Irgacure

Irgacure is a brand line of photoinitiators used to start photopolymerization in UV-curable systems. The line is produced by BASF and originated with Ciba Specialty Chemicals, which BASF later acquired. Irgacure products are designed to absorb ultraviolet light and generate free radicals that initiate polymerization of acrylate, methacrylate, and related monomers. The range includes several widely used single-component photoinitiators as well as formulations that combine different initiators to tailor curing performance.

Common members of the Irgacure family include Irgacure 184, Irgacure 2959, Irgacure 651, and Irgacure 819. These differ in their absorption profiles, reactivity, color, odor, and compatibility with various monomers and processing conditions. For example, Irgacure 2959 is noted for water solubility and relatively low odor, making it popular in biomedical and dental applications, while Irgacure 184 and related open-flame photoinitiators offer fast curing and deeper penetration for coatings and inks. Irgacure 819 is often selected for enhanced initiation efficiency in LED or broad-spectrum UV systems.

Applications span UV-curable coatings for wood, plastics, and metals; UV inks and adhesives; dental resins and composites; and photopolymer resins used in 3D printing technologies such as stereolithography and digital light processing. The choice of initiator influences cure speed, depth of cure, yellowing, shrinkage, and the final mechanical properties of the material.

Safety: Photoinitiators can be irritants or hazardous if misused. Proper handling, ventilation, and personal protective equipment are recommended, along with storage away from light and heat to preserve stability.