| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for producing a porous glass where a large-sized porous TiO<SB>2</SB>-SiO<SB>2</SB>glass is stably produced in a high yield. <P>SOLUTION: In the method for producing the porous glass, a TiO<SB>2</SB>precursor and an SiO<SB>2</SB>precursor are supplied from the center nozzle of a multiple pipe burner where a plurality of gas-supplying nozzles are arranged to be concentric, glass fine particles are generated by hydrolysis in an oxyhydrogen flame from the multiple pipe burner and then the porous glass is produced by accumulating and growing the generated glass fine particles on a base material. The porous glass is produced under such conditions that a gas residence time T (sec) in the oxyhydrogen flame calculated by dividing a distance L (mm) from the tip of the multiple pipe burner to the accumulated surface of the glass fine particles on the base material by the average flow rate V (m/sec) of all gases supplied from the multiple pipe burner satisfies 0.002≤T≤0.0045, the flow rate center of gravity r' (mm) of all the gases supplied from the multiple pipe burner normalized by the radius R (mm) of the multiple pipe burner satisfies 0.51≤r'≤0.58 and the average temperature t (°C) of the accumulated surface of the glass fine particles satisfies 1,100≤t<1,400. <P>COPYRIGHT: (C)2011,JPO&INPIT |
