Carbon composite materials comprising particles of metal carbides dispersed therein and method for producing the same

Abstract

This invention provides carbon composite materials, which comprise metal carbide particles, at least the particle surfaces or the entirety of which are metal carbides, synthesized in situ from a metal source, i.e., at least one member selected from the group comprising metal particles, metal oxide particles, and composite metal oxide particles, and a carbon source, i.e., a thermosetting resin, dispersed in a carbon, carbon fiber, or carbon/carbon fiber matrix, and contain no free metal particles. This invention also provides a method for producing such composite carbon materials, which enables the production of carbon composite materials having a high coefficient of friction, high thermostability, and abrasion resistance.

1 - 18 . (canceled)  
   
   
       19 . Friction materials, which comprise metal carbide particles, at least the particle surfaces or the entirety of which are metal carbides, synthesized in situ from a metal source, i.e., at least one member selected from the group comprising metal particles, metal oxide particles, and composite metal oxide particles, and a carbon source, i.e., a thermosetting resin, dispersed in a carbon, carbon fiber, or carbon/carbon fiber matrix, and contain no free metal particles.  
   
   
       20 . The friction materials according to  claim 19 , wherein the metal oxide particles or composite metal oxide particle are at least one type of metal selected from the group comprising SiO 2 , TiO 2 , ZrO 2 , Al 2 O 3 , WO 3 , CrO 3 , or ZnO particles obtained by oxidizing metal powders.  
   
   
       21 . The friction materials according to  claim 20 , wherein the metal oxide particles are SiO 2  particles and the metal carbide particles are SiC particles.  
   
   
       22 . The friction materials according to  claim 20 , wherein the composite metal oxide particles are SiO 2 /ZrO 2  composite metal oxide particles and the metal carbide particles are SiC/ZrC composite carbide particles.  
   
   
       23 . The friction materials according to  claim 21 , wherein the SiO 2  particles are selected from among spherical silica particles obtained by a reaction between silicon metal and oxygen, spherical silica particles obtained by melting fragmented silica, and fragmented silica particles.  
   
   
       24 . A method for producing friction materials comprising metal carbide particles dispersed therein, wherein at least one of metal particles, metal oxide particles, or composite metal oxide particles is dispersed in a thermosetting resin to obtain a slurry mixture, carbon fibers are impregnated with the slurry mixture, and carbonization and calcination are carried out to carbonize the thermosetting resin to generate metal carbides in situ, at least the particle surfaces or the entirety of the particles of which are metal carbides.  
   
   
       25 . The method for producing friction materials according to  claim 24 , wherein the metal oxide particles or composite metal oxide particles are at least one member selected from the group comprising SiO 2 , TiO 2 , ZrO 2 , Al 2 O 3 , WO 3 , CrO 3 , and ZnO particles obtained by oxidizing metal powders.  
   
   
       26 . The method for producing friction materials according to  claim 25 , wherein the metal oxide particles are SiO 2  particles and the metal carbide particles are SiC particles.  
   
   
       27 . The method for producing friction materials according to  claim 25 , wherein the composite metal oxide particles are SiO 2 /ZrO 2  composite metal oxide particles and the metal carbide particles are SiC/ZrC composite carbide particles.  
   
   
       28 . The method for producing friction materials according to  claim 26 , wherein the SiO 2  particles are selected from among spherical silica particles obtained by a reaction between silicon metal and oxygen, spherical silica particles obtained by melting fragmented silica, and fragmented silica particles.  
   
   
       29 . The method for producing friction materials according to  claim 24 , wherein the thermosetting resin is at least one member selected from the group comprising phenol resin, epoxy resin, unsaturated polyester resin, acrylic resin, urea resin, furan resin, diallyl phthalate resin, melamine resin, polyurethane resin, and aniline resin.  
   
   
       30 . The method for producing friction materials according to  claim 24 , wherein a step of thermocompression bonding is carried out by laminating the impregnation product, following the step of impregnation and prior to the step of carbonization.  
   
   
       31 . The method for producing friction materials according to  claim 24 , wherein, prior to in situ production of metal carbide particles by the process of calcination, a step of impregnating the carbon fiber materials with a slurry mixture comprising at least one type of metal oxide particles dispersed in a thermosetting resin for carbonization is carried out two or more times.  
   
   
       32 . The method for producing friction materials according to  claim 24 , wherein, following in situ production of metal carbide particles by the process of calcination, a step of impregnating the carbon fiber materials with a slurry mixture comprising at least one type of metal oxide particles dispersed in a thermosetting resin for carbonization is iterated one or more times.  
   
   
       33 . The method for producing friction materials according to  claim 24 , wherein carbonization is carried out in an inert gas atmosphere at 200° C. to 1600° C.  
   
   
       34 . The method for producing friction materials according to  claim 24 , wherein calcination is carried out in an inert gas atmosphere at 1650° C. or higher.  
   
   
       35 . The friction materials according to  claim 19 , wherein the friction materials are brake rotor and/or pad materials.