| 摘要 |
Relates to an ion-exchange product having at least one small dimension of the order of one-tenth to twenty mils, which is in the form of a fibre, film or like shaped product, and which is a cross-linked product of a linear addition polymer, the product containing, based on the average number of recurring units in the linear addition polymer, at least 7% of ion-exchange groups and at least 0,5% of cross-linkages. The Specification contains particulars of many types of cross-linked ion-exchange resins which may be utilized. In Examples, (1) an aqueous dispersion of a copolymer of acrylonitrile, butoxyethyl acrylate, and methoxymethyl vinyl sulphide is spun, stretched, oxidized to give cross-linkages and then hydrolyzed to introduce carboxylic groups; (2) a copolymer of acrylonitrile, ethyl acrylate and ureidopentyl vinyl ether is spun from solution in dimethyl formamide, stretched, cross-linked by reaction with toluene-2, 4-diisocyanate and then hydrolysed; (4) a copolymer of ethyl acrylate, acrylonitrile and glycidyl methacrylate is spun from aqueous dispersion, stretched, cross-linked by reaction with hexamethylene diamine and then hydrolysed; (5) a copolymer of acrylonitrile and methyl acrylate is spun from aqueous dispersion, aminated with dimethylaminopropylamine, stretched, cross-linked by treatment with p-xylylene dichloride, and then hydrolysed; (6) a copolymer of acrylonitrile, ethyl acrylate, methoxymethyl vinyl sulphide and the butyl ester of ethylene sulphonic acid is spun from solution in dimethylformamide, stretched, acidified to liberate sulphonic acid groups and then cross-linked by oxidation; (8) a product of the type formed in Example 5 is treated with a ceric salt to form a product suitable for the production of a cylindrical filter wad for insertion into the end of a cigarette. Specifications 812,140, 815,745, 834,410, 835,550 and 885,865 are referred to.ALSO:An anion-exchange resin in fibre form (see Group IV(a)) may be treated with an anionic ceric salt, such as an anionic ceric sulphate or nitrate complex, in aqueous solution to provide an oxidative resin which may be incorporated in filters used in cigars, cigarettes or smokers' pipes. Specifications 812,140, 815,745, 834,410, 835,550 and 858,865 are referred to.
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