Spinnable carboxymethylated cotton fibers and their production

Claim 1

IN A PROCESS FOR THE PRODUCTION OF FIBERS CONTAINING ONE CARBOXYMETHYL GROUP PER EACH 5 TO 40 GLUCOSE UNITS BY REACTING A CELLULOSIC MATERIAL WITH AQUEOUS MONOCHLOROACETIC ACID AND AN AQUEOUS ALKALI METAL HYDROXIDE, THE IMPROVEMENT WHICH COMPRISES: IMPREGNATING A CELLULOSIC MATERIAL COMPOSED OF SPINNABLE CELLULOSIC FIBERS WITH AQUEOUS MONOCHLOROACETIC ACID; FURTHER IMPREGNATING THE SO TREATED CELLULOSIC MATERIAL WITH AN AQUEOUS ALKALI METAL HYDROXIDE CONTAINING FROM 20 TO 50% ALKALI METAL HYDROXIDE; ALLOWING THE REACTION TO PROCEED UNTIL ONE CARBOXYMETHYL GROUP PER 5 TO 40 GLUCOSE UNITS HAS BEEN INTRODUCED; MECHANICALLY REMOVING THE AQUEOUS REACTANTS; WASHING THE TREATED CELLULOSIC MATERIAL WITH A WATER-MISCIBLE ORGANIC LIQUID SELECTED FROM THE GROUP CONSISTING OF ALKANOLS AND ALKANONES OF NOT MORE THAN FOUR CARBON ATOMS, SAID ORGANIC LIQUID CONTAINING FROM 1 TO 30% WATER; RECOVERING A SPINNABLE, STRONG, PLIABLE, FLEXIBLE CARBOXYMETHYLATED FIBER; AND SPINNING SAID CARBOXYMETHYLATED FIBER.