Patent ID: 8333904
Filing Date: 2012-12-18
Classification: C09K,C23F

Abstract:
1. A process for protecting internal combustion engines comprising magnesium or magnesium alloys against corrosion, said process comprising adding coolant compositions to cooling systems of the internal combustion engines which comprise magnesium or magnesium alloys, which coolant compositions are based on an antifreeze concentrate which has a pH of from 4 to 11, and is based on alkylene glycols or their derivatives or on glycerol, containing a) from 0.05 to 10% by weight, based on the total amount of the concentrate, of one or more carboxamides and/or sulfonamides and wherein when compound a) is aliphatic, amides of said compound a) are unsubstituted or alkyl-substituted on the nitrogen atom of the amido group.