Patent ID: 7026753

Claim:
A glass tube for a fluorescent lamp, comprising glass, said glass compnsing: CeO 2 in an amount of from 0.1% to 1.0% by mass; Sb 2 O 3 in an amount of 0.05% or lower by mass; SiO2 in an amount of from 60% to 75% by mass; Al 2 O 3 in an amount of from 0.5% to 10% by mass; B 2 O 3 in an amount of from 0% to 5% by mass; CaO in an amount of from 1.9% to 8% by mass; MgO in an amount of from 0% to 8% by mass: SrO in an amount of from 3.1% to 15% by mass; BaO in an amount of from 1% to 12% by mass; R 2O in an amount of from 13.7% to 22% by mass, wherein R represents Li, Na and K, provided that Na 2 O is present in an amount of from 3% to 15% by mass; Fe 2 O 3 in an amount of from 0% to 0.2% by mass; TiO 2 in an amount of from 0% to 1.0% by mass; and PbO in an amount of 0.05% or lower by mass.