高导热低介电性单组分EP灌封胶的研制

以双酚A型环氧树脂(EP)为基体树脂、线性酚醛树脂(PF)和双氰胺为固化剂、烯丙基缩水甘油醚(AGE)为活性稀释剂、2-乙基-4-甲基咪唑为固化促进剂、氮化硼(BN)和三氧化二铝(A12O3)为导热填料,制备单组分EP灌封胶。采用单因素试验法优选出制备灌封胶的最佳工艺条件,并对灌封胶的导热系数、介电常数、剪切强度和玻璃化转变温度(Tg)等进行了表征。结果表明:制备高导热低介电性单组分EP灌封胶的最佳工艺条件是m(EP)∶m(PF)∶m(活性稀释剂)∶m(BN)=10∶3∶2∶6、w(固化促进剂)=w(流平剂)=0.5%(相对于EP质量而言)和固化条件为"120℃/0.5 h→170℃/1 h",此时其剪切强度为42.37 MPa、介电常数为4.6和导热系数为1.214 W/(m.K)。

Study on preparing one-component EP pouring sealant with higher thermal conductivity and lower dielectric property

With bisphenol A type epoxy resin(EP) as matrix resin,linear phenolic resin(PF) and dicyandiamide as curing agents,allyl glycidyl ether(AGE) as reactive diluent,2-ethyl-4-methyl imidazole as curing catalyst,boron nitride(BN) and alumina(A12O3) as thermal conducting fillers,an one-component EP pouring sealant was prepared.The optimal process conditions of preparing pouring sealant were preferred by single-factor experiment method,and the thermal conductivity,dielectric constant,shear strength and glass transition temperature(Tg) of pouring sealant were characterized.The results showed that the optimal process conditions of preparing one-component EP pouring sealant with higher thermal conductivity and lower dielectric property were obtained when mass ratio of m(EP)∶m(PF)∶m(reactive diluent)∶m(BN) was 10∶3∶2∶6,mass fractions of curing catalyst or levelling agent were all 0.5% in EP,and curing condition was "120 ℃/0.5 h→170 ℃/1 h".Here,its shear strength,dielectric constant and thermal conductivity were 42.37 MPa,4.6 and 1.214 W/(m.K) respectively.