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China Suppliers Factory Direct Grey D/Direct Black 17 - High-Quality Black Powder Dye, CAS 2945-96-2
Product Characteristics
💡
Direct Black 17 is a common direct dye of the diazo type. Its core features include a bluish black / grayish black color, good water solubility, easy dyeing at low temperatures, and high cost performance. It is mainly used for dyeing cellulose fibers indoors and industrial coloring, with medium light fastness.
Physical and Chemical Properties
💧 Solubility
- Readily soluble in cold/warm water (≥ 20g/L at 80℃).
- Solution appears clear and dark purple-black.
- Dissolves in ethanol (grayish purple); slightly soluble in acetone.
🧪 Chemical Reactions
- Sulfuric Acid: Deep blue-green; turns orange-brown precipitate on dilution.
- 10% Caustic Soda: Purple-gray (stable color light).
- Hydrochloric Acid: Dark brown precipitate.
⚖️ Stability
- Alkali Resistance: Stable at pH 7–9; precipitates in strong alkali.
- Ion Sensitivity: Sensitive to copper (turns greenish) and iron (turns darker).
Color Fastness (Common Grade)
| Fastness Type | Rating / Grade | Notes |
|---|---|---|
| Light Fastness | 3 (Medium) | Better than Direct Brown 1/2; suitable for indoor use. |
| Wash Fastness | 3 (Average) | Color fixation recommended to improve wet fastness. |
| Dry Rubbing | 4 | Excellent dry performance. |
| Wet Rubbing | 3 | Standard performance. |
| Sweat Fastness | 3 | Standard performance. |
| Chlorine Bleaching | 2–3 | Moderate sensitivity. |
Application Characteristics
🧵 Fiber Affinity
Strong affinity for cotton, viscose, linen, and non-woven fabrics. Optimal dyeing rate achieved at 40–80℃, allowing for low-temperature energy savings.
🎨 Leveling & Compatibility
Good leveling properties and medium migration. Stably mixes with Direct Yellow, Red, or Blue for deep gray, charcoal black, and navy blue shades.
🏭 Industrial Use
Widely used in paper (packaging/newsprint), leather, water-based color pastes, and bamboo or wood fibers.
Advantages and Disadvantages
Advantages
- Quick Dissolution: Dissolves in cold water without forming lumps.
- Unique Color Light: Clean, transparent bluish gray-black.
- Energy Efficient: Effective dyeing at 40℃.
- Discharge Properties: Suitable for discharge printing processes.
Disadvantages
- Light Fastness: Grade 3; prone to fading under long-term outdoor exposure.
- Wash Fastness: Requires fixation agents for high wet fastness requirements.
- Metal Sensitivity: Requires water quality control (sensitive to Cu/Fe ions).
Frequently Asked Questions
❓ What is the primary color light of Direct Black 17?
Direct Black 17 provides a unique bluish black or grayish black color light that is clean and transparent compared to ordinary black dyes.
❓ Is Direct Black 17 suitable for outdoor textiles?
It has a medium light fastness rating of 3. While excellent for indoor and semi-outdoor use, it may fade if exposed to direct sunlight for extended periods.
❓ Can it be used for low-temperature dyeing?
Yes, one of its main advantages is energy saving. It achieves its highest dyeing rate between 40–80℃, making it suitable for large-scale production with lower energy consumption.
❓ Why does the color change when using certain water sources?
Direct Grey D (Direct Black 17) is sensitive to metal ions. Exposure to copper ions can turn it greenish, while iron ions can make the color darker. Using soft water and chelating agents is recommended.
❓ How can I improve the wash fastness of this dye?
Since its wash fastness is average (Grade 3), applying a color fixation treatment after dyeing is highly recommended to improve wet fastness and durability.
❓ What industrial materials can be colored with Direct Grey D?
Beyond textiles like cotton and viscose, it is widely used for industrial coloring of paper (packaging and newsprint), leather, bamboo, wood fibers, and water-based color pastes.