Patent ID: 7402640

Claim:
A fluorocopolymer comprising polymerized units based on ethylene, polymerized units based on tetrafluoroethylene, polymerized units based on hexafluoropropylene and polymerized units based on a perfluoro(alkyl vinyl ether), characterized in that the molar ratio of polymerized units based on ethylene/polymerized units based on tetrafluoroethylene is from 10/90 to 60/40, the content of the polymerized units based on hexafluoropropylene is from 0.3 to 0.8 mol % based on the total polymerized units, and the content of the polymerized units based on a perfluoro(alkyl vinyl ether) is from 0.1 to 1.0 mol % based on the total polymerized units.