Hydrofluoroethers having at least one hydrogenated-OCFX'CH
Hydrofluoroethers of formula: T-CFX′—O—R f —CFX-T′ (II) wherein: T=CH 3 ; X, X′, equal to or different from each other, are selected between F, CF 3 ; T00′=F, Cl, H, C 1 –C 3 perfluoroalkyl, CH 3 , CH 2 OH, COCl, CHO, CO 2 H; R f is a perfluoroalkylene or a perfluoropolyoxyalkylene and respective preparation process by reduction with hydrogen in the presence of a platinum catalyst supported on metal fluorides of the corresponding compounds with at least one —COCl end group.
1. A process for the preparation or hydrofluoroethers of formula:
T-CFX′—O—R f —CFX-T′ (II)
wherein:
T=CH 3 ;
X,X′, equal to or different from each other, are selected between F, CF 3 ;
T′=F, Cl, H, C 1 –C 3 perfluoroalkyl, CH 3 , CH 2 OH, COCl, CHO, CO 2 H;
R f is selected from:
C 2 –C 15 perfluoroalkylene;
—(C 2 F 4 O) m (CF 2 CF(CF 3 )O) n (CF 2 O) p (CF(CF 3 )O) g —
wherein
the sum n+m+p+q ranges from 2 to 200,
the (p+q)/(m+n+p+q) ratio is lower than or eaual to 10:100, the n/m ratio ranges from 0.2 to 6; m, n, p, q are equal to or different from each other and when m, n range from 1 to 100, then p, q range from 0 to 80; the units with n, m, p, q indexes being statistically distributed along the chain;
—(CF 2 CF 2 CF 2 O) r —wherein r ranges from 2 to 200,
—(CF(CF 3 )CF 2 O) s —wherein s ranges from 2 to 200,
comprising the reduction of the formula (III) corresponding precursors:
T″-CFX′—O—R f —CFX-T′″ (III)
wherein:
T″=COCl,
T′″=F, C 1 –C 3 perfluoroalkyl, COCI, H, CI,
X, X′, R f are as defined in formula, carried out with gaseous hydrogen in the presence of a catalyst formed by supported platinum, at a temperature in the range 20° C.–15° C., at a pressure between 1 and 50 atm.
2. A process according to claim 1 , wherein the metal fluorides are selected from the group formed by CaF 2 , BaF 2 , MgF 2 , AlF 3 .
3. A process according to claim 1 , wherein the Pt concentration on the support is comprised between 0.1% and 10% with respect to the total weight of the catalyst.
4. A process according to claim 1 , wherein the catalyst is used in an amount in the range 1%–100% by weight with respect to the weight of the formula (III) compound.
5. A process according to claim 1 , wherein the inert solvent is selected among perfluorotetrahydrofuran, perfluorotetrahydropyran, or their mixtures.
6. A process according to claim 1 , wherein the reduction of the formula (III) corresponding precursors is carred out with gaseous hydrogen in the presence of a catalyst formed by supported platinum on metal fluorides.
7. A process according to claim 1 , wherein the reduction of the formula (III) corresponding precursos is carried out with gaseous hydrogen in the presence of a catalyst formed by supported platinum in the presence of inert solvents.
8. A process according to claim 1 , wherein the temperature is in the range 80° C.–120 C.
9. A process according to claim 1 , wherein the pressure is between 1 and 10 atm.
10. A process according to claim 2 , wherein the metal fluorides are CaF 2 .
11. A process according to claim 3 , wherein the Pt concentration on the support is comprised between 1% and 2% by weight with respect to the total weight of the catalyst.
12. A process according to claim 4 , wherein the catalyst is used in an amount in the range 10%–100% by weight with respect to the weight of the formula (III) compound.