Close relationship between NDA and PEN

摘要

Disclosed is a method for closely linking a process for producing 2,6-naphthalene dicarboxylic acid (2,6-NDA) with a process for producing polyethylene naphthalate, thus eliminating the need for drying 2,6-NDA, handling solid 2,6-NDA, and optimizing particle size of 2,6-NDA which comprises: a) adding an aqueous slurry of polymer grade 2,6-NDA directly into a process for making PEN, either by directly adding a stream from a 2,6 NDA process into a PEN process, or by adding water to polymer grade 2-6 - NDA prior to adding the resulting slurry to a PEN process; b) removing the slurry water during the first esterification reaction at the same time the water of reaction is removed.