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US 5,314,972 AGranted
Acid wash of polyarylene sulfides
AssigneePhillips Petroleum Company
InventorsAfif M. Nesheiwat, John F. Geibel
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AssigneePhillips Petroleum Company
InventorsAfif M. Nesheiwat, John F. Geibel
Estimating the term…
In one embodiment, a process is provided for treating virgin arylene sulfide resins, wherein a heated polymer slurry, comprising a virgin arylene sulfide resin and water, is contacted by a buffer solution having a pH less than about 9.35 but greater than that necessary to result in at least a partial curing of the virgin arylene sulfide resin. In a further embodiment, a process is provided for treating a virgin arylene sulfide resin, wherein a virgin arylene sulfide resin is slurried in a buffer solution having a pH less than about 9.35 but greater than that necessary to result in at least a partial curing of the virgin arylene sulfide resin. The treating process of this invention is conducted at an elevated temperature, below the melting point of the virgin arylene sulfide resin, while in the substantial absence of a gaseous oxidizing atmosphere. The treated arylene sulfide resins are recovered from the polymer slurry in a manner which does not result in at least a partial curing of the treated resin.
In a process for the preparation of polyarylene sulfide comprising subjecting an alkali metal hydrosulfide and a dihalo-aromatic compound to reaction in a polar organic compound to form a polyarylene sulfide, the improvement which comprises subjecting the polymer formed separated from the polymerization mixture to a treatment, without causing substantial cure of said polymer, with an aqueous buffer solution having a pH of about 9.25 and comprising ammonium chloride under conditions suitable for producing a polyarylene sulfide having an increased melt flow rate, said conditions including a temperature below the melting point of said polymer.
Dependencies are inferred from the claim text.