Abstract: This invention pertains to perfluoropolyethers and perhalogenated chlorofluoroether polymers that can be prepared by fluorinating polymers made by the polymerization of acetals, ketals, polyacetals, polyketals and orthoesters with elemental fluorine.
Type:
Grant
Filed:
August 30, 1991
Date of Patent:
April 13, 1993
Assignee:
Exfluor Research Corporation
Inventors:
Thomas R. Bierschenk, Timothy Juhlke, Hajimu Kawa, Richard J. Lagow
Abstract: This invention pertains to the use of chlorofluoropolymers, such as perfluoropolyepichlorohydrin as lubricants for cooling systems which employ hydrofluorocarbon refrigerants, such as 1,1,1,2-tetrafluoroethane.
Type:
Grant
Filed:
June 24, 1991
Date of Patent:
March 30, 1993
Assignee:
Exfluor Research Corporation
Inventors:
Thomas R. Bierschenk, Timothy J. Juhlke, Richard J. Lagow, Hajimi Kawa
Abstract: This invention relates to perfluoroether compounds, and to a general method for creating such compounds. It has been found that such compounds may be created by a three-step method which may be performed using a wide variety of ester starting materials. The first step of the three-step process comprises partial fluorination of a selected polyester compound. This may be performed by contacting the selected polyester with fluorine gas under predetermined conditions until a desired level of partial fluorination is achieved.The second step of this three-step process involves indirect fluorination to convert the partially fluorinated polyester into partially fluorinated polyether compounds. This step may be conducted by contacting the partially fluorinated polyester with SF.sub.4.The third step of the three-step synethetic process comprises direct fluorination of the partially fluorinated polyether compound at conditions which essentially complete the perfluorinated polyether compound.
Abstract: Perfluoroalkylorthocarbonates and perfluoropolyalkoxypropanes are disclosed. The perfluoro compounds are synthesized by direct fluorination procedures. The perfluoro compounds are useful lubricants, heat exchangers, vapor phase soldering fluids, solvents, and oxygen carriers.
Abstract: This invention pertains to perfluoropolyethers and perhalogenated chlorofluoroether polymers that can be prepared by fluorinating polymers made by the polymerization of acetals, ketals, polyacetals, polyketals and orthoesters with elemental fluorine.
Type:
Grant
Filed:
September 28, 1989
Date of Patent:
October 1, 1991
Assignee:
Exfluor Research Corporation
Inventors:
Thomas R. Bierschenk, Timothy Juhlke, Hajimu Kawa, Richard J. Lagow
Abstract: A method of breaking down perfluoropolyethers into lower molecular weight fragments by pyrolysis is disclosed. The perfluoropolyethers are pyrolyzed generally at above about 350.degree. C. Volatile lower molecular weight components are condensed and collected. Various molecular weight fractions and collected. Various molecular weight fractions can be obtained by taking appropriate distillation cuts.
Type:
Grant
Filed:
January 5, 1990
Date of Patent:
June 18, 1991
Assignee:
Exfluor Research Corporation
Inventors:
Richard J. Lagow, Thomas R. Bierschenk, Timothy J. Juhlke, Hajimu M. Kawa
Abstract: This invention pertains to the use of chlorofluoropolyethers, such as perfluoropolyepichlorohydrin as lubricants for cooling systems which employ hydrofluorocarbon refrigerants, such as 1,1,1,2-tetrafluoroethane.
Type:
Grant
Filed:
May 23, 1989
Date of Patent:
June 5, 1990
Assignee:
Exfluor Research Corporation
Inventors:
Thomas R. Bierschenk, Timothy J. Juhlke, Richard J. Lagow, Hajimu Kawa
Abstract: A method of breaking down perfluoropolyethers into lower molecular weight fragments by pyrolysis is disclosed. The perfluoropolyethers are pyrolyzed generally at above about 350.degree. C. Volatile lower molecular weight components are condensed and collected. Various molecular weight fractions can be obtained by taking appropriate distillation cuts.
Type:
Grant
Filed:
September 3, 1987
Date of Patent:
January 16, 1990
Assignee:
Exfluor Research Corporation
Inventors:
Richard J. Lagow, Thomas R. Bierschenk, Timothy J. Juhlke, Hajimu M. Kawa
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 elemental fluorine. The HF scavenger permits use of more severe fluorination conditions than would be possible in the absence of the scavenger, i.e. higher initial fluorine, less gradual increases in fluorine gas concentrations and greater fluorine gas flow rates.
Type:
Grant
Filed:
May 24, 1988
Date of Patent:
August 22, 1989
Assignee:
Exfluor Research Corporation
Inventors:
Thomas R. Bierschenk, Timothy J. Juhlke, Richard J. Lagow
Abstract: Perfluoropolyethers containing an approximate equal number of difluoromethylene and tetrafluoroethylene repeat units distributed either randomly or in alternating sequence along the polymer chain are disclosed. The polymers range in molecular weight from 500-200,000 amu; the lower molecular polymers being fluid and the intermediate and high molecular weight polymers being solid. The perfluorinated copolymers are synthesized by direct fluorination of corresponding methylene oxide/ethylene oxide copolymers.
Type:
Grant
Filed:
November 8, 1985
Date of Patent:
July 26, 1988
Assignee:
Exfluor Research Corporation
Inventors:
Thomas R. Bierschenk, Timothy J. Juhlke, Richard J. Lagow
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.
Type:
Grant
Filed:
October 27, 1986
Date of Patent:
July 5, 1988
Assignee:
Exfluor Research Corporation
Inventors:
Thomas R. Bierschenk, Timothy J. Juhlke, Richard J. Lagow