Comparative Study between Free Radical and Cationic UV Curable Coatings

TANG Xun1, ZHANG J i-de1, CHEN Hong2, N IE L i-Bo2

(1. College of Chemistry and Chemical Engineering, Hunan Univ, Changsha　410082,China;

2. Packaging and Printing College, Zhuzhou Institute of Techno logy, Zhuzhou　412008,China)

　　Abstract: By comparative study between free radical and cationic UV curable coatings, the effect of temperature on cu re speed and the influence of O 2 on cu re speed and film s properties have been investigated. The cu ring rate of both the free radical and cationic UV curable coatings are accelerated with the rise of temperature, and the former’s cu re speed is higher than the latter. The free radical cu -rable film has strong shrink, so it’s adhesive is poor. To the contrary, the cationic UV curable coatings have feeble shrink and good adhesive. The oxygen has an obvious inhibit ion to the free radical curab le coatings, whereas it does no t act to the cationic curable coatings. Furthermore the cationic curable- coatings have a“dark react ion”, w hen the UV -light has been removed , the film s w ill be still curing.

Key words: UV cu re; UV curable coating; free radical curable coatings; cationic curable coatings