Heat-resistant electric wire
A heat-resistant electric wire including a core wire and a coating that covers the core wire. The coating is formed from a modified fluorine-containing copolymer that is obtained by irradiating a copolymer with radiation at an exposure of 250 kGy or lower at a temperature of not higher than the melting point of the copolymer. The copolymer is at least one copolymer selected from a copolymer including a tetrafluoroethylene unit and a perfluoro(alkyl vinyl ether) unit and a copolymer including a tetrafluoroethylene unit and a hexafluoropropylene unit.
1. A heat-resistant electric wire comprising a core wire and a coating that covers the core wire,
the coating being formed from a modified fluorine-containing copolymer that is obtained by irradiating a copolymer with radiation at an exposure of 90 kGy or lower at a temperature of not higher than the melting point of the copolymer,
wherein the copolymer including a tetrafluoroethylene unit and a perfluoro(alkyl vinyl ether) unit includes 2.0 to 12 mass % of the perfluoro(alkyl vinyl ether) unit in all the monomer units,
wherein the copolymer has 191 or more functional groups per 10 6 carbon atoms and the functional groups include at least one selected from the group consisting of —CF═CF 2 , —CF 2 H, —COF, —COOH, —COOCH 3 ; —CONH 2 , and —CH 2 QH.
2. A method of producing the heat-resistant electric wire according to claim 1 , comprising
extrusion-molding, on a core wire, a copolymer including a tetrafluoroethylene unit and a perfluoro(alkyl vinyl ether) unit to provide a coating that covers the core wire, and
irradiating the coating with radiation.
3. The production method according to claim 2 ,
wherein the coating further contains polytetrafluoroethylene.