Patent ID: 6743743
Filing Date: 2004-06-01
Classification: C03C,Y10S

Abstract:
A press-molding glass preform comprised of an optical glass comprising, by means of weight percentages, more than 32 percent and not more than 45 percent P2O5, more than 0.5 percent and not more than 6 percent Li2O, more than 5 percent and not more than 22 percent Na2O, 6-30 percent Nb2O5, 0.5-10 percent B2O3, 0-35 percent WO3, 0-14 percent K2O, and 10-24 percent Na2O+K2O, wherein the sum of the oxides of P, Li, Na, Nb, B, W, and K is not less than 80 percent, and wherein the optical glass does not comprise PbO.