Vat Blue 4

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;

Definition

A blue vat dye or pigment. The molecule consists of two anthraquinone nuclei linked through two –NH groups.

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.

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.

Flammability and Explosibility

Notclassified

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.]