Fluoropolymer and composition thereof

Abstract

The present invention provides a fluoropolymer capable of giving fluorine-containing molded materials and laminates excellent in moldability, productivity, interlaminar bonding and stress cracking resistance, in particular stress cracking resistance upon contacting with various liquid chemicals, without impairing such characteristics intrinsic in fluororesins as chemical resistance, solvent resistance, weathering resistance, antifouling properties, liquid chemical impermeability and nonstickiness. The present invention provides a fluoropolymer which is an oligomer-containing or oligomer-free fluoropolymer, wherein said oligomer has a molecular weight not higher than 10,000 and amounts to not more than 0.05% by mass relative to the fluoropolymer.

1 . An oligomer-containing or oligomer-free fluoropolymer, 
 wherein said oligomer has a molecular weight of not higher than 10,000 and amounts to not more than 0.05% by mass relative to the mass of said fluoropolymer.    
   
   
       2 . An oligomer-containing or oligomer-free fluoropolymer, 
 wherein said oligomer has a molecular weight of not higher than 35,000 and amounts to not more than 0.7% by mass relative to the mass of said fluoropolymer.    
   
   
       3 . The fluoropolymer according to  claim 1 , 
 which has a cohesive site and the number of said cohesive sites is 3 to 800 per 1×10 6  main chain carbon atoms of said fluoropolymer.    
   
   
       4 . The fluoropolymer according to  claim 3 , 
 wherein the cohesive site is carbonyl group, hydroxyl group and/or an amino group.    
   
   
       5 . The fluoropolymer according to  claim 4 , 
 wherein the carbonyl group is derived from at least one selected from the group consisting of formyl group, carboxyl group, a haloformyl group, ester bond, acid anhydride bond, a carbonate group, isocyanate group, an amide group, imide group, urethane bond and ureido group.    
   
   
       6 . The fluoropolymer according to  claim 1 , 
 which has tetrafluoroethylene unit content of not lower than 20 mole percent.    
   
   
       7 . The fluoropolymer according to  claim 1 , 
 which is a copolymer comprising tetrafluoroethylene unit and a perfluoro monomer unit derived from a perfluoro monomer represented by the general formula (i):      CF 2 ═CF—Rf 1    (i)    wherein Rf 1  represents —CF 3  or —ORf 2 , and Rf 2  represents a perfluoroalkyl group containing 1 to 5 carbon atoms.    
   
   
       8 . The fluoropolymer according to  claim 1 , which is a copolymer comprising 
 0 to 60 mole percent as a total of a perfluorovinyl ether unit derived from a perfluorovinyl ether represented by the general formula (ii):      CF 2 ═CF—ORf 2    (ii)    wherein Rf 2  represents a perfluoroalkyl group containing 1 to 5 carbon atoms, and/or a fluoroolefin unit derived from a fluoroolefin represented by the general formula (iii):      CX 1   2 ═CX 2 (CF 2 ) n X 3    (iii)    wherein X 1  and X 2  are the same or different and each represents hydrogen atom or fluorine atom, X 3  represents hydrogen atom, fluorine atom or chlorine atom, and n represents an integer of 1 to 10,    20 to 80 mole percent of tetrafluoroethylene unit and    20 to 80 mole percent of ethylene unit.    
   
   
       9 . The fluoropolymer according to  claim 1 , 
 which is a polymer having vinylidene fluoride unit content of not lower than 10 mole percent.    
   
   
       10 . The fluoropolymer according to  claim 1 , 
 which is a copolymer comprising 15 to 84 mole percent of vinylidene fluoride unit, 15 to 84 mole percent of tetrafluoroethylene unit and 0 to 30 mole percent of hexafluoropropylene unit.    
   
   
       11 . The fluoropolymer according to  claim 1 , 
 which is a fluorine-containing cohesive ethylenic polymer.    
   
   
       12 . A fluoropolymer composition comprising the fluoropolymer according to  claim 1 , and an electrically conductive filler, which gives an extrudate strand showing a surface resistance value of not higher than 10 9  Ω·cm/cm when charged into a melt indexer.  
   
   
       13 . A fluorine-containing molded material which is made from the fluoropolymer according to  claim 1 .  
   
   
       14 . A method of using fluorine-containing molded material, 
 wherein the fluorine-containing molded material according to  claim 13  is used in contact with a liquid.    
   
   
       15 . A laminate comprising the fluorine-containing molded material according to  claim 13  and an other layer, 
 wherein said other layer is made from an organic material, a metallic material and/or a vitreous material.    
   
   
       16 . The laminate according to  claim 15 , 
 wherein the organic material has a site having affinity for a fluoropolymer and/or reactivity with a fluoropolymer.    
   
   
       17 . The laminate according to  claim 16 , 
 wherein the site having affinity for the fluoropolymer and/or reactivity with the fluoropolymer includes hydroxyl group, a carbonate group, an amino group, an amide group, imide group, mercapto group, sulfonic acid group, an epoxy group, ester bond, carboxyl group and/or isocyanato group, and    said mercapto group, said sulfonic acid group and/or said carboxyl group may be in the form of a salt.    
   
   
       18 . The laminate according to  claim 15 , 
 wherein the organic material comprises a polyamide resin, a polyester resin, a polycarbonate resin, a polyamideimide resin, a polyethersulfone resin, a polysulfone resin, a urethane resin, a polyphenylene oxide resin, a polyetherimide resin, a polyacetal resin, a polyvinyl alcohol resin, an ethylene/vinyl alcohol resin and/or a modified polyolefin resin.    
   
   
       19 . The laminate according to  claim 15 , which is one laminated by melt-coextrusion molding.  
   
   
       20 . A fluorine-containing fabricated article made with the fluorine-containing molded material according to  claim 13 , 
 said fluorine-containing fabricated article is a film, a sheet, a hose or a tube.    
   
   
       21 . The fluorine-containing fabricated article according to  claim 20 , wherein the hose is a corrugated hose and the tube is a corrugated tube.  
   
   
       22 . The fluorine-containing fabricated article according to  claim 20 , 
 wherein the tube is a piping tube for a paint, a tube for transport of a drink, a tube for transport of a liquid food, a tube for transport of a liquid chemical, a tube for transport of a fuel, or a hose for transport of a crude oil or a crude oil refined product.    
   
   
       23 . A fluorine-containing molded material which is made from the fluoropolymer composition according to  claim 12 .  
   
   
       24 . A fluorine-containing fabricated article made with the laminate according to  claim 15 , 
 said fluorine-containing fabricated article is a film, a sheet, a hose or a tube.