Phthalic Anhydride, commonly abbreviated as PA, is a pivotal organic compound with the chemical formula C8H4O3. Recognized as the anhydride of phthalic acid, this white, crystalline solid or flake is a cornerstone in various industrial sectors, particularly due to its exceptional reactivity and versatility.

Characteristically, PA exhibits a pungent, acrid odor. It possesses a melting point typically ranging from 131 to 134 °C and a boiling point of approximately 284 to 295 °C, notable for its sublimation properties. While sparingly soluble in cold water, it readily hydrolyzes into phthalic acid in hot water. Its solubility extends to organic solvents such as ethanol, benzene, pyridine, and carbon disulfide, making it a highly adaptable intermediate in numerous chemical syntheses. From a safety perspective, proper handling is essential as it can cause irritation to skin and eyes, and inhalation may lead to respiratory issues, including asthma.

The primary application of Phthalic Anhydride lies in its role as a precursor to phthalate esters, which are extensively used as plasticizers, predominantly for polyvinyl chloride (PVC). These plasticizers impart flexibility and durability to a wide array of plastic products, from wire and cable insulation to coated fabrics and roofing membranes. The production of these phthalate esters involves the alcoholysis of PA, a reaction critical for many industrial processes. In addition to plasticizers, PA is a key ingredient in the manufacture of unsaturated polyester resins (UPR). These resins, often reinforced with fiberglass, find widespread use in construction, marine, and transportation industries for creating durable composite materials.

Another significant outlet for PA is in the production of alkyd resins. These resins are vital for the paint and lacquer industries, providing excellent film-forming properties for architectural, machinery, furniture, and fixture coatings. Furthermore, Phthalic Anhydride serves as an important intermediate in the synthesis of various dyes and pigments, including anthraquinone, phenolphthalein, and phthalocyanine. Its applications also extend to pharmaceuticals, where it is used to create compounds like cellulose acetate phthalate (CAP), a common enteric coating excipient, and other drug intermediates. Minor uses include the formulation of insecticides, fire retardants, and as a rubber scorch inhibitor, underscoring its broad industrial significance.

The industrial production of Phthalic Anhydride is primarily achieved through the catalytic oxidation of ortho-xylene or naphthalene in a gas-phase reaction, typically employing vanadium pentoxide as a catalyst. This modern process ensures high yields and purity, meeting the stringent demands of diverse downstream industries. Alternatively, it can also be prepared via the thermal dehydration of phthalic acid. NINGBO INNO PHARMCHEM CO.,LTD. adheres to rigorous quality control standards throughout its manufacturing process, ensuring a consistently high-grade product for global markets.

As a leading phthalic anhydride manufacturer, NINGBO INNO PHARMCHEM CO.,LTD. is committed to providing a reliable supply of this essential chemical. We serve as a trusted phthalic anhydride supplier for clients across various sectors, offering comprehensive product information, including technical data sheets and safety profiles. For those looking to buy phthalic anhydride, our competitive phthalic anhydride price reflects our commitment to delivering value without compromising on quality. To inquire about our products or to purchase phthalic anhydride in bulk, please reach out to our sales team for a detailed quotation and reliable delivery options tailored to your specific requirements.