| 摘要 |
PURPOSE:To prepare the titled stock having low residual water content, by the two-step heating and sintering of an aggregate of fine glass powder obtained by the thermal reaction of raw material gases, in a gaseous atmosphere containing a halogen and having dehydrative action. CONSTITUTION:In the preparation of glass fiber for light-transmission, the raw material gases are heated and reacted to synthesis fine glass powder, which is deposited and grown on a rotating starting member to obtain an aggregate of fine powder. The aggregate is subjected to (1) the first temperature-raising process which comprises heating in a gaseous atmosphere containing a halogen or a halide (e.g. Cl2, SOCl2, etc.) and having a dehydrative action, to effect the sintering of the aggregate, (2) the holding process which comprises holding of the aggregate at a temperature at which the shrinkage of the aggregate becomes substantial, and (3) the second temperature-raising process to heat the aggregate to the glass-forming temperature. A clear glass stock having suppressed contamination with impurities and surface irregularity, and having a residual water content of about <=0.1ppm, can be prepared by this method. |
