A low-degradability foramsulfuron suspension composition and its preparation method and application

Abstract

The present invention provides a low-degradability foramsulfuron suspension composition, its preparation method, and its use. The composition has a low decomposition rate for the active ingredient foramsulfuron and passes physical and chemical performance tests such as persistent foaming, pourability, wet sieve test, and dispersion stability. The composition can be used to effectively control a variety of weeds.

Description

Technical Field

[0001] The present invention relates to a herbicide composition, in particular to a low-decomposability foramsulfuron suspension composition and a preparation method and application thereof. Background Art

[0002] Foramsulfuron, commonly known as foramsulfuron, is a new sulfonylurea herbicide developed by Aventis. The structural formula is as follows:

[0003]

[0004] The molecular formula of foramsulfuron is C 17 H 20 N6O7S, with a molecular weight of 452·44, is chemically known as 1-(4,6-dimethoxypyrimidin-2-yl)-3-(2-dimethylaminocarbonyl-5-formylaminophenylsulfonyl)urea. Formamidosulfuron can be formulated as an oil-dispersible suspension or water-dispersible granules, and the safener isoxadifen is often added during the formulation process.

[0005] Dispersible oil suspension concentrates (DSCs) consist of one or more solid pesticide active ingredients insoluble in oil solvents dispersed in a non-aqueous medium. These ingredients utilize surfactants and viscosity modifiers to form a highly dispersed and stable suspension. These formulations exhibit excellent adhesion and spreadability, strong resistance to rainwater erosion, and long-lasting efficacy.

[0006] However, during the preparation of dispersible oil suspension concentrates, the decomposition rate of carbosulfan is high. After long-term storage, the content of active ingredients is greatly reduced, which significantly affects the weed control effect. Summary of the Invention

[0007] To address the technical issue of the high decomposition rate of foramsulfuron, it is necessary to rationally select adjuvants in the dispersible oil suspension concentrate and add stabilizers to the formulation. Common stabilizers used in pesticide formulations include 1,2-butanediol, 1,5-diol, epoxy linseed oil, epoxy soybean oil, phthalic anhydride, cyclohexanephthalic anhydride, rosin acid, tall oil, urea, and hexamethylenetetramine. However, not all stabilizers can inhibit the decomposition of foramsulfuron.

[0008] After experiments, the inventors surprisingly found that the stabilizer epoxidized soybean oil combined with the thickener sodium bentonite can inhibit the decomposition of foramsulfuron, meet the stability requirements of the active ingredients in the pesticide formulation, and also enable the formulation to obtain qualified suspension stability.

[0009] Therefore, the first aspect of the present invention provides a low-degradability foramsulfuron suspension composition, comprising foramsulfuron, isoxadiazole, a surfactant, epoxidized soybean oil, sodium bentonite and a dispersion medium.

[0010] Preferably, the low-degradability foramsulfuron suspension composition of the present invention comprises, by weight, 3 parts of foramsulfuron, 3 parts of isoxadiazole, 7 parts of tristyrylphenol polyoxyethylene ether, 4 parts of calcium dodecylbenzenesulfonate, 2 parts of castor oil polyoxyethylene ether, 2 parts of fatty alcohol polyoxyethylene ether, 7 parts of epoxy soybean oil, 1.6 parts of sodium bentonite, and methyl oleate is supplemented to 100 parts.

[0011] Preferably, the average particle size of the sodium bentonite is 2 μm.

[0012] A second aspect of the present invention provides a method for preparing the above-mentioned suspension composition, comprising the steps of:

[0013] (1) Weigh the dispersion medium and add it into the shearing kettle, and control the temperature of the shearing kettle at 25°C;

[0014] (2) adding foramsulfuron and the remaining raw materials in sequence for shearing, with the shearing time being 45 min;

[0015] (3) After the shearing is completed, the mother liquor is sent to the sand mill, and the shearing is continued until all the mother liquor is sent to the sand mill. After two sand millings in the sand mill, it is sent to the mixing kettle;

[0016] (4) Start stirring in the mixing kettle, and then filter through a 120-mesh sieve to obtain the product.

[0017] The obtained composition is in the form of a dispersible oil suspension.

[0018] By adopting the above technical solution, the decomposition rate of the active ingredient formamide sulfone in the composition of the present invention is low. The composition was tested for physical and chemical properties, including persistent foaming, pourability, wet sieve test and dispersion stability, and the results showed that all indicators were qualified. DETAILED DESCRIPTION

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the embodiments described are only a part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0020] 1. Preparation Examples and Comparative Examples

[0021] Example 1

[0022] 3 parts of foramsulfuron-methyl, 3 parts of isoxadiazole, 7 parts of tristyrylphenol polyoxyethylene ether, 4 parts of calcium dodecylbenzenesulfonate, 2 parts of castor oil polyoxyethylene ether, 2 parts of fatty alcohol polyoxyethylene ether, 7 parts of epoxy soybean oil, 1.6 parts of sodium bentonite, and methyl oleate is added to 100 parts.

[0023] The sodium bentonite has an average particle size of 2 μm and is purchased from Suzhou Weidino Technology Co., Ltd.

[0024] The preparation method comprises the following steps:

[0025] (1) Weigh the dispersion medium and add it into the shearing kettle, and control the temperature of the shearing kettle at 25°C;

[0026] (2) adding foramsulfuron and the remaining raw materials in sequence for shearing, with the shearing time being 45 min;

[0027] (3) After the shearing is completed, the mother liquor is sent to the sand mill, and the shearing is continued until all the mother liquor is sent to the sand mill. After two sand millings in the sand mill, it is sent to the mixing kettle;

[0028] (4) Start stirring in the mixing kettle, and then filter through a 120-mesh sieve to obtain the product.

[0029] Comparative Example:

[0030] The amounts of the adjuvants in the composition of Example 1 were adjusted to prepare various comparative examples.

[0031]

[0032] 2. Detection of the decomposition rate and various physical and chemical properties of the active ingredients in the composition

[0033] Persistent Foaming Test Method: Add standard hard water (15°C-25°C) to the 180mL mark in a graduated cylinder. Place the cylinder on a balance and weigh 1.0g of sample. Add hard water to the mark 9cm±0.1cm from the bottom of the cylinder stopper. Replace the stopper and invert the cylinder 30 times 180°, centered on the center. Place the cylinder vertically on a test bench and allow it to rest. Record the foam volume after 1 minute±10 seconds (allowing it to reach 2ml). Repeat this measurement three times and take the arithmetic mean value as the standard for persistent foaming.

[0034] Pourability test method: Place a specified amount of sample in a standard ground-mouth stopper (B34) measuring cylinder for a fixed time, and then measure the amount of residue in the measuring cylinder after pouring and the amount of residue in the measuring cylinder after washing with water according to certain requirements.

[0035] The detection method of wet sieve test is: Place the weighed sample in a beaker, moisten and dilute it, pour it into the moistened test sieve, rinse it directly with a gentle stream of tap water, then place the test sieve in a basin of water to continue washing, transfer the residue in the sieve to a beaker, dry the residue, weigh it, and calculate the fineness.

[0036] Hot Storage Stability Testing Method: Place 20g of sample in a glass bottle, spreading it into a smooth, even layer. Place the bottle in a constant temperature oven (or water bath) at (54±2)°C for 14 days. Remove the sample and place it in a desiccator to cool to room temperature. Complete testing for active ingredient content and other specified parameters within 24 hours.

[0037] Decomposition rate: The decomposition rate is the difference between the active ingredients before heat storage and the active ingredients after heat storage, divided by the active ingredients before heat storage.

[0038] Dispersion stability test method: Add 100mL of 30℃±2℃ standard hard water to a 250mL beaker. Use a pipette to draw an appropriate amount of sample and slowly add it to the hard water while stirring continuously to make 100mL of emulsion. After adding the emulsion, continue stirring at a speed of 2-3r / s for 30s. Immediately transfer the emulsion to a clean, dry 100mL graduated cylinder and place the cylinder in a constant temperature water bath at 30℃±2℃ for 1 hour. Remove the cylinder and observe the emulsion separation. If there is no floating oil (cream), sinking oil, or precipitation in the graduated cylinder, the emulsion stability is qualified.

[0039] The results are recorded in Tables 1 and 2.

[0040] Table 1 Decomposition rate of active ingredients

[0041] Example Decomposition rate of foramsulfuron % Decomposition rate of isoxadiazole% Example 1 4.95 3.46 Comparative Example 1 95 3.13 Comparative Example 2 91 3.42 Comparative Example 3 40 2.45 Comparative Example 4 38.7 2.27 Comparative Example 5 43.2 1.59 Comparative Example 6 54.5 1.21 Comparative Example 7 20 1.78

[0042] Table 2 Physical and chemical performance indicators

[0043]

[0044] The above test data demonstrates that the decomposition rate of formamidosulfuron in the formulation of Example 1 of the present application is less than 5%, meeting the requirements for pesticide formulations. The formulations also meet acceptable standards for persistent foaming, pourable residue, wet sieving test, and dispersion stability. However, the decomposition rates of formamidosulfuron in the comparative examples are higher, exceeding 90% in some, and some also fail to meet the dispersion stability standards.

[0045] Urea, BHT, and epoxidized soybean oil are all commonly used stabilizers in the field, but urea is less effective in maintaining the stability of methylammonium (as shown in Comparative Examples 1 and 2), and adding small amounts of epoxidized soybean oil and / or BHT is also ineffective (as shown in Comparative Examples 3-6). On the other hand, the thickener sodium bentonite can achieve qualified dispersion stability in the formulation (as shown in Comparative Examples 3, 5, and 6), and also plays a role in the stability of methylammonium. As shown in Comparative Example 7, when more epoxidized soybean oil is added without sodium bentonite, the decomposition rate of methylammonium still does not meet the requirements. Without being bound by any theory, the inventors believe that sodium bentonite has an adsorption effect, which can absorb a portion of methylammonium, preventing excessive exposure of the active ingredient to the surrounding environment, thereby playing a role in the stability of methylammonium.

[0046] Experiments have shown that only when the amount of epoxidized soybean oil is high and sodium bentonite is used as a thickener, as shown in Example 1 of the present invention, can the decomposition rate of foramsulfuron-methyl be less than 5% after undergoing a hot storage stability test, thereby meeting the requirements of general pesticide formulations and also having qualified dispersion stability.

[0047] 3. Field weed control test

[0048] There were 5 treatments in the experiment, and the plot area was 9m 2 Each treatment was replicated twice, with one blank control, for a total of 12 experimental plots. The pesticide and water usage for each plot was calculated based on the per-acre dosage and applied evenly using a small handheld sprayer. Three, seven, and 12 days after application, visually inspected the target Setaria viridis in each plot for signs of phytotoxicity, and recorded any changes in phytotoxicity symptoms. See the table below for the experimental design:

[0049]

[0050]

[0051] The test results show that the agent of Example 1 of the present invention has the best effect. 3 days after application, the foxtail grass began to dry up, 7 days after application, and did not turn green again after 12 days. In contrast, due to the partial decomposition of the active ingredient foramsulfuron in the agent, the foxtail grass in the comparative example only turned yellow or white, and turned green again after a period of application, resulting in poor weed control effect.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-degradability foramsulfuron suspension composition, characterized in that: The invention comprises the following components in parts by weight: 3 parts of carbosulfan, 3 parts of isoxadiazole, 7 parts of tristyrylphenol polyoxyethylene ether, 4 parts of calcium dodecylbenzenesulfonate, 2 parts of castor oil polyoxyethylene ether, 2 parts of fatty alcohol polyoxyethylene ether, 7 parts of epoxy soybean oil, 1.6 parts of sodium bentonite, and methyl oleate is added to 100 parts.

2. The low-degradability foramsulfuron suspension composition according to claim 1, characterized in that The average particle size of the sodium bentonite is 2 μm.

3. The method for preparing the low-degradability foramsulfuron suspension composition according to any one of claims 1 to 2, characterized in that: The steps include: (1) Weigh the dispersion medium and add it into the shearing kettle, and control the temperature of the shearing kettle at 25°C; (2) adding foramsulfuron and the remaining raw materials in sequence for shearing, with the shearing time being 45 min; (3) After the shearing is completed, the mother liquor is sent to the sand mill, and the shearing is continued until all the mother liquor is sent to the sand mill. After two sand millings in the sand mill, it is sent to the mixing kettle; (4) Start stirring in the mixing kettle, and then filter through a 120-mesh sieve to obtain the product.

4. Use of the low-degradable formamidosulfuron suspension composition according to claims 1-2 or the low-degradable formamidosulfuron suspension composition prepared by the preparation method according to claim 3 in controlling weeds.

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