Enhancing adhesion properties between rubber compound and brass-plated steel cord by incorporating silica into rubber

The effect of adding silica to rubber compound on its, adhesion to brass-pl ated steel cord was investigated. Silica reduced the curing rate and enhanc ed the physical properties of the rubber compound, especially after thermal aging, when 20 phr of silica was added, The pull-out force increased consi derably with silica loading both before and after thermal aging. Although i mprovements in the rubber coverage were not significant in the unaged start : with silica loading, they users considerably enhanced after aging, especi ally after salt solution aging, The adhesion interphase between silica-cont aining rubber compound and brass film also appeared to differ from samples without silica loading. With silica loading, overgrowth of the adhesion int erphase was suppressed, as was the proliferation of sulfides and oxides of copper and zinc to rubber bulb after humidity and salt solution aging treat ments, The suppression of the excess growth of the adhesion interphase and the improvement of the rubber properties under thermal, humidity, and salt solution aging conditions are considered to be the effects of silica loadin g, resulting in good adhesion durability after aging.