| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polyimide which has not only excellent various physical properties but also improved melt flowability, thermal oxidation stability, optical characteristics, electric characteristics, and so on, and is especially useful as a functional material used in electronic and electric fields, by specifying the purity of a diamine of raw material. SOLUTION: This polyimide is obtained from a diamine of formula I [X is methylene, ethylene, isopropylidene, difluoromethylene or the like; (p) is 0 or 1] purified in a purity of >=99.5% and one or more tetracarboxylic acid dianhydrides of formula II (R is a tetravalent linking group such as a group of formula III), and has repeating units of formula IV. The precursor of the polyimide is a polyamic acid which has repeating units of formula IV and has an inherent viscosity of 0.2 to 2.0 dl/g (in N,N-dimethylacetamide solvent in a concentration of 0.5 g/dl at 35 deg.C). Thereby, the polyamide having improved electric characteristics in addition to the original various physical properties of the polyimide can be provided.
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