Mixed catalyst composition, catalyst containing the same, and method for preparing olefin-based polymers using the same

Abstract

The present invention relates to a mixed catalyst composition comprising a heterogeneous transition metal compound, a catalyst for olefin polymerization comprising the same, and a method for producing an olefin-based polymer using the catalyst in which gel production is suppressed. The method for producing an olefin-based polymer according to one embodiment of the present invention can provide an olefin-based polymer in which heterogeneity, particularly gel production, is suppressed.

Description

Technical Field

[0001] The present disclosure relates to mixed catalyst compositions, catalysts comprising the same, and methods for preparing olefin-based polymers using the same. More particularly, the present disclosure relates to mixed catalyst compositions comprising heterogeneous transition metal compounds, catalysts for olefin polymerization comprising the same, and methods for preparing olefin-based polymers with suppressed gel formation using the catalysts. Background Art

[0002] Polyolefin-based polymers are used in a wide variety of real-world applications, including shopping bags, greenhouses, fishing nets, cigarette packaging, instant noodle bags, yogurt bottles, battery casings, car bumpers, upholstery, shoe soles, and washing machines.

[0003] Traditionally, polyolefin-based polymers such as polyethylene, polypropylene and ethylene-α-olefin copolymers and copolymers thereof are produced by heterogeneous catalysts such as Ziegler-Natta catalysts composed of titanium compounds and alkylaluminum compounds.

[0004] Recently, research has been underway to produce polyolefins using metallocene catalysts, which are homogeneous catalysts with very high catalytic activity. Metallocene catalysts are compounds in which ligands such as cyclopentadienyl, indenyl, and cycloheptadienyl are coordinated with a transition metal or a transition metal halogen compound, and have a basic sandwich structure. Metallocene catalysts have various molecular structures depending on the type of ligand and the type of central metal.

[0005] Whereas other catalysts for olefin polymerization, such as Ziegler-Natta catalysts, have heterogeneous active site characteristics due to the dispersion of metal components as active sites on an inert solid surface, metallocene catalysts are called single-site catalysts because they are compounds with a uniform structure, so all active sites have the same polymerization characteristics, and polymers polymerized using these metallocene catalysts are characterized by a narrow molecular weight distribution and a uniform comonomer distribution.

[0006] Generally, since metallocene catalysts themselves are inactive as polymerization catalysts, they are used together with cocatalysts such as methylaluminoxane. Under the action of the cocatalyst, the metallocene catalyst is activated into a cation, and at the same time, the cocatalyst stabilizes the unsaturated cationic active species with anions that are not coordinated with the metallocene catalyst, thereby forming a catalytic system that is active in the polymerization of various olefins.

[0007] Such metallocene catalysts are easily copolymerized, and the stereostructure of the polymer can be adjusted according to the symmetry of the catalyst. The polymers prepared therefrom have the advantages of narrow molecular weight distribution and uniform comonomer distribution.

[0008] On the other hand, polymers prepared by metallocene catalysts have excellent mechanical strength, but their narrow molecular weight distribution leads to poor processability. In order to solve these problems, various methods have been proposed, such as changing the molecular structure of the polymer or broadening the molecular weight distribution. For example, U.S. Patent No. 5,272,236 improves the processability of the polymer by using a catalyst that introduces long chain branches (LCB) into the main chain of the polymer, but there is a problem of low activity in the case of supported catalysts.

[0009] In order to solve these problems of single metallocene catalyst and in order to more easily develop the catalyst with better activity and improved processability, a method for mixing metallocene catalysts (heterogeneous metallocene catalysts) with different characteristics has been proposed. For example, U.S. Patent No. 4,935,474, U.S. Patent No. 6,828,394, U.S. Patent No. 6,894,128, Korean Patent No. 1437509 and U.S. Patent No. 6,841,631 disclose a method for producing polyolefins with bimodal molecular weight distribution using catalysts with different reactivities to comonomers. The polyolefins with bimodal molecular weight distribution prepared in this way have improved processability, but different molecular weight distributions may cause inhomogeneous polyolefin resins. For example, polyolefins may include a large amount of gels, or the product may have a poor appearance or rapid characteristic changes due to processing.

[0010] Therefore, there is a need for a method for suppressing heterogeneity in polyolefins when polymerizing olefin-based monomers using a metallocene catalyst having a heterogeneous transition metal compound. Summary of the Invention

[0011] Technical issues

[0012] One embodiment of the present disclosure is directed to providing a mixed catalyst composition comprising a heterogeneous transition metal compound, a catalyst for olefin polymerization comprising the same, and a method of preparing an olefin-based polymer having suppressed heterogeneity, especially gel formation, using the catalyst.

[0013] Technical Solution

[0014] In one general aspect, a mixed catalyst composition comprises:

[0015] A first transition metal compound of the following formula 1;

[0016] A second transition metal compound of the following formula 2; and

[0017] The third transition metal compound of the following formula 3,

[0018] wherein the molar ratio of the first transition metal compound to the second transition metal compound is in the range of 1:100 to 100:1, and

[0019] wherein the content of the third transition metal compound is 10 mol% to 90 mol% based on the total moles of the mixed catalyst composition:

[0020] [Formula 1]

[0021]

[0022] [Formula 2]

[0023]

[0024] [Formula 3]

[0025]

[0026] In formulas 1 to 3,

[0027] l, n, p and q are each independently an integer from 0 to 4, each m is independently an integer from 0 to 2, and o is an integer from 0 to 5;

[0028] Each M is independently titanium (Ti), zirconium (Zr) or hafnium (Hf);

[0029] Each X is independently halogen, nitro, C 1-20 Alkyl, C 2-20 Alkenyl, C 2-20 Alkynyl, C 6-20 Aryl, C 1-20 Alkyl C 6-20 Aryl, C 6-20 Aryl C 1-20 Alkyl, C 1-20 Alkylamide, or C 6-20 Arylamide;

[0030] Each Q is independently carbon (C), silicon (Si), germanium (Ge) or tin (Sn);

[0031] R1 to R8 are each independently hydrogen, substituted or unsubstituted C 1-20 Alkyl, substituted or unsubstituted C 2-20 Alkenyl, substituted or unsubstituted C 6-20 Aryl, substituted or unsubstituted C 1-20 Alkyl C 6-20 Aryl, substituted or unsubstituted C 6-20 Aryl C 1-20 Alkyl, substituted or unsubstituted C 1-20 Heteroalkyl, substituted or unsubstituted C 3-20Heteroaryl, substituted or unsubstituted C 1-20 Alkylamide, substituted or unsubstituted C 6-20 Arylamide, substituted or unsubstituted C 1-20 Alkylene, or substituted or unsubstituted C 1-20 Silyl, wherein each of R1 to R6 can be independently connected through adjacent groups to form a substituted or unsubstituted saturated or unsaturated C 4-20 ring.

[0032] In one embodiment, the first transition metal compound, the second transition metal compound, and the third transition metal compound may each be a compound of the following Formula 1-1, Formula 2-1, and Formula 3-1:

[0033] [Formula 1-1]

[0034]

[0035] [Formula 2-1]

[0036]

[0037] [Formula 3-1]

[0038]

[0039] In formulas 1-1 to 3-1,

[0040] Bu is butyl and Ph is phenyl.

[0041] In another general aspect, a catalyst for olefin polymerization comprises:

[0042] A mixed catalyst composition according to one embodiment; and a co-catalyst compound,

[0043] wherein the molar ratio of the first transition metal compound to the second transition metal compound ranges from 1:100 to 100:1, and wherein the content of the third transition metal compound is from 10 mol% to 90 mol% based on the total moles of the mixed catalyst composition.

[0044] In one embodiment, the co-catalyst compound may include at least one selected from the group consisting of a compound of Formula 4 below, a compound of Formula 5 below, and a compound of Formula 6 below:

[0045] [Formula 4]

[0046]

[0047] [Formula 5]

[0048]

[0049] [Formula 6]

[0050] [LH] + [Z(A)4] - or [L] + [Z(A)4] -

[0051] In formula 4,

[0052] n is an integer greater than or equal to 2, R a is a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a hydrocarbon group having 1 to 20 carbon atoms substituted by a halogen,

[0053] In formula 5,

[0054] D is aluminum (Al) or boron (B), and R b 、R c and R d are each independently a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms substituted with a halogen, or an alkoxy group having 1 to 20 carbon atoms,

[0055] In Equation 6,

[0056] L is a neutral Lewis base or a cationic Lewis base, [LH] + and [L] + is a Bronsted acid, Z is a Group 13 element, and each A is independently a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms.

[0057] In one embodiment, the compound of Formula 4 may be at least one selected from the group consisting of methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, and butylaluminoxane.

[0058] In one embodiment, the compound of Formula 5 may be at least one selected from the group consisting of trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylaluminum chloride, triisopropylaluminum, tri-sec-butylaluminum, tricyclopentylaluminum, tripentylaluminum, triisopentylaluminum, trihexylaluminum, trioctylaluminum, ethyldimethylaluminum, methyldiethylaluminum, triphenylaluminum, tri-p-tolylaluminum, dimethylmethoxyaluminum, dimethylethoxyaluminum, trimethylboron, triethylboron, triisobutylboron, tripropylboron, and tributylboron.

[0059] In one embodiment, the compound of Formula 6 may be at least one selected from the group consisting of triethylammonium tetraphenylboron, tributylammonium tetraphenylboron, trimethylammonium tetraphenylboron, tripropylammonium tetraphenylboron, trimethylammonium tetra(p-tolyl)boron, trimethylammonium tetra(o,p-dimethylphenyl)boron, tributylammonium tetra(p-trifluoromethylphenyl)boron, trimethylammonium tetra(p-trifluoromethylphenyl)boron, tributylammonium tetrapentafluorophenylboron, N,N-diethylaniline Tetraphenylboron, N,N-diethylaniline Tetrakispentafluorophenylborane, diethylammonium tetrakispentafluorophenylborane, triphenyl Tetraphenylborane, trimethyl Tetraphenylboron, triethylammonium tetraphenylaluminum, tributylammonium tetraphenylaluminum, trimethylammonium tetraphenylaluminum, tripropylammonium tetraphenylaluminum, trimethylammonium tetra(p-tolyl)aluminum, tripropylammonium tetra(p-tolyl)aluminum, triethylammonium tetra(o,p-dimethylphenyl)aluminum, tributylammonium tetra(p-trifluoromethylphenyl)aluminum, trimethylammonium tetra(p-trifluoromethylphenyl)aluminum, tributylammonium tetrapentafluorophenylaluminum, N,N-diethylaniline Tetraphenylaluminum, N,N-diethylaniline Tetrakispentafluorophenylaluminum, diethylammonium tetrakispentafluorophenylaluminum, triphenyl Tetraphenylaluminum, trimethyl Tetraphenylaluminum, tripropylammonium tetra(p-tolyl)boron, triethylammonium tetra(o,p-dimethylphenyl)boron, tributylammonium tetra(p-trifluoromethylphenyl)boron, triphenylcarbon Tetrakis(p-trifluoromethylphenyl)boron, and triphenylcarbon Tetrakispentafluorophenylborane.

[0060] In one embodiment, the catalyst may further comprise a support that impregnates (supports) the mixed catalyst composition, the promoter compound, or both.

[0061] In one embodiment, the support may include at least one selected from the group consisting of silica, alumina, and magnesia.

[0062] In one embodiment, the total amount of the mixed catalyst composition impregnated in the carrier may be 0.001 to 1 mmol based on 1 g of the carrier, and the total amount of the promoter compound impregnated in the carrier is 2 to 15 mmol based on 1 g of the carrier.

[0063] In another general aspect, there is provided a method for preparing an olefin-based polymer, the method comprising the step of polymerizing an olefin-based monomer in the presence of a catalyst for olefin polymerization.

[0064] In one embodiment, the olefin-based monomer may be ethylene, and the olefin-based comonomer may be at least one 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, and 1-hexadecene. Specifically, the olefin-based monomer may be ethylene, the olefin-based comonomer may be 1-hexene, and the olefin-based polymer may be a linear low-density polyethylene.

[0065] In one embodiment, the polymerization of the olefin-based monomer may be carried out by slurry polymerization, and more specifically, the polymerization of the olefin-based monomer may be carried out in a slurry batch reactor.

[0066] In another general aspect, provided is an olefin-based polymer prepared by the method for preparing an olefin-based polymer, which has a gel index of 1 or less when molded into a 50 μm thick film.

[0067] Beneficial effects

[0068] The method for preparing an olefin-based polymer according to one embodiment of the present invention can provide an olefin-based polymer in which heterogeneity of the olefin-based polymer, particularly, generation of a gel, is suppressed. DETAILED DESCRIPTION

[0069] The following describes in detail embodiments of the present disclosure.

[0070] Mixed catalyst composition

[0071] In one general aspect, a mixed catalyst composition comprises:

[0072] A first transition metal compound of the following formula 1;

[0073] A second transition metal compound of the following formula 2; and

[0074] The third transition metal compound of the following formula 3,

[0075] wherein the molar ratio of the first transition metal compound to the second transition metal compound is in the range of 1:100 to 100:1, and

[0076] The content of the third transition metal compound is 10 mol% to 90 mol% based on the total moles of the mixed catalyst composition.

[0077] [Formula 1]

[0078]

[0079] [Formula 2]

[0080]

[0081] [Formula 3]

[0082]

[0083] In formulas 1 to 3,

[0084] l, n, p, and q are each independently an integer from 0 to 4, each m is independently an integer from 0 to 2, and o is an integer from 0 to 5. Specifically, l, m, p, and q may each be 1, and n and o may each be 0.

[0085] Each M is independently titanium (Ti), zirconium (Zr), or hafnium (Hf). Specifically, each M may be zirconium.

[0086] X is independently halogen, nitro, C 1-20 Alkyl, C 2-20 Alkenyl, C 2-20 Alkynyl, C 6-20 Aryl, C 1-20 Alkyl C 6-20 Aryl, C 6-20 Aryl C 1-20 Alkyl, C 1-20 Alkylamide or C 6-20 Arylamide. Specifically, X can each be halogen. More specifically, X can be chlorine.

[0087] Q is independently carbon (C), silicon (Si), germanium (Ge) or tin (Sn). Specifically, Q can be carbon or silicon.

[0088] R1 to R8 are each independently hydrogen, substituted or unsubstituted C 1-20 Alkyl, substituted or unsubstituted C 2-20 Alkenyl, substituted or unsubstituted C 6-20 Aryl, substituted or unsubstituted C 1-20 Alkyl C 6-20 Aryl, substituted or unsubstituted C 6-20 Aryl C 1-20 Alkyl, substituted or unsubstituted C 1-20 Heteroalkyl, substituted or unsubstituted C 3-20 Heteroaryl, substituted or unsubstituted C 1-20 Alkylamide, substituted or unsubstituted C 6-20 Arylamide, substituted or unsubstituted C 1-20 Alkylene, or substituted or unsubstituted C 1-20Silyl, wherein each of R1 to R6 can be independently connected through adjacent groups to form a substituted or unsubstituted saturated or unsaturated C 4-20 Specifically, R1 to R8 can each be hydrogen, substituted or unsubstituted C 1-20 Alkyl, or substituted or unsubstituted C 6-20 Aryl.

[0089] In one embodiment, the first transition metal compound, the second transition metal compound, and the third transition metal compound may each be a compound of the following Formula 1-1, Formula 2-1, and Formula 3-1:

[0090] [Formula 1-1]

[0091]

[0092] [Formula 2-1]

[0093]

[0094] [Formula 3-1]

[0095]

[0096] In formulas 1-1 to 3-1,

[0097] Bu is butyl and Ph is phenyl.

[0098] In one embodiment, the molar ratio of the first transition metal compound to the second transition metal compound contained in the mixed catalyst composition according to one embodiment may be in the range of 1:100 to 100:1. More specifically, it may be in the range of 1:50 to 50:1, and more specifically, it may be in the range of 1:10 to 10:1. When the molar ratio of the first transition metal compound to the second transition metal compound is within the above range, the mixed catalyst composition may exhibit sufficient supported catalytic activity, which may be advantageous in terms of maintaining the activity and economy of the catalyst. In addition, olefin-based polymers prepared in the presence of a catalyst for olefin polymerization that satisfies the above range may exhibit excellent processability, and films prepared therefrom may exhibit excellent mechanical and optical properties.

[0099] In one embodiment, the content of the third transition metal compound may be 10 mol% to 90 mol% based on the total moles of the mixed catalyst composition. Specifically, the content of the third transition metal compound may be 10 mol% to 80 mol% or 10 mol% to 60 mol%. When the content of the third transition metal compound in the mixed catalyst composition is within the above range, heterogeneity of the olefin-based polymer prepared in the presence of the catalyst for olefin polymerization, particularly the generation of gel, can be suppressed.

[0100] Catalysts for olefin polymerization

[0101] In another general aspect, a catalyst for olefin polymerization comprises:

[0102] A first transition metal compound of the following formula 1;

[0103] A second transition metal compound of the following formula 2;

[0104] a third transition metal compound of the following formula 3; and

[0105] a co-catalyst compound,

[0106] wherein the molar ratio of the first transition metal compound to the second transition metal compound is in the range of 1:100 to 100:1, and

[0107] The content of the third transition metal compound is 10 mol% to 90 mol% based on the total moles of the mixed catalyst composition.

[0108] [Formula 1]

[0109]

[0110] [Formula 2]

[0111]

[0112] [Formula 3]

[0113]

[0114] In Formulas 1 to 3, l, m, n, o, p, q, M, X, Q, and R1 to R8 are as described above in the mixed catalyst composition.

[0115] In one embodiment, the first transition metal compound, the second transition metal compound, and the third transition metal compound may be a compound represented by the following Formula 1-1, a compound represented by Formula 2-1, and a compound represented by Formula 3-1, respectively.

[0116] [Formula 1-1]

[0117]

[0118] [Formula 2-1]

[0119]

[0120] [Formula 3-1]

[0121]

[0122] In Formulas 1-1 to 3-1, Bu is a butyl group and Ph is a phenyl group.

[0123] In one embodiment, the molar ratio of the first transition metal compound to the second transition metal compound contained in the mixed catalyst composition according to one embodiment may be in the range of 1:100 to 100:1. More specifically, it may be in the range of 1:50 to 50:1, and more specifically, it may be in the range of 1:10 to 10:1. When the molar ratio of the first transition metal compound to the second transition metal compound is within the above range, the mixed catalyst composition may exhibit sufficient supported catalytic activity, which may be advantageous in terms of maintaining the activity and economy of the catalyst. In addition, olefin-based polymers prepared in the presence of a catalyst for olefin polymerization that satisfies the above range may exhibit excellent processability, and films prepared therefrom may exhibit excellent mechanical and optical properties.

[0124] In one embodiment, the content of the third transition metal compound may be 10 mol% to 90 mol% based on the total moles of the mixed catalyst composition. Specifically, the content of the third transition metal compound may be 10 mol% to 80 mol% or 10 mol% to 60 mol%. When the content of the third transition metal compound in the mixed catalyst composition is within the above range, heterogeneity of the olefin-based polymer prepared in the presence of the catalyst for olefin polymerization, particularly the generation of gel, can be suppressed.

[0125] In one embodiment, the co-catalyst compound may include at least one selected from the group consisting of a compound of the following Formula 4, a compound of the following Formula 5, and a compound of the following Formula 6.

[0126] [Formula 4]

[0127]

[0128] In Formula 4, n can be an integer greater than or equal to 2, and R a It may be a halogen atom, a hydrocarbon having 1 to 20 carbon atoms, or a halogen-substituted hydrocarbon having 1 to 20 carbon atoms. a It may be a methyl group, an ethyl group, an n-butyl group, or an isobutyl group.

[0129] [Formula 5]

[0130]

[0131] In Formula 5, D can be aluminum (Al) or boron (B), and R b 、R c and R d Each of R and R is independently a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms substituted with a halogen, or an alkoxy group having 1 to 20 carbon atoms. Specifically, when D is aluminum (Al), R b 、R c and R d can each independently be methyl or isobutyl, and when D is boron (B), R b 、R c and R d Each may be a pentafluorophenyl group.

[0132] [Formula 6]

[0133] [LH] + [Z(A)4] - or [L] + [Z(A)4] -

[0134] In Formula 6, L can be a neutral Lewis base or a cationic Lewis base, [LH] + and [L] + is a Bronsted acid, Z may be a Group 13 element, and A may independently be a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. Specifically, [LH] + Dimethylanilinium Cation, [Z(A)4] - It can be [B(C6F5)4] - , and [L] + Yes [(C6H5)3C] + .

[0135] In one embodiment, the compound of Formula 4 may be, for example, methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, or butylaluminoxane, preferably methylaluminoxane, but not limited thereto.

[0136] In one embodiment, the compound of Formula 5 can be, for example, trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylaluminum chloride, triisopropylaluminum, tri-sec-butylaluminum, tricyclopentylaluminum, tripentylaluminum, triisopentylaluminum, trihexylaluminum, trioctylaluminum, ethyldimethylaluminum, methyldiethylaluminum, triphenylaluminum, tri-p-tolylaluminum, dimethylmethoxyaluminum, dimethylethoxyaluminum, trimethylboron, triethylboron, triisobutylboron, tripropylboron, or tributylboron, preferably trimethylaluminum, triethylaluminum, and triisobutylaluminum, but not limited thereto.

[0137] In one embodiment, the compound of formula 6 can be, for example, triethylammonium tetraphenylboron, tributylammonium tetraphenylboron, trimethylammonium tetraphenylboron, tripropylammonium tetraphenylboron, trimethylammonium tetra(p-tolyl)boron, trimethylammonium tetra(o,p-dimethylphenyl)boron, tributylammonium tetra(p-trifluoromethylphenyl)boron, trimethylammonium tetra(p-trifluoromethylphenyl)boron, tributylammonium tetrapentafluorophenylboron, N,N-diethylaniline Tetraphenylboron, N,N-diethylaniline Tetrakispentafluorophenylborane, diethylammonium tetrakispentafluorophenylborane, triphenyl Tetraphenylborane, trimethyl Tetraphenylboron, triethylammonium tetraphenylaluminum, tributylammonium tetraphenylaluminum, trimethylammonium tetraphenylaluminum, tripropylammonium tetraphenylaluminum, trimethylammonium tetra(p-tolyl)aluminum, tripropylammonium tetra(p-tolyl)aluminum, triethylammonium tetra(o,p-dimethylphenyl)aluminum, tributylammonium tetra(p-trifluoromethylphenyl)aluminum, trimethylammonium tetra(p-trifluoromethylphenyl)aluminum, tributylammonium tetrapentafluorophenylaluminum, N,N-diethylaniline Tetraphenylaluminum, N,N-diethylaniline Tetrakispentafluorophenylaluminum, diethylammonium tetrakispentafluorophenylaluminum, triphenyl Tetraphenylaluminum, trimethyl Tetraphenylaluminum, tripropylammonium tetra(p-tolyl)boron, triethylammonium tetra(o,p-dimethylphenyl)boron, tributylammonium tetra(p-trifluoromethylphenyl)boron, triphenylcarbon Tetrakis(p-trifluoromethylphenyl)borane, or triphenylcarbon Tetrakispentafluorophenylborane.

[0138] In one embodiment, the catalyst may further comprise a support impregnated with the mixed catalyst composition. Specifically, the support may be impregnated with both the transition metal compound and the promoter compound.

[0139] In one embodiment, the support may comprise a material containing hydroxyl groups on its surface, and more specifically, a material having highly reactive hydroxyl groups and siloxane groups that has been dried to remove moisture from the surface. For example, the support may comprise at least one selected from silica, alumina, and magnesia. Specifically, silica, silica-alumina, or silica-magnesia dried at high temperatures may be used as the support, which typically contains oxide, carbonate, sulfate, and nitrate components such as Na2O, K2CO3, BaSO4, and Mg(NO3)2. In addition, the support may comprise carbon, zeolite, magnesium chloride, and the like. However, the support is not specifically limited to these.

[0140] In one embodiment, the average particle size of the carrier may be 10 μm to 250 μm, specifically 10 μm to 150 μm, more specifically 20 μm to 100 μm.

[0141] In one embodiment, the micropore volume of the support can be 0.1 cc / g to 10 cc / g, specifically 0.5 cc / g to 5 cc / g, more specifically 1.0 cc / g to 3.0 cc / g.

[0142] In one embodiment, the specific surface area of ​​the carrier may be 1 m 2 / g to 1,000m 2 / g, specifically 100m 2 / g to 800m 2 / g, more specifically 200m 2 / g to 600m 2 / g.

[0143] In one embodiment, when the support is silica, the drying temperature of the silica may be 200° C. to 900° C., specifically 300° C. to 800° C., more specifically 400° C. to 700° C. A drying temperature below 200° C. may result in too much moisture to react with surface moisture and the promoter compound, while a temperature above 900° C. may cause the structure of the support to collapse.

[0144] In one embodiment, the concentration of hydroxyl groups in the dried silica may be 0.1 to 5 mmoles / g, specifically 0.7 to 4 mmoles / g, and more specifically 1.0 to 2 mmoles / g. A hydroxyl group concentration below 0.1 mmoles / g may result in a low supporting capacity of the co-catalyst compound, while a concentration above 5 mmoles / g may result in deactivation of the catalytic component.

[0145] In one embodiment, the total amount of the mixed catalyst composition impregnated in the carrier may be 0.001 mmol to 1 mmol based on 1 g of the carrier. When the ratio of the mixed catalyst composition to the carrier satisfies the above range, it exhibits sufficient impregnation catalytic activity, which is advantageous in maintaining the activity and economic efficiency of the catalyst.

[0146] In one embodiment, the total amount of the promoter compound in the carrier may be 2 mmol to 15 mmol based on 1 g of the carrier. When the ratio of the catalyst compound to the carrier satisfies the above range, it is advantageous in terms of maintaining the activity and economy of the catalyst.

[0147] In one embodiment, one, two, or more supports may be used. For example, a single support may contain both the mixed catalyst composition and the co-catalyst compound, or two or more supports may contain the mixed catalyst composition and the co-catalyst compound, respectively. Alternatively, only one of the mixed catalyst composition and the co-catalyst compound may be contained in the support.

[0148] Preparation of olefin-based polymers

[0149] In another general aspect, a method of preparing an olefin-based polymer according to one embodiment includes the step of polymerizing an olefin-based monomer in the presence of the catalyst for olefin polymerization according to one embodiment.

[0150] In one embodiment, the olefin-based polymer may be a homopolymer of an olefin-based monomer or a copolymer of an olefin-based monomer and a comonomer.

[0151] In one embodiment, the olefin-based monomer may be selected from C 2-20 α-olefins, C 1-20 Diolefins, C 3-20 Cycloolefins and C 3-20 At least one of the cycloalkadienes.

[0152] For example, the olefin-based monomer may be ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, or 1-hexadecene, and the olefin-based polymer may be a homopolymer containing only one of the above-exemplified olefin-based monomers or a copolymer containing two or more thereof.

[0153] In one embodiment, the olefin-based polymer may be ethylene and C 3-20 Copolymers of α-olefins, preferably ethylene and C 4-8 Copolymers of α-olefins, but not limited thereto.

[0154] In one embodiment, the ethylene content may be from 55 wt% to 99.9 wt% or from 90 wt% to 99.9 wt%.In one embodiment, the α-olefin-based comonomer content may be from 0.1 wt% to 45 wt% or from 10 wt% to 40 wt%.

[0155] In one embodiment, the olefin-based polymer may be polymerized by polymerization reactions such as, but not limited to, free radical, cationic, coordination, condensation, addition, and the like.

[0156] In one embodiment, the olefin-based polymer can be prepared by gas phase polymerization, solution polymerization or slurry polymerization. Specifically, the polymerization of olefin monomers can be carried out by slurry polymerization, and more specifically, the polymerization of olefin-based monomers can be carried out in a slurry batch reactor.

[0157] In one embodiment, if the olefin-based polymer is prepared by solution polymerization or slurry polymerization, examples of solvents that may be used include, but are not limited to: C 5-12 Aliphatic hydrocarbon solvents such as pentane, hexane, heptane, nonane, decane, and isomers thereof; aromatic hydrocarbon solvents such as toluene and benzene; hydrocarbon solvents substituted with chlorine atoms such as dichloromethane and chlorobenzene; and mixtures thereof.

[0158] In another general aspect, an olefin-based polymer prepared by the method of preparing an olefin-based polymer is provided. In one embodiment, the olefin-based polymer can have a gel index of 1 or less when molded into a 50 μm thick film.

[0159] Embodiments of the invention

[0160] Example

[0161] Hereinafter, one embodiment will be described in more detail through examples and comparative examples. However, the following embodiments are only intended to illustrate the present invention, and the scope of the present disclosure is not limited thereto.

[0162] As transition metal compounds, compound 1-1 ((dimethylsilylene)bis(2-methyl-4-phenylindenyl)zirconium dichloride) was purchased from sPCI, compound 2-1 ((cyclopentadienyl)(indenyl)zirconium(IV) dichloride) was purchased from MCN, and compound 3-1 (diphenylmethylene(n-butylcyclopentadienyl)(2,7-tert-butylfluoren-9-yl)zirconium dichloride) was purchased from MCN. Silica (XPO-2402) was purchased from Grace, and a 10% aluminoxane solution in toluene was purchased from Lake Materials. Unless otherwise noted, all materials were used as received without purification.

[0163] Example 1

[0164] In a round glass reactor in a glove box, 26 mg of the transition metal compound of Formula 1-1, 12 mg of the transition metal compound of Formula 2-1, 3 mg of the transition metal compound of Formula 3-1, and 8.8 g of a 10% aluminoxane solution in toluene were stirred for 1 hour. At this point, the molar ratio of Compound 1-1:Compound 2-1:Compound 3-1 was 45:40:15.

[0165] After the reaction, the solution was added to 2 g of silica (XPO-2402) and another 1.5 liters of toluene was added and stirred for 3 hours at 75° C. The solution was then washed three times with 10 mL of toluene and dried in vacuum for 1 hour to give 2.2 g of powdered impregnated catalyst.

[0166] Example 2

[0167] 2.17 g of a mixed metallocene supported catalyst was obtained by the same method as in Example 1, except that 17 mg of the transition metal compound of Formula 1-1, 12 mg of the transition metal compound of Formula 2-1, and 20 mg of the transition metal compound of Formula 3-1 were used. At this time, the molar ratio of compound 1-1:compound 2-1:compound 3-1 was 30:40:30.

[0168] Example 3

[0169] 2.15 g of a mixed metallocene supported catalyst was obtained by the same method as in Example 1, except that 3 mg of the transition metal compound of Formula 1-1, 12 mg of the transition metal compound of Formula 2-1, and 36 mg of the transition metal compound of Formula 3-1 were used. At this time, the molar ratio of compound 1-1:compound 2-1:compound 3-1 was 5:40:55.

[0170] Example 4

[0171] A mixed metallocene supported catalyst was prepared in the same manner as in Example 2, except that the compounds used were increased. Specifically, 2.14 g of the transition metal compound of Formula 1-1, 1.56 g of the transition metal compound of Formula 2-1, and 2.47 g of the transition metal compound of Formula 3-1 were used, along with 250 g of silica and 1,103 g of a 10% aluminoxane toluene solution. The amount of the prepared catalyst was 345 g.

[0172] Comparative Example 1

[0173] 2.1 g of a mixed metallocene supported catalyst was obtained by the same method as in Example 1, except that 34 mg of the transition metal compound of Formula 1-1 and 12 mg of the transition metal compound of Formula 2-1 were used, and no transition metal compound of Formula 3-1 was used. At this time, the molar ratio of Compound 1-1: Compound 2-1: Compound 3-1 was 60:40:0.

[0174] Comparative Example 2

[0175] 2.01 g of a mixed metallocene supported catalyst was obtained by the same method as in Example 1, except that 31 mg of the transition metal compound of Formula 1-1, 12 mg of the transition metal compound of Formula 2-1, and 3 mg of the transition metal compound of Formula 3-1 were used. At this time, the molar ratio of compound 1-1:compound 2-1:compound 3-1 was 55:40:5.

[0176] Experimental example

[0177] Olefin-based polymers were prepared using each of the mixed metallocene-impregnated catalysts prepared in Examples 1 to 4 and Comparative Examples 1 to 2 using a slurry polymerization reactor. 50 mg of the mixed metallocene-supported catalyst and 1 liter of hexane were added to the reactor, along with 0.6 mL of 1M triisobutylaluminum (TiBAL) as a scavenger. 1-Hexene was added to the reactor in the amount shown in Table 1 below.

[0178] During the polymerization, the ethylene partial pressure was maintained at 14 kgf / cm 2 , and hydrogen was added in an amount shown in the following Table 1. Polymerization was performed while maintaining the reaction temperature at about 80° C. for 1 hour.

[0179] After the obtained olefin-based polymer was dried at room temperature, properties were measured by the following methods. Specific polymerization conditions and physical properties of the olefin-based polymer are shown in Tables 1 and 2 below.

[0180] (1) Density

[0181] The measurement was performed according to ASTM D1505.

[0182] (2) Melt index and melt flow ratio (MFR)

[0183] The melt index was measured at 190° C. under a load of 21.6 kg and a load of 2.16 kg according to ASTM D1238, and the ratio (MI 21.6 / MI 2.16 ).

[0184] (3) Molecular weight (Mw) and molecular weight distribution (PDI)

[0185] The measurement was performed using 3D gel permeation chromatography-FTIR (GPC-FTIR) at 170°C.

[0186] (4) Thermal characteristics

[0187] The measurement was performed using a differential scanning calorimeter (DSC, equipment name: DSC 2920, manufacturer: TA instrument). Specifically, the polymer was heated to 200°C and maintained at this temperature for 5 minutes, cooled to 20°C, and then heated again, wherein the temperature was increased and decreased at a rate of 20°C / min.

[0188] (5) Gel properties

[0189] After forming a 50 μm thick film using a small blown film extruder, the gel properties of the reference film were measured. The smaller the gel index (GI), the less gel. Specifically, the gel index was measured by the following method.

[0190] Each of the resins polymerized in the Examples and Comparative Examples was molded using an in-house micro-blown film extruder (Labtech). Films were formed by adjusting the extrusion and forming speeds to achieve a film width of approximately 5 cm and a thickness of 50 μm. The total number of gels in the 5 cm × 5 cm films was visually inspected and evaluated according to the following criteria.

[0191] 1: 10 or fewer

[0192] 2: More than 10 but less than 50

[0193] 3: More than 50 to less than 100

[0194] 4: More than 100 to less than 200

[0195] 5: More than 200

[0196] [Table 1]

[0197]

[0198] [Table 2]

[0199]

[0200] Industrial Applicability

[0201] As can be seen from Tables 1 and 2, the olefin-based polymer prepared according to one embodiment has a good degree of gel formation, but Comparative Example 1 containing no third transition metal compound and Comparative Example 1 with a lower amount of the third transition metal compound have increased gel formation and are not suitable for film or pipe applications.

Claims

1. A mixed catalyst composition comprising: A first transition metal compound of the following formula 1; A second transition metal compound of the following formula 2; and The third transition metal compound of the following formula 3, wherein the molar ratio of the first transition metal compound to the second transition metal compound is in the range of 1:10 to 10:1, and Wherein, based on the total moles of the mixed catalyst composition, the content of the third transition metal compound is 10 mol% to 60 mol%: [Formula 1] [Formula 2] [Formula 3] In formulas 1 to 3, l, n, p and q are each independently an integer from 0 to 4, each m is independently an integer from 0 to 2, and o is an integer from 0 to 5; Each M is independently titanium (Ti), zirconium (Zr) or hafnium (Hf); Each X is independently halogen, nitro, C 1-20 Alkyl, C 2-20 Alkenyl, C 2-20 Alkynyl, C 6-20 Aryl, C 1-20 Alkyl C 6-20 Aryl, C 6-20 Aryl C 1-20 Alkyl, C 1-20 Alkylamide or C 6-20 Arylamide; Each Q is independently carbon (C), silicon (Si), germanium (Ge) or tin (Sn); R1 to R8 are each independently hydrogen, substituted or unsubstituted C 1-20 Alkyl, substituted or unsubstituted C 2-20 Alkenyl, substituted or unsubstituted C 6-20 Aryl, substituted or unsubstituted C 1-20 Alkyl C 6-20 Aryl, substituted or unsubstituted C 6-20 Aryl C 1-20 Alkyl, substituted or unsubstituted C 1-20 Heteroalkyl, substituted or unsubstituted C 3-20 Heteroaryl, substituted or unsubstituted C 1-20 Alkylamide, substituted or unsubstituted C 6-20 Arylamide, substituted or unsubstituted C 1-20 Alkylene, or substituted or unsubstituted C 1-20 Silyl, wherein each of R1 to R6 can independently be linked through adjacent groups to form a substituted or unsubstituted saturated or unsaturated C 4-20 ring.

2. The mixed catalyst composition according to claim 1, wherein the first transition metal compound, the second transition metal compound, and the third transition metal compound are each a compound of the following Formula 1-1, Formula 2-1, and Formula 3-1: [Formula 1-1] [Formula 2-1] [Formula 3-1] In formulas 1-1 to 3-1, Bu is butyl and Ph is phenyl.

3. A catalyst for olefin polymerization, comprising: The mixed catalyst composition according to claim 1; and a co-catalyst compound, wherein the molar ratio of the first transition metal compound to the second transition metal compound is in the range of 1:10 to 10:1, and Wherein, based on the total moles of the mixed catalyst composition, the content of the third transition metal compound is 10 mol% to 60 mol%.

4. The catalyst for olefin polymerization according to claim 3, wherein the co-catalyst compound comprises at least one selected from the group consisting of a compound of the following Formula 4, a compound of the following Formula 5, and a compound of the following Formula 6: [Formula 4] [Formula 5] [Formula 6] [L-H] + [Z(A)4] - or [L] + [Z(A)4] - In formula 4, n is an integer greater than or equal to 2, R a is a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a hydrocarbon group having 1 to 20 carbon atoms substituted by a halogen, In formula 5, D is aluminum (Al) or boron (B), and R b 、R c and R d are each independently a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon group having 1 to 20 carbon atoms substituted with a halogen, or an alkoxy group having 1 to 20 carbon atoms, In Equation 6, L is a neutral Lewis base or a cationic Lewis base, [LH] + and [L] + is a Bronsted acid, Z is a Group 13 element, and each A is independently a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. 5 . The catalyst for olefin polymerization according to claim 4 , wherein the compound of Formula 4 is at least one selected from methylaluminoxane, ethylaluminoxane, and butylaluminoxane.

6. The catalyst for olefin polymerization according to claim 4, wherein the compound of Formula 5 is at least one selected from the group consisting of trimethylaluminum, triethylaluminum, tripropylaluminum, tributylaluminum, dimethylaluminum chloride, tricyclopentylaluminum, tripentylaluminum, trihexylaluminum, trioctylaluminum, ethyldimethylaluminum, methyldiethylaluminum, triphenylaluminum, tri-p-tolylaluminum, dimethylmethoxyaluminum, dimethylethoxyaluminum, trimethylboron, triethylboron, tripropylboron, and tributylboron.

7. The catalyst for olefin polymerization according to claim 4, wherein the compound of Formula 6 is at least one selected from the group consisting of triethylammonium tetraphenylboron, tributylammonium tetraphenylboron, trimethylammonium tetraphenylboron, tripropylammonium tetraphenylboron, trimethylammonium tetra(p-tolyl)boron, trimethylammonium tetra(o,p-dimethylphenyl)boron, tributylammonium tetra(p-trifluoromethylphenyl)boron, trimethylammonium tetra(p-trifluoromethylphenyl)boron, tributylammonium tetra(p-trifluoromethylphenyl)boron, tributylammonium tetrapentafluorophenylboron, N,N-diethylaniline Tetraphenylboron, N,N-diethylaniline Tetrakispentafluorophenylborane, diethylammonium tetrakispentafluorophenylborane, triphenyl Tetraphenylborane, trimethyl Tetraphenylboron, triethylammonium tetraphenylaluminum, tributylammonium tetraphenylaluminum, trimethylammonium tetraphenylaluminum, tripropylammonium tetraphenylaluminum, trimethylammonium tetra(p-tolyl)aluminum, tripropylammonium tetra(p-tolyl)aluminum, triethylammonium tetra(o,p-dimethylphenyl)aluminum, tributylammonium tetra(p-trifluoromethylphenyl)aluminum, trimethylammonium tetra(p-trifluoromethylphenyl)aluminum, tributylammonium tetrapentafluorophenylaluminum, N,N-diethylaniline Tetraphenylaluminum, N,N-diethylaniline Tetrakispentafluorophenylaluminum, diethylammonium tetrakispentafluorophenylaluminum, triphenyl Tetraphenylaluminum, trimethyl Tetraphenylaluminum, tripropylammonium tetra(p-tolyl)borane, triethylammonium tetra(o,p-dimethylphenyl)borane, triphenylcarbon Tetrakis(p-trifluoromethylphenyl)boron, and triphenylcarbon Tetrakispentafluorophenylborane.

8. The catalyst for olefin polymerization according to claim 3, wherein the catalyst further comprises a support impregnated with the mixed catalyst composition, the co-catalyst compound, or both. 9 . The catalyst for olefin polymerization according to claim 8 , wherein the support comprises at least one selected from the group consisting of silica, alumina, and magnesia.

10. The catalyst for olefin polymerization according to claim 8, wherein the total amount of the mixed catalyst composition impregnated in the carrier is 0.001 to 1 mmol based on 1 g of the carrier, and the total amount of the co-catalyst compound impregnated in the carrier is 2 to 15 mmol based on 1 g of the carrier.

11. A method for preparing an olefin-based polymer, comprising the step of polymerizing an olefin-based monomer in the presence of the catalyst for olefin polymerization according to claim 3. 12 . The method for preparing an olefin-based polymer according to claim 11 , wherein the olefin-based polymer is a copolymer of an olefin-based monomer and an olefin-based comonomer.

13. The method for preparing an olefin-based polymer according to claim 12, wherein the olefin-based monomer is ethylene, and the olefin-based comonomer is at least one 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, and 1-hexadecene. 14 . The method for preparing an olefin-based polymer according to claim 13 , wherein the olefin-based monomer is ethylene and the olefin-based comonomer is 1-hexene, and the olefin-based polymer is linear low-density polyethylene. 15 . The method for preparing an olefin-based polymer according to claim 11 , wherein the polymerization of the olefin-based monomer is performed by slurry polymerization. 16 . An olefin-based polymer produced by the method for producing an olefin-based polymer according to claim 11 , wherein the olefin-based polymer has a gel index of 1 or less when molded into a 50 μm-thick film.

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