Method of making a coated article and/or glazing for automobiles and/or the like
View Patent ↗Certain example embodiments relate to a method of making a coated article and/or glazing (e.g., for automobile, window, and/or other applications). An opaque paint that is not technically a frit is used to form a desired opaque pattern. The paint is screen printed on a substrate. Screen printing parameters are selected, e.g., so that the mesh has a high threads per inch count; the paint is pushed through the screen using hydraulic forces that account for a sheer thinning property of the paint by balancing squeegee speed, squeegee angle relative to the screen, and hardness of the squeegee; and/or relative humidity above and/or near the screen is at least about 80%. Preferably, the paint is substantially fully curable at 400 degrees C. or less. The substrate with the pattern thereon may be bent using a high temperature process, optionally with another substrate to which it may be laminated.
1. A method of making a laminated glazing for an automobile, the method comprising:
screen printing a water-inclusive opacifying agent, directly or indirectly, on a major surface of a first glass substrate in a desired pattern in connection with a screen mesh that has at least 200 threads per inch and while maintaining an environment that has a relative humidity of at least 80% over and/or proximate to the screen mesh;
heating the first glass substrate with the opacifying agent thereon to a first temperature sufficient to at least partially cure the opacifying agent in the desired pattern, said first temperature being less than 200 degrees C.;
following said heating to the first temperature and said at least partial curing, bending the first glass substrate and a second glass substrate in connection with a second temperature higher than the first temperature, said second temperature used in bending the glass substrates being at least about 600 degrees C.; and
laminating together the first and second glass substrates so that the cured opacifying agent is provided on an interior surface of the glazing.
2. The method of claim 1 , wherein the screen mesh has at least 230 threads per inch.
3. The method of claim 1 , the relative humidity in the environment is 90-95%.
4. The method of claim 1 , wherein the second temperature is at least twice as high as the first temperature.
5. The method of claim 1 , wherein the first temperature is about 125-150 degrees C. and causes at least a majority of organic components provided in the opacifying agent to be driven off.
6. The method of claim 5 , wherein the second temperature causes the opacifying agent to fully cure.
7. The method of claim 1 , wherein the first temperature is about 300 degrees C.
8. The method of claim 7 , wherein the first temperature is held for about 4 minutes.
9. The method of claim 8 , wherein the heating of the first glass substrate with the opacifying agent thereon to the first temperature fully cures the opacifying agent by driving off all organic components initially provided therein.
10. The method of claim 1 , wherein the opacifying agent, when cured, forms an opaque or substantially opaque layer, and the first substrate has a surface stress less than about 250 psi in an area proximate the opaque or substantially opaque layer.
11. The method of claim 1 , wherein the opacifying agent, when cured, forms an opaque or substantially opaque layer, and the first substrate has a surface stress less than about 150 psi in an area proximate the opaque or substantially opaque layer.
12. The method of claim 1 , wherein the opacifying agent has an inorganic base.
13. The method of claim 1 , wherein the opacifying agent comprises:
pigment;
a first aqueous sodium silicate solution wherein the weight ratio of SiO 2 to Na 2 O is approximately 3;
a second aqueous sodium silicate solution wherein the weight ratio of SiO 2 to Na 2 O is approximately 2;
an aqueous potassium silicate solution wherein the weight ratio of SiO 2 to K 2 O is approximately 2;
a colloidal silica thickening agent; and
an aqueous alkali metal hydroxide solution.
14. A method of making a coated article comprising a glass substrate and an opaque film, the method comprising:
screen printing an opaque paint, directly or indirectly, on a major surface of the substrate in a desired pattern, while maintaining an environment with a relative humidity of at least 80% over and/or proximate to a mesh used in the screen printing;
heating the first glass substrate with the opaque paint thereon, wherein the paint is (a) fully cured when heated to a first temperature of 250-400 degrees, and (b) substantially fully cured when heated to a second temperature below 175 degrees C., in making the coated article.
15. The method of claim 14 , further comprising bending to a desired shape at least the substrate with the opaque paint thereon, the bending being performed at a third temperature that is at least twice as high as the first temperature and at least three times as high as the second temperature.
16. The method of claim 15 , wherein heat associated with the bending eliminates any remaining volatiles initially found in the opaque paint.
17. The method of claim 15 , wherein the paint is pushed through the screen, and the resulting deposit is controlled, in connection with hydraulic forces that account for a sheer thinning property of the opaque paint by balancing squeegee speed, squeegee angle relative to the screen, and hardness of the squeegee.
18. The method of claim 14 , wherein the screen mesh has at least 230 threads per inch.
19. A method of making a laminated article, the method comprising:
booking together a second glass substrate and a coated article made according to the method of claim 14 ;
bending the second glass substrate and the coated article at a third temperature that is at least twice as high as the first temperature and at least three times as high as the second temperature;
laminating together the second glass substrate and the coated article in making the laminated article.
20. An automotive glazing made in accordance with the method of claim 1 .