Solvent compositions of urease inhibitors and their applications and uses

Abstract

This invention relates to solvent compositions comprising alkyl glycol ester type solvents and glycol type solvents, non-aqueous solvent delivery formulations comprising solvent compositions and urease inhibitors dissolved in solvent compositions, fertilizers comprising urea-based components and non-aqueous solvent delivery formulations, and the use of fertilizers in agricultural applications.

Description

Technical Field

[0001] This invention relates to solvent compositions comprising alkyl glycol ester type solvents and glycol type solvents, non-aqueous solvent delivery formulations comprising solvent compositions and urease inhibitors dissolved in solvent compositions, fertilizers comprising urea-based components and non-aqueous solvent delivery formulations, the use of non-aqueous solvent delivery formulations in fertilizer treatment, and the use of fertilizers in agricultural applications. Background Technology

[0002] In many crop production systems, essential plant nutrients need to be replenished through fertilizer application. Nitrogen, phosphorus, potassium, sulfur, calcium, and magnesium are required in the largest quantities and are therefore referred to as macronutrients. Nitrogen is the macronutrient that plants absorb in the largest quantities and is also the most volatile and leached. For these reasons, nitrogen is also the nutrient added to the soil in the largest quantity through nitrogen-containing fertilizers. This typically represents a significant cost per hectare of fertilized soil. Urea is the most widely used nitrogen source, followed by nitrate compounds such as ammonium nitrate, calcium nitrate, potassium nitrate, and magnesium nitrate. Globally, most nitrogen fertilizers are applied in granular form, although a large portion is also provided in liquid form.

[0003] Although granular urea is the most widely used nitrogen source, when applied to the soil at the surface for absorption by crops and plants, a significant amount of nitrogen is lost from urea into the atmosphere as ammonia. The average nitrogen loss in surface-applied urea is about 16%, but can be as high as 45% under conditions favorable for volatilization. These nitrogen losses can be addressed at a high cost through timely additional fertilization, but they can also manifest as crop yield losses, potentially having a greater financial impact than the cost of fertilizer. Ammonia is also a significant contributor to the greenhouse effect.

[0004] The hydrolysis of urea on the soil surface is a process that leads to ammonia volatilization and loss. This process is promoted by urease, which is naturally present in organic matter. By inhibiting urease activity, the hydrolysis process is suppressed, and ammonia loss is reduced.

[0005] The hydrolysis of urea typically proceeds according to the following reaction:

[0006]

[0007] However, the inhibition of hydrolysis should only be temporary, allowing urea to leach into the soil, where it becomes less volatile and more readily available for plant uptake. Nitrogen in the urea form is not readily absorbed by plants. Therefore, the hydrolysis of urea and subsequent nitrification of ammonium are crucial for the efficient uptake of nitrogen from urea by plants.

[0008] The most widely accepted urease inhibitor in this field is N-(n-butyl)thiophosphate triamide (nBPT, NBPT, or nBTPT). nBPT was first introduced in the United States in the early 1980s. In 2008, nBPT was also approved as a urease inhibitor in the European Union.

[0009] To reduce ammonia loss from urea applied to the ground, urea-based particles are typically coated with urease inhibitors such as nBPT. nBPT must be dissolved in a liquid non-aqueous delivery system so that the urea particles can be sprayed, for example. Almost all known solvent systems used for nBPT contain N-methyl-2-pyrrolidone (NMP), which is known to increase the solubility of many different substances. However, NMP is classified as a carcinogenic, mutagenic, and toxic (CMR) Group 2 substance. It is reproductively toxic, potentially harming unborn children, and can irritate the eyes, skin, and respiratory system. Since May 2020, the EU has strictly restricted the use of NMP. Therefore, the development of NMP-free liquid non-aqueous delivery systems for nBPT has become an urgent need.

[0010] US20170001921A1 (Koch Agromic Services LLC) describes a liquid carrier system for nBPT consisting of alkanols, enols, hydroxyalkylaryls, ethylene glycol, ethylene glycol ethers, ethylene glycol esters, glycerol, poly(alkylene glycol), poly(alkylene glycol) ethers, poly(alkylene glycol) esters, alkanolamines, hydroxy acids, DMSO, N-methyl-2-pyrrolidone (NMP), and mixtures thereof.

[0011] These compounds are described in detail, and a large list of solvents that can be combined to dissolve nBPT is given. However, no teaching is given regarding which solvent combination yields an improved nBPT solvent system. Furthermore, NMP is used in all liquid carrier systems in the provided examples, and US20170001921A1 provides no teaching regarding NMP-free solvent systems.

[0012] NMP-free solvent systems typically contain compounds with a diol structure. For example, WO 2008 / 000196 (AGRA Group, AS) describes a solvent system for preparing N-alkylthiophosphate triamide solutions, wherein the solvent system comprises one or more diol ethers preferably selected from diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, triethylene glycol monomethyl ether, and diethylene glycol monobutyl ether.

[0013] The most commonly used glycol solvent for nBPT is 1,2-propanediol, as described in WO 2017 / 144698 (Yara International ASA). 1,2-Propanediol itself dissolves relatively low concentrations of nBPT. The dissolution process also requires a relatively long time. Another problem with using pure 1,2-propanediol is that even at relatively low nBPT concentrations, the crystallization temperature is above 0°C. Therefore, 1,2-propanediol is not suitable for use at sub-zero temperatures typically experienced in practice.

[0014] WO 2018 / 152369 describes non-aqueous organic solvent delivery systems (NOSDS) for nBPT, comprising one or more solvents selected from aprotic and protic organic solvents. Specifically, the aprotic organic solvent may be selected from one or more alkylene glycol alkyl ether acetates, wherein the alkylene glycol alkyl ether acetate is selected from dipropylene glycol methyl ether acetate, tripropylene glycol methyl ether acetate, and tripropylene glycol butyl ether acetate. The protic solvent may particularly be selected from one or more alkylene glycols, wherein the alkylene glycol is selected from ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, and butanediol.

[0015] The purpose of WO 2018 / 152369 is to prepare slurries with high concentrations (50 to 90% by weight) of urease inhibitor (nBPT) at 20 to 70 °C using NOSDS.

[0016] Furthermore, this slurry is also used directly for coating solid nitration inhibitors. In this application, low-temperature storage stability is not important because the slurry is processed directly at higher temperatures. No such NOSDS is provided in WO 2018 / 152369, which indicates that the crystallization temperature is low when used to dissolve large amounts of nBPT.

[0017] In Example 3 of WO 2018 / 152369, 1,2-propanediol was used as the independent solvent for nBPT. 33.0 g of nBPT was mixed with 7.0 g of 1,2-propanediol at 45 to 55 °C. The solution exhibited poor dispersion stability at 50 °C. No teachings were found in WO 2018 / 152369 regarding combinations of alkylene glycols and alkylene glycol alkyl ether acetates that could yield improved nBPT solvent systems.

[0018] KR 20110128604 A teaches a diluent composition for removing photosensitive resins, comprising ethylene glycol or a mixture of diethylene glycol and propylene glycol monomethyl ether acetate (PGMEA), wherein a high excess of PGMEA is used.

[0019] CN 109599508 A discloses in Example 1 a composition comprising ZnO, ethylene glycol, DMF and ethylene glycol butyl ether acetate as an electron transport layer ink, wherein ethylene glycol and ethylene glycol butyl ether acetate are used in a ratio of 70:1, and the electron transport layer ink is used to manufacture quantum dot light-emitting diodes.

[0020] US 2019 / 169081 A1 teaches a non-aqueous organic liquid delivery system for dissolving urease inhibitors. This liquid delivery system may contain alkylene glycol alkyl ether acetates or glycols such as ethylene glycol or propylene glycol, but it does not teach the use of either of these different classes of solvents, nor does it teach their use in a specific ratio.

[0021] The applicant unexpectedly discovered that adding certain alkyl glycol esters to certain glycols (e.g., 1,2-propanediol) significantly increased the concentration of soluble nBPT while significantly reducing the time required to dissolve nBPT. Furthermore, certain mixtures of glycols and alkyl glycol esters exhibited significantly lower crystallization temperatures, even at high nBPT concentrations. Summary of the Invention

[0022] General solvent compositions

[0023] According to the present invention, a solvent composition is provided, the solvent composition comprising or consisting of the following substances:

[0024] (A) Alkyl diol ester type solvent of formula (I)

[0025]

[0026] in

[0027] R is hydrogen or a linear or branched C1 to C5 alkyl group.

[0028] R2 is a hydrogen or methyl group.

[0029] R3 is a hydrogen or methyl group.

[0030] X is 1 to 4.

[0031] R6 is a linear or branched C1 to C6 alkyl group.

[0032] Where R2 and R3 can be different for each X, and X is the degree of alkoxylation and the mean; and

[0033] (B) Diol-type solvent of formula (II)

[0034]

[0035] Where R4 is hydrogen or a C1 to C3 alkyl group, R5 is hydrogen or a C1 to C3 alkyl group, and Z is an integer from 0 to 4; and

[0036] The mass ratio of the glycol solvent to the alkyl glycol ester solvent ranges from 1:1 to 9:1, preferably from 3:1 to 9:1, more preferably from 4:1 to 8:1, and most preferably from 5.5:1 to 6.5:1.

[0037] Preferably, R is a C1 to C4 alkyl group, more preferably R is a C1 to C3 alkyl group, and most preferably R is a C1 or C2 alkyl group. R is preferably linear.

[0038] R2 and R3 can be selected such that the alkylene glycol group (AG) is formed.

[0039]

[0040] In the alkyl diol ester type solvent of formula (I), it represents an ethylene oxide (EO) unit or an propylene oxide (PO) unit or both.

[0041] Therefore, when AG is an EO unit, R2 is hydrogen and R3 is hydrogen, while when AG is a PO unit, R2 is hydrogen and R3 is a methyl group, or R2 is a methyl group and R3 is hydrogen.

[0042] AG elements can be EO-only elements, PO-only elements, EO-PO or PO-EO block structures, or random EO / PO elements.

[0043] Preferably, AG represents an EO unit.

[0044] Preferably, R4 is hydrogen or a C1 to C2 alkyl group, more preferably hydrogen or a methyl group.

[0045] Preferably, R5 is hydrogen or a C1 to C2 alkyl group, more preferably hydrogen or a methyl group.

[0046] Preferably, X is 1 to 3, more preferably X is 1 to 2.2.

[0047] Preferably, R6 is a linear or branched C1 to C4 alkyl group, more preferably a linear or branched C2 to C4 alkyl group, wherein for each range, the alkyl group is preferably linear, and most preferably R6 is n-butyl.

[0048] Preferably, Z is an integer from 0 to 3, more preferably Z is an integer from 0 to 2, and most preferably Z is 0 or 1.

[0049] Preferably, the solvent composition does not contain N-methyl-2-pyrrolidone.

[0050] According to a preferred embodiment, the solvent composition is used to dissolve urease inhibitors used in fertilizer applications.

[0051] The urease inhibitor can be an N-alkyl thiophosphate triamide, wherein the alkyl group is preferably C1 to C6, and more preferably N-(n-butyl) thiophosphate triamide (nBPT).

[0052] Preferred solvent compositions

[0053] According to a preferred embodiment of the present invention, the solvent composition is as described above, wherein...

[0054] a) R is a methyl group.

[0055] b) R2 is hydrogen.

[0056] c) R3 is hydrogen.

[0057] d) X is between 1 and 2.2.

[0058] e) R4 is a methyl group and R5 is hydrogen, or R4 is hydrogen and R5 is a methyl group.

[0059] f) R6 is n-butyl, and

[0060] g)Z is 0.

[0061] Therefore, the alkyl diol ester solvent of formula (I) can be diethylene glycol monobutyl acetate (BDG-acetate) or monoethylene glycol monobutyl acetate (BMG-acetate). Most preferably, the alkyl diol ester solvent of formula (I) is diethylene glycol monobutyl acetate (BDG-acetate).

[0062] Therefore, most preferably, the diol solvent of formula (II) is 1,2-propanediol.

[0063] In the solvent composition:

[0064] (A) Alkyl diol ester solvents of formula (I) and

[0065] (B) Diol-type solvent of formula (II)

[0066] The solvent composition is preferably composed of more than 70% by weight, more than 90% by weight, or more than 95% by weight, or the solvent composition is preferably composed of only (A) and (B).

[0067] Non-aqueous solvent delivery formulation

[0068] According to another aspect of the present invention, a non-aqueous solvent delivery formulation is provided, the non-aqueous solvent delivery formulation comprising:

[0069] The solvent composition described above; and

[0070] Urease inhibitor dissolved in solvent composition

[0071] The concentration of the urease inhibitor in the non-aqueous solvent delivery formulation is up to 40% by weight of the total mass of the non-aqueous solvent delivery formulation.

[0072] In a preferred embodiment of the non-aqueous solvent delivery formulation, the solvent composition is consistent with the preferred solvent composition described above.

[0073] Urease inhibitors can be N-alkylthiophosphate triamides, preferably N-(n-butyl)thiophosphate triamide (nBPT). Urease inhibitors are preferably composed of or contain N-alkylthiophosphate triamides (wherein the alkyl group is preferably C1 to C6), most preferably N-(n-butyl)thiophosphate triamide (nBPT).

[0074] Preferably, the concentration of the urease inhibitor in the non-aqueous solvent delivery formulation is 10% to 40% by weight, and most preferably 17.5% to 30% by weight, based on the total mass of the non-aqueous solvent delivery formulation.

[0075] Based on the total mass of the non-aqueous solvent delivery formulation, the solvent composition may be present in the non-aqueous solvent delivery formulation at a concentration preferably at least 50% by weight, more preferably at least 60% by weight, and most preferably at least 70% by weight.

[0076] The crystallization temperature of the non-aqueous solvent delivery formulation can be below 3°C or better, below 0°C, preferably below -10°C, and more preferably below -15°C.

[0077] The non-aqueous delivery formulation may additionally comprise one or more nitration inhibitors selected from dicyandiamide (DCD), nitrapyrin, pronitridine, allyl thiourea, 3,4-dimethylpyrazole phosphate (DMPP), and mixtures thereof. Preferably, the non-aqueous delivery formulation comprises the nitration inhibitor DCD.

[0078] The total concentration of one or more nitration inhibitors in a non-aqueous solvent-delivered formulation may be up to 9% by weight of the total weight of the non-aqueous solvent-delivered formulation.

[0079] Non-aqueous delivery formulations may additionally contain one or more dyes or colorants.

[0080] Non-aqueous delivery formulations may additionally contain one or more pesticide active agents selected from herbicides, fungicides, insecticides, and mixtures thereof.

[0081] Non-aqueous delivery formulations may additionally contain one or more additives selected from micronutrients, biostimulants, plant growth regulators, and mixtures thereof.

[0082] According to a preferred embodiment, the non-aqueous solvent delivery formulation is used for fertilizer applications.

[0083] fertilizer

[0084] According to another aspect of the present invention, a fertilizer is provided, the fertilizer comprising:

[0085] Urea-based components; and

[0086] As described above, non-aqueous solvent delivery formulations.

[0087] The urea component can be at least partially dissolved in the non-aqueous solvent delivery formulation, preferably completely dissolved in the non-aqueous solvent delivery formulation.

[0088] The urea-based component can be urea (especially essentially pure urea) or urea-ammonium nitrate (UAN).

[0089] Fertilizers can be liquid or solid. Solid fertilizers contain solid urea-based components, while liquid fertilizers contain liquid urea-based components.

[0090] Solid urea-based components can be in particulate or granular form.

[0091] Solid fertilizers can be contained in non-aqueous delivery formulations ranging from 0.5 liters to 18 liters per metric ton of solid urea-based components, preferably from 1.5 liters to 12 liters per metric ton of solid urea-based components, and most preferably from 3 liters to 5 liters per metric ton of solid urea-based components.

[0092] Therefore, the solid fertilizer may contain 0.01% to 0.36% by weight of urease inhibitor based on the total mass of the solid fertilizer, preferably 0.03% to 0.24% by weight of urease inhibitor based on the total mass of the solid fertilizer, and most preferably 0.06% to 0.1% by weight of urease inhibitor based on the total mass of the solid fertilizer.

[0093] According to one embodiment of the present invention, the non-aqueous solvent delivery formulation penetrates the microparticles or granules of the solid fertilizer upon contact with the solid fertilizer.

[0094] Typically, non-aqueous delivery formulations are used to treat solid urea-based components in particulate or granular form, which may then undergo further processing steps before being applied to the soil for nitrogen uptake by crops and / or plants. In this way, the solid fertilizer is first nitrogen stabilized with a urease inhibitor before being applied to the soil for nitrogen uptake by crops and / or plants.

[0095] Solid fertilizers may be coated with a coating (unlike non-aqueous solvent delivery formulations) to improve physical properties and / or product handling characteristics, for example.

[0096] Based on the total mass of the liquid fertilizer, the liquid fertilizer may contain up to 17.5% by weight of urea.

[0097] Based on the total mass of the liquid fertilizer, the liquid fertilizer may contain up to 15% by weight of ammonium nitrate.

[0098] The liquid fertilizer may contain 0.02% to 0.30% by weight of urea in the liquid fertilizer, preferably 0.04% to 0.15% by weight of urea in the liquid fertilizer, and most preferably 0.06% to 0.10% by weight of urea in the liquid fertilizer.

[0099] The urea-based component can be a liquid urea-based component. According to one embodiment of the present invention, the liquid urea-based component is a solid urea-based component dissolved in water.

[0100] Uses of solvent compositions

[0101] According to another aspect of the invention, the use of the solvent composition as described above as a solvent for urease inhibitors is provided.

[0102] As mentioned above, further restrictions are placed on urease inhibitors.

[0103] A method for treating urea-based components with a non-aqueous solvent delivery formulation to obtain fertilizer.

[0104] According to another aspect of the present invention, a method for processing fertilizer is provided, the method comprising:

[0105] Provides urea-based components; and

[0106] The urea-based components were treated with the non-aqueous solvent delivery formulation described above to produce fertilizer.

[0107] Urea-based components can be in particulate or granular form.

[0108] The non-aqueous solvent delivery formulation can be applied to the solid urea-based component in the range of 0.5 liters to 18 liters per metric ton of solid urea-based component, preferably in the range of 1.5 liters to 12 liters per metric ton of solid urea-based component, and most preferably in the range of 3 liters to 5 liters per metric ton of solid urea-based component.

[0109] According to one embodiment of the method of the present invention, the non-aqueous solvent delivery formulation infiltrates the solid urea component into microparticles or granules of the solid urea component upon contact with the solid urea component to form a fertilizer.

[0110] Solid fertilizers may optionally include an additional coating different from that of the non-aqueous solvent delivery formulation, for example, to improve physical properties and / or product handling characteristics. When using the method of the present invention, it is preferable to treat the solid urea-based component with a non-aqueous solvent delivery formulation before applying the different coating to obtain the solid fertilizer.

[0111] Fertilizers can be as described above.

[0112] Uses of non-aqueous solvent delivery formulations

[0113] According to another aspect of the invention, the use of the non-aqueous solvent delivery formulation as described above for treating urea-based components to manufacture fertilizers is provided.

[0114] Fertilizers, whether solid or liquid, can be as described above.

[0115] The processing can be carried out according to the methods described above.

[0116] Uses of fertilizer

[0117] According to another aspect of the invention, the use of the fertilizer as described above for treating soil to provide nitrogen for crops and / or plants is provided. Detailed Implementation

[0118] The invention will now be described with reference to non-limiting embodiments, in which:

[0119] Experimental results

[0120] The invention will now be described with reference to the following non-limiting embodiments.

[0121] nBPT solubility test

[0122] In WO 2017144698, the crystallization temperatures of different concentrations of nBPT (referred to as nBTPT in WO2017144698) in pure 1,2-propanediol are shown. Table 1 shows the effect of nBPT concentration in 1,2-propanediol (PG) on the crystallization point when (i) the solution is first sonicated or (ii) the solution is first stored at 70°C for 2 hours.

[0123] Table 1

[0124]

[0125] Results marked with an asterisk (*) are outside the scope of the claims language of WO 2017144698.

[0126] In WO 2017144698, pure diethylene glycol monomethyl ether (DEGMME), pure diethylene glycol monobutyl ether (DEGMBE), and a 1:1 mixture of DEGMBE and 1,2-propanediol were also tested as solvents for a 25% nBPT solution. Using these solvents, a lower crystallization temperature was shown compared to pure 1,2-propanediol. However, both DEGMME and DEGMBE are classified as toxic substances, bearing hazard labels H361d and H319, respectively. Therefore, these components are commercially undesirable and cannot be used as NMP substitutes for modern urease inhibitor delivery systems.

[0127] The preferred diethylene glycol monobutyl acetate (BDG-acetate) of the solvent formulation of the present invention does not have this hazard label, and therefore, when combined with 1,2-propanediol, provides a safe and harmless solvent alternative for nBPT.

[0128] The experiments were conducted using a mixture of monoethylene glycol monobutyl acetate (BMG-acetate) and 1,2-propanediol, and a mixture of diethylene glycol monobutyl acetate (BDG-acetate) and 1,2-propanediol, in 30 wt% nBPT. No precipitation was observed. In contrast, a 1:1 mixture of DEGMBE and 1,2-propanediol in WO 2017144698 failed to dissolve 30 wt% nBPT, producing undesirable turbid precipitates after a period of time. Therefore, the two preferred solvent compositions of the present invention exhibit improved nBPT solubility characteristics compared to the solvents disclosed in WO 2017144698.

[0129] The effects of 1,2-propanediol, mixtures of 1,2-propanediol and BDG-acetate in different proportions, and mixtures of 1,2-propanediol and BMG-acetate in different proportions (containing dissolved nBPT) on crystallization temperature were determined. Measurements were performed using an NTE450 instrument according to ASTM D97. The lowest temperature that could be measured using this instrument was -36°C. The results are shown in Table 2.

[0130] The crystallization temperature is strongly dependent on the measured cooling rate. No cooling rate or standardized method is given in WO 2017144698 (Table 1), therefore the crystallization temperature cannot be determined using a similar method.

[0131] In WO 2017144698, the most preferred embodiment is 17.5% nBPT in 1,2-propanediol. This is used as a reference in this invention; however, 30% nBPT in 1,2-propanediol was also tested (Table 2). The crystallization temperature (-31°C) of 17.5% nBPT in pure 1,2-propanediol determined according to this method (Table 2) is significantly lower than the temperatures described in WO 2017144698 (-4.6°C / -6.4°C) (Table 1). This can be attributed to the slower cooling rate used in WO 2017144698.

[0132] Table 2

[0133]

[0134]

[0135] According to the present invention, the addition of BDG-acetate and BMG-acetate both increase the solubility of nBPT and also significantly reduce the crystallization temperature. The optimal solubility of nBPT is observed at a 6:1 ratio of 1,2-propanediol to BDG-acetate. Similarly, for this 6:1 ratio, the lowest crystallization temperature is also observed at 30% nBPT (Table 2). The lowest crystallization temperature at 30% nBPT was observed at a 9:1 ratio (Table 2).

[0136] Regarding the 6:1 and 9:1 ratios of 1,2-propanediol:BDG-acetate and 1,2-propanediol:BMG-acetate at 30% nBPT, 1,2-propanediol:BDG-acetate should be preferred due to its lower crystallization temperature at the same ratio (Table 2).

[0137] For all 1,2-propanediol:BDG-acetate ratios at 30% nBPT, the crystallization temperature is below 0°C, but when only pure 1,2-propanediol is used at 30% nBPT, the crystallization temperature is between 11 and 12°C (Table 2).

[0138] At a much lower nBPT concentration of 17.5% (the most preferred range in WO 2017144698), the crystallization temperature is -31°C when using only pure 1,2-propanediol, compared to less than -36°C when using a 6:1 ratio of 1,2-propanediol:BDG-acetate (Table 2).

[0139] Therefore, compared with 1,2-propanediol alone, the combination of 1,2-propanediol and BDG-acetate of the present invention significantly reduces the crystallization point at both high and low nBPT concentrations, which is particularly beneficial at sub-zero ambient temperatures commonly encountered in practice.

[0140] Physical test

[0141] A solvent containing 1,2-propanediol:BDG-acetate in a 6:1 ratio was used to dissolve 20% nBPT to form a non-aqueous solvent delivery formulation. Commercially available particulate urea was coated with the non-aqueous solvent delivery formulation, and its physical properties were tested.

[0142] For comparative purposes, untreated commercially available granular urea, commercially available nBPT-pre-coated urea granules (trade names AMIPLUS (granular urea pre-coated with a liquid urease inhibitor formulation from Yara, trade name AMIPLUSLiquid) and KYNOPLUS (granular urea pre-coated with a liquid urease inhibitor formulation from Koch Agronomical Services, trade name AGROTAIN ULTRA)), and commercially available granular urea coated with an nBPT-free urease inhibitor (available from Kimleigh Chemicals under trade names THIOCOTE S and AZANON U) were also tested.

[0143] The tests conducted are summarized in Table 3.

[0144] Table 3

[0145]

[0146] Hardness of coated urea granules

[0147] Hardness testing involved assessing the breaking strength using a force gauge to determine the integrity of the urea granules. The sample particle size distribution (PSD) was normalized to between 3.15 mm and 4.00 mm using a vibrating sieve to obtain consistent representative results. The breaking strength of the urea granules was determined using a Mecmecin compact digital force gauge rated at 50 kg (500 N). The breaking strength value represents the binding force between particles within each granule. A higher breaking strength value indicates a stronger binding force within each particle. Higher breaking strength values ​​are more desirable because they ensure granule integrity, thus reducing pulverization during application using agricultural machinery. Table 4 reports the average breaking strength of 20 selected individual granules.

[0148] When uncoated urea (T1) was treated with the compositions of the present invention at concentrations of 0.3% (T2) and 0.5% (T3), the particle hardness increased in both cases. The particles treated with the compositions of the present invention (T2, T3) also exhibited better hardness compared to any other treatment.

[0149] Total moisture content

[0150] Total moisture content was determined using a Karl Fischer instrument. The minimum sample size was 0.5 g. The results are reported in Table 4.

[0151] When uncoated urea (T1) was treated with the compositions of the present invention (T2, T3), the total moisture content increased slightly. Except for the untreated urea particles (T1), the total moisture content after treatment with the compositions of the present invention (T2, T3) was lower compared to all other treatments (T4, T6, T7) in the absence of NMP. Although treatment T5 showed the lowest total moisture content, it should be noted that this treatment was the only one containing NMP as a solvent, which is unacceptable. The compositions of the present invention appear to have no effect on the physical appearance of the urea particles.

[0152] Table 4

[0153]

[0154] [*Contains NMP]

[0155] Agglomeration and agglomeration

[0156] Agglomeration tests were conducted on granular urea samples under controlled climatic conditions and varying pressure conditions. Each granular urea sample (T1 to T7), ranging from 140 g to 150 g, was loaded into a cylindrical metal agglomeration press and assembled in a humidity chamber preset to 65% relative humidity and 30°C. Each sample underwent three replicates of agglomeration testing at 4 bar (g) for 72 hours. After each agglomeration test, the urea granules or agglomerates were carefully removed from the agglomeration apparatus for breakage strength analysis. The breakage strength of the urea granules or agglomerates was determined using a digital Mecmecin compact force gauge rated at 50 kg (500 N). A low breakage strength value indicates weak binding forces between the individual granules after manual compression or agglomeration. A low breakage strength value is more desirable because it allows the granular agglomerates to easily disintegrate or disperse, enabling free-flowing granules during application using agricultural machinery. The average results from all three replicates are shown in Table 5.

[0157] Table 5

[0158]

[0159]

[0160] [*Contains NMP]

[0161] Compared to untreated urea, urea particles treated with the compositions of the present invention (T2, T3) showed no agglomeration and reduced breakage strength, which is desirable. Urea particles treated with the compositions of the present invention (T2, T3) showed similar agglomeration (i.e., similar breakage strength) compared to T4 and T5. Urea particles of T6 and T7 (non-nBPT urease inhibitor) showed strong agglomeration (i.e., high breakage strength), which is undesirable.

[0162] hygroscopic

[0163] Each type of urea granule sample (T1 to T7) with a mass between 120 g and 150 g was placed in an open container within a sealed humidity chamber to absorb moisture. Hygroscopicity was determined by gravimetric analysis at atmospheric pressure, 30°C, and 55% relative humidity. The hygroscopicity of the urea granules was determined hourly for 6 hours. After determination at 55% relative humidity, the humidity chamber was set to 77% relative humidity, and hygroscopicity was again determined hourly from the sixth to the twelfth hour. The results are shown in Table 6.

[0164] Table 6

[0165]

[0166]

[0167] [*Contains NMP]

[0168] The hygroscopicity at 55% relative humidity was negligible in the first 6 hours, and all treatments showed similar results. This was expected, given that the critical relative humidity for urea is 72.5%. Advantageously, treatment with the compositions of the invention (T2, T3) below the critical relative humidity for urea had no significant effect on the hygroscopicity of the treated particles.

[0169] At 77% relative humidity (slightly higher than the critical relative humidity of 72.5% for urea), hygroscopicity gradually increased over 6 hours in all tests.

[0170] Compared to uncoated urea (T1), urea particles treated with the compositions of the present invention (T2, T3) exhibited reduced hygroscopicity. Urea particles coated with 0.5% of the composition of the present invention (T3) showed even lower hygroscopicity than urea particles coated with 0.3% of the composition of the present invention (T2). The urea particles of T3 (the composition of the present invention) exhibited hygroscopicity comparable to T4 and T6, indicating that the compositions of the present invention have no adverse effect on hygroscopicity.

[0171] Advantages of the present invention

[0172] The non-aqueous solvent delivery compositions of the present invention exhibit advantages in certain respects (e.g., non-toxicity, low crystallization temperature, particle hardness) and are at least comparable to known urease inhibitor formulations in other respects (agglomeration tendency and hygroscopicity). Therefore, for the urease inhibitor nBPT, the solvent compositions of the present invention are superior alternatives to NMP and other non-NMP solvents.

Claims

1. A solvent composition for use in agricultural applications, the solvent composition comprising: (A) an alkyl glycol ester type solvent of formula (I) wherein R is a methyl group, R2 is hydrogen, R3 is hydrogen, X is 1 to 2.2, R6 is n-butyl, and wherein X is the degree of alkoxylation and is the number average; and (B) a glycol type solvent of formula (II) wherein R4 is hydrogen and R5 is a methyl group, or R4 is a methyl group R5 is hydrogen, and Z is 0; wherein the mass ratio of the glycol type solvent and the alkyl glycol ester type solvent ranges from 1 : 1 to 9:

1.

2. The solvent composition according to claim 1, wherein the mass ratio of the glycol type solvent and the alkyl glycol ester type solvent ranges from 3: 1 to 9:

1.

3. The solvent composition according to claim 1, wherein the mass ratio of the glycol type solvent and the alkyl glycol ester type solvent ranges from 4: 1 to 8:

1.

4. The solvent composition according to claim 1, wherein the mass ratio of the glycol type solvent and the alkyl glycol ester type solvent ranges from 5.5: 1 to 6.5:

1.

5. The solvent composition according to claim 1, wherein (A) the alkyl glycol ester type solvent of formula (I) and (B) the glycol type solvent of formula (II) together form more than 70 wt.-% or more than 90 wt.-% or more than 95 wt.-% of the solvent composition, or wherein the solvent composition consists only of (A) and (B).

6. The solvent composition of claim 1, wherein, The solvent composition does not comprise N-methyl-2-pyrrolidone.

7. A non-aqueous solvent delivery formulation comprising: the solvent composition according to any one of claims 1 to 5; and a urease inhibitor dissolved in the solvent composition, wherein the concentration of the urease inhibitor in the non-aqueous solvent delivery formulation is at most 40 wt.-% based on the total mass of the non-aqueous solvent delivery formulation.

8. The non-aqueous solvent delivered formulation according to claim 7, wherein, The urease inhibitor comprises or consists of an N-alkyl thiophosphoric triamide.

9. The non-aqueous solvent delivered formulation according to claim 7, wherein, The urease inhibitor is N-(n-butyl) thiophosphoric triamide.

10. The non-aqueous solvent delivered formulation according to claim 7, wherein, The concentration of the solvent composition is at least 50 wt.-% based on the total mass of the non-aqueous solvent delivery formulation.

11. The non-aqueous solvent delivered formulation according to claim 7, wherein, The concentration of the solvent composition is at least 60 wt.-% based on the total mass of the non-aqueous solvent delivery formulation.

12. The non-aqueous solvent delivered formulation according to claim 7, wherein, The concentration of the solvent composition is at least 70 wt.-% based on the total mass of the non-aqueous solvent delivery formulation.

13. The non-aqueous solvent delivered formulation according to claim 7, wherein, The non-aqueous solvent delivery formulation further comprises one or more nitrification inhibitors selected from the group consisting of dicyandiamide, 2-chloro-6- (trichloromethyl)pyridine, pronamide, allyl thiourea, 3,4-dimethylpyrazole phosphate and mixtures thereof.

14. The non-aqueous solvent delivered formulation according to claim 7, wherein, The non-aqueous solvent delivery formulation further comprises a nitrification inhibitor, and wherein the nitrification inhibitor is dicyandiamide.

15. The non-aqueous solvent delivered formulation according to claim 7, wherein, The non-aqueous solvent delivery formulation further comprises one or more pesticide active agents selected from the group consisting of herbicides, fungicides, insecticides and mixtures thereof.

16. The non-aqueous solvent delivered formulation according to claim 7, wherein, The non-aqueous solvent delivery formulation further comprises an additive selected from the group consisting of micronutrients, biostimulants, plant growth regulators and mixtures thereof.

17. A fertilizer comprising at least a urea-based component and the non-aqueous solvent delivery formulation according to claim 7.

18. The fertilizer of claim 17, wherein, The fertilizer is a solid fertilizer in granular form, and the non-aqueous solvent delivery formulation is dissolved in the fertilizer. wherein the non-aqueous solvent delivery formulation is applied to the urea-based component in a range of 0.5 liters to 18 liters of non-aqueous solvent delivery formulation per metric ton of urea-based component.

19. The fertilizer of claim 17, wherein, The fertilizer is a solid fertilizer in granular form, and wherein the non-aqueous solvent delivery formulation is applied to the urea-based component in a range of 1.5 liters to 12 liters of non-aqueous solvent delivery formulation per metric ton of urea-based component.

20. A method for obtaining a fertilizer, the method comprising: providing a urea component; and treating the urea component with the non-aqueous solvent delivery formulation according to claim 7 to produce a fertilizer, wherein the urea component is a solid, and / or wherein the non-aqueous solvent delivery formulation is applied to the urea-based component in a range of 0.5 liters to 18 liters of non-aqueous solvent delivery formulation per metric ton of urea-based component.

21. The method of claim 20, wherein, The non-aqueous solvent delivery formulation is applied to the urea-based component in a range of 1.5 liters to 12 liters of non-aqueous solvent delivery formulation per metric ton of urea-based component.

22. Use of the solvent composition of any one of claims 1 to 6 as a solvent for urease inhibitors, wherein, The urease inhibitor is N-alkyl thiophosphoric acid triamide.

23. Use of the solvent composition of any one of claims 1 to 6 as a solvent for urease inhibitors, wherein, The urease inhibitor is N-(n-butyl) thiophosphoric acid triamide.

24. Use of the non-aqueous solvent delivery formulation according to claim 7 for treating a urea-based component to produce a fertilizer.

25. Use of a fertilizer obtainable by the method according to claim 20 or 21 or according to any one of claims 17 to 19 or a fertilizer according to any one of claims 17 to 19 or a fertilizer obtainable from a fertilizer according to any one of claims 17 to 19 for treating soil for the uptake of nitrogen by crops and / or plants.

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