A benzotriazole derivative as a pretreatment corrosion inhibitor for copper and copper alloys

摘要

The Protection action of 1- [(2-ethylhexylamino) methyl] benzotoriazole (BT-260) as a pretreatment inhibitor on the corrosion of copper and three copper alloys in 0.5M NaCl and 0.5M Na{sub}2SO{sub}4 at 30℃, as compared with benzotriazole (BTA) has been investigated by means of solution analysis, potentiodynamic polarization technique and time of flight secondary ion mass spectroscopy (TOF-SIMS). Overall inhibition of copper corrosion by the pretreatment of BT-260 increased with its concentration to a maximum 98% at 50mM level. This was superior to BTA under the same conditions. Solution analysis indicated that the BT-260 pretreatment confers protection to 70/30 brass, 60/40 brass and phosphorus bronze in neutral and alkaline 0.5M Na{sub}2SO{sub}4 and 0.5M NaCl solutions. Polarization studies showed that BT-260 acts to suppress cathodic and anodic corrosion reactions. TOF-SIMS spectra suggested that structure of the protective layer formed on copper surface by the pretreatment of BT-260 was a polymeric layer of [-Cu(I) · BTA -]{sub}n (n = 1～6) modified with hydrophobic alkyl chain fragment of N (CH{sub}2) (C{sub}8H{sub}17) H.