Study On Bromize Epoxy Cured By Novolacs

The heat resistance, changing color resistance and dielectric properties of copper-clad laminates can be improved when novolacs replace the dicyandiamide (DICY) as curing agents for bromize epoxy. Therefore they can satisfy the development of copper-clad laminates for higher performances and have a bright applied prospect.The molecular structure of bisphenol F novolac(BPFN) designed by our research group haven't been reported on domestic and oversea literatures. The molecular weight and softening point of bisphenol A novolac (BPAN) and BPFN synthesized in this thesis were characterized by Laser Light Scattering Analyses (LLSA) and Softening-point test. The results showed that the (Mw)|-of BPFN and BPAN were 1600g/mol and 1400g/mol, and the softening-points were 75℃ and 106℃ respectively. That methylene linking benzene ring in the chain structure of BPAN and BPFN was in 2,2' location of phenyl was revealled by Flourier Transmit Infrared (FTIR).The curing characteristics of bromize epoxy A80/novolacs were evaluated by Differential Scanning Calorimetry (DSC) and Gel time. The results indicated that the curing temperature was above 200℃ and curing reaction was very slow without accelerants. All of 2,4,6-tri (dimethylamine methylene) phenol (DMP-30), hexamethylenetetramine (HMTA) and 2-methylimidazole (2-MZ) could accelerate the reaction between A80 and novolacs. The gel time was decreased dramatically with increasing of curing temperature. The temperatures of exothermic peak moved to low temperature with increasing of accelerant content. The curing technique of A80/ novolacs/2-MZ(0.1phr) systems determined by DSC and FTIR methods was 150℃/2h.The dielectric, heat resistance, mechanical and other properties of cured resins and copper-clad laminates made from A80/novolacs/accelerants were studied. The comprehensive properties of A80/BPFN/accelerants systems were the best. The properties of copper-clad laminates (CEM-3) made from A80/BPFN/2-MZ had achieved the industry standard (IPC-4101) and BPFN would replace PN as a curingagent for A80 in fabricating CEM-3 copper-clad laminates.