Abstract: The present invention is directed to the production of essentially dry alkali metal (R.sup.1) aluminofluorophosphate glasses optionally containing at least one divalent metal (R.sup.2) which exhibits a transition temperature below about 350.degree. C., good chemical durability, resistance to weathering, and glass stability, and which demonstrate the capability of being molded at temperatures below 400.degree. C. into complex shapes. The alkali metal aluminofluorophosphate glasses consist essentially, as analyzed on an atomic basis, between about R.sup.1 AlP.sub.2 F.sub.2 O.sub.6 and R.sup.1 .sub.3.75 AlP.sub.3 F.sub.4 O.sub.9 with the requirement that the components comply with the following atomic ratios:F:Al >2 but <4 (preferred 3.+-.0.5)P:Al >2 but <3R.sup.1 :P >0.5 but <1.24 (preferred >0.75 but <1.1)Those values, expressed in terms of weight percent as analyzed on the oxide basis, convert to the following approximate ranges:R.sup.1.sub.2 O 13-38Al.sub.2 O.sub.3 16-23P.sub.2 O.sub.

Abstract: Alkali-Ta.sub.2 O.sub.5 -B.sub.2 O.sub.3 -P.sub.2 O.sub.5 glass compositions suitable for providing molded optical elements or the like, exhibiting glass transition temperatures below 500.degree. C., refractive index values (n.sub.d) above 1.523, and acceptable water durability are disclosed.

Abstract: Glass compositions in the tin-phosphorus-oxyfluoride composition system exhibiting very low glass transition temperatures and capable of being modified by the addition of selected constituents to exhibit excellent stability in a humid environment, are described.

Abstract: The instant invention is concerned with the production of glasses which are capable of being molded or otherwise shaped under pressure at temperatures not exceeding about 450.degree. C. Such glasses consist essentially, in mole percent as analyzed on the oxide basis, of at least 20% but less than 50% P.sub.2 O.sub.5, 15-45% R.sub.2 O, wherein R.sub.2 O consists of 0-45% Li.sub.2 O, 0-20% Na.sub.2 O, and 0-10% K.sub.2 O, and 0-20% RO, wherein RO consists of 0-10% MgO, 0-15% CaO, 0-20% SrO, and 0-20% BaO, with about 0.3-3% by weight F as analyzed in the final glass. Useful additions to the base compositions include PbO, La.sub.2 O.sub.3, ZnO, and B.sub.2 O.sub.3.

Abstract: The present invention is concerned with the production of sodium and/or potassium hydrosilicate glass bodies. The basis of the invention resides in the hydration of anhydrous sodium and/or potassium silicate glass bodies in aqueous alcohol solutions to impart enhanced mechanical strength and thermoplastic properties thereto. The hydrating process, which permits close control to be maintained over the water content absorbed in the glass, can be carried out in liquid solutions of water and relatively short chain, i.e. up to about five carbon atoms, aliphatic alcohols or in gaseous atmospheres of such solutions. An ion exchange reaction of Li.sup.+ ions or protons with Na.sup.+ and/or K.sup.+ ions can be promoted at temperatures above the transformation range of the hydrated glass, and an exchange of K.sup.+ ions for Na.sup.+ and/or Li.sup.+ ions at temperatures below the transformation range.

Abstract: An optical glass article having a desired surface figure and demonstrating maximum theoretical light transmission can be prepared by forming a base anhydrous glass of defined compositional ranges, hydrating the glass, partially dehydrating the glass at a temperature above the softening point and, using an inert gas, at a pressure above the vapor pressure of water contained therein, and then molding a preformed blank of the glass against a die having a desired optical quality surface figure, the molding being under conditions sufficient to transfer the surface figure of the die to the glass. The base glass comprises, in mole percent, about 70 to 82% SiO.sub.2, 10 to 17% Na.sub.2 O and/or K.sub.2 O, and 5 to 15% of an oxide or oxides selected from ZnO and PbO. The water content of the partially dehydrated glass ranges from about 3 to 8 wt. percent and the molded glass has a substantially uniform refractive index throughout its bulk.

Abstract: An optical glass article having a desired surface figure and demonstrating maximum theoretical light transmission can be prepared by forming a base anhydrous glass of defined compositional ranges, hydrating the glass, partially dehydrating the glass at a temperature above the softening point and, using an inert gas, at a pressure above the vapor pressure of water contained therein, and then molding a preformed blank of the glass against a die having a desired optical quality surface figure, the molding being under conditions sufficient to transfer the surface figure of the die to the glass. The base glass comprises, in mole percent, about 70 to 82% SiO.sub.2, 10 to 17% Na.sub.2 O and/or K.sub.2 O, and 5 to 15% of an oxide or oxides selected from ZnO and PbO. The water content of the partially dehydrated glass ranges from about 3 to 8 wt. percent and the molded glass has a substantially uniform refractive index throughout its bulk.