Controlled released fertilizers based on self-assembled molecule coatings

Abstract

Controlled release fertilizers are provided and methods for their preparation, wherein the controlled release fertilizers are obtained through self-assembling molecules on the surfaces of the fertilizer particles, and then, preferably, linking these molecules into a network with another component. The designed molecules have a hydrophilic portion, which can interact with fertilizers, and a hydrophobic portion that make the molecule self-assemble and setup a moisture barrier. The molecules also preferably have at least two functional groups in order to form a network.

We claim:  
     
         1 . A controlled release fertilizer comprising: 
 a nutrient particle having coated thereon a coating comprising molecules of an amphiphilic compound, wherein the amphiphilic compound has a hydrophilic portion and a hydrophobic portion, wherein a plurality of said amphiphilic compound molecules self-assemble to form said coating such that said hydrophilic portion is proximal relative to said nutrient particle and said hydrophobic portion is distal relative to said nutrient particle.    
     
     
         2 . The controlled release fertilizer of  claim 1 , wherein said amphiphilic compound is a compound obtained from reacting unsaturated organic acids and their derivatives with an amine containing compound selected from the group consisting of hydroxylamines, and polyamines or a compound selected from the group consisting of multifunctional alcohols.  
     
     
         3 . The controlled release fertilizer of  claim 1 , wherein said coating further comprises one or more crosslinking agents to provide crosslinking between at least a portion of said amphiphilic compounds.  
     
     
         4 . The controlled release fertilizer of  claim 3 , further comprising one or more catalysts or initiators or both.  
     
     
         5 . The controlled release fertilizer of  claim 1 , wherein said amphiphilic compound is from 0.5 nm to 30 nm in size.  
     
     
         6 . The controlled release fertilizer of  claim 1 , wherein said amphiphilic compound is a member selected from the group consisting of amido polyalcohols, amido polyamines and ester alcohols.  
     
     
         7 . The controlled release fertilizer of  claim 2 , wherein said unsaturated organic acid and derivatives thereof are selected from the group consisting of aromatic and alkyl acids and derivatives thereof.  
     
     
         8 . The controlled release fertilizer of  claim 7 , wherein said unsaturated organic acids and derivatives thereof are a member selected from the group consisting of fatty acids and derivatives thereof.  
     
     
         9 . The controlled release fertilizer of  claim 8 , wherein said fatty acids and derivatives thereof are a member selected from the group consisting of natural oils.  
     
     
         10 . The controlled release fertilizer of  claim 9 , wherein said natural oil is a member selected from the group consisting of castor oil, linseed oil, soybean oil, sunflower oil, tall oil, and tung oil.  
     
     
         11 . The controlled release fertilizer of  claim 2 , wherein said hydroxylamines are selected from the group consisting of ethanolamine, diethanolamine, propanolamine, and dipropanolamine.  
     
     
         12 . The controlled release fertilizer of  claim 2 , wherein said polyamines are selected from the group consisting of ethylenediamine, diethylenetriamine, triethylenetetraamine, tetraethylenepentaamine, and pentaethylenehexaamine.  
     
     
         13 . The controlled release fertilizer of  claim 2 , wherein said multifunctional alcohols are selected from the group consisting of pentaerythyritol, glycerols and polymeric polyols.  
     
     
         14 . The controlled release fertilizer of  claim 3 , wherein said one or more crosslinking agents are a member selected form the group consisting of isocyanate crosslinking agents, polyvinylethers, polyacrylates, and epoxy compounds.  
     
     
         15 . The controlled release fertilizer of  claim 14 , wherein said isocyanate crosslinking agents are a member selected from the group consisting of aromatic isocyanates and aliphatic isocyanates.  
     
     
         16 . The controlled release fertilizer of  claim 4 , wherein said catalysts, initiators or both are a member selected from the group consisting of peroxide compounds, azo compounds, manganese salts, cobalt salts, zinc salts, zirconium salts, calcium salts and mixtures thereof.  
     
     
         17 . The controlled release fertilizer of  claim 1 , wherein the nutrient particle is a member selected from the group consisting of primary nutrients, secondary nutrients and micronutrients.  
     
     
         18 . The controlled release fertilizer of  claim 17 , wherein said primary nutrients are one or more members selected from the group consisting of N, P, K and their combination products.  
     
     
         19 . The controlled release fertilizer of  claim 17 , wherein said secondary nutrients are one or more members selected from the group consisting of calcium, magnesium and sulfur.  
     
     
         20 . The controlled release fertilizer of  claim 17 , wherein said micro nutrients are one or more members selected from the group consisting of boron, copper, iron, manganese, molybdenum and zinc.  
     
     
         21 . The controlled release fertilizer of  claim 1 , wherein said coating further comprises one or more polyols or polyamines in combination with said amphiphilic compound.  
     
     
         22 . The controlled release fertilizer of  claim 1 , wherein said coating is present in an average amount of from 0.5 wt % to 25 wt % based on total coated nutrient particle.  
     
     
         23 . The controlled release fertilizer of  claim 1 , wherein said nutrient particles are a member selected from the group consisting of urea, ammonium nitrate, diammonium phasphate, monoammonium phosphate, potash, potassium chloride, ammonium sulfate, and potassium sulfate.  
     
     
         24 . The controlled release fertilizer of  claim 1 , wherein said controlled release fertilizer is a mixture of two or more different coated nutrient particles.  
     
     
         25 . The controlled release fertilizer of  claim 1 , further comprising a plurality of coatings, wherein each coating layer may be the same as or different from the other coating layers, wherein said controlled release fertilizer has a controlled release rate of from 2 to 10 months.  
     
     
         26 . The controlled release fertilizer of  claim 25 , wherein said plurality of coatings is a number of layers from 2 to 100.  
     
     
         27 . The controlled release fertilizer of  claim 1 , further comprising a non-coated nutrient composition.  
     
     
         28 . The controlled release fertilizer of  claim 27 , wherein said nutrient particles are a member selected from the group consisting of urea, ammonium nitrate, diammonium phasphate, monoammonium phosphate, potash, potassium chloride, ammonium sulfate, and potassium sulfate.  
     
     
         29 . The controlled release fertilizer of  claim 27 , wherein the non-coated nutrient composition is a member selected from the group consisting of phosphorous fertilizers and potassium fertilizers.  
     
     
         30 . A process for preparation of a controlled release fertilizer, comprising: 
 coating a nutrient particle with a coating comprising molecules of an amphiphilic compound, wherein the amphiphilic compound has a hydrophilic portion and a hydrophobic portion, wherein a plurality of said amphiphilic compound molecules self-assemble to form said coating such that said hydrophilic portion is proximal relative to said nutrient particle and said hydrophobic portion is distal relative to said nutrient particle.    
     
     
         31 . The process of  claim 30 , wherein said coating is performed by spraying or ejecting the coating onto said nutrient particle.  
     
     
         32 . The process of  claim 31 , wherein said nutrient particle is being subjected to tumbling during said spraying or ejecting.  
     
     
         33 . The process of  claim 30 , wherein said coating step is performed a plurality of times to apply a plurality of coating layers.  
     
     
         34 . The process of  claim 33 , wherein said plurality of coating layers are coating layers of identical composition.  
     
     
         35 . The process of  claim 33 , wherein said plurality of coating layers comprise two or more different coating compositions.  
     
     
         36 . The process of  claim 30 , wherein said coating is performed at a temperature of from 60 to 80° C.  
     
     
         37 . The process of  claim 36 , wherein said coating is performed for a time of from 5 to 20 min.  
     
     
         38 . The process of  claim 30 , further comprising crosslinking said coating by curing said coating in the presence of one or more crosslinking agents.  
     
     
         39 . The process of  claim 38 , wherein said crosslinking is performed in the presence of one or more catalysts or initiators or both.  
     
     
         40 . The process of  claim 38 , wherein said one or more crosslinking agents are a member selected from the group consisting of isocyanate crosslinking agents, polyvinylethers, polyacrylates, and epoxy compounds.  
     
     
         41 . The process of  claim 40 , wherein said isocyanate crosslinking agents are a member selected from the group consisting of aromatic isocyanates and aliphatic isocyanates.  
     
     
         42 . The process of  claim 39 , wherein said catalysts, initiators or both are a member selected from the group consisting of peroxide compounds, azo compounds, manganese salts, cobalt salts, zinc salts, zirconium salts, calcium salts and mixtures thereof.  
     
     
         43 . A controlled release fertilizer comprising: 
 a nutrient particle coated by a means for forming a self-assembling molecular coating.    
     
     
         44 . A process for production of a controlled release fertilizer, comprising: 
 a step of coating a nutrient particle with a self-assembling molecular coating.    
     
     
         45 . The process of  claim 44 , further comprising a step of curing said self-assembling molecular coating.