The disclosure relates to glass compositions having improved thermal tempering capabilities. The disclosed glass compositions have high coefficients of thermal expansion and Young's moduli, and are capable of achieving high surface compressions. A method of making such glasses is also provided.

The present invention provides a glass sheet having soda-lime-silica glass composition with a high visible light transmittance (L.sub.tC) of at least 89% with a dominant wavelength (DW) from about 490 to 505 nanometers and purity (Pe) of no more than 1% for control thickness of 5.66 mm and methods of making the same. The glass composition comprising a low iron raw material, a total iron oxide (Fe.sub.2O.sub.3) of 0.02 to 0.06 wt. %, ferrous (FeO) from 0.006 to 0.02 wt. %, redox (FeO/Fe.sub.2O.sub.3) from about 0.30 to 0.55, Cr.sub.2O.sub.3 from about 0.3 to 10 ppm, TiO.sub.2 from about 50 to 500 ppm, SnO.sub.2 from about 10 to 500 ppm, and a critical amount from about 0.10 to 0.25 wt. % of SO.sub.3. The low content of iron oxide is achieved by the partial substitution of regular raw materials by low iron raw materials, with a complete substitution of regular dolomite by a low iron dolomite with a maximum content of 0.020 wt. % Fe.sub.2O.sub.3.

The present invention provides a glass sheet having soda-lime-silica glass composition with a high visible light transmittance (L.sub.tC) of at least 89% with a dominant wavelength (DW) from about 490 to 505 nanometers and purity (Pe) of no more than 1% for control thickness of 5.66 mm and methods of making the same. The glass composition comprising a low iron raw material, a total iron oxide (Fe.sub.2O.sub.3) of 0.02 to 0.06 wt. %, ferrous (FeO) from 0.006 to 0.02 wt. %, redox (FeO/Fe.sub.2O.sub.3) from about 0.30 to 0.55, Cr.sub.2O.sub.3 from about 0.3 to 10 ppm, TiO.sub.2 from about 50 to 500 ppm, SnO.sub.2 from about 10 to 500 ppm, and a critical amount from about 0.10 to 0.25 wt. % of SO.sub.3. The low content of iron oxide is achieved by the partial substitution of regular raw materials by low iron raw materials, with a complete substitution of regular dolomite by a low iron dolomite with a maximum content of 0.020 wt. % Fe.sub.2O.sub.3.

A method of manufacturing glass ceramic articles such as glass ceramic plates for cooktops or fireplace windows is provided. The method facilitates the adjustment of a specific hue or a specific absorptivity of the glass ceramic in the visible spectral range. The method is based on the finding that the absorption of light by coloring agents which are appropriate for or present in glass ceramics can be attenuated during the ceramization process by adding substances that have a decoloring effect.

A method of manufacturing glass ceramic articles such as glass ceramic plates for cooktops or fireplace windows is provided. The method facilitates the adjustment of a specific hue or a specific absorptivity of the glass ceramic in the visible spectral range. The method is based on the finding that the absorption of light by coloring agents which are appropriate for or present in glass ceramics can be attenuated during the ceramization process by adding substances that have a decoloring effect.

A coated glass or glass ceramic substrate includes a substrate with a surface area and a coating on that surface area. The coating includes a glass matrix and IR-reflecting pigments. The IR-reflecting pigments have a TSR value of at least 20%, as determined according to ASTM G 173. The coating, at a wavelength of 1500 nm, exhibits a remission of at least 35%, as measured according to ISO 13468.

A coated glass or glass ceramic substrate includes a substrate with a surface area and a coating on that surface area. The coating includes a glass matrix and IR-reflecting pigments. The IR-reflecting pigments have a TSR value of at least 20%, as determined according to ASTM G 173. The coating, at a wavelength of 1500 nm, exhibits a remission of at least 35%, as measured according to ISO 13468.

The present invention provides a microcrystalline glass and microcrystalline glass product with excellent mechanical properties, microcrystalline glass product, the components of which, expressed in weight percent, contain: SiO.sub.2: 65 ∼80%; AI.sub.2O.sub.3: below 5%; Li.sub.2O: 10 ∼25%; ZrO.sub.2: 5 ∼15%; P.sub.2O.sub.5: 1 ∼8%. Through the reasonable component design, the microcrystalline glass product obtained by the present invention have excellent mechanical properties.

The present invention provides a microcrystalline glass and microcrystalline glass product with excellent mechanical properties, microcrystalline glass product, the components of which, expressed in weight percent, contain: SiO.sub.2: 65 ∼80%; AI.sub.2O.sub.3: below 5%; Li.sub.2O: 10 ∼25%; ZrO.sub.2: 5 ∼15%; P.sub.2O.sub.5: 1 ∼8%. Through the reasonable component design, the microcrystalline glass product obtained by the present invention have excellent mechanical properties.

Colored glass articles and methods for making the same are described herein. In embodiments, a colored glass article may include 50 mol. % to 70 mol. % SiO.sub.2; 10 mol. % to 20 mol. % Al.sub.2O.sub.3; 4 mol. % to 10 mol. % B.sub.2O.sub.3; 7 mol. % to 17 mol. % Li.sub.2O; 1 mol. % to 9 mol. % Na.sub.2O; 0.01 mol. % to 1 mol. % SnO.sub.2; and 0.01 mol. % to 5 mol. % Ag. The difference between R.sub.2O and Al.sub.2O.sub.3(R.sub.2O—Al.sub.2O.sub.3) may be greater than 0.2 mol. % and less than or equal to 5.00 mol. % where R.sub.2O is the sum of Li.sub.2O, Na.sub.2O, and K.sub.2O.