Patent ID: 9714188
Date: 2017-07-25
CPC Classifications: C03C,Y10T

Claim:
1. A glass composition comprising: from 63.2 to 69.2 mol % SiO from 8.9 to 12.0 mol % Al from 9.7 to 13.4 mol % B from 3.0 to 7.1 mol % MgO from 8.8 to 11.8 mol % Na wherein the glass composition has a viscosity and the log of the viscosity has a value between 3 and 4 at at least one temperature from 900° C. to 1300° C., and the glass has a coefficient of thermal expansion, CTE 20-300° C. , of from 55 to 68×10 −7 /° C.