Deutsche Spezialglas Ag

Werner Behr

Reinhard Kassner

Georg Gliemeroth

Klaus-Peter Hanke

A highly refractive, low-density phototropic glass in which the carriers of phototropy are precipitates containing silver, halogens and copper oxide, and which has a density equal to or less than 3.0 g/cm.sup.3, a refractive index equal to or greater than 1.60 and an Abbe number equal to or greater than 40, consisting essentially of, in % by weight on an oxide basis:

Highly refractive, low-density, phototropic glass

Dark blue dyed furnace sight glass of soda-lime-silica further containing carbon and oxides of iron and cobalt with substantially no infrared transmission and which sight glass affords a view of details in the melting operation. Other ingredients may include K.sub.2 O, MgO, Al.sub.2 O.sub.3 or ZrO.sub.2.

Dark blue dyed furnace sight glass with high infrared absorption

A phototropic multilayered glass sheet incorporating at least two interfacially laminated layers, one layer consisting of a nonphototropic carrier glass, and at least one other layer consisting of a phototropic glass. In manufacture, at least one of the glass streams is characterized by having a viscosity of less than 10.sup.7.6 d PAS at the location where the streams are brought together.

Growing community of inventors

Alfeld/L., Germany

Werner Behr