Solvent decovery of resins from precipitated asphalt

Claim 1

A PROCESS FOR RECOVERING SUBSTANTIALLY OIL-FREE HIGH VISOCITY INDEX RESINS AND SUBSTANTIALLY OIL-FREE AROMATIC TYPE RESINS IN PETROLEUM WHICH COMPRISES CONTACTING A RESIDUAL STOCK WITH A LIQUID, NORMALLY GASEOUS PARAFFIN PRECIPITANT TO PRECIITATE AN ASPHALT FRACTION WHICH CONTAINS A RAW RESINOUS FRACTION, CONTACTING THE ASPHALT FRACTION WITH A BUTANE SOLVENT AT A BUTANE TO ASPHALT RATIO EXCEEDING ABOUT 5 TO 1 AT AN ELEVATED TEMPERATURE BELOW THE CRITICAL TEMPERATURE OF THE SOLVENT AND UNDER SUPERATMOSPHERIC PRESSURE SUFFICIENT TO MAINTAIN THE SOLVENT IN LIQUID PHASE, SEPARATING THE RAW RESINOUS FRACTION AS EXTRACT, STRIPPING THE SOLVENT FROM THE RAW RESINOUS FRACTION, SUBJECTING THE RAW RESINOUS FRACTION TO EXTRACTION AT A TEMPERATURE OF ABOUT 160* TO 260* F. WITH A SELECTIVE SOLVENT HAVING A HIGH SELECTIVITY FOR AROMATIC COMPONENTS AT A TOTAL SOLVENT TO RAW RESIN RATIO OF ABOUT 0.5 TO 5:1, AND RECOVERING A HIGH VISCOSITY INDEX RESINOUS FRACTION FROM THE RAFFINATE AND AN AROMATIC RESINOUS FRACTION FROM THE EXTRACT.