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AssigneeAsahi Glass Company, Limited
InventorsTomoyuki TSUJIMURA, Manabu Nishizawa, Akio Koike
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The present invention relates to 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 T2 at which a glass viscosity is 102 dPa·s of 1,710° C. or lower, and a temperature T4 at which a glass viscosity is 104 dPa·s of 1,320° C. or lower, the alkali-free glass including, in terms of mol % on the basis of oxides, SiO2: 66 to 70, Al2O3: 12 to 15, B2O3: 0 to 1.5, MgO: more than 9.5 and 13 or less, CaO: 4 to 9, SrO: 0.5 to 4.5, BaO: 0 to 1, and ZrO2: 0 to 2, in which 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, MgO/(MgO+SrO) is 0.6 or more, and the alkali-free glass does not substantially contain an alkali metal oxide.
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 T2 at which a glass viscosity is 102 dPa·s of 1,710° C. or lower, and a temperature T4 at which a glass viscosity is 104 dPa·s of 1,320° C. or lower, the alkali-free glass comprising, in terms of mol % on the basis of oxides:
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 T2 at which a glass viscosity is 102 dPa·s of 1,710° C. or lower, and a temperature T4 at which a glass viscosity is 104 dPa·s of 1,320° C. or lower, the alkali-free glass comprising, in terms of mol % on the basis of oxides:
Dependencies are inferred from the claim text.