インジゴ

解説インジゴ．C.I.7300，C.I.Vat Blue 1ともいう．天然藍(あい)の主成分．古くから知られた天然染料で，インジカンを含む植物を発酵させてつくられた．工業的には，N-フェニルグリシンをアルカリ融解してインドキシルとし，それを空気酸化して合成している．金属光沢のある青色の柱状晶．昇華点約300 ℃，分解点390 ℃．キシレンに微溶，エタノールに難溶．木綿用の青色建染め染料であるが，パラフィン油やデカリン中では赤色を呈す．植物系の天然染料の一つ。アイの葉を発酵させてつくる。一八八〇年、ドイツ人バイヤー（バイエル）が初めて合成。九〇年、ドイツ人ホイマンが工業的製法を発明。藍青色の光沢をもつ柱状結晶で、水に溶けない。もめん、麻、絹、羊毛などの染色に用いる。藍。青藍。藍靛(らんてん)・(らんじょう)。インド藍。

用途建浴の色 : 黄、インジゴイド染法で木綿、羊毛を染めるが、濃く染めるには数回の浸セキ、空気酸化を繰り返す。ほかに亜鉛と水酸化カルシウムによる亜鉛建浴、酵素による建浴法もある。ナッセンにも使える。堅ロウ度 : 日光に可(木綿)、優良(羊毛)。洗タクに弱(木綿)、良(羊毛)。漂白に可。アントラキノン系のすぐれた青色建染メ染料があるにもかかわらず、いまなお多量に使用される。可溶性建染メ染料としても市販されている。

説明Indigo, known chemically as indigotin, is a common blue dye that has been highly valued throughout history and has played a major role in trade and commerce since ancient times. The term indigo is often used to describe many blue dyes produced from a number of plants. For example, woad, a blue dye obtained from the plant Isatis tinctoria, was used throughout the Mediterannean and Europe and is often identified as indigo. True indigo comes from the leguminous plant of the genus Indigofera. The Indigofera genus includes several hundred species, and indigo has been obtained from a number of these, but the dominant species for the dye are Indigofera tinctoria grown mainly in India and tropical Asia and Indigofera suff ructiosa from the tropical Americas. The name indigo comes from the Greek indikon and Latin indicum meaning “dye from India.” There is evidence that indigo was used several thou sand years b.c.e. Persian rugs containing indigo color exist from several thousand years b.c.e. Textile artifacts from Egyptian tombs provide evidence of indigo’s use by royalty from as far back as 2500 b.c.e. The writings of Herodotus from approximately 450 b.c.e. mention indigo’s use in the Mediterranean area.

天然物の起源Indigo is a perennial shrub found in several regions of the world.

来歴Indigotin. The blue dye of the ancient world was derived from indigo and woad. Which plant is the oldest is a matter of conjecture. That indigo was known at least four thousand years ago is evident from ancient Sanskrit writings. Cloth dyed with indigotin (CI Natural Blue; CI 75780) has been found in Egyptian tombs and in the graves of the Incas in South America. Indigo belongs to the legume family. The two most important species are Indigo tinctoria and I. suffruticosa, found in India and the Americas, respectively. The leaves of the indigo plant do not contain the dye as such, but in the form of its precursor, a glycoside known as indican.