| 摘要 |
A strongly basic anion-exchange resin comprises a macromolecular quaternary phosphonium compound in which the groups attached to phosphorus are alkyl, phenyl and at least one alkoxyphenyl group. They may be made by (1) condensing with formaldehyde a quaternary phosphonium compound obtained, for example, by alkylating trianisyl phosphine with dimethyl sulphate or by reacting trianisyl or triphenetyl phosphine with an alkoxyphenyl magnesium bromide in the presence of free oxygen; or (2) alkylating, e.g. with dimethyl sulphate, a macromolecular product containing tertiary phosphine groups, made, for example, by condensing phenetyl-diphenyl, dianisyl-methyl, dianisyl-phenyl or triphenetyl phosphine with formaldehyde. Reaction (1) may be carried out in the presence of added phenol or alkoxybenzene. In the example, trianisyl-methyl or tetra-anisyl phosphonium sulphate is condensed with paraformaldehyde in concentrated sulphuric acid at 40 DEG -50 DEG C. and the gel further heated at 50 DEG -60 DEG C. After washing in sodium hydroxide solution the resin is used to remove silicic acid from water. The product may be cast or moulded in the form of pellets, plates, foils or granules. Specification 737,924 is referred to. |
