The instant invention is directed to the production of essentially lead-free and cadmium-free frits which are eminently suitable for the production of decorative glazes and enamels to be used with glass, glass-ceramic, and ceramic articles. The frits exhibit good glass stability, demonstrate coefficient of thermal expansion (20.degree.-300.degree. C.) between about 52-65.times.10.sup.-7 /.degree.C., display excellent resistance to attack by acids and bases, and can be fired to fusion at temperatures between about 850.degree.-1100.degree. C. The compositions thereof consist essentially, expressed in weight percent on the oxide basis as calculated from the batch, of
A glass composition which is essentially free from lead and cadium comprises, in mole percent, SiO.sub.2 :35 to 75%, Bi.sub.2 O3:0.1 to 15%, Al.sub.2 O.sub.3 :0.1 to 10%, B.sub.2 O.sub.3 :1 to 30%, at least one of Li.sub.2 O, Na.sub.2 O, K.sub.2 O:5 to 30%, ZrO.sub.2 :0.1 to 10%, and certain other optional ingredients, with the proviso that BaO and ZnO are not contained in an amount of more than 2 mole percent. These glass compositions can be used as fluxes for mixing with pigments to provide compositions for the decoration of ceramic materials and/or glass.
Glaze composition for use on bone china and fine china which is essentially free from lead and cadium comprises, by weight, SiO.sub.2 :35 to 60%, Bi.sub.2 O.sub.3 :5 to 45%, Al.sub.2 O.sub.3 :5 to 20%, B.sub.2 O.sub.3 :1 to 15%, at least one of CaO, MgO, SrO or BaO:2 to 20%, at least one of Li.sub.2 O, Na.sub.2 O, K.sub.2 O:1 to 10%, and certain other optional ingredients, with the proviso that BaO is not contained in an amount of more than 2% by weight.
Glaze composition for use on bone china and fine china which is essentially free from lead and cadium comprises, by weight, SiO.sub.2 : 35 to 60%, Bi.sub.2 O.sub.3 : 5 to 45%, Al.sub.2 O.sub.3 :5 to 20%, B.sub.2 O.sub.3 : 1 to 15%, at least one of CaO, MgO, SrO or BaO: 2 to 20%, at least one of Li.sub.2 O, Na.sub.2 O, K.sub.2 O: 1 to 10%, and certain other optional ingredients, with the proviso that BaO is not contained in an amount of more than 2% by weight.
A frit composition for ceramic glazes is disclosed which is free of lead, cadmium and also barium. The composition contains SiO.sub.2, B.sub.2 O.sub.3, Al.sub.2 O.sub.3, alkali metal oxide, CaO, ZnO, and optionally MgO, SrO, TiO.sub.2, Bi.sub.2 O.sub.3, P.sub.2 O.sub.5 or ZrO.sub.2.
The invention is directed to a thick film paste composition comprising electrically conductive particles and finely divided particles of a glass composition comprising by mole % 5-70% Bi.sub.2 O.sub.3, 18-35% SiO.sub.2, 0.1-40% CuO, 0.5-25% ZnO, 0.5-40% CoO, 0.5-40% Fe.sub.2 O.sub.3, and 0.5-40% MnO, which the glass composition is free of lead and cadmium, all dispersed in an organic medium.
