Photoinitiator

Overview
Photoinitiators are chemical compounds that absorb light (usually UV or visible radiation) and produce reactive species such as free radicals or cations, which initiate polymerization. They are essential components in UV-curable systems, enabling rapid curing of inks, coatings, adhesives, and resins under light exposure.

Key Properties

• Efficient light absorption and energy transfer

• Generate free radicals or cations to trigger polymerization

• Enable fast curing at ambient temperature

• Provide excellent surface hardness, chemical resistance, and adhesion

• Available as Type I (cleavage) and Type II (hydrogen abstraction) initiators

Examples of the Item

• Benzophenone Derivatives — common in coatings and printing inks

• α-Hydroxyketones (e.g., 184, 2959) — fast-curing initiators for clear coatings

• Acylphosphine Oxides (e.g., TPO, BAPO) — deep curing with strong absorption in visible range

• Thioxanthones — effective in pigmented systems and thick films

• Blend Photoinitiators — optimized mixtures for balanced curing performance

Applications

• UV-Curable Coatings — wood, plastics, electronics, automotive finishes

• Printing Inks — fast-drying inks for packaging, labels, and graphics

• Adhesives & Sealants — instant bonding, assembly adhesives

• 3D Printing Resins — photopolymerization for SLA and DLP technologies

• Electronics — protective coatings, photoresists, and solder masks

Supply Options

• Grades: Industrial, High-purity, Specialty (low yellowing, low migration)

• Forms: Powders, Granules, Liquid blends

• Compliance: RoHS, REACH, food-contact safe (depending on type)

Note: Selection of photoinitiator depends on curing wavelength, resin system, film thickness, and application requirements.