Imagine a UV curable adhesive that has unique processing properties – so unique that it masters bonding any combination of plastics, glass and metals whether UV transparent or opaque. With low shrinkage and elongation of up to 100%, this UV curable adhesive is unlike others of its kind.

Traditional UV cured adhesives provide distinct advantages in applications, such as high-speed laminating, where performance and assembly efficiency are critical provided one of the substrates to be bonded is UV transparent. IRIS 3030 UV curable adhesive does even more… it has the ability to bond two completely UV opaque materials!

The IRIS 3030 series of adhesives takes advantage of the characteristics for cationic cured epoxies delivering a set of unique adhesive and bonding opportunities with the following properties:

• Capable of bonding opaque materials
• One-part UV cured adhesives with storage life up to 6 months
• No oxygen inhibition
• Very low shrinkage
• Epoxy adhesive bond strength
• Bonding any combination of plastics, glass and metals
• Wide range of viscosities can be achieved
• Low ions
• Low levels of yellowing
• Elongation up to 100%
• Chemical and thermal resistance
• No change in viscosity or wasted adhesives as with two-part epoxy UV hybrids

The IRIS system can be customized to meet specific open time, bond strength, flexibility, and viscosity requirements.

A Scientific Explanation of How UV Adhesives Bond to UV Opaque Materials

When UV cured epoxies are exposed to light of a specific UV frequency, a cationic photoinitiator in the adhesive generates a Lewis Acid. This super acid then reacts with the epoxy rings and other reactive elements in the formulation to form a cross-linked network causing the adhesive to cure. The ring opening reaction of the epoxy, combined with long chain length di-functional reactants, greatly reduces shrinkage in the adhesive.

Unlike free radical cured formulations, cationic cured epoxies continue to react after exposure to UV light is terminated. As with conventional two-part Lewis Acid cured adhesives, the UV light generated super acid in Iris 3030 remains active, allowing the adhesive to continue to cure once exposure to UV light has ceased. The reaction rate can be accelerated with heat, or the reaction process can be slowed down by adding components that temporally tie-up the super acid.

Utilizing the properties of cationic cured epoxies makes lamination of UV opaque films via the print, cure, and nip process possible. Metalized films, PET (polyethylene terphalate), and opaque PP (polypropylene) can be bonded using this UV curing process. The adhesive is applied to one film and exposed to UV light. The adhesive is transformed into a tacky PSA (pressure sensitive adhesive). The second film is bonded to the adhesive coated film. If necessary, the laminate can be die cut. After 24 hours at room temperature, the tacky adhesive continues to cure, forming a tack-free bond.

Iris 3030 UV cured epoxies can also be used in the bonding of metal, glass and plastic components utilizing either automatic and/or manual systems. The cure rate can be dialed into a specific application’s requirement. In some manual operations, a secondary thermal cure may be required.

» Learn more about UV cured adhesives, how they work, areas of application, and new advances.

» Talk to Fielco’s Chief Adhesive Scientist to discover an adhesive solution that will meet your exact needs.