Transition metal compound, catalyst composition including the same, and method for preparing olefin polymer using the same

Abstract

A transition metal compound, a catalyst composition comprising the same, and a method for preparing olefin polymers using the same are provided. The transition metal compound of the present invention, by introducing specific functional groups at specific positions, exhibits high solubility and catalytic activity. Furthermore, the method for preparing olefin polymers using this transition metal compound allows for the easy preparation of olefin polymers with excellent physical properties through a simple process.

Description

Technical Field

[0001] The following disclosure relates to a transition metal compound, a catalyst composition comprising the same, and a method for preparing an olefin polymer using the same, and more specifically, to a transition metal compound having improved solubility by introducing controlled specific functional groups, a catalyst composition comprising the same, and a method for preparing an olefin polymer using the same. Prior Technology

[0002] Typically, in the preparation of homopolymers of ethylene or copolymers of ethylene and α-olefins, a so-called Ziegler-Natta catalyst system has been used, which contains a primary catalyst component of titanium or vanadium compounds and a cocatalyst component of alkyl aluminum compounds.

[0003] However, although the Ziegler-Natta catalyst system exhibits high activity in ethylene polymerization, its drawback is that the polymers produced typically have a wide molecular weight distribution due to heterogeneous catalytic active sites, and specifically, copolymers of ethylene and α-olefins have an uneven compositional distribution.

[0004] Recently, so-called metallocene catalyst systems have been developed, which include metallocene compounds containing Group 4 transition metals (e.g., titanium, zirconium, and hafnium) and methylaluminoxanes as co-catalysts. Since metallocene catalyst systems are homogeneous catalysts with a single catalyst active site, they are characterized by the preparation of polyethylene with a narrow molecular weight distribution and a uniform composition distribution, compared to traditional Ziegler-Natta catalyst systems.

[0005] As a specific example, by using methylaluminoxane as a co-catalyst to activate metallocene compounds such as Cp₂TiCl₂, Cp₂ZrCl₂, Cp₂ZrMeCl, Cp₂ZrMe₂, and ethylene (IndH₄)₂ZrCl₂, ethylene was polymerized with high activity, thereby preparing polyethylene with a narrow molecular weight distribution (Mw / Mn).

[0006] However, it is difficult to obtain high molecular weight polymers using metallocene catalyst systems. Specifically, when metallocene catalyst systems are used in solution polymerization at or above 100°C, the polymerization activity decreases rapidly, and the β-dehydrogenation reaction becomes dominant. Therefore, metallocene catalyst systems are not suitable for preparing high molecular weight polymers with high weight average molecular weight (Mw).

[0007] Meanwhile, it is known that polymers with high catalytic activity and high molecular weight can be prepared by homopolymerization of ethylene or copolymerization of ethylene and α-olefins under solution polymerization conditions at or above 100°C. So-called geometrically constrained ANSA-type metallocene-based catalysts, in which transition metals are linked in a ring, can be used. Compared to metallocene catalysts, ANSA-type metallocene catalysts exhibit significantly improved octene-injection and high-temperature activity. However, most previously known ANSA-type metallocene catalysts contain Cl functional groups or methyl groups, and therefore have issues that need improvement when used in solution processes.

[0008] Since the substituted Cl functional groups in the catalyst can cause corrosion, depending on the materials of the process equipment used in the process, ANSA-type metallocene catalysts with dimethyl substitution have been studied to avoid corrosion problems caused by Cl. However, ANSA-type metallocene catalysts are also difficult to inject into the polymerization process due to their poor solubility. Toluene or xylene can be used to dissolve these poorly soluble catalysts, but in the production of products that may come into contact with food, the use of aromatic solvents such as toluene or xylene can cause problems.

[0009] Therefore, there is an urgent need to study a competitive catalyst with properties such as excellent solubility, high-temperature activity, reactivity with higher α-olefins, and the ability to prepare high molecular weight polymers. Summary of the Invention

[0010] [Technical Issues]

[0011] One embodiment of the present invention relates to providing a transition metal compound to which controlled specific functional groups are introduced to improve the above-mentioned problems, and a catalyst composition comprising the same.

[0012] One embodiment of the present invention relates to a method for preparing olefin polymers using the transition metal compound of the present invention as a catalyst. [Technical Solutions]

[0013] In a general embodiment, a transition metal compound exhibiting significantly improved solubility in non-aromatic hydrocarbons is provided, and the transition metal compound of the present invention is represented by the following chemical formula 1: [Chemical Formula 1] in, The M series are group 4 transition metals in the periodic table; The A series consists of carbon or silicon; R1 to R4 are each independently hydrogen or C1 to C20 alkyl; R5 to R12 are independently hydrogen, C1 to C20 alkyl, C1 to C20 alkoxy, C3 to C20 cycloalkyl, C6 to C20 aryl, C6 to C20 arylC1 to C20 alkyl, C1 to C20 alkylC6 to C20 aryl, triC1 to C20 alkylsilyl, or triC6 to C20 arylsilyl, or each of R5 to R12 may be attached to an adjacent substituent by a C3 to C12 alkenylyl group having or not having a fused ring, to form an alicyclic ring or a monocyclic or polycyclic aromatic ring; R13 and R14 are independent of each other and are C6 to C20 aryl groups; The X series consists of conjugated or non-conjugated C4 to C20 dienes; The diene may be further substituted with one or more substituents selected from the group consisting of: C1 to C20 alkyl, C3 to C20 cycloalkyl, C6 to C20 aryl, C6 to C20 arylC1 to C20 alkyl, C1 to C20 alkylC6 to C20 aryl, C1 to C20 alkoxy, C6 to C20 aryloxy, triC1 to C20 alkylsilyl, and triC6 to C20 arylsilyl; and The diene forms a π-complex with the central metal M.

[0014] Preferably, in chemical formula 1 of an exemplary embodiment of the present invention, M may be a group 4 transition metal in the periodic table; A may be carbon or silicon; R1 to R4 may be hydrogen or C1 to C10 alkyl; R5 to R12 may be hydrogen, C1 to C10 alkyl, C1 to C10 alkoxy, C3 to C10 cycloalkyl, C6 to C10 aryl, C6 to C10 arylC1 to C10 alkyl, C1 to C10 alkylC6 to C10 aryl, triC1 to C10 alkylsilyl, or triC6 to C10 arylsilyl, or each of R5 to R12 may be formed by having or not having a fused ring of C3 to C12 alkyl or C3 to C10 alkylsilyl. R12 is an alkenyl group attached to an adjacent substituent to form an alicyclic or monocyclic or polycyclic aromatic ring; R13 and R14 can be independently C6 to C10 aryl groups; X can be a conjugated or non-conjugated C4 to C10 diene; the diene can be further substituted with one or more substituents selected from the group consisting of: C1 to C10 alkyl, C3 to C10 cycloalkyl, C6 to C10 aryl, C6 to C10 aryl C1 to C10 alkyl, C1 to C10 alkyl C6 to C10 aryl, C1 to C10 alkoxy, C6 to C10 aryloxy, triC1 to C10 alkylsilyl, and triC6 to C10 arylsilyl; and the diene can form a π-wedge with the central metal M.

[0015] More preferably, in chemical formula 1 of an exemplary embodiment of the present invention, M may be Ti, Zr, or Hf; A may be carbon or silicon; R1 to R4 may be hydrogen or C1 to C4 alkyl; R5 to R12 may be hydrogen, C1 to C4 alkyl, or C1 to C4 alkoxy; R13 and R14 may be C6 to C10 aryl; X may be a conjugated or non-conjugated C4 to C7 diene; the diene may be further substituted by one or more substituents selected from the group consisting of: C1 to C10 alkyl, C3 to C10 cycloalkyl, C6 to C10 aryl, C6 to C10 aryl C1 to C10 alkyl, C1 to C10 alkyl C6 to C10 aryl, C1 to C10 alkoxy, C6 to C10 alkyl, C6 to C10 alkyl, C6 to C10 alkoxy, C6 to C10 alkyl, C6 to C10 alkyl, C1 to C10 alkoxy, C6 to C10 alkyl, C1 ... 10 aryloxy, tri-C1 to C10 alkylsilyl and tri-C6 to C10 arylsilyl; and the diene can form a π-wedge with the central metal M.

[0016] In one exemplary embodiment of the present invention, the transition metal compound may be represented by the following chemical formula 2: [Chemical Formula 2] in, The M series consists of Ti, Zr, or Hf; The A series consists of carbon or silicon; R1 to R4 are each independently hydrogen or C1 to C4 alkyl; R13 and R14 are independent of each other and are C6 to C10 aryl groups; X series , , , , , , , ,or ; R 21 to R 27 are each independently hydrogen, C1 to C10 alkyl, C3 to C10 cycloalkyl, C6 to C10 aryl, C6 to C10 arylC1 to C10 alkyl, C1 to C10 alkylC6 to C10 aryl, C1 to C10 alkoxy, C6 to C10 aryloxy, triC1 to C10 alkylsilyl, or triC6 to C10 arylsilyl; m is an integer from 1 to 3; and X forms a π-wrong compound with the central metal M.

[0017] Specifically, in one exemplary embodiment of the present invention, the transition metal compound may be selected from the following compounds: .

[0018] According to one exemplary embodiment of the present invention, the solubility of the transition metal compound in methylcyclohexane at 25°C can be 5% by weight or greater than 5% by weight.

[0019] In another general embodiment, a transition metal catalyst composition for preparing ethylene homopolymers or copolymers of ethylene and α-olefins is provided, the transition metal catalyst composition comprising a transition metal compound according to the present invention, and the transition metal catalyst composition comprising: a transition metal compound represented by the following chemical formula 1; and a co-catalyst: [Chemical Formula 1] in, The M series are group 4 transition metals in the periodic table; The A series consists of carbon or silicon; R1 to R4 are each independently hydrogen or C1 to C20 alkyl; R5 to R12 are independently hydrogen, C1 to C20 alkyl, C1 to C20 alkoxy, C3 to C20 cycloalkyl, C6 to C20 aryl, C6 to C20 arylC1 to C20 alkyl, C1 to C20 alkylC6 to C20 aryl, triC1 to C20 alkylsilyl, or triC6 to C20 arylsilyl, or each of R5 to R12 may be connected to an adjacent substituent by a C3 to C12 enylalkyl or C3 to C12 enylene group having or not having a fused ring, to form an alicyclic ring or a monocyclic or polycyclic aromatic ring; R13 and R14 are independent of each other and are C6 to C20 aryl groups; The X series consists of conjugated or non-conjugated C4 to C20 dienes; The diene may be further substituted with one or more substituents selected from the group consisting of: C1 to C20 alkyl, C3 to C20 cycloalkyl, C6 to C20 aryl, C6 to C20 arylC1 to C20 alkyl, C1 to C20 alkylC6 to C20 aryl, C1 to C20 alkoxy, C6 to C20 aryloxy, triC1 to C20 alkylsilyl, and triC6 to C20 arylsilyl; and The diene forms a π-wrong compound with the central metal M.

[0020] The co-catalyst included in the transition metal catalyst composition may be an aluminum compound co-catalyst, a boron compound co-catalyst, or a mixture thereof.

[0021] In another general embodiment, a method for preparing olefin polymers using transition metal compounds according to the present invention is provided.

[0022] A method for preparing olefin polymers includes: obtaining an olefin polymer by solution polymerization of one or more monomers selected from ethylene and α-olefins in the presence of a transition metal compound represented by chemical formula 1, a co-catalyst, and a non-aromatic solvent.

[0023] The non-aromatic solvent may be selected from one or more of the following groups: methylcyclohexane, cyclohexane, n-heptane, n-hexane, n-butane, isobutane, n-pentane, n-octane, isooctane, nonane, decane, and dodecane, and at 25°C, the solubility of the transition metal compound according to one exemplary embodiment of the present invention in the non-aromatic solvent may be 5% by weight or greater than 5% by weight.

[0024] Preferably, in the method for preparing an olefin polymer according to an exemplary embodiment of the present invention, the co-catalyst may be an aluminum compound co-catalyst, a boron compound co-catalyst, or a mixture thereof. Specifically, the boron compound co-catalyst may be a mixture of one or more compounds selected from those represented by chemical formulas 11 to 14, and the aluminum compound co-catalyst may be a mixture of one or more compounds selected from those represented by chemical formulas 15 to 19. [Chemical Formula 11] BR 31 3 [Chemical Formula 12] [R 32] +[BR 31 4] - [Chemical Formula 13] [R 33 pZH] +[BR 31 4] - [Chemical Formula 14] in, The B series consists of boron atoms; R 31 is a phenyl group, and the phenyl group may be further substituted with 3 to 5 substituents selected from the group consisting of: fluorine atom, C1 to C20 alkyl, C1 to C20 alkyl group substituted with fluorine atom, C1 to C20 alkoxy group, and C1 to C20 alkoxy group substituted with fluorine atom; The R32 series consists of C5 to C7 aromatic radicals, C1 to C20 alkyl-C6 to C20 aryl radicals, or C6 to C20 aryl-C1 to C20 alkyl radicals. The Z series consists of nitrogen or phosphorus atoms; R33 series refers to C1 to C20 alkyl radicals or anilinium radicals that are substituted with two C1 to C10 alkyl groups and one nitrogen atom. The R34 series consists of C5 to C20 alkyl groups; The R 35 series consists of C5 to C20 aryl or C1 to C20 alkyl and C6 to C20 aryl groups; and p is an integer of 2 or 3. [Chemical Formula 15] -(Al(R 41)-O) r- [Chemical Formula 16] (R 42) 2Al-(-O(R 42)-) sO-Al(R 42) 2 [Chemical Formula 17] (R 43) tAl(E) 3-t [Chemical Formula 18] (R 44) 2AlOR 45 [Chemical Formula 19] R 44Al(OR 45) 2 in, R 41 and R 42 are independently C1 to C20 alkyl groups; r and s are independent integers from 5 to 20; R 43 and R 44 are independently C1 to C20 alkyl groups; The E series consists of hydrogen or halogens; t is an integer from 1 to 3; and The R 45 series are C1 to C20 alkyl or C6 to C30 aryl.

[0025] Preferably, in the method for preparing an olefin polymer according to one exemplary embodiment of the present invention, solution polymerization can be carried out at 100°C to 220°C. [Beneficial Effects]

[0026] By introducing controlled specific functional groups, the transition metal compounds of the present invention exhibit significantly improved solubility in non-aromatic hydrocarbon solvents, and therefore high catalytic activity, which is maintained without decrease during solution polymerization.

[0027] Furthermore, by introducing specific functional groups to specific locations, the transition metal compounds according to the present invention can be easily injected and transferred during solution processing, thereby significantly improving the polymerization process and potentially being highly advantageous for commercialization.

[0028] Furthermore, since the transition metal compound according to the present invention has excellent solubility in non-aromatic hydrocarbon solvents, it has excellent reactivity with olefins, making it easy to polymerize olefins and resulting in high yields of olefin polymers. Therefore, a catalyst composition containing a transition metal compound according to an exemplary embodiment of the present invention can be used industrially in a method for preparing olefin polymers with excellent physical properties.

[0029] The method for preparing olefin polymers according to the present invention uses the transition metal compound of the present invention, which has excellent solubility in non-aromatic hydrocarbon solvents, thereby facilitating the transport and injection of this catalyst, and enabling the preparation of olefin polymers in a more environmentally friendly and efficient manner. Simple Explanation of the Diagram

[0030] none Implementation

[0031] The following will describe in detail the transition metal compounds according to the present invention, the catalyst compositions comprising them, and the methods for preparing olefin polymers using them.

[0032] Unless otherwise stated in the context, the singular form used in this specification may be intended to include the plural form as well.

[0033] The term "comprising" as used in this specification is an open-ended term that has the same meaning as terms such as "equipped with," "containing," "having," or "characterized by," and does not exclude components, materials, or processes not further listed.

[0034] In this specification, the terms "substituent", "free radical", "group", "moiety" and "fraction" are used interchangeably.

[0035] In this specification, the terms "CA to CB" refer to "a carbon number of A or greater than A and a carbon number of B or less than B".

[0036] As used in this specification, the term "alkyl" refers to a saturated straight-chain or branched acyclic hydrocarbon having 1 to 20 carbon atoms, wherein the number of carbon atoms is not particularly limited. 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 alkyl groups include isopropyl, secondary butyl, isobutyl, tert-butyl, isopentyl, 2-methylhexyl, 3-methylbutyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, 2,3-dimethylbutyl, 2,3-dimethylpentyl, 2,4-dimethylpentyl, 2,3-dimethylhexyl, 2,4-dimethylhexyl, 2,5-dimethyl... Hexyl, 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, and 2,2-diethylhexyl.

[0037] As used in this specification, "alkenyl" refers to a saturated straight-chain or branched acyclic hydrocarbon containing preferably 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, and at least one carbon-carbon double bond. Representative straight-chain or branched C2 to C10 alkenyl groups include vinyl, allyl, 1-butenyl, 2-butenyl, isobutenyl, 1-pentenyl, 2-pentenyl, 3-methyl-1-butenyl, 2-methyl-2-butenyl, 2,3-dimethyl-2-butenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 1-heptenyl, 2-heptenyl, 3-heptenyl, 1-octenyl, 2-octenyl, 3-octenyl, 1-nonenyl, 2-nonenyl, 3-nonenyl, 1-dicenyl, 2-dienyl, and 3-dienyl. Alkenyl groups include cis- and trans-oriented radicals, or alternatively, radicals with E and Z orientations.

[0038] In this specification, "alkoxy" refers to -O- (alkyl), including -OCH 3, -OCH 2CH 3, -O(CH 2) 2CH 3, -O(CH 2) 3CH 3, -O(CH 2) 4CH 3, -O(CH 2) 5CH 3, etc., wherein alkyl is as defined above.

[0039] In this specification, "alkyl" and "alkenyl" refer to divalent organic radicals obtained from "alkyl" and "alkenyl" respectively by removing a hydrogen atom, wherein alkyl and alkenyl are as defined above.

[0040] As used in this specification, the term "cycloalkyl" refers to a monocyclic or polycyclic saturated ring having carbon and hydrogen atoms and no carbon-carbon multiple bonds. Examples of cycloalkyl groups include C3 to C10 cycloalkyl groups, and include, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl, but are not limited thereto. In an exemplary embodiment, the cycloalkyl group is monocyclic or bicyclic.

[0041] The term "aryl" as used in this specification refers to an organic radical derived from an aromatic hydrocarbon by removing a hydrogen atom, and includes monocyclic or fused-ring systems containing 4 to 7, preferably 5 or 6 ring atoms in each ring, and even systems in which multiple aryl groups are linked by single bonds. Fused-ring systems may contain aliphatic rings, such as saturated or partially saturated rings, and must contain one or more aromatic rings. Furthermore, aliphatic rings may contain nitrogen, oxygen, sulfur, carbonyl, etc. Specific examples of aryl radicals include, but are not limited to, phenyl, naphthyl, biphenyl, indyl, fumonisinyl, phenanthrene, anthracene, triphenylenyl, pyrene, chrysenyl, naphthacenyl, 9,10-dihydroanthrayl, etc.

[0042] In this specification, the term "alkylaryl" refers to an aryl radical substituted with at least one alkyl group, wherein "alkyl" and "aryl" are as defined above. Specific examples of alkylaryl groups include, but are not limited to, tolyl groups.

[0043] In this specification, the term "arylalkyl" refers to an alkyl radical substituted with at least one aryl group, wherein "alkyl" and "aryl" are as defined above. Specific examples of arylalkyl groups include, but are not limited to, benzyl groups.

[0044] In this specification, the term "aryloxy group" refers to the -O-aryl radical, where "aryl" is as defined above.

[0045] Specific examples of "alkylsilyl" and "arylsilyl" as described in this specification include, but are not limited to, trimethylsilyl, triethylsilyl, tributyldimethylsilyl, propyldimethylsilyl, triphenylsilyl, diphenylsilyl, phenylsilyl, etc.

[0046] As used in this specification, the term "diene" means a compound containing two double bonds between carbon atoms and may be selected from the following compounds: s-trans-1,3-butadiene, s-cis-1,3-butadiene, 2,4-pentadiene, cyclopentadiene, 1,3-cyclohexadiene, 1,4-cyclohexadiene and bicyclo[2.2.1]hept-1,3-diene, or derivatives thereof. For example, it can be s-trans-n4-1,4-diphenyl-1,3-butadiene; s-trans-n4-3-methyl-1,3-pentadiene; s-trans-n4-1,4-dibenzyl-1,3-butadiene; s-trans-n4-1,3-pentadiene; s-trans-n4-2,4-hexadiene; s-trans-n4-1,4-dimethyl-1,3-butadiene; s-trans-n4-1,4-bis(trimethylsilyl)-1,3-butadiene; s-cis-n4-1,4-diphenyl-1,3-butadiene; s-cis-n4-3-methyl-1,3-pentadiene; s-cis-n4-1,4-dibenzyl-1,3-butadiene; s-cis-n4-1,3-pentadiene; s-cis-n4-2,4-hexadiene; s-cis-n4-1,4-dimethyl-1,3-butadiene; or s-cis-n4-1,4-bis(trimethylsilyl)-1,3-butadiene, but not limited to these.

[0047] As used herein, the term "olefin polymer" refers to a polymer prepared using olefins within the scope that is readily apparent to those skilled in the art. Specifically, olefin polymers include both homopolymers of olefins and copolymers of olefins, and refer to homopolymers of olefins or copolymers of olefins and α-olefins.

[0048] This invention provides a transition metal compound represented by the following chemical formula 1, which, due to the improved solubility and thermal stability achieved by introducing conjugated or non-conjugated diene functional groups, can be used extremely effectively for olefin polymerization: [Chemical Formula 1] in, The M series are group 4 transition metals in the periodic table; The A series consists of carbon or silicon; R1 to R4 are each independently hydrogen or C1 to C20 alkyl; R5 to R12 are independently hydrogen, C1 to C20 alkyl, C1 to C20 alkoxy, C3 to C20 cycloalkyl, C6 to C20 aryl, C6 to C20 arylC1 to C20 alkyl, C1 to C20 alkylC6 to C20 aryl, triC1 to C20 alkylsilyl, or triC6 to C20 arylsilyl, or each of R5 to R12 may be connected to an adjacent substituent by a C3 to C12 enylalkyl or C3 to C12 enylene group having or not having a fused ring, to form an alicyclic ring or a monocyclic or polycyclic aromatic ring; R13 and R14 are independent of each other and are C6 to C20 aryl groups; The X series consists of conjugated or non-conjugated C4 to C20 dienes; The diene may be further substituted with one or more substituents selected from the group consisting of: C1 to C20 alkyl, C3 to C20 cycloalkyl, C6 to C20 aryl, C6 to C20 arylC1 to C20 alkyl, C1 to C20 alkylC6 to C20 aryl, C1 to C20 alkoxy, C6 to C20 aryloxy, triC1 to C20 alkylsilyl, and triC6 to C20 arylsilyl; and The diene forms a π-wrong compound with the central metal M.

[0049] According to one exemplary embodiment of the present invention, the transition metal compound is represented by chemical formula 1, and by introducing a conjugated or non-conjugated diene having 4 to 20 carbon atoms as X into chemical formula 1, the solubility in non-aromatic hydrocarbon solvents is significantly improved, and olefin polymers with high catalytic activity can be prepared in a more environmentally friendly manner through a simple process.

[0050] Specifically, the transition metal compound of the present invention, which serves as the ANSA-type catalyst of the present invention, can increase its solubility in non-aromatic hydrocarbon solvents and maintain its catalytic activity by introducing diene functional groups at specific positions. At the same time, olefin polymers can be easily prepared by solution processing.

[0051] Preferably, in chemical formula 1 of an exemplary embodiment of the present invention, M may be a group 4 transition metal in the periodic table; A may be carbon or silicon; R1 to R4 may be hydrogen or C1 to C10 alkyl; R5 to R12 may be hydrogen, C1 to C10 alkyl, C1 to C10 alkoxy, C3 to C10 cycloalkyl, C6 to C10 aryl, C6 to C10 arylC1 to C10 alkyl, C1 to C10 alkylC6 to C10 aryl, triC1 to C10 alkylsilyl, or triC6 to C10 arylsilyl, or each of R5 to R12 may be formed by having or not having a fused ring of C3 to C12 alkyl or C3 to C10 alkylsilyl. R12 is an alkenyl group attached to an adjacent substituent to form an alicyclic ring or a monocyclic or polycyclic aromatic ring; R13 and R14 can be independently C6 to C10 aryl groups; X can be a conjugated or non-conjugated C4 to C10 diene; the diene can be further substituted with one or more substituents selected from the group consisting of: C1 to C10 alkyl, C3 to C10 cycloalkyl, C6 to C10 aryl, C6 to C10 aryl C1 to C10 alkyl, C1 to C10 alkyl C6 to C10 aryl, C1 to C10 alkoxy, C6 to C10 aryloxy, triC1 to C10 alkylsilyl, and triC6 to C10 arylsilyl; and the diene can form a π-wedge with the central metal M.

[0052] More preferably, in chemical formula 1 of an exemplary embodiment of the present invention, M may be Ti, Zr, or Hf; A may be carbon or silicon; R1 to R4 may be hydrogen or C1 to C4 alkyl; R5 to R12 may be hydrogen, C1 to C4 alkyl, or C1 to C4 alkoxy; R13 and R14 may be C6 to C10 aryl; X may be a conjugated or non-conjugated C4 to C7 diene; the diene may be further substituted by one or more substituents selected from the group consisting of: C1 to C10 alkyl, C3 to C10 cycloalkyl, C6 to C10 aryl, C6 to C10 aryl C1 to C10 alkyl, C1 to C10 alkyl C6 to C10 aryl, C1 to C10 alkoxy, C6 to C10 alkyl, C6 to C10 alkyl, C6 to C10 alkoxy, C6 to C10 alkyl, C6 to C10 alkyl, C1 to C10 alkoxy, C6 to C10 alkyl, C1 ... 10 aryloxy, tri-C1 to C10 alkylsilyl and tri-C6 to C10 arylsilyl; and the diene can form a π-wedge with the central metal M.

[0053] In one exemplary embodiment of the present invention, the transition metal compound may be represented by the following chemical formula 2: [Chemical Formula 2] in, The M series consists of Ti, Zr, or Hf; The A series consists of carbon or silicon; R1 to R4 are each independently hydrogen or C1 to C4 alkyl; R13 and R14 are independent of each other and are C6 to C10 aryl groups; X series , , , , , , , ,or ; R 21 to R 27 are each independently hydrogen, C1 to C10 alkyl, C3 to C10 cycloalkyl, C6 to C10 aryl, C6 to C10 arylC1 to C10 alkyl, C1 to C10 alkylC6 to C10 aryl, C1 to C10 alkoxy, C6 to C10 aryloxy, triC1 to C10 alkylsilyl, or triC6 to C10 arylsilyl; m is an integer from 1 to 3; and X forms a π-wrong compound with the central metal M.

[0054] Specifically, in one exemplary embodiment of the present invention, the transition metal compound may be selected from the following compounds: .

[0055] According to one exemplary embodiment of the present invention, the solubility of the transition metal compound in methylcyclohexane at 25°C can be 5% by weight or greater than 5% by weight, preferably 5.5% by weight to 50% by weight.

[0056] Furthermore, the present invention provides a transition metal catalyst composition for preparing ethylene homopolymers or copolymers of ethylene and α-olefins, the transition metal catalyst composition comprising a transition metal compound according to the present invention, and the transition metal catalyst composition comprising: a transition metal compound represented by the following chemical formula 1; and a co-catalyst: [Chemical Formula 1] in, The M series are group 4 transition metals in the periodic table; The A series consists of carbon or silicon; R1 to R4 are each independently hydrogen or C1 to C20 alkyl; R5 to R12 are independently hydrogen, C1 to C20 alkyl, C1 to C20 alkoxy, C3 to C20 cycloalkyl, C6 to C20 aryl, C6 to C20 arylC1 to C20 alkyl, C1 to C20 alkylC6 to C20 aryl, triC1 to C20 alkylsilyl, or triC6 to C20 arylsilyl, or each of R5 to R12 may be connected to an adjacent substituent by a C3 to C12 enylalkyl or C3 to C12 enylene group having or not having a fused ring, to form an alicyclic ring or a monocyclic or polycyclic aromatic ring; R13 and R14 are independent of each other and are C6 to C20 aryl groups; The X series consists of conjugated or non-conjugated C4 to C20 dienes; The diene may be further substituted with one or more substituents selected from the group consisting of: C1 to C20 alkyl, C3 to C20 cycloalkyl, C6 to C20 aryl, C6 to C20 arylC1 to C20 alkyl, C1 to C20 alkylC6 to C20 aryl, C1 to C20 alkoxy, C6 to C20 aryloxy, triC1 to C20 alkylsilyl, and triC6 to C20 arylsilyl; and The diene forms a π-wrong compound with the central metal M.

[0057] The co-catalyst included in the transition metal catalyst composition may be an aluminum compound co-catalyst, a boron compound co-catalyst, or a mixture thereof.

[0058] Furthermore, the present invention provides a method for preparing olefin polymers using transition metal compounds according to the present invention.

[0059] A method for preparing olefin polymers includes: obtaining an olefin polymer by solution polymerization of one or more monomers selected from ethylene and α-olefins in the presence of a transition metal compound represented by chemical formula 1, a co-catalyst, and a non-aromatic solvent.

[0060] The non-aromatic solvent may be selected from one or more of the following groups: methylcyclohexane, cyclohexane, n-heptane, n-hexane, n-butane, isobutane, n-pentane, n-octane, isooctane, nonane, decane, and dodecane. At 25°C, the solubility of the transition metal compound according to an exemplary embodiment of the present invention in the non-aromatic solvent may be 5% by weight or greater than 5% by weight, preferably 5.5% by weight to 50% by weight.

[0061] Preferably, in the method for preparing an olefin polymer according to an exemplary embodiment of the present invention, the co-catalyst may be an aluminum compound co-catalyst, a boron compound co-catalyst, or a mixture thereof, and the molar ratio of the transition metal compound to the co-catalyst may be from 1:0.5 to 10,000.

[0062] Specifically, the boron compound co-catalyst may be one or a mixture of two or more compounds selected from those represented by chemical formulas 11 to 14: [Chemical Formula 11] BR 31 3 [Chemical Formula 12] [R 32] +[BR 31 4] - [Chemical Formula 13] [R 33 pZH] +[BR 31 4] - [Chemical Formula 14] in, The B series consists of boron atoms; R 31 is a phenyl group, and the phenyl group may be further substituted with 3 to 5 substituents selected from the group consisting of: fluorine atom, C1 to C20 alkyl, C1 to C20 alkyl group substituted with fluorine atom, C1 to C20 alkoxy group, and C1 to C20 alkoxy group substituted with fluorine atom; The R32 series consists of C5 to C7 aromatic radicals, C1 to C20 alkyl-C6 to C20 aryl radicals, or C6 to C20 aryl-C1 to C20 alkyl radicals, such as triphenylmethylium radicals. The Z series consists of nitrogen or phosphorus atoms; The R33 series consists of C1 to C20 alkyl radicals or phenylamine radicals substituted with two C1 to C10 alkyl groups and one nitrogen atom; The R34 series consists of C5 to C20 alkyl groups; The R 35 series consists of C5 to C20 aryl or C1 to C20 alkyl and C6 to C20 aryl groups; and p is an integer of 2 or 3.

[0063] The boron compound co-catalyst may be selected from one or more of the following: 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, bis(pentafluorophenyl)(phenyl)borane, etc.

[0064] The boron compound co-catalyst may be one or more boron compounds having one, two or more borate anions selected from the following group: tetra(pentafluorophenyl)borate, tetra(2,3,5,6-tetrafluorophenyl)borate, tetra(2,3,4,5-tetrafluorophenyl)borate, tetra(3,4,5-trifluorophenyl)borate, tetra(2,2,4-trifluorophenyl)borate, tri(pentafluorophenyl)(phenyl)borate and tetra(3,5-bistrifluoromethylphenyl)borate.

[0065] The boron compound co-catalyst may be a boron compound having one or more cations selected from the following group: triphenylmethylium, triethylammonium, tripropylammonium, tri(n-butylammonium), N,N-dimethylanilinium, N,N-diethylanilinium, N,N-2,4,6-pentamethylanilinium, diisopropylammonium, dicyclohexylammonium, triphenylphosphonium, tri(methylphenyl)phosphonium, and tri(dimethylphenyl)phosphonium.

[0066] Specifically, the boron compound co-catalyst may be one or more boron compounds having a cation and a borate anion, wherein the cation is selected from the group consisting of: triphenylmethylonium, triethylammonium, tripropylammonium, tri(n-butylammonium), N,N-dimethylphenylammonium, N,N-diethylphenylammonium, N,N-2,4,6-pentamethylphenylammonium, diisopropylammonium, dicyclohexylammonium, triphenylphosphonium, tri(methylphenyl)phosphonium and tri(dimethylphenyl)phosphonium; and the borate anion is selected from the group consisting of: tetra(pentafluorophenyl)borate, tetra(2,3,5,6-tetrafluorophenyl)borate, tetra(2,3,4,5-tetrafluorophenyl)borate, tetra(3,4,5-trifluorophenyl)borate, tetra(2,2,4-trifluorophenyl)borate, tri(pentafluorophenyl)(phenyl)borate and tetra(3,5-bistrifluoromethylphenyl)borate.

[0067] More specifically, the boron compound co-catalyst may be selected from one or more of the following groups: triphenylmethylium tetrakis(pentafluorophenyl)borate, triphenylmethylium tetrakis(3,5-bistrifluoromethylphenyl)borate, triethylammonium tetrakis(pentafluorophenyl)borate, tripropylammonium tetrakis(pentafluorophenyl)borate, tri(n-butyl)ammonium tetrakis(pentafluorophenyl)borate, tri(n-butyl)ammonium tetrakis(3,5-bistrifluoromethylphenyl)borate, N,N-dimethylphenylammonium tetrakis(pentafluorophenyl)borate, N,N-diethylphenylammonium tetrakis(pentafluorophenyl)borate, N,N-2,4,6-pentamethylphenylammonium tetrakis(pentafluorophenyl)borate, and N,N-2,4,6-pentamethylphenylammonium tetrakis(pentafluorophenyl)borate. Pentafluorophenyl)borate, N,N-dimethylphenylammonium tetra(3,5-bis(trifluoromethylphenyl)borate, diisopropylammonium tetra(pentafluorophenyl)borate, dicyclohexylammonium tetra(pentafluorophenyl)borate, triphenylphosphonium tetra(pentafluorophenyl)borate, tri(methylphenyl)phosphonium tetra(pentafluorophenyl)borate and tri(dimethylphenyl)phosphonium tetra(pentafluorophenyl)borate, and more preferably, selected from one or more of the following groups: triphenylmethylonium tetra(pentafluorophenyl)borate, N,N-dimethylphenylammonium tetra(pentafluorophenyl)borate and tri(pentafluorophenyl)borane.

[0068] Specifically, the aluminum compound co-catalyst may be one or a mixture of two or more of the following: aluminum oxane compound of formula 15 or 16, organoaluminum compound of formula 17, organoaluminum alkyl oxide compound of formula 18 or 19, or organoaluminum aryl oxide compound. [Chemical Formula 15] -(Al(R 41)-O) r- [Chemical Formula 16] (R 42) 2Al-(-O(R 42)-) sO-Al(R 42) 2 [Chemical Formula 17] (R 43) tAl(E) 3-t [Chemical Formula 18] (R 44) 2AlOR 45 [Chemical Formula 19] R 44Al(OR 45) 2 in, R 41 and R 42 are independently C1 to C20 alkyl groups; r and s are independent integers from 5 to 20; R 43 and R 44 are independently C1 to C20 alkyl groups; The E series consists of hydrogen or halogens; t is an integer from 1 to 3; and The R 45 series are C1 to C20 alkyl or C6 to C30 aryl.

[0069] Aluminoxane compounds may include, for example, methylaluminoxane and modified methylaluminoxane. Examples of organoaluminoxanes include: trialkylaluminum, including trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, and trihexylaluminum; dialkylaluminum chloride, including dimethylaluminum chloride, diethylaluminum chloride, dipropylaluminum chloride, diisobutylaluminum chloride, and dihexylaluminum chloride; alkylaluminum chloride, including methylaluminum chloride, ethylaluminum chloride, propylaluminum chloride, isobutylaluminum chloride, and hexylaluminum chloride; dialkylaluminum hydride, including dimethylaluminum hydride, diethylaluminum hydride, dipropylaluminum hydride, diisobutylaluminum hydride, and dihexylaluminum hydride; and alkylalkoxyaluminum, including methyldimethoxyaluminum, dimethylmethoxyaluminum, ethyldiethoxyaluminum, diethylethoxyaluminum, isobutyldibutoxyaluminum, diisobutylbutoxyaluminum, hexyldimethoxyaluminum, dihexylmethoxyaluminum, and dioctylmethoxyaluminum.

[0070] Preferably, it may be methylaluminoxane, modified methylaluminoxane, tetraisobutylaluminoxane, trialkylaluminum, triethylaluminum, triisobutylaluminum or a mixture thereof, and more preferably, it may be methylaluminoxane, modified methylaluminoxane or trialkylaluminum, specifically triethylaluminum and triisobutylaluminum.

[0071] In a catalyst composition according to one exemplary embodiment of the present invention, when an aluminum compound is used as a co-catalyst, the ratio between the transition metal compound of the present invention and the co-catalyst, in terms of the molar ratio of transition metal (M): aluminum atom (Al), is preferably in the range of 1:10 to 1,000, specifically 1:25 to 500.

[0072] In a catalyst composition according to one exemplary embodiment of the present invention, when both the aluminum compound and the boron compound are used as co-catalysts, the ratio between the transition metal compound and the co-catalyst, in terms of the molar ratio of transition metal (M):boron atom (B):aluminum atom (Al), is preferably in the range of 1:0.1 to 100:10 to 1,000, specifically 1:0.5 to 5:25 to 500. Within this range of the ratio between the transition metal compound and the co-catalyst of the present invention, excellent catalytic activity is exhibited for the preparation of olefin polymers, and this ratio range varies depending on the purity of the reaction.

[0073] As an exemplary embodiment of another aspect of the present invention, a method for preparing olefin polymers using transition metal compounds can be carried out by contacting a transition metal compound, a co-catalyst, and ethylene or ethylene-based comonomers (if necessary) in the presence of a non-aromatic solvent.

[0074] Here, the transition metal compound and the co-catalyst component can be added to the reactor separately, or each component can be pre-mixed and then added to the reactor, and the mixing conditions, such as the order of addition, temperature or concentration, are not restricted separately.

[0075] Preferred organic solvents used in the preparation method may be non-aromatic hydrocarbon solvents, specifically non-aromatic hydrocarbons having 3 to 20 carbon atoms, and for example, butane, isobutane, pentane, hexane, heptane, octane, isooctane, nonane, decane, dodecane, cyclohexane, methylcyclohexane, etc.

[0076] Specifically, when preparing copolymers of ethylene and α-olefins, α-olefins having 3 to 18 carbon atoms as comonomers can be used with ethylene, and preferably, can be selected from one or more of the following group: propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-hexadecene, and 1-octadecene. More specifically, 1-butene, 1-hexene, 1-octene, or 1-decene can be copolymerized with ethylene, and the preferred pressure of the ethylene is from 1 atmosphere (atm) to 1,000 atmospheres, more preferably from 10 atmospheres to 150 atmospheres.

[0077] Furthermore, in a method for preparing olefins according to one exemplary embodiment of the present invention, solution polymerization can be carried out at 100°C to 220°C, preferably 100°C to 200°C, and even more preferably 100°C to 150°C.

[0078] The copolymer prepared according to the method of the present invention may contain 50% to 99% ethylene, specifically 60% to 99% ethylene.

[0079] In a method for preparing olefin polymers according to one exemplary embodiment of the present invention, linear low-density polyethylene (LLDPE) prepared using α-olefins having 4 to 10 carbon atoms as comonomers has a density range of 0.940 g / cc or less than 0.940 g / cc, and this preparation can be extended to ultra-low-density polyethylene (ULDPE), very low-density polyethylene (VLDPE), or even olefin elastomers with a density range of 0.900 g / cc or less than 0.900 g / cc. Furthermore, in the preparation of ethylene copolymers according to the present invention, hydrogen can be used as a molecular weight regulator to adjust the molecular weight, and the prepared copolymer has a weight average molecular weight (Mw) of 80,000 to 500,000 g / mol.

[0080] As a specific example of an olefin-diene copolymer prepared by means of a catalyst composition according to an exemplary embodiment of the present invention, the ethylene-propylene-diene copolymer may have an ethylene content of 30% to 80% by weight, a propylene content of 20% to 70% by weight, and a diene content of 0% to 15% by weight. The diene monomers used in this invention have two or more double bonds and may be selected from one or more of the following group: 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, 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 ...4-hexadiene, 3,3-dimethyl-1,5-hexadiene, 3,3-dimethyl-1,4-hexadiene, 3,3-dimethyl-1,5-dimethyl-1,4 7-Hexadiene, 5-vinyl-2-norbornene, 2,5-norbornadiene, 7-methyl-2,5-norbornene, 7-ethyl-2,5-norbornene, 7-propyl-2,5-norbornene, 7-butyl-2,5-norbornene, 7-phenyl-2,5-norbornene, 7-hexyl-2,5-norbornene, 7,7-dimethyl-2,5-norbornene, 7-methyl-7-ethyl-2,5-norbornene, 7-chloro-2,5-norbornene, 7-bromo-2,5-norbornene, 7-fluoro-2,5-norbornene -Nobornene, 7,7-dichloro-2,5-norbornene, 1-methyl-2,5-norbornene, 1-ethyl-2,5-norbornene, 1-propyl-2,5-norbornene, 1-butyl-2,5-norbornene, 1-chloro-2,5-norbornene, 1-bromo-2,5-norbornene, 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]octa-2,5-diene, 4-vinyl-1- Cyclohexene, bicyclo[2,2,2]octa-2,6-diene, 1,7,7-trimethylbicyclo[2,2,1]hept-2,5-diene, dicyclopentadiene, phenyltetrahydroindene, 5-phenylbicyclo[2,2,1]hept-2-ene, 1,5-cyclooctadiene, 1,4-diphenylbenzene, butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-butadiene, 4-methyl-1,3-pentadiene, 1,3-pentadiene, 3-methyl-1,3-pentadiene, 2,4-dimethyl-1,3-pentadiene, and 3-ethyl-1,3-pentadiene, preferably 5-ethylidene-2-norcamphene, dicyclopentadiene, or mixtures thereof.The diene monomer can be selected based on the processing properties of the ethylene-propylene-diene copolymer.

[0081] The ethylene-olefin-diene copolymer prepared according to one exemplary embodiment of the present invention may have an ethylene content of 30% to 80% by weight, an olefin content of 20% to 70% by weight, and a diene content of 0% to 15% by weight, based on the total weight.

[0082] Generally, in the preparation of ethylene-propylene-diene copolymers, the molecular weight of the copolymer decreases as the propylene content increases. However, in the preparation of ethylene-propylene-diene copolymers according to an exemplary embodiment of the present invention, even when the propylene content is increased to as high as 50% by weight, a product with a relatively high molecular weight can be prepared without reducing the molecular weight.

[0083] Since the catalyst composition presented in this invention exists in a homogeneous form in the polymerization reactor, it is preferably applied to solution polymerization processes carried out at temperatures 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 slurry polymerization or gas-phase polymerization processes as a multiphase catalyst composition, which is obtained by loading a transition metal compound and a co-catalyst onto a porous metal oxide support.

[0084] The present invention will be described in more detail below with reference to specific embodiments, including novel transition metal compounds, catalyst compositions comprising the present invention, and methods for preparing olefin polymers using the present invention.

[0085] Unless otherwise stated, all experiments for the synthesis of transition metal compounds were conducted under a nitrogen atmosphere using standard Schlenk or glove box techniques, and the organic solvents used in the reactions were refluxed with sodium metal and benzophenone to remove moisture, followed by distillation immediately before use. The synthesized transition metal compounds were analyzed by 1H nuclear magnetic resonance (NMR) at room temperature using a Bruker 400 or 500 MHz.

[0086] The heptane used as the polymerization solvent was passed through a tube filled with 5 Å molecular sieves and activated alumina, and bubbled with high-purity nitrogen to thoroughly remove moisture, oxygen, and other toxic catalyst substances. The polymer was analyzed using the following method:

[0087] 1. Melt flow index (MI)

[0088] The melt flow index was measured at 190°C and a load of 2.16 kg using the ASTM D1238 analytical method.

[0089] 2. Density

[0090] The density was measured using the ASTM D792 analytical method.

[0091] 3. Molecular weight and molecular weight distribution

[0092] The molecular weight was measured by gel chromatography using a three-stage mixed column.

[0093] The solvent used in this paper is 1,2,4-trichlorobenzene, and the measurement temperature is 120℃.

[0094] [Example 1] Synthesis of Compound 1

[0095] Under a nitrogen atmosphere, 9-fluorenyl-1-diphenylmethylcyclopentadienyl zirconium dichloride (S-PCI product, 10.0 g, 18.0 mmol) was dissolved in 100 mL of toluene in a 250 mL round-bottom flask. After cooling to -15 °C, 1,3-pentadiene (cis and trans mixture; 3.7 g, 54.0 mmol) and 1.6 M butyllithium (22.5 mL, 35.9 mmol) were slowly added, and the temperature was raised to room temperature and stirred for 5 hours. The solvent was removed under vacuum, the concentrate was dissolved in 200 mL of methylcyclohexane, and the solution was filtered through a filter packed with dry diatomaceous earth to remove solids. All solvents were removed from the filtrate to obtain compound 1 (9.98 g, yield: 95.0%), which was red in color. 1H NMR (500 MHz, chloroform-d): δ = 8.23 ​​(d, 2H), 7.88 (dd, 4H), 7.45 (m, 4H), 7.31 (m, 4H), 7.01 (m, 2H), 6.42 (m, 4H), 5.64 (m, 2H), 4.01 (dd, J= 9.3, 7.3 Hz, 1H), 3.86 (ddd, J= 13.2, 9.3, 8.9 Hz, 1H), 2.98 (dd, J= 8.9, 8 Hz, 1H), 2.13 (m, 1H), 1.90 (d, J= 5.5 Hz, 3H), 1.76 (dd, J= 13.2, 7.3 Hz, 1H).

[0096] [Comparative Example 1]

[0097] The compound in Comparative Example 1 was purchased from S-PCI and used.

[0098] [Comparative Example 2]

[0099] Under a nitrogen atmosphere, 9-pyro-1-diphenylmethylcyclopentadienyl zirconium dichloride (10.0 g, 18.0 mmol) was dissolved in 100 mL of toluene in a 250 mL round-bottom flask. After the temperature was lowered to -15 °C, 1.5 M lithium methyl (24.0 mL, 35.9 mmol) was slowly added, the temperature was raised to room temperature, and the mixture was stirred for 3 hours. The solution was then filtered through a filter filled with dry diatomaceous earth to remove solids. After filtration, all solvent was removed from the filtrate to obtain the yellow compound of Comparative Example 2 (8.5 g, yield: 91.4%). 1H NMR (500 MHz, chloroform-d): 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).

[0100] [Experimental Example 1] Measurement of the solubility of the prepared transition metal compound

[0101] At 25°C and under a nitrogen atmosphere, 1 gram of a transition metal compound was dissolved in 4 grams of each of the solvents described in the table below to prepare a saturated solution. The solid was then removed using a 0.45-micron filter. After all solvents were removed, the weight of the remaining catalyst was measured, and the solubility of the catalyst was calculated and shown in Table 1 below. [Table 1] transition metal compounds Solubility in toluene (weight%) Solubility in methylcyclohexane (weight%) Example 1 >30 28.6 Comparative Example 1 0.3 Insoluble Comparative Example 2 1.1 Insoluble

[0102] As shown in Table 1, it was found that the transition metal compound prepared in Example 1 of the present invention has extremely high solubility in hydrocarbon solvents compared to Comparative Examples 1 and 2, and specifically, it exhibits surprisingly improved solubility in non-aromatic hydrocarbon solvents.

[0103] [Example 2] Copolymerization of ethylene and 1-octene via a continuous solution polymerization process

[0104] The copolymerization of ethylene and 1-octene was carried out in a continuous polymerization reactor equipped with a mechanical stirrer, which allowed for temperature control.

[0105] The transition metal compound of Example 1, as described in Table 2 below, was used as the catalyst, n-heptane as the solvent, and modified methylaluminoxane (20% by weight), Nouryon, as the co-catalyst. The catalysts were dissolved in toluene at a concentration of 0.2 g / L and injected, and polymerization was carried out using 1-octene as the comonomer. When one polymer was polymerized under each reaction condition, the reactor conversion rate could 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 to vary with reactor temperature and 1-octene content, and the conditions and results are shown in Table 2 below.

[0106] [Comparative Example 3]

[0107] The process was carried out in the same manner as in Example 2, except that the transition metal compound of Comparative Example 2 was used instead of the transition metal compound of Example 1 as the catalyst. [Table 2] Example 2 Comparative Example 3 Aggregation conditions transition metal compounds Example 1 Comparative Example 2 Total solution flow rate (kg / h) 5 5 Ethylene input (weight %) 8 8 Input molar ratio of 1-octene to ethylene (1-C8 / C2) 2.3 2.3 Zr input (millomoles / kg) 5.0 6.0 Al / Zr Mörby 200 200 Reaction temperature (°C) 120 120 Aggregation results C2 conversion rate (%) 85 82 MI 2.05 2.35 Density (grams per milliliter (g / mL)) 0.8699 0.8685 -Zr: refers to Zr in catalysts. -Al: refers to Al (20 wt%, Norinone) in co-catalyst-modified methylaluminoxane.

[0108] As shown in Table 2, in Example 2 where the transition metal compound of the present invention was used as a catalyst, although the amount of catalyst used was reduced compared to Comparative Example 3 where the transition metal compound of Comparative Example 2 was used, excellent activity was maintained, and it was found that the catalytic activity was significantly improved compared to conventional catalysts.

[0109] According to one exemplary embodiment of the present invention, the transition metal compound significantly increases its solubility in non-aromatic hydrocarbon solvents by introducing diene functional groups at specific positions, thereby maintaining and improving the activity of the catalyst. Although the amount of catalyst used is reduced, the catalyst can produce polymers with excellent physical properties, and olefin polymers can be easily prepared by solution processing. Therefore, the use of transition metal compounds can show economic savings in industrial processes.

[0110] none

Claims

1. A transition metal compound represented by the following chemical formula 2: [Chemical Formula 2] wherein M is Ti, Zr or Hf; A is carbon; R1 to R4 are independently hydrogen or C1 to C4 alkyl; R13 and R14 are independently C6 to C10 aryl; X is or; R21 to R24 are independently hydrogen, C1 to C10 alkyl, C6 to C10 aryl, C6 to C10 arylC1 to C10 alkyl, C1 to C10 alkylC6 to C10 aryl, or triC1 to C10 alkylsilyl; and X forms a π-wedge with the central metal M.

2. The transition metal compound as described in claim 1, wherein the transition metal compound is selected from the following compounds:

3. The transition metal compound as claimed in claim 1, wherein the solubility of the transition metal compound in methylcyclohexane at 25°C is 5% by weight or greater than 5% by weight.

4. A transition metal catalyst composition for preparing ethylene homopolymers or copolymers of ethylene and α-olefins, comprising: a transition metal compound represented by the following chemical formula 2; and a cocatalyst: [Chemical Formula 2] wherein, The M series is Ti, Zr, or Hf; the A series is carbon; R1 to R4 are independently hydrogen or C1 to C4 alkyl; R13 and R14 are independently C6 to C10 aryl; the X series is or; R21 to R24 are independently hydrogen, C1 to C10 alkyl, C6 to C10 aryl, C6 to C10 aryl-C1 to C10 alkyl, C1 to C10 alkyl-C6 to C10 aryl, or tri-C1 to C10 alkylsilyl; and X forms a π-wedge with the central metal M.

5. The transition metal catalyst composition as described in claim 4, wherein the co-catalyst is an aluminum compound co-catalyst, a boron compound co-catalyst, or a mixture thereof.

6. A method for preparing an olefin polymer, the method comprising: obtaining the olefin polymer by solution polymerization of one or more monomers selected from ethylene and α-olefins in the presence of a transition metal compound represented by Formula 2, a co-catalyst, and a non-aromatic solvent: [Formula 2] wherein, The M series is Ti, Zr, or Hf; the A series is carbon; R1 to R4 are independently hydrogen or C1 to C4 alkyl; R13 and R14 are independently C6 to C10 aryl; the X series is or; R21 to R24 are independently hydrogen, C1 to C10 alkyl, C6 to C10 aryl, C6 to C10 aryl-C1 to C10 alkyl, C1 to C10 alkyl-C6 to C10 aryl, or tri-C1 to C10 alkylsilyl; and X forms a π-wedge with the central metal M.

7. The method for preparing an olefin polymer as described in claim 6, wherein the non-aromatic solvent is selected from one or more of the following group: methylcyclohexane, cyclohexane, n-heptane, n-hexane, n-butane, isobutane, n-pentane, n-octane, isooctane, nonane, decane, and dodecane.

8. The method for preparing an olefin polymer as described in claim 6, wherein the solubility of the transition metal compound in the non-aromatic solvent is 5% by weight or greater than 5% by weight at 25°C.

9. The method for preparing an olefin polymer as described in claim 6, wherein the co-catalyst is an aluminum compound co-catalyst, a boron compound co-catalyst, or a mixture thereof.

10. The method for preparing an olefin polymer as described in claim 9, wherein the boron compound co-catalyst is a compound represented by the following chemical formulas 11 to 14: [Chemical Formula 11] BR313 [Chemical Formula 12] [R32]+[BR314]- [Chemical Formula 13] [R33pZH]+[BR314]- [Chemical Formula 14] wherein, The B series is a boron atom; the R31 series is a phenyl group, which may be further substituted with 3 to 5 substituents selected from the following group: fluorine atom, C1 to C20 alkyl, fluorine-substituted C1 to C20 alkyl, C1 to C20 alkoxy, and fluorine-substituted C1 to C20 alkoxy; the R32 series is a C5 to C7 aromatic radical, a C1 to C20 alkyl-C6 to C20 aryl radical, or a C6 to C20 aryl-C1 to C20 alkyl radical; the Z series is a nitrogen or phosphorus atom; the R33 series is a C1 to C20 alkyl radical or ananilinium radical substituted with two C1 to C10 alkyl groups and one nitrogen atom; the R34 series is a C5 to C20 alkyl group; the R35 series is a C5 to C20 aryl group or a C1 to C20 alkyl-C6 to C20 aryl group; and the p series is an integer of 2 or 3.

11. The method for preparing an olefin polymer as described in claim 9, wherein the aluminum compound co-catalyst is a compound represented by the following chemical formulas 15 to 19: [Chemical Formula 15] -(Al(R41)-O)r- [Chemical Formula 16] (R42)2Al-(-O(R42)-)sO-Al(R42)2 [Chemical Formula 17] (R43)tAl(E)3-t [Chemical Formula 18] (R44)2AlOR45 [Chemical Formula 19] R44Al(OR45)2 Wherein, R41 and R42 are independently C1 to C20 alkyl groups; r and s are independently integers from 5 to 20; R43 and R44 are independently C1 to C20 alkyl groups; E series are hydrogen or halogen; t series are integers from 1 to 3; and R45 series are C1 to C20 alkyl groups or C6 to C30 aryl groups.

12. The method for preparing an olefin polymer as described in claim 6, wherein the solution polymerization is carried out at 100°C to 220°C.