MEDIUM EXPANSION LEADED COPPER BOROALUMINOSILICATE GLASSES

• Main Authors: YOUNG, DIANA, M, HARES, GEORGE, B
• Format: Patent
• Language: English; French
• Published: 23.07.2009
• Subjects: CHEMICAL COMPOSITION OF GLASSES, GLAZES, OR VITREOUSENAMELS; CHEMISTRY; GLASS; JOINING GLASS TO GLASS OR OTHER MATERIALS; METALLURGY; MINERAL OR SLAG WOOL; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS,MINERALS OR SLAGS; SURFACE TREATMENT OF GLASS

The present invention is directed at a leaded copper boroaluminosilicate glass, (20, 22) having coefficients of thermal expansion (CTEs) of between 25 - 55 x 10-7 / °C (over a range of 25-300 °C) and a softening point in the range of 550-725 °C, being suitable for use as a sealing glass, especially for borosilicate glasses, and having a composition consisting essentially, in terms of weight percent on an oxide basis, of 27-60 SiO2, 3-14 Al2O3, 9-28 B2O3, 0.0-10 R2O, 0.1-40 PbO, 0.1-11 CuO, where R2O is an alkali oxide selected from the group consisting of Li2O, Na2O, K2O, Rb20 and Cs2O. La présente invention concerne un verre plombé au boroaluminosilicate de cuivre dont les coefficients de dilatation thermique se situent entre 25 - 55 x 10-7 / °C (sur une plage de températures de 25-300 °C) et le point de ramollissement entre 550 et 725 °C. Ce verre, qui convient comme verre de scellement, en particulier dans le cas de verres borosilicatés, comprend essentiellement, en pourcentage en poids par rapport à l'oxyde, 27-60 SiO2, 3-14 Al2O3, 9-28 B2O3, 0.0-10 R2O, 0.1-40 PbO, 0.1-11 CuO. Dans cette composition, R2O est un oxyde alcalin pris dans le grroupe composé de Li2O, Na2O, K2O, Rb20 et Cs2O.