Oral
Abstract
Research summary supplied by the authors
This presentation offers a selective representation of several innovative and successful developments carried out in our company to detoxify wet-end leather products, ensuring high performance on leather while minimizing negative impacts on both human health and the environment. One of our studies highlighted the ecological and toxicological advantages of using the tanning agent sodium p-[(4,6-dichloro-1,3,5-triazin-2-yl)amino]benzenesulphonate compared to glutaraldehyde and Cr(III) salts. As a chrome-free tanning agent, it eliminates the risk of generating carcinogenic Cr(VI). Another project demonstrated the application benefits of a resin structurally similar to melamine resins. This polymer, synthesized through aromatic nucleophilic substitution of triazine derivatives—rather than traditional condensation of melamine with formaldehyde —eliminates free melamine and formaldehyde in both products and leather, while enhancing retanning performance. The presentation also shows a patented discovery: the use of rice husk in leather retanning. This product not only delivers superior results compared to conventional syntans and vegetable tannins, but also avoids the risks associated with bisphenols and formaldehyde. Lastly, we present an example of process optimization aimed at reducing the free content of SVHCs such as Cyclotetrasiloxane (D4), Cyclopentasiloxane (D5), and Cyclohexasiloxane (D6) in waterproofing agents. GC-MS analysis confirmed that, through the use of suitable thin-layer evaporators and precise control of temperature and pH during emulsification, the content of free D4, D5, and D6 was reduced from thousands of ppm to just a few tens of ppm in the final formulations.