JP7380259B2 - Manufacturing method of polycarbonate diol - Google Patents

Description

The present invention relates to a method for producing polycarbonate diols. Specifically, the present invention relates to a method for producing polycarbonate diol, which is useful as a raw material for polycarbonate-based polyurethane, which is suitably used for elastic fibers with an excellent balance of physical properties, synthetic or artificial leather, and high-performance elastomers.

Traditionally, the main raw materials for the soft segment part of polyurethane resins produced on an industrial scale are ether type typified by polytetramethylene glycol, polyester polyol type typified by adipate esters, and polylactone typified by polycaprolactone. and polycarbonate types represented by polycarbonate diol (Non-Patent Document 1).

Among these, the ether type has excellent hydrolysis resistance, flexibility, and stretchability, but is said to have poor heat resistance and light resistance.
Although the polyester polyol type has improved heat resistance and weather resistance, the hydrolysis resistance of the ester portion is low and it cannot be used depending on the application.

The polylactone type is considered to be a grade with excellent hydrolysis resistance compared to the polyester polyol type, but it cannot completely suppress hydrolysis due to the presence of ester groups.
It has also been proposed to use a mixture of these polyester polyol types, ether types, and polylactone types, but it has not been possible to completely compensate for the drawbacks of each.

On the other hand, polycarbonate types that use polycarbonate diol are considered to be the best durable grade in terms of heat resistance and hydrolysis resistance, and are widely used as durable films, artificial leather for automobiles, (water-based) paints, and adhesives. ing.

However, the polycarbonate diol that is currently widely available on the market is mainly polycarbonate diol synthesized from 1,6-hexanediol, and because it is crystalline, it is waxy and has no fluidity at room temperature, making it difficult to handle. The problem was that it was difficult.

In addition, polyurethane manufactured using polycarbonate diol synthesized from 1,6-hexanediol has a problem of high cohesiveness of soft segments and poor flexibility, elongation, bending, and elastic recovery, especially at low temperatures. was restricted. Furthermore, the resulting polyurethane solution had a high solution viscosity and had poor operability during molding or coating. Furthermore, it has been pointed out that artificial leather manufactured using polyurethane as a raw material has a hard texture and has a worse "texture" than natural leather.

In order to solve these problems, polycarbonate diols with various structures have been proposed.
For example, there is a method of copolymerizing polycarbonate by mixing 1,6-hexanediol and another dihydroxy compound. Specifically, a method of copolymerizing 1,6-hexanediol and 1,4-butanediol ( Patent Document 1) and a method of copolymerizing 1,5-pentanediol (Patent Document 2) have been proposed.

In addition, methods of combining dihydroxy compounds other than 1,6-hexanediol have also been proposed; for example, a method of combining 1,3-propanediol and 1,4-butanediol or 1,5-pentanediol (patented Document 3), and a method of combining two or more types of linear dihydroxy compounds having an average carbon number of 6 or more (Patent Document 4).
Furthermore, as an effective method for inhibiting the crystallinity of sites derived from dihydroxy compounds, a method using dihydroxy compounds having substituents in the main chain has been proposed, such as 2-methyl-1,3-propanediol and other Examples include combinations of alkylene glycols (Patent Document 5), and combinations of 3-methyl-1,5-pentanediol and other alkylene diols (Patent Document 6).

Conventionally, various catalysts used in the production of polycarbonate diol have been studied based on combinations of diester carbonate and dihydroxy compound used as raw materials.

For example, in the production of copolymerized polycarbonate diol of diethyl carbonate, 1,6-hexanediol, and 1,5-pentanediol, metallic sodium is used as a catalyst (Patent Document 2), and diethyl carbonate and 1,3 In combination with diols such as -propanediol, 2-methyl-1,3-propanediol, and 1,3-butanediol, sodium ethoxide and magnesium acetate are used as catalysts (Patent Document 7).
In addition, in the production of copolymerized polycarbonate diol with ethylene carbonate and diols such as 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 2-methyl-1,3-propanediol, Lead acetate and tetra-n-butyl titanate are used as catalysts (Patent Document 5), and polycarbonate diols are produced by combining ethylene carbonate with various alkylene diols and oxyalkylene diols such as diethylene glycol and dibutylene glycol. In , tetra-n-butyl titanate is used as a catalyst (Patent Document 5).

In the past, in addition to tetra-n-butyl titanate, dibutyltin dilaurate, sodium acetate, lithium hydroxide, tin powder, etc. were used as catalysts in the combination of ethylene carbonate and 1,6-hexanediol (Patent Document 8).
Furthermore, magnesium acetate is successfully used as a catalyst in the production of copolymerized polycarbonate diol of diphenyl carbonate, 1,6-hexanediol, and neopentyl glycol (Patent Document 9).

Japanese Patent Application Publication No. 5-51428 Japanese Patent Application Publication No. 2-289616 International Publication No. 2002/070584 Japanese Patent Application Publication No. 2000-95852 International Publication No. 2006/088152 Japanese Unexamined Patent Publication No. 60-195117 Japanese Patent Application Publication No. 2012-46659 Japanese Unexamined Patent Publication No. 51-144492 Japanese Patent Application Publication No. 2013-010950

"Basics and Applications of Polyurethane" pages 96-106, supervised by Katsuji Matsunaga, published by CMC Publishing Co., Ltd., November 2006.

With previously known technology, in order to polycondensate various dihydroxy compounds with different reactivities, it is necessary to set the reaction temperature high or add a large amount of catalyst, and it is more susceptible to thermal deterioration than aromatic polycarbonate. There was a problem in that the aliphatic polycarbonate was colored and thermally deteriorated. Therefore, transesterification catalysts known in the art have not been sufficient for producing various polycarbonate diols.

For example, when a strong base such as an alkali metal or alkaline earth metal or an alkoxide thereof is used as a catalyst, it is necessary to neutralize the produced polycarbonate diol when it is used in the next step.
Furthermore, when a titanium compound is used as a catalyst, there is a problem in that coloring occurs during the production of polycarbonate diol and during storage of the obtained polycarbonate diol.

On the other hand, lead compounds and organic tin compounds have recently been shown to be harmful to the human body and to have a negative impact on the ecosystem. These compounds are therefore used as catalysts and are undesirable as residual components in polycarbonate diols.

Furthermore, all of the conventionally used catalysts have had the problem of requiring a high reaction temperature. High reaction temperatures promote the formation of undesirable ether and vinyl groups. When polycarbonate diol is used as a polyurethane raw material, these terminal groups are undesirable as a polyurethane raw material because they act as chain terminators in the polymerization reaction for polyurethanization.

When magnesium acetate or magnesium alkoxide is used as a catalyst, the polymerization activity is low, and when a dihydroxy compound with low reactivity or a carbonate diester with low reactivity is used as a raw material, the polymerization activity is insufficient, resulting in a high reaction temperature or A high catalyst concentration and a long reaction time are required, which may cause side reactions such as those mentioned above or reduce industrial productivity. Furthermore, there is also the problem that the resulting polycarbonate diol becomes colored or cloudy due to the high catalyst concentration.

The present invention is industrially advantageous in producing polycarbonate diol that satisfies the various physical properties required for polyurethane without impairing its color tone, transparency, or thermal stability, using milder reaction conditions than conventional methods. The purpose is to provide a method for manufacturing. Furthermore, it is an object of the present invention to improve the degree of freedom in designing polycarbonate diol.

As a result of intensive research to solve these problems, the present inventors found that when producing polycarbonate diol by polycondensation using a dihydroxy compound and carbonic acid diester as raw material monomers through transesterification, It has been found that a polycarbonate diol having a specific molecular weight can be efficiently produced using a transesterification catalyst, and the above problems can be solved.
That is, the gist of the present invention is as follows.

[1] A method for producing a polycarbonate diol having a number average molecular weight of 250 or more and 10,000 or less by polycondensation by transesterification reaction in the presence of a transesterification catalyst using a dihydroxy compound and a diester carbonate as raw material monomers, the method comprising:
A composition in which the transesterification catalyst contains at least one metal (M) selected from zinc and metals of Group 2 of the long period periodic table and at least one compound represented by the following formula (1), or A method for producing polycarbonate diol, which is at least one salt represented by the following formula (2) and a composition using the salt as a precursor.

(In the formula, R ₁ and R ₃ each independently represent a monovalent hydrocarbon group having 1 to 20 carbon atoms, which may be substituted with a halogen atom or may have an oxygen atom.
R ₂ represents a monovalent hydrocarbon group having 1 to 20 carbon atoms or a halogen atom, and the hydrocarbon group may be substituted with a halogen atom or may have an oxygen atom.
M represents zinc or a metal of group 2 of the long period periodic table, and n=2. )

[2] The method for producing polycarbonate diol according to [1], wherein the metal (M) is at least one metal selected from zinc, magnesium, calcium, and barium.

[3] The method for producing polycarbonate diol according to [2], wherein the metal (M) is zinc and/or magnesium.

[4] The method for producing polycarbonate diol according to [3], wherein the metal (M) is magnesium.

[5] In the formulas (1) and (2), R ₁ and R ₃ each independently have 1 to 12 carbon atoms, which may be substituted with a halogen atom, or may have an oxygen atom. _R2 is a monovalent hydrocarbon group having 1 to 12 carbon atoms or a halogen atom which may be substituted with a halogen atom or have an oxygen atom [1 ] to [4]. The method for producing polycarbonate diol according to any one of [4].

[6] In the formulas (1) and (2), R ₁ and R ₃ each independently have 1 to 7 carbon atoms, which may be substituted with a halogen atom, or may have an oxygen atom. _R2 is a monovalent hydrocarbon group having 1 to 7 carbon atoms or a halogen atom, which may be substituted with a halogen atom or have an oxygen atom. The method for producing polycarbonate diol according to [5].

[7] The method for producing a polycarbonate diol according to any one of [1] to [6], wherein the metal (M) is present in a total amount of 1 μmol or more and 500 μmol or less per 1 mol of all dihydroxy compounds.

[8] The method for producing a polycarbonate diol according to [7], wherein the metal (M) is present in a total amount of 5 μmol or more and 200 μmol or less per 1 mol of the total dihydroxy compound.

[9] The dihydroxy compound is at least one selected from aliphatic dihydroxy compounds having a structure represented by the following formula (3), alicyclic dihydroxy compounds, and poly(oxyalkylene) diols having a number average molecular weight of 100 to 1000. The method for producing polycarbonate diol according to any one of [1] to [8], which contains seeds.
HO-R ₄ -OH (3)
(In the formula, R ₄ represents a straight chain or branched divalent hydrocarbon group having 2 to 60 carbon atoms, and may have a cyclic structure and/or an ether oxygen atom.)

[10] The dihydroxy compound includes an aliphatic dihydroxy compound and/or an alicyclic dihydroxy compound having a structure represented by the formula (3), and R ₄ in the formula (3) has 2 to 20 carbon atoms. A method for producing polycarbonate diol according to [9].

[11] The method for producing polycarbonate diol according to [10], wherein R ₄ in formula (3) has 2 to 12 carbon atoms.

[12] The method for producing polycarbonate diol according to [9], wherein the dihydroxy compound contains a poly(oxyalkylene) diol having a number average molecular weight of 100 or more and 1000 or less.

[13] The method for producing polycarbonate diol according to [12], wherein the dihydroxy compound contains polyoxytetramethylene glycol having a number average molecular weight of 100 or more and 1000 or less.

[14] The method for producing polycarbonate diol according to [13], wherein the dihydroxy compound contains polyoxytetramethylene glycol having a number average molecular weight of 150 or more and 700 or less.

[15] The method for producing polycarbonate diol according to any one of [1] to [14], wherein the diester carbonate is at least one selected from alkylene carbonate, dialkyl carbonate, and diaryl carbonate.

[16] The method for producing a polycarbonate diol according to [15], wherein the diester carbonate is at least one selected from ethylene carbonate, dimethyl carbonate, diethyl carbonate, propylene carbonate, trimethylene carbonate, and diphenyl carbonate.

[17] The method for producing polycarbonate diol according to [16], wherein the diester carbonate is at least one selected from ethylene carbonate, dimethyl carbonate, diethyl carbonate, and diphenyl carbonate.

[18] A method for producing polyurethane using a polycarbonate diol produced by the method for producing polycarbonate diol according to any one of [1] to [17].

According to the method for producing polycarbonate diol of the present invention, polycarbonate diol having excellent color tone, transparency, etc. can be efficiently produced under milder conditions than conventionally known techniques. Furthermore, since high polymerization activity can be obtained by combining various raw material monomers, there is a high degree of freedom in designing polycarbonate diol. It also has the advantage of being able to be synthesized by freely changing the combination of diesters.

Hereinafter, the embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments, and can be implemented with various modifications within the scope of the gist.

[1. Production method of polycarbonate diol]
The method for producing polycarbonate diol of the present invention uses a dihydroxy compound and diester carbonate as raw material monomers, and polycondenses them through a transesterification reaction in the presence of a specific transesterification catalyst to produce a polycarbonate diol having a number average molecular weight of 250 to 10,000. (hereinafter sometimes referred to as "the polycarbonate diol of the present invention").

<1-1. Raw material monomer＞
The polycarbonate diol of the present invention is made from a dihydroxy compound and a carbonic acid diester.

<1-1-1. Dihydroxy compound>
Specifically, the dihydroxy compounds that are raw materials for the polycarbonate diol of the present invention include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol and 1,20-eicosanediol, etc. linear terminal dihydroxy compounds, dihydroxy compounds having an ether group such as diethylene glycol, triethylene glycol, tetraethylene glycol and polytetramethylene glycol, thioether diols such as bishydroxyethyl thioether, 2-ethyl-1, 6-hexanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol and 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 2-pentyl-2-propyl 2,2-dialkyl-substituted 1,3-propanediols such as -1,3-propanediol (hereinafter sometimes referred to as 2,2-dialkyl-1,3-propanediols.However, the alkyl group 2,2,4,4-tetramethyl-1,5-pentanediol and 2,2,9,9-tetramethyl-1,10-decanediol. Substituted alkylene diols, dihydroxy compounds containing cyclic groups such as 3,9-bis(1,1-dimethyl-2-hydroxyethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, 2,2-diphenyl-1,3-propanediol, 2,2-divinyl-1,3-propanediol, 2,2-diethynyl-1,3-propanediol, 2,2-dimethoxy-1,3-propane Diols, bis(2-hydroxy-1,1-dimethylethyl)ether, bis(2-hydroxy-1,1-dimethylethyl)thioether and 2,2,4,4-tetramethyl-3-cyano-1,5 - Dihydroxy compounds with branched chains such as pentanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 4,4-dicyclohexyldimethylmethanediol, 2,2'- Bis(4-hydroxycyclohexyl)propane, 1,4-dihydroxyethylcyclohexane, isosorbide, spiroglycol, 2,5-bis(hydroxymethyl)tetrahydrofuran, 4,4'-isopropylidene dicyclohexanol and 4,4'-isopropylene Dihydroxy compounds with a cyclic group in the molecule such as redenbis(2,2'-hydroxyethoxycyclohexane), 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene, 9,9-bis(4 - Dihydroxy compounds having an aromatic ring such as (2-hydroxyethoxy-2-methyl)phenyl)fluorene, nitrogen-containing dihydroxy compounds such as diethanolamine and N-methyl-diethanolamine, and sulfur-containing dihydroxy compounds such as bis(hydroxyethyl)sulfide. Compounds, 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'-dihydroxydiphenylsulfone, Bis(4-hydroxyphenyl) sulfide, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dichlorodiphenyl ether, 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis Aromatic bisphenols such as (4-hydroxy-2-methylphenyl)fluorene and the like can be mentioned.

Among them, from the viewpoint of the light resistance of the polyurethane obtained using the polycarbonate diol of the present invention, at least one kind selected from the group consisting of aliphatic dihydroxy compounds and alicyclic dihydroxy compounds represented by the following formula (3). Preferably, it is a compound.
HO-R ₄ -OH (3)
(In the formula, R ₄ represents a linear or branched divalent hydrocarbon group having 2 to 60 carbon atoms, and may have a cyclic structure and/or an ether oxygen atom)

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

Among such dihydroxy compounds, aliphatic dihydroxy compounds include 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,10-decanediol. , neopentyl glycol are preferred, and as the alicyclic dihydroxy compound, 1,4-cyclohexanedimethanol and tricyclodecane dimethanol are particularly preferred, but from the viewpoint of color tone, ease of handling, and ease of synthesis of polycarbonate diol. Preferred are 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, neopentyl glycol, and 1,4-cyclohexanedimethanol.

As the dihydroxy compound having an etheric oxygen atom, poly(oxyalkylene) diol is preferable, and diethylene glycol, triethylene glycol, tetraethylene glycol and polyoxytetramethylene glycol are preferable, and among them, easily and inexpensively available as an industrial raw material. Particularly preferred are diethylene glycol, triethylene glycol, and polyoxytetraethylene glycol.
As the polyoxytetramethylene glycol, polyoxytetramethylene glycol having a number average molecular weight of 100 or more and 1000 or less is preferable from the viewpoint of ease of handling and ease of synthesizing polycarbonate diol. Oxytetramethylene glycol is particularly preferred.
Here, the number average molecular weight in poly(oxyalkylene) diol means the molecular weight calculated from the terminal group concentration, 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 types depending on the required performance of the resulting polycarbonate diol, but it is preferable to combine two or more to form a copolymerized polycarbonate diol. Copolymerized polycarbonate diols generally have inhibited crystallization and have higher fluidity than homopolycarbonate diols, making them not only easier to manipulate when processed into polyurethane, but also imparting flexibility and texture to polyurethane. can do.

The composition ratio of the copolymerization is, for example, when two types of dihydroxy compounds are used, each dihydroxy compound is 5 mol% or more, preferably 10 mol% or more, more preferably 20 mol% or more, based on the total dihydroxy compounds. More preferably, it is used in an amount of 30 mol% or more.
Normally, when dihydroxy compounds with different molecular structures are copolymerized, the polymerization reaction may become nonuniform or inhibited due to the difference in reactivity. However, in the present invention using a specific transesterification catalyst described below, According to this method, a copolymerized polycarbonate diol can be easily obtained. In particular, when a dihydroxy compound having a substituent at the α or β position of the hydroxyl group is used, polymerization tends to be inhibited by steric hindrance in conventional methods, but the present invention uses a specific transesterification catalyst described below. Since a copolymerized polycarbonate diol can be easily obtained according to the method, the effects of the present invention can be effectively obtained.

<1-1-2. Carbonic diester＞
The diester carbonate that can be used as a raw material for producing the polycarbonate diol of the present invention is not limited as long as it does not impair the effects of the present invention, but examples include dialkyl carbonate, diaryl carbonate, and alkylene carbonate. Among these, use of diaryl carbonate has the advantage that the reaction proceeds quickly. However, on the other hand, when diaryl carbonate is used as a raw material, phenols with a high boiling point are produced as by-products, and the phenols produced by-products are monofunctional compounds, so they can become polymerization inhibiting factors during polyurethanization, and are also irritating substances. Therefore, there is a risk that the problem of becoming a coloring agent may occur. From this point of view, it is preferable that the residual amount of phenols in the polycarbonate diol of the present invention be as small as possible.

Among diester carbonates that can be used in the production of the polycarbonate diol of the present invention, specific examples of dialkyl carbonates include dimethyl carbonate, diethyl carbonate, dibutyl carbonate, dicyclohexyl carbonate, diisobutyl carbonate, ethyl-n-butyl carbonate, and ethyl isobutyl carbonate. etc.

Examples of diaryl carbonates include diphenyl carbonate, ditolyl carbonate, bis(chlorophenyl) carbonate, di-m-cresyl 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, etc. It will be done.

These may be used alone or in combination of two or more.

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

As the dialkyl carbonate, dimethyl carbonate and diethyl carbonate are preferred, which are easily and inexpensively available as industrial raw materials and whose by-product alcohol has a low boiling point and can be easily removed.

On the other hand, alkylene carbonate is preferable because the terminals of the polycarbonate diol molecular chain are not alkyloxy groups or aryloxy groups unlike dialkyl carbonates and diaryl carbonates, but both ends of the polycarbonate diol molecular chain are hydroxyl groups, which are hydroxyl groups. . Among them, ethylene carbonate, which is easily and inexpensively available as an industrial raw material, is more preferred.

According to the present invention, which uses a specific transesterification catalyst, even when relatively low reactivity dialkyl carbonate or alkylene carbonate is used as a carbonate source, the polymerization reaction proceeds well without excessively raising the reaction temperature. , the effects of the present invention can be effectively obtained.

<1-1-3. Usage ratio of raw material monomer>
In the method for producing polycarbonate diol of the present invention, the amount of diester carbonate to be used needs to be appropriately changed depending on the target molecular weight of the polycarbonate diol, and is not particularly limited, but usually the lower limit is preferably the molar ratio to 1 mole of dihydroxy compounds in total. is 0.50, 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 diester carbonate used exceeds the above upper limit, the proportion of the resulting polycarbonate diol whose end groups are not hydroxyl groups will increase, or the molecular weight will not fall within the predetermined range, making it impossible to produce the polycarbonate diol of the present invention. If it is less than that, polymerization may not proceed to a predetermined molecular weight.

<1-1-4. Purification of raw material monomers, etc.>
If a halogen component such as chloride ion or bromide ion is contained in the dihydroxy compound and/or diester carbonate used as a raw material for producing polycarbonate diol, it may cause problems during the polycarbonation reaction and further when converting the obtained polycarbonate diol into polyurethane. It is preferable that the content is small, since it may affect the reaction of the compound or cause coloring. Usually, the upper limit of the content of the halogen component in the dihydroxy compound and/or carbonic acid diester used in the present invention is 10 ppm, preferably 5 ppm, and more preferably 1 ppm as a halogen weight based on the weight of these compounds.

Dihydroxy compounds and/or carbonic acid diesters that have deteriorated due to oxidation or the like or contain the above-mentioned impurities can be purified by distillation or the like.
It is also effective to add a stabilizer to prevent oxidative deterioration again after distillation. As a specific stabilizer, any stabilizer that is generally used as an antioxidant for organic compounds can be used without any restriction, and examples include butylated hydroxytoluene, butylated hydroxyanisole, and 2,6-di-t- Butyl-4-methylphenol, 2-[1-(2-hydroxy-3,5-di-t-pentylphenyl)ethyl]-6-di-t-pentylphenyl acrylate (manufactured by Sumitomo Chemical, product name: Smiizer ( Phenolic stabilizers such as GS), 6-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetra-t-butyldibenz [d,f][1,3,2]dioxaphosphepine (manufactured by Sumitomo Chemical, trade name Smilizer (registered trademark) GP), bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite Examples include phosphorus stabilizers such as

<1-2. Transesterification catalyst>
<1-2-1. Catalyst composition (1), (2)>
When producing polycarbonate diol by the method of the present invention, at least one metal selected from the group consisting of zinc and a metal of Group 2 (hereinafter sometimes simply referred to as "Group 2") in the long period periodic table is used. A composition containing one kind of metal (M) and at least one kind of compound represented by the following formula (1) (hereinafter sometimes referred to as "catalyst composition (1)"), or a composition containing the following formula (2) At least one salt represented by the above formula and a composition using them as a precursor (hereinafter referred to as "catalyst composition (2)", and catalyst composition (1) and catalyst composition (2) as "catalyst of the present invention") ) is present as a transesterification catalyst (hereinafter sometimes simply referred to as "catalyst").

(In the formula, R ₁ and R ₃ each independently represent a monovalent hydrocarbon group having 1 to 20 carbon atoms, which may be substituted with a halogen atom or may have an oxygen atom.
R ₂ represents a monovalent hydrocarbon group having 1 to 20 carbon atoms or a halogen atom, and the hydrocarbon group may be substituted with a halogen atom or may have an oxygen atom.
M represents zinc or a metal of group 2 of the long period periodic table, and n=2. )

The stable form of zinc or Group 2 metal compound usually includes the salt form represented by the above formula (2), and therefore, it is effective to use the catalyst composition (2). When it is difficult to obtain salt, or when it is desired to arbitrarily adjust the composition ratio between zinc or Group 2 metal and the compound represented by formula (1), the metal compound and the compound represented by formula (1) may be used. A catalyst composition (1) with a compound having the structure may also be used.
Further, catalyst composition (1) and catalyst composition (2) may be used together.

As a method for preparing the catalyst composition (2), for example, as shown in the following formula (4), using a method similar to the method for synthesizing the acetylacetone salt of a metal, a halide salt of a metal is mixed in the presence of a base. A method of preparing a catalyst composition (2) by reacting with an acetylacetone analog, or a method of preparing a catalyst composition (2) by exchanging a metal alkoxide with an acetylacetone analog, as shown in the following formula (5). Examples include, but are not limited to, methods of doing so.

(In the above formulas (4) and (5), R ₁ , R ₂ , R ₃ , M and n are defined as in the above formula (2), and R ₅ is an arbitrary hydrocarbon group.)

Catalyst compositions (1) and (2) may be prepared in advance and mixed with a dihydroxy compound and diester carbonate as raw material monomers, or each component may be mixed with the raw material monomers in any order.

In addition, in addition to these catalyst compositions (1) and (2), a basic compound such as a transition metal compound, a basic boron compound, a basic phosphorus compound, a basic ammonium compound, or an amine compound may be used in combination. It is also possible.

In the above formulas (1) and (2), R ₁ and R ₃ are each independently a monovalent group having 1 to 12 carbon atoms, which may be substituted with a halogen atom or may have an oxygen atom. The catalyst composition is preferably a monovalent hydrocarbon group having 1 to 7 carbon atoms, which may be substituted with a halogen atom, or may have an oxygen atom. It is more preferable from the viewpoints of ease of interaction with the metal (M) contained therein, solubility as a catalyst composition, thermal stability, and low coloring property. R ₂ is preferably a monovalent hydrocarbon group having 1 to 12 carbon atoms or a halogen atom, which may be substituted with a halogen atom, and which may have an oxygen atom. A monovalent hydrocarbon group having 1 to 7 carbon atoms or a halogen atom, which may have an oxygen atom, can easily interact with the metal (M) in the catalyst composition. It is more preferable from the viewpoints of solubility in the sheath organic solvent and raw material monomer, acid-base strength, low coloring property, etc. Furthermore, when R ₁ to R ₃ are the above-mentioned suitable functional groups, the resulting polycarbonate has high solubility and low coloration, so that a polycarbonate diol without turbidity and low coloration can be obtained.

Specifically, R ₁ and R ₃ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, neopentyl group, Examples include hexyl group, cyclohexyl group, phenyl group, benzyl group, monofluoromethyl group, difluoromethyl group, trifluoromethyl group, monochloromethyl group, dichloromethyl group, trichloromethyl group, etc. Among these, methyl group, Preferred are ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, phenyl group, benzyl group, trifluoromethyl group, and trichloromethyl group. Note that R ₁ and R ₃ may be the same or different, but are preferably the same in terms of ease of synthesis and availability.

Further, R ₂ specifically includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a neopentyl group, and a hexyl group. group, cyclohexyl group, phenyl group, benzyl group, monofluoromethyl group, difluoromethyl group, trifluoromethyl group, monochloromethyl group, dichloromethyl group, trichloromethyl group, fluorine atom, chlorine atom, bromine atom, iodine atom, etc. Among these, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, phenyl group, benzyl group, trifluoromethyl group , trichloromethyl group, fluorine atom, and chlorine atom are preferred.

As the metal (M) selected from zinc and Group 2 metals, zinc, magnesium, calcium, and barium are particularly preferred from the viewpoint of reactivity, zinc and magnesium are more preferred, and magnesium is most preferred.

The composition ratio of the compound represented by the catalyst composition (1) and the metal (M) is a molar ratio, and the lower limit is usually 0.1 or more, preferably 0.25 or more, and more preferably 0.5 or more. It is. On the other hand, the upper limit is usually 50 or less, preferably 10 or less, and more preferably 5 or less.

The amount of catalyst composition (1) and/or catalyst composition (2) used is usually 1 to 500 μmol, preferably 1 to 500 μmol, as the amount of metal (M) per 1 mol of the total dihydroxy compound used as the raw material monomer. The amount is preferably 5 to 200 μmol, more preferably 10 to 100 μmol, particularly preferably 15 to 50 μmol.

If the amount of catalyst used is too small, sufficient polymerization activity will not be obtained and the progress of the polymerization reaction will be slowed down, making it difficult to obtain polycarbonate diol with the desired molecular weight. This will not only reduce production efficiency but also cause the raw material monomer to polymerize. During the reaction, the amount of time it remains unreacted in the system increases, which may lead to deterioration in color tone. In addition, the amount of monomer distilled out together with by-product monohydroxy compounds increases, resulting in a worsening of the raw material consumption rate and the possibility of requiring extra energy for its recovery. In the case of copolymerization using a compound, the composition ratio of monomers used as raw materials and the composition ratio of constituent monomer units in the product polycarbonate diol may change.

On the other hand, if the amount of catalyst used is too large, the distillation of unreacted monomers as described above will be improved, but on the other hand, the color tone, transparency, light resistance, and thermal stability of the resulting polycarbonate diol will be affected. Not only may this cause deterioration, but also abnormal reactions may occur during the polyurethanization reaction.

The catalyst may be added directly to the polymerization reaction tank, or may be added to the dihydroxy compound or diester carbonate in advance. Alternatively, the dihydroxy compound and diester carbonate may be added to a raw material adjustment tank where they are mixed in advance, and then allowed to exist in the polymerization reaction tank, or it may be added in the piping where the raw materials are 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 homogeneity of the catalyst and dihydroxy compound increases and the polymerization reaction becomes stable.

The catalyst usually does not volatilize and remains in the polycarbonate diol, but if too much catalyst remains, it becomes difficult to control the reaction during the polyurethanization reaction, which may accelerate the polyurethanization reaction more than expected or cause abnormal reactions. The residual amount, as a weight ratio of metal (M) to polycarbonate diol, must be 200 ppm or less, preferably 100 ppm or less, and more preferably 100 ppm or less. is 50 ppm or less, particularly preferably 20 ppm or less. On the other hand, since a small amount of catalyst may cause the above-mentioned problems, the residual amount needs to be 1 ppm or more, preferably 2 ppm or more, and particularly preferably 3 ppm or more.

<1-2-2. Other transesterification catalysts>
In the present invention, in addition to the above catalyst composition (1) and/or catalyst composition (2), a transition metal compound, a basic boron compound, a basic phosphorus compound, a basic ammonium compound, an amine, etc. It is also possible to use a basic compound such as a series compound as an auxiliary catalyst.

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

Examples of basic boron compounds include tetramethylboron, tetraethylboron, tetrapropylboron, tetrabutylboron, trimethylethylboron, trimethylbenzylboron, trimethylphenylboron, triethylmethylboron, triethylbenzylboron, triethylphenylboron, and tributylbenzyl. Examples include sodium salts, potassium salts, lithium salts, calcium salts, barium salts, magnesium salts, and strontium salts of boron, tributylphenylboron, tetraphenylboron, benzyltriphenylboron, methyltriphenylboron, butyltriphenylboron, etc. It will be done.

Examples of basic phosphorus compounds include tertiary phosphines such as triethylphosphine, tri-n-propylphosphine, triisopropylphosphine, tri-n-butylphosphine, triphenylphosphine, tributylphosphine, and tri(ethylhexyl)phosphine, and diethyl phosphine. Secondary phosphines such as phosphine, di-n-propylphosphine, diisopropylphosphine, di-n-butylphosphine, diphenylphosphine, dibutylphosphine, di(ethylhexyl)phosphine, quaternary phosphonium salts, phosphoric acid, phosphorous acid, etc. Examples include inorganic phosphoric acid and organic phosphoric esters such as dibutyl phosphate, tributyl phosphate, trioctyl phosphate, triphenyl phosphate, di(ethylhexyl) phosphate, and triphenyl phosphite.

Examples of the basic ammonium compound include tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylbenzylammonium hydroxide, trimethylphenylammonium hydroxide, Triethylmethylammonium hydroxide, triethylbenzylammonium hydroxide, triethylphenylammonium hydroxide, tributylbenzylammonium hydroxide, tributylphenylammonium hydroxide, tetraphenylammonium hydroxide, benzyltriphenylammonium hydroxide, methyltriphenylammonium hydroxide, Examples 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, -dimethylaminoimidazole, 2-methoxyimidazole, imidazole, 2-mercaptoimidazole, 2-methylimidazole, aminoquinoline and the like.

These auxiliary catalysts may be used alone or in combination of two or more.

When these auxiliary catalysts are used, the upper limit of the amount used is preferably 100 times or less, particularly 10 times or less, relative to the metal (M) in the catalyst composition. The lower limit is preferably 0.01 times or more, particularly 0.1 times or more. The combined use of these auxiliary catalysts may have the effect of improving catalytic activity and selectivity, or suppressing the decline in catalytic activity caused by impurities in raw materials or reaction by-products, but the amount used is too large. Excessive reaction may not only cause deterioration of the color tone, transparency, light resistance, thermal stability, etc. of the polycarbonate diol obtained, but also cause an abnormal reaction during the polyurethanization reaction, which is not preferable. If it is too small, the effect may not be sufficiently obtained.

<1-3. Manufacturing method of polycarbonate diol>
In the present invention, polycarbonate diol is produced by transesterifying one or more of the aforementioned dihydroxy compounds and one or more of the aforementioned carbonic acid diesters in the presence of the aforementioned transesterification catalyst.

<1-3-1. Reaction conditions etc.>
There are no particular restrictions on the method of charging the reaction raw materials, and there is a method in which one or more types of dihydroxy compound, carbonic acid diester, and the entire amount of the catalyst are simultaneously charged and subjected to the reaction, or if the carbonic acid diester is solid, the carbonic acid diester is first charged and heated. The method can be freely selected, such as melting and adding the dihydroxy compound catalyst later, or conversely, charging the dihydroxy compound first, melting it, and then adding the carbonic acid diester and the catalyst. In order to reduce the number of alkyloxy or aryloxy groups at the end of the molecular chain of the resulting polycarbonate diol, it is also possible to adopt a method in which a portion of the dihydroxy compound used is added at the end of the reaction. be.

The reaction temperature during the transesterification reaction can be arbitrarily selected as long as it provides a practical reaction rate. The temperature is not particularly limited, but the lower limit is usually 70°C, preferably 100°C, more preferably 130°C. Further, the upper limit of the reaction temperature is usually 250°C, preferably 200°C, more preferably 190°C, still more preferably 180°C, particularly preferably 170°C. If the reaction temperature is below the lower limit, the transesterification reaction may not proceed at a practical rate. Furthermore, if the reaction temperature exceeds the above upper limit, quality problems such as coloring of the obtained polycarbonate diol, formation of an ether structure, and deterioration of turbidity may occur.

Although the reaction can be carried out at normal pressure, the transesterification reaction is an equilibrium reaction, and the reaction can be biased toward the production system by distilling off the produced monohydroxy compound or dihydroxy compound from the system. Therefore, it is usually preferable to employ reduced pressure conditions in the latter half of the reaction to carry out the reaction while distilling off the monohydroxy compound or dihydroxy compound. Alternatively, it is also possible to carry out the reaction while gradually lowering the pressure during the reaction and distilling off the produced monohydroxy compound or dihydroxy compound. If the pressure is lowered too much in the early stage of the reaction, the volatilization of low-boiling unreacted monomers may be promoted, making it impossible to obtain a polycarbonate diol with a predetermined molecular weight, or in the case of copolymerization, resulting in a polycarbonate diol with a predetermined copolymerization composition ratio. Sometimes I can't.

On the other hand, if the reaction is carried out with a high degree of vacuum at the end of the reaction, mono- or dihydroxy compounds such as by-produced phenols, alcohols and diols, residual monomers such as diester carbonate, and even turbidity may occur. This is preferable because possible cyclic carbonates (cyclic oligomers) and the like can be distilled off.
The reaction pressure at the end of the reaction is not particularly limited, but the upper limit is usually 10 kPa, preferably 5 kPa, and more preferably 1 kPa. In order to effectively distill off these light boiling components, the reaction can be carried out while passing a small amount of an inert gas such as nitrogen, argon, or helium into the reaction system.

When using a carbonate diester or dihydroxy compound with a low boiling point during the transesterification reaction, the reaction is carried out near the boiling point of the carbonate diester or dihydroxy compound at the initial stage of the reaction, and as the reaction progresses, the temperature is gradually raised to further increase the temperature. A method of allowing the reaction to proceed can also be adopted. In this case, it is possible to prevent unreacted diester carbonate or dihydroxy compound from being distilled off at the early stage of the reaction, which is preferable. Furthermore, in order to prevent the raw materials from being distilled off in the early stages of the reaction, a reflux tube is attached to the reactor, and while the carbonic acid diester and dihydroxy compound are refluxed, the by-produced monohydroxy compound or dihydroxy compound is distilled off to carry out the transesterification reaction. It is also possible. In this case, the raw material monomers charged are not lost and the quantitative ratio of the reagents can be adjusted accurately, which is preferable.

<1-3-2. Polymerization reactor＞
The polymerization reaction (polycondensation reaction) can be carried out either batchwise or continuously, but the continuous method is superior in terms of stability of product quality such as molecular weight. The apparatus used may be of any type, such as a tank type, a pipe type, or a tower type, and known polymerization vessels equipped with various types of stirring blades can be used. There are no particular restrictions on the atmosphere during the heating of the apparatus, but from the viewpoint of product quality, it is preferable to carry out the heating in an inert gas such as nitrogen gas under normal pressure or reduced pressure.

<1-3-3. Reaction time>
The time required for the transesterification reaction (polymerization reaction or polycondensation reaction) to obtain polycarbonate diol by the method of the present invention varies greatly depending on the type and amount of the dihydroxy compound, carbonic acid diester, and catalyst used, so it is not generally specified. However, the reaction time required to reach a predetermined molecular weight is usually 50 hours or less, preferably 20 hours or less, and more preferably 10 hours or less.

As mentioned above, when a catalyst is used during the transesterification reaction, the catalyst usually remains in the polycarbonate diol obtained, and the residual metal catalyst may make it impossible to control the reaction during the polyurethanization reaction. be. In order to suppress the influence of this residual catalyst, a catalyst deactivator, such as an acidic compound or a phosphorus-based or sulfur-based compound that decomposes into an acidic compound, may be added in an amount approximately equimolar to the used catalyst. Furthermore, after addition, the transesterification catalyst can be efficiently inactivated by heat treatment as described below. In addition, the addition of a catalyst deactivator suppresses coloration and changes in physical properties that occur due to changes in the terminal structure and skeleton of the polycarbonate diol and residual catalyst when the resulting polycarbonate diol composition is stored at high temperatures, for long periods of time, or handled. can do.

Examples of compounds used to deactivate transesterification catalysts (hereinafter sometimes referred to as catalyst deactivators) include inorganic phosphoric acids such as phosphoric acid and phosphorous acid, dibutyl phosphate, and tributyl phosphate. , organic phosphoric acid esters such as trioctyl phosphate, triphenyl phosphate, and triphenyl phosphite, sulfonic acids, and sulfonic acid esters. These may be used alone or in combination of two or more.

The amount of the catalyst deactivator used is not particularly limited, but as mentioned above, it may be approximately equimolar to the transesterification catalyst used, and specifically, On the other hand, the upper limit is preferably 5 mol, more preferably 2 mol, and the lower limit is preferably 0.8 mol, more preferably 1.0 mol. If a smaller amount of catalyst deactivator is used, the transesterification catalyst in the reaction product will not be sufficiently deactivated, and when the resulting polycarbonate diol is used as a raw material for producing polyurethane, for example, the polycarbonate It may not be possible to sufficiently reduce the reactivity of diols toward isocyanate groups. Furthermore, if a catalyst deactivator exceeding this range is used, the resulting polycarbonate diol may be colored.

Deactivation of the transesterification catalyst by adding a catalyst deactivator can be carried out at room temperature, but heating treatment is more efficient. The temperature of this heat treatment is not particularly limited, but the upper limit is preferably 150°C, more preferably 120°C, even more preferably 100°C, and the lower limit is preferably 50°C, more preferably 60°C, even more preferably is 70°C. If the temperature is lower than this, deactivation of the transesterification catalyst takes time and is not efficient, and the degree of deactivation may be insufficient. On the other hand, at temperatures exceeding 150°C, the obtained polycarbonate diol may be colored.
The time for reacting with the catalyst deactivator is not particularly limited, but is usually 1 to 5 hours.

<1-3-4. Purification＞
After the polymerization reaction, impurities in the polycarbonate diol whose terminal structure is an alkyloxy group, impurities whose terminal structure is an aryloxy group, monohydroxy compounds or dihydroxy compounds such as phenols, alcohols, and diols, dihydroxy compounds, carbonic acid diesters, and secondary Purification can be performed for the purpose of removing the light-boiling cyclic carbonate produced and further the added catalyst. For purification at that time, a method of distilling off light boiling compounds can be adopted. Specific methods of distillation include vacuum distillation, steam distillation, thin film distillation, etc., and are not particularly limited in form, but thin film distillation is particularly effective. Further, in order to remove water-soluble impurities, washing may be performed with water, alkaline water, acidic water, a solution containing a chelating agent, or the like. In that case, the compound to be dissolved in water can be arbitrarily selected.

Although there are no particular limitations on the thin film distillation conditions, the upper limit of the temperature during thin film distillation is preferably 250°C, more preferably 200°C. Further, the lower limit is preferably 120°C, more preferably 150°C.
By setting the lower limit of the temperature during thin film distillation to the above value, the effect of removing light boiling components is sufficient. Further, by setting the upper limit to 250°C, it is possible to prevent the polycarbonate diol obtained after thin film distillation from being colored.

The upper limit of the pressure during thin film distillation is preferably 500 Pa, more preferably 150 Pa, and even more preferably 50 Pa. By controlling the pressure during thin film distillation to be equal to or lower than the above upper limit, a sufficient effect of removing light boiling components can be obtained.

Further, the upper limit of the temperature at which the polycarbonate diol is kept warm immediately before thin film distillation is preferably 250°C, and more preferably 150°C. Further, the lower limit is preferably 80°C, more preferably 120°C.
By setting the temperature at which the polycarbonate diol is kept warm immediately before the thin film distillation to be equal to or higher than the above lower limit, it is possible to prevent the fluidity of the polycarbonate diol immediately before the thin film distillation from decreasing. On the other hand, by setting it below the above upper limit, it is possible to prevent the polycarbonate diol obtained after thin film distillation from being colored.

<1-4. Physical properties of polycarbonate diol>
Preferred physical properties of the polycarbonate diol of the present invention produced by the method for producing polycarbonate diol of the present invention will be explained below.

<1-4-1. Molecular weight/molecular weight distribution>
The lower limit of the number average molecular weight (Mn) of the polycarbonate diol of the present invention is 250, preferably 500, more preferably 700, still more preferably 900. On the other hand, the upper limit is 10,000, preferably 5,000, more preferably 3,000, particularly preferably 2,000. If the number average molecular weight of the polycarbonate diol is less than the above-mentioned lower limit, flexibility etc. may be impaired when it is made into polyurethane. On the other hand, if the above upper limit is exceeded, the viscosity of the polycarbonate diol increases, which may cause problems in handling during polyurethane production.
Here, the number average molecular weight of the polycarbonate diol is determined by gel permeation chromatography (GPC) as shown in the Examples below.

The molecular weight distribution (Mw/Mn) of the polycarbonate diol of the present invention is not particularly limited, but the lower limit is usually 1.5, preferably 1.7, and more preferably 2.0. The upper limit is usually 3.5, preferably 3.0.
If the molecular weight distribution exceeds the above range, the physical properties of polyurethane produced using this polycarbonate diol tend to deteriorate, such as becoming hard at low temperatures and becoming less elongated, making it difficult to produce polycarbonate diol with a molecular weight distribution below the above range. If this is attempted, advanced purification operations such as removing oligomers may be required.
Here, Mw is a weight average molecular weight, and Mn is a number average molecular weight, which can usually be determined by GPC measurement.

<1-4-2. Ratio of the number of alkyloxy or aryloxy groups at the end of the molecular chain / hydroxyl value>
The terminal structure of the polymer of the polycarbonate diol of the present invention is basically a hydroxyl group. However, in the polycarbonate diol product obtained by the reaction of a dihydroxy compound and a carbonic acid diester, there may be some impurities that have a structure in which the terminal end of the polymer is not a hydroxyl group. A specific example of the structure is one in which the molecular chain terminal is an alkyloxy group or an aryloxy group, and most of them are structures derived from carbonic acid diesters.

For example, when diphenyl carbonate is used as the carbonic acid diester, the aryloxy group is a phenoxy group (PhO-), when dimethyl carbonate is used, the alkyloxy group is a methoxy group (MeO-), and when diethyl carbonate is used, an ethoxy group is used. (EtO-), if ethylene carbonate is used, a hydroxyethoxy group (HOCH ₂ CH ₂ O-) may remain as a terminal group (here, Ph represents a phenyl group, Me represents a methyl group, Et represents an ethyl group).

The proportion of the structure in which the molecular chain end is an alkyloxy group or an aryloxy group contained in the polycarbonate diol produced in the present invention is 5 mol% or less of the total number of terminal groups, particularly 3 mol % or less of the total number of terminal groups. % or less, particularly preferably 1 mol% or less. The lower limit of the number of alkyloxy groups or aryloxy groups at the end of this molecular chain is not particularly limited, and is usually 0.01 mol%, preferably 0.001 mol%, and most preferably 0 mol%. If the proportion of alkyloxy or aryloxy end groups is large, problems may arise such as the degree of polymerization not increasing during the polyurethanization reaction.

As mentioned above, the polycarbonate diol of the present invention has a number ratio of 5% or less in which the terminal end of the molecular chain is an alkyloxy group or an aryloxy group, and both terminal groups of the molecular chain are basically hydroxyl groups. In the reaction, it is preferable that this hydroxyl group has a structure that can react with isocyanate. In particular, from the viewpoint of reactivity with isocyanates, it is preferable that the number of primary or secondary hydroxyl groups at the end of the molecular chain is 95% or more, in order to synthesize a polyurethane with a larger molecular weight and higher strength. The proportion of primary hydroxyl groups is preferably 95% or more.

The hydroxyl value of the polycarbonate diol of the present invention is not particularly limited, but the lower limit is usually 10 mg-KOH/g, preferably 20 mg-KOH/g, more preferably 35 mg-KOH/g, even more preferably 80 mg-KOH/g. . Further, the upper limit is usually 230 mg-KOH/g, preferably 160 mg-KOH/g, and more preferably 140 mg-KOH/g. If the hydroxyl value is less than the above-mentioned lower limit, the viscosity may become too high and handling during polyurethane formation may become difficult, and if it exceeds the above-mentioned upper limit, strength and hardness may be insufficient when polyurethane is formed.
The method for measuring the hydroxyl value of polycarbonate diol is as described in the Examples section below.

<1-4-3. Ether structure>
The polycarbonate diol of the present invention has a basic structure in which a dihydroxy compound is polymerized by a carbonate group. However, depending on the manufacturing method, ether structures may be mixed in due to the dehydration reaction of some dihydroxy compounds, and if their abundance increases, weather resistance and heat resistance may decrease. It is desirable to manufacture so that the ratio does not become excessively large. In terms of reducing the ether structure in the polycarbonate diol and ensuring properties such as weather resistance and heat resistance, the ratio of ether bonds to carbonate bonds contained in the molecular chain of the polycarbonate diol of the present invention is not particularly limited. The molar ratio is usually 2/98 or less, preferably 1/99 or less, more preferably 0.5/99.5 or less. These values can be determined by alkaline hydrolysis and liquid chromatography measurement or ¹ H-NMR measurement. However, this does not apply when a poly(oxyalkylene) diol containing an ether bond is used as the dihydroxy compound depending on the required properties of the polycarbonate diol and polyurethane.

<1-4-4. Viscosity>
The lower limit of the viscosity at 40° C. of the polycarbonate diol of the present invention is preferably 0.1 Pa·s, more preferably 1 Pa·s, and even more preferably 5 Pa·s. Further, the upper limit is preferably 500 Pa·s, more preferably 200 Pa·s, even more preferably 150 Pa·s, particularly preferably 120 Pa·s, and preferably 100 Pa·s. Most preferred. By controlling the viscosity of the polycarbonate diol within this range, handling becomes easier.

<1-4-5. APHA value>
The color of the polycarbonate diol of the present invention is preferably 50 or less in Hazen color number (based on JIS K0071-1:1998) (hereinafter referred to as "APHA value"), and preferably 40 or less. is more preferable, still more preferably 30 or less, particularly preferably 20 or less. If the APHA value exceeds 50, the color tone of the polyurethane obtained using polycarbonate diol as a raw material may deteriorate, leading to a decrease in commercial value or poor thermal stability.

In order to keep the APHA value below 50, it is necessary to comprehensively control the selection of the type and amount of catalyst during polycarbonate diol production, thermal history, and the concentration of monohydroxy compounds and unreacted monomers during and after polymerization. There is a need to. In addition, shielding from light during and after polymerization is also effective. Furthermore, it is also important to set the molecular weight of the polycarbonate diol and to select the type of dihydroxy compound that is the monomer. In particular, polycarbonate diols made from aliphatic dihydroxy compounds having alcoholic hydroxyl groups exhibit various excellent properties such as flexibility, water resistance, and light resistance when processed into polyurethane. Thermal history and coloration due to the catalyst tend to be more pronounced than in the case where the APHA value is 60 or less.

<1-4-6. Turbidity>
The turbidity of the polycarbonate diol of the present invention is measured using an integrating sphere turbidity meter PT-200 manufactured by Mitsubishi Chemical Corporation. The value measured using a calibration curve is preferably 2.0 ppm or less, more preferably 1.0 ppm or less, particularly preferably 0.5 ppm or less. If the turbidity is greater than 2.0 ppm, the transparency of polyurethane obtained using polycarbonate diol as a raw material may deteriorate, resulting in a decrease in commercial value or mechanical properties. Further, if the turbidity is greater than 2.0 ppm, turbidity will be seen when the polycarbonate diol is visually observed.

This turbidity is thought to be mainly caused by the deactivation/precipitation of catalyst components and the formation of cyclic oligomers with low solubility.In order to reduce the turbidity to 2.0 ppm or less, the type of catalyst used during polycarbonate diol production must be adjusted. It is necessary to comprehensively control the selection of the amount, thermal history, concentration of monohydroxy compound during polymerization and after completion of polymerization, and concentration of unreacted monomer. For example, if the solubility of the catalyst itself in polycarbonate diol is low, precipitation of the catalyst will easily occur, and if the concentration is high, precipitation will be promoted. On the other hand, in order to suppress the formation of cyclic oligomers with poor solubility, the selection and combination of dihydroxy compounds as monomers are also important. For example, in the case of a homopolymer, a cyclic oligomer tends to be easily produced, but by copolymerization, it becomes difficult to form a stable cyclic structure, and the turbidity tends to decrease. Furthermore, if the temperature during production of polycarbonate diol is high, cyclic oligomers are thermodynamically more likely to be produced, so lowering the polymerization temperature is effective. However, if it is lowered too much, it is not preferable because it may hinder productivity, take too much time, cause deterioration of color tone, or deterioration of turbidity.

<1-4-7. Phenols＞
When an aromatic carbonic acid diester such as diphenyl carbonate is used as a raw material, phenols are produced as a by-product during the production of polycarbonate diol. Since phenols are monofunctional compounds, they can be a polymerization inhibiting factor during polyurethanization, and the urethane bonds formed by phenols have weak bonding strength, so they dissociate due to heat in subsequent steps. , regenerating isocyanates and phenols may cause problems, and they are also irritating substances, so it is preferable that the residual amount of phenols in the polycarbonate diol of the present invention be as small as possible. Specifically, the weight ratio to the polycarbonate diol is usually 1000 ppm or less, preferably 500 ppm or less, more preferably 300 ppm or less, and especially preferably 100 ppm or less. In order to reduce the amount of phenols in polycarbonate diol, it is effective to use a high vacuum of 1 kPa or less as an absolute pressure during the polymerization reaction of polycarbonate diol, or to perform thin film distillation after the synthesis of polycarbonate diol.

<1-4-8. Carbonic diester＞
In the polycarbonate diol of the present invention, carbonic acid diester used as a raw material during production may remain. Although the amount of carbonic acid diester remaining in the polycarbonate diol of the present invention is not limited, it is preferably as small as possible, and the upper limit is usually 5% by weight, preferably 3% by weight, and more preferably 1% by weight. If the carbonate diester content of the polycarbonate diol is too large, the reaction during polyurethanization may be inhibited. On the other hand, the lower limit is not particularly limited and is 0.1% by weight, preferably 0.01% by weight, and more preferably 0% by weight.

<1-4-9. Dihydroxy compound>
Dihydroxy compounds used during production may remain in the polycarbonate diol of the present invention. Although the amount of the dihydroxy compound remaining in the polycarbonate diol of the present invention is not limited, it is preferably as small as possible, usually 1% by weight or less, preferably 0.1% by weight or less, and more preferably 0.1% by weight or less. 05% by weight or less. If the residual amount of the dihydroxy compound in the polycarbonate diol is large, the molecular length of the soft segment portion when formed into polyurethane is insufficient, and desired physical properties may not be obtained.

<1-4-10. Cyclic carbonate>
Polycarbonate diol may contain a cyclic carbonate (cyclic oligomer) that is produced as a by-product during production. For example, when 1,3-propanediol is used as a dihydroxy compound, 1,3-dioxan-2-one or two or more molecules of 1,3-dioxan-2-one or a cyclic carbonate formed by two or more molecules of these are formed and contained in the polycarbonate diol. There may be cases where In addition, when 2,2-dimethyl-1,3-propanediol (neopentyl glycol) is used as the dihydroxy compound, 5,5-dimethyl-1,3-dioxan-2-one (hereinafter referred to as neopentyl glycol) pentyl carbonate (sometimes abbreviated as pentyl carbonate), or two or more molecules of these molecules formed into a ring may be produced as a cyclic compound. These compounds may cause side reactions in the polyurethanization reaction, and cause turbidity as mentioned above. It is desirable to remove as much as possible by performing thin film distillation after the synthesis. The content of these cyclic carbonates contained in the polycarbonate diol of the present invention is not limited, but is usually 3% by weight or less, preferably 1% by weight or less, and more preferably 0.5% by weight or less.

[2. polyurethane]
Polyurethane can be produced using the polycarbonate diol that is one embodiment of the present invention described above. Moreover, polyurethane can be manufactured using the polycarbonate diol-containing composition that is one embodiment of the present invention described above. Polyurethanes made using polycarbonate diols or compositions containing polycarbonate diols made according to the invention Polyurethanes are another form of the invention.
In a method for producing polyurethane using polycarbonate diol or a polycarbonate diol composition, known polyurethanization reaction conditions for normally producing polyurethane are used.
For example, polyurethane can be produced by reacting a polycarbonate diol, a polyisocyanate, and a chain extender at a temperature ranging from room temperature to 200°C.
Alternatively, polyurethane can be produced by first reacting polycarbonate diol with excess polyisocyanate to produce a prepolymer having an isocyanate group at the end, and then increasing the degree of polymerization using a chain extender.

<2-1. Polyisocyanate>
The polyisocyanate used when producing polyurethane using polycarbonate diol includes various known aliphatic, alicyclic, or aromatic polyisocyanate compounds.
For example, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, and converting the carboxyl group of dimer acid into an isocyanate group. Aliphatic diisocyanates such as dimer diisocyanate; 1,4-cyclohexane diisocyanate, isophorone diisocyanate, 1-methyl-2,4-cyclohexane diisocyanate, 1-methyl-2,6-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate and Alicyclic diisocyanates such as 1,3-bis(isocyanatomethyl)cyclohexane and 1,4-bis(isocyanatomethyl)cyclohexane; xylylene diisocyanate, 4,4'-diphenyl diisocyanate, 2,4-tolylene diisocyanate, 2 , 6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, dialkyl diphenylmethane diisocyanate, tetraalkyl Aromatic diisocyanates such as diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, polymethylene polyphenylisocyanate, phenylene diisocyanate, and m-tetramethylxylylene diisocyanate, etc. Can be mentioned. These may be used alone or in combination of two or more.

Among these, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate and Isophorone diisocyanate is preferred.

<2-2. Chain extender>
The chain extender used in producing polyurethane is a low molecular weight compound having at least two active hydrogen atoms that react with isocyanate groups in the production of a prepolymer having isocyanate groups, which will be described later. etc. can be mentioned.

Specific examples include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol. , 1,10-decanediol, 1,12-dodecanediol and other linear diols; 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2,2-diethyl -1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2-methyl-1,4-butanediol, 1,2-butanediol, 2,4-heptanediol, 1, 4-dimethylolhexane, 2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl Diols with branched chains such as -1,3-propanediol and dimer diol; Diols with ether groups such as diethylene glycol and propylene glycol; 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,4 - Diols with an alicyclic structure such as dihydroxyethylcyclohexane, diols with an aromatic group such as xylylene glycol, 1,4-dihydroxyethylbenzene, 4,4'-methylenebis(hydroxyethylbenzene); glycerin, trimethylolpropane , polyols such as pentaerythritol; hydroxyamines such as N-methylethanolamine and N-ethylethanolamine; ethylenediamine, 1,3-diaminopropane, hexamethylenediamine, triethylenetetramine, diethylenetriamine, isophoronediamine, 4,4 '-Diamino dicyclohexylmethane, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, 4,4'-diphenylmethane Polyamines such as diamine, methylenebis(o-chloroaniline), xylylenediamine, diphenyldiamine, tolylenediamine, hydrazine, piperazine, N,N'-diaminopiperazine; and water.

These chain extenders may be used alone or in combination of two or more. Among these, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,4-cyclohexanedimethanol, 1,4-dihydroxyethylcyclohexane, ethylenediamine, 1,3-diaminopropane, isophoronediamine, 4 , 4'-diaminodicyclohexylmethane is preferred.

Further, the chain extender used in producing a prepolymer having a hydroxyl group, which will be described later, is a low molecular weight compound having at least two isocyanate groups, and specifically, <2-1. Polyisocyanate> Compounds such as those described in ``Polyisocyanate'' can be mentioned.

<2-3. Chain terminator>
When producing polyurethane, a chain terminator having one active hydrogen group can be used as necessary for the purpose of controlling the molecular weight of the resulting polyurethane.
These chain terminators include aliphatic monools such as methanol, ethanol, propanol, butanol, and hexanol that have one hydroxyl group, and diethylamine, dibutylamine, n-butylamine, monoethanolamine, and diethanolamine that have one amino group. Examples include aliphatic monoamines such as morpholine and the like.
These may be used alone or in combination of two or more.

<2-4. Catalyst＞
In the polyurethane formation reaction when manufacturing polyurethane, amine catalysts such as triethylamine, N-ethylmorpholine, triethylenediamine, acid catalysts such as acetic acid, phosphoric acid, sulfuric acid, hydrochloric acid, sulfonic acid, trimethyltin laurate, dibutyltin, etc. Known urethane polymerization catalysts such as tin-based compounds such as dilaurate, dioctyltin dilaurate, and dioctyltindineodecanate, and organic metal salts such as titanium-based compounds can also be used. One type of urethane polymerization catalyst may be used alone, or two or more types may be used in combination.

<2-5. Polyols other than polycarbonate diol which is one embodiment of the present invention>
In the polyurethane forming reaction when producing polyurethane, the polycarbonate diol that is one embodiment of the present invention may be used in combination with other polyols (hereinafter also referred to as other polyols) as necessary.
Here, other polyols are not particularly limited as long as they are used in normal polyurethane production, and include, for example, polyether polyols, polyester polyols, polycaprolactone polyols, and polycarbonates other than the polycarbonate diol that is one embodiment of the present invention. Examples include polyols. For example, when used in combination with polyether polyol, it is possible to produce a polyurethane with further improved flexibility, which is a characteristic of polycarbonate diol.
The weight ratio of the polycarbonate diol, which is one embodiment of the present invention, to the combined weight of the polycarbonate diol, which is one embodiment of the present invention, and other polyols is preferably 70% or more, and more preferably 90% or more. If the weight ratio of the polycarbonate diol, which is one form of the present invention, is small, the strength and handleability of the polyurethane, which are the characteristics of the present invention, may be lost.

<2-6. Modification of polycarbonate diol>
In the present invention, the above-described polycarbonate diol, which is one embodiment of the present invention, may be modified and used for producing polyurethane. Methods for modifying polycarbonate diol include adding an epoxy compound such as ethylene oxide, propylene oxide, or butylene oxide to polycarbonate diol to introduce an ether group, or modifying polycarbonate diol by adding an epoxy compound such as ethylene oxide, propylene oxide, or butylene oxide to the polycarbonate diol, or adding a cyclic lactone such as ε-caprolactone, adipic acid, or succinic acid to polycarbonate diol. There is a method of introducing an ester group by reacting with a dicarboxylic acid compound such as , sebacic acid, terephthalic acid, or an ester compound thereof. Ether modification is preferable because modification with ethylene oxide, propylene oxide, etc. lowers the viscosity of the polycarbonate diol and improves handleability. In particular, in the polycarbonate diol of the present invention, by modifying it with ethylene oxide or propylene oxide, the crystallinity of the polycarbonate diol is reduced and its flexibility at low temperatures is improved. Since the water absorption and moisture permeability of the manufactured polyurethane increases, its performance as artificial leather, synthetic leather, etc. may be improved. However, when the amount of ethylene oxide or propylene oxide added increases, the physical properties such as mechanical strength, heat resistance, and chemical resistance of polyurethane manufactured using modified polycarbonate diol decrease, so the amount added to polycarbonate diol is A suitable amount is 5 to 50% by weight, preferably 5 to 40% by weight, more preferably 5 to 30% by weight, based on the weight of the polycarbonate diol. Furthermore, the method of introducing an ester group is preferable because the viscosity of the polycarbonate diol is lowered by modification with ε-caprolactone, and it is easier to handle. The amount of ε-caprolactone added to the polycarbonate diol is suitably 5 to 50% by weight, preferably 5 to 40% by weight, and more preferably 5 to 30% by weight. If the amount of ε-caprolactone added exceeds 50% by weight, the hydrolysis resistance, chemical resistance, etc. of the polyurethane produced using the modified polycarbonate diol will decrease.

<2-7. Solvent>
A solvent may be used in the polyurethane forming reaction when producing polyurethane.
Preferred solvents include amide solvents such as dimethylformamide, diethylformamide, dimethylacetamide, and N-methylpyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; ketone solvents such as methyl ethyl ketone, cyclohexanone, and methyl isobutyl ketone; tetrahydrofuran, dioxane, and the like. Examples include ether solvents; ester solvents such as methyl acetate, ethyl acetate, and butyl acetate; and aromatic hydrocarbon solvents such as toluene and xylene. These solvents may be used alone or as a mixed solvent of two or more.
Among these, preferred organic solvents include dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, methylethylketone, ethyl acetate, and toluene.
Furthermore, an aqueous dispersion of polyurethane can also be produced from a polyurethane composition containing a polycarbonate diol, a polydiisocyanate, and the above-mentioned chain extender, which is one embodiment of the present invention.

<2-8. Polyurethane manufacturing method>
As a method for producing polyurethane using the above-mentioned reaction reagent, production methods generally used experimentally or industrially can be used.
Examples include a method in which polycarbonate diol, which is an embodiment of the present invention, other polyols, polyisocyanate, and a chain extender are mixed all at once and reacted (hereinafter sometimes referred to as "one-step method"); First, a method of reacting a polycarbonate diol, which is an embodiment of the present invention, other polyols, and polyisocyanate to prepare a prepolymer having isocyanate groups at both ends, and then reacting the prepolymer with a chain extender (hereinafter referred to as " (sometimes referred to as "two-step method").

In the two-step method, the polycarbonate diol that is one form of the present invention and other polyols are reacted in advance with 1 equivalent or more of polyisocyanate to form isocyanate intermediates at both ends of the portion corresponding to the soft segment of polyurethane. It goes through a process of preparation. In this way, if the prepolymer is once prepared and then reacted with a chain extender, it may be easier to adjust the molecular weight of the soft segment portion, and if it is necessary to ensure phase separation between the soft segment and the hard segment. It is useful for

<2-9. One step method>
The one-stage method is also called a one-shot method, and is a method in which a reaction is carried out by charging polycarbonate diol, which is one embodiment of the present invention, other polyols, polyisocyanate, and a chain extender all at once.
The amount of polyisocyanate used in the one-stage method is not particularly limited, but is based on the total number of hydroxyl groups of the polycarbonate diol that is one embodiment of the present invention and other polyols, and the total number of hydroxyl groups and the number of amino groups of the chain extender. When it is 1 equivalent, the lower limit is preferably 0.7 equivalent, more preferably 0.8 equivalent, still more preferably 0.9 equivalent, particularly preferably 0.95 equivalent, and the upper limit is preferably 3.0 equivalent. equivalent, more preferably 2.0 equivalents, still more preferably 1.5 equivalents, particularly preferably 1.1 equivalents.

If too much polyisocyanate is used, unreacted isocyanate groups tend to cause side reactions, making the resulting polyurethane too viscous, making it difficult to handle, and reducing its flexibility. If it is too high, the molecular weight of the polyurethane will not be sufficiently large, and there will be a tendency that sufficient polyurethane strength will not be obtained.
The amount of the chain extender to be used is not particularly limited, but when the number of isocyanate groups in the polyisocyanate is subtracted from the total number of hydroxyl groups in the polycarbonate diol that is one form of the present invention and other polyols, 1 equivalent is used. , the lower limit is preferably 0.7 equivalents, more preferably 0.8 equivalents, even more preferably 0.9 equivalents, particularly preferably 0.95 equivalents, and the upper limit is preferably 3.0 equivalents, more preferably 2 equivalents. .0 equivalent, more preferably 1.5 equivalent, particularly preferably 1.1 equivalent. If the amount of chain extender used is too large, the resulting polyurethane tends to be difficult to dissolve in solvents and difficult to process. If it is too small, the resulting polyurethane will be too soft and will not have sufficient strength, hardness, elastic recovery performance, or elasticity. In some cases, retention performance may not be obtained or heat resistance may deteriorate.

<2-10. Two-stage method＞
The two-stage method is also called the prepolymer method, and mainly includes the following methods.
(a) Polycarbonate diol and other polyols which are one embodiment of the present invention and excess polyisocyanate are mixed in advance so that the reaction equivalent ratio of polyisocyanate/(polycarbonate diol and other polyol which is one embodiment of the present invention) is 1. A method for producing polyurethane by reacting an amount exceeding 10.0 to 10.0 to produce a prepolymer having an isocyanate group at the end of the molecular chain, and then adding a chain extender to the prepolymer.
(b) Polyisocyanate and excess polycarbonate diol and other polyols are mixed in advance so that the reaction equivalent ratio of polyisocyanate/(polycarbonate diol and other polyol which is an embodiment of the present invention) is from 0.1 to 1.0. A method of producing a polyurethane by reacting a prepolymer with a hydroxyl group at the end of the molecular chain, and then reacting a polyisocyanate with an isocyanate group at the end as a chain extender.

The two-step method can be carried out without a solvent or in the presence of a solvent.
Polyurethane production by the two-step method can be carried out by any of the methods (1) to (3) described below.
(1) Without using a solvent, first, polyisocyanate, polycarbonate diol, and other polyols are directly reacted to synthesize a prepolymer, and the prepolymer is used as it is in the chain extension reaction.
(2) A prepolymer is synthesized by the method of (1), then dissolved in a solvent, and used for the subsequent chain extension reaction.
(3) Using a solvent from the beginning, polyisocyanate, polycarbonate diol, and other polyols are reacted, and then a chain extension reaction is performed.

In the case of method (1), in the chain extension reaction, the polyurethane is formed in a form that coexists with the solvent by dissolving the chain extender in the solvent or dissolving the prepolymer and the chain extender in the solvent at the same time. It is important to get it.
The amount of polyisocyanate used in the two-step method (a) is not particularly limited, but the lower limit is the number of isocyanate groups when the total number of hydroxyl groups of the polycarbonate diol and other polyols is taken as 1 equivalent. Preferably the amount exceeds 1.0 equivalents, more preferably 1.2 equivalents, still more preferably 1.5 equivalents, and the upper limit is preferably 10.0 equivalents, more preferably 5.0 equivalents, still more preferably 3.0 equivalents. It is in the range of 0 equivalents.

If the amount of isocyanate used is too large, the excess isocyanate groups will cause side reactions, making it difficult to achieve the desired physical properties of the polyurethane. If the amount is too small, the molecular weight of the resulting polyurethane may not be sufficiently increased, resulting in lower strength and thermal stability.
The amount of the chain extender to be used is not particularly limited, but the lower limit is preferably 0.1 equivalent, more preferably 0.5 equivalent, and even more preferably 0.1 equivalent to several equivalents of isocyanate groups contained in the prepolymer. The upper limit is preferably 5.0 equivalents, more preferably 3.0 equivalents, and even more preferably 2.0 equivalents.

When performing the chain extension reaction, monofunctional organic amines or alcohols may be present in order to adjust the molecular weight.

In addition, the amount of polyisocyanate used when creating a prepolymer with a hydroxyl group at the end in the two-step method (b) is not particularly limited, but the total number of hydroxyl groups in the polycarbonate diol and other polyols should be determined. As for the number of isocyanate groups in case of 1 equivalent, the lower limit is preferably 0.1 equivalent, more preferably 0.5 equivalent, still more preferably 0.7 equivalent, and the upper limit is preferably 0.99 equivalent, more preferably is 0.98 equivalent, more preferably 0.97 equivalent.

If the amount of isocyanate used is too small, it will take a long time to obtain the desired molecular weight in the subsequent chain extension reaction, which tends to reduce production efficiency. If it is too large, the viscosity will become too high and the flexibility of the resulting polyurethane will be reduced. This may result in poor handling or poor productivity.
The amount of chain extender used is not particularly limited, but when the total number of hydroxyl groups of the polycarbonate diol used in the prepolymer and other polyols is taken as 1 equivalent, the equivalent of the isocyanate group used in the prepolymer is added. As for the total equivalent, the lower limit is preferably 0.7 equivalent, more preferably 0.8 equivalent, still more preferably 0.9 equivalent, and the upper limit is preferably less than 1.0 equivalent, more preferably 0.99 equivalent, and further Preferably it is in the range of 0.98 equivalent.

When performing the chain extension reaction, monofunctional organic amines or alcohols may be present in order to adjust the molecular weight.

The chain extension reaction is usually carried out at 0°C to 250°C, but this temperature varies depending on the amount of solvent, the reactivity of the raw materials used, the reaction equipment, etc., and is not particularly limited. If the temperature is too low, the reaction progresses slowly or the solubility of raw materials and polymers is low, which may lengthen the production time. If the temperature is too high, side reactions and decomposition of the resulting polyurethane may occur. . The chain extension reaction may be carried out under reduced pressure while defoaming.

Moreover, a catalyst, a stabilizer, etc. can be added to the chain extension reaction, if necessary.
Examples of the catalyst include compounds such as triethylamine, tributylamine, dibutyltin dilaurate, stannous octylate, acetic acid, phosphoric acid, sulfuric acid, hydrochloric acid, and sulfonic acid, and one type may be used alone, or two or more types may be used. may be used together.
Examples of the stabilizer include 2,6-dibutyl-4-methylphenol, distearylthiodipropionate, N,N'-di-2-naphthyl-1,4-phenylenediamine, and tris(dinonylphenyl)phosphite. These compounds may be used alone or in combination of two or more. Incidentally, if the chain extender is highly reactive such as a short-chain aliphatic amine, the reaction may be carried out without adding a catalyst.

<2-11. Water-based polyurethane emulsion＞
It is also possible to produce an aqueous polyurethane emulsion using polycarbonate diol, which is one embodiment of the present invention.
In that case, when producing a prepolymer by reacting a polyol containing a polycarbonate diol with an excess of polyisocyanate, a compound having at least one hydrophilic functional group and at least two isocyanate-reactive groups is mixed. A prepolymer is formed, and a water-based polyurethane emulsion is obtained through a process of neutralizing and salting hydrophilic functional groups, an emulsification process by adding water, and a chain extension reaction process.

The hydrophilic functional group used in the compound having at least one hydrophilic functional group and at least two isocyanate-reactive groups is, for example, a carboxyl group or a sulfonic acid group, which can be neutralized with an alkaline group. is a possible group. In addition, isocyanate-reactive groups are groups that generally react with isocyanates to form urethane bonds and urea bonds, such as hydroxyl groups, primary amino groups, and secondary amino groups, and these groups are mixed in the same molecule. It doesn't matter if you stay there.

Specifically, the compounds having at least one hydrophilic functional group and at least two isocyanate-reactive groups include 2,2'-dimethylolpropionic acid, 2,2-methylolbutyric acid, 2,2'-dimethylolpropionic acid, and 2,2'-dimethylolpropionic acid. '-dimethylolvaleric acid and the like. Also included are diaminocarboxylic acids such as lysine, cystine, 3,5-diaminocarboxylic acid, and the like. These may be used alone or in combination of two or more. When actually using these, they must be neutralized with amines such as trimethylamine, triethylamine, tri-n-propylamine, tributylamine, and triethanolamine, or alkaline compounds such as sodium hydroxide, potassium hydroxide, and ammonia. be able to.

When producing an aqueous polyurethane emulsion, the lower limit of the amount of the compound having at least one hydrophilic functional group and at least two isocyanate-reactive groups is set at the polycarbonate diol in order to improve the dispersion performance in water. The amount is preferably 1% by weight, more preferably 5% by weight, and even more preferably 10% by weight based on the total weight of the polyol and the other polyols. On the other hand, if too much of this is added, the properties of the polycarbonate diol may not be maintained, so the upper limit is preferably 50% by weight, more preferably 40% by weight, and still more preferably 30% by weight.

When producing an aqueous polyurethane emulsion, the reaction may be carried out in the presence of a solvent such as methyl ethyl ketone, acetone, or N-methyl-2-pyrrolidone in the prepolymer step, or the reaction may be carried out without a solvent. Further, when a solvent is used, it is preferable to distill off the solvent after producing the aqueous emulsion.

When producing an aqueous polyurethane emulsion without a solvent using polycarbonate diol as a raw material, the upper limit of the number average molecular weight determined from the hydroxyl value of the polycarbonate diol is preferably 5,000, more preferably 4,500, and still more preferably 4,000. Further, the lower limit of the number average molecular weight is preferably 300, more preferably 500, and even more preferably 800. If the number average molecular weight determined from the hydroxyl value exceeds the above upper limit or is smaller than the above lower limit, emulsification may become difficult.

In addition, when synthesizing or preserving aqueous polyurethane emulsions, anionic interfaces such as higher fatty acids, resin acids, acidic fatty alcohols, sulfuric esters, higher alkyl sulfonates, alkylaryl sulfonates, sulfonated castor oil, and sulfosuccinates are used. Active agents, cationic surfactants such as primary amine salts, secondary amine salts, tertiary amine salts, quaternary amine salts, pyridinium salts, or combinations of ethylene oxide and long-chain fatty alcohols or phenols. Emulsion stability may be maintained by using a nonionic surfactant represented by a known reaction product.

In addition, when making an aqueous polyurethane emulsion, an emulsion is produced by mechanically mixing water with an organic solvent solution of a prepolymer at high shear in the presence of an emulsifier without a neutralization and salting process if necessary. You can also do that.
The water-based polyurethane emulsion produced in this way can be used for various purposes. In particular, recently there has been a demand for chemical raw materials with low environmental impact, and they can be substituted for conventional products without using organic solvents.

Specific uses of the water-based polyurethane emulsion include, for example, coating agents, water-based paints, adhesives, synthetic leather, and artificial leather. In particular, the aqueous polyurethane emulsion produced using polycarbonate diol, which is one embodiment of the present invention, has flexibility because it has a structural unit derived from the compound represented by the formula (B) in the polycarbonate diol. It can be used more effectively as a coating agent than conventional water-based polyurethane emulsions using polycarbonate diol.

<2-12. Storage stability of polyurethane solutions and aqueous polyurethane emulsions>
The storage stability of polyurethane solutions and aqueous polyurethane emulsions produced using polycarbonate diol, which is an embodiment of the present invention, using an organic solvent and/or water is determined by the concentration of polyurethane in the solution or emulsion (hereinafter referred to as " After adjusting the solid content concentration (sometimes referred to as "solid content concentration") to 1 to 80% by weight and storing it under specific temperature conditions, the presence or absence of changes in the solution or emulsion can be visually measured. For example, a polyurethane solution (N,N-dimethylformamide/toluene mixed solution, When the solid content concentration is 30% by weight), the period during which no change is observed in the polyurethane solution when stored at 10°C is preferably 1 month, more preferably 3 months or more, and even more preferably 6 months. More than a month.

<2-13. Additive>
Polyurethane produced using polycarbonate diol, which is one embodiment of the present invention, includes heat stabilizers, light stabilizers, colorants, fillers, stabilizers, ultraviolet absorbers, antioxidants, anti-blocking agents, flame retardants, Various additives such as anti-aging agents and inorganic fillers can be added and mixed within the range that does not impair the properties of the polyurethane.

Compounds that can be used as heat stabilizers include aliphatic, aromatic, or alkyl-substituted aromatic esters of phosphoric acid and phosphorous acid, hypophosphorous acid derivatives, phenylphosphonic acid, phenylphosphinic acid, diphenylphosphonic acid, polyphosphonates, dialkyl Phosphorus compounds such as pentaerythritol diphosphite and dialkyl bisphenol A diphosphite; phenol derivatives, especially hindered phenol compounds; Compounds containing sulfur; tin-based compounds such as tin malate and dibutyltin monoxide can be used.

Specific examples of hindered phenol compounds include "Irganox1010" (product name: manufactured by BASF Japan Ltd.), "Irganox1520" (product name: manufactured by BASF Japan Ltd.), and "Irganox245" (product name: manufactured by BASF Japan Ltd.). ) etc.

Examples of phosphorus compounds include "PEP-36", "PEP-24G", "HP-10" (all product names: manufactured by ADEKA Co., Ltd.), "Irgafos 168" (product name: manufactured by BASF Japan Co., Ltd.), etc. can be mentioned.

Specific examples of compounds containing sulfur include thioether compounds such as dilaurylthiopropionate (DLTP) and distearylthiopropionate (DSTP).

Examples of light stabilizers include benzotriazole-based and benzophenone-based compounds, and specifically, "TINUVIN622LD", "TINUVIN765" (manufactured by Ciba Specialty Chemicals Co., Ltd.), and "SANOL LS-2626". ", "SANOL LS-765" (manufactured by Sankyo Co., Ltd.), etc. can be used.

Examples of ultraviolet absorbers include "TINUVIN328" and "TINUVIN234" (all manufactured by Ciba Specialty Chemicals Co., Ltd.).

Coloring agents include dyes such as direct dyes, acid dyes, basic dyes, and metal complex dyes; inorganic pigments such as carbon black, titanium oxide, zinc oxide, iron oxide, and mica; and coupled azo-based, condensed azo-based, Examples include organic pigments such as anthraquinone, thioindigo, dioxazone, and phthalocyanine pigments.

Examples of inorganic fillers include short glass fibers, carbon fibers, alumina, talc, graphite, melamine, and clay.

Examples of flame retardants include additive and reactive flame retardants such as phosphorus- and halogen-containing organic compounds, bromine- or chlorine-containing organic compounds, ammonium polyphosphate, aluminum hydroxide, and antimony oxide.

These additives may be used alone or in any combination and ratio of two or more.
The lower limit of the amount of these additives added is preferably 0.01% by weight, more preferably 0.05% by weight, even more preferably 0.1% by weight, and the upper limit is preferably 10% by weight, as a weight ratio to the polyurethane. % by weight, more preferably 5% by weight, even more preferably 1% by weight. If the amount of additive added is too small, the effect of the addition cannot be obtained sufficiently, and if it is too large, precipitation may occur in the polyurethane or turbidity may occur.

<2-14. Polyurethane film/polyurethane board＞
When producing a film using polyurethane, the lower limit of the thickness of the film is preferably 10 μm, more preferably 20 μm, even more preferably 30 μm, and the upper limit is preferably 1000 μm, more preferably 500 μm, still more preferably 100 μm. be.
If the film is too thick, sufficient moisture permeability may not be obtained; if the film is too thin, pinholes may occur or the film may easily block, making it difficult to handle.

<2-15. Molecular weight>
The molecular weight of polyurethane is appropriately adjusted depending on its use and is not particularly limited, but it is preferably 50,000 to 500,000 as a weight average molecular weight (Mw) in terms of polystyrene measured by GPC, and 100,000 to 30,000. More preferably, it is 10,000. If Mw is smaller than the above-mentioned lower limit, sufficient strength and hardness may not be obtained, and if it is larger than the above-mentioned upper limit, there is a tendency for handling properties such as workability to be impaired.

<2-16. Room temperature tensile test>
<2-16-1. Tensile elongation at break and strength in room temperature tensile test>
Tensile breakage of polyurethane was measured on a rectangular sample with a width of 10 mm, a length of 100 mm, and a thickness of approximately 50 to 100 μm at a chuck distance of 50 mm and a tensile speed of 500 mm/min at a temperature of 23°C and a relative humidity of 50%. It is preferable that the elongation and breaking strength are within the following ranges.

The lower limit of the elongation at break is preferably 200%, more preferably 300%, even more preferably 350%, and the upper limit is preferably 1000%, more preferably 800%, still more preferably 600%. When the elongation at break is less than the above lower limit, handling properties such as workability tend to be impaired, and when it exceeds the above upper limit, sufficient solvent resistance may not be obtained.
Further, the lower limit of the breaking strength is preferably 30 MPa, more preferably 40 MPa, and still more preferably 50 MPa, and the upper limit is preferably 200 MPa, more preferably 100 MPa, and even more preferably 80 MPa. If the breaking strength is less than the above-mentioned lower limit, handling properties such as workability tend to be impaired, and if it exceeds the above-mentioned upper limit, flexibility may be impaired.

<2-16-2. 100% modulus, 300% modulus in room temperature tensile test>
Polyurethane can be obtained by reacting 2 equivalents of 4,4'-dicyclohexylmethane diisocyanate with polycarbonate diol, which is one form of the present invention, and further performing a chain extension reaction with isophorone diamine to obtain polyurethane in a two-step process. The lower limit of the 100% modulus measured at a temperature of 23°C and a relative humidity of 60% with a distance between chucks of 50 mm and a tensile speed of 500 mm/min for a strip-shaped sample of 10 mm in length, 100 mm in length, and approximately 50 to 100 μm in thickness is Preferably it is 3.0 MPa, more preferably 4.0 MPa, still more preferably 5.0 MPa, and the upper limit is preferably 20 MPa, more preferably 10 MPa, and still more preferably 8 MPa. If the 100% modulus is less than the above lower limit, the hardness may not be sufficient, and if it exceeds the above upper limit, the flexibility may be insufficient or handling properties such as workability may be impaired. Further, the lower limit of the 300% modulus of the polyurethane is preferably 10 MPa, more preferably 15 MPa, and still more preferably 20 MPa. The upper limit is preferably 100 MPa, more preferably 50 MPa, even more preferably 40 MPa. If the 300% modulus is less than the above lower limit, hardness may be insufficient. If the 300% modulus exceeds the above upper limit, flexibility may be insufficient or handling properties such as workability may be impaired.

<2-17. 100% modulus, 300% modulus in low temperature tensile test>
When polyurethane is obtained in a two-step process by reacting 2 equivalents of 4,4'-dicyclohexylmethane diisocyanate with polycarbonate diol, which is one form of the present invention, and further performing a chain extension reaction with isophorone diamine, the polyurethane has a width of 10 mm. , the lower limit of the 100% modulus measured at a temperature of -10°C on a strip-shaped sample with a length of 100 mm and a thickness of about 50 to 100 μm at a distance between chucks of 50 mm and a tensile speed of 500 mm/min is preferably 5 MPa, and more Preferably it is 10 MPa, more preferably 15 MPa, and the upper limit is preferably 20 MPa, more preferably 19 MPa, still more preferably 18 MPa. If the 100% modulus is less than the above lower limit, the hardness may not be sufficient, and if it exceeds the above upper limit, the flexibility may be insufficient or handling properties such as workability may be impaired.

<2-18. Solvent resistance＞
<2-18-1. Olein resistance＞
For example, in evaluating polyurethane by the method described in the Examples section below, the rate of change (%) in the weight of a polyurethane test piece after immersion in oleic acid with respect to the weight of the polyurethane test piece before immersion in oleic acid. However, it is preferably 40% or less, more preferably 30% or less, even more preferably 25% or less, particularly preferably 20% or less, and most preferably 18% or less.
If this weight change rate exceeds the above upper limit, sufficient oleic acid resistance may not be obtained.

<2-18-2. Ethanol resistance>
For example, in evaluating polyurethane by the method described in the Examples section below, the rate of change (%) in the weight of the polyurethane test piece after immersing in ethanol with respect to the weight of the polyurethane test piece before immersion in ethanol is It is preferably 40% or less, more preferably 30% or less, even more preferably 25% or less, particularly preferably 20% or less, and most preferably 18% or less.
If this weight change rate exceeds the above upper limit, sufficient ethanol resistance may not be obtained.

<2-18-3. Ethyl acetate resistance>
For example, when evaluating polyurethane using the method described in the Examples section below, the rate of change (%) in the weight of a polyurethane test piece after immersion in a chemical relative to the weight of the polyurethane test piece before immersion in ethyl acetate is , is preferably 150% or less, more preferably 100% or less, and even more preferably 90% or less.
If this weight change rate exceeds the above upper limit, sufficient ethyl acetate resistance may not be obtained.

<2-19. Application>
Polyurethane has excellent solvent resistance, good flexibility, and mechanical strength, so it is used in foams, elastomers, elastic fibers, paints, fibers, adhesives, adhesives, flooring materials, sealants, medical materials, artificial leather, It can be widely used in synthetic leather, coating agents, water-based polyurethane paints, active energy ray-curable polymer compositions, etc.
In particular, when the polyurethane of one form of the present invention is used for applications such as artificial leather, synthetic leather, water-based polyurethane, adhesives, elastic fibers, medical materials, flooring materials, paints, and coating agents, it has excellent solvent resistance and flexibility. It has a good balance of elasticity and mechanical strength, so it is highly durable in areas that come in contact with human skin or where cosmetic chemicals or disinfectant alcohol are used, and has sufficient flexibility and physical strength. Good properties such as resistance to impact can be imparted. 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 in thermosetting elastomers and cast polyurethane elastomers. Specific applications include rolls such as rolling rolls, paper rolls, office equipment, pretension rolls, solid tires for forklifts, automobiles, new trams, trolleys, transport vehicles, etc., and industrial products such as conveyor belt idlers and guides. These products include rolls, pulleys, steel pipe linings, ore rubber screens, gears, connection rings, liners, pump impellers, cyclone cones, and cyclone liners. It can also be used for office automation equipment belts, paper feed rolls, copying cleaning blades, snow plows, toothed belts, surf rollers, etc.

Polyurethanes also find application as thermoplastic elastomers. For example, it can be used for tubes and hoses, spiral tubes, fire hoses, etc. in pneumatic equipment used in the food and medical fields, painting equipment, analytical equipment, physical and chemical equipment, metering pumps, water treatment equipment, industrial robots, etc. It is also used as belts such as round belts, V-belts, and flat belts in various power transmission mechanisms, spinning machines, packing equipment, printing machines, and the like. It can also be used for heel tops and soles of footwear, equipment parts such as couplings, packing, pole joints, bushes, gears, and rolls, sporting goods, leisure goods, and watch straps. Furthermore, examples of automobile parts include oil stoppers, gear boxes, spacers, chassis parts, interior parts, and tire chain substitutes. It can also be used for keyboard films, automobile films, curl cords, cable sheaths, bellows, conveyor belts, flexible containers, binders, synthetic leather, dipping products, adhesives, etc.

Polyurethane can also be used as a solvent-based two-component paint, and can be applied to wood products such as musical instruments, Buddhist altars, furniture, decorative plywood, and sporting goods. 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. Paints, strippable paints, magnetic tape coatings, floor tiles, floor coverings, paper, overprint varnishes for wood grain printing films, wood varnishes, 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, etc.

Polyurethane can also be applied as a pressure-sensitive adhesive or adhesive in food packaging, shoes, footwear, magnetic tape binders, decorative paper, wood, structural components, etc., and can also be used as a component of low-temperature adhesives and hot melts. I can do it.
Polyurethane can be used as a binder in magnetic recording media, inks, foundries, fired bricks, graft materials, microcapsules, granular fertilizers, granular pesticides, polymer cement mortars, resin mortars, rubber chip binders, recycled foams, glass fiber sizing, etc. be.

Polyurethane can be used as a component of a fiber finishing agent for shrink-proofing, wrinkle-proofing, water-repellent finishing, etc.
When polyurethane is used as an elastic fiber, the fiberization method can be carried out without particular limitation as long as it can be spun. For example, a melt spinning method can be employed in which the pellets are once pelletized, then melted, and then spun directly through a spinneret. When obtaining elastic fibers 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.

Polyurethane elastic fibers can be used as bare yarns as they are, or can be covered with other fibers and used as covered yarns. Examples of other fibers include conventionally known fibers such as polyamide fibers, wool, cotton, and polyester fibers, among which polyester fibers are preferably used in the present invention. Moreover, the elastic fiber using polyurethane may contain a dyeing type disperse dye.

Polyurethane is used as a sealant and caulk for concrete walls, induced joints, around sashes, wall-type PC (Precast Concrete) joints, ALC (Autoclaved Light-weight Concrete) joints, board joints, composite glass sealant, and heat-insulating sash sealant. , can be used in automotive sealants, etc.
Polyurethane can be used as a medical material, and as a blood-compatible material, it can be used in tubes, catheters, artificial hearts, artificial blood vessels, artificial valves, etc., and as a disposable material, it can be used in catheters, tubes, bags, surgical gloves, artificial kidneys, etc. Can be used as potting material, etc.
Polyurethane can be used as a raw material for UV curable coatings, electron beam curable coatings, photosensitive resin compositions for flexo printing plates, photocurable optical fiber coating compositions, etc. by modifying the terminals.

<2-20. Urethane (meth)acrylate oligomer>
A urethane (meth)acrylate oligomer can be produced by carrying out an addition reaction between a polyisocyanate and a hydroxyalkyl (meth)acrylate using a polycarbonate diol. When other raw material compounds such as polyols and chain extenders are used together, urethane (meth)acrylate oligomers can be produced by addition-reacting these other raw material compounds to polyisocyanate. .

In the present invention, "(meth)acrylic" as in (meth)acrylate and (meth)acrylic acid means acrylic and/or methacrylic.
Further, the charging ratio of each raw material compound at that time is substantially the same as or the same as the composition of the target urethane (meth)acrylate oligomer.
The amount of all isocyanate groups in the urethane (meth)acrylate oligomer and the amount of all functional groups that react with isocyanate groups such as hydroxyl groups and amino groups are usually theoretically equimolar.

When producing a urethane (meth)acrylate oligomer, the amount of hydroxyalkyl (meth)acrylate used is determined by adjusting the amount of hydroxyalkyl (meth)acrylate, polyol, which is a hydroxyalkyl (meth)acrylate, polycarbonate diol, and other raw material compounds used as necessary; Usually 10 mol% or more, preferably 15 mol% or more, more preferably 25 mol% or more, and usually 70 mol% or less, based on the total amount of compounds containing functional groups that react with isocyanates such as chain extenders. , preferably 50 mol% or less. Depending on this ratio, the molecular weight of the resulting urethane (meth)acrylate oligomer can be controlled. When the proportion of hydroxyalkyl (meth)acrylate is high, the molecular weight of the urethane (meth)acrylate oligomer tends to be small, and when the proportion is small, the molecular weight tends to be large.

The amount of polycarbonate diol used is preferably 25 mol% or more, more preferably 50 mol% or more, and even more preferably It is 70 mol% or more. It is preferable that the amount of polycarbonate diol used is equal to or greater than the lower limit value because the obtained cured product tends to have good elongation, hardness, weather resistance, and stain resistance.

Furthermore, the amount of polycarbonate diol used is preferably 10% by weight or more, more preferably 30% by weight or more, based on the total amount of polycarbonate diol that is one embodiment of the present invention and other polyols. It is more preferably 50% by weight or more, particularly preferably 70% by weight or more. When the amount of polycarbonate diol used is more than the above lower limit, the viscosity of the resulting composition decreases and workability improves, and the resulting cured product tends to have improved mechanical strength, hardness, and abrasion resistance. It's very desirable.

Furthermore, when using a chain extender, the amount of the polycarbonate polyol and other polyol used relative to the total amount of the compound used, which is a combination of the polycarbonate diol that is one embodiment of the present invention, other polyols, and the chain extender. is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, particularly preferably 95 mol% or more. If it exceeds the lower limit, the liquid stability tends to improve, which is preferable.

During the production of urethane (meth)acrylate oligomers, a solvent can be used for the purpose of adjusting the viscosity. One type of solvent may be used alone, or two or more types may be used in combination. As the solvent, any known solvent can be used. Preferred solvents include toluene, xylene, ethyl acetate, butyl acetate, cyclohexanone, methyl ethyl ketone, and methyl isobutyl ketone. The solvent can usually be used in an amount of less than 300 parts by weight based on 100 parts by weight of solid content in the reaction system.

During the production of urethane (meth)acrylate oligomers, the total content of the urethane (meth)acrylate oligomers produced and their raw material compounds is preferably 20% by weight or more based on the total amount of the reaction system, and preferably 40% by weight or more based on the total amount of the reaction system. % or more is more preferable. Note that the upper limit of this total content is 100% by weight. It is preferable that the total content of the urethane (meth)acrylate oligomer and its raw material compound is 20% by weight or more because the reaction rate tends to increase and the production efficiency tends to improve.

An addition reaction catalyst can be used in the production of urethane (meth)acrylate oligomers. Examples of the addition reaction catalyst include dibutyltin laurate, dibutyltin dioctoate, dioctyltin dilaurate, and dioctyltin dioctoate. The addition reaction catalyst may be used alone or in combination of two or more. Among these, dioctyltin dilaurate is preferred as the addition reaction catalyst from the viewpoints of environmental adaptability, catalytic activity, and storage stability.

The upper limit of the addition reaction catalyst is usually 1000 ppm by weight, preferably 500 ppm, and the lower limit is usually 10 ppm by weight, preferably 10 ppm by weight, based on the total content of the urethane (meth)acrylate oligomer to be produced and its raw material compound. It is used at 30 ppm by weight.
Furthermore, when the reaction system contains a (meth)acryloyl group during the production of the urethane (meth)acrylate oligomer, a polymerization inhibitor can be used in combination. Examples of such polymerization inhibitors include hydroquinone, methylhydroquinone, hydroquinone monoethyl ether, phenols such as dibutylhydroxytoluene, amines such as phenothiazine and diphenylamine, copper salts such as copper dibutyldithiocarbamate, and manganese such as manganese acetate. Examples include salts, nitro compounds, nitroso compounds, and the like. The polymerization inhibitors may be used alone or in combination of two or more. Among these, phenols are preferable as the polymerization inhibitor.

The upper limit of the polymerization inhibitor is usually 3000 ppm, preferably 1000 ppm by weight, particularly preferably 500 ppm by weight, and the lower limit is It is usually used at 50 ppm by weight, preferably 100 ppm by weight.
During the production of urethane (meth)acrylate oligomers, the reaction temperature is usually 20°C or higher, preferably 40°C or higher, and more preferably 60°C or higher. It is preferable that the reaction temperature is 20° C. or higher because the reaction rate tends to increase and production efficiency tends to improve. Further, the reaction temperature is usually 120°C or lower, preferably 100°C or lower. It is preferable that the reaction temperature is 120° C. or lower because side reactions such as allophanatization reactions are less likely to occur. In addition, when a solvent is included in the reaction system, the reaction temperature is preferably below the boiling point of the solvent, and when (meth)acrylate is included, from the viewpoint of preventing the reaction of the (meth)acryloyl group, the reaction temperature is preferably 70°C. It is preferable that it is below. The reaction time is usually about 5 to 20 hours.

The number average molecular weight of the urethane (meth)acrylate oligomer thus obtained is preferably at least 500, particularly preferably at least 1,000, and preferably at most 10,000, particularly preferably at most 5,000, particularly preferably at most 3,000. When the number average molecular weight of the urethane (meth)acrylate oligomer is equal to or higher than the above lower limit, the obtained cured film has good three-dimensional processing suitability, and tends to have an excellent balance between three-dimensional processing suitability and stain resistance, which is preferable. When the number average molecular weight of the urethane (meth)acrylate oligomer is below the above upper limit, the cured film obtained from the composition will have good stain resistance, and will tend to have an excellent balance between three-dimensional processing suitability and stain resistance. Therefore, it is preferable. This is because the suitability for three-dimensional processing and stain resistance depend on the distance between the crosslinking points in the network structure, and as this distance increases, the structure becomes flexible and stretches easily, resulting in excellent suitability for three-dimensional processing. This is presumed to be because the structure is strong and has excellent stain resistance.

<2-21. Polyester elastomer>
Polycarbonate diol, which is one embodiment of the present invention, can be used as a polyester elastomer. A polyester elastomer is a copolymer composed of a hard segment mainly made of aromatic polyester and a soft segment mainly made of aliphatic polyether, aliphatic polyester, or aliphatic polycarbonate. When polycarbonate diol is used as a component of the soft segment, physical properties such as heat resistance and water resistance are superior to those using aliphatic polyether or aliphatic polyester. Furthermore, compared to known polycarbonate diols, it is a polycarbonate ester elastomer that has fluidity during melting, that is, a melt flow rate suitable for blow molding and extrusion molding, and has an excellent balance with mechanical strength and other physical properties. It can be suitably used in various molding materials such as fibers, films, and sheets, such as elastic yarns and molding materials such as boots, gears, tubes, and packing. Specifically, it can be effectively applied to joint boots for automobiles, home appliance parts, etc., which require heat resistance and durability, and electric wire covering materials.

<2-22. Active energy ray-curable polymer composition>
An active energy ray curable polymer composition (hereinafter sometimes simply referred to as "active energy ray curable polymer composition") containing the above-mentioned urethane (meth)acrylate oligomer will be explained.
The active energy ray-curable polymer composition preferably has a calculated network crosslinking point molecular weight of 500 to 10,000.

In this specification, the calculated molecular weight between network crosslinking points of a composition is the average molecular weight between active energy ray reactive groups (hereinafter sometimes referred to as "crosslinking points") forming a network structure in the entire composition. represents a value. This calculated molecular weight between crosslinking points in the network has a correlation with the network area at the time of network structure formation, and the larger the calculated molecular weight between crosslinking points in the network, the lower the crosslinking density. In the reaction by active energy ray curing, when a compound having only one active energy ray reactive group (hereinafter sometimes referred to as a "monofunctional compound") reacts, it becomes a linear polymer; A network structure is formed when a compound having two or more linearly reactive groups (hereinafter sometimes referred to as a "polyfunctional compound") reacts.

Therefore, the active energy ray-reactive groups possessed by the polyfunctional compound are the crosslinking points, and the calculation of the molecular weight between crosslinking points in the calculation network is centered on the polyfunctional compound having the crosslinking points, and the monofunctional compound is the crosslinking point possessed by the polyfunctional compound. The molecular weight between the crosslinking points of the calculation network is calculated by treating the molecular weight between the crosslinking points as having the effect of elongation. In addition, the calculation of the molecular weight between the calculated network crosslinking points is performed on the assumption that all active energy ray reactive groups have the same reactivity and that all active energy ray reactive groups react with active energy ray irradiation. .

In a single polyfunctional compound composition in which only one type of polyfunctional compound reacts, the calculated molecular weight between network crosslinking points is twice the average molecular weight per active energy ray reactive group of the polyfunctional compound. . For example, for a bifunctional compound with a molecular weight of 1,000, (1000/2) x 2 = 1000, and for a trifunctional compound with a molecular weight of 300, (300/3) x 2 = 200.
In a polyfunctional compound mixed system composition in which multiple types of polyfunctional compounds react, the average value of the molecular weight between the calculated network crosslinking points of each of the above single systems with respect to the total number of active energy ray-reactive groups contained in the composition is This is the calculated molecular weight between network crosslinking points of the composition. For example, in a composition consisting of a mixture of 4 moles of a bifunctional compound with a molecular weight of 1,000 and 4 moles of a trifunctional compound with a molecular weight of 300, the total number of active energy ray-reactive groups in the composition is 2 x 4 + 3 x 4 = 20. Therefore, the calculated molecular weight between network crosslinking points of the composition is {(1000/2)×8+(300/3)×12}×2/20=520.

When a monofunctional compound is included in the composition, it is calculated that the active energy ray-reactive group (that is, the crosslinking point) of the polyfunctional compound has an equivalent mole of each, and the molecule formed by connecting the monofunctional compound to the crosslinking point. Assuming that the reaction occurs at the center of the chain, the amount of extension of the molecular chain by the monofunctional compound at one crosslinking point will reduce the total molecular weight of the monofunctional compound to the total active energy ray reaction of the polyfunctional compound in the composition. It is half of the value divided by the base number. Here, since the calculated molecular weight between crosslinking points in the network is considered to be twice the average molecular weight per crosslinking point, the amount elongated by the monofunctional compound is the molecular weight between the calculated network crosslinking points calculated for the polyfunctional compound. , is the value obtained by dividing the total molecular weight of the monofunctional compound by the total number of active energy ray-reactive groups of the polyfunctional compound in the composition.

For example, in a composition consisting of a mixture of 40 moles of a monofunctional compound with a molecular weight of 100 and 4 moles of a bifunctional compound with a molecular weight of 1,000, the number of active energy ray-reactive groups in the polyfunctional compound is 2 x 4 = 8. , the amount of elongation due to the monofunctional compound in the calculated molecular weight between network crosslinking points is 100×40/8=500. That is, the calculated molecular weight between network crosslinking points of the composition is 1000+500=1500.
From the above, it can be seen that in a mixture of moles of monofunctional compound M _A with molecular weight W _A , moles of f _B functional compound M _B with molecular weight W _B , and moles of f _C functional compound M _C with molecular weight _{W C} , the composition The calculated molecular weight between network crosslinking points of a substance can be expressed by the following formula.

The calculated molecular weight between network crosslinking points of the active energy ray-curable polymer composition calculated in this way is preferably 500 or more, more preferably 800 or more, and preferably 1,000 or more. More preferably, it is 10,000 or less, more preferably 8,000 or less, even more preferably 6,000 or less, even more preferably 4,000 or less, 3. 000 or less is particularly preferable.

It is preferable that the calculated molecular weight between network crosslinking points is 10,000 or less because the cured film obtained from the composition has good stain resistance and tends to have an excellent balance between three-dimensional processing suitability and stain resistance. Further, when the calculated molecular weight between network crosslinking points is 500 or more, the obtained cured film has good three-dimensional processing suitability, and tends to have an excellent balance between three-dimensional processing suitability and stain resistance, which is preferable. The suitability for three-dimensional processing and stain resistance depend on the distance between the crosslinking points in the network structure; the longer this distance is, the more flexible and stretchable the structure becomes; This is presumed to be because the network structure becomes strong and has excellent stain resistance.

The active energy ray-curable polymer composition may further contain components other than the urethane (meth)acrylate oligomer. Examples of such other components include active energy ray-reactive monomers, active energy ray-curable oligomers, polymerization initiators, photosensitizers, additives, and solvents.

In the active energy ray-curable polymer composition, the content of the urethane (meth)acrylate oligomer is 40% by weight or more based on the total amount of active energy ray-reactive components containing the urethane (meth)acrylate oligomer. It is preferably 60% by weight or more, and more preferably 60% by weight or more. Note that the upper limit of this content is 100% by weight. When the content of the urethane (meth)acrylate oligomer is 40% by weight or more, the curability will be good, and the mechanical strength of the cured product will not become too high, and the suitability for three-dimensional processing will tend to improve. It is preferable because it is.

In addition, in the active energy ray-curable polymer composition, the content of the urethane (meth)acrylate oligomer is preferably higher in terms of elongation and film-forming properties, and on the other hand, in terms of lowering the viscosity, Less is better. From this point of view, the content of the urethane (meth)acrylate oligomer is preferably 50% by weight or more based on the total amount of all components including other components in addition to the active energy ray-reactive component. , more preferably 70% by weight or more. Note that the upper limit of the content of the urethane (meth)acrylate oligomer is 100% by weight, and this content is preferably less than that.

In addition, in the active energy ray-curable polymer composition, the total content of the active energy ray-reactive components containing the urethane (meth)acrylate oligomer is such that the composition has excellent curing speed and surface curability, and is tack-resistant. From the viewpoint of not leaving any residue, it is preferably 60% by weight or more, more preferably 80% by weight or more, even more preferably 90% by weight or more, and still more preferably 95% by weight, based on the total amount of the composition. % or more is particularly preferable. Note that the upper limit of this content is 100% by weight.

As the active energy ray-reactive monomer, any known active energy ray-reactive monomer can be used. These active energy ray-reactive monomers are used for the purpose of adjusting the hydrophilic and hydrophobic properties of urethane (meth)acrylate oligomers and the physical properties such as hardness and elongation of the cured product when the resulting composition is made into a cured product. be done. The active energy ray-reactive monomers may be used alone or in combination of two or more.

Such active energy ray-reactive monomers include, for example, vinyl ethers, (meth)acrylamides, and (meth)acrylates, and specifically, for example, styrene, α-methylstyrene, α-chlorostyrene, etc. , vinyl toluene, divinylbenzene, etc.; vinyl acetate, vinyl butyrate, N-vinylformamide, N-vinylacetamide, N-vinyl-2-pyrrolidone, N-vinylcaprolactam, divinyl adipate, etc. Ester monomers; Vinyl ethers such as ethyl vinyl ether and phenyl vinyl ether; Allyl compounds such as diallyl phthalate, trimethylolpropane diallyl ether, and allyl glycidyl ether; (meth)acrylamide, N,N-dimethylacrylamide, N,N-dimethylmethacrylate Amide, N-methylol (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide, Nt-butyl (meth)acrylamide, (meth)acryloylmorpholine, methylenebis(meth)acrylamide, etc. (meth)acrylamides; (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, (meth)acrylate- i-Butyl, t-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, (meth)acrylic acid Tetrahydrofurfuryl, morpholyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, glycidyl (meth)acrylate , dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, phenoxyethyl (meth)acrylate, tricyclodecane (meth)acrylate, ( Dicyclopentenyl meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, allyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, (meth)acrylate Monofunctional (meth)acrylates such as isobornyl acrylate and phenyl (meth)acrylate; and ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, di( Tetraethylene glycol meth)acrylate, polyethylene glycol di(meth)acrylate (n=5-14), propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, triethylene di(meth)acrylate Propylene glycol, tetrapropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate (n=5-14), 1,3-butylene glycol di(meth)acrylate, di(meth)acrylic acid- 1,4-butanediol, polybutylene glycol di(meth)acrylate (n=3-16), poly(1-methylbutylene glycol) di(meth)acrylate (n=5-20), di(meth)acrylate 1,6-hexanediol acrylate, 1,9-nonanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, neopentyl glycol hydroxypivalate di(meth)acrylate, di(meth)acrylate dicyclopentanediol meth)acrylate, tricyclodecane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate ) acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trimethylolpropanetrioxyethyl(meth)acrylate, trimethylolpropanetrioxypropyl(meth)acrylate Acrylate, trimethylolpropane polyoxyethyl (meth)acrylate, trimethylolpropane polyoxypropyl (meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, tris(2-hydroxyethyl)isocyanurate di( meth)acrylate, ethylene oxide added bisphenol A di(meth)acrylate, ethylene oxide added bisphenol F di(meth)acrylate, propylene oxide added bisphenol A di(meth)acrylate, propylene oxide added bisphenol F di(meth)acrylate, tricyclo Examples include polyfunctional (meth)acrylates such as decanedimethanol di(meth)acrylate, bisphenol A epoxy di(meth)acrylate, and bisphenol F epoxy di(meth)acrylate.

Among these, (meth)acryloylmorpholine, (meth)acrylic acid tetrahydrofurfuryl, (meth)acrylic acid benzyl, (meth)acrylic acid cyclohexyl, (meth)acrylic acid Having a ring structure in the molecule, such as trimethylcyclohexyl, phenoxyethyl (meth)acrylate, tricyclodecane (meth)acrylate, dicyclopentenyl (meth)acrylate, isobornyl (meth)acrylate, and (meth)acrylamide. Monofunctional (meth)acrylates are preferred; on the other hand, in applications where mechanical strength of the resulting cured product is required, di(meth)acrylic acid-1,4-butanediol, di(meth)acrylic acid-1, 6-hexanediol, 1,9-nonanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, tricyclodecane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol Polyfunctional (meth)acrylates such as tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate are preferred. .

In the active energy ray-curable polymer composition, the content of the active energy ray-reactive monomer is determined based on the total amount of the composition from the viewpoint of adjusting the viscosity of the composition and adjusting physical properties such as hardness and elongation of the obtained cured product. It is preferably 50% by weight or less, more preferably 30% by weight or less, even more preferably 20% by weight or less, particularly preferably 10% by weight or less.

The active energy ray-curable oligomers may be used alone or in combination of two or more. Examples of the active energy ray-curable oligomer include epoxy (meth)acrylate oligomers and acrylic (meth)acrylate oligomers.
In the active energy ray-curable polymer composition, the content of the active energy ray-reactive oligomer is 50% by weight based on the total amount of the composition, from the viewpoint of adjusting physical properties such as hardness and elongation of the obtained cured product. % or less, more preferably 30% by weight or less, even more preferably 20% by weight or less, particularly preferably 10% by weight or less.

The polymerization initiator is mainly used for the purpose of improving the initiation efficiency of a polymerization reaction that proceeds by irradiation with active energy rays such as ultraviolet rays and electron beams. As the polymerization initiator, a radical photopolymerization initiator, which is a compound having the property of generating radicals when exposed to light, is generally used, and any known radical photopolymerization initiator can be used. The polymerization initiators may be used alone or in combination of two or more. Furthermore, a photoradical polymerization initiator and a photosensitizer may be used together.

Examples of the photoradical polymerization initiator include benzophenone, 2,4,6-trimethylbenzophenone, 4,4-bis(diethylamino)benzophenone, 4-phenylbenzophenone, methylorthobenzoylbenzoate, thioxanthone, diethylthioxanthone, isopropylthioxanthone, chloro Thioxanthone, 2-ethylanthraquinone, t-butylanthraquinone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyl dimethyl ketal, 1-hydroxycyclohexylphenyl ketone, benzoin methyl ether, benzoin ethyl Ether, benzoin isopropyl ether, benzoin isobutyl ether, methylbenzoylformate, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2,6-dimethylbenzoyldiphenylphosphine oxide, 2 , 4,6-trimethylbenzoyldiphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and 2- Examples include hydroxy-1-[4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl]-2-methyl-propan-1-one.

Among these, benzophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2,4,6 -trimethylbenzoyldiphenylphosphine oxide and 2-hydroxy-1-[4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl]-2-methyl-propan-1-one Preferably, 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and 2-hydroxy-1-[4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl ]-2-methyl-propan-1-one is more preferred.

In addition, when the active energy ray-curable polymer composition contains a compound having a cationically polymerizable group such as an epoxy group as well as a radically polymerizable group, the active energy ray-curable polymer composition may be used as a polymerization initiator together with the above-mentioned photoradical polymerization initiator. A polymerization initiator may be included. Any known photocationic polymerization initiator can be used.

The content of these polymerization initiators in the active energy ray-curable polymer composition is preferably 10 parts by weight or less, and 5 parts by weight, based on a total of 100 parts by weight of the active energy ray-reactive components. It is more preferable that it is below. It is preferable that the content of the polymerization initiator is 10 parts by weight or less, since decomposition products of the initiator hardly cause a decrease in mechanical strength.

The photosensitizer can be used for the same purpose as the polymerization initiator. The photosensitizers may be used alone or in combination of two or more. As the photosensitizer, any known photosensitizer can be used as long as the effects of the present invention can be obtained. Examples of such photosensitizers include ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, amyl 4-dimethylaminobenzoate, and 4-dimethylaminoacetophenone.

In the active energy ray-curable polymer composition, the content of the photosensitizer is preferably 10 parts by weight or less, and 5 parts by weight or less, based on a total of 100 parts by weight of the active energy ray-reactive components. It is more preferable that the amount is less than 100%. It is preferable that the content of the photosensitizer is 10 parts by weight or less, since mechanical strength is less likely to decrease due to a decrease in crosslinking density.

The additives are optional, and various materials added to compositions used for similar purposes can be used as additives. The additives may be used alone or in combination of two or more. Examples of such additives include glass fibers, glass beads, silica, alumina, calcium carbonate, mica, zinc oxide, titanium oxide, talc, kaolin, metal oxides, metal fibers, iron, lead, metal powder, etc. Fillers; carbon fibers, carbon black, graphite, carbon nanotubes, carbon materials such as fullerenes such as C60 (hereinafter, fillers and carbon materials may be collectively referred to as "inorganic components"); oxidation prevention agent, heat stabilizer, ultraviolet absorber, HALS (hindered amine light stabilizer), anti-fingerprint agent, surface hydrophilic agent, antistatic agent, slipperiness agent, plasticizer, mold release agent, antifoaming agent, leveling agent, Modifiers such as antisettling agents, surfactants, thixotropy agents, lubricants, flame retardants, flame retardant aids, polymerization inhibitors, fillers, and silane coupling agents; coloring of pigments, dyes, hue modifiers, etc. and curing agents, catalysts, and curing accelerators necessary for the synthesis of monomers and/or oligomers thereof, or inorganic components.

In the active energy ray-curable polymer composition, the content of the additive is preferably 10 parts by weight or less, and 5 parts by weight or less, based on a total of 100 parts by weight of the active energy ray-reactive components. It is more preferable that It is preferable that the content of the additive is 10 parts by weight or less because mechanical strength is unlikely to decrease due to a decrease in crosslink density.
The solvent can be used, for example, for the purpose of adjusting the viscosity of the active energy ray curable polymer composition, depending on the coating method for forming a coating film of the active energy ray curable polymer composition. One type of solvent may be used alone, or two or more types may be used in combination. As the solvent, any known solvent can be used as long as the effects of the present invention can be obtained. Preferred solvents include toluene, xylene, ethyl acetate, butyl acetate, isopropanol, isobutanol, cyclohexanone, methyl ethyl ketone, and methyl isobutyl ketone. The solvent can usually be used in an amount of less than 200 parts by weight based on 100 parts by weight of the solid content of the active energy ray-curable polymer composition.

The method for incorporating optional components such as the above-mentioned additives into the active energy ray-curable polymer composition is not particularly limited, and conventionally known mixing and dispersion methods may be used. Incidentally, in order to more reliably disperse the optional component, it is preferable to perform a dispersion process using a dispersion machine. Specifically, for example, two-roll, three-roll, bead mill, ball mill, sand mill, pebble mill, thoron mill, sand grinder, segmental attritor, planetary stirrer, high-speed impeller disperser, high-speed stone mill, high-speed impact Examples include processing methods using a mill, kneader, homogenizer, ultrasonic disperser, etc.

The viscosity of the active energy ray-curable polymer composition can be adjusted as appropriate depending on the intended use and manner of use of the composition, but from the viewpoint of handleability, coatability, moldability, three-dimensional sculptability, etc. The viscosity at 25°C in a type viscometer (rotor 1° 34' x R24) is preferably 10 mPa s or more, more preferably 100 mPa s or more, and on the other hand, 100,000 mPa s It is preferably at most 50,000 mPa·s, more preferably at most 50,000 mPa·s. The viscosity of the active energy ray-curable polymer composition can be adjusted, for example, by the content of the urethane (meth)acrylate oligomer described above, the types of the optional components, their blending ratios, and the like.

Coating methods for the active energy ray-curable polymer composition include bar coater method, applicator method, curtain flow coater method, roll coater method, spray method, gravure coater method, comma coater method, reverse roll coater method, and lip coater method. Known methods such as the method, die coater method, slot die coater method, air knife coater method, and dip coater method can be applied, but among them, the bar coater method and the gravure coater method are preferable.

<2-23. Cured film and laminate>
The active energy ray-curable polymer composition can be made into a cured film by irradiating it with active energy rays.
As the active energy rays used for curing the composition, infrared rays, visible rays, ultraviolet rays, X-rays, electron beams, α-rays, β-rays, γ-rays, etc. can be used. From the viewpoint of equipment cost and productivity, it is preferable to use electron beams or ultraviolet rays, and examples of light sources include electron beam irradiation equipment, ultra-high pressure mercury lamps, high-pressure mercury lamps, medium-pressure mercury lamps, low-pressure mercury lamps, metal halide lamps, and Ar. Lasers, He-Cd lasers, solid state lasers, xenon lamps, high frequency induction mercury lamps, sunlight, etc. are suitable.

The irradiation amount of the active energy ray can be appropriately selected depending on the type of the active energy ray. For example, in the case of curing by electron beam irradiation, the irradiation amount is preferably 1 to 10 Mrad. Further, in the case of ultraviolet irradiation, it is preferably 50 to 1,000 mJ/cm ² . The atmosphere during curing may be air, or an inert gas such as nitrogen or argon. Alternatively, irradiation may be performed in a closed space between a film or glass and a metal mold.

The thickness of the cured film is appropriately determined depending on the intended use, but the lower limit is preferably 1 μm, more preferably 3 μm, particularly preferably 5 μm. Further, the upper limit is preferably 200 μm, more preferably 100 μm, particularly preferably 50 μm. When the film thickness is 1 μm or more, the appearance of design and functionality after three-dimensional processing is good, and on the other hand, when it is 200 μm or less, internal hardening property and suitability for three-dimensional processing are good, so it is preferable. In addition, for industrial use, the lower limit of the thickness of the cured film is preferably 1 μm, and the upper limit is preferably 100 μm, more preferably 50 μm, particularly preferably 20 μm, and most preferably 10 μm.

A laminate having a layer made of the above-mentioned cured film on a base material can be obtained. This laminate is not particularly limited as long as it has a layer made of a cured film, and may have a layer other than the base material and the cured film between the base material and the cured film, or on the outside thereof. may have. Further, the laminate may have multiple layers of base materials and cured films.
Methods for obtaining a laminate having multiple layers of cured films include a method in which all layers are laminated in an uncured state and then cured with active energy rays, or a method in which the lower layer is cured or semi-cured with active energy rays, and then the lower layer is cured or semi-cured with active energy rays. Known methods include applying the upper layer and curing it again with active energy rays, and applying each layer to a release film or base film and then bonding the layers together in an uncured or semi-cured state. Although applicable, from the viewpoint of improving the adhesion between layers, a method in which the layers are laminated in an uncured state and then cured with active energy rays is preferred. As a method for laminating layers in an uncured state, known methods such as sequential coating, in which a lower layer is applied and then an upper layer is applied, and simultaneous multilayer coating, in which two or more layers are simultaneously applied through multiple slits, are applied. It is possible, but not limited to this.

Examples of the base material include polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyolefins such as polypropylene and polyethylene, various plastics such as nylon, polycarbonate, and (meth)acrylic resin, and plates made of glass or metal. Examples include shaped articles.
The cured film can be made into a film that has excellent stain resistance and hardness against general household contaminants such as ink and ethanol, and laminates using the cured film as coatings on various substrates have excellent design and surface properties. It can provide excellent protection.

In addition, the active energy ray-curable polymer composition has flexibility that can follow deformation during three-dimensional processing, elongation at break, mechanical strength, stain resistance, and It is possible to provide a cured film that has both hardness and hardness at the same time.
Furthermore, it is expected that the active energy ray-curable polymer composition will be able to easily produce a thin film-like resin sheet by coating in one layer.

The elongation at break of the cured film was determined by cutting the cured film into 10 mm width pieces and using a Tensilon tensile tester (manufactured by Orientec, Tensilon UTM-III-100) at a temperature of 23°C, a tensile speed of 50 mm/min, and a chuck interval. The value measured by conducting a tensile test at a distance of 50 mm is preferably 50% or more, more preferably 75% or more, even more preferably 100% or more, and 120% or more. is particularly preferred.
The above-mentioned cured films and laminates can be used as paint substitute films, and can be effectively applied to, for example, interior/exterior building materials, automobiles, home appliances, and other various parts.

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

〔Evaluation results〕
Evaluation methods for various physical properties, performance, etc. in the following Examples and Comparative Examples are as follows.

[Evaluation of catalyst performance]
In the production of polycarbonate diol from a dihydroxy compound and diester carbonate, as shown in formula (A) below, the monomer raw materials dihydroxy compound and diester carbonate are reduced in the esterification step, and monohydroxy derived from the diester carbonate is produced in the transesterification step. A compound (dihydroxy compound in the case of alkylene carbonate) is produced as a by-product. As an indicator of performance as a catalyst for the production of polycarbonate diol, the production rate of by-product monohydroxy compounds (dihydroxy compounds for alkylene carbonates) is important, as well as the reduction rate (conversion rate) of dihydroxy compounds and diester carbonates. . More specifically, for example, as shown in the following formula (B), in the production of polycarbonate diol from 1,4-butanediol (BG) and ethylene carbonate (EC), the conversion rate of BG and EC is high. In addition, a high production rate of ethylene glycol (EG), which is a by-product, indicates a high production rate of polycarbonate diol, and is an indicator that it is excellent as a transesterification catalyst for producing polycarbonate diol. Furthermore, in the production of polycarbonate diol using 1,4-butanediol, tetrahydrofuran (THF) is produced as a by-product due to undesirable etherification. This is an indicator that the catalyst can produce .
Therefore, the conversion rate of dihydroxy compounds (diols) and carbonate diesters (carbonates) that are monomer raw materials, the production rate of monohydroxy compounds or dihydroxy compounds as by-products, and the production rate of undesirable ether by-products are measured, The performance of a transesterification catalyst for producing polycarbonate diol was evaluated.

<Phenoxide terminal amount, ether bond amount, diphenyl carbonate amount, neopentyl glycol amount, phenol amount, neopentyl carbonate amount>
The product was dissolved in CDCl ₃ and measured by 400 MHz ¹ H-NMR (ECZ-400 manufactured by JEOL Ltd.), and calculated from the integral value of the signal of each component. A similar method was also used to determine the ratio of each structural unit in polycarbonate diol.

<APHA value>
Measurements were made in accordance with JIS K0071-1 by comparing with a standard solution placed in a colorimetric tube.

<Hydroxyl value>
The hydroxyl value of the polycarbonate diol was measured by a titration method using an acetylation reagent in accordance with JIS K1557-1 or a titration method using a urethanization reagent in accordance with ASTM E1899-16.

<Number average molecular weight>
Measurement method 1: From the hydroxyl value obtained by a titration method using an acetylation reagent or a titration method using a urethanization reagent, the number average molecular weight was determined by the following formula (II).
Number average molecular weight = 2 x 56.1/(hydroxyl value x 10-3) ... (II)
Measurement method 2: Polycarbonate diol was dissolved in CDCl3 (tetramethylsilane internal standard), and 400MHz ¹ H-NMR (ECZ-400 manufactured by JEOL Ltd.) was measured. From the signal position of each component, the terminal structural unit of polycarbonate diol derived from a hydroxyl group (signal position: 3.5 to 3.8 ppm) and the repeating structural unit of polycarbonate diol derived from a carbonate group (signal position: 3.5 ~3.8 ppm) were determined. The number average molecular weight of the polycarbonate diol was calculated from the ratio of the repeating structural unit to the terminal structural unit. Note that no difference was observed in the number average molecular weight values between measurement method 1 and measurement method 2.

<Catalytic metal content concentration>
When using a metal catalyst that does not volatilize or decompose under the polycarbonate diol reaction conditions, the catalyst metal content concentration (ppm) corresponds to the ratio of the amount of metal catalyst used for preparation (g) to the yield (g) of polycarbonate diol. do.
Further, as an analysis method, for example, the following method (ICP-MS) can be used.
0.2 g of polycarbonate diol was accurately weighed into a Kjeldahl flask, and subjected to wet decomposition using concentrated sulfuric acid and concentrated nitric acid. After cooling to room temperature, the solution was made to a constant volume using pure water and measured using ICP-MSELEMENT 2 (manufactured by Thermo Fisher Scientific), and the concentration (ppm) of the catalytic metal content in the polycarbonate diol was calculated.

[Evaluation of polyurethane]
<Isocyanate group concentration>
Dilute 20 mL of di-n-butylamine/toluene (weight ratio: 2/25) mixed solution with 90 mL of acetone, titrate with 0.5N hydrochloric acid aqueous solution, measure the amount of hydrochloric acid aqueous solution required for neutralization, and obtain a blank value. And so. Thereafter, 1 to 2 g of the reaction solution was extracted, 20 mL of a mixed solution of di-n-butylamine/toluene was added, and the mixture was stirred at room temperature for 30 minutes, then diluted with 90 mL of acetone as in the blank measurement, and a 0.5 N aqueous hydrochloric acid solution was added. The amount of aqueous hydrochloric acid required for neutralization was determined by titration, and the amount of remaining amine was determined. The concentration of isocyanate groups was determined from the volume of aqueous hydrochloric acid solution required for neutralization using the following formula.
Isocyanate group concentration (wt%) = A x 42.02/D
A: Isocyanate groups (mol) contained in the sample used for this measurement
A=(B-C)×0.5/1000×f
B: Amount of 0.5N hydrochloric acid aqueous solution required for blank measurement (mL)
C: Amount of 0.5N hydrochloric acid aqueous solution required for this measurement (mL)
f: Titer of hydrochloric acid aqueous solution D: Sample used for this measurement (g)

<Molecular weight of polyurethane>
To determine the molecular weight of polyurethane, prepare a dimethylacetamide solution so that the concentration of polyurethane is 0.14% by weight, and use a GPC device [manufactured by Tosoh Corporation, product name "HLC-8220" (column: TskgelGMH-XL, 2 columns)] The number average molecular weight (Mn) and weight average molecular weight (Mw) in terms of standard polystyrene were measured using.

<Room temperature tensile test>
According to JIS K6301, a rectangular polyurethane test piece with a width of 10 mm, a length of 100 mm, and a thickness of about 50 μm was chucked using a tensile tester [manufactured by Orientech Co., Ltd., product name: "Tensilon UTM-III-100"]. A tensile test was conducted at a temperature of 23°C (relative humidity 60%) with a distance of 50 mm and a tensile speed of 500 mm/min. , "300% M"), as well as the elongation at break (elongation at break) and stress (strength at break).

<Solvent resistance>
A polyurethane solution was applied onto a fluororesin sheet (Fluorine Tape Nitoflon 900, thickness 0.1 mm, manufactured by Nitto Denko Corporation) using a 9.5 mil applicator, and heated at 50°C for 5 hours and at 100°C for 0.5 hours. It was dried under vacuum conditions at 100°C for 0.5 hours and then at 80°C for 15 hours. A 3 cm x 3 cm test piece was cut out from the obtained polyurethane film, and placed in a glass petri dish with an inner diameter of 10 cm, each containing 50 mL of the test solvent. After immersion in each test solvent at the following temperature for the following time, the weight was calculated. The weight change rate (%) between the weight of the test piece before immersion and the weight of the test piece after immersion (= (weight of test piece after immersion - weight of test piece before immersion) / test before immersion The weight of the piece x 100) was calculated. Here, the closer the weight change rate is to 0%, the better the solvent resistance is.
Oleic acid resistance: A test piece was immersed in oleic acid at 80° C. for 16 hours.
Ethyl acetate resistance: The test piece was immersed in ethyl acetate for 20 minutes at room temperature.
Ethanol resistance: The test piece was immersed in ethanol for 1 hour at room temperature.

[Compound abbreviation]
The abbreviations of compounds in the following Examples and Comparative Examples are as follows.
EC: Ethylene carbonate BG: 1,4-butanediol EG: Ethylene glycol THF: Tetrahydrofuran DEC: Diethyl carbonate EtOH: Ethanol DPC: Diphenyl carbonate PHL: Phenol 15PD: 1,5-pentanediol 16HD: 1,6-hexanediol 110DD : 1,10-decanediol NPG: Neopentyl glycol DEG: Diethylene glycol PTMG #250: Polyoxytetramethylene glycol (number average molecular weight 250)
PTMG #650: Polyoxytetramethylene glycol (number average molecular weight 650)
PTMG#2000: Polyoxytetramethylene glycol (number average molecular weight 2000)
Mg(acac) ₂ : Magnesium(II) acetylacetonate Mg(tBuCOCH ₂ COtBu) _{2.2H 2} O: 2,2,6,6-tetramethyl-3,5-heptanedionato Magnesium(II) dihydrate Zn(acac) ₂ : Zinc(II) acetylacetonate Zn(tBuCOCH ₂ COtBu) ₂ : 2,2,6,6-tetramethyl-3,5-heptanedionatozinc(II)
Zn( _{CF3COCH2COCF3} ) _2.2H2O : _{Hexafluoroacetylacetonatozinc dihydrate Ca(acac)2.xH2O : Calcium acetylacetone hydrate Ba} (acac) _2.xH2O : Barium acetylacetone hydrate Ti (OBu) ₄ : Tetra-n-butyl titanate Ti (acac) ₂ (OiPr) ₂ : Titanium (IV) bis(acetylacetonate) diisopropoxide Mg (OAc) _{2.4H 2} O : Magnesium acetate tetrahydrate Mg (OTf) ₂ : Magnesium trifluoromethanesulfonate Mg (OEt) ₂ : Magnesium ethoxide Zn (OAc) _{2.2H 2} O: Zinc acetate dihydrate

[Production and evaluation of polycarbonate diol]
[Example 1-1]
14.1 g of 1,4-butanediol (Mitsubishi Chemical Co., Ltd.) and 15.9 g of ethylene carbonate (Tokyo Kasei Kogyo Co., Ltd.) were placed in a glass test tube reactor with a diameter of 30 mm, and heated using an aluminum block heater under a nitrogen atmosphere. It was heated and stirred with a magnetic stirrer at 300 rpm. After the internal temperature reached 140° C., a toluene diluted solution containing 1.42 mg of magnesium (II) acetylacetonate (Tokyo Kasei Kogyo Co., Ltd.) as a catalyst was added to start the reaction, and the mixture was heated and stirred.
Sampling was performed 1 hour and 3 hours after the start of the reaction, and the monomer compositions in the reactor, 1,4-butanediol (BG), ethylene carbonate (EC), and ethylene glycol (EG), were analyzed using gas chromatography using the following method. ) and tetrahydrofuran (THF) to determine the number of moles of each in the reactor.

<Gas chromatography analysis>
About 100 mg of the reaction solution and about 50 mg of N-methyl-2-pyrrolidone as an internal standard were each accurately weighed and diluted with about 5 mL of acetonitrile. Either analyze this liquid as it is, or collect 1 mL of this liquid, add 0.2 mL of N-trimethylsilylimidazole (Wako Pure Chemical Industries, Ltd., for gas chromatography), shake well, let stand for at least 10 minutes, and pass through a syringe filter. I analyzed what I did.
(Gas chromatography analysis conditions)
Column: DB-WAX 30m x 0.250mm x 0.25μm, I. D. (Agilent Technologies) or equivalent Carrier gas: Helium, 1.23 mL/min Column temperature: 50°C (held for 5 minutes) → Increase temperature at 10°C/min → 250°C (held for 5 minutes)
Inlet temperature: 250°C, injection volume: 1 μL, split ratio: 1:50
Detector temperature: 250℃, detector: FID

(Formula for calculating conversion rate and production rate)
BG conversion rate = (number of moles of BG charged - number of moles of BG in the reactor) / number of moles of charged BG x 100 (mol%)
EC conversion rate = (Number of EC moles charged - Number of EC moles in the reactor) / Theoretical number of EC moles charged (*) x 100 (mol%)
EG production rate = Number of moles of EG in the reactor/Number of moles of theoretically produced EG (**) x 100 (mol%)
THF production rate = number of moles of THF in the reactor/number of moles of EG in the reactor x 100 (mol%)
* Theoretical number of moles of EC charged = number of moles of theoretically produced EG (**) indicates the number of moles of EC theoretically required for BG to obtain polycarbonate diol with a number average molecular weight of 2000, and the stoichiometric corresponds to the number of moles of EG produced when reacting with
The THF production rate was defined as the percentage (mol%) of the number of moles of THF relative to the number of moles of generated carbonate bonds, that is, the number of moles of EG produced (=the number of moles of EC introduced into the polycarbonate diol).
The conversion rate of various diols is calculated in the same manner as the BG conversion rate.

[Examples 1-2 to 7, Comparative Examples 1-1 to 5]
The experiments were conducted in the same manner as in Example 1-1, except that the catalyst and the amount of catalyst were changed as shown in Table 1.
The respective values are shown in Table 1.

In Examples 1-1 to 5 and Comparative Examples 1-1 to 1-5, the weight concentration of metal relative to the raw material monomer was adjusted to be the same for each catalyst, so the weight of metal contained in the resulting polycarbonate diol was approximately constant. be.
As shown in Examples 1-1 to 1-5, transesterification reactions of 1,4-butanediol and ethylene carbonate were carried out using acetylacetone analogue salts of magnesium and zinc as catalysts, resulting in the conventional ester shown in Comparative Example 1-1. It was found that the BG conversion rate, EC conversion rate, and EG production rate were higher, and the transesterification activity was higher than when tetra-n-butyl titanate, which is frequently used as an exchange catalyst, was used.
Furthermore, although the transesterification activity, that is, the polymerization activity is high, the production rate of THF as a by-product due to undesirable etherification is lower than when tetra-n-butyl titanate is used, making it highly selective as a catalyst for producing polycarbonate diol. was found to be expressed.
As shown in Comparative Example 1-2, titanium (IV) bis(acetylacetonato) diisopropoxide, which is a titanium acetylacetone compound, did not exhibit high polymerization activity and the by-product rate of THF was also high.

On the other hand, as shown in Examples 1-1 and 1-2 and Comparative Examples 1-3 and 1-4, transesterification reactions were carried out using an acetylacetone analogue salt of magnesium as a catalyst (Examples 1-1 and 2). The BG conversion rate, EC conversion rate, and EG production rate are higher than when magnesium trifluoromethanesulfonate is used as a catalyst at the same magnesium concentration (Comparative Examples 1-3 and 1-4), and the production rate of by-product THF is higher. was low.
In addition, as shown in Examples 1-3 to 5 and Comparative Example 1-5, transesterification reactions were carried out using zinc acetylacetone analog salts as catalysts (Examples 1-3 to 5). Compared to the case where zinc concentration was used as a catalyst (Comparative Example 1-5), the BG conversion rate, EC conversion rate, and EG production rate were high, and the production rate of by-product THF was low.

These results show that the acetylacetone analogue salts of magnesium and zinc have a higher metal weight concentration than conventionally used catalysts, or when other salts of magnesium and zinc are used as catalysts. The conversion rate of dihydroxy compounds and carbonate diesters (BG and EC in Table 1), which are monomer raw materials, is high, the production rate of by-product hydroxy compounds (EG in Table 1) is high, and the undesirable ether by-product (EG) is high. In Table 1, the production rate of THF) is low, and it is clear that the catalyst is excellent as a transesterification catalyst for producing polycarbonate diol.
Note that calcium acetylacetone hydrate and barium acetylacetone hydrate, which are acetylacetone salts of Group 2 metals like magnesium, can also be used to produce polycarbonate diol at the same molar concentration as magnesium acetylacetone salt, as shown in Examples 1-6 and 7. It acts well as a transesterification catalyst for

[Examples 2-1 to 2, Comparative Examples 2-1 to 3]
Experiments were conducted in the same manner as in Example 1-1, except that the catalyst was magnesium (II) acetylacetonate or tetrabutyl orthotitanate, and the catalyst amount and reaction temperature were changed as shown in Table 2.
The respective values are shown in Table 2 together with the results of Example 1-1 and Comparative Example 1-1.

As shown in Examples 1-1 and 2-1 and Comparative Examples 1-1 and 2-1, when the transesterification reaction of 1,4-butanediol and ethylene carbonate was carried out at 140°C, magnesium (II) acetyl For acetonate and tetra-n-butyl titanate, which is conventionally used as a transesterification catalyst, even when the catalyst concentration is combined by metal weight concentration (Example 1-1 and Comparative Example 1-1), it is different when combined by metal molar concentration. (Example 1-1 and Comparative Example 2-1 and Example 2-1 and Comparative Example 1-1), the use of magnesium (II) acetylacetonate as a catalyst improved the BG conversion rate, EC conversion rate, and EG production. The THF production rate was high and the THF production rate was low.
In addition, when comparing 1 hour after the start of the reaction in Example 1-1 and 3 hours after the start of the reaction in Comparative Example 2-1, it is found that when the BG conversion rate, EC conversion rate, and EG production rate are the same, that is, the transesterification is at the same level. When proceeding, THF production was low with the magnesium(II) acetylacetonate catalyst. That is, it was shown that the magnesium (II) acetylacetonate catalyst exhibits high transesterification activity while causing less undesirable etherification.

On the other hand, as shown in Example 2-2 and Comparative Example 2-2, when the catalyst metal weight concentration was adjusted and the reaction temperature was lowered to 120°C, both magnesium (II) acetylacetonate and tetra-n-butyl titanate Although THF production was suppressed, in the case of tetra-n-butyl titanate, the BG conversion rate, EC conversion rate, and EG production rate were significantly reduced. The BG conversion rate, EC conversion rate, and EG production rate at a reaction temperature of 120°C (Example 2-2) using a magnesium (II) acetylacetonate catalyst are different from those at 140°C (Comparative Example 1) using a tetra-n-butyl titanate catalyst. -2 and 2-1) and comparable to 150°C (Comparative Example 2-3), the THF production rate decreased dramatically at 120°C with the magnesium (II) acetylacetonate catalyst.

Etherification, which is an undesirable side reaction, is highly dependent on the reaction temperature, and it is clear that the higher the reaction temperature, the higher the formation rate of ether byproducts, and magnesium (II) acetylacetonate is frequently used as a conventional transesterification catalyst. Compared to tetra-n-butyl titanate, which is used in .
From these results, it is clear that the catalyst used in the present invention has high activity and reduces by-products in the production of polycarbonate diol, and therefore polycarbonate diol can be efficiently produced by using the catalyst of the present invention.

[Examples 3-1 to 9, Comparative Example 3-1]
As the catalyst, magnesium ethoxide and the acetylacetone analog shown in Table 3 were used in the same manner as in Example 1-1, except that a toluene diluted solution containing the acetylacetone analog at a predetermined molar ratio to magnesium was used. An experiment was conducted (However, in Comparative Example 3-1, only magnesium ethoxide was used as a catalyst).
The respective values are shown in Table 3 together with the results of Example 1-1.

In Examples 3-1 to 3-9, a catalyst composition was prepared using magnesium ethoxide as a metal alkoxide and an acetylacetone analog, and a transesterification reaction between 1,4-butanediol and ethylene carbonate was carried out.
As shown in Examples 3-1 to 3-5 and Comparative Example 3-1, when acetylacetone and magnesium ethoxide were mixed at the molar ratio shown in Table 3 and used as a transesterification catalyst composition, only magnesium ethoxide was used as a catalyst. The BG conversion rate, EC conversion rate, and EG production rate were higher, and the THF production rate was lower than when used as a catalyst. As the molar ratio of acetylacetone and magnesium increases, the BG conversion rate, EC conversion rate, and EG production rate become higher and the THF generation rate becomes lower. When the molar ratio of acetylacetone and magnesium is 2 or more, magnesium (II) acetyl It showed the same catalytic performance as acetonate.
As shown in Examples 3-6 to 3-9, when transesterification reactions were also performed on compositions of various acetylacetone analogs and magnesium ethoxide, the BG conversion rate and EC were lower than when only magnesium ethoxide was used as a catalyst. The conversion rate and EG production rate were high, and the THF production rate was low.
These results showed that the catalyst of the present invention works well as a transesterification catalyst for producing polycarbonate diol even in a composition prepared from a metal compound and an acetylacetone analog.

[Example 4-1, Comparative Example 4-1]
A glass test tube reactor with a diameter of 30 mm was charged with 12.0 g of 1,4-butanediol (Mitsubishi Chemical Corporation) and 18.0 g of diethyl carbonate (Wako Pure Chemical Industries), and the respective catalysts and catalyst amounts are shown in Table 4. An experiment was conducted in the same manner as in Example 1-1, with the aluminum block heater set at 140°C. Sampling was performed 3 hours and 5 hours after the start of the reaction.

(Formula for calculating conversion rate and production rate)
BG conversion rate = (number of moles of BG charged - number of moles of BG in the reactor) / number of moles of charged BG x 100 (mol%)
DEC conversion rate = (number of moles of charged DEC - number of moles of DEC in the reactor) / theoretical number of moles of charged DEC (*) x 100 (mol%)
EtOH production rate = Number of moles of EtOH in the reactor/Number of moles of theoretically produced EtOH (**) x 100 (mol%)
THF production rate = number of moles of THF in the reactor/(number of moles of EtOH in the reactor/2) x 100 (mol%)
*Theoretical number of moles of DEC charged = number of moles of theoretically produced EtOH (**)/2... Indicates the number of moles of DEC theoretically required for BG to obtain a polycarbonate diol with a number average molecular weight of 2000, and the amount The number of moles of EtOH produced when reacting theoretically is equivalent to twice that amount.
The THF production rate was defined as the percentage (mol %) of the number of THF moles relative to the carbonate bonds produced, that is, one half of the number of moles of EtOH produced (=the number of moles of DEC introduced into the polycarbonate diol).

Table 4 shows the respective values.

As is clear from Table 4, when tetra-n-butyl titanate, which is conventionally frequently used as a transesterification catalyst, was used in the transesterification reaction of 1,4-butanediol and diethyl carbonate (Comparative Example 4-1) In comparison, when magnesium (II) acetylacetonate was used as a catalyst (Example 4-1), the BG conversion rate, DEC conversion rate, and EG production rate were improved without significantly increasing the by-product THF production rate. was shown to be high.
These results showed that the catalyst of the present invention works well as a transesterification catalyst for producing polycarbonate diol using dialkyl carbonate as a carbonate source.

[Example 5-1, Comparative Example 5-1]
A glass test tube reactor with a diameter of 30 mm was charged with 9.3 g of 1,4-butanediol (Mitsubishi Chemical Corporation) and 20.7 g of diphenyl carbonate (Mitsubishi Chemical Corporation), and the catalyst and catalyst amount were as shown in Table 5. The experiment was conducted in the same manner as in Example 1-1 except that the aluminum block heater was set at 140°C.

(Formula for calculating conversion rate and production rate)
BG conversion rate = (number of moles of BG charged - number of moles of BG in the reactor) / number of moles of charged BG x 100 (mol%)
DPC conversion rate = (Number of moles of DPC charged - Number of moles of DPC in the reactor) / Number of moles of theoretically charged DPC (*) x 100 (mol%)
PHL production rate = Number of moles of PHL in the reactor/Number of moles of theoretically generated PHL (**) x 100 (mol%)
THF production rate = number of moles of THF in the reactor/(number of moles of PHL in the reactor/2) x 100 (mol%)
*Theoretical number of moles of DPC charged = number of moles of theoretically generated PHL (**)/2... Indicates the number of moles of DPC theoretically required for BG to obtain a polycarbonate diol with a number average molecular weight of 2000, and the amount The number of moles of PHL produced when reacting theoretically is equivalent to twice that number.
The THF production rate was defined as the percentage (mol %) of the number of THF moles relative to the carbonate bonds produced, that is, one-half of the number of moles of PHL produced (=the number of moles of DPC introduced into the polycarbonate diol).

The respective values are shown in Table 5.

As is clear from Table 5, in the transesterification reaction of 1,4-butanediol and diphenyl carbonate, magnesium (II) When acetylacetonate was used as a catalyst (Example 5-1), the BG conversion rate, DPC conversion rate, and EG production rate were high, and it was shown that the production rate of by-product THF was reduced.
These results showed that the catalyst of the present invention works well as a transesterification catalyst for producing polycarbonate diol using diaryl carbonate as a carbonate source.

From the above, it has become clear that the catalyst of the present invention works well as a transesterification catalyst for producing polycarbonate diol even when any carbonic acid diester such as alkylene carbonate, dialkyl carbonate, and diaryl carbonate is used as a raw material monomer.

[Examples 6-1 to 19, Comparative Examples 6-1 to 7]
Example 1-1 except that one or more diols and ethylene carbonate were charged in a glass test tube reactor with a diameter of 30 mm as shown in Table 6, and the catalyst and catalyst amount were changed as shown in Table 6. A similar experiment was conducted.

(Formula for calculating conversion rate and production rate)
Diol conversion rate = (number of moles of diol charged - number of moles of diol in the reactor) / number of moles of diol charged x 100 (mol%)
EC conversion rate = (Number of EC moles charged - Number of EC moles in the reactor) / Theoretical number of EC moles charged (*) x 100 (mol%)
EG production rate = Number of moles of EG in the reactor/Number of moles of theoretically produced EG (**) x 100 (mol%)
THF production rate = number of moles of THF in the reactor/number of moles of EG in the reactor x 100 (mol%)
*Theoretical number of moles of EC charged = number of moles of theoretically produced EG (**) indicates the number of moles of EC theoretically required for the total amount of diol in order to obtain polycarbonate diol with a number average molecular weight of 2000. It corresponds to the number of moles of EG produced when the reaction occurs.
The THF production rate was defined as the percentage (mol%) of the number of THF moles relative to the number of produced carbonate bonds, that is, the number of produced EG moles.
The total diol conversion rate when two or more types of diols are used as raw material monomers is:
Total diol conversion rate = (total number of moles of diol charged - total number of moles of diol in the reactor) / total number of moles of diol charged x 100 (mol%)
It was calculated as

Table 6 shows the respective values.

As is clear from Table 6, transesterification reactions between various diols and ethylene carbonate were carried out using magnesium (II) acetylacetonate as a catalyst. As shown in Examples 6-1 to 6-12, the transesterification reaction progressed favorably in both cases of one type of linear and branched aliphatic diol or a mixture of two types. When 1,5-pentanediol or 1,6-hexanediol and a mixture of them and 1,4-butanediol were used as raw material monomers, and when magnesium (II) acetylacetonate was used as a catalyst (Example 6-1) ~4) Compared to the case of using tetra-n-butyl titanate, which is frequently used as a conventional transesterification catalyst (Comparative Examples 6-1 to 6-4), the diol conversion rate, EC conversion rate, and EG production rate are lower. The THF production rate was high and low.
Further, as shown in Examples 6-5 to 7 and 9 to 11, two or more types of diols can be used in a wide range of mixing ratios.
As shown in Examples 6-13 to 6-16, when diethylene glycol or a mixture of diethylene glycol and 1,4-butanediol, which is a dihydroxy compound having an etheric oxygen atom, is used as a raw material monomer, tetra-n-butyl titanate Compared to the case where the catalyst was used as a catalyst (Comparative Examples 6-5 and 6-6), when the catalyst was used with magnesium (II) acetylacetonate having the same catalyst metal weight concentration (Examples 6-15 and 16), the diol The conversion rate, EC conversion rate, and EG production rate are high, and even when a lower concentration of magnesium (II) acetylacetonate is used as a catalyst (Examples 6-13 to 6-14), the diol conversion rate and EC conversion rate are the same or higher. and EG production rate, and the reaction proceeded better than existing transesterification catalysts.
In addition, as shown in Examples 6-17 to 6-19, polyoxytetramethylene glycol (PTMG#250) having a number average molecular weight of 250, which is poly(oxyalkylene) glycol, or poly(oxyalkylene) glycol was used as the dihydroxy compound. The transesterification reaction also proceeded when a mixture with 1,4-butanediol was used as the raw material monomer, and when tetra-n-butyl titanate was used as a catalyst at an equivalent molar concentration to the raw material monomer (Example 6-17 and Compared to Comparative Examples 6-7), both the EC conversion rate and the EG production rate were shown to be high.

From these results, the catalyst of the present invention can be used as a transesterification catalyst for polycarbonate diol production even when a wide range of dihydroxy compounds and mixtures thereof, such as diols, polyalkylene glycols, and poly(oxyalkylene) glycols, are used as raw material monomers. It became clear that it worked well.

As described above, the catalyst of the present invention has a high conversion rate of dihydroxy compounds (diols) and carbonic acid diesters (carbonates), which are monomer raw materials, and a high production rate of by-product hydroxy compounds or dihydroxy compounds, and is further desirable. This is a transesterification catalyst for the production of polycarbonate diol with a low production rate of ether by-products.
Furthermore, since the catalyst of the present invention exhibits high activity even at a lower reaction temperature than conventional catalysts, the reaction temperature can be set lower. Etherification, which is an undesirable side reaction, is highly dependent on the reaction temperature, and the amount of byproducts increases at high temperatures. Therefore, the catalyst of the present invention, which exhibits high activity at low reaction temperatures, can dramatically reduce the amount of ether byproducts. I can do it.
Since the catalyst of the present invention has high activity and reduces by-products in the production of polycarbonate diol, polycarbonate diol can be produced efficiently and economically by using the catalyst of the present invention.
That is, the catalyst of the present invention has a high conversion rate of dihydroxy compounds (diols) and carbonic acid diesters (carbonates) which are monomer raw materials, a high production rate of hydroxy compounds or dihydroxy compounds as by-products, and furthermore, a high conversion rate of dihydroxy compounds (diols) and carbonate diesters (carbonates) which are monomer raw materials, a high production rate of by-product hydroxy compounds or dihydroxy compounds, and furthermore, an undesirable ether This is a transesterification catalyst for producing polycarbonate diol with a low production rate of by-products.

[Example 7-1]
1,4-butanediol (14BD): 471 g (5.2 mol) was placed in a 2 L glass separable flask equipped with a stirrer, a distillate trap, a pressure regulator, a 30 mm diameter distillation column with irregular packing, and a fractionator. , ethylene carbonate (EC): 529 g (6.0 mol), Mg (acac) 2: 47 mg (0.21 mmol, catalytic metal concentration 40 μmol/mol, 5 ppm), and the atmosphere was replaced with nitrogen gas. While stirring, the internal temperature was raised to 130°C, and the contents were dissolved by heating. Thereafter, the reaction was carried out at normal pressure for 3 hours, and then the pressure was lowered to 6 kPa, and the reaction was carried out for 12 hours while removing ethylene glycol and ethylene carbonate from the system. Next, the pressure was lowered to 1 kPa over 12 hours, and the reaction was carried out at 130°C to 160°C. During the process, 69 g (0.78 mol) of ethylene carbonate (EC) was added. After further reducing the pressure to 0.5 kPa and continuing the reaction for 8 hours, it was confirmed by ¹ H-NMR (measurement method 2) that the number average molecular weight was equivalent to 1900, and a polycarbonate diol-containing composition was obtained (total reaction time 32 hours).
Thereafter, 0.2 mL (0.2 mmol) of 8.5% phosphoric acid aqueous solution was added to the polycarbonate diol-containing composition to deactivate the catalyst. Thereafter, the distillation column was removed and residual monomers were removed at 0.5 kPa and 170°C to obtain 488 g of a polycarbonate diol-containing composition. When the distillate trap was checked, it was found that 3.2 mol% of tetrahydrofuran, which was a by-product from BG, was generated based on the charged BG.

The obtained polycarbonate diol-containing composition was sent to a thin film distillation apparatus at a flow rate of 20 g/min, and thin film distillation (temperature: 210° C., pressure: 53 Pa) was performed to obtain polycarbonate diol. As the thin film distillation apparatus, a special model molecular distillation apparatus MS-300 manufactured by Shibata Kagaku Co., Ltd. with an internal condenser and a jacket having a diameter of 50 mm, a height of 200 mm, and an area of 0.0314 m2 was used. Table 7 shows the analytical values of the obtained polycarbonate diol. The number average molecular weight of the obtained polycarbonate diol was 1873 (hydroxyl value 59.9 mgKOH/g) by titration (measurement method 1) and 1900 by ¹ H-NMR (measurement method 2), and there was no significant difference.

[Comparative Example 7-1]
The reaction was carried out in the same manner as in Example 7-1, except that Ti(OBu)4 was used instead of Mg(acac)2, and the molecular weight was confirmed to be equivalent to 2000 by ¹ H-NMR. , a polycarbonate diol-containing composition was obtained (total reaction time 44 hours). When the distillate trap was checked, it was found that tetrahydrofuran, a by-product from BG, was produced in an amount of 12 mol % based on the charged BG. Table 7 shows the analytical values of the obtained polycarbonate diol.

[Examples 7-2 to 7, Comparative Example 7-2]
Polycarbonate diol was obtained by carrying out the same operations as in Example 7-1 or Comparative Example 7-1, respectively, except that the substrate diol and carbonate were changed, and the catalyst metal concentration was changed to 20 to 42 ppm. Ta. Table 7 shows the type and amount of the substrate and the analytical values of the obtained polycarbonate diol. The number average molecular weight and hydroxyl value were calculated by titration (measurement method 1) or ¹ H-NMR (measurement method 2), respectively.

[Example 7-7]
Polyoxytetramethylene glycol (PTMG #250): 3633 g (16.5 mol) was placed in a 5 L glass separable flask equipped with a stirrer, a distillate trap, a pressure regulator, a 30 mm diameter distillation column with irregular packing, and a fractionator. ), ethylene carbonate (EC): 1672 g (19.0 mol) were added, and the atmosphere was replaced with nitrogen gas. After heating and dissolving the contents by raising the internal temperature to 130° C. while stirring, 0.755 g (6.6 mmol) of Mg(OEt) 2 and 1.32 g (13. A catalyst preparation solution (catalyst metal concentration 400 μmol/mol vs. diol, 30 ppm vs. substrate) in which 2 mmol) was dissolved in 30 mL of toluene was added, and the glass container was washed with 20 mL of toluene. Thereafter, the reaction was carried out at normal pressure for 1 hour at an internal temperature of 150° C. to 158° C., and then the pressure was gradually lowered to 3.5 kPa, and the reaction was carried out for 5.5 hours while removing ethylene glycol and ethylene carbonate from the system. Next, 436 g (4.95 mol) of ethylene carbonate (EC) was added, the pressure was gradually lowered to 4 to 3.5 kPa, and the reaction was carried out at 152° C. to 154° C. over 9.5 hours. Furthermore, 218 g (2.48 mol) of ethylene carbonate (EC) was added, the pressure was gradually lowered to 3 kPa, and the reaction was continued for 24 hours. After that, the number average molecular weight was determined to be 1824 by ¹ H-NMR (measurement method 2). It was confirmed that the reaction was equivalent, and a polycarbonate diol-containing composition was obtained (total reaction time: 40 hours).
Thereafter, 5.7 mL (5.6 mmol) of 8.5% phosphoric acid BG solution was added to the polycarbonate diol-containing composition to deactivate the catalyst. Thereafter, the distillation column was removed and residual monomers were removed at a pressure of 0.7 to 0.1 kPa and an internal temperature of 160 to 170°C, thereby obtaining 3749 g of a polycarbonate diol-containing composition.

The obtained polycarbonate diol-containing composition was subjected to thin film distillation in the same manner as in Example 7-1 to obtain polycarbonate diol. Table 7 shows the analytical values of the obtained polycarbonate diol. The number average molecular weight of the obtained polycarbonate diol was 2033 (hydroxyl value 55.2 mgKOH/g) by titration (measurement method 1) and 2016 by ¹ H-NMR (measurement method 2), and there was no significant difference.

In Example 7-1, as a result of using Mg(acac)2 as a catalyst, a polycarbonate diol with a short reaction time, less tetrahydrofuran by-product, and a low coloration and a molecular weight of about 2000 was obtained.
On the other hand, in Comparative Example 7-1, using Ti(OBu)4 as a catalyst under the same conditions, the reaction time was long, a large amount of tetrahydrofuran was produced as a by-product, and the obtained polycarbonate diol with a molecular weight of about 2000 was highly colored. Ta. Similar results were also observed from a comparison between Examples 7-2 and 7-3 and Comparative Example 7-2.

As shown in Examples 7-4 and 7-5, it was found that the present invention can be well applied to the production of polycarbonate diols using polyoxytetramethylene glycols of various molecular weights as raw materials.
Furthermore, as shown in Examples 7-6 and 7-7, instead of magnesium (II) acetylacetonate, magnesium ethoxide and acetylacetone, which are easily available industrially, may be mixed and used as a transesterification catalyst composition. , was found to exhibit catalytic performance equivalent to that of magnesium (II) acetylacetonate.

[Production and evaluation of polyurethane]
[Example 8]
65.3 g of the polypolycarbonate diol produced in Example 7-1, which had been preheated to 80°C, was placed in a separable flask equipped with a thermocouple and a cooling tube, and the flask was immersed in an oil bath at 60°C. 17.5 g of 4,4'-dicyclohexylmethane diisocyanate (manufactured by Tokyo Kasei Kogyo Co., Ltd.) and 0.4 g of triisooctyl phosphite (manufactured by Tokyo Kasei Kogyo Co., Ltd.) were added, and the inside of the flask was heated at 60 rpm under a nitrogen atmosphere. While stirring, the temperature was raised to 80°C over about 1 hour. After raising the temperature to 80°C, 9.4 mg of Neostan U-830 (manufactured by Nitto Kasei Co., Ltd.) was added as a urethanization catalyst, and after the heat generation subsided, the oil bath was heated to 100°C for about 4 hours. Stirred. The concentration of isocyanate groups was analyzed to confirm that the theoretical amount of isocyanate groups had been consumed, and a prepolymer (hereinafter sometimes abbreviated as PP) was obtained.

Subsequently, 256.6 g of dehydrated N,N-dimethylformamide (manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the flask was immersed in an oil bath at 55° C. to dissolve the PP while stirring at about 200 rpm. After analyzing the concentration of isocyanate groups in the prepolymer solution, the flask was immersed in an oil bath set at 35°C, and while stirring at 150 rpm, the required amount of isophoronediamine (manufactured by Tokyo Kasei Kogyo Co., Ltd.) 4 calculated from the remaining isocyanate was added. .4g was added. After stirring for about 1 hour, 0.5 g of morpholine (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was added and further stirred for 1 hour to obtain a polyurethane solution. GPC analysis of the obtained polyurethane solution revealed that the weight average molecular weight (Mw) was 159,000. This polyurethane solution was applied onto a polyethylene film to a uniform thickness using a doctor blade and dried in a drier to obtain a polyurethane film. Table 8 shows the evaluation results of the physical properties of this polyurethane film.

As is clear from Table 8, by using the polycarbonate diol produced in Example 7-1, polyurethane with excellent solvent resistance, mechanical strength, and flexibility can be produced.

Claims (17)

A method for producing a polycarbonate diol having a number average molecular weight of 250 or more and 10,000 or less by polycondensing it by transesterification reaction in the presence of a transesterification catalyst using a dihydroxy compound and a carbonic acid diester as raw material monomers, the method comprising:
A composition in which the transesterification catalyst contains at least one metal (M) selected from zinc , magnesium, calcium, and barium and at least one compound represented by the following formula (1), or the following formula (2) A method for producing polycarbonate diol, which is at least one salt represented by the following and a composition using the salt as a precursor.

(In the formula, R ₁ and R ₃ each independently represent a monovalent hydrocarbon group having 1 to 20 carbon atoms, which may be substituted with a halogen atom or may have an oxygen atom.
R ₂ represents a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a halogen atom, and the hydrocarbon group may be substituted with a halogen atom or may have an oxygen atom.
M represents zinc or a metal of group 2 of the long period periodic table, and n=2. ) The method for producing polycarbonate diol according to claim 1 , wherein the metal (M) is zinc and/or magnesium. The method for producing polycarbonate diol according to claim 2 , wherein the metal (M) is magnesium. In the formulas (1) and (2), R ₁ and R ₃ are each independently a monovalent group having 1 to 12 carbon atoms, which may be substituted with a halogen atom or may have an oxygen atom. is a hydrocarbon group in which R ₂ is a hydrogen atom, a monovalent hydrocarbon group having 1 to 12 carbon atoms, which may be substituted with a halogen atom, or may have an oxygen atom, or a halogen atom. A method for producing polycarbonate diol according to any one of claims 1 to 3 . In the formulas (1) and (2), R ₁ and R ₃ are each independently a monovalent group having 1 to 7 carbon atoms, which may be substituted with a halogen atom or may have an oxygen atom. is a hydrocarbon group in which R ₂ is a hydrogen atom, a monovalent hydrocarbon group having 1 to 7 carbon atoms, or a halogen atom, which may be substituted with a halogen atom, and which may have an oxygen atom. The method for producing polycarbonate diol according to claim 4 . The method for producing a polycarbonate diol according to any one of claims 1 to 5 , wherein the metal (M) is present in a total amount of 1 μmol or more and 500 μmol or less per mol of the total dihydroxy compound. 7. The method for producing a polycarbonate diol according to claim 6 , wherein the metal (M) is present in a total amount of 5 μmol or more and 200 μmol or less per 1 mol of the total dihydroxy compound. The dihydroxy compound contains at least one selected from an aliphatic dihydroxy compound having a structure represented by the following formula (3), an alicyclic dihydroxy compound, and a poly(oxyalkylene) diol having a number average molecular weight of 100 to 1000. A method for producing polycarbonate diol according to any one of claims 1 to 7 .
HO-R ₄ -OH (3)
(In the formula, R ₄ represents a straight chain or branched divalent hydrocarbon group having 2 to 60 carbon atoms, and may have a cyclic structure and/or an ether oxygen atom.) The dihydroxy compound includes an aliphatic dihydroxy compound and/or an alicyclic dihydroxy compound having a structure represented by the formula (3), and R ₄ in the formula (3) has 2 to 20 carbon atoms. 8. The method for producing polycarbonate diol according to 8 . The method for producing a polycarbonate diol according to claim 9, wherein R ₄ in the formula (3) has 2 to 12 carbon atoms. The method for producing a polycarbonate diol according to claim 8 , wherein the dihydroxy compound contains a poly(oxyalkylene) diol having a number average molecular weight of 100 or more and 1000 or less. The method for producing polycarbonate diol according to claim 11 , wherein the dihydroxy compound contains polyoxytetramethylene glycol having a number average molecular weight of 100 or more and 1000 or less. The method for producing polycarbonate diol according to claim 12 , wherein the dihydroxy compound contains polyoxytetramethylene glycol having a number average molecular weight of 150 or more and 700 or less. The method for producing polycarbonate diol according to any one of claims 1 to 13 , wherein the diester carbonate is at least one selected from alkylene carbonate, dialkyl carbonate, and diaryl carbonate. 15. The method for producing polycarbonate diol according to claim 14 , wherein the diester carbonate is at least one selected from ethylene carbonate, dimethyl carbonate, diethyl carbonate, propylene carbonate, trimethylene carbonate, and diphenyl carbonate. The method for producing polycarbonate diol according to claim 15 , wherein the carbonic acid diester is at least one selected from ethylene carbonate, dimethyl carbonate, diethyl carbonate, and diphenyl carbonate. A method for producing polyurethane using a polycarbonate diol produced by the method for producing polycarbonate diol according to any one of claims 1 to 16 .