Patent ID: 7771489
Filing Date: 2010-08-10
Classification: C14C

Abstract:
1. A method for chrome-free and chrome tanning, comprising contacting an animal hide with a formulation comprising: a clay mineral, which, after vigorous stirring for 30 minutes in water at 50° C., has a number average particle diameter of less than 2 μm, or a bimodal size distribution with a first, finely divided fraction, whose number average particle diameter is less than 0.5 μm, and a second, coarser fraction, whose number average particle diameter is less than 5 μm, determined in each case by the method according to ISO 13320-1, by combined laser light diffraction and light scattering, and wherein, the amount of the first, finely divided fraction is from 10 to 90% by weight; and one or more substances selected from the group consisting of organic polymers, aldehyde tanning agents, sulfone tanning agents, resin tanning agents, phenol tanning agents, fatliquoring agents, vegetable tanning agents, dyes, pigments and mixtures thereof, wherein the clay mineral is a phyllosilicate selected from the group consisting of kaolinite, smectite, muscovite, montmorillonite, bentonite, hectorite and mixtures thereof.