4-CBA对PET产品色相b值的影响

Effect of 4-CBA on b value of PET products

针对聚酯(PET)装置负荷提升后,聚酯产品色泽指标b值波动很大的现象,统计跟踪分析了PET装置原料精对苯二甲酸(PTA)、辅料催化剂、添加剂及工艺操作的变化,讨论了PET产品中b值的影响因素。结果表明:对羟基苯甲醛(4-CBA)是影响PET产品的b值的主要因素;PET切片的b值升高与原料PTA中4-CBA含量变化趋势相近;PET装置负荷大幅提升后,当PET b值上升超过1.5时,生产上要及时控制4-CBA含量;PET装置平稳运行时,PTA中4-CBA含量小于40μg/g,可满足生产要求。

Aiming at the significant fluctuation of hue b value of polyester（PET） products after the load increase of PET plant, the change of purified terephthalic acid （PTA） raw material, catalysts, additives and process operation was tracked and analyzed. The influential factors on b value of PET products were discussed. The results showed that 4-carboxybenzaldehyde （4- CBA） was the principal factor bearing upon b value of PET products; the growth of b value of PET chip comphed with the change tendency of 4-CBA content in PTA; some measures should be taken in time while the b value of PET chip approaching 1.5 after the significant load increase of PET plant; and PTA with 4-CBA content less than 40 μg/g can completely meet the requirement during the stable production of PET plant.