Granular polyarylene sulfide and process for manufacturing the same

摘要

A granular polyarylene sulfide; (i) the granular polyarylene sulfide containing an —S— substituent at the terminal, the substituent being formed by cleavage of a disulfide compound; (ii) the granular polyarylene sulfide being an oversize fraction after sifting with a sieve having a mesh size of at least 38 μm; (iii) the granular polyarylene sulfide having a halogen content of at most 1,500 ppm; and (iv) the granular polyarylene sulfide being a granular polyarylene sulfide having a melt viscosity of 3 to 100 Pa·s when measured under conditions at a temperature of 310° C. and a shear rate of 1,200 sec−1. The granular polyarylene sulfide is well balanced in melt viscosity, halogen content, nitrogen content, thermal stability, and yield.

主权项

1. A process for manufacturing a granular polyarylene sulfide containing an —S— substituent at a terminal, the —S— substituent being formed by cleavage of a disulfide compound, having a halogen content of at most 1,500 ppm, and having a melt viscosity of 3 to 100 Pa·s when measured under conditions at a temperature of 310° C. and a shear rate of 1,200 sec−1, the process comprising the steps of: polymerizing a sulfur source and a dihalo aromatic compound in an organic amide solvent; cooling a liquid phase containing a produced polymer after the polymerization step; separating and recovering the produced polymer; and inducing a liquid-liquid phase separation state in which a produced polymer dense phase and a produced polymer dilute phase are both present in the presence of a phase separation agent during the polymerization step and/or prior to the cooling step;
(i) the polymerization reaction being performed in the presence of a disulfide compound in the polymerization step, wherein the disulfide compound is absent in the polymerization step before a conversion ratio of the dihalo aromatic compound reaches 45%; and (ii) an oversize fraction being obtained by sifting the produced polymer with a sieve having a mesh size of at least 38 μm in the separation/recovery step.