Optical glass

A process for preparation of a press-molding glass preform in which a glass melt is dripped or flowed out of a flow pipe and received in a receiving mold via a gas, and the resulting glass gob is shaped to a desired shape to produce a preform,

• wherein the press-molding glass preform is 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.

The process of claim 1, wherein the dripped glass has a viscosity ranging from 3 to 30 dPa·s.

The process of claim 1, wherein the flowed glass has a viscosity ranging from 5 to 60 dPa·s.

A process for preparation of a press-molding glass preform in which a glass melt is dripped or flowed out of a flow pipe and received in a receiving mold via a gas, and the resulting glass gob is shaped to a desired shape to produce a preform,

• wherein the press-molding glass preform is comprised of an optical glass comprised of phosphate glass comprising, by means of weight percentages, more than 0.5 percent and not more than 6 percent Li2O, more than 5 percent and not more than 22 percent Na2O, 0-14 percent K2O, 10-24 percent Na2O+K2O, 6-30 percent Nb2O5, and not more than 45 percent P2O5, and exhibits a refractive index (nd) of 1.64-1.72, an Abbé number (vd) of 29-36, a sag temperature (Ts) of not more than 520° C.

A process for preparation of a press-molding glass preform in which a glass melt is dripped or flowed out of a flow pipe and received in a receiving mold via a gas, and the resulting glass gob is shaped to a desired shape to produce a preform,

• wherein the press-molding glass preform is comprised of an optical glass comprised of phosphate glass comprising, by means of weight percentages, more than 0.5 percent and not more than 6 percent Li2O, more than 5 percent and not more than 22 percent Na2O, 0-14 percent K2O, 10-24 percent Na2O+K2O, 6-30 percent Nb2O5, 0-35 percent WO3, 0-5 percent Al2O3, and not less than 0 percent but less than 8 percent TiO2, and exhibits a refractive index (nd) of 1.64-1.72, an Abbé number (vd) of 29-36, a sag temperature (Ts) of not more than 520° C.

A process for preparation of a press-molding glass preform in which a glass melt is dripped or flowed out of a flow pipe and received in a receiving mold via a gas, and the resulting glass gob is shaped to a desired shape to produce a preform,

• wherein the press-molding glass preform is comprises, 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, 0-2 percent SiO2, 0-5 percent Al2O3, not less than 0 percent but less than 8 percent TiO2, 0-15 percent ZnO, 0-12 percent BaO, not less than 0 percent but less than 1 percent Sb2O3, and 0-1 percent SnO2, wherein the sum of the oxides of P, Li, Na, Nb, B, W, K, Si, Al, Ti, Zn, Ba, Sb, and Sn is not less than 95 percent, and exhibits a refractive index (nd) of 1.64-1.72, an Abbé number (vd) of 29-36, a sag temperature (Ts) of not more than 520° C.

A process for preparation of a press-molding glass preform in which a glass melt is dripped or flowed out of a flow pipe and received in a receiving mold via a gas, and the resulting glass gob is shaped to a desired shape to produce a preform,

• wherein the press-molding glass preform is comprised of an optical glass comprised of phosphate glass comprising Li2O, Na2O, Nb2O5, and B2O3 as essential components, and 0-2 percent SiO2 with a refractive index (nd) of 1.64-1.72, an Abbé number (vd) of 29-36, a sag temperature (Ts) of not more than 520° C., and a liquidus temperature (LT) of not more than 900° C.

A process for preparation of a press-molding glass preform in which a glass melt is dripped or flowed out of a flow pipe and received in a receiving mold via a gas, and the resulting glass gob is shaped to a desired shape to produce a preform,

• wherein the press-molding glass preform is comprised of an optical glass comprising, by means of weight percentage, not more than 45 percent P2O5, more than 0.5 percent but not more than 6 percent Li2O, not more than 22 percent Na2O, not less than 6 percent Nb2O5, 0-35 percent WO3, 0-14 percent K2O, wherein the sum of the oxides of P, Li, Na, Nb, W, and K is not less than 80 percent, and exhibits a sag temperature (Ts) of not more than 520° C., and a liquidus temperature (LT) of not more than 900° C.

A process for preparation of a press-molding glass preform in which a glass melt is dripped or flowed out of a flow pipe and received in a receiving mold via a gas, and the resulting glass gob is shaped to a desired shape to produce a preform,

• wherein the press-molding glass preform is comprised of an optical glass comprising, by means of weight percentage, not more than 45 percent P2O5, more than 0.5 percent but not more than 6 percent Li2O, not more than 22 percent Na2O, not less than 6 percent Nb2O5, 0-35 percent WO3, 0-14 percent K2O, wherein the sum of the oxides of P, Li, Na, Nb, W, and K is not less than 80 percent, and exhibits a refractive index (nd) of not less than 1.64, and an Abbé number (vd) of not more than 36.