1,6-hexanediol composition and polymer using 1,6-hexanediol composition as reaction raw material

Abstract

Provided are: a 1,6-hexanediol composition capable of improving the quality of a polymer (polycarbonate polyol, polyurethane, or the like) using a 1,6-hexanediol composition as a reaction raw material; and a polymer (polycarbonate polyol, polyurethane, or the like) using the 1,6-hexanediol composition as a reaction raw material.　The 1,6-hexanediol composition contains at least 1,6-hexanediol, wherein the composition has an acid value in the range of 0.001-0.5 mgKOH / g.

Description

1,6-Hexanediol composition and polymer using 1,6-hexanediol composition as a reaction raw material

[0001] The present invention relates to a 1,6-hexanediol composition and a polymer produced using the 1,6-hexanediol composition as a reaction raw material.

[0002] 1,6-hexanediol (1,6-HDO) compositions are useful intermediate products for the production of polymers such as polyesters and polyurethanes. Polymers such as polyesters and polyurethanes obtained by reacting 1,6-hexanediol compositions are widely used in artificial leather and the like. There is a constant demand for improvements in the quality of these polymers, such as polyesters and polyurethanes. Meanwhile, methods for obtaining biomass-derived 1,6-hexanediol (1,6-HDO) compositions from biomass resources using microorganisms such as Corynebacterium sp. and Escherichia coli are known (see, for example, Patent Documents 1 and 2).

[0003] JP 2020-114227 A JP 2016-533162 B

[0004] When microbial fermentation is used, as in Patent Document 1, the hydrogen ion concentration (pH) of the fermentation broth is typically adjusted using a neutralizing agent to efficiently promote fermentation. The neutralizing agent and culture solution contain many alkali metal elements and alkaline earth metals. Furthermore, the inventors' studies have revealed that the biomass-derived 1,6-hexanediol obtained by the production method described in Patent Document 1 contains organic acids such as acetic acid and succinic acid as impurities. These impurities are considered unnecessary and are removed by purification methods as far as cost allows. However, the inventors' studies have revealed that organic acids and alkali metal elements are not unnecessary components to be present with 1,6-hexanediol, and that their coexistence in specific amounts is actually necessary to achieve improved quality of polymers such as polyurethane. Therefore, an object of the present invention is to provide a 1,6-hexanediol composition that can improve the quality of polymers (e.g., polycarbonate polyols and polyurethanes) made using the 1,6-hexanediol composition as a reaction raw material, and to provide polymers (e.g., polycarbonate polyols and polyurethanes) made using the 1,6-hexanediol composition as a reaction raw material.

[0005] The present inventors have discovered that polymers such as polycarbonate polyols and polyurethanes obtained by reacting a 1,6-hexanediol composition having a specific acid value exhibit good quality, and have completed the present invention. That is, the present invention provides the following:

[0006] (1) A 1,6-hexanediol composition containing at least 1,6-hexanediol, wherein the acid value of the composition is in the range of 0.001 to 0.5 mgKOH / g. (2) The 1,6-hexanediol composition according to claim 1, further containing 6-hydroxyhexanal, wherein the content of the 6-hydroxyhexanal is 300 ppm by mass or less. (3) The 1,6-hexanediol composition according to (1) or (2), further containing an alkali metal element, wherein the content of the alkali metal element is in the range of 0.1 to 100 ppm by mass. (4) The 1,6-hexanediol composition according to any one of (1) to (3), wherein the 1,6-hexanediol composition is derived from a biomass resource. (5) A polycarbonate polyol, wherein the 1,6-hexanediol composition according to any one of (1) to (4) is used as a reaction raw material. (6) A polyurethane using the polycarbonate polyol according to (5) as a reaction raw material.

[0007] The present invention can provide a 1,6-hexanediol composition that can improve the quality of polymers (polycarbonate polyols, polyurethanes, etc.) produced using the 1,6-hexanediol composition as a reaction raw material, and a polymer (polycarbonate polyols, polyurethanes, etc.) produced using the 1,6-hexanediol composition as a reaction raw material.

[0008] (1,6-Hexanediol Composition) The 1,6-hexanediol composition of the present invention (hereinafter simply referred to as the composition) is a composition containing at least 1,6-hexanediol (1,6-HDO). From the viewpoint of improving the quality of polymers (such as polycarbonate polyols and polyurethanes) produced using the 1,6-hexanediol composition as a reaction raw material, the acid value of the composition is in the range of 0.001 to 0.5 mgKOH / g.

[0009] There are no particular limitations on the manufacturing method for obtaining the composition, as long as the composition has an acid value within the above-mentioned specific range. The composition may be a petroleum-derived composition, for example, a composition obtained by blending commercially available petroleum-derived 1,6-hexanediol with an appropriate compound. Alternatively, the composition may be a bio-derived composition derived from a biomass resource, for example. However, in the present invention, a bio-derived composition is more preferred. The manufacturing method for the bio-derived composition will be described later.

[0010] The composition also contains components other than 1,6-hexanediol. In particular, when the composition is a bio-derived composition, various other components are added to the composition during the process of producing the composition. For example, the composition contains impurities such as 6-hydroxyhexanal or organic acids such as acetic acid and succinic acid. The composition also contains an alkali metal element. 6-hydroxyhexanal, organic acids, and alkali metal elements are not unnecessary components to be present with 1,6-hexanediol, and their coexistence in specific amounts improves the quality of polymers such as polyurethane, as shown in the examples below. Therefore, it is important to include these components in specific amounts.

[0011] As described above, the composition contains an organic acid, and the acid value of the composition varies depending on the type and content of the organic acid. However, from the viewpoint of improving the quality of polymers (such as polycarbonate polyols and polyurethanes) produced using a 1,6-hexanediol composition as a reaction raw material, the acid value of the composition must be in the range of 0.001 to 0.5 mg KOH / g. Furthermore, as described above, the composition may contain 6-hydroxyhexanal, and in this case, the content of 6-hydroxyhexanal is preferably 300 ppm by mass or less. Furthermore, as described above, the composition may contain an alkali metal element, and in this case, the content of the alkali metal element is preferably in the range of 0.1 to 100 ppm by mass.

[0012] <1,6-Hexanediol> The composition of the present invention contains at least 1,6-hexanediol. In the 1,6-hexanediol composition of the present invention, the content of 1,6-hexanediol is preferably 96.00 to 99.99 mass%, more preferably 99.00 to 99.99 mass%, and even more preferably 99.50 to 99.99 mass%. In this specification, the content of 1,6-hexanediol can be measured by gas chromatography-mass spectrometry (GC-MS).

[0013] <1,6-Hexanediol Composition Derived from Biomass Resources> Environmental awareness has grown in recent years, creating a demand for raw materials derived from biomass resources such as plants, rather than petroleum-derived raw materials that contribute to global warming. Biomass resources are reusable organic resources derived from plants and animals. Preferred resources include plant resources such as wood, rice straw, rice husks, rice bran, used rice, corn, sugarcane, cassava, soybeans, soybean pulp, bagasse, vegetable oils, oils and fats, waste paper, and papermaking residues. These biomass resources generally contain nitrogen and many alkali metal and alkaline earth metal elements, such as sodium, potassium, magnesium, and calcium. Methods for obtaining raw materials derived from biomass resources using microorganisms such as Corynebacterium sp. and Escherichia coli have also been disclosed. In the present invention, a 1,6-hexanediol composition derived from a biomass resource, obtained by the production method described in Patent Document 1, for example, can be suitably used. When microbial fermentation is used, the hydrogen ion concentration (pH) of the fermentation liquid is usually adjusted using a neutralizing agent to efficiently promote fermentation. The neutralizing agent and culture liquid contain many alkali metal elements and alkaline earth metals. Furthermore, the 1,6-hexanediol composition derived from biomass resources obtained by the production method described in Patent Document 1 above contains impurities such as organic acids, such as acetic acid and succinic acid. These impurities are removed using various purification methods while taking cost into consideration. However, it is necessary to leave impurities to a degree that satisfies the requirements of the present invention. By combining known purification methods, components other than 1,6-hexanediol are removed so as to leave predetermined amounts of 6-hydroxyhexanal, organic acids, and alkali metal elements in the composition.

[0014] <Acid Value of the 1,6-Hexanediol Composition of the Present Invention> The upper limit of the acid value of the 1,6-hexanediol composition of the present invention is 0.5 mgKOH / g or less, preferably 0.3 mgKOH / g or less, and more preferably 0.1 mgKOH / g or less. The lower limit of the acid value is 0.001 mgKOH / g or more, preferably 0.01 mgKOH / g or more. Any combination of these upper and lower limits can be used. The acid value of the 1,6-hexanediol composition of the present invention is 0.001 to 0.5 mgKOH / g, preferably 0.001 to 0.3 mgKOH / g, and more preferably 0.01 to 0.3 mgKOH / g. When the 1,6-hexanediol composition is used to prepare a polymer (e.g., polycarbonate polyol, polyurethane, etc.), improved performance of the polymer is expected. In this specification, the acid value is a value measured in accordance with JIS K 0070-1992.

[0015] <Organic Acid> As described above, the composition contains an organic acid.As organic acids, for example, acetic acid, succinic acid, propionic acid, adipic acid, valeric acid, pivalic acid, catechol, phenol, glycine, alanine, valine, leucine, isoleucine, serine, cysteine, methionine, aspartic acid, asparagine, glutamic acid, glutamine, arginine, lysine, histidine, phenylalanine, tyrosine, tryptophan, proline, etc.These may be contained alone or in combination of two or more.Among them, it is preferable that acetic acid and succinic acid are contained, and it is more preferable that acetic acid is contained.

[0016] The organic acid content in the 1,6-hexanediol composition of the present invention may be any content that allows the acid value of the composition of the present invention to fall within the above-mentioned range. For example, the upper limit of the organic acid content in the 1,6-hexanediol composition of the present invention is preferably 2,000 ppm by mass or less, more preferably 1,000 ppm by mass or less. The lower limit of the content is preferably 0.001 ppm by mass or more, more preferably 0.01 ppm by mass or more. Any combination of these upper and lower limits can be used. When the 1,6-hexanediol composition of the present invention is derived from a biomass resource, the organic acid content in the 1,6-hexanediol composition is preferably 1 to 2,000 ppm by mass, more preferably 10 to 1,000 ppm by mass, for reasons of economic efficiency in the purification process. Here, the organic acid content refers to the total content when multiple organic acids are contained. The same applies to the contents of other components. Furthermore, the content of organic acid in the 1,6-hexanediol composition generally means the content of free organic acid, but may also include the content of organic acid in the form of a salt. In this specification, the content of organic acid is a value measured by high performance liquid chromatography mass spectrometry (LC / MS).

[0017] <6-Hydroxyhexanal> As described above, the composition of the present invention may contain 6-hydroxyhexanal. 6-Hydroxyhexanal is produced as an intermediate in the metabolic pathway for producing 1,6-hexanediol using biomass resources.

[0018] In the composition, the upper limit of the 6-hydroxyhexanal content is preferably 300 ppm by mass or less, more preferably 150 ppm by mass or less, and even more preferably 100 ppm by mass or less. The lower limit of the content is preferably 10 ppm by mass or more, and more preferably 20 ppm by mass or more. Any combination of these upper and lower limits can be used. In the composition, the 6-hydroxyhexanal content is preferably 10 to 300 ppm by mass, and more preferably 20 to 150 ppm by mass. In this specification, the 6-hydroxyhexanal content is measured by high-performance liquid chromatography mass spectrometry (LC / MS).

[0019] <Alkali Metal Element> The composition of the present invention may contain an alkali metal element. The upper limit of the total content of alkali metal elements relative to the total amount of the composition is preferably 200 ppm by mass or less, more preferably 100 ppm by mass or less, and even more preferably 50 ppm by mass or less. The lower limit of the total content is preferably 0.1 ppm by mass or more, and more preferably 1 ppm by mass or more. Any combination of these upper and lower limits can be used. In the composition, the total content of alkali metal elements is preferably 0.1 to 100 ppm by mass, and more preferably 0.1 to 50 ppm by mass.

[0020] When the alkali metal element is contained at 200 ppm by mass, the APHA color number value in PCD and the storage stability of the NCO-terminated prepolymer do not achieve good results, as shown in Example 10 below, so the alkali metal element content is preferably 100 ppm by mass or less. However, even when the alkali metal element of Example 10 is contained at 200 ppm by mass, when such an NCO-terminated prepolymer is used to produce a polyurethane (PU), the PU sheet can show good results in the evaluation items of tensile strength, elongation at break, and hydrolysis resistance (see the results in Table 1 below).

[0021] The alkali metal element is not particularly limited, and examples thereof include lithium, sodium, potassium, rubidium, and cesium. These elements may be contained alone or in combination of two or more. Among these, sodium and potassium are preferably contained.

[0022] The state of existence of the alkali metal element contained in the composition of the present invention is not particularly limited, and may be an alkali metal element, an alkali metal compound, an alkali metal ion, etc. As a specific example of the alkali metal compound, for example, the above-mentioned alkali metal element is present in the composition of the present invention as an alkali metal salt after reacting with the above-mentioned organic acid.

[0023] In the composition, the upper limit of the total content of alkali metal elements (preferably the total content of either or both of sodium metal element and potassium metal element) is preferably 100 ppm by mass, as described above. The lower limit of the total content is preferably 0.1 ppm by mass or more. In the composition, the total content of alkali metal elements (preferably the total content of either or both of sodium metal element and potassium metal element) is preferably 0.1 to 100 ppm by mass, more preferably 1 to 50 ppm by mass. In this specification, the total content of alkali metal elements is measured by inductively coupled plasma mass spectrometry (ICP-MS).

[0024] <Polycarbonate Polyol> The polycarbonate polyol of the present invention is a polyol obtained by reacting the 1,6-hexanediol composition of the present invention with a carbonate. Thus, the polycarbonate polyol of the present invention has at least structural units derived from the 1,6-hexanediol composition of the present invention and structural units derived from carbonate, and also contains 6-hydroxyhexanal, an organic acid, an alkali metal element, and the like contained in the 1,6-hexanediol composition of the present invention.

[0025] Examples of carbonates that can be used as raw materials for the polycarbonate polyol of the present invention include dialkyl carbonates (dimethyl carbonate, diethyl carbonate, etc.), ethylene carbonate, and diphenyl carbonate. Of these, dialkyl carbonates are preferred, and diethyl carbonate is particularly preferred.

[0026] The polycarbonate polyol of the present invention is particularly preferably a polycarbonate diol. There are no particular limitations on the production method, and it can be synthesized by various known methods, for example, by reacting the 1,6-hexanediol composition of the present invention with a carbonate to cause a transesterification reaction in the presence of a transesterification catalyst.

[0027] The content of structural units derived from the 1,6-hexanediol composition of the present invention in 100% by mass of the polycarbonate polyol of the present invention is preferably 10 to 95% by mass, more preferably 30 to 90% by mass. This tends to more favorably achieve the desired effects. In this specification, the content of each structural unit in the polycarbonate polyol is measured by NMR.

[0028] In the polycarbonate polyol of the present invention, the total content of alkali metal elements (preferably the total content of either or both of sodium metal element and potassium metal element) is preferably 0.05 to 90 mass ppm, more preferably 0.05 to 45 mass ppm, which tends to more suitably achieve the effects of the present invention.

[0029] In the polycarbonate polyol of the present invention, the content of the organic acid, including the amount incorporated into the polycarbonate polyol structure during polycarbonate polyol synthesis (the amount consumed during polycarbonate synthesis), is preferably 0.001 to 1800 ppm by mass, more preferably 1 to 900 ppm by mass, and even more preferably 5 to 450 ppm by mass. This tends to more suitably achieve the effects of the present invention.

[0030] In the polycarbonate polyol of the present invention, the content of 6-hydroxyhexanal, including the amount consumed during the synthesis of the polycarbonate polyol, is preferably 5 to 270 ppm by mass, more preferably 15 to 135 ppm by mass. This tends to more suitably obtain the effects of the present invention.

[0031] As described above, in this specification, the polycarbonate polyol of the present invention containing an acid includes not only an embodiment in which the polycarbonate polyol of the present invention contains a free organic acid, but also an embodiment in which the polycarbonate polyol has a structural unit derived from an organic acid in the polycarbonate polyol skeleton, and therefore the organic acid content includes the content of free organic acid and the content of structural units derived from an organic acid present in the polycarbonate polyol skeleton.

[0032] The number average molecular weight (Mn) of the polycarbonate polyol of the present invention is preferably 300 to 1,000,000, more preferably 500 to 10,000, and particularly preferably 1,000 to 5,000. In this specification, the number average molecular weight (Mn) of the polymer is a value measured by gel permeation chromatography (GPC).

[0033] <Polyurethane> The polyurethane of the present invention is a reaction product obtained by reacting the polycarbonate polyol of the present invention with a polyisocyanate. Furthermore, if necessary, polyols other than the polycarbonate polyol of the present invention, chain extenders, chain terminators, crosslinking agents, etc. may be used in combination as reaction raw materials for the polyurethane of the present invention. Thus, the polyurethane of the present invention has structural units derived from the polyol and structural units derived from the polyisocyanate, and has at least structural units derived from the 1,6-hexanediol composition of the present invention, as well as 6-hydroxyhexanal, organic acids, alkali metal elements, etc., contained in the 1,6-hexanediol composition of the present invention.

[0034] Examples of polyols other than the polycarbonate polyol of the present invention include polyols that do not use the 1,6-hexanediol composition of the present invention as a raw material, such as polycarbonate polyols, polyether polyols, polyester polyols, etc. These polyols may or may not use the 1,6-hexanediol composition as a reaction raw material, and the polyurethane of the present invention may use at least a polyol that uses the 1,6-hexanediol composition as a reaction raw material.

[0035] The polycarbonate polyol of the present invention not using the 1,6-hexanediol composition as a raw material may be a polyol obtained by the reaction of a known glycol with a carbonate. Examples of the glycol include saturated or unsaturated glycols such as diethylene glycol, ethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-pentanediol, octanediol, 1,4-butynediol, dipropylene glycol, tripropylene glycol, polytetramethylene ether glycol, 2-methyl-1,3-propanediol, and 2-ethyl-2-butyl-1,3-propanediol; alicyclic glycols such as 1,4-cyclohexanediglycol and 1,4-cyclohexanedimethanol; and polyhydric alcohols such as trimethylolpropane and pentaerythritol. Examples of carbonates include dialkyl carbonates (dimethyl carbonate, diethyl carbonate, etc.), ethylene carbonate, and diphenyl carbonate.

[0036] The polyether polyol is, for example, a polyether polyol obtained by addition polymerization of alkylene oxide using various glycols as an initiator. Examples of alkylene oxides include ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, etc. Examples of various glycols include the same glycols as those of the polycarbonate diol.

[0037] Examples of polyester polyols include condensation polyester polyols and lactone polyester polyols. Condensation polyester polyols include, for example, low molecular weight polyhydric alcohols (ethylene glycol (EG), diethylene glycol, propylene glycol (PG), dipropylene glycol, (1,3- or 1,4-) butanediol, pentanediol, neopentyl glycol, cyclohexanedimethanol, glycerin, 1,1,1-trimethylolpropane (TMP), 1,2,5-hexanetriol, pentaerythritol, 1,4-cyclohexanedimethanol, and other low molecular weight polyols, saccharides such as sorbitol), and polybasic carboxylic acids (glutaric acid, adipic acid, azelaic acid, fumaric acid, maleic acid, pimelic acid, suberic acid, sebacic acid, phthalic acid, terephthalic acid, isophthalic acid, dimer acid, pyromellitic acid, oligomer acid, hexahydrophthalic anhydride, 1,4-cyclohexanedicarboxylic acid, and the like). The lactone polyester polyol is, for example, a polycaprolactone polyol obtained by ring-opening polymerization of lactone such as ε-caprolactone, α-methyl-ε-caprolactone, or ε-methyl-ε-caprolactone.

[0038] In addition to the above-mentioned polyols, polyacrylic polyols, dimer diols, polybutadiene polyols, hydrogenated polybutadiene polyols, etc. may be used as the polyols. These polyols may be used alone or in combination of two or more.

[0039] At least the polycarbonate polyol of the present invention is used as the polyol, and the content of the polycarbonate polyol made from the composition of the present invention as a raw material in 100% by mass of polyol is preferably 10 to 100% by mass, more preferably 50 to 100% by mass.

[0040] Examples of polyisocyanates include 1,3- and 1,4-phenylene diisocyanate, 1-methyl-2,4-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl-2,5-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl-3,5-phenylene diisocyanate, 1-ethyl-2,4-phenylene diisocyanate, 1-isopropyl-2,4 -phenylene diisocyanate, 1,3-dimethyl-2,4-phenylene diisocyanate, 1,3-dimethyl-4,6-phenylene diisocyanate, 1,4-dimethyl-2,5-phenylene diisocyanate, diethylbenzene diisocyanate, diisopropylbenzene diisocyanate, 1-methyl-3,5-diethylbenzene diisocyanate, 3-methyl-1,5-diethylbenzene-2,4-diisocyanate, 1,3,5- Triethylbenzene-2,4-diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, 1-methyl-naphthalene-1,5-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-2,7-diisocyanate, 1,1-dinaphthyl-2,2'-diisocyanate, biphenyl-2,4'-diisocyanate, biphenyl-4,4'-diisocyanate, 3,3'-dimethylbiisocyanate Aromatic polyisocyanates such as phenyl-4,4'-diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, diphenylmethane-2,4-diisocyanate, and toluene diisocyanate; aliphatic polyisocyanates such as tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate, and trimethylhexamethylene diisocyanate;Alicyclic polyisocyanates such as 1,3-cyclopentylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, 1,3-di(isocyanatomethyl)cyclohexane, 1,4-di(isocyanatomethyl)cyclohexane, lysine diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, 2,2'-dicyclohexylmethane diisocyanate, and 3,3'-dimethyl-4,4'-dicyclohexylmethane diisocyanate can be used. These polyisocyanates can also be derived from biomass resources. These may be used alone or in combination of two or more. Among these, aromatic polyisocyanates are preferred, with 4,4'-diphenylmethane diisocyanate and toluene diisocyanate being more preferred. ;

[0041] Examples of chain extenders include aliphatic polyol compounds such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, sucrose, methylene glycol, glycerin, sorbitol, and neopentyl glycol; and aromatic polyol compounds such as bisphenol A, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfone, hydrogenated bisphenol A, and hydroquinone. Examples of suitable chain extenders include: amine compounds such as ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2-methylpiperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, 3,3'-dimethyl-4,4'-dicyclohexylmethanediamine, 1,2-cyclohexanediamine, 1,4-cyclohexanediamine, aminoethylethanolamine, hydrazine, diethylenetriamine, triethylenetetramine, isophoronediamine, and 4,4'-methylenebis(2-chloroaniline). These chain extenders may also be derived from biomass resources. These chain extenders may be used alone or in combination of two or more. Of these, neopentyl glycol, 1,4-butanediol (1,4-butylene glycol), trimethylolpropane, isophoronediamine, and 4,4'-methylenebis(2-chloroaniline) are more preferred.

[0042] For the purpose of controlling the molecular weight of the resulting polyurethane, a chain terminator having one active hydrogen group can also be used as needed. Examples of these chain terminators include aliphatic monohydroxy compounds having a hydroxyl group, such as methanol, ethanol, propanol, butanol, and hexanol, and aliphatic monoamines having an amino group, such as morpholine, diethylamine, dibutylamine, monoethanolamine, and diethanolamine. These may be used alone or in combination of two or more.

[0043] For the purpose of increasing the heat resistance and strength of the resulting polyurethane, a crosslinking agent having three or more active hydrogen groups or isocyanate groups can be used as needed.

[0044] The polyurethane of the present invention can be obtained by a known polyurethane manufacturing method. Specific examples include a manufacturing method in which the polyol, the polyisocyanate, and the chain extender are charged and reacted, and a method in which the polyol and the polyisocyanate are reacted to synthesize a prepolymer, and then the prepolymer is reacted with the chain extender. These reactions are preferably carried out at a temperature of 50 to 100°C for 3 to 10 hours. The reaction may also be carried out in an organic solvent.

[0045] Examples of organic solvents that can be used include ketone solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, methyl ethyl ketone, methyl-n-propyl ketone, acetone, and methyl isobutyl ketone; ester solvents such as methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, isopropyl acetate, isobutyl acetate, isobutyl acetate, and sec-butyl acetate; and alcohol solvents such as methanol, ethanol, isopropyl alcohol, and butanol. These organic solvents may also be derived from biomass resources. These organic solvents may be used alone or in combination of two or more.

[0046] The polyurethane is made from the polycarbonate polyol of the present invention as a raw material, and the content of structural units derived from the polycarbonate polyol of the present invention in 100% by mass of the polyurethane is preferably 10 to 90% by mass, and more preferably 20 to 90% by mass. This tends to more favorably achieve the effects of the present invention. Furthermore, the content of structural units derived from the 1,6-hexanediol composition of the present invention in 100% by mass of the polyurethane of the present invention is preferably 1 to 63% by mass, and more preferably 2 to 63% by mass. This tends to more favorably achieve the effects of the present invention. In this specification, the content of each structural unit in the polyurethane is measured by NMR.

[0047] In the polyurethane of the present invention, the total content of alkali metal elements (preferably the total content of either or both of sodium metal element and potassium metal element) is preferably 0.01 to 75 mass ppm, more preferably 0.01 to 36 mass ppm, which tends to more suitably achieve the effects of the present invention.

[0048] In the polyurethane of the present invention, the content of the organic acid, including the amount consumed during polycarbonate polyol synthesis and the urethane reaction, is preferably 0.5 to 1500 ppm by mass, more preferably 0.5 to 750 ppm by mass, and even more preferably 3 to 360 ppm by mass. This tends to more suitably achieve the effects of the present invention.

[0049] In the polyurethane of the present invention, the content of 6-hydroxyhexanal, including the amount consumed during polycarbonate polyol synthesis and the urethane reaction, is preferably 5 to 240 ppm by mass, and more preferably 10 to 110 ppm by mass, which tends to more suitably achieve the effects of the present invention.

[0050] The number average molecular weight (Mn) of the polyurethane of the present invention is preferably 5,000 to 1,000,000, and more preferably 10,000 to 500,000. This tends to more favorably achieve the effects of the present invention. In this specification, the number average molecular weight (Mn) of the polyurethane is a value measured by gel permeation chromatography (GPC).

[0051] <<Preferred Embodiment of the Method for Producing Polyurethane Using a 1,6-Hexanediol Composition as a Reaction Raw Material>> For example, polyurethane can be produced through the following steps (i) to (iii). Step (i): The 1,6-hexanediol composition of the present invention is reacted with diethyl carbonate to obtain polycarbonate diol (PCD). Step (ii): The polycarbonate diol (PCD) obtained in step (i) above is reacted with 4,4'-diphenylmethane diisocyanate (MDI) to obtain an isocyanate (NCO)-terminated prepolymer. Step (iii): The isocyanate (NCO)-terminated prepolymer obtained in step (ii) above is mixed with 1,4-butylene glycol (1,4BG) / trimethylolpropane (TMP) as a crosslinking agent and reacted to obtain a polyurethane elastomer (PU sheet).

[0052] In each of steps (i) to (iii) in the above preferred embodiment, each polymer is obtained in a stepwise manner: PCD → NCO-terminated prepolymer → PU sheet. In each polymer, for example, the alkali metal element remains in the form of a salt with an organic acid. The organic acid that does not form a salt with the alkali metal element reacts with 1,6-HDO to form an ester, which is then incorporated into the polymer. 6-Hydroxyhexanal is incorporated into the polymer as an end-capping structure during PCD synthesis. That is, in the following examples, the physical properties of polymers containing alkali metal salts, organic acids (carboxylic acids), and 6-hydroxyhexanal are evaluated.

[0053] For example, the polycarbonate diol (PCD) obtained in step (i) preferably has a color number APHA value of less than 50, more preferably not more than 20. The color number APHA value can be measured in accordance with JIS K0071-2017 using, for example, a petroleum product color tester, Model OME2000, manufactured by Nippon Denshoku Industries Co., Ltd.

[0054] Furthermore, for example, the storage stability (viscosity change rate) of the isocyanate (NCO)-terminated prepolymer obtained in step (ii) is preferably less than 4, and more preferably less than 3. Furthermore, for example, the storage stability (viscosity change rate) of the NCO-terminated prepolymer is more preferably 2 or more and less than 3, and even more preferably 1 or more and less than 2. The viscosity change rate can be determined as follows. The isocyanate (NCO)-terminated prepolymer is stored at 100°C for one week, and the 75°C viscosity before and after the test is measured, and the viscosity change rate is determined from the following formula (t): Viscosity change rate = viscosity after test / viscosity before test (t)

[0055] For example, the polyurethane elastomer obtained in step (iii) preferably has a tensile strength of 25 MPa or more, more preferably 30 MPa or more. The elongation at break of the polyurethane elastomer is preferably 300% or more, more preferably 320% or more. The tensile strength and elongation at break can be determined as follows. A polyurethane (PU) sheet is measured in accordance with JIS K7312 using a No. 3 test piece with a grip distance of 60 mm, a gauge length of 20 mm, a head speed of 500 mm / min, and a measurement temperature of 23°C, to determine the tensile strength and elongation at break (elongation at break). An Autograph AGX-V manufactured by Shimadzu Corporation can be used as the measuring instrument.

[0056] Furthermore, the hydrolysis resistance (strength retention) of the polyurethane elastomer is preferably 70% or more, and more preferably 80% or more. The hydrolysis resistance (strength retention) value can be determined as follows: A size 3 tensile test piece of a polyurethane (PU) sheet is immersed in warm water at 95°C for one week, and the tensile strength before and after the test is determined in accordance with JIS K7312. The strength retention (%) is calculated using the following formula (u): Strength retention % = Tensile strength after warm water immersion / Tensile strength before warm water immersion × 100 (u)

[0057] The polymer of the present invention can be used in a wide range of applications, including artificial leather, synthetic leather, shoes, thermoplastic resins, foamed resins, thermosetting resins, paints, laminating adhesives, elastic fibers, urethane raw materials, automobile parts, sporting goods, vibration insulating materials, vibration damping materials, fiber treatment agents, and binders.

[0058] The polyurethane of the present invention can be used in a wide range of applications, including, for example, the surface layer, intermediate layer, foam layer, and adhesive layer of artificial leather and synthetic leather; various coating agents such as paints, metal surface treatment agents, and film primers; binders for inkjet printers, inks, textile printing, and glass fiber sizing agents; adhesives for shoes, thermoplastic resins, foam resins, thermosetting resins, and laminating adhesives; vibration-proofing materials, vibration-damping materials, automobile parts, sporting goods, and fiber treatment agents.

[0059] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the examples, "parts", "%", and the like are based on mass unless otherwise specified.

[0060] (Preparation of Genetically Modified Escherichia coli) Recombinant Escherichia coli for preparing 1,6-hexanediol was prepared with reference to the method for producing recombinant Escherichia coli described in JP-A-2022-530467.

[0061] (Cultivation reaction and membrane treatment of 1,6-hexanediol composition) Genetically modified Escherichia coli (Escherichia coli) was inoculated into an autoclave-sterilized medium (carbon source: glucose, glycerin; nitrogen source: enzyme extract; inorganic salts: potassium phosphate, potassium hydroxide, vitamin B12; antibiotics: carbenicillin, kanamycin, chloramphenicol; pH: 7.0; among the above components, glucose and glycerin were biomass-derived raw materials) and cultured under aerobic conditions at 30°C for 2 to 3 hours. Thereafter, when the optical density at 600 nm of the Escherichia coli reached 0.3 to 0.6, isopropyl-β-thiogalactopyranoside and iron(II) sulfate were added to final concentrations of 0.5 mM and 10 μM, respectively, and the culture was continued for an additional 3 hours at 30°C to express the enzymes of the 1,6-hexanediol pathway. After expression, an appropriate amount of carbon source (glucose, glycerin) was added, and the culture vessel was placed under a nitrogen atmosphere to create anaerobic conditions. Culture was carried out under these conditions at 30°C for 48 hours to produce 1,6-hexanediol. The culture solution was centrifuged at 4°C for 20 minutes, and the supernatant was recovered and then filtered using a membrane filter with an appropriate pore size of 0.2 to 0.4 μm, yielding a 1,6-hexanediol composition as the filtrate.

[0062] (Purification of 1,6-hexanediol composition) <Step (a): Ion exchange to remove cations> Cations contained in the 1,6-hexanediol composition were removed. In step (a), cation exchange was performed batchwise. The temperature for contact with the cation exchange resin was set to 40°C, and DIAION SK1BH manufactured by Mitsubishi Chemical Corporation was added as a cation exchange resin to the 1,6-hexanediol composition, followed by stirring for 3 hours. After stirring, the mixture was filtered, and 1,6-hexanediol composition A was obtained as a filtrate.

[0063] <Step (b): Ion exchange to remove anions> Anions contained in 1,6-hexanediol composition A were removed. In step (b), anion exchange was performed batchwise. The temperature for contact with the anion exchange resin was set to 40°C, and DIAION SA10AOH manufactured by Mitsubishi Chemical Corporation was added as an anion exchange resin to the 1,6-hexanediol composition, followed by stirring for 3 hours. After stirring, the mixture was filtered, and 1,6-hexanediol composition B was obtained as a filtrate.

[0064] <Step (c): Step of Removing Water> Water contained in 1,6-hexanediol composition B was removed. A thin-film distillation apparatus was used as the apparatus for step (c). The jacket temperature was set to 70°C, and the 1,6-hexanediol-containing composition was continuously introduced, and water was distilled off from the top. Simultaneously with the distillation of water, dehydrated 1,6-hexanediol composition C was continuously withdrawn from the bottom as a bottom product. The water concentration in this 1,6-hexanediol composition C was 0.020% by mass (200 ppm by mass).

[0065] <Step (d): Distillative Separation of Low-Boiling Point Components> Components contained in the 1,6-hexanediol composition C and having a boiling point lower than that of 1,6-hexanediol were removed in a continuous distillation column. An Oldershaw distillation column was used as the distillation column in step (d). The 1,6-hexanediol composition C obtained in step (c) was continuously supplied to the distillation column, and the column top temperature was controlled at a constant temperature of 240°C. Continuous distillation was performed from the column top, and continuous withdrawal was performed from the column bottom to remove the low-boiling point components from the 1,6-hexanediol composition C, and a 1,6-hexanediol composition D from which components lower than that of 1,6-hexanediol had been removed was taken out from the column bottom.

[0066] <Step (e): Distillative Separation of High-Boiling Point Components> Components having a boiling point higher than that of 1,6-hexanediol contained in 1,6-hexanediol composition D were removed in a continuous distillation column. An Oldershaw distillation column was used as the distillation column in step (e). 1,6-hexanediol composition D obtained in step (d) was continuously supplied to the distillation column, and the column bottom temperature was controlled to be constant at 260°C. Continuous withdrawal was performed from the column bottom to remove the high-boiling point components in 1,6-hexanediol composition D. 1,6-hexanediol composition E, from which components having a boiling point higher than that of 1,6-hexanediol had been removed, was obtained from the column top (column top distillate).

[0067] (Analysis of 1,6-Hexanediol Composition) The acid value of the obtained 1,6-HDO composition was measured in accordance with JIS K 0070-1992. The 6-hydroxyhexanal content was measured by high-performance liquid chromatography mass spectrometry (LC / MS). The total alkali metal content was measured and calculated by inductively coupled plasma mass spectrometry (ICP-MS).

[0068] Examples 1 to 10, Comparative Examples 1 to 2 1,6-HDO Compositions The 1,6-HDO compositions described in Examples 1 to 10 and Comparative Examples 1 and 2, which satisfy the requirements listed in Tables 1 and 2, were obtained by adjusting the production conditions while taking into consideration the following points (a) to (c). (a) The acid value changes when the amount of anion exchange resin described in the above section "Step (b): Ion exchange for removing anions" in (Purification of 1,6-hexanediol composition) is changed. Therefore, the acid value was adjusted taking this point into consideration. (b) The 6-hydroxyhexanal content changes when the origin of the 6-hydroxyhexanal 1-reductase or the strength of the expression promoter used in the construction of the recombinant Escherichia coli is changed. Therefore, the 6-hydroxyhexanal content was adjusted taking this point into consideration. (c) The alkali metal content changes when the amount of cation exchange resin described above in <Step (a): Ion exchange for removing cations> is changed, and the alkali metal content was adjusted taking this into consideration. The 1,6-hexanediol composition of Example 1 is referred to as 1,6-hexanediol composition-1 ((1,6HDO-1)), and the 1,6-hexanediol composition of Example 2 is referred to as 1,6-hexanediol composition-2 ((1,6HDO-2)). Similarly, reference numerals are assigned to the respective 1,6HDO compositions in order below. The 1,6-hexanediol composition of Comparative Example 1 is referred to as 1,6-hexanediol composition-R1 ((1,6HDO-R1)), and the 1,6-hexanediol composition of Comparative Example 2 is referred to as 1,6-hexanediol composition-R2 ((1,6HDO-R2).

[0069] <Polycarbonate Diol (PCD)> A 1-L four-neck glass flask connected to a rectification column was charged with 800 g of the 1,6-hexanediol composition-1 (1,6HDO-1) obtained above, 800 g of diethyl carbonate, and 0.08 g of catalyst tetraisopropyl titanate (hereinafter abbreviated as TIPT). The mixture was subjected to transesterification at 120°C for 10 hours with stirring under a nitrogen stream, and then the temperature was raised to 190°C. When the amount of eliminated ethanol distilled decreased, the pressure was gradually reduced to 20 kPa, and the reaction was continued for 2 hours. The temperature was then raised to 210°C while maintaining the pressure at 20 kPa. After reaching 210°C, the pressure was reduced to 1.5 kPa or less over 3 hours, and the reaction was continued for an additional 1 hour, yielding polycarbonate diol-1 of Example 1. The hydroxyl value of polycarbonate diol-1 was 56.1 mgKOH / g. In Example 2, polycarbonate diol-2 of Example 2 was obtained in the same manner as in Example 1, except that 1,6-hexanediol composition-1 (1,6HDO-1) in Example 1 was changed to 1,6-hexanediol composition-2 (1,6HDO-2). In Example 3, like Example 2, polycarbonate diol-3 of Example 3 was obtained in the same manner as in Example 1, except that 1,6-hexanediol composition-1 (1,6HDO-1) in Example 1 was changed to 1,6-hexanediol composition-3 (1,6HDO-3). Examples 4 and onwards were also similar to Examples 2 and 3, and the example numbers correspond to the reference numbers of the polycarbonate diol. The same applies to Comparative Examples 1 and 2. In Comparative Example 1, polycarbonate diol-R1 of Comparative Example 1 was obtained in the same manner as in Example 1, except that 1,6-hexanediol composition-1 (1,6HDO-1) in Example 1 was changed to 1,6-hexanediol composition-R1 (1,6HDO-R1). The same was true for polycarbonate diol-R2 of Comparative Example 2.

[0070] <Isocyanate (NCO)-Terminated Prepolymer> Under a nitrogen stream, 800 g of polycarbonate diol-1 and 293.6 g of 4,4'-diphenylmethane diisocyanate (MDI) were reacted at 60°C with stirring in a 2-L glass four-neck flask to obtain isocyanate-terminated prepolymer-1 of Example 1 having an NCOeq of 709. Example 2 was prepared in the same manner as Example 1, except that polycarbonate diol-1 in Example 1 was replaced with polycarbonate diol-2, to obtain isocyanate-terminated prepolymer-2 of Example 2. Examples 3 and subsequent examples were prepared in the same manner as Example 2. Furthermore, in Comparative Example 1, isocyanate-terminated prepolymer-R1 of Comparative Example 1 was prepared in the same manner as Example 1, except that polycarbonate diol-1 was replaced with polycarbonate diol-R1. Comparative Example 2 was also prepared in the same manner as Comparative Example 1.

[0071] <Polyurethane (PU) Sheet> 200 g of isocyanate-terminated prepolymer-1 heated to 80°C was mixed with 25.4 g of a crosslinking agent (1,4BG / TMP = 90 / 10 wt%), degassed under vacuum, poured into a 2 mm-wide mold, cured at 140°C for 1 hour and at 110°C for 16 hours, and then demolded to obtain a 2 mm-thick polyurethane elastomer-1 of Example 1. Polyurethane elastomer-2 of Example 2 was obtained in the same manner as Example 1, except that isocyanate-terminated prepolymer-1 of Example 1 was replaced with isocyanate-terminated prepolymer-2. Examples 3 and subsequent examples were prepared in the same manner as Example 2. Polyurethane elastomer-R1 of Comparative Example 1 was also obtained in the same manner as Example 1, except that isocyanate-terminated prepolymer-1 was replaced with isocyanate-terminated prepolymer-R1. Comparative Example 2 was also prepared in the same manner as Comparative Example 1.

[0072] <Evaluation of PCD, NCO-Terminated Prepolymer, and PU Sheet> <<Measurement of Color Number of Polycarbonate Diol (PCD)>> The color number of polycarbonate diol (PCD) was evaluated by measuring the APHA color number using a petroleum product color tester, Model OME2000, manufactured by Nippon Denshoku Industries Co., Ltd.

[0073] <Storage Stability (Viscosity Change Rate) of Isocyanate (NCO)-Terminated Prepolymer> The isocyanate (NCO)-terminated prepolymer was stored at 100°C for one week, and the viscosity at 75°C was measured before and after the test. The storage stability was evaluated based on the viscosity change rate shown by the following formula (t) and the following criteria: Viscosity Change Rate = Viscosity after Test / Viscosity before Test (t)

[0074] [Evaluation Criteria] A: Viscosity change rate less than 2 B: Viscosity change rate 2 or more but less than 3 C: Viscosity change rate 3 or more but less than 4 D: Viscosity change rate 4 or more but less than 5

[0075] <Tensile Strength and Breaking Elongation of Polyurethane (PU) Sheet> A polyurethane (PU) sheet was measured for tensile strength and elongation at break (breaking elongation) in accordance with JIS K7312 using a No. 3 test piece with a grip distance of 60 mm, a gauge length of 20 mm, a head speed of 500 mm / min, and a measurement temperature of 23°C. The measuring instrument used was an Autograph AGX-V manufactured by Shimadzu Corporation. The tensile strength was evaluated based on the following criteria.

[0076] [Evaluation criteria] A: 35 MPa or more B: 30 MPa or more and less than 35 MPa C: 25 MPa or more and less than 30 MPa D: 20 MPa or more and less than 25 MPa E: 10 MPa or more and less than 20 MPa

[0077] The elongation at break was evaluated based on the following criteria.

[0078] [Evaluation criteria] A: 340% or more B: 320% or more but less than 340% C: 300% or more but less than 320% D: Less than 300%

[0079] <Hydrolysis Resistance (Strength Retention) of Polyurethane (PU) Sheet> A No. 3 tensile test piece of a polyurethane (PU) sheet was immersed in warm water at 95°C for one week, and the tensile strength before and after the test was determined in accordance with JIS K7312. The strength retention (%) was calculated according to the following formula (u): Strength retention (%) = Tensile strength after warm water immersion / Tensile strength before warm water immersion × 100 (u) The hydrolysis resistance was evaluated from the obtained strength retention based on the following criteria.

[0080] [Evaluation criteria] A: 90% or more B: 80% or more but less than 90% C: 70% or more but less than 80% D: Less than 70%

[0081] The evaluation results of Examples 1 to 10 and Comparative Examples 1 and 2 are shown in Tables 1 and 2 below.

[0082]

[0083]

[0084] (Relationship between Purification Step and Cost) The relationship between the purification step for removing impurities contained in the 1,6-hexanediol composition and the cost was evaluated. The results are shown in Table 3 below. In Table 3, the evaluation criteria for the consumption of anion exchange resin are as follows: [Evaluation Criteria] ◎: Less than 10 mL ○: 10 mL or more but less than 100 mL △: 100 mL or more but less than 1 L ×: 1 L or more

[0085] Attempting to achieve a high degree of purification (low acid value) for the 1,6-hexanediol composition increases the consumption of anion exchange resin per unit weight of 1,6-hexanediol produced, resulting in higher costs. "Higher costs" here refers not only to the simple increase in resin costs associated with increased consumption of anion exchange resin, but also to the overall negative impact on costs that can result from increased consumption of anion exchange resin, such as the need for larger ion exchange equipment, extended purification times, the need to stop production lines for other substances in the factory due to the need to use the ion exchange equipment for long periods of time, resulting in reduced production efficiency, and increased labor costs. As shown in Table 3, if the consumption of anion exchange resin can be kept below 10 mL, low costs are achieved (evaluation A), but if the consumption of anion exchange resin exceeds 100 mL, high costs are achieved (evaluation C). In the present invention, by limiting the consumption amount of anion exchange resin to less than 100 mL (the acid value of the 1,6-hexanediol composition is set to 0.001 or more), costs are kept within a practically effective range (evaluation B in Table 3), and a specific amount of impurities is allowed to be present in the 1,6-hexanediol composition, thereby improving the quality of the polymer (such as a polycarbonate polyol or a polyurethane) obtained by reacting the 1,6-hexanediol composition.

[0086]

Claims

1. A 1,6-hexanediol composition containing at least 1,6-hexanediol, wherein the acid value of the composition is in the range of 0.001 to 0.5 mg KOH / g.

2. The 1,6-hexanediol composition according to claim 1, further comprising 6-hydroxyhexanal, the content of said 6-hydroxyhexanal being 300 ppm by mass or less.

3. The 1,6-hexanediol composition according to claim 1, further comprising an alkali metal element, the content of which is in the range of 0.1 to 100 ppm by mass.

4. The 1,6-hexanediol composition according to any one of claims 1 to 3, wherein the 1,6-hexanediol composition is derived from a biomass resource.

5. A polycarbonate polyol using the 1,6-hexanediol composition according to claim 4 as a reaction raw material.

6. A polyurethane using the polycarbonate polyol according to claim 5 as a reaction raw material.

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