US 7,488,538 B2
Coated article including soda-lime-silica glass substrate with lithium and/or potassium to reduce sodium migration and/or improve surface stability and method of making same
Leonid M. Landa, Brownstown, Mich. (US); Ksenia A. Landa, Brownstown, Mich. (US); Anthony V. Longobardo, Oak Grove, Mich. (US); and Vijayen S. Veerasamy, Ann Arbor, Mich. (US)
Assigned to Guardian Industries Corp., Auburn Hills, Mich. (US)
Filed on Aug. 08, 2005, as Appl. No. 11/198,404.
Prior Publication US 2007/0036987 A1, Feb. 15, 2007
Int. Cl. B32B 15/00 (2006.01)
U.S. Cl. 428—432  [428/428; 428/434] 20 Claims
OG exemplary drawing
 
1. A coated article comprising:
a glass substrate;
a low-E coating supported by the glass substrate, the low-E coating including at least one infrared (IR) reflecting layer comprising silver sandwiched between at least first and second dielectric layers;
wherein the glass substrate is comprised of a glass composition comprising:
   
  Ingredient wt. %
   
  SiO2 67-75%
  Na2O  6-20%
  CaO  5-15%
  Al2O3  0-7%
  K2O  0-7%
   
wherein the glass composition of the glass substrate further comprises from about 0.1 to 6.0% lithium oxide in order to reduce mobility of alkali ions in the glass substrate and thus reduce sodium migration.