Phthalic anhydride (PA) is an organic compound with the chemical formula C6H4(CO)2O, representing the anhydride of phthalic acid. It is a vital industrial chemical, primarily synthesized through the catalytic oxidation of ortho-xylene or naphthalene. This process yields a white crystalline solid that serves as a fundamental intermediate in a multitude of manufacturing processes worldwide. The chemical structure of phthalic anhydride, featuring two carbonyl groups attached to a benzene ring and linked by an oxygen atom, dictates its reactivity. This bifunctional nature allows it to readily undergo reactions such as esterification, amidation, and hydrolysis, making it a versatile building block for more complex molecules. Its physical properties, including a melting point of approximately 131-132°C, contribute to its handling and processing in industrial settings. The industrial importance of phthalic anhydride is immense. Its most significant application is in the production of phthalate esters, which are widely used as plasticizers to impart flexibility and durability to PVC. These plasticizers are essential for creating products ranging from wire insulation and flooring to medical devices and automotive components. Beyond plasticizers, phthalic anhydride is a key intermediate in the synthesis of unsaturated polyester resins (UPR) and alkyd resins. UPRs, often reinforced with glass fibers, are used in strong and lightweight composites for construction, marine, and automotive industries. Alkyd resins, on the other hand, are crucial for the formulation of paints and coatings, providing excellent gloss and protective qualities for architectural and industrial applications. Furthermore, phthalic anhydride finds applications in the production of dyes, pigments, herbicides, insecticides, and fire retardants. Its versatility means that it touches upon many aspects of our daily lives, from the colors we see to the materials that build our infrastructure and the efficiency of our agriculture. NINGBO INNO PHARMCHEM CO.,LTD. is a dedicated supplier of high-quality phthalic anhydride, supporting these diverse industrial needs. By ensuring the purity and consistency of this critical intermediate, we enable manufacturers globally to produce innovative and reliable products that shape modern industry and commerce.