Method for removing hydrogenation catalyst residues from hydrogenated conjugated diene polymers
AssigneeShell Oil Company
InventorsCarl L. Willis, Lynn H. Slaugh
Life of this patent
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Abstract
A process is disclosed for removing hydrogenation catalyst residues from hydrogenated conjugated diene polymers by contacting a hydrocarbon solution of said polymers with an aqueous dilute solution of an alpha-hydroxysulfonic acid, separating the aqueous phase from the hydrocarbon phase, removing the hydrocarbon solvent from the hydrocarbon phase, producing a solid polymer, and applying heat and/or vacuum to the solid polymer to remove the residual alpha-hydroxysulfonic acid.
Claims7
A process for removing transition metal hydrogenation catalyst residues from hydrogenated conjugated diene polymers which comprises (1) contacting a hydrocarbon phase which comprises the hydrogenated polymer, the catalyst residue and a hydrocarbon solvent with an aqueous solution of an alpha-hydroxy-sulfonic acid of the general formula R.sub.1 R.sub.2 COHSO.sub.3 H wherein R.sub.1 and R.sub.2 are individually hydrogen or hydrocarbyl of up to about 7 carbon atoms, (2) separating the aqueous phase from the hydrocarbon phase, (3) removing the hydrocarbon solvent from the hydrocarbon phase, producing a solid polymer phase and (4) applying heat and/or vacuum to the solid polymer to remove residual alpha-hydroxysulfonic acid.
Dependencies are inferred from the claim text.