| 摘要 |
PURPOSE:To improve the yield of products and to reduce the producing time by placing a wet gel obtained from a metal alkoxide as the essential raw material in an air-permeable vessel, and then depressurizing the vessel. CONSTITUTION:An aq. soln. contg. a metal alkoxide as the essential component is heated, agitated, and mixed to form a mixed sol, which is transferred into an air-permeable vessel 2 made of a porous polymer, etc. The vessel 2 is then put in a reduced-pressure repository 3, the surroundings of the vessel are depressurized, and the raw sol is gelled and dried at appropriate temp. and humidity. The dry gel 4 is finally sintered at about 1,000-1,200 deg.C to obtain a product. Since the wet gel is dried by using the air-permeable vessel 2, the whole surface of the gel is uniformly dried. Moreover, since the surroundings of the vessel 2 are depressurized, the drying time is drastically reduced. As a result, the yield of products is improved, and the producing time is reduced as a whole. |
