Cobalt-free, black, dual purpose porcelain enamel glass
AssigneeBayer Aktiengesellschaft
InventorsDechun Fu, Vernon J. Grebe
Life of this patent
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Abstract
A borosilicate glass composition suitable for porcelain enamel applications is disclosed. Accordingly, a black, cobalt-free composition which contains a significant amount of iron oxide was found to be suitable for enameling cast iron and non-pickled steel substrates. The inventive glass is suitable for applications requiring black color, acid resistance, thermal durability and water vapor resistance. In particular, the inventive glass can be used both as a ground coat and a cover coat.
Claims8
A cobalt-free, black procelain enamel glass frit composition comprising
- ______________________________________ Na.sub.2 O 9-13.5 K.sub.2 O 0.5-14.2 B.sub.2 O.sub.3 6.6-14.8 Fe.sub.2 O.sub.3 6.6-10.5 SiO.sub.2 49.1-56.2 NiO 2.4-4.4 Li.sub.2 O 0-1.8 ______________________________________
- with the proviso that the total of Li.sub.2 O+Na.sub.2 O+K.sub.2 O is 13.9-25.3, said glass frit prepared by (i) melting a mixture of raw materials to form a molten mixture and (ii) quenching said molten mixture, said enamel
A cobalt-free, black porcelain enamel glass frit composition comprising
- ______________________________________ Na.sub.2 O 9-13.5 K.sub.2 O 0.5-14.2 B.sub.2 O.sub.3 6.6-14.8 Fe.sub.2 O.sub.3 6.6-10.5 SiO.sub.2 49.1-56.2 NiO 2.4-4.4 Li.sub.2 O 0-1.8 ______________________________________
- with the proviso that the total of Li.sub.2 O+Na.sub.2 O+K.sub.2 O is 13.9-25.3, said glass frit prepared by (i) melting a mixture of raw materials to form a molten mixture and (ii) quenching said molten mixture, said enamel having a CIELab "L" value of about 4 to 10, "a" value of about -0.5 to 2.1, and "b" value of about 0 to 3.5 as determined by spectrophotometry, illuminant type C, and a 2 degree observer angle, of a panel fired at 800.degree. C. to 850.degree. C.
A method of using the cobalt-free, black porcelain enamel glass frit composition containing
- ______________________________________ Na.sub.2 O 9-13.5 K.sub.2 O 0.5-14.2 B.sub.2 O.sub.3 6.6-14.8 Fe.sub.2 O.sub.3 6.6-10.5 SiO.sub.2 49.1-56.2 NiO 2.4-4.4 Li.sub.2 O 0-1.8 ______________________________________
- with the proviso that the total of Li.sub.2 O+Na.sub.2 O+K.sub.2 O is 13.9-25.3, said glass frit prepared by (i) melting a mixture of raw materials to form a molten mixture and (ii) quenching said molten mixture, said method comprising applying said composition to the surface of a non-pickled steel.
A method of using the cobalt-free, black porcelain enamel glass frit composition containing
- ______________________________________ Na.sub.2 O 9-13.5 K.sub.2 O 0.5-14.2 B.sub.2 O.sub.3 6.6-14.8 Fe.sub.2 O.sub.3 6.6-10.5 SiO.sub.2 49.1-56.2 NiO 2.4-4.4 Li.sub.2 O 0-1.8 ______________________________________
- with the proviso that the total of Li.sub.2 O+Na.sub.2 O+K.sub.2 O is 13.9-25.3, said glass frit prepared by (i) melting a mixture of raw materials to form a molten mixture and (ii) quenching said molten mixture, said enamel having a CIELab "L" value of about 4 to 10, "a" value of about -0.5 to 2.1, and "b" value of about 0 to 3.5 as determined by spectrophotometry, illuminant type C, a 2 degree observer angle and a large area opening, said method comprising applying said composition to the surface of a non-pickled steel.
Dependencies are inferred from the claim text.