| 摘要 |
PROBLEM TO BE SOLVED: To provide a process for producing PPS, whereby granular PPS can be produced in a shortened cycle and the recovery of unreacted monomers can be facilitated. SOLUTION: This invention provides a process for producing a granular polyphenylene sulfide by polymerizing at least one sulfur source and a polyhaloaromatic compound in an organic polar solvent in a hermetically sealed container and slowly cooling the reaction mixture in the latter stage of the polymerization reaction, which comprises releasing the pressure in the container while keeping the reaction product in the state in which at least 50% of the polymer is in the form of solid granules as a result of the slow cooling in the latter stage of the polymerization and the pressure in the sealed container is 0.39×10<6> Pa or above, whereupon the polymerization mixture comprising a gaseous phase and a liquid phase is degassed to decrease the pressure in the container to 0.20×10<6> Pa or above. |
