高导热低黏度新能源汽车用灌封胶的制备及性能研究

Preparation and Performance of Encapsulant with High Thermal Conductivity and Low Viscosity for New Energy Automobile

采用双酚A型环氧为基体树脂,氧化铝为主填料,氢氧化铝和氢氧化镁为阻燃剂,研制了一种适用于新能源汽车电机的高导热低黏度灌封胶,分析了填料、阻燃剂、偶联剂种类及用量、工艺温度及时间等因素对灌封胶性能的影响。结果表明:较佳配方下制得的灌封胶,60℃下的黏度为800~1 200 mPa·s,80℃下可操作时间大于1 h,便于新能源汽车电机定子的真空脱泡及灌封操作;固化物热导率达到1.4 W/(m·K),阻燃等级达到UL94 V-0级,密度为1.6~1.8 g/cm^3,弯曲强度大于70 MPa,拉伸强度大于25 MPa,具有优良的耐开裂性,能满足新能源汽车电机的工装要求。

A kind of encapsulant with high thermal conductivity and low viscosity for new energe automobile motors was prepared using bisphenol A epoxy resin as matrix, aluminium oxide as filler, aluminium hydroxide and magnesium hydroxide as flame retardants. The effect of type and dosage of filler, flame retardant, and coupling agent and processing temperature and time on the properties of the encapsulant were investigated. The results show that the viscosity of the encapsulant prepared by an optimum formula at 60 ℃ is ranging from 800 mPa.s to 1 200 mPa.s, and the operable time at 80 ℃ is more than lh, which is convenient for vacuum defoamation and encapsulation for new energy automobile motor stator. The thermal conductivity of the cured product reaches to 1.4 W/（m. K）, its flame retardant rating reaches to UL94 V-0 level, its density is from 1.6 g/cm^3 to 1.8 g/cm^3, its bending strength and tensile strength are more than 70 MPa and 25 MPa, respectively, and it has excellent anti-cracking ability, which can meet the requirements of new energy automobile motors.