Heat dissipating member and method for producing the same

Abstract

The present invention provides a heat dissipating member having excellent heat dissipation properties and suitable for use in an oil environment. The present invention is a heat dissipating member including: a porous base material containing a fluorine resin and a thermally-conductive filler; and an oil contained in pores of the porous base material. The fluorine resin contains polytetrafluoroethylene. The heat dissipating member can be produced, for example, by a method including the steps of: (1) stacking and rolling together a plurality of sheet-shaped formed bodies each containing a polytetrafluoroethylene-containing fluorine resin, a thermally-conductive filler, and a molding aid, so as to obtain a rolled laminated sheet; (2) removing the molding aid from the obtained rolled laminated sheet to obtain a porous base material; and (3) impregnating the obtained porous base material with an oil.

1 . A heat dissipating member comprising:
 a porous base material containing a fluorine resin and a thermally-conductive filler; and   an oil contained in pores of the porous base material, wherein   the fluorine resin contains polytetrafluoroethylene.   
     
     
         2 . The heat dissipating member according to  claim 1 , wherein the fluorine resin further contains at least one selected from the group consisting of perfluoroalkoxy resins and tetrafluoroethylene-hexafluoropropylene copolymers. 
     
     
         3 . The heat dissipating member according to  claim 1 , containing the oil in an amount of 1% by mass or more. 
     
     
         4 . The heat dissipating member according to  claim 1 , wherein the oil is at least one selected from the group consisting of automatic transmission fluids, engine oils, universal oils, gear oils, hydrostatic transmission oils, and silicone oils. 
     
     
         5 . The heat dissipating member according to  claim 1 , wherein the thermally-conductive filler is at least one insulating filler selected from the group consisting of boron nitride, aluminum nitride, alumina, silicon nitride, and magnesium oxide. 
     
     
         6 . The heat dissipating member according to  claim 1 , wherein the thermally-conductive filler is at least one electrically-conductive filler selected from the group consisting of graphite, carbon black, carbon fibers, metal fibers, and metal particles. 
     
     
         7 . The heat dissipating member according to  claim 1 , packaged in a pack with an oxygen barrier film. 
     
     
         8 . A method for cooling a vehicle motor, comprising using the heat dissipating member according to  claim 1 . 
     
     
         9 . A method for producing a heat dissipating member, comprising the steps of:
 (1) stacking and rolling together a plurality of sheet-shaped formed bodies each containing a polytetrafluoroethylene-containing fluorine resin, a thermally-conductive filler, and a molding aid, so as to obtain a rolled laminated sheet;   (2) removing the molding aid from the obtained rolled laminated sheet to obtain a porous base material; and   (3) impregnating the obtained porous base material with an oil.   
     
     
         10 . The method for producing a heat dissipating member according to  claim 9 , further comprising a step (4) of subjecting the porous base material to pressure molding between the step (2) and the step (3). 
     
     
         11 . The method for producing a heat dissipating member according to  claim 9 , wherein the step (3) is performed by immersing the porous base material in an oil after removing air from pores of the porous base material, and then by pressurizing the oil.