| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for obtaining a high-purity aromatic dihydroxy compound by inexpensively mass treatment of waste aromatic polycarbonates. <P>SOLUTION: The method for obtaining the aromatic dihydroxy compound from the waste aromatic polycarbonates comprises the following consecutive steps: (A) The waste aromatic polycarbonates are depolymerized in the presence of an organic solvent and an aqueous solution of metal hydroxide (a-step). (B) The resulting deposited solids are dissolved by adding water to the reaction liquid after the depolymerization (b-step). (C) The organic solvent phase and the aqueous metal hydroxide solution phase are separated to retrieve the latter (c-step). (D) An acid is added to the aqueous metal hydroxide solution to deposit and filter the resulting aromatic dihydroxy compound (d-step). (E) The aromatic dihydroxy compound thus obtained is washed with an organic solvent and/or water followed by (E-1) removing the washings using a centrifugal separator (e-1 step) or (E-2) removing the washings using a filter (e-2 step). <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
