Direct Red 31

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Product Name:?Direct Red 31
Chemical Name:??disodium 7,7′-iminobis[4-hydroxy-3-(phenylazo)naphthalene-2-sulphonate]
disodium 7,7′-iminobis[4-hydroxy-3-(phenylazo)naphthalene-2-sulphonate];Direct Pink 12B;2-Naphthalenesulfonic acid, 7,7-iminobis4-hydroxy-3-(phenylazo)-, disodium salt;7,7′-iminobis[4-hydroxy-3-(phenylazo)-2-naphthalenesulfonic aci disodium sa;Benzo Rhoduline Red B;C.I. Direct red 31;C.I.Direct Red 31(29100);Chloramine Rose B,Pyrazol Pink 2B
CAS No:?5001-72-9
MW:? 713.6
Dyes Intermediate


Reddish brown powder. Water-soluble is still good, aqueous solution was blue-red, concentrated hydrochloric acid produced red dates precipitation, add concentrated alkali to orange-brown. Soluble in ethylene glycol ether, ethanol-soluble, red orange, insoluble in other organic solvents. In concentrated sulfuric acid was orange to brown, diluted to produce dark blue red precipitate; in concentrated nitric acid in brown solution, a precipitate. In the concentrated alkali does not dissolve; in concentrated ammonia was jujube red.


Direct pink is the main red dye varieties, widely used in cotton, viscose fabric dyeing and printing, but also for silk and viscose fabric. A good transfer of dyeing and level dyeing, the dyeing rate. It can also be used for dyeing silk, vinyl fabric and silk fabric direct printing. For cotton, viscose and other fiber blended fabric, the silk was slightly shallow color, wool and nylon can be stained, two acetate fibers are stained, polyester, acrylic slightly stained.

Storage: Storage should be cool and ventilated, away from heat, fire, to prevent sun exposure, heat is strictly prohibited.
Package:?25kg PP bag for solid powder. 200L or 250KG Drum for Liquid.


Appearance Reddish brown powder
Content ≥100%
Moisture ≤0.1%
Insoluble ≤0.1%
Melting point /

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