Method for preparing polyester polyol sucrose rigid foams

Claim 1

A METHOD OF PREPARING A POLYETHER HAVING A MOLECULAR WEIGHT OF ABOUT 700 TO ABOUT 1800, AND BEING SUBSTANTIALLY FREE OF REACTION BY-PRODUCTS, WHICH COMPRISES FORMING A MIXTURE COMPRISING SUCROSE AND WATER, IN WHICH THE WATER IS PRESENT IN AN AMOUNT FROM ABOUT 5 PERCENT TO ABOUT 90 PERCENT BY WEIGHT BASED UPON THE TOTAL WEIGHT OF SUCROSE AND WATER, INTRODUCING AN ALKYLENE OXIDE SELECTED FROM THE CLASS CONSISTING OF ETHYLENE OXIDE, PROPYLENE OXIDE, 1,2-BUTYLENE OXIDE AND MIXTURES OF THE THREE OXIDES, INCREMENTALLY INTO SAID AQUEOUS MIXTURE IN AN AMOUNT OF ABOUT 10 TO 25 MOLES OF SAID ALKYLENE OXIDE FOR EACH MOLE OF SUCROSE, UNDER A PRESSURE NOT EXCEEDING ABOUT 200 POUNDS PER SQUARE INCH AT A TEMPERATURE OF ABOUT 70*F. TO ABOUT 270F., AND IN THE PRESENCE OF A BASIC OXYALKYLATION CATALYST, THE WATER BEING MAINTAINED IN THE MIXTURE UNTIL SUBSTANTIALLY ALL THE OXIDE PRESENT HAS REACTED, AND REMOVING SUBSTANTIALLY ALL OF THE CATALYST FROM THE REACTION MIXTURE.