Hydrophilic-like sputtered AR coating
An ophthalmic article having a coating system which provides antireflective and easy clean properties to the ophthalmic article. The coating system includes alternating layers of low refractive index metal oxide and high refractive index metal oxynitrides and corresponding high refractive index metal oxides. The coating system provides favorable surface energy to the ophthalmic article when at least one layer of the high refractive index metal oxynitride is encapsulated between two layers of low refractive index metal oxide.
1. An ophthalmic article having easy-clean and anti-reflective properties comprising:
a substrate having a surface; and
a stack on said surface; said stack comprising a plurality of alternating low refractive index layers comprising a metal oxide and high refractive index layers comprising 1) at least one metal oxynitride layer, or 2) at least one metal oxynitride layer and at least one metal oxide layer;
wherein the ophthalmic article comprises a surface free energy in a range of about 50-70 mN/m for a prolonged period when the at least one high refractive index metal oxynitride layer is encapsulated between two layers of the low refractive index metal oxide;
wherein the at least one high refractive index metal oxynitride layer comprises a titanium oxynitride layer or a zirconium oxynitride layer.
2. The ophthalmic article of claim 1 , wherein said low refractive index metal oxide comprises silicon dioxide.
3. The ophthalmic article of claim 1 , wherein said high refractive index metal oxide comprises titanium dioxide or zirconium dioxide.
4. The ophthalmic article of claim 1 , wherein said ophthalmic article comprises a polar surface energy in a range of about 15-40 mN/m for a prolonged period when said at least one high refractive index metal oxynitride is encapsulated between two layers of said low refractive index metal oxide.
5. The ophthalmic article of claim 4 , wherein said at least one high refractive index metal oxynitride comprises zirconium oxynitride which is encapsulated between said two layers of said low refractive index metal oxide comprising silicon dioxide.
6. The ophthalmic article of claim 4 , wherein said at least one high refractive index metal oxynitride comprises titanium oxynitride which is encapsulated between said two layers of said low refractive index metal oxide comprising silicon dioxide.
7. The ophthalmic article of claim 4 , wherein a surface cleanability ratio of the ophthalmic article, when said at least one high refractive index metal oxynitride is encapsulated between two layers of said low refractive index metal oxide, is greater than 90%.
8. The ophthalmic article of claim 7 , wherein said surface cleanability ratio of the ophthalmic article is 97.63% when said at least one high refractive index metal oxynitride comprising zirconium oxynitride is encapsulated between two layers of said low refractive index metal oxide comprising silicon dioxide.
9. An optical stack that imparts easy-cleaning and anti-reflective properties on a surface comprising:
at least one high refractive index layer of a metal oxynitride encapsulated between two low refractive index layers of metal oxide material;
wherein a surface free energy of the optical stack, comprising the high refractive index layer of the metal oxynitride encapsulated between the two low refractive index layers of the metal oxide material, remains in a range of about 50-70 mN/m for a prolonged period;
wherein the at least one high refractive index layer of the metal oxynitride comprises a titanium oxynitride layer or a zirconium oxynitride layer.
10. The optical stack of claim 9 , wherein said low refractive index layers of said metal oxide material comprises silicon dioxide.
11. The optical stack of claim 9 , wherein the optical stack further comprises a high refractive index layer of a metal oxide comprising titanium dioxide or zirconium dioxide.
12. The optical stack of claim 9 , wherein said optical stack comprises a polar surface energy in a range of about 15-40 mN/m for about 40 days of time when said at least one high refractive index metal oxynitride is encapsulated between said two low refractive index layers of said metal oxide material.
13. The optical stack of claim 11 , wherein said high refractive index layer of said metal oxynitride and said high refractive index layer of said metal oxide have about same refractive indexes.
14. The optical stack of claim 9 , wherein said high refractive index layer of said metal oxynitride having a surface roughness higher than a surface roughness of a high refractive index layer of a metal oxide.
15. The optical stack of claim 14 , wherein said high refractive index layer of said metal oxynitride having said surface roughness of about 4.43 nm.
16. The optical stack of claim 14 , wherein said high refractive index layer of said metal oxide having said surface roughness of about 3.80 nm.