Process for producing cellular insulating materials

Claim 1

IN THE MANUFACTURE OF CELLULAR THERMAL INSULATION FROM A SLURRY HAVING A FINELY DIVIDED AND REACTIVE SOLIDS CONTENT CONSISTING ESSENTIALLY OF SILICA AND AN ALKALINE EARTH METAL OXIDE PRESENT IN PROPORTIONS SUFFICIENT TO REACT AND FORM A THICK GELATINOUS MASS AT TEMPERATURES OF ABOUT 98*C.-107*C., THE METHOD WHICH COMPRISES: DISPERSING THROUGHOUT SAID SLURRY AN ABSORBENT SLURRY-INSOLUBLE AND CHEMICALLY INERT CARRIER IMPREGNATED WITH A SLURRY-INSOLUBE LIQUID, SAID SLURRY-INSOLUBLE LIQUID BEING CHEMICALLY INERT WITH RESPECT TO SAID SLURRY AND HAVING A VAPOR PRESSURE SLIGHTLY GREATER THAN SATURATED STEAM WITHIN THE TEMPERATURE RANGE OF APPROXIMATELY 98*C.-107*C., BUT NOT GREATER THAN THAT OF SATURATED STEAM AT TEMPERATURES IN EXCESS OF APPROXIMATELY 107*C.; REACTING SAID DISPERSION TO A SEMI-SOLID SHAPE RETAINING CONDITION WHILE CONCURRENTLY VAPORIZING SAID SLURRY-INSOLUBLE LIQUID TO FORM A CELLULAR BODY CONTAINING A MYRIAD OF INDEPENDENT AND UNCONNECTED CELLS OF SUBSTANTIALLY UNIFORM SIZE BY HEATING SAID DISPERSION TO A TEMPERATURE WITHIN THE TEMPERATURE RANGE OF APPROXIMATELY 98*C.-107*C. UNDER A PRESSURE LESS THAN THE VAPOR PRESSURE OF SAID SLURRY-INSOLUBLE LIQUID, BUT NOT LESS THAN THE VAPOR PRESSURE OF SAID SLURRY.