Optical Articles
An optical article includes a plastic substrate, a first layer which is adjacent to the plastic substrate and the refractive index of which decreases in the direction to be remoter from the plastic substrate, a second layer which is adjacent to the first layer and the refractive index of which is not higher than the refractive index of the surface part of the first layer, and a hard coat layer which is adjacent to the second layer and the refractive index of which is lower than the refractive index of the plastic substrate.
1 . An optical article comprising a plastic substrate,
a first layer which is adjacent to the plastic substrate and the refractive index of which decreases in the direction to be remoter from the plastic substrate,
a second layer which is adjacent to the first layer and the refractive index of which is not higher than the refractive index of the surface part of the first layer, and
a hard coat layer which is adjacent to the second layer and the refractive index of which is lower than the refractive index of the plastic substrate.
2 . The optical article as claimed in claim 1 , wherein the first layer is formed of a first material that comprises a polyurethane resin, metal oxide particles and an organosilicon compound.
3 . The optical article as claimed in claim 1 , wherein the second layer is formed of a second material that comprises an urethane-based, ester-based, epoxy-based, acryl-based or silicone-based organic resin and metal oxide particles.
4 . The optical article as claimed in claim 1 , wherein the first material to form the first layer, the second material to form the second layer and a third material to form the hard coat layer each contain metal oxide particles and an organic resin, and wherein the ratio of the metal oxide particles to the organic resin in the first material is larger than the ratio of the metal oxide particles to the organic resin in the second material.
5 . The optical article as claimed in claim 4 , wherein the ratio of the metal oxide particles to the organic resin in the third material is larger than the ratio of the metal oxide particles to the organic resin in the second material.
6 . The optical article as claimed in one of the claims 1 to 5 , wherein the refractive index of the plastic substrate is at least 1.7.