Patent ID: 7838618

Claim:
A process for producing a phenylene ether oligomer comprising oxidative polymerization of a bivalent phenol compound represented by formula (1) and a monovalent phenol compound represented by formula (2) in an aromatic hydrocarbon solvent, wherein the aromatic hydrocarbon solvent of the phenylene ether oligomer solution obtained after the termination of the polymerization is replaced with a water-soluble organic solvent having a boiling point higher than the boiling point of the aromatic hydrocarbon solvent to obtain a phenylene ether oligomer water-soluble organic solvent solution, and the phenylene ether oligomer water-soluble organic solvent solution is brought into contact with water, thereby precipitating the phenylene ether oligomer as particles, wherein R1, R2, R3, R7, R8, R9 and R10 are the same or different and represent a halogen atom, an alkyl group having 6 or less carbon atoms or a phenyl group, and R4, R5, R6, R11 and R12 are the same or different and represent a hydrogen atom, a halogen atom; an alkyl group having 6 or less carbon atoms or a phenyl group, wherein the aromatic hydrocarbon solvent is toluene, the water-soluble organic solvent is at least one selected from the group consisting of dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone and dimethylsulfoxide, and a heating vaporization operation is carried out at a heating temperature of 90° C. to 160° C. in the replacement of the aromatic hydrocarbon solvent with the water-soluble organic solvent.