Effect of bonding systems on the adhesion of nitrile rubber to nylon cord

A tricomponent system composed of resorcinol, hexamethylene tetramine (HMT), and hydrated silica was used as an adhesion promoter with a nitrile rubber (NBR) mix. The resorcinol was replaced by o-aminophenol, m-aminophenol, p-aminophenol, or m-phenylene diamine. The rubber-textile cord samples were subjected to aging or exposed to ionizing radiation and their adhesions were examined. The effect of the cross-link density of different nitrile rubber mixes on the adhesion was also studied. The results showed that aminophenols and m-phenylene diamine used have an effect on the adhesion. However, their adhesion levels are lower than those obtained by resorcinol. The results also showed that, on aging, m-aminophenol and m-phenylene diamine have either better stability or enhancement of adhesion levels than other bonding systems. On exposure to radiation, the results showed that the bonds formed between NBR mixes, containing different types of bonding material, and undipped nylon cords are more stable than those formed with dipped ones.