| abstract |
To provide nanoparticles having a high refractive index and excellent compatibility with (meth) acrylic monomers. Nanoparticles coated with a surface treatment agent, having a refractive index of 1.8 or more. Preferably, the surface treatment agent is a part (A) having adsorptivity or reactivity to the nanoparticles, and a part (B) that imparts compatibility to the (meth) acrylic monomer to the nanoparticles coated with the surface treatment agent. , And a portion (C) having a high refractive index. |