TiO{11 {13 P{11 O{11 {13 Na{11 O{13 WO{11 {11 OPTICAL GLASSES AND METHOD

Claim 2

The optical glass of claim 1 being composed of 32.3 percent, by weight, of phosphorus pentoxide, 17.7 percent, by weight, of sodium oxide, 30.0 percent, by weight, of titanium dioxide, and 20.0 percent, by weight, of tungsten oxide, said glass having an ne of 1.8012, a Nu e of 20.8, a Delta Nu e of + 18.7, a specific gravity of 3.33 g./cc.

Claim 3

The optical glass of claim 1 being composed of 32.3 percent, by weight, of phosphorus pentoxide, 17.7 percent, by weight, of sodium oxide, 5.0 percent, by weight, of lead monoxide, 10.0 percent, by weight, of titanium dioxide, 15.0 percent, by weight, of niobium pentoxide, 20.0 percent, by weight, of tungsten trioxide, ne: 1.7447 Nu e: 24.9 Delta Nu e: + 14.7 specific gravity: 3.53 g./cc.

Claim 4

The optical glass of claim 1 being composed of 28.7 percent, by weight, of phosphorus pentoxide, 3.0 percent, by weight, of boron trioxide, 16.3 percent, by weight, of sodium oxide, 19.5 percent, by weight, of titanium dioxide, 15.0 percent, by weight, of niobium pentoxide, 17.5 percent, by weight, of tungsten trioxide, ne: 1.8051 Nu e: 21.6 Delta Nu e: + 21.5 specific gravity: 2.87 g./cc.

Claim 5

The optical glass of claim 1 being composed of 32.3 percent, by weight, of phosphorus pentoxide, 17.7 percent, by weight, of sodium oxide, 30.0 percent, by weight, of titanium dioxide, 7.5 percent, by weight, of niobium pentoxide, 12.5 percent, by weight, of tungsten trioxide, ne: 1.8191 Nu e: 20.4 Delta Nu e: + 15.2 specific gravity: 3.29 g./cc.

Claim 6

The optical glass of claim 1 being composed of 35.7 percent, by weight, of phosphorus pentoxide, 7.7 percent, by weight, of sodium oxide, 6.6 percent, by weight, of magnesium oxide, 30.0 percent, by weight, of titanium dioxide, 20.0 percent, by weight, of tungsten trioxide, ne: 1.8640 Nu e: 19.2 specific gravity: 3.43 g./cc.

Claim 7

The optical glass of claim 1 being composed of 27.0 percent, by weight, of phosphorus pentoxide, 10.8 percent, by weight, of sodium oxide, 12.2 percent, by weight, of lead monoxide, 30.0 percent, by weight, of titanium dioxide, 20.0 percent, by weight, of tungsten trioxide, ne: 1.8975 Nu e: 18.5 specific gravity: 3.72 g./cc.

Claim 8

In a process of producing an optical glass of high index of refraction ne between 1.74 and 1.90, high dispersion Nu e between 25 and 17, and high positive anomalous partial dispersion, said process comprising the step of melting a mixture of glass components consisting of between 35.0 and 50.0 percent, by weight, of sodium metaphosphate, between 0 and 15.0 percent, by weight, of sodium pyrophosphate, between 20.0 and 30.0 percent, by weight, of titanium dioxide, and between 20.0 and 30.0 percent, by weight, of tungsten trioxide at a temperature between about 1,200* C. and about 1,300* C., while stirring, to form a glass melt of the above given composition.

Claim 9

In a process of producing an optical glass of high index of refraction ne between 1.74 and 1.90, high dispersion Nu e between 25 and 17, and high positive anomalous partial dispersion, said process comprising the step of melting a mixture of glass components consisting of between 10.0 and 50.0 percent, by weight, at least one of an alkali metal phosphate compound selected from the group consisting an alkali metal metaphosphate and an alkali metal pyrophosphate with the proviso that the content of lithium metaphosphate, sodium metaphosphate, or potassium metaphosphate is between 0 and 50 percent, by weight; between 10.0 and 30.0 percent, by weight, of titanium dioxide; between 12.5 and 30.0 percent, by weight, of a tungsten compound selected from the group consisting of tungsten trioxide and sodium tungstate with the proviso that the content of sodium tungstate is between 12.5 and 26.3 percent, by weight; between 0 and 40.0 percent, by weight, of a metaphosphate selected from the group consisting of magnesium metaphosphate, calcium metaphosphate, and barium metaphosphate with the proviso that the content of magnesium metaphosphate or barium metaphosphate is between 0 and 30 percent, by weight; between 0 and 10.0 percent, by weight, of aluminum metaphosphate; between 0 and 20.0 percent, by weight, of lead metaphosphate; between 0 and 5.0 percent, by weight, of lead monoxide; between 0 and 21.0 percent, by weight, of niobium pentoxide; between 0 and 5.7 percent, by weight, of boron trioxide; and between 0 and 12.0 percent, by weight, of sodium metaborate at a temperature between about 1,200* C. and about 1,300* C., while stirring, to form a glass melt of the above given composition.