US 12,077,471 B2
Alkali-free glass plate
Atsushi Mushiake, Shiga (JP); and Atsuki Saito, Shiga (JP)
Assigned to NIPPON ELECTRIC GLASS CO., LTD., Shiga (JP)
Appl. No. 17/282,480
Filed by Nippon Electric Glass Co., Ltd., Shiga (JP)
PCT Filed Sep. 25, 2019, PCT No. PCT/JP2019/037489
§ 371(c)(1), (2) Date Apr. 2, 2021,
PCT Pub. No. WO2020/071193, PCT Pub. Date Apr. 9, 2020.
Claims priority of application No. 2018-189873 (JP), filed on Oct. 5, 2018.
Prior Publication US 2021/0380468 A1, Dec. 9, 2021
Int. Cl. C03C 3/093 (2006.01); C03C 3/083 (2006.01); C03C 3/085 (2006.01); C03C 3/087 (2006.01); C03C 3/091 (2006.01); C03C 3/095 (2006.01)
CPC C03C 3/091 (2013.01) [C03C 3/083 (2013.01); C03C 3/085 (2013.01); C03C 3/087 (2013.01); C03C 3/093 (2013.01); C03C 3/095 (2013.01)] 8 Claims
 
1. An alkali-free glass sheet, comprising as a glass composition, in terms of mol %, 55% to 80% of SiO2, 10% to 25% of Al2O3, 0.1% to 4% of B2O3, 0% to 30% of MgO, 0% to 25% of CaO, 0% to 15% of SrO, 0% to 15% of BaO, 0% to 5% of ZnO, and 0% to less than 1.0% of Y2O3+La2O3, being substantially free of an alkali metal oxide, and having a strain point of 750° C. or more,
wherein the alkali-free glass sheet satisfies a relationship of [SiO2]+14×[Al2O3]−15×[B2O3]+6×[MgO]+[CaO]+14×[SrO]+16×[BaO]≥380 mol %.