Strengthened glass substrates with glass frits and methods for making the same

Abstract

Strengthened glass substrates with glass frits and methods for forming the same are disclosed. According to one embodiment, a method for forming a glass frit on a glass substrate may include providing a glass substrate comprising a compressive stress layer extending from a surface of the glass substrate into a thickness of the glass substrate, the compressive stress having a depth of layer DOL and an initial compressive stress CS i . A glass frit composition may be deposited on at least a portion of the surface of the glass substrate. Thereafter, the glass substrate and the glass frit composition are heated in a furnace to sinter the glass frit composition and bond the glass frit composition to the glass substrate, wherein, after heating, the glass substrate has a fired compressive stress CS f which is greater than or equal to 0.70*CS i .

What is claimed is: 
     
         1 . An automotive glazing comprising:
 a glass substrate comprising a compressive stress layer extending from a surface of the glass substrate into a thickness of the glass substrate, the compressive stress layer having a depth of layer DOL and a fired compressive stress CS f ;   a glass frit is fully vitrified and bonded to at least a portion of the surface of the glass substrate, wherein:
 the glass frit has a softening point of less than or equal to 400° C., a glass transition temperature which is less than or equal to 375° C., and a sintering temperature of less than 450° C.; and 
 the fired compressive stress CS f  is greater than or equal to 0.70 of an initial compressive stress CS i  of the glass substrate prior to the glass frit being bonded to at least a portion of the glass substrate. 
   
     
     
         2 . The glazing of  claim 1 , wherein the substrate comprises a substrate coefficient of thermal expansion CTE S  is in a range from about 80×10 −7 /° C. to about 95×10 −7 /° C. over a temperature range from 0° C. to 300° C.; and
 the glass frit has a frit coefficient of thermal expansion CTE F  which is within +/−10×10 −7 /° C. of the substrate coefficient of thermal expansion CTE S . 
 
     
     
         3 . The glazing of  claim 2 , wherein the glass frit has a coefficient of thermal expansion CTE F  which is within +/−5×10 −7 /° C. of the coefficient of thermal expansion CTE S  of the glass substrate. 
     
     
         4 . The glazing of  claim 2 , wherein the glass frit has a coefficient of thermal expansion CTE F  which is within +/−2.5×10 −7 /° C. the coefficient of thermal expansion CTE S  of the glass substrate. 
     
     
         5 . The glazing of  claim 2 , wherein the glass frit has a coefficient of thermal expansion CTE F  which is within +/−0.5×10 −7 /° C. the coefficient of thermal expansion CTE S  of the glass substrate. 
     
     
         6 . The glazing of  claim 1 , wherein the glass substrate comprises an alkali aluminosilicate glass or an alkali borosilicate glass. 
     
     
         7 . The glazing of  claim 1 , wherein the glass substrate comprises a first surface, a second surface opposite the first surface, and a perimeter edge, wherein the glass frit is positioned on the first surface of the glass substrate directly adjacent to the perimeter edge of the glass substrate. 
     
     
         8 . The glazing of  claim 7 , further comprising any one or more of an electrical lead, wires, and antennas, wherein the glass frit conceals the one or more of the electrical lead, wires, and antennas. 
     
     
         9 . The glazing of  claim 1 , wherein the initial compressive stress CS i  is greater than about 600 MPa. 
     
     
         10 . The glazing of  claim 1 , wherein the DOL is greater than about 30 μm. 
     
     
         11 . The glazing of  claim 1 , wherein the glass frit is substantially black in color. 
     
     
         12 . The glazing of  claim 1 , wherein the glass frit comprises a Sb—V-phosphate glass frit composition. 
     
     
         13 . The glazing of  claim 12 , wherein the glass frit composition comprises V 2 O 5  in an amount greater than or equal to about 40 mol. % and less than or equal to about 60 mol. %, P 2 O 5  in an amount greater than equal to about 15 mol. % and less than or equal to about 30 mol. %, and Sb 2 O 3  in an amount greater than or equal to about 10 mol. % and less than or equal to about 35 mol. %. 
     
     
         14 . The glazing of  claim 12 , wherein the glass frit composition further comprises any one or more of Al 2 O 3 , Fe 2 O 3 , and TiO 2 . 
     
     
         15 . The glazing of  claim 1 , wherein the glass frit comprises a composition having a glass transition temperature in the range from about 300° C. to about 350° C. and a sintering temperature from about 400° C. to about 425° C. 
     
     
         16 . An automotive glazing comprising:
 a glass substrate comprising a compressive stress layer extending from a surface of the glass substrate into a thickness of the glass substrate, the compressive stress layer having a depth of layer DOL and a fired compressive stress CS f , and a substrate coefficient of thermal expansion CTE S  is in a range from about 80×10 −7 /° C. to about 95×10 −7 /° C. over a temperature range from 0° C. to 300° C.   a glass frit is fully vitrified and bonded to at least a portion of the surface of the glass substrate, wherein the glass frit has a softening point of less than or equal to 400° C., a glass transition temperature which is less than or equal to 375° C., a sintering temperature of less than 450° C., and a frit coefficient of thermal expansion CTE F  which is within +/−10×10 −7 /° C. of the substrate coefficient of thermal expansion CTE S ; and
 the fired compressive stress CS f  is greater than or equal to 0.70 of an initial compressive stress CS i  of the glass substrate prior to the glass frit being bonded to at least a portion of the glass substrate. 
   
     
     
         17 . The automotive glazing of  claim 16 , wherein the glass frit comprises a Sb—V-phosphate glass frit composition, the glass frit composition includes from about 40 mol. % to about 60 mol. % V 2 O 5 ; from about 15 mol. % to about 30 mol. % P 2 O 5 ; from about 20 mol. % to about 35 mol. % Sb 2 O 3 ; from about 0 mol. % to about 2 mol. % Al 2 O 3 ; from about 0 mol. % to about 5 mol. % Fe 2 O 3 ; and from about 0 mol. % to about 2 mol. % TiO 2 . 
     
     
         18 . The automotive glazing of  claim 17 , wherein the glass frit composition is free of antimony and compounds containing antimony. 
     
     
         19 . The automotive glazing of  claim 17 , wherein the glass substrate comprises a first surface, a second surface opposite the first surface, and a perimeter edge, wherein the glass frit is positioned on the first surface of the glass substrate directly adjacent to the perimeter edge of the glass substrate, wherein the glazing further comprises any one or more of an electrical lead, wires, and antennas attached to the glass substrate, and wherein the glass frit conceals the one or more of the electrical lead, wires, and antennas. 
     
     
         20 . An automotive glazing comprising:
 a glass substrate comprising a first surface, a second surface opposite the first surface, a perimeter edge, and any one or more of an electrical lead, wires, and antennas, the glass substrate further comprising a compressive stress layer extending from a surface of the glass substrate into a thickness of the glass substrate, the compressive stress layer having a depth of layer DOL and a fired compressive stress CS f  that is greater than or equal to 420 MPa and a substrate coefficient of thermal expansion CTE S  is in a range from about 80×10 −7 /° C. to about 95×10 −7 /° C. over a temperature range from 0° C. to 300° C.;   a glass frit fully vitrified and bonded to at least a portion of the first surface of the glass substrate directly adjacent to the perimeter edge of the glass substrate, wherein the glass frit has a softening point of less than or equal to 400° C., a glass transition temperature which is less than or equal to 375° C., a sintering temperature of less than 450° C., and a frit coefficient of thermal expansion CTE F  which is within +/−10×10 −7 /° C. of the substrate coefficient of thermal expansion CTE S .