Nylon Dye Acid Orange Ⅱ Acid Orange 7

Acid Orange II is a water-soluble, single azo anionic acid dye.

1. Water Solubility: Solubility at room temperature (30°C) is approximately 116 g/L; solubility increases to up to 300 g/L in hot water (90–100°C). It dissolves rapidly and is suitable for aqueous formulation production.  

2. Organic Solvents: Acid Orange II is soluble in methanol and ethanol, forming orange-yellow solutions; slightly soluble in acetone.  

3. Reaction with Acid: When concentrated hydrochloric acid is added dropwise to an aqueous solution of Acid Orange II, a brownish-yellow precipitate forms.  

4. Reaction with Alkali: Upon addition of sodium hydroxide, the solution turns dark brown; **insoluble in concentrated NaOH**.  

5. Concentrated Sulfuric Acid: The dye exhibits a magenta color, and upon dilution with water, a brownish-yellow precipitate forms.  

6. Concentrated Nitric Acid: The solution appears golden yellow.

1. Wool Dyeing with Acid Orange II: Start dyeing at 40°C, add acetic acid and sodium sulfate, then slowly raise the temperature at 1–2°C/min to 95–98°C, hold for 30–45 minutes, then gradually cool and wash.  

2. Silk Dyeing with Acid Orange II: Maintain pH between 4.5–5.0 and temperature at 85–90°C; reduce heating rate to prevent fiber surface abrasion and color irregularities.  

3. Nylon (Polyamide) Dyeing with Acid Orange II: Best results achieved using formic acid bath at 95–98°C; suitable for direct printing on nylon fabrics.  

4. Acid Orange II can be used for simultaneous printing of wool, silk, and nylon in the same bath; slight staining may occur on cellulose fibers—caution required during color blending.

1. Textile Printing and Dyeing  

Dyeing and direct printing of wool, cashmere, silk, and nylon fabrics. Acid Orange II is ideal for producing solid orange shades and is an essential component in creating Acid Black ATT through color mixing.  

2. Industrial Coloring  

Leather: Water-based dyeing of shoe uppers and apparel leathers  

Paper: Water-based coloring of decorative and specialty papers  

Water-based inks: Fountain pen inks and water-based marker dyes (note: control pH and metal ions to avoid gelation or precipitation)  

Crafts, incense, and water-based color pastes

Advantages  

1. Acid Orange II offers bright, saturated color with pure red-orange hue and excellent compatibility in color blending.  

2. Excellent water solubility—even in cold water—facilitates easy preparation of stock solutions.  

3. Superior leveling and strong penetration minimize color spots and streaks.  

4. Fast dye uptake, high production efficiency, cost-effective, and readily available with stable supply.  

Disadvantages  

1. Moderate lightfastness makes it unsuitable for products exposed to prolonged outdoor sunlight.  

2. Highly sensitive to heavy metal ions such as copper and iron, which can alter color tone.  

3. Prone to discoloration and precipitation under strongly alkaline conditions.

Standard package: 25kg woven bag / fibre drum. Store hermetically, keep dry. Do not store together with strong oxidants.