Patent ID: 9670087
Date: 2017-06-06
CPC Classifications: C03C

Claim:
1. An alkali-free glass having a strain point of 725° C. or higher, an average thermal expansion coefficient at from 50 to 300° C. of from 30×10 −7 to 40×10 −7 /° C., a temperature T 2 at which a glass viscosity is 10 2 dPa·s of 1,710° C. or lower, and a temperature T 4 at which a glass viscosity is 10 4 dPa·s of 1,320° C. or lower, the alkali-free glass comprising, in terms of mol % on the basis of oxides: wherein MgO+CaO+SrO+BaO is more than 18.2 and 21 or less, MgO/(MgO+CaO+SrO+BaO) is 0.25 or more, MgO/(MgO+CaO) is 0.3 or more, MgO/(MgO+SrO) is 0.6 or more, Al the alkali-free glass does not substantially contain an alkali metal oxide.