| 摘要 |
PROBLEM TO BE SOLVED: To provide a polyphenylene ether copolymer excellent in heat resistance, moldability, solvent resistance and a color tone.SOLUTION: This method for producing the polyphenylene ether copolymer includes: a step of preparing a polymerization solution which comprises 10-25 pts.mass of a phenolic compound (M) containing 2,6-dimethylphenol (which may be called a phenolic compound 1 or M1 for short, below) and 2,3,6-trimethylphenol (which may be called a phenolic compound 2 or M2 for short, below); 75-90 pts.mass of an aromatic solvent (A); and 0.1-10 pts.mass of a catalyst (C) containing a metal salt as a component (wherein, the total parts by mass of the phenolic compound (M) and the aromatic solvent (A) is 100 pts.mass, M1/M2: a ratio of the phenolic compound 1 (M1) to the phenolic compound 2 (M2) is 95/5-70/30); a step of aerating the polymerization solution with an oxygen-containing gas (O) to oxidatively polymerize the phenolic compound (M); a step of terminating the polymerization by mixing an aqueous chelating agent solution with the polymerization solution; a step of treating a diphenoquinone compound (Q) formed as a by-product; and a step of separating the metal salt, the chelating agent and an aqueous phase by liquid-liquid separation to obtain the polyphenylene ether copolymer. In this method, before the liquid-liquid separation, 0.001-0.005 of pt.wt. of an ionic catalyst (D) is added to the polymerization solution. |
