Process for producing olefin polymer

Abstract

To provide a method that can efficiently produce olefin polymers.SOLUTION: A method for producing an olefin polymer includes polymerizing an α-olefin having carbon atoms of two or more and 20 or less in the presence of a catalyst for olefin polymerization containing a metallocene compound (A) of formula [I] [L is carbon or silicon, M is a metal of group 4 or group 5 in the periodic table].SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing an olefin polymer, and more particularly to a method for efficiently producing an olefin polymer. [Background technology]

[0002] In the polymerization of α-olefins using a metallocene compound as a catalyst component, it is known that the polymerization reactivity of the olefin and the structure and physical properties of the resulting olefin polymer can be controlled by structural design of the metallocene compound. For example, Patent Document 1 describes a method for producing isotactic polypropylene using a metallocene compound with a specific structure having a ligand in which a cyclopentadienyl ring and a fluorenyl ring are bridged. Patent Document 2 describes a method for producing isotactic polypropylene with excellent modulus, impact resistance, and transparency using a metallocene compound with a specific structure having a ligand in which a cyclopentadienyl ring and a fluorenyl ring are bridged. Patent Document 3 describes a method for producing a propylene-ethylene copolymer with high polymerization activity using a metallocene compound with a specific structure having a ligand in which a cyclopentadienyl ring and a fluorenyl ring are bridged. These conventional techniques have improved some of the physical properties of the resulting olefin polymer.

[0003] The present applicant has previously disclosed a metallocene compound that exhibits extremely high ethylene polymerization activity (Patent Document 4). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 6-122718 [Patent Document 2] International Publication No. 01 / 27124 [Patent Document 3] International Publication No. 2006 / 126608 [Patent Document 4] International Publication No. 2004 / 29062 Summary of the Invention [Problem to be solved by the invention]

[0005] For example, it is expected that separator materials for capacitors, lithium-ion batteries, etc. will require increasingly high performance and purity in the future. To meet this demand, it will be necessary to further increase the polymerization activity during the production of polyolefins, which are the raw materials.

[0006] Therefore, the present inventors have conducted research aimed at providing a method for efficiently producing an olefin polymer. [Means for solving the problem]

[0007] As a result of intensive investigations aimed at solving the above problems, the present inventors have found that an olefin polymerization catalyst containing a metallocene compound having a specific structure is highly effective, and have thus completed the present invention. That is, the present invention is characterized by the following features.

[0008] [1] A method for producing an olefin polymer, comprising polymerizing an α-olefin having from 2 to 20 carbon atoms in the presence of an olefin polymerization catalyst containing a metallocene compound (A) represented by the following general formula [I]:

[0009] [ka]

[0010] [In general formula [I], R 1 , R 1 ', R 2 , and R 2 ' is a hydrogen atom, a hydrocarbon group, or a silicon-containing group, R 3 and R 3 ' are hydrocarbon groups, silicon-containing groups or halogen-containing hydrocarbon groups, which may be the same or different and may be bonded to each other to form a ring; R 4 , R 4 ', R 5 , and R 5 ' is a hydrogen atom, a hydrocarbon group, a silicon-containing group, a halogen atom or a halogen-containing hydrocarbon group, R 4 and R 4 ' are mutually different, R 5 and R 5 ' are mutually different, R 4 and R 5 and are mutually different, R 4 ' and R 5 ' and are mutually different, or R 4 and R 5 and are mutually different, and R 4 ' and R 5 ' and are mutually different. L is carbon or silicon, M is a metal of Group 4 or 5 of the periodic table, Q is a halogen atom, a hydrocarbon group, a neutral conjugated or non-conjugated diene having 10 or less carbon atoms, an anionic ligand, or a neutral ligand capable of coordinating with a lone electron pair, and when there are multiple Qs, they may be the same or different, and j is an integer of 1 to 4.

[0011] [2] In the general formula [I], R 4 and R 5 ', or R 4 ' and R 5 is a hydrocarbon group, a silicon-containing group, a halogen atom, or a halogen-containing hydrocarbon group, and R 4 and R 5 ' may be the same or different from each other, and R 4 ' and R 5 and may be the same or different from each other.

[0012] [3] In the general formula [I], R 4 and R 5 ', or R 4 ' and R 5 is a hydrocarbon group, and R 4 and R 5' may be the same or different from each other, and R 4 ' and R 5 and may be the same or different from each other.

[0013] [4] In the general formula [I], R 4 and R 5 When R ' is a hydrocarbon group, 4 ' and R 5 is a hydrogen atom, and R 4 ' and R 5 When R is a hydrocarbon group, 4 and R 5 The method for producing an olefin polymer according to [3], wherein ' is a hydrogen atom.

[0014] [5] The olefin polymerization catalyst is (B) (b-1) organoaluminum oxy compound, (b-2) a compound that reacts with the metallocene compound (A) to form an ion pair, and (b-3) Organoaluminum compounds At least one compound selected from The method for producing an olefin polymer according to any one of [1] to [4], further comprising:

[0015] [6] The method for producing an olefin polymer according to any one of [1] to [5], wherein an α-olefin having 2 to 20 carbon atoms is polymerized at a temperature of 40°C or higher and 200°C or lower. [Effects of the Invention]

[0016] In the present invention, an olefin polymerization catalyst containing a metallocene compound having a specific structure is used, so that an olefin polymer can be produced with high polymerization activity. DETAILED DESCRIPTION OF THE INVENTION

[0017] The method for producing an olefin polymer of the present invention is characterized by polymerizing an α-olefin having from 2 to 20 carbon atoms in the presence of an olefin polymerization catalyst containing a metallocene compound (A).

[0018] [Metallocene Compound (A)] The metallocene compound (A) used in the present invention is a bridged metallocene compound represented by the following general formula [I].

[0019] [ka]

[0020] [In general formula [I], R 1 , R 1 ', R 2 , and R 2 ' is a hydrogen atom, a hydrocarbon group, or a silicon-containing group, R 3 and R 3 ' are hydrocarbon groups, silicon-containing groups or halogen-containing hydrocarbon groups, which may be the same or different and may be bonded to each other to form a ring; R 4 , R 4 ', R 5 , and R 5 ' is a hydrogen atom, a hydrocarbon group, a silicon-containing group, a halogen atom or a halogen-containing hydrocarbon group, R 4 and R 4 ' are mutually different, R 5 and R 5 ' are mutually different, R 4 and R 5 and are mutually different, R 4 ' and R 5 ' and are mutually different, or R 4 and R 5 and are mutually different, and R 4 ' and R 5 ' and are mutually different. L is carbon or silicon, M is a metal of Group 4 or 5 of the periodic table, Q is a halogen atom, a hydrocarbon group, a neutral conjugated or non-conjugated diene having 10 or less carbon atoms, an anionic ligand, or a neutral ligand capable of coordinating with a lone electron pair, and when there are multiple Qs, they may be the same or different, and j is an integer of 1 to 4.

[0021] In general formula [I], R 1 , R 1 ', R 2 , and R 2 ' is a hydrogen atom, a hydrocarbon group, or a silicon-containing group. As the hydrocarbon group, particularly preferred are hydrocarbon groups having 1 to 20 carbon atoms, such as alkyl groups having 1 to 20 carbon atoms, saturated alicyclic groups having 3 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, and aralkyl groups having 7 to 20 carbon atoms.

[0022] Specific examples of the alkyl group having 1 to 20 carbon atoms include linear alkyl groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decanyl; isopropyl, tert-butyl, amyl, 3-methylpentyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-methyl-1-propylbutyl, 1,1-propylbutyl, 1,1-dimethyl-2-methylpropyl, and 1-methyl-1-isopropyl-2-methylpropyl. The alkyl group preferably has 1 to 10 carbon atoms.

[0023] Specific examples of the saturated alicyclic group having 3 to 20 carbon atoms include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; and alicyclic polycyclic groups such as a norbornyl group and an adamantyl group. The saturated alicyclic group preferably has 5 to 11 carbon atoms.

[0024] Specific examples of the aryl group having 6 to 20 carbon atoms include unsubstituted aryl groups such as phenyl, naphthyl, phenanthryl, anthracenyl, and biphenyl, and alkylaryl groups such as o-tolyl, m-tolyl, p-tolyl, ethylphenyl, n-propylphenyl, iso-propylphenyl, n-butylphenyl, sec-butylphenyl, tert-butylphenyl, and xylyl. The number of carbon atoms in the aryl group is preferably 6 to 10.

[0025] Specific examples of aralkyl groups having 7 to 20 carbon atoms include unsubstituted aralkyl groups such as benzyl, cumyl, α-phenethyl, β-phenethyl, diphenylmethyl, naphthylmethyl, and neophyl; and alkylaralkyl groups such as o-methylbenzyl, m-methylbenzyl, p-methylbenzyl, ethylbenzyl, n-propylbenzyl, isopropylbenzyl, n-butylbenzyl, sec-butylbenzyl, and tert-butylbenzyl. The number of carbon atoms in the aralkyl group is preferably 7 to 12.

[0026] R 1 , R 1 ', R 2 , and R 2 When "'" is a silicon-containing group, specific examples thereof include alkylsilyl groups such as methylsilyl group, dimethylsilyl group, trimethylsilyl group, ethylsilyl group, diethylsilyl group, triethylsilyl group, and dimethyl-tert-butylsilyl group; and arylsilyl groups such as dimethylphenylsilyl group, diphenylmethylsilyl group, and triphenylsilyl group. The alkylsilyl group preferably has 1 to 10 carbon atoms, and the arylsilyl group preferably has 8 to 18 carbon atoms.

[0027] In general formula [I], R 3 , R 3 ' are hydrocarbon groups, silicon-containing groups or halogen-containing hydrocarbon groups, which may be the same or different and may be bonded to each other to form a ring.

[0028] R 3, R 3 When ' is a hydrocarbon group, it is particularly preferably a hydrocarbon group having 1 to 20 carbon atoms, such as an alkyl group having 1 to 20 carbon atoms, a saturated alicyclic group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms.

[0029] Specific examples of the alkyl group having 1 to 20 carbon atoms include linear alkyl groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decanyl; isopropyl, tert-butyl, amyl, 3-methylpentyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-methyl-1-propylbutyl, 1,1-propylbutyl, 1,1-dimethyl-2-methylpropyl, and 1-methyl-1-isopropyl-2-methylpropyl. The alkyl group preferably has 1 to 10 carbon atoms.

[0030] Specific examples of the saturated alicyclic group having 3 to 20 carbon atoms include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; and alicyclic polycyclic groups such as a norbornyl group and an adamantyl group. The saturated alicyclic group preferably has 5 to 11 carbon atoms.

[0031] Specific examples of the aryl group having 6 to 20 carbon atoms include unsubstituted aryl groups such as phenyl, naphthyl, phenanthryl, anthracenyl, and biphenyl, and alkylaryl groups such as o-tolyl, m-tolyl, p-tolyl, ethylphenyl, n-propylphenyl, iso-propylphenyl, n-butylphenyl, sec-butylphenyl, tert-butylphenyl, and xylyl. The number of carbon atoms in the aryl group is preferably 6 to 10.

[0032] Specific examples of aralkyl groups having 7 to 20 carbon atoms include unsubstituted aralkyl groups such as benzyl, cumyl, α-phenethyl, β-phenethyl, diphenylmethyl, naphthylmethyl, and neophyl; and alkylaralkyl groups such as o-methylbenzyl, m-methylbenzyl, p-methylbenzyl, ethylbenzyl, n-propylbenzyl, isopropylbenzyl, n-butylbenzyl, sec-butylbenzyl, and tert-butylbenzyl. The number of carbon atoms in the aralkyl group is preferably 7 to 12.

[0033] R 3 , R 3 When ' is a silicon-containing group, specific examples thereof include alkylsilyl groups such as methylsilyl group, dimethylsilyl group, trimethylsilyl group, ethylsilyl group, diethylsilyl group, triethylsilyl group, and dimethyl-tert-butylsilyl group; and arylsilyl groups such as dimethylphenylsilyl group, diphenylmethylsilyl group, and triphenylsilyl group. The alkylsilyl group preferably has 1 to 10 carbon atoms, and the arylsilyl group preferably has 8 to 18 carbon atoms.

[0034] R 3 , R 3When ' is a halogen-containing hydrocarbon group, particularly preferred are groups in which at least one hydrogen atom of the hydrocarbon group has been substituted with a halogen atom. Specific examples thereof include halogen-substituted alkyl groups such as fluoroalkyl groups (e.g., trifluoromethyl groups); halogen substituents of the above-mentioned unsubstituted aryl groups such as fluoroaryl groups (e.g., pentafluorophenyl groups), chloroaryl groups (e.g., o-chlorophenyl groups, m-chlorophenyl groups, p-chlorophenyl groups, chloronaphthyl groups), bromoaryl groups (e.g., o-bromophenyl groups, m-bromophenyl groups, p-bromophenyl groups, bromonaphthyl groups), and iodoaryl groups (e.g., o-iodophenyl groups, m-iodophenyl groups, p-iodophenyl groups, iodonaphthyl groups); fluoroalkylaryl groups (e.g., trifluoromethylphenyl groups), bromoaryl groups, and the like. halogen substituents of the above alkylaryl groups, such as alkylaryl groups (e.g., bromomethylphenyl group, dibromomethylphenyl group) and iodoalkylaryl groups (e.g., iodomethylphenyl group, diiodomethylphenyl group); and halogen substituents of the above unsubstituted aralkyl groups, such as chloroaralkyl groups (e.g., o-chlorobenzyl group, m-chlorobenzyl group, p-chlorobenzyl group, chlorophenethyl group), bromoaralkyl groups (e.g., o-bromobenzyl group, m-bromobenzyl group, p-bromobenzyl group, bromophenethyl group), and iodoaralkyl groups (e.g., o-iodobenzyl group, m-iodobenzyl group, p-iodobenzyl group, iodophenethyl group).

[0035] R 3 , R 3 ' may be bonded to each other to form a ring. Two or more such rings may be present in a molecule. The ring may be, for example, an alicyclic ring, an aromatic ring, or a heterocyclic ring. Specific examples include heterocyclic rings such as a cyclohexane ring; a benzene ring; a hydrogenated benzene ring; a cyclopentene ring; a furan ring, and a thiophene ring, and corresponding hydrogenated heterocyclic rings. Of these, a cyclohexane ring, a benzene ring, and a hydrogenated benzene ring are preferred. The ring may further have a substituent such as an alkyl group.

[0036] In general formula [I], R 4 , R4 ', R 5 , and R 5 ' is a hydrogen atom, a hydrocarbon group, a silicon-containing group, a halogen atom or a halogen-containing hydrocarbon group. R 4 , R 4 ', R 5 , and R 5 When ' is a hydrocarbon group, it is particularly preferably a hydrocarbon group having 1 to 20 carbon atoms, such as an alkyl group having 1 to 20 carbon atoms, a saturated alicyclic group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms.

[0037] Specific examples of the alkyl group having 1 to 20 carbon atoms include linear alkyl groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decanyl; isopropyl, tert-butyl, amyl, 3-methylpentyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-methyl-1-propylbutyl, 1,1-propylbutyl, 1,1-dimethyl-2-methylpropyl, and 1-methyl-1-isopropyl-2-methylpropyl. The alkyl group preferably has 1 to 10 carbon atoms.

[0038] Specific examples of the saturated alicyclic group having 3 to 20 carbon atoms include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; and alicyclic polycyclic groups such as a norbornyl group and an adamantyl group. The saturated alicyclic group preferably has 5 to 11 carbon atoms.

[0039] Specific examples of the aryl group having 6 to 20 carbon atoms include unsubstituted aryl groups such as phenyl, naphthyl, phenanthryl, anthracenyl, and biphenyl, and alkylaryl groups such as o-tolyl, m-tolyl, p-tolyl, ethylphenyl, n-propylphenyl, iso-propylphenyl, n-butylphenyl, sec-butylphenyl, tert-butylphenyl, and xylyl. The number of carbon atoms in the aryl group is preferably 6 to 10.

[0040] Specific examples of aralkyl groups having 7 to 20 carbon atoms include unsubstituted aralkyl groups such as benzyl, cumyl, α-phenethyl, β-phenethyl, diphenylmethyl, naphthylmethyl, and neophyl; and alkylaralkyl groups such as o-methylbenzyl, m-methylbenzyl, p-methylbenzyl, ethylbenzyl, n-propylbenzyl, isopropylbenzyl, n-butylbenzyl, sec-butylbenzyl, and tert-butylbenzyl. The number of carbon atoms in the aralkyl group is preferably 7 to 12.

[0041] R 4 , R 4 ', R 5 , and R 5 When "'" is a silicon-containing group, specific examples thereof include alkylsilyl groups such as methylsilyl group, dimethylsilyl group, trimethylsilyl group, ethylsilyl group, diethylsilyl group, triethylsilyl group, and dimethyl-tert-butylsilyl group; and arylsilyl groups such as dimethylphenylsilyl group, diphenylmethylsilyl group, and triphenylsilyl group. The alkylsilyl group preferably has 1 to 10 carbon atoms, and the arylsilyl group preferably has 8 to 18 carbon atoms.

[0042] R 4 , R 4 ', R 5 , and R 5When "a" is a halogen-containing hydrocarbon group, particularly preferred is a group in which at least one hydrogen atom of the hydrocarbon group has been substituted with a halogen atom. Specific examples thereof include halogen-substituted alkyl groups such as fluoroalkyl groups (e.g., trifluoromethyl groups); halogen-substituted aryl groups such as fluoroaryl groups (e.g., pentafluorophenyl groups), chloroaryl groups (e.g., o-chlorophenyl groups, m-chlorophenyl groups, p-chlorophenyl groups, chloronaphthyl groups), bromoaryl groups (e.g., o-bromophenyl groups, m-bromophenyl groups, p-bromophenyl groups, bromonaphthyl groups), and iodoaryl groups (e.g., o-iodophenyl groups, m-iodophenyl groups, p-iodophenyl groups, iodonaphthyl groups); fluoroalkylaryl groups (e.g., trifluoromethylphenyl groups), bromoaryl groups (e.g., o-iodophenyl groups, m-iodophenyl groups, p-iodophenyl groups, iodonaphthyl groups), and the like. halogen substituents of the above alkylaryl groups, such as alkylaryl groups (e.g., bromomethylphenyl group, dibromomethylphenyl group) and iodoalkylaryl groups (e.g., iodomethylphenyl group, diiodomethylphenyl group); and halogen substituents of the above unsubstituted aralkyl groups, such as chloroaralkyl groups (e.g., o-chlorobenzyl group, m-chlorobenzyl group, p-chlorobenzyl group, chlorophenethyl group), bromoaralkyl groups (e.g., o-bromobenzyl group, m-bromobenzyl group, p-bromobenzyl group, bromophenethyl group), and iodoaralkyl groups (e.g., o-iodobenzyl group, m-iodobenzyl group, p-iodobenzyl group, iodophenethyl group).

[0043] R 4 , R 4 ', R 5 , and R 5 When ' is a halogen atom, specific examples thereof include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Preferably R 4 , R 4 ', R 5 , and R 5 At least one of the groups ' is a substituent other than a hydrogen group, and is preferably a hydrocarbon group.

[0044] In the present invention, R 4 and R4 ' and R 5 and R 5 ' and 'R' are mutually different. 4 and R 5 " and / or "R 4 ' and R 5 ' is different from R 4 and R 5 and are mutually different and R 4 ' and R 5 ' and are the same as each other, or R 4 and R 5 and are mutually equal and R 4 ' and R 5 ' and are mutually different, or R 4 and R 5 and are mutually different, and R 4 ' and R 5 In other words, the metallocene compound used in the present invention is characterized in that the fluorenyl group portion in the metallocene compound has an asymmetric structure.

[0045] There are no particular limitations on the metallocene compound used in the present invention as long as it satisfies the above requirements. Preferred embodiments include the following. R 4 and R 5 ', or R 4 ' and R 5 is preferably a hydrocarbon group, a silicon-containing group, a halogen atom or a halogen-containing hydrocarbon group, and R 4 and R 5 ' may be the same or different from each other, and R 4 ' and R 5 may be the same as or different from each other.

[0046] R 4 and R 5 ', or R 4 ' and R 5 is preferably a hydrocarbon group, and R 4 and R 5 ' may be the same or different from each other, and R 4 ' and R 5may be the same as or different from each other.

[0047] R 4 and R 5 When ' is a hydrocarbon group, R 4 ' and R 5 is a hydrogen atom, and R 4 ' and R 5 is a hydrocarbon group, R 4 and R 5 It is preferred that ' is a hydrogen atom. For example, R 4 and R 5 If ' is a hydrogen atom, R 4 ' and R 5 is a substituent other than hydrogen, and R 4 and R 5 ' is a hydrogen atom, and R 4 ' and R 5 is preferably a hydrocarbon group. The hydrocarbon group is more preferably an alkyl group having 1 to 20 carbon atoms, further preferably a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, or a cyclohexyl group, and particularly preferably a methyl group.

[0048] In addition, the combination may be the exact opposite of the above combination. 4 ' and R 5 is a hydrogen atom, R 4 and R 5 ' is a substituent other than hydrogen, and R 4 ' and R 5 is a hydrogen atom, and R 4 and R 5 It is preferred that ' is a hydrocarbon group.

[0049] In general formula [I], M is an element selected from Group 4 or 5 metals in the periodic table. Specific examples include Ti, Zr, Hf, and V. Among these, Ti, Zr, or Hf is preferred, Zr and Hf are more preferred, and Zr is particularly preferred.

[0050] In the general formula [I], Q is a halogen atom, a hydrocarbon group, a neutral conjugated or non-conjugated diene having 10 or less carbon atoms, an anionic ligand, or a neutral ligand capable of coordinating with a lone electron pair. When Q is a halogen atom, specific examples thereof include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0051] When Q is a hydrocarbon group, alkyl groups having 1 to 10 carbon atoms and cycloalkyl groups having 3 to 10 carbon atoms are particularly preferred. Specific examples of alkyl groups having 1 to 10 carbon atoms include methyl, ethyl, n-propyl, isopropyl, 2-methylpropyl, 1,1-dimethylpropyl, 2,2-dimethylpropyl, 1,1-diethylpropyl, 1-ethyl-1-methylpropyl, 1,1,2,2-tetramethylpropyl, sec-butyl, tert-butyl, 1,1-dimethylbutyl, 1,1,3-trimethylbutyl, and neopentyl. Examples of cycloalkyl groups having 3 to 10 carbon atoms include cyclohexylmethyl, cyclohexyl, and 1-methyl-1-cyclohexyl. It is particularly preferred that the hydrocarbon group have 5 or fewer carbon atoms.

[0052] When Q is a neutral conjugated or non-conjugated diene having 10 or less carbon atoms, specific examples thereof include s-cis- or s-trans-η 4 -1,3-butadiene, s-cis- or s-trans-η 4 -1,4-diphenyl-1,3-butadiene, s-cis- or s-trans-η 4 -3-Methyl-1,3-pentadiene, s-cis- or s-trans-η 4 -1,4-Dibenzyl-1,3-butadiene, s-cis- or s-trans-η 4 -2,4-Hexadiene, s-cis- or s-trans-η 4 -1,3-pentadiene, s-cis- or s-trans-η 4 -1,4-Ditolyl-1,3-butadiene, s-cis- or s-trans-η 4 -1,4-bis(trimethylsilyl)-1,3-butadiene.

[0053] When Q is an anionic ligand, specific examples thereof include alkoxy groups such as methoxy and tert-butoxy; aryloxy groups such as phenoxy; carboxylate groups such as acetate and benzoate; and sulfonate groups such as mesylate and tosylate.

[0054] When Q is a neutral ligand capable of coordinating with a lone electron pair, specific examples thereof include organic phosphorus compounds such as trimethylphosphine, triethylphosphine, triphenylphosphine, and diphenylmethylphosphine; and ethers such as tetrahydrofuran (THF), diethyl ether, dioxane, and 1,2-dimethoxyethane. Of the atoms and groups exemplified above, a halogen atom or an alkyl group having 1 to 5 carbon atoms is particularly preferred as Q.

[0055] In the general formula [I], j is an integer of 1 to 4, and is preferably 2. In general formula [I], specific examples of MQj include ZrCl2, ZrBr2, ZrMe2, Zr(Me)(Et), Zr(OTs)2, Zr(OMs)2, Zr(OTf)2, TiCl2, TiBr2, TiMe2, Ti(Me)(Et), Ti(OTs)2, Ti(OMs)2, Ti(OTf)2, HfCl2, HfBr2, HfMe2, Hf(Me)(Et), Hf(OTs)2, Hf(OMs)2, and Hf(OTf)2. Me represents a methyl group, Et represents an ethyl group, Ts represents a p-toluenesulfonyl group, Ms represents a methanesulfonyl group, and Tf represents a trifluoromethanesulfonyl group.

[0056] Specific examples of the metallocene compound (A) are shown below, but the scope of the present invention is not particularly limited by these. For convenience of explanation, the ligand structure of the metallocene compound (A) excluding the MQj (metal portion) is divided into three parts: a bridge portion (α), a fluorenyl portion (β), and a cyclopentadienyl derivative portion (γ). In the present invention, the metallocene compound (A) may be used alone or in combination of two or more types.

[0057] First, specific examples of the partial structure of the crosslinked portion (α) are shown in Table 1.

[0058] [Table 1]

[0059] Next, specific examples of the partial structure of the fluorenyl moiety (β) are shown in Table 2.

[0060] [Table 2]

[0061] Next, specific examples of the partial structure of the cyclopentadienyl derivative portion (γ) are shown in Table 3.

[0062] [Table 3]

[0063] Preferred examples of the transition metal compound (A) include compounds represented by the following formula: According to the above table, when the ligand structure is a combination of α18, β1 and γ1 and the metal moiety MQj is ZrCl2, the transition metal compound represented by the following formula is exemplified.

[0064] [ka]

[0065] The metallocene compound that can be used in the olefin polymerization of the present invention has a fluorenyl group with a so-called asymmetric structure, as described above. Furthermore, by using an olefin polymerization catalyst containing this metallocene compound, which will be described later, an olefin polymer can be produced with high polymerization activity.

[0066] The reason why the catalyst containing the metallocene compound exhibits high polymerization activity is not clear, but the present inventors have hypothesized, for example, as follows. Since the metallocene compound has an asymmetric fluorenyl group, it is likely that the spatial structure around the metal component M will be somewhat distorted compared to metallocene compounds with a highly symmetric structure. If this distorted space (e.g., a slightly wider space) is considered to be a state in which olefins can be easily inserted, this explains the high polymerization activity. Furthermore, if the space is wider, it may be advantageous for copolymerizing various olefins.

[0067] It is believed that the above-described effects are manifested due to the asymmetric structure of the present invention, particularly the asymmetric structure of the fluorenyl group located near the metal component M.

[0068] [Olefin polymerization catalyst] The olefin polymerization catalyst used in the present invention is a catalyst containing at least the metallocene compound (A) described above. The olefin polymerization catalyst preferably further contains a compound (B) described below. The catalyst may further contain a carrier (C) described below, with the metallocene compound (A) being supported on the carrier (C). The catalyst may further contain components such as an organic compound (D) described below.

[0069] [Compound (B)] The compound (B) preferably used in the present invention is (B) (b-1) organoaluminum oxy compound, (b-2) a compound that reacts with the metallocene compound (A) to form an ion pair; (b-3) Organoaluminum compounds The compound is at least one compound selected from the group consisting of: Among the above compounds (b-1) to (b-3), (b-1) is particularly preferred. Each of the compounds (b-1) to (b-3) will be explained below.

[0070] Examples of the organoaluminum oxy compound (b-1) that can be used include aluminoxanes such as compounds represented by general formula [B1] and compounds represented by general formula [B2], modified methylaluminoxanes having a structure represented by general formula [B3], and boron-containing organoaluminum oxy compounds represented by general formula [B4].

[0071] [ka]

[0072] In general formulas [B1] and [B2], R is a hydrocarbon group having 1 to 10 carbon atoms, preferably a methyl group, and n is an integer of 2 or greater, preferably 3 or greater, and more preferably 10 or greater. In general formulas [B1] and [B2], methylaluminoxane, in which R is a methyl group, is particularly preferred.

[0073] [ka]

[0074] In general formula [B3], R is a hydrocarbon group having 2 to 10 carbon atoms, m and n are each independently an integer of 2 or greater, and Me is a methyl group. Multiple Rs may be the same or different. This modified methylaluminoxane can be prepared, for example, using trimethylaluminum and an alkylaluminum other than trimethylaluminum. Such modified methylaluminoxane is generally called MMAO (modified methyl aluminoxane).

[0075] [ka]

[0076] In general formula [B4], R c is a hydrocarbon group having 1 to 10 carbon atoms, and R d are hydrogen atoms, halogen atoms or hydrocarbon groups having 1 to 10 carbon atoms, and may be the same or different.

[0077] Examples of the compound (b-2) (hereinafter also referred to as "ionic compound (b-2)") that reacts with the metallocene compound (A) to form an ion pair include Lewis acids, ionic compounds, borane compounds, and carborane compounds described in, for example, JP-T-1-501950, JP-T-1-502036, JP-A-3-179005, JP-A-3-179006, JP-A-3-207703, JP-A-3-207704, JP-A-2004-51676, and U.S. Pat. No. 5,321,106. Heteropoly compounds and isopoly compounds can also be used. Among these, compounds represented by general formula [B5] are preferred.

[0078] [ka]

[0079] In general formula [B5], R e+ As for H + Examples include oxonium cation, carbenium cation, ammonium cation, phosphonium cation, cycloheptyltrienyl cation, and ferrocenium cation having a transition metal. f , R g , R h and R i each independently represents an organic group, preferably an aryl group or a halogen-substituted aryl group.

[0080] Specific examples of the carbenium cation include trisubstituted carbenium cations such as triphenylcarbenium cation, tris(methylphenyl)carbenium cation, and tris(dimethylphenyl)carbenium cation.

[0081] Specific examples of ammonium cations include trialkylammonium cations such as trimethylammonium cation, triethylammonium cation, tri(n-propyl)ammonium cation, triisopropylammonium cation, tri(n-butyl)ammonium cation, and triisobutylammonium cation; N,N-dialkylanilinium cations such as N,N-dimethylanilinium cation, N,N-diethylanilinium cation, and N,N,2,4,6-pentamethylanilinium cation; and dialkylammonium cations such as diisopropylammonium cation and dicyclohexylammonium cation.

[0082] Specific examples of the phosphonium cation include triarylphosphonium cations such as triphenylphosphonium cation, tris(methylphenyl)phosphonium cation, and tris(dimethylphenyl)phosphonium cation.

[0083] R e+ As the cation, a carbenium cation and an ammonium cation are particularly preferred, and a triphenylcarbenium cation, an N,N-dimethylanilinium cation and an N,N-diethylanilinium cation are more preferred.

[0084] R e+ When is a carbenium cation, specific examples of the carbenium salt include triphenylcarbenium tetraphenylborate, triphenylcarbenium tetrakis(pentafluorophenyl)borate, triphenylcarbenium tetrakis(3,5-ditrifluoromethylphenyl)borate, tris(4-methylphenyl)carbenium tetrakis(pentafluorophenyl)borate, and tris(3,5-dimethylphenyl)carbenium tetrakis(pentafluorophenyl)borate.

[0085] R e+When it is an ammonium cation, specific examples of the ammonium salt include trialkylammonium salts, N,N-dialkylanilinium salts, and dialkylammonium salts.

[0086] As the organoaluminum compound (b-3), for example, an organoaluminum compound represented by the general formula [B6] and a complex alkylated product of a Group 1 metal of the periodic table and aluminum represented by the general formula [B7] can be used.

[0087] R a m Al(OR b ) n [[ID=M15]]H p X q [B6] In the general formula [B6], R a and R b are each independently a hydrocarbon group having 1 to 15 carbon atoms (preferably 1 to 4 carbon atoms), X is a halogen atom, m is a number where 0 < m ≦ 3, n is a number where 0 ≦ n < 3, p is a number where 0 ≦ p < 3, q is a number where 0 ≦ q < 3, and m + n + p + q = 3.

[0088] M 2 AlR a 4[B7] In the general formula [B7], M 2 is Li, Na or K, and R a are each independently a hydrocarbon group having 1 to 15 carbon atoms (preferably 1 to 4 carbon atoms).

[0089] Specific examples of the organoaluminum compound represented by the general formula [B6] include tri-n-alkylaluminums such as trimethylaluminum, triethylaluminum, tri-n-butylaluminum, trihexylaluminum, and trioctylaluminum; tri-branched alkylaluminums such as triisopropylaluminum, triisobutylaluminum, tri-sec-butylaluminum, tri-tert-butylaluminum, tri-2-methylbutylaluminum, tri-3-methylhexylaluminum, and tri-2-ethylhexylaluminum; tricycloalkylaluminums such as tricyclohexylaluminum and tricyclooctylaluminum; triarylaluminums such as triphenylaluminum and tritolylaluminum; dialkylaluminum hydrides such as diisopropylaluminum hydride and diisobutylaluminum hydride; and compounds of the general formula (i-C4H9) x Al y (C5H 10 ) z (wherein x, y, and z are positive numbers, and z≦2x), such as alkenyl aluminums represented by the formula R; alkyl aluminum alkoxides such as isobutyl aluminum methoxide and isobutyl aluminum ethoxide; dialkyl aluminum alkoxides such as dimethyl aluminum methoxide, diethyl aluminum ethoxide, and dibutyl aluminum butoxide; alkyl aluminum sesquialkoxides such as ethyl aluminum sesquiethoxide and butyl aluminum sesquibutoxide; a 2.5 Al(OR b ) 0.5 (In the formula, R a and R b is R in formula [B6] a and R balkylaluminum aryloxides such as diethylaluminum phenoxide and diethylaluminum (2,6-di-tert-butyl-4-methylphenoxide); dialkylaluminum halides such as dimethylaluminum chloride, diethylaluminum chloride, dibutylaluminum chloride, diethylaluminum bromide and diisobutylaluminum chloride; alkylaluminum sesquihalides such as ethylaluminum sesquichloride, butylaluminum sesquichloride and ethylaluminum sesquibromide; partially halogenated alkylaluminums such as alkylaluminum dihalides such as ethylaluminum dichloride; partially hydrogenated alkylaluminums such as dialkylaluminum hydrides such as diethylaluminum hydride and dibutylaluminum hydride, and alkylaluminum dihydrides such as ethylaluminum dihydride and propylaluminum dihydride; and partially alkoxylated and halogenated alkylaluminums such as ethylaluminum ethoxychloride, butylaluminum butoxychloride and ethylaluminum ethoxybromide.

[0090] Specific examples of the alkylated complex represented by the general formula [B7] include LiAl(C2H5)4, LiAl(C7H 15 )4. Compounds similar to the alkylated complexes represented by general formula [B7] can also be used, such as organoaluminum compounds in which two or more aluminum compounds are bonded via nitrogen atoms. A specific example of such a compound is (C2H5)2AlN(C2H5)Al(C2H5)2.

[0091] As the organoaluminum compound (b-3), trimethylaluminum and triisobutylaluminum are particularly preferred.

[0092] [Carrier (C)] The carrier (C) optionally used in the present invention is an organic or inorganic compound, and is a granular or fine particle solid.

[0093] Examples of inorganic compounds that can be used to form the support (C) include porous oxides, inorganic halides, clay minerals, clay (usually clay minerals are the main component), and ion-exchangeable layered compounds (most clay minerals are ion-exchangeable layered compounds).

[0094] Specific examples of porous oxides include SiO2, Al2O3, MgO, ZrO, TiO2, B2O3, CaO, ZnO, BaO, and ThO2; and composites or mixtures containing these oxides. Specific examples of composites or mixtures include natural or synthetic zeolites, SiO2-MgO, SiO2-Al2O3, SiO2-TiO2, SiO2-V2O5, SiO2-Cr2O3, and SiO2-TiO2-MgO. Among these, porous oxides containing either or both of SiO2 and Al2O3 as the main components are preferred. The particle size of the porous oxide is preferably 10 to 300 μm, more preferably 20 to 200 μm, and the specific surface area is preferably 50 to 1,000 m. 2 / g, more preferably 100 to 700m 2 / g, and the pore volume is preferably 0.3 to 3.0 cm 3 The porous oxide is calcined at 100 to 1000°C, preferably 150 to 700°C, as required, before use.

[0095] Specific examples of inorganic halides include MgCl, MgBr, MnCl, and MnBr. The inorganic halides may be used as they are, or may be used after being pulverized using a ball mill or a vibration mill. Alternatively, the inorganic halides may be dissolved in a solvent such as alcohol, and then precipitated into fine particles using a precipitating agent.

[0096] Clays, clay minerals, and ion-exchangeable layered compounds are not limited to natural products, but can also be artificially synthesized. Ion-exchangeable layered compounds are compounds with a crystalline structure in which planes formed by ionic bonds or the like are stacked parallel to each other with weak bonding forces, and the ions contained therein are exchangeable. Specific examples of clays and clay minerals include kaolin, bentonite, kibushi clay, gairome clay, allophane, hisingerite, pyrophyllite, and synthetic mica-like compounds, as well as montmorillonite, vermiculite, ryokudeite, palygorskite, kaolinite, nacrite, dickite, hectorite, taeniolite, and halloysite. Examples of ion-exchangeable layered compounds that can be used include ionic crystalline compounds with layered crystalline structures such as hexagonal close-packed type, antimony type, CdCl2 type, and CdI2 type. Specific examples include crystalline acid salts of polyvalent metals such as α-Zr(HAsO4)2·H2O, α-Zr(HPO4)2, α-Zr(KPO4)2·3H2O, α-Ti(HPO4)2, α-Ti(HAsO4)2·H2O, α-Sn(HPO4)2·H2O, γ-Zr(HPO4)2, γ-Ti(HPO4)2, and γ-Ti(NH4PO4)2·H2O.

[0097] The organic compound constituting the carrier (C) may be, for example, a granular or particulate solid organic substance having a particle size of 10 to 300 μm. Specific examples thereof include polymers synthesized mainly from an α-olefin having 2 to 14 carbon atoms, such as ethylene, propylene, 1-butene, and 4-methyl-1-pentene; polymers synthesized mainly from vinylcyclohexane and styrene; and modified products of these polymers.

[0098] [Organic compounds (D)] The organic compound (D) optionally used in the present invention is used as needed for the purpose of improving the polymerization performance during the polymerization reaction of α-olefins or the physical properties of the resulting olefin polymer. Specific examples of the organic compound (D) include alcohols, phenolic compounds, carboxylic acids, phosphorus compounds, and sulfonates.

[0099] In olefin polymerization, the components may be used in any manner and in any order, but examples include the following methods. (1) A method in which the metallocene compound (A) and the compound (B) are added to a polymerization reactor in any order. (2) A method in which a catalyst component in which a metallocene compound (A) is supported on a carrier (C) and a compound (B) are added to a polymerization reactor in any order. (3) A method in which a catalyst component in which the compound (B) is supported on the carrier (C) and the metallocene compound (A) are added to a polymerization reactor in any order. (4) A method in which a catalyst component in which a metallocene compound (A) and a compound (B) are supported on a carrier (C) is added to a polymerization reactor. (5) A method in which the metallocene compound (A), the compound (B) and the component (D) are added to a polymerization reactor in any order.

[0100] In each of the above methods (1) to (5), at least two of the catalyst components may be contacted in advance. In each of the above methods (3) and (4) in which the compound (B) is supported, the unsupported compound (B) may be added in any order, if necessary. In this case, the compounds (B) may be the same or different.

[0101] Furthermore, it is also a preferred method to contact the component obtained by contacting the support (C) with the compound (B) with the metallocene compound (A) to obtain a supported solid catalyst component, which is then used for polymerization.

[0102] In the contact between the support (C) and the compound (B), the reactive sites in the compound (B) react with the reactive sites in the support (C) to chemically bond them, forming a contact product of the compound (B) and the support (C). The contact time between the compound (B) and the support (C) is usually 1 minute to 20 hours, preferably 30 minutes to 10 hours, and the contact temperature is usually −50 to 200°C, preferably −20 to 120°C. If the initial contact between the compound (B) and the support (C) is carried out too quickly, the support (C) may collapse due to the heat generated by the reaction or the reaction energy, resulting in poor morphology of the resulting solid catalyst component. When this solid catalyst component is used in polymerization, poor polymer morphology often makes continuous operation difficult. Therefore, it is preferable to initially contact the compound (B) and the support (C) at a lower temperature to suppress the heat generated by the reaction, or to control the heat generated by the reaction and react at a rate that maintains the initial contact temperature. This also applies when the compound (B) is further contacted after the contact between the compound (B) and the support (C). The contact weight ratio between compound (B) and carrier (C) (weight of compound (B) / weight of carrier (C)) can be selected arbitrarily. However, a higher contact weight ratio tends to support a larger amount of the metallocene compound (A), which is expected to improve the catalytic activity per weight of the solid catalyst component. On the other hand, if the contact weight ratio is too high, the structure of the carrier (C) may change more than necessary, making it more susceptible to collapse. From this perspective, the contact weight ratio between compound (B) and carrier (C) [=weight of compound (B) / weight of carrier (C)] is preferably 0.05 to 3.0, particularly preferably 0.1 to 2.0.

[0103] When the contact product of compound (B) and support (C) is contacted with metallocene compound (A), the contact time is usually 1 minute to 20 hours, preferably 1 minute to 10 hours, and the contact temperature is usually within the range of -50 to 200°C, preferably -50 to 100°C.

[0104] When compound (B) is compound (b-3), it is used in an amount such that the molar ratio of compound (b-3) to the total transition metal atoms (M) in metallocene compound (A) [(b-3) / (M)] is usually 0.01 to 100,000, preferably 0.05 to 50,000.

[0105] When compound (B) is compound (b-1), it is used in an amount such that the molar ratio of compound (b-1) (in terms of aluminum atoms) to the total transition metal atoms (M) in metallocene compound (A) [(b-1) / M] is generally 10 to 500,000, preferably 20 to 100,000.

[0106] When compound (B) is compound (b-2), it is used in an amount such that the molar ratio of compound (b-2) to the total transition metal atoms (M) in metallocene compound (A) [(b-2) / M] is usually 1 to 10, preferably 1 to 5.

[0107] The ratio of the compound (B) to the total transition metal atoms (M) in the metallocene compound (A) can be determined by inductively coupled plasma emission spectrometry (ICP analysis). In addition, the solid catalyst component in which the metallocene compound (A) is supported on the carrier (C) and the solid catalyst component in which the metallocene compound (A) and the compound (B) are supported on the carrier (C) may be prepolymerized with an olefin, or the prepolymerized solid catalyst component may have further catalyst components supported on it.

[0108] The prepolymerization catalyst component can be produced, for example, by the following method. That is, it can be prepared by polymerizing an olefin (e.g., ethylene) or the like in the presence of the olefin polymerization catalyst according to the present invention, usually in an inert hydrocarbon solvent, under mild conditions, such as a temperature and pressure lower than those used in the main polymerization described below. The polymerization can be carried out in any of batch, semi-continuous, and continuous modes, and can be carried out under reduced pressure, normal pressure, or increased pressure. Furthermore, the amount of polymerization in the prepolymerization is preferably 0.01 to 1000 g, more preferably 0.1 to 800 g, and even more preferably 0.2 to 500 g per gram of the solid catalyst component.

[0109] The prepolymerized catalyst component produced in the inert hydrocarbon solvent can be separated from the suspension and then prepolymerized again. In this case, the prepolymerized catalyst can be resuspended in an inert hydrocarbon and an olefin (e.g., ethylene) can be introduced into the resulting suspension, or the prepolymerized catalyst can be dried and then contacted with an olefin (e.g., ethylene).

[0110] The prepolymerization temperature is -20 to 80°C, preferably 0 to 60°C, and the prepolymerization time is 0.5 to 100 hours, preferably about 1 to 50 hours. The prepolymerization temperature is preferably lower than the polymerization temperature in the method for producing an olefin polymer, which will be described later. More preferably, it is at least 10°C lower than the polymerization temperature in the method for producing an olefin polymer. The olefin used in the prepolymerization may be the same as or different from the olefin used in the method for producing an olefin polymerization, which will be described later, but is usually the same olefin. For example, in the method for producing an ethylene polymer, an olefin containing ethylene as a main component is used in the prepolymerization.

[0111] The form of the solid catalyst component used in the prepolymerization can be any of those already mentioned above without any limitations. If necessary, a compound (B) can be used, and preferably an organoaluminum compound [B-3] can be used.

[0112] When compound (B) is used, compound (B) is used in an amount such that the molar ratio (Al / M) of the aluminum atom (Al) in compound (B) to the transition metal atom (M) in the transition metal compound [A] is 0.1 to 10,000, preferably 0.5 to 5,000.

[0113] The concentration of the olefin polymerization catalyst according to the present invention in the prepolymerization system is usually 1 to 1,000 g / L, preferably 10 to 500 g / L, in terms of the volume ratio of catalyst for olefin polymerization / polymerization. During the prepolymerization, other components may be used in combination for the purpose of suppressing fouling or improving particle properties.

[0114] In addition, for the purpose of improving the fluidity of the prepolymerized solid catalyst component and suppressing the occurrence of heat spots, sheeting, and polymer lumps during polymerization, other components such as an antistatic agent may be used in combination with the prepolymerized solid catalyst component once produced by prepolymerization.

[0115] [Method for producing olefin polymer] The method for producing an olefin polymer of the present invention is a method characterized by polymerizing an α-olefin having from 2 to 20 carbon atoms in the presence of the olefin polymerization catalyst described above. Here, "polymerization" is used to collectively refer to homopolymerization and copolymerization. Furthermore, "polymerizing in the presence of an olefin polymerization catalyst" encompasses any method, such as the above methods (1) to (5), in which each component of the olefin polymerization catalyst is charged into a polymerization vessel and a monomer is polymerized.

[0116] Polymerization can be carried out by either a liquid-phase polymerization method such as solution polymerization or suspension polymerization, or a gas-phase polymerization method. Examples of inert hydrocarbon media used in liquid-phase polymerization include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene; alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane; aromatic hydrocarbons such as benzene, toluene, and xylene; and halogenated hydrocarbons such as ethylene chloride, chlorobenzene, and dichloromethane. The inert hydrocarbon medium may be used alone or in combination of two or more. Alternatively, a so-called bulk polymerization method may be used in which the liquefied olefin to be supplied to the polymerization itself is used as the solvent.

[0117] When polymerizing a monomer using the above-mentioned olefin polymerization catalyst, the amount of each component that can constitute the olefin polymerization catalyst is as described in the following (1) to (5). In addition, in the above-mentioned olefin polymerization catalyst, the content of each component can be set as follows.

[0118] (1) When a monomer is polymerized using an olefin polymerization catalyst, the metallocene compound (A) is usually used in an amount of 10 to 100 ppm in terms of total transition metal atoms (M) per liter of reaction volume. -9 ~10 -1 moles, preferably 10 -8 ~10 -2 It is used in molar amounts.

[0119] (2) When the organoaluminum oxy compound (b-1) is used as a component of the olefin polymerization catalyst, it is used in an amount such that the molar ratio [Al / M] of the aluminum atom (Al) in the compound (b-1) to the total transition metal atoms (M) in the metallocene compound (A) is generally 0.01 to 5000, preferably 0.05 to 2000.

[0120] (3) When the ionic compound (b-2) is used as a component of the olefin polymerization catalyst, it is used in an amount such that the molar ratio of the compound (b-2) to the total transition metal atoms (M) in the metallocene compound (A), [(b-2) / M], is usually 1 to 10, preferably 1 to 5.

[0121] (4) When the organoaluminum compound (b-3) is used as a component of the olefin polymerization catalyst, it is used in an amount such that the molar ratio of the compound (b-3) to the total transition metal atoms (M) in the metallocene compound (A), [(b-3) / M], is generally 10 to 5,000, preferably 20 to 2,000.

[0122] (5) When an organic compound (D) is used as a component of an olefin polymerization catalyst, if compound (B) is an organoaluminum oxy compound (b-1), it is used in an amount such that the molar ratio of the organic compound (D) to the compound (b-1) [(D) / (b-1)] is usually 0.01 to 10, preferably 0.1 to 5; if compound (B) is an ionic compound (b-2), it is used in an amount such that the molar ratio of the organic compound (D) to the compound (b-2) [(D) / (b-2)] is usually 0.01 to 10, preferably 0.1 to 5; if compound (B) is an organoaluminum compound (b-3), it is used in an amount such that the molar ratio of the organic compound (D) to the compound (b-3) [(D) / (b-3)] is usually 0.005 to 2, preferably 0.01 to 1.

[0123] The polymerization temperature is usually 40 to 200°C, preferably 40 to 180°C, and more preferably 40 to 150°C. The polymerization pressure is usually atmospheric pressure to 10 MPa gauge pressure, and preferably atmospheric pressure to 5 MPa gauge pressure. The polymerization reaction can be carried out by any of batch, semi-continuous, and continuous methods. Furthermore, the polymerization can be carried out in two or more stages with different reaction conditions. The molecular weight of the obtained olefin polymer can be adjusted by adding hydrogen or the like to the polymerization system, changing the polymerization temperature, or by the amount of compound (B) used.

[0124] The process for producing an olefin polymer of the present invention makes it possible to produce an olefin polymer such as a propylene polymer or a 4-methyl-1-pentene polymer having a high melting point and a high molecular weight while maintaining high catalytic activity even under high-temperature conditions that are advantageous in industrial production processes.

[0125] Hydrogen may be added to the system during polymerization. Hydrogen may have the effect of improving the polymerization activity of the catalyst and increasing or decreasing the molecular weight of the polymer. When hydrogen is added to the system, the appropriate amount is about 0.00001 to 100 NL per mole of monomer.

[0126] In the method for producing an olefin polymer of the present invention, an α-olefin having 2 to 20 carbon atoms is polymerized. The α-olefin may be either linear or branched. Specific examples include ethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-icosene. Two or more α-olefins may be used in combination. Among these, ethylene and propylene are particularly preferred.

[0127] When propylene is used as the α-olefin, other α-olefins, i.e., at least one α-olefin selected from ethylene and α-olefins having 4 to 20 carbon atoms (preferably 4 to 10), can be used in combination as necessary. Specific examples include ethylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, and 1-decene. Among these, ethylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene are preferred, and 1-butene and 4-methyl-1-pentene are more preferred.

[0128] When propylene and another α-olefin are used in combination as the α-olefin, the ratio of the amounts of the two, propylene:other α-olefin (molar ratio), is usually 1:10 to 5000:1, preferably 1:5 to 1000:1.

[0129] Polymerization can also be carried out by adding at least one monomer selected from cyclic olefins, polar group-containing monomers, hydroxyl-terminated vinyl compounds, and aromatic vinyl compounds to the α-olefin having 2 to 20 carbon atoms in the reaction system. Polyenes can also be used in combination. Other monomers, such as vinylcyclohexane, may also be copolymerized. The amount of these monomers is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, per 100 parts by mass of the α-olefin having 2 to 20 carbon atoms.

[0130] Specific examples of cyclic olefins include cyclopentene, cycloheptene, norbornene, 5-methyl-2-norbornene, tetracyclododecene, and 2-methyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene.

[0131] Specific examples of polar group-containing monomers include α,β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, fumaric acid, maleic anhydride, itaconic acid, itaconic anhydride, and bicyclo(2,2,1)-5-heptene-2,3-dicarboxylic anhydride, and metal salts thereof such as sodium salts, potassium salts, lithium salts, zinc salts, magnesium salts, calcium salts, and aluminum salts; methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, and tert-butyl acrylate. Examples of the α,β-unsaturated carboxylic acid esters include butyl, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, and isobutyl methacrylate; vinyl esters such as vinyl acetate, vinyl propionate, vinyl caproate, vinyl caprate, vinyl laurate, vinyl stearate, and vinyl trifluoroacetate; and unsaturated glycidyl acrylate, glycidyl methacrylate, and monoglycidyl itaconic acid ester.

[0132] Specific examples of the terminal hydroxylated vinyl compounds include linear terminal hydroxylated vinyl compounds such as 1-butene hydroxide, 1-pentene hydroxide, 1-hexene hydroxide, 1-octene hydroxide, 1-decene hydroxide, 1-undecene hydroxide, 1-dodecene hydroxide, 1-tetradecene hydroxide, 1-hexadecene hydroxide, 1-octadecene hydroxide, and 1-eicosene hydroxide; and branched vinyl compounds having terminal hydroxyl groups such as hydroxylated 1-butene, hydroxylated 3-methyl-1-pentene, hydroxylated 4-methyl-1-pentene, hydroxylated 3-ethyl-1-pentene, hydroxylated 4,4-dimethyl-1-pentene, hydroxylated 4-methyl-1-hexene, hydroxylated 4,4-dimethyl-1-hexene, hydroxylated 4-ethyl-1-hexene, and hydroxylated 3-ethyl-1-hexene.

[0133] Specific examples of aromatic vinyl compounds include styrene; mono- or polyalkylstyrenes such as o-methylstyrene, m-methylstyrene, p-methylstyrene, o,p-dimethylstyrene, o-ethylstyrene, m-ethylstyrene, and p-ethylstyrene; functional group-containing styrene derivatives such as methoxystyrene, ethoxystyrene, vinylbenzoic acid, methyl vinylbenzoate, vinylbenzyl acetate, hydroxystyrene, o-chlorostyrene, p-chlorostyrene, and divinylbenzene; 3-phenylpropylene, 4-phenylpropylene, and α-methylstyrene.

[0134] The polyene is preferably selected from dienes and trienes. The polyene can be used in an amount of preferably 0.0001 to 1 mol% based on the total olefins supplied to the polymerization reaction. Specific examples of the diene include α,ω-non-conjugated dienes such as 1,4-pentadiene, 1,5-hexadiene, 1,4-hexadiene, 1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7-octadiene, and 1,9-decadiene; non-conjugated dienes such as ethylidene norbornene, vinyl norbornene, dicyclopentadiene, 7-methyl-1,6-octadiene, and 4-ethylidene-8-methyl-1,7-nonadiene; and conjugated dienes such as butadiene and isoprene. Specific examples of trienes include 6,10-dimethyl-1,5,9-undecatriene, 4,8-dimethyl-1,4,8-decatriene, 5,9-dimethyl-1,4,8-decatriene, 6,9-dimethyl-1,5,8-decatriene, 6,8,9-trimethyl-1,5,8-decatriene, 6-ethyl-10-methyl-1,5,9-undecatriene, 4-ethylidene-1,6-octadiene, 7-methyl-4-ethylidene-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene (EMND), and 7-methyl-4-ethylidene-1,6-nonadiene. non-conjugated trienes such as 7-ethyl-4-ethylidene-1,6-nonadiene, 6,7-dimethyl-4-ethylidene-1,6-octadiene, 6,7-dimethyl-4-ethylidene-1,6-nonadiene, 4-ethylidene-1,6-decadiene, 7-methyl-4-ethylidene-1,6-decadiene, 7-methyl-6-propyl-4-ethylidene-1,6-octadiene, 4-ethylidene-1,7-nonadiene, 8-methyl-4-ethylidene-1,7-nonadiene, and 4-ethylidene-1,7-undecanediene; and conjugated trienes such as 1,3,5-hexatriene.

[0135] [Olefin polymer] The composition of the monomer structural units of the olefin polymer produced by the present invention is not particularly limited. However, the olefin polymer preferably contains structural units derived from propylene. The content of the propylene-derived structural units is preferably 50 mol% or more, more preferably 55 mol% or more, particularly preferably 80 mol% or more, and most preferably 90 mol% or more. When the olefin polymer contains structural units derived from an α-olefin having 4 to 20 carbon atoms other than propylene in addition to structural units derived from propylene, the upper limit of the content of the propylene-derived structural units is preferably 99.5 mol%, more preferably 99 mol% (where the total of both monomers is 100 mol%).

[0136] The olefin polymer is preferably an α-olefin polymer consisting essentially of structural units derived from an α-olefin having 2 to 20 carbon atoms, and most preferably a propylene polymer consisting essentially of structural units derived from propylene. "Substantially" means that, relative to all structural units, the proportion of structural units derived from an α-olefin having 2 to 20 carbon atoms is 95% by weight or more in the α-olefin polymer, and the proportion of structural units derived from propylene is 95% by weight or more in the propylene polymer.

[0137] Specific examples of the olefin polymer include propylene homopolymer, propylene / ethylene copolymer, propylene / 1-butene copolymer, propylene / ethylene / 1-butene copolymer, propylene / 1-octene copolymer, propylene / 1-hexene copolymer, propylene / 4-methyl-1-pentene copolymer, propylene / ethylene / 1-octene copolymer, propylene / ethylene / 1-hexene copolymer, and propylene / ethylene / 4-methyl-1-pentene copolymer. Furthermore, the polymer may be a block copolymer obtained by mixing or continuously producing two or more polymers selected from these polymers.

[0138] The olefin polymer obtained by the method for producing an olefin polymer of the present invention may be subjected to known post-treatment steps such as a catalyst deactivation step, a catalyst residue removal step, and a drying step, if necessary.

[0139] The olefin polymer obtained by the method for producing an olefin polymer of the present invention can be used in any known applications, such as films and fibers obtained by inflation molding, extrusion molding, or stretch molding, various injection-molded articles, various bottles obtained by blow molding, and various parts obtained by vacuum molding, rotational molding, stamping molding, etc.

[0140] The olefin polymer production method of the present invention tends to produce polymers with relatively low amounts of catalyst residue because the catalyst used has high polymerization activity. Therefore, the polymers may be suitable for applications related to electrical products. Examples include separator films for capacitors and separator films for secondary batteries such as lithium-ion batteries. The polymers may also be suitable for various insulator applications. [Example]

[0141] The present invention will be explained in more detail below based on examples, but the present invention is not limited to these examples in any way. First, methods for measuring the physical properties and characteristics of olefin polymers will be described.

[0142] [Melting point (Tm)] The differential scanning calorimeter (DSC) used was a PerkinElmer DSC Pyris1 or a SII NanoTechnology DSC7020, and measurements were carried out as follows. Under a nitrogen atmosphere (20 mL / min), a sample (approximately 5 mg) was heated to 230°C, held at 230°C for 3 minutes, cooled to 30°C at 10°C / min, held at 30°C for 1 minute, and then heated to 230°C at 10°C / min. The melting point (Tm) was calculated from the peak apex of the crystalline melting peak during the heating process. If multiple crystalline melting peaks were observed, the peak at the higher temperature was taken as the melting point (Tm) of the olefin polymer. (Of course, the heating range in the above measurement can be changed as appropriate depending on the melting point of the resulting polymer.)

[0143] [Weight average molecular weight (Mw)] Gel permeation chromatography (GPC) was performed using a Tosoh gel permeation chromatograph HLC-8321. Two TSKgel GMH6-HT and two TSKgel GMH6-HTL columns were used. Each column had a diameter of 7.5 mm, a length of 300 mm, a column temperature of 140 °C, and a mobile phase of o-dichlorobenzene (containing 0.025 wt.% BHT) at a flow rate of 1.0 mL / min. The sample concentration was 30 mg / 20 mL or 15 mg / 10 mL, the sample injection volume was 400 μL, and a differential refractometer was used as the detector. Tosoh monodisperse polystyrene was used as the standard polystyrene. The weight-average molecular weight (Mw) was calculated using the polystyrene molecular weight equivalent according to the general-purpose calibration procedure.

[0144] [Identification of the target] The structure of the metallocene compound obtained in the synthesis example is 270MHz 1 The NMR spectra were determined by standard methods using a H-NMR (GSH-270 manufactured by JEOL Ltd.) and FD-MS (SX-102A manufactured by JEOL Ltd.).

[0145] [Synthesis Example of Metallocene Compound] The catalyst used in this example can also be synthesized by the methods described in the following patent publications: JP 2000-212194 A, JP 2004-168744 A, JP 2004-189666 A, JP 2004-161957 A, JP 2007-302854 A, JP 2007-302853 A, and WO 01 / 027124.

[0146] [Synthesis Example 1] Synthesis of metallocene compound (A) A metallocene compound (A) represented by the following formula (A) was synthesized by the following method.

[0147] [ka]

[0148] (i) Synthesis of Ligand (A) Under a nitrogen atmosphere, 567 mg (2.92 mmol) of 2,6-dimethylfluorene and 30 mL of dehydrated cyclopentyl methyl ether were added to a 100 mL Schlenk flask. While cooling in a dry ice methanol bath, 2.00 mL (3.14 mmol) of a 1.57 M n-butyllithium / hexane solution was slowly added, and the mixture was stirred at room temperature for 18 hours. This solution was cannulated into another 100 mL Schlenk flask containing 903 mg of di-p-tolyldichlorosilane and 30 mL of dehydrated cyclopentyl methyl ether, which had been cooled in a dry ice methanol bath. 10 mL of cyclopentyl methyl ether, which had been used to rinse the flask, was also added. The mixture was then gradually warmed to room temperature and stirred for 22 hours. The solvent was removed under reduced pressure and then washed with pentane. The resulting solid was dried under reduced pressure, yielding 1110 mg of a white solid.

[0149] Next, under a nitrogen atmosphere, a 100 ml Schlenk flask was charged with 1110 mg of the white solid obtained in the previous reaction, 40 ml of THF, and 0.55 ml (5.10 mmol) of 1,3-dimethyl-2-imidazolidinone (DMI). While cooling in a dry ice methanol bath, 2.55 ml (5.10 mmol) of a 2.0 M solution of cyclopentadienylsodium in tetrahydrofuran was added, and the mixture was stirred for 21 hours while gradually returning to room temperature. The reaction was terminated by the addition of saturated aqueous ammonium chloride, followed by extraction with diethyl ether. The organic phase was washed with water and saturated brine. After drying over magnesium sulfate, it was concentrated to dryness. The resulting solid was washed with methanol and dried under reduced pressure to yield 647 mg of a white solid. The solid formed in the filtrate was collected by filtration, washed with methanol, and then dried under reduced pressure to yield 198 mg of a white solid (total yield: 845 mg, two-step yield: 62%). The target substance was identified by FD-MS spectroscopy, and the measurement results are shown below. FD-MS: m / z = 468.2 (M+)

[0150] (ii) Synthesis of metallocene compound (A) Under a nitrogen atmosphere, 469 mg (1.00 mmol) of ligand (A) and 40 mL of diethyl ether were added to a 100 mL Schlenk flask. While cooling in a dry ice methanol bath, 1.31 mL (2.06 mmol) of n-butyllithium / hexane solution (1.57 M) was gradually added, and the mixture was stirred for 19 hours while gradually warming to room temperature. After adding 15 mL of diethyl ether, the mixture was cooled in a dry ice methanol bath, and 233 mg (1.00 mmol) of zirconium tetrachloride was added. The mixture was stirred for 26 hours while gradually warming to room temperature. The solvent was removed by distillation under reduced pressure, and the mixture was extracted with dichloromethane using Celite. The solvent was removed by distillation under reduced pressure, and the mixture was washed with hexane. The resulting solid was dried under reduced pressure to obtain the desired metallocene compound (A). (Yield: 402 mg, 64%) Identification of the target substance 1 The results were obtained by H NMR spectroscopy and FD-MS spectroscopy. 1H NMR (270 MHz, CDCl3) 2.12(s, 3H), 2.43(s, 6H), 2.57(s, 3H), 5.88-5.93(m, 2H), 6.56 (s, 1H), 6.66-6.76(m, 3H), 6.90 (dd, 1H, J = 8.6 Hz, J = 1.3 Hz), 7.33-7.43 (m, 5H), 7.89-8.01 (m, 6H) FD-MS: m / z = 626.1 (M+)

[0151] [Synthesis Example 2] Synthesis of metallocene compound (B) A metallocene compound (B) represented by the following formula (B) was synthesized by the following method.

[0152] [ka]

[0153] (i) Synthesis of Ligand (B) Under a nitrogen atmosphere, 595 mg (3.00 mmol) of 2,6-dimethylfluorene and 30 ml of dehydrated t-butyl methyl ether were added to a 100 ml Schlenk flask. While cooling in an ice bath, 2.09 ml (3.24 mmol) of a 1.55 M n-butyllithium / hexane solution was gradually added, and the mixture was heated to reflux for 4 hours. While cooling in an ice bath, 853 mg of 6,6-bis(4-methylphenyl)fulvene was added, and the mixture was gradually warmed to room temperature and stirred for 23 hours. The reaction was terminated by adding saturated aqueous ammonium chloride solution, and the mixture was extracted with diethyl ether. The organic phase was washed with water and saturated brine, dried over magnesium sulfate, and concentrated to dryness. The resulting solid was washed with methanol and dried under reduced pressure to obtain 1076 mg of Ligand (B) as a white solid (79% yield). The target substance was identified by FD-MS spectroscopy, and the measurement results are shown below. FD-MS: m / z = 452.2 (M+)

[0154] (ii) Synthesis of metallocene compound (B) Under a nitrogen atmosphere, 477 mg (1.05 mmol) of ligand (B) and 60 mL of diethyl ether were added to a 100 mL Schlenk flask. While cooling in an ice bath, 1.40 mL (2.20 mmol) of n-butyllithium / hexane solution (1.57 M) was gradually added, and the mixture was stirred for 24 hours while gradually warming to room temperature. After cooling in a dry ice methanol bath, 245 mg (1.05 mmol) of zirconium tetrachloride was added, and the mixture was stirred for 24 hours while gradually warming to room temperature. The solvent was evaporated under reduced pressure, and the mixture was extracted with dichloromethane using Celite. After the solvent was evaporated under reduced pressure, the mixture was extracted with hexane. After the solvent was evaporated under reduced pressure, the mixture was dissolved in a small amount of dichloromethane and added dropwise to hexane. The solid was removed by filtration to obtain a filtrate. The precipitated solid was recovered by decantation, washed with hexane, and dried under reduced pressure to obtain the desired metallocene compound (B). (Yield: 92 mg, 14%) Identification of the target substance 1 The results were obtained by H NMR spectroscopy and FD-MS spectroscopy. 1H NMR (270 MHz, CDCl3) 2.12(s, 3H), 2.34(s, 6H), 2.57(s, 3H), 5.74(t, 2H, J = 2.6 Hz), 6.12 (s, 1H), 6.32-6.37(m, 3H), 6.85-6.89 (m, 1H), 7.11-7.23 (m, 4H), 7.35-7.38 (m, 1H), 7.68-7.78 (m, 4H), 7.95 (s, 1H), 8.04 (d, 1H, J = 8.2 Hz), FD-MS: m / z = 610.1 (M+)

[0155] [Example 1] Propylene polymerization Under a nitrogen atmosphere, 5.25 μmol of metallocene compound (A) was placed in a Schlenk flask and dissolved in 9.9 mL of toluene. 0.54 mL of a suspension of modified methylaluminoxane (trade name: TMAO341, manufactured by Tosoh Finechem Co., Ltd.) (n-hexane solvent, 2.93 M in terms of aluminum atom, 1.58 mmol) was then added, and the mixture was stirred at room temperature for 30 minutes to prepare a catalyst solution with a metallocene compound (A) concentration of 0.50 mmol / L.

[0156] A 15 mL stainless steel autoclave was charged with 0.4 mL of an n-heptane solution of triisobutylaluminum (0.05 M, 20.0 μmol) and 2.7 mL of n-heptane as a polymerization solvent, and the mixture was stirred at 600 rpm. The solution was heated to 60°C and then pressurized with propylene until the total pressure reached 7 bar. To the autoclave, 0.2 mL of the catalyst solution (0.10 μmol of metallocene compound (A)) and 0.7 mL of n-heptane were added to initiate polymerization. After polymerization at 60°C for 15 minutes, a small amount of isobutyl alcohol was added to terminate the polymerization. The solvent was removed from the resulting slurry, and the recovered polymer was dried under reduced pressure to obtain 0.246 g of a propylene polymer.

[0157] [Example 2] Propylene polymerization The same procedure as in Example 1 was carried out except that the polymerization temperature was set to 70°C, to obtain 0.206 g of a propylene polymer.

[0158] [Comparative Example 1] Propylene polymerization The same procedure as in Example 1 was carried out except that a known metallocene compound (C) represented by the following formula (C) was used as the metallocene compound and the polymerization time was changed to 20 minutes, thereby obtaining 0.263 g of a propylene polymer.

[0159] [ka]

[0160] [Comparative Example 2] Propylene polymerization The same procedure as in Example 2 was carried out except that metallocene compound (C) was used as the metallocene compound and the polymerization time was changed to 20 minutes, to obtain 0.240 g of a propylene polymer. Table 4 shows the polymerization conditions and polymerization activity of Examples 1 and 2 and Comparative Examples 1 and 2, as well as the melting points (Tm) and weight average molecular weights (Mw) of the propylene polymers.

[0161] [Table 4]

[0162] [Example 3] Propylene polymerization The same procedure as in Example 1 was carried out except that metallocene compound (B) was used as the metallocene compound and the polymerization time was changed to 9 minutes, to obtain 0.705 g of a propylene polymer.

[0163] [Example 4] Propylene polymerization The same procedure as in Example 2 was carried out except that metallocene compound (B) was used as the metallocene compound and the polymerization time was changed to 9 minutes, to obtain 0.632 g of a propylene polymer.

[0164] [Comparative Example 3] Propylene polymerization The same operation as in Example 1 was carried out except that a known metallocene compound (D) represented by the following formula (D) was used as the metallocene compound, the amount of catalyst solution used was 0.1 mL (0.050 μmol of metallocene compound (D)), and the polymerization time was 10 minutes, thereby obtaining 0.244 g of a propylene polymer.

[0165] [ka]

[0166] [Comparative Example 4] Propylene polymerization The same operation as in Example 1 was carried out except that a known metallocene compound (E) represented by the following formula (E) was used as the metallocene compound and the amount of catalyst solution used was 0.1 mL (0.050 μmol of metallocene compound (E)), thereby obtaining 0.310 g of a propylene polymer.

[0167] [ka]

[0168] [Comparative Example 5] Propylene polymerization The same procedure as in Example 2 was carried out except that metallocene compound (E) was used as the metallocene compound and the amount of catalyst solution used was 0.1 mL (metallocene compound (E) 0.050 μmol), to obtain 0.260 g of a propylene polymer. Table 5 shows the polymerization conditions and polymerization activity of Examples 3 and 4 and Comparative Examples 3 to 5, as well as the melting points (Tm) and weight average molecular weights (Mw) of the propylene polymers.

[0169] [Table 5]

[0170] [Example 5] Ethylene polymerization Under a nitrogen atmosphere, 5.25 μmol of metallocene compound (A) was placed in a Schlenk flask and dissolved in 9.9 mL of toluene. 0.54 mL of a suspension of modified methylaluminoxane (trade name: TMAO341, manufactured by Tosoh Finechem Co., Ltd.) (n-hexane solvent, 2.93 M in terms of aluminum atom, 1.58 mmol) was then added, and the mixture was stirred at room temperature for 30 minutes to prepare a catalyst solution with a metallocene compound (A) concentration of 0.50 mmol / L.

[0171] A 15 mL stainless steel autoclave was charged with 0.2 mL of an n-heptane solution of triisobutylaluminum (0.05 M, 10 μmol) and 3.0 mL of n-heptane as a polymerization solvent, and the mixture was stirred at 600 rpm. The solution was heated to 60°C and then pressurized with ethylene until the total pressure reached 7.0 bar. To the autoclave, 0.10 mL of the catalyst solution (0.05 μmol of metallocene compound (A)) and 0.7 mL of n-heptane were added to initiate polymerization. After polymerization at 60°C for 10 minutes, a small amount of isobutyl alcohol was added to terminate the polymerization. The solvent was removed from the resulting slurry, and the recovered polymer was dried under reduced pressure to obtain 0.207 g of an ethylene polymer.

[0172] [Comparative Example 6] Ethylene Polymerization The same procedure as in Example 5 was carried out except that metallocene compound (C) was used as the metallocene compound, to obtain 0.062 g of an ethylene polymer. Table 6 shows the polymerization conditions and polymerization activity of Example 5 and Comparative Example 6, as well as the melting points (Tm) and weight average molecular weights (Mw) of the ethylene polymers.

[0173] [Table 6]

[0174] [Example 6] Ethylene polymerization The same procedure as in Example 5 was carried out except that metallocene compound (B) was used as the metallocene compound, to obtain 0.183 g of an ethylene polymer.

[0175] [Comparative Example 7] Ethylene Polymerization The same procedure as in Example 6 was carried out except that a known metallocene compound (D) was used as the metallocene compound, the amount of catalyst solution used was 0.20 mL (0.10 μmol of metallocene compound (D)), and the polymerization time was 15 minutes, thereby obtaining 0.105 g of an ethylene polymer.

[0176] [Comparative Example 8] Ethylene Polymerization The same procedure as in Example 6 was carried out except that a known metallocene compound (E) was used as the metallocene compound, the amount of catalyst solution used was 0.15 mL (0.075 μmol of metallocene compound (E)), and the polymerization time was 30 minutes, thereby obtaining 0.211 g of an ethylene polymer. Table 7 shows the polymerization conditions and polymerization activity of Example 6 and Comparative Examples 7 and 8, as well as the melting points (Tm) and weight average molecular weights (Mw) of the ethylene polymers.

[0177] [Table 7]

[0178] Examples 1 and 2 had higher polymerization activity in propylene polymerization than Comparative Examples 1 and 2, and Examples 3 and 4 had higher polymerization activity in propylene polymerization than Comparative Examples 3 to 5. Furthermore, Example 5 had higher polymerization activity in ethylene polymerization than Comparative Example 6, which in turn had higher polymerization activity in ethylene polymerization than Comparative Examples 7 and 8, and the polymerization activity was at least three times, preferably four times, the polymerization activity when a metallocene compound having an unsubstituted fluorenyl structure (symmetric structure) was used as a comparative example. That is, according to the present invention, olefin polymers can be obtained with high productivity. [Industrial Applicability]

[0179] According to the method for producing an olefin polymer of the present invention, an olefin polymer can be produced efficiently. Therefore, the present invention is extremely valuable in that industrially useful olefin polymers can be produced economically and industrially.

Claims

1. A method for producing an olefin polymer, comprising polymerizing an α-olefin having from 2 to 20 carbon atoms in the presence of an olefin polymerization catalyst containing a metallocene compound (A) represented by the following general formula [I]: 【Chemistry 1】 [In general formula [I], R 1 , R 1 ', R 2 , and R 2 ' is a hydrogen atom, a hydrocarbon group, or a silicon-containing group, R 3 and R 3 ' are hydrocarbon groups, silicon-containing groups or halogen-containing hydrocarbon groups, which may be the same or different and may be bonded to each other to form a ring; R 4 , R 4 ', R 5 , and R 5 ' is a hydrogen atom, a hydrocarbon group, a silicon-containing group, a halogen atom or a halogen-containing hydrocarbon group, R 4 and R 4 ' are mutually different, R 5 and R 5 ' are mutually different, R 4 and R 5 and are mutually different, R 4 ' and R 5 ' and are different from each other, or R 4 and R 5 and are different from each other, and R 4 ' and R 5 ' and are mutually different, R 4 and R 5 ' are a methyl group, an ethyl group, an n-propyl group, an isopropyl group, or a cyclohexyl group, or R 4 ' and R 5 are a methyl group, an ethyl group, an n-propyl group, an isopropyl group, or a cyclohexyl group; R 4 and R 5 ' may be the same or different, and R 4 ' and R 5 may be the same or different. L is carbon or silicon, M is a metal of Group 4 or 5 of the periodic table, Q is a halogen atom, a hydrocarbon group, a neutral conjugated or non-conjugated diene having 10 or less carbon atoms, an anionic ligand, or a neutral ligand capable of coordinating with a lone electron pair, and when there are multiple Qs, they may be the same or different, and j is an integer of 1 to 4.

2. In the general formula [I], R 4 and R 5 When R ′ is a methyl group, an ethyl group, an n-propyl group, an isopropyl group, or a cyclohexyl group, 4 ' and R 5 is a hydrogen atom, and R 4 ' and R 5 is a methyl group, an ethyl group, an n-propyl group, an isopropyl group, or a cyclohexyl group, R 4 and R 5 2. The process for producing an olefin polymer according to claim 1, wherein ' is a hydrogen atom.

3. A method for producing an olefin polymer according to claim 1, wherein, in general formula [I], R 4 and R 5 ' are a methyl group, an ethyl group, an n-propyl group, or an isopropyl group, or R 4 ' and R 5 are a methyl group, an ethyl group, an n-propyl group, or an isopropyl group.

4. The olefin polymerization catalyst (B) (b-1) organoaluminum oxy compound, (b-2) a compound that reacts with the metallocene compound (A) to form an ion pair, and (b-3) Organoaluminum compounds At least one compound selected from The method for producing an olefin polymer according to any one of claims 1 to 3, further comprising:

5. The method for producing an olefin polymer according to any one of claims 1 to 4, wherein an α-olefin having from 2 to 20 carbon atoms is polymerized at a temperature of from 40°C to 200°C.

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