Tanning agent

Natural Brown 6 (constitution not available), basic structure gallic acid (gallotannin 1), is based on a large variety of vegetable products having a high content of hydrolyzable tannin, which mostly form gallic acid when hydrolyzed. 

Natural Brown 3, 75250 (catechu) has the basic structure of catechin (2) and is a condensed tannin, e.g., gambier from leaves and twigs of the Uncaria gambler bush. Many of these tanning agents are based on a catechin flavanoid. 

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Synthetic rubbers Synthetics Synthetic silicates Synthetic surfactants Synthetic tanning agents... 

In retanning, vegetable tannins may be used in conjunction with or may be entirely replaced by synthetic tanning agents called syntans. The syntans and other specialty chemicals allow the creation of leathers not possible using vegetable tannins alone. 

In the manufacture of 2-naphthalenol, 2-naphthalenesulfonic acid must be converted to its sodium salt this can be done by adding sodium chloride to the acid, and by neutralizing with aqueous sodium hydroxide or neutralizing with the sodium sulfite by-product obtained in the caustic fusion of the sulfonate. The cmde sulfonation product, without isolation or purification of 2-naphthalenesulfonic acid, is used to make 1,6-, 2,6-, and 2,7-naphthalenedisulfonic acids and 1,3,6-naphthalenetrisulfonic acid by further sulfonation. By nitration, 5- and 8-nitro-2-naphthalenesulfonic acids, [89-69-1] and [117-41-9] respectively, are obtained, which are intermediates for Cleve s acid. All are dye intermediates. The cmde sulfonation product can be condensed with formaldehyde or alcohols or olefins to make valuable wetting, dispersing, and tanning agents. 

Naphthalenesulfonic Acid—Formaldehyde Condensates. The sodium salts of the condensation products of naphthalenesulfonic acid with formaldehyde constitute an important class of compounds which are mainly used in the area of concrete additives (32,33), agricultural formulations, mbber formulations, and synthetic tanning agents. They are also used in photographic materials (34). Hampshire Chemical Co. and Henkel of America, Inc., are the largest suppHers of naphthalene sulfonate in concrete additives (superplasticizer) and reportedly hold 75—80% of this market. It was estimated that naphthalene sulfonate demand from U.S. producers would reach approximately... 

In 1994 estimated naphthalene consumption in western Europe and Japan for the production of alkylnaphthalene sulfonates, naphthalene sulfonate formaldehyde condensates, and synthetic tanning agents was... 

Naphthalenolsulfonic acid formaldehyde condensates are used in tanning agents. Other uses of 2-naphthalenol are in the manufacture of perfuming agents, eg, 2-naphthyl methyl e e [93-04-9] (Yara Yara), R = CH (30), and 2-naphthyl ethyl ether/Pi-/ -37 (nerolin, BromeUa) R = ... 

Hydroxynaphthalenesulfonic acids are important as intermediates either for coupling components for a2o dyes or a2o components, as well as for synthetic tanning agents. Hydroxynaphthalenesulfonic acids can be manufactured either by sulfonation of naphthols or hydroxynaphthalenesulfonic acids, by acid hydrolysis of arninonaphthalenesulfonic acids, by fusion of sodium naphthalenepolysulfonates with sodium hydroxide, or by desulfonation or rearrangement of hydroxynaphthalenesulfonic acids (Table 6). 

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. 

In afterscouting, most often a synthetic tanning agent is used to prevent redeposition of dye on unptinted areas and to improve wetfastness properties of the print. 

Used industrially as a chemical intermediate for the synthesis of esters, manufacture of varnish, as a tanning agent, and as a food additive (flavor). 

Synthetic tanning agents (syntans), 9 190 Synthetic transporter, 24 58 Synthetic water-soluble polymers, 20 441-443... 

Rhus coriaria L. is a shrab, which reaches 3M p in high in the wild. Its powdered leaves were used as a tanning agent for its high tannin content [10]. Tannins are found in the leaves, fmit, barks, roots and wood of trees. They can be classified into two groups condensed tannins and hydroly sable tannins [11]. The co-occurrence of both kinds of tannins in the same plant or plant tissue is often observed [12]. The main compounds present mRhus coriaria L. are hydrolysable gallatonnins. 

Uses Intermediate in the manufacture of dyestuffs, emulsifying agents, pharmaceuticals, mbber and agricultural chemicals, insecticides, corrosion inhibitors, and synthetic tanning agents, plasticizers, and isocyanates for coatings. 

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