Acid mordant dye - Sanseibaisensenryo

Dyes that have the properties of both acid dyes and mordants. They are also called chromium dyes because they use chromium compounds such as potassium dichromate as mordants. Like acid dyes, they contain dissociable hydrophilic groups such as sulfonic acid groups in the molecule, and mordant formation of insoluble metal complexes on the fiber improves wet fastness. This generally increases light fastness, but the color tone becomes deeper than before mordant treatment. Structurally, most are azo dyes, with some anthraquinone dyes and triphenylmethane dyes also present. The azo group has -OH, _-NH2 , -COOH, and salicylic acid derivatives' -COOH and -OH in the ortho position. There are also methods in which the fiber is treated with a mordant beforehand (mordant method) and methods in which the dye and mordant are used simultaneously (metachrome method). They are important dyes for fast dyeing of wool, but are also used for silk and nylon. There are over 100 types of commercially available products. As a representative example, the structure of Eriochrome Black T (CI Mordant Black 11) is shown.

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

酸性染料と媒染染料の両方の性質をもつ染料．媒染剤として二クロム酸カリウムなどのクロム化合物を用いるので，クロム染料(chrom dye)ともいう．酸性染料同様，分子内にスルホン酸基など解離性の親水性基を含み，さらに媒染により繊維上で不溶性の金属錯塩を形成することによって，湿潤堅ろう度を改善するものである．これによって，一般に日光堅ろう度が増すが，媒染前に比べて色調は深くなる．構造的には，大部分がアゾ染料であり，そのほか，アントラキノン染料やトリフェニルメタン染料も若干ある．分子内にはアゾ基のオルト位に-OH，-NH₂，-COOHやサリチル酸誘導体の-COOH，-OHなどをもつ．繊維をあらかじめ媒染剤で処理する方法(媒染法)や，染料と媒染剤とを同時に用いる方法(メタクロム法)もある．羊毛の堅ろう染色に重要な染料であるが，そのほか，絹やナイロンにも用いられる．市販品は100種類を超える．代表的な例として，エリオクロムブラックT(C.I.Mordant Black 11)の構造を示した．

出典　森北出版「化学辞典（第2版）」化学辞典 第2版について　情報