ES2354351A1 - Ophthalmic and/or solar lens and corresponding manufacturing procedure. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Ophthalmic and/or solar lens and corresponding manufacturing procedure. Ophthalmic and/or solar lens comprising a substrate of a polymeric material and coated with a hardening layer. In at least one of its surfaces is covered with a metal layer, a metal of the group consisting of cu, ag, al, au, ni, ti, cr, mo, pt, rh, zr and mixtures of the above. The thickness of the metal layer is between 1 and 20 nm and the visible reflection of the lens is less than 10%. The lens has a value of abrasion resistance greater than 5 br, good resistance to aging and square electrical resistivity on the coated surface less than 20 ohm/sgr. The manufacturing process comprises a step of deposition, by physical deposition of vapor with evaporation by electron gun, of the metal layer. (Machine-translation by Google Translate, not legally binding)

Description

Ophthalmic and / or solar lens and procedure corresponding manufacturing.

Field of the Invention

The invention relates to an ophthalmic lens and / or solar, which comprises a substrate of a polymeric material, and It is coated with a hardening layer. The invention is also refers to a manufacturing process of an ophthalmic lens and / or solar according to the invention.

State of the art

The lens coating is well known, and in particular of ophthalmic lenses of polymeric nature or organic, with hardener layers to improve resistance to abrasion of them. This coating procedure is performed because the scratch resistance of this type of lens Polymers are much smaller than that of mineral lenses. This hardener coating (lacquer) is usually applied by immersion in a (poly) siloxane, acrylic, methacrylic or polyurethane and its subsequent curing in an oven at temperatures between 100ºC and 130ºC. Through this procedure layers are obtained hardeners of thicknesses between 1 micron to 3 microns. Other technique possible to make the hardener coating is by application of lacquers by the spinning technique with characteristics mechanics similar to the previous ones but with a productive process which performs only one face of the lens per stage.

On the other hand, the application of AR anti-reflective treatments to reduce reflection. For achieve this anti-reflective effect of visible light, a multilayer stack is usually performed (typically between 1 and 6), of thicknesses between 10 nm to 150 nm each. Them and usually uses PVD techniques (Physical Vapor Deposition) by electron gun or thermal evaporation although there are other techniques such as Plasma enhanced Chemical Vapor Deposition (PeCVD) or Sputtering.

The measure of abrasion resistance of a polymer ophthalmic lens is usually performed in the field industrial through the so-called Bayer test of the company Colts Laboratories with standard operating procedure reference L-11-10-08 and compare the abrasion resistance to that of a CR39 substrate. So, a value of BR = 10 means that the treated lens is 10 times more abrasion resistant than a CR39 lens. At the moment Invention this test has been used.

A test of measurement of abrasion resistance under lens pressure called Steel Wool SW of the company Colts Laboratories with Standard operating procedure reference L-11-12-08. In the This invention also uses this test.

On the other hand the lenses are known ophthalmic and / or solar polymer-based incorporating a filter infrared. In some cases the infrared filter is achieved based on include absorbent pigments in the polymer base, typically polycarbonate However this limits the available materials and does not allow choosing those materials that are optimal for lenses ophthalmic

Summary of the invention

The invention aims to overcome these inconvenience This purpose is achieved through a lens ophthalmic and / or solar of the type indicated at the beginning characterized because on at least one of its surfaces is covered with a metallic layer, where the metallic layer is of a group metal formed by Cu, Ag, Al, Au, Ni, Ti, Cr, Mo, Pt, Rh, Zr and mixtures of the above, and a thickness between 1 and 20 nm, and because the visible reflection of said lens, calculated according to ISO 8980-4 (Rv), is less than 10%, preferably less than 2.5%.

Indeed, the inclusion of a metallic layer of one of the indicated metals and within the indicated ranges It has a high reflective effect of infrared radiation, specifically infrared (IR) radiation called solar according to EN-1836, which is the one included in of the wavelength range of 780 nm (nanometers) and 2000 nm. From In this way it is possible to include in the lens a solar IR filter that Acts mostly by reflection. Additionally this layer metallic has optical transmission properties in the suitable visible spectrum, both for use in solar lenses and For use in non-solar ophthalmic lenses.

Additionally this layer is suitable to act as one of the necessary layers in a layer structure anti-reflective (or interferential) suitable for reducing the amount of visible light reflected by the lens. The metal layer according with the invention it is suitable to be part of this structure, which simplifies the total multilayer structure of the lens since this layer is able to perform two functions simultaneously.

Another additional advantage of this metallic layer is that it avoids the accumulation of static electricity in the lens, for example that generated by rubbing the polymers in the lens cleaning process. It is known that charged surfaces attract dust motes, which impairs the quality of vision. Currently, attempts are being made to avoid the accumulation of static electricity in the lenses by including a conductive and transparent layer of ITO (indium oxide and
tin). However, the metal layer is much more effective in this regard thanks to its lower electrical resistivity.

Preferably the metal layer is a metal of the group formed by Cu, Ag, Pt, Al and Au, and most preferably it is of Ag.

Advantageously the metal layer has a thickness between 5 and 15 nm.

In general, the metal layer will be on one of the lens surfaces, however, could be applied on the two surfaces of the lens (that of the inner face and that of the external face). Also, there will usually be a single metallic layer as indicated, but you could also consider the possibility that, within a more complex multilayer structure including more than one metallic layer as indicated.

Preferably between the hardening layer and the metal layer there is a first layer of low index of refraction, which, advantageously, has a thickness of less than 200 nm.

Advantageously between the first bass layer refractive index and the metal layer there is a first high layer refractive index, which preferably has a thickness less than 100 nm, and most preferably the thickness is comprised between 20 and 50 nm.

Preferably on the metal layer there is a second layer of high refractive index that, advantageously, has a thickness of less than 100 nm, and most preferably the thickness is between 20 and 50 nm.

Advantageously the first and second layers of high refractive index are of a group material formed by oxides, nitrides or oxynitrides of Zr, Ti, Sb, In, Sn, Ce, Zn, Ta, Nb, Hf and mixtures of the foregoing, and preferably are of ZrO2.

Preferably on the second high layer index of refraction there is a second layer of low index of refraction which, advantageously, has a thickness of less than 200 nm. It is particularly advantageous if the thickness is between 20 and 50 nm.

Both the first and second bass layer Refractive index are preferably SiO2.

Advantageously enter at least one of the layers of high index of refraction and the metal layer there is a layer of interface of a material of the group formed by Si, Cr, Ti, Ni, Ni / Cr, SnO2, Al2O3, AlN, ZnO, SiOx, SiO / Cr, SiO_ {2} / Al_ {2} O_ {3}, ITO, and MoO_ {3}. In the event that it it is a material of the type SiO_ {2} / Al_ {2} O_ {3} advantageously it is the material called "Lima", which is SiO 2 with 5% Al 2 O 3. Preferably the layer of interface has a thickness less than 10 nm, and most preferably the thickness is between 1 and 3 nm.

Preferably on the hardener layer there are an initial interface layer, which is of a group material formed by Si, Cr, Ti, Ni, Ni / Cr, SnO2, Al2O3, AIN, ZnO, SiO_ {x}, SiO / Cr, SiO_ {2} / Al_ {2} {3}, ITO, and MoO_ {3}, and that has a thickness less than 20 nm. It is particularly advantageous. the thickness is between 5 and 15 nm.

Advantageously the lens has a layer of primer between the substrate and the hardener layer.

An embodiment particularly advantageous of the invention consists of an ophthalmic and / or solar lens which comprises a substrate of a polymeric material and is covered with a hardening layer and comprising, on the layer hardener, the following layer structure:

[a] an ITO interface layer between 6 and 10 nm thick,

[b] an interface layer of Cr between 1 and 3 nm thick,

[c] said metallic layer, of Ag, between 6 and 12 nm thick,

[d] an interface layer of Cr between 1 and 3 nm thick,

[e] a layer of high refractive index, of ZrO2, between 20 and 30 nm thick,

[f] a second layer of low index of refraction, SiO2, between 30 and 50 nm thick.

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This structure is particularly interesting. for solar lenses.

In general, it is advantageous for the lens to include always a hydrophobic outer layer, preferably perfluorinated, which advantageously has a thickness between 2 nm and 40 nm.

Preferably the lens according to the invention has a transmittance in the solar infrared spectrum T_ {IR} and a transmittance in the visible spectrum T_ {V}, both calculated according to EN 1836, such that its ratio T_ {V} / T_ {IR} is less than or equal to 1, with TV being less than 80%. This is particularly interesting for sun glasses.

Alternatively, the lens according to the invention preferably has a transmittance in the spectrum solar infrared T_ {IR} less than 80% and a transmittance in the visible spectrum T_ {V}, between 80% and 100%, both calculated according to EN 1836. This is the preferred case for lenses not solar. In fact, it is ISO 8980-3 that stipulates the way in which spectrum transmittance is calculated Visible to non-solar ophthalmic lenses. However, the way calculation is the same as that used in the EN 1836 standard, so It is technically equivalent to refer to one or the other standard.

The lens coated with the structure according with the present invention presents a visible reflection according to the ISO 8080-4 Rv standard less than 10%, and preferably less than 2.5%, on the surface where the filter has been applied solar infrared

On the other hand, it is particularly advantageous that the lenses meet a series of mechanical requirements (in particular resistance to abrasion) and resistance to aging (corrosion resistance, lightning resistance ultraviolet) In this sense, it is particularly advantageous that the Lens meets some (or all) of the following requirements:

- Have an abrasion resistance value greater than 5, measured in Bayer Ratio (BR) units according to the test of Bayer, according to the standard L-11-10-08 of Colts Laboratories

- Have an abrasion resistance value less than 0.2, measured in Haze units according to the Steel Wool test a 3 kg for 1 minute and with 0000 mesh, according to the standard L-11 -12-08 of Colts Laboratories

- Do not show visible deterioration after apply the tests in point 4.6.10.2 of immersion resistance to saline solutions and section 4.6.10.1 severe abrasion of the norm MIL-F-48616A.

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On the other hand, it is particularly advantageous that the lens has a square electrical resistivity value over the Coated surface less than 20 \ Omega / sgr, measured according to ASTM D-254. Indeed, the metallic layer It has a decisive effect on the square electrical resistivity of the lens assembly. This electrical resistivity will depend directly from the thickness of the metal layer, so an expert in the matter it will be able to establish a correlation between the resistivity Electric square lens and metal layer thickness, taking into account the nature of the metal chosen to conform The metal layer Therefore the value of the electrical resistivity square lens can serve as an indicator of the properties reflective in the solar infrared spectrum of the lens, and also will serve as an indicator of the goodness of the properties anti-electrostatic lens.

The object of the invention is also a manufacturing process of an ophthalmic and / or solar lens of according to the invention characterized in that it comprises a stage of deposition, by physical vapor deposition with evaporation by electron cannon, on at least one of the surfaces of the lens, of a metallic layer as indicated above.

Brief description of the drawings

Other advantages and features of the invention they are appreciated from the following description, in which, without no limitation, preferential modes of embodiment of the invention, mentioning the drawings that are accompany. The figures show:

Fig. 1, a schematic view of a section transverse of an embodiment of a lens according to the invention.

Fig. 2, a schematic view of a section transverse of a solar infrared filter coating of according to the invention.

Fig. 3, a schematic view of a section transverse of another solar infrared filter coating of according to the invention.

Detailed description of some embodiments of the invention

Fig. 1 shows an example of structure lens of a lens according to the invention. The lens comprises a base P of polymeric material on which there is a primer layer IM. Next there is a hardener layer E on which it is arranged the coating R that acts as a solar IR filter. This R coating, as will be seen below, also complies with other functions, since you can include some layers so that the set has anti-reflective properties of visible light, have electrostatic properties (basically derived from the metal layer) and have mechanical and anti-aging properties suitable to meet the different regulations. Finally the lens has an hydrophobic outer layer H.

In Fig. 2 the detail of the R coating, in what could be understood as the most complex. The bottom layer of the coating R is a layer of initial interface IN0. On the initial interface layer IN0 there are a first layer of low refractive index B1. Next there are a first layer of high refractive index A1. On the first high refractive index layer A1 a metallic layer M which has, above and below, an IN1 interface layer. Then there is a second layer of high refractive index A2 and finally there is a second layer of low index of refraction B2.

This scheme in Fig. 2 is, as has already been said, the most general and complete case. It must be taken into account, without However, not all layers have to be always present. In addition, it should be borne in mind that, although each of the layers have a main function, all of them affect in greater or lesser measure in the optical and / or mechanical properties of set. Therefore, sometimes it may be the case that what conceptually they are two different layers, in practice they are made with the same material so in practice they are physically a single layer.

In general the low index layers of refraction B1 and B2 and the high refractive index layers A1 and A2 they are particularly important to achieve the properties lens mechanics, in terms of resistance to striped, while the interface layers IN0, IN1 and IN2 are particularly important to achieve the properties of adhesion, wear and barrier against oxidation and diffusion. However, all of them also have optical properties that can be used, such as to get the anti-reflective properties of the visible light of the set. For his part the metal layer fulfills the basic function of being the filter IR solar by reflection, but also has optical properties in the visible range that can be used to achieve the objectives of the lens assembly (for example the properties anti-reflective visible light). This will logically depend on the materials and thicknesses used in each case.

In Fig. 3 another example of a R. coating In this case the structure is simpler since it comprises only an initial interface layer IN0 on which an IN1 interface layer is directly found (that is, there is no neither a first layer of low refractive index B1 nor a first high refractive index layer A1). About the interface layer IN1 is the metallic layer M and another interface layer IN1. TO then there is a layer of high refractive index A2 and a layer low refractive index B2. A2 nomenclature has been retained and B2 for these layers to be consistent with Fig. 2, although not they are "second layers" since there are no "first layers" In this specific case. However, in this specific case, you can ensure that the metallic layer M can supply the effect of the First layer of high refractive index A1. Also the layer of Initial interface IN0 collaborates in this regard.

Claims (26)

1. Ophthalmic and / or solar lens, which comprises a substrate of a polymeric material, and is coated with a hardener layer, characterized in that at least one of its surfaces is covered with a metal layer, where said metal layer is of a metal of the group formed by Cu, Ag, Al, Au, Ni, Ti, Cr, Mo, Pt, Rh, Zr and mixtures of the above, and a thickness between 1 and 20 nm, and because the visible reflection of said lens, calculated according to ISO 8980-4 (Rv), is less than 10%. 2. Lens according to claim 1, characterized in that said metallic layer is of a metal of the group formed by Cu, Ag, Pt, Al and Au, and preferably is Ag. 3. Lens according to one of claims 1 or 2, characterized in that said metal layer has a thickness between 5 and 15 nm. 4. Lens according to any one of claims 1 to 3, characterized in that between said hardener layer and said metal layer there is a first layer of low refractive index. 5. Lens according to claim 4, characterized in that said first layer of low refractive index has a thickness of less than 200 nm. 6. A lens according to one of claims 4 or 5, characterized in that between said first layer of low refractive index and said metallic layer there is a first layer of high refractive index. 7. A lens according to claim 6, characterized in that said first layer of high refractive index has a thickness of less than 100 nm, preferably between 20 and 50 nm. 8. Lens according to any of claims 1 to 7, characterized in that on said metallic layer there is a second layer of high refractive index. 9. A lens according to claim 8, characterized in that said second layer of high refractive index has a thickness of less than 100 nm, preferably between 20 and 50 nm. 10. Lens according to any of claims 6 to 9, characterized in that said first and second layers of high refractive index are of a group material consisting of oxides, nitrides or oxynitrides of Zr, Ti, Sb, In, Sn, Ce, Zn, Ta, Nb, Hf and mixtures of the foregoing are preferably ZrO2. 11. Lens according to any of claims 8 to 10, characterized in that on said second layer of high refractive index there is a second layer of low refractive index. 12. A lens according to claim 11, characterized in that said second layer of low refractive index has a thickness of less than 200 nm, preferably between 20 and 50 nm. 13. Lens according to any of claims 4 to 12, characterized in that said first and second layers of low refractive index are SiO2. 14. Lens according to any of claims 6 to 13, characterized in that between at least one of said layers of high refractive index and said metal layer there is an interface layer of a material of the group formed by Si, Cr, Ti, Ni , Ni / Cr, SnO_ {2}, Al_ {2} {3}, AlN, ZnO, SiO_ {x}, SiO / Cr, SiO_ {2} / Al_ {2} O_ {3}, ITO, and MoO_ {3}. 15. Lens according to claim 14, characterized in that said interface layer is less than 10 nm thick, preferably between 1 and 3 nm. 16. A lens according to any one of claims 1 to 15, characterized in that on said hardener layer there is an initial interface layer, wherein said initial interface layer is of a material of the group formed by Si, Cr, Ti, Ni, Ni / Cr , SnO_ {2}, Al_ {2} {3}, AlN, ZnO, SiO_ {x}, SiO / Cr, SiO_ {2} / Al_ {2} {3}, ITO, and MoO_ {3}, wherein said initial interface layer has a thickness less than 20 nm, preferably between 5 and 15 nm. 17. Lens according to any of claims 1 to 16, characterized in that it has a primer layer between said substrate and said hardener layer. 18. Lens according to claim 1, characterized in that it comprises, on said hardener layer, the following layer structure: [a] an ITO interface layer between 6 and 10 nm thick, [b] an interface layer of Cr between 1 and 3 nm thick, [c] said metallic layer, of Ag, between 6 and 12 nm thick, [d] an interface layer of Cr between 1 and 3 nm thick, [e] a layer of high refractive index, of ZrO2, between 20 and 30 nm thick, [f] a second layer of low index of refraction, SiO2, between 30 and 50 nm thick.

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19. Lens according to any of claims 1 to 18, characterized in that it comprises a hydrophobic outer layer, preferably perfluorinated. 20. A lens according to any one of claims 1 to 19, characterized in that it has a transmittance in the solar infrared spectrum T IR and a transmittance in the visible spectrum T V, both calculated according to EN 1836, such that its ratio T_ {V} / T_ {IR} is less than or equal to 1, with TV being less than 80%. 21. Lens according to any one of claims 1 to 19, characterized in that it has a transmittance in the solar infrared spectrum T IR of less than 80% and a transmittance in the visible spectrum T V, between 80% and 100% , both calculated according to EN 1836. 22. Lens according to any of claims 1 to 21, characterized in that it has an abrasion resistance value greater than 5, measured in BR units according to the Bayer test, according to the L-11-10-08 standard of Colts Laboratories. 23. Lens according to any of claims 1 to 22, characterized in that it has an abrasion resistance value of less than 0.2, measured in Haze units according to the Steel Wool test at 3 kg for 1 minute and with 0000 mesh, according to L-11-12-08 of Colts Laboratories. 24. Lens according to any one of claims 1 to 23, characterized in that it does not show visible deterioration after the tests of point 4.6.10.2 of immersion resistance to saline solutions and point 4.6.10.1 of severe abrasion of MIL standard are applied consecutively -F-48616A. 25. Lens according to any one of claims 1 to 24, characterized in that it has a square electrical resistivity value on the coated surface of less than 20 Ω / sgr, measured according to ASTM D-254. 26. Method of manufacturing an ophthalmic and / or solar lens according to any one of claims 1 to 25, characterized in that it comprises a deposition stage, by physical vapor deposition with evaporation by electron gun, on at least one of the surfaces of said lens, of said metallic layer.