Leather, tanning

Enzymes are used in baking, cheese manufacture, wine-making, brewing and distillation, pharmaceuticals, leather tanning, paper manufacture, adhesives, sewage disposal, animal feeds and in detergents. 

Leather-like materials Leather processing Leather tanning... 

In addition to its ptincipal use in biocide formulations (94), glutaialdehyde has been used in the film development and leather tanning industries (95). It may be converted to 1,5-pentanediol [111 -29-5J or glutaric acid [110-94-1]. 

Fig. 4. Schematic of a leather tanning faciUty fitted with a wastewater treatment plant. Treatment of the combined wastes using sulfide oxidation and waste effluent pH adjustment greatiy decreases the suspended soHds and BOD loading (3). Courtesy of Krieger Publishing Co.

Oxahc acid is used in various industrial areas, such as textile manufacture and processing, metal surface treatments (qv), leather tanning, cobalt production, and separation and recovery of rare-earth elements. Substantial quantities of oxahc acid are also consumed in the production of agrochemicals, pharmaceuticals, and other chemical derivatives. 

Leather Taiming. Oxahc acid is used as a pH modifier in leather tanning by tannin and basic chromium sulfate. It also functions as a bleaching agent for leather (qv). 

Anhydrous ammonium oxalate is obtained when the monohydrate is dehydrated at 65°C. The monohydrate is a colorless crystal or white powder, and dissolves in water at 0°C up to 2.17 wt %, and 50°C up to 9.63 wt %. It is slightly soluble in alcohol and insoluble in ether. It is used for textiles, leather tanning, and precipitation of rare-earth elements. 

OxazoHdines, formed by reaction of alkanolamines with aldehydes, ate useful as leather tanning agents and ate effective curing agents for proteins, phenoHc resins, moisture-cure urethanes, etc. They also find use as antimicrobial agents. 

Sodium thiosulfate is still used in chrome leather tanning as a reducing agent in two-bath processes to reduce dichromate (hexavalent chromium) to chrome alum (trivalent chromium) (see Leather). 

Corrosion inhibitors Cosmetics, drugs Electrical insulation Electrolytic refining Fertilizers Fire retardants Glass and glass wool Herbicides Insecticides Leather tanning Photography Textile dyes Wax emulsifier Wool preservatives... 

Leather Tanning and Textiles. Although chromium (VT) compounds are the most important commercially, the bulk of the appHcations in the textile and tanning industries depend on the abiUty of Cr(III) to form stable complexes with proteins, ceUulosic materials, dyestuffs, and various synthetic polymers. The chemistry is complex and not well understood in many cases, but a common denominator is the coordinating abiUty of chromium (ITT) (see LEATHER Textiles). 

Leather and leather products Leather tanning and finishing, manufacture of leather belting and packing Scrap leather, thread, dyes, oils, processing and curing compounds... 

A number of water-soluble cellulose ethers are marketed." Methyl cellulose is prepared by a method similar to that used for ethyl cellulose. A degree of substitution of 1.6-1.8 is usual since the resultant ether is soluble in cold water but not in hot. It is used as a thickening agent and emulsifier in cosmetics, as a paper size, in pharmaceuticals, in ceramics and in leather tanning operations. 

Persulphate salts and henna leather tanning Manufacture of hair care products and their application... 

Leather tanning and finishing 3131 Boot and shoe cut stock and findings... 

Miscellaneous (nuclear shielding, metallurgy, corrosion control, leather tanning, flame-proofing, catalysts) 19% (26%)... 

Abtragimg, /. carrying off, etc. (see abtragen). AbtrankbrUhe,/. (Leather) tan liquor, abtrttnken, v.t. saturate, impregnate (Leather) fill up with tan liquor. 

Glutaraldehyde Hospitals, laboratories, cooling tower systems and leather tanning... 

The largest known htiman exposures to exogenous nltrosamines have been shown to occur in the work place, particularly in the rubber and leather tanning industries. Recent data for amines, nitrosating potential and nitrosamines will be presented in the framework of assessing the extent of the various exposures. 

Chromium(III) is a commonly-used crosslinker for preparing profile control gels with polymers having carboxylate and amide functionalities (la,b). Cr(III) is applied in many forms. For example, it can be used in the form of simple chromic salts of chloride and sulfate, or as complexed Cr(III) used in leather tanning (2), or as in situ generated Cr(III) from the redox reaction of dichromate and bisulfite or thiourea. The gelation rate and gel quality depend on which form of Cr(III) is used. 

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