Method of making a heat-treated coated glass article using a polymer dispersion
A temporary protective coating is provided over a coated glass substrate. The temporary protective coating is preferably applied in an aqueous dispersion then solidified on the substrate. In some instances, the temporary protective coating may be removed by treatment with a basic solution. In certain example embodiments, the temporary protective coating is applied after heat treatment before the coated substrate is coupled to another substrate to form a window unit such as an IG window unit or a laminated vehicle windshield.
1 . A method of making an insulating glass (IG) window unit, the method comprising:
sputtering a multi-layered low-E coating onto a glass substrate, wherein the low-E coating comprises at least one infrared (IR) reflecting layer comprising silver sandwiched between at least first and second dielectric layers;
thermally tempering the glass substrate with the low-E coating thereon;
after said tempering, applying a polymer dispersion in liquid form to a top surface of the low-E coating and evaporating the liquid to form a protective polymer sheet so as to create a protected coated article;
removing the protective sheet off the low-E coating by treating at least a portion of the protective polymer sheet with a basic solution to form an unprotected coated article; and
after removing the protective sheet off the low-E coating, coupling the tempered coated article including the glass substrate and low-E coating to another substrate to form an IG window unit.
2 . The method of claim 1 , wherein an uppermost layer of the low-E coating comprises silicon nitride.
3 . The method of claim 1 , wherein the polymer dispersion comprises an aqueous polymer dispersion.
4 . The method of claim 1 , wherein the polymer dispersion comprises an aqueous polymer dispersion comprising an acrylic polymer.
5 . The method of claim 1 , wherein the protective sheet has a visible transmission of less than 70%.
6 . The method of claim 1 , wherein the IG window unit has a visible transmission of from 50 to 75%.
7 . The method of claim 1 , wherein the protective sheet is blue and/or green colored.
8 . The method of claim 1 , wherein the protective sheet is not water soluble.
9 . The method of claim 1 , wherein the step of removing the protective sheet to form an unprotected coated article further comprises mechanically washing the low-E coating using physical contact.
10 . A method of making a window unit, the method comprising:
forming a multi-layer coating on a glass substrate;
heat treating the glass substrate with the coating thereon;
after said tempering, applying a polymer dispersion in liquid form to a top surface of the multi-layer coating and evaporating the liquid to form a protective polymer sheet so as to create a protected coated article;
removing the protective sheet off the multi-layer coating by treating at least a portion of the protective polymer sheet with a basic solution to form an unprotected coated article; and
after removing the protective sheet off the coating, coupling the heat treated coated article including the glass substrate and coating to another substrate to form a window unit.
11 . The method of claim 10 , wherein an uppermost layer of the low-E coating comprises silicon nitride.
12 . The method of claim 10 , wherein the polymer dispersion comprises an aqueous polymer dispersion.
13 . The method of claim 10 , wherein the polymer dispersion comprises an aqueous polymer dispersion comprising an acrylic polymer.
14 . The method of claim 10 , wherein the protective sheet has a visible transmission of less than 70%.
15 . The method of claim 10 , wherein the IG window unit has a visible transmission of from 50 to 75%.
16 . The method of claim 10 , wherein the protective sheet is blue and/or green colored.
17 . The method of claim 10 , wherein the protective sheet is not water soluble.
18 . The method of claim 10 , wherein the step of removing the protective sheet further comprises mechanically washing the multi-layer coating using physical contact.
19 . A method of making a protected coated substrate, the method comprising applying an aqueous polymer dispersion comprising acrylic polymer in liquid form to a top surface of a heat-treated substrate and drying the polymer dispersion to form a protective film so as to create a protected coated article, wherein the substrate comprises monolithic glass, and wherein the protective film may be partially removed via alkaline treatment.
20 . The method of claim 19 , wherein the substrate comprises glass having UV-blocking properties, low-E and/or low emissivity properties
21 . The method of claim 19 , wherein the substrate comprises a portion of a solar power mirror or an energy efficient window.