Tetrafluoroethylene/hexafluoropropylene copolymer and the production method thereof, and electrical wire
A tetrafluoroethylene/hexafluoropropylene copolymer has improved moldability in melt extrusion molding, especially with significant reduction of defects in high-speed extrusion coating of an electrical wire. The tetrafluoroethylene/hexafluoropropylene copolymer is obtained by polymerization of at least tetrafluoroethylene and hexafluoropropylene selected from the group consisting of tetrafluoroethylene, hexafluoropropylene and a third monomer without mixing with the resin which has the melting point with the difference of 20 degree C. and more from the melting point of the tetrafluoroethylene/hexafluoropropylene copolymer; and has a complex viscosity of from 2.0×I0 3 to 10.0×I0 3 Pa*s and a storage modulus of from 0.1 to 3.5 Pa*s in melt viscoelasticity measurement under the condition of atmosphere temperature of 310 degree C. and angular frequency of 0.01 radian/second. The tetrafluoroethylene/hexafluoropropylene copolymer can be used in an electrical wire as a coating on a conductive core.
1. A fluoropolymer composition including tetrafluoroethylene/hexafluoropropylene copolymer made from at least tetrafluoroethylene, hexafluoropropylene and a third monomer and not including a resin having a melting point at least 20 degrees C. different from the melting point of the tetrafluoroethylene/hexafluoropropylene copolymer; and
the fluoropolymer composition having a complex viscosity of from 2.0×10 3 to 10.0×10 3 Pa*s and a storage modulus of from 0.2 to 3.5 Pa in melt viscoelasticity measurement under a condition of atmosphere temperature of 310 degree C. and angular frequency of 0.01 radian/second,
a weight ratio of the third monomer to a total weight of the tetrafluoroethylene, the hexafluoropropylene and the third monomer being 1.0 to 10 parts by weight, and
a melt flow rate at 372 degree C. being 20 grams/10 minutes or more.
2. The fluoropolymer composition according to claim 1 , wherein
the tetrafluoroethylene/hexafluoropropylene copolymer is obtained in a process without a mixing process different from a polymerization process.
3. The fluoropolymer composition according to claim 2 , wherein
melt tension at 372 degree C. is from 0.08 to 0.16 N.
4. The fluoropolymer composition according to claim 3 , wherein
a sum of a number of thermally unstable end groups and the number of —CF 2 H end groups per 1×10 6 carbon atoms is fewer than or equal to 50.
5. The fluoropolymer composition according to claim 2 , wherein
a sum of a number of thermally unstable end groups and the number of —CF 2 H end groups per 1×10 6 carbon atoms is fewer than or equal to 50.
6. The fluoropolymer composition according to claim 1 , wherein
melt tension at 372 degree C. is from 0.08 to 0.16 N.
7. The fluoropolymer composition according to claim 6 , wherein
a sum of a number of thermally unstable end groups and the number of —CF 2 H end groups per 1×10 6 carbon atoms is fewer than or equal to 50.
8. The fluoropolymer composition according to claim 1 , wherein
a sum of a number of thermally unstable end groups and the number of —CF 2 H end groups per 1×10 6 carbon atoms is fewer than or equal to 50.
9. The fluoropolymer composition according to claim 1 , wherein
the third monomer is perfluorovinylether.
10. The fluoropolymer composition according to claim 1 , wherein
the third monomer is perfluoro (propylvinylether).
11. The fluoropolymer composition according to claim 1 , wherein
the weight ratio of the third monomer to the total weight of the tetrafluoroethylene, the hexafluoropropylene and the third monomer is 3 parts by weight or less.
12. The fluoropolymer composition according to claim 1 , wherein
the melt flow rate at 372 degree C. is 60 grams/10 minutes or less.
13. The fluoropolymer composition according to claim 1 , wherein
the melt flow rate at 372 degree C. is 40 grams/10 minutes or less.
14. The fluoropolymer composition according to claim 1 , wherein
a weight ratio of hexafluoropropylene to the total weight of the tetrafluoroethylene, the hexafluoropropylene and the third monomer is 4 to 11.2 parts by weight.