| 摘要 |
PROBLEM TO BE SOLVED: To provide a powder evaluation that can objectively discriminate whether powder has a pearl-like pattern or not from not only a visual observation but also an optical index.SOLUTION: Powder is evaluated with a following (1) as a half value width of a BRDF obtained by measuring the powder and following (2) as a change in a peak value of the BRDF used as a reference. (1)(a) the half value width of the BRDF in which an evaluation angle of incidence is in a low angle region and/or intermediate angle region, and a change width of the half value width, or (b) a half value width of the BRDF in which the evaluation angle of incidence is an arbitrary angle of incidence present in the low angle region and/or intermediate angle region, and (2)(a) a change in percentage of the peak value of the BRDF in which the elevation angle of incidence is in a high angle region to the peak value of the BRDF in which the elevation angle of incidence is in the intermediate angle region, or (b) a percentage of a peak value of the BRDF at an arbitrary elevation angle of incidence present in the high angle region to the peak value of the BRDF in which the elevation angle of incidence is in the intermediate angle region.SELECTED DRAWING: Figure 8 |
