Patent ID: 7193104

Claim:
A process for producing bis-β-hydroxyethyl terephthalate and/or a low condensate thereof from an aromatic polyester, comprising the steps of: heating the aromatic polyester comprising terephthalic acid as a main dicarboxylic acid component and ethylene glycol as a main glycol component together with bis-β-hydroxyethyl terephthalate and/or a low condensate thereof in an amount of 1 part by weight of the aromatic polyester and 0.1 to 4.5 parts by weight of the bis-β-hydroxyethyl terephthalate and/or the low condensate thereof in the absence of free ethylene glycol to decompose the aromatic polyester, and then, reacting the decomposed product with ethylene glycol in an amount of 1 part by weight of the decomposed product and 3.0 to 10.0 parts by weight of ethylene glycol to convert the terephthalic acid component of the decomposed product into bis-β-hydroxyethyl terephthalate and/or a low condensate thereof having a molar ratio of ethylene glycol to terephthalic acid between 10.6 and 40.5, wherein each of said low condensates is a compound containing ethylene terephthalate as the main constituent component and has an average polymerization degree of 1 to 10.