水性环氧乳液非离子乳化剂的制备

Preparation of Non-Ionic Emulsifier for Waterborne Epoxy Latex

非离子乳化剂是以聚乙二醇和环氧树脂为原料,其中聚乙二醇具有大量醚键,可作为乳化剂的亲水链段;环氧树脂为亲油端链段。环氧树脂上的环氧基与聚乙二醇上的伯羟基发生反应,生成的环氧树脂与聚乙二醇的高分子交替缩聚产物具有一个醚键和一个仲羟基。详细分析了催化剂、反应温度、时间、物料比例对此乳化剂合成的影响,并确定了乳化剂合成的设备及工艺。最终选用环氧E20和聚乙二醇4000为主要原料合成非离子型乳化剂,使用三氟化硼乙醚络合物为催化剂,反应时间控制在7~8 h,反应温度65℃,环氧基与羟基的比例控制在1. 20~1. 25之间,所制备的乳化剂性能较好,可以满足制备乳液的要求,所制备的乳液可储存15 d不返粗,可以与颜填料混合研磨。

The non-ionic emulsifier was prepared by polyethylene glycol and epoxy resin.polyethylene glycol was used as the hydropilic chain of emulsifier,because of its large number of ether groups. The epoxy resin was used as hydrophobic segment. An ether group and a secondary hydroxyl group were formed during the reaction of the epoxy group on the epoxy resin reacts with the primary hydroxyl group on polyethylene glycol,forming an altrnative condensation polymer product with both ether group and secondary hydroxyl group The effects of catalyst,reaction temperature and time and materials ratio on the synthesis of emulsifier were analyzed in detial. The equipment and process and of emulsifier synthesis were finalized.Finally the epoxy E20 and polyethylene glycol 4 000 was choosed as the main raw materials to prepare the nonionic emulsifier. The boron trifluoride ether complex was used as catalyst. The reaction time was controled at 7~8 h. The reaction temperature was 65 ℃. The proportion of the epoxy groups and hydroxyl was controled between 1. 20~1. 25. The prepraed emulsifier showed good performance,which met the requirements for preparation of latex. The latex will not be flocculated after heat storage for 15 days. It can be co-grinded with pigments and fillers.