Recovery of resinous compositions consisting of, and including, polyphenylene ethers in particulate form from liquid media

Claim 2

A process for recovering a resinous composition consisting of or including a polyphenylene ether resin from a liquid medium having a component which vaporizes readily, said process comprising introducing the resinous composition and said liquid medium into an enclosed chamber through means to effect the atomization thereof, said resinous composition and said liquid medium being at a temperature of from about 15°C to about 32°C, atomizing the resinous composition and said liquid medium under pressure into said enclosed chamber and producing an atomized spray of fine droplets of the resinous composition and said liquid medium in said chamber, mixing the fine droplets in said chamber with a hot inert gas, a superheated vaporized form of said component, or a mixture thereof, and flashing off said component which vaporizes readily, thereby forming particles of said resinous composition and a vaporized mixture of said component which vaporizes readily and said inert gas or said superheated vaporized form of said component, removing said vaporized mixture from said chamber, and collecting the resinous composition in a discrete particulate form.

Claim 3

A process as defined in claim 1 wherein said resinous composition comprises a polyphenylene ether, a blend of a polyphenylene ether and a styrene resin or a graft copolymer of a polyphenylene ether and a styrene resin.

Claim 4

A process as defined in claim 2 wherein said polyphenylene ether is poly(2,6-dimethyl-1,4-phenylene)ether.

Claim 5

A process as defined in claim 2 wherein said resinous composition comprises a polyphenylene ether, a blend of a polyphenylene ether and a styrene homopolymer resin or a graft copolymer of a polyphenylene ether with a styrene homopolymer resin.

Claim 6

A process as defined in claim 2 wherein said resinous composition comprises a polyphenylene ether, a blend of a polyphenylene ether and a rubber modified high impact polystyrene or a graft copolymer of a polyphenylene ether with a rubber modified high impact polystyrene.

Claim 7

A process as defined in claim 1 wherein the hot inert gas passes co-currently to the direction of flow of said droplets.

Claim 8

A process as defined in claim 1 wherein the resinous composition and liquid medium is introduced at the top of the chamber and the particles are removed from the bottom of the chamber.

Claim 9

A process as defined in claim 1 including the step of recovering the vaporized component from said volatilized mixture and heating and recycling the inert gas into said enclosed chamber.

Claim 10

A process as defined in claim 8 including the step of recovering fine particles of said resinous composition from said volatilized mixture before recycling said inert gas into said enclosed chamber.

Claim 11

In a process for forming a polyphenylene ether by an oxidative coupling reaction in the presence of a metal-amine complex catalyst comprising passing an oxygen-containing gas through a reaction solution of a phenol and said metal-amine catalyst in a reaction solvent, said reaction solution being capable of liquid-liquid extraction with an aqueous solution, and terminating the reaction and separating the metal-amine catalyst residue from the reaction solution by contacting the reaction solution with an aqueous solution of mineral acid, organic acid, carbon dioxide or a mixture thereof in a countercurrent liquid-liquid extraction column and then separating the aqueous solution, the improvement which comprises feeding the aqueous solution-treated reaction solution into an enclosed chamber through means to effect the atomization thereof, said aqueous solution treated reaction solution being at a temperature of from about 15°C to 32°C, atomizing the aqueous solution-treated reaction solution under pressure into said enclosed chamber and producing an atomized spray of fine droplets of the reaction solution in said chamber, mixing the fine droplets in said chamber with a hot inert gas, superheated vaporized solvent or a mixture thereof and flashing off the solvent in the droplets to form solvent-free particles of said polyphenylene ether and a vaporized mixture of the solvent and said inert gas, removing said vaporized mixture from the chamber, and collecting the polyphenylene ether in a discrete particulate form.

Claim 12

In a process for forming a polyphenylene ether by an oxidative coupling reaction in the presence of a metal-amine complex catalyst comprising passing an oxygen-containing gas through a reaction solution of a phenol and said metal-amine catalyst in a reaction solvent, said reaction solution being capable of liquid-liquid extraction with an aqueous solution, and terminating the reaction and separating the metal-amine catalyst residue from the reaction solution by contacting the reaction solution with an aqueous solution of mineral acid, organic acid, carbon dioxide or a mixture thereof in a countercurrent liquid-liquid extraction column and then separating the aqueous solution, the improvement which comprises feeding the aqueous solution-treated reaction solution into an enclosed chamber through means to effect the atomization thereof, said aqueous solution treated reaction solution being at a temperature of from about 15°C to 32°C, atomizing the aqueous solution-treated reaction solution under pressure into said enclosed chamber and producing an atomized spray of fine droplets of the reaction solution in said chamber, mixing the fine droplets in said chamber with a hot inert gas, superheated vaporized solvent or a mixture thereof and flashing off the solvent in the droplets to form solvent-free particles of said polyphenylene ether and a vaporized mixture of the solvent and said inert gas, removing said vaporized mixture from the chamber, and collecting the polyphenylene ether in a discrete particulate form.

Claim 13

A process as defined in claim 10 wherein the reaction solution comprises a phenol, a metal-amine catalyst and an aromatic solvent.

Claim 14

A process as defined in claim 11 wherein the aromatic solvent is selected from the group consisting of benzene, toluene and xylene.

Claim 15

A process as defined in claim 10 wherein the inert gas is nitrogen.

Claim 16

A process as defined in claim 10 wherein the polyphenylene ether is poly(2,6-dimethyl-1,4-phenylene)ether having at least 50 repeating units.

Claim 17

A process as defined in claim 12 wherein the aqueous solution-treated reaction solution fed to the enclosed chamber comprises from about 5 to about 40% by weight of polyphenylene ether in benzene.

Claim 18

A process as defined in claim 12 wherein said aqueous solution-treated reaction solution fed to the enclosed chamber comprises from about 5 to about 40% by weight of polyphenylene ether in toluene.

Claim 19

A process as defined in claim 1 wherein said liquid medium is selected from the group consisting of benzene, toluene and xylene.

Claim 20

A process as defined in claim 17 wherein said liquid medium is toluene.

Claim 21

A process as defined in claim 12 wherein said aromatic solvent is toluene.