Trade Name: REACTOBOND TURQUOISE BLUE G · CI Number: Reactive Blue 21
Reactive Blue 21 is the only reactive dye that produces a true turquoise shade on cotton — a colour that cannot be achieved by blending blue and green reactives. Its unique phthalocyanine chemistry delivers an intensely bright turquoise with excellent wash fastness, making it indispensable for fashion, sportswear, and home textile applications. Supplied by Yobai Industries as REACTOBOND TURQUOISE BLUE G.
The copper phthalocyanine chromophore that gives REACTOBOND TURQUOISE BLUE G its distinctively stable turquoise hue also accounts for its slower diffusion rate into cotton compared to standard azo-based reactive dyes. Extended dyeing time — 90 to 120 minutes after alkali addition — and carefully staged salt and alkali dosing are essential to achieve level turquoise across the fabric. Levelness correction after the process is complete is substantially more difficult than prevention. The same copper chelate structure is inherently UV-stable, which is why this dye class consistently delivers light fastness 5–6 — significantly better than most azo reactive blues.
Specifications are indicative. Contact us for a batch-specific TDS before placing a bulk order.
| Parameter | Value |
|---|---|
| Product Name | Reactive Blue 21 |
| Trade Name | REACTOBOND TURQUOISE BLUE G |
| CI Number | Reactive Blue 21 |
| CAS Number | Available on request |
| Colour | Turquoise Blue |
| Appearance | Turquoise Blue Powder |
| Ionic Character | Anionic (sulphonate groups, copper complex) |
| Solubility | Soluble in water. |
| Application pH | 10–11 (alkaline bath) |
| Application Temp. | 60–80°C |
| Required Auxiliaries | NaCl 60–80 g/L + Na₂CO₃ 20–25 g/L; extended dyeing time (90–120 min); careful staged addition essential |
| Dye Class | Copper Phthalocyanine Reactive (hot-brand exhaust) |
| Fixation Yield | 55–70% (exhaust, optimised conditions) |
| Exhaustion Rate | 55–65% at 60–80°C, NaCl 60–80 g/L |
| Wash Fastness | 4–5 |
| Light Fastness | 5–6 |
| Packaging | 1 kg · 5 kg · 10 kg · 25 kg · 50 kg · Custom packaging available |
| Shelf Life | 5 years from manufacture (cool, dry storage) |
| Manufacturer | Yobai Industries, Sayakha, Gujarat, India |
| GSTIN | GST Registered |
Need a full TDS, COA, or MSDS? Request it here or WhatsApp us directly.
Fixation yield and exhaustion rates are indicative values under standard laboratory conditions. The lower fixation yield compared to azo reactive dyes is a known characteristic of the copper phthalocyanine structure — compensate with proper staging and extended dyeing time. Contact technical@yobaiindustries.in for application-specific support.
| Property | Value / Rating |
|---|---|
| Physical Form | Fine turquoise blue powder |
| Bulk Density | Approx. 0.4–0.6 g/cm³ |
| Solubility in Water | 20–30 g/L at room temp; 40–50 g/L at 50°C |
| Dye Bath Stability | Stable at pH 7–11; hydrolyses rapidly above pH 12 |
| Wash Fastness (ISO 105-C06) | 4–5 |
| Light Fastness (ISO 105-B02) | 5–6 |
| Rubbing Fastness — Dry | 4–5 |
| Rubbing Fastness — Wet | 3–4 |
| Perspiration Fastness (Acid) | 4 |
| Perspiration Fastness (Alkaline) | 4 |
| Chlorine Fastness | 2–3 (avoid chlorine bleaching) |
| Solution Temp. Stability | Stable to 80°C at neutral pH |
Fastness ratings are on the standard 1–5 scale (5 = best). Values are achieved after proper hot soaping at 95°C post-dyeing. Batch-specific COA with fastness data available on request from technical@yobaiindustries.in.
REACTOBOND TURQUOISE BLUE G is notably less soluble than standard azo-based reactive dyes — approximately 20–30 g/L at room temperature, rising to 40–50 g/L at 50°C. The large copper phthalocyanine molecular structure is the reason for this; it diffuses and dissolves more slowly than small-molecule reactive dyes. Undissolved particles added directly to the bath produce spots that are particularly difficult to correct in turquoise shades — prevention during dissolution is the only practical approach.
Start with a cold-water paste, then bring up to 50°C with continuous stirring for a minimum of 10 minutes. Screen through a 100-mesh filter before adding to the bath. Never dissolve in alkaline solution — the dye should be loaded into the bath in neutral form; alkali is added separately after the substrate has loaded with dye. Use the dissolved solution within 4 hours for consistent fixation yield.
All values are for cotton exhaust dyeing at liquor ratio 1:10–1:15. Add NaCl in 3 stages before alkali addition. Extended dyeing time (90–120 min after alkali addition) is essential — do not cut this short.
| Shade Depth | Dye (%owf) | NaCl (g/L) | Na₂CO₃ (g/L) | Temp (°C) | Time (min) |
|---|---|---|---|---|---|
| Light Turquoise | 0.5–1.0% | 40–50 | 15 | 60 | 90 |
| Medium Turquoise | 1.5–2.5% | 60–70 | 20 | 60–70 | 90–100 |
| Deep Turquoise | 3–5% | 70–80 | 25 | 70–80 | 100–120 |
| Teal / Aqua Blend | 2–3% RB21 + partner | 60–80 | 20–25 | 60–80 | 90–120 |
Contact our technical team at technical@yobaiindustries.in for process optimisation specific to your machine type and water quality.
The swatches below represent typical application outcomes on 100% combed cotton under standard exhaust bath conditions. Actual shade depends on fibre quality, water hardness, and process variables. Request a sample dyed swatch before committing to bulk production.
Request a shade card or sample dyed swatch from technical@yobaiindustries.in to verify shade match before production.
Store in a cool, dry location below 25°C. Reactive dyes are sensitive to moisture and elevated temperatures — keep containers sealed at all times. Avoid storage near acidic materials. Protect from direct sunlight.
This dye is used by manufacturers across the following industries. Contact us with your specific application for a grade recommendation.
Yobai Industries carries the following grades in this dye family. Click any grade to view specifications, or view the full catalogue →
Don't see the grade you need? We carry 250+ dye grades. Contact us and we'll source or develop it for you.
MOQ 10 kg · Samples in 24 hours · Bulk in 7–15 days · Export worldwide · GST invoice with every order.