Dipentyl 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 materials, making it suitable for applications such as cables, hoses, and synthetic leather. Additionally, it is employed in the formulation of adhesives and coatings, where it improves the performance and longevity of the final product. Its compatibility with various polymers also makes it useful in the manufacturing of inks and sealants.