Dicarboxylic acids containing triazine rings

A compound of the formula ##STR17## in which n has a value from 1 to 100,

• R.sup.1, R.sup.2, R.sup.3 and R.sup.5 independently of one another are each a hydrogen atom, a straight- or branched-chain alkyl of 1 to 22 C atoms, cycloalkyl of 5 to 7 C atoms, cyclohexylmethyl, aryl of 6 to 10 C atoms, benzyl, or said cycloalkyl, said cyclohexylmethyl, said aryl or said benzyl substituted with alkyl of 1 to 4 C atoms, or
• R.sup.1 and R.sup.2 together are alkylene of 3 to 7 C atoms, 3-oxapentylene or 3-thiapentylene,
• R.sup.4 is a straight- or branched-chain alkylene of 2 to 18 C atoms, cycloalkylene of 5 to 7 C atoms, arylene of 6 to 10 C atoms, cycloalkylenealkylene or cycloalkylenebisalkylene with 1 to 4 C atoms in the alkylene group, arylenealkylene or arylenebisalkylene with 1 to 4 C atoms in the alkylene group;
• or said cycloalkylene, said cycloalkylenealkylene or said cycloalkylenebisalkylene substituted with alkyl of 1 to 4 C atoms, or said arylene, said arylenealkylene or said arylenebisalkylene substituted by alkyl of 1 to 6 C atoms or by halogen, or
• R.sup.4 is phenylene-X-phenylene where X is a direct bond, O, S, SO.sub.2, alkylene of 1 to 3 C atoms, alkylidene of 2 to 12 C atoms, cycloalkylidene of 5 to 6 C atoms, benzylidene, bisphenylmethylidene, 1,1,1-trichloroethylidene or -O-p-phenylene-O--, or
• R.sup.4 together with one R.sup.3 and the N atom to which they are bound form a ring having 4 to 7 C atoms, or R.sup.4, and also both R.sup.3 s together, are alkylene groups having 1 to 5 atoms, and forming together with the two N atoms a 5- to 7-membered ring, and
• R.sup.6 is a straight- or branched-chain alkylene or alkylidene of 1 to 12 C atoms, o-phenylene, m-phenylene, p-phenylene, p-benzylene or p-cyclohexylene or
• the corresponding acid halides, or the corresponding esters where the ester moiety is alkyl or hydroxyalkyl of 1 to 12 C atoms, cycloalkyl or hydroxycycloalkyl of 5 to 6 ring carbon atoms or aryl of 6 to 10 C atoms.