Product Description
Direct Red 23 (CAS 3441-14-3, C.I. 29160), also known as Direct Fast Scarlet 4BS, is a water-soluble disazo direct dye widely used for cellulose fibers and paper. It gives a bright scarlet (yellowish red) shade with good build-up and level dyeing behavior, and is a cost-effective choice for cotton, viscose, linen and pulp coloring.
Key features:
Direct dyeing on cellulose in neutral-to-saline dyebaths; no mordant required.
Bright yellowish red shade, easy to combine with other direct dyes for shading.
Good acid and alkali resistance, stable across a wide pH range.
Good build-up and level-dyeing properties on cotton and viscose.
Suitable for exhaust dyeing, padding and printing, as well as paper/pulp coloring.
Can be after-treated with fixing agent Y or UF resin to improve wet fastness.
Product Parameters
| Item | Specification |
|---|---|
| Product Name | Direct Red 23 |
| CAS No. | 3441-14-3 |
| Color Index No. | 29160 |
| Synonyms | Direct Fast Scarlet 4BS, Diamine Fast Scarlet 4BS |
| Dye Type | Water-soluble disazo direct dye |
| Appearance | Reddish-brown / red powder |
| Shade | Bright yellowish scarlet red |
| Solubility | Soluble in water |
| pH Stability | Stable from weak acid to weak alkali |
| Light Fastness | Grade 2 – 3 (typical) |
| Acid / Alkali Resistance | Good |
| Application Method | Exhaust, padding, printing |
| After-treatment | Fixing agent Y / UF resin for wet fastness |
| Packaging | 25 kg carton / fiber drum |
Product Application
Direct Red 23 is a versatile substantive dye mainly used for cellulose fibers, but it also finds use in protein fibers, paper, leather and pigment lake manufacture.
In textile dyeing, it is the standard scarlet dye for cotton, viscose/rayon, linen and ramie, applied by the exhaust method in neutral dyebaths with Glauber's salt or common salt. It is also used for silk and wool in weakly acidic or neutral baths, and for blended fabrics containing cellulose. It is often combined with yellow, orange and brown direct dyes to produce scarlet, red-orange and brick-red shades, and after-treated with fixing agents to improve wash fastness.
In paper and pulp, it is widely used for coloring writing paper, packaging paper, tissue and board, either directly in the pulp or by surface coloring, where its good water solubility and bright shade give even coloration.
In other fields, it is used for leather dyeing, soap and detergent colorants, and as a starting material for preparing pigment lakes. It is also used in agriculture for seed-coating and fertilizer colorants where a low-cost red dye is needed.
