Patent ID: 8431503

Claim:
An alkali-free glass, comprising, in terms of mol % on the basis of oxides: SiO 2 : 66 to 70; Al 2 O 3 : 12 to 13.5; B 2 O 3 : 0.7 to 1.5; MgO: 6 to 9.5; CaO: 4.5 to 6; SrO: 4 to 7; BaO: 0 to less than 1; and ZrO 2 : 0 to 0.5, provided that: MgO+CaO+SrO+BaO is 14 to 18.2; MgO/(MgO+CaO+SrO+BaO) is 0.35 or greater; MgO/(MgO+CaO) is 0.52 or greater; and MgO/(MgO+SrO) is 0.45 or greater, wherein the alkali-free glass does not substantially contain alkali metal oxides, and has the following characteristics: a strain point of 725° C. or higher; an average thermal expansion coefficient at 50 to 300° C. of 30×10 −7 to 40×10 −7 /° C.; a temperature T 2 at which a glass viscosity becomes 10 2 dPa·s of 1,710° C. or lower; a temperature T 4 at which a glass viscosity becomes 10 4 dPa·s of 1,315° C. or lower; a Young's modulus of 84 GPa or higher; a glass surface devitrification temperature (T c ) of 1,330° C. or lower; and a glass internal devitrification temperature (T d ) of 1,250° C. or lower, such that T 4 −T d is equal to or greater than 80° C.