Diisobutyl 3,6-dihydroxyphthalate is primarily used as a plasticizer in the production of flexible polymers and resins. It enhances the flexibility, durability, and workability of materials such as PVC, making them suitable for applications in the manufacturing of cables, hoses, and synthetic leather. Additionally, it is employed in coatings and adhesives to improve their performance and adhesion properties. Its compatibility with various polymers also makes it useful in the formulation of inks and dyes, where it aids in achieving consistent color distribution and stability.