Abstract:

2-hydroxyterephthalic acid（HTA）was synthesized by modified Koble-Schmitt atmospheric carboxylation method. and refined. The new synthesis method was compared with 2-bromoterephthalic acid（BTA）catalytic hydrolysis. The results showed that crude product HTA with purity of 90% was prepared from HBA by CO₂ atmospheric carboxylation for 6 h at 230—240 ℃ in the presence of K₂CO₃ and potassium formate solvent，and purified through two times acid-alkali refining to obtain polymerization-grade HTA with high-purity of 99.5 % and metal ions of below 50 mg/kg，total yield of  above 56%（base on HBA）. The prepared HTA was identified by FT-IR and MS，and the process had the advantages of atmospheric carboxylation，convenient operation，excellent product quality，good economy and easy commercialization. The prepared HTA could provide the raw material for new high-preformance materials modified with hydroxy group and new monomers.

摘要：

系统地研究了以间羟基苯甲酸（HBA）为原料、经改进的Koble-Schmitt法常压合成2-羟基对苯二甲酸（HTA）的新工艺及其精制方法，并与2-溴对苯二甲酸（BTA）催化水解法制备HTA技术进行了比较。结果表明：以HBA为原料，甲酸钾为溶剂，在碳酸钾存在下，反应温度为230～240 ℃时，CO₂常压羧化反应6 h制得纯度约90%的HTA粗品，采用二次酸碱精制法可使HTA质量达聚合级单体的水平（纯度>99.5%，金属离子<50 mg/kg），总收率56%以上。产品经FT-IR和MS表征确认。该技术具有常压反应、操作方便、产品质量优异、经济性良好及易于产业化等优点，能为进一步合成羟基改性的新型高性能材料及新单体提供原料。