High nitrogen liquid fertilizer
View Patent ↗The present invention is directed to liquid fertilizer composition having a high nitrogen content comprising an aqueous mixture of a urea-formaldehyde resin and a nitrogen fertilizer source selected from the group consisting of urea, ammonium nitrate, and a mixture of urea and ammonium nitrate, wherein the liquid fertilizer possess surprisingly depressed freeze points and salt-out temperatures.
1. An aqueous nitrogen fertilizer solution comprising a mixture of a urea-formaldehyde resin and a nitrogen fertilizer source selected from the group consisting of urea, ammonium nitrate and a mixture of urea and ammonium nitrate, wherein the urea-formaldehyde resin is prepared by reacting urea, formaldehyde and ammonia at a formaldehyde/urea/ammonia mole ratio of 1-4/1/0.5-1.
2. The aqueous nitrogen fertilizer solution of claim 1 wherein the urea-formaldehyde resin is prepared by reacting urea, formaldehyde and ammonia in water under an alkaline reaction condition to yield an aqueous urea-formaldehyde resin solution.
3. The aqueous nitrogen fertilizer solution of claim 1 wherein the urea-formaldehyde resin is prepared by reacting a solution of urea, formaldehyde and ammonia at a temperature from 80° C. to 95° C. and a pH from 7.5 to 10.5 for 45 to 120 minutes.
4. The aqueous nitrogen fertilizer solution of claim 1 wherein the urea-formaldehyde resin has a cyclic urea content, based on 100% resin solids, of greater than 20% by weight.
5. The aqueous nitrogen fertilizer solution of claim 4 wherein the urea-formaldehyde resin has a cyclic urea content, based on 100% resin solids, of greater than 40% by weight.
6. The aqueous nitrogen fertilizer solution of claim 5 wherein the urea-formaldehyde resin has a free urea content, based on 100% resin solids, of less than 10% by weight.
7. The aqueous nitrogen fertilizer solution of claim 1 prepared by blending an aqueous urea-ammonium nitrate solution having a nitrogen content from 28 to 32% by weight with an aqueous solution of a urea-formaldehyde resin.
8. The aqueous nitrogen fertilizer solution of claim 1 wherein an aqueous urea-formaldehyde resin solution (UF) is mixed with a nitrogen fertilizer source selected from the group consisting of an aqueous solution of urea (U), an aqueous solution of ammonium nitrate (AN) and an aqueous solution of urea-ammonium nitrate (UAN) in a weight ratio (UF:U, UF:AN or UF:UAN) of 90:10 to 10:90.
9. The aqueous nitrogen fertilizer solution of claim 1 wherein an aqueous urea-formaldehyde resin solution (UF) is mixed with a nitrogen fertilizer source selected from the group consisting of an aqueous solution of urea (U), an aqueous solution of ammonium nitrate (AN) and an aqueous solution of urea-ammonium nitrate (UAN) in a weight ratio (UF:U, UF:AN or UF:UAN) of 70:30 to 30:70.
10. The aqueous nitrogen fertilizer solution of claim 1 wherein an aqueous urea-formaldehyde resin solution (UF) is mixed with a nitrogen fertilizer source selected from the group consisting of an aqueous solution of urea (U), an aqueous solution of ammonium nitrate (AN) and an aqueous solution of urea-ammonium nitrate (UAN) in a weight ratio (UF:U, UF:AN or UF:UAN) of 30:70 to 50:50.
11. The aqueous nitrogen fertilizer solution of claim 9 wherein the aqueous urea-formaldehyde resin solution has a solid concentration of above 70% by weight.
12. The aqueous nitrogen fertilizer solution of claim 10 wherein the aqueous urea-formaldehyde resin solution has a solid concentration of above 70% by weight.
13. An aqueous nitrogen fertilizer solution of claim 1 having a solids concentration of at least 70% by weight.
14. An aqueous nitrogen fertilizer solution of claim 1 having a solids concentration of at least 80% by weight.
15. An aqueous nitrogen fertilizer solution of claim 4 having a solids concentration of at least 70% by weight.
16. An aqueous nitrogen fertilizer solution of claim 4 having a solids concentration of at least 80% by weight.
17. An aqueous nitrogen fertilizer solution of claim 9 having a solids concentration of at least 70% by weight.
18. An aqueous nitrogen fertilizer solution of claim 9 having a solids concentration of at least 80% by weight.
19. A method of fertilizing comprising applying to a plant the aqueous fertilizer solution of claim 1 , 2 , 4 , 7 , 9 , 13 , 15 , or 17 .
20. An aqueous nitrogen fertilizer solution comprising a mixture of a urea-formaldehyde resin and a nitrogen fertilizer source selected from the group consisting of urea, ammonium nitrate and a mixture of urea and ammonium nitrate, wherein the urea-formaldehyde resin is prepared by reacting urea, formaldehyde and ammonia in water under an alkaline reaction condition to yield an aqueous urea-formaldehyde resin solution at a formaldehyde/urea/ammonia mole ratio of 0.6-1/1/0.25-0.35.
21. The aqueous nitrogen fertilizer solution of claim 20 wherein the urea-formaldehyde resin is prepared by reacting urea, formaldehyde and ammonia in water under an alkaline reaction condition to yield an aqueous urea-formaldehyde resin solution.
22. The aqueous nitrogen fertilizer solution of claim 20 wherein the urea-formaldehyde resin is prepared by reacting a solution of urea, formaldehyde and ammonia at a temperature from 80° C. to 95° C. and a pH from 7.5 to 10.5 for 45 to 120 minutes.
23. The aqueous nitrogen fertilizer solution of claim 20 prepared by blending an aqueous urea-ammonium nitrate solution having a nitrogen content from 28 to 32% by weight with an aqueous solution of a urea-formaldehyde resin.
24. The aqueous nitrogen fertilizer solution of claim 20 wherein an aqueous urea-formaldehyde resin solution (UF) is mixed with a nitrogen fertilizer source selected from the group consisting of an aqueous solution of urea (U), an aqueous solution of ammonium nitrate (AN) and an aqueous solution of urea-ammonium nitrate (UAN) in a weight ratio (UF:U, UF:AN or UF:UAN) of 90:10 to 10:90.
25. The aqueous nitrogen fertilizer solution of claim 20 wherein an aqueous urea-formaldehyde resin solution (UF) is mixed with a nitrogen fertilizer source selected from the group consisting of an aqueous solution of urea (U), an aqueous solution of ammonium nitrate (AN) and an aqueous solution of urea-ammonium nitrate (UAN) in a weight ratio (UF:U, UF:AN or UF:UAN) of 70:30 to 30:70.
26. An aqueous nitrogen fertilizer solution of claim 20 having a solids concentration of at least 70% by weight.
27. The aqueous nitrogen fertilizer solution of claim 20 wherein the urea-formaldehyde resin has a cyclic urea content, based on 100% resin solids, of 14 to 20% by weight.