Solvents for tetrafluoroethylene polymers
AssigneeE. I. Du Pont de Nemours and Company
InventorsWilliam Howard Tuminello, Robert John Cavanaugh
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Abstract
Perfluorinated cycloalkane solvents for dissolving high melting polymers containing tetrafluoroethylene, are disclosed. These solvents dissolve such polymers more rapidly, and/or are more stable, than previously known solvents. Also disclosed is a process for dissolution of the polymers and their resulting solutions. The solutions are useful for making polymer films, coatings and for encapsulating objects.
Claims2
In a process for making a solid object using a solution of a polymer containing tetrafluoroethylene units dissolved in a perfluorinated cycloalkane, said process being selected from the group of processes consisting of
- (1) wet spinning a fiber;
- (2) casting from solution in a mold and allowing the solvent to evaporate, then removing the article from the mold;
- and
- (3) drawing the solution and then removing the solvent to form a film;
- the improvement of using as the solvent a perfluorinated cycloalkane or a perfluorinated cycloalkane containing one or more perfluoroalkyl and perfluoroalkylene groups;
- wherein the total number of carbon atoms in said perfluoroalkyl and perfluoroalkylene groups, when present, is less than the total number offing carbon atoms in said perfluorocycloalkane;
- with the provisos that:
- (a) the critical temperature of said solvent is 340.degree. C. or more;
- and
- (b) the melting point of said polymer is about 250.degree. C. or more.
Dependencies are inferred from the claim text.