Plasticized sponge material and method of making same

Claim 1

THE METHOD OF MAKING A SOFT, RESILIENT SPONGE MATERIAL HAVING INTERCONNECTED PORES BY REACTING POLYVINYL ALCOHOL AND FORMALDEHYDE, WHICH COMPRISES: PROVIDING AN AQUEOUS SOLUTION OF FORMALDEHYDE, POLYVINYL ALCOHOL CONTAINING LESS THAN 10% RESIDUAL HYDROLYZABLE MATERIAL IN THE MOLECULE, AN ACID CATALYST IN WHICH THE ACID FUNCTIONAL GROUP IS INORGANIC AND HAVING A DISSOCIATION CONSTANT OF AT LEAST 10-2 AND A FROTHSTABILIZING WETTING AGENT SOLUBLE IN AND SUBSTANTIALLY STABLE TO SAID SOLUTION; FORMING A SUBSTANTIALLY STABLE AND HOMOGENEOUS FROTH WITH SAID SOLUTION STABILIZED WITH THE WETTING AGENT; REACTING THE POLYVINYL ALCOHOL AND FORMALDEHYDE IN THE SOLUTION THEREBY CAUSING GELLATION AND SOLIDIFICATION OF THE FROTH WITH THE PRODUCTION OF INTERCONNECTED PORES SIMULTANEOUSLY WITH THE PROGRESSION OF THE REACTION, THE FROTH BEING FORMED PRIOR TO APPRECIABLE REACTION BETWEEN THE POLYVINYL ALCOHOL AND THE FORMALDEHYDE; STOPPING SAID REACTION WHEN APPROXIMATELY 35-80% OF THE HYDROXYL GROUPS OF THE POLYVINYL ALCOHOL HAVE BEEN REACTED WITH THE FORMALDEHYDE; WHEREBY A SPONGE MATERIAL IS FORMED IMPREGNATING SAID SPONGE WITH A LIQUID INCLUDING A MEMBER OF THE CLASS CONSISTING OF SUBSTANTIALLY ANHYDROUS POLYETHYLENE GLYCOLS AND POLYALKANOLAMINES HEATED TO A TEMPERATURE OF UP TO ABOUT 100* C. AND AQUEOUS SOLUTIONS OF SAID AMINES, AND REMOVING EXCESS OF SAID LIQUID UNTIL THERE REMAINS DEPOSITED ON SAID SPONGE ABOUT 20-100% OF SAID LIQUID BASED ON THE DRY WEIGHT OF THE SPONGE.

Claim 2

THE METHOD OF MAKING A SOFT, RESILIENT SPONGE MATERIAL HAVING INTERCONNECTED PORES BY REACTING POLYVINYL ALCOHOL AND FORMALDEHYDE, WHICH COMPRISES: PROVIDING AN AQUEOUS SOLUTION OF FORMALDEHYDE, POLYVINYL ALCOHOL CONTAINING LESS THAN 10% RESIDUAL HYDROLYZABLE MATERIAL IN THE MOLECULE, AN ACID CATALYST IN WHICH THE ACID FUNCTIONAL GROUP IS INORGANIC AND HAVING A DISSOCIATION CONSTANT OF AT LEAST 10-2 AND A FROTHSTABILIZING WETTING AGENT SOLUBLE IN AND SUBSTANTIALLY STABLE TO SAID SOLUTION; FORMING A SUBSTANTIALLY STABLE AND HOMOGENEOUS FROTH WITH SAID SOLUTION STABILIZED WITH THE WETTING AGENT; REACTING THE POLYVINYL ALCOHOL AND FORMALDEHYDE IN THE SOLUTION THEREBY CAUSING GELLATION AND SOLIDIFICATION OF THE FROTH WITH THE PRODUCTION OF INTERCONNECTED PORES SIMULTANEOUSLY WITH THE PROGRESSION OF THE REACTION, THE FROTH BEING FORMED PRIOR TO APPRECIABLE REACTION BETWEEN THE POLYVINYL ALCOHOL AND THE FORMALDEHYDE; STOPPING SAID REACTION WHEN APPROXIMATELY 35-80% OF THE HYDROXYL GROUPS OF THE POLYVINYL ALCOHOL HAVE BEEN REACTED WITH THE FORMALDEHYDE; WHEREBY A SPONGE MATERIAL IS FORMED IMPREGNATING SAID SPONGE WITH A LIQUID INCLUDING A MEMBER OF THE CLASS CONSISTING OF SUBSTANTIALLY ANHYDROUS POLYETHYLENE GLYCOLS AND POLYALKANOLAMINES HEATED TO A TEMPERATURE OF UP TO ABOUT 100* C. AND AQUEOUS SOLUTIONS OF SAID AMINES, AND REMOVING EXCESS OF SAID LIQUID UNTIL THERE REMAINS DEPOSITED ON SAID SPONGE ABOUT 20-100% OF SAID LIQUID BASED ON THE DRY WEIGHT OF THE SPONGE.