N-Phenyl-o-phenylenediamine is primarily used as an antioxidant and antiozonant in the rubber industry. It helps to extend the lifespan of rubber products by protecting them against degradation caused by oxygen and ozone exposure. This chemical is particularly valuable in the production of tires, belts, and hoses, where durability and resistance to environmental factors are critical. Additionally, it is employed in the synthesis of dyes and pigments, contributing to the coloration of textiles, plastics, and other materials. Its ability to stabilize and enhance the properties of various materials makes it a versatile compound in industrial applications.