Glass article

Patent metadata

Field	Value
Publication number	US-10435327-B2
Application number	US-201715722611-A
Country	US
Kind code	B2
Filing date	Oct 2, 2017
Priority date	Apr 3, 2015
Publication date	Oct 8, 2019
Grant date	Oct 8, 2019

Abstract

The present invention relates to a glass article having high transmittance, while suppressing the discoloration and the solarization of the glass. The glass article is provided by controlling the contents of cerium oxide and iron oxide in the glass composition within the optimum range, further controlling the contents of manganese oxide and iron oxide in the glass composition within the optimum range, and controlling the basicity of the alkaline earth metal oxides in the glass composition depending on the iron amount contained in the glass.

First claim

The invention claimed is:

1. A glass article comprising a glass comprising, in terms of mass % or mass ppm on the basis of the following oxides, 50 to 80% of SiO 2 , 0 to 10% of K 2 O, 1 to 80 ppm of total iron oxide (t-Fe 2 O 3 ) in terms of Fe 2 O 3 , 0 to 10 ppm of ferrous iron (Fe 2+ ) in terms of Fe 2 O 3 , 0.01 to 5 ppm of total manganese oxide (t-MnO 2 ) in terms of MnO 2 , and 1 to 35% of at least one selected from the group consisting of alkaline earth metal oxides of MgO, CaO, SrO and BaO, in a total amount thereof,
wherein, in the glass, redox of iron represented by the following formula (1) is from 0 to 30%:
(Content of ferrous iron (Fe 2+ ) in terms of Fe 2 O 3 )/[(total content (Fe 2+ +Fe 3+ ) of ferrous iron (Fe 2+ ) and ferric iron (Fe 3+ ) in terms of Fe 2 O 3 ]  formula (1),

and the glass satisfies relational formulae of the following formulae (5), (6) and (8):
[ t -CeO 2 ]/[ t -Fe 2 O 3 ]<1  formula (5),

0.001≤[ t -MnO 2 ]/[ t -Fe 2 O 3 ]≤0.5  formula (6),

80≤(64×[MgO]+100×[CaO]+127×[SrO]+156×[BaO])≤2500   formula (8),

wherein, in formulae (5), (6) and (8), [t-CeO 2 ] is the content (mass ppm) of the total cerium oxide, [t-MnO 2 ] is the content (mass ppm) of the total manganese oxide, [t-Fe 2 O 3 ] is the content (mass ppm) of the total iron oxide, [MgO] is the content (mass %) of MgO, [CaO] is the content (mass %) of CaO, [SrO] is the content (mass %) of SrO, and [BaO] is the content (mass %) of BaO.

2. The glass article according to claim 1 , wherein the glass comprises, in terms of mass ppm, 0 to 4 ppm of ferrous iron (Fe 2+ ) in terms of Fe 2 O 3 .

3. The glass article according to claim 1 , wherein the glass contains substantially none of B 2 O 3 .

4. The glass article according to claim 1 , wherein the glass further comprises, in terms of mass %, more than 0% and 0.5% or less of SO 3 .

5. The glass article according to claim 1 , wherein the glass further comprises, in terms of mass %, 0 to 1% of SnO 2 .

6. The glass article according to claim 1 , wherein the glass has 85% or more of a minimum value of the transmittance within a range of wavelengths from 400 to 700 nm under conditions of an effective optical path length of 50 mm, and the difference between a maximum value and the minimum value of the transmittance is 3.8% or less.

7. The glass article according to claim 1 , wherein the glass is a glass plate at least one side of which has a length of 200 cm or less and which has a thickness of 0.5 mm or more.

8. The glass article according to claim 1 , wherein at least one of end faces of the glass plate is polished.

Assignees

• Asahi Glass Co Ltd
• Agc Inc

Inventors

• Inaba Seiji
• Arai Yusuke
• Hijiya Hiroyuki

Classifications

• C03C4/0092

  for glass with improved high visible transmittance, e.g. extra-clear glass · CPC title

• C03C3/091

  containing aluminium · CPC title

• C03C3/095 Primary

  containing rare earths · CPC title

• C03C3/087

  containing calcium oxide, e.g. common sheet or container glass · CPC title

• C03C3/085

  containing an oxide of a divalent metal · CPC title