| 摘要 |
<p>Laminates of plasticized polyvinyl chloride with a UV-cured top coat with substantial resistance to delayed yellowing with age comprising (a) a barrier to migration of UV-activated free radical-generating species from the top coat to the vinyl layer or (b) a barrier to penetration of UV light into the vinyl layer. Barriers to migration of free radical generating species include physical barriers such a layer of polyethylene between the vinyl layer and the top coat, the use of non-migratory high molecular weight free radical initiator or the use of free radical initiator that is immiscible with the vinyl plasticizer. Barriers to penetration of UV light into the vinyl layer can comprise a layer of UV-absorbing polymer.</p> |
