Lignin Based Coating Compositions

Abstract

The current invention includes coating compositions having a lignin, methods for coating substrates using the coating compositions, and substrates coated with the coating compositions. In some embodiments of the invention, a coating composition having a mixture of a) a lignin, b) a solvent, and c) a crosslinker, wherein the lignin has a neutral or negative charge. The current invention also includes a coating composition having a mixture of a) a lignin, b) a polymeric epoxy crosslinker having glycidyl (meth)acrylate, and c) a solvent. Additionally, the current invention includes a coating composition having a mixture of a) a lignin, b) a solvent, and c) a phenolic crosslinker.

1 .- 18 . (canceled) 
     
     
         19 . A coating composition that is substantially free of bisphenol A for coating a packaging or a container that is usable for packaging food, the coating composition comprising:
 a lignin having a neutral or a negative charge;   a crosslinker that is substantially free of bisphenol A; and   a solvent capable of dissolving the lignin and the crosslinker to form a solution that is thermally curable at a temperature in a range from about 130 degrees Celsius to about 250 degrees Celsius.   
     
     
         20 . The coating composition of  claim 19 , wherein the lignin is an unmodified lignin. 
     
     
         21 . The coating composition of  claim 19 , wherein the coating composition includes polymeric dispersions having between about 10% to about 60% by weight polymeric solids. 
     
     
         22 . The coating composition of  claim 19 , including at least one crosslinker chosen from an epoxy crosslinker, a polymeric epoxy crosslinker, benzoguanamine formaldehyde, glycoluril, melamine formaldehyde, a phenolic crosslinker, urea formaldehyde, an isocyanate, or a blocked isocyanate. 
     
     
         23 . The coating composition of  claim 22 , wherein the polymeric epoxy crosslinker includes glycidyl (meth)acrylate. 
     
     
         24 . The coating composition of  claim 22  wherein the phenolic crosslinker includes phenol formaldehyde. 
     
     
         25 . A can or packaging usable for packaging food that is coated with the coating composition of  claim 19 . 
     
     
         26 . A coating composition that is substantially free of bisphenol A for coating a packaging or a container that is usable for packaging food, the coating composition comprising:
 a lignin;   a polymeric epoxy crosslinker, wherein the polymeric epoxy crosslinker includes glycidyl (meth)acrylate; and   a solvent capable of dissolving the lignin and the polymeric epoxy crosslinker to form a solution that is thermally curable at a temperature in a range from about 130 degrees Celsius to about 250 degrees Celsius.   
     
     
         27 . The coating composition of  claim 26 , wherein the lignin is an unmodified lignin. 
     
     
         28 . The coating composition of  claim 26  wherein the lignin has a neutral or a negative charge. 
     
     
         29 . The coating composition of  claim 26 , wherein the coating composition includes polymeric dispersions having between about 10% to about 60% by weight polymeric solids. 
     
     
         30 . A can or packaging usable for packaging food coated with the coating composition of  claim 26 . 
     
     
         31 . A coating composition that is substantially free of hisphenol A for coating a packaging or a container that is usable for packaging food, the coating composition comprising:
 a lignin;   a solvent capable of dissolving the lignin to form a solution; and   a phenolic crosslinker that is soluble in the solvent and that is thermally curable with the lignin in the solution at a temperature in a range from about 130 degrees Celsius to about 250 degrees Celsius.   
     
     
         32 . The coating composition of  claim 31 , wherein the lignin is an unmodified lignin. 
     
     
         33 . The coating composition of  claim 31 , wherein the lignin has a neutral or a negative charge. 
     
     
         34 . The coating composition of  claim 31 , wherein the coating composition includes polymeric dispersions having between about 10% to about 60% by weight polymeric solids. 
     
     
         35 . A can or packaging usable for packaging food coated with the coating composition of  claim 31 .