乳液型消泡剂的制备工艺研究

摘要

Silicone oil intermediate was prepared by polycondensation with by-products of high-low boiling mixture, and then the emulsion defoamer was perpared by adding fumed silica, complex emulsion, tackifier and water into the silicone oil intermediates in order, stirring with high speed.The optimal preparing condi-tions of the silicone oil intermediates is that 100 g high boiling materials, 100 g low boiling materials, 50 g ethanol, 50 g water, reaction temperature between 50 to 55℃.Dynamic viscosity, refractive index, yielding of silicone oil intermediates is 135 mm2/s, 1.4700~1.5200, 71.20% respectively.The optimal formula of deformer is that 30 g silicone oil intermediates, 6 g silicon dioxide, 8 g emulsion, 4 g polyvinyl alcohol, and some water.The surface tensions of deformer are between 45 to 48 mN/m2 , stratified and disperse rapidly in the water without floccules.The bubble time of the deformer is less than 10 second and the particle size of de-former is 0.12 to 0.15 nm.%以有机硅副产的高、低沸混合物为原料，通过缩聚反应制得硅油中间体；再依次加入气相法白炭黑、复合乳化剂、增稠剂和适量水进行配比，经高速乳化后制得乳液型消泡剂。硅油中间体最佳制备工艺为：高沸物100 g、低沸物100 g、乙醇100 g、水50 g、反应温度50～55℃，所得硅油中间体的黏度为135 mm2／s、折射率为1.4700～1.5200，收率71.20％；消泡剂的最佳配方为：硅油中间体30 g，气相法白炭黑6 g，乳化剂8 g，聚乙烯醇4 g，去离子水余量。该消泡剂的表面张力为45～48 mN／m2，动态稳定性为不分层，在水中迅速分散并无絮状物存在，消泡时间小于10 s，乳液粒径为0.12～0.15 nm。