Method of forming durable glass enamel

1. A method of forming a multi-layered enamel, comprising:

forming an interface layer on a surface of a glass substrate, the interface layer being formed by depositing and firing an interface material comprising from about 35 wt % to about 95 wt % glass frit, from about 5 wt % to about 65 wt % pigment, and from about 2 wt % to about 10 wt % expansion modifier,

forming an opaque layer disposed on the interface layer, the opaque layer being formed by deposition and firing of an opaque material comprising from about 5 wt % to about 60 wt % glass frit, from about 40 wt % to about 95 wt % pigment, and from about 0 wt % to about 15 wt % expansion modifier, and

forming a durable layer disposed on the opaque layer, the durable layer being formed by formed by deposition and firing of a durable material comprising from about 60 wt % to about 98 wt % glass frit, and from about 2 wt % to about 40 wt % pigment,

wherein the durable layer defines an exposed surface of the multi-layer enamel.

2. The method according to claim 1 , wherein:

each of the interface material, the opaque material, and the durable material further comprises a solvent and a binder; and

deposition comprises digitally printing each of the interface material, the opaque material, and the durable material and drying to remove the solvent therefrom.

3. The method according to claim 1 , wherein firing of each of the interface material, the opaque material, and the durable material is performed simultaneously.

4. The method according to claim 1 , wherein firing of each of the interface material, the opaque material, and the durable material is performed separately.

5. The method according to claim 1 , wherein:

the glass frit of the interface material comprises zinc borosilicate glass frit, the pigment of the interface material is selected from the group consisting of mixed metal oxides of CuCr, CuCrMn, FeCrCo, TiO 2 , and combinations thereof, and

the expansion modifier of the interface material is selected from the group consisting of cordierite, beta-eucryptite, zirconia, zircon, and combinations thereof.

6. The method according to calm 5 , wherein the interface material further includes ion exchange control material including at least one of sodium ions or potassium ions.

7. The method according to claim 1 , wherein:

the glass frit of the opaque material is selected from the group consisting of boron based glass frit, zinc based glass frit, and combinations thereof,

the pigment of the opaque material is selected from the group consisting of mixed metal oxides of (a) copper and chromium; (b) copper, chromium, and manganese, (c) iron, chromium, and cobalt, and (d) titanium, and any combination of (a), (b), (c), and (d), and

the expansion modifier of the opaque material is selected from the group consisting of cordierite, beta-eucryptite, zirconia, zircon, and combinations thereof.

8. The method according to claim 1 , wherein the pigment of the durable material is selected from the group consisting of mixed metal oxides of CuCr, CuCrMn, FeCrCo, TiO 2 , and combinations thereof, and the glass frit in the durable material is selected from the group consisting of composition 1, composition 2, composition 3, composition 4, composition 5, and combinations thereof, wherein:

composition 1 comprises:

(a) 38-60 wt % SiO 2 ,

(b) 5.1-22.9 wt % B 2 O 3 ,

(c) 8.1-18 wt % TiO 2 ,

(d) 0.1-14.9 wt % ZnO,

(e) 0.1-4.5 wt % Li 2 O

(f) 0.1-18 wt % K 2 O, and

(g) 1-7 wt % F −1 ;

composition 2 comprises:

(a) 40-70wt % Bi 2 O 3 ,

(b) 25-40 wt % SiO 2 ,

(c) 0-4 wt % TiO 2 ,

(d) 0-5 wt % K 2 O,

(e) 0-4 wt % Li 2 O, and

(f) 0-4 wt % F −1 ;

composition 3 comprises:

(a) 40 - 70 wt % Bi 2 O 3 ,

(b) 25 - 40 wt % SiO 2 ,

(c) 0-4wt % TiO 2

(d) 0-5 wt % K 2 O,

(e) 0-4 wt % Li 2 O,

(f) 0-4 wt % F −1 ,

(g) 0-3 wt % B 2 O 3 ,

(h) 0-5 wt % Al 2 O 3 , and

(i) 0-8 wt % Na 2 O;

composition 4 comprises:

(a) 38-60 wt % SiO 2 ,

(b) 5.1-22.9 wt % B 2 O 3 ,

(c) 8.1-18 wt % TiO 2 ,

(d) 0.1-14.9 wt % ZnO,

(e) 0.1-4.5 wt % Li 2 O,

(f) 0.1-18 wt % K 2 O, and

(g) 1-7 wt % F −1 ; and

composition 5 comprises:

(a) 20.1-22.9 wt % SiO 2 ,

(b) 5.1-22.9 wt % B 2 O 3 ,

(c) 10.5-18 wt % TiO 2 ,

(d) 13.1-14.9 wt % ZnO,

(e) 0.1-4.5 wt % Li 2 O,

(f) 0.1-18 wt % K 2 O, and

(g) 1-7 wt % F −1 .

9. The method according to claim 1 , further including depositing and firing a filler material comprising:

glass frit from about 5 wt % to about 80 wt %, pigment from 0 wt % to about 50 wt %, and

a filler component from about 20 wt % to about 95 wt % and selected from the group consisting of alumina, silicon powder, zircon, zirconia, cordierite, willernite, beta-eucryptite, and transition metal oxides, silicon dioxide, and combinations thereof,

wherein the filler material is deposited and fired to form a filler layer between the interface layer and the opaque layer, or is deposited and fired as part of the opaque layer.

10. The method according to claim 9 , wherein:

the glass frit in the filler material comprises zinc borosilicate glass frit, the pigment in the filler material is selected from the group consisting of mixed metal oxides of (a) copper and chromium; (b) copper, chromium, and manganese, (c) iron, chromium, and cobalt, and (d) titanium, and any combination of (a), (b), (c), and (d), and combinations thereof.

11. The method according to claim 1 , further including forming a silver bleed through layer between the opaque layer and the durable layer, the silver bleed through layer being formed by depositing and firing a silver bleed through material comprising glass frit and a silver migration control additive selected from group consisting of sulfur, silicon metal, iron metal, zinc metal, and combinations thereof.

12. The method according to claim 1 , further including forming an anti-stick layer on the durable layer, the anti-stick layer being formed by depositing and firing an anti-stick material comprising a crystalline seed material from about 5 wt % to 100 wt %, glass frit from 0 wt % to about 70 wt %, and pigment from 0 wt % to about 60 wt %.

13. The method according to claim 12 , wherein:

the glass frit in the anti-stick material comprises bismuth borosilicate glass frit, the pigment in the anti-stick material is selected from the group consisting of mixed metal oxides of CuCr, CuCrMn, FeCrCo, TiO 2 , and combinations thereof, and

the crystalline seed material is selected from the group consisting of silicates, titanates, aluminates, zirconates, borates, clays, feldspars, and combinations thereof.

14. The method according to claim 1 , wherein the substrate is automotive glass and the method further includes heating and bending the automotive glass after the multi-layered enamel is formed thereon.

15. A glass substrate coated with a multi-layer enamel, wherein the multi-layer enamel comprises a fired assembly of a substrate, an interface layer, an opaque layer, and a durable layer, wherein

the interface layer is bonded to the substrate, the interface layer comprising prior to firing:

from about 35 wt % to about 95 wt % glass frit,

from about 5 wt % to about 65 wt % pigment, and

from about 2 wt % to about 10 wt % expansion modifier;

the opaque layer is bonded to the interface layer, the opaque layer comprising prior to firing:

from about 5 wt % to about 60 wt % glass frit,

from about 40 wt % to about 95 wt % pigment, and

from about 0 wt % to about 15 wt % expansion modifier, and

a durable layer over the opaque layer;

the durable layer being formed by depositing and firing a durable material comprising glass frit

from about 60 wt % to about 98 wt %, and pigment from about 2 wt % to about 40 wt %, and

wherein

the enamel has an exposed portion and the durable layer defines the exposed portion.