高速混合法制备80%烯酰吗啉水分散粒剂

High-Speed Mixed Granulation for Producing 80% Dimethomorph Water-Dispersible Granules

研究了高速混合法工艺条件对80%烯酰吗啉水分散粒剂(Dimethomorph water-dispersible granules,DWG)粒的影响。结果发现DWG粒径随用水量增加而增大,随搅拌时间和搅拌速度增加而减小。用水量为18%、搅拌时间240s、搅拌速度为16000r·min-1时,DWG集中分布在0.45～0.9mm,其百分比达68.65%。进一步考察了分散剂用量颗粒大小和干燥时间对DWG悬浮率和崩解性及热贮稳定性的影响,同时测定其悬浮液的稳定性和粒径分布。发现分剂用量增加有利于提高其性能:分散剂由5%增至15%时,悬浮率由89.48%增至97.81%,崩解时间由73s降至32s,浮液总沉淀层厚度由0.41mm降至0.37mm,平均粒径由10.02μm降至4.34μm,分散剂用量超过为8%时,热贮稳性明显变好;DWG颗粒由大于0.9mm降至小于0.2mm时,悬浮率由56.34%增至68.85%,崩解时间由79s降至32总沉淀层厚度由0.59mm降至0.44mm,平均粒径由17.64μm降至7.59μm,其颗粒大小对热贮稳定性影响不大。干燥时间增加,DWG的崩解性和热贮稳定性明显降低,而悬浮液稳定性则先降低后升高。

Effects of the technical parameters of high-speed mixed granulation process for preparing 80% dimethomorph water-dispersible granules （DWG） on the granule size distribution of the prepared DWG were investigated. Experiments show that the granule size increases with increasing water amount used , while decreases with increasing mixing time and speed; and a good DWG granule size distribution of 68.65% DWG granules with size within the range of 0.45~0.9 mm can be obtained by using water adding amount of 18%, mixing speed of 16000 r.min-1 and mixing time of 240 s. Furthermore, the influences of dispersant content, DWG granule size and drying time on suspending ratio, disintegrativity, stability of active ingredients after heat storage and stability of DWG suspensions were also investigated. It was found that, when the dispersant content increases from 5% to 15%, the suspending ratio increases from 89.94% to 97.81%, the disintegrative time decreases from 73 s to 32 s, the sediment thickness decreases from 0.41 mm to 0.37 mm and the volume average particle size of the suspensions decreases from 10.02μm to 4.34 μm, The stability of active ingredients after heat storage of the DWG with dispersant content of 8% is much better than that of DWG with dispersant content of 5%. The results show that, when the DWG granule size decreases, the suspending ratio and disintegrativity of DWG improves, while the sediment thickness and the volume average particle size of the suspensions decreases With increasing drying time, the suspending ratio decreases generally, the disintegrativity and the stability after heat storage become worse obviously and the stability of DWG suspensions becomes worse at first and then turns to become better. It may come to the conclusion that the drying time affects the disintegrativity and the stability of active ingredients after heat storage remarkably, while dispersant content and DWG granule size are the key factors influencing the suspending ratio and stability of DWG suspensions.