We stock three ketone solvents in Chennai: acetone (CAS 67-64-1), MEK — methyl ethyl ketone, CAS 78-93-3 — and MIBK — methyl iso butyl ketone, CAS 108-10-1. All three dissolve resins aggressively. What separates them is how fast they leave the film, and how they behave around water.
This guide compares the three on the axes that decide a formulation: evaporation, boiling point, flash point and water miscibility. It is the selection guide. For stock, packaging and quotes on MEK specifically, our MEK supplier in Chennai page is the commercial one.
The Three Ketones at a Glance
Indicative values for the grades we stock. A batch-specific Certificate of Analysis carries exact figures for any consignment.
| Property | Acetone | MEK | MIBK |
|---|---|---|---|
| CAS number | 67-64-1 | 78-93-3 | 108-10-1 |
| Boiling point | 56.05°C | 79.6°C | 114.0°C initial, 117.0°C dry point |
| Flash point (closed cup) | -20°C | -9°C | — |
| Density at 20°C | 0.791 g/cm³ | 0.805 g/cm³ | 0.799–0.802 g/ml |
| Water behaviour | Miscible in all proportions | Soluble, ~27 g/100 mL at 20°C | Low water miscibility |
| Refractive index at 20°C | 1.3588 | 1.3788 | — |
| Assay, as stocked | 99.5% min (GC) | 99.5% min (GC) | Min 99.5 wt % |
| HSN code | 2914.11.00 | 2914.12.00 | 29141300 |
| UN number | 1090 | 1193 | — |
Acetone and MEK both transport as Class 3 flammable liquids, Packing Group II; MIBK is likewise classed as a flammable liquid. Melting points sit far below any Indian storage condition — -94.7°C for acetone, -86°C for MEK. A dash means the value is not published on our indicative spec sheet; the product SDS carries it.
Evaporation: The Axis That Decides Most Jobs
Boiling point is the quickest proxy for how fast a solvent leaves a film, and the three sit in a clean ladder — 56.05°C, 79.6°C, then 114.0–117.0°C.
- Acetone is the sprinter. It flashes off almost immediately — right for surface cleaning, equipment wash-downs and degreasing, where the solvent must be gone in seconds. In a sprayed coating it can leave before the film levels.
- MEK is the workhorse. Fast evaporation with strong dissolving power. That combination is why it is the default active solvent in PU and nitrocellulose coating systems, adhesives, printing inks and synthetic leather (PU) production.
- MIBK is the unhurried one. It sits between fast solvents like acetone and slow tail solvents, buying a coating longer flow-out and open time. Reach for it when orange peel, dry spray or poor levelling are the defects on the line.
Formulators rarely treat this as either/or. Many coating and adhesive systems run MEK and MIBK together, tuning the blend's overall evaporation profile rather than betting on a single solvent.
Water Behaviour: The Second Filter
Acetone is miscible with water in all proportions. That makes it forgiving in cleaning work where moisture is present — and a liability where water carried into the system is the failure mode.
MEK is partially soluble in water, at roughly 27 g/100 mL at 20°C, and miscible with most organic solvents. In practice it behaves as an organic-phase solvent, but wash-water and condensate will carry some of it.
MIBK has low water miscibility — the property that gives it a second career as a liquid-liquid extraction solvent in pharmaceutical and metallurgical work. Of the three, it is the one that separates cleanly from an aqueous phase.
Where Each One Lands
Acetone — cleaning, thinners and pharma processing
Acetone is the fast, fully water-miscible ketone. It goes into paints and thinners, adhesives, pharmaceutical and cosmetic processing, resin and polymer cleaning, and degreasing. We stock it at 99.5% min assay in Industrial, Technical and Pharma (IP/BP/USP) grades. Sourcing detail sits in our acetone supplier guide.
MEK — PU and NC coatings, inks and adhesives
MEK pairs fast evaporation with strong dissolving power. It is the workhorse solvent for PU and nitrocellulose coatings, adhesives and sealants, printing inks, synthetic leather (PU) production and magnetic tape coating, with degreasing work besides. We stock Industrial and Technical grade at 99.5% min assay (GC). For current packaging and the quote process, see our MEK supplier in Chennai page; the product page carries the full spec table and SDS download.
MIBK — lacquers, extraction and rubber chemicals
MIBK is the medium-evaporating ketone with low water miscibility. It runs in nitrocellulose and acrylic lacquers and surface coatings, as an extraction solvent in pharma and metallurgy, in rubber antiozonant manufacture, in adhesives and in dewaxing. The Technical Grade we stock assays Min 99.5 wt %, with water Max 0.1 wt %, colour Max 10 APHA and acidity (as acetic acid) Max 0.002 wt %. Sourcing notes sit in our MIBK supplier guide.
Handling: All Three Are Flammable
Flash points tell the story: -20°C for acetone and -9°C for MEK, both closed cup — the vapour ignites at any ambient temperature an Indian plant will see. MIBK is likewise a flammable liquid. Store all three in cool, well-ventilated areas away from oxidisers and ignition sources, keep containers tightly closed, and earth and bond during transfer. Each product page carries the SDS as a PDF download; follow it and your site EHS procedure.
Grades, Packaging and Supply from Chennai
- Acetone — 200L MS barrels, 1000L IBC tanks and bulk tankers. Industrial, Technical and Pharma (IP/BP/USP) grades. Ex-stock to 3 working days.
- MEK — 200L MS barrels and 1000L IBC tanks. Industrial and Technical grade. Ex-stock to 5 working days. An imported line, kept stocked through direct import capability.
- MIBK — 160 kg HDPE/MS drums. Technical Grade, Min 99.5%. Also an imported line.
All three dispatch from our Redhills, Chennai warehouse, across Chennai and South India.
Getting the Purchase Order Right
MEK and MIBK differ by two carbon atoms — and therefore by boiling point, evaporation rate and water behaviour. They are not interchangeable in a lacquer formulation, and a purchase order that says only "MEK/MIBK grade solvent" invites the cheaper of the two. Write the full name, the CAS number and the assay: methyl ethyl ketone, CAS 78-93-3, 99.5% min. Our trade abbreviations glossary covers the other name collisions that cause wrong deliveries.
More selection guides in this series: toluene vs mixed xylene and choosing between the glycol ethers.
FAQ
What is the difference between MEK and acetone?
Both are fast ketone solvents we stock at 99.5% min assay. Acetone (CAS 67-64-1) boils at 56.05°C and is miscible with water in all proportions — the faster, water-tolerant cleaner. MEK (CAS 78-93-3) boils at 79.6°C and dissolves in water only partially (~27 g/100 mL at 20°C) — slightly slower, and the default choice of the two in PU and nitrocellulose coating and adhesive formulations.
Is MIBK a direct substitute for MEK?
No. The two differ by two carbon atoms, and therefore by boiling point, evaporation rate and water behaviour. MIBK evaporates more slowly and separates from water; MEK dries faster. Formulations often run the two together to balance the evaporation profile rather than swapping one for the other — and a purchase order should always name which one, with its CAS number.
What are the CAS numbers of acetone, MEK and MIBK?
Acetone is CAS 67-64-1, MEK (methyl ethyl ketone) is CAS 78-93-3, and MIBK (methyl iso butyl ketone) is CAS 108-10-1. Quote the CAS number alongside the grade on every purchase order — the trade names are close enough to be confused in shorthand.
What is the density of MEK?
0.805 g/cm³ at 20°C for the grade we stock, with a boiling point of 79.6°C, a flash point of -9°C (closed cup) and a refractive index of 1.3788 at 20°C. These are indicative values — a batch Certificate of Analysis carries exact figures.
Where can I buy MEK, MIBK or acetone in Chennai?
We stock all three at our Redhills, Chennai warehouse, with dispatch across Chennai and South India. For MEK grades, packaging and the quote process, start at our MEK supplier in Chennai page. For any of the three, call +91 86087 80096, WhatsApp an enquiry, or use the SPC enquiry form.