Appearance of Direct Red 23(Direct Red 4BS) is generally purple-red uniform powder. Dissolved in water is bright red, slightly soluble in alcohol, orange, insoluble in acetone. Large red to magenta in concentrated sulfuric acid After dilution, it turns brownish orange; there is orange-yellow precipitate in concentrated nitric acid; it is red in concentrated sodium hydroxide, and dilute sulfuric acid is added to the blue water in the aqueous solution. Concentrated hydrochloric acid has burgundy precipitate, plus 10% soda ash. Change. When the copper ion color is dimmed, the color of the iron ion is almost unchanged.
Direct Red 4BS,Fast Red 4BS,Direct Scarlet 4BS,Direct Scarlet Lightfast,Direct Scarlet SE,Direct acid resistant red 4BS,Enianil Fast Scarlet 4BS,Erie Fast Scarlet SCB,Nippon Fast Scarlet 4BS,Nyanza Fast Scarlet 4BSA,Orbamin Scarlet 4BS,Paper Scarlet 4BS
It Mainly used in viscose etc of cellulose fiber dyeing, also can be used for silk, wool, paper and pulp dyeing, also can be used in the manufacture color which have pigment.
| Dyeing depth % | 2 |
| Insolubles % | 0.15 |
| Light Fastness | 2-3 |
| Washing Fatness | 3 |
| Rubbing fastness(dry) | 3 |
| Rubbing fastness(wet) | 2 |
sun exposure | soaping | flooding | perspiration | rubbing | ironing | acidand alkali resistant | |||||||
standard depth | 1/12 depth | original color change | white fiber stained | original color change | white fiber stained | original color change | white fiber stained | dry | wet | sulfuric | acetate | sodaash | |
— | — | 3~4 | 1~2 | 4 | 3 | 3~4 | 4 | 4 | 2~3 | 4~5 | 2~3 | 1 | 4 |
When the dark color is dyed slowly, it is easy to control, the light color is dyed very fast, and due to the poor transferability,Direct Red 23 is easy to produce color flowers, which should be noted.
It dyes cellulosic fibers (cotton, rayon) efficiently by direct adsorption; performance on synthetics is limited without special carriers or mordants.
It is an azo dye with environmental persistence and reported toxic concerns in some studies—use gloves, eye protection, and follow SDS/waste disposal rules.
Direct Red 23 Use levels vary by shade depth and substrate (typically measured as % owf — 0.1–3% for lighter shades; higher for deep shades). Always run lab trials.