Ditridecyl phthalate is primarily used as a plasticizer in the production of flexible polyvinyl chloride (PVC) products. It enhances the flexibility, durability, and workability of PVC, making it suitable for applications such as cables, wires, flooring, and automotive parts. Its high molecular weight contributes to low volatility, ensuring long-term performance in demanding environments. Additionally, it is utilized in adhesives, sealants, and coatings to improve their elasticity and resistance to temperature variations. Its compatibility with various polymers also makes it valuable in industrial and consumer goods where stability and flexibility are critical.