Polymerization catalyst and method for producing ethylene-based polymer using the same

Abstract

To provide a polymerization catalyst having excellent copolymerizability capable of efficiently producing a low density and high molecular weight polymer, particularly an ethylene-based polymer and to provide a method for producing an ethylene-based polymer using the same.SOLUTION: There are provided: a polymerization catalyst which comprises a transition metal compound having an electron-donating substituent at a specific site, an organic aliphatic group-modified clay, one or more activation co-catalysts selected from the group consisting of a specific boron compound, a specific aluminum compound, methylaluminoxane and (methyl-isobutyl)aluminoxane and an organic aluminum compound; and a method for producing an ethylene-based polymer using the same.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polymerization catalyst comprising a transition metal compound having a specific structure, a specific activating cocatalyst, and an organoaluminum compound, and a method for producing a polymer using the same. More specifically, the present invention relates to a polymerization catalyst belonging to the metallocene polymerization catalysts that enables efficient production of a polymer having a high molecular weight and excellent copolymerizability with low density, particularly an ethylene polymer, and a method for producing an ethylene polymer using the same. [Background technology]

[0002] In many applications, good mechanical properties such as tensile strength, tear strength, and impact strength are desirable for polymers, and generally, ethylene polymers with higher molecular weights tend to have better mechanical properties. Furthermore, in applications where transparency, heat sealability, processability, and the like are desired, ethylene polymers with lower densities generally tend to have better properties.

[0003] Ethylene polymers, which have low density and high molecular weight, are considered to be high-value-added materials that combine mechanical properties with transparency, heat-sealability, and processability. To lower the density of these polymers, methods of copolymerizing ethylene with comonomers such as 1-butene and 1-hexene have been investigated. Furthermore, methods of increasing the comonomer content have also been investigated to further lower the density.

[0004] However, copolymerization of a comonomer generally tends to decrease the molecular weight of an ethylene polymer. Therefore, if the density is further decreased by increasing the comonomer content, the molecular weight also decreases. For this reason, it has been difficult to produce an ethylene polymer with low density and high molecular weight.

[0005] To address this issue, new methods have been proposed for efficiently synthesizing ethylene polymers with low density and high molecular weight (see, for example, Patent Documents 1 and 2). In this method, a copolymer of ethylene and an α-olefin is produced using a polymerization catalyst containing a transition metal compound having, as ligands, a substituted fluorenyl group and a substituted indenyl group bridged by carbon atoms. This method can efficiently provide a low-density ethylene polymer while preventing a decrease in molecular weight. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-371107 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-197057 Summary of the Invention [Problem to be solved by the invention]

[0007] The methods proposed in Patent Documents 1 and 2 are able to suppress the decrease in molecular weight and to lower the density by copolymerization to some extent, but the effect is limited. Therefore, there has been a demand for the development of copolymers that can achieve even lower density and higher molecular weight, and new polymerization catalysts with excellent copolymerizability that can provide such copolymers. [Means for solving the problem]

[0008] As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a novel polymerization catalyst comprising a transition metal compound having a specific structure, a specific activating cocatalyst, and an organoaluminum compound can achieve both low density and high molecular weight for olefin polymers, particularly ethylene polymers, and enable efficient production of such polymers, thereby completing the present invention.

[0009] That is, the present invention provides a transition metal compound (A) represented by the following general formula (1):

[0010] [ka]

[0011] (In the formula, M 1 represents a Group 4 metal atom, and X 1 and X 2 each independently represents a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a dialkylamino group having 2 to 6 carbon atoms; R 11 ~R 15 , R 21 , R 22 , R 31 ~R 38 , R 41 ~R 46 each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and SG 1 ~SG 5 each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a dialkylamino group having 2 to 6 carbon atoms, provided that SG 1 ~SG 5 Not all of these atoms are hydrogen atoms at the same time, and SG 6 and S.G. 7 each independently represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a dialkylamino group having 2 to 6 carbon atoms. an organically modified clay containing an organic aliphatic group represented by the following general formula (2), one or more activating co-catalysts (B) selected from the group consisting of compounds represented by the following general formulas (3) to (6), methylaluminoxane, and (methyl-isobutyl)aluminoxane;

[0012] [ka]

[0013] (In the formula, R 5 ~R 7are each independently an alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an alkylamino group having 1 to 30 carbon atoms, an alkylsilyl group having 1 to 30 carbon atoms, a substituent in which oxygen is introduced between the carbon-carbon bonds of an alkyl group having 2 to 30 carbon atoms, a substituent in which a portion of an alkyl group having 1 to 30 carbon atoms is substituted with an alkylamino group having 1 to 30 carbon atoms, or a substituent in which a portion of the carbon of an alkyl group having 2 to 30 carbon atoms is substituted with silicon, and R 5 ~R 7 At least one of the groups is an alkyl group having 10 or more carbon atoms, and M 2 is an atom in group 15 of the periodic table.) (HL 1 )(G 1 (Ar 1 )4) (3) (wherein H is a hydrogen atom, G 1 is a boron atom or an aluminum atom, L 1 is a Lewis base, Ar 1 are each independently a halogen-substituted aryl group having 6 to 20 carbon atoms. (DL 2 m )(G 2 (Ar 2 )4) (4) (Wherein, D is Li + , Fe 2+ , Fe 3+ , Ag + is a cation selected from L 2 is a Lewis base or a cyclopentadienyl group, G 2 is a boron atom or an aluminum atom, Ar 2 are each independently a halogen-substituted aryl group having 6 to 20 carbon atoms, and m is an integer of 0 to 2. (E)(G 3 (Ar 3 )4) (5) (Wherein E is a carbonium cation or a tropylium cation, G 3 is a boron atom or an aluminum atom, Ar 3 are each independently a halogen-substituted aryl group having 6 to 20 carbon atoms. G 4 (Ar 4 )3(6) (In the formula, G 4 is a boron atom or an aluminum atom, Ar 4 are each independently a halogen-substituted aryl group having 6 to 20 carbon atoms. and an organoaluminum compound (C), and a process for producing an ethylene polymer using the same.

[0014] The present invention will be described in detail below.

[0015] The polymerization catalyst of the present invention is a polymerization catalyst containing a transition metal compound (A) represented by the above general formula (1), an organically modified clay with an organic fatty group represented by the above general formula (2), a compound represented by the above general formulas (3) to (6), an activating cocatalyst (B) selected from methylaluminoxane and (methyl-isobutyl)aluminoxane, and an organoaluminum compound (C), where the activating cocatalyst (B) is a compound that enables activation of a transition metal compound, preferably a metallocene compound, as a polymerization catalyst. The polymerization catalyst may also be one that falls within the category of so-called metallocene polymerization catalysts.

[0016] The transition metal compound (A) constituting the polymerization catalyst of the present invention is a transition metal compound represented by the above general formula (1), and belongs to the category of metallocene compounds.

[0017] The definition of each symbol in the general formula (1) is explained in detail below. 1 represents a Group 4 metal atom, examples of which include a titanium atom, a zirconium atom, and a hafnium atom. 1 When M is one of these specific metal atoms, it becomes possible to efficiently produce an olefin polymer having a low density and a high molecular weight, and in particular, it becomes a catalyst for producing an ethylene polymer that can efficiently produce an ethylene polymer having a low density and a high molecular weight. 1 is preferably a zirconium atom.

[0018] X 1 and X 2are each independently a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a dialkylamino group having 2 to 6 carbon atoms, and examples of the halogen atom include a chlorine atom, a bromine atom, and an iodine atom; examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a cyclopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a cyclobutyl group, a pentyl group, a cyclopentyl group, a hexyl group, and a cyclohexyl group; examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropyloxy group, a butoxy group, a tert-butoxy group, a pentyloxy group, a cyclopentyloxy group, a hexyloxy group, and a cyclohexyloxy group; and examples of the dialkylamino group include a dimethylamino group, an ethyl(methyl)amino group, a diethylamino group, a dipropylamino group, and a diisopropylamino group. 1 and X 2 is preferably a halogen atom, more preferably a chlorine atom or a bromine atom, and particularly preferably a chlorine atom.

[0019] R 11 ~R 15 , R 21 , R 22 , R 31 ~R 38 and R 41 ~R 46 Each of the groups independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and examples of the alkyl group include the above-mentioned X 1 and X 2 The catalyst of the present invention has good polymerization activity and copolymerizability, and therefore R 11 ~R 15 , R 21 , R 22 , R 31 ~R 38 and R 41 ~R 46 is preferably a hydrogen atom.

[0020] SG 1 ~SG 5each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a dialkylamino group having 2 to 6 carbon atoms, provided that SG 1 ~SG 5 cannot all be hydrogen atoms at the same time. Examples of the alkyl group, alkoxy group and dialkylamino group include the above X 1 and X 2 The catalyst of the present invention has good polymerization activity and copolymerizability, and is therefore suitable for SG 1 ~SG 5 is preferably a hydrogen atom, a methoxy group, a tert-butyl group or a dimethylamino group.

[0021] SG 6 and S.G. 7 represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a dialkylamino group having 2 to 6 carbon atoms, and examples of the alkyl group, alkoxy group, and dialkylamino group include the above-mentioned X 1 and X 2 The catalyst of the present invention has good polymerization activity and copolymerizability, and is therefore suitable for SG 6 and S.G. 7 is preferably a tert-butyl group.

[0022] Specific examples of the transition metal compound (A) are shown below, but the present invention is not limited to these.

[0023] [ka]

[0024] [ka]

[0025] [ka]

[0026] In view of the good polymerization activity and copolymerizability of the catalyst of the present invention, the transition metal compound (A) is preferably A1, A2, A5, A6, A8, A9, A10, A23 or A24, and more preferably A1, A2, A9, A10, A23 or A24.

[0027] Next, the method for producing the transition metal compound (A) will be described.

[0028] Manufacturing method 1 is X 1 and X 2 is a halogen atom, and the transition metal compound (A) is produced by reacting a ligand (L1) with an anionizing agent to prepare a dianion (DA1), which is then reacted with a transition metal salt (MS1).

[0029] An example of Production Method 1 is shown below.

[0030] [ka]

[0031] (In the formula, M 1 , X 1 , X 2 , R 11 ~R 15 , R 21 , R 22 , R 31 ~R 38 , R 41 ~R 46 , S.G. 1 ~SG 7 represents the same meaning as the definition of each substituent in general formula (1). The ligand (L1) used as a starting material in Production Method 1 can be synthesized according to the method described in Patent Document 1 or Patent Document 2. Examples of transition metal salts (MS1) include titanium tetrachloride, zirconium tetrachloride, and hafnium tetrachloride, and commercially available products can be used. Examples of anionizing agents used to dianionize the ligand (L1) include organolithium salts such as methyllithium, ethyllithium, butyllithium, phenyllithium, and benzyllithium, and alkali metal amides such as lithium diethylamide, lithium diisopropylamide, lithium bis(trimethylsilyl)amide, sodium bis(trimethylsilyl)amide, and potassium bis(trimethylsilyl)amide. In terms of the yield of the transition metal compound A, butyllithium, sodium bis(trimethylsilyl)amide, and potassium bis(trimethylsilyl)amide are preferred. The amount of dianionizing agent used relative to the ligand (L1) is preferably 2.0 equivalents or more and 2.6 equivalents or less, in terms of the yield of the transition metal compound A. The dianionization can be carried out in an organic solvent. Examples of the organic solvent include ether solvents such as tetrahydrofuran (THF), diethyl ether, cyclopentyl methyl ether (CPME), and dioxane; and aromatic hydrocarbon solvents such as benzene, toluene, ethylbenzene, and xylene. These solvents may be mixed in any ratio as needed. From the viewpoint of high yield, an ether solvent alone or a mixture of toluene and an ether solvent is preferred. The temperature and reaction time for dianionization may be appropriately selected from those skilled in the art when preparing fluorenyl anions by deprotonating the methylene hydrogen atoms of the fluorene ring. Transition metal compound A can be produced by reacting dianion (DA1) with transition metal salt (MS1). The reaction between dianion (DA1) and transition metal salt (MS1) can be carried out in an organic solvent. Examples of the organic solvent include ether solvents such as THF, diethyl ether, CPME, and dioxane; alkane solvents such as pentane, hexane, and heptane; and aromatic hydrocarbon solvents such as toluene, ethylbenzene, and xylene. These solvents may be mixed in any ratio as needed.Regarding the method of mixing the dianion (DA1) and the transition metal salt (MS1), it is preferable to mix them at a temperature of -20°C or lower in terms of good yield. There are no particular restrictions on the order of mixing. There are no particular restrictions on the reaction temperature or time, and these may be adjusted appropriately while checking the progress of the reaction by common analytical means such as NMR spectroscopy. In terms of good yield, it is preferable to react at a temperature of 0°C to 50°C for 6 hours or more.

[0032] The resulting transition metal compound A can be purified as needed by using common purification methods such as extraction, washing, recrystallization, etc. that are commonly used by those skilled in the art when purifying Group 4 metallocenes.

[0033] X of transition metal compounds A 1 and / or X 2 is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a dialkylamino group having 2 to 6 carbon atoms, 1 and X 2 The compound A can be produced by reacting a transition metal compound A in which the atom is a chlorine atom or a bromine atom with an alkyl lithium, an alkali metal alkoxide, or a lithium dialkylamide.

[0034] The activating cocatalyst (B) constituting the polymerization catalyst of the present invention is one or more selected from the group consisting of organically modified clays modified with an organic aliphatic group represented by the general formula (2) above, compounds represented by the general formulas (3) to (6) above, methylaluminoxane, and (methyl-isobutyl)aluminoxane, and the activating cocatalyst (B) is a compound that exhibits catalytic activation when combined with the transition metal compound (A).

[0035] When the activating cocatalyst (B) is an organically modified clay containing an organic aliphatic group represented by the general formula (2), R 5 ~R 7are each independently an alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an alkylamino group having 1 to 30 carbon atoms, an alkylsilyl group having 1 to 30 carbon atoms, a substituent in which oxygen is introduced between the carbon-carbon bonds of an alkyl group having 2 to 30 carbon atoms, a substituent in which a portion of an alkyl group having 1 to 30 carbon atoms is substituted with an alkylamino group having 1 to 30 carbon atoms, or a substituent in which a portion of the carbon of an alkyl group having 2 to 30 carbon atoms is substituted with silicon, and R 5 ~R 7 At least one of R is an alkyl group having 10 or more carbon atoms. 5 ~R 7 When any of the above is an alkyl group having less than 10 carbon atoms or a substituent other than an alkyl group, the activity of the resulting catalyst is poor, and it becomes difficult to efficiently produce an ethylene polymer having a low density and a high molecular weight, in particular.

[0036] And R 5 ~R 7Specific examples of the alkyl group include alkyl groups having 1 to 30 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a 2-methylbutyl group, a 1-methylbutyl group, a 1-ethylpropyl group, a neopentyl group, a tert-pentyl group, an n-hexyl group, a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group, an octadecyl group, an oleyl group, and a behenyl group; alkoxy groups having 1 to 30 carbon atoms, such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and an isopropoxy group; dimethylamino group, a diethylamino group, a dipropylamino group, a dibutylamino group, and a diisopropylamino group; alkylsilyl groups having 1 to 30 carbon atoms, such as a trimethylsilyl group, a tri-tert-butylsilyl group, a di-tert-butylmethylsilyl group, and a tert-butyldimethylsilyl group; substituents in which oxygen is introduced between the carbon-carbon bonds of an alkyl group having 2 to 30 carbon atoms, such as a methoxymethylene group and an ethoxymethylene group; substituents in which a portion of an alkyl group having 1 to 30 carbon atoms, such as a dimethylaminomethylene group and a diethylaminomethylene group, is substituted with an alkylamino group having 1 to 30 carbon atoms; and substituents in which a portion of the carbon of an alkyl group having 2 to 30 carbon atoms is substituted with silicon, such as a trimethylsilylmethylene group and a tert-butyldimethylsilylmethylene group.

[0037] Applicable R 5 ~R 7 At least one of the substituents is an alkyl group having 10 or more carbon atoms, such as a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group, an octadecyl group, an oleyl group, or a behenyl group.

[0038] The M 2 is an atom of Group 15 of the periodic table, and if it is an atom other than Group 15 of the periodic table, the catalyst obtained will have poor activity, making it difficult to efficiently produce ethylene polymers with particularly high molecular weights. 2 Examples of the atom include a nitrogen atom and a phosphorus atom.

[0039] Specific examples of the organic aliphatic group include aliphatic ammonium groups such as an N,N-dimethyl-behenylammonium group, an N-methyl-N-ethyl-behenylammonium group, an N-methyl-Nn-propyl-behenylammonium group, and an N,N-dioleyl-behenylammonium group; and aliphatic phosphonium groups such as a P,P-dimethyl-behenylphosphonium group, a P,P-diethyl-behenylphosphonium group, and a P,P-dipropyl-behenylphosphonium group.

[0040] The clay constituting the organically modified clay may be any clay as long as it falls within the category of clay. Generally, the organically modified clay is formed by stacking many layers called silicate layers, which are composed of a tetrahedral sheet of two-dimensionally connected silica tetrahedra and an octahedral sheet of two-dimensionally connected alumina octahedrons or magnesia octahedrons in a 1:1 or 2:1 combination. The Si in some of the silica tetrahedra is replaced by Al, the Al in the alumina octahedron by Mg, and the Mg in the magnesia octahedron by Li, etc., resulting in a lack of positive charge within the layer, and the layer as a whole is negatively charged. To compensate for this negative charge, Na is introduced between the layers. + Ya Ca 2+ The clay is known to contain cations such as kaolinite, talc, smectite, vermiculite, mica, brittle mica, and mercury, both natural and synthetic, and these can be used, with smectite being preferred due to its ease of availability and ease of organic modification, and hectorite or montmorillonite being even more preferred among smectites.

[0041] When preparing the organically modified clay, it is possible to carry out a method in which the clay is brought into contact with an organic aliphatic salt, ion exchange occurs between the clay layers, and an ion complex into which an organic aliphatic group is introduced is formed.The organic aliphatic salt in this case is a salt capable of providing the above-mentioned organic aliphatic group, such as N,N-dimethyl-behenylamine hydrochloride, N-methyl-N-ethyl-behenylamine hydrochloride, N-methyl-Nn-propyl-behenylamine hydrochloride, N,N-dioleyl-methylamine hydrochloride, N,N-dimethyl-behenylamine hydrofluoride, N-methyl-N-ethyl-behenylamine hydrofluoride, N-methyl-Nn-propyl-behenylamine hydrofluoride, N,N-dioleyl-methylamine hydrofluoride, N,N-dimethyl-behenylamine hydrobromide, N-methyl-N-ethyl-behenylamine hydrobromide, N-methyl-Nn-propyl-behenylamine hydrobromide, N,N-dioleyl-methylamine hydrobromide, N,N-dimethyl-behenylamine hydroiodide, N-methyl-N-ethyl-behenylamine hydroiodide, N-methyl-Nn-propyl-behenylamine hydroiodide, N,N-dioleyl-methylamine hydroiodide, N,N-dimethyl-behenylamine sulfate, N-methyl aliphatic amine salts such as N-ethyl-behenylamine sulfate, N-methyl-Nn-propyl-behenylamine sulfate, and N,N-dioleyl-methylamine sulfate; P,P-dimethyl-behenylphosphine hydrochloride, P,P-diethyl-behenylphosphine hydrochloride, P,P-dipropyl-behenylphosphine hydrochloride, P,P-dimethyl-behenylphosphine hydrofluoride, P,P-diethyl-behenylphosphine hydrofluoride, P,P-dipropyl-behenylphosphine hydrofluoride, and P,P-dimethyl-behenyl Examples of the phosphine salts include aliphatic phosphine salts such as phosphine hydrobromide, P,P-diethyl-behenylphosphine hydrobromide, P,P-dipropyl-behenylphosphine hydrobromide, P,P-dimethyl-behenylphosphine hydroiodide, P,P-diethyl-behenylphosphine hydroiodide, P,P-dipropyl-behenylphosphine hydroiodide, P,P-dimethyl-behenylphosphine sulfate, P,P-diethyl-behenylphosphine sulfate, and P,P-dipropyl-behenylphosphine sulfate.

[0042] When preparing the organically modified clay, it is preferable to select conditions for a clay concentration of 0.1 to 30% by weight and a treatment temperature of 0 to 150°C. The organic aliphatic salt may be prepared as a solid and dissolved in a solvent, or a solution of the organic aliphatic salt may be prepared by chemical reaction in the solvent and used as is. Regarding the reaction ratio of the clay and the organic aliphatic salt, it is preferable to use an equivalent or greater amount of organic aliphatic salt relative to the exchangeable cations of the clay. Examples of suitable treatment solvents include aliphatic hydrocarbons such as pentane, hexane, and heptane; aromatic hydrocarbons such as benzene and toluene; alcohols such as ethyl alcohol and methyl alcohol; ethers such as ethyl ether and n-butyl ether; halogenated hydrocarbons such as methylene chloride and chloroform; acetone; 1,4-dioxane; THF; and water. Preferably, alcohols or water are used alone or as one of the solvent components.

[0043] There is no limitation on the particle size of the organically modified clay, but a particle size of 1 to 100 μm is preferred because it provides excellent efficiency in preparing the polymerization catalyst of the present invention and in producing polymers, particularly ethylene polymers. There is also no limitation on the method for adjusting the particle size; large particles may be pulverized to an appropriate particle size, small particles may be granulated to an appropriate particle size, or pulverization and granulation may be combined. The particle size adjustment may be performed on the clay before organic modification or on the organically modified clay after modification.

[0044] There are no limitations on the methods of crushing or granulation used to control the particle size of the organically modified clay. Examples of crushing include crushing using equipment such as an impact mill, rotary mill, cascade mill, cutter mill, cage mill, impact crusher, conical mill, colloid mill, compound mill, jet mill, vibration mill, stamp mill, tube mill, disc mill, tower mill, media stirring mill, hammer mill, pin mill, fret mill, pebble mill, ball mill, attritor, planetary mill, ring ball mill, ring roll mill, rod mill, roller mill, and roll crusher. Examples of granulation include rolling granulation, fluidized bed granulation, stirring granulation, compression granulation, extrusion granulation, crushing granulation, melt granulation, and spray granulation.

[0045] When the activating cocatalyst (B) is a compound represented by any one of the general formulas (3) to (6), in the compound represented by the general formula (3), H is a hydrogen atom, G 1 is a boron atom or an aluminum atom, L 1 is a Lewis base, Ar 1 each independently represents a halogen-substituted aryl group having 6 to 20 carbon atoms; L 1 Examples of the amines include diethyl ether, tetrahydrofuran, trimethylamine, tri(n-butyl)amine, and N,N-dimethylaniline. 1 Examples of the phenyl group include a pentafluorophenyl group and a p-trifluoromethyl-phenyl group.

[0046] Specific examples of the compound represented by the general formula (3) include diethyloxonium tetrakis(pentafluorophenyl)borate, dimethyloxonium tetrakis(pentafluorophenyl)borate, tetramethyleneoxonium tetrakis(pentafluorophenyl)borate, hydronium tetrakis(pentafluorophenyl)borate, trimethylammonium tetrakis(pentafluorophenyl)borate, tri(n-butyl)ammonium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, diethyloxonium tetrakis(pentafluorophenyl)aluminate, dimethyloxonium tetrakis(pentafluorophenyl)aluminate, tetramethyleneoxonium tetrakis(pentafluorophenyl)aluminate, hydronium tetrakis(pentafluorophenyl)aluminate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)aluminate, tri(n-butyl)ammonium tetrakis(pentafluorophenyl)aluminate, and the like.

[0047] In the compound represented by the general formula (4), D is Li + , Fe 2+ , Fe 3+ , Ag + a cation selected from L 2 is a Lewis base or a cyclopentadienyl group, G 2 is a boron atom or an aluminum atom, Ar 2 each independently represents a halogen-substituted aryl group having 6 to 20 carbon atoms, m represents an integer of 0 to 2, and L 2 If is a Lewis base, then L 1 and Ar 2 As for Ar 1 The same can be mentioned.

[0048] Specific examples of the compound represented by general formula (4) include lithium salts such as lithium tetrakis(pentafluorophenyl)borate and lithium tetrakis(pentafluorophenyl)aluminate, or ether complexes thereof; ferrocenium salts such as ferrocenium tetrakis(pentafluorophenyl)borate and ferrocenium tetrakis(pentafluorophenyl)aluminate; and silver salts such as silver tetrakis(pentafluorophenyl)borate and silver tetrakis(pentafluorophenyl)aluminate.

[0049] In the compound represented by the general formula (5), E is a carbonium cation or a tropylium cation, G 3 is a boron atom or an aluminum atom, Ar 3 are each independently a halogen-substituted aryl group having 6 to 20 carbon atoms, and Ar 3 As for Ar 1 The same can be mentioned.

[0050] Specific examples of the compound represented by the general formula (5) include trityl tetrakis(pentafluorophenyl)borate, trityl tetrakis(pentafluorophenyl)aluminate, tropylium tetrakis(pentafluorophenyl)borate, and tropylium tetrakis(pentafluorophenyl)aluminate.

[0051] In the compound represented by the general formula (6), G 4 is a boron atom or an aluminum atom, Ar 4 are each independently a halogen-substituted aryl group having 6 to 20 carbon atoms, and Ar 4 As for Ar 1 The same can be mentioned.

[0052] Specific examples of the compound represented by the general formula (6) include tris(pentafluorophenyl)borane, tris(2,3,5,6-tetrafluorophenyl)borane, tris(2,3,4,5-tetrafluorophenyl)borane, tris(3,4,5-trifluorophenyl)borane, phenylbis(pentafluorophenyl)borane, and tris(3,4,5-trifluorophenyl)aluminum.

[0053] When the activating cocatalyst (B) is methylaluminoxane and / or (methyl-isobutyl)aluminoxane, examples include (trade name) TMAO-200 (methylaluminoxane type) and (trade name) MMAO-3A ((methyl-isobutyl)aluminoxane type) manufactured by Tosoh Finechem Corporation.

[0054] Use of these activating cocatalysts (B) enables activation of the transition metal compound (A), resulting in a polymerization catalyst that enables the polymerization reaction of various monomers, such as ethylene and α-olefins, and in particular, a polymerization catalyst that enables efficient production of low-density, high-molecular-weight ethylene polymers. In this case, it is more preferable that the catalyst be an organically modified clay with an organic aliphatic group.

[0055] The organoaluminum compound (C) constituting the polymerization catalyst of the present invention further activates the transition metal compound (A) activated by the activating cocatalyst (B) to exhibit the action as a polymerization catalyst, and any compound belonging to the category called an organoaluminum compound can be used. Among these, an organoaluminum compound represented by the following general formula (7) is preferred because it is particularly suitable as a polymerization catalyst with improved polymerization efficiency for ethylene and α-olefins, and further as a catalyst for producing ethylene-based polymers.

[0056] [ka]

[0057] (In the formula, R 8is a hydrocarbon group having 1 to 20 carbon atoms, and R 9 are each independently a hydrocarbon group having 1 to 20 carbon atoms, a hydrogen atom, or a chlorine atom. Examples of the organoaluminum compound include alkylaluminum such as trimethylaluminum, triethylaluminum, and triisobutylaluminum. These organoaluminum compounds are particularly capable of easily alkylating the transition metal compound (A) and are suitable as catalysts for low-density, high-molecular-weight ethylene polymers.

[0058] The proportions of the transition metal compound (A) (hereinafter sometimes referred to as component (A)), the activating cocatalyst (B) (hereinafter sometimes referred to as component (B)), and the organoaluminum compound (C) (hereinafter sometimes referred to as component (C)) that constitute the polymerization catalyst of the present invention are not subject to any particular limitation as long as they can be used as a polymerization catalyst. In particular, in order to provide a catalyst for producing an ethylene-based polymer that can efficiently produce an ethylene-based polymer, the molar ratio per metal atom of component (A) to component (C) is preferably in the range of (component (A):(component (C)) = 100:1 to 1:100000, and particularly preferably in the range of 1:1 to 1:10000.

[0059] The weight ratio of component (A) to component (B) is preferably (component (A):(component (B))=10:1 to 1:10000, and more preferably 3:1 to 1:1000.

[0060] Regarding the method for preparing the polymerization catalyst of the present invention, any method may be used as long as it is possible to prepare a polymerization catalyst containing the (A), (B), and (C) components. For example, a method in which components (A), (B), and (C) are mixed in a solvent inert to them or using the monomer to be polymerized as a solvent can be mentioned. Furthermore, there are no limitations on the order in which these components are reacted, nor on the temperature or time at which this treatment is carried out. It is also possible to prepare a polymerization catalyst using two or more types of each of components (A), (B), and (C).

[0061] The polymerization catalyst of the present invention can be used for the polymerization of ethylene, α-olefins, etc. to produce olefin polymers typified by ethylene polymers and propylene polymers. In particular, the ethylene polymers may be not only homopolymers of ethylene but also copolymers with other olefins, and the ethylene polymers obtained by these polymerizations are used in the sense of including not only homopolymers but also copolymers.

[0062]

[0023] Examples of production methods for producing an ethylene polymer using the polymerization catalyst of the present invention, particularly a catalyst for producing an ethylene polymer, include solution polymerization, bulk polymerization, gas phase polymerization, and slurry polymerization. Among these, slurry polymerization is preferred because it enables efficient and stable production of an ethylene polymer having a regular particle shape. The solvent used in the slurry polymerization may be any commonly used organic solvent, such as benzene, toluene, xylene, pentane, hexane, or heptane. Olefins such as propylene, 1-butene, 1-octene, or 1-hexene may also be used as the solvent.

[0063] Examples of other olefins that can be copolymerized with ethylene to produce copolymers of ethylene-based polymers include α-olefins such as propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene; styrene derivatives such as styrene; conjugated and non-conjugated dienes such as butadiene, 1,4-hexadiene, 5-ethylidene-2-norbornene, dicyclopentadiene, 4-methyl-1,4-hexadiene, and 7-methyl-1,6-octadiene; and cyclic olefins such as cyclobutene. Furthermore, copolymers using three or more components, such as ethylene, propylene, and styrene, ethylene, 1-hexene, and styrene, and ethylene, propylene, and ethylidenenorbornene, can also be produced.

[0064] The polymerization conditions, such as polymerization temperature, polymerization time, polymerization pressure, and monomer concentration, when using the polymerization catalyst of the present invention, particularly a catalyst for producing an ethylene polymer, to produce an ethylene polymer can be selected as desired. Among these, it is preferable to carry out the polymerization at a temperature of 30 to 200°C, for a polymerization time of 10 seconds to 20 hours, and at a polymerization pressure in the range of atmospheric pressure to 100 MPa. The polymerization can be carried out by any of batch, semi-continuous, and continuous methods, and can also be carried out in two or more stages by changing the polymerization conditions. The ethylene polymer obtained after the completion of the polymerization can be separated and recovered from the polymerization solvent by a conventionally known method and dried.

[0065] The polymerization catalyst of the present invention has a property of excellent copolymerization with ethylene, particularly when used as a catalyst for producing an ethylene polymer, and is therefore suitable for producing a low-density, high-molecular-weight ethylene polymer. The resulting ethylene polymer has excellent mechanical properties such as tensile strength, tear strength, and impact strength, and therefore preferably has a weight-average molecular weight of 5,000 or more. Furthermore, the resulting ethylene polymer has excellent transparency, heat-sealability, and processability, and therefore preferably has a density of 910 kg / m or more. 3 It is preferable that it is less than 10 ... [Effects of the Invention]

[0066] The polymerization catalyst of the present invention, which comprises a transition metal compound (A) having a specific structure, a specific activating cocatalyst (B), and an organoaluminum compound (C), is particularly suitable as a catalyst for producing ethylene polymers, and enables efficient production of low-density ethylene polymers which have a sufficient molecular weight to provide excellent mechanical properties such as tensile strength, tear strength, and impact strength, and which are excellent in transparency, heat-sealability, processability, etc. [Example]

[0067] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The diethyl ether, tetrahydrofuran, cyclopentyl methyl ether, and toluene used in the synthesis and the heptane used in the polymerization catalyst preparation were commercially available ultra-dehydrated products. The hexane and 1-hexene used in the synthesis and polymerization were commercially available products that had been dehydrated and deoxygenated. Other reagents, solvents, etc. used were commercially available products or those synthesized according to known methods.

[0068] The organically modified clay was pulverized using a jet mill (Seishin Enterprise Co., Ltd., product name CO-JET SYSTEM α MARK III), and the particle size after pulverization was measured using a Microtrac particle size distribution analyzer (Nikkiso Co., Ltd., product name MT3000) using ethanol as a dispersant. The preparation of the polymerization catalyst, the production of the ethylene polymer, and the solvent purification were all carried out under an inert gas atmosphere. A hexane solution (20 wt%) of triisobutylaluminum was used, manufactured by Tosoh Finechem Co., Ltd.

[0069] Furthermore, the physical properties of the ethylene polymers in the examples were measured by the following methods.

[0070] ~Measurement of weight average molecular weight, number average molecular weight and molecular weight distribution~ A GPC system (Tosoh Corporation, product name: HLC-8121GPC / HT) and a column (Tosoh Corporation, product name: TSKgel GMHhr-H(20)HT) were used. The column temperature was set to 140°C, and 1,2,4-trichlorobenzene was used as the eluent. The measurement sample was prepared at a concentration of 1.0 mg / mL, and 0.3 mL was injected for measurement. The molecular weight calibration curve was calibrated using polystyrene samples with known molecular weights, and the weight-average molecular weight (hereinafter referred to as Mw), number-average molecular weight (hereinafter referred to as Mn), and molecular weight distribution (hereinafter referred to as Mw / Mn) were obtained. Mw and Mn were calculated as values ​​converted to linear polyethylene.

[0071] ~Density measurement~ Measurements were made in accordance with JIS K 6922-1 (1997).

[0072] ~Melt mass flow rate (hereinafter referred to as MFR) measurement~ Measurement was carried out in accordance with JIS K 7210 (1999) at a measurement temperature of 190°C and a load of 2.16 kg (D method).

[0073] Preparation Example 1 [Preparation of organically modified clay (B1)] An aqueous solution of N,N-dimethylbehenylammonium hydrochloride was prepared by adding 35.3 g of N,N-dimethylbehenylamine (Lion Corporation, trade name: Lipomin DM22D) and 10 mL of 37% hydrochloric acid to 500 mL of deionized water. 100 g of montmorillonite with an average particle size of 7.8 μm (prepared by grinding Kunipia F (Kunimine Industries, trade name) in a jet mill) was added to the aqueous solution of N,N-dimethylbehenylammonium hydrochloride and reacted for 6 hours. After the reaction was completed, the reaction solution was filtered, and the resulting cake was dried under reduced pressure for 6 hours to obtain 120 g of organically modified clay. The amount of N,N-dimethylbehenylammonium groups introduced was 0.83 mmol / g.

[0074] Preparation Example 2 [Preparation of organically modified clay (B2)] An aqueous solution of N-methyl-dioleylammonium hydrochloride was prepared by adding 53.3 g of N-methyl-dioleylamine (Lion Corporation, trade name: Lipomin MO) and 10 mL of 37% hydrochloric acid to 500 mL of deionized water. 100 g of montmorillonite with an average particle size of 7.8 μm (prepared by grinding Kunipia F, Kunimine Industries, in a jet mill) was added to the above aqueous solution of N,N-dimethyl-behenylammonium hydrochloride and allowed to react for 6 hours. After the reaction was complete, the reaction solution was filtered, and the resulting cake was dried under reduced pressure for 6 hours to obtain 138 g of organically modified clay. The amount of N-methyl-dioleylammonium groups introduced was 0.72 mmol / g.

[0075] Example 1 (1) [Synthesis of transition metal compounds] Synthesis of di(4-methoxy-phenyl)methylene(4-phenyl-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride represented by the following formula (A1):

[0076] [ka]

[0077] Under an argon atmosphere, (4-phenyl-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)di(4-methoxyphenyl)methane (1.06 g, 1.53 mmol), 20 mL of toluene, and 1 mL of tetrahydrofuran were added to a reaction vessel and cooled to -78°C. After that, a hexene solution of n-butyllithium (3.17 mmol) was slowly added, and the mixture was warmed to room temperature and stirred for 14 hours. The resulting solution was cooled to -78°C, and a suspension of zirconium tetrachloride (0.356 g, 1.53 mmol) in 10 mL of toluene was added, and the mixture was stirred at room temperature for 8 hours. After removing the solvent, 40 mL of toluene was added, heated to 50°C, and the solution was recovered by filtration through Celite. After concentrating the solvent (approximately 3 mL), 30 mL of hexane was added, and the precipitated solid was recovered by filtration and dried to obtain a purple solid of di(4-methoxy-phenyl)methylene(4-phenyl-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride (0.975 g, 1.14 mmol, yield 74%).

[0078] 1 As a result of measuring H-NMR (400 MHz, chloroform-d), measurement peaks (ppm) were observed at the following positions, confirming the production of di(4-methoxy-phenyl)methylene(4-phenyl-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride. 8.05(m, 1H), 7.99(dd, J=8.6, 2.4Hz, 1H), 7.96(d, J=8.8Hz, 2H), 7.92(d, J=8.8Hz, 1H), 7.78(dd, J=8.8, 2.5 Hz, 1H), 7.58(dd, J=8.8, 1.6Hz, 1H) 7.57-7.53(m, 2H), 7.42-7.33(m, 3H), 7.57-7.53(m, 2H), 7.42-7.33(m, 3 H), 7.30(m, 1H), 7.17(s, 1H), 7.08-6.96(m, 5H), 6.91(dd, J=8.8, 2.8Hz, 1H), 6.68(dd, J=9.0, 6.9Hz, 1H), 6. 53(d, J=3.4Hz, 1H), 6.31(s, 1H), 6.08(d, J=3.4Hz, 1H), 3.87(s, 3H), 3.81(s, 3H), 1.07(s, 9H), 1.04(s, 9H).

[0079] (2) [Preparation of polymerization catalyst] Under a nitrogen atmosphere, 1.0 g of the organically modified clay (B1) obtained in Preparation Example 1 and 18.4 mL of heptane were placed in a 100 mL Schlenk tube, and then 11.0 mmol (9.0 mL) of a hexane solution of triethylaluminum (20 wt% diluted product) per aluminum atom was added, followed by stirring for 1 hour to form a suspension.

[0080] Separately, in a separately prepared 50 mL Schlenk tube under a nitrogen atmosphere, 25 μmol of di(4-methoxyphenyl)methylene(4-phenyl-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride obtained in (1), 14.8 mL of heptane, and 11.5 mmol (9.5 mL) of a hexane solution of triethylaluminum (20 wt % diluted product) per aluminum atom were added, and the mixture was stirred for 1 hour to form a solution.

[0081] The resulting solution was added to the above suspension, and then the mixture was stirred at room temperature for 12 hours to prepare a polymerization catalyst (zirconium concentration: 0.48 mmol / L).

[0082] (3) [Production of ethylene-1-hexene copolymer] After the air in a 1-liter autoclave was replaced with nitrogen, 600 mL of a C9-C13 saturated hydrocarbon solvent (trade name IP Solvent 1620 (Idemitsu Petrochemical Co., Ltd.)) and 15 mL of 1-hexene were added, and the temperature of the autoclave was raised to 170°C. After that, the internal pressure of the autoclave was adjusted to 0.1 MPa with nitrogen, and then the internal pressure of the autoclave was adjusted to 0.95 MPa with ethylene.

[0083] Next, the polymerization catalyst obtained in (2) was fed into the autoclave under nitrogen pressure in an amount of 0.86 μmol (1.79 mL) per di(4-methoxy-phenyl)methylene(4-phenyl-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride, and polymerization was carried out for 10 minutes.

[0084] After the polymerization reaction was completed, the unreacted ethylene was released from the pressure, and the polymer solution was extracted from the bottom of the autoclave and dried under reduced pressure at 120°C in an oven to obtain 33 g of ethylene-1-hexene copolymer. The evaluation and analysis results of the obtained ethylene-1-hexene copolymer are shown in Table 1.

[0085] Example 2 (1) [Synthesis of transition metal compounds] Synthesis of diphenylmethylene(4-(3,4,5-trimethoxy-phenyl)-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride represented by the following formula (A23):

[0086] [ka]

[0087] Under an argon atmosphere, (4-(3,4,5-trimethoxy-phenyl)-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)diphenylmethane (1.07 g, 1.48 mmol) obtained by a standard method, 12 mL of toluene, and 3 mL of tetrahydrofuran were added to a reaction vessel and cooled to -78°C. After that, a solution of potassium (hexamethyldisilazide) in toluene (3.1 mmol) was slowly added, and the mixture was warmed to room temperature and stirred for 6 hours. The resulting reaction solution was cooled to -78°C, and a suspension of zirconium tetrachloride (0.344 g, 1.48 mmol) in 10 mL of toluene was added. The mixture was warmed to room temperature and stirred for 16 hours. The solvent was evaporated under reduced pressure, washed with 20 mL of toluene, dissolved in dichloromethane, and the solution was recovered by filtration through Celite. The resulting solution was concentrated to 10 mL, 30 mL of hexane was added, and the precipitated solid was collected by filtration and dried to give a purple solid of diphenylmethylene(4-(3,4,5-trimethoxy-phenyl)-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride (0.529 g, 0.59 mmol, 40% yield).

[0088] 1 As a result of measuring H-NMR (400 MHz, chloroform-d), measurement peaks (ppm) were observed at the following positions, confirming the production of diphenylmethylene(4-(3,4,5-trimethoxy-phenyl)-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride. 8.19(m, 1H), 8.12(d, J=8.1Hz, 1H), 8.08(d, J=7.8Hz, 1H), 7.98(dd, J=8.8, 0.5Hz.1H), 7.95(dd, J=9.0, 0.5Hz, 1H), 7.92(d, J=8.0Hz, 1H), 7.59(dd, J=8.9, 1.6Hz, 1H), 7.51-7.44(m, 3H), 7.43-7.33(m, 3H), 7.29(d, J=7.3Hz, 1H), 7.1 0(d, J=0.5Hz, 1H), 7.02(d, J=9.0Hz, 1H), 6.98(d, J=6.3Hz, 1H), 6.77(s, 2H), 6.67(dd, J=9.0, 6.8Hz, 1H), 6.57(dd, J=3.7, 0.5Hz, 1H), 6.26(d, J=0.5Hz, 1H), 6.09(d, J=3.7Hz, 1H), 3.83(s, 3H), 3.79(s, 6H), 1.04(s, 9H), 1.02(s, 9H).

[0089] (2) [Preparation of polymerization catalyst] In a nitrogen-purged 100 mL Schlenk tube, 1.0 g of the organically modified clay (B1) prepared in Preparation Example 1 and 18.4 mL of heptane were added, and then a hexane solution of triethylaluminum (20 wt% diluted product) was added at 11.0 mmol (9.0 mL) per aluminum atom, followed by stirring for 1 hour to form a suspension.

[0090] Separately, in a separately prepared 50 mL Schlenk tube under a nitrogen atmosphere, 25 μmol of diphenylmethylene(4-(3,4,5-trimethoxyphenyl)-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride prepared in (1), 14.8 mL of heptane, and 11.5 mmol (9.5 mL) of a hexane solution of triethylaluminum (20 wt% diluted product) per aluminum atom were added, and the mixture was stirred for 1 hour to form a solution.

[0091] The resulting solution was added to the above suspension, and then the mixture was stirred at room temperature for 12 hours to prepare a polymerization catalyst (zirconium concentration: 0.48 mmol / L).

[0092] (3) [Production of ethylene-1-hexene copolymer] After replacing the air in a 1-liter autoclave with nitrogen, 600 ml of a C9-C13 saturated hydrocarbon solvent (trade name IP Solvent 1620 (Idemitsu Petrochemical Co., Ltd.)) and 15 ml of 1-hexene were added, and the temperature of the autoclave was raised to 170°C. After that, the internal pressure of the autoclave was adjusted to 0.1 MPa with nitrogen, and then the internal pressure of the autoclave was adjusted to 0.95 MPa with ethylene.

[0093] Next, the polymerization catalyst prepared in (2) was fed into the autoclave under nitrogen pressure in an amount of 0.86 μmol (1.79 mL) per diphenylmethylene(4-(3,4,5-trimethoxy)-phenyl-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride, and polymerization was carried out for 10 minutes.

[0094] After the polymerization reaction was completed, the unreacted ethylene was depressurized, and the polymer solution was extracted from the bottom of the autoclave and dried under reduced pressure in an oven at 120°C to obtain 30 g of ethylene-1-hexene copolymer. The analytical and evaluation results of the obtained ethylene-1-hexene copolymer are shown in Table 1.

[0095] Example 3 (1) [Synthesis of transition metal compounds] Synthesis of di(4-methoxy-phenyl)methylene(4-(4-methoxy-phenyl)-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride shown in the following formula (A2)

[0096] [ka]

[0097] Under an argon atmosphere, (4-(4-methoxyphenyl)-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)di(4-methoxyphenyl)methane (0.825 g, 1.14 mmol) obtained by a standard method, 10 mL of toluene, and 5 mL of tetrahydrofuran were added to a reaction vessel and cooled to -78 ° C. After that, a solution of potassium (hexamethyldisilazide) in toluene (2.4 mmol) was slowly added, and the mixture was warmed to room temperature and stirred for 6 hours. The resulting reaction solution was cooled to -78 ° C., and a suspension of zirconium tetrachloride (0.265 g, 1.14 mmol) in 10 mL of toluene was added, and the mixture was stirred at room temperature for 16 hours, after which the solvent was distilled off under reduced pressure. 20 mL of toluene and 10 mL of hexane were added, and the solution was recovered by celite filtration. The solvent was evaporated under reduced pressure, and then the residue was dissolved in 5 mL of toluene. 30 mL of hexane was added, and the precipitated solid was recovered by filtration and dried to obtain a purple solid of di(4-methoxy-phenyl)methylene(4-(4-methoxy-phenyl)-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride (0.605 g, 0.684 mmol, yield 60%).

[0098] 1 As a result of measuring H-NMR (400 MHz, chloroform-d), measurement peaks (ppm) were observed at the following positions, confirming the production of di(4-methoxy-phenyl)methylene(4-(4-methoxy-phenyl)-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride. 8.07-7.93(m, 4H), 7.91(d, J=8.9Hz, 1H), 7.77(dd, J=8.7, 2.4Hz, 1H), 7.58(dd, J=8.9, 1. 5Hz, 1H), 7.49(d, J=8.8Hz, 1H), 7.39(dd, J=8.9, 1.5Hz, 1H), 7.16(d, J=0.9Hz, 1H), 7.04-6 .88(m, 8H), 6.66(dd, J=9.1, 6.9Hz, 1H), 6.53(dd, J=3.6, 0.7Hz, 1H), 6.31(d, J=0.7Hz, 1H ), 6.07(d, J=3.6Hz, 1H), 3.87(s, 3H), 3.81(s, 3H), 3.79(s, 3H), 1.07(s, 9H), 1.04(s, 9H).

[0099] (2) [Preparation of polymerization catalyst] In a 100 mL Schlenk tube purged with nitrogen, 1.0 g of the organically modified clay (B1) obtained in Preparation Example 1 and 18.4 mL of heptane were added, and then a hexane solution of triethylaluminum (20 wt% diluted product) was added in an amount of 11.0 mmol (9.0 mL) per aluminum atom, followed by stirring for 1 hour to obtain a suspension.

[0100] Separately, in a separately prepared 50 mL Schlenk tube under a nitrogen atmosphere, 25 μmol of di(4-methoxyphenyl)methylene(4-(4-methoxyphenyl)-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride obtained in (1), 14.8 mL of heptane, and 11.5 mmol (9.5 mL) of a hexane solution of triethylaluminum (20 wt% diluted product) per aluminum atom were added, and the mixture was stirred for 1 hour to obtain a solution.

[0101] The resulting solution was added to the above suspension, and then the mixture was stirred at room temperature for 12 hours to prepare a polymerization catalyst (zirconium concentration: 0.48 mmol / L).

[0102] (3) [Production of ethylene-1-hexene copolymer] After the air in a 1-liter autoclave was replaced with nitrogen, 600 mL of a C9-C13 saturated hydrocarbon solvent (trade name IP Solvent 1620 (Idemitsu Petrochemical Co., Ltd.)) and 15 mL of 1-hexene were added, and the temperature of the autoclave was raised to 170°C. After that, the internal pressure of the autoclave was adjusted to 0.1 MPa with nitrogen, and then the internal pressure of the autoclave was adjusted to 0.95 MPa with ethylene.

[0103] Next, the polymerization catalyst obtained in (2) was fed into the autoclave under nitrogen pressure in an amount of 0.86 μmol (1.79 mL) per di(4-methoxy-phenyl)methylene(4-(4-methoxy)-phenyl-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride, and polymerization was carried out for 10 minutes.

[0104] After the polymerization reaction was completed, the unreacted ethylene was depressurized, and the polymer solution was extracted from the bottom of the autoclave and dried under reduced pressure in an oven at 120°C to obtain 52 g of ethylene-1-hexene copolymer. The analytical and evaluation results of the obtained ethylene-1-hexene copolymer are shown in Table 1.

[0105] Example 4 (1) [Synthesis of transition metal compounds] Synthesis of diphenylmethylene(4-(3,5-di-tert-butyl-phenyl)-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride represented by the following formula (A24)

[0106] [ka]

[0107] Under an argon atmosphere, (4-(3,5-di-tert-butyl-phenyl)-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)diphenylmethane (0.875 g, 1.17 mmol), 10 mL of toluene, and 1.5 mL of tetrahydrofuran were added to a reaction vessel by a standard method and cooled to -78 °C. After that, a solution of potassium (hexamethyldisilazide) in toluene (2.45 mmol) was slowly added, and the mixture was warmed to room temperature and stirred for 14 hours. The resulting reaction solution was cooled to -78 °C, and a suspension of zirconium tetrachloride (0.273 g, 1.17 mmol) in 10 mL of toluene and 4.5 mL of tetrahydrofuran were added. The mixture was warmed to room temperature and stirred for 2 hours, and then stirred at 60 °C for 1 hour. After the solvent was distilled off under reduced pressure, 100 mL of toluene was added, and the insoluble matter was removed by celite filtration at 70°C. The resulting solution was concentrated to 10 mL, and 40 mL of hexane was added. The precipitated solid was recovered by filtration and dried to give a purple solid of diphenylmethylene(4-(3,5-di-tert-butyl-phenyl)-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride (0.662 g, 0.73 mmol, yield 62%).

[0108] 1 As a result of measuring H-NMR (400 MHz, chloroform-d), measurement peaks (ppm) were observed at the following positions, confirming the production of diphenylmethylene(4-(3,5-di-tert-butyl-phenyl)-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride. 8.20(dd, J=6.0,1.6Hz,1H), 8.13(d, J=8.0Hz, 1H), 8.09(d, J=7.8Hz, 1H), 7.98(d, J=8.9Hz , 1H), 7.94-7.70(m, 2H), 7.59(dd, J=8.8, 1.6Hz, 1H), 7.51-7.43(m, 3H), 7.42-7.32(m, 6H), 7.28(d, J=7.3Hz, 1H), 7.13(s, 1H), 7.03-6.98(m, 2H), 6.68(dd, J=8.5, 7.3Hz, 1H), 6.54(d , J=3.5Hz, 1H), 6.27(s, 1H), 6.09(d, J=3.5Hz, 1H), 1.29(s, 18H), 1.05(s, 9H), 1.03(s, 9H).

[0109] (2) [Preparation of polymerization catalyst] In a 100 mL Schlenk tube purged with nitrogen, 1.0 g of the organically modified clay (B1) obtained in Preparation Example 1 and 18.4 mL of heptane were added, and then a hexane solution of triethylaluminum (20 wt% diluted product) was added in an amount of 11.0 mmol (9.0 mL) per aluminum atom, followed by stirring for 1 hour to obtain a suspension.

[0110] Separately, in a separately prepared 50 mL Schlenk tube under a nitrogen atmosphere, 25 μmol of diphenylmethylene(4-(3,5-di-tert-butyl-phenyl)-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride obtained in (1), 14.8 mL of heptane, and 11.5 mmol (9.5 mL) of a hexane solution of triethylaluminum (20 wt% diluted product) per aluminum atom were added, and the mixture was stirred for 1 hour to obtain a solution.

[0111] The resulting solution was added to the above suspension, and then the mixture was stirred at room temperature for 12 hours to prepare a polymerization catalyst (zirconium concentration: 0.48 mmol / L).

[0112] (3) [Production of ethylene-1-hexene copolymer] After the air in a 1-liter autoclave was replaced with nitrogen, 600 mL of a C9-C13 saturated hydrocarbon solvent (trade name IP Solvent 1620 (Idemitsu Petrochemical Co., Ltd.)) and 15 mL of 1-hexene were added, and the temperature of the autoclave was increased to 170°C. After that, the internal pressure of the autoclave was adjusted to 0.1 MPa with nitrogen, and then the internal pressure of the autoclave was adjusted to 0.95 MPa with ethylene.

[0113] Next, the polymerization catalyst obtained in (2) was fed into the autoclave under nitrogen pressure in an amount of 0.86 μmol (1.79 mL) per diphenylmethylene(4-(3,5-di-tert-butyl-phenyl)-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride, and polymerization was carried out for 10 minutes.

[0114] After the polymerization reaction was completed, the unreacted ethylene was depressurized, and the polymer solution was extracted from the bottom of the autoclave and dried under reduced pressure in an oven at 120°C to obtain 27 g of ethylene-1-hexene copolymer. The analytical and evaluation results of the obtained ethylene-1-hexene copolymer are shown in Table 1.

[0115] Example 5 (1) [Synthesis of transition metal compounds] The procedure was carried out according to Example 1.

[0116] (2) [Preparation of polymerization catalyst] Under a nitrogen atmosphere, 1.15 g of the organically modified clay (B2) obtained in Preparation Example 2 and 18.4 ml of heptane were placed in a 100 mL Schlenk tube, and then 11.0 mmol (9.0 mL) of a hexane solution of triethylaluminum (20 wt% diluted product) per aluminum atom was added, followed by stirring for 1 hour to form a suspension.

[0117] Separately, in a separately prepared 50 mL Schlenk tube under a nitrogen atmosphere, 25 μmol of di(4-methoxyphenyl)methylene(4-phenyl-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride obtained in (1), 14.8 mL of heptane, and 11.5 mmol (9.5 mL) of a hexane solution of triethylaluminum (20 wt % diluted product) per aluminum atom were added, and the mixture was stirred for 1 hour to form a solution.

[0118] The resulting solution was added to the above suspension, and then the mixture was stirred at room temperature for 12 hours to prepare a polymerization catalyst (zirconium concentration: 0.48 mmol / L).

[0119] (3) [Production of ethylene-1-hexene copolymer] After the air in a 1-liter autoclave was replaced with nitrogen, 600 mL of a C9 to C13 saturated hydrocarbon solvent (trade name IP Solvent 1620 (Idemitsu Petrochemical Co., Ltd.)) and 15 mL of 1-hexene were added, and the temperature of the autoclave was raised to 170°C. After that, the internal pressure of the autoclave was adjusted to 0.1 MPa with nitrogen, and then the internal pressure of the autoclave was adjusted to 0.95 MPa with ethylene.

[0120] Next, the polymerization catalyst obtained in (2) was fed into the autoclave under nitrogen pressure in an amount of 0.86 μmol (1.79 mL) per di(4-methoxy-phenyl)methylene(4-phenyl-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride, and polymerization was carried out for 10 minutes.

[0121] After the polymerization reaction was completed, the unreacted ethylene was released from the pressure, and the polymer solution was extracted from the bottom of the autoclave and dried under reduced pressure at 120°C in an oven to obtain 30 g of ethylene-1-hexene copolymer. The evaluation and analysis results of the obtained ethylene-1-hexene copolymer are shown in Table 1.

[0122] Comparative Example 1 (1) [Catalyst Preparation] In a 100 mL Schlenk tube, 1.0 g of the organically modified clay (B1) obtained in Preparation Example 1 and 18.4 mL of heptane were added, and then 11.0 mmol (9.0 mL) of a hexane solution of triethylaluminum (20 wt% diluted product) per aluminum atom was added, followed by stirring for 1 hour to form a suspension.

[0123] Separately, in a separately prepared 50 mL Schlenk tube under a nitrogen atmosphere, 25 μmol of diphenylmethylene(4-phenyl-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride represented by the following formula (K1), synthesized by standard methods, 14.8 mL of heptane, and 11.5 mmol (9.5 mL) of a hexane solution of triethylaluminum (20 wt% diluted product) per aluminum atom were added, and the mixture was stirred for 1 hour to obtain a solution. The resulting solution was added to the above suspension, and then stirred at room temperature for 12 hours to prepare a catalyst (zirconium concentration 0.48 mmol / L).

[0124] [ka]

[0125] (2) [Polymerization] After the air in a 1-liter autoclave was replaced with nitrogen, 600 mL of a C9-C13 saturated hydrocarbon solvent (trade name IP Solvent 1620 (Idemitsu Petrochemical Co., Ltd.)) and 15 mL of 1-hexene were added, and the temperature of the autoclave was raised to 170°C. After that, the internal pressure of the autoclave was adjusted to 0.1 MPa with nitrogen, and then the internal pressure of the autoclave was adjusted to 0.95 MPa with ethylene.

[0126] Next, the catalyst obtained in (1) was fed into the autoclave under nitrogen pressure in an amount of 0.86 μmol (1.79 mL) per diphenylmethylene(4-phenyl-1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride, and polymerization was carried out for 10 minutes.

[0127] After the polymerization reaction was completed, the unreacted ethylene was released from the pressure, and the polymer solution was extracted from the bottom of the autoclave and dried under reduced pressure at 120°C in an oven to obtain 36 g of polymer. The analytical and evaluation results of the obtained polymer are shown in Table 1.

[0128] The polymer obtained had a low molecular weight and a high density, and the catalyst was poor in activity and copolymerizability.

[0129] Comparative Example 2 (1) [Catalyst Preparation] In a 100 mL Schlenk tube, 1.0 g of the organically modified clay (B1) obtained in Preparation Example 1 and 18.4 mL of heptane were added, and then 11.0 mmol (9.0 mL) of a hexane solution of triethylaluminum (20 wt% diluted product) per aluminum atom was added, followed by stirring for 1 hour to obtain a suspension.

[0130] Separately, in a 50 mL Schlenk tube under a nitrogen atmosphere, 25 μmol of diphenylmethylene(1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride (represented by general formula (K2)) synthesized by standard methods, 14.8 mL of heptane, and 11.5 mmol (9.0 mL) of a hexane solution of triethylaluminum (20 wt% diluted product) per aluminum atom were added, followed by stirring for 1 hour to obtain a solution. The resulting solution was added to the above suspension, and then stirred at room temperature for 12 hours to prepare a catalyst (zirconium concentration 0.48 mmol / L).

[0131] [ka]

[0132] (2) [Polymerization] After the air in a 1-liter autoclave was replaced with nitrogen, 600 mL of a C9-C13 saturated hydrocarbon solvent (trade name IP Solvent 1620 (Idemitsu Petrochemical Co., Ltd.)) and 15 mL of 1-hexene were added, and the temperature of the autoclave was increased to 170°C. After that, the internal pressure of the autoclave was adjusted to 0.1 MPa with nitrogen, and then the internal pressure of the autoclave was adjusted to 0.95 MPa with ethylene.

[0133] Next, the catalyst obtained in (1) was fed into the autoclave by nitrogen pressure in an amount of 0.86 μmol (1.79 mL) per diphenylmethylene(1-indenyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride, and polymerization was carried out for 10 minutes.

[0134] After the polymerization reaction was completed, the unreacted ethylene was depressurized, and the polymer solution was extracted from the bottom of the autoclave and dried under reduced pressure at 120°C in an oven to obtain 48 g of polymer. The analytical and evaluation results of the obtained polymer are shown in Table 1.

[0135] The polymer obtained had a low molecular weight and a high density, and the catalyst was poor in activity and copolymerizability.

[0136] Comparative Example 3 (1) [Catalyst Preparation] In a 100 mL Schlenk tube, 1.0 g of the organically modified clay (B1) obtained in (1) and 18.4 mL of heptane were added, and then 11.0 mmol (9.0 mL) of a hexane solution of triethylaluminum (20 wt% diluted product) per aluminum atom was added, followed by stirring for 1 hour to obtain a suspension.

[0137] Separately, in a separately prepared 50 mL Schlenk tube under a nitrogen atmosphere, 25 μmol of diphenylmethylene(cyclopentadienyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride represented by the following general formula (K3), synthesized by a standard method, 14.8 mL of heptane, and 11.5 mmol (9.5 mL) of a hexane solution of triethylaluminum (20 wt% diluted product) per aluminum atom were added, and the mixture was stirred for 1 hour to obtain a solution. The resulting solution was added to the above suspension, and then stirred at room temperature for 12 hours to prepare a catalyst (zirconium concentration 0.48 mmol / L).

[0138] [ka]

[0139] (2) [Polymerization] After the air in a 1-liter autoclave was replaced with nitrogen, 600 mL of a C9-C13 saturated hydrocarbon solvent (trade name IP Solvent 1620 (Idemitsu Petrochemical Co., Ltd.)) and 15 mL of 1-hexene were added, and the temperature of the autoclave was increased to 170°C. After that, the internal pressure of the autoclave was adjusted to 0.1 MPa with nitrogen, and then the internal pressure of the autoclave was adjusted to 0.95 MPa with ethylene.

[0140] Next, the catalyst obtained in (1) was fed into the autoclave by nitrogen pressure in an amount of 0.86 μmol (1.79 mL) per diphenylmethylene(cyclopentadienyl)(2,7-di-tert-butyl-9-fluorenyl)zirconium dichloride, and polymerization was carried out for 10 minutes.

[0141] After the polymerization reaction was completed, the unreacted ethylene was depressurized, and the polymer solution was extracted from the bottom of the autoclave and dried under reduced pressure at 120°C in an oven to obtain 34 g of polymer. The analytical and evaluation results of the obtained polymer are shown in Table 1.

[0142] The polymer obtained had a low molecular weight and a high density, and the catalyst was poor in activity and copolymerizability.

[0143] [Table 1] [Industrial Applicability]

[0144] The polymerization catalyst of the present invention, which comprises a transition metal compound (A) having a specific structure, a specific activating cocatalyst (B), and an organoaluminum compound (C), is particularly suitable as a catalyst for producing ethylene polymers, and enables efficient production of low-density ethylene polymers which have sufficient molecular weight to provide excellent mechanical properties such as tensile strength, tear strength, and impact strength, and which are excellent in transparency, heat-sealability, processability, etc., and therefore has extremely high industrial applicability.

Claims

1. A transition metal compound (A) represented by the following general formula (1): 【Chemistry 1】 (In the formula, in the formula, M １ represents a Group 4 metal atom, and X １ and X ２ each independently represents a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a dialkylamino group having 2 to 6 carbon atoms; R １１ ~R １５ , R ２１ , R ２２ , R ３１ ~R ３８ , R ４１ ~R ４６ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; １ ~SG ５ each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a dialkylamino group having 2 to 6 carbon atoms, provided that SG １ ~SG ５ All of these do not become hydrogen atoms at the same time, and SG ６ and S.G. ７ each independently represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a dialkylamino group having 2 to 6 carbon atoms. an activating co-catalyst (B) which is at least one selected from the group consisting of an organically modified clay containing an organic aliphatic group represented by the following general formula (2), compounds represented by the following general formulas (3) to (6), methylaluminoxane, and (methyl-isobutyl)aluminoxane; 【Chemistry 2】 (In the formula, R ５ ~R ７ are each independently an alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an alkylamino group having 1 to 30 carbon atoms, an alkylsilyl group having 1 to 30 carbon atoms, a substituent in which oxygen is introduced between the carbon-carbon bonds of an alkyl group having 2 to 30 carbon atoms, a substituent in which a portion of an alkyl group having 1 to 30 carbon atoms is substituted with an alkylamino group having 1 to 30 carbon atoms, or a substituent in which a portion of the carbon of an alkyl group having 2 to 30 carbon atoms is substituted with silicon, and R ５ ~R ７ At least one of M is an alkyl group having 10 or more carbon atoms; ２ is an atom in group 15 of the periodic table.) (H) １ ()(G １ (A) １ ) ４ (3) (wherein H is a hydrogen atom, G １ represents a boron atom or an aluminum atom, L １ is a Lewis base, Ar １ are each independently a halogen-substituted aryl group having 6 to 20 carbon atoms. (DL ２ ｍ )(G ２ (Ar ２ ) ４ ) (4) (Wherein, D is Li ＋ , Fe ２＋ , Fe ３＋ , Ag ＋ is a cation selected from L ２ is a Lewis base or a cyclopentadienyl group, G ２ is a boron atom or an aluminum atom, Ar ２ are each independently a halogen-substituted aryl group having 6 to 20 carbon atoms, and m is an integer of 0 to 2. (5)(1) ３ (2r ３ ) ) ４ ) (5) (Wherein E is a carbonium cation or a tropinium cation, G ３ is a boron atom or an aluminum atom, Ar ３ are each independently a halogen-substituted aryl group having 6 to 20 carbon atoms. G ４ (Ar ４ ) ３ (6) (In the formula, G ４ is a boron atom or an aluminum atom, Ar ４ are each independently a halogen-substituted aryl group having 6 to 20 carbon atoms. and an organoaluminum compound (C).

2. M １ The polymerization catalyst according to claim 1, characterized in that is a zirconium atom.

3. 3. The polymerization catalyst according to claim 1, wherein the organoaluminum compound (C) is an organoaluminum compound represented by the following general formula (7): 【Transformation 3】 (In the formula, R ８ is a hydrocarbon group having 1 to 20 carbon atoms, and R ９ are each independently a hydrocarbon group having 1 to 20 carbon atoms, a hydrogen atom, or a chlorine atom.

4. 2. The polymerization catalyst according to claim 1, which is a catalyst for producing an ethylene polymer.

5. A method for producing an ethylene polymer, comprising polymerizing an ethylene monomer in the presence of the polymerization catalyst according to claim 1.

6. 6. The method for producing an ethylene polymer according to claim 5, wherein ethylene and an α-olefin are copolymerized.

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