Economy chrome tanning process with aldehyde-acids and keto-acids

Abstract

Economy chrome tanning process wherein the pelts are pretreated before the tanning with 0.1 to 2% of an aldehyde- or keto-acid, preferably with glyoxylic acid or pyruvic acid, and are then tanned by customary methods. In this pretreatment, which is preferably carried out in the pickle, the tanning requires a chromium supply of only 1.25 to 1.5% of Cr.sub.2 O.sub.3 on weight of pelt. Despite this reduced amount of chrome tannin the results obtained are boil-resistant leathers with uniform chromium distribution, excellent color levelness and very good physical properties.

Dependencies are inferred from the claim text.