Manufacture of free-flowing watersoluble carboxyalkyl cellulose ethers

Claim 1

A PROCESS FOR CONVERTING FIBROUS CARBOXYALKYL CELLULOSE DERIVATIVES INTO FREE-FLOWING SUBSTANTIALLY GRANULAR POWDER WHICH COMPRISES AGITATING A LOOSE FIBROUS MASS COMPRISING A WATER-SOLUBLE CARBOXYALKYL CELLULOSE DERIVATIVE MOIST WITH AN AQUEOUS ALCOHOL AND CONTAINING WATER AND ALCOHOL IN SUCH PROPORTIONS THAT THE MASS WOULD NORMALLY DRY TO A LOOSE FIBROUS PRODUCT, SIMULTANEOUSLY INTRODUCING THERETO A DISPERSED STREAM OF AQUEOUS FLUID UNTIL THE AMOUNT OF WATER INTRODUCED IS SUFFICIENT TO FORM WITH THE AQUEOUS ALCOHOL PRESENT IN THE MASS AN ACTIVE SOLVENT FOR THE CARBOXYALKYL CELLULOSE DERIVATIVE, SAID ACTIVE SOLVENT CONTAINING AT LEAST ABOUT 67.5% BY WEIGHT OF WATER, MAINTAINING THE TOTAL LIQUID CONTENT IN THE MASS BELOW ABOUT 4 PARTS BY WEIGHT BASED ON THE DRY WEIGHT OF THE CARBOXYALKYL CELLULOSE DERIVATIVE, CONTINUING AGITATION UNTIL THE FIBROUS STRUCTURE OF THE MASS IS SUBSTANTIALLY DESTROYED AND THE CARBOXYALKYL CELLULOSE DERIVATIVE IS CONVERTED INTO A MASS OF SEPARTE, DISCRETE GEL PARTICLES, DISCONTINUING AGITATION WHILE THE MASS IS STILL SUBSTANTIALLY IN THE FORM OF SEPARATE, DISCRETE GEL PARTICLES AND BEFORE SAID GELS COALESCE INTO DOUGHY MASSES, AND DRYING THE GELS THUS FORMED TO OBTAIN A FREEFLOWING SUBSTANTIALLY GRANULAR POWDER.