Process for treating polyamide containing articles to enhance their moulding stability

A process for treating polyamide fibers to enhance their moulding stability, which comprises applying to the fibers before, during or after a whitening step, an aqueous dispersion of a compound or formula ##STR32## wherein R.sub.1 is unsubstituted or substituted phenyl, wherein the substituents are selected from 1 to 3 alkyl radicals containing not more than 18 carbon atoms, C.sub.1 -C.sub.12 alkoxy, C.sub.1 -C.sub.18 alkoxycarbonyl, chloro or a mixture of these substituents,

• R.sub.2 is hydrogen or C.sub.1 -C.sub.4 alkyl,
• R.sub.4 is hydrogen, C.sub.1 -C.sub.12 alkyl, unsubstituted or C.sub.1 -C.sub.4 alkyl-substituted C.sub.5 -C.sub.4 cycloalkyl, phenyl, C.sub.7 -C.sub.12 phenylalkyl or chloro,
• R.sub.3 is R.sub.4, ##STR33## wherein n is 0, 1 or 2,
• R.sub.6 is hydrogen, C.sub.1 -C.sub.18 alkyl, C.sub.2 -C.sub.18 alkyl which is interrupted by oxygen or sulfur, dialkylaminoalkyl containing a total of 3 to 16 carbon atoms, cyclopentyl, cyclohexyl, phenyl or phenyl which is substituted by 1 to 3 alkyl radicals together containing not more than 18 carbon atoms, the substituents R.sub.7 are each independently of the other hydrogen, C.sub.1 -C.sub.18 alkyl, cyclopentyl, cyclohexyl, phenyl, phenyl which is substituted by 1 or 2 alkyl radicals together containing not more than 16 carbon atoms, a radical of formula --C.sub.2 H.sub.4 OH, --C.sub.2 H.sub.4 --C.sub.2 H.sub.4 --O--C.sub.m H.sub.2m+1 or ##STR34## or, together with the linking nitrogen atom, form a piperidino or morpholino radical
• m is 1 to 18,
• R.sub.10 is hydrogen, C.sub.1 -C.sub.22 alkyl or C.sub.5 -C.sub.12 cycloalkyl,
• A is alkylene of 2 to 22 carbon atoms which may be interrupted by nitrogen, oxygen or sulfur,
• R.sub.8 is hydrogen, C.sub.1 -C.sub.18 alkyl, cyclopentyl, cyclohexyl, phenyl, phenyl which is substituted by 1 or 2 alkyl radicals together containing not more than 16 carbon atoms, or benzyl,
• R.sub.9 is C.sub.1 -C.sub.18 alkyl,
• D is --O--, S--, --SO--, --SO.sub.2 -- or --C(R.sub.11).sub.2 --, the substituents R.sub.11 are each independently of the other hydrogen, alkyl together containing not more than 16 carbon atoms, phenyl or a radical of formula ##STR35## wherein n, R.sub.6 and R.sub.7 have the given meanings,
• E is a radical of formula ##STR36## wherein R.sub.1, R.sub.2 and R.sub.4 have the given meanings, and
• R.sub.5 is hydrogen, C.sub.1 -C.sub.30 alkyl, cyclopentyl, cyclohexyl, chloro or a radical of formula ##STR37## wherein R.sub.6 and R.sub.7 have the given meanings, or R.sub.5 together with R, form a tetramethylene radical.