Method for producing fluoropolyether group-containing carboxylic acid

Abstract

To provide a method for producing a fluoropolyether group-containing carboxylic acid from a fluoropolyether group-containing carboxylic acid ester, while facilitating post treatment.SOLUTION: The present invention provides a method for producing a fluoropolyether group-containing carboxylic acid from a fluoropolyether group-containing carboxylic acid ester, by using propionic acid.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a method for producing a fluoropolyether group-containing carboxylic acid. [Background technology]

[0002] It is known that the method for producing fluoropolyether group-containing carboxylic acid can be produced from fluoropolyether group-containing carboxylic acid ester.For example, Patent Document 1 discloses that fluoropolyether group-containing carboxylic acid can be obtained by hydrolyzing fluoropolyether group-containing carboxylic acid ester in the presence of an aqueous solution containing alkali metal hydroxide. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2019 / 163712 Summary of the Invention [Problem to be solved by the invention]

[0004] In the method described in Patent Document 1, after obtaining a fluoropolyether group-containing carboxylic acid, steps such as quenching, separation, dehydration, and concentration are required, making the post-treatment complicated.

[0005] An object of the present disclosure is to provide a method for producing a fluoropolyether group-containing carboxylic acid from a fluoropolyether group-containing carboxylic acid ester, which allows easy post-treatment. [Means for solving the problem]

[0006] The present disclosure includes the following aspects. [1] A method for producing a fluoropolyether group-containing carboxylic acid from a fluoropolyether group-containing carboxylic acid ester by using propionic acid. [2] The fluoropolyether group-containing carboxylic acid ester is represented by the following formula (1) or (2): Rf 1 -R F -X-CO-OR 1 (1) R 1 -O-CO-X-Rf 2 -R F -X-CO-OR 1 (2) [In formula: Rf 1 C, which may be substituted by one or more fluorine atoms, independently at each occurrence; 1-16 is an alkyl group; Rf 2 C may be substituted with one or more fluorine atoms. 1-6 is an alkylene group; R F is independently at each occurrence a divalent fluoropolyether group; X is a single bond or a divalent organic group; R 1 is C 1-6 is an alkyl group. The method for producing a compound represented by the above [1]. [3] R F may independently at each occurrence represent the formula: -(OC6F 12 ) a -(OC5F 10 ) b -(OC4F8) c -(OC3R Fa 6) d -(OC2F4) e -(OCF2) f - [In the formula, R Fa is independently at each occurrence a hydrogen atom, a fluorine atom, or a chlorine atom; a, b, c, d, e, and f each independently represent an integer of 0 to 200, the sum of a, b, c, d, e, and f is 1 or more, and the order of the repeating units enclosed in parentheses with a, b, c, d, e, or f is arbitrary in the formula, provided that all R Fa is a hydrogen atom or a chlorine atom, at least one of a, b, c, e and f is 1 or greater.] The method according to the above [2], wherein the group is represented by the formula: [4] R Fa is a fluorine atom. [5] R F represents, independently at each occurrence, the following formula (f1), (f2), (f3), (f4), (f5), or (f6): -(OC3F6) d -(OC2F4) e - (f1) [In the formula, d is an integer of 1 to 200, and e is 0 or 1.] -(OC4F8) c -(OC3F6) d -(OC2F4) e -(OCF2) f - (f2) [In the formula, c and d each independently represent an integer of 0 to 30; e and f each independently represent an integer of 1 to 200; The sum of c, d, e, and f is an integer of 10 to 200; The order of occurrence of each repeat unit enclosed in parentheses with the subscript c, d, e, or f is arbitrary in the formula. -(R 6 -R 7 ) g - (f3) [In the formula, R 6 is OCF2 or OC2F4; R 7 are OC2F4, OC3F6, OC4F8, OC5F 10 and OC6F 12 or a combination of two or three groups selected from these groups; g is an integer from 2 to 100. -(R 6 -R 7 ) g -R r -(R 7’ -R 6’ ) g’ - (f4) [In the formula, R 6 is OCF2 or OC2F4, R 7 are OC2F4, OC3F6, OC4F8, OC5F 10 and OC6F 12 or a combination of two or three groups independently selected from these groups; R 6’ is OCF2 or OC2F4, R 7’ are OC2F4, OC3F6, OC4F8, OC5F 10 and OC6F 12 or a combination of two or three groups independently selected from these groups; g is an integer from 2 to 100; g' is an integer from 2 to 100, R r teeth, [ka] (In the formula, * indicates the bond position.) ]; -(OC6F 12 ) a -(OC5F 10 ) b -(OC4F8) c -(OC3F6) d -(OC2F4) e -(OCF2) f - (f5) [In the formula, e is an integer of 1 or more and 200 or less, a, b, c, d, and f are each independently an integer of 0 or more and 200 or less, and the order of the repeating units enclosed in parentheses with a, b, c, d, e, or f is arbitrary in the formula.] -(OC6F12 ) a -(OC5F 10 ) b -(OC4F8) c -(OC3F6) d -(OC2F4) e -(OCF2) f - (f6) [In the formula, f is an integer of 1 or more and 200 or less, a, b, c, d, and e are each independently an integer of 0 or more and 200 or less, and the order of the repeating units enclosed in parentheses with a, b, c, d, e, or f is arbitrary in the formula.] The method according to any one of the above [2] to [4], wherein the group is represented by the following formula: [6] R F represents, independently at each occurrence, the following formula (f2): -(OC4F8) c -(OC3F6) d -(OC2F4) e -(OCF2) f - (f2) [In the formula, c and d each independently represent an integer of 0 to 30; e and f each independently represent an integer of 1 to 200; The sum of c, d, e, and f is an integer of 10 to 200; The order of occurrence of each repeat unit enclosed in parentheses with the subscript c, d, e, or f is arbitrary in the formula. The method according to any one of the above [2] to [5], wherein the group is represented by the following formula: [7] R 1 is a methyl group. [8] The method according to any one of the above [2] to [7], wherein X is a single bond group. [9] The method according to any one of the above [1] to [8], wherein the number of equivalents of propionic acid relative to the ester group of the fluoropolyether group-containing carboxylate is 2.0 or more equivalents.

[10] The method according to any one of the above [1] to [9], wherein the number of equivalents of propionic acid relative to the ester group of the fluoropolyether group-containing carboxylate is 2.8 equivalents or more.

[11] R 1 is a methyl group, X is a single bond, R F represents, independently at each occurrence, the following formula (f2): -(OC4F8) c -(OC3F6) d -(OC2F4) e -(OCF2) f - (f2) [In the formula, c and d each independently represent an integer of 0 to 30; e and f are each independently 0 or 1; The sum of c, d, e, and f is an integer of 20 to 50; The order of occurrence of each repeat unit enclosed in parentheses with the subscript c, d, e, or f is arbitrary in the formula. The method according to any one of the above [2] to [9], wherein the group is represented by the following formula:

[12] The method according to any one of the above [1] to

[11] , further comprising using water.

[13] The method according to the above

[12] , wherein the number of equivalents of water relative to the ester group of the fluoropolyether group-containing carboxylic acid ester is 10 or less.

[14] The method for producing the present invention described in

[12] or

[13] above, wherein the number of equivalents of water relative to the ester group of the fluoropolyether group-containing carboxylic acid ester is 3.0 equivalents or less.

[15] The method according to any one of the above

[12] to

[14] , wherein the number of equivalents of water relative to the ester group of the fluoropolyether group-containing carboxylic acid ester is 0.5 to 3.0 equivalents.

[16] The method according to any one of the above

[12] to

[15] , wherein the number of equivalents of propionic acid relative to the ester group of the fluoropolyether group-containing carboxylic acid ester is 2.0 equivalents or more, and the number of equivalents of water relative to the ester group of the fluoropolyether group-containing carboxylic acid ester is 10 equivalents or less.

[17] The method for producing the fluoropolyether group-containing carboxylic acid ester according to any one of the above [1] to

[16] , comprising mixing the fluoropolyether group-containing carboxylic acid ester with propionic acid and heating the mixture to 100° C. or higher.

[18] The method for producing the fluoropolyether group-containing carboxylic acid ester according to any one of the above [1] to

[16] , comprising mixing the fluoropolyether group-containing carboxylic acid ester with propionic acid and water and heating the mixture to 100° C. or higher. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a method for producing a fluoropolyether group-containing carboxylic acid from a fluoropolyether group-containing carboxylic acid ester, which is easy to post-treat. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The present disclosure provides a method for producing a fluoropolyether group-containing carboxylic acid from a fluoropolyether group-containing carboxylic acid ester using propionic acid.

[0009] (Fluoropolyether group-containing carboxylic acid ester) The fluoropolyether group-containing carboxylate means a compound having a fluoropolyether group and a carboxylate group.

[0010] In a preferred embodiment, the fluoropolyether group-containing carboxylic acid ester is represented by the following formula (1) or (2): Rf 1 -R F -X-CO-OR 1 (1) R 1 -O-CO-X-Rf 2 -R F-X-CO-OR 1 (2) [In formula: Rf 1 C, which may be substituted by one or more fluorine atoms, independently at each occurrence; 1-16 is an alkyl group; Rf 2 C may be substituted with one or more fluorine atoms. 1-6 is an alkylene group; R F is independently at each occurrence a divalent fluoropolyether group; X is a single bond or a divalent organic group; R 1 is C 1-6 is an alkyl group. It is a compound represented by the formula:

[0011] The fluoropolyether group-containing carboxylic acids obtained from the fluoropolyether group-containing carboxylic acid esters represented by the formulas (1) and (2) are represented by the following formulas (3) and (4), respectively. Rf 1 -R F -X-COOH (3) HOCO-X-Rf 2 -R F -X-COOH (4)

[0012] In one embodiment, the fluoropolyether group-containing carboxylic acid ester is a compound represented by formula (1).

[0013] In another embodiment, the fluoropolyether group-containing carboxylic acid ester is a compound represented by formula (2).

[0014] In another embodiment, the fluoropolyether group-containing carboxylic acid ester includes both a compound represented by formula (1) and a compound represented by formula (2).

[0015] In the above formula, Rf 1C, which may be substituted by one or more fluorine atoms, independently at each occurrence; 1-16 It is an alkyl group.

[0016] C which may be substituted by one or more fluorine atoms 1-16 "C" in alkyl group 1-16 The "alkyl group" may be a straight chain or a branched chain, and is preferably a straight chain or branched chain C 1-6 Alkyl groups, especially C 1-3 is preferably a straight-chain C 1-6 Alkyl groups, especially C 1-3 It is an alkyl group.

[0017] Above Rf 1 is preferably C substituted by one or more fluorine atoms 1-16 is an alkyl group, more preferably CF2H-C 1-15 A perfluoroalkylene group, more preferably C 1-16 It is a perfluoroalkyl group.

[0018] Above C 1-16 The perfluoroalkyl group may be linear or branched, and is preferably a linear or branched C 1-6 Perfluoroalkyl groups, especially C 1-3 A perfluoroalkyl group, more preferably a linear C 1-6 Perfluoroalkyl groups, especially C 1-3 A perfluoroalkyl group, specifically, -CF3, -CF2CF3, or -CF2CF2CF3.

[0019] In the above formula, Rf 2 C may be substituted with one or more fluorine atoms. 1-6 It is an alkylene group.

[0020] C which may be substituted by one or more fluorine atoms 1-6 "C" in the alkylene group 1-6The "alkylene group" may be a straight chain or a branched chain, and is preferably a straight chain or branched chain C 1-3 It is preferably a linear alkylene group. 1-3 It is an alkylene group.

[0021] Above Rf 2 is preferably C substituted by one or more fluorine atoms 1-6 is an alkylene group, more preferably C 1-6 A perfluoroalkylene group, more preferably C 1-3 It is a perfluoroalkylene group.

[0022] Above C 1-6 The perfluoroalkylene group may be linear or branched, and is preferably a linear or branched C 1-3 A perfluoroalkylene group, more preferably a linear C 1-3 A perfluoroalkyl group, specifically, -CF2-, -CF2CF2-, or -CF2CF2CF2-.

[0023] In the above formula, R F is independently at each occurrence a divalent fluoropolyether group.

[0024] R F is preferably -(OC h1 R Fa 2h1 ) h3 -(OC h2 R Fa 2h2-2 ) h4 - [In formula: R Fa is independently at each occurrence a hydrogen atom, a fluorine atom, or a chlorine atom; h1 is an integer from 1 to 6, h2 is an integer from 4 to 8; h3 is an integer equal to or greater than 0, h4 is an integer equal to or greater than 0, However, the sum of h3 and h4 is 1 or more, preferably 2 or more, and more preferably 5 or more, and the order of the repeating units enclosed in parentheses with h3 and h4 is arbitrary in the formula.] It may contain a group represented by:

[0025] In one embodiment, R F R can be linear or branched. F is preferably of the formula: -(OC6F 12 ) a -(OC5F 10 ) b -(OC4F8) c -(OC3R Fa 6) d -(OC2F4) e -(OCF2) f - [In formula: R Fa is independently at each occurrence a hydrogen atom, a fluorine atom, or a chlorine atom; a, b, c, d, e, and f are each independently an integer of 0 to 200, and the sum of a, b, c, d, e, and f is 1 or more. The order of the repeating units enclosed in parentheses with a, b, c, d, e, or f is arbitrary in the formula. However, all R Fa is a hydrogen atom or a chlorine atom, at least one of a, b, c, e and f is 1 or greater.] It is a group represented by the following formula:

[0026] R Fa is preferably a hydrogen atom or a fluorine atom, more preferably a fluorine atom. However, all R Fa is a hydrogen atom or a chlorine atom, at least one of a, b, c, e and f is 1 or greater.

[0027] a, b, c, d, e and f may each independently be an integer of preferably 0 to 100, more preferably 0 to 60, for example, 1 to 100, 5 to 100, 10 to 100, 20 to 100, 25 to 100, 1 to 60, 5 to 60, 10 to 60, 20 to 60, 25 to 60, 1 to 50, 5 to 50, 10 to 50, 20 to 50, 25 to 50, 1 to 40, 5 to 40, 10 to 40, 20 to 40, or 25 to 40.

[0028] The sum of a, b, c, d, e and f is preferably 5 or more, more preferably 10 or more, and may be, for example, 15 or more or 20 or more. The sum of a, b, c, d, e and f is preferably 200 or less, more preferably 100 or less, and further preferably 60 or less, and may be, for example, 50 or less or 30 or less. The sum of a, b, c, d, e and f may be, for example, 15 to 100, 20 to 100, 15 to 60, 20 to 60, 15 to 50, or 20 to 50.

[0029] These repeating units may be linear or branched. For example, -(OCF 12 )- may be -(OCF2CF2CF2CF2CF2CF2CF2)-, -(OCF(CF3)CF2CF2CF2CF2)-, -(OCF2CF(CF3)CF2CF2CF2)-, -(OCF2CF2CF(CF3)CF2CF2)-, -(OCF2CF2CF2CF(CF3)CF2)-, -(OCF2CF2CF2CF2CF(CF3)CF2)-, -(OCF2CF2CF2CF2CF(CF3))-, etc. 10)- may be -(OCF2CF2CF2CF2CF2)-, -(OCF(CF3)CF2CF2CF2)-, -(OCF2CF(CF3)CF2CF2)-, -(OCF2CF2CF(CF3)CF2)-, -(OCF2CF2CF2CF(CF3))-, etc. -(OC4F8)- may be any of -(OCF2CF2CF2CF2)-, -(OCF(CF3)CF2CF2)-, -(OCF2CF(CF3)CF2)-, -(OCF2CF2CF(CF3))-, -(OC(CF3)2CF2)-, -(OCF2C(CF3)2)-, -(OCF(CF3)CF(CF3))-, -(OCF(C2F5)CF2)-, and -(OCF2CF(C2F5))-. -(OC3F6)- (i.e., in the above formula, R Fa is a fluorine atom) may be any of -(OCF2CF2CF2)-, -(OCF(CF3)CF2)-, and -(OCF2CF(CF3))-. -(OC2F4)- may be any of -(OCF2CF2)- and -(OCF(CF3))-.

[0030] In one embodiment, the repeat unit is linear.

[0031] In one embodiment, the repeat unit is branched.

[0032] In one embodiment, R F may include a ring structure.

[0033] The ring structure may be a three-, four-, five-, or six-membered ring as described below. [ka] [In the formula, * indicates the bond position.]

[0034] The ring structure may be preferably a four-, five-, or six-membered ring, more preferably a four-, or six-membered ring.

[0035] The repeating unit having a ring structure may preferably be the following unit. [ka] [In the formula, * indicates the bond position.]

[0036] In one embodiment, R F represents, independently in each occurrence, a group represented by any one of the following formulas (f1) to (f6). -(OC3F6) d -(OC2F4) e - (f1) [In the formula, d is an integer of 1 to 200, and e is 0 or 1.]; -(OC4F8) c -(OC3F6) d -(OC2F4) e -(OCF2) f - (f2) [In the formula, c and d each independently represent an integer of 0 or more and 30 or less, and e and f each independently represent an integer of 1 or more and 200 or less, The sum of c, d, e, and f is 2 or more, The order of occurrence of each repeat unit enclosed in parentheses with the subscript c, d, e, or f is arbitrary in the formula. -(R 6 -R 7 ) g - (f3) [In the formula, R 6 is OCF2 or OC2F4, R 7 are OC2F4, OC3F6, OC4F8, OC5F 10 and OC6F 12 or a combination of two or three groups independently selected from these groups; g is an integer from 2 to 100; -(R 6 -R 7 ) g -R r -(R 7’ -R 6’ ) g’ - (f4) [In the formula, R 6 is OCF2 or OC2F4, R7 are OC2F4, OC3F6, OC4F8, OC5F 10 and OC6F 12 or a combination of two or three groups independently selected from these groups; R 6’ is OCF2 or OC2F4, R 7’ are OC2F4, OC3F6, OC4F8, OC5F 10 and OC6F 12 or a combination of two or three groups independently selected from these groups; g is an integer from 2 to 100; g' is an integer from 2 to 100, R r teeth, [ka] (In the formula, * indicates the bond position.) ]; -(OC6F 12 ) a -(OC5F 10 ) b -(OC4F8) c -(OC3F6) d -(OC2F4) e -(OCF2) f - (f5) [In the formula, e is an integer of 1 or more and 200 or less, a, b, c, d, and f are each independently an integer of 0 or more and 200 or less, and the order of the repeating units enclosed in parentheses with a, b, c, d, e, or f is arbitrary in the formula.] -(OC6F 12 ) a -(OC5F 10 ) b -(OC4F8) c -(OC3F6) d -(OC2F4) e -(OCF2) f - (f6) [In the formula, f is an integer of 1 or more and 200 or less, a, b, c, d, and e are each independently an integer of 0 or more and 200 or less, and the order of the repeating units enclosed in parentheses with a, b, c, d, e, or f is arbitrary in the formula.]

[0037] In the above formula (f1), d is preferably an integer of 5 to 200, more preferably 10 to 100, further preferably 15 to 50, for example, an integer of 25 to 35. In one embodiment, e is 1. In another embodiment, e is 0. In the above formula (f1), -(OC3F6) d - is preferably -(OCF2CF2CF2) d -or-(OCF(CF3)CF2) d More preferably, it is a group represented by -(OCF2CF2CF2) d - is a group represented by the formula:

[0038] In the above formula (f2), e and f are each independently preferably an integer of 5 to 200, more preferably an integer of 10 to 200, and further preferably an integer of 10 to 100, for example, an integer of 10 to 50, 10 to 30, or 20 to 30. c and d are each independently preferably 0 or 1. The sum of c, d, e, and f is preferably 5 or more, more preferably 10 or more, and may be, for example, 15 or more or 20 or more. For example, the sum of c, d, e, and f may be 15 or more and 100 or less, 15 or more and 60 or less, 15 or more and 50 or less, 20 or more and 60 or less, or 20 or more and 50 or less. In one aspect, the above formula (f2) is preferably -(OCF2CF2CF2CF2) c -(OCF2CF2CF2) d -(OCF2CF2) e -(OCF2) f In another embodiment, formula (f2) is a group represented by -(OC2F4) e -(OCF2) f - may be a group represented by the formula:

[0039] In the above formula (f3), R 6is preferably OC2F4. In the above (f3), R 7 is preferably a group selected from OC2F4, OC3F6 and OC4F8, or a combination of two or three groups independently selected from these groups, and more preferably a group selected from OC3F6 and OC4F8. The combination of two or three groups independently selected from OC2F4, OC3F6 and OC4F8 is not particularly limited, and examples thereof include -OC2F4OC3F6-, -OC2F4OC4F8-, -OC3F6OC2F4-, -OC3F6OC3F6-, -OC3F6OC4F8-, -OC4F8OC4F8-, -OC4F8OC3F6-, -OC4F8OC2F4-, -OC Examples of the 2F4OC2F4OC3F6-, -OC2F4OC2F4OC4F8-, -OC2F4OC3F6OC2F4-, -OC2F4OC3F6OC3F6-, -OC2F4OC4F8OC2F4-, -OC3F6OC2F4OC2F4-, -OC3F6OC2F4OC3F6-, -OC3F6OC3F6OC2F4-, and -OC4F8OC2F4OC2F4- are mentioned. In the above formula (f3), g is preferably an integer of 3 or more, more preferably an integer of 5 or more. The above g is preferably an integer of 50 or less. In the above formula (f3), OC2F4, OC3F6, OC4F8, OC5F 10 and OC6F 12 may be either linear or branched, and is preferably linear. In this embodiment, the above formula (f3) is preferably -(OC2F4-OC3F6) g -or- (OC2F4-OC4F8) g -It is.

[0040] In the above formula (f4), R 6 , R 7 and g have the same meanings as those described in the above formula (f3) and have the same embodiments. 6’ , R 7’ and g' are R 6 , R 7 and g have the same meaning and behavior. r is preferably [ka] [In the formula, * indicates the bond position.] and more preferably [ka] [In the formula, * indicates the bond position.] It is.

[0041] In the above formula (f5), e is preferably an integer of 1 or more and 100 or less, more preferably an integer of 5 or more and 100 or less. The sum of a, b, c, d, e and f is preferably 5 or more, more preferably 10 or more, for example, 10 or more and 100 or less.

[0042] In the above formula (f6), f is preferably an integer of 1 or more and 100 or less, more preferably an integer of 5 or more and 100 or less. The sum of a, b, c, d, e and f is preferably 5 or more, more preferably 10 or more, for example, 10 or more and 100 or less.

[0043] In one embodiment, the R F is a group represented by the above formula (f1).

[0044] In one embodiment, the R F is a group represented by the above formula (f2).

[0045] In one embodiment, the R F is a group represented by the above formula (f3).

[0046] In one embodiment, the R F is a group represented by the above formula (f4).

[0047] In one embodiment, the R F is a group represented by the above formula (f5).

[0048] In one embodiment, the R F is a group represented by the above formula (f6).

[0049] Above R F In the formula, the ratio of e to f (hereinafter referred to as "e / f ratio") is 0.1 to 10, preferably 0.2 to 5, more preferably 0.2 to 2, even more preferably 0.2 to 1.5, and still more preferably 0.2 to 0.85.

[0050] In the above fluoropolyether group-containing silane compound, R F The number average molecular weight of the portion is not particularly limited, but is, for example, 500 to 30,000, preferably 1,500 to 30,000, and more preferably 2,000 to 10,000. F1 and R F2 The number average molecular weight of 19 The value is measured by F-NMR.

[0051] In another embodiment, R F1 and R F2 The number average molecular weight of the portion may be from 500 to 30,000, preferably from 1,000 to 20,000, more preferably from 2,000 to 15,000, even more preferably from 2,000 to 10,000, for example from 3,000 to 6,000.

[0052] In another embodiment, R F1 and R F2 The number average molecular weight of the portion may be from 4,000 to 30,000, preferably from 5,000 to 10,000, and more preferably from 6,000 to 10,000.

[0053] In the above formula, X is a single bond or a divalent organic group.

[0054] In one embodiment, X is a single bond.

[0055] In another embodiment, X is a divalent organic group.

[0056] As used herein, the term "divalent organic group" refers to a divalent group containing carbon. The divalent organic group is not particularly limited, but may be a divalent hydrocarbon group or a derivative thereof. A derivative of a hydrocarbon group refers to a group having one or more of N, O, S, Si, amide, sulfonyl, siloxane, carbonyl, carbonyloxy, etc. at the end or in the molecular chain of the hydrocarbon group.

[0057] As used herein, the term "divalent hydrocarbon group" refers to a group containing carbon and hydrogen, which is a group in which two hydrogen atoms have been eliminated from a hydrocarbon. Such a hydrocarbon group is not particularly limited, but includes a divalent C 1-20 Examples of the hydrocarbon group include an aliphatic hydrocarbon group and an aromatic hydrocarbon group. The "aliphatic hydrocarbon group" may be linear, branched, or cyclic, and may be saturated or unsaturated. The hydrocarbon group may contain one or more ring structures. The "divalent hydrocarbon group" may be substituted with one or more substituents.

[0058] As used herein, examples of the substituent of the "hydrocarbon group" include, but are not limited to, a halogen atom, a C 1-6 Alkyl group, C 2-6 Alkenyl group, C 2-6 Alkynyl group, C 3-10 Cycloalkyl groups, C 3-10 Unsaturated cycloalkyl groups, 5-10 membered heterocyclyl groups, 5-10 membered unsaturated heterocyclyl groups, C 6-10 Examples of the alkyl group include one or more groups selected from an aryl group and a 5- to 10-membered heteroaryl group.

[0059] The divalent organic group is preferably C 1-6 Alkylene group, -(CH2) z1 -O-(CH2) z2 - (wherein z1 is an integer of 0 to 6, for example, an integer of 1 to 6, and z2 is an integer of 0 to 6, for example, an integer of 1 to 6), or -(CH2)z3 -Phenylene-(CH2) z4 - (wherein z3 is an integer of 0 to 6, for example, an integer of 1 to 6, and z4 is an integer of 0 to 6, for example, an integer of 1 to 6). 1-6 The alkylene groups may be linear or branched, but are preferably linear. These groups may contain, for example, fluorine atoms, C 1-6 Alkyl group, C 2-6 Alkenyl groups, and C 2-6 It may be substituted by one or more substituents selected from alkynyl groups, but is preferably unsubstituted.

[0060] In the above formula, R 1 is C 1-6 It is an alkyl group.

[0061] Above C 1-6 The alkyl group may be linear or branched. 1-6 The alkyl group is linear. 1-6 The alkyl group is branched. 1-6 The alkyl group is preferably C 1-4 Alkyl groups, more preferably C 1-3 It is preferably an alkyl group, more preferably a methyl group or an ethyl group, and even more preferably a methyl group.

[0062] (Production of fluoropolyether group-containing carboxylic acid) In the method of the present disclosure, by using propionic acid, the fluoropolyether group-containing carboxylic acid ester can be converted into the fluoropolyether group-containing carboxylic acid in a short time and at a high conversion rate, compared with the case of using other acids such as formic acid, etc. In addition, by using propionic acid, the influence on the apparatus can be reduced, and for example, corrosion of the reaction vessel can be prevented, compared with the case of using inorganic acids such as hydrochloric acid.

[0063] In the manufacturing method of the present disclosure, without being bound by theory, the fluoropolyether group-containing carboxylic acid ester is hydrolyzed.

[0064] (Embodiment 1) In embodiment 1, the production method of the present disclosure is carried out as follows using a fluoropolyether group-containing carboxylic acid ester and propionic acid.

[0065] A predetermined amount of fluoropolyether group-containing carboxylic acid ester and a predetermined equivalent amount of propionic acid relative to the fluoropolyether group-containing carboxylic acid ester are added to a reaction vessel and mixed. The mixture is stirred at high temperature. After a predetermined time has passed, volatile components are distilled off under reduced pressure to obtain a fluoropolyether group-containing carboxylic acid.

[0066] In this embodiment, the propionic acid is added in one portion. Adding it in one portion facilitates the operation.

[0067] In the manufacturing method of the present disclosure, the amount of propionic acid used is preferably 2.0 equivalents or more, more preferably 2.8 equivalents or more, for example 5.0 equivalents or more, or 5.2 equivalents or more, based on the ester group of the fluoropolyether group-containing carboxylic acid ester.The amount of propionic acid used is preferably 20 equivalents or less, more preferably 10 equivalents or less, for example 6.0 equivalents or less, based on the ester group of the fluoropolyether group-containing carboxylic acid ester.By setting the amount of propionic acid used within the above range, the reaction rate from the fluoropolyether group-containing carboxylic acid ester to the fluoropolyether group-containing carboxylic acid is increased.

[0068] Here, the number of ester groups in the fluoropolyether group-containing carboxylic acid ester is determined by the weight of the fluoropolyether group-containing carboxylic acid ester, and 19 It can be calculated from the results of F-NMR measurements.

[0069] The reaction temperature of the above reaction may be preferably 100° C. or higher, more preferably 110° C. or higher, and even more preferably 130° C. or higher. The upper limit of the reaction temperature is not particularly limited as long as the compound is not decomposed at that temperature, and may be, for example, 180° C. or lower, preferably 150° C. or lower.

[0070] The reaction time of the above reaction is preferably 20 hours or more, more preferably 30 hours or more, for example, 40 hours or more. The upper limit of the reaction time is not particularly limited, but may be, for example, 100 hours or less.

[0071] (Embodiment 2) In embodiment 2, the production method of the present disclosure is carried out as follows using a fluoropolyether group-containing carboxylic acid ester, propionic acid and water.

[0072] A predetermined amount of fluoropolyether group-containing carboxylic acid ester, and a predetermined equivalent amount of propionic acid and water relative to the fluoropolyether group-containing carboxylic acid ester are added to a reaction vessel and mixed. The mixture is stirred at high temperature. After a predetermined time has passed, volatile components are distilled off under reduced pressure to obtain a fluoropolyether group-containing carboxylic acid.

[0073] In the second embodiment, in addition to the first embodiment, water is further used. By using water, the reaction rate from the fluoropolyether group-containing carboxylic acid ester to the fluoropolyether group-containing carboxylic acid is increased. In this embodiment, propionic acid and water are added at one time. By adding at one time, the operation is easy.

[0074] In this embodiment, the amount of water used can be preferably 10 equivalents or less, more preferably 3 equivalents or less, based on the ester group of the fluoropolyether group-containing carboxylic acid ester.The amount of water used can be preferably 0.1 equivalents or more, more preferably 0.5 equivalents or more, for example 1.0 equivalents or more, or 2.0 equivalents or more, based on the ester group of the fluoropolyether group-containing carboxylic acid ester.By setting the amount of water used within the above range, the reaction rate from the fluoropolyether group-containing carboxylic acid ester to the fluoropolyether group-containing carboxylic acid is increased.

[0075] In this embodiment, the amount of propionic acid used, the reaction temperature, and the reaction time may be the same as those in the first embodiment.

[0076] (Embodiment 3) In embodiment 3, the production method of the present disclosure is carried out as follows using a fluoropolyether group-containing carboxylic acid ester, propionic acid and water.

[0077] A predetermined amount of fluoropolyether group-containing carboxylic acid ester and a predetermined equivalent amount of propionic acid and water relative to the fluoropolyether group-containing carboxylic acid ester are added to a reaction vessel and mixed. The mixture is stirred at high temperature. After a predetermined time has elapsed, preferably when the reaction approaches equilibrium, a predetermined equivalent amount of propionic acid and water relative to the amount of unreacted ester groups is added, and the mixture is stirred at high temperature. Volatile components are distilled off under reduced pressure to obtain a fluoropolyether group-containing carboxylic acid.

[0078] In the second embodiment, in addition to the first embodiment, water is further used. By using water, the reaction rate from the fluoropolyether group-containing carboxylic acid ester to the fluoropolyether group-containing carboxylic acid is increased. In this embodiment, propionic acid and water are added at one time. By adding at one time, the operation is easy.

[0079] By adding propionic acid and water in two separate portions, a high conversion rate can be achieved in a shorter time. In this embodiment, the propionic acid and water are added in two separate portions, but they may be added in multiple separate portions. The number of additions is not particularly limited, but may be, for example, 2 to 5 times, preferably 2 or 3 times. Even when water is not used, propionic acid may be added in multiple separate portions.

[0080] When propionic acid and water are added in several portions, the amount of addition is preferably the same equivalent as that of the first addition, relative to the unreacted ester group of the fluoropolyether group-containing carboxylic acid ester at the time of addition.For example, when propionic acid and water are used in the first portion in an amount of 5.0 equivalents and 2.5 equivalents, respectively, relative to the ester group of the fluoropolyether group-containing carboxylic acid ester, it is preferable to use 5.0 equivalents and 2.5 equivalents, respectively, in the second and subsequent additions.

[0081] In this embodiment, the amounts of propionic acid and water used, the reaction temperature, and the reaction time may be the same as those in embodiments 1 and 2. Note that the amounts used refer to the total amounts in all additions. EXAMPLES

[0082] The article of the present disclosure will be described below in the examples, but the present disclosure is not limited to the following examples. In the examples, the order of the repeating units constituting the fluoropolyether is arbitrary, and the chemical formula shown below shows the average composition.

[0083] Example 1 In a 100 mL four-neck flask equipped with a reflux condenser, thermometer, and stirrer, add 10 mL of water with an average composition of CH3OCOCF2O (CF2CF2O). 23 (CF2O) 22A perfluoropolyether modified methyl ester (1) (51.6 g) represented by CF2COOCH3 (however, the mixture also contains trace amounts of compounds containing trace amounts of (CF2CF2CF2O) and / or (CF2CF2CF2CF2O) repeating units) was charged, and water (1.2 g, 2.6 equivalents relative to the ester group of compound (1)) and propionic acid (9.3 g, 5.3 equivalents relative to the ester group of compound (1)) were added in two portions. At the time of the second addition of the reagents, the cooling water of the reflux condenser was stopped, and the mixture was stirred at 110°C to 130°C for 32 hours. 19 After confirming that the conversion rate was 99% or more by F-NMR, the volatile components were distilled off under reduced pressure to obtain 51.1 g of perfluoropolyether compound (2) having a carboxyl group at its end. The product obtained contained a small amount of water and propionic acid. HOOCCF2O(CF2CF2O) 23 (CF2O) 22 CF2COOH (2)

[0084] Example 2 In a 100 mL four-neck flask equipped with a reflux condenser, thermometer, and stirrer, add 10 mL of water with an average composition of CH3OCOCF2O (CF2CF2O). 23 (CF2O) 22 A perfluoropolyether modified methyl ester (1) (50.3 g) represented by CF2COOCH3 (however, the mixture also contains trace amounts of compounds containing trace amounts of (CF2CF2CF2O) and / or (CF2CF2CF2CF2O) repeating units) was charged, and water (1.4 g, 2.8 equivalents relative to the ester group of compound (1)) and propionic acid (5.0 g, 2.8 equivalents relative to the ester group of compound (1)) were added in four portions. At the second addition of the reagents, the cooling water in the reflux condenser was stopped, and the mixture was stirred at 120°C for 40 hours. 19 After confirming that the conversion rate was 99% or more by F-NMR, the volatile components were distilled off under reduced pressure to obtain 49.5 g of perfluoropolyether compound (2) having a carboxyl group at its end. The obtained product contained a small amount of water and propionic acid.

[0085] Example 3 In a 100 mL four-neck flask equipped with a reflux condenser, thermometer, and stirrer, add 10 mL of water with an average composition of CH3OCOCF2O (CF2CF2O). 23 (CF2O) 22 A perfluoropolyether modified methyl ester (1) (50.2 g) represented by CF2COOCH3 (however, the mixture also contains trace amounts of compounds containing trace amounts of (CF2CF2CF2O) and / or (CF2CF2CF2CF2O) repeating units) was charged, and propionic acid (9.1 g, 5.2 equivalents relative to the ester group of compound (1)) was added in four portions, followed by stirring at 120°C for 88 hours. 19 After confirming that the conversion rate was 99% or more by F-NMR, the volatile components were distilled off under reduced pressure to obtain 49.4 g of perfluoropolyether compound (2) having a carboxyl group at its end. The product obtained contained a small amount of water and propionic acid.

[0086] Example 4 In a 100 mL four-neck flask equipped with a reflux condenser, thermometer, and stirrer, add 10 mL of water with an average composition of CH3OCOCF2O (CF2CF2O). 23 (CF2O) 22 A perfluoropolyether modified methyl ester (1) (51.0 g) represented by CF2COOCH3 (however, the mixture also contains trace amounts of compounds containing trace amounts of (CF2CF2CF2O) and / or (CF2CF2CF2CF2O) repeating units) was charged, water (4.0 g, 9.5 equivalents relative to the ester group of compound (1)) was added in four portions, and propionic acid (8.9 g, 5.2 equivalents relative to the ester group of compound (1)) was added in six portions. At the fifth addition of propionic acid, the cooling water to the reflux condenser was stopped, and the mixture was stirred at 100°C to 120°C for 82 hours. 19 After confirming that the conversion rate was 99% or more by F-NMR, the volatile components were distilled off under reduced pressure to obtain 50.2 g of perfluoropolyether compound (2) having a carboxyl group at its end. The product obtained contained a small amount of water and propionic acid.

[0087] Comparative Example 1 In a 100 mL four-neck flask equipped with a reflux condenser, thermometer, and stirrer, add 10 mL of water with an average composition of CH3OCOCF2O (CF2CF2O). 23 (CF2O) 22 A perfluoropolyether modified methyl ester (1) (51.6 g) represented by CF2COOCH3 (however, the mixture also contains trace amounts of compounds containing trace amounts of (CF2CF2CF2O) and / or (CF2CF2CF2CF2O) repeating units) was charged, and water (1.2 g, 2.6 equivalents relative to the ester group of compound (1)) was added in two portions. During the second addition, the cooling water in the reflux condenser was stopped, and the mixture was stirred at 110°C to 130°C for 280 hours. 19 After confirming that the conversion rate was 99% or more by F-NMR, the volatile components were distilled off under reduced pressure to obtain 51.0 g of perfluoropolyether compound (2) having a carboxyl group at its end. The product obtained contained a small amount of water and propionic acid.

[0088] Comparative Example 2 In a 100 mL four-neck flask equipped with a reflux condenser, thermometer, and stirrer, add 10 mL of water with an average composition of CH3OCOCF2O (CF2CF2O). 23 (CF2O) 22 A perfluoropolyether modified methyl ester (1) (51.6 g) represented by CF2COOCH3 (however, the mixture also contains trace amounts of compounds containing trace amounts of (CF2CF2CF2O) and / or (CF2CF2CF2CF2O) repeating units) was charged, and water (1.2 g, 2.6 equivalents relative to the ester group of compound (1)) and formic acid (5.8 g, 5.3 equivalents relative to the ester group of compound (1)) were added in two portions. At the time of the second addition of the reagents, the cooling water of the reflux condenser was stopped, and the mixture was stirred at 110°C to 130°C for 100 hours. 19 The conversion rate was confirmed by F-NMR and was found to be 80%.

[0089] Comparative Example 3 In a 100 mL four-neck flask equipped with a reflux condenser, thermometer, and stirrer, add 10 mL of water with an average composition of CH3OCOCF2O (CF2CF2O). 23(CF2O) 22 A perfluoropolyether modified methyl ester (1) (50.3 g) represented by CF2COOCH3 (however, the mixture also contains trace amounts of compounds containing trace amounts of (CF2CF2CF2O) and / or (CF2CF2CF2CF2O) repeating units) was charged, and water (1.4 g, 2.8 equivalents relative to the ester group of compound (1)) and formic acid (3.1 g, 2.8 equivalents relative to the ester group of compound (1)) were added in four portions. At the second addition of the reagents, the cooling water in the reflux condenser was stopped, and the mixture was stirred at 120°C for 100 hours. 19 The conversion rate was confirmed by F-NMR and was found to be 71%.

[0090] [Table 1] [Industrial Applicability]

[0091] The production method of the present disclosure can be suitably used for producing a fluoropolyether group-containing carboxylic acid.

Claims

1. A method for producing a fluoropolyether group-containing carboxylic acid from a fluoropolyether group-containing carboxylic acid ester using propionic acid, comprising the steps of: The fluoropolyether group-containing carboxylic acid ester is represented by the following formula (1) or (2): Rf １ -R Ｆ -E---O-R １ (1) R １ -O-A-E-Rf ２ -R Ｆ -E---O-R １ (2) [In formulas (1) and (2): Rf １ each occurrence independently represents a C which may be substituted by one or more fluorine atoms; １－１６ is an alkyl group; Rf ２ C optionally substituted with one or more fluorine atoms １－６ is an alkylene group; X is a single bond, a C 1-6 alkylene group, -(CH 2 ) z1 -O-(CH 2 ) z2 - (wherein z1 is an integer from 0 to 6 and z2 is an integer from 0 to 6) or -(CH 2 ) z3 -phenylene-(CH 2 ) z4 - (wherein z3 is an integer from 0 to 6 and z4 is an integer from 0 to 6); R 1 is a C 1-6 alkyl group; R Ｆ represents, independently at each occurrence, the formula (5): -(OC ６ F １２ ) ａ -(OC ５ F １０ ) ｂ -(OC ４ F ８ ) ｃ -(OC ３ R Ｆａ ６ ) ｄ -(OC ２ F ４ ) ｅ -(OCF ２ ) ｆ - (5) is a group represented by In formula (5): R Ｆａ is independently at each occurrence a hydrogen atom, a fluorine atom, or a chlorine atom; a, b, c, d, e, and f each independently represent an integer of 0 to 200, the sum of a, b, c, d, e, and f is 1 or more, and the order of the repeating units enclosed in parentheses with a, b, c, d, e, or f is arbitrary in the formula, provided that all R Ｆａ is a hydrogen atom or a chlorine atom, at least one of a, b, c, e and f is 1 or more. The compound represented by the formula:

2. R Ｆａ The method according to claim 1 , wherein is a fluorine atom.

3. R Ｆ each occurrence independently represents the following formula (f1), (f2), (f3), (f5) or (f6): -(OC ３ F ６ ) ｄ -(OC ２ F ４ ) ｅ - (f1) [In formula (f1), d is an integer of 1 to 200, and e is 0 or 1.] -(OC ４ F ８ ) ｃ -(OC ３ F ６ ) ｄ -(OC ２ F ４ ) ｅ -(OCF ２ ) ｆ - (f2) [In formula (f2), c and d each independently represent an integer of 0 to 30; e and f are each independently an integer from 1 to 200; The sum of c, d, e and f is an integer from 10 to 200; The order of occurrence of each repeat unit enclosed in parentheses with the subscript c, d, e, or f is arbitrary in the formula. -(R ６ -R ７ ) ｇ - (f3) [In formula (f3), R ６ is O.C.F. ２ Or O.C. ２ F ４ and R ７ , O.C. ２ F ４ , O.C. ３ F ６ , O.C. ４ F ８ , O.C. ５ F １０ and O.C. ６ F １２ or a combination of two or three groups selected from these groups; g is an integer from 2 to 100. -(OC ６ F １２ ) ａ -(OC ５ F １０ ) ｂ -(OC ４ F ８ ) ｃ -(OC ３ F ６ ) ｄ -(OC ２ F ４ ) ｅ -(OCF ２ ) ｆ - (f5) [In formula (f5), e is an integer of 1 or more and 200 or less, a, b, c, d, and f are each independently an integer of 0 or more and 200 or less, and the order of the repeating units enclosed in parentheses with a, b, c, d, e, or f is arbitrary in the formula.] -(OC ６ F １２ ) ａ -(OC ５ F １０ ) ｂ -(OC ４ F ８ ) ｃ -(OC ３ F ６ ) ｄ -(OC ２ F ４ ) ｅ -(OCF ２ ) ｆ - (f6) [In formula (f6), f is an integer of 1 or more and 200 or less, a, b, c, d, and e are each independently an integer of 0 or more and 200 or less, and the order of the repeating units enclosed in parentheses with a, b, c, d, e, or f is arbitrary in the formula.] The method according to claim 1 or 2, wherein the group is represented by the formula:

4. R Ｆ represents, independently at each occurrence, the following formula (f2): -(OC ４ F ８ ) ｃ -(OC ３ F ６ ) ｄ -(OC ２ F ４ ) ｅ -(OCF ２ ) ｆ - (f2) [In the formula, c and d each independently represent an integer of 0 to 30; e and f are each independently an integer from 1 to 200; The sum of c, d, e and f is an integer from 10 to 200; The order of occurrence of each repeating unit enclosed in parentheses with the subscript c, d, e, or f is arbitrary in the formula. The method according to claim 1 or 2, wherein the group is represented by the formula:

5. R １ The method according to claim 1 or 2, wherein R is a methyl group.

6. The method according to claim 1 or 2, wherein X is a single bond.

7. 3. The method according to claim 1, wherein the number of equivalents of propionic acid relative to the ester group of the fluoropolyether group-containing carboxylic acid ester is 2.0 or more.

8. 3. The method according to claim 1, wherein the number of equivalents of propionic acid relative to the ester group of the fluoropolyether group-containing carboxylic acid ester is 2.8 or more.

9. R １ is a methyl group, X is a single bond; R Ｆ represents, independently at each occurrence, the following formula (f2): -(OC ４ F ８ ) ｃ -(OC ３ F ６ ) ｄ -(OC ２ F ４ ) ｅ -(OCF ２ ) ｆ - (f2) [In the formula, c and d each independently represent 0 or 1; e and f are each independently an integer from 10 to 30; The sum of c, d, e and f is an integer from 20 to 50; The order of occurrence of each repeating unit enclosed in parentheses with the subscript c, d, e, or f is arbitrary in the formula. The method according to claim 1 or 2, wherein the group is represented by the formula:

10. The method according to claim 1 or 2, further comprising using water.

11. The method according to claim 10, wherein the number of equivalents of water relative to the ester group of the fluoropolyether group-containing carboxylic acid ester is 10 or less.

12. The method according to claim 10, wherein the number of equivalents of water relative to the ester group of the fluoropolyether group-containing carboxylic acid ester is 3.0 or less.

13. The method according to claim 10, wherein the number of equivalents of water relative to the ester group of the fluoropolyether group-containing carboxylic acid ester is 0.5 to 3.0 equivalents.

14. The method according to claim 10, wherein the number of equivalents of propionic acid relative to the ester group of the fluoropolyether group-containing carboxylic acid ester is 2.0 equivalents or more, and the number of equivalents of water relative to the ester group of the fluoropolyether group-containing carboxylic acid ester is 10 equivalents or less.

15. The method according to claim 1 or 2, comprising mixing the fluoropolyether group-containing carboxylic acid ester and propionic acid and heating the mixture to 100° C. or higher.

16. The method according to claim 1 or 2, comprising mixing the fluoropolyether group-containing carboxylic acid ester, propionic acid and water, and heating the mixture to 100° C. or higher.

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