Factory Direct Supply of High-Quality Direct Red 23
Direct Red 23 is a widely used disazo direct dye, offering bright yellowish-red shade and high exhaustion. It is mainly for cotton, viscose and cellulosic fabrics, also applicable for silk, wool, linen, paper, leather and coatings.
Physicochemical Properties
1.Solubility
● Water: Moderate solubility (approx. 30 g/L at 80°C), bright red aqueous solution
● Ethanol: Slightly soluble, orange color
● Acetone: Insoluble
2. Chemical Color Reactions
● Dilute sulfuric acid: Aqueous solution turns pale blue
● Concentrated hydrochloric acid: Wine-red precipitate forms
● Concentrated NaOH: Turns reddish-orange brown
● Concentrated sulfuric acid: Bright red → magenta; turns brownish-orange upon dilution
● Concentrated nitric acid: Orange-yellow precipitate forms
● Concentrated ammonia water: Bright red
3. Ion Effects
● Copper ions: Color shade darkens significantly
● Iron ions: Almost no effect
● Hard water / calcium-magnesium ions: Prone to precipitation; soft water required
Fastness Properties
● Light fastness: Grade 2–3 (low, not suitable for long-term sunlight exposure)
● Washing fastness: Grade 3
● Dry rubbing fastness: Grade 3
● Wet rubbing fastness: Grade 2
● Perspiration fastness: Medium
● Chlorine fastness: Fair
Dyeing Characteristics
1.Directness: Medium to high, dyes up rapidly
2.Migration: Poor → prone to streaks, uneven dyeing and barre
3.Salt sensitivity: Strong promotion by sodium sulfate; must be added in batches
4.Preferred pH: Neutral to weakly alkaline (pH 7–8)
●Excess alkali: Dull, brownish shade
● Excess acid: Precipitation and uneven dyeing
5. Compatibility
● Compatible for combination dyeing with direct yellow, orange, red, brown
● Not compatible in the same bath with reactive, vat or disperse dyes
6. Staining behavior
● Silk / wool: Light shade pickup
● Polyamide: Severe staining
● Diacetate, polyester: Slight staining
Main Applications
1.Textile Printing & Dyeing
● Main substrates: Cotton, viscose and other cellulosic fabrics, especially knitwear
● Shade: Yellowish red (scarlet / rose red)
● Features: High exhaustion, poor migration, salt-sensitive, medium wet fastness; fixing treatment required
● Others: Also used for dyeing and printing silk, wool, linen; small amount for paper dyeing
2. Other Applications
Can be used to prepare pigment pastes for leather, coatings and related fields.
