| abstract |
In the process of tanning for the production of leather comprising subjecting pickled uncured hides to the action of an aqueous liquor containing (1) chemical tanning or pretanning agents, and (2) auxiliary chemicals to tanning and recovering leather, the improvement consisting essentially of employing a water-insoluble aluminosilicate, containing bound water, of the formula (Cat2/nO)x.Al2O3.(SiO2)y 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 the 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 mu to 5 mm and a calcium binding power of from 0 to 200 mg CaO/gm of anhydrous active substance measured at 22 DEG C. according to the Calcium Binding Power Test Method set out in the specification, as partial replacement of said chemical tanning or pretanning agents and said auxiliary chemicals to tanning. |