| 摘要 |
Cation exchange resins are made by reacting cross linked resorcinol-aldehyde condensation products with chloracetic acid under alkaline conditions. Specified alkalies are caustic soda, sodium carbonate, ammonia and pyridine. Mono-, di- or trichloracetic acid may be used. The chloracetic acid may be neutralized with alkali before the reaction and excess alkali added slowly to the reaction mixture as the reaction proceeds. In the example, resorcinol is heated with excess formaldehyde and caustic soda at a pH of 9, the resultant gel being dried and granulated and heated with sodium chloracetate and sodium hydroxide solution, the solid resin being separated and washed with water. Specification 598,139, [Group IV], is referred to. |
