Optical article and method for producing the same
A method for producing an optical article includes laminating on a plastic substrate a first layer using a first composition, the first composition including two or more kinds of polyurethane resins each having a different average particle diameter, metal oxide particulates, and an organosilicon compound.
1. An optical article comprising a plastic substrate and a first layer formed on the plastic substrate,
the first layer having a refractive index decreasing in a direction away from the plastic substrate, and
the first layer being formed using a first composition including two or more kinds of polyurethane resins each having a different average particle diameter, metal oxide particulates, and an organosilicon compound, wherein
the first composition includes:
(i) a first small-diameter polyurethane resin having an average particle diameter d11,
(ii) a second small-diameter polyurethane resin having an average particle diameter d12, and
(iii) a large-diameter polyurethane resin having an average particle diameter d2, and
the first small-diameter polyurethane resin, the second small-diameter polyurethane resin and the large-diameter polyurethane resin have a different average particle diameter, and d11, d12 and d2 satisfy the following conditional expression:
20 nm≦d11≦40 nm
40 nm≦d12≦60 nm, and
60 nm≦d2≦400 nm.
2. The optical article according to claim 1 , further comprising a second layer formed on the first layer, the second layer having a refractive index lower than that of the plastic substrate.
3. The optical article according to claim 1 , wherein:
the metal oxide particulates have an average particle diameter dm that satisfies the following conditional expression:
5 nm≦dm≦60 nm.