METHOD FOR PRODUCING POLYARYLENE SULFIDE, CYCLIC POLYARYLENE SULFIDE PELLET AND METHOD FOR PRODUCING SAME

摘要

By having a step (I) of heating under reduced pressure a cyclic polyarylene sulfide composition, and a step (II) of heating and polymerizing the same, the present invention is capable of achieving a high molecular weight form of polyarylene sulfide by a simple method and producing a polyarylene sulfide that has a small molecular weight distribution and has a low gassing tendency, thereby being industrially useful. Further, by pelletizing the composition after the step (I), cyclic polyarylene sulfide pellets can be produced which are excellent in transportability as well as moldability and processabilty, and which generate less gas and are therefore industrially useful.