[0089] Example two, formula components of alachlor microcapsule suspension
[0090]
[0091] Heat 20 kg of the herbicide alachlor to a molten state, add 2 kg of polyphenyl polymethylene polyisocyanate PAPI (Bayer, Germany) and 1 kg of diphenylmethane diisocyanate MDI (Yantai Wanhua Polyurethane Co., Ltd.) Stir evenly (oil phase); add 0.2kg of methyl cellulose CMC to 50kg of deionized water, stir evenly (water phase), put the prepared oil phase materials into the water phase and turn on high-speed homogenization to form a stable O /W emulsion; start stirring (maintain 400 revolutions/min), then heat the homogenized emulsion to 40°C, and slowly add 0.5 kg of ethylene diamine to maintain a stable curing temperature of the capsule wall material for 20 hours, and then add the lubricant Wet agent NNO 3.0kg (Shanghai Tiantan Auxiliary Factory), dispersant sodium lignosulfonate (made in Russia) 5.0kg, disintegrant modified starch 1.0kg, white carbon black 17kg, pH regulator 0.2kg glacial acetic acid, 0.4 kg of organosilicon defoamer is stirred evenly to obtain 20% alachlor microcapsule suspension.
[0092] Please refer to figure 1 , figure 1 It is a schematic diagram of the spray drying granulation process used in the embodiment of the present invention. The spray dryer used in this example is a ZPG-150 spray dryer (Changzhou Xianfeng Drying Engineering Co., Ltd.), which includes the slurry storage tank 1, the feed pump 2, the nozzle 3, and the atomizer 4 connected in sequence by pipelines. , Drying tower 5, cyclone separator 6, induced draft fan 7, water film dust collector 8, using steam heat exchanger for heating. An inlet thermometer 91 is provided at the hot air inlet, and an outlet thermometer 91 is provided at the outlet. The main technical parameters of the ZPG-150 spray dryer equipment are: water evaporation 50-100Kg/h; tower diameter/tower height 4M/9.7M; operating temperature: inlet temperature 50-100/outlet temperature 30-70; atomization LPG-150; Rotation speed: 18000r.pm; Disk diameter: 150mm; Steam consumption: about 325~375kg/h; Drying system: Open circulation system; Feeding method: High-pressure pump stable feeding; Hot air contact method: Parallel flow; Atomization method: centrifugal atomization.
[0093] When granulating, control the temperature of the hot air inlet in the spray dryer at 80℃, pour the 20% alachlor microcapsule suspension agent into the slurry storage tank, and pump it into the atomizer through the feed pump to atomize the slurry , And then produce high-speed rotation in the drying tower, and form spherical droplets after rotating and spraying from the atomizer nozzle. After the droplets are heated, the surface moisture evaporates rapidly to form porous solid particles, which are finally dried to form microcapsule granules. Finally, 50 kg of alachlor microcapsule granules with an appearance of brown granules, a moisture control of about 3% and a content of about 40%, are obtained.
[0094] Example 3: 28% chlorpyrifos microcapsule suspension
[0095]
[0096] Heat 28 kg of chlorpyrifos original drug into a hot melt state, then add 3.0 kg of polyphenyl polymethylene polyisocyanate PAPI (Bayer, Germany) and 1.0 kg of toluene diisocyanate TDI (Cangzhou Dahua TDI Co., Ltd.) and stir well It is the oil phase; add 1.0kg of emulsifier NP-10 (Nanjing Taihua Co., Ltd.), 5kg of binder xanthan gum (2%) aqueous solution into 57.5kg of deionized water and stir to form the water phase; From the oil phase to the water phase and turn on high-speed homogenization to form a stable O/W emulsion; turn on the stirring (maintain 1000 revolutions/min), and then heat the homogenized emulsion to 60°C, while slowly adding 0.5 kg of diethylene Triamine, maintain a stable curing temperature of the capsule wall material for 8 hours, then add 1.0kg of EO/PO block polyether dispersant DP-30, wetting agent NNO 2kg (Shanghai Tiantan Auxiliary Factory), preservative sodium benzoate 0.05 kg, 0.2 kg of organosilicon defoaming agent, stir evenly to obtain 28% chlorpyrifos microcapsule suspension.
[0097] Similarly, use ZPG-150 spray dryer to granulate, control the temperature of the hot air inlet at 70°C, pour 28% chlorpyrifos microcapsule suspension into the slurry storage tank, and pump it into the atomizer through the feed pump to make the slurry After atomization, high-speed rotation is generated in the drying tower, and spherical droplets are formed after rotating and spraying from the atomizer nozzle. After the droplets are heated, the surface moisture evaporates rapidly to form porous solid particles, which are finally dried to form microcapsule granules. Finally, 40 kg of chlorpyrifos microcapsule granules with an appearance of yellow-brown particles, a moisture content of about 2.5% and a content of about 72% are obtained.
[0098] The main technical indicators of the product of the present invention are as follows:
[0099]
[0100] Example three
[0101] The invention has the following advantages because the pesticide is microencapsulated first and then made into granules:
[0102] 1. It inhibits the adverse effects of many environmental factors such as light, heat, air, rain, soil, microorganisms and other chemical substances on the active ingredients of pesticides, reduces the rate of volatilization, decomposition, oxidation, degradation and loss of pesticides, thereby enhancing The stability of pesticides expands the scope of use.
[0103] 2. The content of active ingredients in microcapsule granules is generally between 5% and 75%. Compared with emulsifiable concentrate, the active ingredients are concentrated in the heart of the capsule. Due to the effect of solid particles after use, the adhesion strength is strengthened and it is not easy to volatilize with the solvent, which is also a factor for the improvement of the control effect.
[0104] 3. Reduce the acute toxicity of the original medicine, reduce the irritation to humans and animals, environmental pollution and phytotoxicity to crops, and it is safer and more reliable for humans and animals or the ecological environment.
[0105] 4. After the microencapsulation, the permeability of the active ingredients through the capsule wall material can be controlled artificially, and the slow release rate can be designed in advance. Due to the protection of the capsule skin, the degradation speed of the active ingredients is slowed down, and the duration of pesticides can be extended by 3 to 10 times. Prolonging the effective period can improve the control effect, reduce the frequency of pesticide application and reduce agricultural costs.
[0106] 5. Effectively reduce organic solvents such as toluene and xylene, thereby effectively reducing environmental pollution and reducing the usage of organic solvents.
[0107] 6. Good storage stability and physical and chemical stability, fast disintegration speed of particles and good use effect.
[0108] 7. Compared with wettable powders and suspending agents, the content of active ingredients is high, the relative density of the product is large, and the volume is small, which is convenient for packaging, storage and transportation.