| 摘要 |
PURPOSE:To obtain an aromatic polyamide which can give a stretched film excellent in strength, by reacting tolylene diisocyanate with purified terephthalic acid obtained by a specified production process by heating in a solvent in the presence of an alkali metal compound. CONSTITUTION:p-Xylene is oxidized with, e.g., air in the presence of an oxidation catalyst to produce crude terephthalic acid. This crude terephthalic acid is recrystallized from water to produce purified terephthalic acid. This purified terephthalic acid is reacted with tolylene 2,4-diisocyanate and/or tolylene 2,6- diisocyanate at a reaction temperature >=100 deg.C in a solvent (e.g., dimethylethyleneurea) in the presence of an alkali metal compound (e.g., sodium hydroxide or cesium fluoride) to obtain the purpose aromatic polyamide. A film obtained by forming the obtained polyamide into a film and stretching this film can be suitably used as a material for various reinforcements, etc.
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