Introduction

The present invention describes the use furanic derivatives, non-toxic and biodegradable compounds, as tanning agents in the pre-tanning, tanning or re-tanning steps of pelts. The proposed tanning process is economically viable, comprising a step of treating pelts directly with aqueous solutions containing said furanic derivatives, obtained by hydrolysis of a lignocellulosic biomass. These solutions demonstrated tanning capacities that guarantee the obtainment of a finished product with optimal aesthetic and functional characteristics, also responding to the requirements of health, ecology and environmental safety of the tanning sector.

Technical features

The compounds object of the invention, extracted from renewable materials, including waste, have proved to be tanning agents when the main conditions adopted for the tanning process vary on bovine, egg-goat and exotic skins prepared for the tanning phase. These tanning agents can also be used as pickling agents and as pre-tanning agents, for example in vegetable and chromium tanning processes. They can be used both as the sole tanning agents for processing and in combination with other tanning agents; both in pure form (pure molecules of furan derivatives, figure 1) and in crude aqueous solution obtained from the hydrolysis of a biomass of a lignocellulosic nature or in general from products containing mixtures of saccharides or polysaccharides.

The absence of heavy metals (e.g. Aluminum, Chromium, Iron, Titanium and Zirconium) in the patented manufacturing process considerably reduces the environmental impact of this type of processing and the additional costs for the disposal of large quantities of wastewater which generally strongly affect the production costs of the finished product.

Possible Applications

• Tanning industry: toxic agents used in the tanning sector, or more generally in the whole textile sector, are bad not only for the workers of the industries, forced to be in daily contact with these substances. Skins or clothes can also be harmful for those who use or wear them, if they present important traces of the chemicals used during the production process.

Advantages

• Renewable raw materials (agricultural waste);
• Non-toxic and biodegradable class of tanner, even used in crude mixture;
• Lower cost for wastewater disposal;
• Metal-Free production and subsequent use of hypoallergenic and hypotoxic leathers.