Quick drying polymeric coating
View Patent ↗Improved agriculturally useful products are provided, including solid materials such as nitrogenous fertilizers (e.g., urea), together with a polycarboxylated polymer selected from the group consisting of a salts of copolymers containing individual quantities of maleic and itaconic moieties. The polymer composition also includes from about 10-60% by weight of an organic drying agent such as a lower alcohol which enhances the quick drying properties thereof. The compositions may also include an amount of boron, and bimodal vinylic polymer made up of quantities of high and low molecular weight (MW) vinylic polymers such as PVA.
1. A fertilizer product comprising:
a quantity of a solid fertilizer; and
a polymer-containing composition applied to said fertilizer,
said polymer-containing composition including a substantially water soluble copolymer containing individual quantities of maleic and itaconic moieties, water, an organic compound drying agent,
said composition further including from about 0.5-5% by weight boron as boric acid, an amount of bimodal vinyl polymer therein, said bimodal vinyl polymer including individual high and low molecular weight vinyl polymer fractions, said bimodal vinyl polymer comprising low MW PVA having a weight averaged molecular weight Mw of from about 13,000-23,000, and high MW PVA having a weight averaged molecular weight Mw of about 145,000 and above, said low MW PVA being present in an amount greater than said high MW PVA,
said fertilizer product prepared by applying said polymer-containing composition to said solid fertilizer, and allowing said drying agent and a substantial part of the water present in the applied composition to evaporate, so that the fertilizer product does not contain said drying agent or water to any substantial degree.
2. The fertilizer product of claim 1 , said fertilizer being a nitrogenous fertilizer.
3. The fertilizer product of claim 2 , said fertilizer selected from the group consisting of urea, ammonium sulfate, ammonium nitrate, MAP, and DAP in the form of granules or prills, said composition applied to the surface of said fertilizer at a level of from about 0.1-1 gallons of said polymer-containing composition per ton of said solid fertilizer.
4. The fertilizer product of claim 1 , said fertilizer being urea, said polymer-containing composition comprising:
(1) from about 20-50% by weight of maleic-itaconic copolymer, in the form of a partial salt and having at least about 93% itaconic and maleic moieties therein;
(2) volatile organic solvent present at a level of from about 5-60% by weight;
(3) low MW PVA at a level of from about 0.5-10% by weight;
(4) high MW PVA at a level of from about 0.1-4% by weight;
(5) a ratio of high MW PVA to low MW PVA of from about 1:2 to 1:20.
5. The fertilizer product of claim 1 , said fertilizer composition formed by spraying said polymer-containing composition onto said solid fertilizer.
6. The fertilizer product of claim 1 , said copolymer containing from about 10-90% by maleic moieties, and from about 90-10% by itaconic moieties.
7. The fertilizer product of claim 1 , said drying agent selected from the group consisting of organic alcohols and ketones.
8. The fertilizer product of claim 7 , said drying agent selected from the group consisting of C1-C4 alcohols.
9. The fertilizer product of claim 1 , said copolymer being in partial salt form and having at least about 93% itaconic and maleic moieties.
10. The fertilizer product of claim 1 , said composition comprising from about 20-70% by weight of said copolymer in partial salt form, from about 5-60% by weight methanol, and from about 10-50% by weight water.
11. The fertilizer product of claim 10 , said copolymer salt being present at a level of from about 30-60% by weight, from about 30-50% by weight methanol, and from about 10-25% by weight water.
12. The fertilizer product of claim 1 , the ratio of said high MW PVA to said low MW PVA being from about 1:2 to 1:20.
13. The fertilizer product of claim 12 , said ratio being from about 1:4 to 1:12.
14. A method of fertilizing soil comprising the step of applying the fertilizer product of claim 1 to soil.
15. The method of claim 14 , said polymer-containing composition comprising:
(1) from about 20-50% by weight of maleic-itaconic copolymer, in the form of a partial salt and having at least about 93% itaconic and maleic moieties therein;
(2) volatile organic solvent present at a level of from about 5-60% by weight;
(3) low MW PVA at a level of from about 0.5-10% by weight;
(4) high MW PVA at a level of from about 0.1-4% by weight;
(5) a ratio of high MW PVA to low MW PVA of from about 1:2 to 1:20.
16. The method of claim 14 , said solid fertilizer being urea, said polymer-containing composition comprising:
(1) from about 20-50% by weight of maleic-itaconic copolymer, in the form of a partial salt and having at least about 93% itaconic and maleic moieties therein;
(2) volatile organic solvent present at a level of from about 5-60% by weight;
(3) low MW PVA at a level of from about 0.5-10% by weight;
(4) high MW PVA at a level of from about 0.1-4% by weight;
(5) a ratio of high MW PVA to low MW PVA of from about 1:2 to 1:20.
17. A method of forming a fertilizer composition, comprising the steps of:
applying a polymer-containing composition onto a quantity of a solid fertilizer, said polymer-containing composition including a substantially water soluble copolymer containing individual quantities of maleic and itaconic moieties, water, and an organic compound drying agent,
said composition further including from about 0.5-5% by weight boron as boric acid, an amount of bimodal vinyl polymer therein, said bimodal vinyl polymer including individual high and low molecular weight vinyl polymer fractions, said bimodal vinyl polymer comprising low MW PVA having a weight averaged molecular weight Mw of from about 13,000-23,000, and high MW PVA having a weight averaged molecular weight Mw of about 145,000 and above, said low MW PVA being present in an amount greater than said high MW PVA; and
allowing said drying agent and a substantial part of the water present in said polymer-containing composition to evaporate, so that the fertilizer composition does not contain said drying agent or water to any substantial degree.
18. The method of claim 17 , said solid fertilizer selected from the group consisting of urea, ammonium nitrate, ammonium sulfate, and mixtures thereof.
19. The method of claim 17 , said solid fertilizer being granular.
20. The method of claim 17 , said copolymer being a partial salt containing from about 10-90% by maleic moieties, and from about 90-10% by itaconic moieties.
21. The method of claim 20 , said copolymer salt having about a 1:1 ratio of maleic moieties to itaconic moieties.
22. The method of claim 17 , said drying agent selected from the group consisting of organic alcohols and ketones.
23. The method of claim 22 , said drying agent selected from the group consisting of C1-C4 alcohols.
24. The method of claim 23 , said drying agent being methanol.
25. The method of claim 17 , said drying agent selected selected from the group consisting of organic compounds having a vapor pressure of at least about 40 mmHg at STP.
26. The method of claim 17 , including the step of spraying said polymer-containing composition onto said solid fertilizer.
27. The method of claim 17 , said polymer-containing composition comprising a quantity of said copolymer suspended in a liquid phase comprising said water and said drying agent.
28. The method of claim 27 , said drying agent being methanol, and said methanol being present in the fertilizer composition at a level of from about 10-60% by weight.
29. The method of claim 28 , said level being of from about 35-45% by weight.
30. The method of claim 29 , said polymer-containing composition including from about 20-70% by weight of said copolymer from about 10-60% by weight methanol, and from about 10-50% by weight water.
31. The method of claim 17 , said polymer-containing composition including about 40% by weight of a partial salt of a maleic-itaconic copolymer, about 45% by weight methanol, and about 15% by weight water.
32. The method of claim 17 , said polymer-containing composition having a pH of from about 1-4.
33. The method of claim 17 , the ratio of said high MW PVA to said low MW PVA being from about 1:2 to 1:20.
34. The method of claim 33 , said ratio being from about 1:4 to 1:12.