| 摘要 |
PROBLEM TO BE SOLVED: To obtain a sheet showing excellent decorating effect independently of whether the sheet is used in daytime or at night, especially to obtain excellent effect to give rainbow colors, by specifying the range of the selection coefft. of film thickness in a specified formula, which specifies the film thickness of the optimum focusing resin layer to reflect light only in the light source direction. SOLUTION: This sheet contains glass particles sealed and fixed in a resin layer and a focusing resin layer combined to the particles. The focusing resin layer of the sheet consists of a patterned resin layer. The optimum film thickness of the focusing resin layer which reflects light only in the light source direction is specified by formulae I and II, and the selection coefft. X of film thickness specified by the formula II ranges 0.16 to 0.95. In formulae, f is the coefft. of the optimum film thickness of the focusing resin layer, d is the diameter of glass particles, h is the film thickness of the focusing resin layer, nb is the refractive index of the resin which fixes the glass particles, ng is the refractive index of the glass particles, and ns is the refractive index of the resin of the focusing resin layer. |
