Fep pellet

Abstract

An FEP pellet having a volatile content of 0.2% by weight or less. The FEP pellet satisfies the following requirements (i) and (ii) when used to form a insulating material coating a core wire by extrusion coating at a coating speed of 2,800 ft/min.: (i) an adhesive strength between the insulating material and said core wire of 0.8 kg or more; and (ii) an average number of cone-breaks in the insulating material of one or less per 50,000 feet of the coated core wire.

1 . An FEP pellet having a volatile content of 0.2% by weight or less, 
 wherein said FEP pellet satisfies the following requirements (i) and (ii) when used to form an insulating material coating a core wire by extrusion coating at a coating speed of 2,800 ft/min.:    (i) an adhesive strength between said insulating material and said core wire of 0.8 kg or more; and    (ii) an average number of cone-breaks in said insulating material of one or less per 50,000 ft of the coated core wire.    
     
     
         2 . The FEP pellet as claimed in  claim 1 , 
 which comprises an FEP having an adhesion terminus,    said adhesion terminus comprising at least one functional group species selected from the group consisting of —COOM, —SO 3 M, —OSO 3 M, —SO 2 F, —SO 2 Cl, —COF, —CH 2 OH, —CONH 2  and —CF═CF 2 , and    M being the same or different and representing an alkyl group, a hydrogen atom, a metallic cation or a quaternary ammonium cation.    
     
     
         3 . The FEP pellet as claimed in  claim 2 , 
 wherein the adhesion terminus comprises —COF, —COOH and/or —CH 2 OH, and    the total number of —COF, —COOH and —CH 2 OH is 15 to 150 per 1,000,000 carbon atoms.    
     
     
         4 . The FEP pellet as claimed in  claim 3 , 
 wherein the total number of —COF and —COOH is 2 to 25, and    the number of —COF is 0 to 5, —COOH is 2 to 25 and —CH 2 OH is 0 to 148 per 1,000,000 carbon atoms.    
     
     
         5 . The FEP pellet as claimed in  claim 1 ,  2 ,  3  or  4 , having a melt flow rate of 30 (g/10 minutes) or more.  
     
     
         6 . The FEP pellet as claimed in  claim 1 ,  2 ,  3 ,  4  or  5 , having a die swell of 18 to 35%.  
     
     
         7 . The FEP pellet as claimed in  claim 6 , having an MIT bending life of 4,000 cycles or more, and 
 said FEP pellet comprising a tetrafluoroethylene/hexafluoro-propylene copolymer modified with perfluoro(alkyl vinyl ether).    
     
     
         8 . The FEP pellet as claimed in  claim 7 , 
 wherein said perfluoro(alkyl vinyl ether) is perfluoro(propyl vinyl ether).    
     
     
         9 . An FEP pellet 
 comprising a tetrafluoroethylene/hexafluoro-propylene copolymer modified with perfluoro(alkyl vinyl ether),    having a melt flow rate of 30 (g/10 minutes) or more, and    having a volatile content of 0.2% by weight or less,    wherein said tetrafluoroethylene/hexafluoro-propylene copolymer modified with perfluoro(alkyl vinyl ether) has an adhesion terminus,    said adhesion terminus comprisisng at least one functional group species selected from the group consisting of —COOM, —SO 3 M, —OSO 3 M, —SO 2 F, —SO 2 Cl, —COF, —CH 2 OH, —CONH 2  and —CF═CF 2 , and    M being the same or different and representing an alkyl group, a hydrogen atom, a metallic cation or a quaternary ammonium cation.    
     
     
         10 . The FEP pellet as claimed in  claim 9 , 
 wherein said adhesion terminus comprises —COF, —COOH and/or —CH 2 OH, and    the total number of —COF, —COOH and —CH 2 OH is 15 to 150 per 1,000,000 carbon atoms.    
     
     
         11 . The FEP pellet as claimed in  claim 10 , 
 wherein the total number of —COF and —COOH is 2 to 25, and    the number of —COF is 0 to 5, —COOH is 2 to 25 and —CH 2 OH is 0 to 148 per 1,000,000 carbon atoms.    
     
     
         12 . The FEP pellet as claimed in  claim 9 , 
 wherein the tetrafluoroethylene/hexafluoro-propylene copolymer modified with perfluoro(alkyl vinyl ether) is one having a weight ratio of contents of tetrafluoroethylene, hexafluoropropylene and perfluoro(alkyl vinyl ether) as monomer components of 70 to 90:10 to 20:0 to 10.    
     
     
         13 . The FEP pellet as claimed in  claim 9 , 
 wherein said perfluoro(alkyl vinyl ether) is perfluoro(propyl vinyl ether).    
     
     
         14 . The FEP pellet as claimed in  claim 9 , 
 wherein the melt flow rate is 30 to 50 (g/10 minutes).    
     
     
         15 . An insulating material formed from the FEP pellet as claimed in  claim 1 .  
     
     
         16 . An insulated cable comprising a core wire extrusion-coated with an insulating material prepared from the FEP pellet as claimed in  claim 1 .  
     
     
         17 . A process for insulating a core wire, which comprises extrusion coating the core wire with a molten insulating material comprising the FEP pellet as claimed in  claim 1.