Tempered glass and manufacturing method for the same

Abstract

A tempered glass of the present invention having a compression stress layer is characterized in that a β-OH value is 0.01 to 0.5/mm. Here, the “β-OH value” is a value obtained from the following equation by measuring the transmittance of glass by FT-IR. β-OH value=(1/ X )log 10( T 1 /T 2 ) X: thickness of glass (mm) T 1 : transmittance (%) at a reference wavelength of 3,846 cm −1 T 2 : minimum transmittance (%) at a hydroxyl group absorption wavelength of around 3,600 cm −1

1 - 21 . (canceled) 
     
     
         22 . A tempered glass, which has a compression stress layer, and has a glass composition comprising, in terms of mass %, 45 to 75% of SiO 2 , 5 to 25% of Al 2 O 3 , 8 to 30% of Li 2 O+Na 2 O+K 2 O, 8 to 20% of Na 2 O, and 0 to 10% of K 2 O,
 wherein the tempered glass has a β-OH value of 0.01 to 0.45/mm, and   wherein the tempered glass is formed by a float method or an overflow down draw method after melting in a continuous melting furnace.   
     
     
         23 . The tempered glass according to  claim 22 , which has a β-OH value of 0.4/mm or less. 
     
     
         24 . The tempered glass according to  claim 22 , which has a β-OH value of 0.35/mm or less. 
     
     
         25 . The tempered glass according to  claim 22 , which has a β-OH value of 0.3/mm or less. 
     
     
         26 . The tempered glass according to  claim 22 , which has a liquidus viscosity of 10 4.0  dPa·s or more. 
     
     
         27 . The tempered glass according to  claim 22 , which has a substrate shape. 
     
     
         28 . The tempered glass according to  claim 22 , which is used as a cover glass of a touch panel display. 
     
     
         29 . The tempered glass according to  claim 22 , which is used as a cover glass of a mobile phone. 
     
     
         30 . A glass for tempering, which has a glass composition comprising, in terms of mass %, 45 to 75% of SiO 2 , 5 to 25% of Al 2 O 3 , 8 to 30% of Li 2 O+Na 2 O+K 2 O, 8 to 20% of Na 2 O, and 0 to 10% of K 2 O,
 wherein the glass has a β-OH value of 0.01 to 0.45/mm, and   wherein the glass is formed by a float method or an overflow down draw method after melting in a continuous melting furnace.