WERKWIJZE TER BEREIDING VAN OPAALGLAS.

摘要

This invention relates to spontaneously opacifiable glasses containing fluorine and having as the principal opacifying phase an immiscible, or insoluble, fluorine containing glass; the opal is an alkali aluminosilicate glass with additions of divalent oxides, fluorine, and boric-oxide. These glasses are opacified by cooling the glass body from the melt to a temperature below about the opal liquidus thereof at a rate greater than about 2 DEG C./minute so as to homogeneously separate an insoluble glassy opacifying phase.