Process for recovering polytetramethylene ether glycol

Claim 1

THE PROCESS FOR RECOVERING POLYTETRAMETHYLENE ETHER GLYCOL POLYMER FROM A CATALYTICALLY ACTIVE TETRAHYDROFURAN-POLYMER-FLUOSULFONIC ACID MIXTURE CONSISTING ESSENTIALLY OF THE FOLLOWING STEPS: (1) SUBSTANTIALY TERMINATING THE CATALYTIC ACTIVITY OF SAID MIXTURE BY ADMIXING WATER THEREWITH; (2) REMOVING TETRAHYDROFURAN FROM THE MIXTURE RESULTING FROM STEP 1 BY STEAM DISTILLING OR BY HEATING THE WHOLE MASS; (3) ADMIXING A WATER-IMMISCIBLE POLYMER SOLVENT WITH THE TETRAHYDROFURAN-FREE MIXTURE RESULTING FROM STEP 2, THEREBY FORMING A POLYMER SOLUTION, SAID SOLVENT BEING SELECTED FROM UNREACTIVE INERT SOLVENTS WHICH BOIL BELOW 150*C. AT ATMOSPHERIC PRESSURE, WHICH ARE LESS THAN 10% SOLUBLE BY WEIGHT IN WATER BASED ON THE WEIGHT OF WATER, AND WHICH DISSOLVE ONE GRAM OR MORE OF 1000 M.W. POLYTETRAMETHYLENE ETHER GLYCOL POLYMER PER 9 ML. OF SOLVENT; (4) ADMIXING WITH SAID POLYMER SOLUTION A NEUTRALIZER SELECTED FROM THE GROUP CONSISTING OF CARBONATES, BICARBONATES, HYDROXIDES AND OXIDES OF ALKALINE EARTH METALS, AMMONIA, CARBONATES AND BICARBONATES OF ALKALI METALS, AND MIXTURES THEREOF, SAID NEUTRALIZER BEING ADMIXED IN A QUANTITY WHICH IS IN STOCHIOMETRIC EXCESS OF THE ACID REMAINING IN THE POLYMER; (5) REMOVING UNCOMBINED WATER FROM THE MIXTURE RESULTING FROM STEP 4 BY AZEOTROPIC DISTILLATION, OR BY CONTACT WITH SOLID DESICCANTS, SUFFICIENT WATER BEING ADDED DURING THE PROCESS PRIOR TO STEP 5 TO PROVIDE UNCOMBINED WATER IN THE ADMIXTURE RESULTING FROM STEP 4; (6) SUBSTANTIALLY REMOVING SUSPENDED SLIDS BY A MECHANICAL METHOD FROM THE MIXTURE RESLTING FROM STEP 5; AND FINALLY, (7) DISTILLING THE SOLVENT FROM THE MIXTURE RESULTING FROM STEP 6 UNDER REDUCED PRESSURE.