Method for producing olefin copolymer

Abstract

To provide a catalyst that can be used as a catalyst for olefinic polymerization, allows the production of polyethylene, and facilitates precise evaluation of purity and the like after the production, and a method for producing an olefinic polymer using the same.SOLUTION: A method for producing an olefinic polymer includes the step of polymerizing an olefinic compound by using, as a polymerization catalyst component, a catalyst including a low-spin complex having metal atoms of group 8 or 9 in the periodic table.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a novel catalyst composition containing a complex having a specific structure, and more specifically, to a catalyst composition containing a low-spin transition metal complex as an essential component, and a method for producing an olefin copolymer using the same. [Background technology]

[0002] Among resin materials, olefin polymers are excellent in various properties such as physical properties and moldability, and are highly economical and environmentally friendly, making them very versatile and important industrial materials. However, because olefin polymers do not have polar groups, they have many problems, such as the difficulty of applying them to applications that require physical properties such as adhesion to other materials, printability, or compatibility with fillers.

[0003] In recent years, as a method for producing an olefin polymer having a polar group, a method using a polar monomer in the polymerization stage has been attracting attention. For this purpose, late transition metal complex catalysts, so-called postmetallocenes, have been developed, and the physical properties of olefin polymers have been controlled using them. As postmetallocene catalysts for olefin polymerization, for example, paramagnetic iron complex catalysts such as tridentate iron complexes having a diiminopyridine skeleton and bisaryliminopyridine iron are used, and the results of ethylene polymerization using these catalysts are known (Patent Documents 1 to 3, Non-Patent Document 1). In addition, ethylene polymerization using paramagnetic iron complexes and cobalt complexes is known (Patent Documents 4, 5, Non-Patent Documents 2, 3). In addition, as a catalyst design using a ligand, a group 10 complex called a SHOP catalyst is known (Patent Document 6). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2006-501067 [Patent Document 2] Patent No. 4108141 [Patent Document 3] Special Publication No. 2002-513823 [Patent Document 4] JP 2018-172644 A [Patent Document 5] JP 2020-056021 A [Patent Document 6] Patent No. 5292059 [Non-patent literature]

[0005] [Non-Patent Document 1] Campora et al. Organometallics, 2005, 24, 4878-4881 [Non-Patent Document 2] Britovsek et al. Chem. Commun. 1998, 849. [Non-Patent Document 3] Britovsek et al. J. Am. Chem. Soc. 1999, 121, 8728. Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, ethylene polymerization using metal complex catalysts has been reported, but in the evaluation of polymerization, it is necessary to properly evaluate the catalytic activity, and using a catalyst with high purity is important for accurate catalyst evaluation. However, in Patent Documents 1, 2, 3, 4, 5 and Non-Patent Documents 1, 2, 3, high-spin transition metal complexes are used for 8-9 group complex catalysts, and it is not possible to identify the catalyst or evaluate its purity, etc., by commonly used methods such as NMR. Correct evaluation of the purity of the catalyst not only leads to a correct evaluation of its function as a polymerization catalyst, but also has an impact on the reproducibility of olefin polymerization. Thus, there is a demand for the development of a catalyst that can be used as an olefin polymerization catalyst, enables the production of polyethylene, and allows easy and accurate evaluation of purity, etc. after production. [Means for solving the problem]

[0007] The object of the present invention is to create a catalyst composition that can be easily evaluated for purity and functions effectively as an olefin polymerization catalyst. As a result of intensive research aimed at solving the above problems, the present inventors have found that a composition containing a specific iron complex functions as a component of a polymerization catalyst that meets the above objective, and have created the present invention.

[0008] In a first aspect of the present invention, there is provided a method for producing an olefin polymer, comprising a step of polymerizing an olefin monomer using, as a polymerization catalyst component, a catalyst containing a complex having a metal atom of Group 8 or 9 of the periodic table in a low spin state.

[0009] In a second aspect of the present invention, there is provided the process for producing an olefin polymer according to the first aspect, wherein the complex has a tridentate or tetradentate ligand having a phosphorus atom at a coordination site.

[0010] In a third aspect of the present invention, there is provided the method for producing an olefin polymer according to the first or second aspect, wherein the complex is represented by the following general formula (1): [ka] [In general formula (1), M is iron with an oxidation state of +2, ruthenium with an oxidation state of +2, cobalt with an oxidation state of +1, or rhodium with an oxidation state of +1; n represents an integer of 0 or 1; R 1a , R 1b , R 1c and R 1d each independently represents a hydrocarbon group having 3 to 12 carbon atoms, R 2a and R 2b each independently represents a hydrogen atom or a hydrocarbon having 1 to 3 carbon atoms, R 3a , R 3b , R 3c , R 3d , R 3e , R3f , R 3g and R 3h each independently represents a substituent selected from the group consisting of a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 30 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a hydrocarbon group having 1 to 30 carbon atoms substituted with a halogen atom, a hydrocarbon group having 2 to 30 carbon atoms substituted with an alkoxy group, and a silyl group substituted with a hydrocarbon group having 1 to 30 carbon atoms; R 4a and R 4b each independently represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, or R 4a and R 4b are linked together to form a ring, L, at each occurrence, independently represents a metal ancillary ligand selected from a neutral monodentate ligand or an anionic monodentate ligand; X is absent or a counter anion species with a valence of −1 or 2.

[0011] In a fourth aspect of the present invention, there is provided the method for producing an olefin polymer according to the third aspect, wherein M in the formula (1) is iron having an oxidation number of +2 or ruthenium having an oxidation number of +2.

[0012] In a fifth aspect of the present invention, there is provided a method for producing an olefin polymer according to any one of the first to fourth aspects, characterized in that the weight average molecular weight of the obtained olefin polymer is 100,000 or more and 10,000,000 or less. Effect of the Invention

[0013] The catalyst composition of the present invention provides a novel olefin polymerization catalyst. The purity of the metal complex of the catalyst can be specified by NMR measurement, and a catalyst containing a high-purity metal complex can be used as a polymerization catalyst component. The polyolefin polymerization catalyst using the metal complex of the present invention and the olefin polymerization method using the same are very useful from an industrial point of view. [Brief description of the drawings]

[0014] [Figure 1] 3 is a 31P-NMR chart of Fe(II) Complex A of Example 1. [Diagram 2] 1 is a 1H-NMR chart of Fe(II) Complex A of Example 1. [Diagram 3] 3 is a 31P-NMR chart of Fe(II) complex B in Example 2. [Figure 4] 1 is a 1H-NMR chart of Fe(II) complex B in Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, the polymerization catalyst component of the present invention and the process for producing an olefin polymer using the same will be described in detail for each item.

[0016] <Transition metal complexes> The polymerization catalyst component used in the method of the present invention contains as a polymerization catalyst component a transition metal complex containing a metal atom of Group 8 or 9 of the periodic table in a low spin state. The transition metal complex is not particularly limited in type, so long as it is a Group 8 or 9 metal complex and can be identified by NMR measurement. It is preferable that the NMR measurement is highly sensitive and observes a nuclide that gives a result with a simple peak. A specific NMR measurement method is as follows: 1 H-NMR, 31 P-NMR is preferred because the peaks are clearly visible and the measurement environment is often uniform. When the ligand contains a phosphorus atom, 31 P-NMR is particularly preferred. 31In P-NMR, the position of the signal changes depending on the atoms and functional groups surrounding the phosphorus atom, but in order to simplify the peaks observed in the NMR measurement, the type of signal of the phosphorus atom may be one or two. In addition, since a characteristic peak is observed by coordination with a metal atom, it is preferable that the phosphorus atom is at a coordination site and is coordinately bonded to the metal atom. More preferably, the transition metal complex has a tridentate or tetradentate ligand having at least one phosphorus atom at a coordination site.

[0017] When the ligand is a tridentate ligand, examples thereof include a ligand having a structure in which a phosphorus atom, a nitrogen atom, and a phosphorus atom are arranged clockwise as shown in the following general formula (2) (hereinafter referred to as PNP), and a ligand having a structure in which a phosphorus atom, a nitrogen atom, and a nitrogen atom are arranged clockwise as shown in the following general formula (3) (hereinafter referred to as PNN). When the ligand is a tetradentate ligand, a representative example thereof is a tetradentate ligand having a structure in which a phosphorus atom, a nitrogen atom, a nitrogen atom, and a phosphorus atom are arranged clockwise as shown in the above general formula (1) (hereinafter referred to as PNNP). Such ligands are generally considered to be prone to form regular octahedral complex structures, and as a result, the Group 8 or 9 metal complex is prone to be in a paramagnetic and low spin state. In addition, in the general formulas (2) and (3), R 1a , R 1b , R 2a , R 3a , R 3b , R 3c , R 3d , R 4a , R 4b and n are as defined in the general formula (1), R 5 is the above R 1a This is the same as the definition of [ka] [ka]

[0018] In terms of sensitivity, it is desirable that the sample in the NMR measurement is a solution. Therefore, it is preferable that the transition metal complex used in the method of the present invention is soluble in an organic solvent. In particular, it is preferable that the transition metal complex is soluble in any one of deuterated benzene, deuterated toluene, deuterated acetone, deuterated acetonitrile, deuterated methylene chloride, and deuterated chloroform. The solubility of the transition metal complex is 31 It is preferable that the concentration is equal to or higher than the level required for P-NMR measurement (1 g / L).

[0019] The transition metal complexes used in the method of the present invention contain metal atoms of Group 8 or 9 of the periodic table in a low spin state. Group 8 or 9 transition metals have 6 or 7 electrons in five d orbitals, with the number of unpaired electrons varying depending on the mode of orbital filling. "Low spin" refers to a state in which the number of unpaired electrons is zero. Examples of metal species that can be employed include iron, ruthenium, or osmium with a valence of +2, and cobalt, rhodium, or iridium with a valence of +1.

[0020] Specific examples of the transition metal complexes used in the method of the present invention include transition metal complexes represented by the following general formula (1). [ka] [In general formula (1), M is iron with an oxidation state of +2, ruthenium with an oxidation state of +2, cobalt with an oxidation state of +1, or rhodium with an oxidation state of +1; n represents an integer of 0 or 1; R 1a , R 1b , R 1c and R 1d each independently represents a hydrocarbon group having 3 to 12 carbon atoms, R 2a and R 2b each independently represents a hydrogen atom or a hydrocarbon having 1 to 3 carbon atoms, R 3a , R 3b , R 3c , R 3d , R 3e , R 3f, R 3g and R 3h each independently represents a substituent selected from the group consisting of a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 30 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a hydrocarbon group having 1 to 30 carbon atoms substituted with a halogen atom, a hydrocarbon group having 2 to 30 carbon atoms substituted with an alkoxy group, and a silyl group substituted with a hydrocarbon group having 1 to 30 carbon atoms; R 4a and R 4b each independently represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, or R 4a and R 4b are linked together to form a ring, L, at each occurrence, independently represents a metal ancillary ligand selected from a neutral monodentate ligand or an anionic monodentate ligand; X is absent or a counter anion species with a valence of −1 or 2.

[0021] "Hydrocarbon group" means a structure consisting of a carbon skeleton having a specific number of carbon atoms, and includes structures formed by bonding two or more of linear or branched alkyl groups, alkenyl groups, alkynyl groups, cycloalkyl groups, cycloalkenyl groups, cycloalkynyl groups, aryl groups, benzyl, biphenyl, etc. In the present specification, "hydrocarbon group" generally refers to a monovalent group, but when it is specifically stated that the "hydrocarbon group" has a valence of two or more, the "hydrocarbon group" indicates a structure in which at least one hydrogen atom in the above group or structure is replaced with a bond depending on the valence.

[0022] The hydrocarbon group having 1 to 30 carbon atoms is preferably an alkyl group, a cycloalkyl group, an alkenyl group, or an aryl group. Examples of the alkyl group and the cycloalkyl group include a methyl group, an ethyl group, a 1-propyl group, an isopropyl group, a 1-butyl group, an isobutyl group, a t-butyl group, a 1-pentyl group, a 1-hexyl group, a 1-heptyl group, a 1-octyl group, a 1-nonyl group, a 1-decyl group, a tricyclohexylmethyl group, a 1,1-dimethyl-2-phenylethyl group, a 1-dimethylpropyl group, a 1,1,2-trimethylpropyl group, a 1,1-diethylpropyl group, a 1-phenyl-2-propyl group, a 1,1-dimethylbutyl group, a 2-pentyl group, a 3-pentyl group, a 2-hexyl group, a 3-hexyl group, a 2-ethyl ... Examples of the substituent include cyclopropyl, 2-heptyl, 3-heptyl, 4-heptyl, 2-propylheptyl, 2-octyl, 3-nonyl, cyclopropyl, cyclobutyl, cyclopentyl, methylcyclopentyl, cyclohexyl, methylcyclohexyl, cycloheptyl, cyclooctyl, cyclododecyl, 1-adamantyl, 2-adamantyl, exo-norbornyl, endo-norbornyl, 2-bicyclo[2.2.2]octyl, nopinyl, decahydronaphthyl, menthyl, neomenthyl, neopentyl, and 5-decyl. Among these, preferred substituents are isopropyl, isobutyl, and cyclohexyl.

[0023] Examples of the alkenyl group include a vinyl group, an allyl group, a butenyl group, a cinnamyl group, and a styryl group.

[0024] Examples of the aryl group include a phenyl group, a naphthyl group, an anthracenyl group, and a fluorenyl group, and the aromatic ring of these aryl groups may have a substituent. Examples of the substituent that may be present include an alkyl group, an aryl group, a fused aryl group, a phenylcyclohexyl group, a phenylbutenyl group, a tolyl group, a xylyl group, and a p-ethylphenyl group. Among these, preferred aryl groups are a phenyl group and a substituted phenyl group, and preferred specific examples of the substituent of the substituted phenyl group are a methyl group, an ethyl group, and a phenyl group, and more preferably, a methyl group.

[0025] "Halogen" means an element belonging to Group 17 of the periodic table, specifically fluorine, chlorine, bromine, and iodine, preferably chlorine and bromine. The hydrocarbon group having 1 to 30 carbon atoms substituted with a halogen atom preferably has a structure in which one or more hydrogen atoms of the above-mentioned hydrocarbon group having 1 to 30 carbon atoms are substituted with a halogen atom. Specific preferred examples include a trifluoromethyl group or a pentafluorophenyl group.

[0026] The term "alkoxy group" refers to a hydrocarbon group having an oxygen atom bonded to the terminal thereof, but the oxygen atom is not bonded to an aromatic ring. An alkoxy group having 1 to 4 carbon atoms is preferred, and specific examples of the alkoxy group include a methoxy group, an ethoxy group, an isopropoxy group, a 1-propoxy group, a 1-butoxy group, and a t-butoxy group. Among these, more preferred substituents are a methoxy group, an ethoxy group, or an isopropoxy group, and a methoxy group is particularly preferred.

[0027] The hydrocarbon group having 2 to 30 carbon atoms substituted with an alkoxy group preferably has a structure in which the aforementioned hydrocarbon group having 1 to 30 carbon atoms is substituted with an alkoxy group. Specific preferred examples include a methoxymethyl group and a methoxyethyl group.

[0028] The term "silyl group" refers to a substituent having silicon at its terminal, and the silyl group substituted with a hydrocarbon group having 1 to 30 carbon atoms is preferably a silyl group having 3 to 18 carbon atoms, and preferred specific examples are a trimethylsilyl group, a dimethylphenylsilyl group, a diphenylmethylphenylsilyl group, and a triphenylsilyl group. Among these, more preferred substituents are a trimethylsilyl group or a dimethylphenylsilyl group, and particularly preferred is a trimethylsilyl group.

[0029] M in the general formula (1) is a transition metal of Group 8 or 9, and is particularly selected from the group consisting of iron with an oxidation number of +2, ruthenium with an oxidation number of +2, cobalt with an oxidation number of +1, or rhodium with an oxidation number of +1. Preferably, it is iron with an oxidation number of +2 or cobalt with an oxidation number of +1.

[0030] In the portion corresponding to the tetradentate ligand in general formula (1), n ​​represents an integer of 0 or 1. When the value of n is 0, R 4a The carbon to which R is bonded 4b The carbon atom to which n is bonded is directly bonded. Since there are many types of n as a raw material for ligand synthesis, the value of n is preferably 0.

[0031] R 1a , R 1b , R 1c and R 1d R each independently represents a hydrocarbon group having 3 to 12 carbon atoms. 1a , R 1b , R 1c and R 1d may be the same or different, but are preferably the same from the viewpoints of availability of raw material compounds, ease of synthesis of the ligand, and control of the steric environment of the metal complex. 1a ~R 1d Examples of R include alkyl groups having 3 to 12 carbon atoms, particularly isopropyl and t-butyl groups; cycloalkyl groups having 3 to 12 carbon atoms, particularly cyclohexyl groups; and aryl groups having 6 to 12 carbon atoms, particularly phenyl, toluyl and naphthyl groups. Of these, alkylaryl groups such as phenyl, toluyl and naphthyl groups are preferred, and alkylaryl groups having no substituents at the 2- and 6-positions are more preferred, with phenyl being particularly preferred. 1a , R 1b , R 1c and R 1b It is desirable for the group to have an appropriate size in terms of the molecular weight of the polymer, polymerization activity, and ease of synthesis.

[0032] R 2a and R 2beach independently represents a hydrogen atom or a hydrocarbon having 1 to 3 carbon atoms. 2a and R 2b The electronic state of the metal M can be controlled via the nitrogen atom, and can be selected without being limited within the above range. From the viewpoint of increasing the yield of the ligand synthesis, it is preferable to select a hydrogen atom.

[0033] R 3a , R 3b , R 3c , R 3d , R 3e , R 3f , R 3g and R 3h each independently represents a substituent selected from the group consisting of a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 30 carbon atoms, a hydrocarbon group having 1 to 30 carbon atoms substituted with a halogen atom, an alkoxy group substituted with a hydrocarbon group having 1 to 4 carbon atoms, a hydrocarbon group having 2 to 30 carbon atoms substituted with an alkoxy group, and a silyl group substituted with a hydrocarbon group having 1 to 30 carbon atoms. In order to reduce the steric bulkiness of the entire ligand, a hydrogen atom is preferable. In particular, R 3d and R 3e is a hydrogen atom, R 1a ~R 1d This is preferable because it is easy to control the steric state by R. 3a and R 3e It is preferable that R is a hydrogen atom, since this makes it easier to synthesize the ligand. 3a ~R 3h When any of R has a group other than a hydrogen atom as a substituent, 3b and R 3g In terms of availability, those having a substituent at R are preferred. 3b , R 3c ,R 3g ,R 3h From the viewpoint of improving the solubility of the entire complex, is preferably a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, or a halogen atom.

[0034] R 4a and R 4beach independently represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, or R 4a and R 4b may be linked to each other to form a ring. They can be selected without limitation within the above range depending on the synthesis raw materials of the ligand. 4a and R 4b When R are bonded to each other to form a ring, the ring structure may be any of an alicyclic ring, a heterocyclic ring, and an aromatic ring. The number of ring members is preferably 5 to 8. From the viewpoint of synthesis cost, R 4a and R 4b When both are hydrogen atoms or both are methyl groups, it is advantageous in terms of procuring raw materials.

[0035] L independently represents an auxiliary ligand for a metal selected from a neutral monodentate ligand or an anionic monodentate ligand in each occurrence. An example of a neutral monodentate ligand is a ligand that is electrically neutral and can form a coordinate bond by coordinating an unpaired electron to a central metal M, and is a molecule having a nitrogen atom, a phosphorus atom, an arsenic atom, an oxygen atom, a sulfur atom, a selenium atom, or the like having an unpaired electron. Another example is a molecule such as ethylene that forms a π-donor bond by donating a π-electron. Examples of neutral monodentate ligands that can be used as L include those known as neutral ligands for metal complexes, such as acetonitrile, isonitrile, carbon monoxide, ethylene, and tetrahydrofuran. An example of an anionic monodentate ligand is a ligand that can formally donate an even number of electrons to a metal atom, and examples thereof include halogens, alkyl groups, aryl groups, alkoxides, amides, and silyl groups. Among these, neutral monodentate ligands with weak coordinating power are preferred because they tend to lead to high catalytic activity. In particular, acetonitrile and ethylene are preferred.

[0036] X is absent or a counter anion species with a valence of -1 or 2. When M is iron or ruthenium with a valence of +2 and both L are anionic monodentate ligands, or when M is cobalt or rhodium with a valence of +1 and one of L is an anionic monodentate ligand, X is absent. When X is present, its valence and the type of anion species are selected according to the valence of the complex portion composed mainly of metal M. Examples of -1 anion species include halide ions, NO 2 , and the like. 3 - , SbF 6 - , P.F. 6 - , B.F. 4 - , B(C 6 F 5 ) 4 - , etc. Examples of divalent anion species include SO 4 2- , S.O. 3 2- , CO 3 2- , FeCl 4 2- Among them, SbF has a weak coordination ability with metals. 6 - , P.F. 6 - , B.F. 4 - , B(C 6 F 5 ) 4 - , etc. are desirable from the standpoint of catalytic activity.

[0037] Preferable specific examples of the transition metal complex having a tetradentate ligand represented by the general formula (1) include the following compounds. These are illustrative only and it is obvious that the present invention is not limited to these.

[0038] [ka]

[0039] <Synthesis of metal complexes> (1) Basic synthetic route The synthesis of the transition metal complex used in the method of the present invention can be carried out using a method known to those skilled in the art. That is, the transition metal complex can be obtained by reacting a compound that is a ligand with a complex precursor containing a transition metal. Conditions such as reaction temperature, reaction solvent, atmosphere, and time can be appropriately selected from known conditions depending on the ligand and complex precursor used. Since many of them are unstable to water and oxygen, it is preferable to carry out the reaction in a dehydrated and deoxygenated atmosphere. The synthesis method of the ligand can also be a method known to those skilled in the art. As a specific example, when the structure of the ligand contains a phosphine and an imine, a method of condensing an amine compound with an aldehyde having a phosphine as a raw material can be mentioned. The synthesis route of the metal complex obtained by reacting a complex precursor with a ligand can be arbitrarily determined from the structure of the target compound.

[0040] (2) Complex Precursor The complex precursor is a transition metal compound of Group 8 to 9. Preferred specific examples are compounds or complexes of divalent iron or ruthenium, monovalent or trivalent cobalt or rhodium, particularly metal halides such as iron chloride, cobalt chloride, and ruthenium chloride; acetates such as iron acetate and cobalt acetate; and complexes having ligands such as carbonyl, triphenylphosphine, acetylacetone, η4-cyclooctadiene, acetonitrile, and pyridine.

[0041] (3) Reaction with complex precursor The amount of the complex precursor used in the preparation of the transition metal complex used in the method of the present invention is usually in the range of 0.5 mol to 3 mol, preferably 0.7 mol to 1.5 mol, per mol of the ligand. The reaction between the ligand and the complex (complex synthesis reaction) may be carried out in a reactor used for copolymerization with α-olefin, or in a vessel separate from the reactor. After the complex synthesis reaction, the complex may be isolated and extracted before use as a catalyst, or may be used as a catalyst without being isolated. In either case, it is desirable to determine the purity of the complex by NMR measurement.

[0042] <Second component> In a further embodiment, the olefin polymerization catalyst of the present invention may be a composition containing, as component (A), a transition metal complex represented by the above general formula (1) or a transition metal complex having a ligand represented by general formula (2) or (3), and, as component (B), a compound that reacts with component (A) to form an ion pair or an ion-exchangeable layered silicate.

[0043] (1) A compound that reacts with component (A) to form an ion pair An example of a compound that is one of the components (B) and reacts with the component (A) to form an ion pair is an organoaluminum oxy compound. The organoaluminum oxy compound has an Al-O-Al bond in the molecule, and the number of bonds is usually in the range of 1 to 100, preferably 1 to 50. Such an organoaluminum oxy compound is usually a product obtained by reacting an organoaluminum compound with water. The reaction of organoaluminum with water is usually carried out in an inert hydrocarbon (solvent). Examples of the inert hydrocarbon that can be used include aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons such as pentane, hexane, heptane, cyclohexane, methylcyclohexane, benzene, toluene, and xylene, but it is preferable to use aliphatic hydrocarbons or aromatic hydrocarbons.

[0044] As the organoaluminum compound used in the preparation of the organoaluminum oxy-compound, any compound represented by the following general formula can be used, but trialkylaluminum is preferably used. (R 1 ) t Al(X 3 ) (3-t) (In the above formula, R 1 represents a hydrocarbon group having 1 to 18 carbon atoms, preferably 1 to 12 carbon atoms, such as an alkyl group, an alkenyl group, an aryl group, or an aralkyl group; X 3 represents a hydrogen atom or a halogen atom, and t represents an integer of 1≦t≦3. The alkyl group of the trialkylaluminum may be any of methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, octyl, decyl, and dodecyl groups, but is preferably methyl or isobutyl, and particularly preferably methyl. The above organoaluminum compounds may be used in combination of two or more kinds.

[0045] The reaction ratio of water to the organoaluminum compound (water / Al molar ratio) is preferably 0.25 / 1 to 1.2 / 1, particularly 0.5 / 1 to 1 / 1, and the reaction temperature is usually in the range of -70°C to 100°C, preferably -20°C to 20°C. The reaction time is usually selected in the range of 5 minutes to 24 hours, preferably 10 minutes to 5 hours. As the water required for the reaction, not only simple water but also crystal water contained in copper sulfate hydrate, aluminum sulfate hydrate, etc., or a component that can generate water in the reaction system can be used. Among the above-mentioned organoaluminum oxy compounds, those obtained by reacting alkylaluminum with water are usually called aluminoxanes, and in particular, methylaluminoxane (including those substantially composed of methylaluminoxane (MAO)) is suitable as an organoaluminum oxy compound. Solid dry methylaluminoxane (DMAO) obtained by distilling off the solvent from the MAO solution is also suitable. Of course, two or more of the above-mentioned organoaluminum oxy compounds may be used in combination as the organoaluminum oxy compound, and a solution in which the organoaluminum oxy compound is dissolved or dispersed in the above-mentioned inert hydrocarbon solvent may be used.

[0046] Other specific examples of component (B) include borane compounds and borate compounds. More specific examples of the borane compounds include triphenylborane, tri(o-tolyl)borane, tri(p-tolyl)borane, tri(m-tolyl)borane, tris(o-fluorophenyl)borane, tris(p-fluorophenyl)borane, tris(m-fluorophenyl)borane, tris(2,5-difluorophenyl)borane, tris(3,5-difluorophenyl)borane, tris(4-trifluoromethylphenyl)borane, tris(3,5-ditrifluoromethylphenyl)borane, tris(2,6-ditrifluoromethylphenyl)borane, tris(pentafluorophenyl)borane, tris(perfluoronaphthyl)borane, tris(perfluorobiphenyl)borane, tris(perfluoroanthryl)borane, and tris(perfluorobinaphthyl)borane.

[0047] Among these, tris(3,5-ditrifluoromethylphenyl)borane, tris(2,6-ditrifluoromethylphenyl)borane, tris(pentafluorophenyl)borane, tris(perfluoronaphthyl)borane, tris(perfluorobiphenyl)borane, tris(perfluoroanthryl)borane, and tris(perfluorobinaphthyl)borane are more preferred, and tris(2,6-ditrifluoromethylphenyl)borane, tris(pentafluorophenyl)borane, tris(perfluoronaphthyl)borane, and tris(perfluorobiphenyl)borane are even more preferred.

[0048] Moreover, to specifically express the borate compound, a first example is a compound represented by the following general formula: [L1-H] + [B(R2)(R3)(X4)(X5)] - In the above formula, L1 is a neutral Lewis base, and [L1-H] represents a Bronsted acid such as ammonium, anilinium, or phosphonium. Examples of ammonium include trialkyl-substituted ammonium such as trimethylammonium, triethylammonium, tripropylammonium, tri(t-butyl)ammonium, and tri(n-butyl)ammonium, and dialkylammonium such as di(n-propyl)ammonium and dicyclohexylammonium. Examples of anilinium include N,N-dialkylanilinium such as N,N-dimethylanilinium, N,N-diethylanilinium, and N,N-dimethyl-2,4,6-pentamethylanilinium. Further, examples of the phosphonium include triarylphosphonium and trialkylphosphonium, such as triphenylphosphonium, tributylphosphonium, tri(methylphenyl)phosphonium, and tri(dimethylphenyl)phosphonium.

[0049] In the above general formula, R2 and R3 are the same or different aromatic or substituted aromatic hydrocarbon groups containing 6 to 20, preferably 6 to 16, carbon atoms, which may be linked to each other by a bridging group, and the substituent of the substituted aromatic hydrocarbon group is preferably an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, etc., or a halogen such as fluorine, chlorine, bromine, or iodine. Furthermore, X4 and X5 are a hydride group, a halide group, a hydrocarbon group containing 1 to 20 carbon atoms, or a substituted hydrocarbon group containing 1 to 20 carbon atoms in which one or more hydrogen atoms are substituted by a halogen atom.

[0050] Specific examples of the compound represented by the above general formula include tributylammonium tetra(pentafluorophenyl)borate, tributylammonium tetra(2,6-ditrifluoromethylphenyl)borate, tributylammonium tetra(3,5-ditrifluoromethylphenyl)borate, tributylammonium tetra(2,6-difluorophenyl)borate, tributylammonium tetra(perfluoronaphthyl)borate, dimethylanilinium tetra(pentafluorophenyl)borate, dimethylanilinium tetra(2,6-ditrifluoromethylphenyl)borate, dimethylanilinium tetra(3,5-ditrifluoromethylphenyl)borate, dimethylanilinium tetra(2,6-difluorophenyl)borate, dimethylanilinium tetra(perfluoronaphthyl)borate, triphenylphosphonium tetra(pentafluorophenyl)borate, triphenylphosphonium tetra(2,6-ditrifluoromethylphenyl)borate, nyl)borate, triphenylphosphonium tetra(3,5-ditrifluoromethylphenyl)borate, triphenylphosphonium tetra(2,6-difluorophenyl)borate, triphenylphosphonium tetra(perfluoronaphthyl)borate, trimethylammonium tetra(2,6-ditrifluoromethylphenyl)borate, triethylammonium tetra(pentafluorophenyl)borate, triethylammonium tetra(2,6-ditrifluoromethylphenyl)borate, triethylammonium tetra(perfluoronaphthyl)borate, tripropylammonium tetra(pentafluorophenyl)borate, tripropylammonium tetra(2,6-ditrifluoromethylphenyl)borate, tripropylammonium tetra(perfluoronaphthyl)borate, tripropylammonium tetra(pentafluorophenyl)borate, dicyclohexylammonium tetraphenylborate, and the like can be exemplified.

[0051] Among these, tributylammonium tetra(pentafluorophenyl)borate, tributylammonium tetra(2,6-ditrifluoromethylphenyl)borate, tributylammonium tetra(3,5-ditrifluoromethylphenyl)borate, tributylammonium tetra(perfluoronaphthyl)borate, dimethylanilinium tetra(pentafluorophenyl)borate, dimethylanilinium tetra(2,6-ditrifluoromethylphenyl)borate, dimethylanilinium tetra(3,5-ditrifluoromethylphenyl)borate, and dimethylanilinium tetra(perfluoronaphthyl)borate are preferred.

[0052] A second example of the borate compound is represented by the following general formula: [L2] + [B(R2)(R3)(X4)(X5)] - In the general formula, L2 is a carbocation, a methyl cation, an ethyl cation, a propyl cation, an isopropyl cation, a butyl cation, an isobutyl cation, a t-butyl cation, a pentyl cation, a tropinium cation, a benzyl cation, a trityl cation, a sodium cation, a proton, etc. R2, R3, X4, and X5 are as defined above.

[0053] Specific examples of the above compounds include trityl tetraphenylborate, trityl tetra(o-tolyl)borate, trityl tetra(p-tolyl)borate, trityl tetra(m-tolyl)borate, trityl tetra(o-fluorophenyl)borate, trityl tetra(p-fluorophenyl)borate, trityl tetra(m-fluorophenyl)borate, trityl tetra(3,5-difluorophenyl)borate, trityl tetra(pentafluorophenyl)borate, trityl tetra(2,6-ditrifluoromethylphenyl)borate, trityl tetra(3,5-ditrifluoromethylphenyl)borate, trityl tetra(perfluoronaphthyl)borate, and tropinium tetraborate. Tropinium tetra(o-tolyl)borate, tropinium tetra(p-tolyl)borate, tropinium tetra(m-tolyl)borate, tropinium tetra(o-fluorophenyl)borate, tropinium tetra(p-fluorophenyl)borate, tropinium tetra(m-fluorophenyl)borate, tropinium tetra(3,5-difluorophenyl)borate, tropinium tetra(pentafluorophenyl)borate, tropinium tetra(2,6-ditrifluoromethylphenyl)borate, tropinium tetra(3,5-ditrifluoromethylphenyl)borate, tropinium tetra(perfluoronaphthyl)borate, NaBPh 4 , NaB(o-CH 3 -Ph) 4 , NaB(p-CH 3 -Ph) 4 , NaB(m-CH 3 -Ph) 4 , NaB(oF-Ph) 4 , NaB(pF-Ph) 4 , NaB(mF-Ph) 4 , NaB(3,5-F 2 -Ph) 4 , NaB(C 6 F 3 ) 4 , NaB(2,6-(CF 3 ) 2 -Ph) 4 , NaB(3,5-(CF 3 ) 2-Ph) 4 , NaB(C 10 F 7 ) 4 , H.B.P.h. 4 2-Diethyl ether, HB(3,5-F 2 -Ph) 4 2Diethyl ether, HB(C 6 F 5 ) 4 2-Diethyl ether, HB(2,6-(CF 3 ) 2 -Ph) 4 2-Diethyl ether, HB(3,5-(CF 3 ) 2 -Ph) 4 2Diethyl ether, HB(C 10 H 7 ) 4 An example is 2-diethyl ether.

[0054] Among these, trityl tetra(pentafluorophenyl)borate, trityl tetra(2,6-ditrifluoromethylphenyl)borate, trityl tetra(3,5-ditrifluoromethylphenyl)borate, trityl tetra(perfluoronaphthyl)borate, tropinium tetra(pentafluorophenyl)borate, tropinium tetra(2,6-ditrifluoromethylphenyl)borate, tropinium tetra(3,5-ditrifluoromethylphenyl)borate, tropinium tetra(perfluoronaphthyl)borate, NaB(C 6 F 3 ) 4 , NaB(2,6-(CF 3 ) 2 -Ph) 4 , NaB(3,5-(CF 3 ) 2 -Ph) 4 , NaB(C 10 F 7 ) 4 , HB(C 6 F 5 ) 4 2-Diethyl ether, HB(2,6-(CF 3 ) 2 -Ph) 42-Diethyl ether, HB(3,5-(CF 3 ) 2 -Ph) 4 2Diethyl ether, HB(C 10 H 7 ) 4 2-Diethyl ether is preferred.

[0055] Among these, trityl tetra(pentafluorophenyl)borate, trityl tetra(2,6-ditrifluoromethylphenyl)borate, tropinium tetra(pentafluorophenyl)borate, tropinium tetra(2,6-ditrifluoromethylphenyl)borate, NaB(C 6 F 3 ) 4 , NaB(2,6-(CF 3 ) 2 -Ph) 4 , HB(C 6 F 5 ) 4 2-Diethyl ether, HB(2,6-(CF 3 ) 2 -Ph) 4 2-Diethyl ether, HB(3,5-(CF 3 ) 2 -Ph) 4 2Diethyl ether, HB(C 10 H 7 ) 4 2-Diethyl ether is an example.

[0056] Among the above-listed compounds, the component (B) is preferably an aluminoxane or a boron compound.

[0057] (2) Ion-exchange layered silicate Further, a specific example of component (B) is an ion-exchangeable layered silicate (hereinafter, sometimes abbreviated as "silicate"). An ion-exchangeable layered silicate is a silicate compound that has a crystal structure in which faces formed by ionic bonds or the like are stacked in parallel with each other by binding forces, and the ions contained therein are exchangeable. Various types of silicate are known, and specific examples are described in "Clay Mineralogy" by Shiramizu Haruo, Asakura Publishing (1995). In the present invention, the ion-exchangeable layered silicate of component (B) is preferably one belonging to the smectite group, and specific examples thereof include montmorillonite, sauconite, beidellite, nontronite, saponite, hectorite, stevensite, etc. Among these, montmorillonite is preferred from the viewpoint of increasing the polymerization activity and molecular weight of the copolymer portion.

[0058] Most silicates are naturally produced as the main component of clay minerals, and therefore often contain impurities other than ion-exchangeable layered silicates (such as quartz and cristobalite), and the smectite group silicates used in the present invention may contain impurities. The silicate may be treated with an acid and / or a salt, in which case the corresponding acid and base may be mixed to form a salt in the reaction system.

[0059] As component (B), a mixture of the above-mentioned organoaluminum oxy compound with a borane compound, a borate compound, or an ion-exchangeable layered silicate can also be used. Furthermore, each of them can be used alone or in combination of two or more.

[0060] <Third component> Yet another embodiment of the present invention contains an alkylaluminum compound as component (C) in addition to the components (A) and (B). An example of the alkylaluminum compound used as component (C) is represented by the following general formula: Al(R4) a X (3-a) In the general formula, R4 represents a hydrocarbon group having 1 to 20 carbon atoms, X represents hydrogen, a halogen, an alkoxy group, or a siloxy group, and a represents a number greater than 0 and equal to or less than 3. Specific examples of the organoaluminum compound represented by the general formula include trialkylaluminums such as trimethylaluminum, triethylaluminum, tripropylaluminum, and triisobutylaluminum, and halogen- or alkoxy-containing alkylaluminums such as diethylaluminum monochloride and diethylaluminum monomethoxide.

[0061] Among these, triisobutylaluminum is preferred. Two or more of the above organoaluminum compounds may be used in combination. The above aluminum compounds may be modified with alcohol, phenol, or the like. Examples of these modifying agents include methanol, ethanol, 1-propanol, isopropanol, butanol, phenol, 2,6-dimethylphenol, and 2,6-di-t-butylphenol, and preferred specific examples are 2,6-dimethylphenol and 2,6-di-t-butylphenol.

[0062] <Method for preparing catalyst composition> In one embodiment of the present invention, the method for preparing an olefin polymerization catalyst includes, for example, contacting component (A) and, if necessary, components (B) and (C). The specific method, such as the contacting order, is not particularly limited, but the following methods can be exemplified. (i) A method in which component (A) is contacted with component (B) and then component (C) is added. (ii) A method in which component (A) is contacted with component (C) and then component (B) is added (iii) A method in which component (B) is contacted with component (C) and then component (A) is added. (iv) A method in which components (A), (B) and (C) are contacted simultaneously. Furthermore, among the components, different kinds of components may be used as a mixture, or may be contacted separately in a different order. This contact may be carried out not only during catalyst preparation, but also during prepolymerization with olefins or during olefin polymerization. Also, the components may be divided and contacted with each component, for example, by contacting component (B) with component (C) and then adding a mixture of component (A) and component (C).

[0063] The contact of the above components (A), (B), and (C) is preferably carried out in an inert gas such as nitrogen, and in an inert hydrocarbon solvent such as pentane, hexane, heptane, toluene, xylene, etc. The contact can be carried out at a temperature between -20°C and the boiling point of the solvent, and is particularly preferably carried out at a temperature between room temperature and the boiling point of the solvent.

[0064] <Polymerization method> (1) Monomer The above-mentioned olefin polymerization catalyst containing a group 8 or 9 complex can be used for homopolymerization of an α-olefin or copolymerization of two or more kinds of α-olefins. The α-olefins include those having 2 to 30 carbon atoms, preferably 2 to 8 carbon atoms, and specific examples thereof include ethylene, propylene, 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene. More preferred are ethylene and propylene. The α-olefins can also be copolymerized with two or more kinds of α-olefins. The copolymerization may be any of alternating copolymerization, random copolymerization, and block copolymerization. Of course, it is also possible to use a small amount of a comonomer other than an α-olefin. In this case, examples of the comonomer include compounds having a polymerizable double bond, such as styrenes such as styrene, 4-methylstyrene, and 4-dimethylaminostyrene; dienes such as 1,4-butadiene, 1,5-hexadiene, 1,4-hexadiene, and 1,7-octadiene; cyclic compounds such as norbornene and cyclopentene; and oxygen-containing compounds such as hexenol, hexenoic acid, methyl octenoate, methyl acrylate, methyl methacrylate, methoxystyrene, and vinyl acetate.

[0065] (2) Polymerization method The polymerization reaction can be carried out in the presence of the above-mentioned olefin polymerization catalyst, preferably by slurry polymerization, bulk polymerization, or gas phase polymerization. In the case of slurry polymerization, ethylene or the like is polymerized in the presence of an inert hydrocarbon solvent selected from aliphatic hydrocarbons such as isobutane, hexane, and heptane, aromatic hydrocarbons such as benzene, toluene, and xylene, and alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, in a state substantially free of oxygen and water. Bulk polymerization in which liquid monomers such as liquid ethylene and liquid propylene are also used as a solvent is also one of the preferred modes.

[0066] The polymerization conditions are generally a temperature of 0°C to 250°C, preferably 20°C to 110°C, and more preferably 60°C to 100°C, a pressure of normal pressure to 10 MPa, preferably normal pressure to 4 MPa, and more preferably 0.5 MPa to 2 MPa, and a polymerization time of 5 minutes to 10 hours, and preferably 5 minutes to 5 hours.

[0067] The polymerization system can be carried out without any trouble even if a component for removing water, that is, a so-called scavenger, is added to the polymerization system. As the scavenger, organic aluminum compounds such as trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-octylaluminum, the above-mentioned organic aluminum oxy compounds, modified organic aluminum compounds containing branched alkyl, organic zinc compounds such as diethylzinc, dibutylzinc, organic magnesium compounds such as diethylmagnesium, dibutylmagnesium, ethylbutylmagnesium, and Grignard compounds such as ethylmagnesium chloride, butylmagnesium chloride, etc. are used. Of these, triethylaluminum, triisobutylaluminum, ethylbutylmagnesium, and tri-n-octylaluminum are preferred, with triethylaluminum and triisobutylaluminum being particularly preferred.

[0068] The olefin polymerization catalyst of the present invention can also be used without any problems in a multi-stage polymerization method having two or more stages in which the polymerization conditions are different from each other. EXAMPLES

[0069] The present invention will be specifically described below with reference to examples, to demonstrate the rationality and significance of the configuration of the present invention and its superiority over the prior art.

[0070] <Evaluation method>

[0071] (1) NMR measurements of metal complexes [Sample preparation] In a nitrogen-substituted glove box, 20 mg of the complex sample, 0.7 ml of deuterated acetonitrile, and 5.0 mg of tris(orthotoluyl)phosphine as an arbitrary internal standard were placed in an NMR sample tube with an inner diameter of 5 mm, sealed, and then stirred at room temperature for 10 minutes to dissolve uniformly. 31 P-NMR and 1 It was used for H-NMR measurements. [ 31 P-NMR measurement] The NMR measurements were performed using an AV400 NMR instrument manufactured by Bruker Japan Ltd. equipped with a normal probe having a diameter of 5 mm. 31 The P-NMR measurement conditions were a sample temperature of 30°C, a pulse angle of 45°, a pulse interval of 2.76 seconds, and an accumulation count of 256. The chemical shift was determined based on the external standard of the instrument. The purity of the complex was calculated by calculating the molar concentration of the complex from the peak area ratio with the internal standard substance, and converting this into the complex concentration in 20 mg of sample. However, when there was only one peak originating from the target complex, the purity was determined to be 100%. [ 1 H-NMR measurement] The NMR measurements were performed using an AV400 NMR instrument manufactured by Bruker Japan Ltd. equipped with a normal probe having a diameter of 5 mm. 1 The H-NMR measurement conditions were a sample temperature of 30°C, a pulse angle of 45°, a pulse interval of 2.76 seconds, and an accumulation number of 16. The chemical shift was determined based on the acetonitrile peak in deuterated acetonitrile. (2) Molecular weight and molecular weight distribution (Mw, Mn, Q value) (Measurement conditions) Model used: Waters 150C Detector: FOXBORO MIRAN1A IR detector (measurement wavelength: 3.42 μm) Measurement temperature: 140°C Solvent: orthodichlorobenzene (ODCB) Column: Showa Denko AD806M / S (3 columns) Flow rate: 1.0 mL / min Injection volume: 0.2 mL (Sample Preparation) A 1 mg / mL solution of the sample was prepared using ODCB (containing 0.5 mg / mL BHT (2,6-di-t-butyl-4-methylphenol)), and dissolved at 140° C. for about 1 hour. (Calculation of molecular weight) The standard polystyrene method was used, and the conversion from retention volume to molecular weight was performed using a calibration curve prepared in advance using standard polystyrene. All of the standard polystyrenes used were brands manufactured by Tosoh Corporation, namely F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, and A1000. A calibration curve was prepared by injecting 0.2 mL of a solution in which each was dissolved in ODCB (containing 0.5 mg / mL BHT) so that the concentration was 0.5 mg / mL. A cubic equation obtained by approximating the calibration curve using the least squares method was used. The viscosity equation used for conversion to molecular weight is [η] = K × M α The following values ​​were used: PS:K = 1.38 x 10 -4 , α=0.7 PE:K = 3.92 x 10 -4 , α=0.733 PP:K = 1.03 x 10 -4 , α=0.78

[0072] The synthetic route of the transition metal complex of the present invention is shown below. For the synthesis, reference was made to the non-patent document: Sui-Seng et al. Angew. Chem. Int. Ed. 2008, 47, 930. In the following synthesis examples, unless otherwise specified, the operations were carried out under an inert gas atmosphere, and the solvents used were dehydrated and deoxygenated.

[0073] Example 1 (1) Synthesis Example 1: Complex A [ka] 300 mg (0.455 mmol) of (S,S)-N,N-bis[2-(diphenylphosphino)benzylidene]cyclohexane-1,2-diamine was weighed out in a Schlenk flask, and 10 mL of acetonitrile was added. 115 mg (0.91 mmol) of iron(2) chloride dissolved in 2 mL of acetonitrile was added at room temperature and stirred for 1 hour. After that, the solvent was distilled off leaving about 2 mL, and the residue was washed with 20 mL of ether. After washing, the solvent was completely distilled off, 15 mL of chloroform was added, and insoluble matter was removed with a glass filter. The collected solution was completely dried and recrystallized with 5 mL of chloroform and 20 mL of hexane to obtain 211 mg of solid. This complex A 31 P-NMR( 31 P-NMR (162MHz, CD 3 The chart of CN) is shown in Figure 1. 1 The H-NMR chart is shown in Figure 2. A sharp singlet peak was observed at 52.4 ppm. The purity was 100%.

[0074] (2) Polymerization example: Homopolymerization of ethylene Complex A (18 mg) was dissolved in 10 mL of toluene, to which 20 mL of MMAO-3A / hexane solution (Al = 5.9 wt%) was added, and the mixture was stirred at 25°C for 5 minutes to prepare a complex solution. 1000 mL of toluene was introduced into a 3 L stirring autoclave, followed by the addition of 20 mL of the MMAO-3A / hexane solution. The inside of the reactor was replaced with ethylene, and the temperature was raised to 60°C. The pressure was raised to 2.5 MPa with ethylene. The previously prepared complex solution was poured into the mixture, and N 2 The ethylene pressure was maintained at 2.5 MPa for 60 minutes, and ethanol was injected to terminate the polymerization. The resulting slurry was poured into hydrochloric acid / ethanol, filtered, washed with ethanol, and dried to obtain 0.2 g of polymer. The melting point of the resulting polymer was 135.1°C, and the weight average molecular weight was 2,477,000.

[0075] Example 2 (1) Synthesis Example 2: Complex B [ka] 300 mg (0.50 mmol) of N,N-bis[o-(diphenylphosphino)benzylidene]ethylenediamine was weighed out in a Schlenk flask, and 11 mL of acetonitrile was added. 127 mg (1.0 mmol) of iron(II) chloride dissolved in 3 mL of acetonitrile was added at room temperature and stirred for 3 hours. After that, the solvent was distilled off leaving about 1 mL, and 30 mL of ether was added to the residue to precipitate, and the precipitate was collected using a glass filter. The precipitate was washed with 15 mL of chloroform and then recrystallized with 1.2 mL of chloroform and 6 mL of hexane to obtain 114 mg of a solid (complex B). This complex B 31 P-NMR( 31 P-NMR (162MHz, CD 3 The chart of CN) is shown in Figure 3. 1 The H-NMR chart is shown in Figure 4. 31 A sharp singlet peak was observed at 53.5 ppm from P-NMR. Since no peaks other than those of the complex were observed, it was confirmed that the complex prepared this time was of high purity. The purity was 100%.

[0076] (2) Polymerization example: Homopolymerization of ethylene Ethylene polymerization was carried out in the same manner as in Polymerization Example 1(2) except that the complex used was changed to Complex B. The amount of polyethylene obtained was 0.84 g. The weight average molecular weight of the obtained polymer was 539,000.

[0077] Comparative Example 1 The Fe(II) complex having the pyridyldiimine ligand described in Non-Patent Document 2 was synthesized according to Non-Patent Document 2. 1 H-NMR measurement was attempted, but was unsuccessful due to magnetism, and the purity of the complex could not be determined by NMR measurement. Comparative Example 2 The Fe(III) complex having the bisoxazolidylphenylamine ligand described in Example 1 of Patent Document 4 was synthesized according to Patent Document 4.1 H-NMR measurement was attempted, but was unsuccessful due to magnetism, and the purity of the complex could not be determined by NMR measurement.

Claims

1. A method for producing an olefin polymer, comprising a step of polymerizing an olefin monomer using, as a polymerization catalyst component, a catalyst containing a complex represented by the following general formula (1) having a low-spin metal atom of Group 8 or 9 of the periodic table: 【Chemistry 8】 [In general formula (1), M is iron with an oxidation state of +2, ruthenium with an oxidation state of +2, cobalt with an oxidation state of +1, or rhodium with an oxidation state of +1; n represents an integer of 0 or 1; R 1a , R 1b , R 1c and R 1d each independently represent a hydrocarbon group having 3 to 12 carbon atoms; R 2a and R 2b each independently represent a hydrogen atom or a hydrocarbon having 1 to 3 carbon atoms; R 3a , R 3b , R 3c , R 3d , R 3e , R 3f , R 3g and R 3h each independently represent a substituent selected from the group consisting of a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 30 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a hydrocarbon group having 1 to 30 carbon atoms substituted with a halogen atom, a hydrocarbon group having 2 to 30 carbon atoms substituted with an alkoxy group, and a silyl group substituted with a hydrocarbon group having 1 to 30 carbon atoms; R 4a and R 4b each independently represent a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms, or R 4a and R 4b are bonded to each other to form a ring; L represents a metal auxiliary ligand, and when M is iron having an oxidation number +2 or ruthenium having an oxidation number +2, one of them is a neutral monodentate ligand and the other is an anionic monodentate ligand, or both are neutral monodentate ligands, when M is cobalt having an oxidation number +1 or rhodium having an oxidation number +1, both are neutral monodentate ligands; X is a counter anion species having a valence of −1 or 2.

2. 2. The method for producing an olefin polymer according to claim 1, wherein M is iron having an oxidation number of +2 or ruthenium having an oxidation number of +2.

3. 3. The process for producing an olefin polymer according to claim 1 or 2, wherein the weight average molecular weight of the obtained olefin polymer is 100,000 or more and 10,000,000 or less.

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