Vat Blue 20

DescriptionViolanthrone, Indanthren Dark Blue BOA,is generated by potash fusion of benzanthrone , . Direct potash fusion leads to side products, such as isoviolanthrone and 4-hydroxybenzanthrone. The crude product may be used directly or in mixtures with other dyes in vat dyeing. It is also used to generate violanthrone derivatives. Several processes have been developed to decrease the amounts of undesirable side products of the direct potash fusion of benzanthrone or to purify the bibenzanthronyl or the crude violanthrone . Especially effective is the addition of high-boiling solvents such as naphthalene, the so-called low carbazole anthracene residues, or sodium acetate to the melt. The quality of the products prepared by these methods is satisfactory for the production of almost all violanthrone dyes.

UsesDIBENZANTHRONE is mainly used for dyeing and printing cotton fibers and fabrics. It has good affinity, fast color uptake, and moderate leveling properties. It is rarely used alone for printing, but more often for color matching. It can also be used for dyeing silk, viscose fiber, viscose cotton, and vinylon, as well as for hot-melt dyeing of polyester-cotton blended fabrics with disperse dyes in the same bath. It is also used to prepare organic pigments.

General DescriptionBluish-black to black powder.