| 摘要 |
PURPOSE: Provided is a method for manufacturing transparent silica glass with good transparency and near theoretical density by vacuum sintering silica compacts derived from the silica sol comprising silica powder(fumed silica), dispersant and polyethyl oxazoline-dissolved water. CONSTITUTION: The method for manufacturing transparent silica glass comprises the steps of: (i) preparing a silica sol by mixing silica powder, fumed silica (40-100nm), dispersant such as tetramethyl ammonium hydroxide(TMAH) or tetraethyl ammonium hydroxide(TEAH), and deionized water containing polyethyl oxazoline(PEOZ), being 1,000-1,000,000 in molecular weight, as a binder; (ii) adding gelling agents, aliphatic ester compounds such as methyl lactate and ethyl formate; (iii) pouring the silica sol into a mold and gelling; (iv) demolding to get a bulky gel; (v) drying at 30-80deg.C; (vi) thermal treating at 5-50deg.C/hr to 300-600deg.C for removal of organics; (vii) thermal treating at 100deg.C/hr to 500-1000deg.C in Cl2 atmosphere for removal of hydroxide ions and metallic impurities; (viii) sintering at 1350deg.C for 1hr under vacuum between 10-1 and 10-6 torr. The step for removing foams in silica sol is optionally added to the next of step (i). |
