PRODUCTION METHOD FOR POLYBUTYLENE TEREPHTHALATE

摘要

The purpose of the present invention is to provide a production method for polybutylene terephthalate (PBT) having good color tones said method using a biological resource derived 1, 4 butanediol (BG). This production method for PBT has: a step in which a dicarboxylic acid component and a diol component including a raw material 1, 4-BG having a nitrogen atom content of 0.01 50 ppm by mass are esterized or transesterified; and a polycondensation step in which PBT is obtained from the reaction product. The gamma butyrolactone content in the raw material 1, 4-BG is 1-100 ppm by mass.