| 摘要 |
A cation-exchange resin is made by reacting an aromatic or hydro-aromatic hydrocarbon which is liquid at room temperature (e.g. benzene, toluene or xylene) with a polyhalogenated paraffin in presence of a Friedel-Crafts catalyst until the product becomes hard, infusible and inelastic and treating this product with a sulphonating agent. Specified halogenated paraffins are ethylene halides, 1-3-dihalopropanes; 1, 2, 4-trihalobutanes, and 1, 2, 3, 5-tetrahalopentanes. Reaction may be performed in presence of an aromatic hydrocarbon which is solid at room temperature (e.g. naphthalene). The reaction is performed by heating 1 mol. of the hydrocarbon with more than 1.3 mols. of the polyhalogenated paraffin at 75-80 DEG C. until a plastic, elastic mass is obtained which is then heated for about 1-2 hours until it becomes hard, infusible and inelastic. Sulphonation is then effected by concentrated or fuming sulphuric acid or by chlorosulphonic acid, if desired in presence of ammonium vanadate. The sulphonated resins may be used for softening water; for removing copper from ammoniacal solutions (e.g. in the cuprammonium rayon industry); or as catalysts for effecting acetylation of carbohydrates, esterification or etherification [see Group IV (b)]. In examples the following are reacted with ethylene chloride in presence of aluminium chloride (1), (2) and (5) toluene, (3) benzene, (4) toluene benzene and naphthalene. The products are then sulphonated. U.S.A. Specification 2,235,971 is referred to.ALSO:Esters, ethers and acetyl carbohydrates are prepared in presence of a catalyst which is a sulphonated cation-exchange resin made by condensing a liquid aromatic or hydro-aromatic hydrocarbon with a poly-halogenated paraffin in presence of a Friedel-Crafts catalyst and sulphonating the product (see Group IV (a)). The esters and ethers may be prepared continuously by passing the alcohol and acid, or alcohol alone through a column packed with the cation-exchanger. Esters.-Butylene-glycol-bis-valeriate is made by heating a mixture of valerianic acid, butylene glycol, toluene and the cation-exchange resin. After all water has been distilled off, the exchanger is filtered off and the product distilled under 15 mm. pressure. Acetyl carbohydrates are prepared by boiling the carbohydrate, e.g. dextrose, dextrin or starch with acetic anhydride in presence of the cation-exchange resin. Ethers. Specified are ethers derived from ethyl, butyl, dodecyl and octadecyl alcohols. In examples: (8) dodecyl alcohol and the cation-exchange resin is heated in an open flask. After distillation of the water, the heating is continued for 8-12 hours. Then the reaction mass is filtered and the filtrate which includes didodecyl ether distilled in vacuo. (9) Diethyl ether is prepared in an apparatus comprising a vertical iron tube connected 10 cm. below its top with a condenser and surrounding another tube extending almost to the bottom of the outer tube. The space between the two tubes is packed with the cation-exchange resin. The apparatus is heated to 170-180 DEG C. and ethyl alcohol introduced into the top of the inner tube at the same rate at which the reaction mixture distils off. The reaction mixture is then fractionally distilled to yield ethyl alcohol, which is recycled, and diethyl ether.ALSO:Ammoniacal copper salt solutions of the cuprammonium rayon industry may be worked up by means of sulphonated cation-exchange resins made by reacting an aromatic or hydroaromatic hydrocarbon with a polyhalogenated paraffin in presence of a Friedel-Crafts catalyst and sulphonating the products. The resins take up 8-10 per cent. of their weight of copper. |
