A method for producing a polyphenylene ether (PPE) provides the PPE that includes less gel and that is good in mechanical property and heat resistance, wherein the method includes a polymerization step of subjecting a phenol compound to oxidative polymerization in the presence of a polymerization catalyst in a good solvent for a polyphenylene ether to thereby provide a polyphenylene ether solution, a catalyst extraction step of adding an aqueous chelating agent solution to the polyphenylene ether solution and extracting the polymerization catalyst into the aqueous chelating agent solution to thereby provide a catalyst-removed polyphenylene ether solution, a concentration step of removing a part of the good solvent from the catalyst-removed polyphenylene ether solution to provide a concentrated polyphenylene ether solution, and a gel removal step of removing at least a visually observable chloroform-insoluble substance from the concentrated polyphenylene ether solution, to thereby provide a gel-removed polyphenylene ether solution.

Provided is a method for producing polyphenylene ether (PPE) having excellent mechanical properties, heat aging resistance, and color, and in which the content of impurities such as low molecular weight components and catalyst metal is low. The method for producing PPE includes: performing oxidative polymerization of a phenolic compound in a polymerization solution containing the phenolic compound, a catalyst, and an aromatic solvent to obtain a PPE mixed liquid; precipitating PPE to obtain a slurry containing particulate PPE through addition of a polar solvent to the PPE mixed liquid; solid-liquid separating the slurry to obtain wet PPE particles; washing the wet PPE particles to obtain PPE particles through at least one cycle of a washing and solid-liquid separation process in which washing is performed with a washing liquid containing an aromatic solvent and a polar solvent, and in which solid-liquid separation is performed; and drying the PPE particles.

Provided is a method for producing polyphenylene ether (PPE) having excellent mechanical properties, heat aging resistance, and color, and in which the content of impurities such as low molecular weight components and catalyst metal is low. The method for producing PPE includes: performing oxidative polymerization of a phenolic compound in a polymerization solution containing the phenolic compound, a catalyst, and an aromatic solvent to obtain a PPE mixed liquid; precipitating PPE to obtain a slurry containing particulate PPE through addition of a polar solvent to the PPE mixed liquid; solid-liquid separating the slurry to obtain wet PPE particles; washing the wet PPE particles to obtain PPE particles through at least one cycle of a washing and solid-liquid separation process in which washing is performed with a washing liquid containing an aromatic solvent and a polar solvent, and in which solid-liquid separation is performed; and drying the PPE particles.

Process for producing polyarylene ether beads from a polyarylene ether solution, comprising the steps of i) dividing the polyarylene ether solution into droplets, ii) transferring the droplets into a precipitation bath to form polyarylene ether beads in the precipitation bath which (A) comprises at least one aprotic solvent (component (1)) and at least one protic solvent (component (2)), (B) has a temperature of 0° C. to T.sub.c, where the critical temperature T.sub.c in [° C.] can be determined by the numerical equation T.sub.c=(99−c)/0.61 in which c is the concentration of component (1) in the precipitation bath in [% by weight] and (C) has component (1) in concentrations of 5% by weight to c.sub.c, where the critical concentration c.sub.c in [% by weight] can be determined by the numerical equation c.sub.c=99−0.61*T in which T is the temperature in the precipitation bath in [° C.], where
the percentages by weight are each based on the sum of the percentages by weight of component (1) and of component (2) in the precipitation bath.

Process for producing polyarylene ether beads from a polyarylene ether solution, comprising the steps of i) dividing the polyarylene ether solution into droplets, ii) transferring the droplets into a precipitation bath to form polyarylene ether beads in the precipitation bath which (A) comprises at least one aprotic solvent (component (1)) and at least one protic solvent (component (2)), (B) has a temperature of 0° C. to T.sub.c, where the critical temperature T.sub.c in [° C.] can be determined by the numerical equation T.sub.c=(99−c)/0.61 in which c is the concentration of component (1) in the precipitation bath in [% by weight] and (C) has component (1) in concentrations of 5% by weight to c.sub.c, where the critical concentration c.sub.c in [% by weight] can be determined by the numerical equation c.sub.c=99−0.61*T in which T is the temperature in the precipitation bath in [° C.], where
the percentages by weight are each based on the sum of the percentages by weight of component (1) and of component (2) in the precipitation bath.

The invention relates to a process for producing polyarylene ether beads from a polyarylene ether solution, comprising the steps of i) dividing the polyarylene ether solution in a division apparatus which is made to vibrate with a frequency of 10 to 1400 Hz to obtain droplets, ii) transferring the droplets into a precipitation bath to form polyarylene ether beads in the precipitation bath which (A) comprises at least one aprotic solvent (component (1)) and at least one protic solvent (component (2)), (B) has a temperature of 0° C. to T.sub.c, where the critical temperature T.sub.c in [° C.] can be determined by the numerical equation T.sub.c=(77−c)/0.58 in which c is the concentration of component (1) in the precipitation bath in [% by weight] and (C) has component (1) in concentrations of 5% by weight to c.sub.c, where the critical concentration c.sub.c in [% by weight] can be determined by the numerical equation c.sub.c=77−0.58*T in which T is the temperature in the precipitation bath in [° C.], where
the percentages by weight are each based on the sum of the percentages by weight of component (1) and of component (2) in the precipitation bath.

The invention relates to a process for producing polyarylene ether beads from a polyarylene ether solution, comprising the steps of i) dividing the polyarylene ether solution in a division apparatus which is made to vibrate with a frequency of 10 to 1400 Hz to obtain droplets, ii) transferring the droplets into a precipitation bath to form polyarylene ether beads in the precipitation bath which (A) comprises at least one aprotic solvent (component (1)) and at least one protic solvent (component (2)), (B) has a temperature of 0° C. to T.sub.c, where the critical temperature T.sub.c in [° C.] can be determined by the numerical equation T.sub.c=(77−c)/0.58 in which c is the concentration of component (1) in the precipitation bath in [% by weight] and (C) has component (1) in concentrations of 5% by weight to c.sub.c, where the critical concentration c.sub.c in [% by weight] can be determined by the numerical equation c.sub.c=77−0.58*T in which T is the temperature in the precipitation bath in [° C.], where
the percentages by weight are each based on the sum of the percentages by weight of component (1) and of component (2) in the precipitation bath.

The present invention provides a high-molecular-weight polyether polyol ensuring that when used as a polyurethane raw material, a polyurethane having excellent flexibility and elastic recovery can be obtained; and a method for producing, with high productivity, a polyether polyol having a higher number average molecular weight and a narrower molecular weight distribution than those of the raw material polyether polyol, and the polyether polyol of the present invention has a number average molecular weight of 3,500 to 5,500 and a molecular weight distribution of 1.7 to 3.0.

The present invention provides a high-molecular-weight polyether polyol ensuring that when used as a polyurethane raw material, a polyurethane having excellent flexibility and elastic recovery can be obtained; and a method for producing, with high productivity, a polyether polyol having a higher number average molecular weight and a narrower molecular weight distribution than those of the raw material polyether polyol, and the polyether polyol of the present invention has a number average molecular weight of 3,500 to 5,500 and a molecular weight distribution of 1.7 to 3.0.

Provided is a polyether ether ketone, comprising a repeating unit represented by the following formula (1), the polyether ether ketone having a crystallization temperature Tc of 255° C. or more, and satisfying one or both of the following conditions (A) and (B): (A) a fluorine atom content a is less than 2 mg/kg; and (B) a chlorine atom content b is 2 mg/kg or more.

##STR00001##