Optical article having a dual layer temporary coating
View Patent ↗Disclosed is an optical article comprising on at least one of its main surfaces an outer hydrophobic and/or oleophobic coating and in direct contact with the outer hydrophobic and/or oleophobic coating a dual-layer temporary coating, wherein the dual-layer temporary coating is removable and comprises: a first layer, in direct contact with the outer hydrophobic and/or oleophobic coating comprising halogenated olefin polymers or polyurethanes; and a water barrier second layer comprising a polymer or polymer mixture acting as a water barrier deposited on the first layer comprising at least one vinyl polymer, polyepoxide, polyepisulfide, polyester, polyether, polyester-ether, poly(meth)acrylate, polythio(meth)acrylate, styrene polymer, or cellulosic polymer.
1. An optical article which is optically transparent comprising an organic or mineral glass substrate comprising on at least one of its main surfaces an outer hydrophobic and/or oleophobic coating and in direct contact with the outer hydrophobic and/or oleophobic coating a dual-layer temporary coating protecting said outer hydrophobic and/or oleophobic coating before and/or during an edging process, wherein the dual-layer temporary coating is removable and consists of:
a first layer, in direct contact with the outer hydrophobic and/or oleophobic coating comprising halogenated olefin polymers or polyurethanes, wherein the polyurethanes, if present, represent at least 80% by weight of the total weight of the first layer; and
a second layer which is the outermost layer of the optical article, comprising a polymer or polymer mixture acting as a water barrier deposited on the first layer, wherein the second layer comprises at least one vinyl polymer, polyepoxide, polyepisulfide, polyester, polyether, polyester-ether, poly(meth)acrylate, polythio(meth)acrylate, styrene polymer, or cellulosic polymer
wherein the polymer of the first layer and the polymer of the second layer are different from each other.
2. The optical article of claim 1 , wherein the first layer of the temporary coating is a polyurethane layer.
3. The optical article of claim 2 , wherein the polyurethane layer is a layer of a dried polyurethane based latex composition.
4. The optical article of claim 3 , wherein the polyurethane based latex composition comprises at least one poly(meth)acrylic latex.
5. The optical article of claim 4 , wherein the poly(meth)acrylic latex is a polyacrylic latex.
6. The optical article of claim 4 , wherein the poly(meth)acrylic latex represents from 0.1 to 10% by weight of the composition.
7. The optical article of claim 6 , wherein the poly(meth)acrylic latex represents from 2 to 6% by weight of the composition.
8. The optical article of claim 1 , wherein the polymer of the second layer comprises a polyacrylate, polyalkylcellulose, or polyhydroxyalkylcellulose.
9. The optical article of claim 1 , wherein the temporary coating is a strippable film.
10. The optical article of claim 1 , wherein the outer hydrophobic and/or oleophobic coating is deposited on a mono- or multilayered antireflection coating.
11. The optical article of claim 1 , further defined as an ophthalmic lens.
12. The optical article of claim 1 , wherein the outer hydrophobic and/or oleophobic coating comprises compounds carrying fluorinated groups and Si—R groups, wherein R represents a hydroxyl group or a precursor thereof.
13. The optical article of claim 1 , in which said second layer comprises at least one vinyl polymer, polyepoxide, polyepisulfide, polyester, polyether, polyester-ether, styrene polymer, or cellulosic polymer.