Preparation of carboxyalkyl cellulose derivatives

Claim 1

A PROCESS OF BLEACHING, REDUCING THE VISCOSITY, AND DENSIFYING LOWER CARBOXYALKYL CELLULOSE DERIVATIVES IN A SINGLE OPERATION WHICH COMPRISES AGITATING A LOOSE FIBROUS MASS INCLUDING A WATER-SOLUBLE LOWER CARBOXYALKYL CELLULOSE DERIVATIVE MOIST WITH AN AQUEOUS ALKANOL AND CONTAINING WATER AND ALKANOL IN SUCH PROPORTIONS THAT THE MASS WOULD NORMALLY DRY TO LOOSE FIBROUS PRODUCT, INTRODUCING TO THE MASS DURING AGITATION A BLEACHING VICOSITY REDUCING AGENT SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL, ALKALINE EARTH AND AMMONIUM HYPOHALITES, PEROXIDES AND PERIODATES, INTRODUCING TO THE MASS DURING AGITATION A DISPERSED STREAM OF AQUEOUS FLUID AS A DENSIFYING AGENT UNTIL THE AMOUNT OF WATER PRESENT IS AT LEAST SUFFICIENT TO CAUSE INCIPIENT GELATION AT THE SURFACE OF THE INDIVIDUAL FIBERS, MAINTAINING THE TOTAL LIQUID CONTENT IN THE MASS BELOW ABOUT 4 PARTS BY WEIGHT BASED ON THE DRY WEIGHT OF THE CARBOXYALKYL CELLULOSE DERIVATIVE, AND SUBSTANTIALLY DRYING THE RESULTING MASS.