New corrosion inhibitor compositions based on salts of mercapto acids and imidazoline(s)

摘要

Corrosion inhibitor compositions for iron and ferrous metals in carbonated salt solutions comprise an active constituent based on an alkyl-poly(ethylamino)-imidazoline or 2-alkyl 3-(ethyl-amino)-1,3,diazoline of formula (I) and a mercaptoacid of formula R1-(R2CR3)-R4CR5-A (II). R = 10-22C hydrocarbyl(optionally unsaturated); n = 0-3; n = 0-3; R1 = H or SH ; R2 and R3 = 1 - 4C, CON(R6)(R7), COOR8; R4 and R5 = OH, NH2 or SH (when R1 is not SH); R6 and R7 = H, 1-4C; R8 = H, 1-8C; R2-R5 may be included in an aliphatic ring ; R3-R5 may be included in an aromatic ring when n = 1; and A = COOH, SO3H, OSO3H, PO3H or OPO3H. The molar ratio of the mercaptoacid component(s) to the imidazoline component(s) is between 1.0 to 1.5. Also claimed is a process for the inhibition of iron and ferrous metals using the new compositions as above.