Titanium-containing quartz glass having excellent UV absorption, and method for producing same

Patent metadata

Field	Value
Publication number	US-12286374-B2
Application number	US-202017601624-A
Country	US
Kind code	B2
Filing date	Jan 17, 2020
Priority date	Apr 5, 2019
Publication date	Apr 29, 2025
Grant date	Apr 29, 2025

Abstract

Provided is a titanium-containing quartz glass having excellent UV absorption. The quartz glass absorbs ultraviolet rays having a wavelength of 250 nm or less, ozone generation-related adverse effects on the human body, are prevented, a decrease in transmittance of the quartz glass in the range from near-ultraviolet to visible light due to being colored when irradiated with ultraviolet rays does not occur, absorption build-up or lamp burst-inducing deformation build-up, which is caused by a structural change in the quartz glass that occurs in the range of 200-300 nm when irradiated with ultraviolet rays, is suppressed, and a decrease in transmittance at intended wavelength ranges does not occur even when exposed to ultraviolet rays. The titanium-containing quartz glass having excellent UV absorption is colorless, wherein the average concentration of titanium is 10-500 ppm, the concentration of OH group is 10-350 ppm.

First claim

The invention claimed is:

1. A titanium-containing quartz glass having excellent UV absorption comprising:
an average concentration of titanium between 10 ppm by mass and 500 ppm by mass;
an OH group concentration in a range of between 10 ppm by mass and 350 ppm by mass;
wherein the concentration of each of the elements Al, Li, Na, K, Ca, Mg, Fe, Ni, Cu, Cr, Mo and V is 50 ppb or less by mass;
wherein the total concentration of the elements Al, Li, Na, K, Ca, Mg, Fe, Ni, Cu, Cr, Mo and V is 150 ppb or less by mass;
wherein a chlorine concentration is less than 30 ppm by mass; and
wherein the titanium-containing quartz glass is colorless.

2. The titanium-containing quartz glass as claimed in claim 1 , wherein the titanium-containing quartz glass contains two or fewer air bubbles or foreign matter inclusions having a diameter of equal to or greater than 0.1 mm, and less than 0.5 mm per 100 g, no more than one air bubble or foreign matter inclusion having a diameter of between 0.5 mm and 1 mm per 100 g, and no air bubbles or foreign matter inclusions having a diameter in excess of 1 mm.

3. A method for producing the titanium-containing quartz glass as claimed in claim 1 , said method comprising:
a titanium doping step in which a porous quartz glass parent material produced by chemical vapor deposition is introduced into a hermetically sealed vessel and held at a temperature of between 100° C. and 500° C. under a reduced-pressure atmosphere of 0.1 MPa or less, after which a titanium compound is introduced therein as a liquid or in a state of having already been gasified in a vaporizer, and the materials are held to perform doping in such a way that an average concentration of titanium in the resulting titanium-containing quartz glass is between 10 ppm by mass and 500 ppm by mass; and
a step in which the porous quartz glass parent material after the titanium doping step is subjected to a heating treatment under an oxygen-containing atmosphere, and then subjected to a transparent vitrification treatment to obtain a colorless titanium-containing quartz glass having an OH group concentration in a range of between 10 ppm by mass and 350 ppm by mass.

4. The method for producing titanium-containing quartz glass as claimed in claim 3 , wherein the titanium compound is at least one selected from the group consisting of titanium chloride and an organic titanium compound.

Assignees

• Shin Etsu Quartz Prod Co Ltd
• Heraeus Quarzglas

Inventors

• Shimada Atsushi
• Orikasa Katsuhide
• Tanaka Makoto
• Kumata Tomoichi
• TARUKAWA Hiromi

Classifications

• C03C2203/54

  in a dopant containing atmosphere · CPC title

• C03C2201/42

  containing titanium · CPC title

• C03C4/085

  for ultraviolet absorbing glass · CPC title

• C03B32/00

  Thermal after-treatment of glass products not provided for in groups {C03B19/00} , C03B25/00 - C03B31/00 {or C03B37/00}, e.g. crystallisation, eliminating gas inclusions or other impurities; {Hot-pressing vitrified, non-porous, shaped glass products} · CPC title

• C03B37/014

  made entirely or partially by chemical means {, e.g. vapour phase deposition of bulk porous glass either by outside vapour deposition [OVD], or by outside vapour phase oxidation [OVPO] or by vapour axial deposition [VAD] (C03C17/02 takes precedence)} · CPC title