| 摘要 |
<p>A process for producing an aromatic polyester having an increased degree of polymerization, which comprises reacting a substantially linear, fiber forming aromatic polyester containing terminal hydroxyl groups and having an aromatic dicarboxylic acid as a main acid component at an elevated temperature with a bis-cyclic imino ether compound of the formula (I) such as 2,2'bis(2-oxazoline), 2,2'-bis(5,6-dihydro-4H-1,3-oxadine) thereby bonding the molecular chains of the aromatic polyester to each other by the terminal carboxyl groups thereof to rapidly form said aromatic polyester having an increased degree of polymerization. Said reaction can be carried out under atmospheric or elevated pressure. According to the process, an aromatic polyester having a low terminal carboxyl concentration and an increased degree of polymerization can be obtained.</p> |
