E.i. Dupont De Nemours and Company

The Chemours Company Fc, LLC

Gregory Allen Chapman

Paul Douglas Brothers

Subhash Vishnu Gangal

David Elton Bidstrup

Adam Paul Smith

Jon Lee Howell

Dipti Dilip Khasnis

A composition comprising a mixture of fluoropolyether acids or salts having a number average value of about 800 to about 2500 g/mol. The amount of fluoropolyether acids or salt in the mixture having a molecular weight of not more than 500 g/mol is not more than 50 ppm by weight of the total amount of fluoropolyether acids or salts in the mixture. The amount of fluoropolyether acids or salts in the mixture having a molecular weight of 2500 g/mol or greater is not more than 40% by weight of the total amount of fluoropolyether acids or salts in the mixture. Preferably the fluoropolyether acids or salts comprise an anionic group selected from the group consisting of carboxylate, sulfonate, sulfonamide anion and phosphonate. Also disclosed is an aqueous dispersion polymerization process for fluoropolymer manufacture employing polymerization agent comprising the specified mixture of fluoropolyether acids or salts.

Aqueous polymerization of fluorinated monomer using a mixture of fluoropolyether acids or salts

A process for reducing thermally induced discoloration of fluoropolymer resin produced by polymerizing fluoromonomer in an aqueous dispersion medium to form aqueous fluoropolymer dispersion and isolating the fluoropolymer from the aqueous medium to obtain fluoropolymer resin. The process comprises contacting the aqueous fluoropolymer dispersion with sorbent.

Fluoropolymer resin treatment employing sorbent to reduce fluoropolymer resin discoloration

Process for reducing thermally induced discoloration of fluoropolymer resin produced by polymerizing fluoromonomer in an aqueous dispersion medium to form aqueous fluoropolymer dispersion and isolating fluoropolymer from said aqueous medium by separating wet fluoropolymer resin from the aqueous medium and drying to produce fluoropolymer resin. The process comprises exposing the wet fluoropolymer resin to an oxygen source during drying.

Drying wet fluoropolymer resin and exposing to oxygen source to reduce discoloration

Process for reducing thermally induced discoloration of fluoropolymer resin produced by polymerizing fluoromonomer in an aqueous medium to form aqueous fluoropolymer dispersion and isolating said fluoropolymer from said aqueous medium to obtain said fluoropolymer resin. The process comprises: heating the fluoropolymer resin to a temperature of about 160&#xb0; C. to about 400&#xb0; C.; and exposing the heated fluoropolymer resin to an oxygen source.

Fluoropolymer resin treatment employing heating and oxygen source to reduce discoloration

Process for reducing thermally induced discoloration of melt-processible fluoropolymer resin produced by polymerizing fluoromonomer in an aqueous medium to form aqueous fluoropolymer dispersion and isolating said fluoropolymer from said aqueous medium to obtain said fluoropolymer resin. The process comprises melt extruding said fluoropolymer resin to produce molten fluoropolymer resin; and exposing said molten fluoropolymer resin to an oxygen source during said melt extruding.

Fluoropolymer resin treatment employing melt extrusion and exposure to oxygen source to reduce discoloration

Process for reducing thermally induced discoloration of fluoropolymer resin produced by polymerizing fluoromonomer in an aqueous dispersion medium to form aqueous fluoropolymer dispersion and isolating said fluoropolymer from the aqueous medium by separating fluoropolymer resin in wet form from the aqueous medium and drying to produce fluoropolymer resin in dry form. The process comprises:

Employing pretreatment and fluorination of fluoropolymer resin to reduce discoloration

Process for reducing thermally induced discoloration of fluoropolymer resin produced by polymerizing fluoromonomer in an aqueous dispersion medium to form aqueous fluoropolymer dispersion and isolating said fluoropolymer from said aqueous medium to obtain said fluoropolymer resin. The process comprises exposing the aqueous fluoropolymer dispersion to ultraviolet light in the presence of an oxygen source.

Fluoropolymer dispersion treatment employing ultraviolet light and oxygen source to reduce fluoropolymer resin discoloration

The present invention relates to the reduction of oligomer content of melt-processible fluoropolymer so that the fluoropolymer has at least 25 ppm less oligomer than the as-polymerized fluoropolymer.

Reduced fuming fluoropolymer

The present invention relates to the reduction of oligomer content of melt-processible fluoropolymer so that the fluoropolymer has at least 25 ppm less oligomer than the as-polymerized fluoropolymer, the reduction being obtained by melting the fluoropolymer forming a surface of molten fluoropolymer and regenerating this surface, contacting the regenerating surface with inert gas, and devolatilizing the resultant molten fluoropolymer.

Process for the preparation of low fuming fluoropolymer

Chemical reactions are carried out with molten fluoropolymer, most conveniently in an extruder, wherein the reaction zone in the extruder is isolated from the melting zone, and the molten fluoropolymer is subdivided in the reaction zone sufficiently that contact and reaction between the reactant and the molten fluoropolymer in the reaction zone is essentially free of mass transfer limitation, followed by devolatilization in isolation from the reaction zone, and cooling the devolatilized fluoropolymer.

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Washington, WV, United States of America

Gregory Allen Chapman