Glass sheet capable of being inhibited from warping through chemical strengthening

Patent metadata

Field	Value
Publication number	US-9663396-B2
Application number	US-201414498055-A
Country	US
Kind code	B2
Filing date	Sep 26, 2014
Priority date	Mar 26, 2012
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

A glass sheet has one surface and the other surface facing the one surface in a thickness direction, wherein a fluorine concentration (average fluorine concentration by SIMS at a depth of 1 to 24 μm) in the one surface is higher than that in the other surface. The following expression is satisfied: 0.07≦ΔF/ΔH 2 O. ΔF (mol %) is a value obtained by subtracting an average fluorine concentration in the surface having the lower fluorine concentration from that in the surface having the higher fluorine concentration, and ΔH 2 O (mol %) is an absolute value of a value obtained by subtracting an average H 2 O concentration in the surface having the higher fluorine concentration from that in the surface having the lower fluorine concentration.

First claim

The invention claimed is:

1. A glass sheet, having one surface and the other surface facing the one surface in a thickness direction, wherein a fluorine concentration in the one surface is higher than the fluorine concentration in the other surface in which the fluorine concentration is an average fluorine concentration (mol %) by SIMS at a depth of 1 to 24 μm, and the following expression (1) is satisfied:
0.07≦ΔF/ΔH 2 O  (1)

wherein ΔF is a value obtained by subtracting an average fluorine concentration (mol %) by SIMS at the depth of 1 to 24 μm in the surface having the lower fluorine concentration from the average fluorine concentration (mol %) by SIMS at the depth of 1 to 24 μm in the surface having the higher fluorine concentration, and
ΔH 2 O is an absolute value of a value obtained by subtracting an average H 2 O concentration (mol %) by SIMS at the depth of 1 to 24 μm in the surface having the higher fluorine concentration from the average H 2 O concentration (mol %) by SIMS at the depth of 1 to 24 μm in the surface having the lower fluorine concentration,
wherein the surface having the higher fluorine concentration does not include a recess having a diameter of 10 nm or more; or wherein the surface having the higher fluorine concentration comprises one or more recesses with a density of 6 recesses/μm 2 or less.

2. The glass sheet according to claim 1 , which is manufactured by a float method.

3. The glass sheet according to claim 1 , which has a thickness of 1.5 mm or less.

4. The glass sheet according to claim 1 , which has a thickness of 0.8 mm or less.

5. A glass sheet, which is obtained by chemically strengthening the glass sheet according to claim 1 .

6. A flat panel display device, comprising a cover glass, wherein the cover glass is the glass sheet according to claim 5 .

7. The glass sheet according to claim 1 , which is prepared by contacting a glass sheet with fluorine wherein the glass sheet has a surface temperature of greater than 650° C.

Assignees

• Asahi Glass Co Ltd

Inventors

• Miyasaka Satoshi
• NAKADA Hideko
• Hayashi Yasuo
• Fukawa Makoto
• Nihei Toshifumi
• SHIRAI Masanobu
• Okahata Naoki
• Nakagawa Koji
• Yamanaka Kazuhiko
• Watanabe Kunio
• Tanii Shiro
• IKAWA Nobuaki
• Kobayashi Daisuke
• Miyashita Junichi
• Kato Ryosuke

Classifications

• C03C15/00

  Surface treatment of glass, not in the form of fibres or filaments, by etching (etching or surface-brightening compositions, in general C09K13/00) · CPC title

• C03C2204/00

  Glasses, glazes or enamels with special properties · CPC title

• Y10T428/315

  Surface modified glass [e.g., tempered, strengthened, etc.] · CPC title

• C03C3/112 Primary

  containing fluorine · CPC title

• C03C23/0055

  by ion implantation · CPC title