To decompose an aromatic polyester into an aromatic dihydric carboxylic acid in a form of methyl ester and a dihydric alcohol in a short time and recover these monomers in a high yield by reacting the aromatic polyester with a supercritical methanol.
An aromatic polyester (e.g. polyethylene terephthalate) is reacted with a supercritical methanol to provide dimethyl aromatic dihydric carboxylic acid and a dihydric alcohol. The reaction is preferably carried out by packing the aromatic polyester and methanol into a reactor and heating the reactor under supercritical conditions of methanol. The supercritical conditions are preferably 523-653K° temperature and 5 to 25MP pressure. Methanol is preferably used in a ratio of 20-70mol based on 1mol aromatic dihydric carboxylic aid contained in the aromatic polyester. The aromatic dihydric carboxylic acid dimethyl ester and the dihydric alcohol can be recovered from the reaction product in high purity from a method such as distillation or crystallization.
SATO SHINJI
SUGATA TAKESHI
OTAKE KATSUTO
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