Patent application number | Description | Published |
20140325767 | METHOD FOR REMOVING SULFUR FROM FIBER USING HALIDE ACID 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 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. | 11-06-2014 |
20140331415 | PROCESS FOR PREPARING ARAMID COPOLYMER YARN USING A HALIDE ACID WASH - 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. | 11-13-2014 |
20140336351 | METHOD FOR REMOVING SULFUR FROM FIBER USING A WEAK BASE - 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. | 11-13-2014 |
20140353858 | PROCESS FOR PREPARING ARAMID COPOLYMER YARN HAVING LOW RESIDUAL SULFUR - 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. | 12-04-2014 |
20140356610 | SULFUR-CONTAINING IMIDAZOLE FIBER HAVING IONICALLY BONDED 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. | 12-04-2014 |
20140356611 | SULFUR AND ALKALI METAL CONTAINING IMIDAZOLE FIBER HAVING IONICALLY BOUND HALIDES - 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. | 12-04-2014 |
20150007859 | PROCESS FOR PREPARING ARAMID COPOLYMER YARN USING AN ACID WASH - 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. | 01-08-2015 |
20150021812 | PROCESS FOR PREPARING YARN DERIVED FROM ARAMID COPOLYMER FIBER HAVING LOW RESIDUAL SULFUR - 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. | 01-22-2015 |
20150047130 | 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: 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. | 02-19-2015 |