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.

Method (1) for metal-free tanning of a quantity of hide having initial weight (w), said quantity of hide being contained in a drum, wherein said method (1) comprises at least one tanning treatment (B) of said hide including at least the following operating steps: B.1 feeding aliphatic aldehyde into said drum, in a percentage ranging between about 1% and 3% by weight with respect to the initial weight (w) of said hide, optionally equal to about 2% by weight, and B.2 moving said drum for a time period of at least about 10 min, optionally approximately 20 min at an operating speed between 1 and 8 revolutions/minute, preferably comprised between 4 and 5 revolutions/minute; B.3 feeding citric acid into said drum, in a percentage ranging between about 0.1% and 0.3% by weight with respect to the initial weight (w) of said hide, optionally equal to about 0.2% by weight, and B.4 moving said drum for a time period of at least about other 10 min, optionally approximately 20 min at said operating speed; B.5 feeding aliphatic aldehyde into said drum, in a percentage ranging between about 1% and about 3% by weight with respect to the initial weight (w) of said hide, optionally equal to about 2% by weight, and B.6 moving said drum for a time period of at least about 150 min, optionally approximately 180 min at said operating speed; B.7 feeding sodium formate into said drum, in a percentage ranging between about 0.3% and about 0.7% by weight with respect to the initial weight (w) of said hide, optionally equal to about 0.5% by weight, and B.8 moving said drum for a time period of at least about 20 min, optionally approximately 30 min at said operating speed; B.9 feeding magnesium oxide into said drum, in a percentage ranging between about 0.3% and about 0.7% by weight with respect to the initial weight (w) of said hide, optionally equal to about 0.5% by weight, and B.10 moving said drum for a time period of at least about 60 min, optionally approximately 90 min at said operating speed; B.11 feeding water into said drum, at a temperature ranging between about 30 C. and about 60 C., optionally equal to about 50 C., in a percentage ranging between about 30% and 50% by weight with respect to the initial weight (w) of said hide, optionally equal to about 40% by weight, and B.12 moving said drum for a time period of at least about 100 min, optionally approximately 120 min at said operating speed; B.13 feeding aliphatic aldehyde into said drum, in a percentage ranging between about 1% and 5% by weight with respect to the initial weight (w) of said hide, optionally equal to about 3% by weight, and B.14 moving said drum for a time period of at least about 100 min, optionally appro

A method for forming chrome-free retanned leather including: (a) contacting wet white (chrome-free tanned hide) with a retanning mixture comprising from 2% to 15%, by solids weight, based on the wet weight of the wet white, of an amphoteric polymer composition comprising amine functional units and acid functional units; and (b) applying a polymeric overcoat containing an acrylic copolymer with one or more metal transition elements, with a thickness of no greater than 100 microns, to the retanned wet white, is provided. The present invention also provides a chrome-free retanned leather formed by the method.

The invention discloses a method for treating an animal substrate comprising: agitating the moistened animal substrate with a treatment formulation and a solid particulate material in a sealed apparatus wherein the treatment formulation comprises a tanning agent or a tannery process agent. The method can comprise applying the tanning agent or tannery process agent to the animal substrate wherein at least some of the agent so applied originates from the treatment formulation. There is also disclosed an animal substrate obtained by the method. The treatment formulation can be aqueous.

The invention discloses a method for treating an animal substrate comprising: agitating the moistened animal substrate with a treatment formulation and a solid particulate material in a sealed apparatus wherein the treatment formulation comprises a tanning agent or a tannery process agent. The method can comprise applying the tanning agent or tannery process agent to the animal substrate wherein at least some of the agent so applied originates from the treatment formulation. There is also disclosed an animal substrate obtained by the method. The treatment formulation can be aqueous.

The present invention relates to a process for the tanning of animal hides characterised, compared to currently adopted processes, by the non-adoption of the step known in the industry as pickling. The invention also concerned hides tanned by said process.

The present invention relates to a process for the tanning of animal hides characterised, compared to currently adopted processes, by the non-adoption of the step known in the industry as pickling. The invention also concerned hides tanned by said process.

A method of preparing hydrophobicizing leather treatment compositions includes the steps of a) free-radically initiated copolymerization of i) at least one ethylenically unsaturated carboxylic acid or its derivatives, and ii) at least one (meth)acrylate of a primary saturated C.sub.8 to C.sub.22 alcohol, b) mixing the reaction mixture obtained after step a) with water, c) salting at least some of the carboxyl groups of the reaction mixture obtained after step b) with a base, and d) shearing the reaction mixture obtained after step c) to an average particle size of 0.05-10 m,
wherein step a) is carried out in oil as reaction medium and wherein the atmosphere in step a) contains less than 0.1% by volume of an oxidizing gas.

Use of probiotic technology to support tanners to reduce waste and increase the value of by-products reducing the need of synthetic chemicals, improving the quality of effluents and reducing the carbon footprint to the environment. Probiotics or beneficial microorganisms are used to obtain biochemicals through a controlled fermentation of natural ingredients. The result of the process is a consortium of metabolites including viable probiotic microorganisms with properties very similar to traditional leather auxiliaries extensively needed during leather production, eliminating or reducing the need for use of toxic chemicals and compositions.

There is provided a process for tanning animal hide comprising treating an animal hide with at least one tanning agent and exposing the treated hide to a dose of ionising radiation of from 1 to 500 kJ/kg wherein the ionising radiation is in the form of a charged particle beam.