| 摘要 |
<p>1,151,606. Separating xylenes. IMPERIAL SMELTING CORP. (N.S.C.) Ltd. 29 Jan., 1968 [1 Feb., 1967; 21 July, 1967], Nos. 4888/67 and 33647/67. Heading C5E. m-Xylene is separated from p-xylene by adding to a liquid mixture of m-xylene and pxylene, in which the m: p ratio is more than 70: 30, an aromatic substance which forms solid molecular complexes with m-xylene where there is no specific bond to any particular carbon atom, and adjusting the temperature so as to precipitate and remove said complex. The aromatic complexing substance may be a fluorinated benzene, e.g. perfluorobenzene or 1,3,5-trifluoro-2,4,6-trichlorobenzene, or pyromellitic dianhydride. Solvents, such as alcohols, ketones and aliphatic hydrocarbons, which have a b.p. substantially different from both the xylenes and the aromatic substance may be present. A solvent suitable for use in conjunction with perfluorobenzene is methylcyclohexane.</p> |
