表面処理によるMg合金とゴムとの直接加硫接着

抄録

Mg alloys (AZ31) have been treated with various aqueous alkali or acid solution, and then were adhered to SBR-NR rubber. After treatment with aqueous NaOH, it was found that oxidation of Mg is promoted and extra hydroxides are formed in the top layers of Mg alloys in thickness about 70nm. In this case, extremely high adhesion strength was obtained, and the peel strength of rubber-Mg samples increased with higher treatment temperature or longer treatment time, may be due to the increasing thickness of hydroxide layers. The rubber-to-Mg interface was analyzed by XPS depth profile following vulcanization of rubber against a Mg alloy surface. From the interface analysis results, it is suggested that the extra hydroxides formed in the top layers of Mg alloys can reduce the formation of ZnS at interface, since the hydroxides react with stearic acid in rubber and it seems to compete against the reaction between ZnO and stearic acid during vulcanization.