TANNING AGENT FOR LEATHER PRODUCTION COMPRISING A CONDENSATION POLY MER OF SULFONATED PHENOL, UREA, AND FORMALDEHYDE

摘要

The present invention relates to a condensation polymer of sulfonated phenol, urea, and formaldehyde, wherein sulfonated phenol contains ortho phenol sulfonic acid and para phenol sulfonic acid in a molar ratio of 2: 1 to 1:5. The present invention also relates to a process for manufacturing the condensation polymer comprising the steps of a) providing a sulfonated phenol by contacting phenol and sulfuric acid at a temperature below 75 °C, b) contacting the sulfonated phenol with urea, and c) contacting the reaction product of step b) with formaldehyde. The present invention also relates to a tanning agent for self-tanning, pre-tanning and co-tanning of unhaired hides and unhaired skins and for post-tanning of leather and pelts comprising water and the condensation polymer; and to a use of the condensation polymer for making leather.