| 摘要 |
PROBLEM TO BE SOLVED: To obtain a composition of which cured substance has little change in the characteristics over a long period and has particularly an excellent light resistance, by incorporating (A) a polymerizable oligomer with a specific struc tural unit, (B) a phenol-based anti-oxidizing agent, and (C) an ultraviolet ray absorber. SOLUTION: Component (A) is an oligomer having both a structural unit expressed by formula I: -CH2CH(CH3)O- and a polymerizable double bond, and a blend for the synthetic materials shall have a ratio, to one equivalent of the hydroxyl group contained in polyether polyol, of 1.1-2 equivalents of isocyanate groups of a diisocyanate compound, and 0.1-1 equivalent of a hydroxyl group of a hydroxyl group-containing (meth)acrylate. A blending amount loadings of the component (A) is 20-85 wt.% of the composition. Component (B) has preferably a structure of formulae II or III, and is blended in the amount of 0.1-3 wt.% of the composition. Component (C) is preferably a benzophenone- based ultraviolet ray absorber, and is incorporated in the amount of 0.05-3 wt.% of the composition. |
