Omega-hydrofluoroalkyl ethers, precursor carboxylic acids and derivatives thereof, and their preparation and application
Assignee3M Innovative Properties Company
InventorsGeorge G. I. Moore, Richard M. Flynn, Miguel A. Guerra, John G. Owens
Life of this patent
Estimating the term…
Abstract
Normally liquid, omega-hydrofluoroalkyl ether compounds (and selected mixtures thereof) have a saturated perfluoroaliphatic chain of carbon atoms interrupted by one or more ether oxygen atoms. The compounds can be prepared, e.g., by decarboxylation of the corresponding fluoroalkyl ether carboxylic acids and are useful, e.g., in cleaning and drying applications.
Claims15
A normally liquid, omega-hydrofluoroalkyl ether compound represented by the general formula:
- X—Rf—O—(Rf′—O)n—Rf″—H
- wherein:
- H is a primary hydrogen atom;
- X is a fluorine atom;
- n is an integer of 0 to 7;
- and
- Rf, Rf′, and Rf″ are independently selected from the group consisting of linear or branched, unsubstituted perfluoroalkylene groups;
- linear or branched, perfluoroalkyl- or perfluorocycloalkyl-substituted perfluoroalkylene groups;
- and linear or branched perfluoroalkylene groups substituted with an ether oxygen-containing moiety;
- with the proviso that when X is F, then Rf has at least 4 chain carbon atoms, Rf′ has 1 or more chain carbon atoms, and Rf″ has 2 or more chain carbon atoms.
A normally liquid, omega-hydrofluoroalkyl ether compound represented by the general formula:
- X—Rf—O—(Rf′—O)n—Rf′″—H
- wherein:
- H is a primary hydrogen atom;
- X is a fluorine atom;
- n is an integer of 0 to 7;
- and
- Rf, Rf′, and Rf′″ are independently selected from the group consisting of linear or branched, unsubstituted perfluoroalkylene groups;
- linear or branched, perfluoroalkyl- or perfluorocycloalkyl-substituted perfluoroalkylene groups;
- and linear or branched perfluoroalkylene groups substituted with an ether oxygen-containing moiety;
- with the proviso that when X is F, then Rf has at least 4 chain carbon atoms, and each of Rf′ and Rf′″ independently has 1 or more chain carbon atoms;
- and with the further proviso that when n is zero, then Rf is a perfluorocycloalkyl-substituted perfluoroalkylene group.
A method for converting —CF2Cl groups to —CF2H groups comprising the step of contacting at least one compound containing at least one —CF2Cl group with hydrogen gas, said contacting being carried out at a temperature below about 200° C. in the presence of both a solution of base and a catalytic amount of at least one metal or supported metal, said metal being selected from the group consisting of nickel, palladium, and platinum.
In a method of vapor phase soldering wherein a component to be soldered is immersed in or enveloped by a body of fluorinated liquid vapor to melt the solder, and the component is then withdrawn from the body of vapor, the improvement comprising using as the fluorinated liquid a composition comprising at least one normally liquid omega-hydrofluoroalkyl ether compound having a saturated perfluoroaliphatic chain of carbon atoms interrupted by one or more ether oxygen atoms, the chain carbon atom at one end (the proximal end) of the chain being that of a difluoromethyl group which is bonded to another chain carbon atom or to a said ether-oxygen atom, the carbon atom at the other end (the distal end) of the chain being part of a distal group selected from the group consisting of difluoromethyl, difluorochloromethyl, a straight-chain perfluoroalkyl, a branched-chain perfluoroalkyl, and a perfluoroalkyl substituted with a saturated perfluoroalicyclic moiety, with the proviso that where said difluoromethyl group at the proximal end is bonded to a said ether-oxygen atom, then said straight-chain perfluoroalkyl has at least 6 chain carbon atoms and said branched-chain perfluoroalkyl has at least 4 carbon atoms.
Dependencies are inferred from the claim text.