Synthetic tanning agents

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. 

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... 

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). 

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. 

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

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. 

Uses. Intermediate for pharmaceuticals, dyestuffs, rubber chemicals, emulsifying agents, insecticides, synthetic tanning agents... 

Aftertreatment The wetfastness of dyeings produced with acid dyes is often unsatisfactory. Formerly, tannic acid and tartar emetic were used, which form a 1 1 adduct on the material by hydrogen bonding. This process is expensive and said to be carcinogenic. Synthetic tanning agents (Synthanes) are preferred. They are condensation products of aromatic sulfonic acids with formaldehyde [106] or of phenols with formaldehyde, which are made water-soluble by reaction with bisulfite. These products deposit on the fiber surface and form an electrostatic barrier... 

Aftertreatment. Frequently, textiles manufactured from polyamide fibers (hosiery, underwear) come into close contact with the skin. Therefore, the material has to be carefully rinsed or washed after dyeing. For the treatment with synthetic tanning agents to improve the wet fastness, see above (Acid Dyes). 

Straight melamine-formaldehyde resins are used primarily in the preparation of molding compounds, laminates, and textile finishes. Nearly 90% of these molding powders are used to make dinnerware. Melamine dinnerware can be made very decorative for popularity. This resin has better physical properties than phenolics and it can be very easily colored, which phenolics cannot. Methylolmelamine also is used as a synthetic tanning agent for white leather. 

Leukanol [Rohm Haas] Synthetic tanning agent... 

Leukotan. [Rohm Haas] Acrylic synthetic tanning agent retanning agents for leather. 

Synthetic tanning agents are sulfonated condensation products of formaldehyde and phenols. They have fungistatic properties and are therefore used in combination with vegetable tannins. 

The research tasks of the central laboratory at BASF between 1890 and 1914 were related mainly to the well established requirements of the dye-using industries. Direct azo dyes and the rhodamines were major research fields. In 1897 these were supplemented by the sulphur dyes, at that time also a main research area. In 1899, azo lake dyes were a new and very successful form of application. The twentieth century started with novel research into the anthraquinones, until then completely dominated by the alizarin laboratory. This widened the research potential for research into the important indanthrene-type vat dyes. Just before World War I the main laboratory participated in diversification with catalytic hydrogenation and the invention of synthetic tanning agents. In this period, the central laboratory controlled the core technology, and the most important market of BASF, namely the dyestuff business. The research laboratories of the aniline and the alizarin departments continued with the same tasks in their respective fields. 

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