Abstract: A process for tanning leathers including a pre-tanning step and a tanning step is provided. In the pre-tanning step leathers are treated with a cationic active agent including a quatemized ester of a fatty acid and triethanolamine, or mixtures thereof and, subsequently, with an anionic active agent including tannins vegetable extracts and a natural or synthetic dispersant selected from the group consisting of lignosulfonates, distillation stillages, sulfonated disulfonic polymers, sulfonated naphthalene polymers or mixtures thereof, to obtain leathers with a shrinkage temperature of at least 65° C. The pre-tanning and tanning steps do not include treatment with aldehydes or aldehyde donor compounds and/or with metal salts.

Abstract: A composition for manufacturing a foam material based on flavonoid tannins, includes a flavonoid tannin powder mainly of the prorobineditinidin and/or the profisetinidin type, according to an amount in weight in the range between 40% and 45% of the composition, furfuryl alcohol, a blowing agent, and a catalyst. The composition is totally formaldehyde-free, and contains an amount of furfuryl alcohol greater than 20% in weight of the composition. The composition makes possible to obtain foam materials of high characteristics and low cost, that can typically be used in the fields of building and in the automotive industry and in the vehicles in general.

Abstract: A polymeric composition for manufacturing a polyphenolic based foam material includes isocyanate, an acid catalyst and tannins. The composition has a mixed tannin-furan-isocyanate structure in which the tannins are part of a resin having the function of reactant for the composition, and it is completely free of low-boiling solvents. The amount of isocyanate is substantially greater than 1% by weight of the composition, preferably not less than 10% by weight with respect to the composition. The composition is adapted to obtain foam materials by means of the plants used for manufacturing polyurethane foam materials.

Abstract: A composition for manufacturing an elastic tannin based foam material comprises tannins according to an amount generally comprised between 10% and 80% by weight, and an isocyanate according to an amount comprised between 5% and 80% by weight. The composition further includes a substance having an aminic functionality and a alkoxylated functionality, which substance includes at least one amino group and at least one alkoxylated group, these groups being part of the same molecule or of different molecules.

Abstract: A composition for manufacturing a foam material includes flavonoid tannins, mainly of the prorobineditinidin and/or profisetinidin type, according to an amount generally in the range between 40% and 50% by weight of the composition, furfuryl alcohol according to an amount greater than 15% by weight of the composition, and an acid catalyst. The composition contains an amount of water not greater than 15% by weight of the composition, and includes a substance adapted to release a gas having the function of a foaming agent, such as an isocyanate, according to an amount not greater than 10% by weight of the STD SF composition, preferably less than 1% by weight, the composition being totally free from formaldehyde and of low-boiling organic solvents.

Abstract: A composition for manufacturing a foam material based on flavonoid tannins, includes a flavonoid tannin powder mainly of the prorobineditinidin and/or the profisetinidin type, according to an amount in weight in the range between 40% and 45% of the composition, furfuryl alcohol, a blowing agent, and a catalyst. The composition is totally formaldehyde-free, and contains an amount of furfuryl alcohol greater than 20% in weight of the composition. The composition makes possible to obtain foam materials of high characteristics and low cost, that can typically be used in the fields of building and in the automotive industry and in the vehicles in general.