초록 ▼

A glass for tungsten halogen lamp glass envelopes, glass filter lenses, and glass filters consisting essentially in terms of weight percent on the oxide basis, of about 50-62% SiO2, 10-17% Al2O3, 0-6% B2O3, 3.6-10% CaO, 0-7.5% MgO, 0.1-0.3% SrO, 2.4-18% BaO, 0-1% ZnO, 1-8% Nd2O3. The glass exhibits

A glass for tungsten halogen lamp glass envelopes, glass filter lenses, and glass filters consisting essentially in terms of weight percent on the oxide basis, of about 50-62% SiO2, 10-17% Al2O3, 0-6% B2O3, 3.6-10% CaO, 0-7.5% MgO, 0.1-0.3% SrO, 2.4-18% BaO, 0-1% ZnO, 1-8% Nd2O3. The glass exhibits the following physical properties: strain point between about 665.degree. C. to about 750.degree. C., coefficient of thermal expansion to the set point of between about 49-59.times.10-7/.degree. C., liquidus temperature below 1320.degree. C., viscosity at liquidus temperature greater than 2,000 poises, and transmission at 585 nm of between 5-60% for a 1.2 mm thickness. The lamp color temperature for a tungsten halogen lamp containing a glass envelope, a glass filter lens, or a glass filter prepared from the glass composition is increased from about 3 to 7% above a similar glass with no Nd2O3, and the total visible lumen loss is limited to less than about 10%.

대표청구항 ▼

1. Glass compositions suitable as an envelope for a tungsten halogen lamp, consisting essentially in terms of weight percent on the oxide basis, of about 50-62% SiO2, 10-17% Al2O3, 0-6% B2O3, 3.6-10% CaO, 0-7.5% MgO, 0.1-0.3% SrO, 2.4-18% BaO, 0-1% ZnO, 1-8% Nd2O3, and exhibiting a strain point betw

1. Glass compositions suitable as an envelope for a tungsten halogen lamp, consisting essentially in terms of weight percent on the oxide basis, of about 50-62% SiO2, 10-17% Al2O3, 0-6% B2O3, 3.6-10% CaO, 0-7.5% MgO, 0.1-0.3% SrO, 2.4-18% BaO, 0-1% ZnO, 1-8% Nd2O3, and exhibiting a strain point between about 665.degree. C. to about 750.degree. C., a coefficient of thermal expansion from 25.degree. C. to the set point, 5.degree. C. above the glass strain point, between about 49-59.times.10-7/.degree. C., a liquidus temperature below about 1320.degree. C., a viscosity at the liquidus temperature greater than about 2,000 poises, and a transmission at 585 nm of about 5 to about 60% for a 1.2 mm thickness.