Method for the antimicrobial protection of hides during the tanning process which includes a biocidal composition and a luminescent additive allowing the identification thereof

A method for the antimicrobial protection of hides during the tanning process which includes a biocidal composition and a luminescent additive that allows the identification thereof, comprising:

• adding a composition in the tanning process of a material to be tanned immediately after adding chromium or titanium salts in an amount between 0.1% and 5% by weight of the material to be tanned, wherein the composition comprises:
• silver phosphate glass between 3% and 5%;
• silicone in an amount between 1% and 3.5%;
• aliphatic hydrocarbons between 0.1% and 0.30%;
• and water between 90% and 95%,
• adding a luminescent additive in an amount between 0.1% and 5% by weight of the material to be tanned, wherein the luminescent additive comprises between 20% and 40% silica;
• alumina in a proportion between 10% and 30%;
• calcium fluoride between 30% and 50%;
• erbium (III) fluoride between 0.5% and 3%;
• ytterbium (III) fluoride between 5% and 15%;
• thulium (III) fluoride in a maximum amount of 5%;
• and europium (III) fluoride in a maximum amount of 5%, with respect to the total weight of the luminescent additive.