Characterization of Volatile Products from Raw Lacquer Film During Ultraviolet Irradiation Using On-Line Micro Ultraviolet Pyrolysis-GC/MS

Abstract

Oriental lacquer has been used as a durable and beautiful coating material in Asian countries for more than 7,000 years. However, lacquer ware is susceptible to damage by light and therefore is usually stored in a dark, cool environment. This research focused on volatilized constituents from raw lacquer film by ultraviolet irradiation. This paper discussed research that examined volatile deterioration products generated when the lacquer film, which was not proved although the existence was pointed out until now, was irradiated with ultraviolet rays. We analyzed about the volatile deterioration product of the lacquer film using newly developed on-line ultraviolet/thermal degradation-gas chromatography/mass spectrometry. In particular, this research examined the ultraviolet exposure conditions to the raw lacquered film. As a result, it was suggested that the oxidative cleavage reaction was triggered because oxygen combines the volatilization ingredient following ultraviolet exposure with the portion which the double combination of the urushiol origin that remains on a lacquer film activated in connection with the allylic rearrangement by ultraviolet rays is the cause. Thus, the present work, we considered the reaction of the oxidative cleavage that starts in the case of ultraviolet ray degradation by analysis using newly developed equipment to the volatilization output from the lacquered film which was not started until now, and acquired the fixed view on an ultraviolet-ray-degradation mechanism.