什么是染料

能使其他材料着色的有强烈色彩的复杂有机化合物，用於使纺织品、纸张、皮革和许多其他物质着色。在染色过程中，染料分子由溶液中沈积在材料上，且随後不会被原来溶解它们的溶剂除去。古人所知的主要染料是由茜草属植物和能产生靛蓝的植物或软体动物制得，现在一般由煤焦油和石油化工产品合成制得。第一种合成染料苯胺紫是1856年英国化学家珀金（W. H. Perkin）发明的，是一种煤焦油衍生物反应的意外产物，结果在19世纪末叶兴起了大规模的煤焦油染料工业。染料分子的化学结构已证明易於改动，於是可制得范围广泛的煤焦油染料。化学合成的发展导致生产出许多新染料，可牢固地着色在许多不同类型的物质上。染料工业的一个重大进步，是发展了与纤维反应型染料，这种染料分子与它着色的纤维之间形成共价键，是将染料分子附着在纤维上的最牢固的方法。对於棉、毛、丝等天然材料，必须合成适合这些材料的独特化学结构的染料。另一方面，也可以改变合成纤维的化学结构，以改变它们的染色性能。亦请参阅azo dye。

dye

Any of a class of complex organic compounds that are intensely colored, used to color textiles, leather, paper, and other materials. Major dyes known to the ancients came from plants such as indigo and madder (see madder family) or from the shells of mollusks; today most dyes are made from coal tar and petrochemicals. The chemical structure of dyes is relatively easy to modify, so many new colors and types of dyes have been synthesized. Dye molecules are deposited from solution onto materials in such a way that they cannot be removed by the original solvent. Fiber-reactive dyes form a covalent bond with the fiber. Other dyes require previous application of a mordant, an inorganic material that causes the dye to precipitate as an insoluble salt, or vat dyeing, in which a soluble colorless compound is absorbed by the fibers, then oxidized (see oxidation-reduction) to the insoluble colored compound, making it remarkably fast to washing, light, and chemicals. See also azo dye.