Use of a coating on a chromium-free tinplate substrate

Patent metadata

Field	Value
Publication number	US-11613657-B2
Application number	US-201716347344-A
Country	US
Kind code	B2
Filing date	Nov 3, 2017
Priority date	Nov 3, 2016
Publication date	Mar 28, 2023
Grant date	Mar 28, 2023

Abstract

Use of a coating composition on a chromium free tinplate substrate, the coating composition comprising: a polyester material, and benzoguanamine or a derivative thereof, wherein the coating composition is substantially free of bisphenol A (BPA), bisphenol F (BPF), bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE).

First claim

The invention claimed is:

1. A coating system on a chromium free tinplate substrate the coating system comprising:
an undercoat coating composition comprising a polyester material, and a crosslinking material comprising benzoguanamine or a derivative thereof, wherein the crosslinking material further comprises a phenolic resin and an isocyanate resin; and
an overcoat coating composition comprising a powder composition comprising a further polyester material,
wherein the undercoat coating composition is substantially free of bisphenol A (BPA), bis phenol F (BPF), bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE).

2. The coating system of claim 1 , wherein the undercoat coating composition comprises at least 4.5 wt. % of the benzoguanamine or a derivative thereof based on the total solid weight of the undercoat coating composition.

3. The coating system of claim 1 , wherein the powder coating composition is a thermoplastic coating composition.

4. A food or beverage can at least partially formed from a chromium free tinplate material, wherein the chromium free tinplate material is coated on at least a portion thereof with the coating system of claim 1 .

5. The food or beverage can of claim 4 , wherein the coating system is applied to a seam line or weld along the body of the food or beverage can.

6. The coating system of claim 1 , when cured, has a flexibility of at least 20 mm as measured according to the draw and re-draw test method with processing in 1% salt (NaCl) solution in tap water at 130° C. for 60 minutes and a scratch resistance of at least 700 g as measured according to ISO Standard 1518-1:2011.

Assignees

• Ppg Ind Ohio Inc

Inventors

• Maral Jean-Luc
• Ducrocq Laudine
• Foucher Sylvie
• Hamon Yves

Classifications

• C08L2312/04

  with phenolic resin · CPC title

• C08L67/02

  Polyesters derived from dicarboxylic acids and dihydroxy compounds (C08L67/06 takes precedence) · CPC title

• B05D7/52

  Two layers · CPC title

• B05D7/14

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

• C08G63/20

  Polyesters having been prepared in the presence of compounds having one reactive group or more than two reactive groups · CPC title