| 摘要 |
PURPOSE:To produce the titled resin excellent in transparency, heat resistance, and chemical resistance, by polycondensing a specified cyclic tetracarboxylic acid dianhydride with an aromatic diamine and ring-closing the polycondensate by dehydration. CONSTITUTION:A tetracarboxylic acid anhydride component containing at least 90mol% 3,5,6-tricarboxy-2-carboxymethyl-norbornane-2:3,5:6-dianhydride of formula I is polycondensed with a diamine component containing at least 90mol% aromatic diamine of formula II (wherein R is a bivalent aromatic hydrocarbon), e.g., p-phenylenediamine, and the polycondensate is ring-closed by dehydration to produce a polyimide resin containing at least 90mol%, based on the total repeating units, repeating units of formula III (wherein R is as defined above). This resin is excellent in transparency, heat resistance, and chemical resistance, and particularly suitable for use in display materials (e.g., base film of a transparent electroconductive film, or liquid crystal orientation film) and has possibility of application to films, sheets, enamels, adhesives, etc.
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