Antioxidant retan from Cromogenia16 November 2009
Retanal AOX, a retanning agent with an antioxidant effect, from Spanish leather chemical producer, Cromogenia provides the leather with a soft feel. It also has a good filling effect and produces clean, level dyeing. However, the main difference with synthetic retanning agents is that Retanal AOX has antioxidant power with oxidisable fatliquors types such as lecithin, fish etc. This avoids aging of the leather and the possible formation of chrome VI.
Its advantage over vegetable retanning agents is that it has better lightfastness, heat resistance and less astringency.
This is particularly useful for soft items where it is necessary to use larger quantities of fatliquors to produce soft effects such as gloving and garment as well as some upholstery and footwear leathers, particularly on items requiring high heat resistance.
Retanal AOX is a slightly anionic poly-hydroxy-phenolic condensate and forms a light brown powder. The pH is a 10% solution is 5 ± 1 and between 2-3% is added for garment and gloving articles based on shaved wet-blue. Slightly higher offers of 3-4% (on shaved wet-blue) can be added for footwear and upholstery articles together with the rest of the retanning agents prior to fatliquoring.