70%增效型吡虫啉水分散粒剂的制备及其性能评价

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

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。

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 I m（silica） ： m（kaolin） = 1 ： 4 I （ 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.