| 摘要 |
<p>Continuous preparation of unsaturated carboxylic acid anhydride (A) comprises reacting a ketene with an unsaturated carboxylic acid (B); in an apparatus containing a reaction medium (1) for reacting ketene (3) with (B), a reaction medium (2) for the further reaction of the formed raw anhydride mixture (4), and a rectification column (7) with an upper, middle and lower region, whose sump comprises an inert boiling oil. Continuous preparation of unsaturated carboxylic acid anhydride (A) of formula R-C(O)-O-C(O)-R comprises reacting a ketene (3) with an unsaturated carboxylic acid (B) of formula R-COOH, where the reaction comprises the steps of: (a) providing (B) into a reaction medium (1) of an apparatus; (b) providing the raw anhydride mixture formed in the step (a) into another reaction medium (2), for further reaction; (c) introducing the raw anhydride mixture emerged out of the second medium into a rectification column (7) comprising an upper, middle and lower region, whose sump comprises an inert boiling oil; (d) removing the emerged unreacted components from the top of the rectification column; (e) providing the unreacted educts and formed intermediates in first- and/or second reaction medium for reacting again; and (f) collecting the obtained (A) from the rectification column. R : 2-12C-unsaturated organic remainder.</p> |
