Cassella Aktiengesellschaft

Hoechst Aktiengesellschaft

Hermann Becker

Werner Lotz

Karlfried Keller

Ulrich Riegel

Fritz Engelhardt

Kuno Reh

Helmut Croon

Frank Forster

Hides, skins and pelts are tanned by use of a tanning agent which comprises the reaction product of acetaldehyde, formaldehyde and a formylamino compound.

Tanning agent and a process for its preparation

An improved process for tanning leather by treating animal skins with a water-soluble melamine-formaldehyde resin in the presence of an acid catalyst towards the end is improved by using a melamine-formaldehyde resin which is at least partially etherified with a glycol ether, alkyl glycol ether, or both.

Processing for tanning leather

Use of a resin mixture of, or of a mixed resin from, a melamine-formaldehyde resin and an anionically modified melamine-formaldehyde resin for tanning leather. The anionic modification of the melamine-formaldehyde resin is obtained by preparing the resin in the presence of alkali metal sulfite, alkali metal hydrogensulfite or alkali metal sulfamate. By partial modification it is possible to obtain a mixed resin, while mixing a modified with an unmodified resin gives a resin mixture.

Process for tanning leather

Growing community of inventors

Rodgau, Germany

Hermann Becker