| 摘要 |
PROBLEM TO BE SOLVED: To provide a jacket tube for a fluorescent lamp which is suitable as the jacket tube of an external electrode fluorescent lamp. SOLUTION: The jacket tube consists of glass having a composition consisting of, by mass, 40 to 64% SiO2 , 0 to 10% B2 O3 , 0 to 10% Al2 O3 , 0 to 7% MgO, 0 to 8% CaO, 0 to 25% SrO, 4 to 25% BaO, 0 to 25% ZnO, 0 to 10% TiO2 , 0 to 10% Li2 O, 0 to 10% Na2 O, 4.5 to 20% K2 O, 0 to 3% CeO2 , <=2,000 ppm Fe2 O3 , 15 to 40% SrO+BaO+ZnO+TiO2 and 4.5 to 25% Li2 O+Na2 O+K2 O.
|
