Direct Dyes
Direct Red 28
Classic direct red coloration for paper and cellulosic applications.
Overview
Direct Red 28 is a direct red dye commonly identified with Congo Red. It provides a strong red shade and is used across paper and other industrial coloration applications. As Congo Red, it is one of the most extensively documented direct dyes: a disazo compound long used as a textile and paper colourant, and separately known as a laboratory pH indicator that shifts from blue in acid to red in neutral-to-alkaline conditions.
Colour Reference
Appearance, dilution, and application
Appearance
Dilution
Application
Applications
Where it is used
- Paper and paper products
- Cellulosic substrates
- Industrial coloration
- Selected textile and leather applications
Benefits
Why mills choose it
Strong red coloration
Water-soluble direct dye
Suitable for paper coloration
Consistent shade development
Identity & Data
Technical data
Typical values. For a full technical datasheet or safety data sheet, get in touch.
- C.I. Name
- C.I. Direct Red 28
- C.I. Number
- 22120
- CAS Number
- 573-58-0
- Molecular Weight
- 696.66
- Molecular Formula
- C32H22N6Na2O6S2
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