorophenyl)boric acid silver, tetrakis(pentafluorophenyl)boric acid trityl, tetrakis(3,5-bis(trifluoromethylphenyl)boric acid trityl, tetrakis(pentafluorophenyl)boric acid triethylammonium, tetrakis(pentafluorophenyl)boric acid tripropylammonium, tetrakis(pentafluorophenyl)boric acid tri-n-butylammonium, tetrakis(3,5-bis(trifluoromethylphenyl)boric acid tri-n-butylammonium, tetrakis(pentafluorophenyl)boric acid N,N-dimethylphenylammonium, tetrakis(pentafluorophenyl)boric acid N,N-diethylphenylammonium, tetrakis(pentafluorophenyl)boric acid The preferred amine is N,N-2,4,6-pentamethylbenzoammonium tetrakis(pentafluorophenyl)boric acid, N,N-dimethylbenzoammonium tetrakis(3,5-bis(trifluoromethylphenyl)boric acid, diisopropylammonium tetrakis(pentafluorophenyl)boric acid, dicyclohexylammonium tetrakis(pentafluorophenyl)boric acid, triphenylphosphonium tetrakis(pentafluorophenyl)boric acid, trimethylbenzophosphonium tetrakis(pentafluorophenyl)boric acid or tris(dimethylbenzophosphonium tetrakis(pentafluorophenyl)boric acid, preferably any one or two or more selected from the group consisting of triphenylmethyl tetrakis(pentafluorophenyl)boric acid, N,N-dimethylbenzoammonium tetrakis(pentafluorophenyl)boric acid, triphenylmethyl tetrakis(pentafluorophenyl)boric acid and tris(pentafluoro)borane.

Examples of aluminum compounds that can be used as co-catalysts in the catalyst composition according to the exemplary embodiment of the present invention may include aluminoxane compounds of Formula 15 or 16, organic aluminum compounds of Formula 17, or organic aluminum alkyl oxides or organic aluminum aryl oxide compounds of Formula 18 or 19: [Formula 15] -AlR ²⁶ -O- _m

[Formula 17] R ²⁸ _r AlE _3-r

[Formula 18] R ²⁹ ₂ AlOR ³⁰

[Formula 19] R ²⁹ AlOR ³⁰ ₂

wherein R ²⁶ and R ²⁷ are each independently (C1-C20) alkyl, m and q are integers from 5 to 20; R ²⁸ and R ²⁹ are each independently (C1-C20) alkyl; E is a hydrogen atom or a halogen atom; r is an integer between 1 and 3; and R ³⁰ is (C1-C20) alkyl or (C6-C30) aryl.

Specific examples of aluminum compounds that can be used include methylaluminium oxide, modified methylaluminium oxide or tetraisobutylaluminium oxide as examples of aluminum oxide compounds; trialkylaluminiums including trimethylaluminium, triethylaluminium, tripropylaluminium, triisobutylaluminium and trihexylaluminium; dialkylaluminium chlorides including dimethylaluminium chloride, diethylaluminium chloride, dipropylaluminium chloride, diisobutylaluminium chloride and dihexylaluminium chloride; alkylaluminium dichlorides including methylaluminium dichloride, ethylaluminium dichloride, propylaluminium dichloride, isobutylaluminium dichloride and hexylaluminium dichloride; dialkylaluminium hydrides including dimethylaluminium hydride, diethylaluminium hydride, dipropylaluminium hydride, Aluminum, diisobutylaluminum hydroxide and dihexylaluminum hydroxide; and alkylaluminum alkoxy, including methyldimethoxyaluminum, dimethylmethoxyaluminum, ethyldiethoxyaluminum, diethylethoxyaluminum, isobutyldibutoxyaluminum, diisobutylbutoxyaluminum, hexyldimethoxyaluminum, dihexylmethoxyaluminum and dioctylmethoxyaluminum as examples of organic aluminum compounds, preferably one selected from the group consisting of methylaluminum oxide, modified methylaluminum oxide, tetraisobutylaluminum oxide, trialkylaluminum, triethylaluminum and triisobutylaluminum or a mixture thereof, and more preferably trialkylaluminum, and even more preferably triethylaluminum and triisobutylaluminum.

Preferably, in the catalyst composition according to the exemplary embodiment of the present invention, the molar ratio of the metal (M) of the aluminum compound co-catalyst: aluminum atom (Al) is 1:50 to 1:5,000, and the ratio between the transition metal compound of Formula 1 and the co-catalyst has a molar ratio of metal (M): boron atom: aluminum atom in the preferred range of 1:0.1 to 100:10 to 1,000, and a more preferred range of 1:0.5 to 5:25 to 500.

As another aspect of an exemplary embodiment of the present invention, the method for preparing an olefin polymer using a transition metal compound can be carried out by contacting a transition metal compound, a cocatalyst and ethylene or, if necessary, a vinyl-based copolymer monomer in the presence of a non-aromatic hydrocarbon solvent. In this case, the transition metal compound and the cocatalyst components can be injected into the reactor separately, or can be injected into the reactor by premixing each component, and there is no limitation on the mixing conditions, such as injection order, temperature or concentration.

Preferred organic solvents that can be used in the above preparation method may be non-aromatic hydrocarbon solvents, and preferably non-aromatic (C3-C20) hydrocarbons, and specific examples thereof are butane, isobutane, pentane, hexane, heptane, octane, isooctane, nonane, decane, dodecane, cyclohexane, methylcyclohexane, etc.

Specifically, in the case of preparing a copolymer of ethylene and an α-olefin, the (C3-C18) α-olefin may be used as a comonomer together with ethylene, and may be preferably selected from propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-heptene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octene and 1-octadecene. More preferably, 1-butene, 1-hexene, 1-octene or 1-decene may be copolymerized with ethylene. In this case, for a preferred reactor pressure and polymerization temperature, the pressure may be 1 to 1000 atm, and more preferably 10 to 150 atm. In addition, it is effective to carry out the polymerization reaction at a temperature between 100°C and 200°C, and preferably between 100°C and 150°C.

In addition, the copolymer prepared according to the method of the present invention may have an ethylene content of 30% to 99% by weight, preferably 50% or more by weight of ethylene, more preferably 60% or more by weight of ethylene, and still more preferably 60% to 99% by weight of ethylene.

The ethylene content contained in the olefin polymer of the present invention is confirmed by a method of converting the comonomer content from a value measured by ¹³ C-nuclear magnetic resonance (NMR) spectroscopy.

As described above, by using (C4-C10) α-olefins as comonomers to prepare linear low density polyethylene (LLDPE) having a density region of 0.940 g/cc or less, this can be extended to the region of very low density polyethylene (VLDPE) or ultra low density polyethylene (ULDPE) or olefin elastomers having a density of 0.900 g/cc or less. In addition, in order to adjust the molecular weight in the preparation of the ethylene copolymer according to the present invention, hydrogen can be used as a molecular weight regulator, and the ethylene copolymer generally has a weight average molecular weight (Mw) in the range of 80,000 g/mol to 500,000 g/mol.

As a specific example of an olefin-diene copolymer prepared by the catalyst composition according to an exemplary embodiment of the present invention, an ethylene-propylene-diene copolymer having an ethylene content of 30 to 80 wt %, a propylene content of 20 to 70 wt % and a diene content of 0 to 15 wt % can be prepared. The diene monomers that can be used in the present invention have two or more double bonds, and examples thereof include 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,5-heptadiene, 1,6-heptadiene, 1,6-octadiene, 1,7-octadiene, 1,7-nonadiene, 1,8-nonadiene, 1,8-decadiene, 1,9-decadiene, 1,12-tetradecadiene, 1,13-tetradecadiene, 2-methyl-1,3-butadiene, 3-methyl-1,4-hexadiene, 3-methyl-1,5-hexadiene, 3-ethyl-1,4-hexadiene, 3-ethyl-1,5-hexadiene, 3,3-dimethyl-1,4- Hexadiene, 3,3-dimethyl-1,5-hexadiene, cyclopentene, cyclohexene, cyclopentadiene, cyclohexadiene, norbornene, 5-vinyl-2-norbornene, 2,5-norbornadiene, 7-methyl-2,5-norbornadiene, 7-ethyl-2,5-norbornadiene, 7-propyl-2,5-norbornadiene, 7-butyl-2,5-norbornadiene, 7-pentyl-2,5-norbornadiene, 7-hexyl-2,5-norbornadiene, 7,7-dimethyl-2,5-norbornadiene, 7-methyl-7-ethyl-2,5-norbornadiene, 7-chloro-2,5-norbornadiene, 7-bromo-2,5-norbornadiene 2,5-norbornadiene, 7-fluoro-2,5-norbornadiene, 7,7-dichloro-2,5-norbornadiene, 1-methyl-2,5-norbornadiene, 1-ethyl-2,5-norbornadiene, 1-propyl-2,5-norbornadiene, 1-butyl-2,5-norbornadiene, 1-chloro-2,5-norbornadiene, 1-bromo-2,5-norbornadiene, 5-isopropyl-2-norbornene, 1,4-cyclohexadiene, bicyclo[2,2,1]hept-2,5-diene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, bicyclo[2,2,2]oct-2,5-diene, 4-vinylcyclohex-1-ene , bicyclo[2,2,2]oct-2,6-diene, 1,7,7-trimethylbicyclo[2,2,1]hept-2,5-diene, dicyclopentadiene, phenethyltetrahydroindene, 5-arylbicyclo[2,2,1]hept-2-ene, 1,5-cyclooctadiene, 1,4-diarylbenzene, butadiene, isoprene, 2,3-dimethylbutadiene-1,3, 1,2-butadiene-1,3, 4-methylpentadiene-1,3, 1,3-pentadiene, 3-methyl-1,3-pentadiene, 2,4-dimethyl-1,3-pentadiene, 3-ethyl-1,3-pentadiene, etc., and the most preferred are 5-ethylidene-2-norbornene and dicyclopentadiene. The diene monomer can be selected according to the processing characteristics of the ethylene-propylene-diene copolymer, and if necessary, it can be used by mixing two or more diene monomers.

In this case, as for the preferred pressure and temperature of the reactor, the pressure is 1 to 1000 atm, preferably 6 to 150 atm, and more preferably 5 to 100 atm. In addition, it is effective that the polymerization reaction is carried out at a temperature between 100 and 200°C, preferably between 100 and 150°C.

In the ethylene-olefin-diene copolymer prepared according to the exemplary embodiment of the present invention, the ethylene content may be 30 wt% to 80 wt%, the olefin content may be 20 wt% to 70 wt%, and the diene content may be 0 wt% to 15 wt%.

Generally, when preparing ethylene-propylene-diene copolymers, increasing the propylene content results in a decrease in the molecular weight of the copolymer. However, when preparing the ethylene-propylene-diene copolymer according to the present invention, it is possible to prepare a product having a relatively high molecular weight without decreasing the molecular weight even if the propylene content is increased by 50%.

Since the catalyst composition proposed in the present invention exists in a homogeneous form in the polymerization reactor, it is preferably used in a solution polymerization process at a temperature equal to or higher than the melting point of the polymer. However, as disclosed in U.S. Patent No. 4,752,597, the catalyst composition can also be used in a slurry polymerization or gas phase polymerization process in the form of a heterogeneous catalyst composition obtained by loading a transition metal compound and a co-catalyst on a porous metal oxide support.

Hereinafter, the present invention will be described in detail by the following examples, but the scope of the present invention is not limited thereto.

Unless otherwise stated, all experiments for synthesizing transition metal compounds were performed under nitrogen atmosphere using standard Schlenk or glove box techniques, and organic solvents used in the reaction were refluxed under sodium metal and benzophenone to remove water and were distilled immediately before use. ¹ H NMR analysis of synthesized transition metal compounds was performed at room temperature using a Bruker 400 or 500 MHz.

n-Heptane was used as the polymerization solvent after passing through a tube equipped with a 5Å molecular sieve and activated alumina and bubbling with high-purity nitrogen to fully remove water, oxygen and other catalyst poisons. The polymerized polymer was analyzed by the following method:

1. Melt flow index (MI)

The melt flow index was measured using the ASTM D1238 analysis method at 190°C and a load of 2.16 kg.

2. Density

Density is measured by ASTM D792 analysis method.

3. Molecular weight and molecular weight distribution

The molecular weight was measured by gel chromatography using a three-stage mixing column. In this case, the solvent used was 1,2,4-trichlorobenzene and the measurement temperature was 120°C.

[Example 1] Synthesis of transition metal compound 1

Under nitrogen atmosphere, 9-fluorenyl 1-diphenylmethyl cyclopentadienyl zirconium dichloride (produced by S-PCI, 10.0 g, 18.0 mmol) was dissolved in 100 mL of toluene in a 250 mL round flask. After the temperature dropped to -15°C, 1.5 M methyl lithium (24.0 mL, 35.9 mmol) was slowly injected therein, and the temperature was raised to room temperature, followed by stirring for 3 hours. The reaction mixture was vigorously stirred while adding 4-dodecylphenol (4.72 g, 18.0 mmol), and stirred at 60°C for 3 hours, followed by removal of the solvent under vacuum. The concentrate was dissolved in 200 mL of n-hexane, and then filtered through a filter filled with dry diatomaceous earth to remove the solid. All solvents in the filtrate were removed to obtain yellow transition metal compound 1 (13.2 g, yield: 91.7%).

¹ H NMR (CDCl ₃ ,500MHz): δ=8.17(d,1H),8.10(d,1H),7.98(d,1H),7.87(d,2H),7.78(d,1H), 7.40(m,2H),7.31(m,2H),7.25(m,3H),7.08(m,2H),6.92(t,1H),6.80(t,1H),6 .67(d,1H),6.43(d,1H),6.30(d,1H),6.24(d,1H),6.08(d,1H),5.79(m,2H),5. 61(dd,2H),2.64(t,2H),1.62(m,2H),1.31(m,18H),0.87(m,3H),-1.36(s,3H).

[Example 2] Preparation of transition metal compound 2

Transition metal compound 2 (18.7 g, yield: 95.4%) was prepared in the same manner as Example 1, except that 4-pentadecylphenol was used instead of 4-dodecylphenol in Example 1.

¹ H NMR (CDCl ₃ ,500MHz): δ=8.16(d,1H),8.10(d,1H),7.95(d,1H),7.88(d,2H),7.78(d,1H), 7.39(m,2H),7.30(m,2H),7.25(m,3H),7.08(m,2H),6.92(t,1H),6.78(t,1H),6 .65(d,1H),6.41(d,1H),6.29(d,1H),6.24(d,1H),6.05(d,1H),5.79(m,2H),5. 60(dd,2H),2.65(t,2H),1.63(m,2H),1.30(m,24H),0.88(m,3H),-1.35(s,3H).

[Example 3] Preparation of transition metal compound 3

In a 250 mL round flask under a nitrogen atmosphere, 9-fluorenyl 1-diphenylmethylcyclopentadienyl zirconium dichloride (produced by S-PCI, 10.0 g, 18.0 mmol) was dissolved in 100 mL of toluene. After the temperature dropped to -15°C, 1.5 M methyl lithium (24.0 mL, 35.9 mmol) was slowly injected therein, and the temperature was raised to room temperature, followed by stirring for 3 hours. 4-(2,4,4,-trimethylpentan-2-yl)phenol (7.41 g, 35.9 mmol) was added thereto under vigorous stirring, and stirred at 60°C for 3 hours, and the solvent was removed under reduced pressure. The resulting mixture was dissolved in 200 mL of n-hexane and then filtered through a filter filled with dry diatomaceous earth to remove the solid. All solvents in the filtrate were removed to obtain a yellow transition metal compound 3 (15.5 g, yield 96.3%).

¹ H NMR (CDCl ₃ ,500MHz): δ=8.24(d,2H),7.95(dd,4H),7.45(t,2H),7.35(m,4H),7.21(m,2H),7.05(t,2H),6.87( t,2H),6.71(d,2H),6.48(d,2H), 6.05(m,2H),5.98(m,4H),5.85(m,2H),1.36(s,4H),0.92(s,30H).

[Example 4] Preparation of transition metal compound 4

Transition metal compound 4 (17.3 g, yield: 95.5%) was prepared in the same manner as Example 3, except that 4-dodecylphenol was used instead of 4-(2,4,4-trimethylpentan-2-yl)phenol in Example 3.

¹ H NMR (CDCl ₃ ,500MHz): δ=8.25(d,2H),7.94(dd,4H),7.45(t,2H),7.35(m,4H),7.20(m,2H),7.08(t,2H),6.88( t,2H),6.70( d,2H),6.47(d,2H),6.03(m,2H),5.98(m,4H),5.85(m,2H),2.64(t,4H),1.62(m,4H),1.31(m ,36H),0.87(m,6H).

[Example 5] Preparation of transition metal compound 5

Transition metal compound 5 (19.1 g, yield: 97.4%) was prepared in the same manner as Example 3, except that 3-pentadecylphenol was used instead of 4-(2,4,4-trimethylpentan-2-yl)phenol in Example 3.

¹ H NMR (CDCl ₃ ,500MHz): δ=8.24(d,2H),7.94(dd,4H),7.45(t,2H),7.35(m,4H),7.22(m,2H),7.09(t,2H),6.88( t,2H), 6.71(d,2H),6.47(d,2H),6.03(m,2H),5.99(m,4H),5.85(m,2H),2.63(t,4H),1.63(m,4H),1.30 (m,48H), 0.89(m,6H).

[Comparative Example 1] Compounds of Comparative Example 1

The compound of Comparative Example 1 was purchased from S-PCI and used.

[Comparative Example 2] Preparation of the compound in Comparative Example 2

Under nitrogen atmosphere, 9-fluorenyl 1-diphenylmethyl cyclopentadienyl zirconium dichloride (produced by S-PCI, 10.0 g, 18.0 mmol) was dissolved in 100 mL of toluene in a 250 mL round flask. After the temperature dropped to -15°C, 1.5 M methyl lithium (24.0 mL, 35.9 mmol) was slowly added thereto, and the temperature was raised to room temperature, stirred for 3 hours, and filtered through a filter filled with dry diatomaceous earth to remove the solid. After filtration, all solvents in the filtrate were removed to obtain the yellow compound of Comparative Example 2 (8.5 g, yield: 91.4%).

¹ H NMR (CDCl ₃ ,500MHz): δ=8.20(d,2H),7.85(dd,4H),7.41(m,4H),7.28(m,4H),6.89(m,2H),6.28(m ,4H),5.54(m,2H),-1.69(s,6H).

[Comparative Example 3] Preparation of the compound of Comparative Example 3

The compound of Comparative Example 3 (12.8 g, yield: 91.4%) was prepared in the same manner as Example 3, except that 4-tert-butylphenol was used instead of 4-(2,4,4-trimethylpentan-2-yl)phenol in Example 3.

¹ H NMR (CDCl ₃ ,500MHz): δ=8.24(d,2H),7.94(dd,4H),7.45(t,2H),7.35(m,4H),7.22(m,2H),7.09(t,2H), 6.88(t,2H),6.70(d,2H),6.47(d,2H),6.03(m,2H),5.99(m,4H),5.85(m,2H),1.30(t,18H).

<Measurement of the solubility of the prepared transition metal compound>

Under nitrogen atmosphere, 1 g of the transition metal compound was dissolved in 4 g of each solvent described in the following table at 25°C to prepare a saturated solution, followed by removal of the solid using a 0.45 μm filter. The weight of the remaining catalyst was measured by removing all the solvent, and the solubility of the catalyst was calculated therefrom and is shown in Table 1 below.

As shown in Table 1, it can be seen that the transition metal compounds prepared in Examples 1, 2, 4 and 5 of the present invention show surprisingly good solubility in non-aromatic hydrocarbon solvents.

[Examples 6 to 8 and Comparative Examples 4 and 5] Copolymerization of ethylene and 1-octene using a batch polymerization apparatus.

The copolymerization of ethylene and 1-octene was carried out using a batch polymerization apparatus as follows.

After sufficient drying, 600 mL of heptane and 60 mL of 1-octene were added to a 1,500 mL stainless steel reactor replaced with nitrogen, and then 2 mL of triisobutylaluminum (1.0 M hexane solution) was added to the reactor. Thereafter, after heating the reactor, 1.0 wt% of the transition metal compound prepared in Examples 2, 3, 5 and Comparative Examples 1 and 2, 0.7 mL of toluene solution and 1.8 g of modified methylaluminoxane (20 wt%, heptane solution manufactured by Nouryon) were added thereto in sequence, ethylene was fed so that the pressure in the reactor was 10 kg/cm ² , and then ethylene was continuously supplied to carry out polymerization. After the reaction was allowed to proceed for 5 minutes, the recovered reaction product was dried in a vacuum oven at 40° C. for 8 hours. The reaction temperature, ΔT, catalytic activity, density and molecular weight are shown in Table 2 below.

As shown in Table 2, it can be seen that in the copolymerization of ethylene and 1-octene, the transition metal compound according to the present invention exhibits an activity equivalent to or higher than that of the transition metal catalysts in Comparative Examples 4 and 5.

[Examples 9 and 10 and Comparative Example 6] Copolymerization of ethylene and 1-octene by continuous solution polymerization process

The copolymerization of ethylene and 1-octene is carried out using a continuous polymerization apparatus as follows:

The transition metal compounds prepared in Examples 2 and 5 and Comparative Example 2 were used as catalysts, heptane was used as a solvent, and the amount of the catalyst used was as described in Table 3 below. Zr represents the catalyst, and Al represents modified methylaluminoxane (20% by weight, Nouryon) as a cocatalyst. Each catalyst was dissolved in toluene at a concentration of 0.2 g/l and added, and 1-octene was used as a comonomer for synthesis. When polymerization was performed with one polymer under each reaction condition, the conversion rate of the reactor can be assumed by the reaction conditions and the temperature gradient in the reactor. In the case of a single active site catalyst, the molecular weight was controlled by varying the reactor temperature and the 1-octene content, and the conditions and results are described in Table 3 below.

Zr refers to the Zr in the catalyst.

Al represents modified methylaluminoxane as a cocatalyst.

As can be seen from Table 3, compared with Comparative Example 6 using the transition metal compound prepared in Comparative Example 2, Examples 9 and 10 using the transition metal compound according to the present invention as a catalyst have better ethylene conversion, lower density and lower MI value, so that when the transition metal compound according to the present invention is used as a catalyst, it is easy to prepare a polymer with superior physical properties and high molecular weight.

[Examples 11 and 12] Copolymerization of ethylene and 1-octene at high temperature by continuous solution polymerization process

The copolymerization of ethylene and 1-octene is carried out at high temperature using a continuous polymerization apparatus as follows:

The transition metal compound prepared in Example 2 was used as a catalyst, heptane was used as a solvent, and the amount of the catalyst used was as described in Table 4 below. Zr represents the catalyst, B represents N,N-dioctadecylphenylammonium tetrakis(pentafluorophenyl)borate as a cocatalyst, and Al represents triisobutylaluminum as a cocatalyst. Each catalyst was dissolved in toluene at a concentration of 0.2 g/l and injected, and 1-octene was used as a comonomer for synthesis. When polymerization was performed with one polymer under each reaction condition, the conversion rate of the reactor can be assumed by the reaction conditions and the temperature gradient in the reactor. In the case of a single active site catalyst, the molecular weight was controlled by varying the reactor temperature and 1-octene content, and the conditions and results are described in Table 4 below.

Zr refers to the Zr in the catalyst.

B represents tetrakis(pentafluorophenyl)boric acid N,N-dioctadecyltetraoctylphenylammonium as a cocatalyst.

Al represents triisobutylaluminum as a cocatalyst.

As can be seen from Table 4, Examples 11 and 12 using the transition metal compound according to the present invention as a catalyst have excellent catalytic activity even at high temperatures, so that when the transition metal compound according to the present invention is used as a catalyst, the polymerization reaction can be carried out more easily under various reaction conditions.

By introducing controlled specific functional groups, the transition metal compound according to the present invention has significantly improved solubility in non-aromatic hydrocarbon solvents, resulting in high catalytic activity and remaining unchanged without degradation during solution polymerization.

In addition, by introducing specific functional groups at specific positions, the transition metal compound according to the present invention can be easily injected and transferred in the solution process, thereby significantly improving the polymerization process, which is very beneficial for commercialization.

In addition, the transition metal compound according to the present invention has excellent solubility in non-aromatic hydrocarbon solvents and has excellent reactivity with olefins, making the polymerization of olefins very easy and the yield of olefin polymers high.

Therefore, the catalyst composition comprising a transition metal compound according to the exemplary embodiment of the present invention can be very useful for preparing olefin polymers having excellent physical properties.

In addition, the method for preparing olefin polymers according to the present invention uses the transition metal compound according to the present invention having excellent solubility in non-aromatic hydrocarbon solvents as a catalyst, so that the catalyst can be easily transferred and injected, and the olefin polymer can be prepared in a more environmentally friendly and efficient manner.

As described above, although the present invention has been described in detail with respect to the exemplary embodiments of the present invention, a person skilled in the art may make various changes to the present invention without departing from the spirit and scope of the present invention, as defined in the scope of the following patent application. Therefore, further modifications in the embodiments of the present invention will not depart from the technology of the present invention.

without.

Claims (16)

A transition metal compound represented by the following formula 1,

wherein M is titanium, zirconium or einsteinium; A is C or Si; Ar is a substituted aryl group, and the substituent of the aryl group of Ar is one or more selected from the group consisting of: (C1-C20)alkyl, (C3-C20)cycloalkyl, (C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl, (C1-C20)alkoxy, (C6-C20)aryloxy, (C1-C20)alkylamino, (C6-C20)arylamino, (C1-C20)alkylthio and (C6-C20)arylthio and has 14 or more carbon atoms; R is (C1-C20)alkyl, (C1-C20)alkoxy, (C6-C20)aryl or (C6-C20)aryloxy; _R1 to R _{R 4} is each independently hydrogen or (C1-C20) alkyl; R ₁₁ to R ₁₈ are each independently hydrogen, (C1-C20) alkyl, (C1-C20) alkoxy, (C3-C20) cycloalkyl, (C6-C20) aryl, (C6-C20) aryl (C1-C20) alkyl, (C1-C20) alkyl (C6-C20) aryl, (C1-C20) alkylsilyl or (C6-C20) aromatic silyl, or each substituent may be linked to an adjacent substituent via a (C3-C12) alkylene or (C3-C12) alkenylene group which may or may not have a condensed ring to form an alicyclic ring or a monocyclic or polycyclic aromatic ring; R ₂₁ and R ₂₂ are each independently (C6-C20) aryl; and R is an alkyl, alkoxy, aryl or aryloxy group, R ₁₁ to R ₁₈ are an alkyl, alkoxy, cycloalkyl, aryl, aralkyl, alkaryl, alkanyl, aromatic silyl, alicyclic ring or aromatic ring, and R ₂₁ and R The aryl group of ₂₂ may be further substituted by one or more substituents selected from the group consisting of a (C1-C20)alkyl group, a (C3-C20)cycloalkyl group, a (C6-C20)aryl group, a (C6-C20)aryl(C1-C20)alkyl group, a (C1-C20)alkoxy group, a (C6-C20)aryloxy group, a (C3-C20)alkylsiloxy group, a (C6-C20)arylsiloxy group, a (C1-C20)alkylamino group, a (C6-C20)arylamino group, a (C1-C20)alkylthio group, a (C6-C20)arylthio group, a (C1-C20)alkylphosphine group, and a (C6-C20)arylphosphine group. The transition metal compound as described in claim 1, wherein in the aforementioned formula 1, Ar is a (C6-C20)aryl group substituted by an alkyl group having 8 or more carbon atoms; and R is a (C1-C20)alkyl group, a (C1-C20)alkyl (C6-C20)aryloxy group or a (C6-C20)aryl (C1-C20)alkyl group. A transition metal compound as described in claim 1, wherein in the aforementioned formula 1, each R is independently (C1-C4)alkyl, (C8-C20)alkyl(C6-C12)aryloxy or (C6-C12)aryl(C1-C4)alkyl; _R1 to _R4 are each independently hydrogen or (C1-C4)alkyl; and _R11 to _R18 are hydrogen. The transition metal compound as claimed in claim 1, wherein the transition metal compound of the aforementioned formula 1 is represented by the following formula 2 or formula 3:

[Formula 3]

wherein M is titanium, zirconium or euryl; _Ar1 and _Ar2 are each independently a substituted (C6-C20)aryl group; and the substituent of the (C6-C20)aryl group of _Ar1 and _Ar2 is a (C1-C20)alkyl group, a (C3-C20)cycloalkyl group, a (C6-C20)aryl group, a (C6-C20)aryl group, a (C6-C20)aryl (C1-C20)alkyl group, a (C1-C20)alkoxy group, a (C6-C20)aryloxy group, a (C1-C20)alkylamino group, a (C6-C20)arylamino group, a (C1-C20)alkylthio group or a (C6-C20)arylthio group and has 14 or more carbon atoms; A is C or Si; _R1 to _R4 are each independently hydrogen or a (C1-C4)alkyl group; _R21 and R _{R 22} is each independently (C6-C20)aryl or (C6-C20)aryl substituted by (C1-C4)alkyl; and R ₃₁ is (C1-C20)alkyl or (C6-C20)aryl(C1-C20)alkyl. The transition metal compound as described in claim 1, wherein the transition metal compound is selected from the following compounds:

The transition metal compound as described in claim 1, wherein the transition metal compound has a solubility of 1 wt% or more in methylcyclohexane solvent at 25°C. A transition metal catalyst composition for preparing an ethylene homopolymer or a copolymer of ethylene and an α-olefin, comprising: a transition metal compound represented by the following formula 1; and a cocatalyst;

wherein M is titanium, zirconium or einsteinium; A is C or Si; Ar is a substituted aryl group, and the substituent of the aryl group of Ar is one or more selected from the group consisting of: (C1-C20)alkyl, (C3-C20)cycloalkyl, (C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl, (C1-C20)alkoxy, (C6-C20)aryloxy, (C1-C20)alkylamino, (C6-C20)arylamino, (C1-C20)alkylthio and (C6-C20)arylthio and has 14 or more carbon atoms; R is (C1-C20)alkyl, (C1-C20)alkoxy, (C6-C20)aryl or (C6-C20)aryloxy; _R1 to R _{R 4} is each independently hydrogen or (C1-C20) alkyl; R ₁₁ to R ₁₈ are each independently hydrogen, (C1-C20) alkyl, (C1-C20) alkoxy, (C3-C20) cycloalkyl, (C6-C20) aryl, (C6-C20) aryl (C1-C20) alkyl, (C1-C20) alkyl (C6-C20) aryl, (C1-C20) alkylsilyl or (C6-C20) aromatic silyl, or each substituent may be linked to an adjacent substituent via a (C3-C12) alkylene or (C3-C12) alkenylene group which may or may not have a condensed ring to form an alicyclic ring or a monocyclic or polycyclic aromatic ring; R ₂₁ and R ₂₂ are each independently (C6-C20) aryl; and R is an alkyl, alkoxy, aryl or aryloxy group, R ₁₁ to R ₁₈ are an alkyl, alkoxy, cycloalkyl, aryl, aralkyl, alkaryl, alkanyl, aromatic silyl, alicyclic ring or aromatic ring, and R ₂₁ and R The aryl group of ₂₂ may be further substituted by one or more substituents selected from the group consisting of a (C1-C20)alkyl group, a (C3-C20)cycloalkyl group, a (C6-C20)aryl group, a (C6-C20)aryl(C1-C20)alkyl group, a (C1-C20)alkoxy group, a (C6-C20)aryloxy group, a (C3-C20)alkylsiloxy group, a (C6-C20)arylsiloxy group, a (C1-C20)alkylamino group, a (C6-C20)arylamino group, a (C1-C20)alkylthio group, a (C6-C20)arylthio group, a (C1-C20)alkylphosphine group, and a (C6-C20)arylphosphine group. The transition metal catalyst composition as described in claim 7, wherein the aforementioned co-catalyst is an aluminum compound co-catalyst, a boron compound co-catalyst or a mixture thereof. A method for preparing an olefin polymer comprises the following steps: obtaining an olefin polymer by solution polymerization of a transition metal compound represented by the following formula 1, a cocatalyst and one or two or more monomers selected from ethylene and comonomers in the presence of a non-aromatic hydrocarbon solvent,

wherein M is titanium, zirconium or einsteinium; A is C or Si; Ar is a substituted aryl group, and the substituent of the aryl group of Ar is selected from one or more of the following groups: (C1-C20)alkyl, (C3-C20)cycloalkyl, (C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl, (C1-C20)alkoxy, (C6-C20)aryloxy, (C1-C20)alkylamino, (C6-C20)arylamino, (C1-C20)alkylthio and (C6-C20)arylthio and has 14 or more carbon atoms; R is (C1-C20)alkyl, (C1-C20)alkoxy, (C6-C20)aryl or (C6-C20)aryloxy; _R1 to R _{R 4} is each independently hydrogen or (C1-C20) alkyl; R ₁₁ to R ₁₈ are each independently hydrogen, (C1-C20) alkyl, (C1-C20) alkoxy, (C3-C20) cycloalkyl, (C6-C20) aryl, (C6-C20) aryl (C1-C20) alkyl, (C1-C20) alkyl (C6-C20) aryl, (C1-C20) alkylsilyl or (C6-C20) aromatic silyl, or each substituent may be linked to an adjacent substituent via a (C3-C12) alkylene or (C3-C12) alkenylene group which may or may not have a condensed ring to form an alicyclic ring or a monocyclic or polycyclic aromatic ring; R ₂₁ and R ₂₂ are each independently (C6-C20) aryl; and R is an alkyl, alkoxy, aryl or aryloxy group, R ₁₁ to R ₁₈ are an alkyl, alkoxy, cycloalkyl, aryl, aralkyl, alkaryl, alkanyl, aromatic silyl, alicyclic ring or aromatic ring, and R ₂₁ and R The aryl group of ₂₂ may be further substituted by one or more substituents selected from the group consisting of a (C1-C20)alkyl group, a (C3-C20)cycloalkyl group, a (C6-C20)aryl group, a (C6-C20)aryl(C1-C20)alkyl group, a (C1-C20)alkoxy group, a (C6-C20)aryloxy group, a (C3-C20)alkylsiloxy group, a (C6-C20)arylsiloxy group, a (C1-C20)alkylamino group, a (C6-C20)arylamino group, a (C1-C20)alkylthio group, a (C6-C20)arylthio group, a (C1-C20)alkylphosphine group, and a (C6-C20)arylphosphine group. The method as described in claim 9, wherein the aforementioned non-aromatic hydrocarbon solvent is one or two or more selected from the group consisting of: methylcyclohexane, cyclohexane, n-heptane, n-hexane, n-butane, isobutane, n-pentane, n-octane, iso-octane, nonane, decane and dodecane. The method as described in claim 9, wherein the transition metal compound has a solubility of 1 wt% or more in a non-aromatic hydrocarbon solvent at 25°C, wherein the solvent is methylcyclohexane. The method as described in claim 9, wherein the aforementioned co-catalyst is an aluminum compound co-catalyst, a boron compound co-catalyst or a mixture thereof. The method of claim 12, wherein the boron compound co-catalyst is a compound represented by the following formula 11 to formula 14, and the aluminum compound co-catalyst is a compound represented by the following formula 15 to formula 19: [Formula 11] BR ²¹ ₃ [Formula 12] [R ²² ] ⁺ [BR ²¹ ₄ ] ^- [Formula 13] [R ²³ _p ZH] ⁺ [BR ²¹ ₄ ] ^-

wherein B is a boron atom; R ²¹ is a phenyl group, and the phenyl group may be further substituted by 3 to 5 substituents selected from the group consisting of a fluorine atom, a (C1-C20)alkyl group, a (C1-C20)alkyl group substituted by a fluorine atom, a (C1-C20)alkoxy group, or a (C1-C20)alkoxy group substituted by a fluorine atom; R ²² is a (C5-C7)aromatic group, a (C1-C20)alkyl group (C6-C20)aryl group, or a (C6-C20)aryl group (C1-C20)alkyl group; Z is a nitrogen or phosphorus atom; R ²³ is a (C1-C20)alkyl group or a phenyl group substituted by two (C1-C10)alkyl groups and a nitrogen atom; R ²⁴ is a (C5-C20)alkyl group; R ²⁵ is (C5-C20)aryl or (C1-C20)alkyl (C6-C20)aryl; and p is an integer of 2 or 3, [Formula 15] -AlR ²⁶ -O- _m

[Formula 17] R ²⁸ _r AlE _3-r [Formula 18] R ²⁹ ₂ AlOR ³⁰ [Formula 19] R ²⁹ AlOR ³⁰ ₂ wherein R ²⁶ and R ²⁷ are each independently a (C1-C20) alkyl group, m and q are integers from 5 to 20; R ²⁸ and R ²⁹ are each independently a (C1-C20) alkyl group; E is a hydrogen atom or a halogen atom; r is an integer between 1 and 3; and R ³⁰ is a (C1-C20) alkyl group or a (C6-C30) aryl group. The method as described in claim 9, wherein the solution polymerization is carried out at a reactor pressure of 6 atm to 150 atm and a polymerization temperature of 100°C to 200°C. The method as described in claim 9, wherein the aforementioned olefin polymer has a weight average molecular weight of 5,000 g/mol to 200,000 g/mol and a molecular weight distribution (Mw/Mn) of 1.0 to 10.0. The method as described in claim 9, wherein the olefin polymer has an ethylene content of 30 wt % to 99 wt %.