2006 年 9 巻 2 号 p. 108-112
Acrylonitrile butadiene rubber (NBR) has been widely used in the electronics materials field because NBR has shown good compatibility with epoxy resins. However, it is not clear if the use of NBR for epoxy compounds is the best choice because the acrylonitrile units in NBR have poor electric properties. Taking both compatibility and electric properties into consideration, we have developed a new modified crosslinked styrene butadiene rubber (SBR) particle, which has a diameter of 70nm. This rubber showed a lower dielectric constant and a lower dissipation factor than NBR. Furthermore, these electric properties have been improved in the epoxy-phenol-SBR formulation. We found it possible to reduce the elastic modulus without sacrificing the electric properties.