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AssigneeKureha Corporation
InventorsHirohito Kawama, Mitsuhiro Matsuzaki, Michihisa Miyahara, Koichi Suzuki, Hiroyuki Sato
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A dehydration step is conducted by heating a mixture containing an organic amide solvent and a sulfur source including an alkali metal hydrosulfide, and a part of an overall charged amount of an alkali metal hydroxide as needed. The mixture remaining within the system after the dehydration step is mixed with a dihalo-aromatic compound, the resultant mixture is heated to conduct a polymerization reaction, and the alkali metal hydroxide is added to the mixture for polymerization reaction continuously or in portions to control the pH of the mixture for polymerization reaction within a range of from 7 to 12.5 from the beginning to the end of the polymerization reaction. The poly(arylene sulfide) according to the present invention has a nitrogen content of at most 800 ppm.
-12. (canceled)
A poly(arylene sulfide) obtained by polymerization in an organic amide solvent and having a nitrogen content of at most 800 ppm.
A poly(arylene sulfide) having a ratio MVL/MVH of a melt viscosity MVL (as measured at a temperature of 310° C. and a shear rate of 1,216 sec−1) of the poly(arylene sulfide), whose pH is adjusted to at most 6.0, to a melt viscosity MVH (as measured at a temperature of 310° C. and a shear rate of 1,216 sec1) of the same poly(arylene sulfide), whose pH is adjusted to at least 8.0, ranging from 0.7 to 1.0.
A poly(arylene sulfide) obtained by polymerization in an organic amide solvent and having a nitrogen content of at most 800 ppm and a ratio MVL/MVH of a melt viscosity MVL (as measured at a temperature of 310° C. and a shear rate of 1,216 sec−1) of the poly(arylene sulfide), whose pH is adjusted to at most 6.0, to a melt viscosity MVH (as measured at a temperature of 310° C. and a shear rate of 1,216 sec1) of the same poly(arylene sulfide), whose pH is adjusted to at least 8.0, ranging from 0.7 to 1.0.
Dependencies are inferred from the claim text.