2-Hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone
[CAS# 106797-53-9]

Identification

• Classification: Catalysts and additives >> UV absorber
• Name: 2-Hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone
• Synonyms: 1-[4-(2-Hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propane-1-one
• Molecular Formula: C₁₂H₁₆O₄
• Molecular Weight: 224.25
• CAS Registry Number: 106797-53-9
• EC Number: 402-670-3
• SMILES: CC(C)(C(=O)C1=CC=C(C=C1)OCCO)O

Properties

• Melting point: 88-90 °C

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302-H412
• Safety Statements: P273

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412

Discovery and Applications

2-Hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, commonly known as HE-HMPP, is an aromatic ketone widely utilized as a photoinitiator in UV-curable systems. This compound, with the molecular formula C₁₂H₁₆O₄, plays a critical role in initiating the polymerization of resins and coatings when exposed to ultraviolet (UV) light, making it a valuable component in various industrial applications.

The discovery of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone is linked to the development of photoinitiators designed for use in radiation curing technologies. As industries sought faster and more efficient curing processes, researchers identified HE-HMPP as an effective compound for initiating polymerization under UV light. The structure of HE-HMPP includes a hydroxyethoxy group, which enhances its solubility in a wide range of monomers and resins, making it versatile in different formulations.

HE-HMPP is primarily used in UV-curable coatings, adhesives, and inks. In these applications, it functions as a Type I photoinitiator, which means it directly absorbs UV light to generate reactive free radicals. These radicals then initiate the polymerization of acrylate or methacrylate monomers, leading to the formation of cross-linked polymer networks. This process occurs rapidly upon exposure to UV light, allowing for the quick curing of materials. The use of HE-HMPP in UV-curable systems is particularly advantageous in industries requiring high-throughput production and low energy consumption, such as the printing, electronics, and automotive sectors.

In the printing industry, HE-HMPP is used in UV-curable inks that offer several benefits, including fast drying times, reduced emissions of volatile organic compounds (VOCs), and enhanced print quality. The rapid curing process facilitated by HE-HMPP ensures that printed materials are immediately ready for handling, improving production efficiency. Similarly, in the electronics industry, this photoinitiator is employed in the manufacture of printed circuit boards and other components where precise and quick curing of coatings is essential.

Another significant application of HE-HMPP is in the production of UV-cured adhesives. These adhesives are used in a variety of industries, including medical devices, electronics, and packaging, where strong bonding and fast curing are required. The photoinitiating properties of HE-HMPP enable the development of adhesives with excellent adhesion properties and resistance to environmental factors.

Despite its effectiveness, the use of HE-HMPP requires careful consideration of formulation parameters, including the concentration of the photoinitiator and the intensity of UV light. Proper formulation ensures optimal curing performance and minimizes the risk of incomplete polymerization, which can affect the mechanical properties and durability of the cured materials.

The discovery and application of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone have significantly contributed to the advancement of UV-curable technologies. Its role as a photoinitiator has enabled the development of innovative materials and processes across various industries, highlighting its importance in modern manufacturing.

References

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DOI: 10.1134/s1810232823040057

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