Zinc containing glasses and enamels
This invention relates to lead free, cadmium free, bismuth free low melting high durability glass and enamel compositions. The compositions comprise silica, zinc, titanium, and boron oxide based glass frits. The resulting compositions can be used to decorate and protect automotive, beverage, architectural, pharmaceutical and other glass substrates.
1. A method of decorating a substrate comprising:
a. applying to the substrate a coating of an enamel composition comprising, prior to firing, an organic vehicle and a solids portion, wherein the solids portion comprises
i. a frit portion wherein the frit portion comprises, prior to firing:
1. 38-60 wt % SiO 2 ,
2. 5.1-22.9 wt % B 2 O 3 ,
3. 8.1-18 wt % TiO 2 ,
4. 0.1-14.9 wt % ZnO,
5. 0.1-4.5 wt % Li 2 O
6. 0.1-18 wt % K 2 O, and
7. 1-7 wt % F, and
ii. 0.1-15 wt % of a crystalline material selected from the group consisting of zinc borates, zinc silicates, zinc titanates, aluminum silicates, and combinations thereof, and
b. firing the substrate and coating at a temperature sufficient to flow the enamel composition to cause the enamel composition to adhere to the substrate,
wherein, after firing, the enamel composition is opaque and exhibits performance of chemical durability against wet through deterioration of at least 24 hours when tested in 0.1 N H 2 SO 4 at 80° C., and
wherein the substrate is selected from the group consisting of glass, automotive glass, architectural glass and tableware.
2. The method of claim 1 , wherein the solids portion further comprises 0.1 to 5 wt % of a metal.
3. The method of claim 1 , wherein the solids portion further comprises, prior to firing, a separate and distinct addition of 0.1 to 30 wt % pigment.
4. The method of claim 1 , wherein, prior to firing, the frit portion further comprises at least one selected from the group consisting of:
a. 0.1-1.9 wt % Al 2 O 3 ,
b. 0.1-4 wt % ZrO 2 , and
c. 0.1-13 wt % Na 2 O.
5. The method of claim 1 , wherein, prior to firing, the frit portion comprises:
a. 41-51 wt % SiO 2 ,
b. 6-17 wt % B 2 O 3 ,
c. 10.5-18 wt % TiO 2 ,
d. 5.1-13 wt % ZnO,
e. 0.1-3 wt % Li 2 O
f. 1-7.9 wt % K 2 O, and
g. 1.5-6 wt % F.
6. The method of claim 1 , wherein, prior to firing, the frit portion comprises:
a. 41-51 wt % SiO 2 ,
b. 6-17 wt % B 2 O 3 ,
c. 8.5-13 wt % TiO 2 ,
d. 5.1-13 wt % ZnO,
e. 0.1-3 wt % Li 2 O
f. 1-7.9 wt % K 2 O, and
g. 1.5-6 wt % F.
7. The method of claim 1 , wherein the frit portion further comprises sulfur or a metallic sulfide, or combinations thereof, so as to provide an amount of sulfur to the frit portion not exceeding 4 wt %, all percentages prior to firing.
8. The method of claim 1 , wherein the frit portion further comprises at least one selected from the group consisting of: (a) 0.1-4.9 wt % Bi 2 O 3 , (b) 0.1-2 wt % Cs 2 O, (c) 0.1-5 wt % MgO, (d) 0.1-5 wt % CeO 2 , (e) 0.1-10 wt % MnO, (f) 0.1-5 wt % CuO, (g) 0.1-5 wt % NiO, (h) 0.1-10 wt % SnO, (i) 0.1-5 wt % P 2 O 5 , (j) 0.1-10 wt % V 2 O 5 , (k) 0.1-5 wt % La 2 O 3 , (l) 0.1-5 wt % Pr 2 O 3 , (m) 0.1-5 wt % Y 2 O 3 , (n) 0.1-5 wt % In 2 O 3 , (o) 0.1-10 wt % Fe 2 O 3 , (p) 0.1-5 wt % Cr 2 O 3 , (q) 0.1-5 wt % CoO, (r) 0.1-4 wt % Nb 2 O 5 , (s) 0.1-4 wt % WO 3 , (t) 0.1-4 wt % MoO 3 , and combinations thereof.
9. The method of claim 1 , wherein the enamel composition further comprises a reducing compound to reduce metals, or to prevent oxidation of metals in the enamel composition, or to control silver migration into the substrate.
10. The method of claim 9 wherein the reducing compounds are selected from the group consisting of silicon metal, zinc sulfide, metallic sulfides, and combinations thereof.
11. The method of claim 1 , wherein the enamel composition further comprises a pigment.
12. The method of claim 1 , wherein the composition lacks intentionally added bismuth in any form.
13. The method of claim 1 , wherein the substrate is glass, automotive glass or architectural glass, and wherein the method further comprises heating the substrate to an elevated temperature and subjecting the substrate to a forming pressure to bend the substrate.
14. The method of claim 13 , wherein the elevated temperature is at least about 570° C., and the forming pressure is in the range of 0.1 to 5 psi, and is applied with a forming die.
15. The method of claim 1 , wherein the enamel composition is substantially free of oxides of tantalum, and the TiO 2 content in the frit portion is in the range of 11-15 wt % TiO 2 .
16. The method of claim 1 , wherein the enamel composition is substantially free of bismuth and antimony.
17. The method of claim 1 , wherein the fired enamel composition is opaque, lead-free, cadmium-free, bismuth-free, tantalum-free and antimony-free, the enamel composition further comprising, prior to firing, an organic vehicle.
18. A method of blocking ultraviolet radiation comprising:
a. applying to the substrate a coating of an enamel composition comprising, prior to firing, an organic vehicle and a solids portion, wherein the solids portion comprises
i. a frit portion wherein the frit portion comprises, prior to firing:
1. 38-60 wt % SiO 2 ,
2. 5.1-22.9 wt % B 2 O 3 ,
3. 8.1-18 wt % TiO 2 ,
4. 0.1-14.9 wt % ZnO,
5. 0.1-4.5 wt% Li 2 O
6. 0.1-18 wt % K 2 O, and
7. 1-7 wt % F, and
ii. 0.1-15 wt % of a crystalline material selected from the group consisting of zinc borates, zinc silicates, zinc titanates, aluminum silicates, and combinations thereof, and
b. firing the substrate and coating at a temperature sufficient to flow the enamel composition to cause the enamel composition to adhere to the substrate,
wherein, after firing, the enamel composition is opaque and exhibits performance of chemical durability against wet through deterioration of at least 24 hours when tested in 0.1 N H 2 SO 4 at 80° C., and
wherein the substrate is selected from the group consisting of glass, automotive glass, architectural glass and tableware.
19. A method of forming an automotive windshield comprising:
a. applying to a glass substrate a coating of an enamel composition comprising, prior to firing, an organic vehicle and a solids portion, wherein the solids portion comprises
i. a frit portion wherein the frit portion comprises, prior to firing:
1. 38-60 wt % SiO 2 ,
2. 5.1-22.9 wt % B 2 O 3 ,
3. 8.1-18 wt % TiO 2 ,
4. 0.1-14.9 wt % ZnO,
5. 0.1-4.5 wt % Li 2 O
6. 0.1-18 wt % K 2 O, and
7. 1-7 wt % F, and
ii. 0.1-15 wt % of a crystalline material selected from the group consisting of zinc borates, zinc silicates, zinc titanates, aluminum silicates, and combinations thereof, and
b. firing the glass substrate and coating at a temperature sufficient to flow the enamel composition to cause the enamel composition to adhere to the substrate,
wherein, after firing, the enamel composition is opaque and exhibits performance of chemical durability against wet through deterioration of at least 24 hours when tested in 0.1 N H 2 SO 4 at 80° C.
20. The method of claim 19 , wherein, prior to applying to the enamel composition to the glass substrate, a conductive silver-containing metal trace is applied to the glass substrate.