Application of tristyrylphenol polyoxyethylene ether in aqueous suspension concentrate of sulfonylurea herbicides

Abstract

The embodiment of the present invention discloses an application of tristyrylphenol polyoxyethylene ether in a sulfonylurea herbicide aqueous suspension. The structural formula of the tristyrylphenol polyoxyethylene ether is as follows: R1-O-(CH2CH2-O) n , wherein R is tristyrylphenyl and n is 15-60. The present invention finds that tristyrylphenol polyoxyethylene ether can not only improve the physical stability of the sulfonylurea herbicide water suspension during storage, but also greatly improve the chemical stability of the sulfonylurea herbicide raw material, which not only keeps the preparation physically and chemically stable during storage, but also prolongs the stability of the sulfonylurea herbicide in a simulated field environment, and has a very broad application prospect.

Description

Technical Field

[0001] The embodiment of the present invention relates to the technical field of pesticides, and specifically to an application of tristyrylphenol polyoxyethylene ether in a sulfonylurea herbicide aqueous suspension concentrate. Background Art

[0002] Tristyrylphenol polyoxyethylene ether is an important surfactant, which includes tristyrylphenyl and ethylene oxide in its structure. Tristyrylphenol polyoxyethylene ether is usually used as an emulsifier in the processing of liquid pesticide formulations, playing the role of wetting, emulsification, dispersion and other functions.

[0003] Aqueous suspension concentrate is a stable pesticide formulation formed by wet grinding solid technical materials to suspend the solid technical materials in water. Since it uses water instead of organic solvents, its processing and use process is more environmentally friendly, and it can be diluted with water in any proportion, making it suitable for aerial spraying. Due to its outstanding advantages, it has been vigorously promoted by the global pesticide industry in recent years.

[0004] Sulfonylurea herbicides are widely used in agriculture. However, since the urea bridge in its molecule is easily hydrolyzed and broken in water, it decomposes and loses its herbicidal activity. Therefore, a large number of sulfonylurea herbicides are developed into wettable powders, water-dispersible granules, film-spreading oils, dispersible oil suspensions and other dosage forms, and less developed into water suspensions, in order to avoid the decomposition and loss of activity of sulfonylurea herbicides in water. Solid dosage forms such as wettable powders and water-dispersible granules will generate a large amount of dust during production and use, which is harmful to the health of producers and users; film-spreading oils and dispersible oil suspensions will use a large amount of organic solvents during the processing process, which will not only endanger the health of users during processing and use, but also pollute the soil and water sources when organic solvents enter the environment, causing serious harm to the environment.

[0005] There are also many reports on stabilizers for sulfonylurea herbicides. For example, patent CN 103960234A discloses triphenylphosphite and dimethyl sulfoxide as stabilizers, which can greatly improve the stability of benzylsulfuron-methyl in film-spreading oils, but the raw materials used will pollute the environment and destroy the ecological balance; patent CN 110692632A discloses that a stabilizer containing metal soaps, auxiliary stabilizers, antioxidants, solvents, etc. is added to sulfonylurea herbicides to improve the stability of mesosulfuron-methyl, pyrazosulfuron-methyl, nicosulfuron-methyl, etc. in dispersible oil suspensions; patent CN 108041033A discloses a stabilizer for sulfonylurea herbicides, which can reduce the decomposition problem of sulfonylurea herbicides in dispersible oil suspensions. The pesticide formulations involved in the above prior art include film-spreading oils and dispersible oil suspensions. Such pesticide formulations have a common feature that the formulations have strict restrictions on moisture, and the above disclosures do not mention the stability of sulfonylurea herbicides in aqueous suspensions, nor the stability of active ingredients in the formulations in the environment after use.

[0006] The aqueous suspension concentrate uses water as a dispersion medium, does not require any organic solvents during processing, is dust-free during use, and has the advantages of low pollution, high safety, and low cost. Therefore, it is of great significance to develop an aqueous suspension concentrate of sulfonylurea herbicides. Summary of the invention

[0007] To this end, an embodiment of the present invention provides a use of tristyrylphenol polyoxyethylene ether in a sulfonylurea herbicide aqueous suspension concentrate.

[0008] In order to achieve the above purpose, the embodiment of the present invention provides the following technical solutions:

[0009] According to a first aspect of an embodiment of the present invention, the present invention provides the use of tristyrylphenol polyoxyethylene ether in improving the stability of sulfonylurea herbicide aqueous suspension concentrate, wherein the tristyrylphenol polyoxyethylene ether has the following structural formula: RO-(CH2CH2-O) n , wherein R is tristyrylphenyl and n is 15-60.

[0010] The present invention has found through a large number of studies that adding the above-mentioned tristyrylphenol polyoxyethylene ether to the aqueous suspension of sulfonylurea herbicides can not only improve the physical stability of the preparation, but also greatly improve the chemical stability of the sulfonylurea herbicides during storage, and when the liquid medicine is sprayed into the environment, it can still maintain a high stability, thereby improving the shelf life and the weed control duration of the preparation.

[0011] Furthermore, n is 16, 20, 25, 40, 50, 55 or 60.

[0012] Furthermore, the sulfonylurea herbicide uses benzylsulfuron-methyl or pyrazosulfuron-methyl as the original drug.

[0013] Furthermore, the mass percentage of the tristyrylphenol polyoxyethylene ether in the sulfonylurea herbicide aqueous suspension concentrate is 3-30%.

[0014] According to a second aspect of an embodiment of the present invention, an embodiment of the present invention provides a sulfonylurea herbicide aqueous suspension concentrate, which is composed of the following components in percentage by mass: 1-50% of benzylsulfuron-methyl or pyrazosulfuron-methyl, 3-30% of tristyrylphenol polyoxyethylene ether, 1-5% of wetting agent, 3-10% of dispersant, 0.1-0.5% of defoaming agent, 3-5% of antifreeze agent, 0.1-1% of thickener, 0.1-0.3% of preservative, and the balance is deionized water.

[0015] Furthermore, the wetting agent is selected from any one or more of sodium dodecyl sulfate, sodium dibutylnaphthalene sulfonate, sodium polyoxyethylene fatty alcohol ether sulfate, tristyrylphenol formaldehyde condensate polyoxyethylene ether sulfonate (sulfate), and fatty alcohol polyoxyethylene ether; the dispersant is selected from any one or more of lignin sulfonate (sodium) salt, alkylnaphthalene sulfonate, polycarboxylate, alkylbenzene sulfonate, styrylphenol polyoxyethylene ether phosphate, and tristyrylphenol polyoxyethylene ether phosphate; the defoamer is an organosilicon defoamer; the antifreeze is selected from any one or more of ethylene glycol, propylene glycol, and glycerol; the thickener is selected from any one or two of xanthan gum and magnesium aluminum silicate; the preservative is any one or two of kason and sodium benzoate.

[0016] According to the third aspect of the embodiments of the present invention, the embodiments of the present invention provide a method for preparing the aqueous suspension of sulfonylurea herbicides as described above, the method comprising: adding each material into a shear kettle, shearing them evenly, and then grinding them with a sand mill so that the average particle size of the material is less than 2 microns.

[0017] The embodiments of the present invention have the following advantages:

[0018] 1. The present invention uses tristyrylphenol polyoxyethylene ether as a stabilizer for sulfonylurea herbicides, and can develop a stable sulfonylurea aqueous suspension concentrate, so that the sulfonylurea herbicides can be processed into a more environmentally friendly and stable formulation.

[0019] 2. The present invention enables tristyrylphenol polyoxyethylene ether to inhibit the decomposition of sulfonylurea herbicides in water while satisfying the surface activity, thereby increasing the shelf life of sulfonylurea aqueous suspension products.

[0020] 3. The present invention can prolong the stability of sulfonylurea herbicides in the use environment and prolong the effective period of weed control, thereby reducing the number of times of drug use and reducing drug use costs. DETAILED DESCRIPTION

[0021] The following specific embodiments illustrate the embodiments of the present invention. People familiar with the technology can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In the following embodiments and comparative examples, unless otherwise specified, all percentages are weight percentages.

[0022] The embodiment of the present invention provides a sulfonylurea herbicide, whose raw materials are: 20% of active ingredient, 5% of tristyrylphenol polyoxyethylene ether, 2% of sodium dibutylnaphthalene sulfonate, 5% of styrylphenol polyoxyethylene ether phosphate, 0.1% of organosilicon defoamer, 5% of ethylene glycol, 0.5% of magnesium aluminum silicate, 0.1% of xanthan gum, 0.05% of kason, and the balance of deionized water.

[0023] The preparation method of the above sulfonylurea herbicide is as follows: various materials are added into a shearing kettle, sheared evenly by a shearing machine, and ground by a sand mill so that the average particle size of the mixed material is less than 2 microns, thereby obtaining a sulfonylurea herbicide in the form of a water suspension.

[0024] In Tables 1 and 2 below, pyrazosulfuron-methyl and benzylsulfuron-methyl are selected as active ingredients respectively, and different types of tristyrylphenol polyoxyethylene ether are selected. According to the above ratio and preparation method, the obtained samples are subjected to 7-day and 14-day hot storage experiments to detect the decomposition rate of pyrazosulfuron-methyl or benzylsulfuron-methyl.

[0025] Table 1 Decomposition rate of 20% pyrazosulfuron-methyl suspension containing different tristyrylphenol polyoxyethylene ethers during hot storage

[0026]

[0027]

[0028] Table 2 Decomposition rate of 20% benzylsulfuron-methyl suspension containing different tristyrylphenol polyoxyethylene ethers during hot storage

[0029]

[0030] The results show that in 20% bensulfuron-methyl suspension and 20% pyrazosulfuron-methyl suspension, within a certain range, with the increase of the amount of ethylene oxide in tristyrylphenol polyoxyethylene ether, the thermal storage decomposition rate of bensulfuron-methyl and pyrazosulfuron-methyl is significantly reduced. Tristyrylphenol polyoxyethylene ether is usually used in pesticide emulsifiable concentrates or dispersible oil suspensions, and its hydrophilic / lipophilic balance value is adjusted by adjusting the amount of ethylene oxide. The present invention selects a specific amount of ethylene oxide tristyrylphenol polyoxyethylene ether and applies it in a sulfonylurea aqueous suspension. As the amount of ethylene oxide increases, the hydrophilicity of tristyrylphenol polyoxyethylene ether increases, and a large amount of free water forms hydrogen bonds with ethylene oxide, thereby reducing the water activity in the aqueous solution. The urea bridge stability of sulfonylurea herbicides is greatly affected by the water activity. When the water activity in the preparation is reduced, the stability of the sulfonylurea herbicide in the aqueous solution is improved.

[0031] Example 1

[0032] This embodiment provides a sulfonylurea herbicide, the raw materials of which are:

[0033] Pyrazosulfuron-methyl 20%, tristyrylphenol polyoxyethylene ether (R1-O-(CH2CH2-O) 55 )5%, sodium dibutylnaphthalene sulfonate 2%, styrylphenol polyoxyethylene ether phosphate 5%, silicone defoamer 0.1%, ethylene glycol 5%, magnesium aluminum silicate 0.5%, xanthan gum 0.1%, Kathon 0.05%, and deionized water balance.

[0034] Example 2

[0035] This embodiment provides a sulfonylurea herbicide, the raw materials of which are:

[0036] Bensulfuron-methyl 20%, tristyrylphenol polyoxyethylene ether (R1-O-(CH2CH2-O) 55 )5%, sodium dibutylnaphthalene sulfonate 2%, styrylphenol polyoxyethylene ether phosphate 5%, silicone defoamer 0.1%, ethylene glycol 5%, magnesium aluminum silicate 0.5%, xanthan gum 0.1%, Kathon 0.05%, and deionized water balance.

[0037] Comparative Example 1

[0038] This comparative example provides a sulfonylurea herbicide, which differs from Example 1 only in that it does not contain tristyrylphenol polyoxyethylene ether.

[0039] Comparative Example 2

[0040] This comparative example provides a sulfonylurea herbicide, which differs from Example 2 only in that it does not contain tristyrylphenol polyoxyethylene ether.

[0041] Comparative Example 3

[0042] This comparative example provides a sulfonylurea herbicide, which is different from Example 1 only in that tristyrylphenol polyoxyethylene ether is replaced by an equal amount of urea.

[0043] Comparative Example 4

[0044] This comparative example provides a sulfonylurea herbicide, which is different from Example 2 only in that tristyrylphenol polyoxyethylene ether is replaced by an equal amount of urea.

[0045] Comparative Example 5

[0046] This comparative example provides a sulfonylurea herbicide, which is different from Example 1 only in that tristyrylphenol polyoxyethylene ether is replaced by an equal amount of BHT.

[0047] Comparative Example 6

[0048] This comparative example provides a sulfonylurea herbicide, which is different from Example 2 only in that tristyrylphenol polyoxyethylene ether is replaced by an equal amount of BHT.

[0049] Comparative Example 7

[0050] This comparative example provides a sulfonylurea herbicide, which is different from Example 1 only in that tristyrylphenol polyoxyethylene ether is replaced by an equal amount of citric acid.

[0051] Comparative Example 8

[0052] This comparative example provides a sulfonylurea herbicide, which is different from Example 2 only in that tristyrylphenol polyoxyethylene ether is replaced by an equal amount of citric acid.

[0053] Comparative Example 9

[0054] This comparative example provides a sulfonylurea herbicide, which is different from Example 1 only in that tristyrylphenol polyoxyethylene ether is replaced by an equal amount of sodium citrate.

[0055] Comparative Example 10

[0056] This comparative example provides a sulfonylurea herbicide, which is different from Example 2 only in that tristyrylphenol polyoxyethylene ether is replaced by an equal amount of sodium citrate.

[0057] Comparative Example 11

[0058] This comparative example provides a sulfonylurea herbicide, which is different from Example 1 only in that tristyrylphenol polyoxyethylene ether is replaced by an equal amount of triphenylphosphite.

[0059] Comparative Example 12

[0060] This comparative example provides a sulfonylurea herbicide, which is different from Example 2 only in that tristyrylphenol polyoxyethylene ether is replaced by an equal amount of triphenylphosphite.

[0061] Test Example 1

[0062] The samples of Examples 1-2 and Comparative Examples 1-12 were subjected to 7-day and 14-day heat storage experiments to detect the decomposition rates of pyrazosulfuron-methyl or benzylsulfuron-methyl. The results are shown in Table 3.

[0063] Table 3

[0064]

[0065] The results show that by comparing Example 1 and Example 2 with the comparative example, it can be clearly found that the thermal storage decomposition rates of bensulfuron-methyl and pyrazosulfuron-methyl in the examples are significantly better than those in the comparative example.

[0066] Test Example 2

[0067] Weigh 1 gram of each sample of Examples 1 and 2 and Comparative Examples 1-12, weigh 15 grams of paddy field soil and 84 grams of paddy field water, cut them evenly with a shearing machine, and divide them into three parts, one of which is stored at room temperature, one is hot stored at 54°C for 7 days, and the other is hot stored at 54°C for 14 days, and the decomposition rates of pyrazosulfuron-methyl and benzylsulfuron-methyl are detected.

[0068] The dosage was 15 g per mu, and paddy field soil was sealed to observe the sealing effect of the agent on broadleaf weeds. The results are shown in Table 4.

[0069] Table 4

[0070]

[0071] The results show that by comparing Example 1 and Example 2 with the comparative example, it can be clearly found that the thermal storage decomposition rates of bensulfuron-methyl and pyrazosulfuron-methyl in the examples are significantly better than those in the comparative example, and the weed-blocking time on broadleaf weeds is significantly better than that in the comparative example.

[0072] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, these modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. The application of tristyrylphenol polyoxyethylene ether in improving the stability of sulfonylurea herbicide aqueous suspension concentrate, characterized in that: The structural formula of the tristyrylphenol polyoxyethylene ether is as follows: RO-(CH2CH2-O) n , wherein R is tristyrylphenyl, n is 25-60, and the sulfonylurea herbicide uses benzylsulfuron-methyl or pyrazosulfuron-methyl as the original drug.

2. The use according to claim 1, characterized in that: n is 25, 40, 50, 55 or 60.

3. The use according to claim 1, characterized in that: n is 55 or 60.

4. The use according to claim 1, characterized in that: The mass percentage of the tristyrylphenol polyoxyethylene ether in the sulfonylurea herbicide aqueous suspension concentrate is 3-30%.

5. A sulfonylurea herbicide aqueous suspension, characterized in that: The aqueous suspension is composed of the following components in percentage by mass: 1-50% of benzylsulfuron-methyl or pyrazosulfuron-methyl, 3-30% of the tristyrylphenol polyoxyethylene ether as claimed in claim 1, 1-5% of a wetting agent, 3-10% of a dispersant, 0.1-0.5% of a defoaming agent, 3-5% of an antifreeze agent, 0.1-1% of a thickener, 0.1-0.3% of a preservative, and the balance is deionized water.

6. The sulfonylurea herbicide aqueous suspension according to claim 5, characterized in that: The wetting agent is selected from any one or more of sodium dodecyl sulfate, sodium dibutylnaphthalene sulfonate, sodium polyoxyethylene fatty alcohol ether sulfate, tristyrylphenol formaldehyde condensate polyoxyethylene ether sulfonate, and fatty alcohol polyoxyethylene ether; The dispersant is selected from any one or more of lignin sulfonate, alkylnaphthalene sulfonate, polycarboxylate, alkylbenzene sulfonate, styrylphenol polyoxyethylene ether phosphate, and tristyrylphenol polyoxyethylene ether phosphate; The defoamer is an organosilicon defoamer; The antifreeze agent is selected from any one or more of ethylene glycol, propylene glycol, and glycerol; The thickener is selected from any one or two of xanthan gum and magnesium aluminum silicate; The preservative is any one or both of kason and sodium benzoate.

7. The method for preparing the sulfonylurea herbicide aqueous suspension concentrate according to claim 6, characterized in that: The method comprises: adding various materials into a shearing kettle, shearing them uniformly, and then grinding them with a sand mill to make the average particle size of the mixed materials less than 2 microns.

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