E.i. Dupont De Nemours and Company

Magellan Systems International LLC

Dupont Safety & Construction, Inc.

Steven R Allen

Christopher William Newton

David J Rodini

Vlodek Gabara

Joseph Lenning Lowery

Andrew J Sitter

Doetze Jakob Sikkema

Steven Raymond Lustig

Qinghong Fu Adkins

Steven D Moore

Sam Louis Samuels

Aziz A Mian

Joachim C Ritter

Michael Schelhaas

Roger Keith Siemionko

Rajiv Dhawan

Frederick K Mallon

Georg Martin

David M Gale

David M Harriss

Stephen Donald Moore

Hsiang Shih

Ralf Demuth

Catherine Fu Adkins

Steve R Lustig

Stephen D Moore

Quinghong Fu Adkins

The present invention concerns yarn comprising polymer, the polymer comprising imidazole groups, the yarn having a sulfur content of 0.01 to 3.0 percent by weight, based on weight of the yarn, the yarn having a tenacity of 30 cN/dtex (33.3 gpd) or higher.

Aramid copolymer yarn having low residual sulfur

The present invention concerns fiber made from a polymer comprising imidazole groups, the polymer further having: i) halide anions being present in an amount in the range of 0.05 to 20.1 weight percent, based on weight of fiber; ii) sulfur, wherein the sulfur is present in the fiber in an amount in the range of 0.05 to 3 weight percent, based on weight of fiber; and iii) alkali metal ion, wherein the alkali metal ion is present in the fiber in an amount in the range of 0.05 to 2 weight percent, based on weight of fiber, the fiber exhibiting hydrochloric acid evolution as identified by TGA-IR between 277.13&#xb0; C. to 448.19&#xb0; C.

Sulfur and alkali metal containing imidazole fiber having ionically bound halides

The present invention concerns fiber made from a polymer comprising imidazole groups, fiber further having: i) a halide anion, the halide anion being present in an amount of 0.05 to 20.1 weight percent, based on weight of fiber; and ii) sulfur, wherein the sulfur is present in the fiber in an amount of 0.05 to 3 weight percent; the fiber exhibiting hydrochloric acid evolution as identified by TGA-IR between 277.13&#xb0; C. to 448.19&#xb0; C.

Sulfur-containing imidazole fiber having ionically bonded halides

The present invention concerns methods for removing sulfur from yarn comprising the steps of: a) contacting never-dried polymeric yarn with an aqueous base, the polymer comprising imidazole groups and said polymer comprising sulfur atoms characterized as being in the form of sulfate anions; b) contacting the yarn with an aqueous acid comprising a halide; and c) rinsing the yarn.

Process for preparing aramid copolymer yarn using a halide acid wash

The present invention concerns fiber made from a polymer comprising imidazole groups, the polymer further having: i) halide anions being present in an amount in the range of 0.05 to 20.1 weight percent, based on weight of fiber; ii) sulfur, wherein the sulfur is present in the fiber in an amount in the range of 0.05 to 3 weight percent, based on weight of fiber; and iii) alkali metal ion, wherein the alkali metal ion is present in the fiber in an amount in the range of 0.05 to 2 weight percent, based on weight of fiber.

The present invention concerns fiber made from a polymer comprising imidazole groups, fiber further having: i) a halide anion, the halide anion being present in an amount of 0.05 to 20.1 weight percent, based on weight of fiber; and ii) sulfur, wherein the sulfur is present in the fiber in an amount of 0.05 to 3 weight percent.

The present invention concerns processes for reducing water in never-dried fiber comprising copolymer derived from the copolymerization of para-phenylenediamine, 5(6)-amino-2-(p-aminophenyl)benzimidazole; and terephthaloyl dichloride, the process having the following steps in a continuous process, (a) a step of drying a never-dried fiber at less than 100 C until the moisture content of the fiber is less than 60 weight percent; and (b) a step of further drying the fiber above 150&#xb0; C. while the moisture content of the fiber is no more than 40 weight percent; and the fiber being further heated to at least 350&#xb0; C. in either an additional continuous or separate step.

Production of and drying of copolymer fibers

The present invention concerns methods for removing sulfur from yarn comprising the steps of: a) contacting never-dried polymeric yarn with an aqueous base, the polymer comprising imidazole groups and said polymer comprising sulfur atoms characterized as being in the form of sulfate anions; b) contacting the yarn with an aqueous acid solution of pH 5 or lower; and c) rinsing the yarn.

Process for preparing aramid copolymer yarn using an acid wash

The present invention concerns methods for producing a yarn comprising the steps of: (a) producing a plurality of dope filaments by spinning a polymer solution in sulfuric acid through a multi-hole spinneret, the polymer comprising imidazole groups; (b) coagulating the plurality of dope filaments into an as-spun yarn; (c) contacting the yarn with an aqueous base having a pKa less than or equal to 11; and (d) rinsing the yarn.

Process for preparing aramid copolymer yarn having low residual sulfur

The present invention concerns methods for removing sulfur from a fiber comprising the steps of: a) contacting never-dried sulfur-containing fiber in a yarn with an aqueous base having a pKa less than or equal to 11 to release at least a portion of said sulfur, said sulfur comprising, at least in part, sulfate anions and said yarn comprising fiber derived from polymer comprising imidazole groups; and b) rinsing said yarn to remove at least a portion of released sulfur.

Method for removing sulfur from fiber using a weak base

The present invention concerns methods for removing sulfur from a fiber made from a polymer comprising imidazole groups, said method comprising: contacting never-dried sulfate anion-containing polymeric-fiber with an aqueous acid having a pKa of less than 5 to displace at least a portion of the sulfate anions; and b) rinsing the fiber to remove the displaced sulfate ions.

Method for removing sulfur from fiber using an aqueous acid

The present invention concerns methods for removing sulfur from a fiber made from a polymer comprising imidazole groups, said method comprising: a) contacting never-dried sulfate anion-containing polymeric-fiber with an halide-containing acid to displace at least a portion of the sulfate ions with halide anions; and b) rinsing the fiber to remove the displaced sulfate ions.

Method for removing sulfur from fiber using halide acid ion exchange

The present invention concerns processes for producing a yarn comprising polymer comprising imidazole groups, the process having the following steps: (a) spinning a solution of polymer in sulfuric acid to give rise to a plurality of dope filaments; (b) coagulating the plurality of dope filaments into a multi-filament as-spun yarn; and (c) washing the as-spun multi-filament yarn with an aqueous acid comprising a halide or an aqueous salt comprising a halide or combination thereof.

Process for preparing yarn derived from aramid copolymer fiber having low residual sulfur

The present invention concerns methods for removing sulfur from a fiber made from a polymer comprising imidazole groups, said method comprising: a) contacting never-dried sulfate anion containing polymeric-fiber with an aqueous salt solution comprising halide anions to displace at least a portion of the sulfate anions with halide anions; and b) rinsing the fiber to remove displaced sulfate anions.

Method for removing sulfur from fiber using halide salt ion exchange

The present invention concerns methods for removing sulfur from a fiber made from a polymer comprising imidazole groups, said method comprising: a) contacting never-dried sulfate anion containing polymeric-fiber with aqueous salt having monovalent anions to displace at least a portion of the sulfate anions; and b) rinsing the fiber to remove displaced sulfate anions.

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Midlothian, VA, United States of America

Steven R Allen