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US 5,491,115 AGranted
Colored glass-ceramics and method
AssigneeCorning Incorporated
InventorsRobert W. Pfitzenmaier, Charles C. Smith, Jr.
Life of this patent
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AssigneeCorning Incorporated
InventorsRobert W. Pfitzenmaier, Charles C. Smith, Jr.
Estimating the term…
A colored glass-ceramic and method of making it. The glass-ceramic has a primary crystal phase selected from the group consisting of beta-quartz solid solution and beta-spodumene solid solution, containing an amount of TiO.sub.2 effective as a nucleating agent up to 6% by weight, 700-900 ppm Fe.sub.2 O.sub.3 and 550-3000 ppm Co.sub.3 O.sub.4, the glass-ceramic having a beta-quartz solid solution as a primary crystal phase being transparent and having a color defined by the color coordinates x=0.2200-0.3100, y=0.0200-0.2400 falling within color box ABCDA in FIG. 1 in the drawings, and the glass-ceramic having a beta-spodumene solid solution as a primary crystal phase being opaque and having a color defined by the color coordinates x=0.2480-0.2880, y=0.2000-0.3150 falling within color box JKLMJ in FIG. 2 in the drawings. Reddish-purple and violet colors are obtained in transparent, beta-quartz glass-ceramics, while light to dark blue colors are obtained in opaque, beta-spodumene glass-ceramics.
A colored glass-ceramic produced from a Li.sub.2 O--Al.sub.2 O.sub.3 --SiO.sub.2 glass and having a primary crystal phase selected from the group consisting of beta-quartz solid solution and beta-spodumene solid solution, the glass-ceramic containing, as a color package, an amount of TiO.sub.2 effective as a nucleating agent up to 6% by weight, 700-900 ppm Fe.sub.2 O.sub.3 and 550-3000 ppm Co.sub.3 O.sub.4, the glass-ceramic being transparent or opaque depending on the primary crystal phase, the glass-ceramic being transparent and having a color defined by the color coordinates x=0.2200-0.3100, y=0.0200-0.2400 falling within color box ABCDA in FIG. 1 in the drawings, when the primary crystal phase is a beta-quartz solution, and the glass-ceramic being opaque and having a color defined by the color coordinates x=0.2480-0.2880, y=0.2000-0.3150 falling within color box JKLMJ in FIG. 2 in the drawings when the primary crystal phase is a beta-spodumene solid solution.
A colored glass-ceramic having a primary crystal phase selected from the group consisting of beta-quart solid solution and beta-spodumene solid solution, the glass-ceramic being transparent or opaque depending on the primary crystal phase, the glass-ceramic being transparent having a color defined by the color coordinates x=0.2200-0.3100, y=0.0200-0.2400 falling within the color box ABCDA in FIG. 1 in the drawings, when the primary crystal phase is a beta-quartz solid solution, and the glass-ceramic being opaque and having a color defined by the color coordinates x=0.2480-0.2880, y=0.2000-0.3150 falling within color box JKLMJ in FIG. 2 in the drawings when the primary crystal phase is a beta-spodumene solid solution, the glass-ceramic consisting essentially of, as calculated in weight percent on an oxide basis:
A method of producing a colored glass-ceramic article comprising melting a Li.sub.2 O--Al.sub.2 O.sub.3 --SiO.sub.2 glass capable of having a beta-quartz solid solution crystal phase or a beta-spodumene solid solution crystal phase thermally developed therein and containing an amount of TiO.sub.2 effective as a nucleating agent up to 6%, 700-900 ppm Fe.sub.2 O.sub.3 and 0-25 ppm Co.sub.3 O.sub.4, adding, as a forehearth additive to the molten glass, a source of Co.sub.3 O.sub.4 in an amount sufficient to provide a Co.sub.3 O.sub.4 level of 550-3000 ppm in the glass-ceramic article, forming an article from the molten glass and heat treating the article at a sufficient temperature and for a sufficient time to develop a beta-quartz solid solution or a beta-spodumene solid solution crystal phase in the glass.
Dependencies are inferred from the claim text.