Extended firing range enamels to produce frost effects
View Patent ↗The invention provides an enamel composition that imparts a frosted appearance to glass articles such as bottles and windows while allowing a wide firing range and maintaining consistent properties such as gloss and light transmittance. The composition comprises a zinc borosilicate glass frit with one or more crystalline materials added thereto.
1. A fired article comprising, prior to firing:
a. a glass substrate,
b. a lead-free and cadmium-free enamel frit coating excluding pigments and comprising, prior to firing,
i. 85 to 99.9 wt % of a glass component excluding Bi 2 O 3 and comprising
1. about 10 to about 15% B 2 O 3 , about 8 to about 55 wt % SiO 2 , about 10 to about 20% ZnO, about 8 to about 12% Na 2 O, about 1 to about 5% fluorine, and 0 to about 3% TiO 2 , and
2. optionally including up to 10% ZrO 2 , up to 7% Al 2 O 3 , up to 10% K 2 O, up to 12% Li 2 O, up to 18% Nb 2 O 5 , up to 7% CeO 2 , up to 10% BaO, up to 10% CaO, up to 10% SrO, up to 10% SnO, up to 10% P 2 O 5 , up to 5% MgO, up to 7% Y 2 O 3 , up to 4% MoO, up to 4% W 2 O 3 , and up to 3% sulfur,
ii. 0.1 to 15 wt % of a crystalline component comprising at least one crystalline material selected from the group consisting of bismuth silicates, zinc silicates, bismuth titanates, zinc borates, zinc titanates, silicon zirconates, bismuth zirconates, alumino silicates, calcium silicates, and combinations thereof, in order to impart a matte effect, and
iii. no pigment,
wherein after being fired at a temperature of 500° C. to 700° C., the coating produces a matte-effect coated substrate having a light transmittance value at 550 nm of at least about 0.5%.
2. The article of claim 1 wherein the glass component comprises
a. about 10 to about 15 wt % B 2 O 3 ,
b. about 8 to about 55 wt % SiO 2 ,
c. about 5 to about 50% ZnO, and
d. at least one secondary ingredient selected from the group consisting of TiO 2 (20%), ZrO 2 (10%), Al 2 O 3 (7%), Na 2 O (15%), K 2 O (10%), Li 2 O (12%), Nb 2 O 5 (18%), CeO 2 (7%), BaO (10%), CaO (10%), SrO (10%), SnO (10%), P 2 O 5 (10%), MgO (5%), Y 2 O 3 (7%), MoO (4%), W 2 O 3 (4%), sulfur (3%),
provided that the amount of each secondary ingredient does not exceed the indicated amount.
3. The article of claim 1 , wherein the glass component comprises 40-55 wt % SiO 2 , 10-20% ZnO, 10-15% B 2 O 3 , 8-12% Na 2 O, 1-5% fluorine, 0-4% K 2 O, 0-2% Li 2 O, 0-3% TiO 2 , 0-3% ZrO 2 , and 0-3% Al 2 O 3 .
4. The article of claim 1 , wherein the crystalline component comprises at least one material selected from the group consisting of Zn 2 SiO 4 , Bi 12 SiO 20 , Bi 4 (SiO 4 ) 3 , Bi 2 SiO 5 , 2ZnO.3TiO 2 , ZnTiO 3 , ZnO.B 2 O 3 , 3ZnO.B 2 O 3 , 5ZnO.2B 2 O 3 , 2Bi 2 O 3 .3ZrO 2 , Bi 7 Ti 4 NbO 21 , Bi 4 Ti 3 O 12 , Bi 2 Ti 2 O 7 , Bi 12 TiO 20 , Bi 4 Ti 3 O 12 , Bi 2 Ti 4 O 11 , Al 2 SiO 5 , and combinations thereof.
5. The article of claim 1 , wherein the 20° gloss value is from about 1 to about 15, the 60° gloss value is from about 5 to about 65, and the 85° gloss value is from about 10 to about 50.
6. The article of claim 1 , wherein the article has a transmittance at 550 nm of at least 80%.
7. The article of claim 1 , wherein the article has a transmittance at 300 nm of no greater than 60%.
8. The article of claim 1 , wherein the article has a root mean square roughness is from about 0.1 micron to about 1 micron.
9. The article of claim 1 , wherein the article has a L color value is about 55 to about 85.
10. The article of claim 1 wherein the substrate is a beverage container.
11. The article of claim 1 wherein the substrate is a piece of glass that has not been press bent.