Diol-containing composition, polycarbonate diol, and polyurethane

Abstract

To provide a diol-containing composition allowing production of a polycarbonate diol having reduced coloration and favorable color tone.SOLUTION: A diol-containing composition comprises an amine and a diol (1) represented by the following general formula (I), wherein the content of the amine contained in the diol-containing composition is 0.1 mass ppm or more and 100 mass ppm or less in terms of nitrogen atoms based on the total mass of the diol-containing composition, the diol-containing composition being used in a process for producing a polycarbonate diol. (In the general formula (I), R represents a hydrocarbon group having 2 to 20 carbon atoms, which may have a substituent or a hetero atom.)SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a diol-containing composition. Furthermore, the present invention relates to a polycarbonate diol made from the diol-containing composition, and a polyurethane made from the polycarbonate diol. [Background technology]

[0002] Polycarbonate diols, polyether polycarbonate diols, and polyester polycarbonate diols produced from diols such as 1,6-hexanediol and 1,4-butanediol as raw materials are widely used as raw materials for polyurethanes (Non-Patent Document 1). For example, polyurethanes using polycarbonate diols have excellent heat resistance and hydrolysis resistance, and are therefore widely used in durable films, artificial leather for automobiles, (water-based) paints, and adhesives. In the production of polyurethane, it is known that the more colored the polycarbonate diol used as a raw material is, the more colored the polyurethane produced using the polycarbonate diol tends to be. Therefore, in the applications such as the above-mentioned artificial leather, (water-based) paints, adhesives, etc., polycarbonate diols with reduced coloration and good color tone are required as raw materials for polyurethane.

[0003] For example, Patent Document 1 discloses a technology in which a tertiary amino alcohol having a specific structure is blended into a polycarbonate diol-containing composition to suppress coloration of the resulting polycarbonate, and also to appropriately improve the reactivity with a polyisocyanate compound, thereby improving the efficiency of polyurethane production. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-053072 [Non-patent literature]

[0005] [Non-Patent Document 1] "Fundamentals and Applications of Polyurethane" pp. 96-106, edited by Katsuji Matsunaga, CMC Publishing Co., Ltd., published November 2006 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the polycarbonate diol disclosed in Patent Document 1 has a problem of insufficient quality such as color tone, etc. Furthermore, Patent Document 1 does not mention at all that a polycarbonate diol with good color tone and suppressed coloration can be obtained by adding a predetermined amount of amine to a diol-containing composition. Therefore, when a diol-containing composition such as 1,6-hexanediol is used as a raw material for polycarbonate diol according to the prior art, the color tone of the obtained polycarbonate diol and further the color tone of polyurethane using the polycarbonate diol as a raw material have not been satisfactorily achieved.

[0007] The present invention has been made in view of the above problems, and an object of the present invention is to provide a diol-containing composition that can produce a polycarbonate diol with reduced coloration and good color tone. [Means for solving the problem]

[0008] As a result of intensive research into solving the above problems, the present inventors have found that the above problems can be solved by using a diol-containing composition in which the amine content is controlled within a specific range as a raw material for polycarbonate diol.

[0009] The present invention provides the following.

[0010] [1] A diol-containing composition used in a process for producing a polycarbonate diol, A diol-containing composition comprising an amine and a diol (1) represented by the following general formula (I): The diol-containing composition, wherein the content of the amine contained in the diol-containing composition is 0.1 ppm by mass or more and 100 ppm by mass or less in terms of nitrogen atoms, relative to the total mass of the diol-containing composition.

[0011] [ka]

[0012] (In the above general formula (I), R represents a hydrocarbon group having 2 to 20 carbon atoms, which may have a substituent or a heteroatom.)

[0013] [2] The diol-containing composition according to [1], further comprising an aldehyde.

[0014] [3] The diol-containing composition according to [1] or [2], wherein the diol (1) comprises a diol represented by the following general formula (Ia):

[0015] [ka]

[0016] (In the above general formula (1), n ​​is an integer of 2 to 20.)

[0017] [4] The diol-containing composition according to [3], wherein the diol (1) includes at least one selected from 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol.

[0018] [5] The diol-containing composition according to any one of [1] to [4], wherein the amine contains one or more amino groups and one or more functional groups, and the functional groups include at least one selected from the group consisting of a hydroxyl group, a carboxyl group, a formyl group, and an amino group.

[0019] [6] The diol-containing composition according to any one of [1] to [4], wherein the amine comprises an alkylamine having an amino group in the molecule and having no functional groups other than the amino group.

[0020] [7] The diol-containing composition according to any one of [1] to [5], wherein the amine comprises an amine represented by the following general formula (II):

[0021] [ka]

[0022] (In the above general formula (II), R 1 represents an alkyl group having 2 to 20 carbon atoms and having r substituents X, which may have substituents other than X. X represents a hydroxyl group, a carboxyl group, a formyl group, or an amino group. r is an integer of 1 to 6. R 2 represents an alkyl group having 1 to 20 carbon atoms, which may have a substituent, or a hydrogen atom. 2 may be the same or different.)

[0023] [8] The diol-containing composition according to [7], wherein the amine comprises at least one selected from 6-amino-1-hexanol, 6-methylamino-1-hexanol, 6-ethylamino-1-hexanol, 6-dimethylamino-1-hexanol, and 6-diethylamino-1-hexanol.

[0024] [9] The diol-containing composition according to any one of [1] to [8], wherein the diol (1) includes a biomass-derived diol.

[0025]

[10] A polycarbonate diol obtained from the diol-containing composition according to any one of [1] to [9] and a carbonate compound as raw materials.

[0026]

[11] A polyurethane made from the polycarbonate diol described in

[10] and an isocyanate compound. [Effects of the Invention]

[0027] According to the present invention, it is possible to provide a diol-containing composition that can produce a polycarbonate diol with reduced coloration and good color tone. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a graph showing the relationship between the content of amine in a diol-containing composition and the color tone (APHA) of the resulting polycarbonate diol, obtained in Examples and Comparative Examples. [Figure 2] 1 is a graph showing the relationship between the aldehyde content in the diol-containing compositions obtained in Examples and Comparative Examples and the color tone (APHA) of the resulting polycarbonate diols. [Figure 3] 1 is a graph showing the relationship between the amine content in a diol-containing composition and the aldehyde content in the diol-containing composition, obtained in Examples and Comparative Examples. DETAILED DESCRIPTION OF THE INVENTION

[0029] The present invention will be described in detail below. The present invention is not limited to the following description, and can be practiced in any modified form without departing from the gist of the present invention.

[0030] Unless otherwise specified, in this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits, and "A to B" means A or more and B or less.

[0031] In this specification, "A or B" means "A," "B," and "A and B," unless otherwise specified. For example, "including A or B" means "including A," "including B," and "including A and B," unless otherwise specified.

[0032] In this specification, "% by mass" indicates the content ratio of a given component contained in a total amount of 100% by mass. In this specification, "mass %" and "weight %", "mass ppm" and "weight ppm", and "parts by mass" and "parts by weight" are synonymous. Furthermore, when simply written as "ppm", it means "ppm by weight".

[0033] In this specification, the term "structural unit" refers to a unit derived from a raw material compound used in the production of a polycarbonate diol, formed by polymerization of the raw material compound, and refers to a partial structure sandwiched between any linking groups in the obtained polymer. It also includes a partial structure at the terminal portion of a polymer, one of which is a linking group and the other of which is a polymerization reactive group. The structural unit may be a unit formed directly by a polymerization reaction, or may be a unit obtained by converting a part of the unit into another structure by treating the obtained polymer.

[0034] As used herein, "optional" or "optionally" means that the subsequently described circumstance may or may not occur, and thus the description includes both the occurrence and non-occurrence of the circumstance.

[0035] As used herein, the term "about" can mean above and below 20% of the stated value. For example, about 75°C encompasses the range of 60°C to 90°C.

[0036] In this specification, the term "obtained polycarbonate diol" refers to a polycarbonate diol produced using the diol-containing composition of the present invention and a carbonate compound as raw materials. In this specification, the term "obtained polyurethane" refers to a polyurethane produced using the polycarbonate diol of the present invention and an isocyanate compound as raw materials.

[0037] In this specification, the "diol-containing composition of the present invention," the "polycarbonate diol of the present invention," and the "polyurethane of the present invention" are collectively referred to as "the present invention."

[0038] All steps described herein can be performed in any suitable order unless otherwise stated herein or clearly contradicted by context.

[0039] <Diol-containing composition> The diol-containing composition of the present invention is a composition containing a diol (1) described below and an amine. The diol-containing composition of the present invention can be used in a process for producing a polycarbonate diol. The diol-containing composition of the present invention is substantially composed of a diol and a trace amount of an amine, and therefore may be generally referred to as a "diol." However, since it is not composed of only a diol, which is a single component, it is referred to as a "diol-containing composition." The amine will be described in detail later.

[0040] The content of the amine contained in the diol-containing composition of the present invention is 0.1 ppm by mass or more and 100 ppm by mass or less in terms of nitrogen atoms, relative to the total mass of the diol-containing composition.

[0041] When the content of the amine contained in the diol-containing composition of the present invention is 100 mass ppm or less in terms of nitrogen atoms relative to the total mass of the diol-containing composition, the higher the content of the amine, the more likely it is that the coloration of the obtained polycarbonate diol will be suppressed and the color tone will be better. On the other hand, when the content of the amine contained in the diol-containing composition is more than 100 mass ppm in terms of nitrogen atoms, the amine will tend to inhibit catalytic action or exhibit coloring action, thereby impairing the yield and color tone of the polycarbonate diol. The upper limit of the amine content in the diol-containing composition of the present invention is 100 ppm by mass or less, preferably 90 ppm by mass or less, more preferably 80 ppm by mass or less, even more preferably 70 ppm by mass or less, and most preferably 60 ppm by mass or less, calculated as nitrogen atoms, relative to the total mass of the diol-containing composition. On the other hand, the lower limit of the content of the amine is not particularly limited, but from the viewpoint of economic efficiency such as the production cost required for purifying the diol-containing composition, the lower limit can usually be set to 0.1 ppm by mass or more in terms of nitrogen atoms, preferably 1 ppm by mass or more, more preferably 2 ppm by mass or more, even more preferably 5 ppm by mass or more, and particularly preferably 10 ppm by mass or more, relative to the total mass% of the diol-containing composition. The above upper and lower limits can be arbitrarily combined. For example, the content of the amine contained in the diol-containing composition of the present invention can be 0.1 mass ppm or more and 100 mass ppm or less, preferably 1 mass ppm or more and 90 mass ppm or less, more preferably 1 mass ppm or more and 80 mass ppm or less, still more preferably 2 mass ppm or more and 80 mass ppm or less, particularly preferably 5 mass ppm or more and 70 mass ppm or less, and most preferably 10 mass ppm or more and 60 mass ppm or less, in terms of nitrogen atoms, relative to the total mass of the diol-containing composition.

[0042] The method for controlling the content of the amine in the diol-containing composition of the present invention is not particularly limited. As described later, for example, since the amine is by-produced when the diol (1) is obtained by fermenting a biomass resource such as sugar with a fungus, the content can be controlled by adjusting the type of fungus, the fermentation time, the distillation and purification conditions, etc.

[0043] <Diol (1)> In the present invention, the diol (1) is a compound represented by the following general formula (I), and is one of the components constituting the diol-containing composition of the present invention.

[0044] [ka]

[0045] (In the above general formula (I), R represents a hydrocarbon group having 2 to 20 carbon atoms, which may have a substituent or a heteroatom.)

[0046] By including the diol (1) in the diol-containing composition of the present invention, a polyurethane having good mechanical properties and chemical resistance can be obtained by using a polycarbonate diol produced using the diol-containing composition as a raw material.

[0047] In the diol-containing composition of the present invention, the diol (1) is not particularly limited, and known dihydroxy compounds used as raw materials for polycarbonate diols can be appropriately selected and used depending on the use of the polycarbonate diol, production conditions, etc.

[0048] Examples of the diol (1) include diols having no side chains, such as 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, 1,13-tridecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, 1,18-octadecanediol, and 1,20-eicosanediol, from the viewpoint of providing the resulting polyurethane with excellent chemical resistance and mechanical strength. Among these, from the viewpoint of providing a polyurethane with an excellent balance of flexibility, low-temperature properties, and chemical resistance, at least one compound selected from the group consisting of 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,10-decanediol is preferred, and at least one compound selected from the group consisting of 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol can be more preferably used. These compounds may be used alone or in combination of two or more.

[0049] Alternatively, the diol (1) may be optionally selected from the following compounds within the range not impairing the effects of the present invention: Diols having a side chain such as 1,3-butanediol, 2-methyl-1,3-propanediol, 2-methyl-1,4-butanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,6-hexanediol, 2-methyl-1,8-octanediol, 2,2-dimethyl-1,3-propanediol, 2,4-diethyl-1,5-pentanediol, 2-butyl-2-ethyl-1,3-propanediol, and 2,2-dimethyl-1,3-propanediol; cyclic diols such as 1,4-cyclohexanedimethanol and 2-bis(4-hydroxycyclohexyl)-propane; oxyalkylene glycols such as diethylene glycol, triethylene glycol, tetraethylene glycol, and polyethylene glycol; and diols having a cyclic ether structure such as isosorbide, isomannide, and isoidet, which are stereoisomers. These compounds may be used alone or in combination of two or more.

[0050] Furthermore, the diol-containing composition of the present invention may contain, as necessary, a polyol having three or more hydroxyl groups per molecule, such as trimethylolethane, trimethylolpropane, hexanetriol, or pentaerythritol, within a range that does not impair the effects of the present invention.

[0051] The content of diol (1) in the diol-containing composition of the present invention is not particularly limited, and from the viewpoint of improving the handleability of the obtained polycarbonate diol and the flexibility and low-temperature properties of the obtained polyurethane, it is preferably 85% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, and particularly preferably 96% by mass or more, relative to 100% by total mass of the diol-containing composition. On the other hand, the upper limit of the content of diol (1) in the diol-containing composition is not particularly limited, and is preferably less than 100% by mass, more preferably 99% by mass or less, even more preferably 98% by mass or less, and particularly preferably 97% by mass or less, relative to 100% by total mass of the diol-containing composition. The above upper and lower limits can be combined in any combination. For example, the content of diol (1) in the diol-containing composition of the present invention is preferably 85% by mass or more but less than 100% by mass, more preferably 90% by mass or more but less than 99% by mass, further preferably 95% by mass or more but less than 98% by mass, and particularly preferably 96% by mass or more but less than 97% by mass, based on 100% by mass of the total mass of the diol-containing composition.

[0052] The diol (1) may contain a diol (1a) represented by the following general formula (Ia), if necessary.

[0053] [ka]

[0054] (In the above general formula (1), n ​​is an integer of 2 to 20.)

[0055] When the diol (1) contains the diol (1a), a polyurethane having better mechanical properties and chemical resistance can be obtained.

[0056] In the diol (1a) represented by the general formula (Ia), the lower limit of n is not particularly limited, and is 2 or more, preferably 3 or more, and more preferably 4 or more. On the other hand, the upper limit of n is 20 or less, preferably 15 or less, more preferably 10 or less, and even more preferably 6 or less. The upper and lower limits can be combined in any combination. For example, in the diol (1a) represented by the general formula (Ia), n is 2 or more and 20 or less, preferably 3 or more and 15 or less, more preferably 4 or more and 10 or less, and even more preferably 4 or more and 6 or less. Among these, the diol (1) is preferably at least one selected from 1,4-butanediol (n=4), 1,5-pentanediol (n=5), and 1,6-hexanediol (n=6). The diol (1) may be used alone or in combination of two or more kinds.

[0057] In such a case, the content of diol (1a) in the diol (1) is not particularly limited, and from the viewpoint of improving the handleability of the polycarbonate diol and the flexibility and low-temperature properties of the obtained polyurethane, it is preferably 10% by mass or more, more preferably 30% by mass or more, still more preferably 50% by mass or more, particularly preferably 70% by mass or more, and most preferably 90% by mass or more, relative to 100% by total mass of the diol (1). On the other hand, the upper limit of the content of diol (1a) in the diol (1) is not particularly limited, and may be 100% by mass, or is preferably less than 100% by mass, more preferably 99% by mass or less, even more preferably 98% by mass or less, particularly preferably 97% by mass or less, and most preferably 96% by mass or less, relative to 100% by total mass of the diol (1). The upper and lower limits can be combined arbitrarily. For example, the content of diol (1a) in diol (1) is preferably 100% by mass, or 10% by mass or more but less than 100% by mass, more preferably 30% by mass or more but 99% by mass or less, still more preferably 50% by mass or more but 98% by mass or less, particularly preferably 70% by mass or more but 97% by mass or less, and most preferably 90% by mass or more but 96% by mass or less, relative to 100% by mass of the total mass of the polycarbonate diol.

[0058] The diol-containing composition of the present invention can achieve the Sustainable Development Goals (SDGs) by using a diol-containing composition containing a biomass-derived diol as the diol (1). Specifically, a biomass-derived diol alone or a mixture containing a biomass-derived diol and a fossil fuel-derived diol can be used. Biomass-derived diols are diols derived from non-edible biomass and / or non-fossil fuels.

[0059] When sugars or the like are used as biomass resources and fermented with fungal cells to obtain the diol (1), the amine may be produced as a by-product. In the present invention, by using a biomass-derived diol as the diol (1), the amine produced as a by-product can be effectively utilized, and coloration of the obtained polycarbonate diol can be suppressed, resulting in a good color tone.

[0060] In the present invention, non-edible biomass refers to resources made from non-edible grasses or trees. Specific examples include, but are not limited to, cellulose, hemicellulose, lignin, etc. obtained from woody biomass such as coniferous and broad-leaved trees, bioethanol and biodiesel obtained from herbaceous biomass such as corn and sugarcane stalks, soybeans, and rapeseed, and plant-derived waste oil. In the present invention, the term "non-fossil fuel" refers to, for example, hydrogen or organic matter derived from plants or animals that is not derived from fossil fuels or non-edible biomass. Specific examples include, but are not limited to, methane and sugar ethanol obtained from firewood, charcoal, dried livestock manure, etc.

[0061] In the present invention, the diol (1) derived from a fossil fuel refers to at least one selected from the group consisting of diol (1) derived from petroleum, diol (1) derived from coal, and diol (1) derived from natural gas.

[0062] The biomass-derived diol (1) may contain the amines described above depending on its origin. Therefore, the effects of the present invention can be achieved by controlling the content of the amines in the diol (1) to produce the diol-containing composition of the present invention, or by controlling the content of the amines in the diol-containing composition produced using the diol (1).

[0063] In the diol-containing composition of the present invention, 1,6-hexanediol derived from fossil fuels can be used alone as the diol (1a). Alternatively, the diol-containing composition of the present invention uses, as the diol (1a), 1,6-hexanediol including biomass-derived 1,6-hexanediol, specifically biomass-derived 1,6-hexanediol alone, or a mixture containing biomass-derived 1,6-hexanediol and fossil fuel-derived 1,6-hexanediol, thereby achieving the Sustainable Development Goals (SDGs). Biomass-derived 1,6-hexanediol is 1,6-hexanediol derived from non-edible biomass and / or non-fossil fuels.

[0064] In the present invention, 1,6-hexanediol derived from a fossil fuel refers to at least one selected from petroleum-derived 1,6-hexanediol, coal-derived 1,6-hexanediol, and natural gas-derived 1,6-hexanediol.

[0065] The above-mentioned biomass-derived 1,6-hexanediol may contain the above-mentioned amines, for example, primary, secondary, or tertiary amines such as 6-amino-1-hexanol, 6-methylamino-1-hexanol, and 6-dimethylamino-1-hexanol, depending on its origin. Therefore, the above-mentioned effects of the present invention can be achieved by producing the diol-containing composition of the present invention by controlling the content of the primary, secondary, or tertiary amine in the 1,6-hexanediol, or by controlling the content of the primary, secondary, or tertiary amine in the diol-containing composition produced using the 1,6-hexanediol.

[0066] <amine> The amine in the present invention is one component constituting the diol-containing composition of the present invention.

[0067] The diol-containing composition of the present invention contains the amine in a range of 0.1 mass ppm or more and 100 mass ppm or less in terms of nitrogen atoms, so that the obtained polycarbonate diol is inhibited from coloring and has a good color tone.

[0068] The amine in the present invention is not particularly limited, and known amine compounds can be used.

[0069] For example, as a first embodiment, the amine in the present invention can include an amine compound in which some or all of the hydroxy groups of the diol (1) are substituted with amino groups, thereby further improving the effect of suppressing coloration of the obtained polycarbonate diol and improving the color tone. Specifically, when the diol (1) is the diol (1a) represented by the general formula (Ia), examples of the amine include those described below. When n=3, primary amine compounds such as 3-amino-1-propanol and 1,3-diaminopropane, secondary amine compounds such as 3-methylamino-1-propanol, and tertiary amine compounds such as 3-dimethylamino-1-propanol; When n=4, primary amine compounds such as 4-amino-1-butanol and 1,4-diaminobutane, secondary amine compounds such as 4-methylamino-1-butanol, and tertiary amine compounds such as 4-dimethylamino-1-butanol; When n=5, primary amine compounds such as 5-amino-1-pentanol and 1,5-diaminopentane, secondary amine compounds such as 5-methylamino-1-pentanol, and tertiary amine compounds such as 5-dimethylamino-1-pentanol; In the case where n=6 (compound (1-2)), primary amine compounds such as 6-amino-1-hexanol and 1,6-diaminohexane, secondary amine compounds such as 6-methylamino-1-hexanol and 6-ethylamino-1-hexanol, and tertiary amine compounds such as 6-dimethylamino-1-hexanol and 6-diethylamino-1-hexanol: Examples include: These compounds may be used alone or in combination of two or more.

[0070] As a second embodiment, the amine in the present invention contains one or more amino groups and one or more functional groups, and the functional group can contain at least one selected from the group consisting of a hydroxyl group, a carboxyl group, a formyl group, and an amino group. This can further improve the effect of suppressing coloration of the obtained polycarbonate diol and improving the color tone.

[0071] As a third embodiment, the amine in the present invention can include an amine represented by the following general formula (II), which can further improve the effect of suppressing coloration of the obtained polycarbonate diol and improving the color tone in the obtained polyurethane.

[0072] [ka]

[0073] (In the above general formula (II), R 1 represents an alkyl group having 2 to 20 carbon atoms and having r substituents X, which may have substituents other than X. X represents a hydroxyl group, a carboxyl group, a formyl group, or an amino group. r is an integer of 1 to 6. R 2 represents an alkyl group having 1 to 20 carbon atoms, which may have a substituent, or a hydrogen atom. 2 may be the same or different.)

[0074] In the above general formula (II), two R 2 When one of R is an alkyl group having 1 to 20 carbon atoms which may have a substituent and the other is a hydrogen atom, or when both of R are alkyl groups having 1 to 20 carbon atoms which may have a substituent (however, when two R 2 The types of alkyl groups in may be the same or different.) and both may be hydrogen atoms.

[0075] In the above general formula (II), N(R 2)2 and X react with the carbonate bond or hydroxyl group of the polycarbonate diol, or with the isocyanate compound used as a raw material for polyurethane. If an excessive number of substituents X are present, a crosslinked structure is formed in the polyurethane during the polymerization step in producing the polyurethane, causing gelation and impairing polymerization stability. Therefore, r, which represents the number of substituents X, is preferably 1 or 2, and more preferably 1. Also, R 1 The number of carbon atoms in R is 2 to 20, but from the viewpoint that the mechanical properties of the polyurethane obtained by using the polycarbonate diol of the present invention are good, R 1 The number of carbon atoms is preferably 3 to 10, more preferably 3 to 6, and even more preferably 4 to 6. Also, R 2 is an alkyl group having 1 to 20 carbon atoms or a hydrogen atom, but from the viewpoint of improving the mechanical properties of the polyurethane obtained by using the polycarbonate diol of the present invention, R 2 is preferably an alkyl group having 3 to 10 carbon atoms or a hydrogen atom, more preferably an alkyl group having 3 to 6 carbon atoms or a hydrogen atom, and even more preferably an alkyl group having 4 to 6 carbon atoms or a hydrogen atom.

[0076] A specific embodiment of the amine represented by the general formula (II) is at least one selected from the following primary amines, secondary amines, and tertiary amines. R 1 is a propylene group having 3 carbon atoms, primary amine compounds such as 3-amino-1-propanol, secondary amine compounds such as 3-methylamino-1-propanol, and tertiary amine compounds such as 3-dimethylamino-1-propanol; R 1 is a butylene group having 4 carbon atoms, primary amine compounds such as 4-amino-1-butanol, secondary amine compounds such as 4-methylamino-1-butanol, and tertiary amine compounds such as 4-dimethylamino-1-butanol; R 1is a pentylene group having 5 carbon atoms, primary amine compounds such as 5-amino-1-pentanol, secondary amine compounds such as 5-methylamino-1-pentanol, and tertiary amine compounds such as 5-dimethylamino-1-pentanol; R 1 When is a hexylene group having 6 carbon atoms, examples of the amine compound include primary amine compounds such as 6-amino-1-hexanol, secondary amine compounds such as 6-methylamino-1-hexanol and 6-ethylamino-1-hexanol, and tertiary amine compounds such as 6-dimethylamino-1-hexanol and 6-diethylamino-1-hexanol. Among these, at least one selected from 6-amino-1-hexanol, 6-methylamino-1-hexanol, 6-ethylamino-1-hexanol, 6-dimethylamino-1-hexanol, and 6-diethylamino-1-hexanol is preferred. These compounds may be used alone or in combination of two or more.

[0077] As a fourth embodiment, the amine in the present invention can include an alkylamine having an amino group in the molecule but no functional groups other than the amino group, which can further improve the effect of suppressing coloration of the obtained polycarbonate diol and improving the color tone. The alkylamine may be at least one selected from the group consisting of monoalkylamines, dialkylamines, and trialkylamines. More specific examples of the alkylamine include trimethylamine, diethylamine, triethylamine, propylamine, dipropylamine, tripropylamine, butylamine, dibutylamine, tributylamine, amylamine, diamylamine, triamylamine, hexylamine, dihexylamine, trihexylamine, heptylamine, diheptylamine, triheptylamine, octylamine, dioctylamine, trioctylamine, nonylamine, dinonylamine, trinonylamine, decylamine, didecylamine, tridecylamine, dodecylamine, didodecylamine, tridodecylamine, etc. Structural isomers and derivatives of these compounds are also included. These compounds may be used alone or in combination of two or more.

[0078] <Aldehyde> According to the investigations of the present inventors, the diol-containing composition contains the following aldehydes: Aldehydes are by-produced during the hydrogenation reaction of the raw material carboxylic acid or ester derivative of carboxylic acid during the production of diols. Aldehydes are produced by oxidation of diols during distillation or long-term storage.

[0079] According to the studies of the present inventors, these aldehydes generate radicals by heating or oxidation during the production of polycarbonate diol or during long-term storage, and aldehyde groups, carboxylic acids, double bonds, etc. are generated in the structure of the polycarbonate diol. As a result, it is presumed that a conjugated structure is formed in the structure of the polycarbonate diol, causing the polycarbonate diol to become colored. Furthermore, according to the investigations of the present inventors, it is presumed that the amine in the diol-containing composition and the structural unit (2) in the polycarbonate diol, which will be described later, suppress the by-production of aldehyde and the generation of radicals from aldehyde, and therefore can suppress the coloration of the polycarbonate diol.

[0080] As described above, when the content of the amine in the diol-containing composition of the present invention is 100 mass ppm or less in terms of nitrogen atoms, the higher the content of the amine, the more effectively the production of aldehyde can be suppressed, and therefore the effect of suppressing coloration and improving color tone in the obtained polycarbonate diol can be further improved.

[0081] The aldehyde in the present invention is not particularly limited, and any known aldehyde compound or an aldehyde compound in which the hydroxy group of the diol (1) is replaced with an aldehyde group can be used.

[0082] The type of aldehyde in the present invention is not particularly limited, but examples thereof include the following in the diol (1a) represented by the general formula (Ia). When n = 3, monoaldehyde compounds such as 3-hydroxypropanal and dialdehyde compounds such as malondialdehyde; When n = 4, monoaldehyde compounds such as 4-hydroxybutanal and dialdehyde compounds such as succinaldehyde; When n = 5, monoaldehyde compounds such as 5-hydroxypentanal and dialdehyde compounds such as glutaraldehyde are used; When n=6, monoaldehyde compounds such as 6-hydroxyhexanal and dialdehyde compounds such as adipaldehyde are produced:

[0083] When the diol (1) is 1,6-hexanediol and is derived from a biomaterial, particularly from non-edible biomass such as glucose or xylose, the 1,6-hexanediol may contain the above-mentioned monoaldehyde compounds such as 6-hydroxyhexanal and adipaldehyde.

[0084] An aldehyde group may react with a hydroxy group to convert to an acetal group. Therefore, the aldehyde in the present invention also includes an acetal compound in which the aldehyde group of the aldehyde compound is replaced with an acetal group (hereinafter, sometimes simply referred to as "acetal"). That is, the content of aldehyde in the present invention means the total content of the aldehyde compound and the acetal which is an acetal-modified product thereof.

[0085] Examples of the acetal include (a) an acetal compound in which the aldehyde group of the aldehyde reacts with a hydroxy group to form an acetal group; (b) an acetal compound in which two molecules of a monohydroxy compound react with one aldehyde group of the aldehyde; (c) an acetal compound in which one molecule of a dihydroxy compound reacts with one aldehyde group of the aldehyde; and (d) a hemiacetal compound in which one molecule of a monohydroxy compound reacts with one aldehyde group of the aldehyde. The acetal may be one of these or two or more of these.

[0086] <Aldehyde content> When the content of the amine contained in the diol-containing composition of the present invention is 100 mass ppm or less in terms of nitrogen atoms, the higher the content of the amine, the more effectively the production of aldehyde in the diol-containing composition can be suppressed for the reasons described below, and therefore the effect of suppressing coloration of the obtained polycarbonate diol can be more significantly obtained. As described above, according to the studies of the present inventors, the diol-containing composition, which is a raw material for polycarbonate diol, contains aldehyde for the reasons described above. When producing polycarbonate diol using such a diol-containing composition, or when storing the obtained polycarbonate diol for a long period of time, the aldehyde generates radicals by heating or oxidation, and aldehyde groups, carboxylic acids, double bonds, etc. are generated in the dihydroxy compound or polycarbonate diol. As a result, it is presumed that a conjugated structure is formed in the structure of the polycarbonate diol, causing the polycarbonate diol to become colored. It is presumed that the amine in the diol-containing composition suppresses the by-production of aldehyde and the generation of aldehyde radicals, thereby preventing the coloration of the obtained polycarbonate diol.

[0087] In the diol-containing composition of the present invention, the upper limit of the content of the aldehyde is not particularly limited. From the viewpoint of obtaining a sufficient effect of the amine, the upper limit of the content of the aldehyde can be 980 mass ppm or less, preferably 950 mass ppm or less, more preferably 900 mass ppm or less, even more preferably 850 mass ppm or less, and particularly preferably 800 mass ppm or less, relative to the total mass of the diol-containing composition. On the other hand, the lower limit of the content is not particularly limited. Usually, from the viewpoint of economic efficiency such as the production cost required for purifying the diol-containing composition, the lower limit of the content of the aldehyde can be set to 1 ppm by mass or more, preferably 10 ppm by mass or more, more preferably 50 ppm by mass or more, still more preferably 100 ppm by mass or more, and particularly preferably 200 ppm by mass or more, relative to the total mass of the diol-containing composition. The above upper and lower limits can be combined arbitrarily. For example, the aldehyde content of the diol-containing composition of the present invention can be 1 mass ppm or more and 980 mass ppm or less, preferably 10 mass ppm or more and 950 mass ppm or less, more preferably 50 mass ppm or more and 900 mass ppm or less, still more preferably 100 mass ppm or more and 850 mass ppm or less, and particularly preferably 200 mass ppm or more and 800 mass ppm or less, relative to the total mass of the diol-containing composition. As mentioned above, the content of aldehyde here refers to the total content of the aldehyde compound and its acetal-modified product, acetal.

[0088] The method for controlling the content ratio of the aldehyde in the diol-containing composition is not particularly limited. For example, when the diol (1) is obtained by a hydrogenation reaction of a carboxylic acid or a carboxylic acid ester, the content ratio of the aldehyde can be controlled by adjusting the conversion rate of the carboxylic acid or the carboxylic acid ester in the hydrogenation reaction step.

[0089] For example, in the production stage of the diol-containing composition, the higher the conversion rate, the lower the content of the aldehyde in the resulting diol-containing composition. Therefore, a method for reducing the content of the aldehyde includes a method for increasing the conversion rate. On the other hand, the content of aldehyde in the diol-containing composition increases due to oxidation. Therefore, a method for increasing the content of aldehyde in the diol-containing composition during production thereof includes, for example, heating the diol-containing composition in a raw material tank or the like in the presence of oxygen to increase the content of aldehyde to a desired value.

[0090] <Polycarbonate diol> The polycarbonate diol of the present invention is a polycarbonate diol compound produced using the diol-containing composition of the present invention and a carbonate compound as raw materials.

[0091] The polycarbonate diol of the present invention can contain the structural unit (1-1) described below and the structural unit (2) described below.

[0092] (Structural unit (1-1)) The above-mentioned structural unit (1-1) is a structural unit represented by the following general formula (I-1) derived from the diol (1) contained in the structure of the polycarbonate diol of the present invention.

[0093] [ka]

[0094] (In the above general formula (I-1), R has the same meaning as R in the above formula (I) and represents a hydrocarbon group having 2 to 20 carbon atoms, which may have a substituent or a hetero atom.)

[0095] The diol (1) in the polycarbonate diol of the present invention is treated as having the same meaning as the diol (1) mentioned in the description of the diol-containing composition of the present invention.

[0096] The polycarbonate diol of the present invention contains the structural unit (1-1) derived from the diol (1), and the obtained polyurethane has good mechanical properties and chemical resistance.

[0097] The lower limit of the content of the structural unit (1-1) in the polycarbonate diol of the present invention is not particularly limited, and from the viewpoint of obtaining good mechanical properties and chemical resistance of the resulting polyurethane, it is preferably 40% by mass or more, more preferably 60% by mass or more, even more preferably 75% by mass or more, and particularly preferably 80% by mass or more, relative to 100% by mass of the total mass of the polycarbonate diol. On the other hand, the upper limit of the content of the structural unit (1-1) is not particularly limited, and it may correspond to 100% by mass of the mass of the structural unit other than the structural unit (2) in the polycarbonate diol of the present invention, or may be less than 100% by mass. Alternatively, from the viewpoint of maintaining good chemical resistance of the resulting polyurethane, it is more preferably 98% by mass or less, even more preferably 95% by mass or less, and particularly preferably 90% by mass or less, relative to 100% by mass of the total mass of the polycarbonate diol. The upper and lower limits can be combined arbitrarily. For example, the content of the structural unit (1) in the polycarbonate diol of the present invention is preferably 40% by mass or more and less than 100% by mass, more preferably 60% by mass or more and 98% by mass or less, still more preferably 75% by mass or more and 95% by mass or less, and particularly preferably 80% by mass or more and 90% by mass or less, relative to 100% by mass of the total mass of the polycarbonate diol.

[0098] In the polycarbonate diol of the present invention, the structural unit (1-1) preferably contains a structural unit represented by the following general formula (Ia-1) derived from the diol (1a), from the viewpoint of improving the mechanical properties and chemical resistance of the resulting polyurethane.

[0099] [ka]

[0100] (In the above general formula (Ia-1), n ​​has the same meaning as n in the above formula (Ia) and is an integer of 2 to 20.)

[0101] The diol (1a) in the polycarbonate diol of the present invention is treated as having the same meaning as the diol (1a) mentioned in the description of the diol-containing composition of the present invention.

[0102] In the general formula (Ia-1), the lower limit of n is not particularly limited, and is 2 or more, preferably 3 or more, and more preferably 4 or more. On the other hand, the upper limit of n is 20 or less, preferably 15 or less, more preferably 10 or less, and even more preferably 6 or less. The upper and lower limits can be combined in any combination. For example, in the diol (1a) represented by the general formula (Ia), n is 2 or more and 20 or less, preferably 3 or more and 15 or less, more preferably 4 or more and 10 or less, and even more preferably 4 or more and 6 or less. The structural unit (1) may be used alone or in combination of two or more types.

[0103] (Structural unit (2)) The above-mentioned structural unit (2) is a structural unit derived from the above-mentioned amine, which is contained in the structure of the polycarbonate diol of the present invention.

[0104] The amines in the polycarbonate diol of the present invention are treated as having the same meaning as the amines mentioned in the description of the diol-containing composition of the present invention.

[0105] Furthermore, the structural unit (2) may contain a structural unit (2-1) represented by the following general formula (II-1).

[0106] [ka]

[0107] (In the above general formula (II-1), m is an integer of 2 to 20. R 2 is R in the formula (II).2 and represents an optionally substituted alkyl group having 1 to 20 carbon atoms or a hydrogen atom.)

[0108] The polycarbonate diol of the present invention can contain a structural unit represented by the following general formula (IIIa) or the following general formula (IIIb) as a terminal structure.

[0109] [ka]

[0110] (In the above general formula (IIIa), m is an integer of 2 to 20. R 2 is R in the formula (II). 2 and represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms which may have a substituent.)

[0111] [ka]

[0112] (In the above general formula (IIIb), m is an integer of 2 to 20. R 2 is R in the formula (II). 2 and represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms which may have a substituent.)

[0113] In the polycarbonate diol of the present invention, the upper limit of the content of the structural unit (2-1) is not particularly limited, and when the diol-containing composition of the present invention is used, the upper limit is preferably 80 ppm by mass or less, more preferably 70 ppm by mass or less, even more preferably 60 ppm by mass or less, particularly preferably 50 ppm by mass or less, and most preferably 40 ppm by mass or less, calculated as nitrogen atoms, relative to the total mass of the polycarbonate diol. On the other hand, the lower limit of the content of the structural unit (2-1) is not particularly limited, and when the diol-containing composition of the present invention is used, the content is preferably 0.1 ppm by mass or more, more preferably 1 ppm by mass or more, even more preferably 2 ppm by mass or more, particularly preferably 5 ppm by mass or more, and most preferably 10 ppm by mass or more, calculated as nitrogen atoms, relative to the total mass of the polycarbonate diol. The upper and lower limits can be combined arbitrarily. For example, the content of the structural unit (2-1) in the polycarbonate diol of the present invention is, in terms of nitrogen atoms, preferably 0.1 to 80 ppm by mass, more preferably 1 to 70 ppm by mass, even more preferably 2 to 60 ppm by mass, particularly preferably 5 to 50 ppm by mass, and most preferably 10 to 40 ppm by mass, relative to the total mass of the polycarbonate diol.

[0114] Furthermore, in the polycarbonate diol of the present invention, when the content of the amine contained in the diol-containing composition is 100 mass ppm or less in terms of nitrogen atoms, the higher the content of the amine, the more effectively the production of aldehyde in the diol-containing composition can be suppressed for the reasons described above. And, since the production of aldehyde can be further suppressed, the effect of suppressing coloration of the obtained polycarbonate diol can be more significantly obtained.

[0115] (Molecular weight of polycarbonate diol) The lower limit of the number average molecular weight (Mn) of the polycarbonate diol of the present invention is not particularly limited, and from the viewpoint of good mechanical properties of the obtained polyurethane, it is preferably 250 or more, more preferably 300 or more, and even more preferably 400 or more. On the other hand, the upper limit of the number average molecular weight (Mn) is not particularly limited, and from the viewpoint of keeping the viscosity of the polycarbonate diol of the present invention to a certain level and maintaining good handleability, and from the viewpoint of maintaining good chemical resistance of the obtained polyurethane, it is preferably 5000 or less, more preferably 4000 or less, and even more preferably 3000 or less. The above upper and lower limits can be combined in any combination. For example, the number average molecular weight (Mn) of the polycarbonate diol in the present invention is preferably 250 or more and 5,000 or less, more preferably 300 or more and 4,000 or less, and even more preferably 400 or more and 3,000 or less. The number average molecular weight (Mn) is a molecular weight calculated from the hydroxyl value, and the measurement conditions are as described in the examples below.

[0116] <Method for producing polycarbonate diol> The method for producing the polycarbonate diol of the present invention is not particularly limited, and for example, known methods for producing polycarbonate diols described in Schnell, Polymer Reviews, Vol. 9, pp. 9-20 (1994) and WO 2015 / 199070 can be used.

[0117]

[0044] A specific embodiment of the method for producing the polycarbonate diol of the present invention is a method in which the diol-containing composition of the present invention containing the amine and a carbonate compound described later are polycondensed by a transesterification reaction, if necessary, in the presence of a catalyst described later, to obtain a polycarbonate diol. As an example of the method for producing the polycarbonate diol of the present invention, a method using diphenyl carbonate as the carbonate will be described below. The production of the polycarbonate diol can be carried out in two stages.

[0118] In the first-stage reaction, the diol-containing composition of the present invention and diphenyl carbonate are mixed in a molar ratio of 20:1 to 1:10, preferably 10:1 to 1:2, and after adding a Mg catalyst as a transesterification catalyst, the mixture is reacted at 100 to 250°C under normal pressure, and the phenol produced is removed from the reaction system to obtain a low-molecular-weight polycarbonate diol. In the second-stage reaction, the reaction product of the first stage is heated at 130 to 250°C under reduced pressure, and the phenol and unreacted diol (1) are removed from the reaction system while the low-molecular-weight polycarbonate diol is self-condensed to obtain a polycarbonate diol of a predetermined molecular weight.

[0119] (carbonate compounds) The carbonate compound that can be used to produce the polycarbonate diol of the present invention is not particularly limited as long as it does not impair the effects of the present invention, and examples thereof include dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, dipropyl carbonate, and dibutyl carbonate; diaryl carbonates such as diphenyl carbonate; alkylene carbonates such as ethylene carbonate, trimethylene carbonate, 1,2-propylene carbonate, 1,2-butylene carbonate, 1,3-butylene carbonate, and 1,2-pentylene carbonate; etc. One or more carbonates from these can be used as raw materials. Among these, from the viewpoints of reactivity with the diol (1), ease of availability, and ease of setting polymerization reaction conditions, it is preferable to use one or more carbonate compounds selected from dimethyl carbonate, diethyl carbonate, diphenyl carbonate, dibutyl carbonate, and ethylene carbonate. The amount of carbonate compound used is not particularly limited, and for example, the conditions described in WO 2015 / 199070 can be appropriately optimized by a person skilled in the art according to known techniques.

[0120] (amine) The amine in the polycarbonate diol of the present invention can be treated as synonymous with the amines mentioned in the description of the diol-containing composition of the present invention, particularly the amines mentioned in the first, second, third, and fourth embodiments.

[0121] Furthermore, as the amine in the production of the polycarbonate diol of the present invention, the amines that form the structural unit (2) mentioned in the description of the polycarbonate diol of the present invention can be used.

[0122] (catalyst) In producing the polycarbonate diol of the present invention, when the diol in the diol-containing composition of the present invention and a carbonate compound are polycondensed by a transesterification reaction to obtain the polycarbonate diol, a known transesterification catalyst (hereinafter sometimes referred to as "catalyst") used in the synthesis of polycarbonate diol can be used as a catalyst for promoting the transesterification reaction. In this case, if an excessive amount of catalyst remains in the obtained polycarbonate diol, the reaction may be inhibited or excessively promoted when producing a polyurethane using the polycarbonate diol. The type and amount of the catalyst, and the amount of catalyst remaining in the polycarbonate diol are not particularly limited. As the catalyst, for example, the conditions described in WO 2015 / 199070 can be appropriately optimized by a person skilled in the art according to known techniques and used.

[0123] (Catalyst deactivator) As mentioned above, when a catalyst is used in the polymerization reaction, the catalyst usually remains in the obtained polycarbonate diol, and the remaining catalyst may cause an increase in molecular weight or a change in composition when the polycarbonate diol is heated, or may make it impossible to control the polyurethane-forming reaction. In order to suppress the influence of this remaining catalyst, a catalyst deactivator such as a phosphorus-based compound can be added, if necessary, in an amount approximately equimolar to the transesterification catalyst used to inactivate the transesterification catalyst. Furthermore, after the addition, the transesterification catalyst can be efficiently inactivated by heat treatment or the like. The type and amount of the catalyst deactivator and the conditions for the heat treatment are not particularly limited. For example, the conditions described in WO 2015 / 199070 can be appropriately optimized by a person skilled in the art according to known techniques.

[0124] <Applications of Polycarbonate Diol> The polycarbonate diol of the present invention can be used as a raw material for thermoplastic elastomers such as polyurethane or polyester, and as a constituent material for paints or adhesives. In particular, when the polycarbonate diol of this embodiment is used as a raw material for polyurethane or thermoplastic elastomer, a polyurethane or thermoplastic elastomer having a smooth surface and a good balance of various mechanical properties, chemical resistance, and other performance characteristics can be obtained. Furthermore, when the polycarbonate diol of the present invention is used as a constituent material for paints or adhesives, a coating film having a smooth surface and a good balance of various mechanical properties, chemical resistance, and other performance characteristics can be obtained.

[0125] <Polyurethane> The polyurethane of the present invention is produced using the polycarbonate diol of the present invention and an isocyanate compound as raw materials. The method for producing the polyurethane of the present invention is not particularly limited, and those skilled in the art can use known polyurethane reaction conditions described in, for example, WO 2015 / 016261 and WO 2018 / 088575, by optimizing them as appropriate in accordance with known techniques.

[0126] For example, the polyurethane of the present invention can be produced by reacting the polycarbonate diol of the present invention with a polyol other than the polycarbonate diol of the present invention, which is used if necessary, an isocyanate compound described below, and a chain extender described below, which is also used if necessary, at a temperature ranging from room temperature to 200°C.

[0127] When a chain extender is used, the chain extender may be added from the beginning of the reaction or during the reaction. For example, the polyurethane of the present invention can be produced by first reacting the polycarbonate diol of the present invention with an excess amount of polyisocyanate to produce a prepolymer having an isocyanate group at its terminal, and then adding a chain extender to react with the prepolymer to increase the degree of polymerization of the polymer.

[0128] (Isocyanate compounds) As the isocyanate compound used in the production of the polyurethane of the present invention, known isocyanate compounds used in the production of polyurethanes can be used. The isocyanate compound is not particularly limited, and for example, the isocyanate compounds described in WO 2015 / 016261 and WO 2018 / 088575 can be used.

[0129] (Chain extender) As the chain extender used in the production of the polyurethane of the present invention, any known chain extender used in the production of polyurethanes can be used. The chain extender is not particularly limited, and examples thereof include diols, amines, water, and the like described in WO 2015 / 016261 and WO 2018 / 088575.

[0130] (chain terminator) When producing the polyurethane of the present invention, a known chain terminator used in the production of polyurethanes can be used, if necessary, for the purpose of controlling the molecular weight of the polyurethane. The chain terminator is not particularly limited, and examples thereof include compounds having one active hydrogen group, such as monohydric alcohols and secondary amines, as described in WO 2015 / 016261 and WO 2018 / 088575.

[0131] (catalyst) When producing the polyurethane of the present invention, any known catalyst used in the production of polyurethanes can be used. The catalyst is not particularly limited, and examples of the catalyst that can be used include known polymerization catalysts such as tertiary amines and organic metal salts of tin, titanium, and the like, as described in International Publication Nos. 2015 / 016261 and 2018 / 088575.

[0132] (solvent) When producing the polyurethane of the present invention, a solvent may be used, if necessary. The solvent is not particularly limited, and examples thereof include the solvents described in WO 2015 / 016261 and WO 2018 / 088575.

[0133] (Amount / How to use) In the method for producing a polyurethane of the present invention, the amounts and methods of use of the polyisocyanate, chain extender, chain terminator, catalyst, and solvent are not particularly limited, and a person skilled in the art can use the conditions described in WO 2015 / 016261 and WO 2018 / 088575 by optimizing them as appropriate in accordance with known techniques.

[0134] (Polyurethane weight average molecular weight (Mw)) The weight average molecular weight (Mw) of the polyurethane of the present invention is not particularly limited, and from the viewpoint of achieving a good balance between the mechanical properties and chemical resistance of the resulting polyurethane, it is preferably from 50,000 to 500,000, more preferably from 100,000 to 300,000, and even more preferably from 150,000 to 200,000.

[0135] <Polyurethane applications> The polyurethane of the present invention has good mechanical properties and chemical resistance, and therefore can be widely used in foams, elastomers, elastic fibers, paints such as water-based polyurethane paints, fibers, pressure-sensitive adhesives, adhesives, flooring materials, sealants, medical materials, artificial leather, synthetic leather, coating agents, active energy radiation-curable polymer compositions, and the like.

[0136] [Action and effect] Since the diol-containing composition of the present invention contains an amine, coloration of the obtained polycarbonate diol is suppressed and the color tone is good. Although the reason for this is not clear, it is presumed as follows. According to the studies of the present inventors, it has been found that the diol-containing composition, which is the raw material for the polycarbonate diol of the present invention, may contain aldehyde for the reasons mentioned above, and that amines suppress the generation of aldehyde during the production or storage of the diol-containing composition, thereby suppressing an increase in aldehyde in the diol-containing composition. When such a diol-containing composition is used to produce a polycarbonate diol, or when the obtained polycarbonate diol is stored for a long period of time, the aldehyde generates radicals by heating or oxidation, and aldehyde groups, carboxylic acids, double bonds, etc. are generated in the polycarbonate diol. As a result, a conjugated structure is formed in the structure of the polycarbonate diol, which is presumed to cause coloration of the polycarbonate diol. The amine-derived structural unit (2) contained in the polycarbonate diol suppresses the generation of aldehyde radicals, which is why coloration of the resulting polycarbonate diol can be suppressed, and furthermore, it is presumed that by setting the content of the amine or the structural unit (2) to a predetermined value or less, coloration of the polycarbonate diol due to the excessive presence of the amine or the structural unit (2) itself can be suppressed. [Example]

[0137] The present invention will be described in more detail below with reference to examples and comparative examples. The present invention is not limited to these examples as long as the gist of the invention is not exceeded.

[0138] [Evaluation method] In the following, the evaluation methods for each physical property value are as follows.

[0139] [Evaluation Method: Diol-Containing Composition] <Amine content> The amine content in 1,6-hexanediol used as the diol-containing composition in the examples and comparative examples was measured according to the following procedure. In this evaluation, the definition of "amine content" is as described above.

[0140] In the following Examples 1 and 2 and Comparative Examples 1 to 3, 6-amino-1-hexanol, a primary amine, is added as the amine of the present invention. However, even when the diol-containing composition contains a secondary amine such as dihexylamine used in Examples 3, 4, and 6, or a tertiary amine such as trihexylamine used in Example 5, a person skilled in the art can measure the contents of the secondary and tertiary amines contained in the diol-containing composition by combining the following procedure with well-known techniques.

[0141] 1,6-Hexanediol was dissolved in CDCl3, and the measurement was performed using a nuclear magnetic resonance spectrometer (400 MHz, manufactured by JEOL Ltd., model name: ECZ400S) at a measurement temperature of 30°C and 32 accumulations. 1 H-NMR measurements were carried out.

[0142] obtained 1 From the H-NMR measurement results, the amine content (unit: mass%) in the diol-containing composition relative to 100% by total mass of the diol-containing composition was calculated using the integral value a of the peak of the 2H proton of the α-methylene group at the amine terminal present at δ 3.15 to 3.05 ppm, the integral value b of the peak of the 2H proton of the α-methylene group at the hydroxyl group terminal present at δ 3.69 to 3.50 ppm, and the following formula:

[0143]

number

[0144] In the above formula, "M(amine)" represents the molecular weight of the primary amine 6-amino-1-hexanol (=117), and "M(16HD)" represents the molecular weight of 1,6-hexanediol (=118).

[0145] The calculated amine content (unit: mass %) and the following formula were used to calculate the amine content (unit: mass ppm) converted to nitrogen atoms.

[0146]

number

[0147] Similarly, the content ratio of amine in the diol-containing composition used in the examples, which contains 1,6-hexanediol, 1,4-butanediol, and neopentyl glycol as diols, is 1 From the H-NMR measurement results, the nitrogen atom content (unit: ppm by mass) of the amine in the diol-containing composition was calculated based on the integral of the peak of the α-methylene group proton in the amine (6-amino-1-hexanol), the integral of the peak of the α-methylene group proton in each diol, the molecular weight of each diol, and a formula similar to the above formula. In this calculation, "M(14BG)" was used as the molecular weight of 1,4-butanediol (= 90), and "M(NPG)" was used as the molecular weight of neopentyl glycol (= 104).

[0148] Similarly, the content ratio of the amine in the diol-containing composition used in the examples, which contains dihexylamine or trihexylamine as the amine, is 1 From the H-NMR measurement results, the nitrogen atom content (unit: ppm by mass) of the amine in the diol-containing composition was calculated based on the integral of the peak of the α-methylene group proton in the amine, the integral of the peak of the α-methylene group proton in each diol, the molecular weight of each diol, and a formula similar to the above formula. In this calculation, the molecular weight of dihexylamine (= 185) or the molecular weight of trihexylamine (= 269) was used as "M (amine)".

[0149] <Aldehyde content> The aldehyde content in 1,6-hexanediol used as the diol-containing composition in the examples and comparative examples was measured according to the following procedure. Note that the definitions of "aldehyde" and "aldehyde content" in this evaluation are as described above in the explanation of aldehyde.

[0150] 1,6-Hexanediol was dissolved in CDCl3, and the measurement was performed using a nuclear magnetic resonance spectrometer (400 MHz, manufactured by JEOL Ltd., model name: ECZ400S) at a measurement temperature of 30°C and 32 accumulations. 1 H-NMR measurements were carried out.

[0151] The aldehyde content (unit: mass ppm) relative to 100% of the total mass of the diol-containing composition containing 1,6-hexanediol was calculated using the integral values ​​a and b used when calculating the amine content, the integral value c of the peak of the 1H proton of the aldehyde group in the aldehyde present at δ 9.80 to 9.75 ppm, and the following formula:

[0152]

number

[0153] In the above formula, "M(amine)" represents the molecular weight of the primary amine 6-amino-1-hexanol (=117), "M(aldehyde)" represents the molecular weight of the aldehyde (6-hydroxyhexanal) (=116), and "M(16HD)" represents the molecular weight of 1,6-hexanediol (=118).

[0154] Similarly, the content ratio of aldehyde in the diol-containing composition used in the examples, which contains 1,6-hexanediol and 1,4-butanediol or neopentyl glycol as diols, is as follows: 1 From the H-NMR measurement results, the integral value of the α-methylene group proton peak in the amine (6-amino-1-hexanol), the integral value of the aldehyde group proton peak in the aldehyde (6-hydroxyhexanal), the integral value of the α-methylene group proton peak in each diol, the molecular weight of each diol, and a formula similar to the above formula were used to calculate the aldehyde content (unit: ppm by mass) in the diol-containing composition relative to 100% by total mass of the diol-containing composition. In this case, "M(14BG)" was used as the molecular weight of 1,4-butanediol (= 90), and "M(NPG)" was used as the molecular weight of neopentyl glycol (= 104).

[0155] Similarly, the content of aldehyde in the diol-containing composition containing dihexylamine or trihexylamine as the amine used in the examples was 1 From the H-NMR measurement results, the integral value of the peak of the proton of the α-methylene group in the amine, the integral value of the peak of the proton of the aldehyde group in the aldehyde (6-hydroxyhexanal), the integral value of the peak of the proton of the α-methylene group in each diol, the molecular weight of each diol, and a formula similar to the above formula were used to calculate the content ratio of the aldehyde in the diol-containing composition (unit: mass ppm) relative to 100% of the total mass of the diol-containing composition. In this case, the molecular weight of dihexylamine (= 185) or the molecular weight of trihexylamine (= 269) was used as "M (amine)".

[0156] [Evaluation method: Polycarbonate diol] <Color tone> As an index of coloration suppression, i.e., color tone, of the polycarbonate diol obtained in Examples and Comparative Examples, the APHA value of the polycarbonate diol sample was measured by comparing it with a standard solution placed in a colorimetric tube in accordance with JIS K0071-1 (1998). The reagent used was a chromaticity standard solution 1000 degrees (1 mg Pt / mL) (manufactured by Kishida Chemical Co., Ltd.).

[0157] <Number average molecular weight of polycarbonate diol> The polycarbonate diols obtained in the examples and comparative examples were dissolved in CDCl3, and measured using a nuclear magnetic resonance spectrometer (400 MHz, manufactured by JEOL Ltd., model name: ECZ400S) at a measurement temperature of 30°C and an accumulation number of 64. 1 H-NMR measurements were carried out. 1 From the H-NMR measurement results, two peaks observed at the following signal positions were identified, and integral values ​​A and B of each peak were obtained. The integral value of the 2H proton peak of the methylene group next to the hydroxyl group terminal in the polycarbonate diol present at δ 3.69-3.50 ppm = A The integral value of the 4H proton peak of the γ methylene group of the structure derived from 1,6-hexanediol in polycarbonate diol present at δ 1.49-1.30 ppm = B

[0158] The integral value of the peak of the structural unit of the polycarbonate diol terminal derived from 1,6-hexanediol (hereinafter abbreviated as "16HD") is referred to as "16HD". m The integral value of the peak of the structural unit derived from 16HD in the polycarbonate diol other than the polycarbonate diol terminal was defined as "16HD o " Taking into account the number of protons in each region, the integral value per proton was calculated using the following formula: 16HD m =A÷2 16HD o =(B-16HD m ×4)÷4

[0159] Next, the number average molecular weight of the polycarbonate diol was calculated using the following formula from the ratio (number of diol units) of the total amount of structural units derived from 16HD to the total amount of structural units at the terminals of the polycarbonate diol derived from 16HD and the molecular weight of the structural units of the polycarbonate diol.

[0160]

number

[0161] In the above formula, M(16HD o ) refers to the molecular weight of the structural unit derived from 16HD in the polycarbonate diol other than the polycarbonate diol terminal (=116), and M (carbonyl group) refers to the molecular weight of the carbonyl group (=28).

[0162] Similarly, the number average molecular weight of the polycarbonate diols used in the examples, which contain 1,6-hexanediol, 1,4-butanediol (hereinafter abbreviated as "14BG"), and neopentyl glycol (hereinafter abbreviated as "NPG") as diols, is1 From the H-NMR measurement results, the number average molecular weight of the polycarbonate diol was calculated using the integral value of the peak derived from the structural unit at the polycarbonate diol terminal, the integral value of the peak derived from the structural unit in the polycarbonate diol other than the polycarbonate diol terminal, and an equation based on the above equation.

[0163] At that time, M(14BG o ) is the molecular weight (=88) of the structural unit derived from 14BG in the polycarbonate diol other than the polycarbonate diol terminal, and similarly, M(NPG o ) was used as the molecular weight (=102) of the structural unit derived from NPG.

[0164] [Raw materials used] The abbreviations for the raw materials used in the examples and comparative examples are as follows: 16HD: 1,6-Hexanediol (BASF Japan Ltd.) 14BG: 1,4-butanediol (Mitsubishi Chemical Corporation) NPG: Neopentyl glycol (Mitsubishi Gas Chemical Company, Inc.) 6-Amino-1-hexanol (Tokyo Chemical Industry Co., Ltd.) Dihexylamine (Tokyo Chemical Industry Co., Ltd.) Trihexylamine (Tokyo Chemical Industry Co., Ltd.) DPC: Diphenyl carbonate (Mitsubishi Chemical Corporation) Mg catalyst: Magnesium acetate tetrahydrate (Fujifilm Wako Pure Chemical Industries, Ltd.)

[0165] [Comparative Example 1] 100 g of 16HD was heated in air at 130°C for 3 hours to oxidize a portion of the 16HD to 6-hydroxyhexanal, yielding HD(1). The amine and aldehyde contents in HD(1) are shown in Table 1.

[0166] A 0.5 L separable glass flask equipped with a stirrer, a distillate trap, and a pressure regulator was charged with 96 g of HD (1) as a diol-containing composition, 154 g of DPC as a carbonate compound, and 0.4 mL of an aqueous Mg catalyst solution (concentration: 8.4 g / L magnesium acetate tetrahydrate) as a transesterification catalyst. The flask was then purged with a nitrogen atmosphere, and the contents were heated to 160 ° C. while stirring, dissolving the contents. The pressure in the flask at this time was 101 kPa. The pressure in the flask was then gradually reduced from 101 kPa to 24 kPa over 2 minutes, and the reaction was allowed to proceed for 90 minutes while removing the produced phenol from the reaction system. Next, the pressure in the flask was gradually reduced to 9.3 kPa over 90 minutes, and then further reduced to 0.7 kPa over 30 minutes to continue the reaction. After that, the temperature of the contents was raised to 170°C, and the reaction was continued for another 90 minutes while removing phenol and unreacted diol from the reaction system. After that, the temperature of the contents was allowed to cool to room temperature to obtain 114 g of polycarbonate diol. The evaluation results of the obtained polycarbonate diol (PCD) are shown in Table 1.

[0167] [Example 1] 0.01 g of 6-amino-1-hexanol (amine) was added to 100 g of 16HD, and the mixture was heated in air at 130°C for 3 hours to oxidize part of the 16HD to 6-hydroxyhexanal, yielding HD(2). The amine and aldehyde contents in HD(2) are shown in Table 1.

[0168] Polycarbonate diol was synthesized by carrying out the reaction under the same conditions as in Comparative Example 1, except that HD (2) was used instead of HD (1) used in Comparative Example 1. The evaluation results of the obtained polycarbonate diol (PCD) are shown in Table 1.

[0169] Comparative Example 2 150 g of 16HD was heat-treated in air at 130°C for 3 hours, and a portion of the 16HD was oxidized to 6-hydroxyhexanal to obtain a 16HD composition, designated HD(3). A diol-containing composition, designated HD(3-1), was obtained by mixing HD(3) and 14BG in the amounts shown in Table 1. The amine content and aldehyde content in HD(3-1) are shown in Table 1.

[0170] Polycarbonate diol was synthesized by carrying out the reaction under the same conditions as in Comparative Example 1, except that HD(3-1) was used instead of HD(1) used in Comparative Example 1, and the blending amounts of the 16HD composition and carbonate compound were as shown in Table 1. The evaluation results of the obtained polycarbonate diol (PCD) are shown in Table 1.

[0171] [Examples 2 to 5] The amines shown in Table 1 were added to 150 g of 16HD in the amounts shown in Table 1, and the mixture was heated in air at 130°C for 3 hours to oxidize a portion of the 16HD to 6-hydroxyhexanal, yielding 16HD compositions designated HD(4) to HD(7). HD(4) to HD(7) and 14BG were mixed in the amounts listed in Table 1 to obtain diol-containing compositions designated HD(4-1) to HD(7-1), respectively. The amine and aldehyde contents in HD(4-1) to HD(7-1) are shown in Table 1.

[0172] Polycarbonate diols were synthesized by carrying out the reaction under the same conditions as in Comparative Example 1, except that HD(4-1) to HD(7-1) were used instead of HD(1) used in Comparative Example 1, and the blending amounts of the 16HD composition and carbonate compound were as shown in Table 1. The evaluation results of the obtained polycarbonate diols (PCD) are shown in Table 1.

[0173] [Example 6] 0.02 g of dihexylamine as an amine was added to 150 g of 16HD, and the mixture was heated in air at 130°C for 3 hours to oxidize a portion of the 16HD to 6-hydroxyhexanal, yielding a 16HD composition designated HD(8). HD(8) and NPG were mixed in the amounts listed in Table 1 to obtain a diol-containing composition designated HD(8-1). The amine and aldehyde contents in HD(8-1) are shown in Table 1.

[0174] Polycarbonate diol was synthesized by carrying out the reaction under the same conditions as in Comparative Example 1, except that HD(8-1) was used instead of HD(1) used in Comparative Example 1, and the blending amounts of the 16HD composition and the carbonate compound were as shown in Table 1. The evaluation results of the obtained polycarbonate diol (PCD) are shown in Table 1.

[0175] Comparative Example 3 HD (9) was obtained in the same manner as in Example 1, except that 0.10 g of 6-amino-1-hexanol was added as the amine to 100 g of 16HD. The amine and aldehyde contents in HD (9) are shown in Table 1. Polycarbonate diol was synthesized by carrying out the reaction under the same conditions as in Comparative Example 1, except that HD (9) was used instead of HD (1) used in Comparative Example 1. The evaluation results of the obtained polycarbonate diol (PCD) are shown in Table 1.

[0176] FIG. 1 shows the relationship between the amine content (in terms of nitrogen atoms) in the diol-containing compositions in the above Examples 1 to 6 and Comparative Examples 1 to 3 and the color tone (APHA) of the resulting polycarbonate diols (PCD). FIG. 2 shows the relationship between the aldehyde content in the diol-containing composition and the color tone (APHA) of the resulting polycarbonate diol (PCD). Furthermore, the relationship between the amine content (in terms of nitrogen atoms) and the aldehyde content in the diol-containing composition is shown in FIG.

[0177] [Table 1]

[0178] Comparison of Examples 1 to 6 with Comparative Examples 1 to 3 reveals that the diol-containing composition of the present invention containing an amine had a reduced aldehyde content in the diol-containing composition after heat treatment. In Examples 1 to 6, the polycarbonate diols produced using the diol-containing compositions of the present invention were inhibited from coloring and had good color tone (APHA). The polycarbonate diols produced in Comparative Examples 1 and 2 had poor color tone (APHA) of the polycarbonate diols because no amine was contained in the diol-containing composition. The polycarbonate diol produced in Comparative Example 3 had an amine content in the diol-containing composition exceeding 100 ppm by mass in terms of nitrogen atoms relative to the total mass of the diol-containing composition, and therefore the color tone (APHA) of the polycarbonate diol was poor. Furthermore, from FIG. 1, it was confirmed that, as long as the amine content (amount produced) of the diol-containing composition is 100 mass ppm or less in terms of nitrogen atoms relative to the total mass of the diol-containing composition, the higher the amine content, the more inhibited is the coloration of the obtained polycarbonate diol, and the better the color tone (APHA) tends to be. From FIG. 2, it was confirmed that the greater the content (amount produced) of aldehyde in the diol-containing composition, the more colored the resulting polycarbonate diol became and the poorer the color tone (APHA) tended to be. From FIG. 3, it was confirmed that the higher the amine content in the diol-containing composition, the lower the aldehyde content in the diol-containing composition, and the more the generation of aldehyde tends to be suppressed.

Claims

1. A diol-containing composition used in a process for producing a polycarbonate diol, A diol-containing composition comprising an amine and a diol (1) represented by the following general formula (I): The diol-containing composition, wherein the content of the amine contained in the diol-containing composition is 0.1 ppm by mass or more and 100 ppm by mass or less in terms of nitrogen atoms, relative to the total mass of the diol-containing composition. 【Chemical 1】 (In the above general formula (I), R represents a hydrocarbon group having 2 to 20 carbon atoms, which may have a substituent or a heteroatom.)

2. The diol-containing composition of claim 1 , wherein the diol-containing composition further comprises an aldehyde.

3. The diol-containing composition according to claim 1 , wherein the diol (1) comprises a diol represented by the following general formula (Ia): 【Chemistry 2】 (In the above general formula (1), n ​​is an integer of 2 to 20.)

4. The diol-containing composition according to claim 3, wherein the diol (1) comprises at least one selected from 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol.

5. 2. The diol-containing composition according to claim 1, wherein the amine contains one or more amino groups and one or more functional groups, and the functional groups include at least one selected from the group consisting of a hydroxyl group, a carboxyl group, a formyl group, and an amino group.

6. The diol-containing composition according to claim 1 , wherein the amine comprises an alkylamine having an amino group in the molecule and having no functional groups other than the amino group.

7. The diol-containing composition according to claim 1 , wherein the amine comprises an amine represented by the following general formula (II): 【Chemistry 3】 (In the above general formula (II), R １ represents an alkyl group having 2 to 20 carbon atoms and r substituents X, which may have substituents other than X. X represents a hydroxyl group, a carboxyl group, a formyl group, or an amino group. r is an integer of 1 to 6. R ２ represents an alkyl group having 1 to 20 carbon atoms, which may have a substituent, or a hydrogen atom. ２ may be the same or different.)

8. The diol-containing composition according to claim 7, wherein the amine comprises at least one selected from 6-amino-1-hexanol, 6-methylamino-1-hexanol, 6-ethylamino-1-hexanol, 6-dimethylamino-1-hexanol, and 6-diethylamino-1-hexanol.

9. The diol-containing composition according to claim 1 , wherein the diol (1) comprises a biomass-derived diol.

10. A polycarbonate diol obtained from the diol-containing composition according to any one of claims 1 to 9 and a carbonate compound.

11. A polyurethane made from the polycarbonate diol according to claim 10 and an isocyanate compound.

Images