Preparation of finely-divided cellulose derivative compositions

Claim 1

THE PROCESS FOR PREPARING UNIFORMLY SMALL, SOLID SPHEROID PARTICLES OF OGRANOSOLUBLE CELLULOSE DERIVATIVE COMPOSITION WHICH CONSISTS ESSENTIALLY OF EMULSIFYING A LACQUER IN WATER TO FORM A LACQUER-IN-WATER EMULSION, SAID LACQUER CONTAINING ORGANOSOLUBLE CELLULOSE DERIVATIVE COMPOSITION DISSOLVED IN A LOW-BOILING SUBSTANTIALLY WATER-IMMISCIBLE SOLVENT THEREFOR, SAID SOLVENT HAVING A BOILING POINT BELOW THE BOILING POINT OF WATER, FORMING FINE MIST-LIKE DROPLETS OF THE LACQUER-IN-WATER EMULSION BY SPRAYING SAID EMULSION AT A TEMPERATURE BELOW THE BOILING POINT OF THE LACQUER SOLVENT THEREIN INTO AN ENCLOSED VESSEL CONTAINING A STEAM ATMOSPHERE AT SUBSTANTIALLY ATMOSPHERIC PRESSURE ADJACENT THE TOP THEREOF, SIMULTANEOUSLY INTRODUCING A QUANTITY OF STEAM INTO THE ENCLOSED VESSEL ADJACENT THE LOWER END THEREOF SUFFICIENT IN TOTAL ENTHALPY CONTENT TO VAPORIZE SUBSTANTIALLY ALL OF THE LOW-BOILING SUBSTANTIALLY WATER-IMMISCIBLE SOLVENT FROM THE EMULSION DROPLETS, EVAPORATING SUBSTANTIALLY ALL OF THE LOW-BOILING SUBSTANTIALLY WATER-IMMISCIBLE SOLVENT FROM THE EMULSIFIED LACQUER DROPLETS BY STEAM STRIPPING WHILE SAID EMULSIFIED LACQUER DROPLETS ARE DESCENDING THROUGH THE STEAM ATMOSPHERE TO PRECIPITATE SUBSTANTIALLY ALL OF THE ORGANOSOLUBLE CELLULOSE DERIVATIVE COMPOSITION AS UNIFORMLY SMALL, SOLID SPHEROIDS HAVING DIAMETERS NOT EXCEEDING ABOUT 5 MICRONS IN THE WATER OF THE DESCENDING EMULSION DROPLETS, SETTLING THE WATER DROPLETS CONTAINING THE PRECIPITATED SPHEROIDS TO FORM A WATER SUSPENSION OF SAID SPHEROIDS IN THE BOTTOM OF THE VESSEL, WITHDRAWING VAPORS CONSISTING ESSENTIALLY OF A MIXTURE OF SOLVENT VAPOR AND WATER VAPOR FROM THE ENCLOSED VESSEL, AND WITHDRAWING THE WATER SUSPENSION OF SOLID SPHEROIDS FROM THE ENCLOSED VESSEL.