Alizarin-Red Staining Solution | TMS-008-C - Merck …
In July l897,using the naphthalene process, BASF began to market synthetic indigo. This was based on the economical oxidation of naphthalene to phthalic anhydride with fuming sulfuric acid and mercury. Sulfur dioxide was evolved and recovered for conversion back into fuming acid by the contact process, developed on a large scale by Knietsch. BASF also undertook the then novel electrochemical production of chlorine and alkali, essential inorganic chemicals in the indigo synthesis.
importance and affordability of alizarin's artificial synthesis ..
James Morton of Carlisle, a complete newcomer to the manufacture of dyes, achieved the first British success in his textile and dyeing factory. In 1914, he engaged a few chemists to undertake the conversion of anthraquinone-2-sulfonic acid to yellow and blue vat dyes of the indanthrone type. Using a steel autoclave, and working at high temperatures and pressures, they achieved these objectives on a small scale. By the end of 1915 the dyes were being produced for in-house use, and the intermediates were also made at Carlisle. In 1916, Morton's team invented a replacement for the alizarin blue wool dye, which became known as Solway blue. Other consumers pressed Morton to place his products on the open market, including the powerful Bradford Dyers' Association, Ltd. Responding to these demands, Morton's Sundour Fabrics Ltd. set up The Solway Dyes Company (which in 1920 became Scottish Dyes Ltd.).
The alizarin process plant also underwent considerable changes in Germany (as well as in Switzerland) during the 1870s and after. Notably, the addition of potassium chlorate prevented the production of hydrogen in the fusion step, and this eliminated the reduction of products, as well as permitting the use of lower pressures. The neglect of such technical improvements and of the process that gave the product most in demand (the violet shade) foreshadowed the end of the innovative edge by British firms during the nineteenth century.
Alizarin Crimson Pigment - Natural Pigments
William Perkin’s firm was the first successful producer of alizarin and of a similar anthraquinone compound. His efforts, as much as those of Caro, Graebe and Lieberman, made the alizarin synthesis commercially viable. Subsequently, anthraquinone dyes were extended such that the full range of shades could be obtained, although the colors ranging from blue to green received the most attention. Their bright and fast dyes were found to be almost without equal. In particular, they were used in the synthesis of later generations of dyes, such as the indanthrenes, disperse dyes, acid wool dyes, and cationic dyes for polyacrylonitrile. They were also found to be applicable to cotton, which resists the simple non-reactive anthraquinone dyes, when converted into azoanthraquinone colorants.
Alizarin red S mono sodiumsalt (C.I. 58005) CAS 130-22 …
The crude product of the sulfonation was diluted in large wooden tanks, a, the solution was brought to boiling by blowing steam into it, and wet slaked lime was added to bring about neutralization. (This operation was later carried out in wooden tubs fitted with mechanical stirrers.) The neutral mixture was then run into the vacuum filters, b, connected to iron reservoirs, dd, that were evacuated by means of an air pump. The mixture was filtered through successive layers of sand, pebbles, and bricks, covered by a coarse canvas stretched out on a wooden frame, such as c. One reservoir was connected so as to receive the concentrated filtrate and first washings; further washings with boiling water were drawn into a second reservoir. Some product remained mixed with the calcium sulfate in the filters and was extracted by removing the solid, boiling it with water, and returning the mixture to the filters.
Alizarin red S mono sodiumsalt (C.I
Synthetic alizarin soon began to replace the natural product, and was also manufactured in Switzerland. Once the various co-products had been isolated and characterized, greater control over the reaction became possible. The quality of alizarin also improved. The color was consistent and easier to apply than the vegetable product, the supply of which was subject to the vagaries of nature.
ALIZARIN YELLOW R | 66676-71-9 - ChemicalBook
The yield was low, but a patent was filed at the end of 1868. Several German and foreign firms were approached regarding licensing rights, and in May 1869 a deal was struck with BASF. In that month, Caro at BASF, as well as Perkin in London, and the Hoechst dyeworks, all independently discovered that sulfonation of anthraquinone could be achieved, with subsequent displacement of sulfonic acid groupings by hydroxyl at elevated temperature. The result was alizarin in high yield. This became the basis of commercial manufacture by Perkin and Hoechst from the end of 1869, and by BASF about one year later.