Lead-free and cadmium-free glass for glazing, enamelling and decorating glasses or glass-ceramics

A lead-free and cadmium-free glass glaze applied on a glass or glass-ceramic body, comprising (in % by weight):

• Li2O
• 0-8
• Na2O
• 0-8
• K2O
• 0-8
• Al2O3
• 3-10
• B2O3
• 6.5-30
• MgO
• 0.1-12
• SrO
• 0-16
• CaO
• [[0-12]] 0-8
• BaO
• 0-13
• ZnO
• 0-17
• SiO2
• 66-75;
• wherein the sum of the alkali metal oxides is between 0.1 and 8 wt.-%;
• the sum of the components selected from the group formed by MgO, CaO, SrO and BaO is at least 1% by weight;
• and
• the glaze has a thickness of 1 to 5 micrometers.

A method of coating a body consisting a glass-ceramic having a coefficient of thermal expansion of no more than 3·10−6/K in the temperature range between 20 and 700° C., the method comprising the steps of:

• preparing a glass comprising (in % by weight):
• Li2O
• 0-8
• Na2O
• 0-8
• K2O
• 0-8
• Al2O3
• [[0-10]] 3-10
• B2O3
• 6.5-35
• MgO
• 0.1-12
• SrO
• 0-16
• CaO
• [[0-12]] 0-8
• BaO
• 0-13
• ZnO
• 0-17
• SiO2
• >65-75;
• wherein the sum of alkali metal oxides is between 0.1 and 10 wt.-%;
• milling the glass to prepare a glass frit therefrom;
• mixing the glass frit with additives to prepare a mixture;
• applying the mixture onto a surface of a body to be coated;
• firing the body with the applied mixture at a temperature between 800 and 1200° C.;
• and
• cooling the body to room temperature.