Two-coat single cure powder coating

Patent metadata

Field	Value
Publication number	US-2021237118-A1
Application number	US-202117148622-A
Country	US
Kind code	A1
Filing date	Jan 14, 2021
Priority date	Mar 21, 2012
Publication date	Aug 5, 2021
Grant date	—

Abstract

Methods and systems for coating metal substrates are provided. The methods and systems include sequential application of low flow and high flow powder coatings followed by a single heating step to provide a cured coating. The methods and systems include a marker that allows coating uniformity to be monitored and assessed during application. The described methods provide coatings with optimal surface smoothness and edge coverage.

First claim

1 - 20 . (canceled)

21 . A coated article made by a process comprising:
providing a metal substrate; providing at least a first powder coating composition with flow of no more than about 40 mm to a surface of the metal substrate; providing at least a second powder coating composition with flow of at least about 40 mm; and heating the first powder coating and second powder coating composition in a single step to form a continuous cured coating on the metal substrate, thereby forming the coated article, wherein the cured coating is corrosion-resistant and having a surface smoothness on the Powder Coating Institute (PCI) scale of at least 4.

22 . The article of claim 21 , wherein the first powder coating composition has a flow of about 15 mm to 40 mm.

23 . The article of claim 21 , wherein the first powder coating composition has a flow of about 20 to 35 mm.

24 . The article of claim 21 , wherein the second powder coating composition has flow of greater than about 50 mm.

25 . The article of claim 21 , wherein the second powder coating composition has flow of greater than about 70 mm.

26 . The article of claim 21 , wherein the second powder coating composition has flow of greater than about 75 mm.

27 . The article of claim 21 , wherein the cured coating has edge coverage equal to at least 2% of face coverage.

28 . The article of claim 21 , wherein the cured coating has 20-degree gloss of at least 50%.

29 . The article of claim 21 , wherein the cured coating has edge coverage equal to about 10% of the face coverage.

30 . The article of claim 21 , wherein the metal substrate is unprimed, clean blasted, or pretreated.

31 . The article of claim 21 , wherein the metal substrate may be heated prior to applying the first powder coating composition.

32 . The article of claim 21 , wherein the first powder coating composition is applied to the metal substrate at ambient temperature.

33 . The article of claim 21 , wherein the first powder coating composition and second powder coating composition are heated in a single step at a temperature of about 180° C. to 200° C.

34 . The article of claim 21 , wherein the first powder coating composition and second coating composition are heated in a single step at a temperature of about 140° C. to 170° C.

35 . The article of claim 21 , wherein the first powder coating composition and second coating composition are heated in a single step at a temperature of about 120° C. to 135° C.

36 . The article of claim 21 , wherein the first powder coating composition is applied only to one or more edges of the substrate.

37 . The article of any claim 21 , wherein the second powder coating composition is applied only to one or more edges of the substrate.

38 . The article of claim 21 , wherein the first powder coating composition and the second coating composition are applied only to one or more edges of the substrate.

39 . The article of claim 21 , wherein the first powder coating composition is applied at a film build of about 20 to 40 micron.

40 . The article of claim 21 , wherein the second powder coating composition is applied at a film build of about 25 to 35 micron.

Assignees

• Sherwin Williams Co

Inventors

• Decker Owen H
• Reno Thomas E
• Breitzman Robert D
• Concha Carlos A
• Rogozinski Jeffrey D

Classifications

• B05D7/14

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

• B05D1/12

  Applying particulate materials (B05D1/06, B05D1/10 take precedence) · CPC title

• C08K3/22

  of metals · CPC title

• B05D3/102

  Pretreatment of metallic substrates (C23C takes precedence) · CPC title

• B05D3/002

  Pretreatement · CPC title