| 摘要 |
<p>Linear polyalkylene terephthalates Title products are obtained by esterification of terephthalic acid or re-esterification of a dialkylterephthalate with an alkylene glycol, followed by polycondensation of the so-obtained bis-(omega-hydroxyalkyl)-terephthalate, in presence of Sb(III)-oxide or Ge(IV)-oxide as catalyst, the polycondensation catalyst being added before or during the (re-)esterification step in form of a soln. in a volatile amino-cpd. (e.g. n-butyl amine or diisopropylamine) which may opt. contain water and/or polyester-forming alkylene glycol as diluent.</p> |
