3-Hydroxyadipic acid-3,6-lactone composition

Abstract

The present invention makes it possible to produce adipic acid at a high selectivity without emitting dinitrogen monoxide by using a 3-hydroxyadipic acid 3,6-lactone composition as a starting material, the composition containing 3 to 30 parts by weight of α-hydromuconic acid per 100 parts by weight of 3-hydroxyadipic acid 3,6-lactone. The resulting adipic acid can be used as a polyamide starting material or a polyester starting material.

Description

[Technical Field]

[0001] The present invention relates to a 3-hydroxyadipic acid-3,6-lactone composition containing 3-hydroxyadipic acid-3,6-lactone as a main component and serving as a raw material for adipic acid, a method for producing adipic acid from the 3-hydroxyadipic acid-3,6-lactone composition, and a method for producing polyamides and polyesters using the adipic acid. [Background technology]

[0002] Adipic acid is a raw material monomer for polyamides and polyesters. It can be produced industrially by oxidizing a mixture of cyclohexanone and cyclohexanol (KA oil) with nitric acid. However, this process produces large amounts of nitrous oxide (NO) gas, which has a strong greenhouse effect, and so a method for producing adipic acid without producing nitrous oxide as a by-product is desired.

[0003] Patent Document 1 describes a process for producing adipic acid without producing nitrous oxide by reacting 3-hydroxyadipic acid-3,6-lactone with hydrogen in the presence of a hydrogenation catalyst, and it is known that 3-hydroxyadipic acid-3,6-lactone can be used as a raw material for adipic acid. Non-Patent Document 1 describes that when α-hydromuconic acid is reacted with hydrogen in the presence of a hydrogenation catalyst, adipic acid is produced without producing nitrous oxide by-product, and it is known that α-hydromuconic acid can be used as a raw material for adipic acid. Furthermore, Patent Document 2 describes that a mixture of 3-hydroxyadipic acid-3,6-lactone and α-hydromuconic acid may be used as a raw material for ε-caprolactam, but does not suggest the applicability of the mixture as a raw material for adipic acid or the appropriate composition of the mixture as a raw material for adipic acid.

[0004] Non-Patent Document 2 discloses the relationship between fatty acid metabolism and urinary 3-hydroxyadipic acid-3,6-lactone concentration. In this document, a reference sample of 3-hydroxyadipic acid-3,6-lactone is chemically synthesized for the purpose of quantifying urinary 3-hydroxyadipic acid-3,6-lactone. The synthesized 3-hydroxyadipic acid-3,6-lactone is described as a 3-hydroxyadipic acid-3,6-lactone composition containing 100 parts by weight of 3-hydroxyadipic acid-3,6-lactone and 2 parts by weight of α-hydromuconic acid. However, there is no mention or suggestion of the applicability of this mixture as a raw material for adipic acid. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2015 / 086821 [Patent Document 2] International Publication No. 2016 / 068108 [Non-patent literature]

[0006] [Non-Patent Document 1] Angewandte Chemie International Edition, vol.53, p.7785-7788(2014). [Non-patent document 2] Metabolism, vol.38, No.7, p.655-661(1989). Summary of the Invention [Problem to be solved by the invention]

[0007] As described above, it is known that 3-hydroxyadipic acid-3,6-lactone or α-hydromuconic acid can be used as a raw material for producing adipic acid. However, the present inventors have newly discovered that when pure 3-hydroxyadipic acid-3,6-lactone or α-hydromuconic acid is actually reacted with hydrogen in the presence of a hydrogenation catalyst to produce adipic acid, there is a problem in that the selectivity for adipic acid is insufficient. [Means for solving the problem]

[0008] The present inventors have conducted extensive research to solve the above-mentioned problems that arise when adipic acid is produced using 3-hydroxyadipic acid-3,6-lactone as a raw material. As a result, they have found that a 3-hydroxyadipic acid-3,6-lactone composition in which 3-hydroxyadipic acid-3,6-lactone contains a specific amount of α-hydromuconic acid as a minor component serves as a good raw material for adipic acid, which is capable of suppressing the production of by-products, and have thus completed the present invention.

[0009] That is, the present invention comprises the following (1) to (11). (1) A 3-hydroxyadipic acid-3,6-lactone composition containing 3 to 30 parts by weight of α-hydromuconic acid per 100 parts by weight of 3-hydroxyadipic acid-3,6-lactone. (2) A method for producing a 3-hydroxyadipic acid-3,6-lactone composition, comprising the step of heating 3-hydroxyadipic acid-3,6-lactone to obtain the 3-hydroxyadipic acid-3,6-lactone composition according to (1). (3) A method for producing adipic acid, comprising a step of reacting the 3-hydroxyadipic acid-3,6-lactone composition according to (1) with hydrogen in the presence of a hydrogenation catalyst (hydrogenation step). (4) A method for producing adipic acid according to (3), comprising the step of obtaining the 3-hydroxyadipic acid-3,6-lactone composition according to (1) by the method according to (2). (5) A method for producing a polyamide, comprising the steps of producing adipic acid by the method according to (3) or (4) above, and polycondensing adipic acid and a diamine. (6) The method for producing a polyamide according to (5), wherein the diamine is a diamine containing 1,4-butanediamine, 1,5-pentanediamine, or hexamethylenediamine. (7) The method for producing a polyamide according to (5) or (6), wherein the polyamide is polyamide 46, polyamide 56 or polyamide 66. (8) A method for producing a polyester, comprising the steps of producing adipic acid by the method according to (3) or (4) above, and polycondensing adipic acid and a glycol, or adipic acid, a glycol, and a dicarboxylic acid. (9) The method for producing a polyester according to (8), wherein the glycol is a glycol containing 1,4-butanediol. (10) The method for producing a polyester according to (8) or (9), wherein the dicarboxylic acid is a dicarboxylic acid containing terephthalic acid or succinic acid. (11) The method for producing a polyester according to any one of (8) to (10), wherein the polyester is polybutylene adipate terephthalate or polybutylene succinate adipate. [Effects of the Invention]

[0010] According to the present invention, the selectivity for adipic acid can be increased when adipic acid is produced using 3-hydroxyadipic acid-3,6-lactone as a raw material. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will now be described in more detail.

[0012] [3-Hydroxyadipic acid-3,6-lactone] 3-Hydroxyadipic acid-3,6-lactone is an organic compound represented by the following chemical formula (1), and can be chemically synthesized, for example, by the method shown in Reference Example 1 of the Examples described later.

[0013] [ka]

[0014] 3-Hydroxyadipic acid-3,6-lactone can be synthesized, for example, by the reaction shown in Scheme 1 below using 3-oxoadipic acid, which can be synthesized from biomass resources, as a raw material.

[0015] [ka]

[0016] 3-Hydroxyadipic acid-3,6-lactone may be a carboxylic acid, a carboxylic acid salt, a carboxylic acid ester, or a mixture thereof, which may also be used as a starting material in the present invention, and these are collectively referred to herein as "3-hydroxyadipic acid-3,6-lactone."

[0017] Examples of carboxylates of 3-hydroxyadipic acid-3,6-lactone include alkali metal salts, alkaline earth metal salts, and ammonium salts, and specific examples include lithium salts, sodium salts, potassium salts, and ammonium salts.

[0018] Examples of carboxylic acid esters of 3-hydroxyadipic acid-3,6-lactone include alkyl esters, and specific alkyl groups include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group.

[0019] In addition, 3-hydroxyadipic acid-3,6-lactone can be prepared by dissolving 3-hydroxyadipic acid represented by the following chemical formula (2) in water and adjusting the pH to 4 or less.

[0020] [ka]

[0021] The acid to be added to adjust the pH to 4 or less is not particularly limited, but mineral acids such as sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, and boric acid, and organic acids such as formic acid, acetic acid, and propionic acid can be preferably used.

[0022] [α-Hydromuconic acid] α-hydromuconic acid is an organic compound represented by the following chemical formula (3), and can be chemically synthesized, for example, by the method shown in Reference Example 2 of the Examples below.

[0023] [ka]

[0024] α-hydromuconic acid can also be obtained by converting a carbon source derived from biomass through microbial fermentation, as described in WO 2019 / 107516. α-hydromuconic acid has one double bond in the molecule, so there are cis and trans geometric isomers. In the production method of the present invention, either the cis isomer, the trans isomer, or a mixture of the cis and trans isomers can be used as the raw material.

[0025] α-hydromuconic acid may be a carboxylic acid, a carboxylic acid salt, a carboxylic acid ester, or a mixture thereof, which may also be used as a starting material in the present invention, and these are collectively referred to as "α-hydromuconic acid" in this specification.

[0026] Examples of carboxylates of α-hydromuconic acid include alkali metal salts, alkaline earth metal salts, and ammonium salts, and specific examples include monolithium salt, dilithium salt, monosodium salt, disodium salt, monopotassium salt, dipotassium salt, magnesium salt, calcium salt, monoammonium salt, and diammonium salt.

[0027] Examples of carboxylic acid esters of α-hydromuconic acid include monoalkyl esters and dialkyl esters, and specific alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl groups.

[0028] [3-Hydroxyadipic acid-3,6-lactone composition] The 3-hydroxyadipic acid-3,6-lactone composition of the present invention is characterized by containing 3-hydroxyadipic acid-3,6-lactone as a main component and α-hydromuconic acid as a minor component. By using the 3-hydroxyadipic acid-3,6-lactone composition of the present invention, adipic acid can be synthesized with high selectivity.

[0029] Here, "mainly composed of" means that the content of 3-hydroxyadipic acid-3,6-lactone in the 3-hydroxyadipic acid-3,6-lactone composition is more than 50% by weight, preferably 60% by weight or more, and more preferably 70% by weight or more.

[0030] In the 3-hydroxyadipic acid-3,6-lactone composition of the present invention, the content of α-hydromuconic acid per 100 parts by weight of 3-hydroxyadipic acid-3,6-lactone is 3 to 30 parts by weight, preferably 4 to 28 parts by weight, and more preferably 5 to 25 parts by weight. This composition reduces the amount of n-valeric acid produced as a by-product, thereby enabling an increase in the selectivity for adipic acid when producing adipic acid.

[0031] The method for producing the 3-hydroxyadipic acid-3,6-lactone composition of the present invention is not particularly limited, and it may be prepared by mixing pure 3-hydroxyadipic acid-3,6-lactone and α-hydromuconic acid which have been separately prepared.

[0032] Furthermore, if α-hydromuconic acid is contained as an impurity during the production of 3-hydroxyadipic acid-3,6-lactone, the 3-hydroxyadipic acid-3,6-lactone composition of the present invention may be prepared by appropriately adjusting the amount of the impurity. Specifically, α-hydromuconic acid may be generated by heating during the production process of 3-hydroxyadipic acid-3,6-lactone. In such cases, the content of α-hydromuconic acid can be adjusted by appropriately adjusting the heating temperature. While a higher heating temperature tends to increase the likelihood of α-hydromuconic acid being generated, if the heating temperature is too high, the 3-hydroxyadipic acid-3,6-lactone composition is susceptible to thermal decomposition. From this perspective, the heating temperature is preferably 100 to 300°C, more preferably 120 to 250°C, and even more preferably 150 to 200°C.

[0033] The 3-hydroxyadipic acid-3,6-lactone and α-hydromuconic acid contained in the 3-hydroxyadipic acid-3,6-lactone composition of the present invention can be quantified by dissolving the composition in water and analyzing the resulting aqueous solution by high-performance liquid chromatography (HPLC). HPLC analysis of 3-hydroxyadipic acid-3,6-lactone and α-hydromuconic acid is performed using a conductivity detector (CDD) and a UV-Vis detector (measurement wavelength: 210 nm), respectively. From the viewpoint of detection sensitivity, the concentration of the 3-hydroxyadipic acid-3,6-lactone composition in the aqueous solution prepared for HPLC analysis is preferably 1 to 10 g / L.

[0034] The 3-hydroxyadipic acid-3,6-lactone composition may contain water, alcohol, carboxylic acid, ether, ester, or ion as a third component other than 3-hydroxyadipic acid-3,6-lactone and α-hydromuconic acid. Specific examples of alcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, and tert-butanol. Specific examples of carboxylic acids include oxalic acid, acetic acid, lactic acid, formic acid, pyruvic acid, propionic acid, malonic acid, succinic acid, citric acid, glycolic acid, malic acid, n-butyric acid, isobutyric acid, hydroxybutyric acid, α-ketoglutaric acid, maleic acid, tartaric acid, glyoxylic acid, citraconic acid, pyroglutaric acid, ascorbic acid, and 3-hydroxyadipic acid. Specific examples of ethers include dimethyl ether, diethyl ether, 1,2-dimethoxyethane, diglyme, tetrahydrofuran, and dioxane. Specific examples of esters include methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, and γ-butyrolactone. Specific examples of ions include H + , Li + , Na + , K. + , NH4 + , Mg 2+ , Ca 2+ , Fe 2+ , Fe 3+ , Zn 2+ , Ni 2+ , Mn 2+ , O.H. - , Cl - , NO3 ― , SO4 2- , PO4 3- , CO3 2- etc.

[0035] In the 3-hydroxyadipic acid-3,6-lactone composition of the present invention, the difference between the sum of the contents of 3-hydroxyadipic acid-3,6-lactone (major component) and α-hydromuconic acid (minor component) and 100% by weight is understood to be composed of the third component. Thus, for example, a mixture consisting of 75% by weight of 3-hydroxyadipic acid-3,6-lactone, 10% by weight of α-hydromuconic acid (equivalent to 13.3 parts by weight of α-hydromuconic acid per 100 parts by weight of 3-hydroxyadipic acid-3,6-lactone), and 15% by weight of water is included in the 3-hydroxyadipic acid-3,6-lactone composition of the present invention.

[0036] The third component may be one or more components, but when included, it is preferably water. When the 3-hydroxyadipic acid-3,6-lactone composition contains water as the third component, the water content in the composition is preferably 40% by weight or less, more preferably 30% by weight or less, even more preferably 25% by weight or less, and particularly preferably 20% by weight or less, based on 100% by weight of the 3-hydroxyadipic acid-3,6-lactone composition.

[0037] [Production of adipic acid] Adipic acid can be produced by reacting the 3-hydroxyadipic acid-3,6-lactone composition of the present invention with hydrogen (hydrogenation) in the presence of a hydrogenation catalyst.

[0038] The hydrogenation catalyst preferably contains a transition metal element, and specifically, it preferably contains one or more elements selected from the group consisting of palladium, platinum, ruthenium, rhodium, rhenium, nickel, cobalt, iron, iridium, osmium, copper, and chromium, and more preferably contains one or more elements selected from the group consisting of palladium, platinum, nickel, cobalt, iron, copper, and chromium.

[0039] The hydrogenation catalyst is preferably used supported on a carrier from the viewpoints of saving the amount of metal used, increasing the active surface of the catalyst, etc. Supporting the hydrogenation catalyst on a carrier can be carried out by known methods such as impregnation, deposition / precipitation, and vapor phase support. Examples of the carrier include carbon, polymers, metal oxides, metal sulfides, zeolites, clays, heteropolyacids, solid phosphoric acid, and hydroxyapatite.

[0040] The hydrogen to be reacted with the 3-hydroxyadipic acid-3,6-lactone composition may be added to the reactor all at once or gradually. The partial pressure of hydrogen is not particularly limited, but if it is too low, the reaction time will be long, while if it is too high, it is undesirable from the viewpoint of equipment safety. Therefore, the partial pressure of hydrogen is preferably 0.1 MPa or more and 10 MPa or less (gauge pressure) at room temperature, more preferably 0.3 MPa or more and 5 MPa or less (gauge pressure), and even more preferably 0.5 MPa or more and 3 MPa or less (gauge pressure).

[0041] The reaction may be carried out in any reactor, such as a batch reactor, a semi-batch reactor, a continuous reactor, a continuous tubular reactor, or a trickle-bed tubular reactor. When a solid hydrogenation catalyst is used, the reaction may be carried out in any of a suspension bed, a fixed bed, a moving bed, or a fluidized bed.

[0042] The hydrogenation reaction temperature is not particularly limited, but if it is too low, the reaction rate will be slow, and if it is too high, the energy consumption will be high, which are undesirable. From these viewpoints, the reaction temperature is preferably 100 to 350°C, more preferably 120 to 300°C, even more preferably 130 to 280°C, still more preferably 140 to 250°C, even more preferably 150 to 230°C, and even more preferably 160 to 220°C.

[0043] The atmosphere in the reactor may contain inert gases such as nitrogen, helium, and argon in addition to hydrogen. However, the oxygen concentration is preferably 5% by volume or less because this can lead to deterioration of the hydrogenation catalyst and the generation of detonation gas. Furthermore, from the viewpoint of the stability of the 3-hydroxyadipic acid-3,6-lactone composition and adipic acid, the amount of ammonia relative to the 3-hydroxyadipic acid-3,6-lactone composition is preferably 5% by weight or less, more preferably 3% by weight or less, and even more preferably 0% by weight (i.e., reaction in the absence of ammonia).

[0044] The hydrogenation of the 3-hydroxyadipic acid-3,6-lactone composition is preferably carried out in the presence of a solvent.

[0045] Examples of solvents that can be used for hydrogenation include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, pentane, hexane, cyclohexane, heptane, octane, decane, dimethyl ether, diethyl ether, 1,2-dimethoxyethane, diglyme, tetrahydrofuran, dioxane, methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, γ-butyrolactone, N-methylpyrrolidone, dimethyl sulfoxide, and aqueous solvents. A mixed solvent of two or more of these may also be used, but from the viewpoints of economy and environment, it is preferable to use an aqueous solvent.

[0046] In the present invention, the aqueous solvent refers to a mixed solvent consisting mainly of water or water-miscible organic solvent. "Consisting mainly of water" means that the proportion of water in the mixed solvent is more than 50% by volume, preferably 70% by volume or more, and more preferably 90% by volume or more.

[0047] Examples of water-miscible organic solvents include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, 1,2-dimethoxyethane, diglyme, tetrahydrofuran, dioxane, γ-butyrolactone, N-methylpyrrolidone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, and acetone.

[0048] The pH of the aqueous solvent is not particularly limited, but in consideration of the prevention of catalyst deterioration, the prevention of by-product formation, and corrosiveness to the reaction apparatus, the pH is preferably 2 to 13, more preferably 3 to 11, and even more preferably 4 to 10.

[0049] Although the amount of the 3-hydroxyadipic acid-3,6-lactone composition to be charged relative to the solvent is not particularly limited, a small amount is industrially undesirable. From this viewpoint, the amount of the 3-hydroxyadipic acid-3,6-lactone composition to be charged relative to 100 parts by weight of the solvent is preferably 0.1 parts by weight or more but 900 parts by weight or less, more preferably 0.2 parts by weight or more but 800 parts by weight or less, and even more preferably 1.0 parts by weight or more but 700 parts by weight or less, in terms of the amount of 3-hydroxyadipic acid-3,6-lactone.

[0050] When a solvent other than primary alcohols and secondary alcohols is used as the hydrogenation solvent, the carboxylic acids, carboxylic acid salts, and carboxylic acid esters of the 3-hydroxyadipic acid-3,6-lactone composition produce the corresponding adipic acid, adipate salts, and adipate esters, respectively. When a solvent containing a primary or secondary alcohol such as methanol, ethanol, n-propanol, isopropanol, n-butanol, or isobutanol is used as the hydrogenation solvent, a mixture of adipic acid, adipate salts, adipic acid monoesters, and adipic acid diesters is obtained after the reaction. In this specification, the carboxylic acids, carboxylic acid salts, and carboxylic acid esters of adipic acid, and mixtures thereof, are collectively referred to as "adipic acid."

[0051] The carboxylic acid of adipic acid obtained in the present invention can be further converted into an adipic acid ester by subjecting it to an esterification reaction. The esterification method is not particularly limited, and examples thereof include dehydration condensation of a carboxylic acid and an alcohol using an acid catalyst or a condensing agent, and a method using an alkylating reagent such as diazomethane or an alkyl halide.

[0052] The adipic acid obtained in the present invention can be separated and purified by conventional unit operations such as centrifugation, filtration, membrane filtration, distillation, extraction, crystallization, and drying.

[0053] [Manufacturing various chemical products using adipic acid as a raw material] Adiponitrile can be produced from the adipic acid obtained by the present invention by a known method (for example, JP-B-61-24555). Hexamethylenediamine can be produced by hydrogenating the obtained adiponitrile by a known method (for example, JP-A-2000-508305).

[0054] Polyamides can be produced by polycondensing the adipic acid obtained by the present invention with diamines by known methods (see, for example, "Polyamide Resin Handbook," edited by Osamu Fukumoto, Nikkan Kogyo Shuppansha, January 1998). Specifically, polyamide 46, polyamide 56, and polyamide 66 can be produced by using 1,4-diaminobutane, 1,5-pentanediamine, and hexamethylenediamine as diamines, respectively.

[0055] Polyamide fibers can be produced by processing polyamides using known methods (e.g., WO 2019 / 208427). The polyamide fibers thus obtained can be used for clothing applications such as innerwear, sportswear, and casual wear, as well as industrial materials such as airbags and tire cords.

[0056] In addition, polyamide can be molded by a known method (for example, WO 2021 / 006257) to produce a polyamide molded product. The polyamide molded product thus obtained can be used for automobile parts, electrical parts, electronic parts, building materials, various containers, daily necessities, household goods, sanitary products, etc.

[0057] Polyesters can be produced by polycondensing the adipic acid obtained by the present invention with glycols using known methods (see, for example, "Paint Research, Vol. 151, pp. 2-8," Kansai Paint Co., Ltd. (November 2009)). Specifically, glycols that can be used include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, and 2-methyl-1,3-propanediol. In this case, in addition to the adipic acid obtained by the present invention, any dicarboxylic acid may be copolymerized. Specifically, examples of dicarboxylic acids to be copolymerized include oxalic acid, malonic acid, succinic acid, glutaric acid, suberic acid, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, and 2,5-furandicarboxylic acid. Here, using 1,4-butanediol as the diol and terephthalic acid or succinic acid as the dicarboxylic acid yields polybutylene adipate terephthalate (PBAT) and polybutylene succinate adipate (PBSA), respectively. These polyesters are biodegradable and therefore environmentally friendly. Polybutylene adipate terephthalate (PBAT) and polybutylene succinate adipate (PBSA) can be produced by known methods (e.g., Journal of Polymer Science: Part A: Polymer Chemistry, vol. 40, pp. 4141-4157 (2002) and International Publication No. 1996 / 019521). "Biodegradable" refers to the property of being decomposed to the molecular level by the action of microorganisms, ultimately resulting in carbon dioxide and water, which are then circulated back into nature.

[0058] Polyester can be processed by known methods (for example, WO 2007 / 037174) to produce polyester fibers. The polyester fibers thus obtained can be made into textile products such as woven fabrics, knitted fabrics, and nonwoven fabrics, as well as clothing, fiber brushes, rugs, and the like.

[0059] Polyester molded articles can be produced by molding the polyester using known methods (e.g., WO 2015 / 072216). The polyester molded articles thus obtained can be used for automobile parts, electrical parts, electronic parts, mechanical parts, building materials, various containers, daily necessities, household goods, and sanitary products.

[0060] Polyester can be stretched by known methods (e.g., WO 2010 / 038655) to produce a polyester film. The polyester film thus obtained can be used in a wide variety of applications, including electronic devices, semiconductor products, electrical products, automotive parts, packaging, and building materials. [Example]

[0061] The present invention will be described in more detail below using examples, but the present invention is not limited to the following examples. The reaction results in the examples and comparative examples are defined by the following formulas.

[0062] Product selectivity (%) = amount of product produced (mol) / reacted raw material (mol) × 100.

[0063] Analysis and quantification of 3-hydroxyadipic acid-3,6-lactone and adipic acid were carried out under the following HPLC analysis condition 1. Analysis and quantification of α-hydromuconic acid and n-valeric acid were carried out under the following HPLC analysis condition 2. Quantification of raw materials and products was carried out using absolute calibration curves prepared using standard samples.

[0064] [HPLC analysis conditions 1] HPLC equipment: "Prominence" (Shimadzu Corporation) Column: "Synergi Polar-RP" (Phenomenex), length 250 mm, inner diameter 4.60 mm, particle size 4 μm + "Synergi hydro-RP" (Phenomenex), length 250 mm, inner diameter 4.60 mm, particle size 4 μm Mobile phase: 5 mM formic acid aqueous solution / acetonitrile = 98 / 2 (volume ratio) Reaction solution: 5 mM formic acid + 20 mM Bis-Tris + 0.1 mM EDTA·2Na aqueous solution / acetonitrile = 98 / 2 (volume ratio) Flow rate: 1.0mL / min Detector: Conductivity detector (CDD) Column temperature: 45°C.

[0065] [HPLC analysis conditions 2] HPLC equipment: "Prominence" (Shimadzu Corporation) Column: "Synergi hydro-RP" (Phenomenex), length 250 mm, inner diameter 4.60 mm, particle size 4 μm Mobile phase: 0.1 wt% phosphoric acid aqueous solution / acetonitrile = 95 / 5 (volume ratio) Flow rate: 1.0mL / min Detector: UV-Vis detector (measurement wavelength 210 nm) Column temperature: 40°C.

[0066] [pH analysis method] A Horiba pH meter F-52 (Horiba, Ltd.) was used. pH calibration was performed using pH 4.01 standard solution (Fujifilm Wako Pure Chemical Industries, Ltd.), pH 6.86 standard solution (Fujifilm Wako Pure Chemical Industries, Ltd.), and pH 9.18 standard solution (Fujifilm Wako Pure Chemical Industries, Ltd.).

[0067] (Reference Example 1) Chemical synthesis of 3-hydroxyadipic acid-3,6-lactone The 3-hydroxyadipic acid-3,6-lactone used in this invention was prepared by chemical synthesis. First, 13.2 g (0.1 mol) of succinic acid monomethyl ester (Fujifilm Wako Pure Chemical Industries, Ltd.) was added to 1.5 L of ultra-dehydrated tetrahydrofuran (Fujifilm Wako Pure Chemical Industries, Ltd.), and then 16.2 g (0.1 mol) of carbonyldiimidazole (Fujifilm Wako Pure Chemical Industries, Ltd.) was added while stirring, and the mixture was stirred at room temperature for 1 hour under a nitrogen atmosphere. 15.6 g (0.1 mol) of malonic acid monomethyl ester potassium salt and 9.5 g (0.1 mol) of magnesium chloride were added to this suspension, and the mixture was stirred at room temperature for 1 hour under a nitrogen atmosphere, followed by stirring at 40°C for 12 hours. After the reaction was complete, 0.05 L of 1 mol / L hydrochloric acid was added, and the mixture was extracted with ethyl acetate. The mixture was then purified by silica gel column chromatography (hexane:ethyl acetate = 1:5) to obtain 13.1 g of pure 3-oxohexanedicarboxylic acid dimethyl ester.

[0068] To 10 g (0.05 mol) of the resulting 3-oxohexanedicarboxylic acid dimethyl ester, 0.1 L of methanol (Kokusan Chemical Co., Ltd.) was added, and 0.02 L of 5 mol / L aqueous sodium hydroxide solution was added while stirring. The mixture was stirred at room temperature for 2 hours. After the reaction was complete, the pH was adjusted to 1 with 5 mol / L hydrochloric acid. 2.0 g (0.05 mol) of sodium borohydride (Fujifilm Wako Pure Chemical Industries, Ltd.) was then added and stirred at room temperature for 2 hours. After concentration on a rotary evaporator, 0.1 L of ultrapure water was added, and 0.01 L of 1 mol / L sulfuric acid was added while stirring. The mixture was stirred at 100 °C for 2 hours. The solution was concentrated on a rotary evaporator and then purified by silica gel column chromatography (chloroform:methanol = 10:1) to obtain 5.8 g of pure 3-hydroxyadipic acid-3,6-lactone (carboxylic acid).

[0069] 1 H-NMR (400MHz, D2O): δ2.03 (m, 1H), δ2.04-2.90 (m, 5H), δ5.00 (m, 1H).

[0070] (Reference Example 2) Chemical synthesis of α-hydromuconic acid The α-hydromuconic acid used in the present invention was prepared by chemical synthesis. 0.1 L of methanol (Kokusan Chemical Co., Ltd.) was added to 10 g (0.05 mol) of 3-oxohexanedicarboxylic acid dimethyl ester obtained in the same manner as in Reference Example 1, and 2.0 g (0.05 mol) of sodium borohydride (Fujifilm Wako Pure Chemical Industries, Ltd.) was added with stirring, followed by stirring at room temperature for 1 hour. Next, 0.02 L of a 5 mol / L aqueous sodium hydroxide solution was added, and the mixture was stirred at room temperature for 2 hours. After the reaction was completed, the pH was adjusted to 1 with 5 mol / L hydrochloric acid, concentrated using a rotary evaporator, and recrystallized in water to obtain 7.2 g of pure α-hydromuconic acid (carboxylic acid).

[0071] 1 H-NMR (400MHz, CD3OD): δ2.48 (m, 4H), δ5.84 (d, 1H), δ6.96 (m, 1H).

[0072] (Reference Example 3) Chemical synthesis of 3-hydroxyadipic acid The 3-hydroxyadipic acid used in the present invention was prepared by chemical synthesis. 0.1 L of methanol (Kokusan Chemical Co., Ltd.) was added to 10 g (0.05 mol) of 3-oxohexanedicarboxylic acid dimethyl ester obtained in the same manner as in Reference Example 1, and 0.02 L of 5 mol / L aqueous sodium hydroxide solution was added while stirring, followed by stirring at room temperature for 2 hours. After the reaction was completed, the pH was adjusted to 1 with 5 mol / L hydrochloric acid, and then 2.0 g (0.05 mol) of sodium borohydride (Fujifilm Wako Pure Chemical Industries, Ltd.) was added and stirred at room temperature for 2 hours. After the reaction was completed, the mixture was concentrated using a rotary evaporator and then recrystallized with water to obtain 7.2 g of pure 3-hydroxyadipic acid (carboxylic acid).

[0073] 1 H-NMR (400MHz, CD3OD): δ1.70 (m, 1H), δ1.83 (m, 1H), δ2.42 (m, 4H), δ4.01 (m, 1H).

[0074] Example 1 A 3-hydroxyadipic acid-3,6-lactone composition containing 8.7 parts by weight of α-hydromuconic acid per 100 parts by weight of 3-hydroxyadipic acid-3,6-lactone was obtained by physically mixing 0.92 g of 3-hydroxyadipic acid-3,6-lactone (carboxylic acid) prepared in Reference Example 1 and 0.08 g of α-hydromuconic acid (carboxylic acid) prepared in Reference Example 2.

[0075] A 0.1 L stainless steel autoclave (manufactured by Taiatsu Glass Industry Co., Ltd.) was charged with 1.0 g of the above 3-hydroxyadipic acid-3,6-lactone composition, 20 g of water, and 0.025 g of Palladium, 5% on gamma alumina powder, reduced (manufactured by Alfa Aesar). After purging the autoclave with nitrogen, hydrogen gas was added and the hydrogen partial pressure in the autoclave was adjusted to 0.9 MPa (gauge pressure). The temperature in the autoclave was raised to 200°C and maintained at 200°C for 3 hours. The autoclave was then cooled to room temperature, the gas in the autoclave was released, and the pressure was returned to normal. The reaction solution was recovered. The catalyst was removed by filtration, and the filtrate was analyzed by HPLC to calculate the product selectivity. The results are shown in Table 1.

[0076] Example 2 0.8 g of 3-hydroxyadipic acid-3,6-lactone (carboxylic acid) prepared in Reference Example 1 and 0.2 g of α-hydromuconic acid (carboxylic acid) prepared in Reference Example 2 were physically mixed to obtain a 3-hydroxyadipic acid-3,6-lactone composition containing 100 parts by weight of 3-hydroxyadipic acid-3,6-lactone and 25 parts by weight of α-hydromuconic acid, and the reaction was carried out in the same manner as in Example 1. The results are shown in Table 1.

[0077] (Comparative Example 1) A reaction was carried out in the same manner as in Example 1, except that 1 g of 3-hydroxyadipic acid-3,6-lactone (carboxylic acid) prepared in Reference Example 1 was used instead of the 3-hydroxyadipic acid-3,6-lactone composition. The results are shown in Table 1.

[0078] (Comparative Example 2) The reaction was carried out in the same manner as in Example 1, except that 1 g of α-hydromuconic acid (carboxylic acid) prepared in Reference Example 2 was used instead of the 3-hydroxyadipic acid-3,6-lactone composition. The results are shown in Table 1.

[0079] Example 3 3 g of 3-hydroxyadipic acid-3,6-lactone (carboxylic acid) prepared in Reference Example 1 was added to a recovery flask, heated to 165°C in an oil bath, maintained at 165°C for 30 minutes, and then allowed to cool to room temperature. 300 mL of water was added to the recovery flask, and the resulting aqueous solution was analyzed by HPLC. The content of α-hydromuconic acid per 100 parts by weight of 3-hydroxyadipic acid-3,6-lactone in the aqueous solution was 5.9 parts by weight. Water was removed using a rotary evaporator to obtain a 3-hydroxyadipic acid-3,6-lactone composition, and 1 g of this composition was used to carry out a reaction in the same manner as in Example 1. The results are shown in Table 1.

[0080] [Table 1]

[0081] Examples 1 to 3 and Comparative Examples 1 and 2 demonstrated that, compared to using pure 3-hydroxyadipic acid-3,6-lactone or pure α-hydromuconic acid as the raw material, using a 3-hydroxyadipic acid-3,6-lactone composition containing 3 to 30 parts by weight of α-hydromuconic acid per 100 parts by weight of 3-hydroxyadipic acid-3,6-lactone as the raw material suppresses the production of the by-product n-valeric acid and enables the production of adipic acid with high selectivity.

[0082] (Comparative Example 3) A 3-hydroxyadipic acid-3,6-lactone composition containing 2 parts by weight of α-hydromuconic acid per 100 parts by weight of 3-hydroxyadipic acid-3,6-lactone was obtained by physically mixing 0.98 g of 3-hydroxyadipic acid-3,6-lactone (carboxylic acid) prepared in Reference Example 1 and 0.02 g of α-hydromuconic acid (carboxylic acid) prepared in Reference Example 2, and the reaction was carried out in the same manner as in Example 1. The results are shown in Table 2.

[0083] Example 4 3 g of 3-hydroxyadipic acid-3,6-lactone (carboxylic acid) prepared in Reference Example 1 was added to a recovery flask, heated to 190°C in an oil bath, maintained at 190°C for 30 minutes, and then allowed to cool to room temperature. 300 mL of water was added to the recovery flask, and the resulting aqueous solution was analyzed by HPLC. The content of α-hydromuconic acid per 100 parts by weight of 3-hydroxyadipic acid-3,6-lactone in the aqueous solution was 11 parts by weight. The water was removed using a rotary evaporator to obtain a 3-hydroxyadipic acid-3,6-lactone composition, and 1 g of this composition was used to carry out a reaction in the same manner as in Example 1. The results are shown in Table 2.

[0084] Example 5 A 3-hydroxyadipic acid-3,6-lactone composition containing 11.1 parts by weight of α-hydromuconic acid per 100 parts by weight of 3-hydroxyadipic acid-3,6-lactone was obtained by physically mixing 0.9 g of the 3-hydroxyadipic acid-3,6-lactone (carboxylic acid) prepared in Reference Example 1 and 0.1 g of the α-hydromuconic acid (carboxylic acid) prepared in Reference Example 2. The reaction was carried out in the same manner as in Example 1, except that 0.005 g of 5% palladium / carbon (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used as the catalyst and the reaction temperature was set to 160° C. The results are shown in Table 2.

[0085] Example 6 The reaction was carried out in the same manner as in Example 1, except that tetrahydrofuran (THF) was used as the solvent instead of water. The results are shown in Table 2.

[0086] Example 7 The reaction was carried out in the same manner as in Example 1, except that a mixed solvent of water and tetrahydrofuran (water / THF 6 / 4 v / v) was used instead of water. The results are shown in Table 2.

[0087] Example 8 20 g of 3-hydroxyadipic acid-3,6-lactone (carboxylic acid) prepared in Reference Example 1 was added to a recovery flask, the temperature was raised to 200°C in an oil bath, and the mixture was maintained at 200°C for 30 minutes, and then allowed to cool to room temperature to obtain a 3-hydroxyadipic acid-3,6-lactone composition containing 8.6 parts by weight of α-hydromuconic acid per 100 parts by weight of 3-hydroxyadipic acid-3,6-lactone.

[0088] 10 g of the 3-hydroxyadipic acid-3,6-lactone composition, 20 g of water, and 0.02 g of 5% palladium-carbon (Fujifilm Wako Pure Chemical Industries, Ltd.) were added to a 0.1 L stainless steel autoclave (Taiatsu Glass Industry Co., Ltd.). The autoclave was purged with nitrogen and then pressurized with hydrogen gas to maintain the internal pressure of the autoclave at 0.9 MPa (gauge pressure) during hydrogenation. The temperature was raised to 150°C and maintained at 150°C for 15 hours. After cooling to room temperature, the gas in the autoclave was released, the pressure was returned to normal, and the reaction solution was recovered. The catalyst was removed by filtration, and the filtrate was analyzed by HPLC to calculate the product selectivity. The results are shown in Table 2.

[0089] Example 9 The reaction was carried out in the same manner as in Example 1, except that 0.05 g of Raney nickel (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used as the catalyst. The results are shown in Table 2.

[0090] [Table 2]

[0091] Comparative Example 3 and Examples 4 to 9 demonstrated that, even with various solvents, reaction temperatures, and catalysts, by using a 3-hydroxyadipic acid-3,6-lactone composition containing 100 parts by weight of 3-hydroxyadipic acid-3,6-lactone and 3 to 30 parts by weight of α-hydromuconic acid as a raw material, the production of the by-product n-valeric acid was suppressed and adipic acid could be produced with high selectivity.

Claims

1. A 3-hydroxyadipic acid-3,6-lactone composition containing 3 to 30 parts by weight of α-hydromuconic acid per 100 parts by weight of 3-hydroxyadipic acid-3,6-lactone.

2. A method for producing a 3-hydroxyadipic acid-3,6-lactone composition, comprising the step of heating 3-hydroxyadipic acid-3,6-lactone to obtain the 3-hydroxyadipic acid-3,6-lactone composition of claim 1.

3. A method for producing adipic acid, comprising a step of reacting the 3-hydroxyadipic acid-3,6-lactone composition according to claim 1 with hydrogen in the presence of a hydrogenation catalyst (hydrogenation step).

4. A method for producing adipic acid according to claim 3, comprising a step of obtaining the 3-hydroxyadipic acid-3,6-lactone composition according to claim 1 by the method according to claim 2.

5. A method for producing a polyamide, comprising: a step of producing adipic acid by the method according to claim 3 or 4; and a step of polycondensing the adipic acid obtained in the step with a diamine.

6. 6. The method for producing a polyamide according to claim 5, wherein the diamine is a diamine containing 1,4-butanediamine, 1,5-pentanediamine or hexamethylenediamine.

7. The method for producing a polyamide according to claim 5 or 6, wherein the polyamide is polyamide 46, polyamide 56 or polyamide 66.

8. A method for producing a polyester, comprising: a step of producing adipic acid by the method according to claim 3 or 4; and a step of polycondensing the adipic acid obtained in the step with a glycol, or adipic acid, a glycol, and a dicarboxylic acid.

9. 9. The method for producing a polyester according to claim 8, wherein the glycol is a glycol containing 1,4-butanediol.

10. The method for producing a polyester according to claim 8 or 9, wherein the dicarboxylic acid is a dicarboxylic acid containing terephthalic acid or succinic acid.

11. The method for producing a polyester according to any one of claims 8 to 10, wherein the polyester is polybutylene adipate terephthalate or polybutylene succinate adipate.

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