Direct Dye Direct Brown N.
Product Characteristics
Direct Brown N belongs to the ordinary type of di-azo direct dye.
Physical and Chemical Properties
Solubility:
Direct Brown N is easily soluble in cold water / warm water (25°C solubility ≥ 20g/L), and the solution is clear chestnut brown.
It dissolves in ethanol to form a light brown color, is slightly soluble in acetone, and is insoluble in non-polar solvents.
Acid-base stability:
Direct Brown N has good alkali resistance: stable at pH 7–11, suitable for weakly alkaline / neutral systems (such as papermaking).
It turns red-brown in concentrated sulfuric acid, forms brown precipitate after dilution; there is no obvious color change in concentrated caustic soda.
Affinity: Direct Brown N has strong affinity for cotton, viscose, hemp, and non-woven fabric, with high dyeing rate at 60–80°C.
Color Fastness (Conventional Level)
Sunlight Fastness: Grade 3 (stable indoors, requires fixation outdoors)
Water Wash Fastness: Grade 2–3 (easily fades during wet washing, can reach Grade 3–4 after fixation)
Dry Friction: Grade 4; Wet Friction: Grade 3
Sweat Fastness: Grade 3
Core Advantages
Direct Brown N has natural color: pure chestnut brown, warm yellow-brown, retro and high-end, suitable for earth tones.
Easy to dissolve: soluble quickly in both cold and hot water, simple to mix, not prone to caking, suitable for automated batching.
Direct Brown N is stable against alkali: pH ≤ 11 does not precipitate, suitable for washing fluids, laundry detergents, water-based color pastes, etc.
High cost-effectiveness: Direct Brown N is affordable, has good uniformity, suitable for medium-light to medium-dark color dyeing.
Removable Dyeing Performance: Removable, suitable for printing and partial fading processes.
Limitations
Sunlight Resistance: Generally, Direct Brown N has a sunlight fastness of Grade 3, and it is prone to fading in the long term outdoors, not as good as Direct Brown 95 (5–6 grades).
Water Wash Fastness: Weak; requires fixation treatment to improve wet fastness.
Direct Brown N is sensitive to hard water: calcium and magnesium ions easily cause color bleeding, recommend using soft water or adding chelating agents.
Typical Applications
Industrial Coloring:
Direct Brown N is used for paper (packaging / art paper), leather, water-based color pastes, bamboo and wood fibers.
Textile Printing and Dyeing: Medium-light chestnut brown dyeing for cotton / viscose / hemp, spot dyeing with coffee, khaki, and tobacco brown.