Process for refining acrylate compounds

Abstract

The present application provides a refining method of an acrylic ester compound and the like. The refining method is a refining method of a compound represented by formula (1) (in the formula, R 1 and R 2 are the same or different, and are an alkyl group, a fluoroalkyl group, an aryl group which can have one or more substituent groups, a halogen atom or a hydrogen atom, R 3 is an alkyl group, a fluoroalkyl group or an aryl group which can have one or more substituent groups, and X is a fluoroalkyl group or a halogen atom), which includes a step (A) of distilling a composition (A) containing (a) the compound represented by formula (1), (b) an alcohol and (c) a salt to obtain a condensed liquid containing the compound represented by formula (1).

Description

TECHNICAL FIELD

[0001] The present application relates to a refining method of an acrylate compound, etc. BACKGROUND

[0002] In Patent Literature 1, a method for separating methanol from a mixture is described.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 62-132925 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] The present application relates to a refining method of an acrylate compound, etc.

[0008] MEANS FOR SOLVING THE PROBLEMS

[0009] Item 1. A method for refining a compound represented by formula (1) shown below, comprising a step A of distilling a composition A containing (a) the compound represented by formula (1) shown above, (b) an alcohol and (c) a salt to obtain a condensed liquid containing the compound represented by formula (1) shown above.

[0010]

[0011] [In the formulae,

[0012] R 1 and R 2 are the same or different, and are an alkyl group, a fluoroalkyl group, an aryl group which can have one or more substituents, a halogen atom or a hydrogen atom,

[0013] R 3 is an alkyl group, a fluoroalkyl group or an aryl group which can have one or more substituents,

[0014] X is a fluoroalkyl group or a halogen atom.

[0015] Item 2. The production method according to item 1, wherein the composition A further contains water.

[0016] Item 3. The production method according to item 1 or 2, wherein the composition A is a homogeneous substance.

[0017] Item 4. The method according to any one of items 1 to 3, wherein the salt (c) is one or more selected from the group consisting of inorganic salts and organic salts.

[0018] Item 5. The method according to any one of items 1 to 4, wherein the amount ratio [alcohol (b) / salt (c)] of the alcohol (b) to the salt (c) is 0.01 mol / mol or more.

[0019] Item 6. The method according to any one of items 1 to 5, wherein the salt (c) is solvated with the alcohol (b) in an amount ratio of 0.5 mol / mol or more.

[0020] Item 7. The method according to any one of items 1 to 6, wherein the cation of the salt (c) is one or more selected from the group consisting of metal cations, NR4 + (wherein R is the same or different at each occurrence, and is H or an organic group, and optionally, any two of R can be bonded to each other to form a ring which can have a substituent), imidazolium which can have a substituent, pyridinium which can have a substituent, and phosphonium which can have a substituent.

[0021] Item 8. The method according to any one of items 1 to 7, wherein the cation of the salt (c) is one or more selected from the group consisting of monovalent metal cations, divalent metal cations, and trivalent metal cations.

[0022] Item 9. The method according to any one of items 1 to 8, wherein the anion of the salt (c) is one or more selected from the group consisting of carbonate ions, bicarbonate ions, carboxylate ions, sulfate ions, hydroxide ions, halide ions, and nitrate ions.

[0023] Item 10. The method according to any one of items 1 to 9, wherein the salt (c) is one or more selected from the group consisting of LiBr, LiI, MgBr2, MgI2, ZnCl2, ZnBr2, AlCl3, CaCl2, MgCl2, LiCl, NaCl, and NaI.

[0024] Item 11. The method according to any one of items 1 to 9, wherein the salt (c) is one or more selected from the group consisting of calcium stearate, calcium tartrate, calcium propionate, and calcium amino acid.

[0025] Item 12. The method according to any one of items 1 to 11, wherein the concentration of the salt (c) in the composition A is 50% or more relative to the saturation concentration thereof.

[0026] Item 13. The method according to any one of items 1 to 12, wherein the concentration of the salt (c) in the composition A is 10 wt% or more.

[0027] Item 14. The method according to any one of items 1 to 13, wherein the alcohol (b) is a linear or branched alcohol having 1 to 5 carbon atoms.

[0028] Item 15. The method according to any one of items 1 to 14, wherein the alcohol (b) is an alcohol represented by formula (2).

[0029] R 4 -OH (2)

[0030] [In the formula, R 4 is an alkyl group or a fluoroalkyl group.]

[0031] Item 16. The production method according to any one of items 1 to 15, wherein the composition A is subjected to direct distillation.

[0032] Item 17. The method according to any one of items 1 to 16, wherein the distillation is distillation under a pressure condition in the range of 0 to 100 kPa.

[0033] Item 18. The method according to any one of items 1 to 17, wherein the distillation is distillation under a temperature condition in the range of 10 to 100°C.

[0034] Item 19. The method according to any one of items 1 to 18, wherein R 1 is a hydrogen atom, an alkyl group or a fluoroalkyl group.

[0035] Item 20. The method according to any one of items 1 to 19, wherein R 2 is a hydrogen atom, an alkyl group or a fluoroalkyl group.

[0036] Item 21. The method according to any one of items 1 to 20, wherein R 3 is an alkyl group.

[0037] Item 22. The method according to any one of items 1 to 21, wherein R 3 is a C 1－4 alkyl group.

[0038] Item 23. The method according to any one of items 1 to 22, wherein X is a fluorine atom or a chlorine atom.

[0039] Item 24. The method according to any one of items 1 to 23, further comprising a process B of washing the coagulum obtained in the process A with water or water containing an alkali metal compound, an alkaline earth metal compound or both thereof.

[0040] Item 25. The method according to any one of items 1 to 23, further comprising a process B of washing the coagulum obtained in the process A with water or water containing one or more selected from the group consisting of lithium chloride, lithium bromide, magnesium bromide, magnesium iodide, magnesium sulfate, lithium iodide, sodium iodide, magnesium chloride and calcium chloride.

[0041] Item 26. The method according to any one of items 1 to 23, further comprising a process B of washing the above-mentioned coagulation liquid obtained in the above-mentioned process A with water containing calcium chloride.

[0042] Item 27. The method according to any one of items 1 to 26, further comprising a process C of recovering an alcohol and a salt, respectively, by distilling the residue portion after the above-mentioned coagulation liquid obtained in the above-mentioned process A.

[0043] Item 28. A composition comprising (a) a compound represented by the formula (1), (b) an alcohol, and (c) a salt.

[0044]

[0045] [In the formulae,

[0046] R 1 and R 2 are the same or different, and are an alkyl group, a fluoroalkyl group, an aryl group which can have one or more substituents, a halogen atom, or a hydrogen atom,

[0047] R 3 is an alkyl group, a fluoroalkyl group, or an aryl group which can have one or more substituents,

[0048] X is a fluoroalkyl group or a halogen atom.

[0049] Item 29. The composition according to item 28, further comprising a polymerization inhibitor.

[0050] Item 30. The composition according to item 28 or 29, further comprising water.

[0051] Item 31. The composition according to any one of items 28 to 30, wherein the vaporization of the above-mentioned alcohol (b) is inhibited as compared with a composition composed of the above-mentioned compound (a) and the above-mentioned alcohol (b).

[0052] Effects of the Invention

[0053] According to the present application, a refining method of an acrylate compound or the like can be provided. DETAILED DESCRIPTION

[0054] The above summary of the present application is not intended to describe each and every implementation of the present application or all implementations of the present application in its entirety.

[0055] The following description of the present application illustrates example implementations in more detail.

[0056] In some portions of the present application, guidance is provided by way of examples, and the examples can be used in various combinations.

[0057] In various cases, the groups exemplified function as non-exclusive and representative groups.

[0058] All publications, patents, and patent applications cited in this specification are herein incorporated by reference as if each individual publication, patent, or patent application were specifically and individually indicated to be incorporated by reference.

[0059] Terminology

[0060] In the specification, the signs and abbreviations unless otherwise specifically defined can be interpreted according to the context of the specification, as is generally used in the technical field to which the present application pertains.

[0061] In the specification, the use of the expression "comprising" is intended to include the expressions "consisting essentially of and "consisting of."

[0062] In the specification, the procedures, treatments, or operations described can be performed at room temperature, unless otherwise specifically defined.

[0063] In the specification, room temperature can refer to a temperature in the range of 10 to 40°C.

[0064] In the specification, the notation "C n－m " (wherein n and m are each a number) means a carbon atom number of n or more and m or less, as is generally understood by those skilled in the art.

[0065] In the specification, as "halogen atom", for example, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and the like can be exemplified.

[0066] In the specification, "alkyl group" can be a linear, branched, or cyclic alkyl group.

[0067] In the specification, "alkyl group" may, for example, be a C 1－20 alkyl group, a C 1－12 alkyl group, a C 1－6 alkyl group, a C 1－4 alkyl group, or a C 1－3 alkyl group.

[0068] In the specification, as "alkyl group", for example, a linear or branched alkyl group such as a methyl group, an ethyl group, a propyl group (n-propyl group, i-propyl group), a butyl group (n-butyl group, i-butyl group, sec-butyl group, t-butyl group), a pentyl group, and a hexyl group, and the like can be exemplified.

[0069] In the specification, as "alkyl group", for example, a cyclic alkyl group or a cycloalkyl group (for example, a C 3－8 cycloalkyl group) such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group, and the like can be exemplified.

[0070] In the specification, "fluoroalkyl group" is an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom.

[0071] In the present specification, the number of fluorine atoms of "fluoroalkyl group" can be 1 or more (e.g., 1 to 3, 1 to 6, 1 to 12, or 1 to the maximum number of substituents).

[0072] In the present specification, "fluoroalkyl group" can be, for example, C 1－20 fluoroalkyl group, C 1－12 fluoroalkyl group, C 1－6 fluoroalkyl group, C 1－4 fluoroalkyl group, or C 1－3 fluoroalkyl group.

[0073] In the present specification, "fluoroalkyl group" can be straight-chain or branched fluoroalkyl group.

[0074] In the present specification, "fluoroalkyl group" can be perfluoroalkyl group or non-perfluoroalkyl group.

[0075] In the present specification, as "fluoroalkyl group", for example, fluoro methyl group, difluoromethyl group, trifluoromethyl group, 2,2,2-trifluoroethyl group, pentafluoroethyl group, tetrafluoropropyl group (e.g., HCF2CF2CH2-), hexafluoropropyl group (e.g., (CF3)2CH-), nonafluorobutyl group, octafluoropentyl group (e.g., HCF2CF2CF2CF2CH2-), and tridecafluorohexyl group, etc. can be exemplified.

[0076] In the present specification, "aryl group" can be, for example, monocyclic, bicyclic, tricyclic, or tetracyclic.

[0077] In the present specification, "aryl group" can be, for example, C 6－18 aryl group, C 6－16 aryl group, C 6－14 aryl group, or C 6－12 aryl group.

[0078] In the present specification, as "aryl group", for example, phenyl group, 1-naphthyl group, 2-naphthyl group, 2-biphenyl group, 3-biphenyl group, 4-biphenyl group, and 2-anthryl group can be exemplified.

[0079] In the present specification, as substituents of "aryl group", for example, halogen atom, cyano group, amino group, alkoxy group, alkylthio group can be exemplified. Of these, 2 or more substituents can be the same as or different from each other.

[0080] In the present specification, "alkoxy group" can be a group (alkyl-O-) in which oxygen atom and alkyl group are bonded.

[0081] In the present specification, "alkoxy group" can be straight-chain or branched alkyl group.

[0082] In the present specification, as the "alkyl group", for example, a linear or branched chain C1-6alkyl group such as methyl, ethyl, propyl (n-propyl, isopropyl), butyl (n-butyl, isobutyl, sec-butyl, t-butyl), pentyl, hexyl, and the like can be mentioned. 1－20 alkoxy group.

[0083] In the present specification, the "alkylthio group" can be a group in which a sulfur atom is bonded to an alkyl group (alkyl-S-).

[0084] In the present specification, the "alkylthio group" can be a linear or branched chain alkylthio group.

[0085] In the present specification, as the "alkylthio group", for example, a linear or branched chain C1-6alkylthio group such as methylthio, ethylthio, propylthio (n-propylthio, isopropylthio), butylthio (n-butylthio, isobutylthio, sec-butylthio, t-butylthio), pentylthio, hexylthio, and the like can be mentioned. 1－20 alkylthio group.

[0086] The number of substituents of the aryl group can be, for example, 1 or more (for example, 1 to 3, 1 to 5, or 1 to the maximum number of substituability).

[0087] Refining process

[0088] The purification method of one embodiment of the present application is a purification method of a compound represented by the formula (1) [sometimes referred to as compound (1) in the present specification] including a step A of subjecting a composition A containing (a) the above-mentioned compound represented by the formula (1), (b) an alcohol, and (c) a salt to distillation to obtain a coagulum containing the above-mentioned compound represented by the formula (1).

[0089]

[0090] [In the formulae,

[0091] R 1 and R 2 are the same or different, an alkyl group, a fluoroalkyl group, an aryl group which can have 1 or more substituents, a halogen atom, or a hydrogen atom,

[0092] R 3 is an alkyl group, a fluoroalkyl group, or an aryl group which can have 1 or more substituents,

[0093] X is a fluoroalkyl group or a halogen atom.

[0094] Process A

[0095] Composition A

[0096] The composition A is a subject of distillation, and contains (a) the compound represented by the above formula (1), (b) an alcohol, and (c) a salt.

[0097] Preferably, the above composition A further contains water.

[0098] The lower limit of the amount of the water in the composition A is preferably 0.0001 mass%, more preferably 0.001 mass%, and further preferably 0.01 mass%.

[0099] The upper limit of the amount of the water in the composition A is preferably 80 mass%, and more preferably 70 mass%.

[0100] In the case where the above composition A contains water, the following advantages can be obtained, for example.

[0101] (1) In the case where the above composition A is a solid or a semi-solid (slurry), an undesirable situation is that lumps are easily generated, and uniform stirring becomes difficult, but in the case where the above composition A contains water, proper stirring becomes easy, and uniformization (or liquidization) is easily achieved.

[0102] (2) By the liquidization in the above (1), heating or cooling is easily performed, and energy and time can be saved.

[0103] (3) By the liquidization in the above (1), the amount of adhesion to the inner surfaces of a reactor (for example, a reaction vessel) and a pipe and the like can be reduced, and thus, transfer loss can be properly suppressed, cleaning operation can be reduced, and failure caused by solidification can be prevented.

[0104] The pH of the above composition A is arbitrary, and for example, from the viewpoint of increasing the hydrolysis resistance of the compound (1), it is preferably in the neutral to acidic range, and specifically, it is preferably 7 or less.

[0105] The above composition A can also contain a solvent (which is neither the above water nor the above alcohol (b)).

[0106] The lower limit of the amount of the solvent is preferably 0.001 mass%, more preferably 0.01 mass%, and further preferably 0.015 mass%, and the upper limit thereof is preferably 80 mass%, more preferably 70 mass%, and further preferably 60 mass%.

[0107] Preferably, the form of the above composition A includes a suspension, a viscous fluid, a semi-solid, and a solid. Preferably, the above composition A is a uniform substance.

[0108] Hereinafter, the description is made in the order of the salt (c), the alcohol (b), and the compound (1).

[0109] Salt (c)

[0110] The above salt (c) is preferably one or more selected from the group consisting of inorganic salts and organic salts.

[0111] The salt (c) can be preferably an inorganic salt.

[0112] The above amount ratio [alcohol (b) / salt (c)] is preferably 0.01 mol / mol or more, and the above salt (c) is further preferably solvated by the alcohol (b) in an amount ratio of 0.01 mol / mol or more.

[0113] The above amount ratio [alcohol (b) / salt (c)] is more preferably 0.05 mol / mol or more, further preferably 0.1 mol / mol or more, and more further preferably 0.5 mol / mol or more.

[0114] The above amount ratio [alcohol (b) / salt (c)] is usually 50 mol / mol or less, preferably 45 mol / mol or less, and more preferably 40 mol / mol or less.

[0115] The lower limit of the amount of the above alcohol (b) is preferably 0.3 parts by mass, more preferably 1.5 parts by mass, and further preferably 3.0 parts by mass, relative to 100 parts by mass of the above salt (c).

[0116] The upper limit of the amount of the above alcohol (b) is preferably 1600 parts by mass, more preferably 1400 parts by mass, and further preferably 1300 parts by mass, relative to 100 parts by mass of the above salt (c).

[0117] The amount of the above alcohol (b) is preferably in the range of 0.3 to 1600 parts by mass, more preferably in the range of 1.5 to 1400 parts by mass, and further preferably in the range of 3.0 to 1300 parts by mass, relative to 100 parts by mass of the above salt (c).

[0118] The above salt (c) is preferably one or more selected from the group consisting of inorganic salts and organic salts. + (In the formula, R is the same or different at each occurrence, and is H or an organic group, and two of them can be bonded to each other to form a ring which can have a substituent), imidazolium which can have a substituent, pyridinium which can have a substituent, and phosphonium which can have a substituent.

[0119] The cation of the salt (c) can be, for example, a metal cation or an ammonium cation.

[0120] As the metal cation, for example, monovalent metal cations (for example, alkali metals such as Li, Na, and the like), divalent metal cations (for example, alkaline earth metals such as Ca, and the like), and trivalent metal cations (for example, metals of Group 13 of the periodic table such as Al, and the like) can be exemplified.

[0121] As the ammonium cation, for example, a quaternary ammonium cation can be exemplified, and as a specific example thereof, a tetra-C 1－6 alkylammonium cation (e.g., tetramethylammonium cation, tetraethylammonium cation, tetrapropylammonium cation, tetrabutylammonium cation).

[0122] The cation of the salt (c) is preferably a metal cation.

[0123] As the anion of the salt (c), for example, a carbonate ion, a bicarbonate ion, a carboxylate ion, a sulfate ion, a hydroxide ion, a halide ion (e.g., a bromide ion, a chloride ion, an iodide ion), a nitrate ion, and the like can be exemplified.

[0124] The anion of the salt (c) is preferably a halide ion.

[0125] As the inorganic salt of the salt (c), a salt containing an alkaline earth metal, an alkali metal, or both is preferable.

[0126] As the inorganic salt of the salt (c), at least one selected from the group consisting of CaCl2, MgCl2, LiI, LiCl, NaCl, and NaI is preferable.

[0127] As the organic salt of the salt (c), at least one selected from the group consisting of calcium propionate and calcium amino acid is preferable.

[0128] The cation of the above-mentioned salt (c) is preferably at least one selected from the group consisting of a monovalent metal cation, a divalent metal cation, and a trivalent metal cation.

[0129] The anion of the above-mentioned salt (c) is preferably at least one selected from the group consisting of a carbonate ion, a bicarbonate ion, a carboxylate ion, a sulfate ion, a hydroxide ion, a halide ion, and a nitrate ion.

[0130] The above-mentioned salt (c) is preferably at least one selected from the group consisting of LiBr, LiI, MgBr2, MgI2, ZnCl2, ZnBr2, AlCl3, CaCl2, MgCl2, LiCl, NaCl, and NaI.

[0131] The above-mentioned salt (c) is preferably at least one selected from the group consisting of a salt containing a carboxyl group and a salt having a molecular weight of 100 or more and a boiling point of 150°C or more.

[0132] The above-mentioned salt (c) is preferably at least one selected from the group consisting of calcium stearate, calcium tartrate, calcium propionate, and calcium amino acid.

[0133] The lower limit of the concentration of the above-mentioned salt (c) in the above-mentioned composition A with respect to the saturated concentration thereof is preferably 5%, more preferably 10%, further preferably 15%, and still further preferably 20%.

[0134] Further, the lower limit of the concentration of the above-mentioned salt (c) in the above-mentioned composition A with respect to its saturated concentration is preferably 25%, more preferably 30%, further preferably 35%, still further preferably 40%, particularly preferably 45%, and particularly more preferably 50%.

[0135] The upper limit of the concentration of the above-mentioned salt (c) in the above-mentioned composition A with respect to its saturated concentration is preferably 99.0%, more preferably 99.3%, further preferably 99.6%, and still further preferably 100%.

[0136] In the present specification, the saturated concentration is the solubility limit concentration in water at the implementation temperature of the distillation of Step A.

[0137] The concentration of the above-mentioned salt (c) in the above-mentioned composition A is preferably 0.001 wt% or more, more preferably 0.01 wt% or more, and further preferably 0.1 wt% or more.

[0138] Further, the concentration of the above-mentioned salt (c) in the above-mentioned composition A is preferably 1 wt% or more, more preferably 5 wt% or more, and further preferably 10 wt% or more.

[0139] Alcohol (b)

[0140] The above-mentioned alcohol (b) is preferably a linear or branched alcohol having 1 to 5 carbon atoms.

[0141] The above-mentioned alcohol (b) is preferably an alcohol represented by formula (2).

[0142] R 4 -OH (2)

[0143] [In the formula, R 4 is an alkyl group (preferably a C 1－6 alkyl group, more preferably a C 1－4 alkyl group, further preferably a C 1－2 alkyl group, particularly preferably a methyl group), or a fluoroalkyl group (preferably a C 1－6 fluoroalkyl group, more preferably a C 1－4 fluoroalkyl group, further preferably a C 1－2 fluoroalkyl group, particularly preferably a fluoromethyl group. Among them, examples of the number of fluorine groups in the fluoroalkyl group can be exemplified by each of the numbers from 1 to the maximum number of substitutable positions.]

[0144] The above-mentioned composition A can also contain a polymerization inhibitor.

[0145] The lower limit of the amount of the polymerization inhibitor with respect to the total amount of the composition A can be, for example, 0.0001 wt%, 0.0005 wt%, 0.001 wt%, 0.005 wt%, 0.01 wt%, 0.05 wt%, or 0.1 wt%.

[0146] The upper limit of the amount of the polymerization inhibitor can be, for example, 20 wt%, 15 wt%, 10 wt%, 5 wt%, 1 wt%, 0.5 wt%, 0.1 wt%, or 0.05 wt%, relative to the total amount of the composition A.

[0147] The amount of the polymerization inhibitor can be, for example, in the range of 0.0001 to 20 wt%, in the range of 0.0005 to 5 wt%, or in the range of 0.001 to 0.05 wt%, relative to the total amount of the composition A.

[0148] As the polymerization inhibitor, for example, the following can be listed:

[0149] amine compounds such as aliphatic primary amines, aliphatic secondary amines, aliphatic tertiary amines, alicyclic secondary amines, alicyclic tertiary amines, aromatic amines, heterocyclic amines, and polymer-supported amine compounds (polymeric amine compounds);

[0150] ammonia;

[0151] terpene compounds;

[0152] nitroso compounds; (including tetramethylpiperidine oxide (tempo), 1,1-diphenyl-2-trinitrophenylhydrazine (dpph)), and

[0153] compounds having one or more atoms selected from oxygen atoms and sulfur atoms, and the like.

[0154] As the aliphatic primary amine, for example, the following can be listed: methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, cyclohexylamine, and ethylenediamine.

[0155] As the aliphatic secondary amine, for example, the following can be listed: dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, and dicyclohexylamine.

[0156] As the aliphatic tertiary amine, for example, the following can be listed: trimethylamine, triethylamine, diisopropylethylamine, tri(n-butyl)amine, and N,N,N',N'-tetramethylethylenediamine.

[0157] As the alicyclic secondary amine, for example, the following can be listed: piperidine, piperazine, pyrrolidine, morpholine.

[0158] As the alicyclic tertiary amine, for example, the following can be listed: N-methylpiperazine, N-methylpyrrolidine, 1,5-diazabicyclo[4,3,0]-5-nonene, and 1,4-diazabicyclo[2,2,2]octane.

[0159] As the aromatic amine, for example, the following can be listed: aniline, methyl aniline, dimethyl aniline, N,N-dimethyl aniline, halogenated aniline, and nitro aniline.

[0160] As the heterocyclic amine, for example, pyridine, melamine, pyrimidine, piperazine, quinoline and imidazole can be exemplified.

[0161] As the polymeric amine compound, for example, polyethyleneimine, polyallylamine and polyvinylpyridine can be exemplified.

[0162] As the terpene compound, for example, α-pinene, camphene, α-terpinene, D-limonene, γ-terpinene, p-cymene and bisnorbornyl alcohol, etc. can be exemplified.

[0163] As the compound having one or more atoms selected from oxygen atom and sulfur atom, a compound having one or more aromatic 6-membered carbon rings and one or more oxygen atoms or sulfur atoms directly bonded to one or more ring-forming carbon atoms of the one or more aromatic 6-membered carbon rings having a carbon number of 6 to 20 is preferable. As examples thereof, specifically, for example, hydroquinone, 4-methoxyphenol, 2,5-di-tert-butylhydroquinone, methylhydroquinone, tert-butylhydroquinone (TBH), p-benzoquinone, methyl-p-benzoquinone, tert-butyl-p-benzoquinone, 2,5-diphenyl-p-benzoquinone, 2,6-di-tert-butyl-4-methylphenol (BHT), phenothiazine, 4-tert-butylcatechol, 6-tert-butyl-2,4-dimethylphenol, catechol, 2,6-di-tert-butylphenol, TEMPO and DPPH, etc. can be exemplified.

[0164] The above composition A can be prepared by mixing the above compound (a), the above alcohol (b) and the above salt (c), and the desired water and the desired other components. The mixing can be carried out by using a publicly known method (for example, mixing by using a mixer).

[0165] The order of addition in the mixing is arbitrary.

[0166] Specifically, examples of the method of addition include the following methods:

[0167] [Method 1] adding the above compound (a) and the above alcohol (b) [for example, a mixed solution of the above compound (a) and the above alcohol (b)] to an aqueous solution of the salt (c) [for example, calcium chloride];

[0168] [Method 2] adding an aqueous solution of the salt (c) [for example, calcium chloride] to the above compound (a) and the above alcohol (b);

[0169] [Method 3] adding water to the above compound (a), the above alcohol (b) and the salt (c) [for example, calcium chloride];

[0170] [Method 4] adding the salt (c) [for example, calcium chloride] to the above compound (a), the above alcohol (b) and water;

[0171] [Mode 5] The above compound (a) and the above alcohol (b) are added to the above salt (c) [for example, calcium chloride];

[0172] [Mode 6] The above compound (a) and the above alcohol (b) [for example, a mixed solution of the above compound (a) and the above alcohol (b)] are added to the above salt (c) [for example, calcium chloride].

[0173] The amount of the above desired water (which includes water in the above aqueous solution) is preferably in the range of 0.001 to 80 mass%, more preferably in the range of 0.01 to 70 mass%, and further preferably in the range of 0.1 to 65 mass%.

[0174] After this preparation, the composition A can be left as it is until distillation described below. By this, the recovery rate of the above compound (a) can be improved. The temperature of this leaving can be, for example, room temperature. The time of this leaving can be, for example, 0.01 to 3 days.

[0175] Distillation

[0176] The distillation method is not particularly limited. Examples thereof include direct distillation, thin film method, continuous distillation, pressure distillation, reduced pressure distillation, normal pressure distillation, and variable pressure distillation.

[0177] The above composition A is preferably directly distilled.

[0178] In the present application, distillation broadly means separation using the difference in boiling point. However, it is to be noted that the boiling point is not to be interpreted as the standard boiling point or the like in a limiting manner, and the boiling point varies depending on various conditions such as pressure. That is, the boiling point can be changed by condition setting as appropriate in accordance with the technical object of the present application.

[0179] As the distillation apparatus that can be employed in the present application, for example, a distillation column, a distiller, a conical dryer (vacuum rotary dryer), a hybrid dryer, a box dryer, and the like can be exemplified.

[0180] As the apparatus, it is preferable to have a configuration in which the state of the contents is easily uniform (for example, the contents can be made free of lumps).

[0181] Specifically, for example, a conical dryer having a protrusion inside and an apparatus having a belt wing, and the like are preferable.

[0182] In addition, in the case where the contents are liquid, as the apparatus, an apparatus that can sufficiently stir is preferable. In the case where the stirring is sufficient, the coagulation effect is improved.

[0183] In the case where the composition A contains a polymerization inhibitor, nitrogen, air, or oxygen can be introduced into the system. The introduction can be performed by, for example, bubbling.

[0184] The pressure conditions for distillation described above can be, for example, 0 kPa or more, preferably 0.01 kPa or more, and more preferably 0.05 kPa or more.

[0185] The pressure conditions for the distillation described above are preferably 700 kPa or less, more preferably 650 kPa or less, and even more preferably 600 kPa or less.

[0186] In addition, the pressure conditions for distillation are preferably 500 kPa or less, more preferably 400 kPa or less, even more preferably 300 kPa or less, even more preferably 200 kPa or less, and particularly preferably 100 kPa or less.

[0187] The pressure conditions for distillation described above are preferably in the range of 0 to 700 kPa, more preferably in the range of 0.01 to 650 kPa, and even more preferably in the range of 0.05 to 600 kPa.

[0188] In addition, the distillation conditions described above are preferably in the range of 0 to 100 kPa.

[0189] The distillation temperature is preferably -10°C or higher, more preferably -5°C or higher, even more preferably 1°C or higher, even more preferably 5°C or higher, and particularly preferably 10°C or higher.

[0190] The distillation temperature is preferably below 150°C, more preferably below 145°C, and even more preferably below 140°C.

[0191] In addition, the distillation temperature is preferably below 130°C, more preferably below 120°C, even more preferably below 110°C, and even more preferably below 100°C.

[0192] The distillation temperature conditions described above are preferably in the range of -10 to 150°C, more preferably in the range of -5 to 145°C, and even more preferably in the range of -1 to 140°C.

[0193] In addition, the distillation temperature is preferably in the range of 10 to 100°C.

[0194] Preferred R 1 It can be a hydrogen atom, an alkyl group, or a fluoroalkyl group.

[0195] Preferred R 2 It can be a hydrogen atom, an alkyl group, or a fluoroalkyl group.

[0196] Preferred R 3 It is an alkyl group.

[0197] Preferred R 3 C1－4 alkyl.

[0198] X is preferably a fluorine atom or a chlorine atom.

[0199] A preferred embodiment of the refining method of the present invention further includes a step B in which the coagulated liquid obtained in step A is washed with water or water containing alkali metal compounds, alkaline earth metal compounds or both.

[0200] A more preferred embodiment of the purification method of the present invention further includes step B, in which the coagulated solution obtained in step A is washed with water or water containing one or more of lithium chloride, lithium bromide, magnesium bromide, magnesium iodide, magnesium sulfate, lithium iodide, sodium iodide, magnesium chloride and calcium chloride.

[0201] A further preferred embodiment of the purification method of the present invention includes a step B in which the coagulated solution obtained in step A is washed with water containing calcium chloride.

[0202] The phrase "containing (a substance) in water" indicates the state in which the substance exists in water. In water, this substance can exist in various forms, depending on its inherent properties and the presence of other substances in the water. For example, the substance can dissolve in the water, dissociate into ions, or exist as a solid.

[0203] The cleaning conditions should be determined appropriately based on common technical knowledge.

[0204] The purification method of the present invention preferably further includes step C, in which the alcohol and salt are recovered separately by distilling the residue after obtaining the condensate in step A. The distillation conditions can be appropriately determined based on common technical knowledge.

[0205] Composition

[0206] The composition of the present invention is a composition containing (a) a compound of formula (1), (b) an alcohol and (c) a salt.

[0207]

[0208] [In the formula,

[0209] R 1 and R 2 Whether the groups are the same or different, they can be alkyl, fluoroalkyl, aryl, halogen, or hydrogen atoms, which may have more than one substituent.

[0210] R 3 It is an alkyl, fluoroalkyl, or aryl group that may have one or more substituents.

[0211] X is a fluorinated alkyl group or a halogen atom.

[0212] The composition can be the above-mentioned Composition A, which can be understood in reference to the above description regarding the above-mentioned Composition A.

[0213] In a preferred mode of the composition, the above-mentioned salt (c) is preferably one or more selected from the group consisting of NH4F, NH4Br, N(C n H 2n+1 )4F (wherein n = 1 to 6), (NH4)2NO3, (NH4)2S2O3, NH4HCO3, NaHCO3, NaHSO4, Na2SO3, Na2CO3, Na2S2O3, Na2SO4, NaOH, NaCl, NaF, Nal, NaBr, LiHCO3, Li2SO3, Li2CO3, Li2S2O3, Li2SO4, LiOH, LiCl, Lil, LiBr, KHCO3, KHSO4, K2SO3, K2CO3, K2S2O3, K2SO4, KOH, KCl, KF, Kl, KBr, MgSO3, MgCO3, MgS2O3, MgSO4, Mg(OH)2, MgCl2, Mgl2, MgBr2, MgO, Mg(CH3COO)2, Ca(HCO3)2, CaSO3, CaCO3, CaSO4, Ca(OH)2, CaCl2, Cai2, CaBr2, CaO, Ca(NO3)2, Ca3(PO4)2, Ca(CH3COO)2, Al2(CO3)3, Al2(SO4)3, Al(OH)3, AlCl3, AlBr3, Al2O3, Al(NO3)3, AlPO4, ZnSO4, Zn(OH)2, ZnCl2, ZnBr2, Zni2, ZnO, Zn(NO3)2, Zn3(PO4)2, Zn(CH3COO)2, calcium stearate, calcium tartrate, calcium propionate, calcium benzoate, calcium lactate, and calcium amino acid, more preferably one or more selected from the group consisting of NH4F, NH4Br, N(C n H 2n+1)4F (wherein n = 1 to 6), (NH4)2NO3, Na2SO3, Na2CO3, Na2SO4, Nal, Li2SO3, Li2CO3, Li2SO4, LiCl, Lil, LiBr, K2SO3, K2CO3, K2SO4, KCl, KF, KI, KBr, MgSO3, MgCO3, MgSO4, Mg(OH)2, MgCl2, Mgl2, MgBr2, MgO, Mg(CH3COO)2, CaSO3, CaCO3, CaSO4, Ca(OH)2, CaCl2, Cai2, CaBr2, CaO, Ca(NO3)2, Ca3(PO4)2, Ca(CH3COO)2, Al2(CO3)3, Al2(SO4)3, Al(OH)3, AlCl3, AlBr3, Al2O3, Al(NO3)3, AlPO4, ZnSO4, Zn(OH)2, ZnCl2, ZnBr2, ZnO, Zn(NO3)2, Zn3(PO4)2, Zn(CH3COO)2, calcium stearate, calcium tartrate, calcium propionate, and calcium amino acid, further preferably one or more selected from N(C n H 2n+1 )4F (wherein n = 1 to 6), Na2SO4, Nal, Li2SO4, LiCl, Lil, LiBr, K2SO4, KCl, KI, KBr, MgCO3, MgSO4, Mg(OH)2, MgCl2, Mgl2, MgBr2, MgO, Mg(CH3COO)2, CaCO3, CaSO4, Ca(OH)2, CaCl2, Cai2, CaBr2, CaO, Ca(CH3COO)2, Al2(SO4)3, Al(OH)3, AlCl3, AlBr3, Al2O3, AlPO4, ZnSO4, Zn(OH)2, ZnCl2, ZnBr2, ZnO, Zn(CH3COO)2, calcium stearate, calcium tartrate, calcium propionate, and calcium amino acid.

[0214] The amount of the above salt is preferably 0.001 to 99.99% by mass, more preferably 0.01 to 99% by mass, and further preferably 0.1 to 95% by mass, relative to the entire composition.

[0215] In a preferred embodiment of the composition, the above polymerization inhibitor is, for example, preferably an amine compound, a nitroso compound, and a compound containing an OH moiety.

[0216] Preferred examples of the compound containing the OH group include hydroquinone, 4-methoxyphenol, 2,5-di-tert-butylhydroquinone, methylhydroquinone, tert-butylhydroquinone (TBH), p-benzoquinone, methyl-p-benzoquinone, tert-butyl-p-benzoquinone, 2,5-diphenyl-p-benzoquinone, 2,6-di-tert-butyl-4-methylphenol (BHT), 4-tert-butylcatechol, 6-tert-butyl-2,4-dimethylphenol, catechol, and 2,6-di-tert-butylphenol, and the like.

[0217] The lower limit of the amount of the above-described polymerization inhibitor can be, for example, 0.0001 wt%, 0.0005 wt%, 0.001 wt%, 0.005 wt%, 0.01 wt%, 0.05 wt%, or 0.1 wt%, relative to the total amount of the composition.

[0218] The upper limit of the amount of the above-described polymerization inhibitor can be, for example, 20 wt%, 15 wt%, 10 wt%, 5 wt%, 1 wt%, 0.5 wt%, 0.1 wt%, or 0.05 wt%, relative to the total amount of the composition.

[0219] The amount of the above-described polymerization inhibitor can be, for example, in the range of 0.0001 to 20 wt%, in the range of 0.0005 to 5 wt%, and in the range of 0.001 to 0.05 wt%, relative to the total amount of the composition.

[0220] The composition is compared with a composition composed of the above-described compound (a) and the above-described alcohol (b) (or the same composition except that it does not contain the salt (c)), and the vaporization property of the above-described alcohol (b) is inhibited.

[0221] The vaporization property can be confirmed, for example, by performing reduced pressure distillation (conditions: 10 kPa, 24°C) and measuring the amount of the alcohol (b) in the distillate.

[0222] As an index indicating the degree of inhibition of vaporization, the vaporization inhibition rate can be used.

[0223] The vaporization inhibition rate (hereinafter sometimes abbreviated as "inhibition rate") is preferably in the range of 10% to 100%, more preferably 20% to 100%, and further preferably 30% to 100%.

[0224] The inhibition rate can be represented by the following formula.

[0225] Inhibition rate (%) = (X1 - X2) / X1 x 100

[0226] In the formula, X1 is the amount of the alcohol (b) in the distillate obtained by distillation of a composition composed of the above-described compound (a) and the above-described alcohol (b), and X2 is the amount of the alcohol (b) in the distillate obtained by distillation of the above-described composition (A).

[0227] Accordingly, the composition can be stably stored.

[0228] The above describes embodiments of the present application, but various changes can be made to the modes and details as long as they do not depart from the gist and scope of the claimed invention.

[0229] Example

[0230] The present application will be described in more detail by way of examples below, but the present application is not limited thereto.

[0231] Example 1

[0232] To a mixed solution of 2-fluoro-methyl acrylate 20 wt% and MeOH (methanol) 80 wt% 100 g, CaCl2 100 g was added. After the resulting solid was left to stand for 48 h, vacuum distillation (conditions: 10 kPa, 24°C) was performed, and as a distillate, a mixed solution of 2-fluoro-methyl acrylate 70 wt% and MeOH 30 wt% was obtained. At this time, the recovery rate of 2-fluoro-methyl acrylate was 99%. The inhibition rate was 89%.

[0233] Example 2

[0234] To a mixed solution of 2-fluoro-methyl acrylate 20 wt% and MeOH 80 wt% 100 g, CaCl2 100 g was added. Vacuum distillation (10 kPa, 24°C) was performed on the resulting solid, and as a distillate, a mixed solution of 2-fluoro-methyl acrylate 67 wt% and MeOH 33 wt% was obtained. At this time, the recovery rate of 2-fluoro-methyl acrylate was 94%. The inhibition rate was 88%.

[0235] Example 3

[0236] To a mixed solution of 2-fluoro-methyl acrylate 15 wt% and MeOH 85 wt% 100 g, CaCl2 100 g and water 110 g were added. At this time, the pH was 5. Vacuum distillation (5 kPa, 24°C) was performed on the resulting liquid, and as a distillate, a mixed solution of 2-fluoro-methyl acrylate 59 wt%, MeOH 39 wt%, and water 2 wt% was obtained. At this time, the recovery rate of 2-fluoro-methyl acrylate was 97%. The inhibition rate was 89%.

[0237] Example 4

[0238] After the distillation of Example 3, vacuum distillation (5 kPa, 30-100°C) was performed while slowly raising the temperature. As a distillate, MeOH was obtained. At this time, the recovery rate of MeOH was 99%. The recovery rate of CaCl2 was 100%.

[0239] Example 5

[0240] To a mixed solution of 2-fluoroacrylic acid methyl ester 59 wt%, MeOH 39 wt% and water 2 wt% 100 g, 47 wt% CaCl2 aqueous solution 110 g was added and stirred. Two phases were separated to obtain a mixed solution of 2-fluoroacrylic acid methyl ester 98 wt% and MeOH 2 wt%. At this time, the recovery rate of 2-fluoroacrylic acid methyl ester was 91%.

[0241] As impurities, the following substances were confirmed by gas chromatography, respectively (<1 GC area %):

[0242] (1) Ester compound (methyl acetate);

[0243] (2) Compound in which the ester compound is aldolized with an alcohol (compound in which methyl acetate is aldolized with an alcohol (MeOH));

[0244] (3) Compound in which the ester compound is hydrolyzed in water (acetic acid, 2-fluoroacrylic acid and / or a salt thereof);

[0245] (4) Compound in which an alcohol is added to an acrylic acid compound (compound in which an alcohol (MeOH) is added to 2-fluoroacrylic acid methyl ester or 2-fluoroacrylic acid); and

[0246] (5) Compound in which water is added to an acrylic acid compound (compound in which water is added to 2-fluoroacrylic acid methyl ester or 2-fluoroacrylic acid).

[0247] Example 6

[0248] To a mixed solution of 2-fluoroacrylic acid methyl ester 15 wt% and MeOH 85 wt% 100 g, CaCl2 100 g, water 110 g and hydroquinone 0.015 g were added. Vacuum distillation (5 kPa, 24°C) was performed on the obtained liquid, and as a distillate, a mixed solution of 2-fluoroacrylic acid methyl ester 59 wt%, MeOH 40 wt%, water 1 wt% was obtained. At this time, the recovery rate of 2-fluoroacrylic acid methyl ester was 98%. The inhibition rate was 88%.

[0249] Example 7

[0250] To a mixed solution of 2-fluoroacrylic acid methyl ester 15 wt% and MeOH 85 wt% 100 g, CaCl2 100 g, water 110 g and BHT 0.3 g were added. Vacuum distillation (5 kPa, 24°C) was performed on the obtained liquid, and as a distillate, a mixed solution of 2-fluoroacrylic acid methyl ester 49 wt%, MeOH 49 wt%, water 2 wt% was obtained. At this time, the recovery rate of 2-fluoroacrylic acid methyl ester was 98%. The inhibition rate was 83%.

[0251] Example 8

[0252] To a mixed solution of 2-fluoroacrylate 15 wt% and MeOH 85 wt% 100 g, CaCl2 100 g, water 110 g and 4-methoxyphenol 0.015 g were added. The resulting liquid was subjected to a reduced pressure distillation (using a Vigreaux column) (5 kPa, 24°C) to give a mixed liquid of 2-fluoroacrylate 58.5 wt%, MeOH 40 wt%, water 1.5 wt% as a fraction. At this time, the recovery rate of 2-fluoroacrylate was 98%. The inhibition rate was 88%.

[0253] Example 9

[0254] To a mixed solution of 2-fluoroacrylate 15 wt% and MeOH 85 wt% 100 g, CaCl2 100 g, water 110 g and TBH 0.015 g were added. The resulting liquid was subjected to a reduced pressure distillation (using a Vigreaux column) (5 kPa, 24°C) to give a mixed liquid of 2-fluoroacrylate 54 wt%, MeOH 44.5 wt%, water 1.55 wt% as a fraction. At this time, the recovery rate of 2-fluoroacrylate was 96%. The inhibition rate was 86%.

[0255] Example 10

[0256] To a mixed solution of 2-fluoroacrylate 15 g, MeOH 85 g and 4-methoxyphenol 0.015 g 100 g, hydrochloric acid was added, and the pH was adjusted to 1. To the resulting solution, CaCl2 100 g and water 110 g were added. The resulting liquid was subjected to a reduced pressure distillation (5 kPa, 24°C) to give a mixed liquid of 2-fluoroacrylate 58.5 wt%, MeOH 40 wt%, water 1.5 wt% as a fraction. At this time, the recovery rate of 2-fluoroacrylate was 98%. The inhibition rate was 88%.

[0257] Example 11

[0258] To a mixed solution of 2-fluoroacrylate 15 wt% and MeOH 85 wt% 100 g, LiCl 60 g was added. The resulting liquid was subjected to a reduced pressure distillation (5 kPa, 25°C) to give a mixed liquid of 2-fluoroacrylate 39 wt%, MeOH 61 wt% as a fraction. At this time, the recovery rate of 2-fluoroacrylate was 100%. The inhibition rate was 72%.

[0259] Example 12

[0260] To a mixed solution of 2-fluoroacrylic acid methyl ester 15 wt% and MeOH 85 wt% 100 g was added NaI 204 g. The resulting liquid was subjected to reduced pressure distillation (5 kPa, 25°C) to obtain a mixed liquid of 2-fluoroacrylic acid methyl ester 20 wt% and MeOH 80 wt% as a distillate. At this time, the recovery rate of 2-fluoroacrylic acid methyl ester was 100%. The inhibition rate was 29%.

[0261] Example 13

[0262] To a mixed solution of 2-fluoroacrylic acid methyl ester 15 wt% and MeOH 85 wt% 100 g was added Na2SO4 103 g. The resulting liquid was subjected to reduced pressure distillation (5 kPa, 25°C) to obtain a mixed liquid of 2-fluoroacrylic acid methyl ester 44 wt% and MeOH 56 wt% as a distillate. At this time, the recovery rate of 2-fluoroacrylic acid methyl ester was 100%. The inhibition rate was 78%.

[0263] Example 14

[0264] To a mixed solution of 2-fluoroacrylic acid methyl ester 15 wt% and MeOH 85 wt% 100 g was added MgCl2 142 g. The resulting liquid was subjected to reduced pressure distillation (5 kPa, 25°C) to obtain a mixed liquid of 2-fluoroacrylic acid methyl ester 43 wt% and MeOH 57 wt% as a distillate. At this time, the recovery rate of 2-fluoroacrylic acid methyl ester was 100%. The inhibition rate was 76%.

Claims

1. A method for purifying a compound represented by formula (1) : ###0001### wherein X represents a halogen atom, comprising a step A of distilling a composition A containing (a) said compound represented by formula (1), (b) an alcohol, and (c) a salt, to obtain a condensed liquid containing said compound represented by formula (1).

2. A method for purifying a compound represented by formula (1) : ###0002### wherein X represents a halogen atom, comprising a step A of distilling a composition A containing (a) said compound represented by formula (1), (b) an alcohol, and (c) a salt, to obtain a condensed liquid containing said compound represented by formula (1).

3. The method according to claim 1 or 2, wherein said composition A is homogeneous. R 1 and R 2 are the same or different and are C 1－6 alkyl, C 1－6 fluoroalkyl or a hydrogen atom, R 3 is C 1－6 alkyl or C 1－6 fluoroalkyl, 4. The method according to claim 1 or 2, wherein the amount of said alcohol (b) relative to said salt (c) is 0.01 mol or more per mol of said salt (c) in terms of alcohol (b) / salt (c).

5. The method according to claim 1 or 2, wherein said salt (c) is solvated by said alcohol (b) in an amount of 0.5 mol or more per mol of said salt (c). R 4 -OH (2) wherein R 4 is C 1－6 alkyl or C 1－6 fluoroalkyl, 6. The method according to claim 1 or 2, wherein the concentration of said salt (c) in said composition A is 50% or more relative to the saturation concentration thereof.

7. The method according to claim 1 or 2, wherein the concentration of said salt (c) in said composition A is 10% by weight or more.

8. The method according to claim 1 or 2, wherein said alcohol (b) is a linear or branched alcohol having 1 to 5 carbon atoms.

9. The method according to claim 1 or 2, wherein said composition A is directly distilled. R 1 and R 2 are the same or different, a C 1－6 alkyl group, a C 1－6 fluoroalkyl group or a hydrogen atom, R 3 is C 1－6 alkyl or C 1－6 fluoroalkyl, 10. The method according to claim 1 or 2, wherein said distillation is performed under a pressure condition in the range of 0 to 100 kPa.

11. The method according to claim 1 or 2, wherein said distillation is performed under a temperature condition in the range of 10 to 100°C.

12. The method according to claim 1 or 2, wherein said composition A further contains water. R 4 -OH (2) wherein R 4 is C 1－6 alkyl or C 1－6 fluoroalkyl, 13. The method according to claim 1 or 2, wherein said alcohol (b) is an alcohol represented by formula (2) : ###0003### 14. The method according to claim 1 or 2, wherein X is a fluorine atom or a chlorine atom.

15. The method according to claim 1 or 2, further comprising a step B of washing said condensed liquid obtained in said step A with water or water containing one or more selected from the group consisting of lithium chloride, lithium bromide, magnesium bromide, magnesium iodide, magnesium sulfate, lithium iodide, sodium iodide, magnesium chloride, and calcium chloride.

16. The method according to claim 1 or 2, wherein said composition A contains one or more selected from the group consisting of CaCl2, LiCl, Nal, Na2SO4, and MgCl2. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ R 3 is C 1－6 alkyl. ​ R 3 is C 1－4 alkyl. ​ ​ ​ ​ ​ A process B of washing the coagulation liquid obtained in the process A with water containing calcium chloride is further included.

17. The method according to claim 1 or 2, wherein: A process C of recovering an alcohol and a salt, respectively, by distilling the residual portion after the coagulation liquid obtained in the process A is further included.

18. A composition, comprising: (a) a compound represented by formula (1), (b) an alcohol, and (c) a salt, (a) a compound represented by formula (1), (b) an alcohol, and (c) a salt, wherein, R 1 and R 2 are identical or different and are C 1－6 alkyl, C 1－6 fluoroalkyl or a hydrogen atom, R 3 is C1-6alkyl or C1-6fluoroalkyl, X is a halogen atom, the alcohol (b) is an alcohol represented by formula (2), R 4 -OH (2) wherein R 4 is C 1－6 alkyl or C 1－6 fluoroalkyl, the salt (c) is one or more selected from the group consisting of CaCl2, LiCl, Nal, Na2SO4, and MgCl2.

19. A composition, comprising: (a) a compound represented by formula (1), (b) an alcohol, and (c) a salt, (a) a compound represented by formula (1), (b) an alcohol, and (c) a salt, wherein, R 1 and R 2 are the same or different, a C 1－6 alkyl group, a C 1－6 fluoroalkyl group or a hydrogen atom, R 3 is C 1－6 alkyl or C 1－6 fluoroalkyl, X is a halogen atom, the composition further comprises water, the alcohol (b) is an alcohol represented by formula (2), R 4 -OH (2) wherein R 4 is C 1－6 alkyl or C 1－6 fluoroalkyl, the salt (c) is one or more selected from the group consisting of CaCl2, LiCl, Nal, Na2SO4, and MgCl2.

20. The composition according to claim 18 or 19, further comprising: a polymerization inhibitor.

21. The composition according to claim 18 or 19, wherein: the vaporization property of the alcohol (b) is inhibited as compared with a composition consisting of the compound (a) and the alcohol (b), the vaporization property being inhibited is represented by a vaporization inhibition rate in the range of 10% to 100%, the vaporization inhibition rate is represented by the following formula: Vaporization inhibition rate (%) = (X1 - X2) / X1 x 100 in the formula, X1 is the amount of the alcohol (b) in a fraction obtained by distilling a composition consisting of the compound (a) and the alcohol (b), and X2 is the amount of the alcohol (b) in a fraction obtained by distilling the composition according to claim 18 or 19. ​ ​

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