Si-69 is a kind of silane coupling agent with multiple functional groups successfully used in rubber industry to improve modulus and tensile strength of rubber, to reduce the compound viscosity and save process energy consumption. It’s especially applicable for polymers with double bond or rubber formulation with hydroxyl fillers. The suitable fillers include silica, silicate, clay, etc. The suitable rubber include natural rubber (NR), Butadiene styrene rubber (SBR), Isoprene rubber (IR), Butadiene rubber (BR), Acrylonitrile butadiene rubber (NBR), Ethylene propylene diene rubber (EPDM), etc.