以聚氨酯为中心介质组成的光学变色薄膜,当有自然光进入光学变色薄膜时,随着入射光和视角的变化,在薄膜上可以看到明显的光变色效果。这种薄膜可以单独成为一种防伪材料或与油墨组合成为一种新颖防伪油墨。根据多层复合膜光干涉原理设计和计算了光变色薄膜,所确定的薄膜膜系结构为PET(聚酯薄膜)/C,价质/Al。介质是有机高聚物聚氨酯。通过调节多元醇、异氰酸酯和氨基甲酸酯以及催化剂的含量和反应方程式,使聚氨酯材料具有较高的折射率,以充分体现光变色的效果。介绍了光变色薄膜的制作方法,研究了薄膜的相关特性。
Polyurethane is a fine optical material as dominating dielectric in color shift film. The film showing obvious color shift effect with the change of incidence and view angle can be used as a counterfeit preventing material. The structure of the film system was designed as PET (polyester) / Cr / polyurethane / Al according to the optics interference theory of multiplayer. The refractive index of the polyurethane can be adjusted between 1.8 and 1.9 by varying the method and condition of catalyst and preparation process.