Compositions containing heterocyclic corrosion inhibitors

Claim 1

A composition which comprises (A) (a) an aqueous or non-aqueous coating composition suitable for preparing a surface coating which is a paint, or (b) a wholly or partly aqueous non-coating system which is a cooling water system, an air-conditioning system, a steam-generating system, a seawater evaporator, a hydrostatic cooker, a closed circuit heating or refrigerant system, an aqueous scouring or metal-working formulation, an antifreeze composition or a water-based hydraulic fluid composition, and (B) an effective corrosion-inhibiting amount of a compound of formula II ##STR29## in which X is sulfur; R is each independently of one another hydrogen, alkyl, haloalkyl, alkoxy, alkylthio, alkylsulfonyl, cycloalkyl, phenyl, alkylphenyl, phenylalkyl, halogen, cyano, nitro, hydroxy, --COOH, --COOalkyl or a primary-, secondary- or tertiary-amino or carbamoyl group; n is 0 or 1; R 1 , R 2 , R 3 and R 4 are independently hydrogen, alkyl, hydroxyalkyl, haloalkyl, cyanoalkyl, alkoxyalkyl, phenyl, phenylalkyl, said phenyl or said phenylalkyl substituted by one or two of halogen, of nitro, of alkyl, of alkoxy, of carboxy or of hydroxy; cyano, carboxy, alkyl substituted by carboxy or by --CONZ 1 Z 2 ; or --CONZ 1 Z 2 where Z 1 and Z 2 are independently hydrogen, C 1 -C 18 -alkyl, said alkyl interrupted by one or more O or S atoms or by one or more NR o groups where R o is C 1 -C 18 -alkyl, C 3 -C 12 -cycloalkyl, phenyl, naphthyl, C 7 -C 9 -phenylalkyl or C 7 -C 18 -alkylphenyl; or said alkyl substituted by --SH, by --NH 2 , by --COOH, by --COOR o , by --CONH 2 , by --CN or by halogen; C 2 -C 10 -hydroxyalkyl or said hydroxyalkyl interrupted by one or more NR o groups or by one or more oxygen atoms; C 3 -C 18 -alkenyl, C 3 -C 12 -cycloalkyl or said cycloalkyl substituted by C 1 -C 4 -alkyl, by --OH, by --SH, by --COOH, by --COOR o , by --CONH 2 , by --CN or by halogen; C 7 -C 9 -phenylalkyl, C 7 -C 18 -alkylphenyl, or C 6 -C 10 -aryl or said phenyl or said aryl substituted by C 1 -C 12 -alkoxy, by C 1 -C 12 -alkylthio, by halogen or by nitro; or Z 1 and Z 2 together form a straight or branched alkylene of 3 to 7 carbon atoms or said alkylene interrupted by O, by S or by NR o ; or (B) is a compound of formula II where the moiety [C(R.sup.1)(R.sup.3)].sub.n CH(R.sup.2)(R.sup.4) contains a group of formula III or IIIa ##STR30## or where R 1 and R 2 or R 1 and R 3 together form a straight or branched alkylene, or said alkylene substituted by one or two --COOH or by one or two --CONZ 1 Z 2 ; or where R 1 and R 2 form a direct bond; with the proviso that at least two of R 1 , R 2 , R 3 and R 4 must contain a carboxy group or a derivative thereof which is a --CONZ 1 Z 2 group, --CN or an imide of formula III or IIIa with the further proviso that at least one of --CONZ 1 Z 2 , --CN or imide groups must be present, or (B) is a non-toxic base addition salt of a compound of formula II which contains a free carboxy group.