CONTROLLED RELEASE FERTILIZER WITH BIOPOLYMER COATING AND PROCESS FOR MAKING SAME

• US 20120090366A1
• Filed: 04/15/2011
• Published: 04/19/2012
• Est. Priority Date: 04/16/2010
• Status: Abandoned Application

• Current Assignee: Pursell Agri-Tech, LLC
• Original Assignee: Pursell Agri-Tech, LLC
• Inventors: Pursell, Taylor, Shirley, Arthur R. Jr., Cochran, Keith D., Miller, Joseph M., Holt, Timothy G., Peeden, Gregory S.
• Application Number:
  US13/088,043
• Publication Number:
  US 20120090366A1
• Time in Patent Office: Days
• US Class Current: 71/28
• CPC Class Codes: C05G 5/37 layered or coated with a polymer
• CPC Class Codes: C05G 5/38 layered or coated with wax or resins

Abstract

A controlled release fertilizer including a fertilizer granule, having an outer surface, a coating of biopolymer composition on the outer surface of the fertilizer granule, wherein the biopolymer composition includes at least one biopolymer, and a process of making the controlled release fertilizer including the steps of screening fertilizer granules to a preselected granule size, heating a biopolymer to become substantially fluid, and applying the biopolymer onto the surface of the fertilizer granule to produce a coating on the granule of a predetermined amount.

Claims

1. A controlled release fertilizer comprising:

a fertilizer granule, having an outer surface;

a coating of biopolymer composition on the outer surface of the fertilizer granule, wherein said biopolymer composition includes at least one biopolymer.

2. The controlled release fertilizer of claim 1, wherein the biopolymer is selected from the group consisting of polylactic acid, polylactide, lactide, and oligomers thereof.

3. The controlled release fertilizer of claim 2, wherein the biopolymer is polylactic acid oligomers.

4. The controlled release fertilizer of claim 1, wherein the amount of biopolymer coating is 1.0 to 10 wt. %.

5. The controlled release fertilizer of claim 1, wherein the biopolymer composition further includes at least one flow-sealant modifier.

6. The controlled release fertilizer of claim 5, wherein the flow-sealant modifier is selected from the group consisting of corn syrup, high fructose syrups, cane syrup, rice syrup and glucose syrup.

7. The controlled release fertilizer of claim 1, further comprising a second outer coating of a water proof or resistant sealant coating over the first coating of biopolymer composition resulting in a twice coated fertilizer granule.

8. The controlled release fertilizer of claim 7, wherein the sealant coating is selected from the group consisting of polyvinyl acetate, waxes, polymer blends, paraffins and micro crystalline waxes.

9. The controlled release fertilizer of claim 7, wherein the amount of sealant coating is 0.05 to 5 wt. %.

10. The controlled release fertilizer of claim 1, wherein the fertilizer granule includes a plant nutrient selected from the group consisting of nitrogen, phosphorus and potassium compounds.

11. The controlled release fertilizer of claim 10, wherein the nitrogen compound is selected from the group consisting of urea, ammonia, ammonium nitrate, ammonium sulfate, calcium nitrate, diammonium phosphate, monoammonium phosphate, potassium nitrate and sodium nitrate.

12. The controlled release fertilizer of claim 10, wherein the phosphorous compound is selected from the group consisting of diammonium phosphate, monoammonium phosphate, monopotassium phosphate, dipotassium phosphate, tetrapotassium pyrophosphate, and potassium metaphosphate.

13. The controlled release fertilizer of claim 10, wherein the potassium compound is selected from the group consisting of potassium chloride, potassium nitrate, potassium sulfate, monopotassium phosphate, dipotassium phosphate, tetrapotassium pyrophosphate, and potassium metaphosphate.

14. The controlled release fertilizer of claim 10, wherein the fertilizer contains nitrogen, phosphorous and potassium compounds in a N:

P;

K ratio selected from the group consisting of 29-3-4, 16-4-8, 10-10-10, 15-5-10, 15-0-15, 22-3-14, 20-28-5 and 12-6-6.

15. The controlled release fertilizer of claim 1, wherein the fertilizer granule includes a macronutrient selected from the group consisting of sulfur, calcium and magnesium and/or micronutrients including boron, copper, iron, manganese, molybdenum and zinc.

16. A process of making a controlled release fertilizer comprising the following steps:

screening fertilizer granules to a preselected granule size;

heating a biopolymer to become substantially fluid; and

applying the biopolymer onto the surface of the fertilizer granule to produce a coating on the granule of a predetermined amount.

17. The process of claim 16, wherein the biopolymer coating, is applied to the surface of the fertilizer granule surface by pouring, hydraulic spraying or pneumatic atomized spraying.

18. The process of claim 16, wherein the amount of coating of biopolymer is determined on a percent weight basis to result in a range of 1.0 to 10 wt. %.

19. The process of claim 16, further comprising after the biopolymer application step, the step of passing a cooling gas over the coated granules to quickly set the biopolymer.

20. The process of claim 16, further comprising after the biopolymer application step, a step of applying a parting agent to the surface of the biopolymer coated fertilizer granules.