Blue glass with improved UV and IR absorption

Abstract

The invention is a soda-lime-silica glass composition which is blue in color and having improved UV and IR absorption. The spectral properties of the blue glass at a 4.0 mm. Thickness include: 477-494 dominant wavelength and 6-40% purity of excitation. The blue glass composition, by weight, comprises a base glass composition of: 68 to 75% SiO.sub.2, 10 to 18% Na.sub.2 O, 5 to 15% CaO, 0 to 10% MgO, 0 to 5% Al.sub.2 O.sub.3, and 0 to 5% K.sub.2 O, where CaO+MgO is 6 to 15% and Na.sub.2 O+K.sub.2 0 is 10 to 20%; and colorants consisting essentially of: 0.4 to 2.0% total iron oxide as Fe.sub.2 O.sub.3, 0.15 to 2.00% manganese oxide as MnO.sub.2 ; 0.005 to 0.025% cobalt oxide as Co, and 0 to 1.00% titanium oxide as TiO.sub.2. The glass is useful for automotive or architectural applications. It preferably is made by a nitrite-free method which may desirably involve the use of a reducing agent during melting operations.

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