Definition of phthalic acid in English:

phthalic acid


  • A crystalline acid derived from benzene, with two carboxylic acid groups attached to the benzene ring.

    Chemical formula: C₆H₄(COOH)₂; three isomers

    • ‘Alkyd is produced by condensation reactions between polycarboxylic acids and polyhydric alcohols - often phthalic acid or anhydride and glycerol.’
    • ‘A wide range of uses has been found for various phthalic acid esters, with the largest portion of these esters being used as plasticizing agents for polyvinyl chloride products.’
    • ‘Capillaries were immersed in phthalic acid, which has an index of refraction that effectively eliminates optical refraction at the outer wall.’


Mid 19th century: phthalic, shortening of naphthalic (see naphthalene).


phthalic acid