Patent ID: 9714193
Date: 2017-07-25
CPC Classifications: C03B,C03C,G01N,Y02P

Claim:
1. A float glass for chemical strengthening, comprising a bottom surface coming into contact with a molten metal at the time of forming of the float glass and a top surface opposing the bottom surface, wherein a difference Δ(N—Na 2 O 2 ) determined by subtracting a square of a normalized Na 2 O surface concentration of the bottom surface from a square of a normalized Na 2 O surface concentration of the top surface is 0.040 or less, where the normalized Na 2 O surface concentration is obtained by dividing an Na 2 O concentration in a measured surface, which is the bottom surface or the top surface, by an Na 2 O concentration at a depth of 100 μm from the measured surface, where the Na 2 O concentration is a value measured by a fluorescent X-ray analysis using an Na—Kα ray.