disodium dibenzo[b,def]chrysene-7,14-diyl bis(sulphate)

(a) in the presence of Pyridine, with chlorosulfonic processing C.I. Vat Yellow 4 leuco; (b) used in Pyridine?metal (such as copper, iron, zinc, etc) and Sulfur trioxide source (such as Sulfur trioxide, Chlorosulfonic acid or Methyl chlorosulfonate) processing ?C.I. Vat Yellow 4. The above two kinds of circumstances are through with alkali, filter out the insoluble,, remove Pyridine and salting-out.

red light yellow. Orange powder. Soluble in water and acetone, slightly soluble in alcohol. The strong sulfuric acid for green light yellow, diluted into gold. The solubility in water is good, aqueous solution for under fluorescent light bright yellow. Used for the cotton fabric dyeing as red light yellow, to dead cotton covering power is better. The affinity of cotton fiber medium. This product can be used for printing of cotton, including direct printing, the dye printing, white color printing. Also can be used for silk, wool and PVA dyeing.

Standard	Ironing Fastness	Chlorine bleach	Light Fastness	Mercerized	Oxygen bleach	Soaping
						Fading	Stain
ISO	4-5	4-5	5-6	5	4-5	3-4	4
AATCC	5	5	4-5	5	4