Patent ID: 6177521
Filing Date: 2001-01-23
Classification: C08C,C08F

Abstract:
A method to hydrogenate a polymer containing ethylenic unsaturation comprising the method comprising the steps of:providing a solution or suspension of the polymer containing ethylenic unsaturation with an amount of Group VIII metal alkoxide or carboxylate and metal alkyl hydrogenation catalyst effective to permit hydrogenation of the ethylenic unsaturation upon exposure to hydrogen;exposing the polymer solution or suspension to a hydrogen partial pressure for a time period sufficient to hydrogenate greater than about 90 percent of the ethylenic unsaturation;adding additional Group VIII metal alkoxide or carboxylate and metal alkyl hydrogenation catalyst to the polymer solution or suspension after greater than about 90 percent of the ethylenic unsaturation has been hydrogenated, the amount of additional Group VIII metal alkoxide or carboxylate and metal alkyl hydrogenation catalyst effective to improve separation of hydrogenation catalyst metal from the polymer solution;mixing the hydrogenated polymer solution or suspension with the additional Group VIII metal alkoxide or carboxylate and metal alkyl hydrogenation catalyst with an aqueous solution of an acid; andseparating a hydrogenated polymer solution or suspension that contains less than about 0.8 percent by weight water from the aqueous solution.