70%增效型吡虫啉水分散粒剂的制备及其性能评价

采用滚动式挤压造粒法,通过配方筛选成功制备了70%增效型吡虫啉水分散粒剂(WG),并考察了增效剂胡椒基丁醚(PB)对制剂的热贮稳定性、表面张力及杀虫活性等性能的影响。优化配方(以质量分数计)为:吡虫啉原药(71.9%),增效剂PB(1.0%),分散剂MORWET-EFW(2.5%)、MORWET D-425或Tesperse 2700(5.0%),崩解剂硫酸铵(3.0%),粘结剂聚乙二醇(2.0%)和载体m(白炭黑):m(高岭土)=1:4] 14.6%。所制备的70%增效型吡虫啉WG热贮(54℃±2 ℃)14 d后有效成分降解率为1.27%(≤1.5%);其表面张力无明显改变;润湿分散性良好,悬浮率≥90%。对蚜虫的室内毒力测定结果显示,含有PB的70%吡虫啉WG的毒力是不含PB成品的6～7倍,表明PB具有极显著的增效作用。

Preparation and characteristics analysis of 70% synergistic imidacloprid water dispersible granule

With Rolling-extrusion granulation method,the optimum formulation of 70% synergistic imidacloprid water dispersible granules(WG) was screened.In addition,effects of synergist piperonyl butoxide(PB) on the thermal stability,surface tension and biological activity of the formulation were studied.The optimum formulation to prepare 70% synergistic imidacloprid WG were imidacloprid ammonium technical(71.9%),synergist PB(1.0%),MORWET-EFW(2.5%),MORWET D-425 or Tesperse 2700(5.0%),disintegration agent ammonium sulfate(3.0%),polyethylene glycol as a binder(2.0%),and carrier m(silica):m(kaolin)=1:4] (14.6%).The bioassay showed that the biological activity of imidacloprid WG with 1% PB was 6 to 7 times as high as that of WG without 1% PB.With good dispersion and a very significant synergies,the suspension rate of the WG with 1.0% PB was over 90%.Degradation composition rate of the WG with 1.0% PB was 1.27% after heat storage at(54±2) ℃ for 14 d and its surface tension was no obvious change.