Slow release nitrogen fertilizer

• US 6,936,681 B1
• Filed: 03/26/2003
• Issued: 08/30/2005
• Est. Priority Date: 03/26/2002
• Status: Expired due to Term

• Current Assignee: KOCH Agronomic Services LLC (KOCH Industries Incorporated)
• Original Assignee: Georgia Pacific Resins, Inc
• Inventors: Wright, James, Wertz, Stacey L., Gabrielson, Kurt, Knight, James, Baxter, Paul, Davis, C. R.
• Primary Examiner(s): Truong, Duc
• Application Number:
  US10/396,701
• Time in Patent Office: 888 Days
• Field of Search: 528/259, 528/266, 528/486, 528/491, 528/502.R, 528/502.E, 524/818, 524/839, 71/28
• US Class Current: 528/259
• CPC Class Codes: A01C 1/06 Coating or dressing seed
• CPC Class Codes: C05C 9/02 containing urea-formaldehyde condensates
• CPC Class Codes: C05D 9/00 Other inorganic fertilisers
• CPC Class Codes: C05D 9/02 containing trace elements
• CPC Class Codes: C05F 11/00 Other organic fertilisers
• CPC Class Codes: C05F 11/02 from peat, brown coal, and similar vegetable deposits
• CPC Class Codes: C05G 1/00 Mixtures of fertilisers belonging individually to different subclasses of C05
• CPC Class Codes: C05G 3/00 Mixtures of one or more fertilisers with additives not having a specially fertilising activity
• CPC Class Codes: C05G 5/12 Granules or flakes
• CPC Class Codes: C05G 5/27 Dispersions, e.g. suspensions or emulsions
• CPC Class Codes: C05G 5/30 Layered or coated, e.g. dust-preventing coatings
• CPC Class Codes: C05G 5/37 layered or coated with a polymer
• CPC Class Codes: Y02P 60/21 Dinitrogen oxide [N2O], e.g. using aquaponics, hydroponics or efficiency measures
• CPC Class Codes: Y10S 47/09 Physical and chemical treatment of seeds for planting

Abstract

A slow release, particulate urea-formaldehyde polymer useful as a fertilizer for enhancing the extended delivery of nitrogen needed for plant development and growth and a granular fertilizer made with the particulate urea-formaldehyde polymer.

Claims

1. A particulate urea-formaldehyde polymer made by acidifying a aqueous methylol urea solution, wherein the aqueous methylol urea solution is made by reacting urea and formaldehyde at a urea:

formaldehyde mole ratio of from 0.7;

1 to 1.25;

1 and wherein the aqueous methylol urea solution either contains a dispersing agent or is subjected to a high shear condition during the acidifying, to form an aqueous dispersion of insoluble urea-formaldehyde polymer particles and drying the dispersion to recover the urea-formaldehyde polymer particles.

2. The particulate urea-formaldehyde polymer of claim 1 wherein the aqueous methylol urea solution is made by reacting urea and formaldehyde at a urea:

formaldehyde mole ratio of approximately 1;

1.

3. The particulate urea-formaldehyde polymer of claim 1 wherein the aqueous methylol urea solution is made by reacting urea and formaldehyde at a urea:

formaldehyde mole ratio of approximately 1;

1 and wherein the methylol urea solution contains a dispersing agent during the acidifying.

4. The particulate urea-formaldehyde polymer of claim 2 wherein the aqueous methylol urea solution is made by reacting urea and formaldehyde at a urea:

formaldehyde mole ratio of from 0.83;

1 to 1.1;

1.

5. The particulate urea-formaldehyde polymer of claim 3 wherein the aqueous methylol urea solution is made by reacting urea and formaldehyde at a urea:

formaldehyde mole ratio of from 0.83;

1 to 1.1;

1.

6. The particulate urea-formaldehyde polymer of claim 1 wherein the aqueous methylol urea solution is made by reacting urea and formaldehyde at a urea:

formaldehyde mole ratio of from 0.95;

1 to 1.05;

1 and wherein the methylol urea solution contains a dispersing agent during the acidifying.

7. The particulate urea-formaldehyde polymer of claim 1 wherein the aqueous methylol urea solution is made by reacting urea and formaldehyde at a urea:

formaldehyde mole ratio of from 0.95;

1 to 1.05;

1.

8. The particulate urea-formaldehyde polymer of claim 1, 2, 3, 4, 5, 6, or 7 wherein the aqueous dispersion of urea-formaldehyde polymer particles is dried by spray drying.

9. A granular fertilizer made by granulating the particulate urea-formaldehyde polymer of claim 8 with a fertilizer-enhancing solid and a binder.

10. The granular fertilizer of claim 9 wherein said fertilizer-enhancing solid is selected from the group consisting of calcium carbonate;

gypsum;

metal silicates;

metal chelates of a metal selected from iron, zinc and manganese;

talc;

elemental sulfur;

activated carbon;

pesticides;

herbicides;

fungicides;

super absorbent polymers;

wicking agents;

wetting agents;

plant stimulants;

urea;

a potassium source and a phosphorus source.

13. The particulate urea-formaldehyde polymer of claim 1 wherein the urea-formaldehyde polymer particles have a number average particle size between 25 and 35 microns.

18. The particulate urea-formaldehyde polymer of claim 6 wherein the dispersing agent is selected from the group consisting of a condensed naphthalene sulfonate, a polyacrylate, a lignosulfonate salt and lignin.

11. A method of producing a particulate urea-formaldehyde polymer comprising forming an aqueous solution of methylol urea by reacting urea and formaldehyde at a urea:

formaldehyde mole ratio of 0.95;

1 to 1.05;

1;

acidifying the aqueous methylol urea solution, wherein the aqueous methylol urea solution either contains a dispersing agent or is subjected to a high shear condition during the acidifying, to form an aqueous dispersion of insoluble urea-formaldehyde polymer particles and drying the dispersion to recover the urea-formaldehyde polymer particles.

12. The method of claim 11 wherein the wherein the methylol urea solution contains a dispersing agent during the acidifying and the aqueous dispersion of urea-formaldehyde polymer particles is dried by spray drying.

19. The particulate urea-formaldehyde polymer of claim 12 wherein the dispersing agent is selected from the group consisting of a condensed naphthalene sulfonate, a polyacrylate, a lignosulfonate salt and lignin.

14. A particulate urea-formaldehyde polymer made by acidifying an aqueous methylol urea solution, wherein the aqueous methylol urea solution is made by reacting urea and formaldehyde at a urea:

formaldehyde mole ratio of from 0.7;

1 to 1.25;

1 and wherein the aqueous methylol urea solution either contains a dispersing agent or is subjected to a high shear condition during the acidifying, to form an aqueous dispersion of insoluble urea-formaldehyde polymer particles, wherein most of the urea-formaldehyde particles have a size between 1 and 150 microns.

15. The particulate urea-formaldehyde polymer of claim 14 wherein most of the urea-formaldehyde particles have a size between 10 and 80 microns.

16. The particulate urea-formaldehyde polymer of claim 15 wherein the urea-formaldehyde particles have a number average particle size between 25 and 35 microns.

17. The particulate urea-formaldehyde polymer of claim 14 wherein the dispersing agent is selected from the group consisting of a condensed naphthalene sulfonate, a polyacrylate, a lignosulfonate salt and lignin.