| Copper Clad Laminate(CCL) is a kind of basic materials for the electronics industry, mainly for manufacturing printed circuit boards,and it is widely used in electronic communications and instrumentation. At present,the production of epoxy CCL is dealt with traditionally in halogenated flame-retardant or phosphorus-based methods,but halogenated or phosphorus-containing epoxy resin materials in the combustion and waste will be dealt with the release of a toxic or carcinogenic substance. As people's awareness of environmental protection strengthening, environmental protection laws and regulations establishing, the market for environmentally friendly products perfecting, as well as the growing demand increasing,the development of a kind of more environmentally friendly material used in CCL is a need to resolve important issue.In this paper, a kind of benzoxazine was synthesized with solvent-free methods, tested its melting point and the solubility and free phenol content,and it was also analyzed by H-NMR and FTIR.With it matching hydantoin epoxy resin, a new mixed resin system was prepared. Then the curing reaction kinetics was studied by DSC,a reasonable curing process was established and the glass transition temperature, thermal stability and flame retardant properties were characterized.The results show that the product of the reaction of the benzoxazine and hydantoin epoxy resin is a new blend resin system;the entire process of curing reaction is not isolated phenomenon;the curing reaction is exothermic reaction, curing process for 120℃/3h+150℃/2h+180℃/3h after treatment process for the 200℃/2h;Tg is 144℃,higher than the commonly used Tetrabromobisphenol A flame retardant epoxy resin.TGA tests show that the resin has more good thermal stability and the initial decomposition temperature of more than 300℃.Oxygen index test shows that when BZ/EP is a certain percentage, the maximum oxygen index is 32.0,so it is much flame- retardant.Then,the mixed resins system of BZ/EP as the base resins impregnated glass fiber cloth, which was prepared a new type of halogen-free and non-phosphorus flame retardant substrate materials used in CCL,and add-on flame retardant–Mg(OH)2 was studied for the substrate used in CCL on the properties of composite materials. The results reveal that for this new halogen-free and non-phosphorus flame retardant substrate material used in CCL, when content is 10%, its impact strength is 131.3 KJ/m2 and flexural strength is 483.6 MPa; the magnitude of electrical surface resistivity and electrical volume resistivity of the substrate material is1014, so this material has a very good electrical insulation, and its flame retardant properties meet UL94V-0, and the addition of Mg (OH) 2 has a good smoke suppression effect.Finally, by the use of LOI, TGA, SEM and XPS, for the matrix resin and its substrate material, their flame-retardant properties were done a further explanation and their flame-retardant mechanism was originally studied. The research shows that In the process of combustion, heat resistant and the amount of carbon has a certain impact for flame-retardant properties, and the flame retardance of the resin acted both in the vapor phase and in the condensed phase. The resinous composites after burning with Mg(OH)2 show that there are great amounts of tiny articles-MgO in the surface of the interior charred layer. This is why the big specific surface area appears in the charred layer, which will also absorb smoke and flammability objects. |
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