Optical glass fiber having cover glass of sodium zinc alumino borosilicate

摘要

This invention provides a light-transmitting glass having superior weatherability which has the following composition in % by weight: -SiO2 38-70 -B2O3 4-22 -Na2O 8-24 -K2O 0-15 -Li2O 0-15 -Cs2O 0-15 -Al2O3 1-22 -ZnO 1-16 -TiO2 0-7 -ZrO2 0-7 -CaO 0-7 -BaO 0-7 -MgO 0-7 - provided that Na2O+K2O+Li2O+Cs2O is 13 to 24, and Al2O3+ZnO+TiO2+ZrO2+CaO+BaO+MgO is 2 to 32. The aforesaid multicomponent glass exhibits superior water resistance even when used as a covering ingredient of a light-transmitting glass fiber.