Athens, Ga. – A new technology that uses visible light for curing a multitude of monomers, oligomers, and polymers-chemical building blocks from which synthetic organic materials are made-has been licensed by the University of Georgia Research Foundation, Inc., to Three Bond International, Inc., a worldwide leader in the adhesives, sealants and bonding industry. Three Bond will implement the technology into new applications for production of adhesives for the medical and automotive markets.
Charles Kutal, professor of chemistry and associate dean in the Franklin College of Arts and Sciences at the University of Georgia, invented the new technology.
Coatings, adhesives, and sealants require heat, light or often noxious adjuvant chemicals to bond components like wood, plastic, metal, paint and other coatings to a substrate. Heat, or thermal curing, can require hours to cure and create a strong bond, and for their volatile solvents to evaporate. Over the last few decades, light-cured adhesives have become widespread in a broad range of industries where applications require speed, control and high bond strength. In light-curing adhesives, the manufacturer shines ultraviolet light onto a surface treated with an adhesive component and, as the light is absorbed, the adhesive cures, setting off a chemical chain reaction that creates a very strong bond between materials in seconds.
The technology allows for the fast cure of myriad polymers, including cyanoacrylate, commonly known as “superglue.” Reactions initiated with UV light, however, generate free radicals (highly reactive electrons) or cations (positive ions), which may be destroyed by oxygen and moisture and impurities, making the curing process inefficient.
Kutal’s innovation allows visible light to initiate the curing process. In contrast to the UV curing process, visible-light curing technology obviates the need for specialized equipment and safety measures associated with UV, because it generates anions (negatively charged ions), which are not as susceptible to side-reactions as their counterparts.
“Anionic photo-initiated adhesives have several advantages,” explained Kutal. “Because they don’t require potentially tissue-damaging high-frequency UV light or noxious chemicals to initiate curing, they can be used in a greater range of medical, surgical, dental and domestic applications.”
Visible-light curing of adhesives also is energy-efficient, making it a “green” technology. UV curing typically requires great amounts of applied energy–approximately 10 kJ/m2 provided by, for instance, a 4-kilowatt high-pressure mercury-vapor lamp. In contrast, the new visible-light curing technology requires 25 times less energy-approximately 0.4 kJ/m2 provided by a simple 250-watt halogen lamp.
The non-exclusive licensing agreement entitles Three Bond to use UGARF technology specifically for the manufacture and sale of light-cured cyanoacrylate adhesives in the United States.
“Our newly formed partnership with Three Bond represents UGARF’s entry into a new market and opens new horizons for our researchers in the areas of polymers and materials,” said Gennaro Gama, a senior UGARF technology manager. “We are glad to have partnered with a high-caliber corporation such as Three Bond, who we believe will be able to effectively supply the U.S. market with new products incorporating our patented technology.”
For more information regarding Three Bond, Inc. and its adhesive products, contact Jeff Speed, Three Bond International, Inc., 6184 Schumacher Park Drive, West Chester, Ohio 45069, telephone 513/779-7300. E-mail UVCA@threebond.com.