Phthalic anhydride, 99.0+%

Phthalic anhydride is the organic compound with the formula C6H4(CO)2O. It is the anhydride of phthalic acid. Phthalic anhydride is a principal commercial form of phthalic acid. It was the first anhydride of a dicarboxylic acid to be used commercially. This colourless solid is an important industrial chemical, especially for the large-scale production of plasticizers for plastics. In 2000, the world wide production volume was estimated to be about 3 million tonnes per year.

The primary use of phthalic anhydride is as a chemical intermediate in the production of plastics from vinyl chloride. Phthalate esters, which function as plasticizers, are derived from Phthalic Anhydride. Phthalate plasticizers are used for the production of flexible PVC products such as cables, pipes and hoses, leather cloth, shoes, film for packaging etc.

Phthalic anhydride has another major use in the production of polyester resins and other minor uses in the production of alkyd resins used in paints and lacquers; certain dyes (anthraquinone, phthalein, rhodamine, phthalocyanine, fluorescin, and xanthene dyes); insect repellents; and polyester polyols for polyurethanes. It is also utilized as a rubber scorch inhibitor and retarder.