Optical glasses lead-free having a refractive index between 1,50 and 1,56 and abbe number of between 50 and 64

摘要

The present invention relates to optical glass free of lead, having a refractive index of the nd between 1 and 50 and 1, 56 and abbe number vd between 50 and 64 and the following composition (in% by weight relative to the oxide): sio2: 62 - 75; b2 o3: 5 - 9, 5; bao: 4, 5 - 21, zno: 0 - & 14; cao: 0 - 0, 5, where zno + cao & = 0, 05 and zno + bao + cao 25; tio2: 1 - 7, na2 o: 2 - 10; k2: 4, 5 - 8, zro2: 0 - 1, nb2 o5: 0 - 1, ta2 o5: 0 - 1, f -: 0 - 0, 5).