Treatment of a hydrogenated polymer solution after hydrogenation catalyst removal to improve subsequent lithiation reaction

Claim 1

A process for the preparation of a nitrogen-containing functionalized hydrogenated polymer, which comprises: preparing a polymer cement comprising a polymer of a conjugated diene, optionally with a monovinylarene, dissolved in hydrocarbon solvent, hydrogenating the polymer in said polymer cement in presence of a hydrogenation catalyst, thereby producing a hydrogenated polymer cement containing hydrogenation catalyst residues, removing hydrogenation catalyst residues from the hydrogenated polymer cement, alkaline-washing the hydrogenated polymer cement with an aqueous alkaline wash, wherein said alkaline wash step employs an aqueous solution or dispersion of an alkali metal hydroxide, alkaline earth metal hydroxide, ammonium hydroxide, ammonium carbonate, or alkali metal carbonate, wherein said alkaline wash employs an aqueous solution/dispersion containing about 0.5 to 50 percent by weight of said alkaline material in water, and employs a ratio of about 100 to 10,000 ppm alkaline compound relative to polymer cement, water-washing said alkaline-washed hydrogenated polymer cement with water to produce a cleansed polymer cement, lithiating the cleansed hydrogenated polymer cement, and reacting the lithiated polymer cement with a nitrogen-containing organic compound reactive with the lithiated polymer and effective to produce a nitrogen-containing functionalized hydrogenated polymer.