Effects of Cycrophenoxyphosphazen as a Halogen-free Flame Retardant on Morphologies and Properties of Cured Epoxy/NBR Blends as Adhesives for Flexible Printed Circuits (FPCs)

摘要

Morphologies (STEM micrographs) and tan d plotted against temperature indicated that CPP performs as a compatibilizer between cured epoxy and NBR. But, since the morphologies of micro-phase-separation were maintained and Tg's of cured epoxy phases were not much decreased by addition of CPP, the performance of CPP as a compatibilizer could be partial. Since elongation of cured blends was increased and tensile strength of them was decreased by addition of CPP, it was found that CPP also performs as a plasticizer. But, since the elongation of cured p-epoxy blends (A series) was much larger than that of cured bis-epoxy blends (B series) and the performance of tensile strength was almost same each other, CPP could show a more excellent performance on A systems than cured bis-epoxy blends (B series). The amount of phosphorus required to achieve the incombustibility of VTM-0 on cured p-epoxy blends (A series) was 2.5 wt%, while that on B systems was 2.0 wt%. The phenomena should be depend on that i.e., nitrogen besides phosphorus as a flame retardant is contained in CPP.Flexibility of cured p-epoxy blends (A series) was much improved when a CPP content was 17 wt%. But that of cured bis-epoxy blends (B series) was not improved. Although insulation reliability and ion migration resistance on both series reduced, they were in permissible ranges.