水溶性低压电子变压器绝缘漆制备及性能研究

Preparation and Properties of Water-soluble Insulating Varnish for Low Voltage Electronic Transformer

为了对现有有机溶剂低压电子变压器绝缘漆进行环保升级,以水溶性聚氨酯树脂为基体、水溶性苯并噁嗪树脂为固化剂制备水溶性低压电子变压器绝缘漆。通过对绝缘漆的水溶性、电气强度、粘结强度、耐焊锡性能和耐温等级进行评价,分析聚氨酯配方中二羟甲基丙酸(DMPA)用量、乙二醇丁醚用量和绝缘漆中苯并噁嗪树脂含量等因素的影响,确定聚氨酯树脂和绝缘漆的最佳配方。结果表明:当DMPA用量为二苯基甲烷二异氰酸酯(MDI)摩尔分数的16%,乙二醇用量为MDI摩尔分数的30%,固化剂用量为聚氨酯树脂质量分数的15%时,该绝缘漆的电气强度为69 kV/mm,粘结强度为2.9 N/mm^2,温度指数为152.8。

In order to improve the environmental protection level of existing insulating varnish with organic solvent for low voltage electronic transformer, a water-soluble insulating varnish for low voltage electronic transformer was prepared using water-soluble polyurethane resin as matrix and water-soluble benzoxazine resin as curing agent. Its water solubility, electric strength, bonding strength, solder resistance, and heat resistance were studied, and the effects of the amount of dimethylolpropionic acid（DMPA） and ethylene glycol butyl ether in the formula of polyurethane and the amount of benzoxazine in the insulating varnish were analyzed. The optimum formula of polyurethane resin and insulating varnish was confirmed.The results show that when the content of DMPA and ethylene glycol is 16% and 30% of mole fraction of methylene diphenyl diisocyanate（MDI）, respectively, and the content of curing agent is 15% of mass fraction of polyurethane resin, the electric strength of the insulating varnish is 69 kV/mm, the bonding strength is 2.9 N/mm^2, and the temperature index is 152.8.