Suspoemulsion containing pendimethalin and pyroxasulfone as well as preparation method and application thereof

Abstract

The invention belongs to the field of pesticides, and particularly relates to a herbicide composition containing pendimethalin and pyroxasulfone, the weight ratio of pendimethalin to pyroxasulfone is (1: 15)-(15: 1), the two active ingredients have a remarkable synergistic effect on various weeds, the two active ingredients are compounded to form a suspoemulsion composition, the stability is good, and the herbicide composition is suitable for industrial production.

Description

Technical Field

[0001] This invention relates to the field of pesticide technology, specifically to a suspension emulsion containing pendimethalin and sulfonylpyrazole, its preparation method, and its application in controlling agricultural weeds. Background Technology

[0002] Sulfonazole is a novel, broad-spectrum, highly active pre-emergence soil-applied herbicide developed by a Japanese combinatorial chemical company. Belonging to the isoxazole class of herbicides, it is absorbed by the young roots and shoots of weeds after application, inhibiting early seedling growth and destroying meristems and coleoptiles. Sulfonazole is mainly used to control annual grasses and broadleaf weeds. Its mechanism of action is to inhibit the synthesis of long-chain fatty acids in plants, classifying it as an ultra-long-chain fatty acid synthesis inhibitor. Sulfonazole can be applied to various crops, such as corn, wheat, soybeans, cotton, sunflowers, potatoes, and peanuts, effectively controlling annual grasses such as foxtail, barnyard grass, Kentucky bluegrass, purslane, wild oats, crabgrass, and ryegrass, as well as annual broadleaf weeds such as black nightshade, amaranth, and purslane.

[0003] Pendimethalin is a selective herbicide belonging to the dinitroaniline class. It primarily inhibits meristem cell division and does not affect weed seed germination. Instead, it takes effect after the seedlings, stems, and roots absorb the herbicide during seed germination. It is widely used in cotton, corn, rice, potato, soybean, peanut, tobacco, and vegetable fields. It is a selective pre- and post-emergence herbicide for dryland fields, where weeds absorb the herbicide through their seedlings, stems, and roots.

[0004] Currently, the main formulation of pendimethalin is emulsifiable concentrate (EC), but EC uses a large amount of aromatic solvents, which has adverse environmental effects. Furthermore, sulfonylpyrazol has low solubility in these solvents. Patent application CN117063938A discloses a herbicide composition containing dichloroisoxane and its application, which discloses a preparation process for a suspension emulsion product containing pendimethalin, dichloroisoxane, and pyrimisulfuron. However, the preparation process described therein involves simple grinding, which easily causes the low-melting-point technical materials pendimethalin and dichloroisoxane to melt-crystallize-melt, resulting in an unstable composition unsuitable for industrial scale-up.

[0005] Therefore, it is necessary to develop a suspension emulsion of pendimethalin and sulfopyrazine and a new preparation method to simultaneously meet the requirements of fully maximizing the activity of both components and the need for industrial-scale preparation. Summary of the Invention

[0006] The first aspect of the present invention is to provide a suspension emulsion comprising pendimethalin and sulfonylpyrazole, characterized in that the weight ratio of pendimethalin to sulfonylpyrazole is 1:15 to 15:1, preferably 3:1 to 12:1, and even more preferably 4:1 to 12:1.

[0007] In some embodiments, the total content of pendimethalin and sulfopyrazole in the suspension emulsion is 1% to 50%, preferably 10% to 40%, based on the total weight of the suspension emulsion.

[0008] In some embodiments, the suspension emulsion further comprises one or more auxiliary components selected from, but not limited to, emulsifiers, dispersants, wetting agents, solvents, antifreeze agents, defoamers, thickeners, disintegrants, synergists, preservatives, and fillers.

[0009] In some embodiments, the emulsifier is a surfactant known to those skilled in the art: alkyl polyoxyethylene ether, phenethylphenol polyoxyethylene polyoxypropylene ether, alkyl aryl polyoxyethylene polyoxypropylene ether, fatty acid polyoxyethylene ether, fatty alcohol polyoxyethylene ether, glycerol laurate polyoxyethylene ether, styrene-phenol polyoxyethylene ether, castor oil polyoxyethylene ether, alkylphenol polyoxypropylene polyoxyethylene ether, styrene-phenyl polyoxyethylene ether, alkylphenol polyoxyethylene ether, sorbitan fatty acid ester polyoxyethylene ether, fatty alcohol polyoxyethylene ether sulfonate, alkylphenol polyoxyethylene formaldehyde condensate, calcium dodecyl sulfonate, alkylphenol polyoxyethylene ether succinate monoester sulfonate, alkylphenol polyoxyethylene phosphate, alkylphenol polyoxyethylene ether sulfonated succinate, but not limited thereto; preferably alkyl polyoxyethylene ether.

[0010] In some embodiments, the dispersant is a surfactant known to those skilled in the art: alkylphenol polyoxyethylene ether sulfate, phenethylphenol polyoxyethylene ether phosphate, polyoxyethylene polyoxypropylene ether block copolymer, sodium lignosulfonate, sodium methylene dinaphthalene sulfonate (dispersant NNO), calcium lignosulfonate, polycarboxylate, sodium methylene dinaphthalene sulfonate, sodium methylene dimethylnaphthalene sulfonate, polyvinylpyrrolidone, alkylamide taurate, sodium alkyl naphthalene sulfonate condensate, sodium methylene dinaphthalene sulfonate formaldehyde condensate, but not limited thereto.

[0011] In some embodiments, the wetting agent is a surfactant known to those skilled in the art: sodium alkylnaphthalene sulfonate, sodium dodecyl sulfate, sodium secondary alkyl sulfate, sodium dodecylbenzene sulfonate, fatty alcohol polyethylene glycol ether sulfate, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, sorbitan fatty acid ester polyoxyethylene ether, alkylnaphthalene sulfonate, but not limited thereto.

[0012] In some embodiments, the solvent is a solvent known to those skilled in the art: methanol, ethanol, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethyloctamide, N,N-dimethyldecylamide, tetrahydrofurfuryl alcohol, toluene, xylene, dimethyl sulfoxide, tetrahydrofuran, cyclohexanone, n-butanol, isopropanol, solvent oil 100# / 150# / 180# / 200#, vegetable oil (including soybean oil, corn oil, flaxseed oil, sunflower oil, rapeseed oil), methylated vegetable oil, but not limited thereto.

[0013] In some implementations, the antifreeze is ethylene glycol, glycerol, propylene glycol, diethylene glycol, or urea.

[0014] In some implementations, the preservative is Kathon or 1,2-benzisothiazolin-3-one.

[0015] In some implementations, the defoamer is a silicone-based defoamer.

[0016] In some implementations, the thickener is xanthan gum, magnesium aluminum silicate, polyvinyl alcohol, gum arabic, but is not limited to these.

[0017] In some embodiments, the suspension emulsion containing pendimethalin and sulfonylpyrazole of the present invention contains 1% to 50% pendimethalin and sulfonylpyrazole, preferably 10% to 40%, emulsifier 0.5% to 5%, dispersant 0.5% to 5%, solvent 15% to 30%, antifreeze 2% to 5%, preservative 0.05% to 0.2%, defoamer 0.05% to 0.2%, thickener 0.1% to 2%, and the remainder is water, by weight percentage.

[0018] In some embodiments, the suspension emulsion of the present invention comprising pendimethalin and sulfonylpyrazole comprises 8%~30% pendimethalin, 2%~10% sulfonylpyrazole, 0.5%~5% emulsifier, 0.5%~5% dispersant, 15%~30% solvent, 2%~5% antifreeze, 0.05%~0.2% preservative, 0.05%~0.2% defoamer, 0.1%~2% thickener, and the remainder being water, by weight percentage.

[0019] A second aspect of the present invention provides a method for preparing a suspension emulsion comprising pendimethalin and sulfonylpyrazole, comprising the following steps: 1) Dissolve the pendimethalin technical in a solvent until fully dissolved to obtain the oil phase; 2) After thoroughly mixing a portion of the emulsifier, antifreeze, defoamer, and water, add the oil phase obtained in step 1) under high-speed shearing to obtain mixture A; 3) Add sulfonylpyrazole to another portion of the mixture of dispersant, emulsifier, defoamer and water, and grind it to the target particle size using a sand mill to obtain mixture B; 4) Add the thickener to the remaining water and disperse thoroughly to obtain the gel phase; 5) Mix mixture A, mixture B and the gel phase obtained in step 4) evenly to obtain a suspension emulsion.

[0020] In some implementations, step (5) involves first adding the mixture A to the mixture B while stirring, and then adding the gel phase obtained in step (4) and stirring until homogeneous to obtain a suspension emulsion.

[0021] In some implementations, the high-speed shearing in step 2) has a shearing rate of 10,000 to 15,000 rpm and a shearing time of 5 to 10 minutes.

[0022] In some implementations, the target particle size mentioned in step 3) refers to D. 50 It is 1-5μm.

[0023] In some implementations, the stirring rate in step 5) is 500-1000 rpm and the stirring time is 30-60 min.

[0024] In some implementations, the amount of each auxiliary component in step 2) is independently 0.1% to 100%, 10% to 70% of the total amount of each auxiliary component, preferably 20% to 50%, and even more preferably 30% to 40%.

[0025] The various auxiliary components described in the second aspect of this invention have the same meaning as those described in the first aspect of this invention. For the sake of simplicity, they will not be described in detail here.

[0026] A third aspect of this invention provides a suspension emulsion as described in the first aspect of this invention, or a suspension emulsion prepared by the method of the second aspect of this invention, for use on crops to control weeds. In some embodiments, the crops include, but are not limited to, corn, wheat, soybeans, peanuts, and potatoes; wheat is preferred.

[0027] In some implementations, the weeds include, but are not limited to, annual grasses and annual broadleaf weeds, preferably crabgrass, ryegrass, lambsquarters, velvetleaf, barnyardgrass, sedge, chickweed, and sedge.

[0028] Beneficial technical effects: 1. The combination of pendimethalin and sulfopyrazole of the present invention has a significant synergistic effect on common weeds in the field, greatly improves the herbicidal activity, reduces the overall dosage of pesticides, and delays the development of weed resistance.

[0029] 2. The preparation method of the compound suspension emulsion composition of pendimethalin and sulfonylpyrazole of the present invention is suitable for the industrial preparation of low melting point technical materials (such as pendimethalin), and provides a wider range of application combinations for the use of pendimethalin with sulfonylpyrazole or other herbicidal active ingredients in agriculture to exert the synergistic effect of pesticides, thereby reducing the amount of pesticides applied and reducing agricultural costs, and achieving environmental benefits. Attached Figure Description

[0030] Figure 1 This is a photograph of the suspension emulsion 1 from Example 1 after storage.

[0031] Figure 2 This is a photograph of the suspension sample of Comparative Example 1 after storage over time. Detailed Implementation

[0032] Unless otherwise specified, all materials and reagents used in this article are commercially available.

[0033] All percentages mentioned in this article refer to weight percentages (all percentages refer to weight percentages).

[0034] Components used in the examples: Dimethylpentylene, N-1-(ethylpropyl)2,6-dinitro-3,4-dimethylaniline Sulfonylpyrazole, 3-(5-(difluoromethoxy)-1-methyl-3-trifluoromethylpyrazole-4-methylsulfonyl)-4,5-2 H -5,5-dimethyl-1,2-oxazole TERGITOL TMN-10 (Dow Chemical) Alkyl Polyoxyethylene Ether SYNPERNIC 13 / 10-LQ-(CQ) (Heda Chemical) Alkyl Polyoxyethylene Ether ETHYLAN NS-500LQ (Nouryon) Polyoxyethylene Polyoxypropylene Ether Block Copolymer MORWET D-425 POWDER (Nouryon) Sodium Alkyl Naphthalene Sulfonate Condensate Xylene, Solvent Oil 150# (Jiangsu Hualun Chemical) Methylated vegetable oil and soybean oil (Hebei Milun Biotechnology) Propylene glycol, ethylene glycol (Wanhua Chemical) CANGUARD™ ULTRA BIT 20 DPG (Dow Chemical) 1,2-Benzisothiazolin-3-one RH-9272 (Jiujiang Runhe Materials) Organosilicon Defoamer AG-RHO POL 23 / W (Specialty Polymers) Xanthan Gum SF04 (Suzhou Zhongcai) Magnesium Aluminum Silicate PVA 0588 (Chuanwei Chemical) Polyvinyl alcohol Water (conductivity less than 0.056 μS / cm) Example 1: Preparation of Suspension Emulsion 1 1) Dissolve 18% of pendimethalin technical in 20% solvent oil (150#) and 5% soybean oil to obtain the oil phase; 2) After thoroughly mixing TERGITOL TMN-10 2.2%, SYNPERNIC 13 / 10-LQ-(CQ) 0.3%, ETHYLAN NS-500LQ 0.5%, PVA 0588 0.15%, propylene glycol 1%, RH-9272 0.1%, and water 15%, the oil phase obtained in step 1) is added under high-speed shear to obtain mixture A; 3) Add 4% sulfonylpyrazole to a mixture of 0.5% ETHYLAN NS-500LQ, 1.5% MORWET D-425 POWDER, 4% propylene glycol, 0.1% RH-9272, 0.5% SFO4, and 10% water. Grind the mixture to the target particle size using a sand mill to obtain mixture B. 4) Add 0.05% AG-RHO POL 23 / W and 0.2% CANGUARD™ ULTRA BIT 20 DPG to the remaining water and disperse thoroughly to obtain the gel phase; 5) First, add the mixture A to the mixture B while stirring, then add the gel phase and stir evenly to obtain the suspension emulsion product.

[0035] Examples 2-6: Preparation of Suspension Emulsions 2-6 The suspension emulsions 2-6 of Examples 2 to 6 were prepared using the same method as in Example 1, except that the composition of the suspension emulsions was different, and their specific composition is listed in Table 1 below.

[0036] Table 1 Composition of suspension emulsions 1-6

[0037] Note: The units of the values ​​in Table 1 are grams (g).

[0038] Example 7: Test of Suspension Emulsion Properties Example: The suspension emulsion samples prepared in the above embodiments should meet the general quality control standards for suspension emulsions, as shown in Table 2.

[0039] Table 2 Quality Control Standards for Suspension Emulsions

[0040] The formulation properties of the suspensions prepared in Examples 1-6 are shown in Table 3.

[0041] Table 3 Formulation properties of suspension emulsions 1-6

[0042] Comparative Example 1: Preparation of suspension concentrates of pendimethalin and sulfonylpyrazole In comparison, a suspending agent was prepared with the following composition:

[0043] Preparation process: The raw material, wetting agent, dispersant, antifreeze, preservative, defoamer, thickener and water are mixed and then ground in a sand mill to obtain the finished product.

[0044] The suspension sample prepared in Comparative Example 1 was unstable during storage, prone to gelation, layering, and other unstable phenomena. In contrast, the suspension emulsion formulation and process of this invention resulted in a stable sample during storage, meeting the quality requirements for product shelf life. See the sample stability comparison below. Figure 1 and Figure 2 ,visible Figure 1 The suspension emulsion has good stability. Figure 2 The suspension sample showed a paste-like stratification phenomenon after storage.

[0045] Example 8: Indoor Bioassay Soil treatment was conducted using an indoor potted plant method. The experiment was conducted according to the Gowing method in Part 7 of the "Guidelines for Indoor Bioassay of Pesticides - Herbicides" of the Agricultural Industry Standard of the People's Republic of China NY / T1155.7-2006.

[0046] Test targets: Digitaria sanguinalis, Lolium multiflorum, Chenopodium album, Abutilon theophrasti Test reagents: 93% sulfonylpyrazole technical grade, 95% pendimethalin technical grade Experimental Methods: When preparing the reagent, first dissolve an appropriate amount of dimethylformamide, then prepare the required concentration using a 1% Tween 80 aqueous solution. The tested weeds were cultivated using a pot method. 180x140mm plastic seedling pots were placed in enamel dishes, filled with topsoil (4 / 5 full) collected from farmland, dried and sieved. Initial soil moisture was controlled at 20%. Plump and uniform weed seeds were selected, soaked in 25℃ warm water for 6 hours, and germinated in a 28℃ biochemical incubator (dark). The newly sprouted weed seeds were evenly placed on the soil surface, 20 seeds per pot, then covered with 0.7cm of soil and transferred to a light-cured incubator. A mobile spray tower was used for spraying, with a spray pressure of 275kPa and a spray volume of 450L / hm². 2 After treatment, the plants were placed in a greenhouse for further cultivation. A 0.1% Tween 80 aqueous solution without the herbicide was used as a blank control. Each treatment consisted of 3 pots, with 4 replicates. Twenty days after treatment, the fresh weight of the tested weeds in each pot was measured, the fresh weight control efficacy was calculated, and the Gowing method was used to evaluate the action type of the mixed herbicide, further exploring the rationality of the ratio.

[0047] Efficacy calculation method: The theoretical fresh weight inhibition rate of each treatment mixture was calculated using the Gowing method (E0 = X + YX*Y / 100), and then compared with the measured inhibition rate (E) to evaluate the combined effect of the two on weeds. When the E-E0 value is greater than 10%, it is a synergistic effect; less than -10%, it is an antagonistic effect; and between -10% and 10%, it is an additive effect.

[0048] The results and analysis are shown in Tables 4-7.

[0049] Table 4. Activity assay results of sulfonylpyrazole and pendimethalin mixed with crabgrass.

[0050] Table 5. Activity assay results of sulfonylpyrazole and pendimethalin mixed with ryegrass.

[0051] Table 6. Activity assay results of sulfonylpyrazine and pendimethalin mixed with lambsquarters

[0052] Table 7. Results of activity assay of sulfonylpyrazine and pendimethalin mixture on velvetleaf.

[0053] As shown in Tables 4-7, when sulfonylpyrazole and pendimethalin are combined in a ratio of 1:4 to 1:12, they have a significant synergistic effect compared to the two single agents, sulfonylpyrazole and pendimethalin. The synergistic effect is most obvious when the ratio is 1:6.

[0054] Example 9: Field Application The efficacy and safety of the suspension emulsions 1-6 provided in Examples 1-6 were tested in wheat fields.

[0055] Experimental site: Wheat field in He County, Ma'anshan City, Anhui Province. The experimental site is flat and has loam soil.

[0056] Experimental method: The experiment included a chemical treatment and a blank control. The blank control was treated with an equal volume of water. Each treatment was replicated four times, and the plot area was 30m². 2 (5m×6m), randomized block design. Soil treatment was applied one day after wheat sowing, with a spray volume of 450 L / hm². 2 Safety survey: 30 days after application, the growth and development of wheat were investigated to evaluate the safety of the tested pesticide on wheat. Weed control efficacy survey: The absolute value method was used. 60 days after application, four sampling points were randomly selected within the plot, each 0.25m in diameter. 2 The fresh weight of the above-ground portion of the weeds was measured. Fresh weight control efficacy = (fresh weight of blank control - fresh weight of treatment) / fresh weight of blank control × 100%. The test results are shown in Table 8.

[0057] Table 8. Field trial results of samples of pendimethalin + sulfopyrazole suspension emulsion

[0058] Table 8 shows that field trial results indicate that six different suspension emulsion products prepared with sulfonylpyrazole and pendimethalin in a ratio of 1:3 to 1:12 showed good efficacy against major weeds in wheat fields, including alopecuroides, barnyardgrass, chickweed, and sedge, and significantly reduced the dosage of the active ingredient. Thirty days after application, all suspension emulsion products were safe for wheat; 60 days after application, all suspension emulsion products showed efficacy of over 90% against weeds, significantly improving the integrated control effect against grasses and broadleaf weeds. This demonstrates that the combination of sulfonylpyrazole and pendimethalin has excellent integrated control effects against common weeds in wheat fields, and this suspension emulsion herbicide composition is safe for wheat. It is also worth noting that there are currently no other commercially available formulations of the sulfonylpyrazole and pendimethalin combination. Suspension samples prepared for indoor testing have poor composition stability and cannot proceed to the field testing stage.

[0059] The various embodiments provided by this invention can be combined with each other in any way as needed, and the technical solutions obtained through such combinations are also within the scope of this invention. Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations to this invention fall within the scope of the claims of this invention and their equivalents, then this invention also includes these modifications and variations.

Claims

1. A suspension emulsion comprising pendimethalin and sulfonylpyrazine, characterized in that, The weight ratio of pendimethalin to sulfonylpyrazole is 1:15 to 15:1, preferably 3:1 to 12:1, and even more preferably 4:1 to 12:

1.

2. The suspension emulsion according to claim 1, wherein the total content of pendimethalin and sulfopyrazine is 1%-50% by weight, preferably 10%-40%.

3. The suspension emulsion according to claim 1 or 2, further comprising one or more auxiliary components, said auxiliary components being selected from emulsifiers, dispersants, wetting agents, solvents, antifreeze agents, defoamers, thickeners, disintegrants, synergists, preservatives, and fillers.

4. The suspension emulsion according to claim 3, wherein the emulsifier is selected from one or more of the following components: alkyl polyoxyethylene ether, phenethylphenol polyoxyethylene polyoxypropylene ether, alkyl aryl polyoxyethylene polyoxypropylene ether, fatty acid polyoxyethylene ether, fatty alcohol polyoxyethylene ether, glycerol laurate polyoxyethylene ether, styrene-phenol polyoxyethylene ether, castor oil polyoxyethylene ether, alkylphenol polyoxypropylene polyoxyethylene ether, styrene-phenyl polyoxyethylene ether, alkylphenol polyoxyethylene ether, sorbitan fatty acid ester polyoxyethylene ether, fatty alcohol polyoxyethylene ether sulfonate, alkylphenol polyoxyethylene formaldehyde condensate, calcium dodecyl sulfonate, alkylphenol polyoxyethylene ether succinate monoester sulfonate, alkylphenol polyoxyethylene phosphate, alkylphenol polyoxyethylene ether sulfonated succinate, preferably alkyl polyoxyethylene ether.

5. The suspension emulsion according to claim 3 or 4, comprising the following components: The total content of pendimethalin and sulfonylpyrazole is 1%~50%, preferably 10%~40%, emulsifier 0.5%~5%, dispersant 0.5%~5%, solvent 15%~30%, antifreeze 2%~5%, preservative 0.05%~0.2%, defoamer 0.05%~0.2%, thickener 0.1%~2%, and the remainder is water, based on the total weight of the suspension emulsion.

6. The suspension emulsion according to claim 5, comprising the following components: The ingredients are: 8%~30% pendimethalin, 2%~10% sulfadiazine, 0.5%~5% emulsifier, 0.5%~5% dispersant, 15%~30% solvent, 2%~5% antifreeze, 0.05%~0.2% preservative, 0.05%~0.2% defoamer, 0.1%~2% thickener, and the remainder is water, based on the total weight of the suspension emulsion.

7. A method for preparing a suspension emulsion comprising pendimethalin and sulfonylpyrazole according to any one of claims 1-6, the method comprising the following steps: 1) Dissolve the pendimethalin technical in a solvent until fully dissolved to obtain the oil phase; 2) After thoroughly mixing a portion of the emulsifier, antifreeze, defoamer, and water, add the oil phase obtained in step 1) under high-speed shearing to obtain mixture A; 3) Add sulfonylpyrazole to another portion of the mixture of dispersant, emulsifier, defoamer and water, and grind it to the target particle size using a sand mill to obtain mixture B; 4) Add the thickener to the remaining water and disperse thoroughly to obtain the gel phase; 5) Mix mixture A, mixture B and the gel phase obtained in step 4) evenly to obtain a suspension emulsion.

8. The method according to claim 7, wherein in step (5), the mixture A is first added to the mixture B under stirring, and then the gel phase obtained in step (4) is added and stirred evenly to obtain a suspension emulsion.

9. The method according to claim 7 or 8, wherein the high-speed shearing in step 2) has a shearing rate of 10,000 to 15,000 rpm and a shearing time of 5 to 10 min.

10. The suspension emulsion according to any one of claims 1-6 or the suspension emulsion prepared by the method according to claims 7-9, which can be applied to crops to control weeds, including but not limited to corn, wheat, soybean, peanut, and potato; preferably wheat.

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