| 摘要 |
PURPOSE:To produce transparent glass contg. no crack by separating particles obtd. by hydrolysis of metal alkoxide from a dispersing medium, mixing the particles with an optional solvent and drying, and controlling the particle size and bulk density of dry gel easily. CONSTITUTION:Alkoxide of at least one element selected from Si, B, Ge, Al, Sb, Pb, etc. is hydrolyzed in a dispersing medium such as water, alcohol, etc. and dried by spray drying, etc. while controlling the particle size. Obtd. particles are mixed with an optional solvent (e.g. water) contg. less impurities having adverse effect on optical characteristics, adding, if necessary, at least one element or compd. selected from B, Ge, P, Al, Sb, etc., drying slowly or drying by freezing. Thus, easily sinterable dry gel having large pore size is obtd. with a small dispersion. The dry gel is then sintered at lower temp. (e.g. 1,200-1,500 deg.C) than the m.p. of the component in an atmosphere such as He to eliminate pores. Thus, a transparent glass is obtd. |
