Fluororesin, method of reforming fluororesin, sliding member, and sliding device

Abstract

There is provided a fluororesin which has a low friction coefficient, superior wear resistance and a superior friction characteristic in the presence of a lubricating oil and/or an operating oil. The fluororesin has a structure in which some of the hydrogen atoms and/or fluorine atoms bonded to carbon atoms of a main frame resin are substituted with an oxygen-containing functional group. Visible light transmittance in a wavelength of 600 nm is increased as compared with that of the main frame resin. There is also provided a method of reforming a fluororesin, comprising extracting some of the hydrogen atoms and/or fluorine atoms bonded to carbon atoms of a main frame resin to introduce an unsaturated bond; and applying dissociation energy of the unsaturated bond in the presence of oxygen. There are further provided a sliding member, a sliding apparatus and a sliding system.

1 . A fluororesin comprising a substituted main frame resin, said substituted main frame resin comprising carbon atoms, at least one fluorine atom and at least one oxygen-containing functional group, in which at least one atom selected from the group consisting of hydrogen atoms and fluorine atoms bonded to carbon atoms of a main frame resin is substituted with said oxygen-containing functional group, said at least one fluorine atom being bonded to at least one of said carbon atoms of said substituted main frame resin, said fluororesin having a visible light transmittance in a wavelength of 600 nm which is greater than a visible light transmittance in a wavelength of 600 nm of said main frame resin.  
   
   
       2 . The fluororesin according to  claim 1 , wherein said visible light transmittance in the wavelength of 600 nm of said fluororesin is about 10% or more.  
   
   
       3 . The fluororesin according to  claim 1 , wherein a surface energy of said fluororesin is in the range of from about 20 to about 40 dyne/cm.  
   
   
       4 . The fluororesin according to  claim 1 , wherein said main frame resin comprises at least one resin selected from the group consisting of tetrafluoroethylene resin, perfluoroethylene polypropylene resin, perfluoroalkoxy resin and vinylidene fluoride resin.  
   
   
       5 . A fluororesin precursor comprising a modified main frame resin in which at least one atom selected from the group consisting of hydrogen atoms and fluorine atoms bonded to carbon atoms of a main frame resin is extracted to introduce an unsaturated bond.  
   
   
       6 . The fluororesin precursor according to  claim 5 , wherein said main frame resin comprises at least one resin selected from the group consisting of tetrafluoroethylene resin, perfluoroethylene polypropylene resin, perfluoroalkoxy resin and vinylidene fluoride resin.  
   
   
       7 . A method of reforming a fluororesin, said method comprising: extracting at least one atom selected from the group consisting of hydrogen atoms and fluorine atoms bonded to carbon atoms of a main frame resin to introduce an unsaturated bond; and applying dissociation energy of said unsaturated bond in the presence of oxygen.  
   
   
       8 . The method of reforming a fluororesin according to  claim 7 , wherein in said extracting at least one atom to introduce an unsaturated bond, a component other than a component containing the same monomer as that of the main frame resin is not present.  
   
   
       9 . The method of reforming a fluororesin according to  claim 7 , further comprising applying dissociation energy of said unsaturated bond at an oxygen partial pressure of at least about 13.3 kPa.  
   
   
       10 . The method of reforming a fluororesin according to  claim 7 , further comprising applying dissociation energy of said unsaturated bond by heat energy.  
   
   
       11 . The method of reforming a fluororesin according to  claim 10 , further comprising at least one of mixing said fluororesin and molding said fluororesin, wherein said heat energy is applied in at least one of said mixing said fluororesin and said molding said fluororesin.  
   
   
       12 . The method of reforming a fluororesin according to  claim 11 , wherein said molding is selected from the group consisting of injection molding, ram molding and compression molding.  
   
   
       13 . A sliding member comprising a sliding portion, said sliding portion comprising a fluororesin according to  claim 1 .  
   
   
       14 . The sliding member according to  claim 13 , wherein a content of said fluororesin in said sliding portion is in a range of from about 5 to about 70%.  
   
   
       15 . A sliding apparatus comprising a sliding member as recited in  claim 13  and at least one oil material, said oil material being selected from the group consisting of lubricating oil and operating oil, at least a portion of said oil material being in contact with at least a portion of said sliding member.  
   
   
       16 . A sliding system comprising a sliding apparatus as recited in  claim 15  and a target material, wherein the target material comprises a sliding surface which has a surface roughness of Rz=about 10 μm or less and wherein the sliding member slides on the sliding surface.