Dibutyl phthalate (diisobutyl PHTHALATE,DIBP) can be prepared by esterification reaction of isobutyl alcohol and phthalic anhydride. The structural type is C6H4 (cooch2ch (CH3) 2) 2. The refractive index is 1.488-1.492 (20℃,d). DIBP is a tasteless plasticizer with excellent heat and light stability and is the cheapest plasticizer for nitrocellulose. The density and freezing point of DIBP are lower than that of DBP (Dibutyl phthalate, CAS no.:84-74-2). has similar characteristics to DBP and can be used as a substitute. DIBP is used in nitrocellulose plastics, nail polish, explosive materials, and paints, and is applied together with methyl methacrylate.