Conversion coating for cans containing hydrogen sulfide producing liquids

Abstract

This disclosure relates to use of a conversion coating for reduction or prevention of hydrogen sulfide production in cans holding hydrogen sulfide producing liquids, such as wine. This disclosure also relates to metal cans comprising a conversion coating layer deposited on at least a portion of the inside surface of the metal can, a film-forming layer deposited on such conversion coating layer, and a hydrogen sulfide producing liquid deposited inside the metal can.

1 . A metal can comprising:
 a conversion coating layer deposited on at least a portion of the inside surface of the metal can, wherein the conversion coating layer comprises a lanthanide series element, a Group VIB metal, a Group IIIB metal, a Group IVB metal, and/or a homopolymer or copolymer comprising a phosphorous-containing monomeric subunit m1 and optionally a non-phosphorous-containing monomeric subunit m2;   a film-forming layer deposited on at least a portion of the conversion coating layer; and   a hydrogen sulfide producing liquid deposited inside the metal can.   
     
     
         2 . The metal can of  claim 1 , wherein the metal can comprises aluminum, aluminum alloy, and/or steel. 
     
     
         3 . The metal can of  claim 1 , wherein the homopolymer or copolymer comprising a phosphorous-containing monomeric subunit m1 and optionally a non-phosphorous-containing monomeric subunit m2 comprises a homopolymer, a dipolymer and/or a terpolymer, the lanthanide series element comprises lanthanum and/or cerium, the Group VIB metal comprises chromium and/or molybdenum, Group IIIB metal comprises yttrium, and the Group IVB metal comprises zirconium, titanium, and/or hafnium. 
     
     
         4 . The metal can of  claim 1 , wherein the Group IVB metal comprises zirconium. 
     
     
         5 . The metal can of  claim 3 , wherein the chromium comprises chromium (III) and/or chromium (VI). 
     
     
         6 . The metal can of  claim 1 , wherein the hydrogen sulfide producing liquid deposited in the metal can comprises wine, beer, fruit juice, vinegar, cordial, coconut milk, soft drink, cider, kombucha, or mead. 
     
     
         7 . The metal can of  claim 1 , wherein the average thickness of the conversion coating layer on the metal can is 0.001 msi to 0.05 msi. 
     
     
         8 . The metal can of  claim 1 , wherein the film forming layer comprises an acrylic, a polyester, a phenolic, a polyolefin, and/or an epoxy. 
     
     
         9 . The metal can of  claim 1 , wherein the film forming layer has a dry film thickness of 2 microns to 20 microns. 
     
     
         10 . The metal can of  claim 1 , wherein the conversion coating layer is on at least a portion of a can body of the metal can. 
     
     
         11 . The metal can of  claim 1 , wherein the conversion coating layer is on at least a portion of a can end of the metal can. 
     
     
         12 . The metal can of  claim 1 ,
 wherein the conversion coating layer is deposited from a conversion coating composition comprising the lanthanide series element, the Group VIB metal, the Group IIIB metal, the Group IVB metal, and/or the homopolymer or copolymer comprising the phosphorous-containing monomeric subunit m1 and optionally the non-phosphorous-containing monomeric subunit m2.   
     
     
         13 . The metal can of  claim 12 , wherein the Group IVB metal is hexafluorozirconic acid. 
     
     
         14 . The metal can of  claim 12 , wherein the conversion coating composition further comprises a source of phosphate ions. 
     
     
         15 . The metal can of  claim 14 , wherein the source of phosphate ions comprises phosphoric acid. 
     
     
         16 . The metal can of  claim 12 , wherein the conversion coating composition further comprises a source of free fluoride. 
     
     
         17 . The metal can of  claim 12 , wherein the conversion coating composition further comprises an electropositive metal. 
     
     
         18 . The metal can of  claim 12 , wherein the Group IVB metal in the conversion coating composition comprises a source of free fluoride. 
     
     
         19 . A method of packaging a hydrogen sulfide producing liquid in a metal can, the method comprising:
 depositing the hydrogen sulfide producing liquid inside the metal can,   wherein the metal can comprises:
 a conversion coating layer deposited on at least a portion of the inside surface of the metal can, wherein the conversion coating layer comprises a lanthanide series element, a Group VIB metal, a Group IIIB metal, a Group IVB metal, and/or a homopolymer or copolymer comprising a phosphorous-containing monomeric subunit m1 and optionally a non-phosphorous-containing monomeric subunit m2; and 
 a film-forming layer deposited on at least a portion of the conversion coating layer. 
   
     
     
         20 . The metal can of  claim 1 ,
 wherein the hydrogen sulfide producing liquid exhibits a hydrogen sulfide concentration of less than 35 ppb as measured by a gas detection tube for at least two months after the metal can is sealed.