A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution and may require a mordant to improve the fastness of the dye on the fiber.
Indigo dye is an organic compound with a distinctive blue color. Indigo is a natural dye extracted from the leaves of some plants of the Indigofera genus, in particular Indigofera tinctoria. Dye-bearing Indigofera plants were commonly grown and used throughout the world, particularly in Asia, with the production of indigo dyestuff economically important due to the historical rarity of other blue dyestuffs.
A lake pigment is a pigment made by precipitating a dye with an inert binder, or mordant, usually a metallic salt. Unlike vermilion, ultramarine, and other pigments made from ground minerals, lake pigments are organic. Manufacturers and suppliers to artists and industry frequently omit the lake designation in the name. Many lake pigments are fugitive because the dyes involved are not lightfast. Red lakes were particularly important in Renaissance and Baroque paintings; they were often used as translucent glazes to portray the colors of rich fabrics and draperies.
Copper phthalocyanine (CuPc), also called phthalocyanine blue, phthalo blue and many other names, is a bright, crystalline, synthetic blue pigment from the group of dyes based on phthalocyanines. Its brilliant blue is frequently used in paints and dyes. It is highly valued for its superior properties such as light fastness, tinting strength, covering power and resistance to the effects of alkalis and acids. It has the appearance of a blue powder, insoluble in most solvents including water.
Azo compounds are organic compounds bearing the functional group diazenyl.
Acenaphthene is a polycyclic aromatic hydrocarbon (PAH) consisting of naphthalene with an ethylene bridge connecting positions 1 and 8. It is a colourless solid. Coal tar consists of about 0.3% of this compound.
Quinacridone is an organic compound used as a pigment. Numerous derivatives constitute the quinacridone pigment family, which finds extensive use in industrial colorant applications such as robust outdoor paints, inkjet printer ink, tattoo inks, artists' watercolor paints, and color laser printer toner. As pigments, the quinacridones are insoluble. The development of this family of pigments supplanted the alizarin dyes.
An acid dye is a dye that is typically applied to a textile at low pH. They are mainly used to dye wool, not cotton fabrics. Some acid dyes are used as food colorants, and some can also be used to stain organelles in the medical field.
In organic chemistry, an azo coupling is an reaction between a diazonium compound and another aromatic compound that produces an azo compound. In this electrophilic aromatic substitution reaction, the aryldiazonium cation is the electrophile, and the activated carbon, serves as a nucleophile. Classical coupling agents are phenols and naphhthols. Usually the diazonium reagent attacks at the para position of the coupling agent. When the para position is occupied, coupling occurs at a ortho position, albeit at a slower rate.
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.
2-Naphthol, or β-naphthol, is a fluorescent colorless (or occasionally yellow) crystalline solid with the formula C10H7OH. It is an isomer of 1-naphthol, differing by the location of the hydroxyl group on the naphthalene ring. The naphthols are naphthalene homologues of phenol, but more reactive. Both isomers are soluble in simple alcohols, ethers, and chloroform. 2-Naphthol is a widely used intermediate for the production of dyes and other compounds.
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.
Methine dyes are dyes whose chromophoric system consists of conjugated double bonds (polyenes) flanked by two end groups: an electron acceptor A and an electron donor D.
Structural of methine dyes
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-type compounds.
Pigment Violet 29 is an organic compound that is used as a pigment and vat dye. Its colour is dark red purple, or bordeaux.
Violanthrone, also known as dibenzanthrone, is an organic compound that serves as a vat dye and a precursor to other vat dyes. X-ray crystallography confirms that the molecule is planar with C2v symmetry. Isomeric with violanthrone is isoviolanthrone, which has a centrosymmetric structure.
Pigment Red 190, also called Vat Red 29, is a synthetic organic compound that is used both as a pigment and as a vat dye. Although structurally a derivative of perylene, it is produced from acenaphthene.
Dibromoanthanthrone is a scarlet or orange-red-hue synthetic organic colourant.
Pigment violet 23 is an organic compound that is a commercial pigment. It is member of the dioxazine family of heterocyclic compounds, but derived from carbazoles. It is prepared by condensation of chloranil and 3-amino-N-ethylcarbazole. It has a centrosymmetric angular structure. For many years, the structure was assigned, incorrectly, as having a "linear structure" which differ in terms of the carbazole ring fusion.
Carbonyl dyes are dyes which comprise at least two conjugated carbonyl groups. Both anthraquinone dyes and indigo dyes belong to the group of carbonyl dyes. The most important natural dyes - indigo, Tyrian purple, alizarin and carmine - have this partial structure. The most important synthetic carbonyl dyes are based on anthraquinone.
