PROCESS FOR THE PREVENTION OF CORROSION ON METAL MATERIALS IN THE PRODUCTION OF CARBOXYLIC ACID CHLORIDES

摘要

2081374 9113189 PCTABS00007 Process for the prevention of corrosion on metal materials in the production of aliphatic, aromatic or araliphatic carboxylic acid chlorides from phosgene and the corresponding carboxylic acids or carboxylic acid anhydrides in the presence of dialkylised carboxylic acid amines and/or trisubstituted phosphane oxides and/or sulphides as phosgenation catalysts, in which metal compounds with an electron negativity of 1.2 or above or these metals themselves are added to the reaction mixtures once phosgenisation is complete in at least equimolar quantities related to the phosgenisation catalyst as corrosion inhibitors and caused to act at temperatures of some 80 to 180 ·C.