Patent ID: 6916887

Claim:
A specialty fluoroelastomer comprising copolymerized units of 10 to 40 mole percent ethylene; 20 to 40 mole percent perfluoro ether selected from the group consisting of perfluoro(alkyl vinyl ethers), perfluoro(alkyl alkenyl ethers) and perfluoro(alkoxy alkenyl ethers); 32-60 mole percent tetrafluoroethylene; and 0.1 to 15 mole percent of a cure site monomer having the formula R f —(CF 2 ) n —CH═CH 2 wherein R f is a perfluorinated alkyl group or perfluorinated alkoxy group containing between 1 and 7 carbon atoms, n is an integer between 1 and 6 and wherein the total number of carbon atoms in the cure site monomer is less than 10, with the proviso that if the perfluoro ether is a perfluoro(alkyl vinyl ether), the cure site monomer may not contain a bromine or iodine atom.