| abstract |
PROBLEM TO BE SOLVED: To provide a jacket for an external electrode fluorescent lamp having a small dielectric loss and hardly causing a variation in dielectric capacitance. An outer electrode fluorescent lamp envelope used for manufacturing an external electrode fluorescent lamp having a structure in which an electrode is provided on an outer surface, wherein a dielectric loss tangent at 40 KHz and 250 ° C. is 0.02 or less, and a strain point. It consists of glass which is 650 degrees C or less. The glass is SiO 2 35 to 65% in mass percentage, B 2 O 3 0.1~25%, Al 2 O 3 2~20%, Li 2 O + Na 2 O + K 2 O 0.1~5%, or mass percentage in SiO 2 35~65%, B 2 O 3 0.1~25%, Al 2 O 3 2~12.5%, Li 2 O + Na 2 O + K alumino borosilicate having a composition of less than 2 O 0 to 0.1% Made of acid glass. [Selection] Figure 5 |