Condensates of bis-(4-hydroxyphenyl) sulfone as tanning assistants, their preparation and use in the tanning of leather

摘要

A condensate of bis-(4-hydroxyphenyl) sulfone, an aldehyde, a dialdehyde and/or glyoxylic acid and aminoacetic acid or an N-substituted aminoacetic acid is prepared and used as a tanning assistant, in a process for tanning leather in combination with, in particular, aluminum tanning agents.