Method of making amber glass composition having low thermal expansion

摘要

A method of making an amber borosilicate glass having a thermal expansion coefficient which ranges from 29x10<-7 >cm/cm/° C. to 48x10<-7 >cm/cm/°C. having the steps of: forming a substantially homogeneous melt comprising, in weight %, 70.0-80.0% SiO2; 10.0-15.0% B2O3; 1.0-5.0% Al2O3; 0.0-7.0% Na2O; 0.0-8.0% K2O; 0.1-2.0% Fe2O3; 0.1-5.0% TiO2; 0.0-4.0% CaO; 0.0-4.0% MgO; 0.0-4.0% BaO and SrO combined; 0.0-1.0% ZnO; 0.0-1.0% Cl2; 0.0-1.0% F2; and 0.0-1.0% ZrO2; refining the melt to remove substantially all gas bubbles from the melt; and cooling the melt to form amber glass. The amber glass formed according to the method of the present invention meets both the hydrolytic resistance requirements and light protection requirements for Type I glass in accordance with USP containers.