Preparation of perfluorinated vinyl ethers having a sulfonyl fluoride end-group

• US 6,624,328 B1
• Filed: 12/17/2002
• Issued: 09/23/2003
• Est. Priority Date: 12/17/2002
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Guerra, Miguel Antonio
• Primary Examiner(s): Vollano, Jean F.
• Application Number:
  US10/322,226
• Time in Patent Office: 280 Days
• Field of Search: 562/821, 562/824, 562/825, 568/28, 568/35, 204/157.6, 204/157.76, 204/157.78, 204/157.8
• US Class Current: 562/825
• CPC Class Codes: C07C 303/22 from sulfonic acids, by reactions not involving the formation of sulfo or halosulfonyl groups; from sulfonic halides by reactions not involving the formation of halosulfonyl groups
• CPC Class Codes: C07C 309/82 of a carbon skeleton substituted by singly-bound oxygen atoms
• CPC Class Codes: C25B 3/28 Fluorination

Abstract

A method is provided for making a perfluorinated vinyl ether having a sulfonyl fluoride end-group according to the formula FSO₂—(CF₂)_n—O—CF═CF₂, where n is 2-5, comprising the steps of: a) fluorination of:

to produce FSO₂—(CF₂)_(n−1)—COF; b) reaction of FSO₂—(CF₂)_(n−1)—COF with hexafluoropropylene oxide (HFPO) to produce FSO₂—(CF₂)_(n)—O—CF(CF₃)—COF; c) reaction of FSO₂—(CF₂)_(n)—O—CF(CF₃)—COF with a salt of a metal cation M+P, where p is the valence of M, to produce (FSO₂—(CF₂)_(n)—O—CF(CF₃)—COO⁻)_pM+P; and d) thermal cracking of FSO₂—(CF₂)_(n)—O—CF(CF₃)—COO⁻)_pM+P to produce FSO₂—(CF₂)_(n)—O—CF═CF₂.

Claims

1. A method of making a perfluorinated vinyl ether having a sulfonyl fluoride end-group according to the formula FSO₂—

(CF₂)_n—

O—

CF═

CF₂, where n is 2-5, comprising the steps of;

a) fluorination of;

 

to produce FSO₂—

(CF₂)<sub>(n−

1)</sub>—

COF;

b) reaction of FSO₂—

(CF₂)(<sub>n−

1</sub>)—

COF with hexafluoropropylene oxide (HFPO) to produce FSO₂—

(CF₂)_(n)—

O—

CF(CF₃)—

COF;

c) reaction of FSO₂—

(CF₂)_(n)—

O—

CF(CF₃)—

COF with a salt of a metal cation M+P , where p is the valence of M, to produce (FSO₂—

(CF₂)_(n)—

O—

CF(CF₃)—

COO⁻

)_pM+P; and

d) thermal cracking of FSO₂—

(CF₂)_(n)—

O—

CF(CF₃)—

COO⁻

)_pM+P to produce FSO₂—

(CF₂)_(n)—

O—

CF═

CF₂.

2. The method according to claim 1 wherein n=4.

3. The method according to claim 1 wherein step c) is performed in a polar solvent.

4. The method according to claim 1 wherein said salt of a metal cation is Na₂CO₃.

5. The method according to claim 3 wherein said salt of a metal cation is Na₂CO₃.

6. The method according to claim 1 wherein said step b) is performed in the presence of a fluoride catalyst.

7. The method according to claim 6 wherein said step b) is performed in the absence of any catalyst other than a fluoride catalyst.

8. The method according to claim 6 wherein said fluoride catalyst is KF.

9. The method according to claim 7 wherein said fluoride catalyst is KF.

10. The method according to claim 1 wherein, throughout said step b), the molar amount of FSO₂—

(CF₂)<sub>(n−

1)</sub>—

COF present remains in excess of the molar amount of HFPO present by at least 10%.

11. The method according to claim 6 wherein, throughout said step b), the molar amount of FSO₂—

(CF₂)<sub>(n−

1)</sub>—

COF present remains in excess of the molar amount of HFPO present by at least 10%.

12. The method according to claim 1 wherein said step a) comprises electrochemical fluorination.

13. The method according to claim 2 wherein said step a) comprises electrochemical fluorination.

14. The method according to claim 5 wherein said step a) comprises electrochemical fluorination.

15. The method according to claim 6 wherein said step a) comprises electrochemical fluorination.

16. The method according to claim 10 wherein said step a) comprises electrochemical fluorination.

17. The method according to claim 11 wherein said step a) comprises electrochemical fluorination.