EMULSION FOR TREATING UREA-CONTAINING FERTILIZERS

Abstract

The invention relates to an emulsion for treating urea-containing fertilizers, containing an aqueous phase B and a non-aqueous phase A, which is emulsified with phase B, wherein phase A contains at least one (thio)phosphoric acid triamide of the general formula (I) and/or (thio)phosphoric acid diamide of the general formula (II), R.sup.1R.sup.2NP(X)(NH.sub.2).sub.2, R.sup.1OP(X)(NH.sub.2).sub.2 where X means oxygen or sulfur, R.sup.1 and R.sup.2 mean, independently of each other, hydrogen, respectively substituted or unsubstituted 2-nitrophenyl, C.sub.1-10 alkyl, C.sub.3-10 cycloalkyl, C.sub.3-10 heterocycloalkyl, C.sub.6-10 aryl, C.sub.6-10 heteroaryl or diaminocarbonyl, wherein R.sup.1 and R.sup.2, together with the nitrogen atom connecting them, can also form a 5 or 6-membered saturated or unsaturated heterocyclic group, which can optionally also contain one or two additional heteroatoms, selected from the group consisting of nitrogen, oxygen and sulfur, as component A1, dissolved in an organic solvent, which is not miscible with water, as component A2, and wherein phase B 2-(N-3,4-dimethylpyrazole)succinic acid, which is present as dialkali salt, earth alkali salt, diammonium salt or a mixture thereof, as component B1, dissolved in water.

Claims

1-18. (canceled)

19. An emulsion for treatment of urea-containing fertilizers, comprising an aqueous phase B and a nonaqueous phase A emulsified with phase B, where phase A comprises at least one (thio)phosphoric acid triamide of the general formula (I) and/or (thio)phosphoric acid diamide of the general formula (II)
R.sup.1R.sup.2NP(X)(NH.sub.2).sub.2(I)
R.sup.1OP(X)(NH.sub.2).sub.2(II) with the following definitions: X is oxygen or sulfur, R.sup.1 and R.sup.2 are independently hydrogen, respectively substituted or unsubstituted 2-nitrophenyl, C.sub.1-10-alkyl, C.sub.3-10-cycloalkyl, C.sub.3-10-heterocycloalkyl, C.sub.6-10-aryl, C.sub.6-10-heteroaryl, or diaminocarbonyl, where R.sup.1 and R.sup.2 together with the nitrogen atom connecting them may also form a 5- or 6-membered saturated or unsaturated heterocyclic radical that may optionally also contain one or two further heteroatoms selected from the group consisting of nitrogen, oxygen, and sulfur, as component A1, dissolved in a water-immiscible organic solvent as component A2, and where phase B comprises 2-(N-3,4-dimethylpyrazole)succinic acid, as component B1, dissolved in water.

20. The emulsion of claim 19, wherein the (thio)phosphoric acid triamides of the general formula (I) used are N-alkylthiophosphoric acid triamides with the definitions of XS and R.sup.2H and/or N-alkylphosphoric acid triamides with the definitions of XO and R.sup.2H.

21. The emulsion of claim 19, wherein phase A comprises at least one compound containing an amino group or a substituted amino group and having a boiling point of more than 100 C., as component A3.

22. The emulsion of claim 19, wherein phase A further comprises a polymer in dissolved or dispersed form as component C.

23. The emulsion of claim 19, wherein components A1 and B1 are present in a weight ratio in the range from 1:1 to 1:6.

24. The emulsion of claim 19, wherein component A1 used is N-(n-butyl)thiophosphoric acid triamide or a mixture of N-(n-butyl)thiophosphoric acid triamide and N-(n-propyl)thiophosphoric acid triamide.

25. The emulsion of claim 19, wherein component A2 is selected from water-immiscible alcohols, ethers, esters, hydrocarbons, polyalkylene polyols and ethers thereof, liquid amides, or mixtures thereof.

26. The emulsion of claim 19, wherein phase B has a pH in the range from 6 to 9.

27. The emulsion of claim 19, wherein phase A comprises 15% to 35% by weight of component A1, based on the total weight of phase A.

28. The emulsion of claim 19, wherein phase B comprises 20% to 60% by weight of component B1, based on the total weight of phase B.

29. The method of using an emulsion of claim 19 as an additive or a coating composition for urea-containing nitrogen fertilizers.

30. The method of claim 29, wherein the emulsion is deployed on soil or plant substrate separately or simultaneously with the fertilizer or is introduced into the fertilizer or applied to the fertilizer.

31. A process for producing treated urea-containing fertilizers, comprising the steps of a) separately producing phases A and B as defined in claim 19, b) mixing phases A and B from step a) for production of an emulsion of phases A and B, and c) applying the emulsion from step b) to a particulate urea-containing fertilizer or introducing the emulsion from step b) into a particulate urea-containing fertilizer.

32. The process of claim 31, wherein there is a period of not more than 60 seconds between step c) and step b).

33. The process of claim 31, wherein the emulsion is applied to the urea-containing fertilizer in step c) by spray and/or drum application.

34. The process of claim 31, wherein the emulsion is applied to the urea-containing fertilizer or introduced into the urea-containing fertilizer in step c) in such an amount that the total content of components A and B, based on the urea present in the fertilizer, is 0.02% to 0.38% by weight.

35. The process of claim 31, wherein the emulsion is applied to the surface of the particulate urea-containing fertilizer in step c).

36. A urea-containing fertilizer obtainable by the process of claim 31.

37. The emulsion of claim 19, wherein the 2-(N-3,4-dimethylpyrazole)succinic acid is in the form of a dialkali metal salt, alkaline earth metal salt, diammonium salt or mixture thereof.

38. The emulsion of claim 21, wherein the at least one compound containing an amino group or a substituted amino group and having a boiling point of more than 100 C. is an amine.

39. The emulsion of claim 38, wherein the amine is selected from methyldiethanolamine, tetrahydroxypropylethylenediamine, trimethylaminoethylethanolamine, N,N,N,N-tetramethylhexane-1,6-diamine, N,N,N-tris(dimethylaminopropyl)hexahydrotriazine, 2,2-dimorpholinyldiethyl ether, N,N,N,N,N,N-hexamethyl-1,3,5-triazine-1,3,5(2H,4H,6H)-tripropanamine, N,N,N,N-tetrakis(2-hydroxypropyl)ethylenediamine, or mixtures thereof.

40. The emulsion of claim 21, wherein component A3 is in at least 0.2 times the molar amount of component A1.

41. The emulsion of claim 23, wherein components A1 and B1 are present in a weight ratio in the range from 1:1.5 to 1:5.

42. The emulsion of claim 41, wherein components A1 and B1 are present in a weight ratio in the range from 1:2 to 1:4.5

43. The emulsion of claim 25, wherein component A2 is selected from 2-propyl-1-heptanol, dimethyl phthalate, benzyl alcohol, or mixtures thereof.

44. The emulsion of claim 26, wherein phase B has a pH in the range from 7 to 8.

45. The emulsion of claim 27, wherein phase A comprises 20% to 30% by weight of component A1, based on the total weight of phase A.

46. The emulsion of claim 45, wherein phase A comprises 22% to 26.5% by weight of component A1, based on the total weight of phase A.

47. The emulsion of claim 28, wherein phase B comprises 25% to 50% by weight of component B1, based on the total weight of phase B.

48. The emulsion of claim 28, wherein phase B comprises 30% to 40% by weight of component B1, based on the total weight of phase B.

49. The process of claim 32, wherein there is a period of not more than 30 seconds between step c) and step b).

50. The process of claim 34, wherein the emulsion is applied to the urea-containing fertilizer or introduced into the urea-containing fertilizer in step c) in such an amount that the total content of components A and B, based on the urea present in the fertilizer, is 0.04% to 0.27% by weight.

Description

EXAMPLES

[0130] In the examples which follow,

[0131] NBPT: N-(n-butyl)-thiophosphoric acid triamide=urease inhibitor UI

[0132] DMPSA or DMPBS: 2-(N-3,4-dimethylpyrazole)succinic acid=nitrification inhibitor NI

A. Preparation Examples for 2-(N-3,4-dimethylpyrazole)succinic Acid (DMPSA)

[0133] Preparation is effected as described in EP-A-3 109 223 in example 1 or 2.

B. Production of Phases A and B

[0134] 79 g of a DMPSA formulation was prepared as a 35% by weight aqueous, pH-neutral formulation of DMPSA as the dipotassium salt.

[0135] 35 g of an NBPT formulation was prepared as a 23% by weight anhydrous solution of NBPT in 2-propyl-1-heptanol with addition of 46% by weight of a mixture of N,N,N,N,N,N-hexamethyl-1,3,5-triazine-1,3,5(2H,4H,6H)-tripropanamine and N,N,N,N-tetrakis(2-hydroxypropyl)-ethylenediamine.

C. Application of Phases A and B to the Fertilizer

[0136] 20 kg of granulated urea was initially charged in a mixer. 35 g of the NBPT formulation and 79 g of DMPSA formulation were introduced into a spray bottle and shaken until a homogeneous emulsion had formed. The formulation emulsion was immediately sprayed onto the urea, with intermittent shaking of the spray bottle in order to prevent settling of the emulsion. The mixer was operated for a further 10 minutes until a homogeneous product was obtained.

[0137] In a comparative experiment, identical amounts of DMPSA and NBPT were applied to urea. DMPSA formulation was applied first to the urea by the method described above, and the NBPT formulation was applied after drying.

[0138] Storage stability tests were conducted for both the urea fertilizers treated. They were stored for a period of 90 days under standard conditions in a climate-controlled cabinet. The NBPT and DMPSA content was determined at time intervals. FIG. 1 shows the decrease in the NBPT and DMPSA content over time after the number of days specified for the comparative formulation.

[0139] FIG. 2 shows the results of the stability test for the urea-containing fertilizers of the invention in which DMPSA and NBPT were applied as an emulsion mixture.

[0140] It is clearly apparent from the figures that the decrease both in DMPSA and in NBPT was significantly smaller for the urea-containing fertilizers produced in accordance with the invention than in the comparative experiment.

D. Dissolution Experiments

[0141] In addition, dissolution experiments were conducted for DMPSA and NBPT:

[0142] In aqueous media, the solubility of NBPT was much too small to obtain a sufficiently high concentration. The application rate of the solution would be too high for application to fertilizers.

[0143] Although both active substances were soluble in a sufficient amount in standard organic solvents, there were chemical reactions after a short time between NBPT and solvent constituents or between the two active substances, resulting in breakdown.

[0144] It can be inferred from this that there is no way of keeping the two active substances stable together in the same solvent system in suitable concentrations.

E. Comparative Experiments

[0145] In the comparative experiment, rather than a DMPBS formulation, 79 g of a DMPP formulation in the form of a 35% by weight aqueous, pH-neutral formulation was used in phase B. Otherwise, the procedure was as described in examples B. and C.

[0146] For both treated urea fertilizers, rapid degradation characteristics were observed both for NBPT and for DMPP. After a period of 7 days, about 50% of the DMPP and 100% of the NBPT had been broken down. It can be concluded from HPLC chromatograms for the two urea fertilizers treated that there were chemical reactions between the two substances that lead to degradation of DMPP and NBPT.