Patent ID: 8058356

Claim:
A method for manufacturing a substantially hydrogenated block copolymer, comprising: hydrogenating a block copolymer of a vinyl aromatic polymer block and a conjugated diene polymer block by contacting with a hydrogenating agent in the presence of a hydrogenation catalyst to obtain a polymer solution including a hydrogenated block copolymer having a hydrogenation level of greater than 90 percent and a solvent; filtering said polymer solution before removing said solvent from said polymer solution; adding an antioxidant into said polymer solution after filtering said polymer solution, removing said solvent from said polymer solution by a flash devolatilization at a temperature of 200 to 300Â° C. and a pressure of 1 to 10 Bar to obtain a concentrated polymer solution with a residual solvent in an amount of 1 to 50 weight percent based on the total weight of said concentrated polymer solution; and removing said residual solvent from said concentrated polymer solution by a devolatilizer at a pressure below 100 torr to isolate said hydrogenated block copolymer.