Process for continuously producing polyester
AssigneeTeijin Limited
InventorsMikio Nakane, Kentaro Yamaguchi, Fuminori Takenaga
Life of this patent
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Abstract
A process for continuously producing a polyester comprising an aromatic dicarboxylic acid or a lower alkyl ester thereof and an alkylene glycol having 2 to 4 carbon atoms as the main glycol component by recycling part or all of a distillate comprising an alkylene glycol having 2 to 4 carbon atoms recovered from a polycondensation reaction step as the main component as a raw material for the polyester. Low-boiling substances contained in the distillate are separated by flush distillation and the distillate is supplied to an ester exchange reaction step or esterification reaction step.
Claims8
A process for continuously producing an aromatic polyester from an aromatic dicarboxylic acid as the main dicarboxylic acid component and at least one glycol selected from the group consisting of ethylene glycol, 1,3-propanediol and 1,4-butanediol as the main glycol component through an esterification or ester exchange reaction and a polycondensation reaction, wherein
- a distillate containing said glycol from the polycondensation reaction is subjected to at least flush distillation to remove low-boiling substances and at least part of the residue is recycled as part of said glycol for said esterification or ester exchange reaction.
Dependencies are inferred from the claim text.