Use of a coating on a chromium-free tinplate substrate

Abstract

Use of a coating composition on a chromium free tinplate substrate, the coating composition comprising:a polyester material, andbenzoguanamine 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).

1 - 15 . (canceled) 
     
     
         16 . A method of coating a chromium free tinplate substrate, comprising:
 (i) contacting a coating composition with the substrate to form a coating on the substrate, the coating composition comprising:
 an undercoat coating comprising a polyester material and a crosslinking material; and 
 an overcoat coating composition comprising a further polyester material; 
   (ii) curing the coating composition to form a cured coating that is essentially-free of organic solvent, and   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).   
     
     
         17 . The method of  claim 16 , wherein the polyester material is present at 40 wt. % to 95 wt. %, based on the total solid weight of the coating composition. 
     
     
         18 . The method of  claim 16 , wherein the crosslinking material comprises benzoguanamine or a derivative thereof, a phenolic resin, and an isocyanate resin. 
     
     
         19 . The method of  claim 16 , wherein the crosslinking material is present at up to 30 wt. %, based on the total solid weight of the coating composition. 
     
     
         20 . The method of  claim 18 , wherein the coating composition comprises at least 4.5 wt. % of the benzoguanamine or a derivative thereof, based on the total solid weight of the coating composition. 
     
     
         21 . The method of  claim 16 , wherein the coating 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. 
     
     
         22 . The method of  claim 16 , wherein the overcoat coating composition comprises a powder composition. 
     
     
         23 . 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; and   an overcoat coating composition comprising a further polyester material,   wherein the undercoat coating composition is substantially free of bisphenol A (BPA), bisphenol F (BPF), bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE).   
     
     
         24 . The coating system of  claim 23 , wherein the crosslinking material comprises benzoguanamine or a derivative thereof, a phenolic resin, and an isocyanate resin. 
     
     
         25 . The coating system of  claim 24 , wherein the crosslinking material comprises at least 4.5 wt. % of the benzoguanamine or a derivative thereof, based on the total solid weight of the undercoat coating composition. 
     
     
         26 . 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  8 . 
     
     
         27 . The food or beverage can of  claim 16 , wherein the coating system is applied to a seam line or weld along the body of the food or beverage can. 
     
     
         28 . The coating system of  claim 23 , 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. 
     
     
         29 . The coating system of  claim 23 , wherein the overcoat coating composition comprises a powder composition. 
     
     
         30 . The coating system of  claim 29 , wherein the powder composition is a thermoplastic coating composition. 
     
     
         31 . A chromium free tinplate substrate coated with the coating system of  claim 23 .