Abstract
Direct adhesion between natural rubber (NR) and nickel plated steel cords (nickel cords) during vulcanization has been investigated to develop new type steel cord for tire. Nickel plated cords were not adhered with NR compounds composed of sulfur and sulfenamide type accelerators. The NR compound was adhered to nickel cords treated with the monosodium salt of triazine trithiol. The highest pull-out strength and rubber coverage in NR-nickel adherends were obtained when nickel cords were treated with 0.4% TTN aqueous solution at 80°C for 15min. Pull-out strength and rubber coverage in the adherends were influenced by TTN concentration, treating time and temperature, the amount and kind of accelerators, sulfur concentration, and Co salt concentration. The water resistance of the adherends were influenced by sulfur concentration, accelerators, and Co salt. Particularly, the presence of Co salt in vulcanizates decreased markedly the pull-out strength and rubber coverage of NR-nickel adherends.
