钛系瓶级PET切片的合成及其固相增黏工艺研究

Synthesis and solid phase polycondensation of titanium-containing bottle-grade PET chip

使用自制钛催化剂在2L聚合反应釜中合成钛系聚酯(PET)基础切片,探讨了调色剂、稳定剂、助剂对反应过程及切片性能的影响;然后在50 L聚合反应釜中进行了放大试验,并将基础切片在真空转鼓中进行固相增黏,得到瓶级PET切片。结果表明:在相同的聚合反应条件下,钛催化剂用量(以钛离子计,相对于精对苯二甲酸(PTA))为7μg/g时,合成的钛系基础切片的色相、乙醛含量与乙二醇锑用量(以锑离子计,相对于PTA)为220μg/g时得到的锑系基础切片相当;在钛系基础切片合成中添加助剂,在固相增黏时合理控制升温过程,可有效解决钛系基础切片在固相缩聚反应中存在的固相增黏速率、切片色相与乙醛含量之间相互制约的矛盾,增黏后的钛系瓶级PET切片的色相、乙醛含量等指标优于锑系瓶级PET切片。

Titanium-containing polyester （PET） basic chip was synthesized in the presence of self-made titanium catalyst in a 2-1itre polymerization reactor. The effects of the toning agent, stabilizer and auxiliaries on the reaction process and the properties of the chip were discussed. The scale-up experiment was performed in a 50-litre polymerization reactor. The basic chip was exposed to solid phase polycondensation in a vacuum drum to produce bottle-grade PET chip. The results showed that the hue and acetaldehyde content of the titanium-containing PET basic chip using 7 μg/g titanium catalyst （ titianium ion based on purified terephthalic acid （PTA）） was equal to those of antimony-containing PET basic chip using 220 μg/g antimony catalyst （antimony ion based on PTA） ; the mutual restriction of solid phase polycondensation rate and the hue and acetaldehyde content of the chip could be efficiently solved by adding auxiliaries into the titanium-containing PET basic chip and rationally controlling temperature rising process during the solid phase polycondensation process ; and the titanium-containing bottle-grade PET chip was superior to antimony-containing bottle-grade PET chip in the hue and acetaldehyde content after solid phase polycondensation.