Honeycomb filter for purifying exhaust gas

Abstract

An object of the present invention is to provide a honeycomb filter for purifying exhaust gases having a structure in that, even when comparatively large sealing material layer is included therein, there is hardly any increase in the amount of organic components contained in exhaust gases to be discharged. The present invention provides a honeycomb filter for purifying exhaust gases, having a structure in that a sealing material layer is formed on a circumference of a columnar body made of porous ceramics, which has a number of through holes placed in parallel with one another in the length direction with wall portion interposed therebetween, and the wall portion which separate the through holes from each other functions as a filter for collecting particulates, wherein the rate Sα of an area occupied by the sealing material layers to the total area of a cross-section including the through holes in the direction perpendicular to the through holes is set to 0.5% or more, and the rate Vα of organic components to the honeycomb filter for purifying exhaust gases is set to 0.5% by weight or less.

1 . A honeycomb filter for purifying exhaust gases which has a structure in which: 
 a columnar body made of porous ceramic comprises a number of through holes, said through holes being placed in parallel with one another in the length direction with wall portion interposed therebetween;    a sealing material layer is formed on a circumference portion of said columnar body; and    said wall portion which separates said through holes functions as a filter for collecting particulates,    wherein    a rate Sα of an area occupied by the sealing material layers to the total area of a cross-section including the through holes in the direction perpendicular to the through holes, in said honeycomb filter for purifying exhaust gases, is set to 0.5% or more, and    a rate Vα of organic components to the honeycomb filter for purifying exhaust gases is set to 0.5% by weight or less.    
     
     
         2 . The honeycomb filter for purifying exhaust gases according to  claim 1 , 
 wherein    a catalyst for purifying exhaust gases is supported inside the columnar body.    
     
     
         3 . A honeycomb filter for purifying exhaust gases which has a structure in which: 
 a plurality of a columnar porous ceramic member are combined with one another through a sealing material layer to form a ceramic block, each of said columnar porous ceramic member comprising a number of through holes, said through holes being placed in parallel with one another in the length direction with partition wall interposed therebetween;    a sealing material layer is formed on a circumference portion of said ceramic block; and    said partition wall which separates said through holes functions as a filter for collecting particulates,    wherein    a rate Sβ of an area occupied by the sealing material layers to the total area of a cross-section including the through holes in the direction perpendicular to the through holes, in said honeycomb filter for purifying exhaust gases, is set to 2% or more, and    a rate Vβ of organic components to said honeycomb filter for purifying exhaust gases is set to 0.5% by weight or less.    
     
     
         4 . The honeycomb filter for purifying exhaust gases according to  claim 3 , 
 wherein    a catalyst for purifying exhaust gases is supported inside the porous ceramic member.    
     
     
         5 . The honeycomb filter for purifying exhaust gases according to  claim 1 , 
 wherein    a sealing material layer has adhesive function.    
     
     
         6 . The honeycomb filter for purifying exhaust gases according to  claim 1 , 
 wherein    a sealing material layer contains an inorganic binder and/or inorganic particles.    
     
     
         7 . The honeycomb filter for purifying exhaust gases according to  claim 2 , wherein 
 a sealing material layer has adhesive function.    
     
     
         8 . The honeycomb filter for purifying exhaust gases according to  claim 3 , 
 wherein    a sealing material layer has adhesive function.    
     
     
         9 . The honeycomb filter for purifying exhaust gases according to  claim 4 , 
 wherein    a sealing material layer has adhesive function.    
     
     
         10 . The honeycomb filter for purifying exhaust gases according to  claim 2 , 
 wherein    a sealing material layer contains an inorganic binder and/or inorganic particles.    
     
     
         11 . The honeycomb filter for purifying exhaust gases according to  claim 3 , 
 wherein    a sealing material layer contains an inorganic binder and/or inorganic particles.    
     
     
         12 . The honeycomb filter for purifying exhaust gases according to  claim 4 , 
 wherein    a sealing material layer contains an inorganic binder and/or inorganic particles.    
     
     
         13 . The honeycomb filter for purifying exhaust gases according to  claim 5 , 
 wherein    a sealing material layer contains an inorganic binder and/or inorganic particles.    
     
     
         14 . The honeycomb filter for purifying exhaust gases according to  claim 7 , wherein 
 a sealing material layer contains an inorganic binder and/or inorganic particles.    
     
     
         15 . The honeycomb filter for purifying exhaust gases according to  claim 8 , 
 wherein    a sealing material layer contains an inorganic binder and/or inorganic particles.    
     
     
         16 . The honeycomb filter for purifying exhaust gases according to  claim 9 , 
 wherein    a sealing material layer contains an inorganic binder and/or inorganic particles.