Preparation And Properties Of UV-curable Water-borne Wood Coating

UV-curable coating materials have been extensively applied in many fields such aswood coating because they display many advantages over traditional coating materials:high curing speed, low energy consumption, easy production, low pollution andexcellent performance.In this paper, efforts have been made to investigate the formula and properties ofwaterborne UV-light curing wood coatings. The influence of each component of theformula on the overall coating properties, such as adhesion, abrasion resistance, waterresistance, chemical resistance test and so on, was studied so as to find the optimalcoating formula. Finally high-performance UV-curable coating was obtained.The investigation concentrates on the following aspect: the influence of types andcontent of UV initiator on UV curing speed; the influence of silica nanoparticles onvarious coating performances such as mechanical properties, viscosity, refractiveindex, and curing speed; the influence of silane coupling agent amount on hardness,wear resistance and so on; the influence of types and content of water soluble activediluents on curing speed and surface viscosity.According to the theoretical research and experimental analysis, the optimal coatingformula was obtained: the weight percentage of UV-curable waterborne polyurethaneacrylate is52%, the light initiator Darocur4265is3%, the water-soluble thinnerEO15TMPTA is20%, the water-soluble solvent N, N-dimethyl formamide is6%,the wetting agent Tego-270is0.2%, the flow ping agent BYK-349is0.3%, thedefoaming agent Tego-920is0.5%, the silane coupling agent KH-550is4%, silica is2%, and deionized water is12%. The results of performance test and microstructureresearch demonstrated that high-performance UV-curable coating was obtained. Thepencil hardness of final obtained coating could be as much as3H, which is an idealvalue in waterborne UV-curable coating materials. The impact resistance performancewas also good: there was no damage under45N·cm impact. The adhesion of thecoating reached the best grade—grade0. Furthermore, the coating showed nosignificant change either after wiping100times with MEK or after72h hightemperature and high humidity test.