| 摘要 |
PURPOSE:To obtain a catalyst high in reactivity and long in life, by a method wherein a compound containing an ammonium radical is used as the stock material of the catalyst and a slurry comprising the stock material and water is reacted under heating for a long time. CONSTITUTION:A compound containing an ammonium radical and a compound containing no nitrate radical are used as the stock material of a catalyst for preparing methacrylic acid. In addition, prior to concentrating a slurry comprising the catalyst stock material and water to dryness, a process wherein said slurry is reacted under heating at 80 deg.C for one hour or more to prepare a heteropolyacid salt of a P:Mo=1:9 type as a catalyst precursor is included. By this method, a catalyst high in reactivity, not lowered in reactivity even if molded into an industrial catalyst and made longer in life is obtained. |
