| 摘要 |
<p>1377333 Aromatic carboxylic acids SUN RESEARCH & DEVELOPMENT CO 2 Feb 1973 [3 Feb 1972] 5245/73 Heading C2C Aromatic carboxylic acids are made from aromatic nitriles by a process which comprises the non-catalytic hydrolysers of an aqueous solution of said nitriles at 200‹ to 300‹ C. in the presence of recycled hydrolysis product of said nitrile, venting steam and ammionic vapours at about 200‹ to about 300‹ C. and at autogenous pressure, cooling to precipitate the aromatic carboxylic acid, separating said solid acid from the solution of soluble hydrolysis products and recycling said aqueous solution to a subsequent hydrolysis. Nitriles and/or other precursors of nitrile hydrolysis products can be added to the reaction mixture. To ensure that the acid products have a significantly lowered nitrogen content, the hydrolysis medium should contain 0À2 to 2À0 recycle carboxylic acid, hydrolysis equivalents per equivalent of nitrile charged. Examples of the nitriles used in the process are benzonitrile, phthalonitrile, terephthalonitrile, isophthalonitrile, toluonitriles and naphthonitriles.</p> |
