JP2021147339A - Metal complex - Google Patents

Abstract

To provide a metal complex that has high catalyst activity and high selectivity as a transesterification catalyst and is available at low cost with excellent safety and stability.SOLUTION: The present disclosure provides a metal complex represented by formula (1): (M)x(A)p(B)q(C)r (1) (where (M) is a divalent metal of group 2 in the periodic table; x, p, q, r each denote any integer excluding 0 and satisfy formula (2) and formula (3): p+q=2x (2) and p+q+r≤6x (3). A ligand (A) is a diketonate ligand; a ligand (B) is an anion ligand excluding the ligand (A); a ligand (C) is a neutral ligand).SELECTED DRAWING: Figure 1

Description

The present invention relates to group 2 metal complexes having a specific ligand and structure. The metal complex of the present invention is typically useful as a transesterification reaction catalyst.

The transesterification reaction is a method of synthesizing a higher value-added ester by reacting an alcohol with a lower ester that is synthesized in large quantities industrially. It has been actively studied. The transesterification reaction is also being studied as a method for polymerizing resins such as polyester and polycarbonate, and these resins are industrially produced on a large scale.

In the conventional transesterification reaction, various metals such as sodium, potassium, aluminum, titanium, iron, cobalt, zinc, tin, and rare earth metals are used as catalyst metals, and metal complexes in which their ligands and anions are modified are used. Activities in various transesterification reaction catalysts have been investigated (for example, Non-Patent Document 1).

J. Otera and J. Nishikido, Esterification, p. 52-99, Wiley 2010

However, a catalyst that can efficiently proceed with the polymerization reaction of polyester or polycarbonate, which is required to reduce the amount of residual catalyst, or can obtain sufficient activity in a transesterification reaction using a low-reactivity alcohol such as a tertiary alcohol. Has not yet been offered. In addition, even with highly active catalysts, expensive metals, toxic metals, or metals that are unstable to water and oxygen are often used as catalyst metals, and the cost, safety, stability, etc. of the catalyst are increased. The catalysts that satisfy the above conditions and can be used industrially have been limited.

An object of the present invention is to provide a metal complex having high catalytic activity and high selectivity as a transesterification reaction catalyst, which cannot be achieved by the prior art, and having excellent safety and stability at low cost.

As a result of diligent research to solve the above problems, the present inventors have shown that a metal complex having a specific ligand and structure in a group 2 metal of the periodic table exhibits high catalytic activity and selectivity in an ester exchange reaction. , It has been found that the above-mentioned problems can be solved by giving a non-colored product.

That is, the gist of the present invention is as follows.

[1] A metal complex represented by the following general formula (1).
(M) x (A) p (B) q (C) r (1)
(In the above general formula (1), (M) represents a group 2 divalent metal in the long periodic table, and (A), (B) and (C) represent ligands, respectively.
x, p, q, and r represent arbitrary integers other than 0, and satisfy the following equations (2) and (3).
p + q = 2x (2)
p + q + r ≦ 6x (3)
The ligand (A) is a diketonate ligand represented by the following formula A1.
The ligand (B) is an anionic ligand other than the ligand (A), and is an anion of a compound having at least one oxygen atom and / or a nitrogen atom and having 1 to 20 carbon atoms, or an OH ^- anion. Is.
Ligand (C) is a ligand of the neutral compound having 1 to 20 carbon atoms and having at least one oxygen atom and / or nitrogen atoms, or a H _{2 O.} )

(In the formula (A1), R ₁ , R ₂ , and R ₃ independently represent a monovalent hydrocarbon group having 1 to 20 carbon atoms, a hydrogen atom, or a halogen atom. The hydrocarbon group has a halogen atom. It may be substituted or may have an oxygen atom.)

[2] The metal complex according to [1], wherein (M) in the general formula (1) is at least one metal selected from magnesium, calcium and / or barium.

[3] The metal complex according to [2], wherein the metal (M) in the general formula (1) is magnesium and / or calcium.

[4] The metal complex according to any one of [1] to [3], _{wherein R 2} in the formula (A1) is a hydrogen atom.

_{[5] Of [1] to [4], R 1} and R ₃ in the formula (A1) are independently monovalent hydrocarbon groups or hydrogen atoms having 1 to 7 carbon atoms. The metal complex according to any one.

[6] The ligand (C) in the general formula (1) is a compound having at least one selected from a hydroxyl group, an amino group, a carbonate group, an ester group, a carbonyl group, and an amide group. The metal complex according to any one of [1] to [5].

[7] The metal complex according to any one of [1] to [6], wherein the ligand (B) in the general formula (1) is an anion of a compound having 1 to 3 hydroxyl groups. ..

[8] The metal complex according to any one of [1] to [7], wherein the ligand (C) in the general formula (1) is a compound having 1 to 3 hydroxyl groups.

[9] The metal complex according to any one of [1] to [8], wherein the ligand (B) in the general formula (1) is an anion of the ligand (C).

[10] The metal complex according to any one of [1] to [9], wherein x in the general formula (1) is 2 or 4.

[11] The metal complex according to [10], wherein x in the general formula (1) is 4.

[12] The metal complex according to any one of [1] to [11], wherein in the general formula (1), x: p: q: r = 1: 1: 1: 1.

[13] The metal complex according to any one of [1] to [12], wherein the crystal structure analyzed by X-ray structure analysis has an octahedral structure composed of metal atoms and oxygen atoms.

[14] A halide of the metal (M), a metal salt having the ligand (B), the ligand (A), the ligand (C), or a precursor having these structures. The method for producing a metal complex according to any one of [1] to [13], which comprises a step of mixing.

[15] A step of mixing the ligand (A), the ligand (C), or a precursor having these structures with the metal salt having the metal (M) and the ligand (B). The method for producing a metal complex according to any one of [1] to [13], which comprises.

[16] A transesterification reaction using the metal complex according to any one of [1] to [13] as a catalyst.

[17] A polymerization method including a transesterification reaction using the metal complex according to any one of [1] to [13] as a catalyst.

[18] A method for producing a polycarbonate and / or a polycarbonate diol using the polymerization method according to [17].

[19] A method for producing a polyester and / or a polyester diol using the polymerization method according to [17].

[20] A method for producing a polycarbonate diol by polycondensing a dihydroxy compound and a carbonic acid diester as a raw material monomer by a transesterification reaction in the presence of the metal complex, wherein the metal complex is 1 mol of the total dihydroxy compound. The method for producing a polycarbonate diol according to [18], wherein the total amount of the metal (M) is 1 μmol or more and 5000 μmol or less.

[21] A method for producing a polyurethane using a polycarbonate diol produced by the method for producing a polycarbonate diol according to [18] or [20].

The metal complex of the present invention has higher catalytic activity and selectivity than conventional transesterification reaction catalysts, and transesterification reaction and / or polymerization with higher yield, shorter reaction time, mild conditions, and smaller amount of catalyst. Can be advanced. Therefore, when the metal complex of the present invention is used as a catalyst in the industrial production of chemicals and pharmaceuticals, a high-quality product with higher productivity can be obtained. It is also possible to carry out a transesterification reaction using a substrate with low reactivity, which could not be reacted in the past, and it is possible to obtain a wider variety of high value-added products.
In addition, since the metal complex of the present invention is inexpensive, has low coloring, has low toxicity, and has high stability, it is possible to construct an industrial process excellent in safety, environmental friendliness, economy, and operability.

¹ H-NMR chart (FIG. 1 (a)) and ¹³ C-NMR chart (FIG. 1 (b)) of the metal complex C-1 produced in Example 1-1. ¹ H-NMR chart (FIG. 2 (a)) and ¹³ C-NMR chart (FIG. 2 (b)) of the metal complex C-2 produced in Example 1-2. ^{It is 1} H-NMR chart of the metal complex C-4 produced in Example 1-4. ^{It is 1} H-NMR chart of the polymerization reaction solution of L-lactide in Example 3-1. ^{It is 1} H-NMR chart of the polymerization reaction solution of ε-caprolactone in Example 3-2.

Hereinafter, the present invention will be described in detail, but the present invention is not limited to the following description, and can be arbitrarily modified and carried out without departing from the gist of the present invention.
In addition, in this specification, when a numerical value or a physical property value is put before and after using "~", it is used as including the value before and after that. Further, in the present specification, "mass%" and "weight%", "mass ppm" and "weight ppm", and "parts by mass" and "parts by weight" are synonymous with each other. Moreover, when it simply describes as "ppm", it means "weight ppm".

[1. Metal complex]
The metal complex of the present invention (hereinafter, may be referred to as “the present metal complex”) is represented by the following general formula (1).
A metal complex represented by the following general formula (1).
(M) x (A) p (B) q (C) r (1)
(In the above general formula (1), (M) represents a Group 2 divalent metal in the long periodic table (hereinafter, may be simply referred to as "Group 2 metal"), and (A), (B) and (C) represent ligands, respectively.
x, p, q, and r represent arbitrary integers other than 0, and satisfy the following equations (2) and (3).
p + q = 2x (2)
p + q + r ≦ 6x (3)
The ligand (A) is a diketonate ligand represented by the following formula A1.
The ligand (B) is an anionic ligand other than the ligand (A), and is an anion of a compound having at least one oxygen atom and / or a nitrogen atom and having 1 to 20 carbon atoms, or an OH ^- anion. Is.
Ligand (C) is a ligand of the neutral compound having 1 to 20 carbon atoms and having at least one oxygen atom and / or nitrogen atoms, or a H _{2 O.} )

(In the formula (A1), R ₁ , R ₂ , and R ₃ independently represent a monovalent hydrocarbon group having 1 to 20 carbon atoms, a hydrogen atom, or a halogen atom. The hydrocarbon group has a halogen atom. It may be substituted or may have an oxygen atom.)

The present metal complex may be isolated and used by prior complex preparation, or may be generated before and / or during the transesterification reaction. During the transesterification reaction, the types and numbers of the metal (M), the ligand (A), the ligand (B), and the ligand (C) can be changed within the range included in the general formula (1). It may change.

In the general formula (1), x, p, q, and r represent arbitrary integers other than 0, and satisfy the above formulas (2) and (3).
That is, in this metal complex, each of the metal (M), the ligand (A), the ligand (B), and the ligand (C) has different effects, and each of them has one or more. By doing so, each effect can be obtained.

<1-1. Equation (2)>
Group 2 metal (M) is a divalent metal, and p and q each represent a monovalent anion ligand. By doubling the sum of the numbers of p and q with respect to the number x of the metal, the complex as a whole becomes electronically stable and can be treated stably as a catalyst. For example, when x = 4, p = 4, and q = 4, the complex (2) is satisfied and an electronically stable complex is obtained.

<1-2. Equation (3)>
The total number of ligands per metal (M) atom is 6 or less.
When p + q + r exceeds 6x, the complex tends to be unstable due to electronic factors of the metal.

<1-3. Metal (M)>
The metal (M) represents at least one metal selected from the group consisting of Group 2 metals. Examples of the Group 2 metal include beryllium, magnesium, calcium, strontium, barium, and radium. From the viewpoint of stability, magnesium, calcium, and barium are preferable, and since they are inexpensive, calcium and magnesium are preferable, and magnesium is most preferable. ..

<1-4. Ligand (A)>
The ligand (A) is a diketonate ligand represented by the following formula (A1). The diketonate ligand has a structure as shown in the following formula (A1) and can be stably coordinated to the metal (M) by a bidentate coordination with two carbonyl groups. That is, even under high temperature conditions and reduced pressure conditions, the metal (M) can remain coordinated and remain present. In addition, the structure represented by the following formula (A1) makes it possible to improve the stability, electronic state, steric hindrance, solvent solubility, etc. of the present metal complex.

(In the formula (A1), R ₁ , R ₂ , and R ₃ each independently represent a monovalent hydrocarbon group having 1 to 20 carbon atoms, a hydrogen atom, or a halogen atom. The hydrocarbon group is substituted with a halogen atom. It may have an oxygen atom.)

In the formula (A1), R ₁ , R ₂ , and R ₃ independently represent a monovalent hydrocarbon group having 1 to 20 carbon atoms, a hydrogen atom, or a halogen atom. The hydrocarbon group may be substituted with a halogen atom or may have an oxygen atom. Examples of the hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, s-butyl group and t-butyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Examples of the alkyl group substituted with the halogen atom include a perfluoroalkyl group such as a trichloromethyl group, a tribromomethyl group, a trifluoromethyl group, a pentafluorethyl group, a heptafluoropropyl group and a heptafluoroisopropyl group. Can be mentioned.

Preferred groups of R ₁ and R ₃ include monovalent hydrocarbon groups having 1 to 7 carbon atoms or hydrogen atoms which may be substituted with halogen atoms, and among these, from the viewpoint of easy availability. A methyl group, a t-butyl group, a trichloromethyl group and a trifluoromethyl group are preferable, and a t-butyl group and a methyl group are most preferable from the viewpoint of the stability of the complex and the solubility in an organic solvent.
Preferred groups of R ₂ include monovalent hydrocarbon groups or hydrogen atoms having 1 to 7 carbon atoms which may be substituted with halogen atoms, and methyl groups or hydrogen atoms are preferable from the viewpoint of easy availability. , Hydrogen atom is preferable from the viewpoint of steric hindrance.

<1-5. Ligand (C)>
Ligand (C) is at least one compound having 1 to 20 carbon atoms having an oxygen atom and / or nitrogen atoms, or a neutral ligand consisting of H _{2 O.}
The ligands (A) and (B) are anionic ligands, whereas the ligand (C) is a neutral ligand.
The neutral ligand (C), which does not have an ionic bond, is bound to the central metal (M) with a weak covalent bond and may easily exchange with other ligands contained in the reaction system. .. That is, it may act as an active site by exchanging with a substrate that activates as a catalyst. For example, the raw material alcohols and / or amines used in the transesterification reaction may be introduced as the ligand (C).

Examples of the neutral ligand (C) include the following compounds.
Monools: Methanol, ethanol, propanol, butanol, hexanol, etc.
Diores: ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1, Linear terminal dihydroxy compounds such as 9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,20-eicosanediol; diethylene glycol, triethylene glycol, Dihydroxy compounds having an ether group such as tetraethylene glycol and polytetramethylene glycol; thioetherdiols such as bishydroxyethylthioether; 2-ethyl-1,6-hexanediol, 2-methyl-1,3-propanediol, 3-Methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (also referred to as neopentyl glycol), 2-ethyl 2,2-Dialkyl substitutions 1,3 such as -2-butyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-pentyl-2-propyl-1,3-propanediol -Propanediols, etc.
Triols: Trimethylolpropane, trimethylolethane, glycerin, cyclohexanetrimethanol, cyclododecanetrimethanol, phenyltrimethanol, etc.
Ethers in which an alkyl group is bonded to the hydroxyl groups of the monools, diols, and triols.
Phenols: Phenol, cresol, biphenol, bisphenol A, etc. Monoamines: diethylamine, dibutylamine, n-butylamine, monoethanolamine, diethanolamine, morphophorin, etc.
Diamines, polyamines: ethylenediamine, 1,3-diaminopropane, hexamethylenediamine, triethylenetetramine, diethylenetriamine, isophoronediamine, 4,4'-diaminodicyclohexylmethane N-containing heterocyclics: pyridine, N, N-dimethylamino Pyridine, imidazole, bipyridine, phenanthroline, etc.
Alkyl amines in which an alkyl group is bonded to the above monoamines, diamines, polyamines, and N-containing heterocycles.
Carbonates: Dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, diisobutyl carbonate, ethyl-n-butyl carbonate, ethyl isobutyl carbonate, diphenyl carbonate, ditril carbonate, ethylene carbonate, trimethylene carbonate, tetramethylene carbonate, 1, 2 -Propylene carbonate, 1,2-butylene carbonate, neopentyl carbonate, etc.

The following esters Chain alkyl esters: methyl formate, ethyl formate, propyl formate, butyl formate, amyl formate, hexyl formate, heptyl formate, octyl formate, nonyl formate, decyl formate, methyl Acetate, ethyl acetate, propyl acetate, butyl acetate, amyl acetate, hexyl acetate, heptyl acetate, octyl acetate, nonyl acetate, decyl acetate, methyl propionate, ethyl propionate, propyl propionate, butyl propionate, amyl Propionate, hexyl propionate, heptyl propionate, octyl propionate, nonyl propionate, decyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, butyl butyrate, amyl butyrate, hexyl Butylate, heptylbutylate, octylbutyrate, nonylbutyrate, decylbutyrate, etc.
Cycloalkyl ester: cyclopentylformate, cyclohexylformate, cycloheptylformate, cyclooctylformate, cyclopentylacetate, cyclohexylacetate, cycloheptylacetate, cyclooctylacetate, cyclopentylpropionate, cyclohexylpropionate, cycloheptylpropio Nate, cyclooctyl propionate, cyclopentyl butyrate, cyclohexyl butyrate, cycloheptyl butyrate, cyclooctyl butyrate, etc.
Unsaturated aliphatic esters: vinyl formate, allyl formate, metalyl formate, crotonyl formate, vinyl acetate, allyl acetate, metharyl acetate, crotonyl acetate, vinyl propionate, allyl propionate, metalylyl Propionate, crotonyl propionate, vinyl butyrate, allyl butyrate, metallicyl butyrate, crotonyl butyrate, etc.
Unsaturated ester: Methyl acrylate, methyl crotonate, methyl oleate, allyl acrylate, etc.
Cycloalkenyl esters: cyclopentenylformates, cyclohexenylformates, cycloheptenylformates, cyclooctenylformates, cyclopentenylacetates, cyclohexenylacetates, cycloheptenylacetates, cyclooctenylacetates, cyclopentenylpropionates, Cyclohexenyl propionate, cycloheptenyl propionate, cyclooctenyl propionate, cyclopentenyl butyrate, cyclohexenyl butyrate, cycloheptenyl butyrate, cyclooctenyl butyrate, etc.
Aryl ester: benzyl formate, benzyl acetate, benzyl propionate, benzyl butyrate, benzyl benzoate, etc.

Amides: Dimethylformamide (DMF), dimethylacetamide (DMAc), N-methylpyrrolidone (NMP) and the like.

Among these, from the viewpoint of small steric hindrance, easy formation of a stable structure as a ligand, and easy synthesis, monools, diols, triols, which have N-containing heterocyclics and 1 to 3 hydroxyl groups, Phenols are preferable, monools and diols are more preferable from the viewpoint of solubility, and methanol and ethanol are particularly preferable from the viewpoint of steric hindrance.
From the viewpoint of the catalytic activity of the transesterification reaction, methanol and ethanol, which easily exchange with the reaction substrates alcohol, ester and carbonate, are preferable.
A compound having a hydroxyl group, an amino group, a carbonate group, an ester group, a carbonyl group, or an amide group in the raw material used for the transesterification reaction may be introduced as the ligand (C).

<1-6. Ligand (B)>
The ligand (B) is an anionic ligand different from the ligand (A), and is an anion of a compound having at least one oxygen atom and / or a nitrogen atom and having 1 to 20 carbon atoms, or OH ^−. Represents an anion. Specific examples thereof include anions of the compounds exemplified in the ligand (C) in the previous section. Among these, anions of monools, diols, triols, and phenols having 1 to 3 hydroxyl groups are preferable from the viewpoint of solubility of the complex, and steric hindrance is observed from the viewpoint of easily forming a stable structure as a ligand. Since the size is small, methoxydo and ethoxydo are preferable, and the ligand (B) is preferably derived from the same compound as the ligand (C) from the viewpoint of stabilization due to the regularity of the complex structure.
Further, alcohols and / or amines as raw materials used in the transesterification reaction may be introduced as the ligand (B).

Since the ligand (B) has an anionic property, it is involved in activation by anionization of the reaction substrate, anionizes the hydroxyl group of the alcohol of the reaction substrate for transesterification, and plays a role of improving nucleophilicity.

<1-7. Metal (M) number x>
The number x of the metal (M) contained in one molecule of the metal complex is not particularly limited, but if x is too large, the metal atoms will be more agglomerated, the solubility in the organic solvent will decrease, and the reaction will occur. It may reduce the properties or cause turbidity in the product. Therefore, x is preferably 10 or less, more preferably 8 or less, still more preferably 6 or less, and particularly preferably 4 or less from the viewpoint of solubility of the present metal complex. On the other hand, the lower limit of x is 1 or more, and is preferably 2 or more from the viewpoint that the metal (M) is bonded to each other and the stability is improved. From the above viewpoint, x is preferably 2 or 4, and most preferably 4. Further, during a reaction such as a transesterification reaction, the number x of the metal (M) increases or decreases due to the reaction or coordination of the reaction substrate or solvent, or the influence of changes in temperature or pressure. In some cases. Further, a mixture in which metal complexes having different numbers x of the metal (M) are mixed may be produced.

<1-8. Number of ligands>
The number p of the ligand (A) is not particularly limited, but if it is too small, the solubility of the metal complex is lowered, and if it is too large, steric hindrance around the metal (M) is caused and the reactivity is lowered. The number p of the ligand (A) is preferably 2 times or less with respect to the number x of the metal (M), and most preferably 1 time in order to stabilize the complex as a highly symmetric complex.
The number q of the ligand (B) is not particularly limited, but is preferably 2 times or less with respect to the number x of the metal (M), and is 1 time in order to stabilize as a highly symmetric complex. Is the most preferable. Further, the relationship between x, p and q satisfies the above formula (2) in order to make the valence of the anion the same with respect to the divalent metal (M) number x.
The number r of the ligand (C) is not particularly limited, but the above formula (3) is used to stabilize the metal complex.
Meet. In addition, the ligands (A), (B), and (C) are affected by the reaction and coordination of the reaction substrate and the solvent during the reaction such as the transesterification reaction, and the change in temperature and pressure. ) May increase or decrease.

<1-9. Ligand mol ratio>
The number x of the metal (M) in one molecule of the metal complex is an arbitrary integer larger than 0, and the ratio of x: p: q: r in the general formula (1) may be any value. It is preferable that the ratio is 1: 1: 1: 1 because an octahedral structure having a stable structure can be obtained. In particular, the present metal complex is preferably a cubane-type metal complex having an octahedral structure in which the crystal structure analyzed by X-ray structure analysis is composed of metal atoms and oxygen atoms from the viewpoint of its stability. In the following, the "octahedral structure" may be referred to as a "cuban type".

<1-10. Structure determination of metal complex>
The metal (M) contained in this metal complex, the types of ligands (A) to (C), and their mol ratios (x, p, q, r) are X-ray structure analysis, MASS, NMR, FT-IR, It is determined by an analytical method such as UV-VIS. In the case of a mixture of a plurality of complexes, the mol ratio is observed as an average value of the plurality of complexes by NMR and may not be an integer.

<1-11. Mixture of metal complex>
This metal complex is a mixture of a plurality of catalyst species having different x, p, q, and r in the metal complex (M) x (A) p (B) q (C) r represented by the general formula (1). There may be. When the metal complex is a mixture, the solvent solubility of the metal complex may be improved, or the catalytic activity may be improved by mutual interaction.

<1-12. Method for manufacturing metal complex>
The method for producing the metal complex is not particularly limited, and for example, it can be produced by the following method. Further, during the transesterification reaction, the alcohol or ester used as a raw material may be coordinated with the divalent metal to form the present metal complex in the reaction system.

The method for producing the present metal complex is not particularly limited, but for example, a metal (M) and / or a salt thereof, a ligand (A), (B), and (C) are mixed in a solvent to obtain a obtained complex. Can be manufactured by Further, different complexes may be obtained depending on the difference in the mixing ratio and the mixing conditions.
Examples of the salt of the metal (M) include halides (chlorides, bromides, iodides), oxides, alkoxy salts (methoxy salts, ethoxy salts, propyroxy salts, butoxy salts, etc.), acetylacetone salts, etc. Halides, alkoxy salts or acetylacetone salts are preferable from the viewpoint of ease of use and solubility in organic solvents, and halides or alkoxy salts are most preferable from the viewpoint of ease of ligand exchange reaction and ease of removal of by-products.
The solvent is not particularly limited, but for example, an aromatic solvent such as toluene, xylene or benzene chloride; an aliphatic hydrocarbon solvent such as hexane, heptane or octane; diethyl ether, diisopropyl ether, tert-butyl methyl ether, etc. Ether solvent such as tetrahydrofuran or 1,4-dioxane; alcohol solvent such as methanol, ethanol, isopropanol; amide solvent such as dimethylformamide (DMF), dimethylacetamide (DMAc) or N-methylpyrrolidone (NMP); dimethylsulfoxide (DMSO) and the like can be used. Of these, aromatic solvents and ether solvents, which are less likely to cause coordination of the metal complex and have high solubility of the metal complex, are preferable. Further, alcohol, ester, carbonate or the like used in the next transesterification reaction may be used as a solvent.
Further, a metal salt different from the metal (M) may be used in order to smoothly synthesize the metal complex. For example, when a monovalent metal alkoxide of Group 1 of the periodic table such as lithium alkoxide is used, the anion produced as a by-product from the metal (M) can be trapped and removed as a lithium salt from the reaction system. A highly pure metal complex can be efficiently synthesized.

The method for producing the metal complex is not particularly limited, but specific preferred production methods include the following two methods.

Production method 1: A halide of the metal (M), a metal salt having a ligand (B), and a ligand (A), (C) or a precursor having these structures are mixed.
As the metal salt having the ligand (B), metal salts such as lithium, sodium, potassium and barium are preferable from the viewpoint of easy availability, and lithium methoxide and lithium ethoxide are particularly preferable from the viewpoint of reactivity and separation of by-products. , Sodium methoxide, sodium methoxide, potassium methoxide, potassium methoxide are preferred. When this production method is used, a halide different from the metal (M) is produced as a by-product. Since they have different solubility from the present metal complex or are insoluble in an organic solvent, they can be easily removed by filtration or the like, and there is an advantage that the present metal complex having high purity can be obtained.

Production method 2: The ligand (A), (C) or a precursor having these structures is mixed with the metal salt having the metal (M) and the ligand (B).
As the metal salt having the metal (M) and the ligand (B), the compound of the combination of the metal (M) and the ligand (B) described above is used, but calcium and calcium are used because of their availability and solubility. Magnesium dialkoxides are preferred, and ethoxydos and methoxides are preferred, especially from the standpoint of substitution reactivity. Since the ligand (A) can be stably coordinated with respect to the metal atom in a bidentate coordination, the exchange from the ligand (B) to the ligand (A) easily proceeds. Further, different ligands (B1) and ligands (C1) react with a metal complex having a metal (M), ligands (A), (B), and (C), and the ligands are exchanged. In some cases, this metal complex can be obtained. This production method has an advantage in that it is easy to prepare because no post-treatment or purification step is required because by-products containing other metals are not produced. Further, it is possible to prepare a metal complex immediately before in the same reaction solution using the reaction vessel used for the transesterification reaction, and it can be used without the need to isolate an unstable metal complex, and the synthesis of the metal complex can be performed. Since the total production time from the process to the transesterification reaction can be reduced, it is effective from the viewpoint of handleability and productivity, especially in actual production at the time of scale-up.

Production method 3: The ligand (B), (C) or a precursor having these structures is mixed with the metal salt having the metal (M) and the ligand (A).
As the metal salt having the metal (M) and the ligand (A), the compound of the combination of the metal (M) and the ligand (A) described above is used, but calcium and calcium are used because of their availability and solubility. The diacetylacetonato salt of magnesium is preferred. Further, a different ligand (B1) and a ligand (C1) react with a metal complex having a metal (M), a ligand (A), (B), and (C), and the ligand is exchanged. In some cases, this metal complex can be obtained.

These production methods may be carried out by using the substrates and solvents used in the reaction as ligands (A), (B) and (C) before the reaction such as transesterification reaction. Further, during the transesterification reaction, the reaction substrate (alcohol, ester, carbonate, etc.) or solvent may react and coordinate to produce the present metal complex. In this production method, since the metal salt having the metal (M) and the ligand (A) is highly soluble in the organic solvent, the solvent into which the ligands (B) and (C) are introduced is in the organic solvent. It has the advantage of proceeding efficiently.

<1-13. How to use the metal complex>
The present metal complex may be used as it is after synthesis without purification, or may be purified and used. Further, a plurality of the present metal complexes may be mixed and used. From the viewpoint of industrial handling, the metal complex solution obtained by the above production method may be used as it is. Further, the reaction may be carried out while synthesizing a metal complex using a reaction substrate such as an ester or alcohol used for the transesterification reaction or a solvent.

<1-14. Use of metal complexes>
This metal complex can be used as a transesterification reaction catalyst. The specific reactions are as listed below.

[2. Usage as a transesterification reaction catalyst]
Hereinafter, an application example in which the present metal complex is used as a transesterification reaction catalyst (hereinafter, may be referred to as “the present catalyst”) will be described.

<2-1. Amount of catalyst>
The amount of the catalyst used is not particularly limited, but is usually preferably 0.00001 to 0.9 mol, more preferably 0.00001 to 0.3 mol, still more preferably 0.00001 to 0.3 mol, as the metal (M) atomic weight with respect to 1 mol of the raw material. The ratio is 0.00001 to 0.1 mol. However, when the product is a polymer or the like and it is difficult to remove the catalyst, the metal (M) atomic weight is preferably 0.00001 to 0.01 mol with respect to 1 mol of the raw material, and the ratio is 0.00001 to 0.001 mol. More preferably.

<2-2. Solvent>
When this catalyst is used, the reaction solvent may or may not be used. It is preferable not to use it from the viewpoint of productivity and environmental load. On the other hand, in order to improve the reaction efficiency of the solid raw material, it may be preferable to use a reaction solvent.

Specific examples of the reaction solvent are not particularly limited, but for example, aromatic solvents such as toluene, xylene or benzene chloride; aliphatic hydrocarbon solvents such as hexane, heptane or octane; diethyl ether, diisopropyl ether, tert-. Ether solvents such as butyl methyl ether, tetrahydrofuran, cyclopentyl methyl ether or 1,4-dioxane; amide solvents such as dimethylformamide (DMF), dimethylacetamide (DMAc) or N-methylpyrrolidone (NMP); dimethylsulfoxide (DMSO) ) Etc. can be mentioned. Only one of these solvents may be used, or two or more of these solvents may be mixed and used.

<2-3. Auxiliary catalyst>
Along with this catalyst, a transition metal compound or a basic compound such as a basic boron compound, a basic phosphorus compound, a basic ammonium compound, or an amine compound can be used in combination as an auxiliary catalyst. Auxiliary catalysts may be referred to as additives or additives depending on the situation. Auxiliary catalysts may be incorporated during the reaction as part of the metal atoms and ligands of the metal complexes of the invention.

Examples of the transition metal compound include titanium alkoxides such as tetraethyl titanate, tetraisopropyl titanate and tetra-n-butyl titanate; halides of titanium such as titanium tetrachloride; tin (II) chloride, tin (IV) chloride and tin acetate ( Tin compounds such as tin acetate (IV), dibutyltin dilaurate, dibutyltin oxide, dibutyltin dimethoxydo; zirconium compounds such as zirconium acetylacetonate, zirconium oxyacetate, zirconium tetrabutoxide; lead acetate (II), lead acetate (IV) ), Lead compounds such as lead (IV) chloride, and the like.

Examples of the basic boron compound include tetramethylboron, tetraethylboron, tetrapropylboron, tetrabutylboron, trimethylethylboron, trimethylbenzylboron, trimethylphenylboron, triethylmethylboron, triethylbenzylboron, triethylphenylboron and tributylbenzyl. Examples include sodium salts such as boron, tributylphenyl boron, tetraphenyl boron, benzyl triphenyl boron, methyl triphenyl boron, and butyl triphenyl boron, potassium salts, lithium salts, calcium salts, barium salts, magnesium salts, and strontium salts. Be done.

Examples of the basic phosphorus compound include tertiary phosphines such as triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, tributylphosphine, and tri (ethylhexyl) phosphine; diethyl. Secondary phosphines such as phosphine, di-n-propylphosphine, diisopropylphosphine, di-n-butylphosphine, diphenylphosphine, dibutylphosphine, di (ethylhexyl) phosphine and / or quaternary phosphonium salts; phosphoric acid, phosphite Inorganic phosphoric acid such as dibutyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate, di (ethylhexyl) phosphate, organic phosphoric acid ester such as triphenyl phosphite; and the like.

Examples of the basic ammonium compound include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylbenzylammonium hydroxide, and trimethylphenylammonium hydroxide. Triethylmethylammonium hydroxide, triethylbenzylammonium hydroxide, triethylphenylammonium hydroxide, tributylbenzylammonium hydroxide, tributylphenylammonium hydroxide, tetraphenylammonium hydroxide, benzyltriphenylammonium hydroxide, methyltriphenylammonium hydroxide, Examples thereof include butyltriphenylammonium hydroxide.

Examples of amine compounds include 4-aminopyridine, 2-aminopyridine, N, N-dimethyl-4-aminopyridine, 4-diethylaminopyridine, 2-hydroxypyridine, 2-methoxypyridine, 4-methoxypyridine, 2 -Dimethylaminoimidazole, 2-methoxyimidazole, imidazole, 2-mercaptoimidazole, 2-methylimidazole, aminoquinoline, bipyridine, phenanthroline, 1-benzylimidazole and the like.

Only one kind of these auxiliary catalysts may be used, or two or more kinds thereof may be used in combination.

When these auxiliary catalysts are used, the amount used is preferably 100 times or less, particularly 10 times or less, in terms of mol ratio, as an upper limit with respect to the metal (M) of the present catalyst. The lower limit is preferably 0.01 times or more, particularly 0.1 times or more. The combined use of these cocatalysts may have the effect of improving catalytic activity and / or selectivity, or suppressing a decrease in catalytic activity due to impurities or reaction by-products in the raw material, but the amount used may be achieved. If the amount is too large, the color tone, transparency, light resistance, thermal stability, etc. of the obtained product may be deteriorated, which is not preferable. On the other hand, if the amount is too small, the effect of using the auxiliary catalyst may not be sufficiently obtained.

<2-4. Transesterification reaction>
The transesterification reaction corresponds to ^{the OR B} of an ester in which an ester such as a carboxylic acid ester ( ^RA COOR ^B ) or a carbonic acid ester ( ^RA OCOOR ^{B ) reacts with an alcohol (RC} OH) having one or more hydroxyl groups. It is a reaction in which the partial structure is exchanged for alcohol. For example, the transesterification reaction of a carboxylic acid ester can be represented by the following reaction scheme. Further, the catalyst effective in the transesterification reaction can also be applied to the transesterification reaction with an amide group or a thioester group having the same reactivity as an ester, an amine or a thiol having the same reactivity as an alcohol.

<2-4-1. Carboxylate ester>
In the above reaction scheme, the carboxylic acid ester is represented by the formula ^{(R A COOR B), R} A and ^{R B} represents an optional organic group.

Specific examples of carboxylic acid esters include chain alkyl esters such as methyl formate, ethyl formate, propyl formate, butyl formate, amyl formate, hexyl formate, heptyl formate, and octyl formate. Nonylformate, decylformate, methylacetate, ethylacetate, propylacetate, butylacetate, amylacetate, hexylacetate, heptylacetate, octylacetate, nonylacetate, decylacetate, methylpropionate, ethylpropionate, propylpro Pionate, Butyl Propionate, Amil Propionate, Hexyl Propionate, Heptyl Propionate, Octyl Propionate, Nonyl Propionate, Decyl Propionate, Methyl Butyrate, Ethyl Butyrate, Propyl Butyrate, Examples thereof include butyl butylate, amylbutyrate, hexylbutyrate, heptylbutyrate, octylbutyrate, nonylbutyrate, decylbutyrate and the like.
Examples of cycloalkyl esters include cyclopentyl formate, cyclohexyl formate, cycloheptyl formate, cyclooctyl formate, cyclopentyl acetate, cyclohexyl acetate, cycloheptyl acetate, cyclooctyl acetate, cyclopentyl propionate, and cyclohexyl propionate. , Cycloheptyl propionate, cyclooctyl propionate, cyclopentyl butyrate, cyclohexyl butyrate, cycloheptyl butyrate, cyclooctyl butyrate and the like.
Examples of unsaturated aliphatic esters include vinyl formate, allyl formate, methallyl formate, crotonyl formate, vinyl acetate, allyl acetate, metharyl acetate, crotonyl acetate, vinyl propionate, and allyl propionate. , Metallyl propionate, crotonyl propionate, vinyl butyrate, allyl butyrate, metallicl butyrate, crotonyl butyrate and the like.
Examples of unsaturated esters include methyl acrylate, methyl crotonate, methyl oleate, allyl acrylate and the like.
Examples of the cycloalkenyl ester include cyclopentenylformate, cyclohexenylformate, cycloheptenylformate, cyclooctenylformate, cyclopentenylacetate, cyclohexenylacetate, cycloheptenylacetate, cyclooctenylacetate, and cyclopentenylpro. Pionate, cyclohexenyl propionate, cycloheptenyl propionate, cyclooctenyl propionate, cyclopentenyl butyrate, cyclohexenyl butyrate, cycloheptenyl butyrate, cyclooctenyl butyrate and the like can be mentioned.
Examples of the aryl ester include benzylformate, benzylacetate, benzylpropionate, benzylbutyrate, benzylbenzoate and the like.

Among these, methyl ester, ethyl ester, propyl ester and phenyl ester are preferable from the viewpoint of easy availability, and methyl ester is most preferable from the viewpoint of high reactivity.

<2-4-2. Alcohol>
In the reaction scheme described above, the alcohol is ^{represented by the formula (RC-} OH), where ^RC represents any organic group.
The alcohol used is not particularly limited, and any alcohol having a primary, secondary, or tertiary hydroxyl group can be used. Specific examples include the following.

Monools: As primary alcohols, methanol, ethanol, 1-propanol, 1-butanol, 1-hexanol, etc., as secondary alcohols, 2-propanol, cyclohexanol, etc., as tertiary alcohols, t-butanol, 1-adamantan, etc. Alcohol and other diols: ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, Linear terminal dihydroxy compounds such as 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,20-eicosandiol; diethylene glycol, triethylene Dihydroxy compounds having an ether group such as glycol, tetraethylene glycol, polytetramethylene glycol; thioetherdiols such as bishydroxyethylthioether; 2-ethyl-1,6-hexanediol, 2-methyl-1,3-propane Didiol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2-ethyl-2- 2,2-Dialkyl-substituted 1,3-propanediols such as butyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-pentyl-2-propyl-1,3-propanediol Kind

Since the reactivity of the hydroxyl group decreases in the order of primary, secondary, and tertiary, a primary alcohol is preferable from the viewpoint of reactivity. However, esters derived from secondary alcohols and tertiary alcohols are generally low in productivity and are synthesized using other manufacturing methods with high raw material costs, so they tend to be high value-added products, so their product value. It is preferable from the viewpoint of.

<2-5. Polymerization by transesterification reaction>
This catalyst can be utilized in a polymerization reaction in which transesterification reactions occur continuously, and can be applied to, for example, polyester synthesis and polycarbonate synthesis. Specific monomers that can be used for polyester and polycarbonate are as shown in the following sections. Also, the R ^A and R ^B is may form a cyclic structure. In that case, the polymerization proceeds in the form of ring-opening polymerization, and specific monomers include lactide and ε-caprolactone which are cyclic esters, ethylene carbonate and trimethylene carbonate which are cyclic carbonates, and the like.

<2-6. Manufacture of polyesters and / or polyester polyols>
Polyester is mainly synthesized by polymerization of a dicarboxylic acid ester and a dihydroxy compound. Examples of the dicarboxylic acid include an aromatic dicarboxylic acid ester and an aliphatic dicarboxylic acid (including an alicyclic dicarboxylic acid) ester.

Examples of the aromatic dicarboxylic acid include terephthalic acid and isophthalic acid. Examples of the aromatic dicarboxylic acid ester include lower alkyl esters of the aromatic dicarboxylic acid. Specific examples of the lower alkyl ester of the aromatic dicarboxylic acid include methyl ester, ethyl ester, propyl ester and butyl ester. Of these, as the aromatic dicarboxylic acid ester, dimethyl terephthalate and dimethyl isophthalate are preferable.

As the aliphatic dicarboxylic acid ester, a chain-type (including linear and branched chain-like) or alicyclic dicarboxylic acid ester having 2 to 40 carbon atoms is usually preferable. The lower limit of the number of carbon atoms of the chain or alicyclic dicarboxylic acid ester is more preferably 4 or more, while the upper limit is preferably 30 or less, particularly 20 or less.
Specific examples of the chain or alicyclic dicarboxylic acid ester having 2 to 40 carbon atoms include oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedioic acid, dimer acid and cyclohexanedicarboxylic acid. Examples include esters such as acids.

[3. Manufacture of Polycarbonate Diol]
This catalyst is highly effective as a catalyst for producing polycarbonate diol, which is useful as a urethane raw material.
In the method for producing a polycarbonate diol using this catalyst, a dihydroxy compound and a carbon dioxide diester are used as raw material monomers, and polycondensation is carried out by a transesterification reaction in the presence of the present catalyst as a transesterification reaction catalyst to produce the polycarbonate diol. The method. The number average molecular weight of the polycarbonate diol produced by the method for producing a polycarbonate diol using this catalyst is preferably 250 or more and 10,000 or less. The number average molecular weight can be measured from NMR, GPC, hydroxyl value and the like.
Hereinafter, a method for producing a polycarbonate diol using the present catalyst (hereinafter, may be referred to as “polycarbonate diol of the present invention”) will be described.

<3-1. Raw material monomer>
The polycarbonate diol of the present invention uses a dihydroxy compound and a carbonic acid diester as raw materials.

<3-1-1. Dihydroxy compound>
Specific examples of the dihydroxy compound used as a raw material for the polycarbonate diol of the present invention include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol. 1,7-Heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol and / or 1,20-eikosanji Linear terminal dihydroxy compounds such as oars, dihydroxy compounds having an ether group such as diethylene glycol, triethylene glycol, tetraethylene glycol and / or polytetramethylene glycol, thioetherdiols such as bishydroxyethylthioether, 2- Ethyl-1,6-hexanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol and / or 2,4-diethyl-1,5-pentanediol, 2,2- Dimethyl-1,3-propanediol (hereinafter sometimes abbreviated as neopentyl glycol), 2-ethyl-2-butyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol and / Alternatively, it shall be described as 2,2-dialkyl-substituted 1,3-propanediols such as 2-pentyl-2-propyl-1,3-propanediol (hereinafter, 2,2-dialkyl-1,3-propanediols). However, the alkyl group is an alkyl group having 15 or less carbon atoms), 2,2,4,4-tetramethyl-1,5-pentanediol and / or 2,2,9,9-tetramethyl-. Tetraalkyl-substituted alkylenediols such as 1,10-decanediol, 3,9-bis (1,1-dimethyl-2-hydroxyethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane Dihydroxy compounds containing cyclic groups such as, 2,2-diphenyl-1,3-propanediol, 2,2-divinyl-1,3-propanediol, 2,2-dietinyl-1,3-propanediol, 2, , 2-Dimethoxy-1,3-propanediol, bis (2-hydroxy-1,1-dimethylethyl) ether, bis (2-hydroxy-1,1-dimethylethyl) thioether and 2,2,4,5- Dihydroxy compounds having branched chains such as tetramethyl-3-cyano-1,5-pentanediol, 1,3-si Clohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 4,4-dicyclohexyldimethylmethanediol, 2,2'-bis (4-hydroxycyclohexyl) propane, 1,4-dihydroxyethylcyclohexane, Cyclic such as isosorbide, spiroglycol, 2,5-bis (hydroxymethyl) tetrahydrofuran, 4,4'-isopropyridene dicyclohexanol and / or 4,4'-isopropyridenebis (2,2'-hydroxyethoxycyclohexane) Dihydroxy compounds whose groups are in the molecule, 9,9-bis (4- (2-hydroxyethoxy) phenyl) fluorene, 9,9-bis (4- (2-hydroxyethoxy-2-methyl) phenyl) fluorene, Dihydroxy compounds having an aromatic ring such as diethanolamine, nitrogen-containing dihydroxy compounds such as diethanolamine and / or N-methyl-diethanolamine, and sulfur-containing dihydroxy compounds such as bis (hydroxyethyl) sulfide, 2,2-bis (4-hydroxyphenyl). ) Propane [= bisphenol A], 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-diethylphenyl) propane, 2,2- Bis (4-hydroxy- (3,5-diphenyl) phenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxyphenyl) pentane, 2 , 4'-dihydroxy-diphenylmethane, bis (4-hydroxyphenyl) methane, bis (4-hydroxy-5-nitrophenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 3,3-bis (4) -Hydroxyphenyl) pentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, bis (4-hydroxyphenyl) sulfone, 2,4'-dihydroxydiphenyl sulfone, bis (4-hydroxyphenyl) sulfide, 4,4' -Dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dichlorodiphenyl ether, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-2-methylphenyl) fluorene, etc. Aromatic bisphenols, etc. can be mentioned.

Above all, from the viewpoint of the light resistance of the polyurethane obtained by using the polycarbonate diol of the present invention, at least one selected from the group consisting of the aliphatic dihydroxy compound represented by the following formula (4) and / or the alicyclic dihydroxy compound. It is preferably a compound of the species.
HO-R _4- OH (4)
(In the formula (4), R ₄ represents a linear or branched divalent hydrocarbon group having 2 to 60 carbon atoms, which may have a cyclic structure and / or / or ether oxygen atoms)

Preferably the formula (4) the number of carbon atoms of R ₄ in the melting point of the polycarbonate diols obtained, the glass transition temperature, from the viewpoint of solvent resistance 2 to 20, especially 2 to ease of industrial availability It is preferably 12, and more preferably 3 to 10.

Among such dihydroxy compounds, the aliphatic dihydroxy compounds include 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,10-decanediol. , Neopentyl glycol is preferable, and as the alicyclic dihydroxy compound, 1,4-cyclohexanedimethanol and tricyclodecanedimethanol are particularly preferable. From the viewpoint, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, neopentyl glycol, and 1,4-cyclohexanedimethanol are preferable.

As the dihydroxy compound having an etheric oxygen atom, poly (oxyalkylene) diol is preferable, diethylene glycol, triethylene glycol, tetraethylene glycol and / or polyoxytetramethylene glycol are preferable, and among them, it is easily and inexpensively obtained as an industrial raw material. Possible diethylene glycol, triethylene glycol and polyoxytetraethylene glycol are particularly preferred.
As the polyoxytetramethylene glycol, polyoxytetramethylene glycol having a number average molecular weight of 100 or more and 1000 or less is preferable, and polyoxytetramethylene glycol having a number average molecular weight of 150 or more and 700 or less is preferable from the viewpoint of ease of handling and synthesis of polycarbonate diol. Oxytetramethylene glycol is particularly preferred.
Here, the number average molecular weight means the molecular weight calculated from the terminal group concentration in the poly (oxyalkylene) diol, and can be calculated from the hydroxyl value ([OHV]) of the poly (oxyalkylene) diol.

These dihydroxy compounds may be used alone or in combination of two or more depending on the required performance of the obtained polycarbonate diol, but it is preferable to combine a plurality of them to form a copolymerized polycarbonate diol. Copolymerized polycarbonate diols are generally inhibited from crystallization, have higher fluidity than homopolycarbonate diols, and are not only superior in operability when processed into polyurethane, but also impart flexibility and texture to polyurethane. can do.

The composition ratio of the copolymerization is, for example, when two kinds of dihydroxy compounds are used, each dihydroxy compound is 5 mol% or more, preferably 10 mol% or more, more preferably 20 mol% or more, still more preferably 20 mol% or more, based on the total dihydroxy compounds. It is desirable to use 30 mol% or more.
Normally, when copolymerizing dihydroxy compounds having different molecular structures, the polymerization reaction may become non-uniform or the polymerization may be inhibited due to the difference in reactivity. However, according to this catalyst, the copolymerized polycarbonate diol can be easily obtained. Can be obtained. In particular, when a dihydroxy compound having a substituent at the α or β position of the hydroxyl group is used, the conventional method tends to inhibit the polymerization due to steric hindrance, but according to this catalyst, the copolymerized polycarbonate diol can be easily inhibited. Therefore, the effect of the present invention can be effectively obtained.

<3-1-2. Carbonic acid diester>
The carbonic acid diester that can be used as a raw material for producing the polycarbonate diol of the present invention is not limited as long as the effect of the present invention is not lost, and examples thereof include dialkyl carbonate, diaryl carbonate, and alkylene carbonate. Of these, the use of diaryl carbonate has the advantage that the reaction proceeds rapidly. However, on the other hand, when diaryl carbonate is used as a raw material, phenols having a high boiling point are by-produced, and since the by-produced phenols are monofunctional compounds, they can be a polymerization inhibitor during polyurethane formation and can be an irritant. There is also a possibility that a problem may occur in which it also becomes a coloring causative substance. From this point of view, it is preferable that the residual amount of phenols in the polycarbonate diol of the present invention is smaller.

Among the carbonic acid diesters that can be used for producing the polycarbonate diol of the present invention, specific examples of the dialkyl carbonate are dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, diisobutyl carbonate, ethyl-n-butyl carbonate, and ethyl isobutyl carbonate. And so on.

Examples of diaryl carbonate include diphenyl carbonate, ditril carbonate, bis (chlorophenyl) carbonate, dim-credyl carbonate and the like.

Examples of alkylene carbonates include ethylene carbonate, trimethylene carbonate, tetramethylene carbonate, 1,2-propylene carbonate, 1,2-butylene carbonate, 1,3-butylene carbonate, 2,3-butylene carbonate, 1,2- Pentylene carbonate, 1,3-pentylene carbonate, 1,4-pentylene carbonate, 1,5-pentylene carbonate, 2,3-pentylene carbonate, 2,4-pentylene carbonate, neopentyl carbonate and the like. Be done.

One of these may be used alone, or two or more thereof may be used in combination.

Among these, diaryl carbonate is preferable because it is superior in reactivity to dialkyl carbonate as described above, and therefore, when it is used as a carbonate source, the reaction proceeds under mild conditions even with a dihydroxy compound having low reactivity. Of these, diphenyl carbonate, which can be easily and inexpensively obtained as an industrial raw material, is more preferable.

As the dialkyl carbonate, dimethyl carbonate and diethyl carbonate, which can be easily and inexpensively obtained as an industrial raw material and can easily remove by-produced alcohol at a low boiling point, are preferable.

On the other hand, unlike dialkyl carbonate and diaryl carbonate, the alkylene carbonate does not have an alkyloxy group or an aryloxy group at the end of the polycarbonate diol molecular chain, but a hydroxyalkylene group having both ends of the polycarbonate diol molecular chain having a hydroxyl group, which is preferable. .. Of these, ethylene carbonate, which can be easily and inexpensively obtained as an industrial raw material, is more preferable.

According to this catalyst, even when dialkyl carbonate or alkylene carbonate having relatively low reactivity is used as a carbonate source, the polymerization reaction proceeds satisfactorily without raising the reaction temperature excessively, so that the effect of the present invention is effective. Can be obtained.

<3-1-3. Ratio of raw material monomer used>
In the production of the polycarbonate diol of the present invention, the amount of the carbonic acid diester used needs to be appropriately changed depending on the target molecular weight of the polycarbonate diol and is not particularly limited. It is .50, more preferably 0.70, still more preferably 0.80, and the upper limit is usually 1.20, preferably 1.15, more preferably 1.10. If the amount of carbonic acid diester used exceeds the above upper limit, the proportion of the obtained polycarbonate diol whose terminal group is not a hydroxyl group may increase, or the molecular weight may not be within a predetermined range and a suitable polycarbonate diol may not be produced, which is less than the above lower limit. In some cases, the polymerization does not proceed to a predetermined molecular weight.

<3-2. Amount of catalyst>
In the production of the polycarbonate diol of the present invention, the amount of the catalyst used is usually preferably 1 to 500 μmol, more preferably 5 to 500 μmol, as the amount of the metal (M) per 1 mol of the total dihydroxy compound used as the raw material monomer. It is 200 μmol, more preferably 10 to 100 μmol, and particularly preferably 15 to 50 μmol.

If the amount of this catalyst used is too small, sufficient polymerization activity cannot be obtained and the progress of the polymerization reaction is slowed down. Therefore, it is difficult to obtain a polycarbonate diol having a desired molecular weight, and not only the production efficiency is lowered, but also the raw material monomer is used. During the polymerization reaction, the time that the reaction remains unreacted in the system becomes long, which may lead to deterioration of the color tone. In addition, the amount of monomer distilled out together with the by-produced monohydroxy compound may increase, resulting in deterioration of the raw material basic unit and the need for extra energy for its recovery, and further, a plurality of dihydroxys. In the case of copolymerization using a compound, it may cause a change in the composition ratio of the monomer used as a raw material and the composition ratio of the constituent monomer units in the product polycarbonate diol.

On the other hand, if the amount of this catalyst used is too large, the distillation of unreacted monomers as described above tends to be improved, but on the other hand, the color tone, transparency, light resistance, and thermal stability of the obtained polycarbonate diol are improved. Not only may it cause deterioration of properties, but it may also cause an abnormal reaction during the polyurethaneization reaction.

The present catalyst may be added directly to the polymerization reaction tank, may be added to the dihydroxy compound in advance, or may be added to the carbonic acid diester. Further, the dihydroxy compound and the carbonic acid diester may be added to the raw material adjusting tank in advance and then allowed to exist in the polymerization reaction tank, or may be added in the pipe where the raw material is supplied to the raw material reaction tank. good. In any case, when the dihydroxy compound is a solid, it is preferable to add it after melting it at a temperature of 50 ° C. or higher because the uniformity of the catalyst and the dihydroxy compound is increased and the polymerization reaction is stabilized. ..

This catalyst usually does not volatilize and remains in the polycarbonate diol, but if an excessive amount of this catalyst remains, it becomes difficult to control the reaction during the polyurethaneization reaction, and the polyurethaneization reaction may be accelerated more than expected or abnormal. Since it may cause a reaction or deteriorate the color tone and transparency, the residual amount needs to be 200 ppm or less, preferably 100 ppm or less, as the weight ratio of the metal (M) to the polycarbonate diol. It is more preferably 50 ppm or less, and particularly preferably 20 ppm or less. On the other hand, if the amount of the present catalyst is small, the above-mentioned problems may occur. Therefore, the residual amount of the catalyst needs to be 1 ppm or more, preferably 2 ppm or more, and particularly preferably 3 ppm or more.

[4. Polyurethane]
Polyurethane can be produced using the above-mentioned polycarbonate diol of the present invention. In addition, polyurethane can be produced using the composition containing the polycarbonate diol of the present invention. Polyurethane produced using the polycarbonate diol or the polycarbonate diol-containing composition of the present invention is another embodiment of the present invention.

As a method for producing polyurethane using a polycarbonate diol or a polycarbonate diol composition, known polyurethane-forming reaction conditions for producing polyurethane are usually used.
For example, polyurethane can be produced by reacting polycarbonate diol with polyisocyanate and a chain extender in the range of room temperature to 200 ° C.
Further, a polycarbonate diol and an excess of polyisocyanate can be first reacted to produce a prepolymer having an isocyanate group at the terminal, and a chain extender can be used to increase the degree of polymerization to produce a polyurethane.

Polyurethane has excellent solvent resistance, good flexibility, and mechanical strength, so foam, elastomers, elastic fibers, paints, fibers, adhesives, adhesives, flooring materials, sealants, medical materials, artificial leather, etc. It can be widely used in synthetic leathers, coating agents, water-based polyurethane paints, active energy ray-curable polymer compositions and the like.
In particular, when polyurethane, which is a form of the present invention, is used for artificial leather, synthetic leather, water-based polyurethane, adhesives, elastic fibers, medical materials, flooring materials, paints, coating agents, etc., it is solvent resistant and flexible. Because it has a good balance of sex and mechanical strength, it is highly durable, flexible, and physical where it comes into contact with human skin or where cosmetic chemicals or disinfectant alcohol are used. It is possible to impart good characteristics such as resistance to impact. Further, it can be suitably used for automobile applications such as automobile parts that require heat resistance and outdoor applications that require weather resistance.

Polyurethane can be used for thermosetting elastomers and cast polyurethane elastomers. Specific applications include rolling rolls, papermaking rolls, office equipment, rolls such as pretension rolls, forklifts, solid tires for automobile vehicle nutrams, trolleys, transport vehicles, casters, etc., as industrial products such as conveyor belt idlers and guides. There are rolls, pulleys, steel pipe linings, rubber screens for ore, gears, connection rings, liners, pump impellers, cyclone cones, cyclone liners, etc. It can also be used for belts of OA equipment, paper feed rolls, cleaning blades for copying, snow plows, toothed belts, surf roller and the like.

Polyurethane is also applied for use as a thermoplastic elastomer. For example, it can be used for pneumatic equipment, coating equipment, analytical equipment, physics and chemistry equipment, metering pumps, water treatment equipment, tubes and hoses in industrial robots, spiral tubes, fire hoses, etc. used in the food and medical fields. Further, as a belt such as a round belt, a V-belt, a flat belt, etc., it is used in various transmission mechanisms, spinning machines, packing machines, printing machines and the like. It can also be used for heel tops and soles of footwear, couplings, packing, pole joints, bushes, gears, rolls and other equipment parts, sports equipment, leisure equipment, watch belts and the like. Further, examples of automobile parts include oil stoppers, gear boxes, spacers, chassis parts, interior parts, tire chain substitutes and the like. It can also be used for keyboard films, films such as automobile films, curl cords, cable sheaths, bellows, conveyor belts, flexible containers, binders, synthetic leather, diping products, adhesives and the like.

Polyurethane can also be applied as a solvent-based two-component paint, and can be applied to wood products such as musical instruments, Buddhist altars, furniture, decorative plywood, and sports equipment. It can also be used for automobile repair as tar epoxy urethane.
Polyurethane can be used as a component of moisture-curable one-component paints, blocked isocyanate-based solvent paints, alkyd resin paints, urethane-modified synthetic resin paints, ultraviolet curable paints, water-based urethane paints, etc., for example, for plastic bumpers. Overprint varnishes for paints, strippable paints, magnetic tapes, floor tiles, flooring materials, paper, wood grain printing films, etc., varnishes for wood, coil coats for high processing, optical fiber protective coatings, solder resists, tops for metal printing It can be applied to coats, base coats for vapor deposition, white coats for food cans, and the like.

Polyurethane can also be applied to food packaging, shoes, footwear, magnetic tape binders, decorative paper, wood, structural members, etc. as an adhesive or adhesive, and can also be used as a low-temperature adhesive, a component of hot melt. Can be done.
Polyurethane is used as a binder in magnetic recording media, ink, castings, fired bricks, graft materials, microcapsules, granular fertilizers, granular pesticides, polymer cement mol tar, resin mol tar, rubber chip binders, recycled foam, glass fiber sizing, etc. It is possible.

Polyurethane can be used as a component of a fiber processing agent for shrink-proofing, wrinkle-proofing, water-repellent processing and the like.
When polyurethane is used as an elastic fiber, the method of fiberizing the polyurethane can be carried out without particular limitation as long as it can be spun. For example, a melt spinning method can be adopted in which pellets are once pelletized, melted, and spun directly through a spinneret. When elastic fibers are obtained from polyurethane by melt spinning, the spinning temperature is preferably 250 ° C. or lower, more preferably 200 ° C. or higher and 235 ° C. or lower.

The polyurethane elastic fiber can be used as a bare yarn as it is, or can be coated with another fiber and used as a coating yarn. Examples of other fibers include conventionally known fibers such as polyamide fibers, wool, cotton, and polyester fibers, and among them, polyester fibers are preferably used in the present invention. Further, the elastic fiber using polyurethane may contain a dyeing type disperse dye.

Polyurethane is used as a sealant coking for concrete casting walls, induced joints, around sashes, wall-type PC (Precast Concrete) joints, ALC (Autoclaved Light-weight Concrete) joints, board joints, sealants for composite glass, and heat insulating sash sealants. , Can be used for automobile sealants, etc.
Polyurethane can be used as a medical material, and as a blood compatible material, a tube, a catheter, an artificial heart, an artificial blood vessel, an artificial valve, etc., and as a disposable material, a catheter, a tube, a bag, a surgical glove, an artificial kidney, etc. Can be used for potting materials, etc.
Polyurethane can be used as a raw material for UV curable paints, electron beam curable paints, photosensitive resin compositions for flexographic printing plates, photocurable optical fiber coating material compositions, etc. by modifying the ends.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples as long as the gist thereof is not exceeded.

In the following, the abbreviations of compounds and substituents are as follows.
acac: 2,4-pentadione or acetylacetone tmhd: 2,2,6,6-tetramethyl-3,5-heptanedione or dipivaloylmethane Et: ethyl Me: methyl

[Synthesis of metal complex]
<Example 1-1: Synthesis of metal complex C-1>
The metal complex C-1 was synthesized according to the following reaction formula.
MgCl ₂ + acac + LiOEt + EtOH
→ Mg ₄ (acac) ₄ (OEt) ₄ (EtOH) ₄
Magnesium chloride (286 mg, 3.00 mmol) and 2,4-pentadione (acac) (0.310 mL, 3.00 mmol, 1.0 equiv.) Were dissolved in 10 mL ethanol in a Schlenk tube (Solution A). Lithium ethoxydo (343 mg, 6.60 mmol, 2.2 equiv.) Was dissolved in 5 mL of ethanol in another Schlenk tube (Solution B). Solution B was slowly added dropwise to Solution A and stirred overnight at room temperature under argon. The supernatant solution was removed, the obtained white solid was extracted with toluene, and two-layer recrystallization with ethanol was carried out to obtain 112 mg of colorless crystals in a yield of 17%.
The obtained colorless crystals were used for various NMR ( ¹ H-NMR, ¹³ C { ¹ H} NMR, 2D ¹ H- ¹ H COSY, 2D ¹ H- ¹³ C HMQC, 2D ¹ H- ¹³ C HMBC) and / or simple. When analyzed by crystalline X-ray structure analysis, it was identified as _{Mg 4} (acac) ₄ (OEt) ₄ (EtOH) _4. This is referred to as a metal complex C-1.
The composition of the metal complex C-1 is summarized in Table 1.

<Example 1-2: Synthesis of metal complex C-2>
The metal complex C-2 was synthesized according to the following reaction formula.
MgCl ₂ + tmhd + KOME + MeOH
→ Mg ₄ (tmhd) ₄ (OMe) ₄ (MeOH) ₄
7 mL of magnesium chloride (286 mg, 3.00 mmol) and 2,2,6,6-tetramethyl-3,5-heptane (tmhd) (0.620 mL, 3.00 mmol, 1.0 equiv.) In a Schlenk tube. Was dissolved in methanol (solution A). Potassium methoxydo (463 mg, 6.60 mmol, 2.2 equiv.) Was dissolved in 7 mL of methanol in another Schlenk tube (Solution B). Solution A was slowly added dropwise to Solution B, and the mixture was stirred for 3 hours at room temperature under argon. The supernatant solution was removed, and the obtained white solid was extracted with toluene and recrystallized from a two-layer system with methanol to obtain 377.9 mg, 0.349 mmol, and a yield of 47% colorless crystals.
The obtained colorless crystals were used for various NMR ( ¹ H-NMR, ¹³ C { ¹ H} NMR, 2D ¹ H- ¹ H COSY, 2D ¹ H- ¹³ C HMQC, 2D ¹ H- ¹³ C HMBC) and / or simple. When analyzed by crystalline X-ray structure analysis, it was identified as _{Mg 4} (tmhd) ₄ (OMe) ₄ (MeOH) _4. This is referred to as a metal complex C-2.
The composition of the metal complex C-2 is summarized in Table 1.

<Example 1-3: Synthesis of metal complex C-3>
The metal complex C-3 was synthesized according to the following reaction formula.
Mg (OEt) ₂ + acac → Mg ₄ (acac) ₄ (OEt) ₄ (EtOH) ₄
2,4-Pentadione (acac) (1.0 mL, 10 mmol, 1.0 equiv.) Is slowly added dropwise to a toluene suspension (10 mL) of magnesium ethoxydo (Mg (OEt) _{2) (1.14 g, 10 mmol).} After that, when the mixture was stirred overnight in an argon atmosphere, a pale yellow suspension having a lighter color than that before the reaction was obtained. When the supernatant solution was recovered and then dried under reduced pressure, 1.18 g of a pale yellow powder was obtained with a crude yield of 55%.
When the obtained pale yellow powder was analyzed by various NMR measurements, it was identified as _{Mg 4} (acac) ₄ (OEt) ₄ (EtOH) _4. This is referred to as a metal complex C-3.
The composition of the metal complex C-3 is summarized in Table 1.

<Example 1-4: Synthesis of metal complex C-4>
The metal complex C-4 was synthesized according to the following reaction formula.
Ca (OEt) ₂ · (EtOH) ₄ + tmhd
→ Ca ₄ (tmhd) ₄ (OEt) ₄ (EtOH) ₄
Calcium (1.60 g, 40.0 mmol) was heated in EtOH (100 mL) at 60 ° C. until all the calcium was dissolved to prepare a transparent solution. By distilling off the solvent, _{a white solid of Ca (OEt) 2} and (EtOH) ₄ was obtained (9.95 g, 31.6 mmol, yield 79%). ¹ It was confirmed by 1 H-NMR measurement that 4 molecules of ethanol were coordinated.
Ca (OEt) ₂ · (EtOH) ₄ (6.29 g, 20.0 mmol) was suspended in hexane (20 mL) and 2,2,6,6-tetramethyl-3,5-heptane (tmhd) ( 4.17 mL, 20.0 mmol) was added to obtain a nearly transparent solution. After stirring at room temperature for 10 minutes, the supernatant was removed and dried under reduced pressure to obtain a white paste. Further, it was dried under reduced pressure at 50 ° C. to obtain a white solid.
This white solid was extracted with toluene (15 mL), left at −20 ° C. overnight, the solvent was removed, and the mixture was dried under reduced pressure to obtain a white solid (3.69 g, 11.8 mmol, yield 59%). .. When the obtained white solid was ^{analyzed by 1} H-NMR measurement, it was identified as _{Ca 4} (tmhd) ₄ (OEt) ₄ (EtOH) _4. This is referred to as a metal complex C-4.
The composition of the metal complex C-4 is summarized in Table 1.

[Comparative metal complex]
The following commercially available metal complexes were used for comparison of the composition and / or catalytic activity of the metal complexes. The composition of each metal complex is summarized in Table 1.

<Comparative Example 1-1: Metal Complex C-N1>
Metal complex C-N1: Mg (acac) ₂ (A reagent manufactured by Tokyo Chemical Industry was used.)
<Comparative Example 1-2: Metal Complex C-N2>
Metal complex C-N2: Mg (OEt) ₂ (A reagent manufactured by Fuji Film Wako Pure Chemical Industries, Ltd. was used.)

[NMR analysis of metal complex]
NMR analysis was performed to identify the composition and structure of the metal complex in solution. Bruker Avance III-400 was used as the NMR apparatus. NMR measurement was carried out after completely dissolving about 20 mg of the metal complex in about 0.8 g of a predetermined solvent.

The NMR measurement results of the metal complex C-1: Mg ₄ (acac) ₄ (OEt) ₄ (EtOH) _{4 are shown below.} From the peak position and the peak integral value, it was identified that the composition was described.
^{1 1} H-NMR (C ₆ D ₆ , 400MHz, 30 ℃): d5.38 (s, 1H, CH), 4.45 (brs, 1H, OH), 4.12 (q, 2H, J = 6.8Hz, -OCH ₂ CH ₃ ), 3.53 (q, 2H, J = 6.8Hz, HOCH ₂ CH ₃ ), 1.88 (s, 6H, Me), 1.49 (t, 3H, J = 6.8Hz, -OCH ₂ CH ₃ ), 1.08 ( t, 3H, J = 6.8Hz, HOCH ₂ CH ₃ ).
¹³ C-NMR (C ₆ D ₆ , 100MHz, 30 ℃): d191.3,100.1,58.6,58.0,27.9,19.8,18.4.
^{The 1} H-NMR chart and the ¹³ C-NMR chart of the metal complex C-1 are shown in FIG.

The NMR measurement results of the metal complex C-2: Mg ₄ (tmhd) ₄ (OMe) ₄ (MeOH) _{4 are shown below.} From the peak position and the peak integral value, it was identified that the composition was described.
_{^{1 H-NMR (C 6 D}} 6, 400MHz, 30 ℃): d5.89 (s, 1H, CH), 5.39 (q, J = 4.6Hz, 1H, OH), 3.60 (s, 3H, -OCH 3 ), 3.34 (d, J = 4.6Hz, 3H, HOCH ₃ ), 1.30 (s, 18H, tBu).
¹³ C-NMR (C ₆ D ₆ , 100MHz, 30 ℃): d201.2,89.8,51.2,50.6,41.2,28.9.
^{The 1} H-NMR chart and the ¹³ C-NMR chart of the metal complex C-2 are shown in FIG.

The NMR measurement results of the metal complex C-3: Ca ₄ (tmhd) ₄ (OEt) ₄ (EtOH) _{4 are shown below.} From the peak position and the peak integral value, it was identified that the composition was described.
_{^{1 H-NMR (C 6 D}} 6, 400MHz, 30 ℃): d5.89 (s, 1H, CH), 4.93 (brs, 1H, OH), 3.92 (brs, 4H, -OCH 2 CH 3, HOCH 2 CH ₃ ), 1.38 (brs, 6H, -OCH ₂ CH ₃ , HOCH ₂ CH ₃ ), 1.30 (s, 18H, tBu).
^{A 1} H-NMR chart of the metal complex C-4 is shown in FIG.

As a reference experiment, the NMR of only MeOH and EtOH was measured under the above NMR measurement conditions, and the peak was confirmed. The results are shown below.
As a result, the peaks corresponding to MeO, MEOH, EtO, and EtOH contained in the metal complexes of Examples 1 to 4 are all different from the peaks of the pure MeOH and EtOH products. It was confirmed that each of the ligands involved was appropriately coordinated with the metal and the NMR peak was changed.
NMR measurement result of MeOH:
_{^{1 H-NMR (C 6 D}} 6, 400MHz, 30 ° C): 3.07 (s, 3H).
¹³ C-NMR (C ₆ D ₆ , 100MHz, 30 ℃): 49.97.
NMR measurement result of EtOH:
_{^{1 H-NMR (C 6 D}} 6, 400MHz, 30 ℃): 3.34 (q, 2H), 0.96 (t, 3H).
¹³ C-NMR (C ₆ D ₆ , 100MHz, 30 ℃): 57.86, 18.72

[X-ray structure analysis of metal complex]
Single crystal X-ray structure analysis of the metal complexes C-1 and C-2 of Examples 1-1 and 1-2 was performed. Rigaku XtaLAB P200 was used for the measurement of the crystal structure.
The structure of the complex and the analysis results are shown below.
As described below, the metal complex C-1 and the metal complex C-2 were Cuban-type metal complexes having an octahedral structure in which the crystal structure analyzed by X-ray structure analysis was composed of metal atoms and oxygen atoms. ..

[Evaluation of catalytic performance for polycarbonate diol production]
In the production of the polycarbonate diol from the dihydroxy compound and the carbonic acid diester, as shown in the following reaction formula (A), the dihydroxy compound and the carbonic acid diester are transesterified to obtain the polycarbonate diol, and alcohol is produced as a by-product. The degree of polymerization of the produced polycarbonate diol can be evaluated by the degree of polymerization (m). Further, as an index of the performance of the polycarbonate diol as a production catalyst, it can be evaluated by the degree of polymerization (m) per unit time. Therefore, the higher the degree of polymerization (m) per unit time, the better the index as a transesterification reaction catalyst in the production of polycarbonate diol.

The reaction formula (A) below shows the process for producing the polycarbonate diol by the transesterification reaction. Further, as a typical example, a reaction example of producing polycarbonate diol (PCD) and ethylene glycol (EG) by the reaction of 1,4-butanediol (BG) and ethylene carbonate (EC) is shown in the following reaction formula (B). ..

The degree of polymerization (m) is shown as follows.

The degree of polymerization (m) of the polycarbonate diol was calculated by the following formula (5) from the measurement result ^{of 1 H-NMR.}
Degree of polymerization (m) = Hb / Ha (5)
Ha: Integral value of δ1.50 to 1.69ppm Hb: Integral value of δ1.70 to 1.88ppm

<Example 2-1>
To Schlenk, 1.32 mg of the metal complex C-1 obtained in Example 1-1, 15.9 g of ethylene carbonate and 14.0 mL of 1,4-butanediol were added, and the mixture was stirred at 120 ° C. for 3 hours under an argon atmosphere. bottom.
The amount of the metal complex C-1 used with respect to 1,4-butanediol (mol amount of Mg / mol amount of diol) is 39.6 (μmol / mol).
After completion of the reaction, ¹ H-NMR measurement of the reaction solution was carried out, and it was confirmed that polycarbonate diol was produced.
From this ¹ H-NMR measurement result, the catalytic activity was evaluated by calculating the degree of polymerization (m) at 120 ° C. for 3 hours from the above formula (5).
The evaluation results are shown in Table 2 together with the color of the reaction solution.

<Examples 2-2 to 4>
Instead of the metal complex C-1, the metal complexes C-2 to C-4 of Examples 2-2-4 are used in the same amount as in Example 2-1 (amount of metal in the metal complex / mol of diol). The catalytic activity was evaluated by the same experimental procedure, and the results are shown in Table 2 together with the color and turbidity of the reaction solution. The color and turbidity of the reaction solution were visually confirmed by checking the reaction solution in the Schlenk container.

From Table 2, it can be seen that the present metal complex is a catalyst having high catalytic activity in the transesterification reaction and does not cause coloring or turbidity.

[Evaluation of catalyst performance in polyester production]
Using this metal complex, ring-opening polymerization of polyester was carried out to produce polyesters corresponding to various raw material monomers, and the catalytic performance at that time was evaluated.

<Example 3-1: Polymerization of lactide>
L-lactide (50.4 mg, 0.35 mmol) and the metal complex C-2: Mg ₄ (tmhd) ₄ ( _{OME) 4} (MeOH) _{4 obtained in Example 1-2 were placed in a J-benzene NMR tube.} To (3.82 mg, 3.52 μmol), 2.0 mL of heavy benzene was added, and 0.50 mL of a separately prepared catalyst solution (1.8 mM) was added. The amount of the metal complex C-2 used was set to be 1 mol% with respect to L-lactide in terms of Mg. Subjected to ^{1 H-NMR} measurement before reaction, then heated in an oil bath at 100 ° C., was calculated conversion performed each time ^{the 1 H-NMR} measurement after a predetermined time has elapsed.
As a result, it was confirmed that the polymerization reaction proceeded at a conversion rate of 33% in 1 hour, a conversion rate of 54% in 2 hours, and a conversion rate of 93% by reacting overnight.

The reaction formula of lactide polymerization is as follows.
The ¹ H-NMR measurement chart is shown in FIG.

<Example 3-2: Polymerization of caprolactone>
When the same experiment as in Example 3-1 was carried out by changing the reaction substrate from L-lactide to ε-caprolactone (37.5 μL, 0.35 mmol), the conversion rate was 99% or more in 1 hour of the reaction, and the amount was quantified. It was confirmed that the polymerization reaction proceeded.
The reaction formula of caprolactone polymerization is as follows.
The ¹ H-NMR measurement chart is shown in FIG.

[Evaluation of catalytic performance of transesterification reaction using tertiary alcohol]
The catalytic performance of this metal complex in a transesterification reaction using a tertiary alcohol, which has low reactivity and is generally difficult to react, was evaluated.

<Example 4-1>
The reaction shown in the following formula was carried out.

Methyl2-naphthoate (93.1 mg, 0.500 mmol) as an ester substrate and 2,2'-bipyridine (3.90 mg, 25.0 mmol, 5 mol%) as an auxiliary catalyst were added to 5 mL Schlenk and dried under vacuum for 1 hour. I let you. Then, the metal complex obtained in Example 1-2 under air: Mg ₄ (tmhd) ₄ (OMe) ₄ (MeOH) ₄ (6.79 mg, 6.25 mmol, 5 mol% in terms of metal Mg) Was added. Further, 1-adamantanol (91.3 mg, 0.600 mmol) was added as an alcohol substrate and replaced with air again, then cyclopentyl methyl ether (CPME) (0.25 mL) was added as a solvent, and the mixture was placed in an oil bath at 120 ° C. The mixture was heated and stirred for 18 hours. After completion of the reaction, the mixture was cooled to room temperature. Short pad silica gel column chromatography was performed using acetoxyethane to remove metal salts, and then the yield was determined by GC measurement under the following measurement conditions.
As a result, it was confirmed that 1-adamantyl-2-naphthate, which is the target product of the transesterification reaction, was obtained in a yield of 70%.

(GC measurement conditions)
Equipment: GC-2014 (manufactured by SHIMAZU GAS CHROMATOGRAPH)
Column: Agilent J & W GC Column DB-5
(Inner diameter 0.25 mm, length 30 m, film thickness 0.25 μm)
Carrier gas: helium (injection amount: 1 μL, injection port temperature: 300 ° C)
Detector: Hydrogen flame ionization detector Detection temperature: 320 ° C
Heating program: 100 ° C (holding, 1 minute) 100 → 300 ° C (10 minutes) 300 ° C (holding, 9 minutes)
Internal standard: Triphenylmethane Retention time of target: 13.7 minutes

<Example 4-2>
In Example 4-1 the reaction was carried out under the same conditions as in Example 4-1 by substituting 5 mol% of 2,2'-bipyridine with 10 mol% of 1-benzylimidazole, and transesterification was carried out with a yield of 71%. The target product of the reaction, 1-adamantyl-2-naphthate, was obtained.

<Example 4-3>
When the reaction was carried out under the same conditions as in Example 4-1 without adding 2,2'-bipyridine in Example 4-1. 1-adamantyl, which is the target of the transesterification reaction, had a yield of 94%. 2-Naftate was obtained.

<Example 4-4>
The metal complex C-2 was replaced with the metal complex C-4 obtained in Example 1-4: Ca ₄ (tmhd) ₄ (OEt) ₄ (EtOH) _{4 under} the same conditions as in Example 4-1. As a result, 1-adamantyl-2-naphthate, which was the target of the transesterification reaction, was obtained in a yield of 82%.

<Comparative Example 4-1>
When the metal complex C-2 was replaced with the metal complex C-N1: Mg (acac) ₂ (reagent manufactured by Tokyo Chemical Industry Co., Ltd.) of Comparative Example 1-1, the reaction was carried out under the same conditions as in Example 4-1. The yield was 2%, and the transesterification reaction hardly proceeded.

<Comparative Example 4-2>
When the metal complex C-2 was replaced with the metal complex C-N2: Mg (OEt) ₂ (reagent manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) of Comparative Example 1-2 and the reaction was carried out under the same conditions, the yield was 3 The desired reaction hardly progressed in%. In addition, the reaction solution was turbid.

[Discussion]
From the above results, it can be seen that the metal complex of the present invention has high transesterification reaction catalytic activity. Further, according to the present metal complex, the polymerization reaction can be allowed to proceed with a small amount of catalyst, polyester and polycarbonate can be efficiently produced, and turbidity and coloring of the product are unlikely to occur. Furthermore, it can be seen that even a less reactive alcohol substrate such as a tertiary alcohol can be sufficiently reacted with a small amount of catalyst.

Claims (21)

A metal complex represented by the following general formula (1).
(M) x (A) p (B) q (C) r (1)
(In the above general formula (1), (M) represents a group 2 divalent metal in the long periodic table, and (A), (B) and (C) represent ligands, respectively.
x, p, q, and r represent arbitrary integers other than 0, and satisfy the following equations (2) and (3).
p + q = 2x (2)
p + q + r ≦ 6x (3)
The ligand (A) is a diketonate ligand represented by the following formula A1.
The ligand (B) is an anionic ligand other than the ligand (A), and is an anion of a compound having at least one oxygen atom and / or a nitrogen atom and having 1 to 20 carbon atoms, or an OH ^- anion. Is.
Ligand (C) is a ligand of the neutral compound having 1 to 20 carbon atoms and having at least one oxygen atom and / or nitrogen atoms, or a H _{2 O.} )

(In the formula (A1), R ₁ , R ₂ , and R ₃ independently represent a monovalent hydrocarbon group having 1 to 20 carbon atoms, a hydrogen atom, or a halogen atom. The hydrocarbon group has a halogen atom. It may be substituted or may have an oxygen atom.) The metal complex according to claim 1, wherein (M) in the general formula (1) is at least one metal selected from magnesium, calcium and / or barium. The metal complex according to claim 2, wherein the metal (M) in the general formula (1) is magnesium and / or calcium. The metal complex according to any one of claims 1 to 3, wherein _{R 2} in the formula (A1) is a hydrogen atom. _{According to any one of claims 1 to 4, wherein R 1} and R ₃ in the formula (A1) are independently monovalent hydrocarbon groups or hydrogen atoms having 1 to 7 carbon atoms. The metal complex described. Claim 1 is characterized in that the ligand (C) in the general formula (1) is a compound having at least one selected from a hydroxyl group, an amino group, a carbonate group, an ester group, a carbonyl group, and an amide group. The metal complex according to any one of 5 to 5. The metal complex according to any one of claims 1 to 6, wherein the ligand (B) in the general formula (1) is an anion of a compound having 1 to 3 hydroxyl groups. The metal complex according to any one of claims 1 to 7, wherein the ligand (C) in the general formula (1) is a compound having 1 to 3 hydroxyl groups. The metal complex according to any one of claims 1 to 8, wherein the ligand (B) in the general formula (1) is an anion of the ligand (C). The metal complex according to any one of claims 1 to 9, wherein x in the general formula (1) is 2 or 4. The metal complex according to claim 10, wherein x in the general formula (1) is 4. The metal complex according to any one of claims 1 to 11, wherein in the general formula (1), x: p: q: r = 1: 1: 1: 1. The metal complex according to any one of claims 1 to 12, wherein the crystal structure analyzed by X-ray structure analysis has an octahedral structure composed of metal atoms and oxygen atoms. A step of mixing a halide of the metal (M), a metal salt having the ligand (B), the ligand (A), the ligand (C), or a precursor having these structures. The method for producing a metal complex according to any one of claims 1 to 13, wherein the metal complex comprises. The step of mixing the metal salt having the metal (M) and the ligand (B) with the ligand (A), the ligand (C) or a precursor having these structures is included. The method for producing a metal complex according to any one of claims 1 to 13, which is characteristic. A transesterification reaction using the metal complex according to any one of claims 1 to 13 as a catalyst. A polymerization method including a transesterification reaction using the metal complex according to any one of claims 1 to 13 as a catalyst. A method for producing a polycarbonate and / or a polycarbonate diol using the polymerization method according to claim 17. A method for producing a polyester and / or a polyester diol using the polymerization method according to claim 17. A method for producing a polycarbonate diol by using a dihydroxy compound and a carbonic acid diester as a raw material monomer and polycondensing them by a transesterification reaction in the presence of the metal complex.
The method for producing a polycarbonate diol according to claim 18, wherein the metal complex is used as a total amount of the metal (M) of 0.00001 mol or more and 0.1 mol or less per 1 mol of the total dihydroxy compound. A method for producing a polyurethane using a polycarbonate diol produced by the method for producing a polycarbonate diol according to claim 18 or 20.

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