Water-insoluble alkali metal aluminosilicates and polycarboxylic acids in the tanning process for the production of leather

摘要

In the process of tanning for the production of leather comprising subjecting uncured hides to the action of an aqueous liquor containing (1) chemical tanning agents, and (2) auxiliary chemicals to tanning and recovering leather, the improvement consisting of essentially of employing water-insoluble aluminosilicate, containing bound water of the formula ##EQU1## wherein Cat represents a cation selected from the group consisting of alkali metals, bivalent metal ions, trivalent metal ions, and mixtures thereof, n represents an integer from 1 to 3 of the valence of said cation, x is an integer from 0.5 to 1.8 and y is an integer from 0.8 to 50, said aluminosilicates having an average particle size in the range of 0.1 to 5 mm and a calcium binding power of from 0 to 200 mg CaO/gm of anhydrous active substance measured at 22 C. according to the Calcium Binding Power Test Method set out in the specification, in combination with a polycarboxylate selected from the group consisting of aliphatic dicarboxylic acids having from 2 to 8 carbon atoms, aliphatic tricarboxylate acids having from 4 to 8 carbon atoms, benzene dicarboxylic acids, benzenetricarboxylic acids and hydrolyzable partial esters thereof with aliphatic alcohols having from 1 to 6 carbon atoms and 1 to 6 hydroxyl groups as partial replacement of said chemical tanning agents and said auxiliary chemicals to tanning.