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High Quality Direct Blue 71 - China Suppliers and Factory for Direct Fast Blue B2RL Dye
Product Characteristics
Direct Blue 71 is a triazene-based direct sun-resistant dye.
Physical and Chemical Properties
๐ง Solubility
1 Water Solubility
- Direct Blue 71 has moderate water solubility. The aqueous solution appears as a bright blue color.
- Slightly soluble in cellulose; extremely slightly soluble in ethanol. Does not dissolve in other organic solvents.
๐ก๏ธ At 60ยฐC
โ 10 g/L
๐ก๏ธ At 97ยฐC
โ 20 g/L
Alkali Resistance Stability: Stable at pH 7โ10. Highly alkaline conditions (pH > 11) cause precipitation easily โ car wash solutions should control pH โค 10.
2 Acid-Base Reaction Characteristics
- Aqueous solution + concentrated hydrochloric acid โ blue precipitate
- Aqueous solution + concentrated alkali โ red-purple precipitate
- Concentrated sulfuric acid โ blue to gray-black; diluted โ red-purple precipitate
3 Dyeing Characteristics
- Color: Deep red blue โ rich and stable
- Affinity: Good affinity for cellulose fibers such as cotton, viscose, and linen
- Dyeing Rate: Medium to high; uniformity and removability are average
Color Fastness Indicators (Reference)
๐ Fastness Ratings
| Fastness Type | Grade / Rating |
|---|---|
| โ๏ธ Sunlight Fastness | 5โ6 Grades |
| ๐ง Water Washing Fastness | 3โ4 Grades |
| ๐งฃ Dry Rubbing Fastness | 4 Grades |
| ๐ฆ Wet Rubbing Fastness | 2โ3 Grades |
Core Advantages & Limitations
โก Key Performance Points
โ
Unique Color Tone: Deep blue-red, more intense than ordinary direct blue โ ideal for dark coloring.
โ
Better Sun Resistance: 5โ6 sunlight exposure levels โ superior to some direct blues; does not fade easily outdoors.
โ
High Cost-Effectiveness: Moderate price with wide applicability across industries.
โ
Alkali Resistance Limitation: pH > 11 tends to cause precipitation. Not suitable for strong alkaline car washing solutions (pH 11โ12).
โ
Iron Ion Sensitivity: Color becomes darker when encountering iron ions during dyeing. Dissolve in soft water is recommended.
Application Scope
๐ญ Industrial & Textile Use
1 Industrial Coloring
- Neutral / weakly alkaline car wash solutions and glass water โ suitable for deep blue coloring. Caution required with strong alkaline systems.
- Applicable in water-based cleaners, laundry detergents, paper, leather, soap, bamboo, and wood fiber coloring.
2 Textile Printing and Dyeing
- Produces red-light deep blue coloring in cotton, viscose, hemp, non-woven fabric, home textiles, and knitted products.
- Also suitable for silk, nylon, and blended fabrics of viscose/nylon.
Usage Process of Direct Blue 71
1
Mixing Solution
Stir and dissolve in 50โ60ยฐC warm water. Avoid lumps and do not use strong alkaline water.
2
Dosage
0.2โ0.5 g/kg (0.002โ0.005% by weight). A 3% by weight dosage is sufficient for deep blue color.
3
pH Control
Strictly control pH 8โ10. Beyond this range, precipitation is likely to occur.
4
Compatibility
Direct Fast Blue B2RL has good compatibility with non-ionic / anionic surfactants and does not affect foaming.
Frequently Asked Questions
Q
What is Direct Blue 71 and what makes it different from other direct dyes?
Direct Blue 71 is a triazene-based direct sun-resistant dye known for its distinctive deep red-blue color tone. Unlike ordinary direct blue dyes, it offers better sunlight fastness (5โ6 grades) and a richer, more intense hue, making it especially suitable for dark coloring applications in both industrial and textile sectors.
Q
What is the recommended pH range when using Direct Blue 71?
Direct Blue 71 is stable within a pH range of 7โ10. It is important to strictly control the pH between 8 and 10 during use. At pH values above 11, the dye tends to precipitate, making it unsuitable for strongly alkaline systems such as car washing solutions with pH 11โ12.
Q
What types of fibers and materials are compatible with Direct Blue 71?
Direct Blue 71 has good affinity for cellulose-based fibers including cotton, viscose, hemp, and linen. It is also suitable for silk, nylon, non-woven fabrics, home textiles, and blended fabrics of viscose/nylon. In industrial applications, it can be used in water-based cleaners, laundry detergents, paper, leather, soap, and bamboo/wood fiber coloring.
Q
How should Direct Blue 71 be dissolved and what dosage is recommended?
Direct Blue 71 should be stirred and dissolved in warm water at 50โ60ยฐC to avoid lumps. Strong alkaline water should not be used. The recommended dosage is 0.2โ0.5 g/kg (0.002โ0.005% by weight) for standard applications. For a deep blue color, a concentration of approximately 3% by weight is sufficient.
Q
Is Direct Blue 71 compatible with surfactants used in cleaning products?
Yes. Direct Blue 71 (Direct Fast Blue B2RL) demonstrates good compatibility with both non-ionic and anionic surfactants commonly found in cleaning formulations. It does not negatively affect foaming performance, making it a reliable choice for coloring liquid detergents, car wash solutions, and water-based cleaners.
Q
What precautions should be taken when using Direct Blue 71 in dyeing processes?
Two key precautions should be observed: First, Direct Blue 71 is sensitive to iron ions โ contact with iron ions during dyeing can cause the color to become darker. It is recommended to dissolve the dye in soft water to avoid this issue. Second, maintain the solution pH within the 8โ10 range at all times to prevent unwanted precipitation and ensure color consistency throughout the dyeing process.