1-Hydroxycyclohexyl phenyl ketone
[CAS# 947-19-3]

Identification

• Classification: Flavors and spices >> Synthetic spice >> Aromatic cinnamic acid, esters and derivatives
• Name: 1-Hydroxycyclohexyl phenyl ketone
• Synonyms: UV 184 ; IHT-PI 184; 1-Hydroxy-Cyclohexyl Phenyl Ketone
• Molecular Formula: C₁₃H₁₆O₂
• Molecular Weight: 204.26
• CAS Registry Number: 947-19-3
• EC Number: 213-426-9
• SMILES: C1CCC(CC1)(C(=O)C2=CC=CC=C2)O

Properties

• Density: 1.17 g/mL
• Melting point: 47-50 °C
• Boiling point: 175 °C (15 mmHg)
• Flash point: 164 °C

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H315-H319-H335
• Safety Statements: P261-P305+P351+P338

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Skin irritation	Skin Irrit.	2	H315
Acute toxicity	Acute Tox.	4	H332
Specific target organ toxicity - single exposure	STOT SE	3	H335
Acute toxicity	Acute Tox.	2	H330

Discovery and Applications

1-Hydroxycyclohexyl phenyl ketone is a widely used photoinitiator, primarily in UV-curable systems. Its ability to efficiently initiate the polymerization of acrylates and methacrylates upon exposure to ultraviolet (UV) light has made it a critical component in many industrial applications, including coatings, inks, adhesives, and 3D printing resins. The compound, often abbreviated as HCPK, is a white crystalline solid with strong absorption in the UV spectrum, making it highly effective in initiating free radical polymerization processes.

The development of 1-hydroxycyclohexyl phenyl ketone dates back to research efforts focused on optimizing the performance of photoinitiators for use in UV-curing technologies. As industries sought faster, more efficient methods of curing resins, particularly in coatings and printing, photoinitiators like HCPK emerged as key solutions. Its balanced reactivity, compatibility with various monomers, and stability made it an attractive choice for manufacturers looking to enhance the curing speed and quality of UV-sensitive systems.

One of the primary applications of 1-hydroxycyclohexyl phenyl ketone is in UV-curable coatings, where it facilitates rapid curing under UV light exposure. This property is highly valuable in industries such as automotive and electronics, where durable and resistant coatings are required. Its use ensures quick drying times, reduced energy consumption, and high-quality finishes with excellent mechanical properties. Furthermore, because UV curing systems rely less on volatile organic compounds (VOCs), they offer a more environmentally friendly alternative to traditional solvent-based systems.

In the printing industry, 1-hydroxycyclohexyl phenyl ketone is a crucial component of UV-curable inks. These inks, used in high-speed printing processes, benefit from HCPK's ability to ensure rapid curing and adhesion to substrates such as paper, plastic, and metal. The fast-curing properties allow for higher production rates and reduced downtime, making UV-curable inks a popular choice in packaging, labels, and specialty printing.

Another significant area of application for 1-hydroxycyclohexyl phenyl ketone is in the field of adhesives. In particular, UV-curable adhesives formulated with HCPK are widely used in industries where quick bonding and strong adhesion are required, such as in electronics and medical device manufacturing. The photoinitiator's effectiveness in initiating polymerization ensures that adhesives cure rapidly, forming strong bonds without the need for heat or additional curing agents.

In recent years, 1-hydroxycyclohexyl phenyl ketone has also become important in 3D printing technologies, especially in stereolithography (SLA) and digital light processing (DLP) systems. These technologies rely on photopolymer resins that cure when exposed to UV light, and HCPK serves as an effective initiator in these resins, enabling the production of highly detailed and durable 3D-printed objects.

References

1992. A water-soluble poly(methylphenylsilylene) derivative as a photoinitiator of radical polymerization of hydrophilic vinyl monomers. Polymer Bulletin, 29(3).
DOI: 10.1007/bf00944819

2024. A review of the curing rate and mechanical properties of epoxy resin on polymer matrix composites. Journal of Polymer Research, 31(10).
DOI: 10.1007/s10965-024-04186-y

2024. Preparation and properties of waterborne UV-curable epoxy soybean oil acrylate resin. Journal of Coatings Technology and Research, 21(6).
DOI: 10.1007/s11998-024-01020-4