| 摘要 |
PROBLEM TO BE SOLVED: To obtain Si3 N4 powder excellent in oxidation resistance, dispersibility to an aq. solvent and easy to be sintered at a low cost by coating the surface of Si3 N4 powder having a specified specific surface area or above with polycarboxylic acid amide. SOLUTION: Lower alcohol such as ethanol or acetone and ammonium polycarboxylate are added by 0.01-5 pts.wt. each to 100 pts.wt. Si3 N4 particles and they are wet-pulverized and mixed. Since the ammonium polycarboxylate is easily dehydrated by external stress applied by the pulverization and sticks uniformly to the surface of the Si3 N4 in the form of polycarboxylic acid amide, the objective Si3 N4 powder having >=6m<2> /g specific surface area surface-coated with polycarboxylic acid amide is obtd. Ammonium polyacrylate, ammonium polymethacrylate, ammonium polymaleate or ammonium polyfumarate is suitable for use as the ammonium polycarboxylate. |
