Process for modifying urea-formaldehyde solid foam

Claim 1

A PROCESS FOR PREPARING A SOLID UREA-FORMALDEHYDE FOAM WHICH COMPRISES EMULSIFYING AN INERT ORGANIC WATERINSOLUBLE LIQUID IN AN AQUEOUS UREA-FORMALDEHYDE RESIN SOLUTION HAVING A VISCOSITY WITHIN THE RANGE OF 200 TO 10.000 CENTIPOISES, THE QUANTITY OF SAID LIQUID BEING FROM 0.02 TO 0.30 PARTS BY WEIGHT PER UNIT WEIGHT OF UREAFORMALDEHYDE, SAID EMULSIFICATION BEING CARRIED OUT IN THE PRESENCE OF AN EMULSIFYING AGENT, INTRODUCING INTO THE EMULSION A CURING AGENT CAPABLE OF ACID-CURING SAID UREAFORMALDEHYDE, VAPORIZING THE SAID LIQUID, SUBJECTING THE RESULTANT MIXTURE, MADE UP OF CELLS CONTAINING THE SAID VAPORS. TO THE HARDENING ACTION OF SAID ACID-CURING CATALYST IN THE PRESENCE OF 10% TO 35%, BASED ON THE WEIGHT OF THE SAID RESIN, OF POLYETHYLENE GLYCOL, HAVING 3 TO 50 OXYETHYLENE GROUPS PER MOLECULE BY MAINTAINING THE MIXTURE AT A CURING TEMPERATURE ABOVE THE BOILING POINT OF THE SAID INERT ORGANIC LIQUID, SAID CURING TEMPERATURE BEING NOT IN EXCESS OF 115*C. WHEREBY A SOLID FOAM OF SUBSTANTIALLY CLOSED CELL STRUCTURE IS OBTAINED.