Development trend of pesticide formulation research

I. Main Pesticide Preparations in China

1. powder: it is the earliest pesticide processing dosage form. Pests and diseases on the ground and soil can be controlled by spraying powder and dressing seeds, which is especially suitable for water-deficient areas and forest areas. Its disadvantages are that powder particles are easy to float and pollute the environment when spraying powder, and powder particles are not easy to attach to the surface of plants, so the utilization rate is low and the loss is high.

2. Wettable powder: it is a kind of powder that is easily wetted by water and can be dispersed and suspended in water for spraying. Wettable powder has better adhesion to the target, less drift, less environmental pollution, good efficacy, higher content of effective components than powder, no organic solvent and easy storage. Pay attention to the dust drift during processing and use, especially the harm of herbicides to crops and the inhalation risk of workers. Therefore, in some areas, small packages have been used for primary spraying.

3. EC: It is one of the most basic pesticide preparations. It is a liquid pesticide preparation made of pesticides, emulsifiers and solvents. It has the characteristics of high content of effective components, good efficacy, convenient use, simple processing and storage resistance, but it consumes a lot of organic solvents and causes environmental pollution. Therefore, the processing of EC should make full use of the solubility of organic solvents, increase the content of effective components in EC preparations as much as possible, and use as little toxic organic solvents as possible to avoid environmental damage caused by the large use of organic solvents in traditional EC.

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4. Concentrated emulsion: it is an oil-in-water opaque emulsion liquid dosage form. It is a water-based pesticide preparation, with water as the continuous phase and pesticide crude oil as the dispersed phase. The volatilization of toxic gases of pesticides was inhibited, the amount of organic solvent in the preparation was reduced, and the surfactant less than or close to the amount of emulsifiable concentrate was used, which improved the safety of production, storage and transportation and reduced the use toxicity and environmental pollution risk, but the technical requirements for formula selection were high.

5. Suspending agent: a pesticide preparation made of water-insoluble solid or oily liquid raw materials and various additives by wet grinding. It has good dispersibility and high suspension rate, and is a new dosage form with good compatibility with the environment. It is also a favorite expression of farmers. The suspending agent can be layered before use, so long as it is gently shaken or stirred, it will not affect the normal use.

6. Granule: It is a solid preparation with uniform particle size made of raw materials, carriers, fillers and additives through a certain processing technology. High-toxic varieties can be used for low toxicity, which can be controlled to improve the safety of use and prolong the duration. Its processing has no special requirements for the original drug, and the formula composition and granulation method can be selected according to the characteristics and physical and chemical properties of the original drug.

7. Oil agent and ultra-low volume spray: Dissolve the original drug in organic solvent to form a single-phase oily liquid, which can be sprayed directly. This preparation is called oil, and its concentration is very high. It can be sprayed with a thermal spraying device to control pests in warehouses and forests. When the concentration is low, it is harmless to human body and can be used for indoor pest control. Its effective components have the characteristics of high efficiency, low toxicity, low residue and safety to crops, and its solvent has good solubility in effective components, low volatility, low viscosity, high ignition point and safety. Ultra-low volume spray can be applied directly, and the droplets formed after application are small and uniform, so the dosage is small and the efficacy is high, but limited by the application machinery, there are few varieties.

8. Smoke-generating agent: original medicine, fuel, combustion improver, flame retardant, etc. Mixing and processing into powder dosage form according to a certain proportion. The effective components of pesticides are gasified by heating and condense into solid particles in the air to form smoke. Solid particles have good permeability, and some drugs can be deposited and attached to various parts of protected crops. When in use, it does not need any instruments, and is suitable for use in crowded environments such as greenhouses, warehouses, shops, warehouses, etc., and can also be used in places with serious water shortage such as forests, bushes, valleys, etc. The effective components of processed tobacco fine pesticides must be volatile, sublimated or evaporated under tobacco forming conditions, but they can be guaranteed not to decompose or decompose very little.

9. Sustained-release agent: It is a pesticide preparation that is stored in the preparation by physical or chemical methods and released slowly and controlled, which can prolong the validity period, reduce the toxicity to people, livestock and beneficial organisms, reduce the phytotoxicity and reduce environmental pollution. Therefore, the sustained-release agent is a pesticide formulation with great development potential.

Other pesticide preparations: soluble powder, aqua, aerosol, seed coating agent, hot fog agent, etc. There are many kinds of pesticide formulations, which are developing rapidly. With the emergence of new varieties of pesticides, new application instruments and processing technologies are constantly emerging, which requires the development of new pesticide formulations.

Second, the development trend of using technology

At present, chemical pesticides are efficient, but the means of use are inefficient. In order to improve the utilization rate of pesticides, we should vigorously develop advanced application machinery and technology, develop new packaging materials and packaging technologies, and fully improve the utilization rate of pesticides.

L, improve pesticide packaging materials and packaging technology

(1) Development of soluble packaging bags: development of soluble packaging bags and disposable small packages. When in use, just put the packaging bag filled with drugs into a certain amount of water, so that the packaging bag is dissolved and the drugs are dispersed in the water, which is convenient and safe to use.

(2) Built-in meter in the packaging bottle: When in use, just squeeze the medicine bottle by hand to make a certain amount of liquid medicine rise into the meter through the catheter, and then open the meter to pour the medicine into human water, thus completely avoiding the contact between the medicine and the skin and ensuring the safety of the operator.

2. New spraying technology and equipment

(1) Anti-drift nozzle: Several foreign companies have successively designed and manufactured "less drift" or "anti-drift" nozzles, which can produce fewer droplets smaller than 50txm, and these droplets are easy to drift. At present, this nozzle has been widely used in production; In addition, the research and development of liquid medicine drift control agent can effectively control the droplet drift. The development of these new technologies has undoubtedly reduced the harm to the environment.

(2) Composite nozzle spraying technology: it was invented by American scholars. Compound nozzles are called double nozzles. One nozzle sprays coarse water droplets, and the other nozzle sprays liquid medicine into human water droplets to become fine water droplets. The fusion of the two droplets not only improves the dispersion of effective components, but also avoids the drift to the environment, which is not only safe to the environment, but also greatly improves the utilization rate of pesticides.

(3) Electrostatic spraying technology: The spraying method of charging fog drops by high-voltage electrostatic generator increases the deposition amount of fog drops on the leaves, so the effective utilization rate of pesticides is increased.

(4) Intelligent target spraying: the target position of pests is determined by modern information identification technology, and pesticides are accurately sprayed on target 7 by control technology. This application technology is still in the development stage. Although chemical pesticides are effective for pests, they have a great negative impact because of their low utilization rate. With the development of pesticide application technology theory and modern science and technology, the effective utilization rate of pesticides will be greatly improved, which can effectively solve the problems of environmental pollution, pest resistance and so on, and make pesticides truly become active ministers for the benefit of mankind.