Perfluorination of ethers in the presence of hydrogen fluoride scavengers
AssigneeExfluor Research Corporation
InventorsThomas R. Bierschenk, Timothy J. Juhlke, Richard J. Lagow
Life of this patent
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Abstract
The direct fluorination of ethers in the presence of hydrogen fluoride (HF) scavengers such as sodium fluoride and potassium fluoride is disclosed. Ethers (liquid or solid) are either mixed with the HF scavenger, coated onto the HF scavenger or placed separately with the HF scavenger into a fluorination reactor and fluorinated by exposure to gradually increasing concentrations of fluorine gas. The HF scavenger permits use of more severe fluorination conditions i.e. higher initial fluorine, less gradual increases in fluorine gas concentrations and greater fluorine gas flow rates.
Claims31
A method of fluorinating a hydrocarbon ether, comprising the steps of:
- a. placing the hydrocarbon ether and a hydrogen fluoride scavenger into a fluorine reactor, the amount of hydrogen fluoride scavenger in relation to the amount of ether being sufficient to react with the hydrogen fluoride formed during fluorination;
- and
- b. fluorinating the ether by:
- (i) establishing a flow of gas mixture of fluorine gas and an inert gas into the reactor under conditions which allow fluorination of the ether, the fluorine concentration of the gas mixture being about 0.5% to about 25%;
- (ii) gradually increasing the concentration of fluorine gas in the gas mixture to fluorinate the ether;
- and
- c. after the fluorination reaction is completed to desired degree, removing the fluorinated ether and the hydrogen fluoride scanvenger from the reactor.
A method of fluorinating a hydrocarbon polyether, comprising the steps of:
- a. mixing the hydrocarbon polyether to be fluorinated and a hydrogen fluoride scavenger in powdered or pellet form, the amount of hydrogen fluoride scavenger in relation to the amount of polyether being sufficient to react with the hydrogen fluoride formed during fluorination;
- b. placing the mixture in a fluorine reactor;
- c. fluorinating the ether by:
- (i) establishing a flow of gas mixture of fluorine gas and an inert gas into the reactor under conditions which allow fluorination of the ether, the fluorine concentration of the gas mixture being about 0.5% to about 25%;
- and
- (ii) gradually increasing the concentration of fluorine gas in the gas mixture to fluorinate the ether;
- and
- d. after the fluorination is completed to desired degree, removing the fluorinated ether and the hydrogen fluoride scavenger from the reactor and separating the fluorinated ether from the hydrogen fluoride scavenger to obtain the fluorinated ether.
In a method of direct fluorination of a hydrocarbon polyether, comprising fluorinating the hydrocarbon polyether by contacting the ether with gradually increasing concentrations of fluorine gas, the improvement of fluorinating the ether in the presence of a hydrogen fluoride scavenger in powdered or pellet form, the hydrogen fluoride scavenger being present in an amount sufficient to react with essentially all of the hydrogen fluoride formed during the fluorination.
A method of perfluorinating a linear polyether, comprising the steps of:
- a. introducing the polyether and a sodium fluoride into a fluorination reactor;
- b. perfluorinating the polyether by:
- (i) establishing a flow of gas mixture of fluorine gas and inert gas into the reactor under conditions which allow fluorination of the ether, the fluorine gas concentration of the gas mixture being about 0.5 to about 25%;
- and
- (ii) gradually increasing the concentration of fluorine gas in the gas mixture of perfluorinate the polyether thereby forming a perfluoropolyether;
- and
- c. thereafter, removing the perfluoropolyether and the hydrogen scavenger from the reactor and, if neccessary, separating the perfluoropolyether and the hydrogen fluoride scavenger.
In a method of direct perfluorination of a linear polyether, comprising perfluorinating the polyether by contacting the polyether with gradually increasing concentrations of fluorine gas, the improvement of perfluorinating the polyether in the presence of hydrogen scavenger.
Dependencies are inferred from the claim text.