| abstract |
A high-purity oxydiphthalic acid anhydride that in the production of a polyimide containing an oxydiphthalic acid anhydride, enables production of one of satisfactorily high strength; and an industrially simple and easy process for producing the same. There is provided a high-purity oxydiphthalic acid anhydride exhibiting a content of insoluble microparticulate matter, the insoluble microparticulate matter having a 5 to 20 μm diameter of circle equivalent to projected area, of ≤ 3000 particles per g, which high-purity oxydiphthalic acid anhydride in the form of an acetonitrile solution of 4 g/L concentration exhibits a 400 nm light transmittance, measured at a light path length of 1 cm, of ≥ 98.5%. |