Method of producing a fluororesin composition and electrical wire

Abstract

A method of producing a fluororesin composition includes copolymerizing at least tetrafluoroethylene with hexafluoropropylene so that a melt flow rate at 372 degree C. of the copolymer formed in the copolymerization changes from 0.05-5.0 grams/10 minutes to 10-60 grams/10 minutes. The tetrafluoroethylene/hexafluoropropylene copolymer can be used as a coating on an electrical wire.

What is claimed is: 
     
         1 . A method of producing a fluororesin composition, the method comprising:
 copolymerizing at least tetrafluoroethylene with hexafluoropropylene so that a melt flow rate at 372 degree C. of the copolymer formed in the copolymerization changes from 0.05-5.0 grams/10 minutes to 10-60 grams/10 minutes.   
     
     
         2 . The method of producing the fluororesin composition according to  claim 1 , wherein
 the copolymerizing at least tetrafluoroethylene with hexafluoropropylene so that the copolymer formed in the copolymerization with the melt flow rate at 372 degree C. of from 0.05-5.0 grams/10 minutes accounts for from 0.1-50 parts by weight of the entire copolymer in the end of the copolymerization.   
     
     
         3 . The method of producing the fluororesin composition according to  claim 2 , wherein
 the fluororesin composition is obtained in a process without a mixing process different from the copolymerizing.   
     
     
         4 . The method of producing the fluororesin composition according to claim wherein
 the copolymerizing at least tetrafluoroethylene with hexafluoropropylene so that the fluororesin composition in the end of the copolymerization has a complex viscosity of from 2.0×10 3  to 1.0.0×10 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.   
     
     
         5 . The method of producing the fluororesin composition according to  claim 2 , wherein
 the copolymerizing at east tetrafluoroethylene with hexafluoropropylene so that the fluororesin composition in the end of the copolymerization has a melt tension at 372 degree C. from 0.08 to 0.16 N.   
     
     
         6 . The method of producing the fluororesin composition according to  claim 2 , wherein
 the copolymerizing at least tetrafluoroethylene with hexafluoropropylene so that the fluororesin composition in the end of the copolymerization has 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 fewer than or equal to 50.   
     
     
         7 . The method of producing the fluororesin composition according to  claim 1 , wherein
 the copolymerizing at least tetrafluoroethylene with hexafluoropropylene so that the difference between the melting point of the copolymer formed in the copolymerization with the melt flow rate at 372 degree C. of from 0.05-5.0 grams/10 minutes and the melting point of the entire copolymer in the end of the copolymerization is less than 20 degree C.   
     
     
         8 . The method of producing the fluororesin composition according to  claim 7 , wherein
 the fluororesin composition is obtained in a process without a mixing process different from the copolymerizing.   
     
     
         9 . The method of producing the fluororesin composition according to  claim 7 , wherein
 the copolymerizing at least tetrafluoroethylene with hexafluoropropylene so that the fluororesin composition in the end of the copolymerization has 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.   
     
     
         10 . The method of producing the fluororesin composition according to  claim 1 , wherein
 the copolymerizing at least tetrafluoroethylene with hexafluoropropylene so that the difference between the melting point of the copolymer formed in the copolymerization with the melt flow rate at 372 degree C. of from 0.05-5.0 grams/10 minutes and the melting point of the entire copolymer in the end of the copolymerization is less than 10 degree C.   
     
     
         11 . The method of producing the fluororesin composition according to  claim 1 , wherein
 the fluororesin composition is obtained in a process without a mixing process different from the copolymerizing,   
     
     
         12 . The method of producing the fluororesin composition according to  claim 1 , wherein
 the copolymerizing at least tetrafluoroethylene with hexafluoropropylene so that the fluororesin composition in the end of the copolymerization has 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.   
     
     
         13 . The method of producing the fluororesin composition according to  claim 1 , wherein
 the copolymerizing at east tetraftuoroethytene with hexafluoropropylene so that the fluororesin composition in the end of the copolymerization has a melt tension at 372 degree C. from 0.08 to 0.16 N.   
     
     
         14 . The method of producing the fluororesin composition according to  claim 1 , wherein.
 the copolymerizing at east tetraftuoroethylene with hexafluoropropylene so that the fluororesin composition in the end of the copolymerization has 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 fewer than or equal to 50.   
     
     
         15 . The method of producing the fluororesin composition according to  claim 1 , further comprising
 drying the fluororesin composition to produce a powder.   
     
     
         16 . The method of producing the fluororesin composition according to  claim 15 , further comprising
 fluorination treating the powder using fluorine gas.   
     
     
         17 . The method of producing the fluororesin composition according to  claim 1 , further comprising
 pelletizing the fluororesin composition using melt extrusion to form at least one pellet.   
     
     
         18 . The method of producing the fluororesin composition according to  claim 17 , further comprising
 fluorination treating the pellet using fluorine gas.   
     
     
         19 . A method of producing an electrical wire using the method of producing the fluororesin composition according to  claim 1 , further comprising coating the electrical wire with the fluororesin composition. 
     
     
         20 . A method of producing an electrical wire using the method of producing the fluororesin composition according to  claim 1 , further comprising
 foam coating the electrical wire with the fluororesin composition.