Document Type and Number:
Japanese Patent JPS5517761
Kind Code:
B2
Abstract:
1405784 Polymer purification using citric acid SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ NV 12 Sept 1972 [14 Sept 1971] 42244/72 Heading C3P A process for removing metal contaminants (Fe, Ni, Co, Al and/or Li) from a polymer comprises treating the polymer in a water-immiscible solvent with an oxidant and with an aqueous solution of citric acid, which may contain an alcohol, intimately mixing the phases, and separating the aqueous phase from the polymer phase. The contaminants may have been derived from polymerization or hydrogenation catalysts or from piping or vessels. In the examples, a polystyrene-polybutadienepolystyrene block copolymer is hydrogenated in cyclohexane using a nickel acetyl-acetonate - triethyl aluminium catalyst and the solution treated with air or hydrogen peroxide, followed by treatment with the aqueous citric acid solution, which in one case contains isopropanol, and separation of the hydrocarbon and aqueous phases.
Application Number:
JP9100472A
Publication Date:
May 14, 1980
Filing Date:
September 12, 1972
Export Citation:
International Classes:
C08C2/04; C08F6/02; C08F6/00; C08F8/00; C08F8/04; (IPC1-7): C08F6/08