Blend Dye Direct Blend Black D-RSN.
Product Characteristics
Direct Blend Black D-RSN is an eco-friendly direct dye (D type) for direct dyeing of blends. It is a compound black dye without benzidine. It is mainly used for one-bath dyeing of polyester-cotton and polyester-viscose blends, has strong compatibility, is heat-resistant, and has a deep black color with a reddish tint. It is for textile printing and dyeing, not for paper use.
Color and Solubility
Color: Deep black with a reddish tint (redder than Direct Black 19/22)
Aqueous solution: Reddish black, transparent
Solubility (90°C): ≈60–70 g/L (medium to high), good dyeing performance
Heat resistance: Does not coagulate at 130°C, suitable for one-bath high-temperature dyeing of polyester-cotton blends (110–130°C)
Dyeing Performance (Core)
1) Uptake and Affinity
Direct Blend Black D-RSN has high directness and fast coloration on cotton and viscose, with good exhaustion.
Direct Blend Black D-RSN does not color or stain polyester and can be used in the same bath as disperse dyes.
Direct Blend Black D-RSN has some affinity for nylon and can dye nylon black (with a reddish tint).
2) Color Fastness (Typical values, 2% owf)
Light fastness (Xenon lamp): 3–4 grades
Wash fastness (CO/cotton): 4–5 grades
Sweat fastness (CO): 4–5 grades
Dry rubbing: 4–5 grades; Wet rubbing: 3 grades
3) pH and Hard Water
pH range: Weakly acidic to neutral (pH 5.5–7.5), commonly used pH in one-bath dyeing is 6–7
Hard water resistance: Good, a small amount of salt can achieve high uptake
Core Advantages (Compared to ordinary direct black)
Special for one-bath dyeing of blends: Direct Blend Black D-RSN can be used in the same bath as disperse dyes for dyeing T/C and T/R, eliminating the need for two baths, reducing costs and improving efficiency.
High-temperature stability: Does not coagulate at 130°C, suitable for high-temperature and high-pressure dyeing.
Strong compatibility: Direct Blend Black D-RSN can be used in combination with direct yellow/red/blue and disperse dyes for stable color matching with good reproducibility.
Good blackness: Direct Blend Black D-RSN has sufficient blackness and a correct reddish tint, commonly used in textile fabrics.
Disadvantages
Reddish tint: Direct Blend Black D-RSN is redder than Direct Black 19/22 and is not suitable for pure blue-black requirements.
Average light fastness: 3–4 grades, lower than Direct Black 22 (4–6 grades) and Direct Black 17 (7–8 grades).
Wet rubbing 3 grades: Deep colors require fixation to improve.
- Typical Application Scenarios (Textile, not for paper use)
Polyester-cotton and polyester-viscose blended fabrics: One-bath one-step black dyeing (most mainstream)
Cotton and viscose woven, knitted fabrics, and yarns
Nylon blends: Can dye nylon black (with a reddish tint)
Recommended process:
Temperature: 110–130°C (T/C); 90–95°C (pure cotton)
pH: 6.0–7.0
Dosage: 1%–4% (owf)
Salt addition: 10–20 g/L sodium sulfate