Patent ID: 6136911
Filing Date: 2000-10-24
Classification: D01D,D01F

Abstract:
A process for the production of flash-spun material comprised of at least 20% partially fluorinated hydrocarbon polymers wherein between 10% and 70% of the total number of hydrogen atoms in each of said partially fluorinated hydrocarbon polymers are replaced by fluorine atoms, which comprises the steps of:forming a spin solution of said partially fluorinated hydrocarbon polymers in a solvent, said spin solution having a cloud point pressure of less than 50 MPa at temperatures in the range of 150.degree. C. to 280.degree. C., said solvent having an atmospheric boiling point between 0.degree. C. and 150.degree. C., and being selected from the group consisting of alcohols, ketones, acetates, carbonates, chlorinated hydrocarbons, hydrofluorocarbons, hydrochlorofluorocarbons, hydrofluoroethers, perfluoroethers, and cyclic hydrocarbons having five to twelve carbon atoms, said partially fluorinated hydrocarbon polymer being selected from the group consisting ofpolymers comprised of 40% to 70% by weight of polymerized monomer units of tetrafluoroethylene and 10% to 60% by weight of polymerized monomer units of ethylene,polymers comprised of 40% to 70% by weight of polymerized monomer units of chlorotrifluoroethylene and 10% to 60% by weight of polymerized monomer units of ethylene,polymers comprised of at least 80% by weight of a homopolymer of vinylidene fluoride,polymers comprised of at least 80% by weight of a homopolymer of vinyl fluoride; andspinning said spin solution at a pressure that is greater than the autogenous pressure of the spin solution into a region of substantially lower pressure and at a temperature at least 50.degree. C. higher than the atmospheric boiling point of the solvent.