SBIR-STTR Award

The Spectra Group Ltd. (SGL) contribution in responding to N94-213 is the ability to cure pigmented coatings with visible light at 500 or lower on demand. This is based On extensive development and testing of a series of new visible light photoinitiators, compounds which form reactive intermediates with visible light. These initiators are versatile and can be formulated in most radiation curable coatings - acrylates such as polyolacrylates, epoxy acrylates, silicon acrylates and urethane acrylates; unsaturated polyesters such as those used to coat particle board and as structural reinforced construction materials; and epoxies such as bis-phenyl-A-epoxide. Formulations of the initiators are infinitely stable in the dark, contain no volatile organic solvents, and can be easily brushed on the surfaces to be coated. Curing is on demand; i.e, when the surface is irradiated with light from a visible source. Alternatively, sunlight maybe used but the irradiation period depends on dose. The objective of Phase I is to (1)develop formulations of pigmented coatings suitable for marine applications;(2) evaluate initiator formulations such that the formulations can be cured with visible sources to a known depth; (3) develop the evaluation procedures for salt fog tests, impact tests, pencil hardness tests, and adherence tests; (4) establish which surface treatments enhance adhesion and (5) set up test protocols to routinely evaluate each.

Spectra Group Ltd., (SGL) has nearly completed Phase I SBIR "Radiation Curing of Pigmented Coatings" (N94-213) with promising results. The goal was to evaluate new curing technology for Navy repair applications. Briefly summarized, acrylate and epoxy resin formulatins have been developed and cured using SGL's novel visible light photoinitiator technology. The resins were cured with visible and UV/visible light forming tough, corrosion resistant coatings that have good metal adhesion and hardness. The Phae I results offers the potential for a Navy repair process that will replace the current standard paint system and its associated problems. In addition, a variety of civilian applications are expected to benefit from this development. These results form the foundation for a Phaes II program to fully develop and optimize an integrated cure system for prototype demonstration. The primary objectives of Phase II include 1) development of optimized resin formulations and cure response for commercial (Navy and civilian) use, 2) comprehensive testing of the cured coatings, 3) development of an intense, visible light source using advanced light technology, 4) design and development of a rail mount system for easy handling of the light source and 5) field testing. The Option period plans to focus on achieving advanced property performance, civilian applications, colors other than gray, filled or reinforced resins.