Chemical Properties
blue needles with a metallic lustre
Uses
Mainly to dye cotton.
General Description
Blue needles with a metallic luster or fine fluffy deep blue powder.
Air & Water Reactions
Insoluble in water.
Fire Hazard
Flash point data for Vat Blue 4 are not available. Vat Blue 4 is probably combustible.
Preparation
(a) in potassium nitrate, LvSuanJia, glucose or organic acid salt (such as formic acid potassium or acetic acid potassium or the mixture of both) under the existence of, with potassium hydroxide treatment 2-Aminoanthracene-9,10-dione;
Reactions
As a pigment, indanthrone is a particulate, insoluble solid dispersed directly into a vehicle, whereas as a dye it is reduced to a base-soluble hydroquinone derivative and then reoxidized onto a solid substrate.
Flammability and Explosibility
Notclassified(100%)
Synthesis
Indanthrone , Indanthren Blue RS
and R, is prepared from 2- (or
1-) aminoanthraquinone by potash fusion , in potassium phenolate , , or
in 50 % potassium hydroxide , .
Chlorination of indanthrone in sulfuric acid
under addition of 1 % or5%manganese dioxide
(5 – 8 % or 13.8 – 14 % Cl) at 50 – 55 ?C affords
dyes of slightly greener shades (Indanthren Blue
GCD or BC).
Properties and Applications
red light blue. Slightly soluble in chloroform (heat), o-chlorophenol,Quinoline, insoluble in acetic acid, acetone, ethanol, pyridine, toluene, xylene. The strong sulfuric acid for brown, after diluted blue precipitation; In alkaline insurance powder solution for blue, acidic solutions for the red light in blue. And C.I. Vat ?Blue 4, C.I. Pigment Blue 60 the same chemical structure.
Purification Methods
Crystallise indanthrene repeatedly from 1,2,4-trichlorobenzene to give a blue powder. It is soluble in alkali and conc H2SO4. [Weinstein & Merritt J Am Chem Soc 81 3759 1959, Beilstein 24 II 317, 24 III/IV 2193.]
