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Vat Yellow 1
Vat Yellow 1 is a vat dye, yellow in appearance under some conditions used in cloth dyeing. Its synonyms are flavanthrone and Indofast Yellow, and it is in the class of anthraquinone Anthraquinone, also called anthracenedione or dioxoanthracene, is an aromatic organic compound with formula . Isomers include various quinone derivatives. The term anthraquinone however refers to the isomer, 9,10-anthraquinone (IUPAC: 9,10-dioxo ...-type compounds. References Anthraquinone dyes Vat dyes Nitrogen heterocycles {{chemistry-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vat Dye
Vat dyes are a class of dyes that are classified as such because of the method by which they are applied. Vat dyeing is a process that refers to dyeing that takes place in a bucket or vat. The original vat dye is indigo, once obtained only from plants but now often produced synthetically. Materials suited for vat dyeing Although almost all dyeing can be done in a vat, the term vat dye is used to describe a chemical class of dyes that are applied to cellulosic fibre (''i.e.'', cotton) using a redox reaction as described below. Because of the use of caustic soda, and the very high pH of the dye bath in the dyeing process, wool cannot be dyed using vat dyestuffs. This is because wool is soluble in caustic soda solutions. Instead, it is possible to dye wool at room temperatures with indigo (vat blue 1) and other low substantive vat dyes using soda ash as the alkali source with very little strength loss. Vat red 10, vat violet 13 and vat orange 1 can be applied in this manner as well. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthraquinone
Anthraquinone, also called anthracenedione or dioxoanthracene, is an aromatic organic compound with formula . Isomers include various quinone derivatives. The term anthraquinone however refers to the isomer, 9,10-anthraquinone (IUPAC: 9,10-dioxoanthracene) wherein the keto groups are located on the central ring. It is a building block of many dyes and is used in bleaching pulp for papermaking. It is a yellow, highly crystalline solid, poorly soluble in water but soluble in hot organic solvents. It is almost completely insoluble in ethanol near room temperature but 2.25 g will dissolve in 100 g of boiling ethanol. It is found in nature as the rare mineral hoelite. Synthesis There are several current industrial methods to produce 9,10-anthraquinone: # The oxidation of anthracene. Chromium(VI) is the typical oxidant. # The Friedel-Crafts reaction of benzene and phthalic anhydride in presence of AlCl3. o-Benzoylbenzoic acid is an intermediate. This reaction is useful for produc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthraquinone Dyes
Anthraquinone dyes are an abundant group of dyes comprising a anthraquinone unit as the shared structural element. Anthraquinone itself is colourless, but red to blue dyes are obtained by introducing electron donor groups such as hydroxy or amino groups in the 1-, 4-, 5- or 8-position. Anthraquinone dyestuffs are structurally related to indigo dyestuffs and are classified together with these in the group of carbonyl dyes. Members of this dye group can be found in natural dyes as well as in synthetic dyes. Anthraquinone dyestuffs are represented in mordant and vat, but also in reactive and disperse dyes. They are characterized by very good light fastness. Natural anthraquinone dyes One of the most important anthraquinone dyes of herbal origin is alizarin, which is extracted from the dyer's madder ( Rubia tinctorum). Alizarin is the eponym for a number of structurally related dyes that use alizarin dyes (sometimes synonymous with anthraquinone dyes). It was the first natural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vat Dyes
A value-added tax (VAT), known in some countries as a goods and services tax (GST), is a type of tax that is assessed incrementally. It is levied on the price of a product or service at each stage of production, distribution, or sale to the end consumer. If the ultimate consumer is a business that collects and pays to the government VAT on its products or services, it can reclaim the tax paid. It is similar to, and is often compared with, a sales tax. VAT is an indirect tax because the person who ultimately bears the burden of the tax is not necessarily the same person as the one who pays the tax to the tax authorities. Not all localities require VAT to be charged, and exports are often exempt. VAT is usually implemented as a destination-based tax, where the tax rate is based on the location of the consumer and applied to the sales price. The terms VAT, GST, and the more general consumption tax are sometimes used interchangeably. VAT raises about a fifth of total tax revenues bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
