RUBBER ADHESION OF AN ELECTROPLATED ZINC-SILICA DISPERSION COATING

Abstract

The effect of the surface morphology and silane coupling treatment in an electroplated zinc-silica dispersion coating on the adhesion of rubber has been studied by shear tensile test. Rubber adhesion strength to an electroplated zinc and zinc-silica dispersion coatings with a surface roughness of 7μm were about 2 to 5 times those with smooth surface. However, the adhesive failure after shear tensile test occurred predominantly at the interface of electrodeposit/primer. On the other hand, the adhesion of rubber to an electroplated zinc-silica dispersion coatings treated with silane coupling agent after salt spray test for 100hrs had the same adhesion strength as that of the initial adhesion, and no addhesive failure occurred at the interface of electrodeposit/primer. In addition, the electroplated zinc-silica dispersion coatings treated with silane coupling agent demonstrated far better rubber adhesion even when the primer was not used. The results are discussed in terms of the synergistic effect of the controlled surface morphology of the electrodeposit and the chemical bonding based on the silane coupling agent fixed onto the electrodeposit.