Borosilicate glass composition for producing glass tubes and its use for producing glass tubes and as outer tube for lamps

US8937027B2 · kind B2 · utility

Assignee

• Schott AG · DE

Inventors

• Erhard Dick · Mitterteich, DE
• Joerg Fechner · Mainz, DE

Key dates

• Filing date: Aug 27, 2012
• Grant date: Jan 20, 2015
• Expiry date: Mar 29, 2033

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C03C1/004
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A glass composition and its use for producing glass tubes is provided. The glass tubes having the provided composition are particularly suitable for the outer tubes of fluorescent lamps in the case of which a phosphor layer is baked at temperatures of up to 700° C. The tubes composed of the glass of the provided composition have a lower tendency to deform or stick together when processed at high temperatures. To obtain the observed effects, the molar ratio of Na2O/(Na2O+K2O), inter alia, is greater than 0.4 and not more than 0.72.