| abstract |
【Task】 Disclosed are an ultrafine particle excellent in dispersibility, light resistance, weather resistance, and transparency with a high refractive index, a sol solution, and a high refractive index coating material excellent in dispersion stability and coating suitability including the same. Furthermore, display surfaces such as LCDs and CRTs that have good light resistance, weather resistance, transparency, scratch resistance, abrasion resistance, heat resistance, etc. when applied to transparent substrates such as resin or glass, and various optical systems Provided is a high refractive index coating composition capable of forming an optical thin film such as an antireflection film, an enhanced reflection film, a selective transmission film, and an ultraviolet cut film that covers the surface of a lens. [Solution] (1) Composite oxide ultrafine particles having a refractive index of 1.5 to 2.8 and rutile-type titanium oxide ultrafine particles as a nucleus and having a coating layer made of a metal oxide, or a sol thereof, (2) Curability A binder component, and (3) a coating composition comprising water or an organic solvent, an optical thin film formed using the coating composition, and an optical substrate having the thin film. [Selection figure] None |