Float glass plate and method of manufacturing thereof

Patent metadata

Field	Value
Publication number	US-9512026-B2
Application number	US-201414483856-A
Country	US
Kind code	B2
Filing date	Sep 11, 2014
Priority date	Mar 14, 2012
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

The present invention relates to a float glass plate that is formed by continuously supplying a molten glass onto a molten metal in a bath and allowing the molten glass to flow on the molten metal, wherein the float glass plate satisfies the following expression (1) when, on a coordinate axis that is parallel to a through-thickness direction and has, as an origin, an arbitrary point on a principal surface which is positioned on the molten metal side in the bath among both principal surfaces of the float glass plate, a water concentration in glass at a coordinate x (μm) indicating a distance from the origin is represented by C(x) (mass ppm), the thickness of the float glass plate is represented by D (μm), a maximum value of the C(x) is represented by Ca (mass ppm), and a coordinate at which the C(x) is maximum is represented by Da (μm).

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First claim

The invention claimed is:

1. A float glass plate that is formed by continuously supplying a molten glass onto a molten metal in a bath and allowing the molten glass to flow on the molten metal,
wherein the float glass plate satisfies the following expression (1) when, on a coordinate axis that is parallel to a through-thickness direction and has, as an origin, an arbitrary point on a principal surface which is positioned on the molten metal side in the bath among both principal surfaces of the float glass plate, a water concentration in glass at a coordinate x (μm) indicating a distance from the origin is represented by C(x) (mass ppm), the thickness of the float glass plate is represented by D (μm), a maximum value of the C(x) is represented by Ca (mass ppm), and a coordinate at which the C(x) is maximum is represented by Da (μm)

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2. The float glass plate according to claim 1 , wherein the thickness is 1.1 mm or less.

3. The float glass plate according to claim 1 , wherein the maximum value of the water concentration is 470 mass ppm or more.

4. The float glass plate according to claim 1 , which comprises an alkali-free glass that contains, by mass % in terms of oxides,
SiO 2 : 50 to 66%,
Al 2 O 3 : 10.5 to 24%,
B 2 O 3 : 0 to 12%,
MgO: 0 to 8%,
CaO: 0 to 14.5%,
SrO: 0 to 24%,
BaO: 0 to 13.5%,
MgO+CaO+SrO+BaO: 9 to 29.5%, and
ZrO 2 : 0 to 5%.

5. The float glass plate according to claim 4 , which comprises an alkali-free glass that contains, by mass % in terms of oxides,
SiO 2 : 58 to 66%,
Al 2 O 3 : 15 to 22%,
B 2 O 3 : 5 to 12%,
MgO: 0 to 8%,
CaO: 0 to 9%,
SrO: 3 to 12.5%,
BaO: 0 to 2%, and
MgO+CaO+SrO+BaO: 9 to 18%.

Assignees

• Asahi Glass Co Ltd

Inventors

• Hayashi Yasuo
• Miyasaka Satoshi

Classifications

• C03C3/091

  containing aluminium · CPC title

• C03C3/093

  containing zinc or zirconium · CPC title

• C03B18/02 Primary

  Forming sheets · CPC title

• Y02P40/57

  Improving the yield, e-g- reduction of reject rates · CPC title