Thiazolylpyrazolinones and their use for protecting technical materials

Thiazolylpyrazolinone derivatives of the formula ##STR614## in which R.sup.1, R.sup.2, R.sup.3 independently of each other each represent hydrogen, alkyl or halogen, and

• R.sup.4 represents hydrogen or unsubstituted or substituted alkyl, alkenyl, alkinyl, cycloalkyl, cycloalkenyl, alkyl (cycloalkyl), alkenyl (cycloalkenyl), alkoxy, alkylthio, aralkoxy, aralkylthio, aralkyl, aryl, hetaryl, aryloxy, hetaryloxy, arylthio, hetarylthio, alkoxycarbonyl, alkoxycarbonalalkyl or cyanoalkyl, or their acid addition products or metal complexes, wherein if R.sup.4 represents substituted hetaryl, then the substituents are selected from the group consisting of halogen, alkyl, alkoxy or alkylthio.