导电有机硅密封剂的研究

以镀银镍粉为导电填料、端羟基聚二甲基硅氧烷为基胶、经硅烷表面处理的白炭黑为补强填料,有机锡为催化剂,制成了高导电室温硫化双组分有机硅密封剂;研究了导电机理、镀银镍粉的加入量对有机硅密封剂的导电性能和电磁屏蔽性能的影响。结果表明,当镀银镍粉的体积分数超过25%时,有机硅密封剂的电性能明显提高;当镀银镍粉的体积分数达到35%以上时,有机硅密封剂的体积电阻率下降近10个数量级;当镀银镍粉的体积分数为50.5%时,有机硅密封剂在高频率范围具有良好的电磁屏蔽性能。

Study on the electrically conductive silicone sealant

With the conductive filler of silver-coated nickel powder,basic gel of hydroxyl-ended polydimethyl siloxane,reinforce filler of fumed silica whose surface treated by silane and the catalyst of organic stannum,the high conductive two-component RTV silicone sealant was prepared.The conductive organism,the influence between the quantity of the silver-coated nickel powder and the conductive capability of sealant and electromagnetism shield performance were discussed.When the volume fraction of the silver-coated nickel powder exceeded 25%,sealant's conductivity was greatly improved.When the volume fraction of the silver-coated nickel powder reached 35% or above,volume resistivity of the silicone sealant decreased to 10 orders of magnitude.As the volume fraction of the silver-coated nickel powder was 50.5%,the silicone sealant had good electromagnetic shielding property during high frequency.