Coated granular fertilizers, methods of manufacture thereof, and uses

Abstract

A coated fertilizer comprises a fertilizer granule; and a coating disposed on a surface of the fertilizer granule, wherein the coating comprises a poly(lactic acid); a second polymer comprising a poly(butylene succinate), a cellulose triacetate, or a combination comprising at least one of the foregoing; and a sealant. Methods of making the coated fertilizer are also disclosed.

1 .- 32 . (canceled) 
     
     
         33 . A coated fertilizer comprising:
 a fertilizer granule; and   a coating disposed on a surface of the fertilizer granule, wherein the coating comprises:
 up to 9 wt. %, based on the weight of the coated fertilizer, of a biodegradable layer comprising poly(lactic acid), poly(butylene succinate), or a combination of poly(lactic acid) and poly(butylene succinate); and 
 up to 5 wt. %, based on the weight of the coated fertilizer, of a sealant layer comprising a hydrophobic sealant, wherein the sealant layer is disposed on the fertilizer granule and the biodegradable layer. 
   
     
     
         34 . The coated fertilizer of  claim 33 , wherein the sealant layer comprises a wax, an oil, or a wax and an oil. 
     
     
         35 . The coated fertilizer of  claim 33 , wherein the biodegradable layer comprises a combination of poly(lactic acid) and poly(butylene succinate). 
     
     
         36 . The coated fertilizer of  claim 33 , wherein the coated fertilizer comprises 42 wt. % to 45 wt. % nitrogen, based on the total weight of the coated fertilizer. 
     
     
         37 . The coated fertilizer of  claim 33 , wherein the coating has a total thickness of 20 to 70 micrometers. 
     
     
         38 . The coated fertilizer of  claim 33 , wherein the biodegradable layer comprises more than one layer. 
     
     
         39 . The coated fertilizer of  claim 38 , wherein the coating comprises poly(lactic acid) and poly(butylene succinate) in two separate layers. 
     
     
         40 . The coated fertilizer of  claim 33 , wherein the biodegradable layer further comprises a further polymer that is not poly(lactic acid) or poly(butylene succinate). 
     
     
         41 . The coated fertilizer of  claim 33 , wherein the coating comprises 3 to 9 wt. % of the biodegradable layer. 
     
     
         42 . The coated fertilizer of  claim 33 , wherein the coating comprises 2 to 5 wt. % of the sealant layer. 
     
     
         43 . The coated fertilizer of  claim 35 , wherein a weight ratio of the poly(lactic acid) to poly(butylene succinate) is 10:1 to 1:10. 
     
     
         44 . The coated fertilizer of  claim 33 , wherein the poly(butylene succinate) has an average molecular weight of 100,000 to 150,000 g/mol 
     
     
         45 . The coated fertilizer of  claim 33 , wherein the poly(lactic acid) has an average molecular weight of 150,000 to 210,000 g/mol or 30,000 to 70,000 g/mol. 
     
     
         46 . The coated fertilizer of  claim 33 , wherein the poly(lactic acid) comprises crystalline poly(lactic acid). 
     
     
         47 . The coated fertilizer of  claim 33 , wherein the poly(lactic acid) comprises recycled poly(lactic acid). 
     
     
         48 . The coated fertilizer of  claim 33 , wherein the sealant layer comprises a wax. 
     
     
         49 . The coated fertilizer of  claim 48 , wherein the wax comprises an alpha-olefin wax. 
     
     
         50 . The coated fertilizer of  claim 48 , wherein the wax comprises a petroleum wax. 
     
     
         51 . A method of making the coated fertilizer of  claim 33 , the method comprising:
 dissolving the poly(lactic acid) and/or the poly(butylene succinate) in a first solvent to provide a first solution;   depositing the first solution on at least a portion of a surface of the fertilizer granule to form the biodegradable layer; and   depositing the hydrophobic sealant on at least a portion of the first layer to form the sealant layer.   
     
     
         52 . A method of fertilizing, the method comprising applying the coated fertilizer of  claim 33  to at least one of a soil, a crop, or a soil and a crop.