Methyl Ethyl Ketone

What is methyl ethyl ketone? Is it butanone?

Yes, methyl ethyl ketone is butanone; both refer to the same substance.
Chemical name: 2-butanone
English abbreviation: MEK (Methyl Ethyl Ketone)
Chemical formula: CH3COCH2CH3
Structure: The carbonyl group is bonded to a methyl group and an ethyl group, hence the name methyl ethyl ketone. It has a 4-carbon main chain with the ketone group at the 2-position, so it is called 2-butanone, often simply referred to as butanone in daily use.

What are the main functions of butanone?

Butanone (methyl ethyl ketone / MEK) is primarily used as an excellent medium-boiling organic solvent and also an important intermediate for organic synthesis, widely applied in coatings, adhesives, electronics, pharmaceuticals and many other industrial fields.

I. Core Use: High-Efficiency Solvent

With strong solvency, moderate volatility (slower than acetone but faster than xylene), and good miscibility with most solvents, butanone is one of the most commonly used solvents in industry.
Coatings and Printing Inks (Largest Application Area)
Used as a solvent for nitrocellulose lacquers, acrylic paints, polyurethane coatings, vinyl resins and other coatings to dissolve resins, adjust viscosity and promote leveling.
Serves as a solvent for gravure inks and flexographic inks, ensuring bright printing colors and fast drying.
Adhesives and Synthetic Leather
A main solvent for PU adhesives, neoprene adhesives, pressure-sensitive adhesives and other binders.
Used in the production of artificial leather and synthetic leather to dissolve polyurethane and other resins.
Petrochemical Industry
Dewaxing of lubricating oils: selectively dissolves oil fractions in refineries to separate paraffin and improve low-temperature fluidity of lubricants.
Electronics Industry
Precision cleaning: used for degreasing, decontamination and photoresist removal in semiconductors and LCD panels.
Photolithography developer: a key process chemical in integrated circuit manufacturing.
Other Solvent Applications
Plastic welding: dissolves ABS, PS and other plastics, used as model cement and PVC pipe adhesive.
Paint remover: powerfully removes old coatings from metal and wood surfaces.
Extractant: used for extracting natural flavors, vegetable oils and active pharmaceutical ingredients.

II. Secondary Use: Intermediate for Organic Synthesis

As a chemical raw material, it is used to synthesize a variety of high value-added products:
Methyl ethyl ketoxime (MEKO): anti-skinning agent for coatings and curing agent for silicone rubber.
Methyl ethyl ketone peroxide: curing initiator for unsaturated polyester resins (commonly used in fiberglass-reinforced plastics).
Fragrances: synthesis of high-grade fragrances such as methyl ionone.
Pharmaceuticals and pesticides: intermediate in the production of antibiotics, acaricides (e.g., pyridaben), etc.

III. Summary of Key Properties

Advantages: strong solvency, moderate boiling point (79.6°C), controllable evaporation rate, non-corrosive to metals.
Disadvantages: extremely flammable (flash point -9°C), vapor has anesthetic effects; strict fireproof, explosion-proof measures and ventilation are required during use.

Methyl ethyl ketone (butanone) is not primarily a "solvent helper"—it is a primary solvent that directly dissolves various resins, glues, and printing inks. At the same time, it can also act as a chemical intermediate for synthesizing other chemical products.

1. As a solvent (main application)

Butanone itself is a powerful solvent, not an auxiliary agent. It directly dissolves:
- Resins in paints and inks
- Adhesive components in glues
- Raw materials for plastics and synthetic leather
- Oil stains and old paint films

2. As an intermediate (secondary but important)

This is where its "intermediate nature" comes into play: butanone is used in chemical reactions to produce:
- Methyl ethyl ketone peroxide (curing agent)
- Methyl ethyl ketoxime (anti-skinning agent)
- Raw materials for fragrances and pharmaceuticals

Performance Comparison Table: MEK, Acetone & Ethyl Acetate

Strong solvency + controlled evaporation → MEK

Item	MEK (2-Butanone)	Acetone	Ethyl Acetate
Solvency	Very strong; strongest for resins & adhesives	Strong; broad solvency	Good; moderate solvency, milder odor
Evaporation Rate	Medium-fast (controllable)	Very fast	Fast (slower than acetone, slightly faster than MEK)
Flash Point / Flammability	Flammable, flash point −9 °C	Extremely flammable, flash point −20 °C	Flammable, flash point −4 °C
Odor	Strongly irritating	Strong, pungent	Relatively mild, fruity odor
Typical Uses	Coatings, inks, PU adhesives, synthetic leather, paint removal	Cleaning, fast-drying thinner, quick degreasing	Screen printing, wood coatings, adhesives, food-grade applications
Application Performance	Good leveling, less blushing, excellent workability	Dries too fast, easy to blush or attack substrates	Evens evaporation, low blushing, good versatility
Cost	Medium to high	Low	Medium
Toxicity & Safety	Moderate	Low, but high inhalation risk due to fast evaporation	Low, relatively safer