Novel transition metal compound, transition metal catalyst composition containing the same, and method for producing copolymer of ethylene and α-olefin using the same

Abstract

To provide a novel transition metal compound.SOLUTION: Provided is a transition metal compound represented by the following chemical formula. [M is Hf; R1 and R2 are arylalkyl; R3 and R4 are aryl; X1 and X2 are halogen, alkyl, cycloalkyl, aryl, arylalkyl, (alkylaryl)alkyl, alkoxy, aryloxy, alkylaryloxy, alkoxyaryloxy, -OSiRaRbRc, -SRd, -NReRf, -PRgRh, or alkylidene; Ra to Rd are alkyl, aryl, arylalkyl, alkylaryl, or cycloalkyl; Re to Rh are alkyl, aryl, arylalkyl, alkylaryl, cycloalkyl, trialkylsilyl, or triarylsilyl; and if one of X1 or X2 is alkylidene, the other is absent].SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a novel transition metal compound, a transition metal catalyst composition for producing a copolymer of ethylene and an α-olefin containing the same, a method for producing a copolymer of ethylene and an α-olefin using the same, and a copolymer of ethylene and an α-olefin produced using the transition metal compound as a catalyst.

Background Art

[0002] Conventionally, for the production of ethylene homopolymers and copolymers of ethylene and α-olefins, a so-called Ziegler-Natta catalyst system composed of a main catalyst component of a titanium or vanadium compound and a cocatalyst component of an alkylaluminum compound has generally been used. The Ziegler-Natta catalyst system exhibits high activity for ethylene polymerization. However, due to non-uniform catalytic active sites, the polymers generally produced have a broad molecular weight distribution, and particularly in the case of copolymers of ethylene and α-olefins, there is a drawback that the composition distribution is not uniform.

[0003] Subsequently, as a homogeneous catalyst having a single type of catalytic active site, compared with the conventional Ziegler-Natta catalyst system, research on a metallocene catalyst system composed of a metallocene compound of a Group 4 transition metal of the periodic table such as zirconium and hafnium, which can produce polyethylene with a narrow molecular weight distribution and a uniform composition distribution, and methylaluminoxane as a cocatalyst has been conducted in various ways. The metallocene compound is currently industrially actively used as a cyclopentadienyl-based catalyst having different substitution patterns, and is used not only for the production of polyethylene but also for the production of polypropylene.

[0004] However, it has been difficult to obtain a high molecular weight polymer with the said catalyst system. That is, when applied to a solution polymerization method carried out at a high temperature, the polymerization activity rapidly decreases, and since the β-dehydrogenation reaction is dominant, it is known that it is not suitable for producing a high molecular weight polymer.

[0005] In the solution polymerization conditions for ethylene homopolymerization or copolymerization of ethylene and α-olefin, a transition metal catalyst in which transition metals are linked in a cyclic manner has been reported as a catalyst capable of producing a polymer with high catalytic activity and high molecular weight.

[0006] US6313240 describes a catalyst system comprising a cyclopentadienyl ligand or an aromatic condensed and substituted cyclopentadienyl ligand; an aromatic condensed and substituted cyclopentadienyl ligand; and a hafnium organometallic compound having a bridge connecting two cyclopentadienyl ligands.

[0007] Also, US6559253 discloses, as an example, a structure in which a bridge substituted with diphenyl and one cyclopentadiene ligand are linked to unsubstituted fluorene. US6300433 discloses the structure of one or more substituted cyclopentadienyl-fluorenyl ligands having a substituted diphenylmethylene bridge.

[0008] In the case of such catalysts, the reactivity with α-olefins has been significantly improved due to the reduced steric hindrance effect of the catalyst itself, but there are many difficulties in commercial use. Therefore, ensuring a more competitive catalyst system is highly regarded, taking into account the required characteristics of a commercial catalyst based on economy, namely, excellent high-temperature activity, excellent reactivity with α-olefins, and the ability to produce polymers with high molecular weight.

Summary of the Invention

Problems to be Solved by the Invention

[0009] One embodiment of the present invention is to provide a novel transition metal compound. Another embodiment of the present invention is to provide a transition metal catalyst composition containing the above-mentioned transition metal compound capable of producing a high molecular weight copolymer of ethylene and α-olefin.

[0010] Yet another embodiment of the present invention provides a method for producing a copolymer of ethylene and an α-olefin using a catalyst composition containing the transition metal compound, which is industrially economical and easy to use.

Means for Solving the Problems

[0011] As a result of research by the present inventors to achieve the above object, it has been found that a high molecular weight copolymer of ethylene and an α-olefin can be produced by stabilizing the active site of the compound used as a catalyst in high temperature solution polymerization, and the present invention has been completed.

[0012] The present invention provides a transition metal compound represented by the following Chemical Formula 1.

[0013] [Chemical Formula 1] TIFF2025094203000001.tif29170

[0014] [In the above Chemical Formula 1, M is a Group 4 transition metal, R1 and R2 are each independently an unsubstituted or (C1-C10) alkyl-substituted (C6-C20) aryl (C1-C20) alkyl, R3 and R4 are each independently an unsubstituted or (C1-C10) alkyl-substituted (C6-C20) aryl, X1 and X2 are each independently halogen, (C1-C20) alkyl, (C3-C20) cycloalkyl, (C6-C20) aryl, (C6-C20) aryl (C1-C20) alkyl, ((C1-C20) alkyl (C6-C20) aryl)(C1-C20) alkyl, (C1-C20) alkoxy, (C6-C20) aryloxy, (C1-C20) alkyl (C6-C20) aryloxy, (C1-C20) alkoxy (C6-C20) aryloxy, -OSiR a R b R c , -SR d , -NR e R f , -PR g Rh or (C1-C20) alkylidene, R a ~R d each independently is (C1-C20) alkyl, (C6-C20) aryl, (C6-C20) aryl(C1-C20) alkyl, (C1-C20) alkyl(C6-C20) aryl, or (C3-C20) cycloalkyl, R e ~R h each independently is (C1-C20) alkyl, (C6-C20) aryl, (C6-C20) aryl(C1-C20) alkyl, (C1-C20) alkyl(C6-C20) aryl, (C3-C20) cycloalkyl, tri(C1-C20) alkylsilyl, or tri(C6-C20) arylsilyl, When one of X1 or X2 is (C1-C20) alkylidene, the other does not exist.]

[0015] Specifically, M in the chemical formula 1 is Ti, Zr, or Hf, R1 and R2 each independently are (C6-C20) aryl(C1-C20) alkyl, R3 and R4 each independently are unsubstituted or (C1-C5) alkyl-substituted (C6-C12) aryl, and X1 and X2 each independently may be halogen, (C1-C20) alkyl, (C6-C20) aryl, or (C6-C20) aryl(C1-C20) alkyl.

[0016] Also, M in the chemical formula 1 is Hf, R1 and R2 each independently are (C6-C12) aryl(C1-C10) alkyl, R3 and R4 each independently are (C6-C12) aryl, and X1 and X2 each independently may be halogen, (C1-C10) alkyl, (C6-C12) aryl, or (C6-C12) aryl(C1-C10) alkyl.

[0017] More specifically, in one embodiment of the present invention, M in the chemical formula 1 is Hf, R3 and R4 are phenyl, X1 and X2 are each independently methyl, benzyl, or Cl, and R1 and R2 may each independently be represented by the following chemical formula 2.

[0018] [Chemical formula 2] TIFF2025094203000002.tif13170

[0019] [In the chemical formula 2, L is a linear or branched (C1-C10) alkylene. ]

[0020] The transition metal compound according to one embodiment of the present invention may be [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-(2-phenylpropan-2-yl)fluorenyl)-1,1-diphenylmethane]hafnium dichloro, [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-(2-phenylpropan-2-yl)fluorenyl)-1,1-diphenylmethane]hafnium dibenzyl, or [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-(2-phenylpropan-2-yl)fluorenyl)-1,1-diphenylmethane]hafnium dimethyl.

[0021] The present invention provides a transition metal catalyst composition for producing a copolymer of ethylene and an α-olefin, which comprises a transition metal compound according to one embodiment of the present invention and a cocatalyst selected from an aluminum compound, a boron compound, or a mixture thereof.

[0022] The aluminum compound used as the cocatalyst may be one or more selected from aluminoxane and organoaluminum. The present invention also provides a method for producing a copolymer of ethylene and an α-olefin, the production method including: a) mixing a transition metal catalyst composition according to an embodiment of the present invention, ethylene, and an α-olefin comonomer; and b) performing a copolymerization reaction at a temperature of 110 to 170°C.

[0023] The α-olefin copolymerized with the ethylene may be one or more selected from propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, cyclopentene, cyclohexene, norbornene, phenylnorbornene, styrene, α-methylstyrene, p-methylstyrene, and 3-chloromethylstyrene.

[0024] Specifically, the step b) may be performed at a temperature of 120°C to 160°C and a pressure of 10 to 100 bar. Also, the method for producing the copolymer of ethylene and an α-olefin may be performed in a C5-C12 aliphatic hydrocarbon solvent.

[0025] The present invention provides a copolymer of ethylene and an α-olefin produced using a transition metal compound according to an embodiment of the present invention as a catalyst.

Advantages of the Invention

[0026] The novel transition metal compound of the present invention can be easily produced in high yield by a simple process under mild conditions. The transition metal compound, which is a single active site catalyst, and the catalyst composition containing the same are excellent in thermal stability and can maintain excellent catalytic activity even at high temperatures. Therefore, by using it, a high molecular weight copolymer of ethylene and an α-olefin can be produced. Such a method for producing a copolymer of ethylene and an α-olefin is a very economical method because a copolymer having various physical properties can be obtained in high yield by a simple process, and it can be easily used for industrial mass production.

Embodiments for Carrying Out the Invention

[0027] Hereinafter, the novel transition metal compound of the present invention, the transition metal catalyst composition containing the same, and the method for producing a copolymer of ethylene and an α-olefin using the same will be described in detail.

[0028] The singular forms used in the present invention are intended to include plural forms as well, unless otherwise indicated by the context. The term "comprising" described in the present invention is an open-ended description having the same meaning as expressions such as "including", "containing", "having", or "characterized by", and does not exclude additional elements, materials, or steps not listed.

[0029] The term "alkyl" described in the present invention means a monovalent linear or branched saturated hydrocarbon group consisting only of carbon and hydrogen atoms. Examples of such alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, octyl, nonyl, and the like.

[0030] "Aryl" as described in the present invention is an organic group derived by removing one hydrogen atom from an aromatic hydrocarbon, and includes a monocyclic or fused ring system appropriately containing 4 to 7, preferably 5 or 6 ring atoms in each ring, and also includes a form in which a plurality of aryls are linked by a single bond. The fused ring system may include an aliphatic ring such as a saturated or partially saturated ring, and necessarily includes one or more aromatic rings. Further, the aliphatic ring may contain nitrogen, oxygen, sulfur, carbonyl, etc. in the ring. Specific examples of the aryl group include, but are not limited to, phenyl, naphthyl, biphenyl, indenyl, fluorenyl, phenanthrenyl, anthracenyl, triphenylenyl, pyrenyl, chrysenyl, naphthacenyl, 9,10-dihydroanthracenyl, and the like.

[0031] "Cycloalkyl" as described in the present invention means a monovalent saturated carbocyclic group consisting of one or more rings. Examples of the cycloalkyl group include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and the like.

[0032] "Halo" or "halogen" as described in the present invention means a fluorine, chlorine, bromine, or iodine atom. "Alkoxy" as described in the present invention means -O-(alkyl) including -OCH3, -OCH2CH3, -O(CH2)2CH3, -O(CH2)3CH3, -O(CH2)4CH3, -O(CH2)5CH3, and the like, where "alkyl" is as defined above.

[0033] "Aryloxy" as described in the present invention means an -O-aryl group respectively, where "aryl" is as defined above. "Alkylidene" as described in the present invention means a linear or branched saturated divalent hydrocarbon group having two valences on one common carbon atom.

[0034] The present invention provides a transition metal compound represented by the following Chemical Formula 1.

[0035] [Chemical Formula 1] TIFF2025094203000003.tif28170

[0036] [In the above Chemical Formula 1, M is a Group 4 transition metal, R1 and R2 are each independently an unsubstituted or (C1-C10) alkyl-substituted (C6-C20) aryl(C1-C20) alkyl, R3 and R4 are each independently an unsubstituted or (C1-C10) alkyl-substituted (C6-C20) aryl, X1 and X2 are each independently halogen, (C1-C20) alkyl, (C3-C20) cycloalkyl, (C6-C20) aryl, (C6-C20) aryl(C1-C20) alkyl, ((C1-C20) alkyl(C6-C20) aryl)(C1-C20) alkyl, (C1-C20) alkoxy, (C6-C20) aryloxy, (C1-C20) alkyl(C6-C20) aryloxy, (C1-C20) alkoxy(C6-C20) aryloxy, -OSiR a R b R c , -SR d , -NR e R f , -PR g R h , or (C1-C20) alkylidene, R a ~R d are each independently (C1-C20) alkyl, (C6-C20) aryl, (C6-C20) aryl(C1-C20) alkyl, (C1-C20) alkyl(C6-C20) aryl, or (C3-C20) cycloalkyl, R e ~R heach independently is (C1-C20)alkyl, (C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl, (C1-C20)alkyl(C6-C20)aryl, (C3-C20)cycloalkyl, tri(C1-C20)alkylsilyl, or tri(C6-C20)arylsilyl, When one of X1 or X2 is (C1-C20)alkylidene, the other does not exist.

[0037] The transition metal compound represented by Chemical Formula 1 has a transition metal of Group 4 of the periodic table as the central metal, which is linked by a cyclopentadienyl group with rich electrons and widely delocalized electrons and a fluorenyl group substituted with arylalkyl substituents at the 2- and 7-positions. The cyclopentadienyl group and the fluorenyl group have a structure linked by carbon. Since the catalytic active site can be stabilized by the fluorenyl group substituted with arylalkyl substituents at the 2- and 7-positions, it can exhibit excellent catalytic activity in the homopolymerization of ethylene or the copolymerization of ethylene and α-olefin. Further, when the transition metal compound is used in a solution polymerization process carried out at a high temperature, a homopolymer of ethylene having a high molecular weight or a copolymer of ethylene and α-olefin can be produced.

[0038] Specifically, M in Chemical Formula 1 is Ti, Zr, or Hf, R1 and R2 are each independently (C6-C20)aryl(C1-C20)alkyl, R3 and R4 are each independently (C6-C12)aryl which is unsubstituted or substituted with (C1-C5)alkyl, and X1 and X2 may each independently be halogen, (C1-C20)alkyl, (C6-C20)aryl, or (C6-C20)aryl(C1-C20)alkyl.

[0039] In one embodiment, M in Chemical Formula 1 is Hf, R1 and R2 are each independently (C6-C12) aryl (C1-C10) alkyl, R3 and R4 are each independently (C6-C12) aryl, and X1 and X2 may each independently be halogen, (C1-C10) alkyl, (C6-C12) aryl, or (C6-C12) aryl (C1-C10) alkyl.

[0040] Also, in one embodiment, M in Chemical Formula 1 is Hf, R1 and R2 are each independently (C6-C12) aryl (C1-C5) alkyl, R3 and R4 are each independently (C6-C12) aryl, and X1 and X2 may each independently be halogen, (C1-C5) alkyl, (C6-C12) aryl, or (C6-C12) aryl (C1-C5) alkyl.

[0041] More specifically, in one embodiment of the present invention, M in Chemical Formula 1 is Hf, R3 and R4 are phenyl, X1 and X2 are each independently methyl, benzyl, or Cl, and R1 and R2 may each independently be represented by the following Chemical Formula 2.

[0042] [Chemical Formula 2] TIFF2025094203000004.tif13170

[0043] [In Chemical Formula 2, L is linear or branched (C1-C10) alkylene.]

[0044] More specifically, L in Chemical Formula 2 may be linear or branched (C1-C5) alkylene. The transition metal compound according to one embodiment of the present invention may be [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-(2-phenylpropan-2-yl)fluorenyl)-1,1-diphenylmethane]hafnium dichloro, [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-(2-phenylpropan-2-yl)fluorenyl)-1,1-diphenylmethane]hafnium dibenzyl, or [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-(2-phenylpropan-2-yl)fluorenyl)-1,1-diphenylmethane]hafnium dimethyl.

[0045] On the other hand, since the transition metal compound according to one embodiment of the present invention serves as an active catalyst component for the production of a copolymer of ethylene and an α-olefin, preferably, while extracting the X1 and X2 ligands of the transition metal compound of Chemical Formula 1 to cationize the central metal, an aluminum compound, a boron compound, or a mixture thereof having a weak binding force, that is, an anion that can act as an anion, can act together as a cocatalyst.

[0046] Therefore, the present invention provides a transition metal catalyst composition for producing a copolymer of ethylene and an α-olefin, which includes the transition metal compound according to one embodiment of the present invention and a cocatalyst selected from an aluminum compound, a boron compound, or a mixture thereof.

[0047] In the transition metal catalyst composition for producing a copolymer of ethylene and an α-olefin according to one embodiment of the present invention, the aluminum compound used as the cocatalyst may be one or more selected from aluminoxane, organoaluminum, and organoaluminum oxide compounds. Specifically, the aluminum compound may be one or more selected from the aluminoxane compounds of the following Chemical Formula 3 or 4, the organoaluminum compounds of the following Chemical Formula 5, or the organoaluminum oxide compounds of the following Chemical Formula 6 or 7.

[0048] [Chemical Formula 3] (-Al(R 11 )-O-) m

[0049] [Chemical Formula 4] (R 11 )2Al-(-O(R 11 )-) q -(R 11 )2

[0050] [Chemical Formula 5] (R 12 ) r Al(E) 3-r

[0051] [Chemical Formula 6] (R 13 )2AlOR 14

[0052] [Chemical Formula 7] R 13 Al(OR 14 )2

[0053] [In the above Chemical Formulas 3 to 7, R 11 is (C1-C20) alkyl, R 12 and R 13 are each (C1-C20) alkyl, E is hydrogen or halogen, R 14 is (C1-C20) alkyl or (C6-C20) aryl, m and q are each an integer from 5 to 20, r is an integer from 1 to 3.]

[0054] Specifically, R 11 in the above Chemical Formulas 3 and 4 may be methyl or isobutyl. Specific examples of the aluminum compound that can be used include, as examples of aluminoxane compounds, methylaluminoxane, modified methylaluminoxane, and tetraisobutylaluminoxane. Examples of organoaluminum compounds include trialkylaluminums including trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, trihexylaluminum, and trioctylaluminum; dialkylaluminum chlorides including dimethylaluminum chloride, diethylaluminum chloride, dipropylaluminum chloride, diisobutylaluminum chloride, and dihexylaluminum chloride; alkylaluminum dichlorides including methylaluminum dichloride, ethylaluminum dichloride, propylaluminum dichloride, isobutylaluminum dichloride, and hexylaluminum dichloride; and dialkylaluminum hydrides including dimethylaluminum hydride, diethylaluminum hydride, dipropylaluminum hydride, diisobutylaluminum hydride, and dihexylaluminum hydride.

[0055] More preferably, the aluminum compound may be one or more selected from methylaluminoxane, modified methylaluminoxane, tetraisobutylaluminoxane, trimethylaluminum, triethylaluminum, trioctylaluminum, and triisobutylaluminum.

[0056] The boron compound that can be used as a cocatalyst in the present invention may be selected from boron compounds represented by the following Chemical Formulas 8 to 10.

[0057] [Chemical Formula 8] B(R 21 )3

[0058] [Chemical Formula 9] [R 22 + [B(R 21 )4] - ​

[0059] [Chemical Formula 10] [(R 23 ) p ZH] + [B(R 21 )4] -

[0060] [In the above Chemical Formulas 8 to 10, B is a boron atom, Z is a nitrogen or phosphorus atom, R 21 is phenyl, the phenyl may be further substituted with 3 to 5 substituents selected from fluoro, fluoro-substituted or unsubstituted (C1-C20) alkyl, and fluoro-substituted or unsubstituted (C1-C20) alkoxy, R 22 is a (C5-C7) aryl group, a (C1-C20) alkyl(C6-C20) aryl group, or a (C6-C20) aryl(C1-C20) alkyl group, R 23 is a (C1-C50) alkyl group or an anilinium group substituted with two (C1-C10) alkyls together with a nitrogen atom. p is an integer of 2 or 3.]

[0061] More specifically, R 22 may be a triphenylmethylium group. Preferably, the boron compound used as the cocatalyst is dimethylphenylammonium tetraphenylborate, trityl tetraphenylborate, dimethylphenylammonium tetrakis(pentafluorophenyl)borate, trityl tetrakis(pentafluorophenyl)borate, trimethylammonium tetraphenylborate, triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, tributylammonium tetraphenylborate, trimethylammonium tetrakis(pentafluorophenyl)borate, triethylammonium tetrakis(pentafluorophenyl)borate, tripropylammonium tetrakis(pentafluorophenyl)borate, tributylammonium tetrakis(pentafluorophenyl)borate, anilinium tetraphenylborate, anilinium tetrakis(pentafluorophenyl)borate, pyridinium tetrakis(pentafluorophenyl)borate, and silver tetrakis(pentafluorophenyl)borate, and may be one or more selected therefrom.

[0062] On the other hand, the cocatalyst can serve as a scavenger that removes impurities that act as poisons to the catalyst in the reactants. In one embodiment according to the present invention, when the aluminum compound and the boron compound are used as cocatalysts, the preferred range of the ratio of the transition metal compound to the cocatalyst of the present invention is such that the molar ratio of transition metal (M): aluminum atom (Al): boron atom (B) may be in the range of 1:(10 - 3,000):(1 - 100), and more preferably in the range of 1:(100 - 1,000):(3 - 10).

[0063] When the ratio of the transition metal compound to the cocatalyst of the present invention is within the above range, the activation of the transition metal compound is sufficiently carried out, so that the catalytic activity of the transition metal compound can be excellent, but it is not limited thereto, and the ratio range can vary according to the reaction conditions and purposes.

[0064] The present invention provides a method for producing a copolymer of ethylene and an α-olefin. The production method may include: a) a step of mixing a transition metal catalyst composition according to an embodiment of the present invention, ethylene, and an α-olefin comonomer; and b) a step of performing a copolymerization reaction at a temperature of 110 to 170°C.

[0065] In addition to the method for producing the copolymer, the present invention also provides a method for producing a homopolymer of ethylene. In the method for producing the copolymer, the same method may be performed using only ethylene instead of the comonomer.

[0066] Specifically, the step b) may be performed at a temperature of 120 to 165°C and a pressure of 10 to 100 bar, and preferably at a temperature of 130 to 160°C and a pressure of 15 to 50 bar.

[0067] In the method for producing a copolymer of ethylene and an α-olefin according to an embodiment of the present invention, as the α-olefin, one or more selected from (C3-C18) α-olefins, (C5-C20) cycloolefins, styrene, and its derivatives may be used. Examples of (C3-C18) α-olefins may include one or more selected from the group consisting of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-octadecene. Examples of (C5-C20) cycloolefins may include one or more selected from the group consisting of cyclopentene, cyclohexene, norbornene, and phenylnorbornene. Examples of styrene and its derivatives may include one or more selected from styrene, α-methylstyrene, p-methylstyrene, and 3-chloromethylstyrene. More specifically, the α-olefin may be one or more selected from 1-butene, 1-hexene, 1-octene, and 1-decene, but is not limited thereto.

[0068] The method for producing a homopolymer of ethylene or a copolymer of ethylene and an α-olefin using the transition metal catalyst composition according to an embodiment of the present invention may be carried out by bringing the above transition metal catalyst, cocatalyst, α-olefin comonomer, and ethylene into contact in the presence of a suitable organic solvent. At this time, the transition metal catalyst, cocatalyst, and α-olefin comonomer components may be separately charged into the reactor or the components may be premixed and charged into the reactor.

[0069] Further, the production method may be carried out in a C5-C12 aliphatic hydrocarbon solvent. Specifically, the C5-C12 aliphatic hydrocarbon solvent may be one or more selected from butane, isobutane, pentane, hexane, heptane, octane, isooctane, nonane, decane, dodecane, cyclohexane, and methylcyclohexane, and preferably may be hexane, cyclohexane, or a mixture thereof.

[0070] The method for producing a copolymer of ethylene and an α-olefin according to an embodiment of the present invention does not use toluene, which is a common cosolvent in the production of copolymers, so the step of removing the toluene solvent in the production process is reduced, and it is a more economical production method.

[0071] The present invention provides a homopolymer of ethylene or a copolymer of ethylene and an α-olefin produced using the transition metal catalyst composition according to an embodiment of the present invention. The produced homopolymer or copolymer has a density of 0.850 g / mL to 0.910 g / mL from an elastomer and a melt flow rate of 0.001 to 20 g / 10 min, and can be very economically and easily produced up to the high-density polyethylene (HDPE) region.

[0072] Further, hydrogen may be used as a molecular weight regulator to adjust the molecular weight during the production of the ethylene homopolymer or copolymer of ethylene and an α-olefin according to the present invention, and the weight average molecular weight of the homopolymer or copolymer to be produced may be 5,000 to 1,000,000 g / mol, specifically 10,000 to 800,000 g / mol, more specifically 30,000 to 500,000 g / mol.

[0073] The catalyst composition according to an embodiment of the present invention can maintain a uniform form in a polymerization reactor, so it is very suitable for a high-temperature solution polymerization process. However, it can also be applied to a slurry polymerization process or a gas-phase polymerization process in the form of a heterogeneous catalyst obtained by supporting the catalyst and the composition containing the catalyst on a porous metal oxide support.

[0074] The present invention provides a high molecular weight ethylene homopolymer or copolymer of ethylene and an α-olefin produced using a transition metal compound according to an embodiment as a catalyst.

[0075] Hereinafter, the novel transition metal compound according to the present invention, the transition metal catalyst composition containing the same, and the method for producing a copolymer of ethylene and an α-olefin using the same will be described in more detail with specific examples.

[0076] All of the following synthetic reactions were carried out under an inert atmosphere such as nitrogen or argon, using standard Schlenk techniques and glove box techniques.

[0077] In addition, synthetic solvents such as tetrahydrofuran (THF), n-hexane, n-pentane, diethyl ether, and methylene chloride (CH2Cl2) were passed through an activated alumina column to remove moisture and then used while stored on activated molecular sieves. Most of the reagents were purchased from Sigma-Aldrich, TCI, Alfa, and Strem and used without special mention.

[0078] 1H NMR analysis of the synthesized compounds was performed using a Bruker 500 MHz at room temperature. The molecular weight and copolymerization characteristics of the ethylene homopolymer or copolymer of ethylene and α-olefin were analyzed by the following methods.

[0079] MFR analysis was carried out by melting the plastic at 190 °C and then measuring the weight of the extrudate flowing through a capillary of a certain standard for 10 minutes under loads of 2.16, 5, and 21.6 kg. According to the ASTM D1238 measurement standard, it was expressed in terms of melt index (MI, g / 10 min). When the MI is low, the molecular weight increases and the fluidity decreases, so the processability decreases and the physical properties improve.

[0080] GPC analysis was performed on a PLXT-20 high-speed GPC polymer analysis system (including a pump, a refractive index detector, and a viscosity detector) from Polymer Laboratories at 160 °C with three 3PLgel Olexis columns (300 × 7.5 mm, Polymer Laboratories) connected in series and analyzed by high-temperature size exclusion chromatography (HTSEC). 1,2,4-Trichlorobenzene containing butylated hydroxytoluene (0.5 g / L) and Irganox 1010 (20 mg / L) was used as the eluent at a flow rate of 1.0 mL / min. Molecular weights were calculated based on polyethylene standards (Mp = 5,310 to 1,510,000 g / mol, Polymer Laboratories). A PL XT-220 robotic sample handling system from Polymer Laboratories was used as the autosampler. The sample concentration was analyzed at 2 to 4 polymer mg / TCBmL.

[0081] The density ranges from 0.850 to 0.910 g / mL, and the closer the density is to 0.85, the higher the copolymerizability. To measure the density, the weight of the resin per unit volume was measured. Using the density gradient method of creating a calibration curve regarding the density of the standard column and the height of the column, the analysis was performed according to the ASTM D1505 (KS M3016) measurement standard.

[0082] The temperature-controlled DSC experiment was carried out in modulation mode according to ISO 11357-1 on a TA Instruments Q2000 DSC calibrated with indium, tin, and zinc. 5 mg of the sample was placed in an aluminum pan, heated to an initial temperature of 180 °C, and then cooled to -88 °C at 10 °C / min as in standard DSC. Then, while performing temperature control of 0.32 °C every 60 seconds, the temperature was raised at a heating rate of 2 °C / min. The glass transition temperature was measured from the reversible heat flow thermogram, showing the inflection point at the transition. The higher the copolymerizability, the lower the measured Tm.

[0083] [Production Example 1]Production of [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-(2-phenylpropan-2-yl)-fluorenyl)-1,1-diphenylmethane]hafnium dichloro (Compound 1)

[0084] Step 1: Production of 2,7-dibenzoyl-fluorene (Compound 1-a) TIFF2025094203000005.tif21170

[0085] Into a Schlenk flask, AlCl3 (17.6 g, 132.3 mmol), DCM (120 mL), and fluorene (10 g, 60.2 mmol) were added. After adding benzoyl chloride (13.9 mL, 120.4 mmol) at 0 °C, the mixture was stirred at room temperature for 18 hours. After gradually adding ice and water to terminate the reaction, DCM was added for extraction. The organic layer was collected, dried over MgSO4, filtered, and concentrated under reduced pressure. Then, recrystallization was carried out using ether / Hex to obtain a yellow solid compound 1-a (20 g, yield 91%).

[0086] 1H NMR (500 MHz, Chloroform-d) δ 7.90 (s, 2H), 7.88 (d, J = 7.7 Hz, 2H), 7.85 (d, J = 7.5 Hz, 2H) 7.83 (m, 4H), 7.60 (d, J = 7.7 Hz, 2H), 7.50 (m, 4H), 4.05 (s, 2H)

[0087] Step 2: Production of 2,7-di-(2-phenylpropan-2-yl)-fluorene (Compound 1-b) TIFF2025094203000006.tif21170

[0088] To a Schlenk flask were added compound 1-a (8.2 g, 22 mmol), toluene (109 mL), and acetic acid (0.3 mL, 5.47 mmol). Then trimethylaluminum (109 mL, 219 mmol, 2.0 M in Hex) was added, and the mixture was refluxed at 100 °C for 6 hours. 1N HCl and ice were added to terminate the reaction, and the mixture was extracted three times with ether. The organic layers were collected, dried over MgSO4, filtered, and concentrated under reduced pressure. Then it was purified by a silica column (solvent Hex) to obtain a yellow solid compound 1-b (8.5 g, yield 96%).

[0089] 1H NMR (500 MHz, Chloroform-d) δ 7.61 (d, J = 7.7 Hz, 2H), 7.38 (s, 2H), 7.23 (m, 8H), 7.21 (m, 2H), 7.17 (m, 2H), 3.78 (s, 2H), 1.72 (s, 12H).

[0090] Step 3: Preparation of 1-(2,4-cyclopentadien-1-yl)-1-(2,7-di-(2-phenylpropan-2-yl)-fluorenyl)-1,1-diphenylmethane (compound 1-c) TIFF2025094203000007.tif33170

[0091] Compound 1-b (12 g, 43.1 mmol) was dissolved in 87 mL of THF. Then nBuLi (1.6 M in Hex, 27.1 mL, 43.1 mmol) was added, and the mixture was stirred at room temperature for 3 hours. 6,6-Diphenylfulvene (10 g, 43.1 mmol) was added, and the reaction solution was stirred for 16 hours. Then an aqueous NH4Cl solution (40 mL) was added to terminate the reaction. The product was extracted into the organic layer, dried over MgSO4, filtered, and concentrated under reduced pressure. The resulting yellow solid was washed with ethanol to obtain a white solid compound 1-c (24 g, yield 94%).

[0092] 1H NMR (500 MHz, Chloroform-d) δ 7.02 - 7.30 (m, 28H), 6.21 (s, 2H), 5.41 (s, 1H), 2.83 (br s, 1H), 1.53 (s, 12H).

[0093] Step 4: Preparation of [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-(2-phenylpropan-2-yl)-fluorenyl)-1,1-diphenylmethane]hafnium dichloro (Compound 1) TIFF2025094203000008.tif33170

[0094] After dissolving Compound 1-c (2.5 g, 3.95 mmol) in 39 mL of ether, nBuLi (1.6 M in Hex, 5.43 mL, 8.69 mmol) was added and stirred for 16 hours. After removing the ether by vacuum drying, Hex was added, decanted, and the pressure was reduced. In the glove box, lithium (2.5 g, 3.89 mmol) and HfCl4 (1.24 g, 3.89 mmol) were weighed and dissolved in 35 mL of ether, then stirred at room temperature for 16 hours, and the ether was removed by vacuum drying. 80 mL of toluene was added and heated at 50 °C for 2 hours, and the resulting LiCl was precipitated and filtered. After vacuum drying the filtrate, it was crystallized to obtain yellow crystalline Compound 1 (2.4 g, yield 71%).

[0095] 1H NMR (500 MHz, Chloroform-d) δ 7.94 (d, J = 9.5 Hz, 2H), 7.80 (d, J = 7.4 Hz, 2H), 7.71 (d, J = 7.5 Hz, 2H), 7.05 - 7.34 (m, 18H), 6.28 (t, J = 7.5 Hz, 2H), 6.19 (s, 2H), 5.28 (t, J = 7.4 Hz, 2H), 1.42 (s, 6H), 1.38 (s, 6H)

[0096] [Comparative Production Example 1] Synthesis of [1-(η5-cyclopentadien-1-yl)-1-(η5-fluorenyl)-1,1-diphenylmethane]hafnium dichloro (Compound 2)

[0097] [1-(η5-Cyclopentadien-1-yl)-1-(η5-fluorenyl)-1,1-diphenylmethane]hafnium dichloride (Compound 2) was synthesized according to the manufacturing process in the literature [A. Razavi, J. L. Atwood, J. Organometallic. Chen, 459 (1993), 117 - 123].

[0098] 1H NMR (500 MHz, Chloroform - d) δ8.19 (d, J = 8.5 Hz, 2H), 7.95 (d, J = 8.3 Hz, 2H), 7.88 (d, J = 8.5 Hz, 2H), 7.55 (t, J = 8.0 Hz, 2H), 7.44 (t, J = 8.2 Hz, 2H), 7.31 (m, 4H), 7.01 (t, J = 8.1 Hz, 2H), 6.47 (d, J = 7.1 Hz, 2H), 6.33 (s, 2H), 5.75 (s, 2H)

[0099] [Comparative Production Example 2] Production of [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-t-butylfluorenyl)-1,1-diphenylmethane]hafnium dichloride (Compound 3)

[0100] Step 1: Production of 1-(2,4-cyclopentadien-1-yl)-1-(2,7-di-t-butylfluorenyl)-1,1-diphenylmethane (Compound 3 - a) TIFF2025094203000009.tif34170

[0101] After dissolving 2,7 - di - t - butylfluorene (12 g, 43.1 mmol) in 87 mL of THF, nBuLi (1.6 M in Hex, 27.1 mL, 43.1 mmol) was added and stirred at room temperature for 3 hours. 6,6 - diphenylfulvene (10 g, 43.1 mmol) was added and stirred for 16 hours, then an aqueous NH4Cl solution (40 mL) was added to terminate the reaction. The product was extracted into the organic layer, dried over MgSO4, filtered, and concentrated under reduced pressure. The resulting yellow solid was washed with ethanol to obtain a white solid of Compound 3 - a (20 g, yield 93%).

[0102] 1H NMR (500 MHz, Chloroform-d) δ 6.21~7.35 (m, 20H), 5.45 (s, 1H), 3.01 (m, 1H), 1.14 (s, 18H)

[0103] Step 2: Preparation of [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-t-butylfluorenyl)-1,1-diphenylmethane]hafnium dichloro (Compound 3) TIFF2025094203000010.tif33170

[0104] After dissolving Compound 3-a (5 g, 9.82 mmol) in 60 mL of ether, nBuLi (1.6 M in Hex, 13.5 mL, 21.6 mmol) was added and stirred for 16 hours. After removing the ether by vacuum drying, hexane was added, decanted, and concentrated under reduced pressure. In a glove box, lithium (5.1 g, 9.79 mmol) and HfCl4 (3.13 g, 9.79 mmol) were weighed and dissolved in 80 mL of ether, and then stirred at room temperature for 16 hours. After removing the ether by vacuum drying, 80 mL of toluene was added and heated at 50 °C for 2 hours to precipitate the generated LiCl and filtered. The filtrate was crystallized after vacuum drying to obtain yellow crystalline Compound 3 (4.4 g, yield 60%).

[0105] 1H NMR (500 MHz, Chloroform-d) δ 8.03 (d, J = 9.0 Hz, 2H), 7.97 (d, J = 2.5 Hz, 2H), 7.96 (d, J = 3.0 Hz, 2H), 7.57 (d, J = 9.0 Hz, 2H), 7.45 (m, 2H), 7.36 (m, 2H), 7.29 (m, 2H), 6.37 (s, 2H), 6.29 (t, J = 2.5 Hz, 2H), 5.63 (t, J = 3.0 Hz, 2H), 1.04 (s, 18H)

[0106] [Comparative Production Example 3] Preparation of [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-diphenylfluorenyl)-1,1-diphenylmethane]hafnium dichloro (Compound 4)

[0107] Step 1: Preparation of 2,7-Di-phenylfluorene (Compound 4-a) TIFF2025094203000011.tif21170

[0108] Into a Schlenk flask, Pd(PPh3)4 (1.8 g, 1.54 mmol) and 2,7-Dibromo-9H-fluorene (5 g, 15.4 mmol) were charged. After adding 100 mL of toluene, phenylboronic acid (7.5 g, 61.7 mmol) was added, and then 50 mL of toluene and an aqueous solution of K2CO3 (30 mL, 2 M) were added. After refluxing at 100 °C for 16 hours, water and ether were added and extraction was carried out three times. The organic layers were collected, dried over MgSO4, filtered, and concentrated under reduced pressure, and then purified by silica column (Hex:Ethyl Acetate = 10:1) to obtain white solid Compound 4-a (3.1 g, 63%).

[0109] 1H NMR (500 MHz, Chloroform-d) δ 7.87 (d, J = 7.7 Hz, 2H), 7.79 (s, 2H), 7.67 (m, 6H), 7.46 (m, 4H), 7.36 (d, J = 7.7 Hz, 2H), 4.03 (s, 2H)

[0110] Step 2: Preparation of 1-(2,4-Cyclopentadien-1-yl)-1-(2,7-Di-phenylfluorenyl)-1,1-diphenylmethane (Compound 4-b) TIFF2025094203000012.tif33170

[0111] Compound 4-a (7 g, 21 mmol) was dissolved in 40 mL of THF, and then nBuLi (1.6 M in Hex, 14 mL, 21 mmol) was added and stirred at room temperature for 3 hours. 6,6-Diphenylfulvene (5 g, 21 mmol) was added and stirred for 16 hours, and then an aqueous solution of NH4Cl (20 mL) was added to terminate the reaction. The product was extracted into the organic layer, dried over MgSO4, filtered, and concentrated under reduced pressure, and then the resulting yellow solid was washed with ethanol to obtain white solid Compound 4-b (20 g, yield 91%).

[0112] 1H NMR (500 MHz, Chloroform-d) δ 7.30~7.73 (m, 30H), 5.61 (s, 1H), 4.09 (s, 1H)

[0113] Step 3: Preparation of [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-phenylfluorenyl)-1,1-diphenylmethane]hafnium dichloro (Compound 4) TIFF2025094203000013.tif35170

[0114] After dissolving Compound 4-b (5 g, 9.11 mmol) in 60 mL of ether, nBuLi (1.6 M in Hex, 13.5 mL, 21.6 mmol) was added and stirred for 16 hours. After removing the ether by vacuum drying, Hex was added and decanted, and then reduced in pressure. In the glove box, lithium (5.1 g, 9.11 mmol) and HfCl4 (2.91 g, 9.11 mmol) were weighed and dissolved in 80 mL of ether. After stirring at room temperature for 16 hours, the ether was removed by vacuum drying, then 80 mL of toluene was added and heated at 50 °C for 2 hours. The resulting LiCl was precipitated and filtered. After vacuum drying the filtrate, it was crystallized to obtain yellow crystalline Compound 4 (10 g, yield 67%).

[0115] 1H NMR (500 MHz, Chloroform-d) δ 8.23 (d, J = 9.0 Hz, 2H), 7.96 (d, J = 2.5 Hz, 2H), 7.94 (d, J = 3.0 Hz, 2H), 7.78 (d, J = 9.0 Hz, 2H), 7.27~7.48 (m, 16H), 6.60 (s, 2H), 6.28 (s, 2H), 5.74 (s, 2H)

[0116] [Example 1] Preparation of Copolymer of Ethylene and α-Olefin At room temperature, 1 L of Hex and triisobutylaluminum (1 M, 2 mL) were added to a 4 L reactor, and then 1-octene (100 mL) was added. In a glove box, after dissolving Production Example 1 (Compound 1) (3.9 μmol) in triisobutylaluminum (0.1 M in Hex, 2 mL), 5 mL of hexane was added and injected into the inlet of the reactor. In a glove box, trityltetrakis(pentafluorophenyl)borate (19.5 μmol) was dissolved in 5 mL of Hex and placed at the inlet. After the reactor was heated to 140 °C, the solution at the inlet was introduced with high-pressure nitrogen. The injection of ethylene was carried out at 300 psig for 15 minutes, and it was found that the initial temperature increased in proportion to the activity. After the polymerization reaction was completed, the temperature of the reactor was cooled to 30 °C, and then the ethylene pressure inside the reactor was gradually exhausted and removed. The polymer produced was washed with ethanol and acetone, filtered, and dried in vacuo. The results of the produced polymer are shown in Table 1.

[0117] [Example 2] In Example 1 above, the procedure of Example 1 was carried out in the same manner except that anilinium tetrakis(pentafluorophenyl)borate was used instead of trityltetrakis(pentafluorophenyl)borate, and the results are shown in Table 1.

[0118] [Example 3] In Example 1 above, the procedure of Example 1 was carried out in the same manner except that the reaction was carried out at 150 °C instead of 140 °C, and the results are shown in Table 1.

[0119] [Example 4] In Example 1 above, the procedure of Example 1 was carried out in the same manner except that the reaction was carried out at 150 °C instead of 140 °C and anilinium tetrakis(pentafluorophenyl)borate was used instead of trityltetrakis(pentafluorophenyl)borate, and the results are shown in Table 1.

[0120] [Comparative Example 1] In Example 1, the procedure of Example 1 was carried out in the same manner except that Compound 2 (Comparative Production Example 1) was used instead of Compound 1 (Production Example 1), and the results are shown in Table 1.

[0121] [Comparative Example 2] In Example 1, the procedure of Example 1 was carried out in the same manner except that Compound 2 (Comparative Production Example 1) was used instead of Compound 1 (Production Example 1) and anilinium tetrakis(pentafluorophenyl)borate was used instead of trityl tetrakis(pentafluorophenyl)borate, and the results are shown in Table 1.

[0122] [Comparative Example 3] In Example 1, the procedure of Example 1 was carried out in the same manner except that Compound 3 (Comparative Production Example 2) was used instead of Compound 1 (Production Example 1), and the results are shown in Table 1.

[0123] [Comparative Example 4] In Example 1, the procedure of Example 1 was carried out in the same manner except that Compound 3 (Comparative Production Example 2) was used instead of Compound 1 (Production Example 1) and anilinium tetrakis(pentafluorophenyl)borate was used instead of trityl tetrakis(pentafluorophenyl)borate, and the results are shown in Table 1.

[0124] [Comparative Example 5] In Example 1, the procedure of Example 1 was carried out in the same manner except that Compound 3 (Comparative Production Example 2) was used instead of Compound 1 (Production Example 1) and the reaction was carried out at 150°C instead of 140°C, and the results are shown in Table 1.

[0125] [Comparative Example 6] In Example 1, the procedure of Example 1 was carried out in the same manner except that Compound 3 (Comparative Production Example 2) was used instead of Compound 1 (Production Example 1), anilinium tetrakis(pentafluorophenyl)borate was used instead of trityl tetrakis(pentafluorophenyl)borate, and the reaction was carried out at 150°C instead of 140°C, and the results are shown in Table 1.

[0126] [Comparative Example 7] In Example 1, the procedure of Example 1 was carried out in the same manner except that Compound 4 (Comparative Production Example 3) was used instead of Compound 1 (Production Example 1), and the results are shown in Table 1.

[0127] [Comparative Example 8] In Example 1, the procedure of Example 1 was carried out in the same manner except that the one of Compound 4 (Comparative Production Example 3) was used instead of Compound 1 (Production Example 1) and anilinium tetrakis(pentafluorophenyl)borate was used instead of trityl tetrakis(pentafluorophenyl)borate, and the results are shown in Table 1.

[0128] The analysis results of the copolymers of Example 1, Comparative Example 1, Comparative Example 3, and Comparative Example 7 using the same temperature and cocatalyst for DSC and GPC are shown in Table 2 below.

[0129] [Table 1]

[0130] [Table 2]

[0131] As shown in Table 1 above, in the production of the copolymer of ethylene and 1-octene, it can be seen that Examples 1 to 4 of the present invention exhibit excellent catalytic activity compared to Comparative Examples under the same conditions where the compound is changed.

[0132] Also, as shown in Table 2 above, as a result of comparing the copolymers of ethylene and 1-octene of Example 1, Comparative Example 1, Comparative Example 3, and Comparative Example 7 produced under the same conditions, Example 1 of the present invention shows a value 1.3 to 2.0 times higher in weight average molecular weight and a value 1.6 to 2.2 times higher in number average molecular weight, indicating that a polymer having a very high molecular weight can be produced when the transition metal compound of the present invention is used as a catalyst.

[0133] Similarly, Example 1 of the present invention shows lower Tm results compared to Comparative Example 1, Comparative Example 3, and Comparative Example 7. In terms of having a lower Tm as the copolymerizability is more excellent as described above, it can be seen that the present invention has excellent copolymerizability when the transition metal compound is used as a catalyst.

[0134] The transition metal compound of the present invention has a structure in which a Group 4 transition metal of the periodic table as the central metal is linked by a cyclopentadienyl group with rich electrons and widely delocalized electrons and a fluorenyl group substituted with arylalkyl at the 2- and 7-positions capable of stabilizing the active site. Therefore, it can exhibit excellent catalytic activity and high molecular weight in the high-temperature solution polymerization of ethylene and olefins.

[0135] Therefore, when using the catalyst composition containing the transition metal compound of the present invention in the production of the copolymer of ethylene and α-olefin, a copolymer with a significantly improved high molecular weight can be produced in a high yield, and it is expected that a large amount of copolymer with excellent physical properties can be mass-produced in an industrially very economical method.

[0136] The present invention has been described above by way of specific matters, examples and comparative examples which are limited, but this is merely provided for a more general understanding of the present invention, and the present invention is not limited to the above examples. Those having ordinary knowledge in the field to which the present invention pertains can make various modifications and variations from such descriptions.

[0137] Therefore, the idea of the present invention should not be determined to be limited to the described examples, and it can be said that not only the appended claims, but also those having equivalent or equivalent modifications to this scope of claims all belong to the scope of the idea of the present invention.

Claims

1. A transition metal compound represented by the following chemical formula 1. [Chemical formula 1] [In the above Chemical Formula 1, M is a Group 4 transition metal; R １ and R ２ are each independently (C6-C20)aryl(C1-C20)alkyl unsubstituted or substituted with (C1-C10)alkyl; R ３ and R ４ are each independently (C6-C20)aryl unsubstituted or substituted with (C1-C10)alkyl; X １ and X ２ are each independently halogen, (C1-C20)alkyl, (C3-C20)cycloalkyl, (C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl, ((C1-C20)alkyl(C6-C20)aryl)(C1-C20)alkyl, (C1-C20)alkoxy, (C6-C20)aryloxy, (C1-C20)alkyl(C6-C20)aryloxy, (C1-C20)alkoxy(C6-C20)aryloxy, -OSiR ａ R ｂ R ｃ , -SR ｄ , -NR ｅ R ｆ , -PR ｇ R ｈ or (C1-C20) alkylidene; R ａ ~R ｄ are each independently (C1-C20)alkyl, (C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl, (C1-C20)alkyl(C6-C20)aryl, or (C3-C20)cycloalkyl; R ｅ ~R ｈ are each independently (C1-C20)alkyl, (C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl, (C1-C20)alkyl(C6-C20)aryl, (C3-C20)cycloalkyl, tri(C1-C20)alkylsilyl, or tri(C6-C20)arylsilyl; X １ or X ２ When one of is (C1-C20) alkylidene, the other is absent.

2. In the formula 1, M is Ti, Zr, or Hf; R １ and R ２ are each independently (C6-C20)aryl(C1-C20)alkyl; R ３ and R ４ are each independently (C6-C12)aryl unsubstituted or substituted with (C1-C5)alkyl; X １ and X ２ is each independently halogen, (C1-C20)alkyl, (C6-C20)aryl, or (C6-C20)aryl(C1-C20)alkyl.

3. In the formula 1, M is Hf; R １ and R ２ are each independently (C6-C12)aryl(C1-C10)alkyl; R ３ and R ４ are each independently (C6-C12)aryl; X １ and X ２ is each independently halogen, (C1-C10) alkyl, (C6-C12) aryl, or (C6-C12) aryl(C1-C10) alkyl.

4. In the formula 1, M is Hf; R ３ and R ４ is phenyl, X １ and X ２ are each independently methyl, benzyl, or Cl; R １ and R ２ The transition metal compound according to claim 1 , wherein each of the formulas is independently represented by the following chemical formula 2: [Chemical formula 2] [In the above Chemical Formula 2, L is a linear or branched (C1-C10) alkylene.

5. The transition metal compound according to claim 1, which is [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-(2-phenylpropan-2-yl)fluorenyl)-1,1-diphenylmethane]hafnium dichloro, [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-(2-phenylpropan-2-yl)fluorenyl)-1,1-diphenylmethane]hafnium dibenzyl, or [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-(2-phenylpropan-2-yl)fluorenyl)-1,1-diphenylmethane]hafnium dimethyl.

6. A transition metal compound according to any one of claims 1 to 5, a cocatalyst selected from an aluminum compound, a boron compound, or a mixture thereof; A transition metal catalyst composition for producing a copolymer of ethylene and an α-olefin, comprising:

7. 7. The transition metal catalyst composition for producing an ethylene / α-olefin copolymer according to claim 6, wherein the aluminum compound used as the co-catalyst is one or more selected from aluminoxanes and organoaluminums.

8. a) mixing the transition metal catalyst composition for producing a copolymer of ethylene and an α-olefin according to claim 6, ethylene, and an α-olefin comonomer; b) carrying out a copolymerization reaction at a temperature of 110-170° C.; The present invention relates to a method for producing a copolymer of ethylene and an α-olefin, comprising the steps of:

9. The α-olefin copolymerized with the ethylene is one or more selected from the group consisting of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, cyclopentene, cyclohexene, norbornene, phenylnorbornene, styrene, α-methylstyrene, p-methylstyrene, and 3-chloromethylstyrene. The method for producing a copolymer of ethylene and α-olefin according to claim 8.

10. The method for producing an ethylene and α-olefin copolymer according to claim 8, wherein the step b) is carried out at a temperature of 120 to 160° C. and a pressure of 10 to 100 bar.

11. The method for producing an ethylene and α-olefin copolymer according to claim 8, wherein the method is carried out in a C5-C12 aliphatic hydrocarbon solvent.

12. A copolymer of ethylene and an α-olefin produced by using the transition metal compound according to any one of claims 1 to 5 as a catalyst.

Images