133440-67-2Relevant articles and documents
4-(5-Amino-6-Hydroxybenzoxazol-2-YL) Ammonium Benzoate and Preparation Method and Use Thereof
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Paragraph 0081; 0082, (2015/09/23)
Disclosed in the present invention are 4-(5-amino-6-hydroxybenzoxazol-2-yl)ammonium benzoate shown in formula (I) and the preparation method and use thereof. The preparation method comprises: fully reacting 4-(5-amino-6-hydroxybenzoxazol-2-yl)benzoic acid shown in formula (II) or 4-(5-amino-6-hydroxybenzoxazol-2-yl)carboxamide benzoate, as a raw material, with ammonia in an aqueous solvent, and directly heating the obtained reaction liquid to remove excess ammonia, so as to obtain 4-(5-amino-6-hydroxybenzoxazol-2-yl)ammonium benzoate. The mass of the 4-(5-amino-6-hydroxybenzoxazol-2-yl)ammonium benzoate (ABAA) prepared in the present invention can reach a polymer grade (where the purity is above 99.5%, the content of metal ions is below 200 ppm, and containing no DMF polymerization inhibition impurities), and the 4-(5-amino-6-hydroxybenzoxazol-2-yl)ammonium benzoate can be used as an AB type monomer for preparing PBO and modified PBO fibres, the resulting PBO having an intrinsic viscosity n of up to 38/dl/g, and the method has such features as ABAA being highly soluble in PPA, a fast polymerization speed, a short time of 2-4 h, a low temperature of 150° C., a high molecular weight of the polymer, fibres of excellent tensile property, being easy to industrialize, etc.