Method for protecting metal surfaces against corrosion in liquid or gaseous media

US6261346A · kind A · utility

Assignee

• Cognis Deutschland GmbH · DE

Inventors

• Wolfgang Breuer · Korschenbroich, DE
• Robert W. Schuetz · Tönisvorst, DE
• Guenther Uphues · Monheim, DE
• Claus-Peter Herold · Mettmann, DE
• Rafael Pi · Granollers, ES

Key dates

• Filing date: Jul 29, 1999
• Grant date: Jul 17, 2001
• Expiry date: Jul 29, 2019

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C23F11/145
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A process useful for protecting metal surfaces against corrosion in is presented involving: (a) forming a corrosion inhibitor having a compound corresponding to formula (I): ##STR1## PA1 where R.sup.1, R.sup.2 and R.sup.3 independently of one another represent an alkyl or hydroxyalkyl group containing 1 to 4 carbon atoms, an aryl or alkylaryl group or a group corresponding to formula (II): ##STR2## PA1 A.sup.- is an anion, n is the number 2 or 3, p is a number of 1 to 3 and R.sup.5 is an alkyl or alkenyl group containing 7 to 23 carbon atoms and 0, 1, 2 or 3 double bonds, and R.sup.4 is a group corresponding to formula (II) or (III): ##STR3## PA2 where R.sup.1, R.sup.2 and R.sup.3 are as defined above and Z is a group --(CH.sub.2).sub.m -- or a group corresponding to formula (IV): ##STR4## PA2 m is an integer of 1 to 6, X is a group NH or an oxygen atom and D is a dimer fatty acid residue containing on average 36 to 54 carbon atoms; (b) combining the corrosion inhibitor with liquid aqueous, liquid non-aqueous or gaseous media; and (c) contacting the corrosion inhibitor with metal. The corrosion inhibitor used in the is biodegradable and shows low aquatic toxicity.