A kind of black leather dyeing method

Abstract

The invention relates to the technical field of tanning chemistry and engineering, and provides a leather black-dyeing method. A chromium-free multi-metal complex tanning agent is adopted for carrying out chromium-free retanning on crust leather, vegetable tannin extracts are added for packed dyeing after neutralization, and the purpose of black-dyeing the leather without dye or with little dye can be realized according to the principle that the chromium-free multi-metal complex tanning agent and the vegetable extracts can develop colors after combined. The crust leather manufactured through the leather black-dyeing method is uniform and full in color, gentle and deep in hue and high in color fastness, the physical and chemical properties of the crust leather can meet the industrial standard, and the subsequent processing property is good; in the implementation process of the leather black-dyeing method, chromium tanning agents are not used, the use amount of the dye is reduced by 60% or above, and therefore the environmental pollution is reduced, the production cost is lowered, and the practicality is high.

Description

technical field [0001] The invention relates to the technical field of tanning chemistry and engineering, in particular to a black leather dyeing method. Background technique [0002] Dyeing is an important process in the process of tanning. Dyeing can improve the appearance of leather, make the leather adapt to the popular style in the market, and increase the commodity value of leather. Except for a few varieties such as bottom leather and natural color leather, most leather needs to be dyed. [0003] At present, there are more than 30,000 dyes in use in the market, and more than 600,000 tons of dyes are discharged into the environment every year, causing serious environmental pollution and waste of resources. Leather dyeing is a complex physical and chemical process, involving dye adsorption from the dye bath to the leather surface, diffusion from the leather surface to the interior of the leather, and fixation in the interior of the leather. During the dyeing process, o...

AI Technical Summary

Problems solved by technology

However, the reducible aromatic amines in azo dyes are potentially carcinogenic to humans or animals, so many countries have set strict limit standards, including the banning of 22 kinds of azo dyes by the EU Directive 2002 / 61 / EC, and the international certification standards for ecological textiles (Oeko—tex Standard 1O0) prohibits 24 types, GB18401—2003 prohibits 23 types, the above standards involve a total of 24 types of aromatic amines