disodium 6-chloro-6'-methoxy-4-methyl[2,2'-bibenzo[b]thiophene]-3,3'-diyl disulphate

(a) in the presence of Pyridine , with Chlorosulfonic acid treatment C.I. VatRed 6 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. VatRed 6, The above two kinds of circumstances are through with alkali, filter out the insoluble,, remove Pyridine and salting-out.

bright pink to red. gray- red powder. Soluble in water nearly colorless, meet strong sulfuric acid turn green. In the neutral or alkaline bath dyeing cotton dyeing, affinity is low. Can use the cotton fabric printing, such as direct printing, the printing and dyeing discharge printing. Also used for silk and wool and polyester/cotton blended fabric dyeing.

Standard	Ironing Fastness	Chlorine bleach	Light Fastness	Mercerized	Oxygen bleach	Soaping
						Fading	Stain
ISO	5	5	6-7	4	4	4-5	5