Process for tanning leather

US4810252A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Hermann Becker · Trier, DE
• Werner Lotz · Niedernhausen, DE
• Karlfried Keller · Frankfurt am Main, DE

Key dates

• Filing date: Oct 5, 1987
• Grant date: Mar 7, 1989
• Expiry date: Oct 5, 2007

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C14C3/18
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

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.