Disclosed herein are opaque glass-ceramics comprising at least one nepheline crystal phase and comprising from about 30 mol % to about 65 mol % SiO.sub.2, from about 15 mol % to about 40 mol % Al.sub.2O.sub.3, from about 10 mol % to about 20 mol % (Na.sub.2O+K.sub.2O), and from about 1 mol % to about 10 mol % (ZnO+MgO). Also disclosed herein are opaque-glass ceramics comprising at least one nepheline crystal phase and at least one spinel-structure phase doped with at least one colorant chosen from transition metals and rare earth elements. Further disclosed herein are methods for making these opaque glass-ceramics.

A white glass contains, in terms of mole percentage on the basis of the following oxides, from 50 to 80% of SiO.sub.2, from 0 to 10% of Al.sub.2O.sub.3, from 11 to 30% of MgO, from 0 to 15% of Na.sub.2O and from 0.5 to 15% of P.sub.2O.sub.5.

A white glass contains, in terms of mole percentage on the basis of the following oxides, from 50 to 80% of SiO.sub.2, from 0 to 10% of Al.sub.2O.sub.3, from 11 to 30% of MgO, from 0 to 15% of Na.sub.2O and from 0.5 to 15% of P.sub.2O.sub.5.

The present application provides LAS type transparent glass-ceramics of β-quartz of composition containing a high content of zinc, articles constituted at least in part of said glass-ceramics, glasses precursors of said glass-ceramics (with a low viscosity at high temperature), and also a method of preparing said articles. Said glass-ceramics present a composition, free of arsenic oxide and antimony oxide, except for inevitable traces, expressed as percentages by weight of oxides, containing: 64.5% to 66.5% of SiO.sub.2; 19.0% to 20.6% of Al.sub.2O.sub.3; 3.0% to 3.6% of Li.sub.2O; 0 to 1% of MgO; 1.7% to 3.4% of ZnO; 2% to 3% of BaO; 0 to 3% of SrO; 0 to 1% of CaO; 2% to 4% of TiO.sub.2; 1% to 2% of ZrO.sub.2; 0 to 1% of Na.sub.2O; 0 to 1% of K.sub.2O; with Na.sub.2O+K.sub.2O+BaO+SrO+CaO≤6%; optionally up to 2% of at least one fining agent comprising SnO.sub.2; and optionally up to 2% of at least one coloring agent.

The present application provides LAS type transparent glass-ceramics of β-quartz of composition containing a high content of zinc, articles constituted at least in part of said glass-ceramics, glasses precursors of said glass-ceramics (with a low viscosity at high temperature), and also a method of preparing said articles. Said glass-ceramics present a composition, free of arsenic oxide and antimony oxide, except for inevitable traces, expressed as percentages by weight of oxides, containing: 64.5% to 66.5% of SiO.sub.2; 19.0% to 20.6% of Al.sub.2O.sub.3; 3.0% to 3.6% of Li.sub.2O; 0 to 1% of MgO; 1.7% to 3.4% of ZnO; 2% to 3% of BaO; 0 to 3% of SrO; 0 to 1% of CaO; 2% to 4% of TiO.sub.2; 1% to 2% of ZrO.sub.2; 0 to 1% of Na.sub.2O; 0 to 1% of K.sub.2O; with Na.sub.2O+K.sub.2O+BaO+SrO+CaO≤6%; optionally up to 2% of at least one fining agent comprising SnO.sub.2; and optionally up to 2% of at least one coloring agent.

An antimicrobial chemically strengthened glass and a method for manufacturing the chemically strengthened antimicrobial glass. The antimicrobial chemically strengthened glass includes an antimicrobial surface layer having at least 0.1 at % of silver ions and at least 0.1 at % of copper ions, wherein the chemically strengthened antimicrobial glass has a CIE color channel b* of less than 1.

Glass frits and enamel compositions from the glass frits for use in automotive application. The enamel composition includes one or more glass frits with reduced amount of bismuth and/or zinc compared to reference enamel compositions available. The glass frits include one or more transition metal oxides. The glass frits exhibit improved chemical durability, reduced glass density, lower L-value, or optimized optical density for an end user depending on the applications.

Glass frits and enamel compositions from the glass frits for use in automotive application. The enamel composition includes one or more glass frits with reduced amount of bismuth and/or zinc compared to reference enamel compositions available. The glass frits include one or more transition metal oxides. The glass frits exhibit improved chemical durability, reduced glass density, lower L-value, or optimized optical density for an end user depending on the applications.

A method of decorating a glass substrate having a coating, said method comprising: applying a paste onto at least a portion of said coating in a desired pattern; drying said paste to form a dried paste in said desired pattern; and firing said dried paste to form an enamel in said desired pattern, said enamel being directly bonded to said glass substrate by dissolution of the portion of the coating to which the paste is applied during the firing step. The paste comprises a solids portion dispersed in a dispersion medium, said solids portion including a composition comprising: 10 to 40 mol % ZnO; 20 to 40 mol % B.sub.2O.sub.3; 25 to 65 mol % Bi.sub.2O.sub.3, TeO.sub.2, or PbO, or mixtures thereof; and to 15 mol % Al.sub.2O.sub.3.

A method of decorating a glass substrate having a coating, said method comprising: applying a paste onto at least a portion of said coating in a desired pattern; drying said paste to form a dried paste in said desired pattern; and firing said dried paste to form an enamel in said desired pattern, said enamel being directly bonded to said glass substrate by dissolution of the portion of the coating to which the paste is applied during the firing step. The paste comprises a solids portion dispersed in a dispersion medium, said solids portion including a composition comprising: 10 to 40 mol % ZnO; 20 to 40 mol % B.sub.2O.sub.3; 25 to 65 mol % Bi.sub.2O.sub.3, TeO.sub.2, or PbO, or mixtures thereof; and to 15 mol % Al.sub.2O.sub.3.