Method for producing C2-C20 fluorine-containing organic acid, and composition comprising C2-C20 fluorine-containing organic acid

Patent metadata

Field	Value
Publication number	US-10759731-B2
Application number	US-201716309497-A
Country	US
Kind code	B2
Filing date	Jun 9, 2017
Priority date	Jun 16, 2016
Publication date	Sep 1, 2020
Grant date	Sep 1, 2020

Abstract

There is provided a method for producing a C2-C20 fluorine-containing organic acid with reduced fluorine-free organic compound. A method for producing a C2-C20 fluorine-containing organic acid, the method including contacting a mixture containing a C2-C20 fluorine-containing organic acid and a fluorine-free organic compound with a concentrated sulfuric acid and then separating a C2-C20 fluorine-containing organic acid phase from a concentrated sulfuric acid phase. The contacting is conducted such that an amount of water present in the concentrated sulfuric acid phase is 10% by mass or less, and the C2-C20 fluorine-containing organic acid is obtained in the form of the C2-C20 fluorinated organic acid phase having a reduced content ratio of the fluorine-free organic compound compared with said mixture.

First claim

The invention claimed is:

1. A method for producing a C 2 -C 20 fluorine-containing organic acid, wherein the method comprises:
contacting a mixture containing a C 2 -C 20 fluorine-containing organic acid and a fluorine-free organic compound with a concentrated sulfuric acid and then separating a C 2 -C 20 fluorine-containing organic acid phase from a concentrated sulfuric acid phase,
wherein the contacting is conducted such that the amount of water present in the concentrated sulfuric acid phase is 10% by mass or less and the amount of a sulfuric acid in the concentrated sulfuric acid phase is 90% by mass or more,
the C 2 -C 20 fluorine-containing organic acid is obtained in the form of the C 2 -C 20 fluorinated organic acid phase,
a content of the fluorine-free organic compound in the C 2 -C 20 fluorinated organic acid phase is less than a content of the fluorine-free organic compound in the mixture,
the C 2 -C 20 fluorine-containing organic acid comprises at least one selected from the group consisting of a C 2 -C 20 fluorocarboxylic acid and salts thereof, and
the fluorine-free organic compound comprises at least one selected from the group consisting of a C 1 -C 50 fluorine-free carboxylic acid and derivatives thereof, a C 8 -C 50 fluorine-free hydrocarbon, a C 6 -C 50 fluorine-free phenol, a C 1 -C 30 fluorine-free alcohol, a C 8 -C 50 fluorine-free polyether, and a C 10 -C 20 fluorine-free alkyl group-containing ionic compound.

2. The method according to claim 1 , wherein the fluorine-free organic compound comprises a C 1 -C 50 fluorine-free carboxylic acid.

3. The method according to claim 1 , wherein the fluorine-free organic compound comprises the C 8 -C 50 fluorine-free hydrocarbon.

4. The method according to claim 1 , wherein, prior to the contacting, the mixture containing the C 2 -C 20 fluorine-containing organic acid and the fluorine-free organic compound is subjected to a dehydration treatment.

5. The method according to claim 4 , wherein the dehydration treatment is carried out by washing the mixture containing the C 2 -C 20 fluorine-containing organic acid and the fluorine-free organic compound with a sulfuric acid aqueous solution having a sulfuric acid concentration of 70% by mass or more.

6. The method of claim 1 , wherein a ratio by mass of the mixture to the concentrated sulfuric acid is 10:1 to 1:1.

7. The method of claim 1 , wherein a content of the fluorine-free organic compound in the mixture is 0.1 ppm by mass to 1000 ppm by mass.

8. The method according to claim 1 , wherein the C 2 -C 20 fluorocarboxylic acid is represented by the following formula (i):
X—Rf—COOH  formula (i),

wherein, in the formula (i), X is H, F or Cl, Rf is a linear or branched C 1 -C 19 fluoroalkylene group, a C 1 -C 19 group having a monooxyfluoroalkylene group or a C 1 -C 19 group having a polyoxyfluoroalkylene group.

9. The method according to claim 8 , wherein Rf is represented by one of the following formula (a) to (f):
(CF 2 ) l —(CF 2 OCF 2 ) m —(CF 2 OCF(CF 3 )) n   formula (a),

(CF 2 ) l —(CHFOCF 2 ) m —(CF 2 OCF(CF 3 )) n   formula (b),

(CF 2 ) l —(CF 2 OCHF) m —(CF 2 OCF(CF 3 )) n   formula (c),

(CHF) l —(CF 2 OCF 2 ) m —(CF 2 OCF(CF 3 )) n   formula (d),

(CHF) l —(CHFOCF 2 ) m —(CF 2 OCF(CF 3 )) n   formula (e),

(CHF) l —(CF 2 OCHF) m —(CF 2 OCF(CF 3 )) n   formula (f),

wherein, in the formula (a) to (f), 1 is 0 or an integer of 1 to 17, m is 0 or an integer of 1 to 9 and n is an integer of 0 to 6, provided that l+2m+3n does not exceed 19 and that a case where m and n are 0 is excluded and that the order of presence of the respective repeating units in parentheses is arbitrary.

10. The method according to claim 8 , wherein X is H or F, and Rf is represented by the following formula (a):
(CF 2 ) l —(CF 2 OCF 2 ) m —(CF 2 OCF(CF 3 )) n   formula (a),

wherein, in the formula (a), l is 0 or an integer of 1 to 17, m is 0 or an integer of 1 to 9 and n is an integer of 0 to 6, provided that l+2m+3n does not exceed 19, that a case where m and n are 0 is excluded, and that the order of presence of the respective repeating units in parentheses is arbitrary.

11. The method according to claim 1 , wherein the C 2 -C 20 fluorocarboxylic acid is selected from the group consisting of:
CF 3 OCF(CF 3 )CF 2 OCF(CF 3 )COOH,
CF 3 CF 2 OCF 2 CF 2 OCF 2 COOH,
CF 3 OCF 2 CF 2 CF 2 OCHFCF 2 COOH,
CF 3 CF 2 OCF 2 CF 2 OCF 2 COOH,
CF 3 OCF 2 CF 2 CF 2 OCHFCF 2 COOH,
CF 3 (CF 2 ) 4 COOH,
CF 3 CF 2 CF 2 OCF(C(CF 3 )COOH,
H(CF 2 ) 6 COOH,
H(CF 2 ) 4 COOH,
CH 2 ═CFCF 2 OCF(CF 3 )COOH,
CF 3 (CF 2 ) 6 COOH, and
CF 3 CFCF 2 COCF 2 CF 2 OCF(CF 3 )COOH.

12. The method according to claim 1 , wherein the fluorine-free organic compound comprises the C 1 -C 50 fluorine-free carboxylic acid, and the C 1 -C 50 fluorine-free carboxylic acid comprises a C 8 -C 50 fluorine-free aromatic carboxylic acid or ester thereof.

13. The method according to claim 1 , wherein the fluorine-free organic compound comprises the C 1 -C 50 fluorine-free carboxylic acid, and the C 1 -C 50 fluorine-free carboxylic acid comprises a C 1 -C 50 fluorine-free aliphatic carboxylic acid or ester thereof.

14. The method according to claim 1 , wherein the fluorine-free organic compound comprises the C 8 -C 50 fluorine-free hydrocarbon, and the C 8 -C 50 fluorine-free hydrocarbon comprises a C 8 -C 50 linear, branched or alicyclic and saturated or unsaturated hydrocarbon.

15. The method according to claim 1 , wherein the fluorine-free organic compound comprises a polyvalent C 6 -C 50 fluorine-free phenol.

16. The method according to claim 1 , wherein the fluorine-free organic compound comprises a polyvalent C 1 -C 30 fluorine-free alcohol.

17. The method according to claim 1 , wherein the fluorine-free organic compound comprises the C 8 -C 50 fluorine-free polyether, and the C 8 -C 50 fluorine-free polyether is selected from the group consisting of a C 8 -C 50 polyethylene glycol, a C 8 -C 50 polypropylene glycol, a C 8 -C 50 polyethylene/polypropylene glycol, a C 8 -C 50 poly(oxyalkylene)alkyl ether, and a C 8 -C 50 poly(oxyalkylene)arylalkyl ether.

18. The method according to claim 1 , wherein the fluorine-free organic compound comprises the C 10 -C 20 fluorine-free alkyl group-containing ionic compound, and the C 10 -C 20 fluorine-free alkyl group-containing ionic compound is selected from the group consisting of a C 10 -C 20 alkyl sulfonate, a C 10 -C 20 alkylamine salt, a C 10 -C 20 alkyl quaternary ammonium salt, a C 10 -C 20 alkyl betaine, and a C 10 -C 20 alkylamine oxide salt.

19. The method according to claim 1 , wherein a content of the fluorine-free organic compound in the C 2 -C 20 fluorinated organic acid phase is less than 0.1 ppm by mass.

20. The method according to claim 1 , wherein a content of the fluorine-free organic compound in the C 2 -C 20 fluorinated organic acid phase is less than 0.05 ppm by mass.

Assignees

• Daikin Ind Ltd

Inventors

• Itatani Shuuji
• Ohashi Mihoko

Classifications

• C07C303/44

  Separation; Purification · CPC title

• C07C51/44

  by distillation · CPC title

• C07C51/48 Primary

  by liquid-liquid treatment · CPC title

• C07C53/21 Primary

  containing fluorine · CPC title

• C07C309/06

  containing halogen atoms, or nitro or nitroso groups bound to the carbon skeleton · CPC title