| 摘要 |
PURPOSE:To stably obtain the subject material in high yield at a low cost by regulating feed rate of a glass raw material, blowing and depositing the raw material on a starting rod having a prescribed outside diameter. CONSTITUTION:A glass raw material consisting of an SiO2 source, such as SiCl4, a combustible gas, such as H2, and an inert gas, such as Ar, are fed and blown through a burner made of quartz glass, such as concentric circular burner (e.g. quadruple layers 7), onto materials 2 to 5 having the tip part of the maximum outside diameter of >=70% based on the outside diameter of a desired cellular preform 1. A glass raw material feed rate is then regulated to <=1/2 of that in a stationary state in the growth initial period of the preform 1 and deposited to produce a silica cellular material. The resultant material 1, as necessary, is treated with a chlorinating agent, such as SOCl2, and then calcined at 1,400-1,550 deg.C in the presence of He gas, etc., to produce a transparent quartz glass. |
