Urushi film cured through thermal polymerisation
Ususally, the oxidative polymerisation method is used to cure urushi film (oriental lacquer). Researchers have now focused on thermal polymerisation and present interesting findings.
Urushi is a natural material that forms thin films with excellent durability and water resistance. There are two methods for curing urushi: oxidative and thermal polymerisations. Urushi is mainly applied to wood; therefore, the oxidative polymerisation method has mainly been used to cure it. Oxidative polymerisation requires temperature and humidity control and takes a long time to fully cure urushi. Urushi mixed with pigments has poor colouration. In contrast, the use of a thermal polymerisation reaction can achieve curing in a short time.
Better colouration and high water repellency
In the new study, researchers focused on the thermal curing reaction of urushi, formed 13 different coloured urushi coating films, and investigated their properties and colouration. They observed that urushi coatings produced through thermal polymerisation took less time to cure than those produced through oxidative polymerisation, and that urushi coatings with better colouration and high water repellency were obtained.
The study has been published in Journal of Coatings Technology and Research, Volume 20, Issue 4, July 2023.
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