Non-alkali glass and method for producing same
AssigneeAsahi Glass Company, Limited
InventorsHirofumi Tokunaga, Tomoyuki Tsujimura, Manabu Nishizawa, Akio Koike
Life of this patent
Estimating the term…
Abstract
The present invention relates to a non-alkali glass having a strain point of from 710° C. to lower than 725° C., an average thermal expansion coefficient at from 50 to 300° C. of from 30×10−7 to 43×10−7/° C., a temperature T2 at which glass viscosity reaches 102 dPa·s of 1710° C. or lower, a temperature T4 at which the glass viscosity reaches 104 dPa·s of 1320° C. or lower, and containing, indicated by mol % on the basis of oxides, SiO2 66 to 70, Al2O3 12 to 14, B2O3 exceeding 0 to 1.5, MgO exceeding 9.5 to 13 (or 5 to 9.5), CaO 4 to 9 (or 4 to 11), SrO 0.5 to 4.5, BaO 0 to 0.5 and ZrO 0 to 2.
Claims8
A non-alkali glass having a strain point of from 710° C. to lower than 725° C., a glass transition point of 780° C. or higher, an average thermal expansion coefficient at from 50 to 300° C. of from 30×10−7 to 43×10−7/° C., a temperature T2 at which glass viscosity reaches 102 dPa·s of 1710° C. or lower, a temperature T4 at which the glass viscosity reaches 104 dPa·s of 1320° C. or lower,
- the non-alkali glass comprising, indicated by mol % on the basis of oxides:
- SiO2
- 66 to 70,
- Al2O3
- 12 to 14,
- B2O3
- exceeding 0 to 1.5,
- MgO
- exceeding 9.5 to 12,
- CaO
- 4 to 9,
- SrO
- 0.5 to 4.5,
- BaO
- 0 to 0.5 and
- ZrO2
- 0 to 2,
- wherein MgO+CaO+SrO+BaO is from 17 to 21,
- MgO/(MgO+CaO+SrO+BaO) is 0.4 or more,
- MgO/(MgO+CaO) is 0.4 or more, and
- MgO/(MgO+SrO) is 0.6 or more.
Dependencies are inferred from the claim text.