Thio(cyclo) alkanepolycarboxylic acids containing heterocyclic substituents

An organic amine addition salt of a compound of formula I ##STR21## in which each of R independently of the others is H, C.sub.1 -C.sub.12 -alkyl, C.sub.1 -C.sub.12 alkoxy, C.sub.1 -C.sub.4 -halogenoalkyl, C.sub.1 -C.sub.12 -alkylthio, C.sub.1 --C.sub.12 -alkylsulfonyl, phenyl, C.sub.7 -C.sub.16 -alkylphenyl, C.sub.7 -C.sub.16 -phenylalkyl, C.sub.5 -C.sub.8 -cycloalkyl, halogen, --NO.sub.2, --CN, --COOH, --COO(C.sub.1 -C.sub.4 -alkyl), --OH or --NH.sub.2,

• X is --S--,
• n is zero or 1, and
• when n is 1, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 independently of one another are H, C.sub.1 -C.sub.18 -alkyl, C.sub.1 -C.sub.4 -hydroxyalkyl, C.sub.2 -C.sub.12 -mono-, di- or tri-carboxyalkyl, C.sub.1 -C.sub.4 -halogenoalkyl, C.sub.2 -C.sub.10 -alkoxyalkyl, --COOH or aryl or aralkyl having 6 to 10 C atoms, or said aryl or said arallkyl substituted with C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, --NO.sub.2, --COOH, --OH or halogen, or
• R.sup.1 and R.sup.2 together are linear or branched C.sub.3 -C.sub.8 -alkylene which is unsubstituted or substituted with 1 or 2 carboxyl groups, or
• R.sup.1 and R.sup.2 together are a direct bond, and
• when n is zero, R.sup.2 and R.sup.4 are carboxyl, subject to the proviso that the group ##STR22## contains at least two and not more than four carboxyl groups.