Tempered glass, tempered glass plate, and glass for tempering

Patent metadata

Field	Value
Publication number	US-2016347656-A1
Application number	US-201615234491-A
Country	US
Kind code	A1
Filing date	Aug 11, 2016
Priority date	Jun 8, 2012
Publication date	Dec 1, 2016
Grant date	—

Abstract

A tempered glass has a compressive stress layer in a surface thereof, includes as a glass composition, in terms of mass %, 50 to 80% of SiO 2 , 10 to 30% of Al 2 O 3 , 0 to 6% of B 2 O 3 , 0 to 2% of Li 2 O, and 5 to 25% of Na 2 O, and is substantially free of As 2 O 3 , Sb 2 O 3 , PbO, and F.

First claim

1 - 26 . (canceled)

27 . A method for manufacturing a tempered glass sheet comprising:
blending glass raw materials so as to obtain a tempered glass sheet comprising as a glass composition, in terms of mass %, 50 to 80% of SiO 2 , 10 to 30% of Al 2 O 3 , 0 to 6% of B 2 O 3 , 0 to 2% of Li 2 O, and 5 to 25% of Na 2 O, and being substantially free of As 2 O 3 , Sb 2 O 3 , PbO, and F; heat-melting and fining the glass raw materials in a continuous melting furnace; loading the resultant molten glass into a forming trough of alumina; forming and annealing the molten glass by an overflow down-draw method so as to attain a fictive temperature Tf of 500° C. or more; and then cutting the tempered glass flowing down from the forming trough of alumina.

28 . The method for manufacturing a tempered glass sheet according to claim 27 ,
wherein the tempered glass sheet is cut at a position spaced apart downwardly by 1,000 mm or more from a lower end of the forming trough of alumina.

29 . The method for manufacturing a tempered glass sheet according to claim 27 ,
wherein the glass raw materials are blended so as to obtain a tempered glass sheet comprising as a glass composition, in terms of mass %, 50 to 76% of SiO 2 , more than 16.0 to 30% of Al 2 O 3 , 0 to 6% of B 2 O 3 , 0 to less than 1.0% of Li 2 O, more than 7.0 to 25% of Na 2 O, 0 to 2% of SrO, 0 to 0.5% of TiO 2 , 0 to 2% of ZrO 2 , 0.2 to 3% of SnO 2 , and 0 to 1% of P 2 O 5 , and having a molar ratio (MgO+CaO+SrO+BaO)/(Al 2 O 3 +B 2 O 3 ) of from 0 to 0.55.

30 . The method for manufacturing a tempered glass sheet according to claim 27 ,
wherein the glass raw materials are blended so as to obtain a tempered glass sheet comprising as a glass composition, in terms of mass %, 50 to 73% of SiO 2 , more than 16.0 to 30% of Al 2 O 3 , 0 to 6% of B 2 O 3 , 0 to less than 1.0% of Li 2 O, more than 7.0 to 25% of Na 2 O, 10 to 30% of Li 2 O+Na 2 O+K 2 O, 0 to 4% of CaO, 0 to 2% of SrO, 0 to 0.5% of TiO 2 , 0 to 2% of ZrO 2 , 0.2 to 3% of SnO 2 , and 0 to 1% of P 2 O 5 , and having a molar ratio (MgO+CaO+SrO+BaO)/(Al 2 O 3 +B 2 O 3 ) of from 0 to 0.55.

31 . A method for manufacturing a tempered glass sheet comprising: subjecting, to ion exchange treatment, the tempered glass sheet obtained by the method according to claim 27 , so that a compression stress value of the compression stress layer is 300 MPa or more and 1,200 MPa or less, and a thickness of the compression stress layer is 10 um or more and 60 um or less;
and obtaining the tempered glass sheet.

32 . The method for manufacturing a tempered glass sheet according to claim 31 ,
wherein the tempered glass sheet is subjected to ion exchange treatment so as to have a dimensional change rate S before and after the ion exchange treatment from −1,000 ppm to +1,000 ppm.

Assignees

• Nippon Electric Glass Co

Inventors

• Kawamoto Kosuke
• Murata Takashi
• TOJYO Takako

Classifications

• C03C3/087

  containing calcium oxide, e.g. common sheet or container glass · CPC title

• C03B25/12

  of glass sheets · CPC title

• C03C3/085

  containing an oxide of a divalent metal · CPC title

• C03C3/093

  containing zinc or zirconium · CPC title

• C03B17/064

  by the overflow downdraw fusion process; Isopipes therefor · CPC title