Particulate aluminum nitride and method for producing thereof

Abstract

A method for producing aluminum nitride includes preparing a slurry containing pseudoboemite and carbon, filtrating and dehydrating the slurry to form a precursor, and calcinating the obtained precursor in an atmosphere containing nitrogen. The slurry is prepared by dispersing a carbon powder in an aqueous solution having a pH adjusted in a range of 8.5 to 9.5, and then synthesizing pseudoboemite by using at least one of an aluminum salt and aluminic acid as an aluminum source, while maintaining the pH of the reaction mixture in a range of 8.5 to 9.5. The aluminum nitrite obtained by the method has a three-dimensional network structure and thus exhibits excellent heat-conducting property and can be suitably used as a filler for an electronic material.

1 . A method for producing aluminum nitride comprising: 
 preparing a slurry containing pseudoboehmite and carbon;    filtrating and dehydrating the prepared slurry to obtain a precursor; and    calcinating the obtained precursor in an atmosphere containing nitrogen.    
     
     
         2 . The method for producing the aluminum nitride according to  claim 1 , wherein the pseudoboehmite is fibrous pseudoboehmite having an aspect ratio of not less than 10.  
     
     
         3 . The method for producing the aluminum nitride according to  claim 1 , wherein the slurry containing the pseudoboehmite and the carbon is prepared by synthesizing the pseudoboehmite in a solution containing the carbon.  
     
     
         4 . The method for producing the aluminum nitride according to  claim 3 , wherein the pseudoboehmite is synthesized by a neutralization reaction in which an aluminum source is at least one of aluminum salt and aluminic acid.  
     
     
         5 . The method for producing the aluminum nitride according to  claim 3 , wherein a carbon source is dispersed in an aqueous solution having pH of a range of 8.5 to 9.5 to prepare an aqueous solution containing the carbon, and the pseudoboehmite is synthesized while maintaining pH of the aqueous solution in a range of 8.5 to 9.5.  
     
     
         6 . The method for producing the aluminum nitride according to  claim 5 , wherein the pseudoboehmite is synthesized while maintaining a temperature of the aqueous solution in a range of 55 to 75° C.  
     
     
         7 . The method for producing the aluminum nitride according to  claim 1 , further comprising granulating the prepared slurry to have an average particle size of 5 to 1,000 μm.  
     
     
         8 . The method for producing the aluminum nitride according to  claim 7 , wherein the granulation is performed with a spray dryer.  
     
     
         9 . The method for producing the aluminum nitride according to  claim 7 , wherein the granulation is performed so that 20 to 50% of all granules exist within a range of ±20% of the average particle size of the precursor.  
     
     
         10 . Aluminum nitride particles produced by the production method as defined in  claim 1 , wherein a three-dimensional network structure is provided in the particle.  
     
     
         11 . The aluminum nitride particles according to  claim 10 , wherein fiber, which constitutes a network of the three-dimensional network structure, has an aspect ratio of not less than 7.  
     
     
         12 . The aluminum nitride particles according to  claim 10 , which are used as a filler for a package molding compound.