PURPOSE: To obtain the subject compsn. applied to a thermoplastic substrate to provide a composite excellent in weatherability and abrasion resistance by adding a specific polymn. initiator and a UV absorber to the subject compsn. composed of a UV curable org. material and/or a UV curable organosilicon material.

CONSTITUTION: In the subject compsn. composed of a UV curable org. material and/or a UV curable organosilicon material (e.g.; aliphatic acrylated urethane), an acrylphosphorus compd. (e.g.; 2,4,6-trimethylbenzoyldiphenylphosphine oxide) effective as a polymn. initiator to the compsn. at a time exposed to light having a wavelength of about 360-410 nm and a stabilizing amt. of a UV absorber (e.g.; 2-hydroxy-4-n-octoxybenzophenone) are added.