The present invention relates to a process for waterproofing leather, particularly leather for the manufacture of shoes, clothes or leather accessories. The present invention also relates to the leather obtained by said process.
Leathers, particularly those which are used for the manufacture of shoes, clothes or leather accessories, are known to be waterproofed by chemical treatments consisting in applying thin layers of water-repellent substances outside the leather itself, for example by means of sprayers. Because of the low efficiency of this process in the long term, a new process has been conceived, consisting in sewing inside the leather a fabric lining combined with a semi-permeable film, which not only prevents water from further penetrating into the shoe or dress article, but also allows the body outward transpiration.
However, this process is disadvantageous in that it allows water to penetrate anyway under the leather, and therefore, especially if the latter is used for the shoe-manufacture, an undesired water-cushion is formed between the waterproofing fabric and the leather internal surface. Further, this process necessarily requires the application of a lining combined with a semi-permeable film, which, besides increasing the production costs, is in some cases inadvisable, for example in the manufacture of summer shoes and clothes. U.S. Pat. No. 5,598,644 discloses a process for waterproofing a tread of leather, wherein a semi-permeable membrane is glued to the perimetric regions thereof. However, this process does not avoid the formation of water-cushions and the need of an upper perimetric part for fastening the membrane to the tread, thus reducing its transpiration properties.