US 9,809,486 B2
Tempered glass and glass
Takashi Murata, Otsu (JP)
Assigned to NIPPON ELECTRIC GLASS CO., LTD., Shiga (JP)
Filed by Nippon Electric Glass Co., Ltd., Shiga (JP)
Filed on Apr. 30, 2014, as Appl. No. 14/265,901.
Application 14/265,901 is a continuation of application No. 13/144,537, granted, now 8,748,002, previously published as PCT/JP2009/070553, filed on Dec. 8, 2009.
Claims priority of application No. 2009-010527 (JP), filed on Jan. 21, 2009.
Prior Publication US 2014/0230492 A1, Aug. 21, 2014
Int. Cl. C03C 3/00 (2006.01); C03C 21/00 (2006.01); C03C 3/093 (2006.01); C03C 3/11 (2006.01); C03C 3/087 (2006.01); C03C 3/091 (2006.01); C03B 17/06 (2006.01); C03B 18/02 (2006.01); C03B 23/023 (2006.01)
CPC C03C 3/093 (2013.01) [C03C 3/087 (2013.01); C03C 3/091 (2013.01); C03C 3/11 (2013.01); C03C 21/002 (2013.01); C03B 17/064 (2013.01); C03B 18/02 (2013.01); C03B 23/023 (2013.01); Y10T 428/26 (2015.01); Y10T 428/315 (2015.01)] 21 Claims
 
1. A method for producing a tempered glass comprising the steps of:
preparing a glass batch so that a glass for tempering comprises, as a glass composition, in terms of mass %, 45 to 57.5% of SiO2, 22 to 30% of Al2O3, 0 to 3% of CaO, 8 to 30% of Li2O+Na2O+K2O, 0 to 0.1% of Li2O, 8 to 20% of Na2O, less than 0.1% of As2O3, and less than 0.1% of Sb2O3, wherein the glass batch comprises a hydroxide raw material;
melting the glass batch to obtain a molten glass,
forming the molten glass into a glass for tempering having a β-OH value of 0.3 to 1/mm; and
subjecting the glass for tempering to an ion-exchange treatment to form a compression stress layer on a surface of the glass for tempering.