Zinc oxide : white hexagonal crystals or powder. Soluble in acid, sodium hydroxide, ammonium chloride.... 1. we ... .037% Copper Oxide 0.02% Use:1 Mainly used for rubber or cable industry as a reinforcing agent and active agent, and ... , paper, matches, and the pharmaceutical industry. In the rubber industry as natural rubber, synthetic rubber and latex vulcanization active agents, reinforcing agents and ...