| 摘要 |
An anion exchange material as claimed in the parent Specification is modified by suitable selection of the raw materials so that 10-60 per cent of the groups attached to the sulphur atoms of the sulphonium groups are aryl or alkylaryl, the remainder being alkoxyaryl. Preferably a low molecular weight sulphonium compound is prepared by reacting sulphur dioxide or a thionyl halide with a mixture of an alkoxy aryl compound and an aryl or alkaryl compound, e.g. toluene or xylene, in the presence of sufficient of a substance promoting catinoid substitution, e.g. AlCl3, to ensure that the derived proportion of aryl or alkaryl compound enters the molecule and the sulphonium compound is then reacted with formaldehyde or a formaldehyde-yielding substance in presence of sulphuric acid. In preparing the sulphonium compound excess aromatic hydrocarbon will act as an inert solvent. The products may be obtained as foils or may be broken and screened to grains. Pellets may be obtained by dispersing the ingredients in an indifferent solvent. In example (1) AlCl3 was dissolved in anisole and toluene and dry gaseous SO2 was introduced. After stirring with rise of temperature the mixture was poured into water and steam introduced with removal of toluene. The sulphonium salt having 45 per cent methoxyphenyl and 55 per cent methyl phenyl group attached to S was extracted with chloroform and condensed to a resin with paraformaldehyde and H2SO4. Example 2 is similar with benzene instead of toluene. Example 3 is similar to Example 1. In Example 4 a sulphonium salt as in Example 3 (2 methoxy and 1 methyl phenyl group per S atom) was mixed with trianisyl sulphonium chloride and condensed with paraformaldehyde in presence of H2SO4. Example 5 is similar to Example 1 with xylene replacing toluene and the sulphonium salt containing about 1.8 methoxy groups per molecule. The products are particularly effective for removing silicic acid from water.ALSO:Sulphonium compounds in which 10-60 per cent of the groups attached to S are aryl or alkaryl the remainder being alkoxyaryl are prepared by reacting SO2 or thionyl halide with a mixture of an alkoxy aryl compound and an aryl or alkaryl compound in presence of such an amount of substance promoting cationoid substitution that the desired amount of each compound enters into reaction. In Examples 1, 3, 4 AlCl3 was dissolved in anisole and toluene. Dry SO2 was introduced at 0 DEG C. and stirring continued while the temperature was raised to 50 DEG C. The mixture was poured into water, toluene distilled off and the sulphonium compound having 45 per cent methoxyphenyl and 55 per cent methyl phenyl groups attached to S was extracted with chloroform from the aqueous solution. Example 2 is similar using benzene in place of toluene, and Example 5 uses a mixture of anisole and xylene. |
