Alternative curing methods of UV curable automotive clearcoats

• Published in: Progress in organic coatings Vol. 49; no. 3; pp. 218 - 224
• Main Authors: Seubert, C.M., Nichols, M.E.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.04.2004; Elsevier Sequoia
• Subjects: Applied sciences; Coatings. Paints, varnishes and inks; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Crosslink density; Exact sciences and technology; Film formation and curing, properties, testing; Infrared and raman spectra and scattering; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Organic compounds, polymers; Physics; Polymer industry, paints, wood; Raman; Scratch resistance; UV curable clearcoats; Raman; Crosslink density; UV curable clearcoats; Scratch resistance; Acrylates; Raman spectra; Ultraviolet radiation; Scratch; Microwave radiation; Cross-linking; Fluorescence; Curing; Differential thermal analysis; Urethane; Experimental study; Coatings
• ISSN: 0300-9440; 1873-331X
• DOI: 10.1016/j.porgcoat.2003.10.002

Alternative methods for curing UV curable clearcoats were characterized using confocal Raman microscopy, nano-scratch measurements, and dynamic mechanical thermal analysis (DMTA). Clearcoats were cured using a xenon flash lamp, fluorescent UV bulbs with various spectral power distributions, and a microwave powered lamp. Raman spectroscopy was used to track acrylate double bond conversion of the clearcoat after each method of curing. DMTA was used to correlate double bond conversion to crosslink density. Nano-scratch results showed scratch resistance to be sensitive to the surface cure state. A combination of the flash and fluorescent methods produced a degree of cure similar to that of the microwave powered lamp. Scratch tests showed that clearcoats with a similar surface cure state achieved using different curing methods effectively had equivalent scratch properties.