Leather or leather products and methods for producing them, hexavalent chromium treatment agent, method for treating hexavalent chromium in crude leather or leather products

摘要

[Problem] The present invention provides a hexavalent chromium which can stay in a leather or leather product for a long time and can be stably rendered harmless over a long period of time even when the leather or leather product contains hexavalent chromium. A treatment agent and a leather or leather product having a hexavalent chromium content of less than 3 ppm by using the treatment agent. [Solution] The leather or leather product of the present invention has at least a structure represented by Chemical Formula 1 which acts with hexavalent chromium and has trivalent reducing properties and a hydroxyphenyl group, and has an aldehyde group and a carboxyl group. The organic compound (A) and trivalent chromium which are not present, and the content of hexavalent chromium measured in accordance with ISO 17075: 2008-02 is less than 3 ppm.