Study On The New Type Electromagnetic Safety Coating

The electromagnetic safety conductive paints have a great future in this realm because of its low cost, simple craft, good applicability, without special equipments etc. We studied systematically the effect of some factors, such as the adding amount of the conductive filling and organobentonite, the dosage and the adding method of KH-550 aminosilane coupling agent, the category of the metal that coated, to the conductive coating on its electric conductivity and its electromagnetic shielding effectiveness, and found out their optimal adding amount and method. In this thesis, the research and the development of electromagnetic safety materials have been reviewed. On the basis of the theory of the electromagnetic field, the electromagnetic wave and the interaction between the materials and the electromagnetic wave, several kinds of new composites have been prepared by adopting new methods, electroless plating and a kind of method of Fe replacement chemical aggradation, and studied by advanced measuring and analyzing components. The wave absorbing properties and electromagnetic shielding effectivenesss of composites of the above have been studied systematically at the frequency range from 2GHz to ISGHz and from 100KHz to 1. 5GHz. ,The properties of the coating with the content of 65~75% copper powder filling are the best. Coupling agent and organobentonite used as additive in the coating can improve the dispersion and the oxidation resistivity of the copper powder filling. When adding amount of coupling agent and organobentonite is 0. 2~0. 3% and 2% respectively, the electricresistivity of the layers is the lowest.In this paper, the electroless plating was utilized to coat Cu, Ni and Ag on the surface of cenosphere and graphite to manufacture the conductive composites. This kinds of particles was used to make electromagnetic safety coating, furthermore, the properties of the electromagnetic shielding or wave absorbing of the coatings were investigated. Proved by Experiment, the electroless plating craft, which was used for manufacturing the conductive composites, is applicable to most inorganic powder and fibre materials and is different for distinct materials. The method of Fe replacement chemical aggradation adopted for manufacturing conductive filling, in which craft iron is used as reducing agent to reduce copper ion to be metallic copper, is simple, low, efficient, but not applicable for fibre materials. Firstly inorganic powder can be only plated a thick copper layer. We analyzed the mechanism of this kind of new electroless plating method. Proved by experiment, the properties of wave absorbing and electromagnetic shielding made a little difference between the composites made by this kinds of metal-coated method and the ones made by the traditional electroless plating.