This article is based on a text from Merck's goods encyclopedia
One calls tar colors (anilin dyes) the large number from the components of the coal tar (see tar) won, in the broader sense in addition, all artificially manufactured organic coloring materials at all. They all contain at least a circular atomic's group (benzene, Naphthalin, anthracene, Chinolin) and besides beside carbon and hydrogen still oxygen, nitrogen, sulfur or several of these elements next to each other.
As raw materials particularly the hydrocarbons benzene, toluol, xylene, Naphthalin, Phenanthren, anthracene come and oxygen-containing phenol and Kresole into consideration, the moreover in addition, numerous halogen derivatives (benzyle chloride), derived from this, nitro compounds (nitrobenzene), Aminoverbindungen (aniline), Diazoverbindungen, hydrazine etc. in place of the thereby given distinction into benzene, toluol etc. of coloring materials divide one the tar colors recently due to their chemical constitution e.g. to and Bucherer into the following groups:
The individual groups as well as their most important representatives are discussed in special sections.
According to its different behavior to the fabrics and Gespinstfasern one differentiates far homochrome, hetero chrome and pigment coloring materials.
The homochromen coloring materials, which pickles directly without colors, form three subsections:
The members of the second group, that heterochromen coloring materials, which possess all weakly sour character and contain at least two sour groups (hydroxyl or Karboxylgruppen), color the fiber not direct, but only after the treatment with one it pickles whereby color lacquers develop. To them the alizarine particularly belongs.
To the pigment coloring materials only relatively few coloring materials, which are produced on the fiber, belong particularly aniline-black, Indigo among other things
According to another organization one also probably differentiates the coloring materials into nouns, which pickles without, and into adjectives, which pickles only with one colors. One finds then that numerous coloring materials behave against animal fibers (wool, silk) noun, against vegetable fibers however adjective, and that e.g. the basic coloring materials of the managing grouping can be both noun and adjective.
The production of the tar colors began with the discovery of the first violet coloring material from aniline, the Mauveins, by William Henry Perkin in the year 1856, which already three years later, 1859, which followed synthesis of the Fuchsins by Verguin and more numerously different aniline coloring materials, so the Anilinblaus by Girard and de Laire, the and the Methylvioletts. Each year brought new coloring materials and groups of coloring materials (1869 the Azofarbstoffe by Johann Peter Griess, Alizarin and other anthracene coloring materials by and dear man), until in the year 1880 with the artificial representation of the Indigos by Adolf of Baeyer a high point of the chemical synthesis was reached. On the basis of this strictly scientific research a flowering industry developed, in which Germany transferred a prominent role. The value of the production rose from 24 million Marks in the year 1874 to 65 million Marks in the year 1890, and in the year 1908 alone export reached the height of 63.000 tons in the value of more than 120 million Marks.
The tar coloring materials found expanded application in the things printering, multicolored paper and the wallpaper production, for coloring wood, metal, leather as well as for the production of Kinderspielzeug and ink.
For many purposes they displaced the natural coloring materials because of their shining tones producible in each desired gradation completely, and in contrast to in former times wide-spread opinion there are now numerous T., which are not only (for Woll and to show completely washgenuine, but also large light resistance. Even the fashionable colors liked for wallpapers can be obtained quite light-genuinly.
The T. the trade often contain additives of not coloring materials, which serve partially permitted purposes, like the achievement of a certain colour or the easement of their use. In addition, direct falsifications or loadings were observed. The recognition of such foreign matter, as far as they are inorganic, like common salt, Glauber's salt, Schwerspat, takes place with the help of the ash determination. Strength and sugars can be recognized microscopically. The proofs of Dextrin arrives usually by treatment with alcohol.
See also: Coloring material
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