JP2024080694A - Compound, metal complex, method for producing metal complex, catalyst for olefin polymerization, method for producing (co)polymer, and ethylene/undecenoic acid ester copolymer - Google Patents

Abstract

[Problem] To provide a transition metal complex catalyst for copolymerizing an olefin with a polar monomer, which has high catalytic activity and gives a high-content olefin/polar monomer copolymer, and a method for producing said copolymer. [Solution] A compound represented by the following general formula (1): [Chemical 1]JPEG2024080694000049.jpg3866 (In the formula, R1 to R5 are each independently hydrogen, halogen, a group containing a heteroatom, or an organic group. R6 is a phenyl group having substituents at at least two of the 2- to 6-positions.) [Selected Figure] None

Description

The present invention relates to a compound, a metal complex, a method for producing a metal complex, a catalyst for olefin polymers, a method for producing a (co)polymer, and an ethylene/undecenoic acid ester copolymer.

Olefin polymers have excellent mechanical properties and are used in the fields of various molded bodies and films. Meanwhile, methods for introducing polar groups into olefin polymers have been developed to impart various functions to the polymers. A representative method is to obtain polar group-containing olefin copolymers by radical polymerization of olefins and polar group-containing vinyl monomers (hereinafter referred to as "polar monomers") at high temperature and pressure, and ethylene-acrylic acid ester copolymers, ethylene-vinyl acetate copolymers, etc. have been synthesized.
In addition, techniques for introducing polar groups by post-modification have also been developed, and known examples include chlorinated polypropylene and maleic anhydride-modified polypropylene. However, because the synthesis of these polar group-containing polymers utilizes radical reactions, many branches exist in the main chain, and the positions and amounts of the branches are generally difficult to control.

As a method for obtaining a polar group-containing olefin polymer without using a radical reaction, a copolymerization reaction of an olefin with a polar monomer using a transition metal complex as a catalyst is known.
For example, Brookhart et al. have reported a method of copolymerizing olefins such as ethylene with polar monomers such as acrylates and olefins containing long-chain esters using a palladium diimine complex (Non-Patent Document 1). Grubbs et al. have reported a method of copolymerizing ethylene with polar group-containing norbornene using a nickel phenoxyimine complex (Non-Patent Document 2).

It is generally known that polar groups in polar monomers interact with the central metal, reducing the catalytic activity of the copolymerization reaction or deactivating the catalyst. It is known that the strength of the interaction between the polar group in a polar monomer and the central metal is greatly affected by the type and valence of the central metal. Early transition metal complex catalysts generally have too high an affinity for donor atoms such as oxygen and nitrogen, which tends to lead to catalyst deactivation, and it is necessary to use methods such as those with bulky substituents on the polar group or adding a large amount of alkyl aluminum to protect the polar group (Non-Patent Documents 3 and 4).

On the other hand, higher transition metal complex catalysts do not have a higher affinity for polar groups than early transition metal complex catalysts, so more common polar monomers can be used. For example, it is known that nickel phosphine phenolate catalysts promote the copolymerization of ethylene/acrylic esters and the copolymerization of propylene/acrylic esters (Patent Documents 1-4, Non-Patent Documents 5-8). However, the copolymerization of olefins and polar monomers still tends to be less active than homopolymerization using only olefins. In this context, there is a demand for the development of an olefin/polar monomer copolymerization catalyst that has the polymerization activity to be deployed on an industrial scale and can efficiently incorporate polar groups, as well as the emergence of a manufacturing method, and vigorous research has continued to this day.

To date, many nickel-palladium catalysts that show catalytic activity for olefin/polar monomer copolymerization have been reported. Most of them have bidentate ligands. Pyridine oxide phosphine ligands are also a type of bidentate ligand, and in 2020, Jian et al. showed that a nickel complex catalyst having the same ligand showed activity of up to 3.50 × 10 ⁵ g/mol h in the copolymerization of ethylene and methyl undecenoate, and also gave a polymer with a maximum content of 1.2 mol% (Non-Patent Document 9).

International Publication No. 2010/050256 U.S. Pat. No. 6,559,326 JP 2005-307021 A JP 2018-24646 A

M. Brookhart et al. J. Am. Chem. Soc. 1995, 117, 6414. R. H. Grubbs et al. Science 2000, 287, 460. T. J. Marks et al. Angew. Chem. Int. Ed. 2020, 59,20522. J. Imuta et al. J. Am. Chem. Soc. 2002, 124, 1176. J. Heinicke et al. Chem. Eur. J. 2003, 9, 6093. B. S. Xin et al. J. Am. Chem. Soc. 2017, 139, 3611. Y. Konishi et al. ACS Macro Lett. 2018, 7, 213. J. Heinicke et al. Eur. J. Inorg. Chem. 2000, 3, 431. Z. Jian et al. Polymer 2020, 194, 122410.

In the above-mentioned documents, the catalytic activity in particular cannot be said to be sufficient for application on an industrial scale, and further improvement in activity is desired. The present invention aims to provide a transition metal complex catalyst for copolymerizing an olefin and a polar monomer, which has high catalytic activity and gives an olefin/polar monomer copolymer having a high content of polar groups, as well as a method for producing said copolymer. The present invention also aims to provide a compound for producing the above-mentioned metal complex catalyst, a metal complex using said compound, and a method for producing said metal complex.

As a result of intensive research aimed at solving the above problems, the inventors have found that a pyridine oxide phosphine ligand with a novel structure and several complex catalysts having the same ligand are more active than reported catalysts, for example, in the copolymerization reaction of ethylene with undecenoic acid ester, and at the same time, the content of undecenoic acid ester in the polymer is high. The present invention was completed based on the above findings.

That is, the present invention relates to the following.
[1] A compound represented by the following general formula (1):

(In the formula, R ¹ to R ⁵ are each independently a hydrogen atom, a halogen atom, a group containing a heteroatom, or an organic group. R ⁶ is a phenyl group having substituents at least at two positions among the 2-position to the 6-position.)

[2] The compound according to the above [1], wherein R ⁶ is a phenyl group having substituents at the 2- and 6-positions and represented by the following formula:

(In the formula, ^R7 and ^R8 are each independently a halogen, a group containing a heteroatom, or an organic group.)

[3] A metal complex represented by the following general formula (2):

(In the formula, M is Ni or Pd, R ¹ to R ⁶ are the same as those described in the general formula (1) above, R ¹⁰ is hydrogen, a halogen, a group containing a heteroatom or an organic group, and may be a monodentate ligand or a polydentate ligand. When R ¹⁰ is a monodentate ligand, L is a neutral Lewis base, and when R ¹⁰ is polydentate and coordinated to M, L may not be present. X is a counter anion.)

[4] A metal complex represented by the following general formula (3):

(In the formula, M is Ni or Pd, R ¹ to R ⁶ are the same as those defined in the general formula (1), R ²⁰ is hydrogen, a group containing a heteroatom, or an organic group, and X is a counter anion.)

[5] A metal complex represented by the following general formula (4):

(In the formula, M is Ni or Pd, R ¹ to R ⁶ are the same as those described in the general formula (1), R ³⁰ is a hydrogen, a halogen, a group containing a heteroatom or an organic group, and is monodentately coordinated to M, L is a neutral Lewis base, and X is a counter anion.)

[6] A method for producing a metal complex, comprising contacting the compound represented by the general formula (1) with a transition metal compound containing nickel or palladium to produce a metal complex represented by the general formula (3).
[7] A method for producing a metal complex represented by the general formula (4) by contacting the compound represented by the general formula (1) with a transition metal compound containing nickel or palladium.
[8] An olefin polymerization catalyst comprising the metal complex according to any one of [3] to [5] above.
[9] A method for producing a (co)polymer, comprising (co)polymerizing an olefin in the presence of the olefin polymerization catalyst according to the above [8].
[10] A method for producing a copolymer, comprising copolymerizing an olefin with a polar group-containing vinyl monomer in the presence of the olefin polymerization catalyst according to the above [8].
[11] The method for producing a copolymer according to the above [10], wherein the polar group-containing vinyl monomer contains an oxygen atom and/or a nitrogen atom.
[12] The method for producing a copolymer according to the above [10] or [11], wherein the olefin is ethylene and the polar group-containing vinyl monomer is an undecenoic acid ester.
[13] An ethylene/undecenoic acid ester copolymer synthesized by coordination copolymerization using a metal complex catalyst, having an alkyl branch derived from chain walk of 3/1000C or less, and containing an undecenoic acid ester content of 2 mol% or more and 50 mol% or less.

According to the present invention, it is possible to provide a transition metal complex catalyst that copolymerizes an olefin and a polar monomer, has high catalytic activity, and gives an olefin/polar monomer copolymer having a high content of polar groups, as well as a method for producing the copolymer. It is also possible to provide a compound for producing the metal complex catalyst, a metal complex using the compound, and a method for producing the metal complex.

The following describes in detail the embodiments of the present invention. Note that the following description is one example (representative example) of the embodiment of the present invention, and the present invention is not limited to these contents as long as it does not exceed the gist of the invention.

[Compound]
The compound of the present invention is a novel compound (ligand) represented by the following general formula (1). Such a pyridine oxide phosphine ligand and a plurality of complex catalysts having the same ligand have higher catalytic activity than conventional catalysts. For example, in the copolymerization reaction of ethylene and an undecenoic acid ester, the activity is superior to that of reported catalysts, and at the same time, the content of the undecenoic acid ester in the polymer is also high.

In general formula (1), R ¹ to R ⁵ are each independently (i) hydrogen, (ii) halogen, (iii) a group containing a heteroatom, or (iv) an organic group, and R ⁶ is a phenyl group having substituents at least at two positions among the 2-position to the 6-position.

The (ii) halogen includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these, a fluorine atom and a chlorine atom are preferred from the viewpoints of improving activity and suppressing side reactions during synthesis.
Examples of the heteroatom in the (iii) heteroatom-containing group include oxygen, nitrogen, phosphorus, sulfur, selenium, and silicon. Among these heteroatoms, oxygen, nitrogen, sulfur, and silicon are preferred from the viewpoint of improving activity.
Incidentally, (iii) the group containing a heteroatom may be a group consisting of a heteroatom or a group containing a heteroatom.

Specific examples of groups containing a hetero atom include OR ¹¹ , CO ₂ R ¹¹ , CO ₂ M', C(O)N(R ¹¹ ) ₂ , C(O)R ¹¹ , SR ¹¹ , SO ₂ R ¹¹ , SOR ¹¹ , OSO ₂ R ¹¹ , P(O)(OR ¹¹ ) _2-y (R ¹² ) _y , CN, NHR ¹¹ , N(R ¹¹ ) ₂ , Si(OR ¹² ) _3-x (R ¹² ) _x , OSi(OR ¹² ) _3-x (R ¹² ) _x , NO ₂ , SO ₃ M', PO ₃ M' ₂ , P(O)(OR ¹¹ ) ₂ M', and epoxy-containing groups. Here, R ¹² is hydrogen or a hydrocarbon group having 1 to 20 carbon atoms, and R ¹¹ is a hydrocarbon group having 1 to 20 carbon atoms. M' is an alkali metal, an alkaline earth metal, ammonium, a quaternary ammonium or a phosphonium, x is an integer from 0 to 3, and y is an integer from 0 to 2.

Specific examples of groups containing heteroatoms include methoxy groups, ethoxy groups, phenoxy groups, nitrile groups, trimethylsilyl groups, triethylsilyl groups, dimethylphenylsilyl groups, trimethoxysilyl groups, triethoxysilyl groups, trimethylsilyloxy groups, trimethoxysiloxy groups, cyclohexylamino groups, sodium sulfonate groups, potassium sulfonate groups, sodium phosphate groups, and potassium phosphate groups.

(iv) Suitable examples of the organic group include a methyl group, an ethyl group, an isopropyl group, a butyl group, a phenyl group, a trifluoromethyl group, a pentafluorophenyl group, a carbazolyl group, a naphthyl group, an anthracenyl group, a 2,6-diisopropylphenyl group, a 2,6-diphenylphenyl group, etc. In addition, (iv) the organic group may have a heteroatom, and (iv) the organic group may be substituted with a group consisting of a heteroatom and/or a group containing a heteroatom, as shown in (iii).
The total number of carbon atoms in each of the substituents of the organic group which may have a heteroatom is preferably 1 to 30, more preferably 1 to 20, and even more preferably 4 to 15. Examples of the organic group include a linear alkyl group, a non-cyclic alkyl group, an alkenyl group, a cycloalkyl group which may have a side chain, an aryl group, an arylalkyl group, and an alkylaryl group.
Incidentally, (iv) the organic group may have a heteroatom, but (iii) and (iv) are not the same.

R ⁶ in the above formula (1) is a phenyl group having substituents at at least two positions among the 2-position to the 6-position. It is sufficient that at least two positions among the 2-position to the 6-position have substituents, and they may be, for example, the 2-position and the 6-position (ortho-position), or the 3-position and the 4-position (meta-position). It may also have substituents at three or more positions, and may be, for example, a tri-substituted compound having substituents at the 2-position, the 4-position, and the 6-position (ortho-position and para-position).
Examples of the substituent in ^R6 include halogens, groups containing heteroatoms, and organic groups. The halogens, groups containing heteroatoms, and organic groups are the same as the specific examples given for ^R1 to ^R5 in the formula (1).
Of these, a disubstituted phenyl group having substituents at the 2- and 6-positions and represented by the following formula is most preferred in terms of fully achieving the effects of the present invention.

In the above formula, ^R7 and ^R8 are each independently a halogen, a group containing a heteroatom, or an organic group. The halogen, the group containing a heteroatom, and the organic group are the same as the specific examples given for ^R1 to ^R5 in the above formula (1). Among these, from the viewpoint of improving the catalytic activity, a group containing a heteroatom is preferred, and ^OR11 is more preferred.
R ¹ in the above formula (1) is selected from the above (i) to (iv). R ¹ is a substituent that is adjacent to the metal center when a metal complex is formed, and the substituent is selected taking into consideration steric influences, and preferably, a t-butyl group or an aryl group having the above-described (iv) organic group as a substituent at the 2- and 6-positions is selected.
In addition, R ² to R ⁴ in the above formula (1) are selected from the above (i) to (iv), and are preferably hydrogen.
^R5 in the above formula (1) is selected from the above (i) to (iv). In order to fully achieve the effects of the present invention, it is preferably a di-substituted phenyl group having substituents at the 2- and 6-positions, similar to ^R6 .
Specific combinations of substituents and the like in the general formula (1) according to the present invention are shown in the following Table 1. However, the specific examples are not limited to the following examples.

In Table 1, MeO is a methoxy group, Ph is a phenyl group, tBu is a tertiary butyl group, Ad is an adamantyl group, Cy is a cyclohexyl group, PhO is a phenoxy group, EtO is an ethoxy group, iPrO is an isopropoxy group, and t-BuO is a tertiary butoxy group.

Examples of compounds represented by general formula (1) include the following formulas (1-a) and (1-b):

In the above formulas (1-a) and (1-b), DMP represents a 2,6-dimethoxyphenyl group, iPr represents an isopropyl group, and tBu represents a tertiary butyl group.

The methods for producing the compounds represented by the above formulas (1-a) and (1-b) are described in detail in the Examples.

[Metal complex and method for producing the metal complex]
A first embodiment of the metal complex of the present invention is a metal complex represented by the following formula (2): The metal complex can be obtained by contacting and reacting a compound represented by the above general formula (1) (hereinafter, sometimes referred to as a "pyridine oxide phosphine compound") with a transition metal compound containing nickel or palladium (hereinafter, sometimes referred to as a "nickel-palladium compound").

In general formula (2), M is Ni (nickel) or Pd (palladium). R ¹ to R ⁶ are the same as those described in general formula (1). R ¹⁰ is hydrogen, halogen, a group containing a heteroatom, or an organic group. The hydrogen, halogen, group containing a heteroatom, or an organic group are the same as those described in general formula (1) above.
Since R ¹⁰ is an initiating group for the polymerization reaction, it is required to efficiently add to the olefin of the monomer. From the above viewpoint, it is preferably one which provides a metal-carbon bond, and more preferably an alkyl group or an aryl group.
When R ¹⁰ is a monodentate ligand, L is a neutral Lewis base, and when R ¹⁰ is coordinated to M in a polydentate manner, L may not be present.
X is a counter anion. The counter anion may be any anion that pairs with the cationic complex and neutralizes the metal complex of general formula (2). X may be an atomic anion, a molecular anion, a polymeric anion, or an anionic carrier surface. The anion is not limited to a monoanion, and may be a dianion or a higher anion. In this case, the amount of anion present is such that the entire general formula (2) is neutral.
Preferred are tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, tetrakis[pentafluorophenyl]borate, hexafluorophosphate, tetrafluoroborate, tetraphenylborate, trifluoromethanesulfonate, bis(trifluoromethylsulfonyl)imide, hexafluoroantimonate, and perchlorate. Particularly preferred are tetrakis[3,5-bis(trifluoromethyl)phenyl]borate and tetrakis[pentafluorophenyl]borate.

Examples of the Lewis base include aromatic amines, aliphatic amines, alkyl ethers, aryl ethers, alkylaryl ethers, cyclic ethers, alkyl nitriles, aryl nitriles, alcohols, amides, aliphatic esters, aromatic esters, phosphates, phosphites, thiophenes, thianthrenes, thiazoles, oxazoles, morpholines, cyclic unsaturated hydrocarbons, etc. Among these, particularly preferred Lewis bases are aromatic amines, aliphatic amines, cyclic ethers, aliphatic esters, and aromatic esters, and particularly preferred Lewis bases are pyridine derivatives, pyrimidine derivatives, piperidine derivatives, imidazole derivatives, aniline derivatives, piperidine derivatives, triazine derivatives, pyrrole derivatives, furan derivatives, and aliphatic ester derivatives.
Among the above Lewis bases, aromatic amines and aliphatic amines are preferred in the present invention, and suitable examples thereof include aromatic amines such as pyridine.

The method for producing the metal complex represented by the general formula (2) includes contacting and reacting the compound represented by the general formula (1) (pyridine oxide phosphine compound) with a transition metal compound containing nickel or palladium (nickel-palladium compound), as described above.
The pyridine oxide phosphine compound and the nickel-palladium compound are contacted and reacted by mixing with each other, but the mixing conditions are not particularly limited. X represents a counter anion site required to pair with the cationic complex and become neutral as a whole, and may be derived from the nickel-palladium compound used to form the complex, or may be derived from the anion exchange reagent. The anion exchange reagent may be reacted with the complex represented by general formula (2), or may be added simultaneously when forming the complex of general formula (2). It is preferable to add an anion reagent simultaneously when forming the complex of general formula (2) to obtain a complex of general formula (2) having a desired counter anion.
Here, mixing means directly mixing these compounds or mixing them in a solution using a solvent. In particular, from the viewpoint of achieving uniform mixing, it is preferable to use a solvent.
It is considered that the metal complex represented by the general formula (2) is produced by the reaction described above, but this does not deny that a metal complex having a structure other than that represented by the general formula (2) can be used for producing a polymer, similarly to the metal complex represented by the general formula (2).

Specific combinations of substituents and the like in the general formula (2) in the present invention are shown in the following Table 2. The combinations of R ¹ to R ⁶ can be arbitrarily selected from the combinations in Table 1. However, specific examples are not limited to the following examples.

An example of a method for synthesizing the metal complex of general formula (2) is the method shown in the following reaction formula (5). Note that this example shows the case where the Lewis base is pyridine (py).

In the above formula (5), NaBArF is sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate. This manufacturing method makes it possible to synthesize a py complex from a pyridine oxide phosphine compound in which an aryl (DMP) is bonded to P.

The second aspect of the present invention is a metal allyl complex represented by the following general formula (3). The metal allyl complex can be synthesized from the compound (ligand) of the present invention represented by general formula (1) by the method for synthesizing a metal complex used in Non-Patent Document 9. In addition, in formula (3), ")>" means "π-allyl structure".

Here, M in the above formula (3) is Ni or Pd. R ¹ to R ⁶ are the same as those described in the general formula (1). R ²⁰ is hydrogen, halogen, a group containing a heteroatom, or an organic group. The hydrogen, halogen, group containing a heteroatom, or an organic group are the same as those described in the above formula (1).
From the viewpoint of promoting the insertion reaction of an olefin, R ²⁰ is preferably hydrogen or an organic group, more preferably hydrogen or a hydrocarbon group having 1 to 4 carbon atoms.
X is a counter anion. The counter anion is the same as that described in the above formula (2).
The metal allyl complex represented by the general formula (3) can be synthesized from the compound (ligand) of the present invention represented by the general formula (1) by a conventional method for synthesizing a metal complex.
More specifically, a metal allyl complex represented by formula (3) can be synthesized from compound (1) of the present invention by the method represented by formula (7) below. Note that, although an example using Ni as the metal is shown here, a palladium complex can also be obtained by a similar reaction using Pd.

The third aspect of the present invention is a metal complex represented by the following general formula (4):

In the general formula (4), M is Ni or Pd, R ¹ to R ⁶ are the same as those described in the general formula (1), and R ³⁰ is a group containing hydrogen, halogen, or a heteroatom, or an organic group, which is monodentately coordinated to M. Since R ³⁰ is an initiating group for the polymerization reaction, it is required to be efficiently added to the olefin of the monomer. From the above viewpoint, it is preferably one which provides a metal-carbon bond, and an alkyl group or an aryl group is more preferable.
L is a neutral Lewis base, and X is a counter anion, which are the same as those described above. The hydrogen, halogen, group containing a hetero atom, or organic group in ^R30 is the same as ^R10 .

[Olefin polymerization catalyst]
The olefin polymerization catalyst of the present invention contains any one of the metal complexes (2) to (4). As described above, the metal complexes represented by the general formulas (2) to (4) can be formed by the reaction of the compound represented by the general formula (1) with a transition metal complex component. When the metal complexes represented by the general formulas (2) to (4) are used as the catalyst component, they may be isolated or generated in the reaction system. Furthermore, the metal complex may be supported on a carrier, and the support on the carrier may be performed in a reactor used for polymerization in the presence or absence of these monomers, or may be performed in a vessel separate from the reactor used for polymerization.

Any carrier can be used as long as it does not impair the gist of the present invention. In general, inorganic oxides and polymer carriers are preferably used. Specifically, SiO ₂ , Al ₂ O ₃ , MgO, ZrO _{2 , TiO 2 ,} B ₂ O ₃ , CaO, ZnO, BaO, ThO ₂ and the like or mixtures thereof can be mentioned, and mixed oxides such as SiO ₂ -Al ₂ O ₃ , SiO ₂ -V ₂ O ₅ , SiO ₂ -TiO ₂ , SiO ₂ -MgO, and SiO ₂ -Cr ₂ O ₃ can also be used, and inorganic silicates, polyethylene carriers, polypropylene carriers, polystyrene carriers, polyacrylic acid carriers, polymethacrylic acid carriers, polyacrylic acid ester carriers, polyester carriers, polyamide carriers, and polyimide carriers can be used. There are no particular limitations on the particle size, particle size distribution, pore volume, specific surface area, etc. of these carriers, and any one can be used.

As the inorganic silicate, clay, clay minerals, zeolite, diatomaceous earth, etc., can be used. These may be synthetic products or naturally occurring minerals.
Specific examples of clay and clay minerals include allophane group such as allophane, kaolin group such as dickite, nacrite, kaolinite, anoxite, halloysite group such as metahalloysite, halloysite, serpentine group such as chrysotile, lizardite, antigorite, smectite such as montmorillonite, sauconite, beidellite, nontronite, saponite, hectorite, vermiculite minerals such as vermiculite, mica minerals such as illite, sericite, glauconite, attapulgite, sepiolite, pyrogorskite, bentonite, kibushi clay, gairome clay, hisingerite, pyrophyllite, ryokudeite group, etc. These may form a mixed layer.
Examples of artificial synthetic substances include synthetic mica, synthetic hectorite, synthetic saponite, and synthetic taeniolite.
Among these specific examples, preferred are kaolin group such as dickite, nacrite, kaolinite, anoxite, etc.; halloysite group such as metahalloysite, halloysite, etc.; serpentine group such as chrysotile, lisardite, antigorite, etc.; smectites such as montmorillonite, sauconite, beidellite, nontronite, saponite, hectorite, etc.; vermiculite minerals such as vermiculite; mica minerals such as illite, sericite, glauconite, etc.; synthetic mica, synthetic hectorite, synthetic saponite, and synthetic taeniolite, and more preferred are smectites such as montmorillonite, sauconite, beidellite, nontronite, saponite, hectorite, etc.; vermiculite minerals such as vermiculite; synthetic mica, synthetic hectorite, synthetic saponite, and synthetic taeniolite.

These carriers may be used as they are, or may be treated with an acid such as hydrochloric acid, nitric acid, or sulfuric acid, and/or a salt such as LiCl, NaCl, KCl, _CaCl2 , _MgCl2 , _Li2SO4 , _MgSO4 , _ZnSO4 , Ti( _SO4 ) ₂ , Zr( _SO4 ) ₂ , or _Al2 ( _SO4 ) _{3 .} In this treatment, the corresponding acid and base may be mixed to generate a salt in the reaction system. Also, shape control such as pulverization or granulation, or drying treatment may be performed.

[Production method of (co)polymer]
One embodiment of the method for producing an olefin (co)polymer of the present invention is to polymerize or copolymerize (a) an olefin in the presence of the above-mentioned olefin polymerization catalyst. In the present invention, the term "polymerization" collectively refers to homopolymerization of one type of monomer and copolymerization of multiple types of monomers, and when there is no particular need to distinguish between the two, they are collectively referred to as "polymerization".
The component (a) in the present invention is ethylene or an olefin represented by the general formula: CH ₂ ═CHR ^13. Here, R ¹³ is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, which may have a branch, a ring, and/or an unsaturated bond. If the number of carbon atoms in R ¹³ is more than 20, sufficient polymerization activity tends not to be exhibited. For this reason, preferred components (a) include ethylene (R ¹³ is a hydrogen atom) or an α-olefin in which R ¹³ is a hydrocarbon group having 1 to 10 carbon atoms.
More preferred examples of the (a) component include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 3-methyl-1-butene, 4-methyl-1-pentene, vinylcyclohexene, and styrene. A single (a) component may be used, or a plurality of (a) components may be used in combination.

Another embodiment of the process for producing an α-olefin polymer of the present invention comprises copolymerizing (a) an olefin and (b) a polar monomer in the presence of the above-mentioned catalyst component for polymerization.
The component (a) is as described above, and may be a single component (a) or a plurality of components (a). The polar monomers of the component (b) of the present invention are the following (i) vinyl monomers, (ii) (meth)acrylic acid ester monomers, and (iii) allyl monomers. The metal complex catalyst of the present invention is particularly effective for copolymerizing olefins with polar group-containing vinyl monomers.

The vinyl monomer (i) is one having a polar group containing halogen, nitrogen, oxygen, sulfur, etc., and in the present invention, a vinyl monomer containing an oxygen atom and/or a nitrogen atom is particularly preferred. In addition, vinyl monomers containing halogen, hydroxyl group, amino group, nitro group, carboxyl group, formyl group, ester group, epoxy group, nitrile group, etc. are also effective.
Specifically, 5-hexen-1-ol, 2-methyl-3-buten-1-ol, methyl 10-undecenoate, ethyl 10-undecenoate, 10-undecen-1-ol, 12-tridecen-2-ol, 10-undecanoic acid, methyl 9-decenate, t-butyl-10-undecenate, 1,1-dimethyl-2-propen-1-ol, 9-decen-1-ol, 3-butenoic acid, 3-buten-1-ol, N-(3-buten-1-yl)phthalimide, 5-hexenoic acid, methyl 5-hexenoate, 5-hexen-2-one, acrylonitrile, methacrylonitrile, vinyl acetate, etc. Among these, undecenoic acid esters such as methyl 10-undecenoate and ethyl 10-undecenoate are particularly preferred.

(ii) Examples of the (meth)acrylic acid ester monomer include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, and phenyl (meth)acrylate.

The allyl monomer of (iii) is exemplified by an allyl monomer having 3 carbon atoms (propenyl monomer) and an allyl-based monomer having 4 or more carbon atoms and an allyl group. As the allyl monomer, an allyl monomer having a polar group containing halogen, nitrogen, oxygen, sulfur, etc. is preferable, and a vinyl monomer containing halogen, a hydroxyl group, an amino group, a nitro group, a carboxyl group, a formyl group, an ester group, an epoxy group, a nitrile group, etc. is particularly preferable.
Preferred specific examples include allyl acetate, allyl alcohol, allylamine, N-allylaniline, Nt-butoxycarbonyl-N-allylamine, N-benzyloxycarbonyl-N-allylamine, N-allyl-N-benzylamine, allyl chloride, allyl bromide, allyl ether, and diallyl ether.

In the present invention, there is no particular restriction on the polymerization type. Slurry polymerization in which at least a part of the polymer produced becomes a slurry in a medium, bulk polymerization in which the liquefied monomer itself is the medium, gas phase polymerization in a vaporized monomer, or high pressure ion polymerization in which at least a part of the polymer produced is dissolved in a monomer liquefied at high temperature and high pressure are preferably used. Also, any of batch polymerization, semi-batch polymerization, and continuous polymerization types may be used.
When the present polymerization reaction is carried out using a solvent, the reaction is carried out in the presence or absence of a liquid such as a hydrocarbon solvent, such as propane, n-butane, isobutane, n-hexane, n-heptane, toluene, xylene, cyclohexane, or methylcyclohexane, or a liquid α-olefin, or a polar solvent, such as diethyl ether, ethylene glycol dimethyl ether, tetrahydrofuran, dioxane, ethyl acetate, methyl benzoate, acetone, methyl ethyl ketone, formamide, acetonitrile, methanol, isopropyl alcohol, or ethylene glycol. A mixture of the liquid compounds described herein may also be used as the solvent. Furthermore, an ionic liquid may also be used as the solvent.

There are no particular limitations on the polymerization temperature, polymerization pressure, and polymerization time, but they can usually be set optimally from the following ranges, taking into account productivity and process capacity. That is, the polymerization temperature can usually be selected from the ranges of -20°C to 290°C, preferably 0°C to 250°C, the polymerization pressure from 0.1 MPa to 300 MPa, preferably 0.3 MPa to 250 MPa, and the polymerization time from 0.1 minutes to 10 hours, preferably 0.5 minutes to 7 hours, and more preferably 1 minute to 6 hours.

In the present invention, the polymerization is generally carried out under an inert gas atmosphere. For example, a nitrogen, argon, or carbon dioxide atmosphere can be used, and a nitrogen atmosphere is preferably used. A small amount of oxygen or air may be mixed in.
There is no particular restriction on the supply of catalyst and monomer to the polymerization reactor, and various supply methods can be used depending on the purpose. For example, in the case of batch polymerization, a method can be used in which a predetermined amount of monomer is supplied to the polymerization reactor in advance and a catalyst is supplied thereto. In this case, additional monomer or additional catalyst may be supplied to the polymerization reactor. In addition, in the case of continuous polymerization, a method can be used in which a predetermined amount of monomer and catalyst are supplied to the polymerization reactor continuously or intermittently to perform the polymerization reaction continuously.

In particular, the copolymer containing polar groups obtained by the present invention exhibits good paintability, printability, antistatic properties, inorganic filler dispersibility, adhesion to other resins, and compatibility with other resins due to the effects of the polar groups of the copolymer. Taking advantage of these properties, the copolymer of the present invention can be used in a variety of applications. For example, it can be used as a film, sheet, adhesive resin, binder, compatibilizer, wax, etc.

The transition metal compound used in the present invention is one that can react with the compound represented by the general formula (1) to form a complex having polymerization ability. These are also called precursors. For example, transition metal complexes containing nickel include [Ni(allyl)X] ₂ and (tmeda)NiArX. Note that tmeda stands for tetramethylethylenediamine.
The anion exchange reagent used in the present invention is one that can react with the general formula (1) and a transition metal complex to form a complex having a polymerizable ability, such as M[tetrakis[3,5-bis(trifluoromethyl)phenyl]borate] (M=alkali metal).

In the present invention, the complex-forming reaction may be carried out in advance in a vessel separate from the reactor used for polymerization, and the complex of general formula [II] obtained may be subjected to polymerization. The complex-forming reaction may also be carried out in a polymerization vessel, and in this case, the components present in the vessel during polymerization may or may not be present at the time of complex formation. In addition, the components represented by general formulas [I] and [II] may each be used alone, or multiple types of components may be used in combination. In particular, the use of multiple types is useful for the purpose of broadening the molecular weight distribution and comonomer distribution.

[Catalyst components for polymerization]
The olefin polymerization catalyst of the present invention contains the above-mentioned metal complex catalyst component, and may use only one type of metal complex or may use two or more types of metal complexes in combination. In some cases, multiple types of metal complexes may be used in order to broaden the molecular weight distribution. In addition to the metal complex catalyst, the following components (A) and (B) may be contained as cocatalysts or additives. When components (A) and (B) are added, mixing with the polymerization catalyst components may be performed in a reactor used for polymerization in the presence or absence of these monomers, or may be performed in a vessel separate from the reactor.

Component (A): A compound or ion-exchangeable layered silicate that reacts with a metal complex catalyst component to form an ion pair. Component (B): An organoaluminum compound.

One example of component (A) is an organoaluminum oxy compound. An 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), which may be an aliphatic hydrocarbon, an alicyclic hydrocarbon, or an aromatic hydrocarbon such as pentane, hexane, heptane, cyclohexane, methylcyclohexane, benzene, toluene, or xylene, but is preferably an aliphatic or aromatic hydrocarbon.

The organoaluminum compound used in the preparation of the organoaluminum oxy-compound may be any of the compounds represented by the following general formula, but trialkylaluminum is preferably used.
(R ⁴⁰ ) _t Al(Q ¹ ) _(3-t) (wherein R ⁴⁰ 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; Q ¹ represents a hydrogen atom or a halogen atom; and t represents an integer satisfying 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, among others, but is preferably methyl or isobutyl, and particularly preferably methyl. The above organoaluminum compounds may also be used in combination of two or more kinds.

The reaction ratio of water to the organoaluminum compound (water/Al molar ratio) is preferably 0.25/1 to 1.2/1, particularly preferably 0.5/1 to 1/1, and the reaction temperature is usually in the range of −70 to 100° C., preferably −20 to 20° C. The reaction time is usually selected in the range of 5 minutes to 24 hours, preferably 10 minutes to 5 hours.
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 preferred as the organoaluminum oxy compound. Dry methylaluminoxane (DMAO) in solid form obtained by distilling off the solvent from a MAO solution is also preferred.
As the organoaluminum oxy-compound, two or more of the above-mentioned organoaluminum oxy-compounds may be used in combination, or a solution in which the organoaluminum oxy-compound is dissolved or dispersed in the above-mentioned inert hydrocarbon solvent may be used.

An example of the organoaluminum compound used as component (B) is represented by the following general formula:
In the general formula Al(R ⁵⁰ ) _a (Q ² ) _(3-a) , R ⁵⁰ represents a hydrocarbon group having 1 to 20 carbon atoms, (Q ² ) 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 above general formula include trialkylaluminums such as trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, and tri(n-octyl)aluminum, and halogen- or alkoxy-containing alkylaluminums such as diethylaluminum monochloride and diethylaluminum monomethoxide. Of these, tri(n-octyl)aluminum is preferred. Two or more of the above organoaluminum compounds may be used in combination.
The aluminum compounds may be modified with alcohol, phenol, etc. Examples of such modifiers 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.

In the method for preparing an olefin polymerization catalyst according to the present invention, the metal complex catalyst component is essential, and component (A) and component (B) are added as necessary.
For example, the metal complex catalyst is represented by the general formulas (2) to (4), and R ¹⁰ , R ²
When R ¹⁰ , R ²⁰ , and R ³⁰ are substituents that initiate polymerization, such as an alkyl group, an aryl group, or an allyl group, components (A) and (B) are not necessarily required. On the other hand, when R ¹⁰ , R 20 , and R ³⁰ are substituents that do not initiate polymerization, it is necessary to introduce a polymerization initiating group onto the metal complex by adding components (A) and (B).
Even when R ¹⁰ , R ²⁰ and R ³⁰ are substituents that initiate polymerization, (A) and (B) may be added as additives for the purpose of changing the molecular weight or copolymerization ratio.

[Ethylene/undecenoic acid ester copolymer]
The ethylene/undecenoic acid ester copolymer obtained by coordination polymerization using the metal complex catalyst of the present invention has an extremely small alkyl branch of 3/1000C or less. This is believed to be because the copolymer of the present invention has extremely little chain walk, a phenomenon frequently seen in high-cycle polymerization catalysts such as nickel and palladium. Chain walk is caused by the formation of an alkyl branch structure when the "metal" part from which the polymer grows moves along the polymer chain. The alkyl branch structure causes a decrease in the mechanical properties of the polymer, and it is found that the ethylene/undecenoic acid ester copolymer of the present invention maintains crystallinity, maintains a high melting point, and has good mechanical properties.
In other words, the polymer of the present invention produced using the metal complex catalyst has very little alkyl branching derived from chain walks, and therefore has a higher melting point and better mechanical properties than polymers with a larger amount of alkyl branches.

The amount of alkyl branches derived from chain walk in the above-described ethylene/undecenoic acid ester copolymer is 3/1000C or less, preferably 2/1000C or less, and more preferably 1/1000C or less.
In addition, since the ester group in the ethylene/undecenoic acid ester copolymer obtained by coordination polymerization using the metal complex catalyst of the present invention is a polar functional group, it is believed that this will lead to improved adhesion and design properties of the polymer. It is also possible to derive the ester group to another polar group by a chemical conversion reaction, which is expected to lead to the production of novel functional polyolefins.
That is, the polymer of the present invention produced using the metal complex catalyst has an ester group derived from the undecenoic acid ester, and has functionality derived from the polar functional group.

The ethylene/undecenoic acid ester copolymer described above has an undecenoic acid ester content of 2 mol % or more, preferably 4 mol % or more, more preferably 7 mol % or more, and particularly preferably 8 mol % or more.
The higher the content of ester groups in the ethylene/undecenoic acid ester copolymer, the more the functions derived from the polar functional groups described above will be manifested, while a high content of undecenoic acid ester will increase the number of branched structures relative to the main chain, which is thought to decrease the crystallinity of the polymer, lowering the melting point and decreasing the mechanical properties.From this viewpoint, the content of undecenoic acid ester in the above-described ethylene/undecenoic acid ester copolymer of the polymer is 50 mol% or less, preferably 30 mol% or less, and more preferably 15 mol% or less.

The present invention will be described in more detail in the following examples and comparative examples, but the present invention is not limited thereto.
In the following synthesis examples and working examples, unless otherwise specified, operations were carried out under a purified nitrogen atmosphere, and solvents that had been dehydrated and deoxygenated were used.

1. Evaluation Method (1) Weight Average Molecular Weight Mw, Number Average Molecular Weight Mn and Molecular Weight Distribution Mw/Mn
The following GPC measurement was performed. Specifically, the procedure was as follows.
First, about 20 mg of a sample was collected in a vial for a high-temperature GPC pretreatment device PL-SP 260VS manufactured by Polymer Laboratory Co., Ltd., and o-dichlorobenzene containing BHT as a stabilizer (BHT concentration = 0.5 g/L) was added to adjust the polymer concentration to 0.1 mass%. The polymer was heated to 135°C in the high-temperature GPC pretreatment device PL-SP 260VS to dissolve, and filtered through a glass filter to prepare a sample. In the GPC measurement of the present invention, no polymer was captured by the glass filter.
Next, GPC measurement was performed using a Tosoh Corporation TSKgel GMH-HT (30 cm x 4 columns) and a Waters Corporation GPCV 2000 equipped with an RI detector. The measurement conditions were as follows: sample solution injection amount: about 520 μL, column temperature: 135° C., solvent: o-dichlorobenzene, flow rate: 1.0 mL/min.
The molecular weight was calculated as follows. That is, a commercially available monodisperse polystyrene was used as a standard sample, and a calibration curve relating to retention time and molecular weight was created from the viscosity equation of the polystyrene standard sample and the ethylene-based polymer, and the molecular weight was calculated based on the calibration curve. The viscosity equation used was [η]=K×Mα, where K=1.38E ^-4 and α=0.70 for polystyrene, K=4.77E ^-4 and α=0.70 for ethylene-based polymer, and K=1.03E ^-4 and α=0.78 for propylene-based polymer.

(2) Catalytic activity Catalytic activity (Vp) is calculated by the following formula (i) using the amount of polymer obtained by polymerization reaction (g), the amount of catalyst used in the polymerization reaction (unit: mol), and the polymerization reaction time (h).

(3) Content of Undecenoic Acid Ester Component in Polymer The content (Xm) of the undecenoic acid ester component in the polymer is given by the following calculation formula (ii).

The amounts of ethylene and undecenoic acid ester components in the polymer were determined by ¹ H-NMR measurement. For ¹ H-NMR measurement, about 30 mg of a sample was dissolved in orthodichlorobenzene- _d4 while heating at 130°C, and NMR measurement was performed at 130°C. The signals derived from this deuterated solvent were 7.11 ppm and 7.39 ppm. In the ethylene/methyl undecenoate copolymer, a signal of the methyl group of the methyl ester was observed at 3.73 ppm. In the ethylene/ethyl undecenoate copolymer, a signal of the methylene group of the ethyl ester was observed at 4.24 ppm.
The amount of undecenoic acid ester can also be calculated from the absorption of carbonyl groups corresponding to 1655-1836 cm ^-1 by casting the obtained polymer on a film and measuring it by IR. In this case, by drawing a calibration curve in advance based on the content obtained by NMR and the amount of absorption derived from carbonyl groups by IR measurement, it becomes possible to calculate the amount of undecenoic acid ester by IR measurement from the next time onwards.

(4) Calculation of the amount of alkyl branches derived from chain walk In a 1000C unit, the amount of alkyl branches derived from chain walk is given by the following calculation formula (iii).

The polymer has a polyethylene structure as the main chain, and has branches derived from undecenoic acid esters and alkyl branches derived from chain walk, which were determined by ¹ H-NMR and ¹³ C-NMR measurements, respectively. For the ¹³ C-NMR measurement, about 30 mg of the sample was dissolved in orthodichlorobenzene- _d4 while heating at 130°C, and NMR measurement was performed at 130°C. The explanation of formula (iii) is described below in [i] to [v].
[i] In the case of an ethylene/undecenoic acid ester copolymer, the composition formula is approximated to C _n H _2n when the undecenoic acid ester content is in the low range.
[ii] The total integral value of ¹ H-NMR is normalized to 2000H.
[iii] The integral value of the signals (alkyl branch and saturated end) at 1.05 ppm in ¹ H-NMR is defined as [I ₁ ].
[iv] In ^13C NMR, the total integral value of the signals of the terminal Me group of the alkyl branch derived from the chain walk is defined as [ _I2 ]. For example, the signal of the Me group is at 19.8 ppm, the signal of the terminal Me group of the Et group is at 11.1 ppm, and the signal of the terminal Me group of the alkyl branch having a longer carbon chain is observed around 14.5 ppm.
[v] The integral value of the signal at 13.8 ppm in ¹³ C-NMR (Me group at the saturated end of the main chain) is defined as [I ₃ ].

2. Synthesis of Ligands Synthesis Example 1: Synthesis of pyridine oxide phosphine X-110 Pyridine oxide phosphine X-110 was synthesized according to the following reaction scheme.
(1) Synthesis of Compound 2

Under a nitrogen atmosphere, 1,3-dimethoxybenzene (1 in the above formula) (20 g, 144.8 mmol) was placed in a flask and dissolved in THF (200 mL). n-BuLi (2.5 M, 59.1 mL, 1 equivalent) was added dropwise at 0°C. The reaction solution was heated to 20°C and stirred for 2 hours, and the reaction solution turned yellow. I ₂ (40.4 g, 159.2 mmol, 1.1 equivalent) was added to the reaction solution at 0°C, and stirred at 20°C for 14 hours to obtain a yellow suspension. A saturated aqueous sodium thiosulfate solution (200 mL) was added, and then the solution was concentrated to remove THF. A solid precipitated, which was filtered to obtain a gray solid. The solid was washed with methanol (100 mL) and organic ether (100 mL) to obtain a yellow solid of the target product 2 (76 g, 287.8 mmol, 99%).

(2) Synthesis of Compound 4

Under a nitrogen atmosphere, ⁱ PrMgBr (2M in THF, 29.8 mL, 1.05 equivalents) was added to a THF solution (50 mL) of compound 2 (15 g, 56.8 mmol) at 0° C. The reaction solution was stirred at 20° C. for 2 hours, and changed to a yellow solution. PCl ₃ (3.90 g, 28.4 mmol, 0.5 equivalents) was added to the reaction solution at −78° C., and the solution was heated to 20° C. and stirred for 1.5 hours to obtain a yellow suspension (suspension of compound 3). Subsequently, LiAlH ₄ (2.37 g, 62.5 mol, 1.1 equivalents) was added at 0° C., and the solution was heated to 20° C. and stirred for 12 hours, and changed to a white suspension. The reaction solution was cooled to 0° C., and distilled water (3 mL), 15% aqueous NaOH solution (3 mL), and distilled water (9 mL) were added in this order. After stirring at room temperature for 1 hour, the reaction solution was filtered and the filtrate was concentrated to obtain a white solid, which was washed with water (100 mL) and extracted with dichloromethane (200 mL x 2).
The organic layer was dried over Na ₂ SO ₄ , filtered, and concentrated. The solid obtained was washed with organic ether (70 mL) and purified by silica column chromatography (PE: EtOAc = 5: 1) to obtain compound 4 (7.9 g, 25.8 mmol, 45%).

(3) Synthesis of Compound 6

Under a nitrogen atmosphere, Mg (3.22 g, 132.69 mmol) was placed in a flask and heated with a heat gun for 10 minutes. The inside of the flask was evacuated and the Mg was activated by vigorously stirring it with a stir bar. Anhydrous THF (10 mL) and 1,2-dibromoethane (62.32 mg, 331.72 μmol) were added. After stirring for a while, anhydrous THF solution (40 mL) of compound 5 (8.0 g, 33.2 mmol, 1 equivalent) was slowly added to the flask. The reaction solution was stirred at 20°C for 30 minutes to obtain a THF solution of compound 6.

(4) Synthesis of Compound 8

Under a nitrogen atmosphere, CuI (9.29 g, 48.8 mmol) was dissolved in anhydrous THF (5 mL). A THF solution of compound 6 (0.63 M, 77.4 mL, 48.8 mmol) was added dropwise at 20° C. over 10 minutes. Compound 7 (8.0 g, 48.8 mmol) was then added dropwise at 20° C. and stirred at 0° C. for 12 hours to obtain a yellow reaction solution. The reaction solution was added to water (50 mL) and extracted with EtOAc (50 mL×2). The organic layer was washed with brine (100 mL), dried over anhydrous Na ₂ SO ₄ , and concentrated to obtain a crude product. The yellow solid of compound 8 was obtained in 8 (1.9 g, 6.6 mmol, 13%) by purification with silica column chromatography (EtOAc:PE=50:1).

(5) Synthesis of compound X-110

In a nitrogen atmosphere, compound 8 (1.5 g, 5.18 mmol), compound 4 (1.90 g, 6.21 mmol, 1.2 equivalents), DPEphos (557.5 mg, 1.04 mmol, 0.2 equivalents), Cs ₂ CO ₃ (5.06 g, 15.5 mmol, 3 equivalents), and Pd ₂ (dba) ₃ (474.0 mg, 517.6 μmol, 0.1 equivalents) were mixed in degassed dioxane (20 mL). The reaction solution was heated at 110° C. for 72 hours under nitrogen to obtain a brown suspension. The reaction solution was concentrated, and the obtained brown oil was purified by silica column chromatography (PE: EtOAc gradient) to obtain a yellow solid of X-110 (600 mg, 1.07 mmol, 21% yield). The following NMR measurement results confirmed that it was X-110.
^1H -NMR ( _CDCl3 , δ, ppm): 0.99 (d, 6H), 1.07 (d, 6H), 2.45 (sept, 2H), 3.51 (s, 12H), 6.42 (d, 4H), 6.9-7.3 (m, 8H). ^31P { ^1H }NMR ( _CDCl3 , δ, ppm): -63.4 (s).

Synthesis Example 2: Synthesis of pyridine oxide phosphine X-140 Pyridine oxide phosphine X-140 was synthesized according to the following reaction formula.

(1) Synthesis of Compound 10

Compound 9 (1.0 g, 6.1 mmol) was placed in a flask, and a THF solution (5 mL) of CuI (46.5 mg, 243.9 μmol) was added. A THF solution (1.7 M, 5.4 mL, 1.5 equivalents) of ^t BuMgCl was added dropwise to the reaction solution at 0° C. The reaction solution was heated to 20° C. and stirred at 20° C. for 12 hours, changing into a yellow solution. The reaction solution was transferred to a container containing distilled water (100 mL) and extracted with EtOAc (100 mL x 3). The organic layers were combined, washed with brine (200 mL), dried over anhydrous Na ₂ SO ₄ , and the organic layers were concentrated to obtain a crude product. The crude was purified by silica column chromatography (EtOAc:PE gradient) to obtain compound 10 (0.48 g, 2.59 mmol, 42%).

(2) Synthesis of compound X-140

Under a nitrogen atmosphere, compound 10 (1.0 g, 5.39 mmol), compound 4 (1.98 g, 6.46 mmol, 1.2 equivalents), Pd ₂ (dba) ₃ (493.3 mg, 538.7 μmol, 0.1 equivalents), DPEphos (580.2 mg, 1.08 mmol, 0.2 equivalents), and tBuONA (1.04 g, 10.8 mmol, 2 equivalents) were mixed in toluene (40 mL). The reaction solution was heated at 110° C. for 16 hours to obtain a brown suspension. The suspension was concentrated to obtain a brown crude product. X-140 (0.95 g, 2.09 mmol, 39%) was obtained by purifying the product by silica gel chromatography (EtOAc:PE gradient). The product was confirmed to be X-140 from the following NMR measurement results.
^1H NMR ( _CDCl3 , δ, ppm): 1.44 (s, 9H), 3.47 (s, 12H), 6.40 (d, 4H), 6.7-7.2 (m, 5H).
^31P { ¹ H}NMR (CDCl ₃ , δ, ppm): −64.2 (s).

3. Production of Metal Complexes Production Example 1 Production of [(X-110)Ni(allyl)] [BArF]

Under a nitrogen atmosphere, X-110 (559.6 mg, 1.0 mmol), [Ni(allyl)Cl] ₂ (135.22 mg, 0.5 mmol), and NaBArF (886.20 mg, 1.0 mmol) were placed in a flask, and CH ₂ Cl ₂ (5 mL) was added to each. The solutions of X-110 and NaBArF were mixed, and the mixture was added to the [Ni(allyl)Cl] ₂ solution. The mixture was stirred at room temperature for 30 minutes and filtered through Celite to obtain an orange solution. The Celite was washed with 10 mL of CH ₂ Cl ₂ and collected together with the filtrate. The filtrate was distilled under reduced pressure to obtain an orange powder of [(X-110)Ni(allyl)][BArF].

Production Example 2 Production of [(X-110)NiAr(py)] [BArF]

Under a nitrogen atmosphere, X-110 (500 mg, 0.893 mmol), (tmeda)NiArBr (Ar = 4-trifluorophenyl group) (357 mg, 0.893 mmol), and NaBArF (791 mg, 0.893 mmol) were placed in a flask, and CH ₂ Cl ₂ (5 mL) was added to each. The solutions of X-110 and NaBArF were mixed, and the mixture was added to the (tmeda)NiArBr solution. The mixture was stirred at room temperature for 30 minutes and filtered through Celite to obtain an orange solution. The Celite was washed with 10 mL of CH ₂ Cl ₂ and collected together with the filtrate. The filtrate was distilled under reduced pressure to obtain an orange powder. 600 mg of the obtained yellow powder was separated into another flask, dissolved in toluene, and then pyridine (272 mg) was added. After stirring at room temperature for 30 minutes, the mixture was evaporated under reduced pressure to obtain a yellow powder of [(X-110)NiAr(py)] [BArF].

Production Example 3 Production of [(X-140)Ni(allyl)] [BArF]

Under a nitrogen atmosphere, X-140 (455 mg, 1.0 mmol), [Ni(allyl)Cl] ₂ (135.22 mg, 0.5 mmol), and NaBArF (886.20 mg, 1.0 mmol) were placed in a flask, and CH ₂ Cl ₂ (5 mL) was added to each. The solutions of X-140 and NaBArF were mixed, and the mixture was added to the [Ni(allyl)Cl] ₂ solution. The mixture was stirred at room temperature for 30 minutes and filtered through Celite to obtain an orange solution. The Celite was washed with 10 mL of CH ₂ Cl ₂ and collected together with the filtrate. The filtrate was distilled under reduced pressure to obtain an orange powder of [(X-140)Ni(allyl)][BArF].

Production Example 4 Production of [(X-140)NiAr(py)] [BArF]

In a nitrogen atmosphere, X-140 (455 mg, 1.0 mmol), (tmeda)NiArBr (Ar=4-trifluorophenyl group) (400 mg, 1.0 mmol), and NaBArF (886 mg, 1.0 mmol) were placed in a flask, and CH ₂ Cl ₂
(5 mL) was added to each. The solutions of X-140 and NaBArF were mixed, and the mixture was added to the (tmeda)NiArBr solution. The mixture was stirred at room temperature for 30 minutes and filtered through Celite to obtain an orange solution. The Celite was washed with 10 mL of CH ₂ Cl ₂ and collected together with the filtrate. The filtrate was distilled off under reduced pressure to obtain an orange powder. 500 mg of the obtained orange powder was separated into another flask, dissolved in toluene, and then pyridine (250 mg) was added. The mixture was stirred at room temperature for 30 minutes, and then distilled off under reduced pressure to obtain a yellow powder of [(X-140)NiAr(py)] [BArF].

Comparative Production Example 1
As a comparative catalyst, [(IM-5D)Ni(allyl)] [BArF] was used. A synthesis example is described below.

(1) Synthesis of amine X-95

1-Naphthylamine (1 in the reaction scheme) (50 g, 349.2 mmol, 49.0 mL, 1 equiv.) and picolinic acid (1A in the reaction scheme) (47.29 g, 384.12 mmol, 1.1 equiv.) were dissolved in dichloromethane (30 mL). HATU (O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate) (146.05 g, 384.12 mmol, 1.1 equiv.) and DIEA (N,N-diisopropylethylamine) (90.26 g, 698.40 mmol, 121.65 mL, 2 equiv.) were added to this solution, and the reaction solution was stirred at 20°C for 12 hours under nitrogen. The reaction solution was poured into water (500 mL) and extracted with dichloromethane (500 mL x 2). The collected organic layer was washed with brine (500 mL) and dried over anhydrous sodium sulfate. The organic layer was concentrated and the resulting solid was washed with EtOAc (10 mL) to obtain the crude product of compound 2 (86.7 g).

Compound 2 (20 g, 80.55 mmol, 1 equiv.), 3,5-dimethyl-1-iodobenzene (3 in the reaction scheme) (73.09 g, 314.97 mmol, 45.40 mL, 3.9 equiv.), silver acetate (20.17 g, 120.83 mmol, 6.19 mL, 1.5 equiv.), and palladium acetate (1.17 g, 5.21 mmol) were mixed and stirred at 140°C for 24 hours. Dichloromethane (200 mL) was added to form a suspension, filtered, and washed with dichloromethane (100 mL twice). The resulting solid was dried to obtain a crude product. The crude product was purified using a silica gel column (developing solvent: petroleum ether/ethyl acetate 10:1) to obtain a brown solid of compound 4 (28 g, 79.45 mmol, 99%).

Compound 4 was heated to reflux at 90°C in an aqueous NaOH ethanol solution (ethanol; 200 mL, water; 24 mL, NaOH; 31.78 g, 794.49 mmol). The reaction solution was cooled to room temperature and the solvent was concentrated. The residue was suspended in dichloromethane (150 mL) and filtered. The filtrate was washed with water (200 mL x 3) and brine (200 mL), and the organic layer was dried over anhydrous sodium sulfate. The organic layer was concentrated to obtain unpurified X-94. The obtained solid was washed with hexane: EtOAc (10:1, 77 mL x 2) to obtain purified X-94 (6.0 g, 24.28 mmol).

X-94 (2 g, 8.09 mmol, 1 equiv.) and diphenylmethanol (2.98 g, 16.17 mmol, 2 equiv. Compound 5 in the reaction formula) were mixed in a 50 mL flask and heated at 120° C. A solution of zinc chloride (551.08 mg, 4.04 mmol) in concentrated hydrochloric acid (796 mg, 8.09 mmol, 37%, 0.5 equiv.) was added to the flask. Immediately after the addition, heat generation and vigorous foaming were confirmed. The reaction solution was heated at 160° C. for 90 minutes, and changed to a brown solution. The reaction solution was cooled to room temperature, and dichloromethane (100 mL) was added to suspend the solution. The organic layer was removed, washed with water (100 mL twice) and brine (50 mL), dried over anhydrous sodium sulfate, and then the organic layer was concentrated to obtain a crude product. X-95 was purified by a preparative column (3.00 g, 5.17 mmol, 64%). The identification results by ¹ H-NMR are shown below.
^1H NMR ( _CDCl3 , δ, ppm): 2.32 (s, 6H), 3.75 (brs, 2H), 5.46 (s, 1H), 6.08 (s, 1H), 6.36 (s, 1H), 6.90-7.00 (m, 9H), 7.02 (s, 2H), 7.05-7.20 (m, 13H), 7.27 (m, 1H), 7.91 (d, J = 8.4 Hz, 1H).

(2) Synthesis of iminoketone IM-5D

1-Methylisatin (166 mg, 1.03 mmol) and X-95 (600 mg, 1.03 mmol) were dissolved in dichloromethane (5 mL), and a few drops of formic acid were added. The mixture was heated under reflux for 40 hours. The product was purified using a silica gel column (developing solvent: hexane:ethyl acetate gradient) to obtain IM-5D (598, 0.922 mmol, 90%). The results of identification by ¹ H-NMR are shown below.
^1H NMR ( _CDCl3 , δ, ppm): 1.82 (s, 3H), 2.43 (s, 3H), 3.02 (s, 3H), 5.24 (d, J = 8.1 Hz), 5.62 (s, 1H), 5.87 (s, 1H), 6.1-8.1 (m, 29H).

(3) Synthesis of [(IM-5D)Ni(allyl)] [BArF]

IM-5D, [Ni(allyl)Cl] ₂ , and NaBArF (BArF = 3,5-(CF ₃ ) ₂ C ₆ H ₃ ) were placed in a flask, and dichloromethane (5 mL) was added to each. A solution of the ligand (IM-5D) and NaBArF was mixed in advance, and the mixed solution was added to the flask containing [Ni(allyl)Cl] _2. After stirring at room temperature for 1 h, the mixture was filtered through Celite. The solvent was distilled off to obtain a metal complex (carbonylimine complex). The results of identification by ¹ H-NMR are shown below.
^1H NMR ( _CDCl3 , δ, ppm): 1.63 (s, 3H), 2.00 (d, J = 12.0 Hz, 1H), 2.22 (d, J = 14.0 Hz, 1H), 2.48 (s, 3H), 2.87 (brs, 1H), 3.02 (s, 3H), 3.13 (brs, 1H), 5.58 (m, 1H), 5.72 (s, 1H), 6.07 (s, 1H), 6.10 (d, J = 7.7 Hz, 1H), 6.26 (s, 1H), 6.65-6.74 (m, 3H), 6.75-6.89 (m, 7H), 6.93-7.02 (m, 5H), 7.15-7.26 (m, 9H), 7.28 (d, J = 6.9 Hz, 1H), 7.34 (t, J = 7.8 Hz, 1H), 7.47 (t, 7.8 Hz, 1H), 7.49 (s, 4H), 7.70 (s, 8H), 8.14 (d, J = 8.4 Hz, 1H).

Examples 1 to 4 and Comparative Example 1
The metal complex catalysts produced in the above Production Examples 1 to 4 and Comparative Production Example 1 were used to evaluate their catalytic activity in the following polymerization reaction. Specifically, the catalytic activity was evaluated in the reaction of ethylene/ethyl undecenoate copolymerization. The metal complex catalysts produced in each Production Example and Comparative Production Example were used to evaluate the catalytic activity in the reaction of ethylene/ethyl undecenoate copolymerization shown in the following reaction formula.

An induction-stirred autoclave with a capacity of 2 L was purged with nitrogen, and dehydrated toluene (400 mL) and dehydrated ethyl undecenoate (73 mL, 300 mmol) were introduced. A complex catalyst (20 μmol) consisting of the complexes listed in Table 1 was diluted in dichloromethane (5 mL) and added to the catalyst feeder. The autoclave was heated to 70° C., and the catalyst solution was introduced using ethylene gas during the heating process. The mixture was stirred at 70° C. for 1 hour, during which ethylene was appropriately replenished so that the ethylene pressure was maintained at 1 MPa. After the reaction, the mixture was cooled to room temperature, and ethanol was added to the resulting suspension to precipitate a polymer. The mixture was filtered by suction, the solid was washed with ethanol and acetone, and dried by heating to obtain a polymer. The weight of the obtained polymer was weighed on a balance, and the catalytic activity was calculated based on the above-mentioned calculation formula (i).
The weight average molecular weight Mw and the molecular weight distribution Mw/Mn were measured by the above-mentioned method, and the content was determined by the above-mentioned calculation formula (ii). These results are shown in Table 3.

Examples 5 to 6 and Comparative Example 2
A polymerization reaction of ethylene and dehydrated methyl undecenoate was carried out using the metal complex shown in Table 4. The reaction conditions were the same as those in Table 1, except that ethyl undecenoate was replaced with methyl undecenoate. Comparative Example 2 shows the result of a similar polymerization reaction carried out using the following complex A, which is a conventional technique (see Non-Patent Document 9). The reaction conditions in Comparative Example 2 are different from the above reaction conditions, and the differences are as follows: the amount of dehydrated toluene was 25 mL, the amount of dehydrated ethyl undecenoate was 0.5 M, the amount of complex catalyst was 10 μmol, the ethylene pressure was 0.8 MPa, and the reaction time was 120 minutes.

Examples 7 to 8
Polymerization reaction of ethylene and dehydrated ethyl undecenoate was carried out using the metal complexes shown in Table 5. The reaction conditions were the same as those in Table 1, except that the amount of ethyl undecenoate added was changed from 300 mmol to 829 mmol and 1326 mmol.

From Table 3, it can be seen that by using the metal complex of the present invention, an ethylene/ethyl undecenoate copolymer can be obtained with high activity. In particular, it was found that a high activity of 5.45×10 ⁶ was obtained in the polymerization reaction using the metal complex described in Example 2.
It is also found that the ratio (content) of ethyl undecenoate/(ethyl undecenoate+ethylene) is high, and copolymerizability is high. In particular, the metal complexes of Examples 2 and 4 had a high content and showed high copolymerizability.
Furthermore, the amount of alkyl branches was low, and only methyl branches were observed. In particular, the metal complex catalyst of the present invention has a significantly low amount of alkyl branches compared to Comparative Example 1. This can also be recognized as a difference in melting point.

Furthermore, the results in Table 4 show that an ethylene/methyl undecenoate copolymer can also be obtained with high activity, and in particular, the use of the metal catalyst described in Example 6 shows higher activity than the conventional metal complex catalyst shown in Comparative Example 2. Furthermore, the molecular weights of the copolymers obtained in Examples 5 and 6 and Comparative Example 2 show that the molecular weight can be increased compared to the conventional metal complex catalyst.
Furthermore, it can be seen from the results in Table 5 that the amount of ethyl undecenoate contained in the resulting copolymer increases by increasing the amount of ethyl undecenoate charged.

By using the metal complex of the present invention, it becomes possible to produce novel functional polyolefins that exhibit novel functionalities due to the inclusion of polar groups, and therefore the complexes are extremely useful industrially, particularly in applications requiring adhesive properties and design properties.

Claims (13)

A compound represented by the following general formula (1):

(In the formula, R ¹ to R ⁵ are each independently a hydrogen atom, a halogen atom, a group containing a heteroatom, or an organic group. R ⁶ is a phenyl group having substituents at least at two positions among the 2-position to the 6-position.) The compound according to claim 1 , wherein R ⁶ is a phenyl group having substituents at the 2- and 6-positions and represented by the following formula:

(In the formula, ^R7 and ^R8 are each independently a halogen, a group containing a heteroatom, or an organic group.) A metal complex represented by the following general formula (2):

(In the formula, M is Ni or Pd, R ¹ to R ⁵ are each independently a group containing hydrogen, a halogen, a heteroatom, or an organic group. R ⁶ is a phenyl group having substituents at at least two of the 2- to 6-positions. R ¹⁰ is a group containing hydrogen, a halogen, a heteroatom, or an organic group, and may be a monodentate or polydentate ligand. When R ¹⁰ is a monodentate ligand, L is a neutral Lewis base, and when R ¹⁰ is polydentate and coordinated to M, L may not be present. X is a counter anion.) A metal complex represented by the following general formula (3):

(In the formula, M is Ni or Pd, R ¹ to R ⁵ are each independently hydrogen, halogen, a group containing a heteroatom, or an organic group, R ⁶ is a phenyl group having substituents at least at two positions among the 2-position to the 6-position, R ²⁰ is hydrogen, halogen, a group containing a heteroatom, or an organic group, and X is a counter anion.) A metal complex represented by the following general formula (4):

(In the formula, M is Ni or Pd, R ¹ to R ⁵ are each independently hydrogen, halogen, a group containing a heteroatom, or an organic group, R ⁶ is a phenyl group having substituents at least at two positions among the 2-position to the 6-position, R ³⁰ is a group containing hydrogen, halogen, a heteroatom, or an organic group, and is monodentately coordinated to M, L is a neutral Lewis base, and X is a counter anion.) A compound represented by the following general formula (1):

(wherein R ¹ to R ⁵ are each independently hydrogen, halogen, a group containing a heteroatom, or an organic group; and R ⁶ is a phenyl group having substituents at at least two of the 2- to 6-positions) with a transition metal compound containing nickel or palladium, thereby producing a metal complex represented by the following general formula (3):

(wherein M is Ni or Pd; R ¹ to R ⁵ each independently represent hydrogen, halogen, a group containing a heteroatom, or an organic group; R ⁶ is a phenyl group having substituents at least at two of the 2- to 6-positions; R ²⁰ is hydrogen, halogen, a group containing a heteroatom, or an organic group; and X is a counter anion). A compound represented by the following general formula (1):

(wherein R ¹ to R ⁵ are each independently hydrogen, halogen, a group containing a heteroatom, or an organic group; and R ⁶ is a phenyl group having substituents at at least two of the 2- to 6-positions) with a transition metal compound containing nickel or palladium, thereby producing a metal complex represented by the following general formula (4):

(In the formula, M is Ni or Pd, R ¹ to R ⁵ are each independently hydrogen, halogen, a group containing a heteroatom, or an organic group, R ⁶ is a phenyl group having substituents at least at two positions among the 2-position to the 6-position, R ³⁰ is a group containing hydrogen, halogen, a heteroatom, or an organic group, and is monodentately coordinated to M, L is a neutral Lewis base, and X is a counter anion.) An olefin polymerization catalyst comprising the metal complex according to any one of claims 3 to 5. A method for producing a (co)polymer, comprising (co)polymerizing an olefin in the presence of the olefin polymerization catalyst according to claim 8. A method for producing a copolymer, comprising copolymerizing an olefin and a polar group-containing vinyl monomer in the presence of the olefin polymerization catalyst according to claim 8. The method for producing a copolymer according to claim 10, wherein the polar group-containing vinyl monomer contains an oxygen atom and/or a nitrogen atom. The method for producing a copolymer according to claim 10, wherein the olefin is ethylene and the polar group-containing vinyl monomer is an undecenoic acid ester. An ethylene/undecenoic acid ester copolymer synthesized by coordination copolymerization using a metal complex catalyst, having an alkyl branch derived from chain walk of 3/1000C or less and an undecenoic acid ester content of 2 mol % or more and 50 mol % or less.