METHOD FOR FORMING ARTICLE USING SOL-GEL METHOD

摘要

PROBLEM TO BE SOLVED: To provide a method for forming an article using sol-gel method capable of forming a more stronger sol-gel body and/or reducing drying time. SOLUTION: A silica body useful for forming an optical fiber preform has at least ultimate strength of 20 MPa with the 10 wt.% decrease of water. It is considered that the strength of the silica body is obtained by precipitating silica on the contact part with the adjacent silica particle to form neck region. The resultant meshlike structure gives the strength to the gel body so that the gel body is capable of drying in a more severe condition compared with a gel body produced by the conventional sol-gel method and has more strength even in handling. The controlled precipitate is attained by conducting gelation at >=pH about 10.5 to be high in the solubility of silica and starting drying. The solubilized silica is likely to be precipitated by the controlled method on the contact part, where is the min. energy part, with the adjacent silica particle by gelating at the pH level and drying.