Patent ID: 7566499
Filing Date: 2009-07-28
Classification: C01P,C09C,Y10T

Abstract:
1. A process for designing optically coherent multilayered film-coated powder, which comprises base particles having thereon at least two coated layers having refractive indexes different from each other, and reflects light with a particular wavelength, the process being characterized by: selecting a substance of the base particles providing an intended function, and an intended color; measuring a spectral intensity curve and values L*0, a*0 and b*0 in CIELAB color system of the intended color; and identifying substances and thicknesses of the coated layers and an order of formation of the layers that provide an optically coherent multilayered film-coated powder having values L*1, a*1 and b*1 that minimize a color difference (ΔZ*) expressed by the following equation (3): and make a hue ratio expressed by the following equation (4): within a range of from 0.9 to 1.1, based on the following recurring formula (1) in case where the base particles have a flat plate form: wherein R j: an integer of at least 1 (j−1=0 represents substance) i: an imaginary unit, r R 2δ λ: an intended wavelength of reflected light, n d φ as an equation for compensating a shape of the base particles, based on a visible light reflection waveform obtained by applying a R wherein θ: an incident angle on an outermost layer.