| abstract |
(57) [Summary] [Purpose] From the viewpoint of resource reuse, we will develop means for increasing the efficiency and cost of the separate collection of aromatic polyesters. [Structure] A mixture of polyethylene naphthalene dicarboxylate (PEN) and polyethylene terephthalate (PET) is mixed with alkali metal, alkaline earth metal, zinc, Using weak acid salts of cobalt and manganese as catalysts, depolymerization with ethylene glycol, transesterification without isolation of the depolymerized product, dimethyl ester is obtained, and dimethyl naphthalenedicarboxylate is crystallized and separated with methanol, and the separated filtrate To recover methanol, ethylene glycol and terephthalic acid dimethyl ester. |