Polymer coated metallic substrate and method for making
View Patent ↗A composite material comprising a metallic substrate and a coating on at least one side of the metallic substrate, wherein the coating comprises an acrylic or styrene-acrylic based polymer and is less than about 0.2 mils thick, wherein the polymer has a molecular weight of 50,000 to 1,000,000, a glass transition temperature (Tg) of 50-80° C., and comprises 90-100 wt. % of the total solids in the coating. The method of applying a coating to a metal substrate using a manifold flood and squeegee roll configuration or alternatively roll coater techniques; wherein the roll hardness, shape, pressure and speed are chosen to ensure that the coating composition forms a continuous wet film on the metallic substrate surfaces when the strip travels at up to 600 feet per minute; and the wet film has a uniform thickness of 2 mil (0.002 inch) or less.
1. A composite material comprising a metallic substrate and a coating on at least one side of the metallic substrate, wherein the coating comprises an acrylic or styrene-acrylic based polymer and has a dried thickness of less than about 0.2 mils, wherein the polymer has a molecular weight of 125,000 to 1,000,000, a glass transition temperature (Tg) of 65-80° C., and comprises 90-100 wt. % of the total solids in the coating, and further wherein the composite material is formable into a 1 inch deep drawn modified Swift cup without galling, flaking, peeling, or powdering, and the coating has a coefficient of friction of less than 0.5 and a weight of 50 to 350 mg/sq ft.
2. The composite material of claim 1 where the coating forms a continuous film on the metallic substrate.
3. The composite material of claim 1 , wherein the coating additionally comprises a surfactant/wetting agent at about 2 wt. % or less of the coating.
4. The composite material of claim 1 , wherein the coating additionally comprises one or more of the following additives:
a) a plasticizer selected from the group consisting of phosphate esters, phthalate esters, benzoic acid esters, and fatty acid esters;
b) a coalescing agent selected from alkyl or aromatic ethers of ethylene glycol or propylene glycol;
c) paraffin, polyethylene or polyolefin wax additives;
d) alkali soluble resins (ASRs) selected from the group consisting of rosin adducts, acrylic resins, and styrene/maleic anhydride resins;
e) polyvalent metal ions;
f) defoamers;
g) tints/colorants; and
h) micron or nano sized particulate; wherein the particulate comprises silver, cerium, lanthanum, zirconium, silicon, yttrium or other rare earth elements.
5. The composite material of claim 1 , wherein the composite material can be:
a) wound onto a mandrel to form a continuous coil; and
b) bent to a 0T radius (ASTM 4145) without galling, flaking, peeling, or powdering.
6. The composite material of claim 1 , wherein the composite material can be temper rolled without flaking or peeling.
7. The composite material of claim 1 , wherein the composite material can be further processed using conventional metalworking techniques including welding, forming, stretching, bending, and drawing.
8. The composite material of claim 1 , wherein the composite material can be:
a) further processed using conventional primers, paints, or powder coatings; or
b) further processed so as to be converted back into a metallic non-composite system using alkaline or solvent cleaning to remove the coating.
9. The composite material of claim 1 , wherein the coating has a pencil hardness of H minimum according to ASTM D3363; and the adhesion of the coating to the metallic substrate is rated 5B when tested according to ASTM D3359.
10. The composite material of claim 1 , wherein the coating has a thickness of 0.05-0.2 mils.
11. The composite material of claim 1 , wherein the coating has a thickness of 0.05-0.1 mils.
12. The composite material of claim 4 , wherein the coating additionally comprises alkali soluble resins (ASRs) selected from the group consisting of rosin adducts, acrylic resins, and styrene/maleic anhydride resins.
13. The composite material of claim 4 , wherein the coating additionally comprises a coalescing agent selected from alkyl or aromatic ethers of ethylene glycol or propylene glycol.