Method for producing perfluoropolyether acyl fluoride

Abstract

A process for producing a perfluoropolyether acyl fluoride which includes reducing a peroxyperfluoropolyether by using a formyl group-containing compound in the presence of a transition metal catalyst.

Claims

1. A process for producing a perfluoropolyether acyl fluoride which comprises reducing a peroxyperfluoropolyether with a formyl group-containing compound in the presence of a transition metal catalyst, wherein the formyl group-containing compound is formic acid or formic acid derivatives.

2. The process according to claim 1 wherein the perfluoropolyether acyl fluoride is a compound of the following formula (I):
X(C.sub.4F.sub.8O).sub.a(C.sub.3F.sub.6O).sub.b(C.sub.2F.sub.4O).sub.c(CF.sub.2O).sub.dY wherein: a, b, c and d are each independently 0 or an integer of 1 or more, the sum of a, b, c and d is at least 1, and the occurrence order of the respective repeating units in parentheses with the subscript a, b, c or d is not limited in the formula, X is R.sup.5, R.sup.5 is F, COF, CF.sub.3-mCl.sub.m, m is an integer of 1-3, Y is (CF.sub.2).sub.nCOF, and n is an integer of 0-3.

3. The process according to claim 1 wherein perfluoropolyether acyl fluoride is a compound of the following formula (I):
X(C.sub.4F.sub.8O).sub.a(C.sub.3F.sub.6O).sub.b(C.sub.2F.sub.4O).sub.c(CF.sub.2O).sub.dY wherein: a and b are each independently 0 or more and 30 or less, c and d are each independently 1 or more and 200 or less, and the occurrence order of the respective repeating units in parentheses with the subscript a, b, c or d is not limited in the formula, X is R.sup.5, R.sup.5 is F, COF, CF.sub.3-mCl.sub.m, m is an integer of 1-3, Y is (CF.sub.2).sub.nCOF, and n is an integer of 0-3.

4. The process according to claim 1 wherein the formyl group-containing compound is formic acid.

5. The process according to claim 1 wherein the peroxyperfluoropolyether compound comprises the following structure (II):
(C.sub.4F.sub.8O).sub.a(C.sub.3F.sub.6O).sub.b(C.sub.2F.sub.4O).sub.c(CF.sub.2O).sub.d(C.sub.4F.sub.8OO).sub.p(C.sub.3F.sub.6OO).sub.q(C.sub.2F.sub.4OO).sub.r(CF.sub.2OO).sub.s wherein: a, b, c, d, p, q, r and s are each independently 0 or an integer of 1 or more, the sum of a, b, c and d is at least 1, and the sum of p, q, r and s is at least 1, and the occurrence order of the respective repeating units in parentheses with the subscript a, b, c, d, p, q, r or s is not limited in the formula.

6. The process according to claim 1 wherein the transition metal is selected form Pd, Pt, Rh, Ru and a mixture thereof.

7. The process according to claim 1 wherein the used amount of the transition metal catalyst is in the range of 0.1 to 10.0% by mass with respect to peroxyperfluoropolyether.

8. The process according to claim 1 wherein the used amount of the transition metal catalyst is in the range of 1.0 to 10.0% by mass with respect to peroxyperfluoropolyether.

9. The process according to claim 1 wherein the reaction temperature is 50 to 200 C.

10. The process according to claim 1 wherein the reaction temperature is 50 to 150 C.

11. The process according to claim 1 which is performed in a solvent-free condition.

12. The process according to claim 1 which is performed in a non-aqueous solvent.

Description

EXAMPLES

Example 1

(1) Peroxyperfluoropolyether (100 g, number average molecular weight=15,600, PO=0.83), a Pd/C catalyst (2.45 g, manufactured by N.E. CHEMCAT CORPORATION, containing 5 wt % of Pd to weight of the catalyst) and formic acid (16.40 g) were added to an autoclave.

(2) Nitrogen gas was introduced at the rate of 10 mL/min, stirring was performed under the pressure of 0.2 MPa, at 120 C. for 12 hours, and then the autoclave was opened. The resulting reaction solution was filtered and the volatiles were distilled off. As a result, the desired perfluoropolyether acyl fluoride containing material (78.78 g) was obtained.

(3) The resulting perfluoropolyether acyl fluoride containing material was analyzed by .sup.19F-NMR, as a result of which, no fluorine substituent adjacent to a peroxy bond (OO) was observed, and the acyl fluoride terminal was 93.6%, the carboxylic acid terminal was 2.2%, and the CHF.sub.2 terminal was 4.2%. Therefore, it was confirmed that the peroxyperfluoropolyether was converted to a perfluoropolyether acyl fluoride at the high conversion.

Example 2

(4) Peroxyperfluoropolyether (50 g, number average molecular weight=15,600, PO=0.83), a Pd/C catalyst(1.05 g, manufactured by N.E. CHEMCAT CORPORATION, containing 5 wt % of Pd to weight of the catalyst) and formic acid (8.20 g) were added to a glass reactor.

(5) Nitrogen gas was bubbled at the rate of 10 mL/min, and stirring was performed at 120 C. for 6 hours. Then, the resulting reaction solution was filtered and the volatiles were distilled off. As a result, the desired perfluoropolyether acyl fluoride containing material (39.27 g) was obtained.

(6) The resulting polyfluoropolyether acyl fluoride containing material was analyzed by .sup.19F-NMR, as a result of which, no fluorine substituent adjacent to a peroxy bond (OO) was observed, and the acyl fluoride terminal was 94.5%, the carboxylic acid terminal was 2.1%, and the CHF.sub.2 terminal was 3.4%.

Example 3

(7) Peroxyperfluoropolyether (50 g, number average molecular weight=15,600, PO=0.83), a Pd/C catalyst(3.55 g, manufactured by N.E. CHEMCAT CORPORATION, containing 1.5 wt % of Pd to weight of the catalyst) and formic acid (8.20 g) were added to a glass reactor.

(8) After stirring at 120 C. for 3 hours, the resulting reaction solution was filtered and the volatiles were distilled off. As a result, the desired perfluoropolyether acyl fluoride containing material (38.72 g) was obtained.

(9) The resulting polyfluoropolyether acyl fluoride containing material was analyzed by .sup.19F-NMR, as a result of which, no fluorine substituent adjacent to a peroxy bond (OO) was observed, and the acyl fluoride terminal was 95.3%, the carboxylic acid terminal was 4.3%, and the CHF.sub.2 terminal was 0.4%.

Example 4

(10) Peroxyperfluoropolyether (50 g, number average molecular weight=14,800, PO=0.69), a Pd/C catalyst(0.91 g, manufactured by N.E. CHEMCAT CORPORATION, containing 5 wt % of Pd to weight of the catalyst) were added to a glass reactor.

(11) After heating the reaction solution to 120 C., formic acid (3.55 g) was added, further stirring was performed at 120 C. for 3 hours. Then, the resulting reaction solution was filtered and the volatiles were distilled off. As a result, the desired perfluoropolyether acyl fluoride containing material (39.89 g) was obtained.

(12) The resulting polyfluoropolyether acyl fluoride containing material was analyzed by .sup.19F-NMR, as a result of which, no fluorine substituent adjacent to a peroxy bond (OO) was observed, and the acyl fluoride terminal was 93.9%, the carboxylic acid terminal was 5.7%, and the CHF.sub.2 terminal was 0.4%.

Comparative Example 1

(13) Peroxyperfluoropolyether (50 g, number average molecular weight=15,600, PO=0.83), a Pd/C catalyst(1.05 g, manufactured by N.E. CHEMCAT CORPORATION, containing 5 wt % of Pd to weight of the catalyst) were added to a glass reactor.

(14) Nitrogen gas was bubbled at the rate of 10 mL/min, and stirring was performed at 120 C. for 6 hours. Then, the resulting reaction solution was filtered and the volatiles were distilled off. As a result, the desired perfluoropolyether acyl fluoride containing material was obtained.

(15) The resulting polyfluoropolyether acyl fluoride containing material was analyzed by .sup.19F-NMR, as a result of which, a signal of the fluorine substituent adjacent to a peroxy bond (OO) was observed, and the reaction conversion was 60.3%.

INDUSTRIAL APPLICABILITY

(16) The present invention is suitably used in producing a perfluoropolyether acyl fluoride compound.