The Effect of UV Irradiation on Lacquer Tree Paint Films Containing UV Absorbents.

The effect of UV irradiation on lacquer tree paint films containing UV absorbents, 2-hydroxybenzophenone and 2-hydroxy-4-octyloxybenzophenone, was investigated and discussed on the basis of reversed micelle structure and the evaluation method for the paint films, which we previously proposed.The development of UV resistance appeared to be related to the effect on the curing reaction and the degradation was not inhibited on insufficient curing. On the other hand, the suppression effect of absorbents on the degradation was observed for the paint films taking a fully developed, reserved-micelle structure. The curing reaction would be little interfered with the absorbent having a molecular structure like Urushiol.