MXPA97009675A - Conductivoelectricame anti-reflective cover - Google Patents

Abstract

The present invention relates to a method for manufacturing a high transmittance ophthalmic lens, comprising the steps of: providing a transparent ophthalmic lens, and forming, on a transparent ophthalmic lens surface, an anti-reflective coating substantially resistant to static and electrically conductive, by the reaction of a metal with an effective non-stoichiometric amount of oxygen, such that the coating comprises at least one layer of electrically conductive oxidized metal material.

Description

CONDUCTIVE I-REFLECTIVE COATING EI.ECTRICALLY DESCRIPTION OF THE INVENTION The present invention relates to anti-reflective coatings for transparent substrates such as ophthalmic lenses and particularly to a method for manufacturing anti-reflective coatings that are anti-static and easy to clean . Ophthalmic lenses have traditionally been made from a single integral glass or plastic body. Recently the lenses have been manufactured by laminating two lens wafers together with a transparent adhesive, regardless of how it is constructed, an ophthalmic lens may include an anti-reflective coating to improve the transmission of visible light. Conventional anti-reflective coatings comprise multilayer structures described for example in US Pat. Nos. 3, 432, 225 and 3, 565, 509. Conventional anti-reflective coatings have a hydrophobic outer layer, typically comprising a fluoroalkylchlorosilane, to promote soil resistance and facilitate cleaning. Despite the presence of this outer layer, the surfaces of ophthalmic lenses tend to attract particles that float in the air. In addition, oil contaminants on the surface of the lens tend to dirty it more than to clean it, making it difficult to keep the lenses in good condition. The present invention is directed to transparent articles such as ophthalmic lenses that are coated with an anti-reflective coating with inherent anti-static properties. In addition to not attracting dust and other particles from the air, the durable anti-reflective coating of the invention is also easy to clean, the anti-reflective coatings of the present invention do not require a hydrophobic outer layer. Therefore one aspect of the invention is directed to a method for manufacturing a high transmittance article comprising the steps of providing a transparent substrate and forming an electrically conductive and transparent anti-reflective coating on the surface of the substrate. Another aspect of the invention is directed to a method for manufacturing a high transmittance article comprising the steps of: providing a transparent substrate; forming, on a substrate surface, a multi-layer transparent anti-reflective coating, wherein at least one layer comprises a highly refractive but electrically conductive index material or a low-electrically conductive refractive index material. In another aspect of the present invention, this concerns an article of high transmittance comprising a transparent substrate; a transparent multilayer film comprising alternating layers of materials of a highly refractive index and low refractive index but both electrically conductive. In still another aspect, the invention relates to a statically resistant ophthalmic lens manufactured by a method comprising the steps of: providing a transparent substrate; and depositing a transparent multilayer anti-reflective coating on the substrate surface, wherein each layer comprises an electrically conductive material of high refractive index or an electrically conductive material with a low refractive index. In another aspect, the invention concerns a basically anti-static ophthalmic lens by a method comprising: providing a transparent substrate; and depositing on a substrate surface a transparent multilayer film comprising alternating layers of a high refractive index material and a low index material, wherein each layer is electrically conductive. In a preferred embodiment, the multilayer film comprises: i) a first layer having a refractive index of ca. 2.0 to 2.55 and comprises a first material of metal oxide; ii) a second layer having a refractive index of approx. 1.38 to 1.5 and comprise a second metallic oxide; iii) a third layer having a refractive index of approx. 2.0 to 2.55 and comprises the first metal oxide material; iv) a fourth layer that has a refractive index of 1.38 to 1.5 approx. comprising the second metal oxide material, wherein the refractive indices are measured with reference to a wavelength of 550 nanometers. In the preferred embodiment, the third layer is electrically conductive. In another preferred embodiment, the first and third layers comprise high refractive index materials selected from the group consisting of titanium oxides, niobium oxides and tantalum oxides and the second and fourth layers comprise silicon dioxide, for substrates comprising ophthalmic lenses, the lens surface will preferably have an electrical potential that is less than about 100 volts BRIEF DESCRIPTION OF THE DRAWINGS: Figure 1 is a partial cross-sectional view of an ophthalmic lens produced in accordance with the invention; Figure 2 is a schematic diagram of an ion assisted deposition apparatus used to produce the anti-reflective coating; Figure 3 is a graph of the electrostatic potential in relation to layers in a coating. The present invention is based in part on the discovery that by increasing the electrical conductivity in one or more layers of a multi-layer anti-reflective coating, antistatic characteristics are imparted to the coating. In fact, even when subjected to frictional forces, the inventive anti-reflective coating does not develop an appreciable amount of electrostatic charge. The inventive coating demonstrates improved resistance to grime and fogging as well as avoiding the need to employ a hydrophobic outer layer on the anti-reflective coating. The presence of that hydrophobic layer can negatively affect the optical characteristics of ophthalmic lenses including, for example, color consistency and reflectivity, increasing their production costs. However, before describing the invention in greater detail, the following terms will be described: The term "substrate" refers to a material that preferably has superior structural and optical properties. Crystalline quartz, fused silica, lime silicate glass and plastics based on allyl diglycol carbonate monomers [available as CR-39 from PPG Industries Inc. Hartford Conn) and polycarbonates such as LEXAN obtainable from General Electric Co are the preferred materials as substrates. Substrates include ophthalmic lenses (including sunglasses). Preferred ophthalmic lenses also include laminated lenses that are fabricated by joining two lens wafers (this is a front wafer and a back wafer) together with a transparent adhesive. Laminated lens wafers are described, for example, in U.S. Patents 5, 149,181 4,857,553 and 4,645, 317 and in British Application 2, 260, 937 A, which are incorporated herein. Commercially available ophthalmic plastic lenses that are covered with a scratch resistant polymer coating can have a thickness of 1 micron to 12 microns, and are also suitable substrates. The thickness of scratch-resistant plastic materials depends, in part, on the substrate material. Generally, plastic materials such as polycarbonates require thicker coatings. Suitable substrates include glass ophthalmic lenses, which are described for example in U.S. Patent 3,899,3145 and 3,899, 314 which are incorporated herein. In this description lens refers both to the integral body type alone and to the laminate. The term "antireflective coating" or "AR coating" refers to a transparent multilayer film that is applied to optical systems (e.g., surfaces thereof) to eliminate reflection in a relatively wide portion of the visible spectrum, and thus increase the transmission of light and reduce the surface reflectance. Known anti-reflective coatings include multilayer films comprising high and low refractive index materials, in turn, (for example metal oxides) as described in US Pat. Nos. 3, 432, 225, 3, 565, 509, 4, 022, 947 and 5, 332, 618. However, unlike the prior art, the AR coatings of the invention employ one or more electrically conductive layers of a high and / or low refractive index. The thickness of the AR coating will depend on the thickness of each individual layer in the multilayer film and the total number of layers in the film. The inventive AR coating can include any number of layers, preferably, the AR coating for ophthalmic lenses has about 3 to 12 layers, more preferably 4 to 7, and still more about 4. Preferably the AR coating has a thickness of 220 to 500nm. The term "adhesion layer" refers to a film or coating formed on the transparent substrate before depositing the multi-layer film of the anti-reflective coating. The adhesion layer promotes the coating bond before reflective to the substrate. Any suitable transparent material can be used to form the adhesion layer including chromium oxide. The use of an adhesion layer is optional and the selection of material employed will depend in part on the material of the substrate and on the one comprising the first layer of the anti-reflective multilayer coating. The thickness of the adhesion layer is not critical although preferably a thickness just enough is maintained to effectively bond the substrate to the coating, but having no optical effect. If the chromium is not sufficiently oxidized or the adhesion layer is too thick, then this layer will cause light and reduce transmission through the AR coating, the adhesion layer can be electrically conductive, which can improve the antistatic properties of the coating anti reflective The term "high refractive index material" refers to materials having a refractive index with a wavelength of 550nm, which is preferably greater than two zero points, more preferably from 2.1 to 2.55, and still more preferred from 2.2 to 2.4. The term "low refractive index" material refers to materials having an index with a wavelength of 550nm, which is preferably less than 1.5, more preferably between 1.38 to 1.5, and still more preferably from 1.45 to 1.46. The term antistatic refers to the ability of a material not to retain or develop an appreciable electrostatic charge. With respect to a coated ophthalmic lens according to the present invention, the lens surface preferably remains electrostatically neutral where the surface has an electrical potential that is less than about 100 volts, more preferably less than 75 volts, and still more preferably less than 50 volts. volts, when measured in the neutral or discharged state. By neutral or discharged state it is indicated that the lens surface has not been subjected to friction or other electrostatic charging generating process in the 5 seconds before the measurement. Then, charged state refers to the condition of a lens immediately and until after 5 seconds, after undergoing friction or other electrostatic charging generating process. Preferably for an ophthalmic lens coated with an anti-reflective, the coated lens surface has an electrical potential that is less than about 300 volts, and preferably from 0 to 500 volts, and more preferably from 0 to 300 volts or less, when measured immediately after of being rubbed with a fabric made of a synthetic, polyester or natural material, for example cotton, in addition to an ophthalmic lens coated with the anti-reflective coating, the surface of the lens will have an electrical potential that is less than 100 volts, preferably from 0 to 75 volts or less and more preferably from 0 to 50 volts or less in the 5 seconds after being rubbed. As one of the characteristics of AR coating is apparent, its ability to discharge or dissipate electrical charge and prevent charge formation is inventive. For the purposes of this invention, volts must include the magnitudes of both positive and negative voltage, so by saying that it has an electrical potential of 100 volts, it covers the space of -100 to + 100 volts. A preferred method for manufacturing a conductive AR coating is to employ electrically conductive materials with high and low refractive index and comprising metal oxides. These with high refractory indices include, for example, titanium oxides, cerium, bismuth, zinc, iron, niobium, tantalum, zirconium, chromium, tin, indium and mixtures thereof. Preferred materials of the above are the niobium and titanium oxides derived by vaporization or deposition reaction. Metal oxides with low refractive indices, include, for example, sackcloth oxides, suitable materials of low refractive index include aluminum and magnesium oxyfluoride. Alternatively, one or more of the metal oxide materials can be replaced with non-oxide materials having the necessary refractive index. For example, zinc sulphide can be used in a high index material and magnesium fluoride and thorium fluoride can be used in low index electrically conductive materials. These non-oxides are described in U.S. Patent 5,332,618.

The multilayer film forming the coating AR, comprises at least one layer that is electrically conductive, it is believed that the presence of one or more conductive layers prevents the formation of an appreciable load as it is continuously discharging. The result is an AR coating, which is at-static. The terms electrically conductive material with high refractive index and electrically conductive material with low refractive index, refers to high and low index materials, which are suitable for use in anti-reflective conductive coatings. Preferably, an electrically conductive material of high refractive index comprises a metal oxide having a high refractive index, and thus an electrically conductive material of low refractive index comprises a metal oxide having a low refractive index. A preferred method for manufacturing such materials is to synthesize a metal oxide in an environment, so that the metal oxide film is non-stoichiometric or sub-oxidized. The resulting metal oxide film has the properties described above. As described hereinafter, in non-stoichiometric metal oxides, the ratio of oxygen to metal is less than the theoretical stoichiometric ratio for any particular structure. (Metal oxides in which the proportion of oxygen metal is stoichiometric are referred to as dielectric materials that are not electrically conductive). However, the electrically conductive materials may also comprise a mixture of (1) stoichiometric metal oxides and (2) stoichiometric oxides or unreacted metal atoms. Methods for synthesizing non-stoichiometric metal oxides include reactive deposition and evaporation of the metal in oxygen deficient environments. It is known that stoichiometric titanium dioxide (that is, Ti02), has a specific conductivity of less than 10"lS / cm, while the value gives lO.iS/cm, thus the electrically conductive high index materials are expected, can be made by reacting titanium with a non-stoichiometric amount of oxygen, so that the titanium oxide produced has the nominal formula TiO *, wherein x is less than 2, preferably from 1.3 to 1.9995, more preferably from 1.5 to 1.9995, and still more preferably from 1.7 to 1.9995 TiOa is believed to be the predominant form of titanium oxide that is formed, however it is believed that other forms are also produced, thus unless otherwise indicated, TiOx represent all The titanium oxide forms produced should be noted that when titanium oxides are used as a layer of electrically conductive material with a high refractive index, the particular structure of the titanium oxides produced It is not critical, as long as the layer has the desired optical characteristics (refractive index and transparency) necessary for the coating and that the coated ophthalmic lenses have the already defined antistatic properties, when the AR coating, inventive is a multi-layer film. layers with a layer of electrically conductive material of low refractive index, expects that the low index materials can be manufactured by reacting silicon with a non-stoichiometric amount of oxygen, so that the silicon oxide has the nominal formula Si0", where x is less than 2, preferably from 1.5 to 1.99, more preferably from 1.7 to 1.99 cOy even more preferably from 1.8 to 1.99. Similarly, it is believed that Ci02 is the predominant form of silicon oxide formed, however it is believed that other forms are also produced. Unless otherwise stated, SiO ?, represent all forms of silicon oxide formed. Equally when using silicon oxides as a layer of low-index material, electrically conductive, the particular structure of the silicon oxides produced, it is not critical, as long as the layer has the necessary optical characteristics for the anti-reflective coating, and the coated ophthalmic lens has the antistatic properties. Thus, in general, the use of metal oxide materials to build a layer of high or low index material, the particular shape or structure is not critical, as long as the layer has the desired optical properties. In the case of forming a layer of high low index material, the other criterion is that the antireflective coating has antistatic properties. Since only one or more layers of the inventive coating film AR, need to be electrically conductive, it is understood that, except in the case where all the layers are electrically conductive, the other electrically non-conductive layers of the film may comprise materials conventional dielectrics, such as, titanium dioxide, for the high index layer and silicon dioxide for the low index layer. It is further understood that the term metal oxide refers to both conductive and non-electrically conductive oxides. Thus, for example, the titanium oxides comprise TiOx, electrically conductive, as well as titanium dioxide (that is Ti02), which is a dielectric, similarly, the silicon oxides comprise SiOx, electrically conductive, as well as silicon dioxide, ( this is Si02) which is a dielectric. When designing and manufacturing the multi-layer film of an anti-reflective coating, it must be taken into account when selecting the material for the conductive layer, the electrical conductivities of various metals, available to form suitable metal oxides. Preferably, high or low electrically conductive refractive materials should be formed of metals having the highest electrical conductivity. Another method for making electrically conductive materials is to first produce dielectric metal oxide films and then introduce dopants into the film. The dopant is selected from conductive materials that may be the same material as the metal. This technique is particularly suitable if a non-oxide is used (for example MgF2), the dopant can be introduced by any means, including diffusion and ion implantation. See for example Wolf & amp;; Tauber, "Silicon Processing for the VLSI Era", Vol. 1, pp. 242-332 (1986). The structure of the substantially transparent multilayer film of the inventive AR coating can be manufactured by conventional film deposition techniques (chemical and physical), including reactive deposition with chemical vapor and evaporation with electrons with or without ion assistance. These techniques are described in "Thin Film Process and Film Process II" editors Vossen & Kern, 1978 and 1991) Academic Press. The most suitable method will depend inter alia on the substrate (material and size) and the particular conductive metal oxides used. Electronic deposition techniques include the physical ejection of the material from a target as a result of the bombardment with ions. Ions are usually created by coalition between gas atoms and electrons in a luminescent discharge. The ions accelerate to the cathode of the target by an electric field. A substrate is placed in a suitable place, so that it intercepts a portion of the ejected atoms. Thus a coating is deposited on the surface of the substrate. In reactive deposition, a reactant gas forms a compound with the material that is deposited from the target. When the target is silicon and the reactive gas is oxygen, for example, silicon oxides, usually of Si02 form, are formed on the surface of the substrate. Another deposition technique is to first form a metal layer on a substrate and then expose this layer to a reactive gas (for example oxygen) to form a metal oxide. Deposition devices are described for example in U.S. Patents 5,047,131, 4,851,095 and 4,166,018. The chemical vapor deposition, is the formation of a non-volatile solid film on a substrate by the reaction of chemical reagents in vapor phase, cining the required constituents. The reactive gases are introduced into a reaction chamber and decompose and reacted by a hot surface to form the thin film. The conditions required to effect such depositions are well known in the art, for example, chemical vapor deposition, including chemical vapor deposition with low pressure (LPCVD), chemical vapor deposition enhanced by plasma (PECVD), chemical deposition of Photon-induced vapor (PHCVD), and the like described by Wolf & Tauber, "Silicon Processing for the VLSI Era", Vol. 1, pp. 161-197 (1986). Other film deposition techniques include electron beam evaporation and ion assist. In electron beam evaporation, a source of evaporation, the electron beam is used to vaporize the desired target material. The evaporated atoms condense on a substrate located inside the vacuum chamber, as cited in "Tim Film Processes II", on pages 79-132. In the assisted deposition of ions, the bombardment with low energy ions of the surface of the substrate during the deposition of evaporated atoms, provides surface cleaning, improved nucleation and growth and a tempering that produces evaporated coatings of improved quality. For a discussion of ion-assisted deposition, one can see Stelmack, et. al., "Review of Ion-Assisted Deposition: Research to Production" Nuclear Instruments and Methods in Physics Research B37 / 38 (1989) 787-793. A preferred embodiment of the invention is illustrated in FIG. 1, which comprises an ophthalmic lens 10, having an anti-reflective conductive coating deposited on a surface. The coating comprises four transparent, colorless layers 11-14 that are formed from at least two different materials, one being a high index, refractive material and the other a low index material. Layers 11-14, comprise an anti-reflective coating that is also referred to as "ARM stacking., before forming the AR stack, an adhesion layer 10A, comprising chromium oxides, is deposited on the surface of the substrate. Preferably the stacking AR, comprises alternating high and low index materials, so that each layer has a refractive index different from that of an adjacent layer. Preferably, the refractive index of each low index material is less than 1.5 at a wavelength of 550 nm, which is a preferred wavelength for the transmission of visible light, the refractive index of the high index material, is greater than 2.0 at a length of 550 μm, and each layer comprises an electrically conductive metal oxide. The first layer of the stack AR, which is formed on the substrate, or on the adhesion promotion layer which is optional, normally comprises a high index material. In the embodiment shown in Fig. 1, the layers 11, 13, comprise high index materials, wherein the layer 11, has a thickness of approximately 7 nm, at 15 nm. , more preferably from 9nm to 13nm, and still more preferably from ln to 12nm, and where layer 13, has a thickness of about 90nm to 130nm, more preferably from about lOOnm to 120nm, and still more preferably from 105nm to 115nm. Layer 11, the first layer of this four layer stack is designed. Layers 12 and 14 comprise a low index material wherein layer 12 has a thickness of about 15 nm to 40 nm, more preferably about 20 nm to 35 nm, and more preferably 23 nm to 31 nm, and where layer 14, it has a thickness of about 55nm to 105nm, more preferably 65nm to 95nm, and more preferably about 75nm to 85nm. The multilayer film forming the coating AR can comprise any number of layers of high / low index materials for most optical applications, it is desirable that Ar coatings reduce the reflectance of the surface to an extremely low value in a broad spectral region in order to maintain the proper balance of color The number of layers depends, among other things, on the substrate material, the desired anti-reflective properties and the compositions of the high / low index materials that are used. Generally the largest antireflection can be achieved by increasing the number of alternating layers of different index, but there is a concomitant decrease in the antireflexion spectral region. In addition, as described in US patents 3, 432, 255 (three layer design), 3, 565,509 (4 layer design) and 5,332, 618 (8 layer design), the mathematical formulas that have been developed to simulate Optical phenomena of anti-reflective coatings, have been to improve their design. The electron beam ion deposition apparatus employed to produce the Ar stacks of the present invention is shown in FIG. 2 and comprises a vacuum chamber 100 containing an ion gun 102 and an electron beam evaporation source 106 which are positioned at the base of the vacuum chamber. The diverter 108 separates the ion cannon from the source of the E beam. Located at the top of the chamber are the lenses 112 and the substrate support 110. The camera can be obtained from Balzer ltd. Balzer Liechtenstein as model Balzer 1200 Box Coater. It is equipped with Balzer EBS 420 Electron Beam. The ion cannon is a trademark of Com onwealth II Ion Source of Commonwealth Corp Alexandria Virginia. When a substrate (eg ophthalmic lenses) is operated it is placed in the substrate holder and a vacuum is subsequently created and maintained with the vacuum pump 114. initially the ion trigger 104 is closed to prevent the ion energy hit the substrate until the ion cannon has stabilized to the preset level. Similarly, trigger 113 covers the beam source -E until the target is close to evaporating. Argon is used as the ionizing gas from the ion cannon. Normally the surface of the substrate is subjected to ionic corrosion before the deposition of the chromium oxide adhesive layer, to produce a metal oxide layer, the beam source -E is activated to produce a metal evaporator of the required concentration . The oxygen from the oxygen source 116 reacts with the evaporator to form metal oxide which is deposited on the surface of the substrate. Subsequent layers of oxide are produced in a similar manner. The coatings Ar have the structure shown in Fig. 1 and were fabricated with the device of Fig. 2. representative functional parameters in the manufacture of a preferred AR coating and the characteristics of the individual layers are indicated in Table 1. used substrates were laminated to viewing lenses only each having a scratch resistant coating.

TABLE 1 Before beginning the deposition, the lens substrates were ultrasonically cleaned using deionized water and then the gas was removed at 95 ° for 2 hours, then the lenses were loaded onto the substrate holder and the pressure in the chamber was lowered to 6x10" ß mbar the surface of the substrate was subjected to ion corrosion for 4 minutes with the ion cannon operating at 0.9 A / 110 V. When forming the adhesive layer, the chromium white material was initially covered with the protector 113 a As the chromium was heated by the electron beam of the E-beam source, the protector was removed before the chromium evaporated, during the formation and deposition of the chromium oxide layer, the oxygen was introduced in sufficient quantity. to raise and maintain the pressure of the chamber to 8x15 at least 1 mbar.As it is apparent the ion cannon guard also removed during the deposition, the 4 successive layers comprising the coating Ar were deposited in a similar manner, preferably, the total pressure of the chamber was maintained at 2 x 10 at least 4 mbar or less through the deposition of each of the layers, the second layer of titanium oxide (layer 3) of the formed stack was found to be electrically conductive. The lenses covered with the AR coating of the Table 1 were tested for anti-static properties. To induce the formation of electrostatic charge, the coatings were rubbed with a rough cotton cloth free of lint and 100% polyester Luminex (Toray Industries Tokyo Japan) which are fabrics for cleaning lenses. The measurements were made in two separate environments, with and without air conditioning. Air conditioning tends to reduce the amount of moisture in the air and therefore affects the static properties. Three measurements were made for each lens. Prior to some rubbing, the lenses were removed from the packaging and allowed to acclimate to the environment for at least 30 minutes, the voltages on the front surfaces were measured with a static meter TI 300 (Static Control Services Inc. Palm Springs CA). Then each lens was rubbed with ten steps (forward and backward 10 cm at a time) on the appropriate cloth, and the electrostatic measurements were made immediately. The third measurement was made at 5 seconds of interval after the lenses had been rubbed. Between each measurement, the lenses were placed in front of an Endstat 2000 Deionizer (Static Control Services inc) to eliminate any residual static charge. The measurements are indicated in Table 2, and demonstrate that the lenses coated with the inventive coating Ar do not develop any static charge or only do so insignificantly. TABLE 2 No FRIC. FRIC. FRIC + without acón.aire rough cloth 0 -50 0 polyester fabric 0 100 0 with acón.aire rough cloth 0 -100 -25 polyester fabric 0 0 0 (measurements were made in volts).

The individual laminated vision lenses each having a scratch-resistant coating and coated with conventional anti-reflective coatings that included a hydrophobic outer layer were tested for anti-static properties in the manner described above, the stacking lenses were obtainable from various manufacturers of ophthalmic lenses. The results are indicated in Table 3 to 6. The degree of hydrophobicity of the outer surface of each coating Ar is proportional to its contact angle which was measured with a Tantee Angle meter obtainable from Tantee inc. Schaumberg IL. Tables 3 (rough cotton cloth) and 4 (polyester cloth) comprise measurements taken in a room without air conditioning. Similarly, Tables 5 (rough cotton cloth) and Table 6 9 polyester cloth) comprise measurements made with air conditioning. The measurements are in volts. As it is apparent, lens number 1 in each of tables 3-6 corresponds to the inventive lens in Table 2. Lenses 2-7 of Table 3 have the same antireflective coating as lenses 2-7 of the Table 4, respectively. Similarly lenses 2-9 of Table 5 have the same anti-reflective coatings as lenses 2-9 of Table 6, respectively. As apparent from the comparative data, the inventive AR coatings demonstrated superior anti-static properties compared to the prior art coatings obtainable from ophthalmic lens manufacturers. In addition, the inventive AR coating does not require an outer hydrophobic coating that was present in all conventional AR coatings that were tested. TABLE 3 Lenses No rubbing rubbing rubs + 5s contact angle 1 0 -50 0 31 * 2 -150 -700 --200 100 3 0 -950 - • 300 95 ° 4 -250 -1000 -500 100 5 -213 -2375 -1000 95 ° 6 -350 -3250 -2000 95 '7 -700 -4500 -2000 81 * TABLE 4 Lenses No rubbing rubbing rubs + 5s contact angle 1 0 100 0 31 ° 2 -150 -950 -325 100 3 0 -1350 -150 95 ° 4 -250 -1000 -500 100 5 -213 -4500 -2750 95 ° -350 -5500 -4000 95 ° -700 - 3000 -2250 81 ° TABLE 5 Lenses No friction or friction rotation + 5s contact angle 1 0 -100 -25 31 ° 2 -100 -800 -500 100"3 -150 -1750 -850 100 ° 4 0 -2000 -700 95" 5 -450 -3500 -2250 81 ° 6 -163 -4500 -3250 95 * 7 -500 -6500 -5000 95 ° 8 -250 -8500 -6000 100 * 9 -1250 -10000 -9500 95 * TABLE 6 Lenses No rubbing rubbing rubs + 5s contact angle 1 0 0 25 31 ° 2 -100 -2250 -450 95"3 -150 -1250 -600 100 ° 4 0 -2750 -650 100 ° 5 -450 -4500 -2250 81 ° 6 -163 -5875 -3500 95 ° 7 -500 -10000 -6000 95 * 8 • 250 -8000 -5000 100 * 9 1250 -10000 -9500 95 * Analysis layer by layer of the AR coating To determine the important effect, if any of the individual layers of the AR coating had anti-static properties of AR coatings, a layer-by-layer analysis of the five-layer AR coating described in Table 1 was made. In this analysis, five plastic front wafers were coated, each having a different number of layers ( used wafers were plastic and coated with a scratch resistant polymer layer.) The first wafer was coated with (1) only the chromium oxide adhesion layer, the second wafer was coated with (1) the oxide adhesion layer of chromium and (2) first TiOx, and so on subsequently so that the fifth wafer comprises the structure of cin After the formation of the five coated wafers, the voltage on the front surfaces of each wafer was measured with a TI 300 static meter. Each wafer was rubbed with ten carvings (forward and backward - 10 centimeters each way 0 on a rough cotton cloth free of blot and measurements were taken immediately.) In the third test, five seconds passed after the lenses were rubbed, As a control the electrostatic voltages of the two plastic front wafers 9 this is the controls 1 and 20 were also measured.Each control wafer was coated with a different scratch resistant polymer coating, the five tested wafers had the same Scratch-resistant coating than control 1. It was found that electrostatic charge remained high for the first, second and third wafer, however the fourth wafer comprising 91) the adhesive layer of chromium oxide, 92) the first layer TiOx, (3) the first layer Si02 and (4) the second layer TiO * showed a dramatic reduction in the electrostatic charge. The analysis showed that for the second TiOx X layer it was about 1.78. Thus at least with respect to the Ar coatings having alternating materials of high and low refractive index comprising titanium oxides and silicon oxides, the second high refractive index material is TiOx wherein x is from about 1.3 to 1.9995, more preferably from 1.5 to 1.9995, and still more preferably from 1.7 to 1.9995. It should be noted that although the examples show only two high and low index materials, namely silicon oxide and titanium oxide, in the particular design, similar anti-static coating structures can be made with two or more high-index materials. and / or two or more low index materials or even a material such as aluminum oxide of some intermediate refractory index. Also in certain cases, it may be advantageous to use mixtures of complex materials or compounds, a mixture of cerium oxide and zinc oxide can be used for the high index films and a mixture of silicon dioxide and magnesium fluoride can be used for the films of low index. Other blends can be selected to suit a particular deposition technique to take advantage of the physical or optical property of a material. Ophthalmic lenses having the antireflective coating preferably have a transmittance of 550 nm of between about 98.0 to 99.55 more preferably between 98.5 to 99.5% and more preferably between 99.0 to 99.55. Furthermore ophthalmic lenses have a reflectance at 500 nm of between 0.5 and 2.%, more preferably between about 0.5 to about 1.5% and still more preferable between about 0.5 to 1.0%. Although only one preferred embodiment has been presented, it will be appreciated that there are multiple changes and modifications without departing from the scope and scope of the present invention.

Claims (48)

1. R E I V I N D I C C O N E S 1.- a method for manufacturing an ophthalmic lens of high transmittance, which comprises the steps of; provide a transparent ophthalmic lens; and forming on a surface of the transparent ophthalmic lens, an anti-reflective coating resistant to static and electrically conductive, by the reaction of a metal with an effective non-stoichiometric amount of oxygen such that the coating comprises one or more layers of metal oxide material electrically conductive 2. Method according to claim 1, characterized in that the coating of the ophthalmic lens in the neutral state has an electric potential of approximately 100 volts. 3. The method according to claim 1 or 2, characterized in that the coating is formed by a deposition assisted with electron beam ions. 4. A method for manufacturing an ophthalmic lens of high transmittance comprising the steps of: providing a transparent ophthalmic lens; and forming on the surface of the ophthalmic lens, a transparent, multilayer, substantially static-resistant, anti-reflective coating, wherein at least one of the layers is electrically conductive. 5. The method according to claim 4 wherein the step of forming the coating comprises reacting a metal with an effective non-stoichiometric amount of oxygen so that the coating comprises one or more layers of electrically conductive metal oxide material. 6. The method according to claim 4 or 5, characterized in that each of at least one electrically conductive layer is formed by electron beam evaporation while the metal reacts with non-stoichiometric amounts of oxygen to form an electrically conductive metal oxide. 7. The method according to any of claims 4-6 characterized in that each of the at least one electrically conductive layer is a material of a high refractive index comprising niobium oxides. 8. The method according to any of claims 4-6 wherein each of at least one electrically conductive layer is of a high refractive index material comprising titanium oxides. 9. The method according to any of claims 4-8 wherein the multilayer anti-reflective coating comprises alternating materials of high index and low refractive so that each layer has a refractive index different from any adjacent layer, wherein the The refractive index of each low refractive index material is less than 1.5 at a wavelength of 550 nm, wherein the refractive index of each high refractive index material is greater than about 2.0 at a wavelength of about 550 nm, and wherein at least one layer comprises an electrically conductive metal oxide material. 10. The method according to any of claims 4-9 wherein the high refractive index material comprises titanium oxides and the low refractive index material comprises silicon oxides. The method according to any of claims 4-9 wherein the high refractive index material comprises niobium oxides and the low index material comprises silicon oxides. 12. The method according to any of claims 4-11 wherein the multilayer anti-reflective coating comprises: i) a first layer having a refractive index of about 2.0 to 2.55 and which is a thickness of 7 to 15nm; ii) a second layer that has a refractive index of approximately 1.38 to 1.5 and that is approximately 15 to 40 nm thick; iii) a third layer having an approximate refractive index of 2.0 to 2.55 and having a thickness of approximately 90 to 130 nm; and iv) a fourth layer having an approximate refractive index of 1.38 to 1.5 and having a thickness of approximately 55 to 105 nm, where the refractive indices are measured at a wavelength of 550 nm. 13. The method according to claim 12, wherein the third layer is electrically conductive. 14. The method according to any of claims 4-13 comprising the step of depositing an adhesion layer on the ophthalmic lens surface prior to forming the multi-reflective anti-reflective coating thereon. 15. The method according to any of claims 4-14 wherein the at least one electrically conductive layer is formed by the reactive tank while the metal reacts with non-stoichiometric amounts of oxygen 16. The method according to any of claims 1-15, wherein the coating has a thickness of about 200 to 500 nm. 17. The method according to any of claims 1-15, wherein the coating of the at least one electrically conductive layer is formed by ion-assisted deposition. 18. The method according to any of claims 4-16, wherein the at least one electrically conductive layer is formed by an electron beam assisted deposition. 19. The lens according to any of claims 4-16, wherein the electrically conductive metal oxide layer is formed by reactive electronic deposition. 20. The method according to any of claims 1-19, wherein the surface of the coating has an electrical potential that is less than 600 volts when measured immediately after being rubbed with a cloth. 21. The method according to any of claims 1-20 wherein the coating surface has an electrical potential that is less than 100 volts within 5 seconds after being rubbed with cloth. 22. The method according to any of claims 1-21 wherein the ophthalmic lens does not include an eternal hydrophobic layer on the anti-reflective coating. 23. an ophthalmic lens of high transmittance comprising: an ophthalmic lens substrate; and a static-resistant transparent multilayer film comprising alternating layers of high index and low refractive index materials, wherein at least one of the layers of the film is electrically conductive. 24. The ophthalmic lens according to claim 23, wherein the multilayer film comprises alternating low and high refractive index materials so that each layer has a refractive index different from any adjacent layer, wherein the index of refraction of each low refractive index material is less than 1.5 at a wavelength of 550 nm, wherein the refractive index of each high refractive index material is greater than about 2.0 at a wavelength of about 550 nm, and wherein at least one layer or more layers comprise non-stoichiometric metal oxides. 25. The ophthalmic lens according to claim 23 or 24, wherein the high refractive index material comprises niobium oxides. 26. The ophthalmic lens according to claim 23 or 24, wherein the high refractive index material comprises titanium oxides. 27. The ophthalmic lens according to any of claims 23-26 wherein the low refractive index material comprises silicon oxides. 28. The ophthalmic lens according to any of claims 23-27 further comprising an adhesion layer interposed between the substrate and the multilayer film. 29. The ophthalmic lens according to any of claims 23-28 wherein the multilayer film comprises: i) a first layer having a refractive index of about 2.0 to 2.55 and that is of a thickness of 7 to 15 nm; ii) a second layer that has a refractive index of approximately 1.38 to 1.5 and that is approximately 15 to 40 nm thick; iii) a third layer having an approximate refractive index of 2.0 to 2.55 and having a thickness of approximately 90 to 130 nm; and iv) a fourth layer having an approximate refractive index of 1.38 to 1.5 and having a thickness of approximately 55 to 105 nm, where the refractive indices are measured at a wavelength of 550 nm. 30. The ophthalmic lens according to claim 29, wherein the third layer is electrically conductive. 31. The ophthalmic lens according to claims 23-30, wherein the multilayer film on its surface has an electrical power that is less than about 600 volts when measured immediately after rubbing with a cloth. 32. The lens according to any of claims 22-30 wherein the surface of the multilayer film has an electrical potential that is less than 100 volts within 5 seconds after being rubbed with cloth. 33. The ophthalmic lens according to any of claims 22-30 wherein the ophthalmic lens does not include an eternal hydrophobic layer on the multilayer film. 34.- an ophthalmic lens manufactured by a method comprising the steps of; Provide a transparent ophthalmic lens substrate ; and depositing on the substrate surface, an anti-reflective, transparent coating, basically resistant to static multilayers where at least one layer is electrically conductive. 35.- The ophthalmic lens according to claim 34, wherein the step of depositing the coating comprises the reaction of a metal with an effective non-stechyraetric oxygen amount to form an electrically conductive metal oxide layer. 36. The ophthalmic lens according to claim 34 or 35 wherein the electrically conductive metal oxide layer is formed by electron beam evaporation. 37. The ophthalmic lens according to claim 35, wherein the electrically conductive metal oxide layer is formed by reactive electronic deposit. 38.- The ophthalmic lens according to claim 35, wherein the electrically conductive metal oxide layer is formed by ion-assisted deposition. 39. The ophthalmic lens according to claim 35, wherein the electrically conductive metal oxide layer is formed by electron beam assisted deposition. 40. An ophthalmic lens manufactured by a method comprising the steps of providing a transparent ophthalmic lens substrate; and depositing on a substrate surface, a transparent antistatic multilayer film comprising alternating layers of high and low refractive index materials wherein at least one of the layers is electrically conductive. 41. The ophthalmic lens according to claim 40 wherein the multilayer film of the ophthalmic lens in the neutral state has an electric potential less than about 100 volts. 42.- The ophthalmic lens according to claim 40 or 41 wherein the multilayer film comprises: alternating materials of high and low refractive index so that each layer has a refractive index different from any adjacent layer, wherein the refractive index of each low refractive index material is less than 1.5 at a wavelength of 550 nm, wherein the refractive index of each high refractive index material is greater than about 2.0 at a wavelength of approximately 550 nm. 43. The ophthalmic lens according to any of claims 40, 42, wherein the material of high refractive index comprises titanium oxides wherein the material of low refractive index comprises silicon oxides. 44. The ophthalmic lens according to any of claims 40-42 wherein the high refractive index material comprises niobium oxides and the low index material comprises silicon oxides. 45.- The ophthalmic lens according to any of claims 40-42 wherein the multilayer film comprises: i) a first layer having a refractive index of about 2.0 to 2.55 and having a thickness of 7 to 15 nm; ii) a second layer that has a refractive index of approximately 1.38 to 1.5 and that is approximately 15 to 40 nm thick; iii) a third layer having an approximate refractive index of 2.0 to 2.55 and having a thickness of approximately 90 to 130 nm; and iv) a fourth layer having an approximate refractive index of 1.38 to 1.5 and having a thickness of approximately 55 to 105 nra, where the refractive indexes are measured at a wavelength of 550 nm. 46. The ophthalmic lens according to claim 45, wherein the third layer is electrically conductive. 47. The ophthalmic lens according to any of claims 40-46 further comprising an adhesion layer located between the surface of the substrate and the multilayer film. 48. The ophthalmic lens according to any of claims 40-47 wherein the coating is formed by evaporation of electron beam ions. R E S UM E N An easy-to-maintain, earth-resistant, anti-reflective coating is provided on a transparent substrate (10). optionally a layer that promotes adhesion can be provided between the substrate and the anti-reflective coating. The anti-reflective coating comprises a multilayer film (11, 12) having alternating layers of high and low refractive index materials that are transparent in a wavelength region of 550nm. The multilayer film is formed by reacting metal with non-stoichiometric quantities of oxygen so that the coating has one or more layers of electrically conductive metal oxide material, the resulting conductivity prevents large static potentials from developing on the coated substrate. The coating is particularly suitable for ophthalmic applications.