Optical Article Coated with an Antireflection Coating Comprising a Sublayer Partially Formed under Ion Assistance and Manufacturing Process

Abstract

The invention relates to an optical article provided with antireflection properties, comprising a substrate having at least one main surface coated with an antireflection coating comprising, starting from the substrate: a sub-layer comprising two adjacent layers formed from the same material, the sum of the thicknesses of the two adjacent layers being greater than or equal to 75 nm; and a multilayered antireflection stack comprising at least one high refractive index layer and at least one low refractive index layer, the deposition of the first of said two adjacent layers of the sub-layer having been carried out without ion assistance and the deposition of the second of said two adjacent layers of the sub-layer having been carried out under ion assistance. The invention also relates to a process for manufacturing such an optical article.

1 .- 23 . (canceled) 
   
   
       24 . An optical article with antireflection properties, comprising a substrate having at least one main surface coated with an antireflection coating comprising, starting from the substrate:
 a sub-layer comprising two adjacent layers, the sum of the thicknesses of the two adjacent layers being greater than or equal to 75 nm; and   a multilayered antireflection stack comprising at least one high refractive index layer and at least one low refractive index layer,   
     wherein the deposition of the first of the sub-layer two adjacent layers has been carried out without ion assistance and the deposition of the second of the sub-layer two adjacent layers has been carried out under ion assistance. 
   
   
       25 . The article of  claim 24 , wherein the two adjacent layers of the sub-layer are formed from the same material. 
   
   
       26 . The article of  claim 24 , wherein the thickness ratio of the sub-layer two adjacent layers to each other varies from 9:1 to 1:9. 
   
   
       27 . The article of  claim 26 , wherein the thickness ratio of the sub-layer two adjacent layers to each other varies from 4:6 to 6:4. 
   
   
       28 . The article of  claim 24 , wherein the sum of the thicknesses of the two adjacent layers is greater than or equal to 80 nm. 
   
   
       29 . The article of  claim 28 , wherein the sum of the thicknesses of the two adjacent layers is greater than or equal to 100 nm. 
   
   
       30 . The article of  claim 29 , wherein the sum of the thicknesses of the two adjacent layers is greater than or equal to 150 nm. 
   
   
       31 . The article of  claim 24 , wherein the sub-layer two adjacent layers are SiO 2 -based layers. 
   
   
       32 . The article of  claim 31 , wherein the sub-layer two adjacent layers are free of Al 2 O 3 . 
   
   
       33 . The article of  claim 31 , wherein the sub-layer two adjacent layers consist of SiO 2  layers. 
   
   
       34 . The article of  claim 24 , wherein the sub-layer comprises, in addition to the two adjacent layers, at most three layers interleaved between the substrate and the two adjacent layers. 
   
   
       35 . The article of  claim 24 , further defined as comprising an ASTM BAYER value greater than or equal to 4.5 of the standard ASTM F 735.81. 
   
   
       36 . The article of  claim 24 , wherein all the low refractive index layers of the multilayered stacks comprise a mixture of SiO 2  and Al 2 O 3 . 
   
   
       37 . The article of  claim 36 , wherein all the low refractive index layers of the multilayered stacks consist of a mixture of SiO 2  and Al 2 O 3 . 
   
   
       38 . The article of  claim 24 , wherein the high refractive index layers of the multilayered stack comprise at least one of TiO 2 , PrTiO 3 , or ZrO 2 , or combinations thereof. 
   
   
       39 . The article of  claim 24 , further defined as an ophthalmic lens. 
   
   
       40 . A process for manufacturing an optical article with antireflection properties, comprising:
 providing an optical article comprising a substrate having at least one main surface;   depositing onto a main surface of the substrate a sub-layer having an exposed surface, where the sub-layer comprises two adjacent layers, the sum of the thicknesses of the two adjacent layers being greater than or equal to 75 nm;   depositing onto the exposed surface of the sub-layer a multilayered antireflection stack comprising at least one high refractive index layer and at least one low refractive index layer,   recovering an optical article comprising a substrate having one main surface coated with an antireflection coating comprising the sub-layer and the multilayered stack,   
     wherein the deposition of the first of the sub-layer two adjacent layers is carried out without ion assistance and the deposition of the second of the sub-layer two adjacent layers is carried out under ion assistance. 
   
   
       41 . The process of  claim 40 , wherein the two adjacent layers of the sub-layer are formed from the same material. 
   
   
       42 . The process of  claim 40 , wherein the sum of the thicknesses of the two adjacent layers is greater than or equal to 80 nm. 
   
   
       43 . The process of  claim 42 , wherein the sum of the thicknesses of the two adjacent layers is greater than or equal to 100 nm. 
   
   
       44 . The process of  claim 43 , wherein the sum of the thicknesses of the two adjacent layers is greater than or equal to 150 nm. 
   
   
       45 . The process of  claim 40 , wherein the sub-layer two adjacent layers are SiO 2 -based layers. 
   
   
       46 . The process of  claim 45 , wherein the sub-layer two adjacent layers are free of Al 2 O 3 . 
   
   
       47 . The process of  claim 45 , wherein the sub-layer two adjacent layers consist of SiO 2  layers. 
   
   
       48 . The process of  claim 40 , wherein the deposition of each of the sub-layer of the antireflection coating layers is carried out by vacuum evaporation. 
   
   
       49 . The process of  claim 40 , wherein, prior to depositing the sub-layer, the surface of the substrate is submitted to a physical or a chemical activation treatment selected from a bombardment using energetic species, a corona discharge treatment, an ion spallation treatment, an ultraviolet treatment or a plasma treatment under vacuum, an acid or base treatment and/or a solvent treatment, or combinations of these treatments. 
   
   
       50 . The process of  claim 40 , wherein the deposition of one or more of the multilayered antireflection stack layers is carried out under ion assistance. 
   
   
       51 . The process of  claim 40 , wherein the thickness ratio of the sub-layer two adjacent layers to each other varies from 9:1 to 1:9. 
   
   
       52 . The process of  claim 51 , wherein the thickness ratio of the sub-layer two adjacent layers to each other varies from 4:6 to 6:4.