Cyclohexanone (CAS 108-94-1) is a colorless to pale yellow cyclic ketone with molecular formula C₆H₁₀O and molecular weight 98.15 g/mol, serving as both a high-performance industrial solvent and the primary chemical intermediate for caprolactam and adipic acid-the respective monomers for Nylon 6 and Nylon 66.
What Is Cyclohexanone?
Cyclohexanone is an organic compound in the ketone family, structurally a six-membered carbocyclic ring with a single ketone functional group. It is also identified under the synonyms oxocyclohexane, cyclohexyl ketone, nadone, and anone. At room temperature it is a clear, oily liquid with a characteristic earthy ketone odor; trace phenol content shifts the odor toward mint-like, which serves as a practical purity indicator in field assessment.
It is produced industrially via two established routes: catalytic air oxidation of cyclohexane to yield a cyclohexanol–cyclohexanone mixture (KA oil), which accounts for the dominant share of global output; and partial hydrogenation of phenol under catalytic conditions, used where higher selectivity toward cyclohexanone is required.
Physical and Chemical properties of cyclohexanone
| Parameter | Value |
|---|---|
| CAS Number | 108-94-1 |
| Molecular Formula | C₆H₁₀O |
| Molecular Weight | 98.15 g/mol |
| Appearance | Colorless to pale yellow liquid |
| Boiling Point | 155.6°C |
| Melting Point | −26°C |
| Density (20°C) | 0.947 g/cm³ |
| Flash Point | 43°C (closed cup) |
| Water Solubility | 8.7 g/L at 20°C |
| Vapor Pressure | 5 mmHg at 25°C |
| Refractive Index | 1.4507 (20°C) |
| Color (fresh, high-purity) | ≤10 APHA |
| Kauri-Butanol (KB) Value | 95–98 |
Notice: Miscible with ethanol, diethyl ether, acetone, and benzene. Limited water miscibility supports formulation stability in solvent-based industrial systems. Color development toward pale yellow during storage reflects oxidative degradation; APHA color is a standard quality checkpoint in industrial receiving inspection.
what is cyclohexanone used for?
Cyclohexanone (CAS 108-94-1) is used across five primary industrial sectors: as the chemical intermediate for Nylon 6 and Nylon 66 production, and as a process solvent in coatings, adhesives, printing inks, and fine chemical synthesis.
Nylon 6 and Nylon 66 - Primary Industrial Use
As of 2025, global cyclohexanone consumption exceeds 3.7 million metric tons, with approximately 70% directed toward the Nylon 6 and Nylon 66 value chains. Caprolactam-produced via cyclohexanone oxime formation followed by Beckmann rearrangement-is the monomer for Nylon 6. Adipic acid, obtained through nitric acid oxidation of KA oil, is the monomer for Nylon 66. Caprolactam application accounts for approximately 59.1% of cyclohexanone market share as of 2024.
Paints and Coatings
With a KB value of 95–98, cyclohexanone achieves complete dissolution of nitrocellulose, alkyd, epoxy, vinyl, and acrylic resin systems. Its moderate evaporation rate controls film formation and reduces surface defects including blushing and cratering. Applied in industrial maintenance coatings, marine topcoats, automotive OEM and refinish systems, and wood finishes. Demand in solvent applications for paints, inks, and coatings increased by approximately 5% annually between 2022 and 2025.
Adhesives and Sealants
Cyclohexanone dissolves PVC, polychloroprene, and polyurethane matrices at room temperature, reducing application viscosity while maintaining open time. Used in PVC pipe adhesives, contact cements, construction sealants, and structural bonding systems for plastics and composites.
Printing Inks
Functions as a resin solvent and viscosity modifier in gravure and packaging ink systems. Its controlled evaporation profile stabilizes rheology across press speeds and supports adhesion to low-surface-energy substrates including polyolefin and PET films.
Fine Chemical Intermediates
Downstream derivatives include peroxycyclohexanone, 2-methylbenzophenone, antioxidant 4010 (N-isopropyl-N′-phenyl-p-phenylenediamine), and cyclohexanone-toluene resins used in rubber and adhesive formulations. Cyclohexanone also serves as a building block in pharmaceutical intermediate synthesis, including precursors to antiepileptic compounds.
cyclohexanone market growth (2024–2025)
The global cyclohexanone market was valued at USD 9.3 billion in 2024 and is projected to reach USD 13.8 billion by 2034, growing at a CAGR of 4.0%. Asia Pacific holds 45.9% of market growth, supported by strong nylon and polymer production expansion. Technical grade cyclohexanone dominates with a 79.3% share of the market by grade in 2024.
cyclohexanone safety precautions
Classified as flammable liquid: UN 1915, IMDG Class 3, Packing Group II. Flash point 43°C (closed cup). Occupational exposure limit: 25 ppm TWA (international standard). Store at 5–30°C in a ventilated warehouse, away from ignition sources and oxidizing agents. Containers must remain sealed when not in use. Shelf life: 12 months from production date under recommended storage conditions.
FAQ
What is cyclohexanone used for?
Cyclohexanone serves two primary functions: as a process solvent in coating, adhesive, ink, and rubber systems; and as a chemical intermediate in caprolactam synthesis (via Beckmann rearrangement) and adipic acid production-the monomers for Nylon 6 and Nylon 66, which together account for approximately 70% of global consumption as of 2025.
What is the CAS number of cyclohexanone?
CAS 108-94-1. Molecular formula C₆H₁₀O, molecular weight 98.15 g/mol.
Is cyclohexanone a solvent or a chemical intermediate?
Both. It functions as a high-KB (95–98) industrial solvent for resins, polymers, and cellulose derivatives, and simultaneously as the key feedstock in caprolactam and adipic acid production for Nylon 6 and Nylon 66 manufacturing.
What purity grade is available for industrial use?
Industrial supply is typically ≥99% purity (GC-verified), with water content ≤0.05% and color ≤10 APHA. Technical grade accounts for 79.3% of global market volume as of 2024.
How should cyclohexanone be stored?
Store at 5–30°C in a sealed, ventilated container away from heat and oxidizing agents. UN 1915, Class 3, PG II. Shelf life 12 months under recommended conditions.