| 摘要 |
<p>A method for decomposing a waste aromatic polycarbonate by an aqueous solution of an alkali metal hydroxide and producing an aqueous solution of an alkali metal salt of an aromatic dihydroxy compound, which comprises (1) a dissolution step of dissolving the waste aromatic polycarbonate into a chlorinated hydrocarbon solvent, (2) a decomposition step of adding an aqueous solution of an alkali metal hydroxide to the resultant solution, to decompose the aromatic polycarbonate, (3) a re- dissolution step of adding water to the liquid decomposed product to dissolve solids, (4) a two-phase forming step of allowing the resultant liquid product from the previous step to stand, to thereby form an organic solvent phase (an organic phase) and an aqueous solution phase (water phase), and (5) a separation and recovery step of separating the water phase from the organic solvent phase and recovering the water phase. The above method allows an aqueous solution of a metal salt of an aromatic dihydroxy compound having high quality and thus being useful as a raw material for a polycarbonate to be produced from a waste aromatic polycarbonate, with a short decomposition time, at a low cost, and thus, advantageously from an industrial view point.</p> |
