Suspension Agent (SC)
It refers to the preparation of solid pesticide technical drugs uniformly dispersed in water with particles less than 4 microns, code named SC.
① No dust hazard, safe for operators and environment;
② With water as the dispersion medium, there is no flammable and harmful problems caused by organic solvents;
③ Compared with the wettable powder, it is allowed to select the raw materials with different particle sizes, so that the biological effect and physical stability of the preparation can reach * better;
④ The liquid suspending agent has good diffusion in water and can be directly made into spray liquid for use;
⑤ . Large proportion, small package volume;
⑥ The dispersivity and expansibility of the suspension agent are relatively good, the suspension rate is high, the ability to adhere to the surface of the plant is relatively strong, and the water erosion resistance is relatively strong, so the efficacy is more significant and lasting than that of the wettable powder;
⑦ It has the characteristics of small particles, large active surface, strong penetration, no dust when dispensing, low cost, high efficacy; It also has the advantages of wettable powder and emulsifiable concentrate, which can be wetted by water and has good suspension after dilution with water.
Emulsifiable concentrates (EC)
It is a kind of pesticide preparation. It is a liquid made by dissolving high concentration of active ingredients in solvent and adding emulsifier. Generally, dilute with a large amount of water to form a stable emulsion, and then use a spray to disperse it* In recent years, low volume spray and even ultra-low volume spray were also conducted.
Most emulsifiers use a mixture of non-ionic and anionic surfactants. Most solvents are petroleum solvents such as xylene and methyl naphthalene. In addition, alcohol solvents such as methyl isobutyl ketone and isopropanol are also used.
The organic solvent in the emulsifiable concentrates can stimulate the young fruits of apples and pears, increase the skin pores and reduce the smoothness of the fruit surface. It is recommended not to use it before bagging, especially for some sensitive species and varieties. It has high efficacy, convenient application and stable property. Due to its long history and mature processing technology, emulsifiable concentrates have a wide range of varieties, large output and applications, and are currently a major pesticide formulation in China and even Southeast Asia.
Microemulsion (ME)
The formulation is composed of liquid pesticide, surfactant, water, stabilizer, etc. It belongs to a thermodynamic time stable dispersion system. It is characterized by taking water as the medium, containing no or less organic solvents, so it is non combustible and non explosive, safe in production and operation, storage and transportation, less environmental pollution, and saves a lot of organic solvents; The pesticide dispersion * is high, reaching the degree of micro refinement. The pesticide particles are generally 0.1~0.01 μ m, and the appearance is similar to transparent or micro transparent liquid; It has good dispersibility in water, strong permeability to target and good adhesion.
Water emulsion (EW)
It refers to the preparation of liquid pesticide technical drug prepared by mixing liquid or solvent into water with small droplets of 0.5-1.5 μ m, and its appearance is milky white milk like liquid. This preparation does not contain organic solvent, is nonflammable, has good safety, and has no harm, irritation and toxicity caused by organic solvent. Concentrated emulsion is a liquid pesticide made of liquid or mixed with solvent, which is dispersed in water with small droplets and water as the medium.
(Difference between emulsifiable concentrates, microemulsions and water emulsions: Macroscopically speaking, if the content of qualified pesticide emulsifiable concentrates, microemulsions and water emulsions is the same and the dilution ratio is the same when used, their efficacy is not different. From a microscopic perspective, because the effective component particles in microemulsions are small in water, and the content of emulsifiers in microemulsions is far higher than that of water emulsions and emulsifiable concentrates, their efficacy is generally good; emulsifiable concentrates contain a large amount of organic solvents, which are often effective There is a synergistic effect, followed by the effect. The content of solvent and emulsifier in water emulsion is very low, and the use effect is equivalent to that of emulsifiable concentrates.
The emulsifiable concentrates contain a lot of organic solvents, which often aggravate the harm to young flowers and fruits; Microemulsions and water emulsions contain a large amount of water, which is less harmful to plants than emulsifiable concentrates with the same effective ingredients. Therefore, microemulsions, water emulsions and emulsifiable concentrates each have their own advantages, and attention should be paid to their selection in use.
The registration of emulsifiable concentrates is now restricted in China because they contain a large amount of organic solvents and pollute the environment.
Microemulsion, using water as the main solvent, is more environmentally friendly than emulsifiable concentrates; However, a large number of surfactants need to be used. Whether they are environment-friendly pesticide preparations is still controversial.
Water emulsion, which uses less organic solvent and surfactant than emulsifiable concentrates and microemulsions, is called environment-friendly pesticide formulation.)
Wettable Powder
Definition: Powder preparation that can be dispersed in water to form a stable suspension.
1. Water insoluble technical drugs can be processed into WP. If they need to be made into high concentration or spray, they are generally processed into WP;
2. Strong adhesion, less drift and less environmental pollution;
3. No organic solvent, good environmental compatibility, convenient for storage and transportation;
4. Low production cost, mature production technology and equipment;
5. The content of active ingredients is higher than that of powder; There is certain dust pollution during processing.
6. It is the basis for developing new dosage forms. SC, WDG, EP, EG, WT, etc.
Water dispersible granule (WDG), also known as dry suspension agent
It is a new pesticide formulation and preparation processing technology developed in the 1980s. It is a solid preparation that can be dispersed in water. At the 6th * * Pesticide Chemistry Conference in 1986, it was considered to be an ideal pesticide formulation with all the advantages of granules and high dispersibility of suspensions, and will be one of the important development trends in pesticide formulation processing.
1. It refers to re granulating the wettable powder or suspension agent into water dispersible granules. The key technology of processing is to prevent the powder particles from re flocculating into coarse powder particles during the granulation process or during the storage of finished products. Therefore, an auxiliary agent called isolating agent should be used in the formula, which can isolate the powder particles. This dosage form requires low abscission rate and no powder in the product. This formulation has good fluidity, convenient use, no dust flying, and is very safe.
2. It is also called dry flow agent and water suspension granule. After entering water, it will automatically disintegrate and disperse into suspension. It is a new dosage form developed on the basis of wettable powder and suspension agent. It has the characteristics of good dispersion, high suspension rate, good stability, convenient use, etc. It avoids the disadvantages of dust generated by wettable powder, inconvenient packaging and transportation of suspension agent, precipitation, caking, poor liquidity, wall sticking, etc. during storage. The production methods include spray granulation, suspension granulation, extrusion granulation, high-strength mixed granulation, fluidized bed granulation, etc.
3. Common auxiliaries of water dispersible granule:
① Polycarboxylate
② Kaolin, diatomite, clay
③ Inorganic salts, such as sodium nitrate, sodium sulfate, sodium chloride, etc
④ Naphthalene sulfonates, etc.
Water agent (AS)
Salt water agents can be prepared for pesticides that are soluble in water and do not decompose in water. Aqueous agent is the aqueous solution of pesticide technical agent. The agent is uniformly dispersed in water in ionic or molecular state. The concentration of the agent depends on the water solubility of the technical agent. Generally, it is * large solubility, and it is diluted with water when used. Compared with emulsifiable concentrates, aqueous solutions do not need organic solvents. They can be spray with a proper amount of surfactant. They have less environmental pollution, simple manufacturing process and good efficacy. They should be developed in the future.
Granule (GR) is abbreviated as Granule
Granular preparation processed from raw drug, carrier and other auxiliary agents. The early field test of granules began in 1946. In the early 1950s, granules were widely used in the United States, and in the early 1960s, they were widely used in Japan. In the late 1960s, due to the development of environmental science, pesticide granules were widely used all over the world to avoid the pollution of the environment and crops caused by particle drift when pesticide powders were spread. The development of granules in China was mainly in the late 1970s. According to the statistics of the Ministry of Chemical Industry in 1989, granules accounted for about 7% of the total pesticide preparations.
The reason why granules can become a commonly used pesticide is that they have many incomparable characteristics. The characteristics of granules are:
① The direction of spraying makes the spreading agent fully reach the target organism and is beneficial to biological safety such as natural enemies;
② The drug particles do not attach to the stems and leaves of the plants, so as to avoid direct contact with them to cause drug damage;
③ No dust flying and environmental pollution during application;
④ During the application process, it can reduce the amount of medicine attached to or inhaled by the operator to avoid poisoning accidents;
⑤ Reduce the toxicity of highly toxic pesticides to avoid human and animal poisoning;
⑥ It can control the release rate of the effective ingredients in the granules and prolong the validity period;
⑦ Easy to use and high efficiency.
Some incomparable characteristics of granule make it a better medicament.
Microcapsule suspension (CS)
Microcapsule suspending agent pesticide refers to the pesticide dosage form that uses natural or synthetic polymer materials to form a micro container with core-shell structure, encapsulates the pesticide in it, and suspends it in water. The utility model comprises a capsule wall and a capsule core. The capsule core is an effective component and solvent of pesticides, and the capsule wall is a polymer material for film formation. This dosage form is divided into continuous phase and discontinuous phase. The continuous phase is water and additives, and the discontinuous phase is coated pesticide microcapsules.
The appearance of microcapsule suspension agent is a viscous flowing liquid, similar to water emulsion and water suspension agent. The shape of the microcapsule is spherical, rugby shaped, grain shaped or other shapes of suspended liquid. The diameter of microcapsules is generally 3-30 microns. It is about the size of millet and mung bean when observed under a 400 fold microscope.
Characteristics of microcapsule suspension pesticide:
Advantage:
1. The residual effect period lasts for 80-120 days (the residual effect period can be controlled manually as required). The pesticide ingredients are released slowly after application, which can ensure the effect of one season of application at a time, saving the medicine, saving the working hours, and taking the advantage of leisure;
2. The exposure toxicity and odor are greatly reduced, so that the operator is free from harm;
3. It is harmless and can avoid the harm of chemicals to seeds and seedlings when it is used for seed dressing;
4. The active ingredients are isolated from water and alkaline pesticides, and the stability will not be affected when they are used together with alkaline pesticides;
5. The amount of organic solvent is reduced by 30-70%, which greatly reduces the environmental pollution caused by harmful aromatic hydrocarbons and is conducive to environmental protection.
6. The drugs used in the flowering period of fruit trees are harmless to beneficial organisms such as bees and play a role in protecting natural enemies.
Disadvantages: The effectiveness is reduced, and it is not suitable for the prevention and control objects requiring fast knockdown speed.
In addition to the above dosage forms, there are also many commonly used dosage forms such as smoke, aerosol, ultra-low volume preparations, fumigants, etc. They shall be applied to agricultural production according to needs and conditions.