CN-122011278-A - Quaternary copolymer-based hard water-resistant agricultural dispersing agent, and preparation method and application thereof

Abstract

The invention belongs to the technical field of agricultural additives, and particularly discloses a preparation method of a tetrapolymer-based hard water resistant agricultural dispersant. The dispersing agent takes a quaternary copolymerization system as a core, and a sulfonic acid group and a long-chain alkyl structure are introduced through molecular design, so that a dual anti-precipitation mechanism of hard water ion chelation and steric hindrance is realized, and the suspension stability of the pesticide water dispersible granule in a high hard water environment is remarkably improved (3 times standard hard water suspension rate is more than or equal to 90%). The preparation process adopts a low VOC water-alcohol mixed solvent system, combines with a chain transfer agent to accurately regulate and control the molecular weight distribution (PDI < 2.0), and has the advantages of cost and green sustainability.

Inventors

• ZHANG HAO
• ZHANG LEI
• WANG XUE
• DU YAZHOU
• OUYANG LEI

Assignees

• 山东德胜精细化工研究院有限公司

Dates

Publication Date

20260512

Application Date

20260204

Claims (10)

1. 1. The preparation method of the tetrapolymer-based hard water-resistant agricultural dispersant is characterized by comprising the following steps of: Mixing unsaturated carboxylic acid, methyl styrene and functional monomer in a solution to obtain a monomer mixed solution; Dissolving a chain transfer agent in a solvent, heating to a reflux state, adding a monomer mixed solution and an initiator A solution, adding an initiator B solution after the initiator A solution is added, carrying out a polymer reaction, cooling, adjusting the pH value to 6-8 after the reaction is completed, removing the solvent, and drying to obtain the chain transfer agent; the functional monomer consists of sodium allyloxy hydroxypropyl sulfonate and alkyl methacrylate.
2. 2. The preparation method of the tetrapolymer-based hard water resistant agricultural dispersant of claim 1, wherein the mass ratio of the methyl styrene, the sodium allyloxy hydroxypropyl sulfonate, the unsaturated carboxylic acid and the alkyl methacrylate is 10-50:1-20:20-80:1-40; or the total mass of the methyl styrene, the sodium allyloxy hydroxypropyl sulfonate, the unsaturated carboxylic acid and the alkyl methacrylate is 20-40% of the solution.
3. 3. The method for preparing the tetrapolymer-based hard water resistant agricultural dispersant according to claim 1, wherein the unsaturated carboxylic acid is at least one selected from itaconic acid, maleic anhydride, methacrylic acid, cinnamic acid and lauric acid; or, the alkyl methacrylate is selected from one or two of n-butyl methacrylate, dodecyl methacrylate and hexadecyl methacrylate.
4. 4. The method for preparing the tetrapolymer-based hard water resistant agricultural dispersant according to claim 1, wherein the chain transfer agent is one selected from the group consisting of t-dodecyl mercaptan, mercaptoethanol, mercaptoacetic acid, and n-dodecyl mercaptan; Or the use amount of the chain transfer agent is 0.1-5% or 2-4% of the total mass of all the reaction monomers.
5. 5. The method for preparing the tetrapolymer-based hard water resistant agricultural dispersant according to claim 1, wherein the molar ratio of the total initiator to the chain transfer agent is 1 (0.5 to 20) or 1 (1 to 10).
6. 6. The method for preparing the tetrapolymer-based hard water resistant agricultural dispersant according to claim 1, wherein the initiator a is one selected from the group consisting of azobisisobutyronitrile, azobisisoheptonitrile, and dimethyl azobisisobutyrate; Or the initiator B is one of azo diisobutyl amidine hydrochloride, azo diiso Ding Mi hydrochloride and potassium persulfate.
7. 7. The method for preparing the tetrapolymer-based hard water resistant agricultural dispersant according to claim 1, wherein the solvent is one or two selected from the group consisting of ethanol, isopropanol, n-propanol and butanone; Or the solvent consists of water and alcohol, wherein the mass fraction of the alcohol solution is 30% -80%.
8. 8. The method for preparing the tetrapolymer-based hard water resistant agricultural dispersant according to claim 1, wherein the tetrapolymer-based hard water resistant agricultural dispersant is heated to 60-90 ℃ or 70-80 ℃ to form a reflux state; or, adjusting the pH to 7-8.
9. 9. A hard water resistant dispersant prepared by the method of any one of claims 1-8.
10. 10. Use of the hard water resistant dispersant of claim 9 in the preparation of pesticides or agricultural adjuvants.

Description

Quaternary copolymer-based hard water-resistant agricultural dispersing agent, and preparation method and application thereof Technical Field The invention belongs to the field of agricultural additives, and particularly relates to a preparation method and application of a tetrapolymer-based hard water resistant agricultural dispersant. Background The disclosure of this background section is only intended to increase the understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art already known to those of ordinary skill in the art. In agricultural production, the pesticide water dispersible granule is an important pesticide formulation, and has the advantages of good dispersibility, high suspension rate, convenient use and the like. However, hard water contains a large amount of calcium and magnesium ions, and the ions are easily combined with anionic groups on the surface of a pesticide dispersing agent to cause the dispersing agent to lose efficacy, so that the problems of precipitation, caking and the like of the pesticide water dispersible granule in the hard water are caused, the dispersibility and the stability of the pesticide are seriously affected, the pesticide effect is reduced, and the use cost is increased. The existing agricultural dispersant still has the problem of insufficient hard water resistance. For example, research discloses a general agricultural polymer dispersing agent, and in an environment of standard hard water (342 ppm of standard hard water) which is 3 times or higher than standard hard water, the general dispersing agent cannot effectively maintain the suspension rate of pesticide active ingredients (the suspension rate of the active ingredients is more than 85%) in the water dispersible granule. The research discloses a dispersant, the performance is improved by adding an additional water repellent agent, the suspension rate can reach more than 95%, but the suspension rate still has a decreasing trend (the suspension rate of active ingredients is less than 95%) under the condition of high-power hard water (such as triple standard hard water). Although some of the dispersants disclosed in other studies are improved by introducing some hard water resistant groups, the molecular structure design is not reasonable enough (such as not fully considering the factors of monomer proportion, molecular weight and distribution thereof), so that the dispersing performance and the hard water resistant performance cannot achieve the ideal effects at the same time. In addition, the preparation method of the dispersing agent adopting the ABA block copolymer structure is complicated, has high cost and is not beneficial to large-scale industrial production and popularization and application. Although the existing copolymer dispersing agent is increasingly widely applied, the process still faces key challenges that 1) the structural design is unreasonable, resulting in poor dispersing effect, 2) the hard water resistance is insufficient, the copolymer dispersing agent is easy to combine with high-salt ions in hard water to fail, and 3) the preparation cost is high and the environment is not friendly. Therefore, there is a need to develop a polymer dispersant which has excellent dispersion stability, strong hard water resistance and environmental friendliness. Disclosure of Invention In order to solve the problems, the invention provides a preparation method and application of a tetrapolymer-based hard water resistant agricultural dispersant. In order to achieve the above purpose, the present invention adopts the following technical scheme: in a first aspect, the invention provides a preparation method of a tetrapolymer-based hard water resistant agricultural dispersant, which comprises the following steps: Mixing unsaturated carboxylic acid, methyl styrene and functional monomer in a solution to obtain a monomer mixed solution; Dissolving a chain transfer agent in a solvent, heating to a reflux state, adding a monomer mixed solution and an initiator A solution, adding an initiator B solution after the initiator A solution is added, carrying out a polymer reaction, cooling, adjusting the pH value to 6-8 after the reaction is completed, removing the solvent, and drying to obtain the chain transfer agent; the functional monomer consists of sodium allyloxy hydroxypropyl sulfonate and alkyl methacrylate. In a second aspect of the present invention, there is provided an anti-hard water dispersant prepared by the above method. In a third aspect, the invention provides the application of the hard water resistant dispersing agent in preparing pesticides or agricultural assistants. The beneficial effects of the invention are that (1) The quadripolymer disclosed by the invention is used as a pesticide hard water resistant auxiliary agent, and has the core advantages that hard water ions