Home › Aniline Colors › Aniline Green

Aniline Green

Aniline green is produced from a solution of sulphate of rosaniline in dilute sulphuric acid and some aldehyde, which is heated till its color has changed As the heat is not sufficient for the complete to dark green. Addition of a solution of hyconversion of the nitro-benzole, steam is intro- posulphite of soda separates the color. duced after a time, and the stirring and steam- 2556. Aniline Green. Several of the ing is continued until no more nitro-benzole aniline greens occurring in the market are apt appears in the distilled vapor. At this point to undergo spontaneous destruction, somethe temperature is increased, and, if necessary, times in less than a day. The following is a aided by direct fire, to cause complete distilla- formula which any one may make: 4 parts of tion of the aniline which has formed, and which pure fuchsine or rosaniline are dissolved in 6 passes off with water, and separates from it on parts water and 16 parts aldehyde (see next standing, as the heavier stratum. The aniline receipt), and are heated at 212º Fahr., until a used for the various colors is taken of different drop of the mixture imparts to water acidulacomposition and boiling-point. A. W. Hofmann has shown that a mixture of an equivated slightly with sulphuric acid a clear blue color, when it is ready to be poured into a boillent of aniline and two of toluidine produces ing solution of hyposulphite of soda, which is the largest yield of rosaniline (fuchsine). The substance used for this manufacture begins to boil at about 347°, and as the heat increases to 390° 80 per cent. will have distilled over.

Aniline blue and purple require an oil which being stirred. A fine green precipitate forms, and a grayish one, which latter must be keptseparate. The green is mordanted principally with acetate of alumina.