| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To establish a method for recovering dimethyl terephthalate and ethylene glycol, useful components in polyester production, while the amount of phosphorus element contained therein is low, from a polyethylene terephthalate product with which a phosphorus-based flame retardant is copolymerized. <P>SOLUTION: A method for producing dimethyl terephthalate and alkylene glycol from a polyester product including polyalkylene terephthalate with which a phosphorus-based flame retardant is copolymerized controls the concentration of phosphorus element in a depolymerization liquid obtained in a depolymerization process, after experiencing the depolymerization process, a transesterification reaction process, and a useful component recovery process, to be 370 ppm or less. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
