Lead-free glasses for glaze materials
AssigneeCorning Glass Works
InventorsJohn W. Nelson, Linda R. Pinckney
Life of this patent
Estimating the term…
Abstract
This invention is directed to lead-free and, where desired, cadmium-free frits for glazes and enamels, said frits consisting essentially, in mole percent on the oxide basis, of ______________________________________ SiO.sub.2 55-75 Na.sub.2 O 3-9 B.sub.2 O.sub.3 8-13 ZrO.sub.2 2-5 Al.sub.2 O.sub.3 0.5-3 BaO 0.5-16 ______________________________________ Various inert refractory materials may be included as fillers.
Claims14
A frit essentially free of lead demonstrating good glass stability, a linear coefficient of thermal expansion (25.degree.-300.degree. C.) between about 45-90.times.10.sup.-7 /.degree.C., a viscosity suitable for firing between about 800.degree.-900.degree. C., a softening point between 640.degree.-800.degree. C., and excellent resistance to attack by acids and bases, as evidenced by essentially no visual change in appearance after an exposure of 16 hours at room temperature to a 5% by weight aqueous solution of acetic acid, to a 5% by weight aqueous solution of H.sub.2 SO.sub.4, and a 5% by weight, aqueous solution of NaOH, said frit consisting essentially, expressed in terms of mole percent on the oxide basis, of
- ______________________________________ SiO.sub.2 60-75 Na.sub.2 O 5-8 B.sub.2 O.sub.3 9-13 ZrO.sub.2 2.5-4.5 Al.sub.2 O.sub.3 1-2 BaO 1-16. ______________________________________
A frit essentially free of lead demonstrating good glass stability, a linear coefficient of thermal expansion (25.degree.-300.degree. C.) between about 45-90.times.10.sup.-7 /.degree.C., a viscosity suitable for firing between about 800.degree.-900.degree. C., a softening point between 640.degree.-800.degree. C., and excellent resistance to attack by acids and bases, as evidenced by essentially no visual change in appearance after an exposure of 16 hours at room temperature to a 5% by weight aqueous solution of acetic acid, to a 5% by weight aqueous solution of H.sub.2 SO.sub.4, and a 5% by weight aqueous solution of NaOH, said frit consisting essentially, expressed in terms of mole percent on the oxide basis, of
- ______________________________________ SiO.sub.2 58-65 Na.sub.2 O 5-7 B.sub.2 O.sub.3 10-12 ZrO.sub.2 2-3.5 Al.sub.2 O.sub.3 1-2 BaO 6-15 Li.sub.2 O 4-8 K.sub.2 O 3-5. ______________________________________
Dependencies are inferred from the claim text.