US 11,834,362 B2
Method for producing multilayered silica glass body
Tatsuya Mori, Koriyama (JP); and Akihiko Sugama, Koriyama (JP)
Assigned to Heraeus Quarzglas GmbH & Co. KG, Hanau (DE); and Shin-Etsu Quartz Products Co., Ltd., Tokyo (JP)
Appl. No. 17/286,062
Filed by Heraeus Quarzglas GmbH & Co. KG, Hanau (DE); and SHIN-ETSU Quartz Products Co., Ltd., Tokyo (JP)
PCT Filed Sep. 3, 2019, PCT No. PCT/JP2019/034534
§ 371(c)(1), (2) Date Apr. 16, 2021,
PCT Pub. No. WO2020/079975, PCT Pub. Date Apr. 23, 2020.
Claims priority of application No. 2018-195764 (JP), filed on Oct. 17, 2018.
Prior Publication US 2021/0371321 A1, Dec. 2, 2021
Int. Cl. C03B 17/02 (2006.01); C03B 18/02 (2006.01); C03C 17/00 (2006.01); C03C 17/02 (2006.01); C03C 23/00 (2006.01)
CPC C03B 18/02 (2013.01) [C03C 17/007 (2013.01); C03C 17/02 (2013.01); C03C 23/007 (2013.01); C03C 2218/117 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A method for producing a multilayer-structure silica glass body, in which a transparent silica glass layer is provided on a surface of a siliceous substrate comprising a siliceous material, the method comprising:
preparing the siliceous substrate;
preparing a silica slurry in which silica particles are dispersed in a liquid;
applying the silica slurry to the surface of the siliceous substrate;
smoothing the silica slurry coated on the surface of the siliceous substrate by applying vibration to the siliceous substrate;
drying the smoothed silica slurry; and
vitrifying the dried silica slurry by means of heating to form the transparent silica glass layer;
wherein the silica slurry contains silica large particles comprising a siliceous material and having a particle size of between 200 μm and 700 μm, and silica medium particles comprising a siliceous material and having a particle size of 30 μm or more, and less than 200 μm;
the total mass of the silica large particles and the silica medium particles contained in the silica slurry is 80% or more of the mass of all particles comprising a siliceous material contained in the silica slurry; and
the silica large particle mass/silica medium particle mass, which is a ratio of the mass of the silica large particles and the mass of the silica medium particles, is set at between 0.25 and 7.0.