Patent ID: 8828898

Claim:
A glass plate, comprising: soda lime silica glass that comprises MgO, CaO, Na 2 O, and Al 2 O 3 , wherein the glass plate is obtained by a float process or a downdraw method, a content of MgO in the glass plate is at least 4.5% by mass percentage based on oxide, a content of Na 2 O in the glass plate is from 10 to 20% by mass percentage based on oxide, a ratio of the content of MgO by mass percentage based on oxide, to a content of CaO by mass percentage based on oxide, ([MgO]/[CaO]), is larger than 1, a value Q obtained by formula (1) is at least 20: Q =([MgO]/[CaO])×([CaO]+[Na 2 O]−[Al 2 O 3 ]) (1), [MgO] is the content of MgO by mass percentage based on oxide, [CaO] is the content of CaO by mass percentage based on oxide, [Na 2 O] is a content of Na 2 O by mass percentage based on oxide, [Al 2 O 3 ] is a content of Al 2 O 3 by mass percentage based on oxide, and a content of B 2 O 3 if present by mass percentage based on oxide is at most 1%.