US Patent No. 10,427,971

ULTRAVIOLET-ABSORBING GLASS ARTICLE


Patent No. 10,427,971
Issue Date October 01, 2019
Title Ultraviolet-absorbing Glass Article
Inventorship Shuichi Akada, Tokyo (JP)
Soshi Watanabe, Tokyo (JP)
Assignee AGC Inc., Chiyoda-ku (JP)

Claim of US Patent No. 10,427,971

1. An ultraviolet absorbing glass article comprising, in terms of % by mass based on oxides:SiO2 66 to 75%,
Na2O 10 to 20%,
CaO 5 to 15%,
MgO 0 to 6%,
Al2O3 0 to 5%,
K2O 0 to 5%,
total iron (t-Fe2O3) as represented by Fe2O3 0.8% or more and less than 2.4%,
Cr2O3 0 to 0.01%,
CoO 0.02 to 0.04%,
Se 0.0005 to 0.0045%, and
TiO2 more than 0% and 1% or less,
a Redox, which is (an content of divalent iron (Fe2+) in terms of Fe2O3)/(a total content of divalent iron (Fe2+) in terms of Fe2O3 and trivalent iron (Fe2+) in terms of Fe2O3), being 20% or more and 30% or less,
the Redox, and the contents of t-Fe2O3 and TiO2 satisfying expression (1),
the contents of t-Fe2O3, Cr2O3, CoO, and Se satisfying expression (2),
the ultraviolet absorbing glass article having:
an ultraviolet transmittance (TUV) (ISO 9050:2003) at a sheet thickness of 3.5 mm being 2% or less,
a visible light transmittance (TVA) (JIS R 3106 (1998)) measured by using a standard illuminant A at a sheet thickness of 3.5 mm being 12% or more and 25% or less,
a solar radiation transmittance (TE) (JIS R 3106 (1998)) at a sheet thickness of 3.5 mm being 22% or less, and
an excitation purity (Pe) measured by using a standard illuminant C at a sheet thickness of 3.5 mm being 10% or less:
1.77×(1?Redox/100)×(t-Fe2O3)+0.48×(TiO2)?1.73  (1), and
5.0?(t-Fe2O3)+10×(Cr2O3)+90×(CoO)+1100×(Se)?8  (2).