| 摘要 |
PROBLEM TO BE SOLVED: To provide an internal reflection-preventing black coating material for optical elements, free of coal tar or methylenedianiline imposing large environmental burden, high in storage stability with time of the coating material, and capable of keeping low internal reflectance of optical elements applied with the coating material even if the optical elements are stored in a high-temperature high-humidity environment.SOLUTION: This coating material includes 0.1-20.0 mass% of carbon black and 20-70 mass% of a metal oxide selected from titanium dioxide, ferric oxide, triiron tetroxide, iron oxyhydroxide and zirconia to the solid content thereof; and 0.5-10.0 mass% of a silane coupling agent having an active hydrogen group or electron-withdrawing group to the whole coating material. The coating material further contains an active hydrogen compound and an electron-withdrawing compound, wherein the dispersed particle diameter D90 of the coating material is 50-800 nm. |
