Factory Sale Direct Grey D Direct Black 17
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:
Direct Grey D is readily soluble in cold water / warm water (dissolution degree at 80℃ ≥ 20g/L), and the solution is clear and dark purple-black.
Direct Black 17 dissolves in ethanol to form a grayish purple color, is slightly soluble in acetone, and insoluble in other organic solvents.
Acid and Base Reactions:
Concentrated sulfuric acid: deep blue-green, turns to orange-brown precipitate after dilution
10% caustic soda: purple-gray (color light is stable)
Concentrated hydrochloric acid: dark brown precipitate
Stability:
Direct Black 17 has medium alkali resistance: stable at pH 7–9, easily precipitates in strong alkali
Direct Grey D is sensitive to copper / iron ions: turns greenish when exposed to copper, turns darker when exposed to iron, requires soft water and chelating agents
Color Fastness (Common Grade)
Light fastness: 3 (medium), Direct Grey D is better than Direct Brown 1/2 (2), suitable for indoor / semi-outdoor use
Wash fastness: 3 (average, color fixation is needed to improve wet fastness)
Dry rubbing: 4; Wet rubbing: 3
Sweat fastness: 3
Chlorine bleaching fastness: 2–3
Application Characteristics
Dyeing affinity: Direct Black 17 has strong affinity for cotton, viscose, linen, and non-woven fabrics, with the highest dyeing rate at 40–80℃, and low-temperature energy saving
Leveling / Migration: Direct Black 17 has good leveling properties and medium migration, suitable for medium and light gray-black colors
Compatibility: Direct Grey D can be stably mixed with Direct Yellow / Red / Blue for deep gray, charcoal black, and navy blue
Industrial coloring:
Direct Grey D is used in paper (packaging / newsprint), leather, water-based color pastes, and bamboo and wood fibers
Advantages and Disadvantages
Advantages:
Direct Black 17 dissolves quickly: dissolves in cold water, simple to prepare, and does not easily form lumps
Direct Black 17 has a unique color light: bluish gray-black, clean and transparent, different from ordinary black
Low-temperature energy saving: dyeing can be done at 40℃, low energy consumption, suitable for large-scale production
Direct Grey D has good discharge properties: can be discharged, suitable for printing processes
Disadvantages:
Direct Black 17 has average light fastness (3): prone to fading when used outdoors for a long time, not as good as Direct Sunlight Black
Direct Black 17 has weak wash fastness: color fixation is needed to improve wet fastness
Direct Grey D is sensitive to metal ions: prone to color change, requires water quality control