Diuron wettable powder herbicide and preparation method thereof
By coating lignin quaternary ammonium salt onto attapulgite soil and combining it with suspending agents and dispersants, the problem of poor suspension effect of diuron wettable powder was solved, improving the suspension rate and thermal storage stability, and ensuring the uniformity of efficacy and safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-05
- Publication Date
- 2026-03-13
AI Technical Summary
Diuron wettable powder has poor suspension properties, which makes the liquid easily settle in the spray can, resulting in uneven efficacy, poor storage stability, and affecting the effect of use.
Modified attapulgite was used as a carrier. By coating lignin quaternary ammonium salt on the attapulgite, the adsorption capacity of diuron was improved by utilizing π-π stacking and electrostatic attraction. Suspension agents, dispersants and detergents were added to form a composite modifier to improve suspension stability.
It improves the suspension rate and thermal storage stability of diuron wettable powder, ensures uniformity of the pesticide solution and consistency of efficacy, reduces the risk of phytotoxicity, and meets the requirements of environmentally friendly pesticides.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of herbicide technology, specifically relating to a diuron wettable powder herbicide and its preparation method. Background Technology
[0002] Diuron is a substituted urea herbicide with the chemical formula C9H. 10 C l2 Nitrogen oxides (N₂O), in their pure form, are white, odorless crystals with a melting point of 158–159°C. At 25°C, their solubility in water is 42 ppm, and they are slightly soluble in hydrocarbons. Chemically stable, they are primarily used for weed control in non-cultivated areas and for weeding crops such as sugarcane, cotton, and citrus.
[0003] In the field of pesticide formulation, wettable powder (WP) is a widely used and important formulation. Its preparation process typically involves mixing and pulverizing diuron technical grade, inert fillers (such as clay, diatomaceous earth, etc.), surfactants (including wetting agents and dispersants), and other functional adjuvants to a certain fineness to obtain a dry powder formulation. This formulation has several significant advantages: First, the production cost is relatively low, making it economically viable; second, the product is a solid dry agent, which can be packaged in paper or plastic bags, making storage and transportation more convenient and safer, and the packaging materials are easy to dispose of; finally, and crucially, compared to emulsifiable concentrates and other formulations, wettable powder requires no or only a small amount of organic solvents and emulsifiers during production and use, thus being safer for crops, less likely to cause phytotoxicity, and reducing environmental pollution, meeting the modern agricultural demand for environmentally friendly pesticides. Therefore, diuron wettable powder occupies an important position in current agricultural production. Although diuron wettable powder has the above advantages, it still has the following shortcomings. For example, the current suspension rate of diuron wettable powder is 60-80%. During use, the liquid is prone to sedimentation in the sprayer, resulting in a low concentration of the first sprayed liquid and a high concentration of the later sprayed liquid, causing uneven efficacy in the field. This may cause phytotoxicity in some areas and poor application effect. Moreover, the product has poor storage stability (such as thermal storage stability), which will affect its dispersion performance in water and lead to a decrease in efficacy. Summary of the Invention
[0004] The purpose of this invention is to provide a diuron wettable powder herbicide and its preparation method, so as to solve the problem of poor suspension effect of diuron wettable powder.
[0005] The objective of this invention can be achieved through the following technical solutions: The first aspect of this invention provides a diuron wettable powder herbicide, comprising diuron technical, a carrier, a suspending agent, a dispersant, and a detergent, wherein the mass ratio of diuron technical to carrier is 3.0-3.2:1; the carrier comprises attapulgite and modified attapulgite, wherein the mass ratio of attapulgite to modified attapulgite is 10:1-4, and the modified attapulgite is attapulgite coated with lignin quaternary ammonium salt.
[0006] In some possible implementations, the modified attapulgite is prepared by the following steps: Anionic surfactant and lignin quaternary ammonium salt were added to water and stirred to adjust the system to acidity. The mixture was centrifuged, washed and dried at 30-35℃ to obtain a composite modifier. The composite modifier and quaternary ammonium salt pre-modified attapulgite were added to ethanol and ultrasonically dispersed for 10-20 minutes. The ethanol was then evaporated to obtain modified attapulgite.
[0007] Under acidic conditions, anionic surfactants and lignin quaternary ammonium salts are induced to recombine, forming a composite modifier. Using pre-modified attapulgite as the core, the composite modifier coats the attapulgite through secondary electrostatic bonding. The resulting modified attapulgite incorporates lignin quaternary ammonium salts for coating. These lignin quaternary ammonium salts contain phenolic hydroxyl groups, carboxyl groups, and quaternary ammonium salt structures. The phenolic hydroxyl groups can form π-π stacking with diuron, while the carboxyl groups exhibit electrostatic attraction with diuron, causing diuron to adsorb onto the lignin quaternary ammonium salt-coated attapulgite, i.e., the modified attapulgite. The -N group in the lignin quaternary ammonium salt... + The positive charge of R3 can neutralize some of the negative charge, balancing the adsorption and dispersing forces, and further improving the thermal storage stability.
[0008] The anionic surfactant is one of sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium dodecyl sulfonate, and sodium dodecylbenzene sulfonate. The ratio of anionic surfactant, lignin quaternary ammonium salt, and quaternary ammonium salt pre-modified attapulgite is 0.1g:0.7g:1.2-1.5g; the concentrations of anionic surfactant and lignin quaternary ammonium salt in water are 1-2g / L, respectively. In some possible implementations, lignin quaternary ammonium salts are prepared via the following steps: Sodium lignosulfonate was added to acetone and stirred at 40-45℃. The pH was adjusted to 10-12 with sodium hydroxide aqueous solution, and stirring continued. Then, epoxide quaternary ammonium salt (2,3-epoxypropyltrimethylammonium chloride) was added, and stirring continued at 45-50℃ for 3-4 hours. After the reaction was complete, the acetone was evaporated to obtain the lignin quaternary ammonium salt. The mass ratio of sodium lignosulfonate to epoxide quaternary ammonium salt was 25-27 g: 6-8 g. The above reaction was carried out in a reflux apparatus. The introduction of quaternary ammonium cations into the molecular structure of sodium lignosulfonate enhances its hydrophilicity.
[0009] In some possible implementations, the quaternary ammonium salt pre-modified attapulgite is prepared by the following steps: Attapulgite is ground into powder and added to hydrochloric acid aqueous solution. It is stirred for 1-2 hours at 65-70℃. After stirring, it is washed with water, dried and crushed to obtain acid-activated attapulgite. Long-chain alkyl quaternary ammonium salt cationic surfactants were dissolved in water, and acid-activated attapulgite was added. The mixture was stirred at 55-60℃ for 1-2 hours, and then washed and dried to obtain quaternary ammonium salt pre-modified attapulgite. The treatment with long-chain alkyl quaternary ammonium salt cationic surfactants introduced hydrophobic alkyl segments into the quaternary ammonium salt pre-modified attapulgite, serving as "anchors" for subsequent treatments. The long-chain alkyl segments formed interaction forces with the benzene rings, ether bonds, and alkane side chains of lignin, which improved the uniformity of coating.
[0010] In some possible implementations, the concentration of the hydrochloric acid aqueous solution is 1.5-2 mol / L; The long-chain alkyl quaternary ammonium salt cationic surfactant is one of octadecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, and tetradecyltrimethylammonium chloride; The mass ratio of long-chain alkyl quaternary ammonium salt cationic surfactant to acid-activated attapulgite is 1:25-30.
[0011] In some possible implementations, the active ingredient content of diuron technical grade is 80%, and the mass ratio of diuron technical grade, suspending agent, dispersant and detergent is 60-65:9-11:5-7:1-2.
[0012] In some possible implementations, the suspending agent is one of xanthan gum, sodium carboxymethyl cellulose, and sodium alginate; The dispersant is one of sodium methylene bisnaphthalene sulfonate and calcium lignin sulfonate; The detergent is one of sodium dodecyl sulfate and sodium butylnaphthalene sulfonate.
[0013] A second aspect of this invention provides a method for preparing a diuron wettable powder herbicide, comprising the following steps: Diuron technical grade herbicide, carrier, suspending agent, dispersant and detergent are mixed, sieved and then pulverized by air jet milling until the particle size is <10μm to obtain diuron wettable powder herbicide.
[0014] The beneficial effects of this invention are: This invention provides a diuron wettable powder herbicide and its preparation method. The invention induces anionic surfactant and lignin quaternary ammonium salt to compound under acidic conditions to form a composite modifier. With quaternary ammonium salt pre-modified attapulgite as the core, the composite modifier forms a coating on the attapulgite through secondary electrostatic bonding, thus solving the problem of poor suspension effect of diuron wettable powder. Detailed Implementation
[0015] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0016] The following is a detailed description of a diuron wettable powder herbicide and its preparation method according to an embodiment of this application.
[0017] The following is a detailed description with reference to specific examples.
[0018] Example 1
[0019] This embodiment provides a diuron wettable powder herbicide, comprising diuron technical, a carrier, a suspending agent, a dispersant, and a detergent. The mass ratio of diuron technical to carrier is 3.0:1. The carrier comprises attapulgite and modified attapulgite, with a mass ratio of attapulgite to modified attapulgite of 10:1. The active ingredient content of diuron technical is 80%, and the mass ratio of diuron technical, suspending agent, dispersant, and detergent is 60:9:5:1. The suspending agent is xanthan gum; the dispersant is sodium methylene bis(naphthalene) sulfonate; and the detergent is sodium butylnaphthalene sulfonate.
[0020] The preparation method includes the following steps: mixing diuron technical, carrier, suspending agent, dispersant and detergent for 20 minutes, passing through a 100-mesh sieve, and then feeding it into an air jet mill at a speed of 150 kg / h. The mixture is then pulverized using air jet milling until the particle size of the material is <10 μm to obtain diuron wettable powder herbicide.
[0021] The modified attapulgite is prepared through the following steps: Sodium lignosulfonate was added to acetone and stirred at 40°C. The pH was adjusted to 10 with sodium hydroxide aqueous solution, and stirring continued. 2,3-epoxypropyltrimethylammonium chloride was added, and stirring was continued at 45°C for 4 hours. After the reaction was completed, the acetone was evaporated to obtain lignin quaternary ammonium salt. The mass ratio of sodium lignosulfonate to 2,3-epoxypropyltrimethylammonium chloride was 25 g: 6 g.
[0022] Attapulgite was ground into powder and added to a 2 mol / L hydrochloric acid aqueous solution. The mixture was stirred at 65°C for 1.5 h. After stirring, the mixture was washed with water, dried, and pulverized to obtain acid-activated attapulgite. A long-chain alkyl quaternary ammonium salt cationic surfactant was dissolved in water, and acid-activated attapulgite was added. The mixture was stirred at 55°C for 1.5 hours, and then washed and dried to obtain quaternary ammonium salt pre-modified attapulgite. The long-chain alkyl quaternary ammonium salt cationic surfactant was octadecyltrimethylammonium chloride; the mass ratio of the long-chain alkyl quaternary ammonium salt cationic surfactant to the acid-activated attapulgite was 1:25.
[0023] Anionic surfactant and lignin quaternary ammonium salt were added to water and stirred. The pH was adjusted to 3. The mixture was centrifuged, washed and dried at 30°C to obtain a composite modifier. The composite modifier and quaternary ammonium salt pre-modified attapulgite were added to ethanol, ultrasonically dispersed for 20 minutes, and the ethanol was evaporated to obtain modified attapulgite.
[0024] The anionic surfactant is sodium dodecyl sulfate; the ratio of anionic surfactant, lignin quaternary ammonium salt and quaternary ammonium salt pre-modified attapulgite is 0.1g:0.7g:1.2g; the concentrations of anionic surfactant and lignin quaternary ammonium salt in water are 1g / L.
[0025] Example 2
[0026] This embodiment provides a diuron wettable powder herbicide, comprising diuron technical, a carrier, a suspending agent, a dispersant, and a detergent. The mass ratio of diuron technical to carrier is 3.2:1. The carrier comprises attapulgite and modified attapulgite, with a mass ratio of attapulgite to modified attapulgite of 10:3. The active ingredient content of diuron technical is 80%, and the mass ratio of diuron technical, suspending agent, dispersant, and detergent is 60:9:5:1. The suspending agent is xanthan gum; the dispersant is sodium methylene bis(naphthalene) sulfonate; and the detergent is sodium butylnaphthalene sulfonate.
[0027] The preparation method includes the following steps: mixing diuron technical, carrier, suspending agent, dispersant and detergent for 20 minutes, passing through a 100-mesh sieve, and then feeding it into an air jet mill at a speed of 150 kg / h. The mixture is then pulverized using air jet milling until the particle size of the material is <10 μm to obtain diuron wettable powder herbicide.
[0028] The modified attapulgite clay is the same as in Example 1.
[0029] Example 3
[0030] This embodiment provides a diuron wettable powder herbicide, comprising diuron technical, a carrier, a suspending agent, a dispersant, and a detergent. The mass ratio of diuron technical to carrier is 3.2:1. The carrier comprises attapulgite and modified attapulgite, with a mass ratio of attapulgite to modified attapulgite of 10:4. The active ingredient content of diuron technical is 80%, and the mass ratio of diuron technical, suspending agent, dispersant, and detergent is 60:9:5:1. The suspending agent is xanthan gum; the dispersant is sodium methylene bis(naphthalene) sulfonate; and the detergent is sodium butylnaphthalene sulfonate.
[0031] The preparation method includes the following steps: mixing diuron technical, carrier, suspending agent, dispersant and detergent for 20 minutes, passing through a 100-mesh sieve, and then feeding it into an air jet mill at a speed of 150 kg / h. The mixture is then pulverized using air jet milling until the particle size of the material is <10 μm to obtain diuron wettable powder herbicide.
[0032] The modified attapulgite clay is the same as in Example 1.
[0033] Example 4
[0034] This embodiment provides a diuron wettable powder herbicide, comprising diuron technical, a carrier, a suspending agent, a dispersant, and a detergent. The mass ratio of diuron technical to carrier is 3.0:1. The carrier comprises attapulgite and modified attapulgite, with a mass ratio of attapulgite to modified attapulgite of 10:1. The active ingredient content of diuron technical is 80%, and the mass ratio of diuron technical, suspending agent, dispersant, and detergent is 65:11:7:2. The suspending agent is xanthan gum; the dispersant is sodium methylene bis(naphthalene) sulfonate; and the detergent is sodium butylnaphthalene sulfonate.
[0035] The preparation method includes the following steps: mixing diuron technical, carrier, suspending agent, dispersant and detergent for 20 minutes, passing through a 100-mesh sieve, and then feeding it into an air jet mill at a speed of 150 kg / h. The mixture is then pulverized using air jet milling until the particle size of the material is <10 μm to obtain diuron wettable powder herbicide.
[0036] The modified attapulgite clay is the same as in Example 1.
[0037] Example 5
[0038] The difference between this embodiment and Example 1 lies in the preparation of the modified attapulgite. Specifically, the modified attapulgite is prepared through the following steps: Sodium lignosulfonate was added to acetone and stirred at 45°C. The pH was adjusted to 11 with sodium hydroxide solution, and stirring continued. 2,3-epoxypropyltrimethylammonium chloride was added, and stirring continued at 50°C for 3 hours. After the reaction was complete, the acetone was evaporated to obtain lignin quaternary ammonium salt. The mass ratio of sodium lignosulfonate to 2,3-epoxypropyltrimethylammonium chloride was 27 g: 8 g.
[0039] The long-chain alkyl quaternary ammonium salt cationic surfactant was dissolved in water and added to acid-activated attapulgite (same as in Example 1). The mixture was stirred at 60°C for 1.5 h, and then washed and dried to obtain quaternary ammonium salt pre-modified attapulgite. The long-chain alkyl quaternary ammonium salt cationic surfactant was octadecyltrimethylammonium chloride; the mass ratio of the long-chain alkyl quaternary ammonium salt cationic surfactant to the acid-activated attapulgite was 1:30.
[0040] Anionic surfactant and lignin quaternary ammonium salt were added to water and stirred. The pH was adjusted to 3. The mixture was centrifuged, washed and dried at 30°C to obtain a composite modifier. The composite modifier and quaternary ammonium salt pre-modified attapulgite were added to ethanol, ultrasonically dispersed for 20 minutes, and the ethanol was evaporated to obtain modified attapulgite.
[0041] The anionic surfactant is sodium dodecyl sulfonate; the ratio of anionic surfactant, lignin quaternary ammonium salt and quaternary ammonium salt pre-modified attapulgite is 0.1g:0.7g:1.2g; the concentrations of anionic surfactant and lignin quaternary ammonium salt in water are 1g / L.
[0042] Example 6
[0043] The difference between this embodiment and Example 1 lies in the preparation of the modified attapulgite. Specifically, the modified attapulgite is prepared through the following steps: Sodium lignosulfonate was added to acetone and stirred at 45°C. The pH was adjusted to 12 with sodium hydroxide solution, and stirring continued. 2,3-epoxypropyltrimethylammonium chloride was added, and stirring continued at 50°C for 4 hours. After the reaction was complete, the acetone was evaporated to obtain lignin quaternary ammonium salt. The mass ratio of sodium lignosulfonate to 2,3-epoxypropyltrimethylammonium chloride was 27 g: 8 g.
[0044] The long-chain alkyl quaternary ammonium salt cationic surfactant was dissolved in water, and acid-activated attapulgite (same as in Example 1) was added. The mixture was stirred at 55°C for 1.5 h, and then washed and dried to obtain quaternary ammonium salt pre-modified attapulgite. The long-chain alkyl quaternary ammonium salt cationic surfactant was octadecyltrimethylammonium chloride; the mass ratio of the long-chain alkyl quaternary ammonium salt cationic surfactant to the acid-activated attapulgite was 1:30.
[0045] Anionic surfactant and lignin quaternary ammonium salt were added to water and stirred. The pH was adjusted to 3. The mixture was centrifuged, washed and dried at 35°C to obtain a composite modifier. The composite modifier and quaternary ammonium salt pre-modified attapulgite were added to ethanol, ultrasonically dispersed for 15 min, and the ethanol was evaporated to obtain modified attapulgite.
[0046] The anionic surfactant is sodium dodecylbenzenesulfonate; the ratio of anionic surfactant, lignin quaternary ammonium salt and quaternary ammonium salt pre-modified attapulgite is 0.1g:0.7g:1.5g; the concentrations of anionic surfactant and lignin quaternary ammonium salt in water are 1g / L.
[0047] Comparative Example 1
[0048] The difference between this comparative example and Example 1 is that "modified attapulgite" is replaced with unmodified attapulgite, while the other raw materials and preparation process remain the same as in Example 1.
[0049] Comparative Example 2
[0050] The difference between this comparative example and Example 1 is that "modified attapulgite" is replaced with quaternary ammonium salt premodified attapulgite in Example 1, while the other raw materials and preparation process remain the same as in Example 1.
[0051] Performance tests were conducted on Examples 1-6 and Comparative Examples 1-2; The thermal storage stability was tested according to standard GB / T19136-2021, and the results are shown in Table 1: Table 1
[0052] According to the test results, the diuron wettable powder herbicide prepared in Examples 1-6 of this invention has better suspension rate and thermal storage stability. The diuron wettable powder herbicide in this invention has modified attapulgite clay, and lignin quaternary ammonium salt is introduced into the attapulgite clay. The active ingredient molecules are more easily "anchored" on the carrier surface, and the active ingredient is less likely to come into direct contact with alkaline sites, moisture, and free metal ions, resulting in a decrease in thermal storage decomposition rate. In contrast, the quaternary ammonium salt pre-modified attapulgite clay in Comparative Example 2 reduced the adsorption sites, resulting in a worse effect than the unmodified attapulgite clay.
[0053] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.
[0054] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A diuron wettable powder herbicide, characterized in that, The product includes diuron technical grade, carrier, suspending agent, dispersant, and detergent. The mass ratio of diuron technical grade to carrier is 3.0-3.2:
1. The carrier includes attapulgite and modified attapulgite, and the mass ratio of attapulgite to modified attapulgite is 10:1-4. The modified attapulgite is attapulgite coated with lignin quaternary ammonium salt.
2. The diuron wettable powder herbicide according to claim 1, characterized in that, The modified attapulgite soil is prepared through the following steps: Anionic surfactant and lignin quaternary ammonium salt were added to water and stirred to adjust the system to a weakly acidic state. The mixture was then centrifuged, washed, and dried at 30-35℃ to obtain a composite modifier. The composite modifier and quaternary ammonium salt pre-modified attapulgite were added to ethanol, ultrasonically dispersed, and the ethanol was evaporated to obtain modified attapulgite.
3. The diuron wettable powder herbicide according to claim 2, characterized in that, The anionic surfactant is one of sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium dodecyl sulfonate, and sodium dodecylbenzene sulfonate.
4. The diuron wettable powder herbicide according to claim 2, characterized in that, The ratio of the anionic surfactant, lignin quaternary ammonium salt, and quaternary ammonium salt pre-modified attapulgite is 0.1g:0.7g:1.2-1.5g.
5. The diuron wettable powder herbicide according to claim 1, characterized in that, The lignin quaternary ammonium salt is prepared by the following steps: Sodium lignosulfonate was added to acetone and stirred at 40-45℃. The pH was adjusted to 10-12 with sodium hydroxide aqueous solution, and stirring was continued. Epoxy quaternary ammonium salt was added, and stirring was continued at 45-50℃ for 3-4 hours. After the reaction was completed, acetone was evaporated to obtain lignin quaternary ammonium salt. The mass ratio of sodium lignosulfonate to epoxy quaternary ammonium salt was 25-27g:6-8g.
6. The diuron wettable powder herbicide according to claim 2, characterized in that, The quaternary ammonium salt pre-modified attapulgite is prepared through the following steps: Long-chain alkyl quaternary ammonium salt cationic surfactants are dissolved in water, and acid-activated attapulgite is added. The mixture is stirred at 55-60℃ for 1-2 hours, and then washed and dried to obtain quaternary ammonium salt pre-modified attapulgite.
7. The diuron wettable powder herbicide according to claim 6, characterized in that, The mass ratio of long-chain alkyl quaternary ammonium salt cationic surfactant to acid-activated attapulgite is 1:25-30; The long-chain alkyl quaternary ammonium salt cationic surfactant is one of octadecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, and tetradecyltrimethylammonium chloride.
8. The diuron wettable powder herbicide according to claim 1, characterized in that, The active ingredient content of diuron technical grade is 80%, and the mass ratio of diuron technical grade, suspending agent, dispersant and detergent is 60-65:9-11:5-7:1-2.
9. The diuron wettable powder herbicide according to claim 1, characterized in that, The suspending agent is one of xanthan gum, sodium carboxymethyl cellulose, and sodium alginate; The dispersant is one of sodium methylene bisnaphthalene sulfonate and calcium lignin sulfonate; The detergent is one of sodium dodecyl sulfate and sodium butylnaphthalene sulfonate.
10. A method for preparing a diuron wettable powder herbicide, used to prepare the diuron wettable powder herbicide according to any one of claims 1-9, characterized in that, Includes the following steps: Diuron technical grade herbicide, carrier, suspending agent, dispersant and detergent are mixed, sieved and then pulverized by air jet milling until the particle size is <10μm to obtain diuron wettable powder herbicide.