Catalyst for olefin polymerization and method for producing olefin polymer

Abstract

To provide a catalyst for olefin polymerization that enables efficient production of an olefin copolymer with high molecular weight.SOLUTION: An olefin polymerization catalyst comprises (A) a specific metallocene compound such as bis(indenyl)zirconium dichloride, and (B) an aluminum compound containing a compound having a structural unit chain represented by formula (Al-1) and optionally a compound represented by formula (Al-2) (where Al represents an aluminum atom, O represents an oxygen atom, Rb independently represents H or a hydrocarbon group having 1 to 20 carbon atoms, and Ra represents H or a hydrocarbon group having 1 to 20 carbon atoms, and a plurality of Ra may be the same or different).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a novel olefin polymerization catalyst, more specifically to an olefin polymerization catalyst containing a specific transition metal compound and a specific aluminoxane compound, and a method for producing an olefin polymer using the catalyst. [Background technology]

[0002] Conventionally, catalysts consisting of metallocene compounds and cocatalysts such as organoaluminum oxy compounds have been known as catalysts for producing olefin polymers such as ethylene-α-olefin copolymers.

[0003] Transition metal compounds such as various types of metallocene compounds have been actively developed, and the present applicant has reported many types of metallocene compounds as representative examples in Patent Documents 1 to 5 and the like. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-175759 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-168744 [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-189869 [Patent Document 4] Japanese Patent Application Laid-Open No. 2004-189667 [Patent Document 5] Japanese Patent Application Laid-Open No. 2004-189666 Summary of the Invention [Problem to be solved by the invention]

[0005] The olefin polymerization catalysts containing the above-mentioned transition metal compounds generally use methylaluminoxane, which is considered to be expensive, as a cocatalyst. Methylaluminoxane is generally more expensive than alkylaluminum compounds having a hydrocarbon group with two or more carbon atoms, such as triethylaluminum, which is the raw material trimethylaluminum. On the other hand, there is a demand from the market for a method for efficiently producing olefin polymers and the like at lower cost and with higher molecular weights.

[0006] The present invention has been made in view of the above circumstances, and aims to develop an olefin polymerization catalyst which can be realized at a lower cost and has the advantage of being capable of producing a high molecular weight. [Means for solving the problem]

[0007] The present inventors have discovered that an olefin polymerization catalyst containing a specific transition metal compound and a specific aluminoxane compound can efficiently produce a high-molecular-weight olefin polymer, and have thus completed the present invention. The present invention is characterized by the following requirements:

[0008] <1> (A) a transition metal compound represented by the following formula [A-1], (B) an aluminum compound containing a compound containing a structural unit sequence of the following formula (Al-1) and, as an optional component, a compound represented by the following formula (Al-2); 1. A catalyst for olefin polymerization comprising:

[0009] [ka]

[0010] [In formula [A-1], R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R11 , R 12 , R 13 and R 14 are each independently selected from a hydrogen atom, a hydrocarbon group, and a heteroatom-containing group, and may be the same or different; R 1 From R 14 Adjacent substituents up to may be bonded to each other to form a ring, M is a metal atom selected from Ti, Zr and Hf, Y is a Group 14 atom, and Q is the same or different combinations selected from halogen atoms and hydrocarbon groups, and j is selected from integers of 1 to 4.

[0011] [ka]

[0012] (Above, Al is an aluminum atom, O is an oxygen atom, R b are each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and R a is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and multiple R a may be the same or different, and multiple R a At least one of the groups contains a hydrocarbon group having 2 to 20 carbon atoms.)

[0013] <2> In the formula [A-1], M is Zr, and each Q is independently a hydrocarbon group having a total of 1 to 20 carbon atoms. <1> The olefin polymerization catalyst according to claim 1. <3> In the formula [A-1], R 13 and R 14 are each independently an unsubstituted aryl group or a substituted aryl group. <1> or <2> The olefin polymerization catalyst according to claim 1. <4> The aluminum compound is the molar fraction [Ra2] of hydrocarbon groups having 2 to 20 carbon atoms in the formula (Al-1) is 50 to 100 mol %, The organoaluminum oxy compound (B-1) is an organoaluminum oxy compound (B-1) in which the molar fraction [Rb2] of hydrocarbon groups having 2 to 20 carbon atoms in the formula (Al-2) is 0 to 50 mol % (provided that the total of [Rb2] and [Rb2] is 100 mol %). <1> ~ <3> 10. The olefin polymerization catalyst according to claim 9, wherein the catalyst is a olefin polymerization catalyst having a molecular weight of 100 or more. <5> R in the formula (Al-1) a and R in the formula (Al-2). b are hydrocarbon groups having 2 to 6 carbon atoms. <1> ~ <4> 10. The olefin polymerization catalyst according to claim 9, wherein the catalyst is a olefin polymerization catalyst having a molecular weight of 100 or more. <6> <1> ~ <5> 1. A method for producing an ethylene / α-olefin copolymer, comprising copolymerizing ethylene and an α-olefin having 3 to 30 carbon atoms in the presence of the olefin polymerization catalyst according to any one of the above. [Effects of the Invention]

[0014] According to one embodiment of the present invention, there is provided an olefin polymerization catalyst that can efficiently produce high-molecular-weight olefin polymers using aluminoxanes other than methylaluminoxane, which has been conventionally considered suitable. DETAILED DESCRIPTION OF THE INVENTION

[0015] The olefin polymerization catalyst and the process for producing an olefin polymer according to the present invention will be described in more detail below. In the present invention, the term "polymerization" may be used to mean not only homopolymerization but also copolymerization, and the term "polymer" may be used to mean not only homopolymer but also copolymer.

[0016] [Transition metal compound (A)] The transition metal compound (A) of the present invention is represented by the following general formula [A-1].

[0017] [ka]

[0018] [In formula [A-1], R1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 , R 14 are selected from a hydrogen atom, a hydrocarbon group, and a heteroatom-containing group, and may be the same or different; R 1 From R 14 Adjacent substituents up to may be bonded to each other to form a ring, M is a metal atom selected from Ti, Zr, and Hf, Y is a Group 14 atom, and Q is the same or different combinations selected from halogen atoms and hydrocarbon groups, and j is selected from integers of 1 to 4.

[0019] The transition metal compounds will now be described in detail. The transition metal compound (A) that can be used in the present invention is not particularly limited as long as it has the above-mentioned skeleton structure. Generally, examples include compounds having the following structure: The transition metal compound (A) can be structurally divided into the following characteristic moieties [m1] to [m3], and its characteristics can be expressed.

[0020] [m1] Of the two ligands, one is a cyclopentadienyl which may have a substituent, and the other is a fluorenyl which has a substituent (hereinafter also referred to as "substituted fluorenyl").

[0021] [m2] The two ligands are linked by an aryl-group-containing covalent bridge (hereinafter also referred to as "bridge") consisting of an aryl-bearing carbon or silicon atom.

[0022] [m3] The transition metal (M) constituting the metallocene compound is titanium, zirconium or hafnium.

[0023] The optionally substituted cyclopentadienyl, the substituted fluorenyl, the crosslinked portion and other features of the transition metal compound (A) will be explained below in order. In the present invention, the transition metal compound (A) may be read as the metallocene compound (A).

[0024] (Optionally substituted cyclopentadienyl) In formula (A-1), R 1 , R 2 , R 3 and R 4 each independently represents a hydrogen atom, a hydrocarbon group, or a heteroatom-containing group. Among these, a hydrogen atom, a hydrocarbon group, an oxygen-containing group, or a silicon-containing group is preferred, and two adjacent groups may be bonded to each other to form a ring.

[0025] For example, R 1 , R 2 , R 3 and R 4 are all hydrogen atoms or R 1 , R 2 , R 3 and R 4 At least one of the above is a hydrocarbon group (preferably a hydrocarbon group having 1 to 20 carbon atoms), an oxygen-containing group, or a silicon-containing group (preferably an oxygen-containing group or a silicon-containing group having 1 to 20 carbon atoms). Other examples include heteroatom-containing groups such as halogenated hydrocarbon groups, oxygen-containing groups, and nitrogen-containing groups.

[0026] R 1 , R 2 , R 3 and R 4 When two or more of R are substituents other than hydrogen atoms, the substituents may be the same or different; 1 , R 2 , R 3 and R 4 Any two adjacent groups among these may be bonded to each other to form an alicyclic or aromatic ring.

[0027] R 1 ~R 4 Examples and preferred hydrocarbon groups in R include the hydrocarbon groups (f1) defined above in the section on substituted cyclopentadienyl. 1 ~R 4 Examples and preferred examples of the silicon-containing group in R include the silicon-containing group (f2) defined above in the section on substituted cyclopentadienyl. 1 ~R 4 Examples of the heteroatom-containing group in include the groups exemplified above for the substituted cyclopentadienyl.

[0028] (substituted fluorenyl) In formula (A-1), R 5 , R 8 , R 9 and R 12 R each independently represents a hydrogen atom, a hydrocarbon group, a silicon-containing group, or a heteroatom-containing group other than a silicon-containing group, and is preferably a hydrogen atom, a hydrocarbon group, or a silicon-containing group. 6 and R 11 are the same atom or the same group selected from a hydrogen atom, a hydrocarbon group, a silicon-containing group, and a heteroatom-containing group other than a silicon-containing group, and are preferably a hydrogen atom, a hydrocarbon group, or a silicon-containing group; R 7 and R 10 are the same atom or the same group selected from a hydrogen atom, a hydrocarbon group, a silicon-containing group, and a heteroatom-containing group other than a silicon-containing group, and are preferably a hydrogen atom, a hydrocarbon group, or a silicon-containing group; R 6 and R 7 may be bonded to each other to form a ring, and R 10 and R 11 may be bonded to each other to form a ring; provided that R 6 , R 7 , R 10 and R 11 are not all hydrogen atoms.

[0029] From the viewpoint of polymerization activity, R 6 and R 11 It is preferable that none of R is a hydrogen atom.6 , R 7 , R 10 and R 11 It is more preferable that none of R is a hydrogen atom. 6 and R 11 are the same group selected from hydrocarbon groups and silicon-containing groups, and R 7 and R 10 It is particularly preferred that R are the same group selected from hydrocarbon groups and silicon-containing groups. 6 and R 7 are bonded to each other to form an alicyclic or aromatic ring, and R 10 and R 11 are also preferably bonded to each other to form an alicyclic or aromatic ring.

[0030] R 5 ~R 12 Examples and preferred hydrocarbon groups in R include the hydrocarbon groups (f1) defined above in the section on substituted cyclopentadienyl. 5 ~R 12 Examples and preferred examples of the silicon-containing group in R include the silicon-containing group (f2) defined above in the section on substituted cyclopentadienyl. 5 ~R 12 Examples of the heteroatom-containing group in include the groups exemplified above for the substituted cyclopentadienyl.

[0031] R 6 and R 7 (R 10 and R 11 ) are bonded to each other to form an alicyclic or aromatic ring, the substituted fluorenyl preferably includes groups derived from compounds represented by general formulas (III) to (VII) described later.

[0032] The hydrocarbon group in the present invention preferably includes a monovalent hydrocarbon group having 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, even more preferably 2 to 8 carbon atoms, particularly preferably 4 to 8 carbon atoms, and most preferably 4 to 6 carbon atoms. Specific examples of such hydrocarbon groups include aliphatic hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups (aryl groups), such as substituted or unsubstituted aryl groups and substituted or unsubstituted cycloalkenyl groups, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, hexyl, heptyl, octyl, 2-ethylhexyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, cyclohexyl, and phenyl groups. Among these, n-butyl, isobutyl, hexyl, octyl, and phenyl groups are preferred, with n-butyl, isobutyl, and phenyl being more preferred.

[0033] More specifically, the aryl group includes, for example, phenyl, naphthyl, anthracenyl, and groups in which one or more of the aromatic hydrogens (sp2 hydrogens) of these groups are substituted with a substituent. The substituent includes the hydrocarbon group (f1) and silicon-containing group (f2) defined in the above section on substituted cyclopentadienyl, a halogen atom, and a halogenated hydrocarbon group.

[0034] Specific examples of aryl include unsubstituted aryls having 6 to 14 carbon atoms, preferably 6 to 10 carbon atoms, such as phenyl, naphthyl, anthracenyl, and biphenyl; alkyl-substituted aryls such as tolyl, dimethylphenyl, isopropylphenyl, n-butylphenyl, and t-butylphenyl; cycloalkyl-substituted aryls such as cyclohexylphenyl; halogenated aryls such as chlorophenyl, bromophenyl, dichlorophenyl, and dibromophenyl; and halogenated alkyl-substituted aryls such as (trifluoromethyl)phenyl and bis(trifluoromethyl)phenyl. The positions of the substituents are preferably meta and / or para positions. Among these, substituted phenyls in which the substituents are located at the meta and / or para positions are more preferred.

[0035] As described above, the hydrocarbon group may be a hydrocarbon group containing a heteroatom such as nitrogen, oxygen, phosphorus, or halogen. Such heteroatoms are particularly oxygen and nitrogen. Such substituents can be selected from known structures. More specifically, preferred examples include carboxylic acid ester groups, aldehyde groups, acetyl groups, carbonyl structure-containing groups such as oxycarbonylalkyl groups, alkoxy groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted alkenyloxy groups, substituted or unsubstituted cycloalkyloxy groups, substituted or unsubstituted cycloalkenyloxy groups, substituted or unsubstituted aryloxy groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted heteroaryloxy groups, and siloxy groups.

[0036] Examples of the heteroatom-containing group include the above-mentioned heteroatom-containing hydrocarbon groups, as well as substituents having a structure in which another group is bonded via a heteroatom.

[0037] Examples of such oxygen-containing groups include alkoxy groups, aryloxy groups, carbonyloxy groups, etc. Specific examples include aliphatic alkoxy groups such as methoxy, ethoxy, propoxy, butoxy, hexoxy, and octoxy groups, and aryloxy groups such as phenoxy and tolyloxy groups.

[0038] Examples of the nitrogen-containing group include an amide group, an amino group, an imido group, and an imino group. Specific examples of the amide group include acetamide, N-methylacetamide, and N-methylbenzamide. Specific examples of the amino group include dimethylamino, ethylmethylamino, and diphenylamino. Specific examples of the imido group include acetimide and benzimide. Specific examples of the imino group include methylimino, ethylimino, propylimino, butylimino, and phenylimino.

[0039] Examples of the sulfur-containing group include an alkylthio group, an arylthio group, a thioester group, a sulfone ester group, and a sulfonamide group. Specific examples of the alkylthio group include methylthio and ethylthio. Specific examples of the arylthio group include phenylthio, methylphenylthio, and naphthylthio. Specific examples of the thioester group include acetylthio, benzoylthio, methylthiocarbonyl, and phenylthiocarbonyl. Specific examples of the sulfone ester group include methyl sulfonate, ethyl sulfonate, and phenyl sulfonate. Specific examples of the sulfonamide group include phenylsulfonamide, N-methylsulfonamide, and N-methyl-p-toluenesulfonamide.

[0040] Examples of the boron-containing group include alkyl-substituted boron, aryl-substituted boron, boron halide, and alkyl-substituted boron halide groups. Examples of alkyl-substituted boron groups include (Et)B-, (iPr)B-, (iBu)B-, (Et)B, (iPr)B, and (iBu)B. Examples of aryl-substituted boron groups include (CH)B-, (CH)B, (CF)B, and (3,5-(CF)CH)B. Examples of boron halide groups include BCl- and BCl. Examples of alkyl-substituted boron halide groups include (Et)BCl-, (iBu)BCl-, and (CH)BCl. Here, Et represents an ethyl group, iPr represents an isopropyl group, and iBu represents an isobutyl group. Additionally, the trisubstituted boron may be in a coordinated state.

[0041] Examples of the aluminum-containing group include alkyl-substituted aluminum, aryl-substituted aluminum, aluminum halide, and alkyl-substituted aluminum halide groups. Examples of alkyl-substituted aluminum groups include (Et)Al-, (iPr)Al-, (iBu)Al-, (Et)Al, (iPr)Al, and (iBu)Al. Examples of aryl-substituted aluminum groups include (C6H5)Al-. Examples of aluminum halide groups include AlCl2- and AlCl3. Examples of alkyl-substituted aluminum halide groups include (Et)AlCl- and (iBu)AlCl-. Here, Et represents an ethyl group, iPr represents an isopropyl group, and iBu represents an isobutyl group. Tri-substituted aluminum may be in a coordinate bond state.

[0042] Examples of silicon-containing groups include silyl groups, siloxy groups, hydrocarbon-substituted silyl groups, and hydrocarbon-substituted siloxy groups. Examples of hydrocarbon-substituted silyl groups include methylsilyl, dimethylsilyl, trimethylsilyl, ethylsilyl, diethylsilyl, triethylsilyl, diphenylmethylsilyl, triphenylsilyl, dimethylphenylsilyl, dimethyl-t-butylsilyl, and dimethyl(pentafluorophenyl)silyl. Among these, methylsilyl, dimethylsilyl, trimethylsilyl, ethylsilyl, diethylsilyl, triethylsilyl, dimethylphenylsilyl, and triphenylsilyl are preferred, and trimethylsilyl, triethylsilyl, triphenylsilyl, and dimethylphenylsilyl are more preferred. Examples of hydrocarbon-substituted siloxy groups include trimethylsiloxy.

[0043] R 1 ~R 4 When at least one of the groups is a germanium-containing group and / or a tin-containing group or a silicon-containing group, specific examples of such groups include those in which the silicon of the silicon-containing groups exemplified above is substituted with germanium or tin.

[0044] (Bridge part) In formula (A-1), R13 and R 14 may be any of the above-mentioned hydrogen atoms, hydrocarbon groups, and heteroatom-containing groups, but is preferably an aryl group. 13 and R 14 The case where is an aryl group will be described. Y 1 is a carbon atom or a silicon atom, preferably a carbon atom. R 13 and R 14 The aryl groups in R may be groups of the same structure or groups of different structures. 13 and R 14 On the other hand, from the viewpoint of the solubility of the transition metal compound (A-1) in a solvent, it is preferable that R 13 and R 14 are groups of different structure.

[0045] Specific examples of the aryl group include the examples of the aryl group described above in the description of the hydrocarbon group.

[0046] (Other features of bridged metallocene compounds) In formula [A-1], M represents a titanium atom, a zirconium atom, or a hafnium atom, and is preferably a zirconium atom or a hafnium atom. In formula (A-1), Q represents alkyl which may contain halogen or heteroatoms, j represents an integer of 1 to 4, and when j is an integer of 2 or greater, multiple Qs may be the same or different.

[0047] Examples of the halogen atom for Q include a chlorine atom, a bromine atom, and an iodine atom, with a chlorine atom being particularly preferred. Examples of the alkyl group for Q include the hydrocarbon groups and heteroatom-containing groups described above. Preferred examples include alkyl groups having 1 to 10 carbon atoms, such as methyl, ethyl, and butyl. More preferred are alkyl groups having 1 to 6 carbon atoms, and even more preferred are alkyl groups having 1 to 4 carbon atoms.

[0048] (Examples of preferred bridged metallocene compounds (II)) Specific examples of the bridged metallocene compound (II) are shown below. Among the example compounds, octamethyloctahydrodibenzofluorenyl refers to a group derived from a compound having a structure represented by formula (III), octamethyltetrahydrodicyclopentafluorenyl refers to a group derived from a compound having a structure represented by formula (IV), dibenzofluorenyl refers to a group derived from a compound having a structure represented by formula (V), 1,1',3,6,8,8'-hexamethyl-2,7-dihydrodicyclopentafluorenyl refers to a group derived from a compound having a structure represented by formula (VI), and 1,3,3',6,6',8-hexamethyl-2,7-dihydrodicyclopentafluorenyl refers to a group derived from a compound having a structure represented by formula (VII).

[0049] [ka]

[0050] [ka]

[0051] [ka]

[0052] [ka]

[0053] [ka]

[0054] The above metallocene compounds can be produced by known methods, and the production method is not particularly limited. Known methods include those described in International Publication Nos. 2001 / 27124, 2004 / 029062, and 2004 / 87775 filed by the present applicant.

[0055] Specific examples of transition metal compounds in which M in formula (A-1) is zirconium are shown below, but the compounds are not limited to these.

[0056] Bis(indenyl)zirconium dichloride, bis(indenyl)zirconium dibromide, bis(indenyl)zirconium bis(p-toluenesulfonate), bis(4,5,6,7-tetrahydroindenyl)zirconium dichloride, bis(fluorenyl)zirconium dichloride, ethylene bis(indenyl)zirconium dichloride, ethylene bis(indenyl)zirconium dibromide, ethylene bis(indenyl)dimethylzirconium, ethylene bis(indenyl)diphenylzirconium, ethylene bis(indenyl) (indenyl)methylzirconium monochloride, ethylene bis(indenyl)zirconium bis(methanesulfonate), ethylene bis(indenyl)zirconium bis(p-toluenesulfonate), ethylene bis(indenyl)zirconium bis(trifluoromethanesulfonate), ethylene bis(4,5,6,7-tetrahydroindenyl)zirconium dichloride, isopropylidene(cyclopentadienyl-fluorenyl)zirconium dichloride, isopropylidene(cyclopentadienyl-methylcyclopentadienyl)zirconium Dimethylsilylenebis(cyclopentadienyl)zirconium dichloride, Dimethylsilylenebis(methylcyclopentadienyl)zirconium dichloride, Dimethylsilylenebis(dimethylcyclopentadienyl)zirconium dichloride, Dimethylsilylenebis(trimethylcyclopentadienyl)zirconium dichloride, Dimethylsilylenebis(indenyl)zirconium dichloride, Dimethylsilylenebis(indenyl)zirconium bis(trifluoromethanesulfonate), rac-Dimethylsilylenebis {1-(2-methyl-4,5-acenaphthocyclopentadienyl)}zirconium dichloride, rac-dimethylsilylenebis{1-(2-methyl-4,5-benzoindenyl)}zirconium dichloride, rac-dimethylsilylenebis{1-(2-methyl-4-isopropyl-7-methylindenyl)}zirconium dichloride, rac-dimethylsilylenebis{1-(2-methyl-4-phenylindenyl)}zirconium dichloride, rac-dimethylsilylenebis{1-(2-methylindenyl)}zirconium dichloride,Dimethylsilylenebis(4,5,6,7-tetrahydroindenyl)zirconium dichloride, dimethylsilylene(cyclopentadienyl-fluorenyl)zirconium dichloride, diphenylsilylenebis(indenyl)zirconium dichloride, methylphenylsilylenebis(indenyl)zirconium dichloride, bis(cyclopentadienyl)zirconium dichloride, bis(cyclopentadienyl)zirconium dibromide, bis(cyclopentadienyl)methylzirconium monochloride, bis(cyclopentadienyl)ethylzirconium dichloride Bis(cyclopentadienyl)cyclohexylzirconium monochloride, Bis(cyclopentadienyl)phenylzirconium monochloride, Bis(cyclopentadienyl)benzylzirconium monochloride, Bis(cyclopentadienyl)zirconium monochloride monohydride, Bis(cyclopentadienyl)methylzirconium monohydride, Bis(cyclopentadienyl)dimethylzirconium, Bis(cyclopentadienyl)diphenylzirconium, Bis(cyclopentadienyl)dibenzyldi Zirconium, bis(cyclopentadienyl)zirconium methoxychloride, bis(cyclopentadienyl)zirconium ethoxychloride, bis(cyclopentadienyl)zirconium bis(methanesulfonate), bis(cyclopentadienyl)zirconium bis(p-toluenesulfonate), bis(cyclopentadienyl)zirconium bis(trifluoromethanesulfonate), bis(methylcyclopentadienyl)zirconium dichloride, bis(dimethylcyclopentadienyl)zirconium dichloride, bis(dimethylcyclopentadienyl)zirconium bis(n-butylcyclopentadienyl)zirconium dichloride, bis(butylcyclopentadienyl)zirconium ethoxychloride, bis(dimethylcyclopentadienyl)zirconium bis(trifluoromethanesulfonate), bis(ethylcyclopentadienyl)zirconium dichloride, bis(methylethylcyclopentadienyl)zirconium dichloride, bis(propylcyclopentadienyl)zirconium dichloride, bis(methylpropylcyclopentadienyl)zirconium dichloride, bis(n-butylcyclopentadienyl)zirconium dichloride, bis(butylcyclopentadienyl)zirconium dichloride,Bis(methylbutylcyclopentadienyl)zirconium dichloride, bis(methylbutylcyclopentadienyl)zirconium bis(methanesulfonate), bis(trimethylcyclopentadienyl)zirconium dichloride, bis(tetramethylcyclopentadienyl)zirconium dichloride, bis(pentamethylcyclopentadienyl)zirconium dichloride, bis(hexylcyclopentadienyl)zirconium dichloride, bis(trimethylsilylcyclopentadienyl)zirconium dichloride, diphenylmethylidene(cyclopentadienyl)(9-fluorenyl)zirconium dichloride, diphenylmethylene(3-tert-butyl-5-methyl-cyclopentadienyl)(2,7-di-tert-butyl-fluorene) Examples include 8-octamethylfluoren-12'-yl-(2-(adamantan-1-yl)-8-methyl-3,3b,4,5,6,7,7a,8-octahydrocyclopenta[a]indene))zirconium dichloride, bis(1,3-n-butylmethylcyclopentadienyl)zirconium(IV) dichloride, di-p-tolylmethylene(cyclopentadienyl)(octamethyloctahydrodibenzofluorenyl)zirconium dichloride, di-p-tolylmethylene(cyclopentadienyl)(octamethyloctahydrodibenzofluorenyl)zirconium(IV) dimethyl, and dimethylsilylene-bis{1-(2-methyl-4-phenylindenyl)}zirconium(IV) dichloride.

[0057] In the above examples, di-substituted cyclopentadienyl rings include 1,2- and 1,3-substituted cyclopentadienyl rings, and tri-substituted cyclopentadienyl rings include 1,2,3- and 1,2,4-substituted cyclopentadienyl rings.

[0058] In the present specification, alkyl groups such as propyl and butyl include various isomers such as structural isomers such as n-, i-, sec- and tert-, and optical isomers.

[0059] In the present invention, transition metal compounds in which the zirconium metal in the zirconium compounds described above is replaced with titanium metal or hafnium metal can also be used. A specific example of the hafnium metal replacement is bis(t-butylcyclopentadienyl)hafnium dichloride. In addition to titanium compounds and hafnium compounds having similar steric structures, as well as bromides and iodides, examples of transition metal compounds include those described in Organometallics, Vol. 13, 1994, pp. 954-963, JP-A-3-9913, JP-A-2-131488, JP-A-3-21607, JP-A-3-106907, JP-A-3-188092, JP-A-4-69394, JP-A-4-300887, WO 2001 / 27124, JP-A-2010-144035, JP-A-2012-92199, and JP-A-2013-60518.

[0060] <Aluminum Compounds (B)> The aluminum compound (B) of the present invention is an aluminum compound containing a compound having a structural unit sequence of the following formula (Al-1) and, as an optional component, a compound represented by the structure of the following formula (Al-2):

[0061] [ka]

[0062] (Above, Al is an aluminum atom, O is an oxygen atom, R b are each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and R a is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and multiple R a may be the same or different, and multiple R a At least one of the groups contains a hydrocarbon group having 2 to 20 carbon atoms.)

[0063] The aforementioned R a and R b Specifically, R of the transition metal compound1 ~R 8 These are the same as the atoms and hydrocarbon groups introduced in . The aforementioned R a There are multiple R a At least one of the groups contains a hydrocarbon group having 2 to 20 carbon atoms, preferably a hydrocarbon group having 2 to 10 carbon atoms. Such a hydrocarbon group is preferably a linear or branched alkyl group having 1 to 20 carbon atoms, such as ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, neopentyl, n-hexyl, isohexyl, heptyl, octyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, or eicosyl; a linear or branched alkenyl group having 2 to 20, preferably 2 to 10, carbon atoms, such as vinyl, allyl, or isopropenyl; linear or branched alkynyl groups having 2 to 20, preferably 2 to 10, carbon atoms, such as ethynyl and propargyl; a cyclic saturated hydrocarbon group having 3 to 20, preferably 3 to 10, carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, or adamantyl; Examples include cyclic unsaturated hydrocarbon groups having 5 to 20 carbon atoms, such as cyclopentadienyl, indenyl, and fluorenyl; aryl groups having 6 to 20, preferably 6 to 10, carbon atoms, such as phenyl, benzyl, naphthyl, biphenyl, terphenyl, phenanthryl, and anthracenyl; and alkyl-substituted aryl groups, such as tolyl, isopropylphenyl, t-butylphenyl, dimethylphenyl, and di-t-butylphenyl.

[0064] Of the above, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, neopentyl, n-hexyl, isohexyl, heptyl, octyl, and decyl are preferred, and alkyl groups having 2 to 6 carbon atoms such as ethyl, isopropyl, n-butyl, isobutyl, and n-hexyl are more preferred, and alkyl groups having 3 to 6 carbon atoms are particularly preferred, with alkyl groups having 4 to 6 carbon atoms being even more preferred. Although it depends on the production conditions of the aluminum compound (B) of the present invention described later, a , R b The larger the number of carbon atoms in the alkyl group, the higher the proportion of the compound having the structure of formula (Al-1) is, which is preferable. Such an R a The compound may be a single type or a mixture of two or more types. Specific examples of such compounds include ethylaluminoxane, n-propylaluminoxane, isopropylaluminoxane, n-butylaluminoxane, isobutylaluminoxane, hexylaluminoxane, octylaluminoxane, and decylaluminoxane. Also, the above R a may contain a methyl group or a hydrogen atom, but R a is a methyl group or a hydrogen atom, relative to the total number of structural units represented by formula (Al-1) (100 mol%), it is preferably 30 mol% or less, more preferably 20 mol% or less, even more preferably 10 mol% or less, and particularly preferably 5 mol% or less.

[0065] The aluminum compound (B) of the present invention may contain a compound represented by the formula (Al-2) above, for example, an unreacted product of the organoaluminum compound in the reaction of the organoaluminum compound with water.

[0066] Each of Ra in formula (Al-1) and Rb in formula (Al-2) is preferably a hydrocarbon group having 2 to 20 carbon atoms, more preferably a hydrocarbon group having 2 to 6 carbon atoms.

[0067] When the sum of the compound containing a structural unit sequence of the formula (Al-1) and the compound represented by the formula (Al-2) is taken as 100 mol %, the proportion of the compound containing a structural unit sequence of the formula (Al-1) is preferably 50 mol % or more, more preferably 70 mol % or more, even more preferably 80 mol % or more, and particularly preferably 90 mol % or more, calculated in terms of aluminum atoms. Such a ratio may be, for example, 1 H NMR measurements and 13 By performing C NMR, the R a and the peak intensity of R in the formula (Al-2) b From the peak intensity derived from R a Mole fraction [Ra2] and R b The mole fraction [Rb2] can be quantified.

[0068] From the viewpoint of excellent polymerization activity and copolymerizability, the aluminum compound is preferably an organoaluminum oxy compound (B-1) in which the molar fraction [Ra2] of the hydrocarbon group having 2 to 20 carbon atoms in the formula (Al-1) is 50 to 100 mol % and the molar fraction [Rb2] of the hydrocarbon group having 2 to 20 carbon atoms in the formula (Al-2) is 0 to 50 mol %; more preferably, the molar fraction [Ra2] is 80 to 100 mol % and the molar fraction [Rb2] is 0 to 20 mol %; even more preferably, the molar fraction [Ra2] is 90 to 100 mol % and the molar fraction [Rb2] is 0 to 10 mol %; and even more preferably, the molar fraction [Ra2] is 90 to 99.9 mol % and the molar fraction [Rb2] is 0.1 to 10 mol %. Furthermore, it is more preferable that the molar fraction [Ra2] is 92 to 99.9 mol% and the molar fraction [Rb2] is 0.1 to 8 mol%, more preferably that the molar fraction [Ra2] is 93 to 99.9 mol% and the molar fraction [Rb2] is 0.1 to 7 mol%, and particularly preferably that the molar fraction [Ra2] is 95 to 99.9 mol% and the molar fraction [Rb2] is 0.1 to 5 mol%, provided that the sum of [Ra2] and [Rb2] is 100 mol%.

[0069] The aluminum compound (B) of the present invention can be produced by any known production method without any limitations. Preferably, it can be produced by reacting a corresponding organoaluminum compound with water. Examples of the organoaluminum compound include the compounds introduced as organoaluminum compound (B-1) described below.

[0070] The ratio of water to the organoaluminum compound, expressed as a molar ratio of HO / Al, is preferably 0.7 to 1.5. A more preferred lower limit is 0.8, and even more preferred is 0.9. Meanwhile, a more preferred upper limit is 1.4, and even more preferred is 1.3, and particularly preferred is 1.2.

[0071] The reaction temperature between water and the organoaluminum compound is usually low, and it is preferably carried out under mild conditions. Specifically, the temperature at the contact stage between water and the organoaluminum compound is preferably -50 to 20°C. A more preferred lower limit is -30°C, and even more preferred is -20°C. On the other hand, a more preferred upper limit is 15°C, and even more preferably 10°C. The contact step between the two is preferably carried out slowly in small amounts, and controlled so as to minimize temperature changes. It is preferable to bring the two compounds into contact under the above conditions, and then gradually raise the temperature until the reaction proceeds sufficiently or is completed.

[0072] (Olefin polymerization catalyst) The olefin polymerization catalyst of the present invention is characterized by containing the transition metal compound (A) and the aluminum compound (B). The molar ratio [(Al-B) / M] of the amount of aluminum compound (B) converted into aluminum atoms to the amount of all transition metals (M) in the transition metal compound (A) is preferably 10 to 200,000. The lower limit is more preferably 20, even more preferably 30, particularly preferably 40, and especially preferably 50. On the other hand, the upper limit is more preferably 100,000, even more preferably 70,000, particularly preferably 50,000, and especially preferably 40,000. The olefin polymerization catalyst of the present invention can be used in combination with other components as long as the object of the present invention is not impaired. The most typical example is an organometallic compound (excluding the aluminum compound (B)) mainly used as a scavenger or an auxiliary cocatalyst. Examples of such compounds include the following organometallic compound (B-1), methylaluminoxane compound (B-2), and compound (B-3) that reacts with the transition metal complex (A) to form an ion pair.

[0073] 《Organometallic compound (B-1》) Examples of the organometallic compound (B-1) (hereinafter also referred to as "component (B-1)") include organoaluminum compounds (B-1a) represented by the general formula (B-1a), complex alkylates (B-1b) of Group 1 metals and aluminum represented by the general formula (B-1b), and dialkyl compounds (B-1c) of Group 2 or Group 12 metals represented by the general formula (B-1c). Organometallic compounds of Groups 1, 2, 12, and 13 are exemplified.

[0074] (B-1a):Ra m Al(ORb) n H p X q In the formula (B-1a), Ra and Rb 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 satisfying 0 < m ≦ 3, n is a number satisfying 0 ≦ n < 3, p is a number satisfying 0 ≦ p < 3, q is a number satisfying 0 ≦ q < 3, and m + n + p + q = 3. Examples of the organoaluminum compound (B-1a) include trialkylaluminums such as trimethylaluminum, triethylaluminum, and triisobutylaluminum, dialkylaluminum hydrides such as diisobutylaluminum hydride, and tricycloalkylaluminum.

[0075] (B-1b):M2AlRa4 In the formula (B-1b), M2 is Li, Na, or K, and Ra is a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms. Examples of the complex alkylate (B-1b) include LiAl(C2H5)4, LiAl(C7H15 )4 can be mentioned.

[0076] (B-1c):RaRbM3 In formula (B-1c), Ra and Rb each independently represent a hydrocarbon group having 1 to 15, preferably 1 to 4, carbon atoms, and M3 represents Mg, Zn, or Cd. Examples of compound (B-1c) include dimethyl magnesium, diethyl magnesium, di-n-butyl magnesium, ethyl-n-butyl magnesium, diphenyl magnesium, dimethyl zinc, diethyl zinc, di-n-butyl zinc, and diphenyl zinc. Among the organometallic compounds (B-1), organoaluminum compounds (B-1a) are preferred. The organometallic compound (B-1) may be used alone or in combination of two or more kinds.

[0077] The organometallic compound (B-1) is preferably used as a scavenger, and is preferably brought into contact in advance with a polymerization reaction vessel, a polymerization solvent, etc. The preferred amount used is 2 mmol or less, more preferably 1.5 mmol or less, and even more preferably 1.2 mmol or less, in terms of metal atoms, per liter of polymerization solvent.

[0078] Methylaluminoxane (B-2) As the methylaluminoxane (B-2) (hereinafter sometimes referred to as "component (B-2)" or MAO), a conventionally known methylaluminoxane can be used as it is. Specifically, a methylaluminoxane represented by the following general formula [B2-1]

[0079] [ka] and / or the following general formula [B2-2]

[0080] [ka]

[0081] (wherein R is an alkyl group essentially containing a methyl group, and n is an integer of 2 or greater) can be mentioned. Among these, preferred examples include benzene-insoluble organoaluminum oxy compounds described in JP-A Nos. 2-78687 and 2-167305, and aluminoxanes having two or more types of alkyl groups described in JP-A No. 3-103407.

[0082] Further, examples of the organoaluminum oxy compound (B-2) include modified methylaluminoxanes represented by the following general formula [B2-3].

[0083] [ka]

[0084] (In the formula, R represents a hydrocarbon group having 1 to 10 carbon atoms, and m and n each independently represent an integer of 2 or greater.)

[0085] This modified methylaluminoxane is prepared using trimethylaluminum and alkylaluminums other than trimethylaluminum. Such compounds are commonly referred to as MMAO. Such MMAOs can be prepared by the methods described in U.S. Patent Nos. 4,960,878 and 5,041,584. When the total of the above methyl groups and the substituent R is taken as 100 mol %, the proportion of methyl groups exceeds 50 mol %.

[0086] As the methylaluminoxane (B-2), commercially available methylaluminoxane and MMAO prepared using trimethylaluminum and triisobutylaluminum are preferred, and among these, MMAO, which has improved solubility in various solvents and storage stability, is particularly preferred.

[0087] (B-2) is a compound known as a promoter for transition metal compounds, and when used, it is preferably used in an amount smaller than that of the compound (B).

[0088] <<Compound (B-3) that reacts with transition metal complex (A) to form an ion pair>> Examples of the compound (B-3) (hereinafter also referred to as "ionic compound (B-3)" or "component (B-3)") that reacts with the transition metal complex (A) to form an ion pair include Lewis acids, ionic compounds, borane compounds, and carborane compounds described in JP-A-1-501950, JP-A-1-502036, JP-A-3-179005, JP-A-3-179006, JP-A-3-207703, JP-A-3-207704, and US Pat. No. 5,321,106. Heteropoly compounds and isopoly compounds are also included. However, this does not include the aforementioned (B-2) organoaluminum oxy compounds.

[0089] The ionic compound (B-3) is preferably a boron compound represented by the following general formula [B3-1].

[0090] [ka]

[0091] In the formula, R e+ As for H + , carbenium cation, oxonium cation, ammonium cation, phosphonium cation, cycloheptyltrienyl cation, ferrocenium cation having a transition metal, etc. f From R i may be the same or different and are substituents selected from hydrocarbon groups having 1 to 20 carbon atoms, silicon-containing groups, nitrogen-containing groups, oxygen-containing groups, halogen atoms and halogen-containing groups, and are preferably substituted aryl groups.

[0092] Examples of the boron compound represented by the general formula [B3-1] include those described in paragraphs

[0133] to

[0144] of WO 2015 / 122414. The ionic compound (B-3) may be used alone or in combination of two or more.

[0093] Such a compound (B3) is used in an amount of less than 10 moles, more preferably less than 5 moles, even more preferably less than 2 moles, and particularly preferably less than 1 mole, per mole of metal atom of the transition metal compound.

[0094] (Carrier (C)) The support (C) is an inorganic or organic compound, and is a granular or fine particle solid. Supports conventionally used in olefin polymerization using a transition metal complex and a support as catalyst components, such as those described in

[0110] to

[0122] of JP 2011-122146 A, can be used.

[0095] (Organic compound component (D)) An organic compound component (D) may be used as a constituent of the olefin polymerization catalyst, if necessary. The organic compound component (D) is used for the purpose of improving the polymerization performance and the physical properties of the resulting polymer. Examples of the organic compound component (D) include alcohols, phenolic compounds, carboxylic acids, phosphorus compounds, amides, polyethers, and sulfonates.

[0096] [Method for producing olefin polymer] The process for producing an olefin polymer of the present invention is characterized by polymerizing an olefin in the presence of the above-mentioned olefin polymerization catalyst of the present invention.

[0097] In the method for producing an olefin polymer of the present invention, an olefin homopolymer may be produced by polymerizing one type of olefin, or an olefin copolymer may be produced by copolymerizing two or more types of olefins. In this specification, polymerization and copolymerization are not particularly distinguished from each other and are also referred to as "polymerization," and olefin homopolymers and olefin copolymers are not particularly distinguished from each other and are also referred to as "olefin polymers."

[0098] The method of using each component constituting the olefin polymerization catalyst of the present invention in polymerization and the order of adding them to a polymerization vessel can be selected arbitrarily, but examples include the following. Hereinafter, the transition metal complex (A), aluminum compound (B), support (C), and organic compound component (D) will also be referred to as "components (A) to (D)," respectively. (1) A method of adding component (A) alone to a polymerization vessel. (2) A method of adding components (A) and (B) to a polymerization vessel in any order. (3) A method of adding a catalyst component in which component (A) is supported on component (C) and component (B) to a polymerization vessel in any order. (4) A method of adding a catalyst component in which component (B) is supported on component (C) and component (A) to a polymerization vessel in any order. (5) A method of adding a catalyst component in which component (A) and component (B) are supported on component (C) to a polymerization vessel.

[0099] In each of the above methods, component (D) may be added at any stage. In each of the above methods, at least two of the catalyst components may be contacted in advance. In the above methods (4) and (5) in which component (B) is supported, unsupported component (B) may be added in any order, if necessary. In this case, the components (B) may be the same or different. Furthermore, the solid catalyst component in which component (A) is supported on component (C) and the solid catalyst component in which components (A) and (B) are supported on component (C) may be prepolymerized with an olefin, or the prepolymerized solid catalyst component may have further catalyst components supported thereon.

[0100] Olefin 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.

[0101] When olefin polymerization is carried out using the above-mentioned olefin polymerization catalyst, the transition metal compound (A) is usually used in an amount of 10 -12 ~10 -2 moles, preferably 10 -10 ~10 -3 It is used in molar amounts.

[0102] When the organometallic compound (B-1) is used, it is used in an amount such that the molar ratio of the organometallic compound (B-1) to the total transition metal atoms (M) in the transition metal compound (A) [(B-1) / M] is usually 0.01 to 50,000, preferably 0.05 to 10,000. When the organometallic compound (B-1) is used as one component of the same olefin polymerization catalyst as the compound (B), it is preferably used in an amount smaller than that of the compound (B).

[0103] The organoaluminum oxy compound (B-2) is used in an amount such that the molar ratio of aluminum atoms in the organoaluminum oxy compound (B-2) to the total transition metals (M) in the transition metal compound (A) [(B-2) / M] is generally 5 to 5,000, preferably 10 to 2,000. When the organometallic compound (B-2) is used as one component of the same olefin polymerization catalyst as the compound (B), it is preferably used in an amount smaller than that of the compound (B).

[0104] The ionizing ionic compound (B-3) is used in an amount such that the molar ratio of the ionizing ionic compound (B-3) to the transition metal atom (M) in the transition metal compound (A) [(B-3) / M] is generally 1 to 10,000, preferably 1 to 5,000. When the organometallic compound (B-3) is used as one component of the same olefin polymerization catalyst as the compound (B), it is preferably used in an amount smaller than that of the compound (B).

[0105] When the carrier (C) is used, it is used in an amount such that the weight ratio of the transition metal compound (A) to the carrier (C) [(A) / (C)] is preferably 0.0001 to 1, more preferably 0.0005 to 0.5, and even more preferably 0.001 to 0.1.

[0106] In the production method of the present invention, the polymerization temperature in the polymerization step is usually -50 to +200°C, preferably 0 to 180°C; the polymerization pressure is usually atmospheric pressure to 10 MPa gauge pressure, preferably atmospheric pressure to 5 MPa gauge pressure. The polymerization reaction can be carried out in any of batch, semi-continuous, and continuous systems. Furthermore, the polymerization can be carried out in two or more stages with different reaction conditions.

[0107] The molecular weight of the resulting olefin polymer can be adjusted by adding hydrogen to the polymerization system, by changing the polymerization temperature, or by the amount of compound (B) used. When hydrogen is added, the amount is suitably about 0.001 to 5,000 NL per kg of the resulting olefin polymer.

[0108] The α-olefin that can be polymerized by the olefin polymerization catalyst of the present invention is not particularly limited as long as it has a polymerizable double bond, and examples thereof include linear or branched α-olefins having 2 to 30, preferably 2 to 20, and more preferably 2 to 10 carbon atoms, such as ethylene, propylene, 1-butene, 2-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-eicosene; Examples of cyclic olefins include those having 3 to 30, preferably 3 to 20, and more preferably 3 to 10 carbon atoms, such as 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.

[0109] The olefin polymerization catalyst of the present invention is more preferably used for the homopolymerization of ethylene or the copolymerization of ethylene with an α-olefin having 3 to 20 carbon atoms, preferably a linear or branched α-olefin having 3 to 10 carbon atoms. The α-olefins may be used alone or in combination of two or more.

[0110] When ethylene is copolymerized with an α-olefin having 3 to 20 carbon atoms, preferably 3 to 10 carbon atoms, the α-olefin (hereinafter also referred to as olefin A) is not particularly limited as long as the effects of the present invention are achieved, but for example, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, and 1-decene are preferred. These α-olefins may be used alone or in combination of two or more, and among these, at least one selected from 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene is more preferred.

[0111] When ethylene is used as the α-olefin and the olefin A is used, the ratio of the amounts of ethylene to the olefin A used is usually 1:10 to 5000:1, preferably 1:5 to 1000:1, in terms of ethylene:olefin A (molar ratio).

[0112] The olefin polymerization catalyst of the present invention may be used to (co)polymerize known chain unsaturated hydrocarbons having polar groups (for example, carbonyl groups, hydroxyl groups, ether-bonded groups, etc.). The olefin polymerization catalyst of the present invention may also be used to (co)polymerize vinylcyclohexane, dienes, polyenes, and the like.

[0113] Examples of the diene or polyene include cyclic or chain compounds having 4 to 30, preferably 4 to 20, carbon atoms and two or more double bonds. Specific examples include butadiene, isoprene, 4-methyl-1,3-pentadiene, 1,3-pentadiene, 1,4-pentadiene, 1,5-hexadiene, 1,4-hexadiene, 1,3-hexadiene, 1,3-octadiene, 1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7-octadiene, ethylidene norbornene, vinyl norbornene, and dicyclopentadiene; 7-methyl-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene, 5,9-dimethyl-1,4,8-decatriene; Furthermore, aromatic vinyl compounds, for example, mono- or polyalkylstyrenes such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o,p-dimethylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, etc.; Functional group-containing styrene derivatives such as methoxystyrene, ethoxystyrene, vinylbenzoic acid, methyl vinylbenzoate, vinylbenzyl acetate, hydroxystyrene, o-chlorostyrene, p-chlorostyrene, and divinylbenzene; and 3-phenylpropylene, 4-phenylpropylene, and α-methylstyrene.

[0114] [Olefin polymer] According to the present invention, an olefin polymer can be efficiently produced by polymerizing one or more olefins selected from α-olefins having 2 to 30 carbon atoms in the presence of the above-mentioned olefin polymerization catalyst; preferably, by homopolymerizing ethylene or copolymerizing ethylene with at least one α-olefin selected from olefins having 3 to 20 carbon atoms.

[0115] One embodiment of the olefin polymer is an ethylene-based polymer containing ethylene-derived structural units in a range of preferably 50 to 100 mol%, more preferably 70 to 100 mol%, and even more preferably 90 to 100 mol%. The ethylene-based polymer contains the olefin A-derived structural units in a total range of preferably 0 to 50 mol%, more preferably 0 to 30 mol%, and even more preferably 0 to 10 mol%, where the sum of the content of ethylene-derived structural units and the content of the olefin A-derived structural units is taken as 100 mol%. An ethylene-based polymer having the olefin A-derived structural unit in the above range has excellent moldability. Furthermore, the polymer may contain other structural units within the scope of the present invention. The content of these structural units can be measured by nuclear magnetic resonance spectroscopy, or, when a standard substance is available, infrared spectroscopy.

[0116] Among these polymers, ethylene homopolymer, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-propylene-1-butene copolymer, ethylene-1-octene polymer, ethylene-1-hexene polymer, ethylene-4-methyl-1-pentene polymer, ethylene-propylene-1-octene polymer, ethylene-propylene-1-hexene polymer, and ethylene-propylene-4-methyl-1-pentene polymer are particularly preferred. The copolymer is usually a random copolymer, but may also be a so-called block copolymer (impact copolymer) obtained by mixing or continuously producing two or more types selected from these polymers.

[0117] Among the polymers having the structural units described above, the ethylene polymer is preferably an α-olefin polymer consisting essentially of structural units derived from an α-olefin having 2 to 20 carbon atoms. "Substantially" means that the proportion of structural units derived from an α-olefin having 2 to 20 carbon atoms is 95% by weight or more of all structural units.

[0118] The weight-average molecular weight of the olefin polymer measured by gel permeation chromatography (GPC) is not particularly limited, but is preferably 10,000 to 5,000,000, more preferably 10,000 to 2,000,000, and particularly preferably 20,000 to 1,000,000. The molecular weight distribution (Mw / Mn), which is the ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn), is not particularly limited, but in cases including those with a broad molecular weight distribution, it is preferably 1 to 15, more preferably 1 to 13, and even more preferably 1 to 12. In other cases, it is preferably 1 to 10, more preferably 1 to 7, and particularly preferably 1 to 5.

[0119] The density of the olefin polymer is not particularly limited, but is preferably 875 kg / m 3 More than 975kg / m 3 It is preferable that: The intrinsic viscosity [η] of the olefin polymer in decalin at 135° C. is not particularly limited, but is preferably 0.1 to 40 dl / g, more preferably 0.5 to 15 dl / g, and particularly preferably 1 to 10 dl / g.

[0120] The melt mass flow rate (MFR; unit: g / 10 min) of the olefin polymer measured in accordance with ASTM D1238-89 at 190°C under a load of 2.16 kg is not particularly limited, but is preferably 0.001 g / 10 min or more and 300 g / 10 min or less, and more preferably 0.001 g / 10 min or more and 200 g / 10 min or less.

[0121] In addition, the MFR value measured under the conditions of 190°C and a load of 10 kg in accordance with ASTM D1238-89 was divided by the MFR value measured under the conditions of 190°C and a load of 2.16 kg (I 10 / I2) is preferably 5.0 or more and less than 300.

[0122] When α-olefins are polymerized in the presence of the olefin polymerization catalyst of the present invention, polymers having higher molecular weights tend to be obtained more easily than when conventional olefin polymerization catalysts are used. In addition, olefin polymers may be produced with a polymerization activity relatively higher than conventional ones. The reason why such an effect is exhibited is currently unknown, but the present inventors speculate as follows. The aluminum compound (B) of the present invention is a so-called organoaluminum oxy compound, and has a structure similar to that of MAO, but since the substituent is larger than the methyl group of MAO, the Lewis acidity of the compound as a whole may be low. Therefore, it is expected that the coordination to the transition metal atom contained in the transition metal compound is weaker than that of MAO. It is known that organoaluminum compounds generally function as chain transfer agents in olefin polymerization reactions. As mentioned above, the aluminum compound (B) of the present invention has a weak coordination with the transition metal atom, and therefore tends to contribute little to chain transfer. Furthermore, as described above, the aluminum compound (B) of the present invention has a lower Lewis acidity than MAO, and from this viewpoint, it may be less likely to cause a chain transfer reaction. Organoaluminum compounds are raw materials used in the production of aluminum oxy compounds and may be present as unreacted compounds. Generally, it is said that the smaller the alkyl group, the more likely chain transfer occurs. For these reasons, the olefin polymerization catalyst of the present invention is likely to facilitate the production of polymers with high molecular weights.

[0123] Conventionally, methylaluminoxane has been considered to be suitable as an organoaluminum oxy-compound as a cocatalyst component of a metallocene catalyst, particularly from the viewpoint of enhancing polymerization activity. On the other hand, as shown in the experimental examples (Examples and Comparative Examples) described below, the combination of the transition metal compound (A) of the present invention with the aluminum compound (B) may result in higher polymerization activity than when MAO is used. This is thought to be because the ligand of the transition metal compound (A) has a relatively large structure and exhibits relatively high steric hindrance, while the aluminum compound (B) of the present invention has a relatively weaker coordination with the transition metal compound (A) than MAO, which tends to facilitate the approach of olefins to the transition metal (active site) of the transition metal compound (A). Due to these multiple factors, it is believed that the olefin polymerization catalyst of the present invention exhibits multiple effects such as "chain transfer is less likely to occur and molecular weight is more likely to increase" and "relatively high polymerization activity."

[0124] The olefin polymer obtained by polymerizing an α-olefin in the presence of the olefin polymerization catalyst of the present invention can be used for known applications without any restrictions, such as films, elastomers, injection molded articles, extrusion molded articles, inflation molded articles, vacuum molded articles, pressure molded articles, and press molded articles. [Example]

[0125] The present invention will be specifically explained below based on synthesis examples and examples, but the present invention is not limited to these examples.

[0126] [Measurement method] [Structures of transition metal compounds and organometallic compounds (aluminoxanes)] The analysis of transition metal compounds was carried out under the following conditions. The solvent used was deuterated chloroform manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. The NMR measurement device used was a GSH-270 model manufactured by JEOL Ltd., and the sample solution using the above solvent was measured. The measurement temperature was room temperature, the observation nucleus was 1H (270MHz), the sequence was single pulse, 45° pulse, the repetition time was 5.5 seconds or more, and the number of accumulations was 32.

[0127] The analysis of organometallic compounds (aluminoxanes) was carried out under the following conditions. The solvent was deuterated tetrahydrofuran that had been thoroughly dehydrated using molecular sieves 3A manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Diphenylmethane was used as the internal standard substance. The NMR measurement device used was a GSH-270 model manufactured by JEOL Ltd., and the sample solution using the above solvent was measured. The measurement temperature was room temperature, the observation nucleus was 1H (270MHz), the sequence was single pulse, 45° pulse, the repetition time was 5.5 seconds or more, and the number of accumulations was 32. The reference chemical shift was set to 3.955 ppm for the methylene hydrogen of diphenylmethane.

[0128] The values ​​of [Ra2] for formula (Al-1) and [Rb2] for formula (Al-2) were determined by the ratio of the absorption intensities of methylene hydrogens bonded to Al (near 2.3 ppm and near 1.2 ppm). 1 Peaks such as H were assigned by conventional methods.

[0129] [Al concentration of aluminoxane] The Al concentration of the aluminoxane obtained in each synthesis example was determined using an ICP emission spectrometer.

[0130] [Comonomer content of polymer] The comonomer content of the ethylene / 1-octene copolymer was measured by FT-IR (infrared spectrophotometer).

[0131] (FT-IR measurement method) The polymers obtained in the examples and comparative examples were heated to 135°C, melt-stretched in a hot press, and then cooled under pressure at room temperature to obtain films, which were used as measurement samples for FT-IR measurement. On the other hand, 13 Calibration curves were prepared by FT-IR measurement of ethylene / 1-octene copolymers of various compositions, the 1-octene structural unit contents of which had been determined by C NMR. Using this calibration curve, the 1-octene structural unit contents of the ethylene / 1-octene copolymers synthesized in the Examples and Comparative Examples were measured.

[0132] [Polymer Tm] DSC measurement was carried out under the following conditions to determine the Tm of the polymer.

[0133] (DSC measurement) The melting point of the ethylene polymer was measured by differential scanning calorimetry (DSC measurement) using the following apparatus and conditions. Measurement equipment: PerkinElmer Diamond DSC type equipment PerkinElmer aluminum pans were used. Amount of sample used: Accurately weigh out approximately 10 mg. Temperature raising / lowering method: First stage: The temperature is raised from room temperature to 200°C at a rate of 500°C / min and maintained at this temperature for 10 minutes. Second step: The temperature is decreased to -40°C at a rate of 10°C / min and maintained for 1 minute. Third stage: Heat to 150°C at 10°C / min and finish. For other measurements, obtain a DSC profile using the usual method and measure the heat of fusion (ΔHm: value at the third stage) etc.

[0134] [Polymer weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn)] The weight average molecular weight (Mw) and number average molecular weight (Mn) of the olefin polymer were determined by gel permeation chromatography (GPC) using a Tosoh HLC-8321 GPC / HT gel permeation chromatograph (high temperature size exclusion chromatograph) under the following operating conditions:

[0135] <Devices and conditions used> Measurement equipment: Gel permeation chromatograph HLC-8321 GPC / HT type (Tosoh Corporation) Analysis software: Empower 3 (Waters) Column: 2x TSKgel GMH6-HT + 2x TSKgel GMH6-HTL (inner diameter 7.5 mm x length 30 cm, Tosoh Corporation) Mobile phase: o-dichlorobenzene (containing 0.025% BHT) Detector; differential refractometer Column temperature: 140°C Flow rate: 1.0 mL / min. Injection volume: 400 μL. Sampling time interval: 0.5 s. Sample concentration: 0.15% (w / v). Molecular weight calibration: A calibration curve was used using monodisperse polystyrene (Tosoh Corporation) / molecular weight #3 standard set sample (molecular weight 4.95 to 20.6 million).

[0136] Examples of synthesis of transition metal compounds, synthesis of aluminoxanes, and production of ethylene / 1-octene copolymers are given below. <(1) Synthesis of transition metal compounds> [Synthesis Example 1-1] Di-p-trimethylmethylene(cyclopentadienyl)(octamethyloctahydrodibenzofluorenyl)zirconium(IV) dimethyl (hereinafter referred to as zirconium compound (1)) represented by the following formula (1) was synthesized by a methylation reaction of di-p-trimethylmethylene(cyclopentadienyl)(octamethyloctahydrodibenzofluorenyl)zirconium(IV) dichloride described in WO 2004 / 029062.

[0137] [ka]

[0138] <(2) Synthesis of aluminoxane compounds> [Synthesis Example 2-1] Under a nitrogen atmosphere, 100 mL of a 0.830 mol / L triisobutylaluminum / toluene solution (83.0 mmol of triisobutylaluminum) was placed in a 250 mL glass reactor. The reactor was then cooled to 0°C, and 1.64 mL (91.3 mmol) of degassed water was added dropwise over 1 hour while stirring. The solution was then stirred at 0°C for 30 minutes, after which it was heated to 50°C at a rate of 0.8°C / min and stirred at 50°C for 1 hour under a nitrogen atmosphere. The solution was then gradually cooled to room temperature, yielding 88.5 mL of a toluene solution (Al concentration 0.932 mol / L) of the target aluminoxane compound (hereinafter referred to as aluminoxane (A-1)). NMR measurement revealed that the molar ratio of isobutyl groups derived from aluminoxane to isobutyl groups derived from isobutylaluminum was 98:2.

[0139] [Synthesis Example 2-2] Under a nitrogen atmosphere, 53.5 mL of a 0.830 mol / L triisobutylaluminum / toluene solution (44.4 mmol of triisobutylaluminum) and 53.5 mL of a 0.955 mol / L triethylaluminum / toluene solution (44.4 mmol of triethylaluminum) were placed in a 250 mL glass reactor. The reactor was then cooled to 0 ° C., and 1.76 mL (97.7 mmol) of degassed water was added dropwise over 1 hour while stirring. The solution was then stirred at 0 ° C. for 30 minutes, after which it was heated to 50 ° C. at a rate of 0.8 ° C. / min and stirred at 50 ° C. for 1 hour under a nitrogen atmosphere. The mixture was then gradually cooled to room temperature to obtain 83.5 mL of a toluene solution (Al concentration 0.823 mol / L) of the target aluminoxane compound (hereinafter referred to as aluminoxane (A-2)). NMR measurement revealed that the molar ratio of the alkyl group derived from aluminoxane to the alkyl groups derived from isobutylaluminum and triethylaluminum was 94:6.

[0140] <(3) Production of ethylene / 1-octene copolymer> Example 1 A 1000 mL glass reactor (equipped with a stirrer, gas supply line, and exhaust line) was charged with 500 mL of toluene and heated to 50 °C. Ethylene was then added at a rate of 100 L / hr with stirring to saturate the liquid and gas phases. Polymerization was then initiated by adding 25.5 mmol of 1-octene, 2.50 mmol of a toluene solution of the aluminoxane (A-1) (Al concentration: 0.932 mol / L) in terms of aluminum atoms, and 0.1 μmol of the zirconium compound (1) obtained in Synthesis Example 1-1 in the form of a toluene solution. Ethylene was continuously supplied at 100 L / hr, and polymerization was carried out at 50 °C under atmospheric pressure for 15 minutes. The polymerization was then terminated by the addition of a small amount of methanol. After polymerization was completed, the reaction mixture was gradually added to 750 mL of methanol (poor solvent) containing a small amount of hydrochloric acid while stirring to precipitate a polymer. The precipitate was washed with methanol and then dried under reduced pressure at 80° C. for 10 hours to obtain 4.44 g of an ethylene / 1-octene copolymer. The physical properties of the obtained polymer are shown in Table 1.

[0141] Example 2 Polymerization was carried out in the same manner as in Example 1, except that 2.50 mmol of a toluene solution of the aluminoxane (A-2) (Al concentration: 0.823 mol / L) was used instead of the aluminoxane (A-1), to obtain 3.99 g of an ethylene / 1-octene copolymer. The physical properties of the polymer are shown in Table 1.

[0142] Comparative Example 1 Polymerization was carried out in the same manner as in Example 1, except that 2.50 mol (in terms of aluminum atom) of MMAO-3A (modified methylaluminoxane) hexane solution (Al concentration 1.66 mol / L) manufactured by Tosoh Finechem was used instead of aluminoxane (A-1), to obtain 2.59 g of ethylene / 1-octene copolymer. The physical properties of the obtained polymer are shown in Table 1.

[0143] [Table 1]

[0144] The results shown in Table 1 show that in Examples 1 and 2, in which the aluminoxane compounds synthesized in Synthesis Examples 2-1 and 2-2 were used as the aluminum compound (B) of the present invention (having an alkyl group having two or more carbon atoms), the weight-average molecular weight (Mw) of the produced polymer was significantly increased without a significant change in molecular weight distribution at the same composition as in Comparative Example 1, in which MMAO-3A was used as the aluminoxane compound. Furthermore, the polymerization activity was also improved.

[0145] It has been found that the olefin polymerization catalyst of the present invention makes it possible to produce a polymer with a high weight average molecular weight (Mw) by changing the aluminoxane compound, which is considered to be structurally relatively easy to prepare, while leaving the transition metal compound, which is considered to be relatively difficult to synthesize, unchanged.

Claims

1. (A) a transition metal compound represented by the following formula [A-1], (B) an aluminum compound containing a compound containing a structural unit sequence of the following formula (Al-1) and, as an optional component, a compound represented by the following formula (Al-2); 1. A catalyst for olefin polymerization comprising: 【Chemical 1】 [In formula [A-1], R １ , R ２ , R ３ , R ４ , R ５ , R ６ , R ７ , R ８ , R ９ , R １０ , R １１ , R １２ , R １３ and R １４ are each independently selected from a hydrogen atom, a hydrocarbon group, and a heteroatom-containing group, and may be the same or different; R １ From R １４ Adjacent substituents up to may be bonded to each other to form a ring, M is a metal atom selected from Ti, Zr and Hf, Y is a Group 14 atom, and Q is the same or different and selected from a halogen atom and a hydrocarbon group, and j is selected from an integer of 1 to 4. 【Chemistry 2】 (Above, Al is an aluminum atom, O is an oxygen atom, R ｂ are each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and R ａ is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and a plurality of R ａ may be the same or different, and multiple R ａ At least one of the groups contains a hydrocarbon group having 2 to 20 carbon atoms.)

2. 2. The olefin polymerization catalyst according to claim 1, wherein, in the formula [A-1], M is Zr, and each Q is independently a hydrocarbon group having a total of 1 to 20 carbon atoms.

3. In the formula [A-1], R １３ and R １４ 2. The olefin polymerization catalyst according to claim 1, wherein each of the groups independently represents an unsubstituted aryl group or a substituted aryl group.

4. The aluminum compound is the molar fraction [Ra2] of hydrocarbon groups having 2 to 20 carbon atoms in the formula (Al-1) is 50 to 100 mol %, The olefin polymerization catalyst according to claim 1, wherein the organoaluminum oxy compound (B-1) is an organoaluminum oxy compound (B-1) of formula (Al-2), in which the molar fraction [Rb2] of hydrocarbon groups having 2 to 20 carbon atoms is 0 to 50 mol % (provided that the sum of [Ra2] and [Rb2] is 100 mol %).

5. R in the formula (Al-1) ａ and R in the formula (Al-2). ｂ and each represent a hydrocarbon group having 2 to 6 carbon atoms.

6. A method for producing an ethylene / α-olefin copolymer, comprising copolymerizing ethylene with an α-olefin having 3 to 30 carbon atoms in the presence of the olefin polymerization catalyst according to claim 1.

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