Non-alkali glass, and process for production of non-alkali glass

摘要

The present invention relates to an alkali-free glass having a strain point of 735° C. or higher, an average thermal expansion coefficient at from 50 to 350° C. of from 30×10−7 to 40×10−7/° C., a temperature T2 at which a glass viscosity is 102 dPa·s of 1,710° C. or lower, a temperature T4 at which a glass viscosity is 104 dPa·s of 1,340° C. or lower, and a devitrification temperature of 1,330° C. or lower, the alkali-free glass including, in terms of mol % on the basis of oxides: SiO2 66 to 69, Al2O3 12 to 15, B2O3 0 to 1.5, MgO 6 to 9.5, CaO 7 to 9, SrO 0.5 to 3, BaO 0 to 1, and ZrO2 0 to 2, in which MgO+CaO+SrO+BaO is from 16 to 18.2, MgO/(MgO+CaO+SrO+BaO) is 0.35 or more, MgO/(MgO+CaO) is 0.40 or more and less than 0.52, and MgO/(MgO+SrO) is 0.45 or more.

主权项

1. An alkali-free glass comprising, in terms of mol % on the basis of oxides:SiO2 66 to 69,Al2O3 12 to 15,B2O3  0 to 1.5,MgO  6 to 9.5,CaO  7 to 9,SrO0.5 to 3,BaO  0 to 1, andZrO2  0 to 2, wherein MgO+CaO+SrO+BaO is from 16 to 18.2, MgO/(MgO+CaO+SrO+BaO) is 0.35 or more, and MgO/(MgO+CaO) is 0.40 or more and less than 0.52, wherein the alkali-free glass has a strain point of 735° C. or higher, an average thermal expansion coefficient at from 50 to 350° C. of from 30×10−7 to 40×10−7/° C., a temperature T2 at which a glass viscosity is 102 dPa·s of 1,710° C. or lower, a temperature T4 at which a glass viscosity is 104 dPa·s of 1,340° C. or lower, and a devitrification temperature of 1,330° C. or lower.