US 4,730,034 AGranted

Recovering poly(arylene sulfide) oligomers from a poly(arylene sulfide) reaction mixture

AssigneePhillips Petroleum Company

InventorsAfif M. Nesheiwat, Guy Senatore, Fred T. Sherk

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Abstract

Poly(arylene sulfide) oligomers are recovered in a process comprising steps of: (a) dehydration of an aqueous admixture of alkali metal hydroxide such as sodium hydroxide, and alkali metal bisulfide such as sodium bisulfide, in a polar organic solvent such as N-methyl-2-pyrrolidone (NMP), wherein the molar ratio of alkali metal hydroxide to alkali metal bisulfide is about 0.90:1 to about 1.05:1 prior to dehydration and 0.99:1 to about 1.05:1 after dehydration; (b) reaction of at least one polyhalo-substituted aromatic compound such as p-dichlorobenzene with the mixture from step (a) under polymerization conditions to produce a reaction mixture; (c) addition of a phase separation agent such as water, to the reaction mixture to produce a phase-separated poly(arylene sulfide) mixture; (d) cooling the mixture from step (c) to produce a slurry of particulate poly(arylene sulfide) and poly(arylene sulfide) oligomers in a liquid; (e) separating particulate poly(arylene sulfide) from the slurry of step (d) leaving a dispersion of poly(arylene sulfide) oligomers in a liquid; and (f) filtering the dispersion of step (e) to recover the poly(arylene sulfide) oligomers therefrom.

Claims24

Dependent claims

A method for recovering poly(arylene sulfide) oligomers comprising the steps:

(a) dehydrating an aqueous admixture of alkali metal hydroxide and alkali metal bisulfide in a polar organic solvent wherein the molar ratio of alkali metal hydroxide to alkali metal bisulfide is about 0.90:1 to about 1.05:1 thereby forming a dehydrated admixture wherein said molar ratio is 0.99:1 to about 1.05:1;
(b) admixing at least one polyhalo-substituted aromatic compound with said dehydrated admixture to form a polymerization reactant mixture;
(c) subjecting said reactant mixture to polymerization conditions effective to produce a polymerization reaction mixture comprising poly(arylene sulfide);
(d) admixing said polymerization reaction mixture at a temperature above that at which said poly(arylene sulfide) is in a molten phase with a sufficient amount of a separation agent characterized as substantially soluble in said polar organic solvent and a non-solvent for said poly(arylene sulfide) to effect a phase separation of said molten poly(arylene sulfide) from said polar organic solvent;
(e) cooling said polymerization reaction mixture from step (d) to produce a slurry comprising particulate poly(arylene sulfide) and poly(arylene sulfide) oligomers in said polar organic solvent;
(f) treating said slurry to recover particulate poly(arylene sulfide) therefrom and produce a dispersion of poly(arylene sulfide) oligomers in said polar organic solvent;
and
(g) filtering said dispersion of poly(arylene sulfide) oligomers from step (f) to recover said oligomers therefrom.

5 more elements

A method for recovering poly(arylene sulfide) oligomers comprising the steps:

(a) dehydrating an aqueous admixture of alkali metal hydroxide and alkali metal bisulfide in a polar organic solvent, employing a molar ratio of alkali metal hydroxide to alkali metal bisulfide of 0.99/1 to about 1.05:1, thereby producing a dehydrated admixture wherein said molar ratio is 0.99:1 to about 1.05:1,
(b) admixing at least one polyhalo-substituted aromatic compound with said dehydrated admixture to form a polymerization reactant mixture,
(c) subjecting said reactant mixture to polymerization conditions effective to produce a polymerization reaction mixture comprising poly(arylene sulfide);
(d) admixing said polymerization reaction mixture of step (c) at a temperature above that at which said poly(arylene sulfide) is in a molten phase with a sufficient amount of a separation agent that is characterized as substantially soluble in said polar organic solvent and is a non-solvent for said poly(arylene sulfide) to effect a phase separation of said molten poly(arylene sulfide) from said polar organic solvent;
(e) cooling said phase-separated polymerization reaction mixture from step (d) to produce a slurry comprising particulate poly(arylene sulfide) and poly(arylene sulfide) oligomers in a liquid comprising said polar organic solvent and separation agent;
(f) recovering said particulate poly(arylene sulfide) from said slurry produced in step (g) to provide a mixture comprising said poly(arylene sulfide) oligomers, said separation agent and said polar organic solvent;
and
(g) filtering said mixture obtained in step (f) to recover said poly(arylene sulfide) oligomers therefrom.

5 more elements

A method for recovering poly(arylene sulfide) oligomers comprising the steps:

(a) dehydrating an admixture of aqueous alkali metal hydroxide and aqueous alkali metal bisulfide in a polar organic solvent employing a molar ratio of alkali metal hydroxide to alkali metal bisulfide of about 0.90:1 to about 1.05:1, thereby preparing a dehydrated admixture wherein said molar ratio is 0.99:1 to about 1.05:1;
(b) admixing at least one polyhalo-substituted aromatic compound with said dehydrated admixture to form a polymerization reactant mixture;
(c) subjecting said reactant mixture to polymerization conditions sufficient to produce a polymerization reaction mixture comprising poly(arylene sulfide);
(d) admixing said polymerization reaction mixture at a temperature above that at which said poly(arylene sulfide) is in a molten phase with a sufficient amount of a separation agent that is characterized as substantially soluble in said polar organic solvent and is a non-solvent for said poly(arylene sulfide) to effect a phase separation of said molten poly(arylene sulfide) from said polar organic solvent;
(e) cooling said polymerization reaction mixture from step (d) to produce a slurry comprising particulate poly(arylene sulfide) and poly(arylene sulfide) oligomers in said polar organic solvent;
(f) heating said slurry under pressure conditions sufficient to evaporate polar organic solvent, separation agent soluble in said polar organic solvent, and volatile impurities at a temperature below the normal boiling point of said polar organic solvent, thereby producing a dried mixture comprising poly(arylene sulfide), poly(arylene sulfide) oligomers, and alkali metal halide;
(g) reslurrying said dried mixture with water to extract said alkali metal halide and disperse said poly(arylene sulfide) oligomers in a reslurried mixture;
(h) separating particulate poly(arylene sulfide) from said reslurried mixture, leaving a filtrate comprising poly(arylene sulfide) oligomers and aqueous alkali metal halide solution and
(i) filtering said filtrate of step (h) to recover poly(arylene sulfide) oligomers therefrom.

6 more elements

Dependencies are inferred from the claim text.