Composite papyraceous material

Abstract

A composite papyraceous material comprising a fibrous polytetrafluoroethylene (in particular, fibrous powder thereof) and fibrous polyimide.

1 . A composite papyraceous material, comprising a fibrous polytetrafluoroethylene and a fibrous polyimide.  
   
   
       2 . The composite papyraceous material according to  claim 1 , wherein the fibrous polyimide is a crystalline fiber.  
   
   
       3 . The composite papyraceous material according to  claim 1 , wherein the polyimide is thermoplastic.  
   
   
       4 . The composite papyraceous material according to  claim 1 , wherein the polyimide is a polyimide represented by the following Chemical Formula (1):  
     
       
         
         
             
             
         
       
     
     wherein R represents a quadrivalent aromatic residue selected from monocyclic aromatic groups, condensed polycyclic aromatic groups, and uncondensed polycyclic aromatic groups in which the aromatic rings are bound to each other directly or via a crosslinking group; X represents a direct bond or a bivalent residue selected from hydrocarbon groups, a carbonyl group, an ether group, a thio group or a sulfonyl group; and Y 1  to Y 4  respectively represent a hydrogen or halogen atom or a monovalent residue selected from an alkyl group or an alkoxyl group.  
   
   
       5 . The composite papyraceous material according to  claim 1 , wherein the polyimide is a polyimide represented by the following Chemical Formula (2):  
     
       
         
         
             
             
         
       
     
   
   
       6 . The composite papyraceous material according to  claim 1 , wherein the fibrous polyimide is a short fiber having an average fiber diameter of 3 to 30 μm and an average fiber length of 1 to 15 mm.  
   
   
       7 . The composite papyraceous material according to  claim 1 , wherein the fibrous polytetrafluoroethylene is a fibrous powder that has an average fiber length of 100 to 5,000 μm and an average shape factor of 5 or more.  
   
   
       8 . The composite papyraceous material according to  claim 1 , wherein the polytetrafluoroethylene has a low temperature-sided peak area ratio of 88.5% or more with respect to the total peak area, as determined from the melting endothermic curve obtained at a heating rate of 5° C. per minute in differential scanning calorimetry analysis.  
   
   
       9 . The composite papyraceous material according to  claim 1 , wherein the fibrous polytetrafluoroethylene is thermally fused and bonded to the fibrous polyimide.  
   
   
       10 . A method for producing the composite papyraceous material according to  claim 1 , wherein the composite papyraceous material is prepared from the fibrous polytetrafluoroethylene and the polyimide by a papermaking method.  
   
   
       11 . The method for producing the composite papyraceous material according to  claim 10 , wherein the papermaking method is a wet papermaking method.  
   
   
       12 . The method for producing the composite papyraceous material according to  claim 11 , wherein the papermaking method include a dispersion step of dispersing a fibrous polytetrafluoroethylene, a mixing step of mixing a fibrous polyimide, a papermaking step, a pressurization step, and a drying step.  
   
   
       13 . The method for producing the composite papyraceous material according to  claim 12 , additionally including a heat-pressurizing step after the drying step.  
   
   
       14 . The composite papyraceous material according to  claim 1 , for used as any one selected from the group consisting of seamless belt, circuit board, stamping mold, filter, guard tube, flame-resistant paper material, solder pattern paper, papyraceous material for polishing, electrolyte film, lubricant member, sealing member and cushioning material.