Manufacturing of silica glass from silica power consolidated with tetramethoxysilane oligomer-derived binder

A sol-gel method was used for manufacturing silica glass. A new method involved making a bulk by hardening a slurry of silica powder with a methoxysilane-derived binder. The bulk manufactured by this method was successfully dried and sintered to produce the silica glass. The significant results of this method are as follows: (1) the amount of reaction water in synthesizing the binder was less than the amount with which the methoxy group in the methoxysilane was completely hydrolyzed and poly-condensed, (2) the methoxy group partially survived in the binder and (3) this survival caused the binder to be flexible. When an oligomer of tetramethoxysilane was used as a starting material the optimum amount of water for the bulk manufacturing is 2.3 equivalents. The bulk manufactured by this method was dried and sintered to form the purified silica glass without the generation of cracks.