| 摘要 |
A water-insoluble anion-exchange resin comprises a copolymer of from 0,1 to 20% of hexahydro- 1,3,5-triacrylyl-s-triazine and 99,9 to 80% of a monovinyl aromatic compound which is halo-alkylated and aminated to introduce the anion-exchange groups. The copolymer is prepared, preferably in bead form by suspension polymerization in a non-solvent such as water with agents such as methyl cellulose or polyvinyl alcohol, with catalysts such as benzoyl or acetyl peroxides, t-butyl hydroperoxide, or water-soluble persulphates or a ,a 1-azodiisobutyronitrile, or with a Redox system which contains as reducing agent sulphur dioxide, formamidine or p-toluene sulphinic acids, formaldehyde and sodium sulphoxylate. The haloalkylation may be by reacting with for example, formaldehyde and hydrochloric acid, or chloromethyl or bromomethyl methyl ether with zinc chloride catalyst and the amination may be by reacting with amines such as trimethyl, triethyl and dimethylethanol amines, ethylene diamine and N,N1-tetramethyl ethylenediamine or quaternary derivatives thereof. Examples describe the preparation of pearls with particularly high grain compactness which may be used to split sodium chloride solutions. Specifications 654,706, 679,850, 700,470 and 779,994 are referred to. |
