TORRINGTON, CT—Dymax, a manufacturer of light-curing adhesives and equipment, has been granted a patent for its HLC (Hybrid Light-Curable) adhesive. The new technology combines the optimal qualities of anionic polymerization and free radical chemistries into one formulation.

HLC technology aims to improve the curing performance of urethane (meth)acrylate compositions commonly used to formulate coatings, adhesives, sealants and inks. The advantages of HLC include fast cure, low-to-no blooming after proper light cure, better aesthetics, humidity resistance, and more flexible joints than ordinary cyanoacrylates.

While standard light-curing materials cure effectively using UV or visible light, they often struggle in areas where the light cannot reach, leaving behind uncured areas. These shadowed regions compromise the reliability of the final product and can weaken adhesive bonds over time. HLC addresses the issue of incomplete curing in dark areas with rapid moisture or contact cure capability. Bonding to a broad range of substrates, including opaque and light-blocking materials, is also possible.

Due to the composition of their light-curing component, Dymax HLC adhesives form a cross-linked polymer framework, enabling the successful bonding of small gaps or larger joints. Light-curing also reduces the risk of “blooming,” a common issue with cyanoacrylates, where a white residue forms at the edges of bond lines when they react with ambient humidity. Light-curing can significantly reduce the risk of blooming as the material cross-links before the monomer can volatilize.

Dymax HLC-M-1000, the first adhesive in the series, is engineered for medical applications and meets several biocompatibility standards. Its light-curing capabilities allow for rapid curing in seconds with low-intensity light, optimizing performance even at 20 milliwatts per square centimeter. With an extremely low viscosity of 3 centipoise, the material is capable of wicking into extremely tight bond joints not typically accessible with other, higher-viscosity adhesives.