Pyrrole stabilizers for chlorine-containing thermoplastics

Abstract

Chlorine-containing thermoplastics, containing a pyrrole of the formula I ##STR1## in which R.sub.1 is hydrogen, alkyl, cycloalkyl, aryl, alkoxycarbonylmethyl, free or esterified .alpha.-hydroxyalkyl, free or esterified .alpha.-hydroxycycloalkylmethyl, free or esterified .alpha.-hydroxyaralkyl, alkoxymethyl, alkylthiomethyl, aryloxymethyl, arylthiomethyl, cycloalkoxymethyl, cycloalkylthiomethyl, aralkoxymethyl, aralkylthiomethyl, alkoxy, alkylthio, cycloalkoxy, cycloalkylthio, aralkoxy, arylalkylthio, aryloxy, arylthio, halogen, mercapto, mercaptomethyl or hydroxyl, R.sub.2 is hydrogen, alkyl, cycloalkyl, aryl, free or esterified .alpha.-hydroxyalkyl, in which the alkyl moiety together with R.sub.1 can be alkylene, or free or esterified .alpha.-hydroxycycloalkylmethyl, free or esterified .alpha.-hydroxyaralkyl, alkoxy, cycloalkoxy, aralkoxy, aryloxy, alkylthio, cycloalkylthio, aralkylthio, arylthio, alkoxymethyl, alkylthiomethyl, aryloxymethyl, arylthiomethyl, cycloalkoxymethyl, cycloalkylthiomethyl, aralkoxymethyl, aralkylthiomethyl, hydroxyl, cyano, free carboxyl or carboxyl in the form of a salt or an ester, or acyl, it being possible for acyl together with R.sub.1 to be --CO-alkylene, in which --CO-- is bonded in the 3-position, or R.sub.2 is halogen, mercapto or mercaptomethyl, and R.sub.3 is alkyl, cycloalkyl, aralkyl, aryl, free or esterified hydroxymethyl, alkoxymethyl, alkylthiomethyl, cycloalkoxymethyl, cycloalkylthiomethyl, aralkoxymethyl, arylalkylthiomethyl, aryloxymethyl or arylthiomethyl, alkoxy, alkylthio, cycloalkoxy, cycloalkylthio, aralkoxy, aralkylthio, aryloxy, arylthio, halogen, mercapto or mercaptomethyl, or if R.sub.2 is carboxyl in the form of a salt, R.sub.3 is hydrogen and R.sub.1 is as defined, or in which R.sub.3 is hydroxyl and R.sub.1 is hydrogen, alkyl or aryl and R.sub.2 is hydrogen, alkyl, aryl or acyl, or a salt thereof.

Dependencies are inferred from the claim text.