摘要 |
PURPOSE:To obtain a large-sized lumpy glass excellent in optical uniformity by gelling at specified temperatures a liquid sol poured into a closed vessel followed by drying and sintering. CONSTITUTION:A mixture comprising a metal alkoxide, ethanol, water and ammonia water is agitated and left at rest to allow particles to be grown and aged. The resultant system is then concentrated under reduced pressure to prepare a dispersion of fine particles of metal oxide. Thence, this dispersion is mixed with a solution prepared by adding a hydrochloric acid solution to metal alkoxide and making a hydrolysis under agitation. The resultant system is then incorporated with ammonia water to obtain a liquid sol of the objective glass component composition. Thence, this sol is poured into a closed vessel of desired shape and cooled to <=20 deg.C. The resultant wet gel is then dried and sintered. |