Method for producing multilayered silica glass body

Patent metadata

Field	Value
Publication number	US-11834362-B2
Application number	US-201917286062-A
Country	US
Kind code	B2
Filing date	Sep 3, 2019
Priority date	Oct 17, 2018
Publication date	Dec 5, 2023
Grant date	Dec 5, 2023

Abstract

One aspect is a method for producing a multilayered silica glass body. The method involves producing a multilayered silica glass body in which a transparent silica glass layer is provided on the surface of a siliceous substrate made of a siliceous material. The method includes 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, leveling the silica slurry applied to the surface of the siliceous substrate by applying vibration to the siliceous substrate, drying the leveled silica slurry, and vitrifying the dried silica slurry by heating to form a transparent silica glass layer. As a result, a transparent silica glass layer of uniform thickness is obtained at excellent yield, and a method for producing a multilayered silica glass body easily in a short time is provided.

First claim

The invention claimed is:

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.

2. The method for producing multilayer-structure silica glass body as claimed in claim 1 , wherein a vibration acceleration of the vibration is set at between 0.10 m/s 2 and 5.0 m/s 2 .

3. The method for producing a multilayer-structure silica glass body as claimed in claim 1 , wherein the silica slurry contains silica small particles comprising a siliceous material and having a particle size of less than 30 μm; and
the silica small particles contained in the silica slurry constitute 2% or more of the mass of all particles comprising a siliceous material contained in the silica slurry.

4. The method for producing a multilayer-structure silica glass body as claimed in claim 1 , wherein the liquid contained in the silica slurry is water.

5. The method for producing a multilayer-structure silica glass body as claimed in claim 1 , wherein the siliceous substrate comprises opaque silica glass.

6. The method for producing a multilayer-structure silica glass body as claimed in claim 1 , wherein the vitrification of the silica slurry is performed by heating, employing a burner.

7. The method for producing a multilayer-structure silica glass body as claimed in claim 1 , wherein the silica slurry is coated on the siliceous substrate while the siliceous substrate is being vibrated.

Assignees

• Heraeus Quarzglas
• Shin Etsu Quartz Prod Co Ltd

Inventors

• Mori Tatsuya
• Sugama Akihiko

Classifications

• C03B18/02 Primary

  Forming sheets · CPC title

• C03C17/007

  containing a dispersed phase, e.g. particles, fibres or flakes, in a continuous phase · CPC title

• C03C17/02 Primary

  with glass (C03C17/34, C03C17/44 take precedence) · CPC title

• C03C23/007

  by thermal treatment · CPC title

• C03C2218/117

  by ultrasonic methods · CPC title