English synonyms

abcolsumack19;abcoltannicacidtech;abcoltannicacidusp/kosher;acaciamollissimatannin;acid,tannic;acidetannique;castaneasativamilltannin;chestnuttannin

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Dermatosis Skin Beauty; Small Molecular Inhibitors, Natural Products; Chemical Auxiliaries; Oil Field Chemicals; Drilling Chemicals; Leather Chemicals; Tanning and Retanning Agents; Raw Materials; Organic Chemicals; Small Molecular Inhibitors; APIs; Food Additives; Pharmaceutical Raw Materials; Other Biochemical Reagents; Agricultural Raw Materials; Organic Chemical Raw Materials; Chemical Raw Materials; Clarifying Agents; Inorganic Salts; Intermediates; Auxiliaries; Chemical Products - Organic Chemicals; Chemical Products - Inorganic Chemicals; Biochemical Reagents - Other Chemicals Reagents;Enzyme preparations;Organic chemical raw materials;Plant extracts;Enzyme preparations;Clarifying agents;Chemicals;Carbonyl compounds;Standards;Nutrition studies;Plant extracts;Reference substances;Tannins;Tannins;Gallic tannins;Tannins ;Tanin;Chinese medicine reference substance;Pharmaceutical intermediate;Plant biochemical extract;Drug astringent;Nutrition agent;Biochemical reagent;Organic chemical raw material;Tannic acid;Medical raw material;Inorganic salt;Reference substance-Chinese medicine reference substance;Conventional product ;Other raw materials;Auxiliaries;Large chemical industry;Standard products-Chinese medicine standard products;Standard products, reference products;Pharmaceuticals, pesticides and dye intermediates;Chemical raw materials;Chemical materials;Cosmetic raw materials;Chemical raw materials and auxiliary materials;Content products;Acidity adjustment Plant Extract; Plant Extract; Food additive and acidulant; Inhibitors; Amino Acids; Inorganic Chemistry

Introduction：

Tannin is also known as Chinese tannin, tannic acid, and pentagon tannin. The structure is still unclear, and it is generally considered to be an ester formed by the combination of five hydroxyl groups of glucose and gallo-galloyl groups. After the gall is extracted and concentrated, it can be made into industrial tannins. After refining, it can be made into medicinal or reagent tannins.
Tannins are pale yellow amorphous powders or glossy scaly or spongy solids. No special odor, bitter and astringent. Gradually darkens upon exposure to air and sunlight. Soluble in cold water, infinitely soluble in hot water; soluble in methanol, ethanol, acetone and ethyl acetate, insoluble in benzene, ether, chloroform, petroleum ether and carbon disulfide. The tannic acid aqueous solution is weakly acidic and easy to oxidize. It oxidizes faster in an alkaline solution and the solution color is darker. In the case of ferric ions, the solution is blue-black, and precipitates with gelatin and alkaloids. It reacts with lead, aluminum, zinc, germanium and other metal ions to form multinuclear complexes, insoluble salts with special colors. Tannin is decomposed into pyrogallic acid and CO2 when heated to 210～215℃. Tannins have low toxicity, but a large amount of ingestion can cause vomiting, abdominal pain, diarrhea, and can lead to circulatory system disorders and death, LD1006.0g/kg (house mouse, oral). It can be decomposed at high temperature to generate pyrogallol and carbon dioxide. Commercially available tannins usually contain 10% water.

Pale yellow amorphous powder or loose glossy scaly or spongy solid, which can turn black when exposed to air. Odorless, with a strong astringent taste. Soluble in water, ethanol, acetone, almost insoluble in benzene, chloroform, ether and petroleum ether. 

Use

●  for the leather industry

●  Suitable for tanning upholstery leather, bottom leather and sheepskin. It should be stored in a cool, dry and ventilated warehouse. Best used in combination with other tanning agents.

●  Mainly used for tanning leather, but also used in medicine, ink, printing and dyeing, rubber and metallurgy and other industries, as well as water treatment, etc.

●  Used for tanning leather, dyeing fishing nets, boiler descaling, drilling, etc.

●  Used as analytical reagent, also used in pharmaceutical industry

●  It is used for pickling of bare hides and pH adjustment of vegetable tanning liquors. Can also be used for vegetable tanning rinses. Due to its strong acidity, it cannot be packed in iron containers. It should be stored in a cool warehouse.

●  Used as water-based drilling viscosity reducer, cement retarder.

●  In the pharmaceutical industry, it is used as the raw material for the preparation of gallic acid, pyrogallol, and sulfonamides. Tannin is a hemostatic drug. It has been used in medicine to treat pharyngitis, tonsillitis, hemorrhoids and skin blistering. It can be used internally to prevent diarrhea and intestinal discharge. Tannins can form precipitates with metals, alkaloids and glycosides, and have a detoxification effect on these substances. Tannin can be used in tanning, ink manufacturing, paper and silk gluing, boiler anti-fouling, etc. It can also be used as mordant, clarifying agent for beer and wine, coagulant for rubber, etc., as well as determination of beryllium, aluminum, nickel, copper and other metals reagent. In chemical production, gallic acid and pyrogallic acid can be prepared. Tannins are used for dilution when processing drill mud. The tannin powder and caustic soda are prepared into tannin lye in proportion, which can reduce the shear force and stickiness of the thickened mud and improve the mud flow. On the contrary, if the tannin powder is directly added to the mud, due to its weak acidity, the pH of the mud will drop due to the ion exchange with the clay particles. Reduce the hydration on the surface of the clay particles, so that the network structure of the clay particles is formed, and the shear force and viscosity of the mud are increased. According to my country's GB 2760-89 regulations, "solidified tannin" can be used in low-alcohol and fruit wines, and as a clarifying agent, it can remove suspended substances such as protein in a cloudy state. In the food industry, it is also used as astringent enhancer and crude oil deodorizer.

●  Precipitation and gravimetric determination of beryllium, aluminum, gallium, indium, niobium, tantalum and zirconium. Colorimetric determination of copper, iron, vanadium, cerium and cobalt. Protein and alkaloid precipitant. Ammonium molybdate is an external indicator for the titration of lead. Dye Mordant. Manufacture of ink, paper, silk, artificial cutin, gallic acid and pyrogallic acid. Clean up beer and wine.

●  Precipitation and gravimetric determination of beryllium, aluminum, gallium, indium, niobium, tantalum and zirconium. Ratiometric determination of copper, iron, vanadium, cerium and cobalt. Protein and alkaloid precipitant. Ammonium molybdate is an external indicator for the titration of lead. Dye Mordant.

●  For precipitation and gravimetric determination of beryllium, aluminum, gallium, indium, niobium, tantalum and zirconium; for colorimetric determination of copper, iron, vanadium, cerium and cobalt; as precipitant for proteins and alkaloids; as molybdenum Ammonium acid is an external indicator for lead titration; it is used as raw material for the preparation of pharmaceutical tannic acid, pyrobenzic acid and sulfonamides; it is used as fixative, mordant and synthetic dye in textile printing and dyeing; it is used in food for beer, Clarifying agent for low alcohol alcohol such as wine

●  React with metal iron to synthesize iron tannate complexes, reducing agents in the synthesis of metal nanoparticles, precipitating agents for proteins and alkaloids, external indicators for ammonium molybdate titration of lead, and dye mordants.

Production method

●  Tannins are found in the fruit of the bark of many trees, such as oak and sumac, and are the main component of 50-70% of the galls that form when these trees are attacked by insects. Pulverize the gall, remove impurities such as insect carcasses and insect excrement, put it into a copper or wooden extraction tank, extract with soft water, concentrate the extract under reduced pressure, add a small amount of ether, and spray dry to obtain light tannic acid. . Medicinal tannin is extracted from the concentrated solution with ether, the leaching solution is bleached with sodium bisulfite, and the ether is recovered to obtain medicinal tannin.

●  The gall is crushed, sieved, and then impregnated with water, the impregnated water is clarified, preheated, spray-dried, and the refined powder is sieved to obtain the finished product.

●  Put 100 kg of refined naphthalene into the sulfonation kettle, heat up to 125 °C, add 120 kg of concentrated sulfuric acid under stirring, and react at 155 to 165 °C for 6 to 8 hours. Sampling to measure the end point, if it is completely dissolved in water, it proves that the sulfonation is complete. Gradually cool down to 110 ℃, add a small amount of water to dilute. Feed the feed into the condensation kettle at about 80°C. Add 39kg of 37% formaldehyde solution dropwise at about 70°C, and react at 80-90°C for 3 hours after dropping, and get a blue-black viscous liquid, which is the finished product.

●  The finished product is obtained by crushing, leaching, purifying, concentrating and drying the bark of larch.

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