Provided is a hexavalent chromium treatment agent capable of penetrating inside of a leather and capable of reducing not only hexavalent chromium present in the vicinity of the surface of the leather but also hexavalent chromium present inside the leather into trivalent chromium. The hexavalent chromium treatment agent of the present invention comprises a hexavalent chromium-reducing compound capable of reducing hexavalent chromium into trivalent chromium, a nonionic surfactant, and an aqueous solvent. The hexavalent chromium-reducing compound preferably comprises an organic compound (A) that has a specific structure capable of acting to reduce hexavalent chromium into trivalent chromium, that has a hydroxyphenyl group, and that has no aldehyde groups and no carboxyl groups.

Provided is a hexavalent chromium treatment agent capable of penetrating inside of a leather and capable of reducing not only hexavalent chromium present in the vicinity of the surface of the leather but also hexavalent chromium present inside the leather into trivalent chromium. The hexavalent chromium treatment agent of the present invention comprises a hexavalent chromium-reducing compound capable of reducing hexavalent chromium into trivalent chromium, a nonionic surfactant, and an aqueous solvent. The hexavalent chromium-reducing compound preferably comprises an organic compound (A) that has a specific structure capable of acting to reduce hexavalent chromium into trivalent chromium, that has a hydroxyphenyl group, and that has no aldehyde groups and no carboxyl groups.

A liquid smoke tanning method uses liquid smoke as a tanning agent for tanning an animal skin, such as a hide or fur. The liquid smoke is used a natural source of aldehydes, which are commonly used in the tanning process and known to introduce toxicity into the animal skin. After the skin is prepared and cleaned for tanning, it is tanned in a liquid smoke solution, which may also include alum in an alternative embodiment. The liquid smoke is efficacious for crosslinking collagen proteins in the animal skin during the tanning process. The liquid smoke provides substantially the same collagen crosslinking capacity of aldehydes such as glutaraldehyde, formaldehyde, or glyoxol. The liquid smoke is, however, organic and does not contain the level of toxins found in chemically produced aldehydes. After the tanning, the skin is dried through known means for production as an organic, nontoxic leather.

A liquid smoke tanning method uses liquid smoke as a tanning agent for tanning an animal skin, such as a hide or fur. The liquid smoke is used a natural source of aldehydes, which are commonly used in the tanning process and known to introduce toxicity into the animal skin. After the skin is prepared and cleaned for tanning, it is tanned in a liquid smoke solution, which may also include alum in an alternative embodiment. The liquid smoke is efficacious for crosslinking collagen proteins in the animal skin during the tanning process. The liquid smoke provides substantially the same collagen crosslinking capacity of aldehydes such as glutaraldehyde, formaldehyde, or glyoxol. The liquid smoke is, however, organic and does not contain the level of toxins found in chemically produced aldehydes. After the tanning, the skin is dried through known means for production as an organic, nontoxic leather.

A decoction of olive leaves comprises an aqueous composition containing at least from about 500 mg/liter to about 3,000 mg/liter of oleuropein, from about 100 mg/liter to about 300 mg/liter of hydroxytyrosol, from about 90 mg/liter to about 280 mg/liter of tyrosol, from about 400 mg/liter to about 1,800 mg/liter of elenolic acid.

A process for the simultaneous tanning and dyeing of collagen containing fibrous material, wherein the said material is treated with a liquor containing at least one reactive dyestuff selected from the group of formula (1) and (2) ##STR00001## wherein A.sub.1, A.sub.2 and A.sub.3 are each independently of the others the radical of a monoazo, polyazo, metal-complexed azo, anthraquinone, phthalocyanine, formazan or dioxazine chromophore having at least one sulfo group, B is an organic bridge member, Q.sub.1, Q.sub.2, Q.sub.3 and Q.sub.4 are each independently of the others hydrogen or unsubstituted or substituted C.sub.1-C.sub.4alkyl, G.sub.1 and G.sub.2 are halogen, 3-carboxypyridin-1-yl or 3-carbamoylpyridin-1-yl, (Z.sub.1).sub.2-3 is 2 to 3 identical or different fiber reactive radicals, Z.sub.2 and Z.sub.3 are each independently of the other identical or different fiber reactive radicals, and b is the number 0 or 1, by combining two steps of leather production, tanning and dyeing, into a single step, thus, preserving resources and reducing the environmental impact.

A process for the simultaneous tanning and dyeing of collagen containing fibrous material, wherein the said material is treated with a liquor containing at least one reactive dyestuff selected from the group of formula (1) and (2) ##STR00001## wherein A.sub.1, A.sub.2 and A.sub.3 are each independently of the others the radical of a monoazo, polyazo, metal-complexed azo, anthraquinone, phthalocyanine, formazan or dioxazine chromophore having at least one sulfo group, B is an organic bridge member, Q.sub.1, Q.sub.2, Q.sub.3 and Q.sub.4 are each independently of the others hydrogen or unsubstituted or substituted C.sub.1-C.sub.4alkyl, G.sub.1 and G.sub.2 are halogen, 3-carboxypyridin-1-yl or 3-carbamoylpyridin-1-yl, (Z.sub.1).sub.2-3 is 2 to 3 identical or different fiber reactive radicals, Z.sub.2 and Z.sub.3 are each independently of the other identical or different fiber reactive radicals, and b is the number 0 or 1, by combining two steps of leather production, tanning and dyeing, into a single step, thus, preserving resources and reducing the environmental impact.

An apparatus includes a process chamber, a controllable compressor for pressurizing a fluid, a pressure reducing member, an inlet for a processing agent and a controller. The process chamber is a pressure chamber. The controllable compressor pressurizes a fluid and introduces the pressurized fluid into the process chamber from a source. Further the controllable compressor controls a predefined pressure in the process chamber to reach a supercritical state of the fluid. An inlet for a processing agent facilitates introduction of the processing agent into the process chamber prior to, during, or subsequent to pressurization of the fluid. The pressure reducing member reduces the pressure of the fluid at least to reach a gaseous state subsequent to processing the leather object such that the time for reduction of pressure exceeds a predefined reduction period or the reduction of pressure does not exceed a predefined leather pressure reduction gradient.

A process for tanning hides using a tanning solution that includes a silicon compound and is free from metals. A method for preparing leathers is also related, the method including a tanning process. Also related are tanned hides obtained by such a tanning process and a process for detanning the hides obtained by this tanning process.

A process for tanning hides using a tanning solution that includes a silicon compound and is free from metals. A method for preparing leathers is also related, the method including a tanning process. Also related are tanned hides obtained by such a tanning process and a process for detanning the hides obtained by this tanning process.