Method and apparatus for precise coating of ophthalmic lenses with photochromic coatings

Abstract

A method of manufacturing an optical article (10) includes supplying a first coating composition (A) and supplying one or more additional coating compositions (B) to an ultrasonic discharge nozzle (102) of a coating device (100). At least one of the first coating composition (A) and the one or more additional coating compositions (B) is a photochromic coating composition. The method includes mixing a first coating composition and one or more additional coating compositions at an ultrasonic discharge nozzle (102) of a coating device (100), and applying a mixture (C) of the first coating composition (A) and the one or more additional coating compositions (B) to at least a portion of the optical article (10), thereby providing a pattern (24) on the optical article when exposed to actinic radiation. A mixture (C) of a first coating composition (A) and one or more additional coating compositions (B) is applied from an ultrasonic discharge nozzle (102) as a controlled, predetermined pattern of atomized droplets.

Description

[0001] This application is a divisional application of Chinese patent application No. 201680087692.5, filed on July 15, 2016, entitled "Method and Apparatus for Precisely Coating Ophthalmic Lenses with Photochromic Coating". Technical Field

[0002] This invention relates to a method of manufacturing optical articles, such as optical lenses, comprising coating the optical article with a mixture of a first coating composition and one or more other coating compositions in a controlled, predetermined pattern of atomized droplets on at least a portion of the optical article. The invention also relates to optical articles having such a coating. Background Technology

[0003] Regarding optical products, such as ophthalmic lenses, one or more surfaces may undergo treatments to enhance the overall performance and function of the optical product. Examples of such treatments include forming one or more coatings on the surface of the optical substrate, such as primer coatings, hard coatings, photochromic coatings, and / or anti-reflective coatings.

[0004] Light-transmitting optical articles made from polymeric materials are known in the art, wherein said optical articles include photochromic dyes. Gradient coatings for tinting optical articles (such as lenses) are also known in the art. The functional advantage of a tinting effect is that the lens typically has a higher color density in the first part of the lens, such as the top of the lens, for improved distance viewing, and a lower color density in the second part of the lens, such as the bottom of the lens. The tinting effect also adds an aesthetic effect to fashion and style.

[0005] Many different techniques can be used to apply one or more coatings to the surface of an optical substrate. In some instances, the optical substrate can be immersed in a liquid. After the optical substrate is pulled out of the liquid, the liquid forms a coating layer on one or more immersed surfaces of the optical substrate. In other instances, a liquid coating is deposited onto the surface of the optical substrate, and then the optical substrate is rotated at a high rate to spread the coating into a thin film covering the surface of the optical substrate. In various instances, one or more coatings can be heated or exposed to radiation, such as ultraviolet radiation, to cure the coating.

[0006] Generally, applying coatings to optical products requires precise control of film thickness to ensure uniform appearance and performance. Various methods are known to achieve gradient photochromic coatings on optical products. Typically, gradient dyeing of spectacle lenses is accomplished by immersing or submerging the lens in a dye bath. This process requires more precise and reproducible processing than solid dyeing or coloring. Furthermore, some optical substrates, such as polycarbonate lens materials, absorb dyes very poorly. While methods have been developed to overcome these processing difficulties, such methods often require additional manufacturing steps, thus increasing additional manufacturing costs.

[0007] There will be a need to develop new methods for producing optical articles using coating methods that produce precise film thicknesses on optical substrates. Additionally, there will be a need to provide cost-effective methods for preparing gradient photochromic optical elements, wherein light-absorbing compositions can be applied to the optical article with a controlled and predetermined gradient pattern on the surface, thereby generating the gradient pattern when the optical article is exposed to photochemical radiation. Summary of the Invention

[0008] According to some embodiments, a method of manufacturing an optical article may include supplying a first coating composition to an ultrasonic venting nozzle of a coating apparatus and supplying one or more additional coating compositions to the ultrasonic venting nozzle of the coating apparatus. At least one of the first coating composition and one or more additional coating compositions may be a photochromic coating composition. The method may further include mixing the first coating composition and one or more additional coating compositions at the ultrasonic venting nozzle of the coating apparatus and applying the mixture of the first coating composition and one or more additional coating compositions to at least a portion of the optical article, thereby providing a pattern on the optical article upon exposure to photochemical radiation. The mixture of the first coating composition and one or more additional coating compositions may be applied from the ultrasonic venting nozzle as a controlled, predetermined pattern of atomized droplets.

[0009] According to other examples, the pattern can be a gradient pattern. The gradient pattern can be linear, curved, radial, or a combination thereof. A gradient pattern can be formed by controlling the flow rate of the first coating composition relative to the flow rate of one or more other coating compositions. Controlling the flow rate of the first coating composition relative to the flow rate of one or more other coating compositions can change the concentration of the photochromic coating composition in the mixture. A gradient pattern can be formed by changing the thickness of the mixture on the optical article. A mixture of the first coating composition and one or more other coating compositions can be applied to the optical article as a coating with a uniform thickness. A mixture of the first coating composition and one or more other coating compositions can be applied to the optical article as a coating with a non-uniform thickness. A mixture of the first coating composition and one or more other coating compositions can be applied to the optical article in a single pass or multiple passes. The first coating composition can have one or more first reactive groups selected from isocyanates and epoxy groups. One or more other coating compositions can have second reactive groups selected from hydroxyl, thiols, primary amines, secondary amines, carbamates, and carboxylic acids. The first coating composition may have an isocyanate first reactive group and one or more other coating compositions may have a hydroxyl second reactive group. The optical article may be selected from optical lenses, filters, windows, visors, mirrors, and displays, preferably optical lenses, more preferably ophthalmic lenses. The ultrasonic emission nozzle may have a frequency of 48-120 kHz. The optical article can be obtained by the method described herein.

[0010] According to another example, an apparatus for applying material to an optical article may include a holder for holding the optical article and an ultrasonic emission nozzle for mixing a first coating composition with one or more other coating compositions. The ultrasonic emission nozzle can be configured to apply an atomized mixture of the first coating composition and one or more other coating compositions to at least a portion of the optical article. The apparatus may include tools for separately supplying the first coating composition and one or more other coating compositions to the ultrasonic emission nozzle, and a controller for positioning at least one of the holder and the ultrasonic emission nozzle relative to each other and controlling the coating operation of the ultrasonic emission nozzle before applying the atomized mixture to at least a portion of the optical article, thereby providing a pattern on the optical article upon exposure to photochemical radiation. The pattern may be a gradient pattern. The gradient pattern may be linear, curvilinear, radial, or a combination thereof.

[0011] These and other features and characteristics of the optical articles described herein, as well as the methods of manufacturing such articles, will become more apparent when considering the following description and appended claims, which form an integral part of this specification, with reference to the accompanying drawings, in which like reference numerals denote corresponding parts in the various figures. However, it should be clearly understood that the drawings are for illustrative and descriptive purposes only. Unless the context clearly indicates otherwise, as used in this specification and claims, the singular forms “a / an” and “the” include a plural of indicators. Attached Figure Description

[0012] Figure 1 A representative perspective view of an optical substrate having one or more coating layers, prepared according to the method of the present invention;

[0013] Figure 2 A representative cross-sectional side view of an optical article based on an example;

[0014] Figure 3 A representative perspective view of a coating apparatus used to apply one or more coatings to an optical article;

[0015] Figure 4 for Figure 3 A representative cross-sectional side view of the nozzle of the coating apparatus shown; and

[0016] Figure 5 A representative top view of an exemplary coating pattern and optical article obtained by the method according to the present invention.

[0017] Figure 6 This is a schematic diagram of the absorbance results of Examples 1 to 3 of this application.

[0018] exist Figure 1-5 In this context, unless otherwise specified, the same character represents the same component. Detailed Implementation

[0019] As used herein, the term "optics" means relating to or related to light and / or vision. For example, according to the various non-limiting examples disclosed herein, optical elements, articles, or devices may be selected from ophthalmic elements, articles, and devices, display elements, articles, and devices, goggles, windows, and mirrors.

[0020] As used herein, the term “ophthalmology” means relating to or concerning the eye and vision. Non-limiting examples of ophthalmic articles or components include corrective and uncorrective lenses, including single or multiple lenses, which may be segmented or non-segmented multiple lenses (e.g., but not limited to, bifocal, trifocal, and progressive lenses), and other components for correcting, protecting, or enhancing (through makeup or otherwise) vision, including but not limited to contact lenses, intraocular lenses, magnifying lenses, and protective lenses or goggles.

[0021] As used in this article, the term “ophthalmic substrate” refers to lenses, partially formed lenses, and lens blanks.

[0022] As used herein, the term "display" means a representation of information that is visible or machine-readable in the form of text, numbers, symbols, designs, or graphics. Non-limiting examples of display elements, articles, and devices include screens and monitors.

[0023] As used herein, the term “coating” means a supported film derived from a flowable composition, which may or may not have a uniform thickness, and specifically excludes polymer sheets.

[0024] As used herein, the term "sheet" refers to a preformed membrane having a generally uniform thickness and being self-supporting.

[0025] As used herein, the term “controlled, predetermined pattern” means a pattern formed by the managed and organized deposition of coating material in predetermined portions on a coated surface.

[0026] As used herein, the term “polymer” means homopolymer (e.g., prepared from a single type of monomer), copolymer (e.g., prepared from at least two types of monomers), and graft polymer.

[0027] As used herein, the term "(meth)acrylate" and similar terms such as "(meth)acrylate" mean methacrylate and / or acrylate. As used herein, the term "(meth)acrylic acid" means methacrylic acid and / or acrylic acid.

[0028] As used herein, the term "photochromic" and similar terms such as "photochromic compound" and "photochromic coating compound" mean having an absorption spectrum for at least visible radiation that changes in response to the absorption of at least photochemical radiation. Additionally, as used herein, the term "photochromic material" means any substance suitable for the photochromic properties of a display (i.e., suitable for having an absorption spectrum for at least visible radiation that changes in response to the absorption of at least photochemical radiation), and includes at least one photochromic compound.

[0029] As used herein, the terms "photochromic compound," "photochromic composition," and "photochromic coating composition" include both thermally reversible and non-thermally reversible photochromic compounds. The term "thermally reversible photochromic compound / material" as used herein means a compound / material capable of transitioning from a first state, such as a "transparent state," to a second state, such as a "colored state," in response to photochemical radiation and returning to the first state in response to thermal energy. The term "non-thermally reversible photochromic compound / material" as used herein means a compound / material capable of transitioning from a first state, such as a "transparent state," to a second state, such as a "colored state," in response to photochemical radiation and returning to the first state in response to photochemical radiation of one or more wavelengths substantially the same as the absorption of the colored state (e.g., continuous exposure to such photochemical radiation).

[0030] As used herein, the term “reactive group” means a group of atoms or combinations of atoms in a chemical structure that is intended or can be reasonably expected to undergo a chemical reaction when exposed to a reactive structural portion.

[0031] The terms "first" and "second" used herein to modify the term "state" are not intended to refer to any particular order or chronology, but rather to two different conditions or properties. For purposes of non-limiting illustration, the first and second states of the photochromic compound in the photochromic layer may differ in at least one optical property, such as, but not limited to, absorption of visible and / or UV radiation. Thus, according to the various non-limiting examples disclosed herein, the photochromic compound in the photochromic layer may have different absorption spectra in each of the first and second states. For example, but not limited herein, the photochromic compound in the photochromic layer may be transparent in the first state and colored in the second state. Alternatively, the photochromic compound in the photochromic layer may have a first color in the first state and a second color in the second state.

[0032] As used herein, the term "photosensitive material" means a material that is physically or chemically responsive to electromagnetic energy, including, but not limited to, phosphorescent and fluorescent materials.

[0033] As used herein, the term “non-photosensitive material” means a material that is not physically or chemically responsive to electromagnetic energy, including, but not limited to, static dyes.

[0034] As used herein, the term "hue" explicitly means a pure color, such as "green," "red," or "magenta," and includes mixtures of two pure colors, such as "red-yellow" (i.e., "orange") or "yellow-green." As used herein, the term "color density" refers to the optical density of an area on the surface of an optical element printed with a colorant composition when exposed to photochemical radiation. Higher color density results in a lower percentage of light transmission. For the purposes of this invention, the bottom of the lens is closest to the wearer's cheekbone, and the top of the lens is closest to the wearer's forehead. This linear gradient color pattern should differ from radial gradient color patterns known in the art, such as color patterns used in conjunction with lenses (where the color density varies radially outward from the center point of the lens to the outer periphery).

[0035] As used in this article, the term “ultrasound” refers to one or more sound waves having frequencies higher than approximately 20,000 Hz (20 kHz).

[0036] As used herein, the terms “formed over,” “deposited over,” “provided over,” “applied over,” “formed over,” “located over,” or “positioned over” mean formed, deposited, provided, applied, situated on, or positioned on or on the surface of a lower element, but not necessarily in direct (or adjacent) contact with the lower element or its surface. For example, a layer “positioned over a substrate” does not preclude the presence of one or more other layers, coatings, or films of the same or different composition located between the positioned or formed layer and the substrate.

[0037] As used herein, spatial or directional terms such as “left,” “right,” “up,” “down,” “inner,” “outer,” “above,” “below,” etc., refer to various features depicted in the accompanying drawings. However, it is to be understood that various alternative directions may be taken, and therefore these terms should not be considered limiting.

[0038] As used herein, the term “substantially parallel” means the relative angle between two objects (if extended to the theoretical intersection), such as the elongated objects and including the reference line, is 0° to 5°, or 0° to 3°, or 0° to 2°, or 0° to 1°, or 0° to 0.5°, or 0° to 0.25°, or 0° to 0.1°, including the values ​​recorded.

[0039] Unless otherwise specified, all ranges or proportions disclosed herein shall be understood to include any and all subranges or subproportions included therein. For example, the range or proportion indicated by “1 to 10” shall be considered to include any and all subranges (inclusive) between the minimum value of 1 and the maximum value of 10; that is, all subranges or subproportions that begin above the minimum value of 1 and end at the maximum value of 10, such as, but not limited to, 1 to 6.1, 3.5 to 7.8, and 5.5 to 10.

[0040] Except as described in the operational examples or otherwise, all figures used in the specification and claims to indicate the amount of ingredients, reaction conditions, etc., should be understood to be modified by the term "about" in all cases.

[0041] Unless otherwise specified, all references cited herein, such as but not limited to published patents and patent applications, shall be considered “incorporated by reference” in their entirety.

[0042] Optical products

[0043] In various instances, this disclosure generally relates to optical article 10. Optical article 10 may be selected from ophthalmic articles or components, display articles or components, goggles, windows, mirrors, active liquid crystal cell articles or components, and passive liquid crystal cell articles or components.

[0044] See Figure 1 The optical article 10 has a frontal or top surface 12, a rearward or bottom surface 14, and a side surface 16 extending between the top surface 12 and the bottom surface 14. When the optical article 10 is an ophthalmic lens, the bottom surface 14 faces the eye of the individual wearing the optical article 10, the side surface 16 is typically located within a support frame, and the top surface 12 faces incident light (not shown), at least a portion of which passes through the optical article 10 and enters the individual's eye. In some instances, at least one of the top surface 12, the bottom surface 14, and the side surface 16 may be a convex, concave, or planar surface, or a combination of one or more of these surfaces.

[0045] See Figure 2 The optical article 10 typically includes an optical substrate 20. The optical article 10 further has a first coating layer 22 applied over at least a portion of at least one of the surfaces of the optical article 10, such as a top surface 12, a bottom surface 14, and a side surface 16. The optical article 10 may optionally include one or more additional coating layers 24 applied over at least a portion of the first coating layer 22. In some instances, the first coating layer 22 and / or one or more additional coating layers 24 may be a mixture of a first coating composition and one or more additional coating compositions.

[0046] According to some embodiments of the present invention, the optical article 10 has an optical substrate 20 having an outer surface 26 that generally defines the overall external physical shape of the optical article 10. The outer surface 26 of the optical substrate may define at least a portion of the top surface 12, bottom surface 14, and / or side surface 16 of the optical article 10 (shown in…). Figure 1 (in Chinese). In several embodiments of this disclosure, at least a portion of the outer surface 26 of the optical substrate 20 may have a concave surface, a convex surface, or a planar surface, or a combination of one or more of these surfaces. In some embodiments, portions of the outer surface 26 may have a coating layer, such as a first coating layer 22 or one or more additional coating layers 24, which are applied directly to the outer surface 26 of the optical substrate 20.

[0047] Examples of ophthalmic articles or components include, but are not limited to, corrective and uncorrective lenses, including single or multiple vision lenses, which may be segmented or non-segmented multiple vision lenses (e.g., but not limited to, bifocal lenses, trifocal lenses, and progressive lenses), and other elements for correcting, protecting, or enhancing (by makeup or otherwise) vision, including but not limited to contact lenses, intraocular lenses, magnifying lenses, and protective lenses or goggles.

[0048] Examples of display articles, components, and devices include, but are not limited to, screens, monitors, and safety elements, including but not limited to safety markings and certification marks.

[0049] Examples of windows include, but are not limited to, transparent elements in automobiles and aircraft, filters, blinds, and optical switches.

[0050] Optical substrate 20 may include inorganic materials, organic polymer materials, and combinations thereof. Optical substrate 20 may, in some instances, be an ophthalmic substrate. Non-limiting examples of organic materials suitable for forming ophthalmic substrates include, but are not limited to, art-recognized polymers that can be used as ophthalmic substrates, such as organic optical resins used to prepare optically transparent castings for optical applications, such as ophthalmic lenses.

[0051] Non-limiting examples of inorganic materials suitable for use in the optical substrate 20 of the optical article 10 forming the present disclosure include glass, such as silica-based glass, minerals, ceramics, and metals. For example, in one non-limiting example, the optical substrate 20 may include glass.

[0052] Non-limiting examples of organic materials that can be used to form the optical substrate 20 of the optical article 10 of this disclosure include polymeric materials, such as homopolymers and copolymers, prepared from monomers or mixtures of monomers disclosed in U.S. Patent 5,962,617 and U.S. Patent 5,658,501, paragraph 28 through paragraph 17 of column 15, the disclosure of which is specifically incorporated herein by reference. For example, such polymeric materials can be thermoplastic or thermosetting polymeric materials, can be transparent or optically clear, and can have any desired reflectivity. Non-limiting examples of such disclosed monomers and polymers include: polyol (allyl carbonate) monomers, such as allyl diethylene glycol carbonates, like diethylene glycol bis(allyl carbonate), whose monomers are sold under the trademark CR-39 by PPGindustries, Inc.; polyurea-polyurethane (polyurea-urethane) polymers, which are prepared, for example, by reacting a polyurethane prepolymer with a diamine curing agent, a composition of such polymers being sold under the trademark TRIVEX by PPGindustries, Inc.; polyol (meth)acryloyl-terminated carbonate monomers; diethylene glycol dimethacrylate monomers; ethoxylated phenolic methacrylate monomers; diisopropenylbenzene monomers; ethoxylated trimethylolpropane triacrylate monomers; ethylene glycol dimethacrylate monomers; poly(ethylene glycol) dimethacrylate monomers; Carbamate acrylate monomers; poly(ethoxylated bisphenol A dimethacrylate); poly(vinyl acetate); poly(vinyl alcohol); poly(vinyl chloride); poly(vinylidene chloride); polyethylene; polypropylene; polyurethane; polythiocarbamate; thermoplastic polycarbonate, such as a resin derived from bisphenol A and phosgene-linked carbonates, one such material being sold under the trademark LEXAN; polyester, such as material sold under the trademark MYLAR; poly(ethylene terephthalate); polyvinyl butyral; poly(methyl methacrylate), such as material sold under the trademark PLEXIIGLAS; and polymers prepared by reacting polyfunctional isocyanates with polythiols or polycyclic sulfur monomers, which are homopolymers or copolymers and / or trimers with polythiols, polyisocyanates, polyisothiocyanates, and optionally alkenyl unsaturated monomers or halogenated aromatic vinyl monomers. Copolymers of such monomers and blends of the described polymers and copolymers with other polymers are also considered, for example, to form block copolymers or interpenetrating network products.

[0053] Coating layer

[0054] According to some other examples of this disclosure, the optical article 10 includes an optical substrate 20 having an outer surface 26 and a first coating layer 22 applied over at least a portion of the outer surface 26. The first coating layer 22 may be optically transparent (without color hue), or may have a desired color hue. In some other examples, the first coating layer 22 may include a static dye, a photochromic material, or a combination of two or more thereof, as will be discussed in further detail herein.

[0055] The method of the present invention further includes forming a first coating layer 22 over at least a portion of the outer surface 26 of the optical substrate 20. In some instances, the first coating layer 22 may be formed over the entire outer surface 26, such as the outer surface 26 corresponding to the top surface 12 of the optical component 10. The first coating layer 22 may be conformal to the outer surface 26 or may form a planar surface over the outer surface 26, such as... Figure 2 As depicted herein. When the first coating layer 22 conforms to the outer surface 26, the morphology of the outer surface 26 remains on the surface of the first coating layer 22 opposite to the surface at the interface between the first coating layer 22 and the outer surface 26. In various embodiments, the first coating layer 22 may be applied as a mixture of at least two coating compositions using an ultrasonic emission nozzle of a coating apparatus over at least a portion of the outer surface 26 of the optical substrate 20, as described herein.

[0056] In some instances, one or more additional coating layers 24 may be formed over the first coating layer 22. In some instances, one or more additional coating layers 24 may be formed over the entire surface of the first coating layer 22. The second coating layer 24 may be conformal to the first coating layer 22, or it may form a planar surface over the outer or top surface of the first coating layer 22, such as... Figure 2 As described herein, at least one of the first coating layer 22 and one or more additional coating layers 24 may be applied as a mixture of at least two coating compositions using an ultrasonic emission nozzle of a coating apparatus over at least a portion of the outer surface 26 of the optical substrate 20.

[0057] The first coating layer 22 and other optional films and / or layers (e.g., but not limited to one or more additional coating layers 24) formed on or above the optical article 10 each have at least sufficient clarity to allow observation of the electromagnetic energy source through the optical article 10 and reflection of electromagnetic energy incident on the surface of the optical article 10. In some instances, the first coating layer 22 and one or more additional layers 24 each independently have a percentage transmittance greater than 0% and less than or equal to 100%, such as 50% to 100%. In other instances, the first coating layer 22 and one or more additional coating layers 24 have at least sufficient reflectivity to allow reflection of at least a portion of the electromagnetic energy incident on the outer surface of the optical article 10.

[0058] Coating method and apparatus

[0059] As discussed herein, the present invention relates to a method and apparatus for preparing optical articles having patterns, such as linear gradient patterns, on their surfaces when exposed to photochemical radiation. For the purposes of this invention, a “gradient pattern” is achieved by depositing a coating composition, such as a photochromic composition (via a coating apparatus having an ultrasonic emission nozzle), onto at least one surface of the optical article 10 in such a manner that a gradual, visually perceptible change in hue and / or color density occurs over a region of the optical article 10 when the optical article 10 is exposed to photochemical radiation.

[0060] See Figure 3 Optical articles 10 can be produced using a coating apparatus 100, such as a coating apparatus 100 with an ultrasonic emission nozzle 102. The coating apparatus 100 is configured to apply coating material in the form of extremely fine microdroplets onto one or more surfaces, such as an optical substrate 20. The emission device associated with the coating apparatus 100, such as the ultrasonic emission nozzle 102, has one or more nozzles associated with it. Each nozzle is configured to controllably emit multiple microdroplets of coating material in a continuous or on-demand manner. The controller can control the size of the droplets (the volume of the coating material) and the rate at which the droplets are formed and delivered.

[0061] Ultrasonic spray coating (atomization) technology is a method that uses high-frequency sound waves to generate atomized sprayed liquids. For example, a metal diaphragm vibrating at an ultrasonic frequency can be used to generate atomized liquid droplets. The resulting droplets can be precisely targeted to the surface to be coated. The ultrasonic emission nozzle 102 typically operates at a specific resonant frequency determined primarily by the length of the ultrasonic emission nozzle 102. The two free ends of the ultrasonic emission nozzle 102 should be antinodes (points of maximum vibration amplitude). The ultrasonic emission nozzle 102 generates sinusoidal longitudinal standing waves, thereby eventually reaching a critical amplitude at which the height of the capillary waves exceeds the height required to maintain their stability. As a result, the capillary waves collapse and eject liquid droplets from the top of the degenerated waves onto the atomized surface of the ultrasonic emission nozzle 102.

[0062] Ultrasonic atomization has been advantageously found, as used in various embodiments according to the invention, to help impart improved process control and precise, uniform, thin film coatings to the lens. Existing and known ultrasonic atomizers (e.g., ultrasonic spray devices for the electronics industry, i.e., devices having ultrasonic emission nozzles including piezoelectric sensors, grounding and active electrodes, and atomizing surfaces) can be used in the invention. Various types of ultrasonic nozzles can be used, such as Sono-Tek... TM 48kHz Impact Style Ultrasonic Nozzle, Model: 06-04-00918-003. The ultrasonic spray power is preferably set between 0.5 watts and 12 watts for the 48kHz nozzle and between 0.5 watts and 5.5 watts for the 120kHz nozzle. It should be noted that the ultrasonic spray power is a parameter that can be adjusted as needed, for example, depending on the density and / or viscosity of one or more coating compositions used.

[0063] See Figure 4An exemplary ultrasonic discharge nozzle 102 has a housing 120 having at least one liquid feed channel extending through the housing 120. The housing 120 has a diaphragm (not shown) that vibrates at an ultrasonic frequency to generate atomized liquid droplets. In some instances, the housing 120 has a first liquid channel 122 and a second liquid channel 124 extending therethrough. The first liquid channel 122 and the second liquid channel 124 extend through the housing 120 substantially parallel to each other. In some instances, the first liquid channel 122 and the second liquid channel 124 may be coaxial, such that one of the first liquid channel 122 and the second liquid channel 124 extends through an aperture of the other of the first liquid channel 122 and the second liquid channel 124. Each of the first liquid channel 122 and the second liquid channel 124 has a first end 126 opposite a second end 128 along a longitudinal axis. The first end 126 of each of the first liquid channel 122 and the second liquid channel 124 is in fluid communication with a reservoir 110 for receiving at least one coating composition. For example, the first end 126 of the first liquid channel 122 may be in fluid communication with a first portion of the reservoir 110 to receive the first coating composition A, while the first end 126 of the second liquid channel 124 may be in fluid communication with a second portion of the reservoir 110 to receive one or more additional coating compositions B. At least one of the first coating composition A and one or more additional coating compositions B may be a photochromic coating composition.

[0064] Continue to refer to Figure 4 The second ends 128 of the first liquid channel 122 and the second liquid channel 124 terminate in a nozzle 130 having an atomizing surface 132. The nozzle 130 has a first outlet 134 for delivering fluid through the first liquid channel 122 and a second outlet 136 for delivering fluid through the second liquid channel 122. In some instances, the first outlet 134 may be configured to deliver a first coating composition through the first liquid channel 122, while the second outlet 136 may be configured to deliver one or more additional coating compositions through the second liquid channel 122. As the first coating composition and one or more additional coating compositions are delivered to the atomizing surface 132 of the nozzle 130, the coating compositions are mixed at the nozzle 130 and atomized into an atomized mixture C by the ultrasonic vibration of the ultrasonic discharge nozzle 102, which is then deposited onto the coating surface of the optical article 10.

[0065] In various examples, one or more ultrasonic emission nozzles 102 can be controlled to apply a coated layer of uniform or non-uniform thickness in a controlled, predetermined pattern of atomized droplets. For example, one or more ultrasonic emission nozzles 102 can apply a coating with a substantially uniform thickness over the entire coated surface of the optical substrate 20. In various examples, the thickness of the coated layer on the coated surface can be a minimum of 1 μm to a maximum of 40 μm, preferably 5 μm to 25 μm. The density of droplets of coating material deposited on the coated surface can be between 725 drops per inch and a maximum of 1400 drops per inch. In various examples, the amount applied can be controlled in regions of the optical substrate 20, taking into account the movement of the coating material on the curved surface of the optical substrate 20. For example, on a convex optical substrate 20, the amount of coating material applied on the radially inner portion of the optical substrate 20 can be higher than the amount of coating material applied on the radially outer portion of the optical substrate 20, thereby forming a coated layer with a uniform thickness. Alternatively, the nozzle height can be variably adjusted along the Z-axis as the nozzle moves across the lens surface to maintain a constant height. In other examples, the coating layer may have a non-uniform thickness across different portions of the optical substrate 20.

[0066] See Figure 3 The coating apparatus 100 includes a housing 104 having a workpiece holder 106 and one or more ultrasonic venting nozzles 102. In some embodiments, the workpiece holder 106 may be configured to securely hold the optical articles 10 during the coating process. Multiple optical articles 10 may be secured within the workpiece holder 106. Each optical article 10 is held within the workpiece holder 106 such that the surface of the optical article 10 to be coated (“coating surface 105”) faces the one or more ultrasonic venting nozzles 102. During the coating process, the ultrasonic venting nozzles 102 are desiccated at a predetermined height above the optical articles 10, for example, such that the tip of the ultrasonic venting nozzle 102 is preferably about 10 mm to about 60 mm above the coating surface 105, and preferably about 25 mm to about 45 mm. In some embodiments, the plane of the coating surface 105 may be substantially perpendicular to the downward direction of the coating spray ejected from the one or more ultrasonic venting nozzles 102. In other examples, the plane of the coating surface 105 may be at an angle between about 10 degrees and about 45 degrees, and preferably about 20 degrees and about 30 degrees, relative to the direction of the paint spray ejected from one or more ultrasonic emission nozzles 102. In some examples, a workpiece holder 106 may be constructed to hold a frame, such as an eyeglass frame, with an optical article 10 mounted therein. Multiple frames may be secured within the workpiece holder 106.

[0067] The workpiece holder 106 can be fixed or movable relative to the ultrasonic emission nozzle 102. In one example, the workpiece holder 106, together with the optical substrate 20 to which it is fixed, is held securely on a base platform 107, while one or more ultrasonic emission nozzles 102 are connected to a movable arm 108. In another example, as in... Figure 3 As shown, the workpiece holder 106 can be positioned on a track that is linearly movable along the base platform 107. The movable arm 108 can be movable on one, two, or three axes to position one or more ultrasonic emitting nozzles 102 at desired locations relative to the workpiece holder 106 and one or more optical substrates 20. Alternatively, the movable arm 108 can be rotatable about one, two, or three axes. In this way, the movable arm 108 can have up to six degrees of freedom (translation on three axes and rotation about three axes) to move the ultrasonic emitting nozzles 102 relative to the workpiece holder 106, thereby positioning the ultrasonic emitting nozzles 102 at predetermined positions relative to the optical substrates 20. The movable arm 108 can be moved manually, or its movement can be controlled by one or more motors electronically communicated with a controller. The movement of the movable arm 108 can be predetermined, such as by computer-executable instructions executed by the controller.

[0068] In some instances, the workpiece holder 106 may be movable with up to six degrees of freedom while keeping one or more ultrasonic venting nozzles 102 stationary. In some aspects, the workpiece holder 106 and the movable arm 108 may be movable with up to six degrees of freedom. In instances with more than one ultrasonic venting nozzle 102, each ultrasonic venting nozzle 102 may be movable with up to six degrees of freedom independently of any other ultrasonic venting nozzle 102. An uncoated optical substrate 20 may be loaded in the workpiece holder 106, and then the surface of the optical substrate 20 may be coated using one or more ultrasonic venting nozzles 102. The coated optical substrate 20 may then be removed from the workpiece holder 106 to allow for the loading of subsequent uncoated optical substrates 20. In some instances, multiple workpiece holders 106 (not shown) may be provided on a continuously moving base 107, thereby enabling the coating of multiple optical substrates 20 in a continuous process.

[0069] Each ultrasonic emission nozzle 102 is in fluid communication with a reservoir 110. Fluid from the reservoir 110 can be delivered to the ultrasonic emission nozzle 102 by one or more pumps, syringes, or other fluid delivery tools. When the coating apparatus 100 has more than one ultrasonic emission nozzle 102, a separate reservoir 110 can be provided for each ultrasonic emission nozzle 102. In some instances, at least two of a plurality of ultrasonic emission nozzles 102 can be connected to a common reservoir 110. Each reservoir 110 is configured to store a coating composition 112 to be delivered to one or more ultrasonic emission nozzles 102. In this way, multiple different coating materials can be deposited simultaneously on the same optical substrate 20 using multiple ultrasonic emission nozzles 102 to produce a variety of coatings and colors. Thus, the first coating layer 22 and / or one or more additional coating layers 24 can be formed as a mixture of two or more coating compositions. In one example, a first reservoir 110 may store a first coating composition, and one or more additional reservoirs 110 may each store one or more additional coating compositions to be delivered to an ultrasonic emission nozzle 102 and deposited as an atomized mixture of the first coating composition and one or more additional coating compositions. In other examples, a first coating layer 22 and / or one or more additional coating layers 24 may be formed from a single coating composition applied in one or more successive layers. Various additional devices, such as heaters, mixers, etc., may be connected to each reservoir 110 for preparing the coating material and then delivering it to one or more ultrasonic emission nozzles 102. In some examples, the viscosity of the coating composition may be controlled, such as by increasing or decreasing the viscosity of the coating material in the reservoir 110. In another example, the coating composition may also be heated within the reservoir 110 to control the coating viscosity before delivering the coating material to the substrate. The preferred viscosity range of the coating composition is from about 5 cps to about 80 cps, preferably from about 30 cps to about 60 cps. Preferred coating compositions desirably comprise solvent-based coatings having a viscosity of about 0.3 cps to about 5 cps.

[0070] In some examples, multiple ultrasonic emission nozzles 102 can be arranged in an array. The multiple ultrasonic emission nozzles 102 can be arranged parallel to each other in a direction angular to the direction in which they move relative to the optical substrate 20. An angular offset of the ultrasonic emission nozzles 102 allows for complete coverage of the optical substrate 20 of various shapes and sizes. In other examples, the ultrasonic emission nozzles 102 can be arranged linearly adjacent to each other in a direction substantially parallel or perpendicular to the direction in which they move relative to the optical substrate 20. The ultrasonic emission nozzles 102 can be offset from each other by a minimum of 0.5 mm to a maximum of 5 mm, preferably 2 mm to 3 mm. In other examples, the distance between the optical substrate 20 and the nozzles of the ultrasonic emission nozzles 102 can be a minimum of 10 mm to a maximum of 60 mm, preferably 25 mm to 45 mm.

[0071] During the coating process, coating materials, such as those used to apply the first coating layer 22 or one or more additional coating layers 24 (shown in...), can be applied. Figure 2 The coating material is applied to the optical substrate 20 in a single pass, wherein the optical substrate 20 is kept stationary and one or more ultrasonic emission nozzles 102 are moved, or wherein the optical substrate 20 is moved and one or more ultrasonic emission nozzles 102 are kept stationary, or wherein both the optical substrate 20 and one or more ultrasonic emission nozzles 102 are moved or kept stationary. A single pass can be performed using a single ultrasonic emission nozzle 102 or multiple ultrasonic emission nozzles 102. In some instances, the coating material can be applied to the optical substrate 20 in two or more passes, wherein the optical substrate 20 is kept stationary and one or more ultrasonic emission nozzles 102 are moved, or wherein both the optical substrate 20 and one or more ultrasonic emission nozzles 102 are moved or kept stationary. Two or more passes can be performed using a single ultrasonic emission nozzle 102 or multiple ultrasonic emission nozzles 102.

[0072] See Figure 5The spray pattern 113 from one ultrasonic exhaust nozzle 102 may at least partially overlap with the spray pattern 113 from at least one other ultrasonic exhaust nozzle 102. The spray pattern 113 may overlap by a minimum of 50% to a maximum of 90%, preferably 60% to 80%, of the spray pattern width. Furthermore, the rate and flow velocity of each ultrasonic exhaust nozzle 102 can be controlled independently. For example, the rate at which each ultrasonic exhaust nozzle 102 moves may vary from a minimum of 5 mm / s to a maximum of 80 mm / s, preferably from 45 mm / s to 55 mm / s. In other examples, the flow velocity of the coating composition flowing through the ultrasonic exhaust nozzle 102 may vary from a minimum of 0.1 ml / s to a maximum of 0.8 ml / s, preferably from 0.3 ml / s to 0.6 ml / s.

[0073] Return to reference Figure 4 The coating apparatus 100 may have a controller 114 for controlling the operation of the coating apparatus 100. The controller 114 may be configured to control the coating operations of one or more ultrasonic exhaust nozzles 102, such as delivering one or more coating compositions to the ultrasonic exhaust nozzles 102, the flow rate of one or more coating compositions through the ultrasonic exhaust nozzles 102, and the spray pattern of each ultrasonic exhaust nozzle 102. The controller 114 may also control the movement of the optical substrate 20 and / or one or more ultrasonic exhaust nozzles 102. Additionally, the controller 114 may be configured to control the filling and delivery operations of coating material in one or more reservoirs 110.

[0074] In some instances, controller 114 may include a wide variety of discrete computer-readable media components for controlling printing and / or relocation operations. For example, the computer-readable medium may include any medium accessible by controller 114, such as volatile media, non-volatile media, removable media, non-removable media, transient media, non-transient media, etc. As another example, the computer-readable medium may include computer storage media, such as media implemented in any method or technology for storing information, such as computer-readable instructions, data structures, program modules, or other data; random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory, or other memory technologies; CD-ROM, digital video disc (DVD), or other optical disk storage; magnetic cartridges, magnetic, disk storage, or other magnetic storage devices; or any other medium that can be used to store desired information and is accessible by controller 114. Additionally, the computer-readable medium may include communication media, such as computer-readable instructions, data structures, program modules, or other data in modulated data signals, and wireless media (such as acoustic signals, radio frequency signals, optical signals, infrared signals, biometric signals, barcode signals, etc.). Of course, any combination of the above should also be included within the scope of computer-readable media.

[0075] Users can input commands, information, and data, such as information related to an art form document requiring a specific print layer, into controller 114 via a user input interface using some attachable or operable input device. Of course, a wide variety of such input devices can be used, such as microphones, trackballs, joysticks, touchpads, touchscreens, scanners, etc., including any arrangement that facilitates inputting data and information from external sources into controller 114. Data and information can be presented or provided to the user in an understandable form or format through some output device, such as a monitor (visually displaying the information and data in electronic form), a printer (physically displaying the information and data in printed form), a speaker (audibly presenting the information and data), etc. Any such output device can be envisioned for providing information and data to the user.

[0076] Controller 114 can operate in a network environment using communication devices integrated into or remotely from controller 114. With this arrangement, controller 114 can connect to or otherwise communicate with one or more remote computers, such as, but not limited to, personal computers, servers, routers, network PCs, peer-to-peer devices, or other common network nodes. Using appropriate communication devices, such as modems, network interfaces, or adapters, controller 114 can operate and communicate within and through local area networks (LANs) and wide area networks (WANs), but may also include other networks such as virtual private networks (VPNs), office networks, corporate networks, intranets, and the Internet.

[0077] As used herein, controller 114 includes or is operable to execute appropriate custom-designed or conventional software to perform and implement the processing steps of the methods and systems of this disclosure, thereby forming a dedicated and specific computing system. Therefore, the methods and systems of the present invention may include one or more controllers 114 or similar computing devices having a computer-readable storage medium storing computer-readable program code or instructions, such that the processing units of controller 114 execute, configure, or otherwise implement the methods, processes, and data manipulations discussed herein in conjunction with this disclosure. Furthermore, controller 114 may be in the form of a personal computer, personal digital assistant, portable computer, laptop computer, handheld computer, mobile device, mobile phone, server, or any other type of computing device having the necessary processing hardware for appropriately processing data to effectively implement the computer-implemented methods and systems of the present invention.

[0078] A coating apparatus 100 having one or more ultrasonic emission nozzles 102 can be used to provide a pattern on an optical article 10. The pattern can be a pattern that produces gradual changes in one or more properties of the optical article 10. For example, a gradual change in hue and / or color density can occur across the surface of the optical article 10 in one direction. For example, when the optical article 10 is a lens, a change in hue and / or color density can occur from the bottom to the top of the lens, or vice versa. That is, deposition of each specific coating composition occurs across the lens from one side to the other, and changes in composition or coating thickness, thereby causing a change in hue and / or color density from bottom to top, or vice versa.

[0079] In some instances, the pattern produced by depositing a mixture of a first coating composition and one or more other coating compositions using an ultrasonic emission nozzle 102 can be a gradient pattern, such as a linear gradient pattern, a curved gradient pattern, a radial gradient pattern, or a combination thereof. In various instances, the gradient pattern transitions from transparent (i.e., hueless) to photochromic, wherein the first coating composition contains at least one photochromic dye and one or more other coating compositions do not contain a dye. In other instances, the gradient pattern transitions from photochromic to one hue of photochromic color. In still other instances, the gradient pattern transitions from fixed dyeing to photochromic, wherein the first coating composition contains at least one photochromic dye and one or more other coating compositions contain fixed dyeing dyes.

[0080] In various examples, a gradient pattern can be formed by controlling the flow rate of the first coating composition through the first liquid channel 122 relative to the flow rate of one or more other coating compositions through the second liquid channel 124. In examples where at least one of the first and second coating compositions has a photochromic coating composition, controlling the flow rate of the first coating composition relative to the flow rate of one or more other coating compositions changes the concentration of the photochromic coating composition in the mixture. In other examples, a gradient pattern can be formed by changing the thickness of the mixture on the optical article 10, such as by forming a thicker coating layer on the first portion of the optical article 10 relative to the thickness of the second portion of the optical article 10.

[0081] [Preprocessing Steps]

[0082] In the method for producing an optical article 10 according to this disclosure, an optical substrate 20 may be subjected to a pretreatment step, followed by coating the optical substrate 20 with a first coating layer 22. In this pretreatment step, at least a portion of the optical substrate 20 may be subjected to corona treatment. The pretreatment may include, but is not limited to, plasma, flame, chemical (e.g., caustic), or any treatment to increase the surface energy of the substrate, thereby causing the first coating to wet the optical substrate and promote adhesion to the optical substrate. For example, the optical substrate may be treated with a corona discharge from a Tantec EST-Electrical Service Treatment unit operating at 500 watts and 54 kVA for 30 to 90 seconds to activate the surface of the substrate, as described in U.S. Patent No. 8,608,988.

[0083] [Curing Steps]

[0084] In some examples of methods for producing optical articles 10 according to this disclosure, the first coating layer 22 and / or one or more additional coating layers 24 may be cured, such as by heating or exposure to radiation, such as ultraviolet (UV) radiation. In various other examples, the curing step may include, in addition to or in lieu of the heating and radiation treatments described herein, exposing at least a portion of the first coating layer 22 and / or one or more additional coating layers 24 to electron beam radiation, microwave radiation, or other methods for curing coating compositions.

[0085] Coating layer examples

[0086] The coating composition, which can be used to form one or more layers of the first coating layer 22 and one or more additional coating layers 24, includes, in some instances, a curable resin composition and optionally a solvent. The coating composition can be in the form of liquid coating compositions and powder coating compositions recognized in the art. The coating composition can be thermoplastic, radiation-curable (e.g., by ultraviolet radiation or electron beam), or thermosetting. In some instances, the coating composition is selected from curable or thermosetting coating compositions.

[0087] Examples of curable resin compositions that can be used with curable coating compositions include, but are not limited to: curable resin compositions comprising epoxide-functionalized polymers, such as (meth)acrylate polymers containing glycidyl acrylate residues, and epoxide reactive crosslinkers (e.g., containing active hydrogen, such as hydroxyl, thiol, and amine); curable resin compositions comprising active hydrogen-functionalized polymers, such as hydroxyl-functionalized polymers, and end-capped (or blocked) isocyanate-functionalized crosslinkers; curable resin compositions comprising active hydrogen-functionalized polymers, such as hydroxyl-functionalized polymers, and melamine crosslinkers; curable polysiloxane coating compositions; and radiation-curable compositions comprising acrylic functional monomers. Further examples of suitable curable coating compositions are those described herein as recognized hard coating materials in the art.

[0088] Vinyl polymers with hydroxyl functionality can be prepared by free radical polymerization methods known to those skilled in the art. In some embodiments of the present invention, the hydroxyl-functionalized vinyl polymers are prepared from most (meth)acrylate monomers and are referred to herein as "hydroxyl-functionalized (meth)acrylate polymers".

[0089] Hydroxyl-functionalized polyesters, which can be used in curable coating compositions comprising end-capped isocyanate-functionalized crosslinking agents, can be prepared by methods recognized in the art. Typically, a diol and a dicarboxylic acid or a diester of a dicarboxylic acid are reacted in such a ratio that the molar equivalent of the hydroxyl groups is greater than the molar equivalent of the carboxylic acid groups (or the ester of the carboxylic acid groups), while water or alcohol is removed from the reaction medium.

[0090] Hydroxyl-functional urethanes can be prepared by methods recognized in the art. Typically, one or more difunctional isocyanates are reacted with one or more materials having two active hydrogen groups (e.g., diols or dithiols) such that the ratio of active hydrogen groups to isocyanate groups is greater than 1, as is known to those skilled in the art.

[0091] "Terminated (or blocked) isocyanate crosslinking agent" means a crosslinking agent having two or more terminal isocyanate groups, which can be determinated (or deblocked) under curing conditions, such as at elevated temperatures, to form free isocyanate groups and free terminal groups. The free isocyanate groups formed by the determination of the crosslinking agent are typically capable of reacting with the active hydrogen groups of active hydrogen functional polymers (e.g., with the hydroxyl groups of hydroxyl functional polymers) and forming substantially permanent covalent bonds.

[0092] It is desirable that the end-capping groups of the isocyanate crosslinking agent do not adversely affect the curable coating composition when they are de-capped from the isocyanate (i.e., when they become free end-capping groups). For example, it is desirable that the free end-capping groups neither become trapped as bubbles in the cured film nor excessively plasticize the cured film. End-capping groups that can be used in this invention typically have the characteristic of being non-fugitive or capable of substantially escaping from the coating during formation before vitrification. Typically, free end-capping groups substantially escape from the coating during formation (e.g., during curing) before vitrification.

[0093] The end-capping groups of the isocyanate crosslinking agent can be selected from, but are not limited to: hydroxyl functional compounds, such as straight-chain or branched C2-C8 alcohols, ethylene glycol butyl ether, phenol, and p-hydroxymethylbenzoate; 1H-azoles, such as 1H-1,2,4-triazole and 1H-2,5-dimethylpyrazole; lactams, such as ε-caprolactam and 2-pyrrolidone; ketoximes, such as 2-acetone oxime and 2-butanone oxime. Other suitable end-capping groups include, but are not limited to, morpholine, 3-aminopropylmorpholine, 3,5-dimethylpyrazole, and N-hydroxyphthalimide.

[0094] The isocyanate or mixture of isocyanates in the end-capped isocyanate crosslinker has two or more isocyanate groups (e.g., three or four isocyanate groups). Examples of suitable isocyanates that can be used to prepare end-capped isocyanate crosslinkers include, but are not limited to, monomeric diisocyanates such as α,α'-xylene diisocyanate, α,α,α',α'-tetramethylxylene diisocyanate, and 1-isocyano-3-isocyanomethyl-3,5,5-trimethylcyclohexane (isophorone diisocyanate or IPDI), and dimers and trimers of monomeric diisocyanates containing isocyanurate, uretidino, biuret, or ureocarbamate linkers, such as trimers of IPDI.

[0095] The end-capped isocyanate crosslinking agent can also be selected from oligomeric end-capped isocyanate functional adducts. As used herein, "oligomeric end-capped polyisocyanate functional adduct" means a substance substantially free of polymer chain extensions. Oligomeric end-capped polyisocyanate functional adducts can be prepared by methods recognized in the art, for example from compounds containing three or more active hydrogen groups, such as trimethylolpropane (TMP), and isocyanate monomers, such as 1-isocyano-3,3,5-trimethyl-5-isocyanomethylcyclohexane (IPDI), in a molar ratio of 1:3. In the case of TMP and IPDI, oligomeric adducts with an average of 3 isocyanate functionalities (e.g., "TMP-3IPDI") can be prepared by using feedless and / or dilute solution synthesis techniques recognized in the art. The three free isocyanate groups of each TMP-3IPDI adduct are then end-capped with end-capping groups, such as linear or branched C2-C8 alcohols.

[0096] To catalyze the reaction between the isocyanate groups of the end-capped polyisocyanate crosslinker and the hydroxyl groups of the hydroxyl-functionalized polymer, one or more catalysts are typically present in the curable photochromic coating composition in an amount, for example, from 0.1 to 5% by weight, based on the total resin solids of the composition. Useful catalysts include, but are not limited to, metal compounds, especially organotin compounds such as tin(II) octanoate and dibutyltin(IV) dilaurate, tertiary amines such as diazabicyclo[2.2.2]octane, bismuth, and zinc and zirconium carboxylates.

[0097] A curable coating composition (comprising a hydroxyl-functionalized polymer and a terminated isocyanate-functionalized crosslinker) that can be used to form one or more layers of a first coating layer 22 and one or more additional coating layers 24 typically has a hydroxyl-functionalized polymer present therein in an amount of 55% to 95% by weight based on the total resin solids of the composition, for example, 75% to 90% by weight based on the total resin solids of the composition. The terminated isocyanate-functionalized crosslinker is typically present in the curable resin composition in an amount corresponding to the balance of these described ranges, i.e., 5% to 45% by weight, particularly 10% to 25% by weight.

[0098] A curable urethane resin composition is used to form one or more layers of a first coating layer 22 and one or more additional coating layers 24. The isocyanate equivalent in the end-capped isocyanate crosslinker and the hydroxyl equivalent in the hydroxyl-functionalized polymer are typically in the range of 1:3 to 50:1, for example, 1:2 to 20:1. The curable coating composition comprising the hydroxyl-functionalized polymer and the end-capped isocyanate crosslinker is typically cured at a temperature of 120°C to 190°C for 10 to 60 minutes.

[0099] A curable resin composition according to various examples of curable coating compositions that can be used to form one or more layers of a first coating layer 22 and one or more additional coating layers 24 comprises: a first reactant (or component) having functional groups and a second reactant (or component) as a crosslinking agent having functional groups reactive to and capable of forming covalent bonds with the functional groups of the first reactant. In some examples, the first coating composition comprises one or more first reactive groups selected from isocyanates and epoxy groups, while one or more additional coating compositions comprise a second reactive group selected from hydroxyl, thiols, primary amines, secondary amines, carbamates, and carboxylic acids. In other examples, the first coating composition comprises an isocyanate first reactive group, and one or more additional coating compositions comprise a hydroxyl second reactive group. In still other examples, the first coating composition comprises an epoxy first reactive group, and one or more additional coating compositions comprise a carboxylic acid second reactive group. A coating composition comprising a first coating composition and one or more other coating compositions may have a ratio between 0.3:1 and 50:1 of a first reactive group in the first coating composition to a second reactive group in one or more other coating compositions. The first and second reactants of the curable resin composition may each independently comprise one or more functional classes, and each is present in an amount sufficient to provide a cured coating having a combination of desired physical properties (e.g., smoothness, optical transparency, solvent resistance, and hardness).

[0100] In some instances, coating compositions that can be used to form one or more layers of a first coating layer 22 and one or more additional coating layers 24 may optionally include a solvent. Examples of suitable solvents include, but are not limited to, acetates, alcohols, ketones, glycols, ethers, aliphatic compounds, cyclic aliphatic compounds, and aromatic compounds. Examples of acetates include, but are not limited to, ethyl acetate, butyl acetate, and ethylene glycol acetate. Examples of ketones include, but are not limited to, methyl ethyl ketone and methyl-N-pentyl ketone. Examples of aromatic compounds include, but are not limited to, toluene, naphthalene, and xylene. In some instances, one or more solvents are added to each of the first and second reactants. Suitable solvent blends include, for example, one or more acetates, propanol and its derivatives, one or more ketones, one or more alcohols, and / or one or more aromatic compounds. If present, the solvent is typically present in an amount of 5 to 60% by weight, or 5 to 40% by weight, or 10 to 25% by weight, based on the total weight of the coating composition (including the weight of the solvent).

[0101] In some instances, the curable resin composition that can be used to form one or more layers of a coating composition comprising a first coating layer 22 and one or more additional coating layers 24 is a curable urethane (or polyurethane) resin composition. The curable urethane resin composition that can be used to form one or more layers of a first coating layer 22 and one or more additional coating layers 24 includes: an active hydrogen-functionalized polymer, such as a hydroxyl-functionalized polymer; and a terminally (or blocked) isocyanate-functionalized crosslinking agent. Hydroxyl-functionalized polymers that can be used in such compositions include, but are not limited to, hydroxyl-functionalized vinyl polymers, hydroxyl-functionalized polyesters, hydroxyl-functionalized polyurethanes, and mixtures thereof recognized in the art.

[0102] Curable coating compositions that can be used to form one or more layers of a first coating layer 22 and one or more additional coating layers 24 may, in some instances, include kinetic enhancing additives, photoinitiators, and thermal initiators. In some instances, the curable coating composition optionally contains additives for flow and wetting, flow control agents such as poly(2-ethylhexyl) acrylate, auxiliary resins for improving and optimizing coating properties, antioxidants, and ultraviolet (UV) light absorbers. Examples of useful antioxidants, hindered amine light stabilizers, and UV light absorbers include those commercially available from BASF under the trademarks IRGANOX and TINUVIN. These optional additives are typically present in an amount of up to 10% by weight (e.g., 0.05 to 5% by weight) based on the total weight of the resin solids in the curable resin composition.

[0103] In some instances, the first coating layer 22 and one or more additional coating layers 24 may each independently comprise a static dye, a photochromic material, or a combination thereof. Alternatively or additionally, the optical substrate 20 of the optical article 10 of the present invention may comprise a static dye, a photochromic material, or a combination thereof. The following description of static dyes and photochromic compounds, which may be present in the first coating layer 22 and one or more additional coating layers 24 in some instances, also applies to static dyes and photochromic compounds that may be alternatively or additionally present in the optical substrate of the optical article 10 of the present invention in some instances.

[0104] The categories and examples of static dyes that may be present in one or more layers of the first coating layer 22 and one or more additional coating layers 24 include, but are not limited to, inorganic static dyes and organic static dyes recognized in the art.

[0105] The class of photochromic compounds that may be present in one or more layers of the first coating layer 22 and one or more additional coating layers 24 includes, but is not limited to, "conventional photochromic compounds." As used herein, the term "conventional photochromic compound" includes both thermally reversible and non-thermally reversible (or photoreversible) photochromic compounds. Generally, although not limited herein, when two or more conventional photochromic materials are used in combination, a variety of materials can be selected to complement each other to produce the desired color or hue. For example, mixtures of photochromic compounds may be used according to certain non-limiting examples disclosed herein to obtain certain activated colors, such as near-neutral gray or near-neutral brown. See, for example, U.S. Patent 5,645,767, column 12, lines 66 through 13, lines 19, the disclosure of which is specifically incorporated herein by reference, which describes parameters defining neutral gray or brown.

[0106] Examples of photochromic materials or compounds that may be present in one or more layers of the first coating layer 22 and one or more additional coating layers 24 include, but are not limited to, indene-fused naphthopyran, naphtho[1,2-b]pyran, naphtho[2,1-b]pyran, spirofluoren[1,2-b]pyran, phenanthropyran, quinoline pyran, fluoroanthenopyrans, spiropyran, benzoxazine, naphthopyran, spiro(indoline)naphthopyran, spiro(indoline)pyridinobenzoxazine, spiro(indoline)fluoroanthenopyran, spiro(indoline)quinoxazines, succinic anhydride, succinic imide, diarylene, diarylenealkylethylene, diarylenealylethylene, thermally reversible photochromic compounds and non-thermally reversible photochromic compounds, and mixtures thereof.

[0107] Further examples of photochromic compounds that may be present in one or more layers of the first coating layer 22 and one or more additional coating layers 24 may be selected in some instances from certain indene-fused naphthopyran compounds, such as those described in U.S. Patent No. 6,296,785 in column 3, line 66 through column 10, line 51, the disclosure of which is incorporated herein by reference.

[0108] In some instances, the photochromic compound, which may be present in one or more layers of the first coating layer 22 and one or more additional coating layers 24, may be covalently bonded to a matrix of any layer, such as an organic matrix. In some instances, the photochromic compound may include one or more reactive groups, such as one or more polymerizable groups. In some instances, the photochromic compound may be selected from 2H-naphtho[1,2-b]pyran, 3H-naphtho[2,1-b]pyran, and / or indo[2,1-f]naphtho[1,2-b]pyran, each having at least one functional group capable of forming a covalent bond with another functional group, such as at least one polymerizable group, such as at least one polyalkoxylated substituent having 1 to 50 alkoxy units per substituent, said substituent being closed (or capped) with a polymerizable group end. Examples of such photochromic compounds include, but are not limited to, those disclosed in U.S. Patent No. 6,113,814, column 2, line 52 through column 8, line 40, the disclosure of which is incorporated herein by reference.

[0109] Photochromic compounds can be introduced into specific films, layers, or optical substrates using methods recognized in the art. Such methods include, but are not limited to, imbibition, and introducing photochromic compounds into compositions from which specific films, layers, or optical substrates are prepared.

[0110] A photochromic compound may be present in an amount (or proportion) of one or more layers of the first coating layer 22 and one or more additional coating layers 24 and / or the optical substrate, thereby causing the optical element of this disclosure to exhibit the desired optical properties. For purposes of non-limiting illustration, the amount and type of photochromic compound may be chosen such that the optical element is transparent and colorless when the photochromic compound is in a closed form (e.g., in a bleached or unactivated state) and can exhibit the desired resulting color when the photochromic compound is in an open form (e.g., when activated by photochemical radiation). The precise amount of the photochromic compound used is not critical, provided that a sufficient amount is used to produce the desired effect. The specific amount of the photochromic compound used may depend on a variety of factors, such as, but not limited to, the absorption characteristics of the photochromic compound, the color and intensity required upon activation, and the method used to introduce the photochromic compound into the specific layer. Although not limited thereto, according to the various non-limiting examples disclosed herein, the amount of photochromic compound in the layer of an optical element may range from 0.01 to 40% by weight, or 0.05 to 15% by weight, or 0.1 to 5% by weight, based on the weight of the layer. The same amounts and ranges may apply to the amount of photochromic compound in the optical substrate of the optical element into which this disclosure is alternatively or additionally introduced.

[0111] In addition to the first coating layer 22 and one or more additional coating layers 24, optical elements prepared by the methods of this disclosure and according to this disclosure may optionally include one or more layers. Examples of such additional layers include, but are not limited to: primer coatings and films; protective coatings and films, including transition coatings and films, and abrasion-resistant coatings and films; antireflective coatings and films; polarizing coatings and films; and combinations thereof. As used herein, the term "protective coating and film" refers to coatings and films that prevent wear or abrasion, provide a change in properties from one coating or film to another, protect against the effects of polymerization chemicals, and / or prevent degradation due to environmental conditions such as moisture, heat, ultraviolet light, oxygen, etc.

[0112] As used herein, the terms “transition coating and film” mean a coating or film that facilitates the creation of a gradient in properties between two coatings or films, or between coatings and films. For example, though not limited thereto, transition coatings can contribute to creating a gradient in hardness between a relatively hard coating and a relatively soft coating. Non-limiting examples of transition coatings include radiation-cured, acrylate-based thin films, as described in U.S. Patent No. 7,452,611B2, which is specifically incorporated herein by reference.

[0113] As used herein, the term "abrasion-resistant coatings and films" refers to protective polymeric materials that exhibit superior performance compared to standard reference materials, such as those available from PPG Industries, Inc. Polymers made from monomers exhibit greater resistance to abrasion, as tested in methods comparable to ASTM F-735, the Standard Test Method for Abrasion Resistance of Transparent Plastics and Coatings Using the Oscillating Sand Method. Non-limiting examples of abrasion-resistant coatings include, for example, abrasion-resistant coatings containing organosilanes or organosiloxanes; abrasion-resistant coatings based on inorganic materials such as silica, titanium dioxide, and / or zirconium oxide; UV-curable organic abrasion-resistant coatings; oxygen-barrier coatings; UV-shielding coatings; and combinations thereof. Non-limiting examples of commercially available hard-coated products include CRYSTALCOAT. TM 124 and The coatings are available from SDC Coatings, Inc. and PPG Industries, Inc., respectively.

[0114] Abrasion-resistant coatings or films (or hard coating layers) may, in some instances, be selected from hard coating materials recognized in the art, such as organosilane abrasion-resistant coatings. Organosilane abrasion-resistant coatings (often referred to as hard coatings, or silicone-based hard coatings) are well known in the art and are commercially available from various manufacturers such as SDC Coatings, Inc. and PPG Industries, Inc. See U.S. Patent No. 4,756,973, column 5, lines 1-45; and U.S. Patent No. 5,462,806, column 1, lines 58-8, column 2, and column 3, lines 52-5, lines 50, the disclosures of which describe organosilane hard coatings and are incorporated herein by reference. See also the disclosures of organosilane hard coatings in U.S. Patent Nos. 4,731,264, 5,134,191, 5,231,156 and International Patent Publication WO 94 / 20581, the disclosures of which are also incorporated herein by reference. Hard coating layers can be applied using coating methods recognized in the art, including but not limited to roller coating, spraying, curtain coating, and spin coating.

[0115] Non-limiting examples of antireflective coatings and films include single layers, multilayers, or films of metal oxides, metal fluorides, or other such materials, which can be deposited onto (or onto films applied to) the articles disclosed herein, for example, by vacuum deposition, sputtering, etc. Non-limiting examples of conventional photochromic coatings and films include, but are not limited to, coatings and films comprising conventional photochromic materials.

[0116] In various examples, the first coating layer 22 and one or more additional coating layers 24 may each independently have a single-layer or multi-layer film inserted between the first coating layer 22 and the optical substrate 20, and / or between the first coating layer 22 and one or more additional coating layers 24, and / or between adjacent additional coating layers 24. In each case, the film may be selected from thermoplastic films, cross-linked films, and combinations thereof. Each film may be formed independently from polymer sheets or coating compositions.

[0117] Examples of polymeric materials that can be used to form one or more films include, but are not limited to, polyvinyl alcohol, polyvinyl chloride, polyurethane, polyimide, polyacrylate, and polycaprolactam. In some instances, one or more polymeric sheets may be at least partially ordered, for example, by stretching on one or both sides.

[0118] Example of coating process

[0119] A T7 gray paint solution, available from Transitions Optical, Inc., Pinellas Park, Florida, was mixed with a methyl isobutyl ketone (MIBK) solution at a 2:1 ratio. A Sontek injection pump (part number 12-05-00144) was filled with this photochromic solution and mounted on a Sono-Tek Flexicoat ultrasonic sprayer (part number W6152), available from Sono-Tek Corporation, Milton, New York.

[0120] Additionally, a T7 coating containing all components except the photochromic dye was mixed with MIBK solvent at a 2:1 ratio. This transparent coating was then used to fill a separate Sonotek injection pump on the same coating machine.

[0121] 76mm CR-39 will be available from PPG Industries, Inc., Pittsburgh, PA. TM The samples of the center-base substrate lens were cleaned with isopropanol (IPA) solvent and then surface-treated using a Tantec Lab corona system model HT-X1-28-02. Each treated lens was placed in the coating chamber of a Sono-Tek Flexicoat ultrasonic sprayer.

[0122] Using a Sonotek 120kHz Impact ultrasonic nozzle (S / N 120-01473) available from Sono-Tek Corporation, Milton, New York, the paint was applied to each lens at a power setting of 5.5 watts. The nozzle rate was set to 30 mm / s, and the nozzle was positioned 35 mm above the center of the lens. The flow rate of the photochromic paint was set to 0.6 ml / min. The subsequent spacing of the area passing over the lens, or the nozzle offset distance, was set to 2 mm. The air shaping pressure used to guide the atomized paint onto the lens was set to 3 psi.

[0123] In Example 1, a photochromic coating is applied in a zone pattern over the upper half of the lens. At the midpoint of the lens, a transparent coating is applied to the remaining portion of the lens using the same process parameters. The photochromic and transparent coatings are blended at the midpoint of the lens, providing a short gradient from the photochromic to the transparent coating.

[0124] In Example 2, photochromic paint is applied in a zone pattern above the upper third of the lens. As the nozzle approaches the second third of the lens, clear paint is fed into the nozzle, thereby coating the second third of the lens with a mixture of 50% photochromic paint and 50% clear paint using the same process parameters as in Example 1. When the nozzle reaches the last third of the lens, the feeding of photochromic paint is stopped, so that only clear paint is applied.

[0125] In Example 3, photochromic paint is applied in a zone pattern above the upper quarter of the lens. As the nozzle approaches the second quarter of the lens, clear paint is fed into the nozzle, thus coating the second quarter of the lens with a mixture of 66% photochromic paint and 33% clear paint using the same process parameters as in Example 1. As the nozzle approaches the third quarter of the lens, the feed of clear paint is increased and the feed of photochromic paint is decreased, thus coating the third quarter of the lens with a mixture of 33% photochromic paint and 66% clear paint. As the nozzle approaches the last quarter of the lens, the feed of photochromic paint is stopped, leaving only clear paint applied.

[0126] The coated lenses from each embodiment were then placed in a Memmert UN 55 thermal oven (part number B214.1731) at 120°C for 60 minutes. The lenses were then placed on a transbonding line for the application of the tie layer and HIGARD. TM 1080 thermosetting hard coating, which is available from PPG Industries, Inc., Pittsburgh, PA.

[0127] The UV absorbance of the lens from each instance was then measured at 390 nm using a Cary 300 Conc UV-Vis spectrometer (model EL08023601, available from Agilent Technologies, Santa Clara, CA). Measurements were taken along the (down) face of the lens, starting at the 12 o'clock position and ending at the 6 o'clock position (at 10 equal intervals). The absorbance values ​​were proportional to the concentration of the photochromic dye and the resulting outdoor activated % transmittance. The decrease in UV absorbance along the (down) lens quantifies the gradient nature of the lens activation. The absorbance results are listed below. Figure 6 In the text, "short", "medium" and "long" refer to Examples 1, 2 and 3, respectively.

[0128] In various instances, the invention may be further characterized by one or more of the following provisions:

[0129] Clause 1. A method for manufacturing an optical article, said method comprising:

[0130] The first coating composition is supplied to the ultrasonic discharge nozzle of the coating apparatus;

[0131] One or more additional coating compositions are supplied to the ultrasonic discharge nozzle of the coating apparatus, wherein at least one of the first coating composition and one or more additional coating compositions is a photochromic coating composition;

[0132] The first coating composition and one or more other coating compositions are mixed at the ultrasonic discharge nozzle of the coating apparatus; and

[0133] A mixture of a first coating composition and one or more other coating compositions is applied to at least a portion of an optical article to provide a pattern on the optical article upon exposure to photochemical radiation.

[0134] The mixture of a first coating composition and one or more other coating compositions is applied from an ultrasonic emission nozzle as a controlled, predetermined pattern of atomized droplets.

[0135] Clause 2. The method according to Clause 1, wherein the pattern is a gradient pattern.

[0136] Clause 3. The method described in Clause 2, wherein the gradient pattern is linear, curved, radial, or a combination thereof.

[0137] Clause 4. The method described in Clause 2 or 3, wherein the gradient pattern is linear.

[0138] Clause 5. The method according to any one of Clauses 2-4, wherein a gradient pattern is formed by controlling the flow rate of the first coating composition relative to one or more other coating compositions.

[0139] Clause 6. The method according to Clause 5, wherein controlling the flow rate of the first coating composition relative to one or more other coating compositions alters the concentration of the photochromic coating composition in the mixture.

[0140] Clause 7. The method according to any one of Clauses 2-4, wherein a gradient pattern is formed by varying the thickness of the mixture on the optical article.

[0141] Clause 8. The method according to any one of Clauses 1-6, wherein a mixture of the first coating composition and one or more other coating compositions is applied as a coating having a uniform thickness to an optical article.

[0142] Clause 9. The method according to any one of Clauses 1-6, wherein a mixture of the first coating composition and one or more other coating compositions is applied as a coating having a non-uniform thickness to an optical article.

[0143] Clause 10. The method according to any one of Clauses 1-9, wherein a mixture of the first coating composition and one or more other coating compositions is applied to the optical article in a single pass.

[0144] Clause 11. The method according to any one of Clauses 1-9, wherein a mixture of the first coating composition and one or more other coating compositions is applied to the optical article in multiple passes.

[0145] Clause 12. The method according to any one of Clauses 1-11, wherein one or more additional coating compositions comprise a second reactive group selected from hydroxyl, thiol, primary amine, secondary amine, carbamate and carboxylic acid.

[0146] Clause 13. The method according to Clause 12, wherein the first coating composition comprises one or more first reactive groups selected from isocyanates and epoxy groups.

[0147] Clause 14. The method according to any one of Clauses 1-13, wherein the first coating composition comprises an isocyanate first reactive group and one or more other coating compositions comprise a hydroxyl second reactive group.

[0148] Clause 15. The method according to any one of Clauses 1-14, wherein the optical article is selected from optical lenses, filters, windows, goggles, mirrors and displays, preferably optical lenses, more preferably ophthalmic lenses.

[0149] Clause 16. The method according to any one of Clauses 1-15, wherein the ultrasonic emission nozzle has a frequency of 48-120 kHz.

[0150] Clause 17. Optical articles that can be obtained by the method described in any one of Clauses 1-16.

[0151] Clause 18. An apparatus for applying material to an optical article, said apparatus comprising:

[0152] Holders used to hold optical products;

[0153] An ultrasonic emission nozzle is used to mix a first coating composition with one or more other coating compositions and to apply the atomized mixture of the first coating composition and one or more other coating compositions to at least a portion of an optical article;

[0154] Tools for individually supplying a first coating composition and one or more other coating compositions to an ultrasonic discharge nozzle; and

[0155] A controller for positioning at least one of a retainer and an ultrasonic emission nozzle relative to each other and controlling the coating operation of the ultrasonic emission nozzle before applying an atomized mixture to at least a portion of an optical article, thereby providing a pattern on the optical article upon exposure to photochemical radiation.

[0156] Clause 19. The apparatus according to Clause 18, wherein the pattern is a gradient pattern.

[0157] Clause 20. The apparatus according to Clause 19, wherein the gradient pattern is linear, curvilinear, radial, or a combination thereof.

[0158] Clause 21. The apparatus according to Clause 19 or 20, wherein the gradient pattern is linear.

[0159] The invention has been described in detail with reference to specific examples thereof. Unless such details are included in the appended claims, they should not be considered as limiting the scope of the invention.

Claims

1. A method for manufacturing an optical article, the method comprising: A first coating composition comprising a first curable resin composition is supplied to the ultrasonic discharge nozzle of a coating apparatus; One or more additional coating compositions comprising one or more additional curable resin compositions are supplied to the ultrasonic discharge nozzle of the coating apparatus, wherein at least one of the first coating composition and the one or more additional coating compositions is a photochromic coating composition. The first coating composition and one or more other coating compositions are mixed at the ultrasonic discharge nozzle of the coating apparatus; and A mixture of the first coating composition and one or more other coating compositions is applied to at least a portion of the optical article to provide a pattern on the optical article upon exposure to photochemical radiation. The mixture of the first coating composition and one or more other coating compositions is applied from the ultrasonic emission nozzle as a controlled, predetermined gradient pattern of atomized droplets, in a manner that produces gradual, visually discernible changes in hue and / or color density over a region of the optical article when the optical article is exposed to photochemical radiation. The gradient pattern is formed by controlling the flow rate of the first coating composition relative to the flow rate of one or more other coating compositions supplied to the ultrasonic emission nozzle. The first curable resin composition and the one or more other curable resin compositions comprise epoxide-functionalized polymers or active hydrogen-functionalized polymers.

2. The method according to claim 1, wherein the gradient pattern is linear, curved, radial, or a combination thereof, preferably linear.

3. The method according to claim 1 or 2, wherein the gradient pattern is formed by controlling the flow rate of the first coating composition relative to the flow rate of the one or more additional coating compositions.

4. The method of claim 3, wherein controlling the flow rate of the first coating composition relative to the flow rate of the one or more additional coating compositions alters the concentration of the photochromic coating composition in the mixture.

5. The method according to claim 1 or 2, wherein the gradient pattern is formed by changing the thickness of the mixture on the optical article.

6. The method according to any one of claims 1-4, wherein the mixture of the first coating composition and one or more other coating compositions is applied to the optical article as a coating having a uniform thickness.

7. The method according to any one of claims 1-4, wherein the mixture of the first coating composition and one or more other coating compositions is applied to the optical article as a coating having a non-uniform thickness.

8. The method according to any one of claims 1-7, wherein the mixture of the first coating composition and one or more other coating compositions is applied to the optical article in a single pass or multiple passes.

9. The method of claim 1, wherein when the first curable resin composition or the one or more other curable resin compositions comprises the epoxide-functionalized polymer, the first curable resin composition or the one or more other curable resin compositions further comprises an epoxide reactive crosslinking agent, the epoxide reactive crosslinking agent comprising active hydrogen, or When the first curable resin composition or the one or more other curable resin compositions contains the active hydrogen functional polymer, the first curable resin composition or the one or more other curable resin compositions further contains a capped isocyanate functional crosslinker.

10. The method according to any one of claims 1-9, wherein the optical article is selected from optical lenses, filters, windows, goggles, mirrors and displays, preferably optical lenses, more preferably ophthalmic lenses.

11. The method according to any one of claims 1-10, wherein the ultrasonic emission nozzle has a frequency of 48-120 kHz.

12. An optical article that can be obtained by the method according to claim 1.

13. An apparatus for applying material to an optical article, the apparatus comprising: A holder for holding the optical article; An ultrasonic emission nozzle is used to mix a first coating composition comprising a first curable resin composition with one or more additional coating compositions comprising one or more additional curable resin compositions and to atomize the mixture of the first coating composition and the one or more additional coating compositions and apply it to at least a portion of the optical article; A tool for individually supplying the first coating composition and one or more other coating compositions to the ultrasonic emission nozzle; and A controller is configured to position at least one of the retainer and the ultrasonic emission nozzle relative to each other before applying the atomized mixture to at least a portion of the optical article, and to control the coating operation of the ultrasonic emission nozzle to provide a gradient pattern on the optical article upon exposure to photochemical radiation, in a manner that produces gradual, visually discernible changes in hue and / or color density over a region of the optical article. The gradient pattern is formed by controlling the flow rate of the first coating composition relative to the flow rate of one or more other coating compositions supplied to the ultrasonic emission nozzle. The first curable resin composition and the one or more other curable resin compositions comprise epoxide-functionalized polymers or active hydrogen-functionalized polymers.

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