| 摘要 |
23305-1111 of the disclosure The present invention relates to a process for the preparation of ion exchange resins of even grain size for analytical and preparative purposes. The process comprises in polymerizing a mixture of styrene and divinyl benzene in the presence of peroxide catalyst and protective colloid in ion-free aqueous medium, removing the volatile impurities, sulfonating the obtained spherical pearl polymer under moderate conditions, eliminating the sulfuric acid medium gradually with water, chloromethylating the pearl polymer with chloromethylether excess and ammonolysing twice. The crude resin is suspended in an aqueous solution of surfactants and centrifuged and the aqueous medium is then replaced by alcoholic medium is the pores of the resin, the dried resin is subjected to air-shifting, the air-shifted product is fractionated by wet sedimentation, the product fraction within + 0.5 micrometer grain size fluctuation is separated, the dried resin is treated first in a mixture of ethanol, methyl-cellosolve and water at 50.degree.C then at 100.degree.C with NaOH, then boiled with HCl, the fractionated resin is filled into chromatographing column, the column is treated with organic aqueous solution containing ions of increasing and then decreasing bond strength and the resin is then subjected to acidic-alkaline treatment by a method known per se. |
