The method of manufacturing water-resistant aluminum nitride

The present invention, in a solvent, the aluminum nitride powder dispersed in the solvent such that the ratio of the median diameter / primary particle diameter is 1.4 to 5, phosphoric acid, metal salts of phosphoric acid and having 12 or less carbon atoms subjected to at least one phosphorus acid compound contacted to phosphoric acid compound treatment step is selected from the group consisting of organic phosphoric acid having an organic group of the on the surface of the aluminum nitride powder, the phosphate compound, orthophosphoric acid characterized in that is present in a proportion of 0.5 to 10 mg /