Vat Blue 4B

Ciba Blue 2B (CAS# 2475-31-2) is a halogenated indigo dye and pollutant contributing 1,3,6,8-tetrabromocarbazole and some other halogenated carbazoles to the environment.

(a) and Acetic anhydride in the presence of Sodium acetate trihydrate in Acetic acid glacial will 3H-indol-3-one,2-(1,3-dihydro-3-oxo-2H-indol-2-ylidene)-1,2-dihydro-? ?tetrabromide?(FIAT764); (b) in the boiling Nitrobenzene with Bromine will 3H-indol-3-one,2-(1,3-dihydro-3-oxo-2H-indol-2-ylidene)-1,2-dihydro- four bromination, (C) 3H-indol-3-one,2-(1,3-dihydro-3-oxo-2H-indol-2-ylidene)-1,2-dihydro- in Chlorosulfonic acid (GP 225227) or in Sulfuryl chloride (GP 229304) and bromine reaction.

blue. Dark blue powder. Etanol and insoluble in water, soluble in Xylene, Nitrobenzene and 1, 2, 3, 4 – Tetrahydronaphthalene. Alkaline reduction leuco for yellow; Acid reduction leuco for pale yellow. In concentrated sulfuric acid to blue light green, diluted into blue, and the emergence of precipitation. Used for cotton of jig dyeing and yarn dyeing, dyeing hair blue cloth color turquoise blue. Is the important dye printing, can direct printing, also can discharge printing and resist printing. Can also be used for viscose, silk and wool dyeing, levelness and affinity are good. Can be processed into organic pigment

Standard	Ironing Fastness	Chlorine bleach	Light Fastness	Mercerized	Oxygen bleach	Soaping
						Fading	Stain
ISO	5	2	4-5	4	3-4	4-5	5
AATCC	5	2	4-5	3-4	4