Methyl isobutyl ketone
Isopropylacetone, Hexone, Isobutyl methyl ketone, 4-Methylpentan-2-one, 4-methyl-2-pentanone, 2-methyl-4-pentanone, 2-methylpropyl methyl ketone, 4-methyl-2-oxopentane, MIK, isobutylmethyl ketone, MIBK, isohexanone
|Molar mass||100.16 g/mol|
|Density||0.802 g/mL, liquid|
|Melting point||−84.7 °C (−120.5 °F; 188.5 K)|
|Boiling point||117 °C (243 °F; 390 K)|
|1.91 g/100 mL (20 °C)|
|Vapor pressure||16 mmHg (20°C)|
Refractive index (nD)
|Viscosity||0.58 cP at 20.0 °C|
|Dipole moment||2.8 D|
|EU classification||Flammable (F)
|R-phrases||R11, R20, R36/37, R66|
|S-phrases||(S2), S9, S16, S29|
|Flash point||14 °C (57 °F; 287 K)|
|449 °C (840 °F; 722 K)|
|Explosive limits||1.2%-8.0% (93°C)|
|US health exposure limits (NIOSH):|
|TWA 100 ppm (410 mg/m3)|
|TWA 50 ppm (205 mg/m3) ST 75 ppm (300 mg/m3)|
IDLH (Immediate danger)
|Methyl isopropyl ketone
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
|what is: / ?)(|
Methyl isobutyl ketone is manufactured from acetone via a three-step process. Firstly acetone undergoes an aldol condensation to give diacetone alcohol, which readily dehydrates to give mesityl oxide. Mesityl oxide can then be hydrogenated to give MIBK:
Modern processes combine these three steps into one.
Several million kilograms are produced annually.
Precursor to 6PPD
Another major use is as a precursor to N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylene diamine (6PPD), an antiozonant used in tires. 6PPD is prepared by reductive coupling of MIBK with 4-aminodiphenylamine.
Solvent and niche applications
Unlike the other common ketone solvents, acetone and MEK, MIBK has quite low solubility in water, making it useful for liquid-liquid extraction. It has a similar polarity to ethyl acetate, but greater stability towards aqueous acid and base. It can be used to extract gold, silver and other precious metals from cyanide solutions, such as those found at gold mines, to determine the levels of those dissolved metals. Diisobutyl ketone (DIBK), a related lipophilic ketone, is also used for this purpose. Methyl isobutyl ketone is also used as a denaturing agent for denatured alcohol. When mixed with water or isopropyl alcohol MIBK serves as a developer for PMMA electron beam lithography resist. MIBK is used as a solvent for CS in the preparation of the CS spray used currently by British police forces.
- "NIOSH Pocket Guide to Chemical Hazards #0326". National Institute for Occupational Safety and Health (NIOSH).
- , Uhde Technology Profile: MIBK
- Stylianos Sifniades, Alan B. Levy, "Acetone" in Ullmann’s Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005.
- Hans-Wilhelm Engels et al., "Rubber, 4. Chemicals and Additives" in Ullmann's Encyclopedia of Industrial Chemistry, 2007, Wiley-VCH, Weinheim. doi:10.1002/14356007.a23_365.pub2
- Peter J Gray; Stark, MM; Gray, P. J; Jones, G R. N (2000). "Is CS spray dangerous? : CS is a particulate spray, not a gas" (RESPONSE TO EDITORIAL). BMJ 321 (7252): 26. doi:10.1136/bmj.321.7252.46. PMC 1127688. PMID 10939811.