Recovery of olefin polymers from solution

Claim 1

IN A PROCESS WHEREIN A NORMALLY SOLID POLYMER OF A 1-OLEFIN HAVING A MAXIMUM OF 8 CARBON ATOMS PER MOLECULE AND NO BRANCHING NEARER THE DOUBLE BOND THAN THE 4-POSITION IS PRODUCED BY POLYMERIZATION OF SUCH OLEFIN IN THE PRESENCE OF A LIQUID HYDROCARBON SELECTED FROM THE GROUP CONSISTING OF ACYCLIC PARAFFINS HAVING FROM 5 TO 12 CARBON ATOMS PER MOLECULE, CYCLOHEXANE AND METHYLCYCLOHEXANE AND SAID POLYMER IS OBTAINED IN SOLUTION IN SAID SOLVENT, THE IMPROVEMENT WHICH COMPRISES INTRODUCING SUCH A SOLUTION IN WHICH THE POLYMER CONCENTRATION IS IN THE RANGE 2 TO 8 WEIGHT PERCENT, AT A TEMPERATURE ABOVE 165*F. AND SUFFICIENT TO MAINTAIN SAID POLYMER IN SOLUTION, INTO A COOLING ZONE MAINTAINED AT A TEMPERATURE BETWEEN THE AFOREDESCRIBED TEMPERATURE OF SAID SOLUTION AND 165*F. AND A PRESSURE RANGING FROM ATMOSPHERIC TO ABOUT 50 P.S.I.G., GRADUALLY REDUCING THE PRESSURE IN SAID ZONE, THUS CAUSING SOLVENT VAPORIZATION, TO PRODUCE A GRADUAL LOWERING OF TEMPERATURE, BY EVAPORATIVE COOLING, WITHIN THE RANGE 1 TO 20 FAHRENHEIT DEGREES PER MINUTE, CONTINUING THE DECREASE IN TEMPERATURE AND PRESSURE UNTIL THE PRESSURE REACHES APPROXIMATELY ATMOSPHERIC AND THE TEMPERATURE HAS BEEN LOWERED TO A VALUE IN THE RANGE 165 TO 180*F., THUS PRECIPITATING FROM 25 TO 95 PERCENT OF THE TOTAL DISSOLVED POLYMER IN GRANULAR FORM, PASSING THE RESULTING MIXTURE TO A FLASH ZONE MAINTAINED AT SUBATMOSPHERIC PRESSURE AND A TEMPERATURE IN THE RANGE 75 TO 160*F. AND SUBSTANTIALLY INSTANTANEOUSLY VAPORIZING SOLVENT FROM SAID MIXTURE TO EFFECT EVAPORATIVE COOLING AND PRECIPITATION OF REMAINING DISSOLVED POLYMER, AND RECOVERING POLYMER THUS PRECIPITATED.