Trade Name: REACTOBOND BLUE MR · CI Number: Reactive Blue 4
Reactive Blue 4 is a DCT (dichlorotriazine) cold brand reactive dye that reacts with cotton at room temperature, making it ideal for cold pad-batch processes. It offers significant energy savings over conventional exhaust dyeing while still delivering good wash fastness through covalent fibre bonding. Supplied by Yobai Industries as REACTOBOND BLUE MR.
In cold pad-batch dyeing, fabric is padded through a dye-alkali liquor (NaOH 15–20 g/L plus sodium silicate 100 g/L), sealed in polythene film, and batched at room temperature for 8–24 hours to allow the dye-cellulose covalent bond to form. The DCT chemistry of REACTOBOND BLUE MR is highly reactive under alkaline conditions at room temperature, so the working solution has a limited pot life — typically 4–8 hours — and should be prepared fresh each shift. No salt is required in cold pad-batch since migration control is achieved by the pad nip and the sealed batching film rather than by dye-bath electrolytes. Energy consumption is substantially lower than hot exhaust dyeing, which is the principal reason mills use pad-batch for large-volume cellulosic dyeing.
Specifications are indicative. Contact us for a batch-specific TDS before placing a bulk order.
| Parameter | Value |
|---|---|
| Product Name | Reactive Blue 4 |
| Trade Name | REACTOBOND BLUE MR |
| CI Number | Reactive Blue 4 |
| CAS Number | Available on request |
| Colour | Bright Blue |
| Appearance | Blue Powder |
| Ionic Character | Anionic (sulphonate groups) |
| Solubility | Soluble in cold water. |
| Application pH | 10–12 (cold pad-batch) |
| Application Temp. | 20–25°C (cold brand process) |
| Required Auxiliaries | NaOH 15–20 g/L + sodium silicate 100 g/L (pad-batch); no salt required for cold-pad process |
| Dye Class | DCT (Dichlorotriazine) Cold Brand Reactive |
| Fixation Yield | 60–75% (cold pad-batch, optimised batching conditions) |
| Pot Life (working solution) | 4–8 hours (prepare fresh each shift) |
| Wash Fastness | 4 |
| Light Fastness | 5 |
| 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.
The DCT reactive group has a shorter pot life than VS-type reactive dyes — always prepare the working pad liquor fresh at the start of each shift. Contact technical@yobaiindustries.in for application-specific guidance.
| Property | Value / Rating |
|---|---|
| Physical Form | Fine blue powder |
| Bulk Density | Approx. 0.4–0.6 g/cm³ |
| Solubility in Water | Good at room temperature; 40–60 g/L in cold water |
| Dye Bath Stability | Limited in alkaline solution — pot life 4–8 hours; stable as dry powder |
| Wash Fastness (ISO 105-C06) | 4 |
| Light Fastness (ISO 105-B02) | 5 |
| Rubbing Fastness — Dry | 4 |
| Rubbing Fastness — Wet | 3–4 |
| Perspiration Fastness (Acid) | 4 |
| Perspiration Fastness (Alkaline) | 3–4 |
| Chlorine Fastness | 2–3 (avoid chlorine bleaching) |
| Solution Temp. Stability | Stable as dry powder; avoid heating alkaline working solution |
Fastness ratings are on the standard 1–5 scale (5 = best). Values are achieved after proper hot soaping at 95°C post-batching. Batch-specific COA available on request from technical@yobaiindustries.in.
REACTOBOND BLUE MR dissolves readily in cold water — approximately 40–60 g/L at room temperature — which is an advantage in cold pad-batch where the process is run entirely at ambient temperature. The anthraquinone structure dissolves cleanly without the pre-pasting step that some reactive dyes require, though thorough stirring before adding to the pad trough is still important to ensure uniform distribution in the liquor.
Important: the dye should be dissolved in plain water first, then the alkali (NaOH and sodium silicate) should be added separately to the pad trough. Never add NaOH directly to the dry dye powder — the heat of dilution can cause localised pre-reaction. The combined pad liquor should be used within 4–8 hours; the DCT reactive group begins hydrolysing in alkaline solution over time, reducing fixation yield if the solution ages.
All values are for cold pad-batch on cotton. Wet pick-up: 70–80%. Batch at 20–25°C in sealed polythene film. Rotate rolls slowly throughout the batching period.
| Shade Depth | Dye (g/L) | NaOH (g/L) | Na₂SiO₃ (g/L) | Temp (°C) | Batch Time (h) |
|---|---|---|---|---|---|
| Light Blue | 10–20 | 15 | 80–100 | 20–25 | 8–12 |
| Medium Blue | 30–50 | 15–18 | 100 | 20–25 | 10–14 |
| Dark Blue | 60–80 | 18–20 | 100–120 | 20–25 | 12–16 |
| Deep / Very Dark | 80–100 | 20 | 120 | 20–25 | 14–20 |
Contact our technical team at technical@yobaiindustries.in for process development specific to your pad-batch setup.
The swatches below represent typical application outcomes on 100% combed cotton at 20–25°C pad-batch conditions. Actual shade depends on fibre quality, pad expression, and batch duration. 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.