Primer compositions for application to sheet materials and methods of applying same

Patent metadata

Field	Value
Publication number	US-2016297973-A9
Application number	US-201414198629-A
Country	US
Kind code	A9
Filing date	Mar 6, 2014
Priority date	Jun 19, 2012
Publication date	Oct 13, 2016
Grant date	—

Abstract

Waterborne primer coating compositions are applied to sheet metal substrates and rapidly cured. The primer coating compositions contain water, a latex resin and corrosion-inhibiting particles. The primer coating compositions may be applied to the metal sheets and rapidly cured at a rolling mill, followed by coiling of the coated sheets.

First claim

We claim:

1 . A rapidly curable waterborne primer coating composition comprising:
water, latex resin; and corrosion-inhibiting particles.

2 . The rapidly curable waterborne primer coating composition of claim 1 , wherein the composition is capable of being cured in less than 10 seconds at a temperature of less than 350° F.

3 . The rapidly curable waterborne primer coating composition of claim 1 , wherein the corrosion-inhibiting particles comprise chrome and are present in an amount of at least 3 weight percent based on the total weight of the coating composition.

4 . The rapidly curable waterborne primer coating composition of claim 3 , wherein the corrosion-inhibiting particles comprise strontium chromate.

5 . The rapidly curable waterborne primer coating composition of claim 1 , wherein the corrosion-inhibiting particles are substantially free of chrome and are present in an amount of at least 5 weight percent based on the total weight of the coating composition.

6 . The rapidly curable waterborne primer coating composition of claim 5 , wherein the corrosion-inhibiting particles comprise a silicate, oxide, phosphate, phosphorsilicate or silica.

7 . The rapidly curable waterborne primer coating composition of claim 1 , wherein the corrosion-inhibiting particles comprise silica and are present in an amount of at least 10 weight percent based on the total weight of the coating composition.

8 . The rapidly curable waterborne primer coating composition of claim 1 , wherein the latex resin is self-crosslinking and is prepared from at least one vinyl aromatic monomer.

9 . The rapidly curable waterborne primer coating composition of claim 1 , wherein the primer coating composition has a volatile organic content of less than 1.5 weight percent based on the total weight of the composition.

10 . The rapidly curable waterborne primer coating composition of claim 1 , further comprising a coalescing agent, wax, viscosity enhancing agent, thickening agent, colored pigment and/or colored tint.

11 . A coated metal sheet comprising:
a metal substrate; and a cured primer coating covering at least a portion of the metal substrate, wherein the cured primer coating comprises a latex resin and corrosion-inhibiting particles, and is cured for less than 10 seconds at a temperature of less than 350° F.

12 . The coated metal sheet of claim 11 , wherein the corrosion-inhibiting particles comprise strontium chromate and/or silica.

13 . The coated metal sheet of claim 11 , wherein the cured primer coating has a dry film thickness of at least 1 micron.

14 . The coated metal sheet of claim 11 , wherein the metal is in the form of a coil.

15 . A method of coating a sheet metal substrate comprising:
applying a primer coating composition comprising water, latex resin and corrosion-inhibiting particles onto the sheet material; and curing the primer coating composition at a temperature of less than 350° F. for a time of less than 10 seconds.

16 . The method of claim 15 , wherein the primer coating composition is applied at a wet film thickness of at least 1 micron.

17 . The method of claim 15 , wherein the primer coating composition has a volatile organic content of less than 1.5 weight percent.

18 . The method of claim 15 , wherein the primer coating composition is applied by roll coating.

19 . The method of claim 18 , wherein the primer coating composition is applied at a rate of at least 200 ft/min.

20 . The method of claim 15 , wherein the primer is cured by passing the sheet material and applied primer coating composition through an oven at a temperature of less than 250° F. for a time of less than 5 seconds.

21 . The method of claim 15 , further comprising applying a topcoat over at least a portion of the primer coating.

22 . The method of claim 15 , further comprising forming the coated metal sheet into a coil.

Assignees

• Ppg Ind Ohio Inc

Inventors

• Schwendeman Irina G
• Conley Carole A
• Millero Jr Edward R

Classifications

• B05D3/0272

  with ovens · CPC title

• B05D7/24

  for applying particular liquids or other fluent materials · CPC title

• B05D7/14

  to metal, e.g. car bodies (involving a chemical reaction between the metal and the coating C23) · CPC title

• C09D5/08 Primary

  Anti-corrosive paints · CPC title

• E04D3/16

  of metal · CPC title