Onium salts, onium salt compositions, liquid compositions containing such onium salts and polysaccharides, methods for producing the same, and methods for recovering polysaccharides

Abstract

The present invention relates to an onium salt, a liquid composition containing the onium salt and a polysaccharide, and a method for recovering a polysaccharide. The invention can provide an onium salt that has a very high polysaccharide solubility at temperatures of 10-50°C, in particular, around room temperature (25°C). Also, the invention can provide a liquid composition containing the aforesaid onium salt and a polysaccharide, as a composition suitable for recovering the polysaccharide, and a method for efficiently recovering a polysaccharide with the use of such a liquid composition containing an onium salt and the polysaccharide.

Description

Technical Field

[0001] The present invention relates to an onium salt, an onium salt composition, a liquid composition containing the onium salt and a polysaccharide, a method for producing the same, and a method for recovering the polysaccharide.

Background Art

[0002] Polysaccharides are substances in which a large number of monosaccharide molecules are polymerized by glycosidic bonds. Among them, cellulose, a polysaccharide composed of β-glucose molecules, is the most abundant biomass resource on earth, and research on dissolution and molding has been widely conducted as an environmentally friendly material. In addition, chitin and chitosan, which are polysaccharides having N-acetylglucosamine and glucosamine as main constituent sugars, are obtained from the shells of crustaceans and are used in various technical fields as materials with excellent biocompatibility and biodegradability. However, since these polysaccharides have strong hydrogen bonds between or within molecular chains, it is difficult to dissolve them in general solvents.

[0003] Onium salts have been proposed as solvents for dissolving cellulose, and Patent Document 1 describes 1-butyl-3-methylimidazolium chloride and the like, and Non-Patent Document 1 describes 1-ethyl-3-methylimidazolium acetate and the like.

[0004] For the purpose of dissolving various polysaccharides such as cellulose near room temperature, Patent Document 2 describes 1-ethyl-3-methylimidazolium dimethyl phosphate and the like. In addition, Patent Document 3 describes N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium 3-(2-methoxyethoxy)propionate and the like as onium salts for dissolving cellulose.

[0005] Similarly, onium salts have been proposed as solvents for dissolving chitin, and Non-Patent Document 2 describes 1-butyl-3-methylimidazolium acetate and the like.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Non-Patent Document

[0007]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] Although various onium salts have been proposed by the prior art, most onium salts have a low cellulose solubility of 5% or less around 25°C. Therefore, it has been necessary to heat these onium salts for use as a solvent for dissolving cellulose. In the case of chitin, sufficient solubility cannot be obtained unless the onium salt is heated to about 100°C. An object of the present invention is to provide an onium salt having a high polysaccharide solubility at a temperature of 10-50°C, particularly around room temperature (25°C). Furthermore, an object of the present invention is to provide a liquid composition containing the onium salt and a polysaccharide as a composition suitable for recovering the polysaccharide, and a method for efficiently recovering the polysaccharide using the liquid composition containing the onium salt and the polysaccharide.

Means for Solving the Problems

[0009] The present inventors have intensively studied substances that can be used as solvents for sufficiently dissolving polysaccharides at a temperature of 10 to 50°C, particularly around room temperature (25°C), and have completed the present invention.

[0010] That is, the present invention provides the following [1] to

[20] . [1] An onium salt represented by the following formula (1). Formula (1):

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[10] A method for producing a compound represented by formula (1), comprising ion-exchanging a compound represented by formula (3) with a compound represented by formula (4). Formula (3):

Chemical formula

Chemical formula

Chemical formula

[11] A polysaccharide-containing liquid composition comprising at least one polysaccharide and an onium salt represented by the following formula (1) or the onium salt composition described in [7], wherein the polysaccharide is dissolved in the onium salt. Formula (1): [Chemical formula] [In the formula, R 1 and R 2 are the same or different and each represents a hydrocarbon group having 2 to 12 carbon atoms containing 1 to 5 heteroatoms, or a group represented by the following formula (1a). -O-R a (1a) (R a represents a hydrocarbon group having 1 to 12 carbon atoms which may contain 1 to 4 heteroatoms.)R 3 represents a hydrogen atom or a hydrocarbon group which may contain a heteroatom. The heteroatom is at least one selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom. R 4 represents a hydrocarbon group. However, when R 1 is (2-methoxyethoxy)methyl, R 2 is 2-[2-(2-methoxyethoxy)ethoxy]ethyl, and R 3 is a hydrogen atom, R 4 represents a hydrocarbon group having 2 or more carbon atoms.)

[12] The polysaccharide-containing liquid composition according to

[11] further contains at least one organic solvent, and the polysaccharide is dissolved in a medium containing the onium salt or the onium salt composition and the organic solvent.

[13] The polysaccharide-containing liquid composition according to

[12] , wherein the organic solvent is at least one organic solvent selected from the group consisting of dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, and N-methyl-2-pyrrolidone.

[14] A polysaccharide-containing liquid composition wherein the polysaccharide described in

[11] is cellulose.

[15] A method for producing a polysaccharide-containing liquid composition according to any one of

[11] to

[14] , comprising dissolving a polysaccharide using an onium salt represented by the following formula (1) or the onium salt composition described in [7]. Formula (1):

Chemical formula

[16] A method for producing a polysaccharide-containing liquid composition according to

[15] , wherein the temperature for dissolving the polysaccharide is 50 °C or lower.

[17] A method for producing a polysaccharide-containing liquid composition according to

[15] or

[16] , wherein the polysaccharide is cellulose.

[18] A method for recovering a polysaccharide, comprising contacting the polysaccharide-containing liquid composition according to any one of

[11] to

[14] with at least one poor solvent.

[19] A method for recovering a polysaccharide according to

[18] , wherein the poor solvent is selected from the group consisting of water, methanol, ethanol, acetone and a mixed solvent thereof.

[20] A method for recovering a polysaccharide according to

[18] or

[19] , wherein the polysaccharide is cellulose.

Advantages of the Invention

[0011] According to the present invention, an onium salt capable of providing very high solubility of a polysaccharide at a temperature of 10 to 50 °C, particularly around room temperature (25 °C), can be provided. Further, a liquid composition containing the onium salt and a polysaccharide can be provided as a composition suitable for recovering the polysaccharide. Furthermore, a method for efficiently recovering a polysaccharide using the liquid composition containing the onium salt and the polysaccharide can be provided.

Mode for Carrying Out the Invention

[0012] Hereinafter, the present invention will be specifically described. The present invention relates to an onium salt represented by the following formula (1) (hereinafter referred to as onium salt (1)).

[0013] Formula (1):

Chemical formula

[0014] In formula (1), the "hydrocarbon group having 2 to 12 carbon atoms containing 1 to 5 heteroatoms" for R 1 and R 2 may be linear, and may contain a branch, a ring structure, a double bond or a triple bond. The number of heteroatoms is preferably 1 to 3, more preferably 1 to 2. The number of carbon atoms of the hydrocarbon group is preferably 3 to 10, more preferably 4 to 7.

[0015] In formula (1), R 1 and R 2 Examples of the "heteroatom" include a nitrogen atom, an oxygen atom, a sulfur atom and the like.

[0016] In formula (1), R 1 and R 2 In the case of the "hydrocarbon group having 2 to 12 carbon atoms containing 1 to 5 heteroatoms", a hydrocarbon group having 2 to 12 carbon atoms not containing a heteroatom is interrupted or substituted by -O-, -N<, -NH-, -S-, -C(=O)-O-, -C(=O)-, =N-, -C(=O)-N<, -C(=O)-NH-, -O-C(=O)-O-, -O-C(=O)-N<, -O-C(=O)-NH-, -C(=O)-N[-C(=O)-]-, -C(=O)-NH-C(=O)-, >N-C(=O)-N<, >N-C(=O)-NH-, -HN-C(=O)-NH-, -S(=O)-, -S(=O) 2 -, -S(=O) 2 -O-, -O-S(=O) 2 -O-, >N-C(=S)-N<, >N-C(=S)-NH-, -HN-C(=S)-NH-, -C(=N-)-, -C(=NH)- and the like, and the number and combination of interruptions or substitutions by these structures are not particularly limited as long as the number of heteroatoms in R 1 , R 2 is in the range of 1 to 5.

[0017] Preferably, the hydrocarbon group is interrupted or substituted by a -O- or -S- structure, and more preferably, the hydrocarbon group is interrupted or substituted by a -O- structure.

[0018] In the present invention, as the structure in which the hydrocarbon group is interrupted or substituted by a -O- or -S- structure, in addition to structures such as an ether structure and a thioether structure, for example, an epoxy structure or a thioepoxy structure such as an epoxy group, a thioepoxy group, a glycidyl ether group, an epoxycyclohexyl group may be formed. In this case, R 1 or R 2It may be an epoxy group, a thioepoxy group, or the like.

[0019] R 1 and R 2 In the case where two or more -O- or / and -S- structures are included, the number of carbon atoms between the -O- or / and -S- structures is preferably 2 or more.

[0020] R 1 and R 2 The carbon number between the nitrogen atom on the imidazole ring to which each of R 1 and R 2 is bonded and the heteroatom closest to the nitrogen atom on the imidazole ring in R

[0021] In formula (1), R 1 and R 2 The "hydrocarbon group having 2 to 12 carbon atoms and containing no heteroatom" may be linear, and may contain a branch, a ring structure, a double bond, or a triple bond. Examples of the hydrocarbon group having 2 to 12 carbon atoms and containing no heteroatom include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, an aryl group, an aralkyl group, etc., but are not particularly limited.

[0022] In formula (1), R 1 and R 2In the context, examples of the "hydrocarbon group having 2 to 12 carbon atoms and containing 1 to 5 heteroatoms" include a linear or branched alkyl group having 2 to 12 carbon atoms and containing 1 to 5 heteroatoms, a linear or branched alkenyl group having 2 to 12 carbon atoms and containing 1 to 5 heteroatoms, a linear or branched alkynyl group having 2 to 12 carbon atoms and containing 1 to 5 heteroatoms, a cycloalkyl group having 3 to 12 carbon atoms and optionally having a branch and containing 1 to 5 heteroatoms, a cycloalkenyl group having 3 to 12 carbon atoms and optionally having a branch and containing 1 to 5 heteroatoms, an aryl group having 6 to 12 carbon atoms and optionally having a branch and containing 1 to 5 heteroatoms, an aralkyl group having 7 to 12 carbon atoms and optionally having a branch and containing 1 to 5 heteroatoms, and the like. Preferably, it is a linear or branched alkyl group having 2 to 12 carbon atoms and containing 1 to 5 heteroatoms, a linear or branched alkenyl group having 2 to 12 carbon atoms and containing 1 to 5 heteroatoms, or a cycloalkyl group having 3 to 12 carbon atoms and optionally having a branch and containing 1 to 5 heteroatoms. The "linear or branched alkyl group having 2 to 12 carbon atoms and containing 1 to 5 heteroatoms" is preferably a linear or branched alkyl group having 3 to 10 carbon atoms and containing 1 to 3 heteroatoms. In another aspect, it is preferably a linear or branched alkyl group having 3 to 10 carbon atoms and containing 1 to 2 heteroatoms, and more preferably a linear or branched alkyl group having 4 to 7 carbon atoms and containing 1 to 2 heteroatoms. The "linear or branched alkenyl group having 2 to 12 carbon atoms and containing 1 to 5 heteroatoms" is preferably a linear or branched alkenyl group having 3 to 10 carbon atoms and containing 1 to 3 heteroatoms. In another aspect, it is preferably a linear or branched alkenyl group having 3 to 10 carbon atoms and containing 1 to 2 heteroatoms, and more preferably a linear or branched alkenyl group having 4 to 7 carbon atoms and containing 1 to 2 heteroatoms. The "cycloalkyl group which may have a branch having 3 to 12 carbon atoms and containing 1 to 5 heteroatoms" is preferably a cycloalkyl group which may have a branch having 3 to 10 carbon atoms and containing 1 to 3 heteroatoms. In another aspect, it is preferably a cycloalkyl group which may have a branch having 3 to 10 carbon atoms and containing 1 to 2 heteroatoms, more preferably a cycloalkyl group which may have a branch having 4 to 7 carbon atoms and containing 1 to 2 heteroatoms.

[0023] In formula (1), R 1 and R 2 As the hydrocarbon group having 2 to 12 carbon atoms and not containing a heteroatom in R and R, specifically, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, isobutyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, octyl group, 2-ethylhexyl group, decyl group, dodecyl group, propenyl group, isopropenyl group, allyl group, propargyl group, butenyl group, crotyl group, butadienyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, norbornyl group, adamantyl group, phenyl group, benzyl group, tolyl group, 2,4,6-trimethylphenyl group, etc. can be mentioned, but it is not particularly limited. When the hydrocarbon group having 2 to 12 carbon atoms and not containing a heteroatom is interrupted or substituted by structures such as -O-, -N<, -NH-, -S-, -C(=O)-O-, -C(=O)-, =N-, -C(=O)-N<, -C(=O)-NH-, -O-C(=O)-O-, -O-C(=O)-N<, -O-C(=O)-NH-, -C(=O)-N[-C(=O)-]-, -C(=O)-NH-C(=O)-, >N-C(=O)-N<, >N-C(=O)-NH-, -HN-C(=O)-NH-, -S(=O)-, -S(=O) 2 -, -S(=O) 2 -O-, -O-S(=O) 2 -O-, >N-C(=S)-N<, >N-C(=S)-NH-, -HN-C(=S)-NH-, -C(=N-)-, -C(=NH)-, etc., it becomes a "hydrocarbon group having 2 to 12 carbon atoms and containing 1 to 5 heteroatoms".

[0024] In formula (1a), R arepresents a hydrocarbon group having 1 to 12 carbon atoms which may contain 1 to 4 heteroatoms. The "hydrocarbon group having 1 to 12 carbon atoms which may contain 1 to 4 heteroatoms" may be linear, and may contain branches, ring structures, double bonds, or triple bonds. R a In, the hydrocarbon group may contain no heteroatoms or may contain 1 to 4 heteroatoms. R a When R does not contain heteroatoms, the hydrocarbon group has 1 to 12 carbon atoms, preferably 1 to 6, more preferably 1 to 3. R a When R contains heteroatoms, the number of heteroatoms is preferably 1 to 2. R a When R contains heteroatoms, the hydrocarbon group has 2 to 12 carbon atoms, preferably 2 to 6.

[0025] In formula (1a), R a When it is a hydrocarbon group having 2 to 12 carbon atoms containing 1 to 4 heteroatoms, examples of the "heteroatom" include a nitrogen atom, an oxygen atom, a sulfur atom, etc.

[0026] In formula (1a), R a In, the "hydrocarbon group having 2 to 12 carbon atoms containing 1 to 4 heteroatoms" means that a hydrocarbon group having 2 to 12 carbon atoms not containing heteroatoms is interrupted or substituted by structures such as -O-, -N<, -NH-, -S-, -C(=O)-O-, -C(=O)-, =N-, -C(=O)-N<, -C(=O)-NH-, -O-C(=O)-O-, -O-C(=O)-N<, -O-C(=O)-NH-, -C(=O)-N[-C(=O)-]-, -C(=O)-NH-C(=O)-, >N-C(=O)-N<, >N-C(=O)-NH-, -HN-C(=O)-NH-, -S(=O)-, -S(=O) 2 -, -S(=O) 2 -O-, >N-C(=S)-N<, >N-C(=S)-NH-, -HN-C(=S)-NH-, -C(=N-)-, -C(=NH)-, etc., and the number and combination of interruptions or substitutions by these structures are not particularly limited as long as the number of heteroatoms in R a is in the range of 1 to 4.

[0027] Preferably, the hydrocarbon group is interrupted or substituted by an -O- or -S- structure, more preferably, the hydrocarbon group is interrupted or substituted by an -O- structure.

[0028] In the present invention, as the structure in which the hydrocarbon group is interrupted or substituted by an -O- or -S- structure, in addition to structures such as an ether structure and a thioether structure, for example, an epoxy structure or a thioepoxy structure such as an epoxy group, a thioepoxy group, a glycidyl ether group, an epoxycyclohexyl group, etc. may be formed. In this case, R a may be an epoxy group, a thioepoxy group or the like.

[0029] In formula (1a), when R a contains two or more -O- or / and -S- structures, it is desirable that the number of carbon atoms between the -O- or / and -S- structures is 2 or more. The number of carbon atoms between the oxygen atom to which R a is bonded and the heteroatom in R a closest to the oxygen atom is more desirably 2 or more.

[0030] In formula (1a), the "hydrocarbon group having 1 to 12 carbon atoms without heteroatoms" and the "hydrocarbon group having 2 to 12 carbon atoms without heteroatoms" in R a may be linear, and may contain a branch, a ring structure, a double bond, or a triple bond. Examples of the "hydrocarbon group having 1 to 10 carbon atoms without heteroatoms" and the "hydrocarbon group having 2 to 12 carbon atoms without heteroatoms" include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, an aryl group, an aralkyl group, etc., but are not particularly limited.

[0031] In formula (1a), R aIn the context, the "hydrocarbon group having 1 to 12 carbon atoms which may contain 1 to 4 heteroatoms" includes an alkyl group having 1 to 12 carbon atoms with a straight or branched chain which may contain 1 to 4 heteroatoms, an alkenyl group having 2 to 12 carbon atoms with a straight or branched chain which may contain 1 to 4 heteroatoms, an alkynyl group having 2 to 12 carbon atoms with a straight or branched chain which may contain 1 to 4 heteroatoms, a cycloalkyl group which may have a branch and has 3 to 12 carbon atoms and may contain 1 to 4 heteroatoms, a cycloalkenyl group which may have a branch and has 3 to 12 carbon atoms and may contain 1 to 4 heteroatoms, an aryl group which may have a branch and has 6 to 12 carbon atoms and contains 1 to 5 heteroatoms, an aralkyl group which may have a branch and has 7 to 12 carbon atoms and may contain 1 to 4 heteroatoms, and the like. Preferably, it is an alkyl group having 1 to 12 carbon atoms with a straight or branched chain which may contain 1 to 4 heteroatoms, an alkenyl group having 2 to 12 carbon atoms with a straight or branched chain which may contain 1 to 4 heteroatoms, or a cycloalkyl group which may have a branch and has 3 to 12 carbon atoms and may contain 1 to 4 heteroatoms. The "alkyl group having 1 to 12 carbon atoms with a straight or branched chain which may contain 1 to 4 heteroatoms" is preferably an alkyl group having 1 to 6 carbon atoms with a straight or branched chain which may contain 1 to 4 heteroatoms. In another aspect, preferably, it is an alkyl group having 2 to 12 carbon atoms with a straight or branched chain which may contain 1 to 2 heteroatoms, and more preferably, it is an alkyl group having 1 to 6 carbon atoms with a straight or branched chain which may contain 1 to 2 heteroatoms. In yet another aspect, preferably, it is an alkyl group having 1 to 12 carbon atoms with a straight or branched chain, more preferably, it is an alkyl group having 1 to 6 carbon atoms with a straight or branched chain, and still more preferably, it is an alkyl group having 1 to 3 carbon atoms with a straight or branched chain. The "alkenyl group having a straight or branched chain with 2 to 12 carbon atoms and optionally containing 1 to 4 heteroatoms" is preferably an alkenyl group having a straight or branched chain with 2 to 6 carbon atoms and optionally containing 1 to 4 heteroatoms. As another embodiment, it is preferably an alkenyl group having a straight or branched chain with 2 to 12 carbon atoms and optionally containing 1 to 2 heteroatoms, more preferably an alkenyl group having a straight or branched chain with 2 to 6 carbon atoms and optionally containing 1 to 2 heteroatoms. As yet another embodiment, it is preferably an alkenyl group having a straight or branched chain with 2 to 12 carbon atoms, more preferably an alkenyl group having a straight or branched chain with 2 to 6 carbon atoms, and even more preferably an alkenyl group having a straight or branched chain with 2 to 3 carbon atoms. The "cycloalkyl group having a branched chain with 3 to 12 carbon atoms and optionally containing 1 to 4 heteroatoms" is preferably a cycloalkyl group having a branched chain with 3 to 6 carbon atoms and optionally containing 1 to 4 heteroatoms. As another embodiment, it is preferably a cycloalkyl group having a branched chain with 3 to 12 carbon atoms and optionally containing 1 to 2 heteroatoms, more preferably a cycloalkyl group having a branched chain with 3 to 6 carbon atoms and optionally containing 1 to 2 heteroatoms. As yet another embodiment, it is preferably a cycloalkyl group having a branched chain with 3 to 12 carbon atoms, more preferably a cycloalkyl group having a branched chain with 3 to 6 carbon atoms, and even more preferably a cycloalkyl group having a branched chain with 3 carbon atoms.

[0032] In formula (1), R aWhen it is a hydrocarbon group having 1 to 12 carbon atoms and containing no heteroatom, the "hydrocarbon group having 1 to 12 carbon atoms" specifically includes a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, an octyl group, a 2-ethylhexyl group, a decyl group, a dodecyl group, a vinyl group, an ethynyl group, a propenyl group, an isopropenyl group, an allyl group, a propargyl group, a butenyl group, a crotyl group, a butadienyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, a phenyl group, a benzyl group, a tolyl group, a 2,4,6-trimethylphenyl group, etc., but is not particularly limited.

[0033] In formula (1), R a In this case, examples of the hydrocarbon group having 2 to 12 carbon atoms and containing no heteroatom include an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, an octyl group, a 2-ethylhexyl group, a decyl group, a dodecyl group, a propenyl group, an isopropenyl group, an allyl group, a propargyl group, a butenyl group, a crotyl group, a butadienyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, a phenyl group, a benzyl group, a tolyl group, a 2,4,6-trimethylphenyl group, etc., but is not particularly limited. The hydrocarbon group having 2 to 12 carbon atoms and containing no heteroatom is -O-, -N<, -NH-, -S-, -C(=O)-O-, -C(=O)-, =N-, -C(=O)-N<, -C(=O)-NH-, -O-C(=O)-O-, -O-C(=O)-N<, -O-C(=O)-NH-, -C(=O)-N[-C(=O)-]-, -C(=O)-NH-C(=O)-, >N-C(=O)-N<, >N-C(=O)-NH-, -HN-C(=O)-NH-, -S(=O)-, -S(=O) 2 -, -S(=O) 2When interrupted or substituted by structures such as -O-, >N-C(=S)-N<, >N-C(=S)-NH-, -HN-C(=S)-NH-, -C(=N-)-, -C(=NH)-, etc., it becomes "a hydrocarbon group having 2 to 12 carbon atoms and containing 1 to 4 heteroatoms".

[0034] R shown in formula (1) 1 and R 2Specifically, as the structure, 2-methoxyethyl, 2-ethoxyethyl, 2-propoxyethyl, 2-isopropoxyethyl, 2-phenoxyethyl, 2-(benzyloxy)ethyl, 2-(p-methoxybenzyloxy)ethyl, 2-(2-methoxyethoxymethoxy)ethyl, 2-(2-benzyloxyethoxy)ethyl, 2-(dimethylamino)ethyl, 3-methoxypropyl, 3-ethoxypropyl, 3-propoxypropyl, 3-allyloxypropyl, 3-isopropoxypropyl, 3-(1-methylpropoxy)propyl, 3-(2-methylpropoxy)propyl, 3-(1,1-dimethylethoxy)propyl, 3-butoxypropyl, 3-pentyloxypropyl, 3-neopentyloxypropyl, 3-hexyloxypropyl, 3-cyclohexyloxypropyl, 3-heptyloxypropyl, 3-octyloxypropyl, 3-nonyloxypropyl, 3-(2-ethylhexan-1-yl)oxypropyl, 3-(2,4,6-trimethylphenoxy)propyl, 3-(2-methoxyethoxy)propyl, 3-(dimethylamino)propyl, 4-methoxybutyl, 4-ethoxybutyl, 4-propoxybutyl, 4-isopropoxybutyl, 4-allyloxybutyl, 4-butoxybutyl, 4-(1-methylpropoxy)butyl, 4-(2-methylpropoxy)butyl, 4-(1,1-dimethylethoxy)butyl, 4-pentyloxybutyl, 4-neopentyloxybutyl, 4-hexyloxybutyl, 4-cyclohexyloxybutyl, 4-heptyloxybutyl, 4-octyloxybutyl, 4-(2-ethylhexan-1-yl)oxybutyl, 5-methoxypentyl, 5-ethoxypentyl, 5-propoxypentyl, 5-isopropoxypentyl, 5-allyloxypentyl, 5-butoxypentyl, 5-(1-methylpropoxy)pentyl, 5-(2-methylpropoxy)pentyl, 5-(1,(1-dimethylethoxy)pentyl, 5-pentyloxypentyl, 5-neopentyloxypentyl, 5-hexyloxypentyl, 5-cyclohexyloxypentyl, 5-heptyloxypentyl, 6-methoxyhexyl, 6-ethoxyhexyl, 6-propoxyhexyl, 6-isopropoxyhexyl, 6-allyloxyhexyl, 6-butoxyhexyl, 6-(1-methylpropoxy)hexyl, 6-(2-methylpropoxy)hexyl, 6-(1,1-dimethylethoxy)hexyl, 6-pentyloxypentyl, 6-neopentyloxypentyl, 6-hexyloxypentyl, 6-cyclohexyloxypentyl, (2-methoxycyclohexan-1-yl)methyl, (2-ethoxycyclohexan-1-yl)methyl, (2-propoxycyclohexan-1-yl)methyl, (2-isopropoxycyclohexan-1-yl)methyl, (2-butoxycyclohexan-1-yl)methyl, [2-(1-methylpropoxy)cyclohexan-1-yl]methyl, [2-(2-methylpropoxy)cyclohexan-1-yl]methyl, [2-(1,1-dimethylethoxy)cyclohexan-1-yl]methyl, (2-pentyloxypentyl)methyl, (2-neopentyloxypentyl)methyl, 2-methylthioethyl, 3-methylthiopropyl, 1-(methoxymethyl)propyl, (oxolan-2-yl)methyl, (furan-2-yl)methyl, 2-[(furan-2-yl)methylthio]ethyl, 2-(methylsulfonyl)ethyl, (thiophen-2-yl)methyl, p-methoxyphenyl, p-ethoxyphenyl, 3,4-methylenedioxyphenyl, 3,4-methylenedioxybenzyl, (7-oxabicyclo[2,2,1]heptan-2-yl)methyl and the like. Preferred are 2-methoxyethyl, 3-methoxypropyl, 3-ethoxypropyl, 3-isopropoxypropyl, 3-butoxypropyl, 3-(2-methoxyethoxy)propyl, 3-methylthiopropyl, 3-(dimethylamino)propyl, more preferred are 2-methoxyethyl, 3-methoxypropyl, 3-(2-methoxyethoxy)propyl, but the present invention is not limited thereto.,

[0035] In formula (1), R 1 and R 2 are preferably the same.

[0036] In formula (1), R 3 represents a hydrocarbon group which may contain a hydrogen atom or a heteroatom. The "hydrocarbon group which may contain a heteroatom" may be linear, and may contain a branch, a ring structure, a double bond or a triple bond. Also, in R 3 , the hydrocarbon group may or may not contain a heteroatom.

[0037] In formula (1), when R 3 is a hydrocarbon group not containing a heteroatom, the number of carbon atoms is preferably 1 to 12, more preferably 1 to 8, and still more preferably 1 to 3. When R 3 is a hydrocarbon group containing a heteroatom, the number of carbon atoms is preferably 2 to 12, more preferably 2 to 8, and still more preferably 2 to 4.

[0038] In formula (1), when R 3 contains a heteroatom, the number of heteroatoms is preferably 1 to 5, more preferably 1 to 2. The number of carbon atoms of the hydrocarbon group is 2 or more, preferably 2 to 12, more preferably 2 to 8, and still more preferably 2 to 4.

[0039] In formula (1), when R 3 is a hydrocarbon group containing a heteroatom, examples of the "heteroatom" include a nitrogen atom, an oxygen atom, a sulfur atom, etc.

[0040] R 3 Examples of the "heteroatom" when it is a hydrocarbon group containing a heteroatom include a nitrogen atom, an oxygen atom, a sulfur atom, etc. Also, the number of heteroatoms is preferably 1 to 5, more preferably 1 to 2.

[0041] In formula (1), R 3In this context, a "hydrocarbon group containing a heteroatom" is a hydrocarbon group without a heteroatom interrupted or substituted by structures such as -O-, -N<, -NH-, -S-, -C(=O)-O-, -C(=O)-, =N-, -C(=O)-N<, -C(=O)-NH-, -O-C(=O)-O-, -O-C(=O)-N<, -O-C(=O)-NH-, -C(=O)-N[-C(=O)-]-, -C(=O)-NH-C(=O)-, >N-C(=O)-N<, >N-C(=O)-NH-, -HN-C(=O)-NH-, -S(=O)-, -S(=O) 2 -, -S(=O) 2 -, -O-S(=O) 2 -, -O-, >N-C(=S)-N<, >N-C(=S)-NH-, -HN-C(=S)-NH-, -C(=N-)-, -C(=NH)-, etc., and the number and combination of interruptions or substitutions by these structures are not particularly limited, but 3 it is preferable that there are 1 to 5 heteroatoms in R, and more preferably 1 to 2 heteroatoms.

[0042] Preferably, the hydrocarbon group is interrupted or substituted by a -O- or -S- structure, and more preferably, the hydrocarbon group is interrupted or substituted by a -O- structure.

[0043] In the present invention, as a structure in which a hydrocarbon group is interrupted or substituted by a -O- or -S- structure, in addition to structures such as an ether structure and a thioether structure, for example, an epoxy structure or a thioepoxy structure such as an epoxy group, a thioepoxy group, a glycidyl ether group, or an epoxycyclohexyl group may be formed. In this case, 3 R may be an epoxy group, a thioepoxy group, or the like.

[0044] R 3 When R contains two or more -O- or / and -S- structures, it is desirable that the number of carbon atoms between the -O- or / and -S- structures is 2 or more.

[0045] In formula (1), R 3Examples of the "hydrocarbon group which may contain a heteroatom" include a linear or branched alkyl group which may contain a heteroatom, a linear or branched alkenyl group which may contain a heteroatom, a linear or branched alkynyl group which may contain a heteroatom, a cycloalkyl group which may contain a heteroatom and may have a branch, a cycloalkenyl group which may contain a heteroatom and may have a branch, an aryl group which may contain a heteroatom and may have a branch, an aralkyl group which may contain a heteroatom and may have a branch, etc. Preferred are a linear or branched alkyl group which may contain a heteroatom, a linear or branched alkenyl group which may contain a heteroatom, and a cycloalkyl group which may contain a heteroatom and may have a branch. The "linear or branched alkyl group which may contain a heteroatom" is preferably an alkyl group having 1 to 12 carbon atoms which may contain 1 to 5 heteroatoms and has a linear or branched structure. In another embodiment, it is preferably an alkyl group having 1 to 12 carbon atoms which may contain 1 to 2 heteroatoms and has a linear or branched structure, more preferably an alkyl group having 1 to 8 carbon atoms which may contain 1 to 2 heteroatoms and has a linear or branched structure, and still more preferably an alkyl group having 1 to 4 carbon atoms which may contain 1 to 2 heteroatoms and has a linear or branched structure. In yet another embodiment, it is preferably an alkyl group having 1 to 12 carbon atoms and having a linear or branched structure, more preferably an alkyl group having 1 to 8 carbon atoms and having a linear or branched structure, and still more preferably an alkyl group having 1 to 3 carbon atoms and having a linear or branched structure. The "alkenyl group which may contain a heteroatom and may have a straight chain or a branch" is preferably an alkenyl group having a straight chain or a branch with 2 to 12 carbon atoms which may contain 1 to 5 heteroatoms. In another embodiment, it is preferably an alkenyl group having a straight chain or a branch with 2 to 12 carbon atoms which may contain 1 to 2 heteroatoms, more preferably an alkenyl group having a straight chain or a branch with 2 to 8 carbon atoms which may contain 1 to 2 heteroatoms, and still more preferably an alkenyl group having a straight chain or a branch with 2 to 4 carbon atoms which may contain 1 to 2 heteroatoms. In yet another embodiment, it is preferably an alkenyl group having a straight chain or a branch with 2 to 12 carbon atoms, more preferably an alkenyl group having a straight chain or a branch with 2 to 8 carbon atoms, and still more preferably an alkenyl group having a straight chain or a branch with 2 to 3 carbon atoms. The "cycloalkyl group which may contain a heteroatom and may have a branch" is preferably a cycloalkyl group which may have a branch with 3 to 12 carbon atoms and may contain 1 to 5 heteroatoms. In another embodiment, it is preferably a cycloalkyl group which may have a branch with 3 to 12 carbon atoms and may contain 1 to 2 heteroatoms, more preferably a cycloalkyl group which may have a branch with 3 to 8 carbon atoms and may contain 1 to 2 heteroatoms, and still more preferably a cycloalkyl group which may have a branch with 3 to 4 carbon atoms and may contain 1 to 2 heteroatoms. In yet another embodiment, it is preferably a cycloalkyl group which may have a branch with 3 to 12 carbon atoms, more preferably a cycloalkyl group which may have a branch with 3 to 8 carbon atoms, and still more preferably a cycloalkyl group with 3 carbon atoms.

[0046] In formula (1), R 3In the above, specific examples of the "hydrocarbon group not containing a hetero atom" include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, an octyl group, a 2-ethylhexyl group, a decyl group, a dodecyl group, a vinyl group, an ethynyl group, a propenyl group, an isopropenyl group, an allyl group, a propargyl group, a butenyl group, a crotyl group, a butadienyl group, a cyclopropyl group, a cyclobutyl ... Examples of the aryl group include a methyl group, an ethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, a phenyl group, a benzyl group, a tolyl group, a styryl group, and a 2,4,6-trimethylphenyl group. Of these, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a neopentyl group, and a hexyl group are preferred, and a methyl group, an ethyl group, a propyl group, an isopropyl group, and a tert-butyl group are more preferred.

[0047] In formula (1), R 3 In the above, the "hydrocarbon group containing a hetero atom" is preferably a 3-indolyl group, a p-methoxyphenyl group, a 7-oxabicyclo[2,2,1]hept-5-en-2-yl group, a 1,2-epoxyethyl group, a 1-methyl-2-methoxyvinyl group, a 2-furyl group, a 2-pyridyl group, a 4-imidazolyl group, or a benzyloxymethyl group, and more preferably a 1-methyl-2-methoxyvinyl group or a 2-furyl group, although the present invention is not limited thereto.

[0048] In formula (1), R 3 is preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

[0049] In formula (1), R 1 ~R 3 may be bonded together with the nitrogen atom or carbon atom to which they are attached to form a ring structure. 1 and R 2 , R 1 and R 3 , or R 2and R 3 Examples thereof include a structure in which they are bonded and crosslinked by a hydrocarbon having 2 to 24 carbon atoms containing 2 to 10 heteroatoms to form a cyclic structure, but it is not particularly limited.

[0050] In formula (1), R 4 represents a hydrocarbon group, which may be linear, and may contain a branch, a ring structure, a double bond, or a triple bond. Preferably, it is a hydrocarbon group having 1 to 12 carbon atoms, more preferably a hydrocarbon group having 1 to 8 carbon atoms, and still more preferably a hydrocarbon group having 1 to 3 carbon atoms.

[0051] In formula (1), examples of the "hydrocarbon group" of R 4 include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, an aryl group, an aralkyl group, etc. Preferably, it is a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkenyl group having 1 to 12 carbon atoms, a linear or branched alkynyl group having 1 to 12 carbon atoms, a cycloalkyl group which may have a branch and has 3 to 12 carbon atoms, a cycloalkenyl group which may have a branch and has 3 to 12 carbon atoms, an aryl group which may have a branch and has 6 to 12 carbon atoms, an aralkyl group which may have a branch and has 7 to 12 carbon atoms, and more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, a linear or branched alkenyl group having 1 to 3 carbon atoms.

[0052] In formula (1), R 4Examples of the "hydrocarbon group" specifically include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, isobutyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonyl group, decyl group, undecyl group, dodecyl group, vinyl group, ethynyl group, propenyl group, isopropenyl group, allyl group, propargyl group, 1-propynyl group, butenyl group, crotyl group, butadienyl group, pentadienyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, norbornyl group, adamantyl group, phenyl group, benzyl group, tolyl group, styryl group, 2,4,6-trimethylphenyl group, naphthyl group, 2,6-dimethyl-1,5-heptadienyl group, etc., but are not particularly limited.

[0053] In formula (1), R 4 -CO-O - Examples of the anion represented by specifically include acetate ion, propionate ion, acrylate ion, propargylate ion, butyrate ion, isobutyrate ion, methacrylate ion, crotonate ion, tetrolate ion, cyclopropanecarboxylate ion, valerate ion, isovalerate ion, pivalate ion, angelate ion, tiglate ion, cyclobutanecarboxylate ion, caproate ion, cyclopentanecarboxylate ion, enanthate ion, sorbate ion, cyclohexanecarboxylate ion, benzoate ion, caprylate ion, 2-ethylhexylcarboxylate ion, toluylate ion, 2-norbornanecarboxylate ion, pelargonate ion, cinnamate ion, capric ion, adamantanecarboxylate ion, geranate ion, undecylate ion, laurate ion, naphthalenecarboxylate ion, etc. Preferably, they are acetate ion, propionate ion, acrylate ion, propargylate ion, butyrate ion, isobutyrate ion, methacrylate ion, crotonate ion, tetrolate ion, valerate ion, isovalerate ion, pivalate ion, and particularly preferably acetate ion, acrylate ion or methacrylate ion, but the present invention is not limited thereto.

[0054] In formula (2), R 5 represents a divalent hydrocarbon group having 2 to 5 carbon atoms. The "divalent hydrocarbon group having 2 to 5 carbon atoms" may be linear, and may contain a branch, a ring structure, a double bond, or a triple bond. Examples thereof include an alkylene group having 2 to 5 carbon atoms, an alkenylene group having 2 to 5 carbon atoms, an alkynylene group having 2 to 5 carbon atoms, a cycloalkylene group having 3 to 5 carbon atoms, a cycloalkenylene group having 3 to 5 carbon atoms, etc. Preferably, it is an alkylene group having 2 to 3 carbon atoms or an alkenylene group having 2 to 3 carbon atoms, and particularly preferably, it is an alkylene group having 3 carbon atoms.

[0055] In formula (2), R 5 Specifically, as R, an ethane-1,2-diyl group, a propane-1,3-diyl group, a propane-1,2-diyl group, a cyclopropane-1,2-diyl group, a butane-1,4-diyl group, a butane-1,3-diyl group, a butane-1,2-diyl group, a cyclobutane-1,3-diyl group, a cyclobutane-1,2-diyl group, a 2-methylpropane-1,2-diyl group, a 2-methylpropane-1,3-diyl group, a pentane-1,5-diyl group, a pentane-1,4-diyl group, a pentane-1,3-diyl group, a pentane-1,2-diyl group, a cyclopentane-1,3-diyl group, a cyclopentane-1,2-diyl group, a 2-methylbutane-2,4-diyl group, a 2-methylbutane-1,3-diyl group, a 2-methylbutane-1,4-diyl group, a 2,2-dimethylpropane-1,3-diyl group, a 1,3-butadiene-1,4-diyl group, a 2-propene-1,3-diyl group, etc. can be mentioned, but it is not particularly limited.

[0056] In formula (2), R 6 represents a hydrocarbon group having 1 to 10 carbon atoms which may contain 1 to 4 heteroatoms.

[0057] R 6In this case, the "hydrocarbon group having 1 to 10 carbon atoms which may contain 1 to 4 heteroatoms" may be linear, and may contain branches, ring structures, double bonds, or triple bonds. Further, it may contain no heteroatoms or may contain 1 to 4 heteroatoms.

[0058] In formula (2), R 6 is preferably 1 to 10, more preferably 1 to 8, and even more preferably 1 to 3 as the number of carbon atoms of the hydrocarbon group which may contain heteroatoms. R 6 When it is a hydrocarbon group containing no heteroatoms, the number of carbon atoms is preferably 1 to 10, more preferably 1 to 7, and even more preferably 1 to 3. R 6 When it is a hydrocarbon group containing heteroatoms, the number of carbon atoms is preferably 2 to 10, more preferably 2 to 7, and even more preferably 2 to 4.

[0059] In formula (2), R 6 When it is a hydrocarbon group containing 1 to 4 heteroatoms, examples of the "heteroatoms" include a nitrogen atom, an oxygen atom, a sulfur atom, etc.

[0060] In formula (2), R 6 In this case, the "hydrocarbon group having 2 to 10 carbon atoms which contains 1 to 4 heteroatoms" is a hydrocarbon group having 2 to 10 carbon atoms containing no heteroatoms interrupted or substituted by structures such as -O-, -N<, -NH-, -S-, -C(=O)-O-, -C(=O)-, =N-, -C(=O)-N<, -C(=O)-NH-, -O-C(=O)-O-, -O-C(=O)-N<, -O-C(=O)-NH-, -C(=O)-N[-C(=O)-]-, -C(=O)-NH-C(=O)-, >N-C(=O)-N<, >N-C(=O)-NH-, -HN-C(=O)-NH-, -S(=O)-, -S(=O) 2 -, -S(=O) 2 -O-, >N-C(=S)-N<, >N-C(=S)-NH-, -HN-C(=S)-NH-, -C(=N-)-, -C(=NH)-, etc., and the number and combination of interruptions or substitutions by these structures are R 6There is no particular limitation as long as the number of heteroatoms therein is in the range of 1 to 4.

[0061] Preferably, it is one in which a hydrocarbon group is interrupted or substituted by a structure of -O- or -S-, and more preferably, it is one in which a hydrocarbon group is interrupted or substituted by a structure of -O-.

[0062] In the present invention, as a structure in which a hydrocarbon group is interrupted or substituted by a structure of -O- or -S-, in addition to structures such as an ether structure and a thioether structure, for example, an epoxy structure or a thioepoxy structure such as an epoxy group, a thioepoxy group, a glycidyl ether group, an epoxycyclohexyl group, etc. may be formed. In this case, R 6 may be an epoxy group, a thioepoxy group or the like.

[0063] R 6 When containing two or more structures of -O- or / and -S-, it is desirable that the number of carbon atoms between the structures of -O- or / and -S- is 2 or more.

[0064] In formula (2), the "hydrocarbon group having 2 to 10 carbon atoms and containing no heteroatom" in R 6 may be linear, and may contain a branch, a ring structure, a double bond or a triple bond. Examples of the hydrocarbon group containing no heteroatom include an alkyl group having a straight chain or a branch, an alkenyl group having a straight chain or a branch, an alkynyl group having a straight chain or a branch, a cycloalkyl group which may have a branch, a cycloalkenyl group which may have a branch, an aryl group which may have a branch, an aralkyl group which may have a branch, etc. Preferably, it is an alkyl group having a straight chain or a branch, an alkenyl group having a straight chain or a branch, or a cycloalkyl group which may have a branch. Examples of the "hydrocarbon group having 1 to 10 carbon atoms which may contain 1 to 4 heteroatoms" include an alkyl group having 1 to 10 carbon atoms which may be linear or branched and may contain 1 to 4 heteroatoms, an alkenyl group having 2 to 10 carbon atoms which may be linear or branched and may contain 1 to 4 heteroatoms, an alkynyl group having 2 to 10 carbon atoms which may be linear or branched and may contain 1 to 4 heteroatoms, a cycloalkyl group having 3 to 10 carbon atoms which may have a branch and may contain 1 to 4 heteroatoms, a cycloalkenyl group having 3 to 10 carbon atoms which may have a branch and may contain 1 to 4 heteroatoms, an aryl group having 6 to 10 carbon atoms which may have a branch and may contain 1 to 5 heteroatoms, an aralkyl group having 7 to 10 carbon atoms which may have a branch and may contain 1 to 4 heteroatoms, and the like. Preferably, they are an alkyl group having 1 to 10 carbon atoms which may be linear or branched and may contain 1 to 4 heteroatoms, an alkenyl group having 2 to 10 carbon atoms which may be linear or branched and may contain 1 to 4 heteroatoms, and a cycloalkyl group having 3 to 10 carbon atoms which may have a branch and may contain 1 to 4 heteroatoms. The "alkyl group having 1 to 10 carbon atoms which may be linear or branched and may contain 1 to 4 heteroatoms" is preferably an alkyl group having 2 to 10 carbon atoms which may be linear or branched and may contain 1 to 2 heteroatoms. In another aspect, it is preferably an alkyl group having 2 to 7 carbon atoms which may be linear or branched and may contain 1 heteroatom, more preferably an alkyl group having 2 to 4 carbon atoms which may be linear or branched and may contain 1 heteroatom. In yet another aspect, it is preferably an alkyl group having 1 to 7 carbon atoms which may be linear or branched, more preferably an alkyl group having 1 to 4 carbon atoms which may be linear or branched. The "alkenyl group having 2 to 10 carbon atoms which may contain 1 to 4 heteroatoms and may be linear or branched" is preferably an alkenyl group having 2 to 10 carbon atoms which may contain 1 to 2 heteroatoms and may be linear or branched. In another aspect, it is preferably an alkenyl group having 2 to 7 carbon atoms which may contain 1 heteroatom and may be linear or branched, more preferably an alkenyl group having 2 to 4 carbon atoms which may contain 1 heteroatom and may be linear or branched. In yet another aspect, it is preferably an alkenyl group having 2 to 7 carbon atoms and may be linear or branched, more preferably an alkenyl group having 2 to 4 carbon atoms and may be linear or branched. The "cycloalkyl group having 3 to 10 carbon atoms which may have a branch and may contain 1 to 4 heteroatoms" is preferably a cycloalkyl group having 3 to 10 carbon atoms which may have a branch and may contain 1 to 2 heteroatoms. In another aspect, it is preferably a cycloalkyl group having 3 to 7 carbon atoms which may have a branch and may contain 1 heteroatom, more preferably a cycloalkyl group having 3 to 7 carbon atoms which may have a branch and may contain 1 heteroatom. In yet another aspect, it is preferably a cycloalkyl group having 3 to 7 carbon atoms and may have a branch, more preferably a cycloalkyl group having 3 to 4 carbon atoms and may have a branch.

[0065] In formula (2), R 6 When it is a hydrocarbon group having 1 to 10 carbon atoms that does not contain a heteroatom, the "hydrocarbon group having 1 to 10 carbon atoms" specifically includes a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, an octyl group, a 2-ethylhexyl group, a decyl group, a dodecyl group, a propenyl group, an isopropenyl group, an allyl group, a propargyl group, a butenyl group, a crotyl group, a butadienyl group, a geranyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, a phenyl group, a benzyl group, a 2,4,6-trimethylphenyl group, etc., but is not particularly limited.

[0066] R 6In this context, examples of the "hydrocarbon group having 2 to 10 carbon atoms and containing no heteroatom" as the "hydrocarbon group having 2 to 10 carbon atoms" include an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, an octyl group, a 2-ethylhexyl group, a decyl group, a vinyl group, an ethynyl group, a propenyl group, an isopropenyl group, an allyl group, a propargyl group, a butenyl group, a crotyl group, a butadienyl group, a geranyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, a phenyl group, a benzyl group, a 2,4,6-trimethylphenyl group, etc. Preferably, it is a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, more preferably a methyl group, an ethyl group, a propyl group, an isopropyl group. When the hydrocarbon group having 2 to 10 carbon atoms and containing no heteroatom is interrupted or substituted by structures such as -O-, -N<, -NH-, -S-, -C(=O)-O-, -C(=O)-, =N-, -C(=O)-N<, -C(=O)-NH-, -O-C(=O)-O-, -O-C(=O)-N<, -O-C(=O)-NH-, -C(=O)-N[-C(=O)-]-, -C(=O)-NH-C(=O)-, >N-C(=O)-N<, >N-C(=O)-NH-, -HN-C(=O)-NH-, -S(=O)-, -S(=O) 2 -, -S(=O) 2 -O-, >N-C(=S)-N<, >N-C(=S)-NH-, -HN-C(=S)-NH-, -C(=N-)-, -C(=NH)-, etc., it becomes a "hydrocarbon group having 2 to 10 carbon atoms and containing 1 to 4 heteroatoms".

[0067] In formula (2), R 6 In this context, the "hydrocarbon group having 2 to 10 carbon atoms and containing no heteroatom" is preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, more preferably a methyl group.

[0068] In formula (2), R 6In this case, the "hydrocarbon group having 2 to 10 carbon atoms containing a heteroatom" is preferably 2-methoxyethyl, 2-(2-methoxyethoxy)ethyl, furfuryl, thienyl, 2-pyridyl, (oxolan-2-yl)methyl, 2-morpholinoethyl, 2-(dimethylamino)ethyl, 1,2-epoxypropyl, more preferably 2-methoxyethyl, but the present invention is not limited thereto.

[0069] In formula (2), R 6 In this case, it is preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, more preferably a methyl group.

[0070] In formula (2), R 5 and R 6 The total number of carbon atoms of is 3 to 12.

[0071] In formula (2), the fact that X represents an oxygen atom or a sulfur atom means that R 5 and R 6 are bonded via an ether group (-O-) or a thioether group (-S-).

[0072] As the imidazolium cation of the onium salt represented by the formula (1), specifically, 1,3-bis(2-methoxyethyl)imidazolium, 1,3-bis(2-ethoxyethyl)imidazolium, 1,3-bis(2-propoxyethyl)imidazolium, 1,3-bis(2-isopropoxyethyl)imidazolium, 1,3-bis(2-phenoxyethyl)imidazolium, 1,3-bis(2-benzyloxyethyl)imidazolium, 1,3-bis[2-(p-methoxybenzyloxy)ethyl]imidazolium, 1,3-bis[2-(2-methoxyethoxymethoxy)ethyl]imidazolium, 1,3-bis[2-(2-benzyloxyethoxy)ethyl]imidazolium, 1,3-bis(3-methoxypropyl)imidazolium, 1,3-bis(3-ethoxypropyl)imidazolium, 1,3-bis(3-propoxypropyl)imidazolium, 1,3-bis(3-isopropoxypropyl)imidazolium, 1,3-bis(3-allyloxypropyl)imidazolium, 1,3-bis(3-butoxypropyl)imidazolium, 1,3-bis[3-(1-methylpropoxy)propyl]imidazolium, 1,3-bis[3-(2-methylpropoxy)propyl]imidazolium, 1,3-bis[3-(1,1-dimethylethoxy)propyl]imidazolium, 1,3-bis[(oxolan-2-yl)methyl]imidazolium, 1,3-bis(3-pentyloxypropyl)imidazolium, 1,3-bis(3-neopentyloxypropyl)imidazolium, 1,3-bis(3-hexyloxypropyl)imidazolium, 1,3-bis(3-cyclohexyloxypropyl)imidazolium, 1,3-bis(3-heptyloxypropyl)imidazolium, 1,3-bis(3-octyloxypropyl)imidazolium, 1,3-bis(3-nonyloxypropyl)imidazolium, 1,3-bis{3-[(2-ethylhexan-1-yl)oxy]propyl}imidazolium, 1,3-bis[3-(2,4,6-trimethylphenoxy)propyl]imidazolium, 1,3-bis[3-(2-methoxyethoxy)propyl]imidazolium, 1,3-bis[2-(dimethylamino)ethyl]imidazolium, 1,3-bis[3-(dimethylamino)propyl]imidazolium, 1,3-Bis(2-methylthioethyl)imidazolium, 1,3-bis{2-[(furan-2-yl)methylthio]ethyl}imidazolium, 1,3-bis[2-(furan-2-yl)methyl]imidazolium, 1,3-bis[1-(methoxymethyl)propyl]imidazolium, 1,3-bis(4-methoxybutyl)imidazolium, 1,3-bis(4-ethoxybutyl)imidazolium, 1,3-bis(4-propoxybutyl)imidazolium, 1,3-bis(4-isopropoxybutyl)imidazolium, 1,3-bis(4-allyloxybutyl)imidazolium, 1,3-bis(4-butoxybutyl)imidazolium, 1,3-bis[4-(1-methylpropoxy)butyl]imidazolium, 1,3-bis[4-(2-methylpropoxy)butyl]imidazolium, 1,3-bis[4-(1,1-dimethylethoxy)butyl]imidazolium, 1,3-bis(4-pentyloxybutyl)imidazolium, 1,3-bis(4-neopentyloxybutyl)imidazolium, 1,3-bis(4-hexyloxybutyl)imidazolium, 1,3-bis(4-cyclohexyloxybutyl)imidazolium, 1,3-bis(4-heptyloxybutyl)imidazolium, 1,3-bis(4-octyloxybutyl)imidazolium, 1,3-bis{4-[(2-ethylhexan-1-yl)oxy]butyl}imidazolium, 1,3-bis(5-methoxypentyl)imidazolium, 1,3-bis(5-ethoxypentyl)imidazolium, 1,3-bis(5-propoxypentyl)imidazolium, 1,3-bis(5-isopropoxypentyl)imidazolium, 1,3-bis(5-allyloxypentyl)imidazolium, 1,3-bis(5-butoxypentyl)imidazolium, 1,3-bis[5-(1-methylpropoxy)pentyl]imidazolium, 1,3-bis[5-(2-methylpropoxy)pentyl]imidazolium, 1,3-bis[5-(1,1-dimethylethoxy)pentyl]imidazolium, 1,3-bis(5-pentyloxypentyl)imidazolium, 1,3-bis(5-neopentyloxypentyl)imidazolium, 1,3-bis(5-hexyloxypentyl)imidazolium, 1,3-bis(5-cyclohexyloxypentyl)imidazolium, 1,3-bis(5-heptyloxypentyl)imidazolium, 1,3-bis(6-methoxyhexyl)imidazolium, 1,3-bis(6-ethoxyhexyl)imidazolium, 1,3-bis(6-propoxyhexyl)imidazolium, 1,3-bis(6-isopropoxyhexyl)imidazolium, 1,3-bis(6-allyloxyhexyl)imidazolium, 1,3-bis(6-butoxyhexyl)imidazolium, 1,3-bis[6-(1-methylpropoxy)hexyl]imidazolium, 1,3-bis[6-(2-methylpropoxy)hexyl]imidazolium, 1,3-bis[6-(1,1-dimethylethoxy)hexyl]imidazolium, 1,3-bis(6-pentyloxyhexyl)imidazolium, 1,3-bis(6-neopentyloxyhexyl)imidazolium, 1,3-bis(6-hexyloxyhexyl)imidazolium, 1,3-bis(6-cyclohexyloxyhexyl)imidazolium, 1,3-bis[(2-methoxycyclohexan-1-yl)methyl]imidazolium, 1,3-bis[(2-ethoxycyclohexan-1-yl)methyl]imidazolium, 1,3-bis[(2-propoxycyclohexan-1-yl)methyl]imidazolium, 1,3-bis[(2-isopropoxycyclohexan-1-yl)methyl]imidazolium, 1,3-bis[(2-butoxycyclohexan-1-yl)methyl]imidazolium, 1,3-bis{[2-(1-methylpropoxy)cyclohexan-1-yl]methyl}imidazolium, 1,3-bis{[2-(2-methylpropoxy)cyclohexan-1-yl]methyl}imidazolium, 1,3-bis{[2-(1,1-dimethylethoxy)cyclohexan-1-yl]methyl}imidazolium, 1,3-bis[(2-pentyloxycyclohexan-1-yl)methyl]imidazolium, 1,3-bis[(2-neopentyloxycyclohexan-1-yl)methyl]imidazolium, 1,3-bis(3-methylthiopropyl)imidazolium, 1,3-bis[2-(methylsulfonyl)ethyl]imidazolium, 1,3-bis[(thiophen-2-yl)methyl]imidazolium, 1,3-bis(p-methoxyphenyl)imidazolium, 1,3-bis(p-ethoxyphenyl)imidazolium, 1,3-bis(3,(4-Methylenedioxyphenyl)imidazolium, 1,3-bis(3,4-methylenedioxybenzyl)imidazolium, 1,3-bis{(7-oxabicyclo[2,2,1]heptan-2-yl)methyl}imidazolium, 1-methoxypropyl-3-methylthiopropylimidazolium, 1,3-bis(3-methoxypropyl)-2-methylimidazolium, 1,3-bis(2-methoxyethyl)-2-methylimidazolium, etc. are mentioned, preferably 1,3-bis(3-methoxypropyl)imidazolium, 1,3-bis(3-ethoxypropyl)imidazolium, 1,3-bis(3-propoxypropyl)imidazolium, 1,3-bis(3-isopropoxypropyl)imidazolium, 1,3-bis(3-allyloxypropyl)imidazolium, 1,3-bis(3-butoxypropyl)imidazolium, 1,3-bis[3-(1-methylpropoxy)propyl]imidazolium, 1,3-bis[3-(2-methylpropoxy)propyl]imidazolium, 1,3-bis[3-(1,1-dimethylethoxy)propyl]imidazolium, 1,3-bis[(oxolan-2-yl)methyl]imidazolium, 1,3-bis[3-(2-methoxyethoxy)propyl]imidazolium, 1,3-bis(3-methylthiopropyl)imidazolium, 1-methoxypropyl-3-methylthiopropylimidazolium, 1,3-bis(3-methoxypropyl)-2-methylimidazolium, 1,3-bis(2-methoxyethyl)-2-methylimidazolium, and more preferably 1,3-bis(3-methoxypropyl)imidazolium, 1,3-bis(3-ethoxypropyl)imidazolium, 1-methoxypropyl-3-methylthiopropylimidazolium, 1,3-bis[3-(2-methoxyethoxy)propyl]imidazolium, 1,3-bis(2-methoxyethyl)-2-methylimidazolium, 1,3-bis(3-methoxypropyl)-2-methylimidazolium, but the present invention is not limited thereto.,

[0073] As the onium salt represented by the formula (1), preferably, it is an onium salt composed of a combination of one cation selected from the group consisting of 1,3-bis(2-methoxyethyl)imidazolium, 1,3-bis(3-methoxypropyl)imidazolium, 1,3-bis(3-ethoxypropyl)imidazolium, 1,3-bis(3-methylthiopropyl)imidazolium, 1,3-bis[3-(2-methoxyethoxy)propyl]imidazolium, 1-methoxypropyl-3-methylthiopropylimidazolium, 1,3-bis(2-methoxyethyl)-2-methylimidazolium, 1,3-bis(3-methoxypropyl)-2-methylimidazolium, and one anion selected from the group consisting of acetate ion, acrylate ion, and methacrylate ion.

[0074] As the onium salt represented by the formula (1), more specifically, 1,3-bis(2-methoxyethyl)imidazolium acetate, 1,3-bis(3-methoxypropyl)imidazolium acetate, 1,3-bis(3-methoxypropyl)imidazolium acrylate, 1,3-bis(3-methoxypropyl)imidazolium methacrylate, 1,3-bis(3-ethoxypropyl)imidazolium acetate, 1-methoxypropyl-3-methylthiopropylimidazolium acetate, 1,3-bis(3-methylthiopropyl)imidazolium acetate, 1,3-bis(2-methoxyethyl)-2-methylimidazolium acetate, 1,3-bis(2-methoxyethyl)-2-methylimidazolium acrylate, 1,3-bis(2-methoxyethyl)-2-methylimidazolium methacrylate, 1,3-bis(3-methoxypropyl)-2-methylimidazolium acetate, 1,3-bis(3-methoxypropyl)-2-methylimidazolium acrylate, 1,3-bis(3-methoxypropyl)-2-methylimidazolium methacrylate, 1,3-bis[3-(2-methoxyethoxy)propyl]imidazolium acetate, 1,3-bis[3-(2-methoxyethoxy)propyl]imidazolium acrylate, 1,3-bis[3-(2-methoxyethoxy)propyl]imidazolium methacrylate, etc. may be mentioned. Preferably, 1,3-bis(3-methoxypropyl)imidazolium acetate, 1,3-bis(3-methoxypropyl)imidazolium acrylate, 1,3-bis(3-methoxypropyl)imidazolium methacrylate are used, but the present invention is not limited thereto.

[0075] The onium salt (1) of the present invention can be easily produced by those skilled in the art based on the method described in the examples. The onium salt (1) can be obtained, for example, by the production method (Production Method 1) shown in the following Reaction Formula 1. Reaction Formula 1:

[0076]

Chemical formula

[0077] Manufacturing method 1 will be described. Glyoxal, R 1 -NH 2 (Formula (6a)) and / or R 2 -NH 2 (Formula (6b)) represented amine compound, R 3 aldehyde compound represented by -CHO (Formula (7)), and R 4 carboxylic acid represented by -COOH (Formula (4)) are reacted.

[0078] R 1 -NH 2 (Formula (6a)) or R 2 -NH 2As the amine compound represented by the formula (6b), specifically, 2-methoxyethylamine, 2-ethoxyethylamine, 2-propoxyethylamine, 2-isopropoxyethylamine, 2-allyloxyethylamine, 2-butoxyethylamine, 2-(1-methylpropoxy)ethylamine, 2-(2-methylpropoxy)ethylamine, 2-(1,1-dimethylethoxy)ethylamine, 2-pentyloxyethylamine, 2-neopentyloxyethylamine, 2-hexyloxyethylamine, 2-phenoxyethylamine, 2-heptyloxyethylamine, 2-octyloxyethylamine, 2-nonyloxyethylamine, 2-decyloxyethylamine, 2-cyclopentyloxyethylamine, 2-cyclohexyloxyethylamine, 2-(2-ethylhexan-1-yl)oxyethylamine, 2-(2,4,6-trimethylphenoxy)ethylamine, 2-(benzyloxy)ethylamine, 2-(p-methoxybenzyloxy)ethylamine, 2-(2-methoxyethoxymethoxy)ethylamine, 2-(2-benzyloxyethoxy)ethylamine, 2-(dimethylamino)ethylamine, 3-methoxypropylamine, 3-ethoxypropylamine, 3-propoxypropylamine, 3-allyloxypropylamine, 3-isopropoxypropylamine, 3-(1-methylpropoxy)propylamine, 3-(2-methylpropoxy)propylamine, 3-(1,1-dimethylethoxy)propylamine, 3-butoxypropylamine, 3-pentyloxypropylamine, 3-neopentyloxypropylamine, 3-hexyloxypropylamine, 3-cyclohexyloxypropylamine, 3-heptyloxypropylamine, 3-octyloxypropylamine, 3-nonyloxypropylamine, 3-(2-ethylhexan-1-yl)oxypropylamine, 3-(2,4,6-(Trimethylphenoxy)propylamine, 3-(2-methoxyethoxy)propylamine, 3-(dimethylamino)propylamine, 4-methoxybutylamine, 4-ethoxybutylamine, 4-propoxybutylamine, 4-isopropoxybutylamine, 4-allyloxybutylamine, 4-butoxybutylamine, 4-(1-methylpropoxy)butylamine, 4-(2-methylpropoxy)butylamine, 4-(1,1-dimethylethoxy)butylamine, 4-pentyloxybutylamine, 4-neopentyloxybutylamine, 4-hexyloxybutylamine, 4-cyclohexyloxybutylamine, 4-heptyloxybutylamine, 4-octyloxybutylamine, 4-(2-ethylhexan-1-yl)oxybutylamine, 5-methoxypentylamine, 5-ethoxypentylamine, 5-propoxypentylamine, 5-isopropoxypentylamine, 5-allyloxypentylamine, 5-butoxypentylamine, 5-(1-methylpropoxy)pentylamine, 5-(2-methylpropoxy)pentylamine, 5-(1,1-dimethylethoxy)pentylamine, 5-pentyloxypentylamine, 5-neopentyloxypentylamine, 5-hexyloxypentylamine, 5-cyclohexyloxypentylamine, 5-heptyloxypentylamine, 6-methoxyhexylamine, 6-ethoxyhexylamine, 6-propoxyhexylamine, 6-isopropoxyhexylamine, 6-allyloxyhexylamine, 6-butoxyhexylamine, 6-(1-methylpropoxy)hexylamine, 6-(2-methylpropoxy)hexylamine, 6-(1,1-(Dimethylethoxy)hexylamine, 6-pentyloxyhexylamine, 6-neopentyloxyhexylamine, 6-hexyloxyhexylamine, 6-cyclohexyloxyhexylamine, 2-methoxycyclohexyl-1-ylmethylamine, (2-ethoxycyclohexan-1-yl)methylamine, (2-propoxycyclohexan-1-yl)methylamine, (2-isopropoxycyclohexan-1-yl)methylamine, (2-butoxycyclohexyl-1-yl)methylamine, [2-(1-methylpropoxy)cyclohexan-1-yl]methylamine, [2-(2-methylpropoxy)cyclohexan-1-yl]methylamine, [2-(1,1-dimethylethoxy)cyclohexan-1-yl]methylamine, (2-pentyloxycyclohexan-1-yl)methylamine, (2-neopentyloxycyclohexan-1-yl)methylamine, 2-methylthioethylamine, 3-methylthiopropylamine, 1-(methoxymethyl)propylamine, (oxolan-2-yl)methylamine, (furan-2-yl)methylamine, 2-[(furan-2-yl)methylthio]ethylamine, 2-(methylsulfonyl)ethylamine, (thiophen-2-yl)methylamine, p-methoxyphenylamine, p-ethoxyphenylamine, 3,4-methylenedioxyaniline, 3,4-methylenedioxybenzylamine, (7-oxabicyclo[2,2,1]heptan-2-yl)methylamine, etc. are mentioned. Preferably, they are 2-methoxyethylamine, 3-methoxypropylamine, 3-ethoxypropylamine, 3-isopropoxypropylamine, 3-butoxypropylamine, 3-(2-methoxyethoxy)propylamine, 3-methylthiopropylamine, 3-(dimethylamino)propylamine. More preferably, they are 2-methoxyethylamine, 3-methoxypropylamine, 3-(2-methoxyethoxy)propylamine. However, the present invention is not limited thereto. R, 1 -NH 2 or R 2 -NH 2 The amine compounds represented by may be the same or different.

[0079] R3 As the aldehyde compound represented by -CHO (formula (7)), specifically, formaldehyde, acetaldehyde, propionaldehyde, butanal, pentanal, hexanal, heptanal, octanal, nonanal, decanal, acrolein, benzaldehyde, cinnamaldehyde, perillaldehyde, vanillin, etc. can be mentioned. Preferably, they are formaldehyde and acetaldehyde, but the present invention is not limited thereto. For formaldehyde, cyclic oligomers or polymers capable of generating formaldehyde such as paraformaldehyde, trioxane, and tetraoxane in the reaction system may be used.

[0080] R 3 The aldehyde compound represented by -CHO (formula (7)) may be used as it is in an aqueous solution or an alcohol solution such as methanol, butanol, and 2-ethylhexanol.

[0081] R 4 Examples of the carboxylic acid represented by -COOH (formula (4)) include acetic acid, propionic acid, acrylic acid, propargylic acid, butyric acid, isobutyric acid, methacrylic acid, crotonic acid, tetrolic acid, cyclopropanecarboxylic acid, valeric acid, isovaleric acid, pivalic acid, angelic acid, tiglic acid, cyclobutanecarboxylic acid, caproic acid, cyclopentanecarboxylic acid, enanthic acid, sorbic acid, cyclohexanecarboxylic acid, benzoic acid, caprylic acid, 2-ethylhexylcarboxylic acid, toluic acid, 2-norbornanecarboxylic acid, pelargonic acid, cubanecarboxylic acid, cinnamic acid, capric acid, 3-noradamantanecarboxylic acid, geranic acid, undecylic acid, 1-naphthalenecarboxylic acid, 2-naphthalenecarboxylic acid, 1-adamantanecarboxylic acid, etc. Preferably, they are acetic acid, propionic acid, acrylic acid, propargylic acid, butyric acid ion, isobutyric acid, methacrylic acid, crotonic acid, tetrolic acid, valeric acid, isovaleric acid, pivalic acid, and particularly preferably acetic acid, acrylic acid, or methacrylic acid, but the present invention is not limited thereto.

[0082] Glyoxal may be used as it is in an aqueous solution or an alcohol solution such as methanol, butanol, 2-ethylhexanol, etc.

[0083] R 1 -NH 2 (Formula (6a)) and R 2 -NH 2 (Formula (6b)), the amount of the amine compound used is usually 0.1 to 10 moles, preferably 0.5 to 3 moles, per mole of glyoxal. When R 1 -NH 2 and R 2 -NH 2 are different, the ratio (molar ratio) of the two amine compounds (R 1 -NH 2 and R 1 -NH 2 and R 2 -NH 2 ) is not particularly limited, and R 1 -NH 2 :R 2 -NH 2 = 0:100 to 100:0. When R 1 -NH 2 :R 2 -NH 2 = 0:100 or 100:0, R 1 = R 2 . When R 1 -NH 2 :R 2 -NH 2 ≠ 0:100 or 100:0, the onium salt (1) obtained by Production Method 1 is a mixture of compounds represented by the following formula. Both the compounds represented by the following formula (1') and formula (1'') are included in the onium salt represented by formula (1), and this mixture may be used as the onium salt composition described later. Further, if necessary, the mixture can be purified into a desired single compound and then used as the onium salt (1).

[0084]

Chemical formula

[0085] R 3 The aldehyde compound represented by -CHO (Formula (7)) may be used as it is in an aqueous solution or an alcohol solution such as methanol, butanol, 2-ethylhexanol, etc. The amount of the aldehyde compound used is usually 0.1 to 10 moles, preferably 0.5 to 5 moles, per mole of glyoxal.

[0086] R 4 The amount of the carboxylic acid represented by -COOH (Formula (4)) used is usually 0.1 to 10 moles, preferably 0.5 to 2 moles, per mole of glyoxal.

[0087] In Production Method 1, a solvent may or may not be used. When a solvent is used, the solvent used is not particularly limited as long as it does not affect the reaction. Specific examples of the solvent include aromatic hydrocarbon solvents such as toluene, benzene, and xylene, hydrocarbon solvents such as methylcyclohexane, cyclohexane, hexane, heptane, and octane, halogenated hydrocarbon solvents such as dichloromethane and chloroform, ether solvents such as diethyl ether, tetrahydrofuran, and 1,4-dioxane, alcohol solvents such as methanol, ethanol, and 2-propanol, N,N-dimethylformamide, acetonitrile, water, etc., and preferably alcohol solvents and water.

[0088] Also, the onium salt (1) prepared in advance can be used as the reaction solvent in Production Method 1. Two or more solvents can be mixed and used as needed. The amount of the solvent used is usually 50 parts by mass or less, preferably 0.1 to 10 parts by mass, per 1 part by mass of glyoxal.

[0089] In Production Method 1, if necessary, the reaction may be carried out under an inert gas atmosphere such as nitrogen, argon, or helium that does not affect the reaction.

[0090] When performing Production Method 1, the reaction pressure is usually under atmospheric pressure, but depending on the raw materials and solvents used, the reaction system may be pressurized to a pressure of atmospheric pressure to 1 MPa for the reaction.

[0091] The reaction temperature varies depending on the raw materials, solvents, etc. used, but is usually -10°C or higher, preferably 0°C to 100°C.

[0092] After the reaction of Production Method 1 is completed, the onium salt (1) may or may not be purified by a known purification method. Examples of the purification method include, but are not particularly limited to, concentration, liquid separation, recrystallization, dialysis, adsorption, filtration, etc.

[0093] When the anion represented by R 4 -COO - in the onium salt (1) obtained by Production Method 1 is not the desired anion, an ion exchange reaction may be further performed as necessary to obtain the desired anion. In this case, for example, the method of Production Method 3 described later can be preferably used. When using the method of Production Method 3, the onium salt (1) obtained by Production Method 1 can be ion-exchanged as the onium salt represented by formula (2) of Production Method 3 to produce an onium salt (1) having the desired anion.

[0094] Also, the onium salt (1) can be obtained by exchanging Y - in the onium salt represented by the following formula (2) (hereinafter referred to as onium salt (2)) with the desired R 4 -COO - anion (ion exchange). Formula (2):

[0095]

Chemical formula

[0096] Y in formula (2) -Examples include, but are not particularly limited to, halogen anions such as chloride ion, bromide ion, and iodide ion, hydroxide anion, carboxylate anion, sulfonate anion, thiocyanate anion, nitrate anion, perchlorate anion, etc. Y - When Y is a carboxylate anion, R of the onium salt (1) represented by formula (1) 4 -COO - is not the same as the anion.

[0097] As the ion exchange method, in addition to the direct exchange method (Production Method 2) as represented by the following Reaction Formula 2, when Y in formula (2) - is not a hydroxide anion, there is a method of ion exchange via a hydroxide salt (3) as represented by the following Reaction Formula 3 (Production Method 3). Reaction Formula 2:

[0098]

Chemical formula

[0099]

Chemical formula

[0100] In Reaction Formula 2, Z n+Examples of the cation represented by include, but are not particularly limited to, alkali metal ions such as lithium cation, sodium cation, and potassium cation, alkaline earth metal ions such as calcium cation, and ammonium cation.

[0101] The manufacturing method 3 will be described. The onium salt (1) includes a reaction (hereinafter referred to as the first reaction) of producing an onium hydroxide salt represented by the formula (3) (hereinafter referred to as the hydroxide salt (3)) by ion-exchanging the onium salt (2) represented by the formula (2) using an ion-exchange resin, silver(I) oxide, or an alkali metal hydroxide, etc., and a reaction (hereinafter referred to as the second reaction) of obtaining the onium salt (1) by reacting the obtained hydroxide salt (3) with a carboxylic acid represented by the formula (4) for ion-exchange.

[0102] The case of using an ion-exchange resin in the first reaction (Reaction 1-1) will be described. As the ion-exchange resin used in Reaction 1-1, for example, a strongly basic ion-exchange resin (OH type) commercially available for water treatment or as a catalyst can be used. The usage amount of the ion-exchange resin is usually 20 molar equivalents or less, preferably 1 to 10 molar equivalents, per 1 mole of the onium salt (2).

[0103] Examples of the method of bringing the onium salt (2) into contact with the ion-exchange resin include a method of passing the onium salt (2) through the ion-exchange resin packed in a column (Reaction 1-1-1) and a method of mixing the onium salt (2) and the ion-exchange resin (Reaction 1-1-2).

[0104] In Reaction 1-1, the onium salt (2) is usually diluted with a solvent and then brought into contact with the ion-exchange resin. Examples of the solvent include alcohols such as acetone, methanol, ethanol, and 2-propanol, acetonitrile, ethyl acetate, and water.

[0105] The amount of the solvent used is not particularly limited. In the case of Reaction 1-1-1, it is usually 1 to 100 parts by mass, preferably 2 to 20 parts by mass, more preferably 3 to 10 parts by mass, per 1 part by mass of the onium salt (2). In the case of Reaction 1-1-2, it is usually 10 parts by mass or less, preferably 1 to 10 parts by mass, per 1 part by mass of the onium salt (2).

[0106] The case of using silver(I) oxide in the first reaction (Reaction 1-2) will be described. The amount of silver(I) oxide used in Reaction 1-2 is usually 10 molar equivalents or less, preferably 0.5 to 2 molar equivalents, per 1 mole of the onium salt (2).

[0107] The case of using an alkali metal hydroxide in the first reaction (Reaction 1-3) will be described. Examples of the alkali metal hydroxide used in Reaction 1-3 include sodium hydroxide and potassium hydroxide. The amount of the alkali metal hydroxide used is usually 3 molar equivalents or less per 1 mole of the onium salt (2).

[0108] Reactions 1-2 and 1-3 are usually carried out in a solvent. Examples of the solvent include alcohols such as acetone, methanol, ethanol, and 2-propanol, acetonitrile, ethyl acetate, and water. The amount of the solvent used is not particularly limited, but it is usually 10 parts by mass or less, preferably 1 to 10 parts by mass, per 1 part by mass of the onium salt (2).

[0109] The reaction temperature of the first reaction is usually 10°C or higher, preferably 10 to 60°C, particularly preferably 10 to 30°C.

[0110] The reaction mixture obtained in the first reaction may be used as it is in the second reaction, or may be used in the second reaction after filtering the reaction solution to remove insoluble substances.

[0111] Examples of the hydroxide salt (3) obtained in the first reaction include compounds in which the R 4 -COO - anion of the onium salt represented by the above formula (1) is replaced with an OH - anion (compounds represented by formula (3)). Specifically, 1,3-bis(2-methoxyethyl)imidazolium hydroxide, 1,3-bis(3-methoxypropyl)imidazolium hydroxide, 1,3-bis(3-ethoxypropyl)imidazolium hydroxide, 1,3-bis(3-propoxypropyl)imidazolium hydroxide, 1,3-bis(3-isopropoxypropyl)imidazolium hydroxide, 1,3-bis(3-allyloxypropyl)imidazolium hydroxide, 1,3-bis(3-butoxypropyl)imidazolium hydroxide, 1,3-bis[3-(1-methylpropoxy)propyl]imidazolium hydroxide, 1,3-bis[3-(2-methylpropoxy)propyl]imidazolium hydroxide, 1,3-bis[3-(1,1-dimethylethoxy)propyl]imidazolium hydroxide, 1,3-bis[(oxolan-2-yl)methyl]imidazolium hydroxide, 1,3-bis[3-(2-methoxyethoxy)propyl]imidazolium hydroxide, 1,3-bis(3-methylthiopropyl)imidazolium hydroxide, 1-methoxypropyl-3-methylthiopropylimidazolium hydroxide, 1,3-bis(3-methoxypropyl)-2-methylimidazolium hydroxide, 1,3-bis(2-methoxyethyl)-2-methylimidazolium hydroxide, etc. are mentioned. Preferably, 1,3-bis(2-methoxyethyl)imidazolium hydroxide, 1,3-bis(3-methoxypropyl)imidazolium hydroxide, 1,3-bis(3-ethoxypropyl)imidazolium hydroxide, 1-methoxypropyl-3-methylthiopropylimidazolium hydroxide, 1,3-bis[3-(2-methoxyethoxy)propyl]imidazolium hydroxide, 1,3-bis(2-methoxyethyl)-2-methylimidazolium hydroxide, 1,3-bis(3-methoxypropyl)-2-methylimidazolium hydroxide, but the present invention is not limited thereto.

[0112] Next, the second reaction will be described. In the second reaction, the carboxylic acid represented by the formula (4) can be the same carboxylic acid as that used in Production Method 1. The amount of the carboxylic acid represented by the formula (4) used in the second reaction is usually 0.8 molar equivalent or more, preferably 0.8 to 1.2 molar equivalents, particularly preferably 0.9 to 1.1 molar equivalents, relative to 1 mole of the hydroxide salt (3) represented by the formula (3).

[0113] The second reaction is usually carried out in a solvent. Examples of the solvent include ketones such as acetone and methyl ethyl ketone, alcohols such as methanol, ethanol, and 2-propanol, acetonitrile, ethyl acetate, tetrahydrofuran, dimethylformamide, water, and the like. The amount used is not particularly limited, but it is usually 10 parts by mass or less, preferably 1 to 10 parts by mass, relative to 1 part by mass of the hydroxide salt (3).

[0114] The reaction temperature of the second reaction is usually 10°C or higher, preferably 10 to 60°C, particularly preferably 10 to 30°C.

[0115] After completion of the second reaction, for example, the onium salt (1) can be obtained by concentrating the resulting reaction mixture. The obtained onium salt (1) may or may not be purified by a known purification method. Examples of the purification method include concentration, liquid separation, recrystallization, dialysis, adsorption, filtration, etc., but are not particularly limited.

[0116] The onium salt (2) can be obtained, for example, by the production method (Production Method 4) shown in the following Reaction Formula 4. Reaction Formula 4:

[0117]

Chemical formula

[0118] Production Method 4 uses glyoxal, R 1 -NH2 (Formula (6a)) and / or R 2 -NH 2 An amine compound represented by (Formula (6b)), R 3 An aldehyde compound represented by -CHO (Formula (7)), and H + Y - React with an acid represented by (Formula (8)). Production method 4 is such that in production method 1, instead of the carboxylic acid represented by R 4 -COOH (Formula (4)), H + Y - It can be carried out in the same manner as production method 1 except that an acid represented by (Formula (8)) is used. That is, R 1 -NH 2 (Formula (6a)) or R 2 -NH 2 (Formula (6b)) an amine compound represented by, R 3 An aldehyde compound represented by -CHO (Formula (7)) and the reaction pressure, reaction temperature, post-treatment after the reaction is completed, purification method, etc. are the same as those in production method 1, and also, in the same manner as production method 1, if necessary, the reaction may be carried out in an inert gas atmosphere such as nitrogen, argon, helium, etc. that does not affect the reaction.

[0119] H + Y - Examples of the acid represented by (Formula (8)) include hydrogen halides such as hydrogen chloride, hydrogen bromide, and hydrogen iodide, carboxylic acids, sulfonic acids, thiocyanic acid, nitric acid, perchloric acid, etc. These acids can be used in production method 4 even if they are in aqueous solution or organic solvent solution.

[0120] In onium salt (2), when Y - is a halogen anion, it can also be produced by the production method shown in the following Reaction Formula 5 (Production Method 5). Reaction Formula 5:

[0121]

Chemical formula

[0122] In Reaction Formula 5, examples of the halogen atom represented by Y include a chlorine atom, a bromine atom, and an iodine atom. Y - Examples of the halogen anion represented by Y include, but are not particularly limited to, a chloride anion, a bromide anion, and an iodide anion.

[0123] The onium salt composition in one embodiment of the present invention contains two or more kinds of onium salts (1).

[0124] Hereinafter, the cation of the onium salt represented by Formula (1) is referred to as an "imidazolium cation (C + )", and the anion of the onium salt represented by Formula (1) is referred to as a "carboxylate anion (A - )". The onium salt composition may contain two or more kinds of imidazolium cations (C + ) and two or more kinds of carboxylate anions (A - ), may contain two or more kinds of imidazolium cations (C + ) and one kind of carboxylate anion (A - ), or may contain one kind of imidazolium cation (C + ) and two or more kinds of carboxylate anions (A - ).

[0125] The onium salt composition can be produced, for example, by mixing two or more kinds of onium salts (1). Examples of the method of mixing two or more kinds of onium salts (1) include direct mixing at an arbitrary temperature, utilization of a co-solvent, dialysis, salt exchange using an ion exchange resin, etc., but are not particularly limited.

[0126] Also, for example, the onium salt composition can be obtained by producing two or more kinds of onium salts (1) by the methods such as (i) and (ii). (i) In Production Method 1, the reaction is carried out using any one of the following (a), (b), (c), or a combination thereof. (a) As the amine compound, R 1 -NH 2 and R 2 -NH 2 (R 1 and R 2 are different), and use an amine compound represented thereby (b) As the aldehyde compound, use two or more aldehyde compounds represented by R 3 -CHO (c) As the carboxylic acid, use two or more carboxylic acids represented by R 4 -COOH(4) (ii) Use the onium salt (1) previously produced in Production Method 1 as a reaction solvent, and do not remove the onium salt (1) used as the reaction solvent after the reaction is completed. In this case, the previously produced onium salt (1) and the onium salt (1) obtained through Production Method 1 using the previously produced onium salt (1) as a solvent are not the same onium salt.

[0127] The polysaccharide in the present invention is a substance in which a large number of monosaccharide molecules are polymerized by a glycosidic bond. Examples of the constituent monosaccharide molecules include glucose, fructose, glucosamine, N-acetylglucosamine, etc. Polysaccharides derived from glucose include glycogen, starch, cellulose, dextrin, curdlan, etc., polysaccharides derived from fructose include fructan, etc., and polysaccharides derived from glucosamine include chitin, chitosan, etc. In particular, cellulose, curdlan, chitin, chitosan, etc., which are particularly poorly soluble, are suitable for the present invention.

[0128] Cellulose refers to polymers in which glucose is polymerized by β-1,4-glucoside bonds and derivatives thereof. The degree of polymerization of glucose in cellulose is not particularly limited, but is preferably 200 or more. Examples of the derivatives include derivatives such as carboxymethylation, aldehyde formation, and esterification. Further, cellulose may contain cellooligosaccharides and cellobiose, which are partial decomposition products thereof. Furthermore, cellulose may be a complex with β-glucoside, lignin and / or hemicellulose, which are glycosides, i.e., lignocellulose, and may further be a complex with pectin or the like. The onium salt of the present invention can dissolve cellulose at 10°C to 50°C even if it is a complex with lignocellulose and further pectin or the like. Cellulose may be crystalline cellulose or amorphous cellulose, but preferably crystalline cellulose. Furthermore, cellulose may be of natural origin or artificially synthesized. The origin of cellulose is not particularly limited. It may be of plant origin, fungal origin, or bacterial origin.

[0129] In addition, the cellulose includes materials containing cellulose. Specific examples of the materials containing cellulose include biomass containing pulp, natural fiber products such as cotton and hemp, regenerated fiber products such as rayon, cupra, and acetate, various straws such as rice straw, agricultural waste such as bagasse and wood chips, waste paper, and various wastes such as construction waste. When dissolving biomass containing the above pulp, natural fiber products such as cotton and hemp, regenerated fiber products such as rayon, cupra, and acetate, various straws such as rice straw, agricultural waste such as bagasse and wood chips, waste paper, and various wastes such as construction waste in the onium salt of the present invention, it is preferable to use those obtained by cutting them in order to shorten the time until dissolution.

[0130] Curdlan is a substantially pure linear polymer in which glucose is polymerized by β-1,3-glucoside bonds. Curdlan is produced from glucose by Agrobacterium bacteria and is mainly used as a food additive as a gelling agent, stabilizer, and thickening agent.

[0131] Chitin is a polymer formed by the polymerization of N-acetyl-D-glucosamine through β-1,4-glycosidic bonds. It is a component of the exoskeletons of arthropods, especially the shells of crustaceans, mollusks, especially the shells of shellfish, and the cell walls of fungi (molds) and basidiomycetes (mushrooms), and is a natural product rich after cellulose. Natural chitin is a polysaccharide composed not only of N-acetylglucosamine but also of glucosamine, and the ratio of N-acetylglucosamine to glucosamine is said to be approximately 9:1.

[0132] Chitosan is a deacetylated product of chitin and is a cationic polysaccharide having a primary amino group.

[0133] The polysaccharide-containing liquid composition in the present invention comprises a polysaccharide and an onium salt (1) or an onium salt composition, and the polysaccharide is dissolved in the onium salt (1) or the onium salt composition. A liquid composition composed of a polysaccharide and an onium salt (1) or an onium salt composition is referred to as a polysaccharide-containing liquid composition (a1).

[0134] Furthermore, this polysaccharide-containing liquid composition (a1) may contain an organic solvent, and the case where it contains an organic solvent is referred to as a polysaccharide-containing liquid composition (a2). Examples of the organic solvent include dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, acetonitrile, pyridine, methylimidazole, 3-methoxy-2-propanol, hexamethylphosphoric triamide, tetramethylurea, 1,3-dimethyl-2-imidazolidinone, γ-butyrolactone, etc., but are not particularly limited, and it may contain two or more kinds of organic solvents. The polysaccharide-containing liquid composition (a2) is formed by dissolving the polysaccharide in a medium containing an onium salt (1) or an onium salt composition and the above organic solvent. The above organic solvents themselves hardly dissolve polysaccharides, but when mixed with an onium salt (1) or an onium salt composition and used, they can contribute to improving the solubility of polysaccharides, accelerating the dissolution rate of polysaccharides due to a decrease in viscosity, improving workability in the polysaccharide recovery process, controlling the physical properties of the recovered polysaccharides, etc.

[0135] The proportion of the onium salt (1) or the onium salt composition and the organic solvent in the medium of the polysaccharide-containing liquid composition (a2), i.e., {(mass of the onium salt (1) or the onium salt composition) / [(mass of the onium salt (1) or the onium salt composition) + mass of the organic solvent]×100}, is usually 0.5 to 99.5% by mass, preferably 10 to 90% by mass, more preferably 20 to 80% by mass.

[0136] The polysaccharide-containing liquid composition (a1) or (a2) may contain known onium salts other than the onium salt (1). Specific examples of the known onium salts other than the onium salt (1) include 1-ethyl-3-methylimidazolium acetate, etc., but are not particularly limited.

[0137] In addition, in the polysaccharide-containing liquid composition (a1) or (a2), additives can be used to the extent that their effects are exhibited. Examples of the additives include fragrances, dyes, pigments for coloring, water repellents, oil repellents, antioxidants, hydrolysis inhibitors, flame retardants, ultraviolet absorbers, light stabilizers, antistatic agents, conductivity-imparting agents, stress relaxants, mold release agents, crystallization accelerators, lubricants, impact imparting agents, sliding property improvers, nucleating agents, reinforcing agents, fillers, flow regulators, thickeners, antibacterial agents, fungicides, rust preventives, sedimentation preventives, sag preventives, defoamers, coupling agents, fillers, etc. These additives can be used alone or in combination of two or more.

[0138] When the polysaccharide-containing liquid composition (a1) contains a polysaccharide, not only the onium salt (1) or the onium salt composition, but also a known onium salt and additives as required, it is referred to as the polysaccharide-containing liquid composition (a3).

[0139] When the polysaccharide-containing liquid composition (a2) contains a polysaccharide, not only the onium salt (1) or the onium salt composition and the organic solvent, but also a known onium salt and additives as required, it is referred to as the polysaccharide-containing liquid composition (a4).

[0140] In the polysaccharide-containing liquid compositions (a1) to (a4), the ratio of the onium salt (1) or the onium salt composition in the medium {(mass of the onium salt (1) or the onium salt composition) / [(mass of the onium salt (1) or the onium salt composition) + mass of the organic solvent + mass of the known onium salt + mass of the additive]×100} is usually 0.5 to 99.5% by mass, preferably 10 to 90% by mass, more preferably 20 to 80% by mass.

[0141] Next, the method for dissolving the polysaccharide of the present invention will be described. First, an onium salt (1) or an onium salt composition, and, if necessary, an organic solvent, a known onium salt, and an additive are mixed with the polysaccharide in a medium and dissolved to obtain any one of the polysaccharide-containing liquid compositions (a1) to (a4).

[0142] The temperature at which the polysaccharide is dissolved in the medium is not particularly limited as long as it is within the temperature range in which the medium is in a liquid state, and it may be maintained in a liquid state at a specific temperature. Preferably it is 100°C or lower, more preferably 10°C or higher and 50°C or lower.

[0143] In the step of dissolving the polysaccharide in the medium, the dissolution of the polysaccharide can be promoted by applying stimuli such as stirring, shaking, ultrasonic irradiation, etc. to the mixture of the polysaccharide and the medium.

[0144] The content rate of the polysaccharide in the polysaccharide-containing liquid compositions (a1) to (a4) [{polysaccharide mass / (polysaccharide-containing liquid compositions (a1) to (a4))}×100] is not particularly limited, and is usually 0.5 to 99.5% by mass, preferably 1 to 50% by mass, more preferably 5 to 30% by mass.

[0145] When the polysaccharide in the polysaccharide-containing liquid compositions (a1) to (a4) is cellulose, the medium other than cellulose can dissolve cellulose at a solubility of preferably 10% by mass or more, more preferably 14% by mass or more, still more preferably 18% by mass or more, particularly preferably 20% by mass or more at 25°C under stirring.

[0146] Although it is better for the solubility of cellulose to be high, the solubility under stirring at 25°C is usually 50% by mass or less, 45% by mass or less, or 40% by mass or less. The measurement of the above solubility can be carried out, for example, using Avicel (registered trademark) PH-101, which is microcrystalline cellulose, manufactured by Sigma-Aldrich Co., LLC, under stirring conditions for 24 hours.

[0147] When the polysaccharide in the polysaccharide-containing liquid compositions (a1) to (a4) is curdlan, the medium other than curdlan can dissolve curdlan at a solubility of preferably 10% by mass or more, more preferably 14% by mass or more, still more preferably 18% by mass or more, and particularly preferably 20% by mass or more at 50°C under stirring.

[0148] When the polysaccharide in the polysaccharide-containing liquid compositions (a1) to (a4) is chitin, the medium other than chitin can dissolve chitin at a solubility of preferably 1% by mass or more, more preferably 2% by mass or more, still more preferably 3% by mass or more, and particularly preferably 5% by mass or more at 50°C under stirring.

[0149] In the step of dissolving the polysaccharide in the medium, the order of mixing the polysaccharide, the onium salt (1), and further a known onium salt, an organic solvent, and an additive, which are optional components, is not particularly limited. The known onium salt, organic solvent, or additive may be mixed before dissolving the polysaccharide in the onium salt (1) or the onium salt composition, may be mixed during the dissolution of the polysaccharide in the onium salt (1) or the onium salt composition, or may be mixed after dissolution.

[0150] In the present invention, "recovery of polysaccharide" means taking out a polysaccharide or a polysaccharide derivative as a composition in an industrially useful form from any of the polysaccharide-containing liquid compositions (a1) to (a4). For example, as the form of the polysaccharide, it can be taken out as, for example, regenerated fiber, nanofiber, film, etc., but is not particularly limited.

[0151] Furthermore, by subjecting the polysaccharide-containing liquid compositions (a1) to (a4) to chemical or physical treatments to modify the polysaccharides or cleave the polysaccharide chains, the recovered composition can also be made functional. These treatments may be performed either before recovering the polysaccharides from the polysaccharide-containing liquid compositions (a1) to (a4) or in conjunction with the recovery. Examples of the chemical and physical treatments include oxidation, reduction, thermal decomposition, hydrolysis, isomerization, esterification, alkoxylation, acetylation, deacetylation, ion exchange, copolymerization, surface coating, saccharification, shearing, application of voltage, and the like. Examples of the recovered composition having functionality include, but are not particularly limited to, a cellulose saccharification treatment composition for producing biomass fuel, a composite composition with organic and inorganic materials, and the like.

[0152] Also, it is not necessary to completely remove the onium salt (1) or the onium salt composition used for dissolution from the recovered polysaccharide or polysaccharide derivative. The recovered composition may be used with the onium salt (1) or the onium salt composition remaining therein.

[0153] Next, the polysaccharide recovery method of the present invention will be described. By bringing any one of the polysaccharide-containing liquid compositions (a1) to (a4) obtained by the above-described method into contact with a poor solvent, polysaccharides precipitate in the mixed solution. The precipitated polysaccharides can be recovered by separating the mixed solution by filtration or the like. The mixed solution after separating the polysaccharides contains the onium salt (1) or the onium salt composition and the poor solvent. Further, when a known onium salt, organic solvent, or additive is used, these are also contained (hereinafter, the mixed solution after separating the polysaccharides is referred to as the "mixed solution").

[0154] Examples of the poor solvent used during the polysaccharide recovery include, but are not particularly limited to, water, methanol, ethanol, acetone, and mixed solvents of two or more of these. The amount of the poor solvent used is not particularly limited as long as the polysaccharides can be sufficiently recovered from any one of the polysaccharide-containing liquid compositions (a1) to (a4), and a person skilled in the art can determine an appropriate amount to use.

[0155] The method of bringing the polysaccharide-containing liquid compositions (a1) to (a4) into contact with the poor solvent is not particularly limited, and examples thereof include a method of dropping the poor solvent into any of the polysaccharide-containing liquid compositions (a1) to (a4), a method of filling any of the polysaccharide-containing liquid compositions (a1) to (a4) into a mold or coating it on a sheet and immersing it in the poor solvent, and a method of discharging any of the polysaccharide-containing liquid compositions (a1) to (a4) into the poor solvent.

[0156] The onium salt (1) or the onium salt composition may be recovered from the mixed solution and reused. When reusing, the recovered onium salt (1) or onium salt composition may contain components derived from the polysaccharide. Further, if necessary, the components derived from the polysaccharide in the recovered onium salt (1) or onium salt composition may be removed by a purification treatment. Examples of the method for recovering the onium salt (1) or the onium salt composition from the mixed solution after separation include, but are not particularly limited to, concentration, liquid separation, recrystallization, dialysis, adsorption, filtration, and the like.

[0157] In addition, the organic solvent and the poor solvent used for dissolving the polysaccharide in the mixed solution can be easily recovered and reused by distillation, concentration, liquid separation, or the like.

Examples

[0158] Next, the present invention will be specifically described based on examples, but the present invention is not limited thereto.

[0159] In Table 1, the solubility indicates the maximum mass% of the dissolved polysaccharide with respect to the onium salt [((maximum mass of the polysaccharide dissolved in the onium salt) / (mass of the onium salt)) × 100].

[0160] In Table 2, the onium salt concentration indicates the mass% of the onium salt with respect to the medium obtained by mixing the onium salt and the organic solvent [((mass of the onium salt) / (mass of the medium obtained by mixing the onium salt and the organic solvent)) × 100].

[0161] In Table 2, the solubility refers to the mass percentage of the dissolved polysaccharide in the medium obtained by mixing the onium salt and the organic solvent or in the organic solvent [(mass of the polysaccharide dissolved in the medium obtained by mixing the onium salt and the organic solvent or in the organic solvent / mass of the medium obtained by mixing the onium salt and the organic solvent or in the organic solvent) × 100].

[0162] In the examples, the dissolution state of the polysaccharide was evaluated using a zoom stereomicroscope manufactured by Reimer Co., Ltd. and a lens filter for polarization observation. The liquid composition (a1) or (a2) containing the polysaccharide was observed with the apparatus, and a state in which there was no undissolved polysaccharide showing birefringence was determined to be a completely dissolved state.

[0163] [Example 1-1] 260 g (3.22 mol) of 37 wt% aqueous formaldehyde solution (manufactured by Tokyo Chemical Industry Co., Ltd.), 290 g (4.83 mol) of acetic acid (manufactured by Junsei Chemical Co., Ltd.), 573 g (6.43 mol) of 3-methoxypropylamine (manufactured by Tokyo Chemical Industry Co., Ltd.), and 461 g (3.22 mol) of 40 wt% aqueous glyoxal solution (manufactured by Tokyo Chemical Industry Co., Ltd.) were charged into a 5 L three-necked reactor purged with nitrogen. The resulting mixture was heated to 40°C and stirred for 3 hours to synthesize 811 g of 1,3-bis(3-methoxypropyl)imidazolium acetate ([(MeOPr) 2 Im][AcO]). The yield was 93%. [(MeOPr) 2 Im][AcO] 1 The results of the 1H NMR data are shown below. 1 1H NMR (DMSO-d 6 ) δ (ppm) = 9.41 (s, 1H), 7.78 (d, 2H), 4.22 (t, 4H), 3.33 (t, 4H), 3.22 (s, 6H), 2.07 - 2.00 (m, 4H), 1.56 (s, 3H)

[0164] [Example 1-2] 4.11 g (50.8 mmol) of 37 wt% aqueous formaldehyde solution (manufactured by Tokyo Chemical Industry Co., Ltd.), 4.55 g (75.8 mmol) of acetic acid (manufactured by Junsei Chemical Co., Ltd.), 12.9 g (96.7 mmol) of 3-(2-methoxyethoxy)propylamine (manufactured by Combi-Blocks), and 7.24 g (50.5 mmol) of 40 wt% aqueous glyoxal solution (manufactured by Junsei Chemical Co., Ltd.) were charged into a 100 mL three-necked reactor purged with nitrogen. The resulting mixture was heated to 40 °C and stirred for 3 hours to synthesize 13.9 g of 1,3-bis[3-(2-methoxyethoxy)propyl]imidazolium acetate ([(MeOEtOPr) 2 Im][AcO]). The yield was 80%. [(MeOEtOPr) 2 The 1 results of the 1H NMR data of [AcO] are shown below. 1 1H NMR (DMSO-d 6 ) δ (ppm) = 9.42 (s, 1H), 7.80 (d, 2H), 4.23 (t, 4H), 3.49 - 3.47 (m, 4H), 3.44 - 3.40 (m, 8H), 3.25 (s, 6H), 2.08 - 2.01 (m, 4H), 1.52 (s, 3H)

[0165] [Example 1-3] 40 g of strongly basic ion exchange resin (DOWEX (registered trademark) MONOSPHERE 550A (OH) manufactured by Fujifilm Wako Pure Chemical Corporation) was mixed with ion-exchanged water and packed into a column tube. 14.0 g of [(MeOPr) 2 Im][AcO] obtained in Example 1-1 was dissolved in ion-exchanged water to prepare a 0.6 M aqueous solution. This aqueous solution was passed through the column packed with the ion exchange resin, and then 120 g of ion-exchanged water was passed through to obtain 204 g of an aqueous solution of 1,3-bis(3-methoxypropyl)imidazolium hydroxide ([(MeOPr) 2 Im]OH). The obtained [(MeOPr) 2To an aqueous solution of Im]OH, 35.3 g of acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) previously prepared in a 10 wt% aqueous solution was added and stirred. After stirring, the resulting reaction solution was concentrated to obtain 14.3 g of 1,3-bis(3-methoxypropyl)imidazolium acrylate ( 2 [(MeOPr) [(MeOPr) 2 Im][OH]'s 1 The results of the 1H NMR data are shown below. 1 1H NMR (D 2 2O) δ (ppm) = 7.5 (s, 2H), 4.28 (t, 4H), 3.47 (t, 4H), 3.31 (s, 6H), 2.13 (m, 4H) [(MeOPr) 2 Im][Acr]'s 1 The results of the 1H NMR data are shown below. 1 1H NMR (DMSO-d 6 ) δ (ppm) = 9.72 (s, 1H), 7.83 (d, 2H), 5.93 (dd, 1H), 5.62 (dd, 1H), 5.09 (dd, 1H), 4.25 (t, 4H), 3.33 (t, 4H), 3.21 (s, 6H), 2.08 - 2.01 (m, 4H)

[0166] [Example 1-4] To a 30 mL three-necked reactor purged with nitrogen, 1.86 g (23.0 mmol) of 37 wt% aqueous formaldehyde solution (manufactured by Tokyo Chemical Industry Co., Ltd.), 2.34 g (38.9 mmol) of acetic acid (manufactured by Junsei Chemical Co., Ltd.), 3.64 g (48.5 mmol) of 2-methoxyethylamine (manufactured by Tokyo Chemical Industry Co., Ltd.), and 3.59 g (24.9 mmol) of 40 wt% aqueous glyoxal solution (manufactured by Junsei Chemical Co., Ltd.) were charged. The resulting mixture was heated to 40 °C and stirred for 3 hours to synthesize 5.03 g of 1,3-bis(2-methoxyethyl)imidazolium acetate ( 2 [(MeOEt) 2 Im][AcO]). The yield was 89%. The 1 results of the 1H NMR data of [(MeOEt) 1 1H NMR (DMSO-d 6 ) δ(ppm) = 9.44 (s, 1H), 7.78 (s, 2H), 4.39 (t, 4H), 3.70 (t, 4H), 3.27 (s, 6H), 1.53 (s, 3H)

[0167] [Example 2-1] 6.46 g (79.8 mmol) of 37 wt% aqueous formaldehyde solution (manufactured by Tokyo Chemical Industry Co., Ltd.), 7.02 g (117 mmol) of acetic acid (manufactured by Junsei Chemical Co., Ltd.), 16.5 g (160 mmol) of 3-ethoxypropylamine (manufactured by Tokyo Chemical Industry Co., Ltd.), and 11.8 g (81.8 mmol) of 40 wt% aqueous glyoxal solution (manufactured by Junsei Chemical Co., Ltd.) were charged into a 100 mL three-necked reactor substituted with nitrogen. The resulting mixture was heated to 40 °C and stirred for 3 hours to synthesize 17.7 g of 1,3-bis(3-ethoxypropyl)imidazolium acetate ([(EtOPr) 2 Im][AcO]). The yield was 74%. [(EtOPr) 2 Im][AcO] 1 The results of 1H NMR data are shown below. 1 1H NMR (DMSO-d 6 ) δ(ppm) = 9.97 (s, 1H), 7.86 (d, 2H), 4.25 (t, 4H), 3.39 - 3.34 (m, 8H), 2.06 - 2.00 (m, 4H), 1.56 (s, 3H), 1.07 (t, 6H)

[0168] [Example 2-2] 7.19 g (88.8 mmol) of 37 wt% aqueous formaldehyde solution (manufactured by Tokyo Chemical Industry Co., Ltd.), 8.09 g (135 mmol) of acetic acid (manufactured by Junsei Chemical Co., Ltd.), 8.19 g (91.9 mmol) of 3-methoxypropylamine (manufactured by Tokyo Chemical Industry Co., Ltd.), 9.17 g (88.8 mmol) of 3-ethoxypropylamine (manufactured by Kanto Chemical Co., Inc.), and 12.9 g (89.3 mmol) of 40 wt% aqueous glyoxal solution (manufactured by Junsei Chemical Co., Ltd.) were charged into a nitrogen-purged 180 mL three-necked reactor. The resulting mixture was heated to 40 °C and stirred for 3 hours to synthesize 21.7 g of a mixture of 1-(3-ethoxypropyl)-3-(3-methoxypropyl)imidazolium acetate ([(EtOPr)(MeOPr)Im][AcO]), [(MeOPr) 2 Im][AcO], [(EtOPr) 2 Im][AcO] ([(EtOPr / MeOPr) 2 Im][AcO]). The yield was 88%. [(EtOPr / MeOPr) 2 Im][AcO] 1 The results of the 1H NMR data are shown below. 1 1H NMR (DMSO-d 6 ) δ (ppm) = 9.75 (s, 1H), 7.82 (d, 2H), 4.24 (t, 4H), 3.40 - 3.31 (m, 6H), 3.21 (s, 3H), 2.07 - 2.00 (m, 4H), 1.58 (s, 3H), 1.07 (t, 3H)

[0169] [Example 2-3] 5.63 g (69.6 mmol) of 37 wt% aqueous formaldehyde solution (manufactured by Tokyo Chemical Industry Co., Ltd.), 6.17 g (103 mmol) of acetic acid (manufactured by Junsei Chemical Co., Ltd.), 17.9 g (136 mmol) of 3-butoxypropylamine (manufactured by Tokyo Chemical Industry Co., Ltd.), and 9.85 g (68.4 mmol) of 40 wt% aqueous glyoxal solution (manufactured by Junsei Chemical Co., Ltd.) were charged into a nitrogen-purged 180 mL three-necked reactor. The resulting mixture was heated to 40 °C and stirred for 3 hours to obtain 1,3-bis(3-butoxypropyl)imidazolium acetate ([(BuOPr) 217.1 g of [[Im][AcO]] was synthesized. The yield was 70%. [(BuOPr) 2 of [[Im][AcO]] 1 The results of the 1H NMR data are shown below. 1 1H NMR (DMSO-d 6 ) δ (ppm) = 9.53 (s, 1H), 7.80 (d, 2H), 4.23 (t, 4H), 3.37 (t, 4H), 3.33 (t, 4H), 2.07 - 2.00 (m, 4H), 1.56 (s, 3H), 1.48 - 1.41 (m, 4H), 1.33 - 1.24 (m, 4H), 0.87 (t, 6H)

[0170] [Example 2 - 4] Except that 35.3 g of a 10 wt% aqueous solution of acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) in Examples 1 - 3 was changed to 36.9 g of a 10 wt% aqueous solution of propionic acid (manufactured by Junsei Chemical Co., Ltd.), in the same manner as in Examples 1 - 4, 1,3 - bis(3 - methoxypropyl)imidazolium propionate ([(MeOPr) 2 Im][PrO]) 13.0 g was obtained. The yield was 87%. 1 1H NMR (CDCl 3 ) δ (ppm) = 11.91 (s, 1H), 7.10 (d, 2H), 4.43 (t, 4H), 3.39 (t, 4H), 3.29 (t, 6H), 2.26 - 2.20 (m, 2H), 2.19 - 2.12 (m, 4H), 1.15 - 1.10 (m, 3H)

[0171] [Example 2 - 5] Except that 35.3 g of a 10 wt% aqueous solution of acrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) in Examples 1 - 3 was changed to 42.4 g of a 10 wt% aqueous solution of methacrylic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), in the same manner as in Examples 1 - 4, 1,3 - bis(3 - methoxypropyl)imidazolium methacrylate ([(MeOPr) 2 Im][MeAcr]) 15.0 g was obtained. The yield was 97%. [(MeOPr) 2 of [[Im][MeAcr]] 1 The results of the 1H NMR data are shown below. 1 1H NMR (DMSO-d 6 ) δ(ppm) = 9.72 (s, 1H), 7.83 (d, 2H), 5.43 - 5.42 (m, 1H), 4.85 - 4.83 (m, 1H), 4.25 (t, 4H), 3.33 (t, 4H), 3.22 (s, 6H), 2.08 - 2.01 (m, 4H), 1.73 (dd, 3H)

[0172] [Example 2 - 6] 6.70 g (82.8 mmol) of 37 wt% aqueous formaldehyde solution (manufactured by Tokyo Chemical Industry Co., Ltd.), 7.64 g (127 mmol) of acetic acid (manufactured by Junsei Chemical Co., Ltd.), 17.3 g (165 mmol) of 3 - methylthiopropylamine (manufactured by Tokyo Chemical Industry Co., Ltd.), and 12.3 g (85.5 mmol) of 40 wt% aqueous glyoxal solution (manufactured by Junsei Chemical Co., Ltd.) were charged into a 100 mL three - necked reactor substituted with nitrogen. The resulting mixture was heated to 40 °C and stirred for 3 hours to synthesize 19.3 g of 1,3 - bis(3 - methylthiopropyl)imidazolium acetate ([(MeSPr) 2 Im][AcO]). The yield was 77%. [(MeSPr) 2 Im][AcO]'s 1 1H NMR data results are shown below. 1 1H NMR (DMSO-d 6 ) δ(ppm) = 9.93 (s, 1H), 7.87 (d, 2H), 4.27 (t, 4H), 2.46 (t, 4H), 2.09 - 2.04 (m, 4H), 2.04 (s, 6H), 1.59 (s, 3H)

[0173] [Evaluation Example 1 - 1] 1.00 g of [(MeOPr) 2 Im][AcO] was placed in a sample tube and maintained at 25 °C. At 25 °C, microcrystalline cellulose (Avicel® PH - 101, manufactured by Sigma - Aldrich Co., LLC) was added in 0.01 g increments and stirred. The operation was repeated until the microcrystalline cellulose no longer completely dissolved after 10 minutes to 24 hours. The solubility results are shown in Table 1.

[0174] [Evaluation Examples 1-2, 1-3, 2-1 to 2-3, and Comparative Example 1-1] The operation was carried out in the same manner as in Evaluation Example 1-1 except that the onium salt of Evaluation Example 1-1 was replaced with the onium salts shown in Table 1. The solubility results are shown in Table 1. For 1-ethyl-3-methylimidazolium acetate used in Comparative Example 1-1, the product of Tokyo Chemical Industry Co., Ltd. was used.

[0175] [Table 1]

[0176] The onium salts shown in Evaluation Examples 1-1 to 1-3 and 2-1 to 2-3 showed excellent cellulose solubility at 25°C compared to the onium salt shown in Comparative Example 1-1.

[0177] [Evaluation Example 1-4] 0.63 g of [(MeOPr) 2 Im][AcO] and 0.44 g of dimethyl sulfoxide (hereinafter abbreviated as DMSO) were placed in a sample tube to obtain a mixed solution. The operation was carried out in the same manner as in Evaluation Example 1-1 except that the onium salt of Evaluation Example 1-1 was replaced with 1.0 g of the above mixed solution. The solubility results are shown in Table 2.

[0178] [Evaluation Examples 1-5, 2-4 to 2-6] The operation was carried out in the same manner as in Evaluation Example 1-4 except that the onium salt of Evaluation Example 1-4 was replaced with the onium salts shown in Table 2. The solubility results are shown in Table 2.

[0179] [Comparative Example 1-2] The operation was carried out in the same manner as in Evaluation Example 1-4 except that the mixed solution of Evaluation Example 1-4 was replaced with DMSO. The solubility results are shown in Table 2.

[0180] [Table 2]

[0181] [Evaluation Example 2-7] [(MeOPr) was placed in a sample tube2 1.00 g of Im][AcO] was added and the temperature was maintained at 50 °C. At 50 °C, curdlan (manufactured by Fujifilm Wako Pure Chemical Corporation) was added in 0.01 g increments and stirred. This operation was repeated until curdlan no longer completely dissolved after 10 minutes to 24 hours. The solubility results are shown in Table 3.

[0182] [Table 3]

[0183] The onium salts shown in Evaluation Example 2-7 exhibited excellent curdlan solubility at 50 °C.

[0184] [Evaluation Example 2-8] 1.00 g of [(MeOPr) 2 Im][AcO] was placed in a sample tube and the temperature was maintained at 50 °C. At 50 °C, chitin (manufactured by Fujifilm Wako Pure Chemical Corporation) was added in 0.01 g increments and stirred. This operation was repeated until chitin no longer completely dissolved after 10 minutes to 24 hours. The solubility results are shown in Table 4.

[0185] [Comparative Example 2-1] The operation was carried out in the same manner as in Evaluation Example 2-8, except that the onium salt shown in Evaluation Example 2-8 was replaced with the onium salts shown in Table 4. The solubility results are shown in Table 4.

[0186] [Table 4]

[0187] The onium salts shown in Evaluation Example 2-8 exhibited excellent chitin solubility at 50 °C compared to the onium salts shown in Comparative Example 2-1.

[0188] [Evaluation Example 1-6] [(MeOPr) 22.00 g of [Im][AcO] and 0.20 g of microcrystalline cellulose were added and stirred at 25 °C to prepare a cellulose-containing liquid composition. It was confirmed that fibrous cellulose could be recovered by filling the cellulose-containing liquid composition into a plastic syringe and extruding it into a water bath under an environment of 15 to 20 °C, followed by washing and drying.

[0189] [Evaluation Example 2-9] 10.00 g of [(MeOPr) 2 Im][AcO] and 2.00 g of microcrystalline cellulose were added and stirred at 25 °C to prepare a cellulose-containing liquid composition. The cellulose-containing liquid composition was applied to a glass plate and stretched using an applicator on a hot plate heated to 60 °C. It was confirmed that film-like cellulose could be recovered by guiding the stretched cellulose-containing liquid composition together with the glass plate into a water bath under an environment of 15 to 20 °C, followed by washing and drying.

Industrial Applicability

[0190] According to the present invention, it is possible to provide an onium salt having a very high polysaccharide solubility at a temperature of 10 to 50 °C, particularly around room temperature (25 °C). Further, as a composition suitable for recovering polysaccharides, there can be provided a liquid composition containing the onium salt and a polysaccharide, and a method for efficiently recovering a polysaccharide using such a liquid composition containing the onium salt and the polysaccharide.

Claims

1. An onium salt represented by the following formula (1). Formula (1): 【Chemical 1】 [wherein, R １ and R ２ are the same or different and each represents a group represented by formula (2). Formula (2): -R ５ -X-R ６ (2) (wherein, R ５ is an alkylene group having 2 or 3 carbon atoms, R ６ is an alkyl group having 1 to 4 carbon atoms which may contain a methyl group or an ether group and which may be linear or branched, X represents an oxygen atom or a sulfur atom.) R ３ represents a hydrogen atom or a methyl group. R ４ represents a hydrocarbon group. However, when R １ and R ２ are methoxyethyl groups and R ３ is a hydrogen atom, R ４ represents a hydrocarbon group having 2 or more carbon atoms. ]

2. R in formula (2) ５ The onium salt according to claim 1, wherein R is a propane-1,3-diyl group and X is an oxygen atom.

3. R in formula (1) １ and R ２ are the same, the onium salt according to claim 1

4. R in formula (1) ４ is a methyl group, CH ２ =CH− or CH ２ =C(CH ３ )−, and the onium salt according to claim 1

5. An onium salt composition containing two or more kinds of onium salts represented by the following formula (1). Formula (1): 【Chemical 2】 [wherein, R １ and R ２ are the same or different and each represents a group represented by formula (2). Formula (2): -R ５ -X-R ６ (2) (wherein, R ５ is an alkylene group having 2 or 3 carbon atoms, R ６ is an alkyl group having a straight chain or a branch with 2 to 4 carbon atoms which may contain one methyl group or an ether group, X represents an oxygen atom or a sulfur atom.) R ３ represents a hydrogen atom or a methyl group. R ４ represents a hydrocarbon group.

6. An onium hydroxide salt represented by the following formula (3). Formula (3): [Chemical Formula 3] [In the formula, R １ and R ２ are the same or different and each represents a group represented by the formula (2). Formula (2): -R ５ -X-R ６ (2) (wherein R ５ is an alkylene group having 2 or 3 carbon atoms, R ６ is an alkyl group having a straight chain or a branch with 2 to 4 carbon atoms which may contain one methyl group or an ether group, X represents an oxygen atom or a sulfur atom.) R ３ represents a hydrogen atom or a methyl group.

7. A method for producing an onium salt represented by formula (1), which includes reacting glyoxal, an amine compound represented by formula (6a), an amine compound represented by formula (6b), an aldehyde compound represented by formula (7), and a carboxylic acid represented by formula (4). Formula (6a): [Chemical Formula 4] Formula (6b): 【Chemical Formula 5】 [In formulas (6a) and (6b), R １ and R ２ are the same or different and represent those represented by formula (2). Formula (2): -R ５ -X-R ６ (2) (wherein R ５ is an alkylene group having 2 or 3 carbon atoms, R ６ is an alkyl group having 1 to 4 carbon atoms, which may contain a methyl group or an ether group and may be linear or branched, X represents an oxygen atom or a sulfur atom.) Formula (7): [Chemical Formula 6] (wherein, R ３ represents a hydrogen atom or a methyl group.) Formula (4): 【Chemical Formula 7】 (R ４ represents a hydrocarbon group.) Formula (1): 【Chemical Formula 8】 (wherein, R １ ~ R ４ are as defined above.)

8. A method for producing an onium salt represented by formula (1), which includes ion-exchanging a compound represented by formula (3) with a compound represented by formula (4). Formula (3): 【Chemical Formula 9】 [wherein, R １ and R ２ are the same or different and each represents a group represented by formula (2). Formula (2): -R ５ -X-R ６ (2) (wherein, R ５ is an alkylene group having 2 or 3 carbon atoms, R ６ is an alkyl group having 1 to 4 carbon atoms, which may contain a methyl group or an ether group and may be linear or branched, X represents an oxygen atom or a sulfur atom.) R ３ represents a hydrogen atom or a methyl group.] Formula (4) 【Chemical Formula 10】 (R ４ represents a hydrocarbon group.) Formula (1): 【Chemical 11】 (wherein, R １ to R ４ are as defined above.)

9. A polysaccharide-containing liquid composition comprising at least one polysaccharide and an onium salt represented by the following formula (1) or the onium salt composition according to claim 5, wherein the polysaccharide is dissolved in the onium salt. Formula (1): 【Chemical 12】 [wherein, R １ and R ２ are the same or different and each represents a group represented by formula (2). Formula (2): -R ５ -X-R ６ (2) (wherein R ５ is an alkylene group having 2 or 3 carbon atoms, R ６ is an alkyl group having 1 to 4 carbon atoms which may contain a methyl group or an ether group and which may be linear or branched, X represents an oxygen atom or a sulfur atom.) R ３ represents a hydrogen atom or a methyl group. R ４ represents a hydrocarbon group.

10. The polysaccharide-containing liquid composition according to claim 9 further comprises at least one organic solvent, and the polysaccharide is dissolved in a medium containing the onium salt or the onium salt composition and the organic solvent.

11. The polysaccharide-containing liquid composition according to claim 10, wherein the organic solvent is at least one organic solvent selected from the group consisting of dimethyl sulfoxide, N,N-dimethylacetamide, N,N-dimethylformamide, and N-methyl-2-pyrrolidone.

12. The polysaccharide-containing liquid composition according to claim 9, wherein the polysaccharide is cellulose.

13. A method for producing the polysaccharide-containing liquid composition according to claim 9, which includes a step of dissolving a polysaccharide using the onium salt represented by the following formula (1) or the onium salt composition according to claim 5. Formula (1): 【Chemical 13】 [In the formula, R １ and R ２ are the same or different and each represents a group represented by formula (2). Formula (2): -R ５ -X-R ６ (2) (wherein R ５ is an alkylene group having 2 or 3 carbon atoms, R ６ is an alkyl group having a straight or branched chain of 2 to 4 carbon atoms which may contain one methyl group or ether group, X represents an oxygen atom or a sulfur atom.) R ３ represents a hydrogen atom or a methyl group. R ４ represents a hydrocarbon group.

14. The method for producing the polysaccharide-containing liquid composition according to claim 13, wherein the temperature for dissolving the polysaccharide is 50°C or lower.

15. The method for producing a polysaccharide-containing liquid composition according to claim 13 or 14, wherein the polysaccharide is cellulose.

16. A method for recovering a polysaccharide, comprising contacting the polysaccharide-containing liquid composition according to any one of claims 9 to 12 with at least one poor solvent.

17. The method for recovering a polysaccharide according to claim 16, wherein the poor solvent is selected from the group consisting of water, methanol, ethanol, acetone, and a mixed solvent thereof.

18. The method for recovering a polysaccharide according to claim 16, wherein the polysaccharide is cellulose.

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