REACTOBOND

Reactive Black 5 Manufacturer in India

Trade Name: REACTOBOND BLACK B  ·  CI Number: Reactive Black 5

Manufacturer: Yobai Industries, Sayakha, Gujarat MOQ: 10 kg Samples: 24 hours Export: Worldwide GST Registered
Request Quote / TDS WhatsApp Enquiry
Overview

Reactive Black 5 — Product Overview

Reactive Black 5 is, by volume, the most produced reactive dye in the world. It has been the standard black for cotton dyeing for decades — not because it's new or novel, but because it works consistently across a wide range of machines, water qualities, and process conditions. For dye houses running jet machines on mercerised cotton, it's often the first dye they stock and the last they'd ever pull from a recipe base. It forms a permanent chemical bond with the cellulose fibre under alkaline conditions, which is why the shade holds through repeated commercial laundering in a way that direct dyes or surface-held colours cannot.

The bifunctional design gives it a meaningful edge over monofunctional reactive blacks — fixation yields of 70–85% under optimised exhaust conditions, which translates directly to better shade reproducibility, less dye in the effluent, and lower cost per kilo of dyed fabric. Shade character is a neutral black with no blue or brown cast, which is why export buyers often specify it by name. At Yobai Industries we supply it as REACTOBOND BLACK B — shade strength and fixation rate checked on every batch before dispatch.

Applications

  • Cotton fabric and yarn exhaust dyeing
  • Denim dyeing
  • Knit and woven fabric dyeing
  • Pad-batch continuous dyeing
  • Garment dyeing
Substrates

Suitable For

  • Cotton
  • Viscose
  • Linen
  • Modal
  • Silk-cotton blends
Benefits

Key Benefits

  • Covalent bond with fibre — best wash fastness of all dye classes
  • Deep, neutral black shade — no blue or brown undertone
  • Excellent colour build-up even at full depth
  • Suitable for exhaust, pad-batch, and continuous processes
  • Industry-standard black for cotton worldwide
Technical Specifications

Reactive Black 5 — Technical Specifications

Specifications are indicative. Contact us for a batch-specific TDS before placing a bulk order.

ParameterValue
Product NameReactive Black 5
Trade NameREACTOBOND BLACK B
CI NumberReactive Black 5
CAS Number17095-24-8
ColourBlack
AppearanceBlack Powder
Ionic CharacterAnionic (sulphonate groups)
SolubilitySoluble in water. Best dissolution in warm water (40–50°C).
Application pH10–11 (alkaline bath with Na₂CO₃ or NaOH)
Application Temp.60°C (exhaust); 20–25°C (cold pad-batch)
Required AuxiliariesNaCl 60–80 g/L (added in stages) + Na₂CO₃ 15–20 g/L or NaOH for fixation; liquor ratio 1:10–1:15
Molecular Weight991.82 g/mol
Dye ClassBifunctional Vinyl Sulphone Reactive (Disazo)
Fixation Yield70–85% (exhaust, optimised conditions)
Exhaustion Rate70–80% (at 60°C, NaCl 60–80 g/L)
Wash Fastness4–5
Light Fastness5–6
Packaging1 kg · 5 kg · 10 kg · 25 kg · 50 kg · Custom packaging available
Shelf Life5 years from manufacture (cool, dry storage)
ManufacturerYobai Industries, Sayakha, Gujarat, India
GSTINGST Registered

Need a full TDS, COA, or MSDS? Request it here or WhatsApp us directly.

Chemical Properties

Chemical Identity & Fixation Performance

Chemical Identifiers

CAS Number17095-24-8
CI NumberReactive Black 5
Molecular Weight991.82 g/mol
Chromophore TypeDisazo
Reactive GroupBifunctional Vinyl Sulphone
Ionic CharacterAnionic
Bond with FibrePermanent covalent bond

Fixation Performance

Fixation Yield70–85% (optimised exhaust)
Exhaustion Rate70–80% at 60°C, NaCl 60–80 g/L
Application Temperature60°C (exhaust); 20–25°C (pad-batch)
Application pH10–11 (Na₂CO₃ or NaOH)
Electrolyte RequirementNaCl 40–100 g/L (staged addition)
After-treatmentHot soaping at 95°C required

Fixation yield and exhaustion rates are indicative values under standard laboratory conditions. Results vary by machine type, water quality, and process control. Contact Yobai Industries for application-specific support.

Physical Properties

Physical & Colour Fastness Properties

PropertyValue / Rating
Physical FormFine black powder
Bulk DensityApprox. 0.4–0.6 g/cm³ (varies by grade)
Solubility in WaterSoluble; 50–80 g/L in warm water (40–50°C)
Dye Bath StabilityStable 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 — Dry4–5
Rubbing Fastness — Wet3–4
Perspiration Fastness (Acid)4–5
Perspiration Fastness (Alkaline)4–5
Chlorine Fastness2–3 (not recommended for chlorine-bleached fabrics)
Solution Temp. StabilityStable to 80°C at neutral pH; accelerated hydrolysis above this

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.

Solubility

Solubility & Dissolution Guidelines

Solubility is around 50 g/L at room temperature and climbs to 80 g/L at 40–50°C. Always pre-dissolve before the dye goes anywhere near the bath. Powder added directly to a hot bath doesn't dissolve evenly — spots and poor fixation are the result, and it's a complaint we hear regularly from dye houses that rush this step under production pressure.

Right method: make a cold-water paste first, then bring up to 40–50°C with continuous stirring. Screen through 100 mesh before adding to the bath. One thing that causes problems is dissolving the dye in alkaline water — don't. Keep the dissolution stage neutral and add alkali only at the main bath stage, after the dye has loaded onto the fibre.

Dissolution Best Practices

  • Use water at 40–50°C for optimum dissolution rate
  • Paste the powder first in cold water before adding hot water
  • Stir continuously — static lumps dissolve unevenly and cause spots
  • Filter through a 100-mesh screen before adding to bath
  • Never pre-dissolve in alkaline solution
  • Use dissolved solution within 4 hours for best fixation results
Recommended Dosage

Exhaust Dyeing — Dosage Guide by Shade Depth

All values are for cotton exhaust dyeing at liquor ratio 1:10–1:15. Add NaCl in 2–3 stages before alkali addition to ensure level exhaustion.

Shade Depth Dye (%owf) NaCl (g/L) Na₂CO₃ (g/L) Temp (°C) Time (min)
Charcoal (light black)1–1.5%40–5010–126045
Medium Black2–3%60–7015–186060
Deep Black4–5%70–8018–206060–75
Jet Black6–8%80–10020–256075–90

Process Notes

  • Salt staging: Add NaCl in 2–3 portions over the first 20–30 minutes to ensure level exhaustion without unlevel strike.
  • Alkali staging: Add Na₂CO₃ in 2 portions after salt exhaustion is complete to control the fixation rate.
  • After-wash: Rinse cold, then hot-soap at 95°C (2 g/L non-ionic surfactant, 15 min) to remove unfixed hydrolysed dye — critical for achieving rated wash fastness.
  • Cold pad-batch: Use NaOH 4–6 g/L + sodium silicate 60–80 g/L; batch 6–24 hours at 20–25°C; roll with even tension to prevent unlevel results.

Contact our technical team at technical@yobaiindustries.in for process optimisation specific to your machinery and water quality.

Available Shades

Black Depth Options — REACTOBOND Series

Reactive Black 5 delivers a range of black depths depending on dye concentration and process parameters. The following shade depths are achievable with standard exhaust conditions on mercerised cotton.

Charcoal
1–1.5% owf
Medium Black
2–3% owf
Deep Black
4–5% owf
Jet Black
6–8% owf

Shade appearance varies depending on fibre preparation (mercerisation, scouring, bleaching), water hardness, and after-treatment. Request a lab dip for colour-critical applications.

Packaging

Packaging Options

All packs are sealed in multi-layer moisture-proof bags. Custom packaging and private labelling available for bulk buyers.

1 kg
Lab / Trial Sample
5 kg
Small Batch / Pilot
10 kg
MOQ — Standard
25 kg
Regular Production
50 kg
Large Production Run
Custom
Bulk / OEM Packing

All shipments include batch-specific COA. Export packing (UN-certified drums) available on request.

FAQ

Frequently Asked Questions — Reactive Black 5

Because it consistently delivers a deep, neutral black with wash fastness that very few dyes in this class can match — and it does it reliably across different machines, water qualities, and process setups. Dye houses that switch to alternatives for cost reasons often come back. Export buyers specify it by name. That level of industry confidence doesn't happen without a reason.

For exhaust dyeing: 60°C bath, pH 10–11, NaCl added in stages before alkali. Soda ash or caustic soda for fixation — both work, choice depends on your machine and water hardness. Cold pad-batch runs at room temperature (20–25°C) with a longer dwell time. Refer to the dosage table on this page for specific concentrations by shade depth.

Yes, it's standard in black denim production. Wash fastness holds through enzyme and stone-wash processes typical in denim finishing. If you're running acid enzyme washing after dyeing, do a trial first — prolonged low-pH exposure is not ideal for any reactive dye. For standard denim processing it's a reliable choice and widely used across Gujarat and Rajasthan denim units.

Minimum order is 10 kg. Samples (1–5 kg) dispatched within 24 hours. Bulk orders in 7–15 days.

For a 2% owf medium black on cotton in a jet or winch machine: start at 40°C, add NaCl in two equal portions at 10 and 20 minutes (60–80 g/L total). Raise to 60°C over 20 minutes. Add soda ash in two portions after temperature is reached — 15–20 g/L total. Run 45–60 minutes. Rinse cold, then hot-soap at 95°C with 2 g/L non-ionic surfactant for 10–15 minutes. Don't skip the soaping — it's what gets you to the rated 4–5 wash fastness.

The difference is smaller than some suppliers make it sound. Both are bifunctional vinyl sulphone blacks, and below 6% owf most dye houses won't see a meaningful difference in depth or fastness. Above 6–7% owf, RB8 can build slightly deeper shade — that's where the higher molecular weight shows. For everything else, RB5 is cheaper, more widely stocked, and has more documented recipes in the field. Unless you specifically need maximum colour build at 8%+ owf, RB5 is the practical choice.

Bifunctional reactive dyes like Reactive Black 5 consistently deliver 10–20 percentage points higher fixation yield than equivalent monofunctional grades under the same exhaust conditions. In practical terms this means less dye cost per kilo of fabric dyed, less colour in the effluent, and better shade consistency batch to batch. For deep and jet black shades where dye dosage is high, the economics of bifunctional chemistry are hard to argue against. The detailed chemistry behind this performance difference is something we discuss with customers during technical consultations — contact our technical team if you'd like a deeper explanation.

After fixation, a portion of the dye will be sitting on the fibre surface without a permanent bond. Leave it there and it bleeds badly in the first wash — your customer's fabric stains adjacent garments and wash fastness drops from 4–5 to 2–3. Hot soaping at 95°C with a non-ionic surfactant (2 g/L, 10–15 minutes) removes that surface dye cleanly. On deep and jet black shades this step is not optional. We've seen dye houses skip it under time pressure and regret it every time.

Cold pad-batch (CPB) is preferred for flat woven fabric processed open-width — denim, shirting, sheeting — where even penetration and level appearance are critical and capital investment in exhaust machines is less economical. CPB operates at 20–25°C using NaOH (4–6 g/L) and sodium silicate (60–80 g/L) as fixation alkali, with a batch dwell time of 6–24 hours depending on ambient temperature. It achieves high fixation yields — often 80–90% for RB5 — with proper process control. Exhaust dyeing (jet, winch, jigger) is preferred for yarn, knitwear, and garments where open-width processing is not feasible.
Storage

Storage & Handling

Below 25°C, dry store, RH below 60% — standard requirements for reactive dyes. Moisture is the main risk. Even a partially open bag left in a humid weighing room can degrade fixation performance permanently — there's no way to recover a batch that's absorbed moisture. Seal the bag immediately after every weighing, not at the end of the shift. Keep the dye away from acids and oxidising agents, both cause irreversible colour degradation. Covered storage only — direct sunlight shifts the shade over time and there's no correcting it.

Shelf Life: 5 Years
Guaranteed from date of manufacture under recommended storage conditions (below 25°C, RH below 60%, sealed containers). After 5 years, test fixation yield on a lab sample before committing to production. Yobai Industries provides batch manufacturing dates on all COAs.

Handling Precautions

  • Wear appropriate PPE — gloves and dust mask during handling
  • Avoid inhalation of fine powder
  • Reseal containers immediately after use
  • Request MSDS from Yobai Industries for full safety data
Industries Served

Who Uses Reactive Black 5?

Most cotton and cellulosic dye houses already work with this grade. These are the end markets it typically ends up in.

Cotton Apparel & Fashion
Home Furnishing & Bedding
Textile Printing
Batik & Hand Dyeing
Export Textile Mills
Available Grades

Reactive Dyes (REACTOBOND) — Available Grades

Yobai Industries carries the following grades in this dye family. Click any grade to view specifications, or view the full catalogue →

Reactive Black 5 (This Grade) Reactive Black 8 Reactive Blue 21 Reactive Blue 4 Reactive Blue 89 Reactive Orange 16 Reactive Red 120 Reactive Red 198 Reactive Red 2 Reactive Yellow 17

Don't see the grade you need? We carry 250+ dye grades. Contact us and we'll source or develop it for you.

Related Products

You May Also Need

Reactive Black 8
Reactive Dyes
Reactive Blue 4
Reactive Dyes
Reactive Orange 16
Reactive Dyes
Reactive Red 198
Reactive Dyes
Reactive vs Direct Dyes Guide
Technical guide — application advice & grade selection
Need COA, MSDS or application guidance? Contact our technical team — technical@yobaiindustries.in

Ready to Order Reactive Black 5?

MOQ 10 kg · Samples in 24 hours · Bulk in 7–15 days · Export worldwide · GST invoice with every order.

Send an Enquiry WhatsApp Us