Process for producing aromatic polyesters having increased degrees of polymerization and moulded articles composed of these polyesters.

摘要

A process for producing an aromatic polyester having an increased degree of polymerization. The process comprises reacting a hydroxyl-terminated, substantially linear, fiber-forming aromatic polyester having an aromatic dicarboxylic acid as a main acid component at an elevated temperature with a bi-cyclic imino ester compound of formula (I) or formula (II). According to the process, the molecularchains of the aromatic polyester are bonded to each other by the terminal hydroxyl groups thereof to form rapidly the aromatic polyester having an increased degree of polymerization.
I Bis-oxazolones
<Chemistry id="chema01" num="0001"><Image id="ia01" he="19" wi="62" file="IMGA0001.TIF" imgContent="chem" imgFormat="TIFF" inline="no" /></Chemistry>
11 Bis-oxazinones e.g.
<Chemistry id="chema02" num="0002"><Image id="ia02" he="31" wi="52" file="IMGA0002.TIF" imgContent="chem" imgFormat="TIFF" inline="no" /></Chemistry>