The C.I. Acid Blue 168(8CI,9CI), with the cas registry number 12219-24-8, has other names like Copper, [2-[[[[5-(aminosulfonyl)-2-hydroxyphenyl]azo]phenylmethyl]azo]benzoato(2-)]. This is a kind of blue to blue grey powder and its products categories are including dye; acidic dye; neutral dye.

The basic information of this chemical is below: When in concentrated sulfuric acid, the color is Bordeaux and then turns into light orange after diluting; When in concentrated nitric acid, it will be ruined; When in soduim hyfroxide, it has no change and then get glow blue after diluting; When in concentrated hydrochloric acid, it also has no change and then turns into light glow blue after diluting with the appearance of sediments.

The production method of this chemical is as follows: First prepare the material of 2-aminophenol-4-sulfonamide and o-carboxydiphenylhydrazone, and secondly diazotize the 2-aminophenol-4-sulfonamide and then couple with o-carboxydiphenylhydrazone; Finally, complex with copper sulfate and then filter and dry to obtain the products.

As to its usage, it is widely applied in many ways. It could be used in dyeing of wool and silk in neutral or faintly acid dye bath and in direct printing of wool, silk and nylon fabrics; It could be used in dyeing of wool and other many kinds of fibres, and then nylon get the darker color while silk get lighter; It could also be mixed with neutral dark yellow GL to produce neutral green GL.